Articles de revues sur le sujet « Falling ball dynamics »

Cageless ball bearings are often preferred as a back-up bearing for active magnetic bearings to support a falling rotor, but the contact between the balls of the cageless ball bearing may lead to the deterioration of the bearing performance and affect the dynamic stability of the rotor system. Thus, we studied the discrete dynamics of cageless ball bearings. First, a model is proposed to change the groove curvature center of the local outer raceway to control the ball velocity to achieve dispersion. Combined with the spatial geometry theory, the mathematical model of the discrete raceway is established, the collision between the balls is considered as an abruptly added constraint, and the non-smooth dynamics equation of the cageless ball bearing with a local discrete raceway is established. Then, the fourth-order Adams prediction correction algorithm is used to numerically solve the dynamic discretization of the ball, and the structural parameters of the discrete raceway are preferably selected, according to the phase diagram of the ball and the change in the angular spacing. The results show that the structure of the discrete raceway has a strong influence on the discrete dynamics of the ball.

In fluid dynamics and related fields, accurately measuring liquid viscosity is vital. The traditional falling ball method, common in education and research, faces challenges in ensuring uniform fall and correcting for phenomena like eddy currents. This thesis introduces a new device based on the Poiseuille method, measuring viscosity through pressure difference and adjustable flow rates. Comparing it with the falling ball method, we found the latter has an average error of 5.21%, while the Poiseuille method has only 1.23%. The Poiseuille method avoids issues like Reynolds coefficient correction and inaccuracies from high ball speeds, offering stability and practical value.

Dropping a water-filled cup with a ping-pong ball inside to the ground expels the ball much higher than its initial height. During free fall, the absence of gravity in the reference frame of the cup makes capillary forces dominant, causing the ball to be sucked into water. At impact, the high velocity ejection is due to the strong Archimedes’ force caused by vertical acceleration. In this paper, we study the dynamics of the capillary sinking of the ball during free fall and the ejection speed at impact, using tracking and high-speed imaging. In particular, we show that at short-time, the sinking is governed by capillary and added mass forces.

AbstractThe dynamics of flowing, concentrated suspensions of non-colloidal particles continues to surprise, despite decades of work and the widespread importance of suspension transport properties to industrial processes and natural phenomena. Blanc, Lemaire & Peters (J. Fluid Mech., 2014, vol. 746, R4) report a striking example. They probed the time-dependent dynamics of concentrated suspensions of rigid and neutrally buoyant spheres by simultaneously measuring the oscillatory rheology and the sedimentation rate of a falling ball. The sedimentation velocity of the ball through the suspension depends strongly on the frequency of oscillation, though the rheology was found to be independent of frequency. The results demonstrate the complexities of suspension flows and highlight opportunities for improving models by exploring suspension dynamics and rheology over a wide range of conditions, beyond steady and unidirectional ones.

Humans demonstrate an amazing ability for intercepting and catching moving targets, most noticeably in fast-speed ball games. However, the few studies exploring the neural bases of interception in humans and the classical studies on visual motion processing and visuomotor interactions have reported rather long latencies of cortical activations that cannot explain the performances observed in most natural interceptive actions. The aim of our experiment was twofold: (1) describe the spatio-temporal unfolding of cortical activations involved in catching a moving target and (2) provide evidence that fast cortical responses can be elicited by a visuomotor task with high temporal constraints and decide if these responses are task or stimulus dependent. Neuromagnetic brain activity was recorded with whole-head coverage while subjects were asked to catch a free-falling ball or simply pay attention to the ball trajectory. A fast, likely stimulus-dependent, propagation of neural activity was observed along the dorsal visual pathway in both tasks. Evaluation of latencies of activations in the main cortical regions involved in the tasks revealed that this entire network of regions was activated within 40 msec. Moreover, comparison of experimental conditions revealed similar patterns of activation except in contralateral sensorimotor regions where common and catch-specific activations were differentiated.

Prevailing views on how we time the interception of a moving object assume that the visual inputs are informationally sufficient to estimate the time-to-contact from the object's kinematics. Here we present evidence in favor of a different view: the brain makes the best estimate about target motion based on measured kinematics and an a priori guess about the causes of motion. According to this theory, a predictive model is used to extrapolate time-to-contact from expected dynamics (kinetics). We projected a virtual target moving vertically downward on a wide screen with different randomized laws of motion. In the first series of experiments, subjects were asked to intercept this target by punching a real ball that fell hidden behind the screen and arrived in synchrony with the visual target. Subjects systematically timed their motor responses consistent with the assumption of gravity effects on an object's mass, even when the visual target did not accelerate. With training, the gravity model was not switched off but adapted to nonaccelerating targets by shifting the time of motor activation. In the second series of experiments, there was no real ball falling behind the screen. Instead the subjects were required to intercept the visual target by clicking a mousebutton. In this case, subjects timed their responses consistent with the assumption of uniform motion in the absence of forces, even when the target actually accelerated. Overall, the results are in accord with the theory that motor responses evoked by visual kinematics are modulated by a prior of the target dynamics. The prior appears surprisingly resistant to modifications based on performance errors.

There are needed energy (heat) accumulators to increase the efficiency of solar installations, including solar collectors (water heaters, air heaters, dryers). One of the tasks of designing heat accumulators is to ensure its minimal heat loss. The article considers the problem of determining the distribution of temperatures and heat losses by convection and radiation of the heat insulation-accumulating body (water) system for a ball heat accumulator under symmetric boundary conditions. The problem is solved numerically according to the program developed on the basis of the proposed «gap method». (Research purpose) The research purpose is in determining heat losses by convection and radiation of a two-layer ball heat accumulator with symmetric boundary conditions. (Materials and methods) Authors used the Fourier heat equation for spherical bodies. The article presents the determined boundary and initial conditions for bodies and their surfaces. (Results and discussion) The thickness of the insulation and the volume of the heat accumulator affect the dynamics and values of heat loss. The effect of increasing the thickness of the thermal insulation decreases with increasing its thickness, starting with a certain volume of the heat accumulator or with R > 0.3 meters, the heat losses change almost linearly over time. The dynamics of heat loss decreases with increasing shelf life, but the losses remain large. (Conclusions) Authors have developed a method and program for numerical calculation of heat loss and temperature over time in a spherical two-layer heat accumulator with symmetric boundary conditions, taking into account both falling and intrinsic radiation. The proposed method allows to unify the boundary conditions between contacting bodies.

The steady-state shear viscosity of low-concentrated Poly(2-ethyl-2-oxazoline) (PEOX) aqueous solutions is measured near the presumed theta temperature using the falling ball viscometry technique. The experimental data are analyzed within the model that joins the Rouse and Zimm bead-spring theories of the polymer dynamics at the theta condition, which means that the polymer coils are considered to be partially permeable to the solvent. The polymer characteristics thus depend on the draining parameterhthat is related to the strength of the hydrodynamic interaction between the polymer segments. The Huggins coefficient was found to be 0.418 at the temperature 20°C, as predicted by the theory. This value corresponds toh= 2.92, contrary to the usual assumption of the infiniteh. This result indicates that the theta temperature for the PEOX water solutions is 20°C rather than 25°C in the previous studies. The experimental intrinsic viscosity is well described coming from the Arrhenius equation for the shear viscosity.

In this study, dynamic hardness tests on solid and engineered wood flooring specimens of Eucalyptus globulus Labill. and Eucalyptus grandis W. Hill ex Maiden hardwoods were performed because nowadays, these fast-growing hardwoods are still scarcely employed for this use. Furthermore, another two examples of hardwood commonly applied on wood flooring, Quercus robur L. and Hymenaea courbaril L., were also tested. To compare their properties, a dynamic impact hardness test based on the impact of steel balls, with several diameters, and drop heights was developed. Accordingly, 120 solid wood flooring specimens and 120 engineering wood flooring specimens were producing with these four hardwood species. Dynamic impact tests were made with three steel balls of different diameters (30–40–50 mm), and they were carried out from five different drop heights (0.60–0.75–0.90–1.05–1.20 m). The impact of the steel ball drew the size of the footprint on the surface and this mark was measured with a digital caliper for both dimensions, diameter and depth, as footprint diameter (FD) and indentation depth (ID). Data from 3000 samples, corresponding to 120 different individual groups (4 species × 3 ball diameters × 5 drop height × 2 floor type) were analyzed. Results indicated that the variability of ID (CV between 19.25–25.61%) is much greater than the values achieved for FD (CV between 6.72–7.91%). Regarding the fast-growing hardwood species tested, E. globulus showed a similar behavior to traditional hardwood applied on wood flooring in Europe, Q. robur, and it could be a promising growth in the flooring industry. However, E. grandis showed the worst values compared to traditional hardwood in all test configurations.

Abstract: Viscosity is the one of the major parameters to be considered in fluid related experiments and also in many industries. A new method of calculation of Dynamic Viscosity using the Viscometer which is easy for experimentation, with less calculation efforts, simple in design, construction with min. investment and no or minimum maintenance. This Paper intends to find the viscosity of Opaque fluids using falling ball viscometer. Falling Ball Viscometer works with Strokes law as the correction factor is multiplied in the calculation. As the correction factor is derived from the outcomes from the experiment and C-Code was written to make the calculation more efficient.

Unexpected ground impacts can seriously affect the stability and operational safety of buried pipelines. In this paper, a full-scale modeling test of the dynamic response of a buried concrete pipeline under falling rock impact based on dynamic sensor testing was conducted. A commercially available reinforced concrete pipeline, buried in a clayey soil site, was used, and a 50 kg concrete ball was used to investigate the impact above the pipeline. Considering the purpose of the test, the falling process of the concrete ball and the surface vibration velocity induced by the touchdown of the concrete ball were monitored using a high-speed camera and a vibration signal tester, respectively. The dynamic response signals of the pipe under surface impact were tested using strain gauges and earth pressure gauges combined with dynamic sensors such as dynamic signal tester, and the dynamic response law was analyzed. The experimental results will provide a basis for the design of the impact resistance of reinforced concrete pipes.

We study the fluctuating motion of a Brownian-sized probe particle as it is dragged by a constant external force through a colloidal dispersion. In this nonlinear-microrheology problem, collisions between the probe and the background bath particles, in addition to thermal fluctuations of the solvent, drive a long-time diffusive spread of the probe's trajectory. The influence of the former is determined by the spatial configuration of the bath particles and the force with which the probe perturbs it. With no external forcing the probe and bath particles form an equilibrium microstructure that fluctuates thermally with the solvent. Probe motion through the dispersion distorts the microstructure; the character of this deformation, and hence its influence on the probe's motion, depends on the strength with which the probe is forced, Fext, compared to thermal forces, kT/b, defining a Péclet number, Pe = Fext/(kT/b), where kT is the thermal energy and b the bath particle size. It is shown that the long-time mean-square fluctuational motion of the probe is diffusive and the effective diffusivity of the forced probe is determined for the full range of Péclet number. At small Pe Brownian motion dominates and the diffusive behaviour of the probe characteristic of passive microrheology is recovered, but with an incremental flow-induced ‘microdiffusivity’ that scales as Dmicro ~ DaPe2φb, where φb is the volume fraction of bath particles and Da is the self-diffusivity of an isolated probe. At the other extreme of high Péclet number the fluctuational motion is still diffusive, and the diffusivity becomes primarily force induced, scaling as (Fext/η)φb, where η is the viscosity of the solvent. The force-induced microdiffusivity is anisotropic, with diffusion longitudinal to the direction of forcing larger in both limits compared to transverse diffusion, but more strongly so in the high-Pe limit. The diffusivity is computed for all Pe for a probe of size a in a bath of colloidal particles, all of size b, for arbitrary size ratio a/b, neglecting hydrodynamic interactions. The results are compared with the force-induced diffusion measured by Brownian dynamics simulation. The theory is also compared to the analogous shear-induced diffusion of macrorheology, as well as to experimental results for macroscopic falling-ball rheometry. The results of this analysis may also be applied to the diffusive motion of self-propelled particles.

A study of the dynamic strength (impact resistance) of grinding bodies cast from low-chromium cast iron in a multi-seat chill mold depending on the chromium content in the alloy is carried out. As a starting point, cast iron of the following composition was used: carbon – 3,0%, silicon – 1,6%, manganese – 0,4%, sulfur – 0,05%, phosphorus – 0,06%. For the study, several batches of balls with a diameter of 60 mm were cast with different chromium content in cast iron, from 0 to 1%. Cast iron was smelted in a medium-frequency induction furnace, such as IChT, with the main lining on a charge of pure pig iron and steel low-carbon scrap. The temperature of cast iron production was 1500 °C. Liquid cast iron was subjected to alloying with medium carbon ferrochrome. Balls were cast in multi-seat chill molds. When tested for impact resistance, the grinding ball received a striking blow of mass 50 kg, falling from a height of 0,5 m. The frequency of application of dynamic loads was 10 beats per minute. Impact resistance was determined by the average number of impacts sustained by the grinding body prior to destruction. An increase in the impact resistance of ball castings has been established with an increase in the mass fraction of chromium in cast iron up to 1%. Moreover, the greatest increase in dynamic strength is observed with an increase in the mass fraction of chromium from 0,3% to 0,5%. With a further increase in the chromium content, the impact resistance of white low-alloy cast iron increases less noticeably, and in the presence of chromium 0,7-0,8% reaches a maximum. The difference in hardness from the surface (~ 52 HRC) to the center of the ball (~ 42 HRC) is a value of about 10 units. The established impact resistance of grinding bodies made it possible to conclude: when grinding solid rocks with high content of solid quartz, the use of low chromium cast iron as a material for grinding media is the most effective, as in terms of achieve high impact resistance, and to ensure cost-effective performance.

Hardness is a key mechanical property of flooring materials. In this study, the performance of veneer floorings (with a top layer thickness of 0.6 mm) was investigated by dynamic hardness tests, comparing it with those of traditional engineered wood floorings (with a top layer thickness of 3 mm) and solid wood floorings. Two hardwoods commonly used on wood flooring, viz. Quercus robur L. and Hymenaea courbaril L., and two fast-growing hardwoods, Eucalyptus globulus Labill. and Eucalyptus grandis W. Hill ex Maiden, were tested as top layers. To compare their usage properties, a dynamic impact hardness test involving steel balls with three diameters and five different drop heights was carried out, measuring the footprint diameter (FD) and the indentation depth (ID). The data from 4800 impacts, corresponding to 180 different individual groups (4 hardwood species × 3 ball diameters × 5 drop heights × 3 floor types) were analyzed. The results showed that the general response in terms of both FD and ID was better in the engineered wood floorings than in solid wood floorings, and that the veneer floorings (0.6 mm) showed better behavior than traditional engineered wood floorings (3.0 mm). Furthermore, for the veneer floorings, the two fast-growing hardwood species tested, which have significantly different densities, showed similar behavior to traditional hardwoods, suggesting that they would be suitable for valorization in the wood flooring industry.

Abstrak Penelitian skripsi ini bertujuan untuk menentukan nilai viskositas dinamik fluida uji dan kecepatan terminal bola uji dengan menerapkan metode bola jatuh. Instrumen ukur yang digunakan dalam penelitian adalah perangkat keras dan lunak yang meliputi sistem sensor transmitter-receiver (LED infra merah dan dioda-foto sebanyak 2 pasang) dan mikrokontroler. Bola uji yang digunakan berdiameter 1,1 cm, 1,5 cm dan 1,9 cm dan tabung silinder berdiameter penampang 3,6 cm dan 5,6 cm sedangkan fluida viskos yang diuji adalah minyak pelumas jenis SAE 30 dan SAE 40. Temuan penelitian ini adalah: (1) viskositas minyak pelumas SAE 30, 0,19 Pa.s berbeda 5% dari nilai referensi sebesar 0,20 Pa.s (https://physics.info/viscosity) dan viskositas minyak pelumas SAE 40, 0,30 Pa.s berbeda 6% dari nilai referensi sebesar 0,32 Pa.s menurut laman tersebut; dan (2) kecepatan terminal bola uji ditemukan lebih besar untuk percobaan dengan diameter bola uji yang lebih besar dengan penyimpangan hasil ukur dalam kisaran 5-8%. Penyimpangan hasil ukur dan sebesar itu masih bisa diterima dengan pertimbangan ketelitian instrumen ukur, teknik pengukuran dan experimental set-up. Kesulitan utama percobaan uji viskositas dengan metode bola jatuh adalah akurasi penentuan panjang fase pengamatan dan akurasi pencatatan selang waktu terukur . Nilai viskositas fluida uji tidak ditentukan oleh kecepatan terminal bola uji karena viskositas adalah besaran karakterisik fluida yang nilainya bergantung pada struktur ikatan molekul dan tidak bergantung pada jenis dan metode percobaan, serta ragam instrumen dan teknik pengukuran. Sebaliknya, kecepatan terminal bola uji merupakan besaran kinematik yang dipengaruhi oleh jenis dan metode percobaan, serta ragam instrumen dan teknik pengukuran. Kata Kunci: percobaan uji viskositas, viskositas dinamik, kecepatan terminal Abstract This study aims to determine viscosity of a fluid and a terminal velocity using a series of falling ball experiments. Experimental instruments include hardware and software involving transmitter-receiver system (2 pairs of infrared LED dan photo-diode) and microcontroller. Falling balls used have dimensions of 1.1 cm, 1.5 cm and 1.9 cm in diameter and cylndrical tubes of 3.6 cm and 5.6 cm in diameter whereas tested fluids are two types of lubricant oils, namely SAE 30 and SAE 40. The results are as follows: (1) the viscosity of SAE 30, 0,19 Pa.s differing from reference for oil of the same type of 0,20 Pa.s given by https://physics.info/viscosity by 5% and the viscosity of SAE 40, 0,30 Pa.s differing from reference for oil of the same type of 0,32 Pa.s referred to the same site by 6%; and (2) terminal velocity for falling balls increases with increasing sizes of the balls with deviations from predicted terminal velocity for measurements are found to be in the range 5-8%. Such deviations are acceptable in the limitation of uncertainties in instruments used, measurement techniques and experimental set-ups. The primary difficulties in doing this study mainly refer to accuracy in determination of the length of observations during each run and experimental time duration record . From all runs, we conclude that the viscosity of a fluid does not correspond to the terminal velocity of a test ball because it is an intrinsic quantity for a particular fluid. Rather, the viscosity of a fluid depends on molecular structures of the fluid, but is independent of experimental methods, types of instruments, and measurement techniques. On the other hand, terminal speed of a falling ball is a kinematic quantity being dependent on the experimental methods, types of instruments, and measurement techniques. Keywords: viscosity experiment, dynamic viscosity, terminal velocity

The bio-inspired honeycomb column thin-walled structure (BHTS) is inspired by the biological structure of beetle elytra and designed as a lightweight buffer interlayer to prevent damage to the reinforced concrete bridge pier (RCBP) under the overload impact from vehicle impact. According to the prototype structure of the pier, a batch of scale models with a scaling factor of 1:10 was produced. The BHTS buffer interlayer was installed on the reinforced concrete (RC) column specimen to carry out the steel ball impact test. Then, the modified numerical model was subjected to the low-energy input impact test of the steel ball without energy loss during the falling process at the equivalent height of 1.0–3.5 m, and the dynamic response characteristics of the RC column were analyzed. By comparing the impact force and impact duration, maximum displacement, and residual displacement in the impact model, the BHTS buffer interlayer’s protective effect on RC columns under lower energy lateral impact was evaluated. Later, a high-energy input lateral impact test of a steel ball falling at an equivalent height of 20.0 m was carried out. According to the material damage, dynamic response, and energy absorption characteristics in the impact model, the failure process of the RC columns was analyzed. The results showed that BHTS absorbed 82.33% of the impact kinetic energy and reduced 77.27% of the impact force, 86.51% of the inertia force, and 64.86% of the base shear force under the failure mode of a 20 m impact condition. It can transform the shear failure of the RC column into bending failure and play an effective protective role for the RC column. This study can provide useful references for collision prevention design in practical engineering.

The failure of plastic ball grid array under intense dynamic loading was studied in the project. This paper presents the drop test reliability results of SnPb flip-chip on a standard JEDEC drop reliability test board. The failure mode and mechanism of planar array package in the drop test was comprehensively analyzed. High acceleration dropping test method was used to research the reliability of BGA (ball grid array) packages during the free-drop impact process. The model RS-DP-03A drop device was used to simulate the falling behavior of BGA chip packages under the real conditions, The drop condition meets the JEDEC22-B111 standards (pulse peak 1500g, pulse duration 0.5 ms) when dropping from the 650mm height . In the testing, according to the real-time changes of dynamic voltage, the relationship between drop times and different phases of package failure was analyzed. With the dye-penetrated method and optical microscopy, it was easy to observe the internal crack and failure locations. The growth mechanism of the cracks in solder joints under the condition of drop-free was analyzed and discussed.

Abstract A study on the rates of decay, falling, and recruitment in a population of snags (standing dead trees) in the Sierra Nevada, California, during 1975-83 showed that large-diameter (>38 cm dbh) snags fell slower than small-diameter snags. Firs (Abies spp.) fell at a lower rate than pines (Pinus spp.). Snags lost all needles and twigs within five years; 75% of pines and 66% of firs had lost most larger limbs within five years. Compared with the numbers of live trees in the parent stand, rates of new mortality were highest among Jeffrey pine (Pinus jeffreyi Grev. and Balf.) <15 cm dbh. Live-tree morality exceeded the rate that snags fell during our study, causing an increase in the snag population from 1978 to 1983. A Leslie matrix model of this snag population was developed that accounted for falling rates, transitions among decay stages, and recruitment of snags. Use of the model was illustrated using field data from five unburned study plots. For. Sci. 33(3):774-783.

A study was made of the impact-abrasive wear resistance and impact resistance of grinding bodies cast in a multi-place mold. Three types of chromium cast irons were adopted for the study: low chromium (~1% Cr), medium chromium (up to 5% Cr) and high chromium (up to 20% Cr). The macro- and microstructure of these alloys as a material for cast grinding balls has been studied. Installed an increase in the impact-abrasive wear resistance and impact resistance of such products with an increase in the mass fraction of chromium in cast iron due to the formation of carbides of the (Fe, Cr)3C and especially (Fe, Cr)7C3. Balls were cast in multi-seat chill molds. Cast iron was smelted in a medium-frequency induction furnace, such as IChT, with the main lining on a charge of pure pig iron and steel low-carbon scrap. The temperature of cast iron production was 1500 °C. Liquid cast iron was subjected to alloying with medium carbon ferrochrome. The wear resistance of cast irons was determined on samples cut from balls in the radial direction. The tests were performed in a laboratory mill When tested for impact resistance, the grinding ball received a striking blow of mass 50 kg, falling from a height of 0,5 m. The frequency of application of dynamic loads was 10 beats per minute. Impact resistance was determined by the average number of impacts sustained by the grinding body prior to destruction. Nevertheless, significant excess of the cost high-chromium over low-chromium cast iron forces us to agree with the opinion of the majority of researchers and the practice of production of such metal products. In today's conditions, low-chromium white cast iron is an economically viable material for grinding media.

Commercially produced hen eggs have been tested by means of dynamic excitation of the egg-shells with following analysis of their response. The falling steel ball have been chosen as a exciting instrument and the laser vibrometer have been used as a measuring device for the egg response. The reproductibility of the experiments has been relatively high and the surface velocity has been found to be significantly dependent on the position around the meridian. Analysed frequency spectrum has shown the peak frequency and frequency history. Proposed numerical model has demonstrated reasonable agreement with experimental results and can be used as an effective tool in modelling of analogous or similar experiments.

Small sized specimen of cement concrete pavement structure was prepared indoors. By utilizing the dynamic signal tester and obtaining the vibration frequency domain signals through the falling-ball vibration impact test method, the attenuation rules of the vibration response of the pavement structure were analyzed and the effects of the flexible functional layer on the vibration-reduction and energy-absorption were studied. The results showed that, after compared with the normal flexible functional layer, the flexible functional layer incorporated with rubber powder resulted in the pavement structure having the better capacities of vibration-reduction energy-absorption and impact resistance. Accordingly, the rupture failure of the cement concrete pavement induced by vehicle load can be reduced.

Experimental data on quasi-static and dynamic loading of fluids with viscoelastic surfactants are used for the prediction of hydraulic fracturing. The paper proposes the dependence of viscosity on shear rate and pressure in a wide range of loading conditions. Experimental studies of liquids were carried out with the use of a falling ball rheometer (the Stokes method), industrial rheometers with a measuring system ‘cone-plane’ or ‘coaxial cylinders’; studies at high shear strain rates were car-ried out by the method of electrical explosion of the conductor. The proposed power-law depend-ence of viscosity on the shear strain rate with taking into account pressure, makes it possible to adequately describe experimental data from laboratory tests in the range of the shear strain rate and fluid pressure characteristic of hydraulic fracturing.

This paper shows experimental study results on the thermophysical and stability of nanofluids of Titanium oxide (TiO2) dispersed in high-purity of Virgin Coconut Oil (VCO). Nanofluid samples that functioned as a lubricant were prepared by a two-step preparation method at different volume fractions (0.1, 0.3, and 0.5 vol.%) and different temperatures (28, 40, and 100°C). The dynamic viscosity and density were performed using Falling Ball Viscometer and Pycnometer, respectively. The sedimentation photograph method using a digital camera was applied to analyze the stability. A maximum dynamic viscosity enhancement of 62.78% was recorded for TiO2/VCO nanofluid with 0.5% nanoparticle volume fraction and at the temperature of 100°C). Whereas, the highest density improvement was recorded for TiO2/VCO nanofluid with 0.5% nanoparticle volume fraction. Freshly prepared nanofluids did not show any significant change in stability. However, a trivial phase separation appeared in the samples after 8 days. The results indicated that adding TiO2 nanoparticles increased the dynamic viscosity and density. It can be concluded that the volume in fraction has the effect to enhance the thermophysical stability of TiO2/VCO nanofluids.

With the aim of achieving more effective friction and wear reduction in sliding bearing applications, surface-modified graphene, which exhibits better dispersion stability than non-modified graphene, was synthesized and applied in this study using various graphene allotropes, including graphene nanoplatelets (GNP), multiwalled carbon nanotubes (MWCNT) and nanostructured graphite (NSG). Friction and wear tests of each type of graphene allotrope under modified and non-modified conditions were studied using a pin-on-ring tribo tester. In addition, the dynamic viscosity of each synthesized nanofluid sample was measured using a falling-ball viscometer. A series of modified graphene-oil nanofluids and non-modified graphene-oil nanofluids were prepared and heated before their friction and wear performance was investigated at room temperature. Friction and wear behavior, as well as the dynamic viscosity of the heated nanofluids vary insignificantly when compared to those of the non-heated nanofluids. The results showed that the best friction and wear reduction was achieved by modified GNP with friction and wear reduction of 60.5% and 99.4%, respectively.

The development of urbanization and the resulting expansion of residential and transport infrastructures pose new challenges related to ensuring comfort for city dwellers. The emission of transport vibrations and household noise reduces the quality of life in the city. To counteract this unfavorable phenomenon, vibration isolation is widely used to reduce the propagation of vibrations and noise. A proper selection of vibration isolation is necessary to ensure comfort. This selection can be made based on a deep understanding of the material parameters of the vibration isolation used. This mainly includes dynamic stiffness and damping. This article presents a comparison of the method for testing dynamic stiffness and damping using a single degree of freedom (SDOF) system and the method using image processing, which involves tracking the movement of a free-falling steel ball onto a sample of the tested material. Rubber granules, rubber granules with rubber fibers, and rebound polyurethanes were selected for testing. Strong correlations were found between the relative indentation and dynamic stiffness (at 10–60 MN/m3) and the relative rebound and damping (for 6–12%). Additionally, a very strong relationship was determined between the density and fraction of the critical damping factor/dynamic stiffness. The relative indentation and relative rebound measurement methods can be used as an alternative method to measure the dynamic stiffness and critical damping factor, respectively.

The work is devoted to the study of the rheological behavior of proppant carrier fluids used for hydraulic fracturing (HF) technology in order to increase oil recovery, including from hard-torecover oil and gas reserves, in a wide range of deformation rates using viscometers of various designs. Rheological properties were studied for proppant carrier fluids based on guar and Surfogel grade D, (type 70–100, produced by JSC “Polyex”) with comparable shear rate 128 s–1. Quasistatic experiments to determine the values of the dynamic viscosity of the liquids under study were carried out using a falling ball viscometer (according to the Stokes method). Using an original viscometer, consisting of two coaxial cylinders (rotary rheometer), the dynamic viscosity of surfogel was investigated in a wide range of shear rates. The viscoelastic properties of surfactants were studied using a Physica MCR501 rheometer, which has a plane-to-plane measuring system and allows rheological studies in rotational and oscillatory modes. A comparison of the rheological properties of fluids based on the guar and the viscoelastic surfactant is carried out and it is established that a fluid based on the viscoelastic surfactant has a higher dynamic viscosity and does not lose its elastic properties, which is an certain advantage over a fluid based on the guar.

There are various types of gel materials used in a wide range of fields, and their gelation mechanisms are extremely diverse. Furthermore, in the case of hydrogels, there exist some difficulties in understanding complicated molecular mechanisms especially with water molecules interacting through hydrogen bonding as solvents. In the present work, the molecular mechanism of the structural formation of fibrous super-molecular gel by the low molecular weight gelator, N-oleyl lactobionamide/water mixture was elucidated using the broadband dielectric spectroscopy (BDS) method. The dynamic behaviors observed for the solute and water molecules indicated hierarchical structure formation processes in various time scales. The relaxation curves obtained at various temperatures in the cooling and heating processes showed relaxation processes respectively reflecting the dynamic behaviors of water molecules in the 10 GHz frequency region, solute molecules interacting with water in MHz region, and ion-reflecting structures of the sample and electrode in kHz region. These relaxation processes, characterized by the relaxation parameters, showed remarkable changes around the sol–gel transition temperature, 37.8 °C, determined by the falling ball method and over the temperature range, around 53 °C. The latter change suggested a structure formation of rod micelles appearing as precursors before cross-linking into the three-dimensional network of the supramolecular gels. These results clearly demonstrate how effective relaxation parameter analysis is for understanding the gelation mechanism in detail.

In today’s automation control systems, the PID controller, as a core technology, is widely used to maintain the system output near the set value. However, in some complex control environments, such as the application of ball screw-driven rotating motors, traditional PID parameter adjustment methods may not meet the requirements of high precision, high performance, and fast response time of the system, making it difficult to ensure the stability and production efficiency of the mechanical system. Therefore, this paper proposes a cuckoo search optimisation coupled with an improved grey wolf optimisation (CSO_IGWO) algorithm to tune PID controller parameters, aiming at resolving the problems of the traditional grey wolf optimisation (GWO) algorithm, such as slow optimisation speed, weak exploitation ability, and ease of falling into a locally optimal solution. First, the tent chaotic mapping method is used to initialise the population instead of using random initialization to enrich the diversity of individuals in the population. Second, the value of the control parameter is adjusted by the nonlinear decline method to balance the exploration and development capacity of the population. Finally, inspired by the cuckoo search optimisation (CSO) algorithm, the Levy flight strategy is introduced to update the position equation so that grey wolf individuals are enabled to make a big jump to expand the search area and not easily fall into local optimisation. To verify the effectiveness of the algorithm, this study first verifies the superiority of the improved algorithm with eight benchmark test functions. Then, comparing this method with the other two improved grey wolf algorithms, it can be seen that this method increases the average and standard deviation by an order of magnitude and effectively improves the global optimal search ability and convergence speed. Finally, in the experimental section, three parameter tuning methods were compared from four aspects: overshoot, steady-state time, rise time, and steady-state error, using the ball screw motor as the control object. In terms of overall dynamic performance, the method proposed in this article is superior to the other three parameter tuning methods.

Today, burns are one of the most common types of injuries in the home and at work around the world. Therefore, the issue of treatment of burns remains relevant today for medicine and pharmacy in particular. In Ukraine, the method of treatment of burns using xenodermoimplants from porcine skin is used, and therefore the crushed substrate of cryolyophilized porcine skin (xenoderm) is a promising active ingredient in the technology of various drug forms. The aim of the work was to study the structural and mechanical properties of water extract from the crushed substrate of the xenoderm and to determine its amino acid composition by using physicochemical analysis, namely using high performance liquid chromatography (HPLC). A glass pycnometer and a Heppler BH 2 MLW drop ball viscometer were used to determine the density and viscosity of the water extract from the xenoderm. The density and viscosity of the water extract were studied at different temperatures. The dependence of the density and viscosity of the water extract from the xenoderm on temperature was studied and it was found that with increasing temperature the dynamic viscosity decreases and the density changes slightly. A glass pycnometer and a viscometer with falling ball were used to determine the density and viscosity of the xenoderm water extract. Chromatographic separation of amino acids was performed on a liquid chromatograph Agilent 1200 with a fluorescent detector. Chromatographic determination of amino acids was performed on a liquid chromatograph Agilent 1200 (USA) with a fluorescent detector G1315A (USA) and an autosampler 1313A. Using the HPLC method, 16 amino acids were identified (essential – 6; conditionally – 2; nonessential – 8). Identified amino acids are almost in a bound state (1.5%), the largest amount is glutamic acid (0.23%), glycine (0.19%), aspartic acid (0.18%), proline (0.17%) and arginine (0.17%). In unbound form, the content of glutamic acid (0.09%) and glycine (0.06%) is the highest. Based on the results of research, you can choose quality indicators, to determine the appropriate criteria that can be proposed for the standardization of water extract from the crushed substrate of the xenoderm.

The objective of this work is to study the effect of impact and blast dynamic loading upon concrete plates reinforced with normal deformed steel bars as well as steel or glass fibers. In order to examine the effect of using different volume and weight fractions of s skeletal bars and steel or glass fiber reinforcements on the impact and blast resistance, 24 plates and 24 prisms were manufactured as test specimens. A set consisting 0f 8 plates were tested under high velocity impact using 14.7 caliber bullets with a shooting distance of 63 m. The specimens with 1.5 % steel fiber and two layers of steel mesh (8 mm at 75 mm) have shown resistance to full perforation of the bullet. Improvements to the resistance to spalling, scabbing and crack growth have also been observed. Field blast testing was carried out on a second set of 8 specimens by using a charge of 100 gm located at the center of each specimen. All the plates were 160 mm thick and with had minimum reinforced of 0.75% glass fiber and a single layer of steel mesh (8 mm at 75 mm). Have shown resistance to full perforation of waves and have restricted the number, the width and the growth of cracks. The last set of the remaining 8 plates was subjected to a low speed impact test performed by a falling steel ball. Test results clearly show the significant effect of using steel and glass fiber besides deformed bars to enhance the impact resistance by 400 % and 20 % by using 1.5 % steel fiber and 0.75 % glass fiber resistance .Energy absorption capacity and ductility were also increased by 100 % and 600 % by using 1.5 steel fiber. Chang in compressive strength of about ±6 % and ± (20 – 30 ) % were observed by using 1.5% steel fibers and 0.75% glass fibers respectively. The inclusion of 1.5% steel fibers and 0.75% glass fibers together with deformed steel bars have improved the tensile strength by 200% and 70% respectively.

The article is a continuation of the author's research, which raises the question of the structural and functional features of the defence structures of the city of Kyiv in the IX-XIII centuries. Based on the analysis of scientific literature, comprising of written and archaeological sources, and reconstructions of urban fortifications of a certain time, the author has proposed his scheme of construction evolution of derelict fortified structures of Ancient Rus. He states that: firstly, at the beginning of erection of earth shafts, their reinforcement was never performed, and secondly, the construction of shafts of complex type (reinforced) arose as a result of repeated repairs and restructuring of initially low timber fortifications, and thirdly, the complexity of fortifications. Only the duration of their active functioning was affected. Particular attention is paid to the construction of the defensive walls of the "city of Yaroslav" in Kyiv, the remains of which were found during archaeological excavations in 1952, 1971-1973, 1981 and 2001. The author argues that in the timber walls of the "city of Yaroslavl" in the areas near the Golden and Liadsky gates and on the Maydan Nezalezhnosti, where vertical auxiliary lattice frames from the cages, which did not connect with the cages of the main structure of the fortification, were fixed - initially there was a thallus. The gap between the main and the auxiliary structures should have prevented the transmission to the main array of dynamic loading walls from falling projectiles. The latter partly rebounded at the enemy, partially destroyed the hack itself, making it an additional obstacle for the attacking side. Taking into account the presence in the defensive fortifications of the thallus, the author concludes that the defenders of the city used not only bows but also metal tools. The article hypothesizes that the material used in the IX-XIII centuries in Kyiv for the production of metal shells, there was unbaked moist clay from which balls of various sizes were made.

The use of magnetic fields allows to modify the trajectory of magnetizable particles in a fluid. If a ring magnet is centered on the cylinder containing the fluid, it enhances the dynamics of a falling ball, and an equilibrium position is found. To compute the particle dynamics, the magnetic force should be found accurately : a method based on virtual works allows to obtain the force as well as the stiffness matrix, to gain accuracy. The computed trajectories are compared to the experimental ones for Newtonian fluids at first, and extended to viscoplastic fluids.

Abstract Projectile penetration into an immersed granular bed is a common phenomenon in both geophysics and engineering, encompassing various scenarios such as immersed crater formation and offshore soil-structure interaction. It involves the complex physical interaction between the fluid and granular materials. In this study, we investigate the dynamics of projectile penetration into a granular bed immersed in a fluid using a coupled computational fluid dynamics and discrete element method (CFD-DEM). The granular bed is composed of polydisperse particles, and the projectile is modeled as a rigid sphere. The morphology of crater formation, the dynamics of the projectile, and the drag force characteristics in immersed cases were studied in detail and compared to the dry scenario. The numerical results show that the final penetration depth of the projectile follows an empirical relation derived from experimental observations, where the falling height and the drag force during penetration obey a power-law function and a modified generalized Poncelet law, respectively. The interstitial fluid not only provides direct drag force, but also enhances the effective drag force of the granular bed by improving its generalized friction and effective viscosity in different configurations. Micro-analyses of the velocity evolution and contact force network in different stages of the fluid–solid interaction were performed to clarify the penetration dynamics. This research provides insights into the mechanisms of projectile penetration and the effects of interstitial fluid on granular media, which are crucial in engineering applications such as offshore anchoring, ball penetration tests in soft sediments, and soil-structure interactions. Graphical Abstract

The free fall of steel balls of different diameters in viscous liquids placed in a cylindrical vessel at rest or rotating at a constant rate as well as the vortex generation in a liquid rotating in a cylindrical vessel were experimentally studied. To solve the problem a test stand including a cylindrical glass vessel mounted on the axis of a governed-speed electric engine shaft, monitoring and measuring devices as part of a digital laser tachometer, a digital USB microscope and a laptop was developed to visualize the processes under study. Experimental dependences of the instantaneous velocity of the balls on the distance traveled by them were obtained. It has been demonstrated, that there is a transition mode of the ball velocity variation when it enters the liquid. The transition mode was characterized by a damped, periodic variation of instantaneous velocity depending on a distance. It has been found that at a certain distance traveled by the ball, the transition mode becomes stationary when the ball moves at a constant velocity. The dependence of the liquid viscosity on the vessel rotation frequency was studied in the stationary mode using the Stokes method. It has been demonstrated that the common behavior of such processes is decreasing the time of balls falling and, consequently, the coefficient of a liquid dynamic viscosity with increasing the rotation frequency of the vessel. A periodic variation in the coefficient of the dynamic viscosity depending on the frequency of the vessel rotation was found experimentally. It has been found experimentally that several threadlike spiral flows of a colored liquid are formed parallel to the axis of the cylinder, when the cylindrical vessel rotates. At that, the velocity of the downward drift of the colored liquid increases with increasing its rotation rate and it increases from the periphery to the center of the vessel.

The free fall of steel balls of different diameters in viscous liquids placed in a cylindrical vessel at rest or rotating at a constant rate as well as the vortex generation in a liquid rotating in a cylindrical vessel were experimentally studied. To solve the problem a test stand including a cylindrical glass vessel mounted on the axis of a governed-speed electric engine shaft, monitoring and measuring devices as part of a digital laser tachometer, a digital USB microscope and a laptop was developed to visualize the processes under study. Experimental dependences of the instantaneous velocity of the balls on the distance traveled by them were obtained. It has been demonstrated, that there is a transition mode of the ball velocity variation when it enters the liquid. The transition mode was characterized by a damped, periodic variation of instantaneous velocity depending on a distance. It has been found that at a certain distance traveled by the ball, the transition mode becomes stationary when the ball moves at a constant velocity. The dependence of the liquid viscosity on the vessel rotation frequency was studied in the stationary mode using the Stokes method. It has been demonstrated that the common behavior of such processes is decreasing the time of balls falling and, consequently, the coefficient of a liquid dynamic viscosity with increasing the rotation frequency of the vessel. A periodic variation in the coefficient of the dynamic viscosity depending on the frequency of the vessel rotation was found experimentally. It has been found experimentally that several threadlike spiral flows of a colored liquid are formed parallel to the axis of the cylinder, when the cylindrical vessel rotates. At that, the velocity of the downward drift of the colored liquid increases with increasing its rotation rate and it increases from the periphery to the center of the vessel.

Dynamic viscosity is a fundamental property of fluids that measures their resistance to flow under applied forces or shear stress. This study aims to calculate the dynamic viscosity of pure glycerol at different temperatures, using the falling ball approach. In this method, a ball was released in a tube filled with glycerol, and its movements were then tracked and analyzed using image processing with a Python program. We then determined the viscosity and compared it with the actual viscosity of the liquid. We hypothesized that this method would yield overall accurate measurements when compared to established reference methods but that there would also be a rise in inaccuracies with the increase in temperature. Our results support our hypothesis and were accurate to within 6.9% error but found no correlation between rise in temperature and measurement errors. We concluded that this approach requires more specialized equipment to investigate low viscosity fluids. Despite this study's limitations, it provided valuable insights into the applicability of the falling ball method and emphasizes the accuracy of this method.

AbstractIsaac Newton once contemplated the fall of an apple, setting in motion a revolution in the understanding of gravity. In a similar spirit of curiosity and inquiry, here a journey is embarked upon to explore the intricate world of viscoelastic damping for polydimethylsiloxanes (PDMS). Inspired by the notion that even the simplest of phenomena can yield profound insights, a novel approach to study damping in silicone elastomers through a simple ball drop test is introduced. This novel solution allowes for precise measuring and analyzing the material's damping characteristics under various conditions. By carefully controlling the release and monitoring, the response of the falling ball by simple video tracking, valuable insights into the key viscoelastic properties of silicone blends are extracted, including rebound resilience, Young's modulus, and complex modulus. Through the analysis of trajectory data generated during the sphere's interaction with the silicone damper, dynamic and static material parameters are determined. Remarkably, these outcomes closely align with results obtained from cost‐intensive and high‐maintenance industrial measurement setups such as dynamic thermomechanical analysis (DTMA) or tensile testing. This approach not only simplifies the complexity of the system but also offers a cost‐effective and efficient means of gaining essential knowledge in material science.

Background: Factors associated with performance outside of a normative range on dynamic exertion test (EXiT) after sport-related concussion (SRC) remain unknown. This study examined the role of demographic and medical history factors on performance using minimal detectable change (MDC) cutoff scores in athletes being cleared to return to sport (RTS) from SRC. Hypothesis: Older age, being female, and body mass index (BMI) ≥50th percentile would be associated with worse EXiT performance and with increased likelihood of falling outside the normative MDC score range. Study Design: Cross-sectional. Level of Evidence: Level 3. Methods: Demographic factors, physiological metrics, performance metrics, symptoms, and ratings of perceived exertion were collected from 55 participants (age, 16.5 ± 2.3 years, 31.5% female) initially evaluated within 14 days of SRC who completed EXiT at medical clearance for RTS. Chi-square analyses, logistic and ordinal regressions, and 1-way analyses of variance examined factors associated with EXiT performance. Results: Most participants fell within the MDC score range on aerobic (71.2-100%), dynamic (75.8-100%), and change-of-direction (36.5-98.0%) tasks, and symptoms (96.2-100%). Older age was associated with better performance on Box Drill Shuffle ( P < 0.01) and lower heart rate (HR) outcomes after Ball Toss ( P = 0.04), Box Drill Shuffle ( P < 0.01), Box Drill Carioca ( P = 0.04), and Pro Agility ( P < 0.01). Greater BMI was associated with higher HR%max after Ball Toss ( P < 0.01) and worse posttreadmill aerobic performance ( P < 0.01). Motion sickness history was associated with longer Zig Zag completion time ( P = 0.036). Conclusion: Most athletes presenting for clearance from concussion performed within MDC score ranges on EXiT metrics. Clinical Relevance: EXiT is accurate and effective in assessing response to dynamic exertion after SRC, and MDC scores can inform RTS decisions. Clinicians should consider age, BMI, and history of motion sickness when assessing EXiT performance.

AbstractAnticipating the behaviour of moving objects in the physical environment is essential for a wide range of daily actions. This ability is thought to rely on mental simulations and has been shown to involve frontoparietal and early visual areas. Yet, the connectivity patterns between these regions during intuitive physical inference remain largely unknown. In this study, participants underwent fMRI while performing a task requiring them to infer the parabolic trajectory of an occluded ball falling under Newtonian physics, and a control task. Building on our previous research showing that when solving the physical inference task, early visual areas encode task-specific and perception-like information about the inferred trajectory, the present study aimed to (i) identify regions that are functionally coupled with early visual areas during the physical inference task, and (ii) investigate changes in effective connectivity within this network of regions. We found that early visual areas are functionally connected to a set of parietal and premotor regions when inferring occluded trajectories. Using dynamic causal modelling, we show that predicting occluded trajectories is associated with changes in effective connectivity within a parieto-premotor network, which may drive internally generated early visual activity in a top-down fashion. These findings offer new insights into the interaction between early visual and frontoparietal regions during physical inference, contributing to our understanding of the neural mechanisms underlying the ability to predict physical outcomes.

Aims: In this study, the physical and rheological properties of three poly-floral honey samples collected from different places in the Kurdistan region were determined. Methods: The honey samples were analyzed for pH, free acidity, total ash content, moisture content, refractive index, soluble solids (Brix), electrical conductivity, volume expansion, density, specific heat capacity, surface tension, and rheological properties. The pH and free acidity of the honey samples varied from 4.10 to 4.81 to 30 to 62 mEq/kg, respectively. The total ash content ranged from 0.166 to 0.408 %. The moisture content, soluble solids, and refractive index ranged from 15.60 to 16.60 g/100 g, 83.40 to 84.40, and 1.4998 to 1.5023, respectively. The electrical conductivity ranged from 40.896 to 44.471 mS/cm. The linear relationship between the electrical conductivity and the ash content was also calculated in this investigation. The volumetric expansion coefficient of the honey samples varied from 6.0098x10-4 to 6.69942x10-4 mm3 /K. The density ranged from 1.42125995 to 1.45501137 g/cm3 . The specific heat capacity of the varied from 2448.078 to 2575.004 J/kg.K. The surface tension varied from 0.2178 to 0.2282 N/m. The apparent viscosity was measured by Brookfield Viscometer, and the dynamic viscosity was measured by HAAKE Falling Ball Viscometer, after changing the temperature from 293 to 323 K. Results and Discussion: The honey samples of lower moisture content showed a greater increase in their apparent and dynamic viscosities. Arrhenius model was used to describe the effect of temperature on the honey viscosity. This model was used to determine the activation energy. Other rheological properties as kinematic viscosity and fluidity, were also determined. Conclusion: All the honey samples behaved as Newtonian fluids in the whole temperature range.

AbstractIn this paper, polyvinyl chloride (PVC) coarse aggregate with different mixing contents is used to solve the problems of plastic pollution, low energy absorption capacity and poor damage integrity, which provides an important reference for PVC plastic concrete used in the initial support structures of highway tunnels and coal mine roadway. At the same time, the energy absorption characteristics and their relationship under different impact loads are studied, which provides an important reference for predicting the energy absorption characteristics of concrete under other PVC aggregate content or higher impact speed. This study replaced natural coarse aggregate in concrete with different contents and equal volume of well-graded flaky PVC particles obtained by crushing PVC soft board. Also, slump, compression, and splitting strength tests, a free falling low-speed impact test of steel balls and a high-speed impact compression test of split Hopkinson pressure bar (SHPB) were carried out. Results demonstrate that the static and dynamic compressive strength decreases substantially, and the elastic modulus and slump decrease slowly with the increase of the mixing amount of PVC aggregate (0–30%). However, the energy absorption rate under low-speed impact and the specific energy absorption per MPa under high-speed impact increase obviously, indicating that the energy absorption capacity is significantly enhanced. Regardless of the mixing amount of PVC aggregate, greater strain rate can significantly enhance the dynamic compressive strength and the specific energy absorption per MPa. After the uniaxial compression test or the SHPB impact test, the relative integrity of the specimen is positively correlated with the mixing amount of PVC aggregate. In addition, the specimens are seriously damaged with the increase of the impact strain rate. When the PVC aggregate content is 20%, the compressive strength and splitting strength of concrete are 33.8 MPa and 3.26 MPa, respectively, the slump is 165 mm, the energy absorption rate under low-speed impact is 89.5%, the dynamic compressive strength under 0.65 Mpa impact air pressure is 58.77 mpa, and the specific energy absorption value per MPa is 13.33, which meets the requirements of shotcrete used in tunnel, roadway support and other impact loads. There is a linear relationship between the energy absorption characteristics under low-speed impact and high-speed impact. The greater the impact pressure, the larger the slope of the fitting straight line. The slope and intercept of the fitting line also show a good linear relationship with the increase of impact pressure. The conclusions can be used to predict the energy absorption characteristics under different PVC aggregate content or higher-speed impact pressure, which can provide important reference for safer, more economical, and environmental protection engineering structure design.

Among the sub-genres of science fiction, one of the most traditional and most machine-laden is space opera. The name is dismissive and was coined in parallel with the now little recognised 'horse opera' (for westerns) in the wake of the success of the term 'soap opera' (for romantic serials). Space operas were adventure sagas across the galaxies with space ships carrying intrepid crews on voyages of discovery, into glorious battles and terrifying encounters with aliens. The 'opera' part presumably refers to their seriality and overstated melodrama. At various times during the last fifty years space opera has seemed as doomed as the horse type, but sufficient examples were published to keep the sub-genre puttering along until new authors could invigorate it. This has now happened and I want in this brief note to see the change, through looking at one current writer's series to see what has been done, how it has been received and how observing the role of a particular novum (Darko Suvin's term for the imaginative invention that characterises sf) -- a machine in this case, of course -- illuminates what has happened. Because this begins with a consideration of sf history, I want to start with one of the key distinctions that has long operated in both popular and academic analysis of science fiction (though admittedly it has more currency now in the popular); that between hard and soft sf. Unsurprisingly, given how loaded those terms are, it is a gendered distinction. Hard sf is the boys' playground; technologically driven, its allegiances are to physics and engineering. From nano-widgets to space ships as big as planets, it loves machines. The boysiness of hard sf was sedimented in popular sf through the generic hegemony achieved by Hugo Gernsback in his US pulp magazine empire starting with Astounding in 1926. Space opera was the quintessential type of hard sf in the early years, though it came to be challenged if not displaced by colonisation narratives that concentrated on engineering. Soft sf, of necessity the girly stuff, has the squishy bits -- biology certainly, but also the social sciences. Both New Wave and feminist sf, the innovative sub-genres of sf in the 60s and 70s, used soft rather than hard tropes in their subsequently incorporated revisions of the genre. In the 80s, cyberpunk presented itself as the hard stuff, but this was pretty disingenuous (all that voodoo, those drugs, the excursions into various social sciences), not to mention, as Samuel Delany among others has pointed out, the way this could only be managed by denying its feminist foremothers. These days, the traces of space opera's pulp-laden past are there to be read in the way that the more serious American writers like Kim Stanley Robinson prefer sober space colonisation narratives while the truly innovative work (as well as the quality writing) is done outside the US, by a Scot -- Iain M. Banks. In addition to Banks's wondrous novels of the Culture, the revivified field includes more traditional series like Lois McMaster Bujold's Vorkosigan saga, David Weber's Honor Harrington sequence and Colin Greenland's tracing of the career of Tabitha Jute. It would not be possible to examine how Banks has remapped the field in a note such as this, but dealing with some of the more traditional examples can provide an interesting case study in the hardness of the sub-genre, as well as pointing to wider movements in the sf world. It is the latter that is evident in the way in which the male writers produce female lead and the female the male (by and large, Bujold does occasional female leads). Not that Weber makes any attempt to make Honor credible as a female, she's laughably improbable and only needs to be placed near Greenland's Tabitha Jute for the disparity to become evident. (I'm using this comparison not just for its power but also because it stops the suggestion that male writers can't produce decent female action heroes.) For the more detailled part of this I want to concentrate on Bujold's series in part to mull over why it might be that her books are dismissed as too soft and 'girly' to be good space opera. There is something of a problem in that I find the whole hard:soft distinction more than a bit juvenile and value it primarily for its power in understanding sf history. The moves to broaden the field beyond what it was so artificially limited to in early to mid-twentieth century America seem to me to be a move to a more integrated adulthood rather than the imposition of a line of squishy feminine referents to be denied or repelled. I don't see 'softness' as a negative quality (nor 'hardness' for that matter), but I am interested in why and how a space opera series with space ships, space weaponry, gadgets galore and large quantities of prime quality derring-do should be deemed soft. Bujold has written a long series of space operas set in an Earth-colonised far-future that centre on the deformed figure of Lord Miles Vorkosigan. A few other fictions are set in the same universe and link in various ways to the core texts. Not all are set on spaceships though the majority require their presence as significant features of the plot while others rely on such standards of space narrative as space stations, terra-forming and the hardware of space warfare. To dismiss Bujold's world as one where the hardness of space opera technology is subsumed in girliness, it is necessary to overlook not just great passages of certain texts, but to dismiss whole novels. The Vor Game for instance follows a long sequence at an arctic weather station which culminates in the necessary destruction of outdated toxic weaponry with an escapade across great reaches of space in a whole range of ships displaying, selling and eventually using all manner of wonderful weaponry climaxing in a battle for control of a wormhole nexus. The only woman of any narrative prominence is a evil mercenary leader ("face of an angel, mind of a rabid mongoose"). One would think that it all sounds rather a sitter as a hard piece of space opera fare written for a readership of boys of all ages. My description though so far fails to convey where it is that Bujold has updated the sub-genre. It could be that the problem lies in the same place as the updating -- in the nuancing of the character of the hero Miles Vorkosigan and the continuing delineation of the interweaving of his double life as mercenary Admiral and loyal Imperial lieutenant. Traditionally the space opera hero comes into the world if not fully formed, then at least ready for a coming-of-age tale. Bujold shows us the formation of the hero, ensuring that he remains located within his extended family. It could be that complaints come from those who would prefer their heroes not to have mothers. But then again it could be about the humour. Bujold doesn't see earnestness as desirable and writes a fantastical adventure romp. It seems to me that this is one core difference between her and fellow Baen writer David Weber. There is no predicting what a descriptive passage about technology will lead to in Bujold; it could be a novel way to win hand to hand combat or a comic sequence making a moral point about abuse of power. For Weber, a sequence of space ships and weaponry is sufficient in itself, being an opportunity to talk of model numbers and ballistic capabilities with all the narrative brio of Tom Clancy (i.e. none), but at least Clancy is usually talking about something that has an existence in the real world. When both the machine and the science it operates by are more than speculative, labouring the trainspotters'-guide-to-hyperspace-technology talk can only delight anoraks. Machines are ends in themselves for Weber, means to a narrative or characterological point in Bujold. As well as why the machine is mentioned, there is also the question of what kind of machines are favoured. Maybe over the whole sequence, Bujold pays more attention to biologically-based technologies; when she focusses on engineering it is more often as a means to a biological end (usually terraforming), though in Falling Free, the least closely linked of the novels, the biology which enables the creation of the 'quads' -- freefall workers with four arms rather than arms and legs -- is in the service of engineering advantage. The passion in her work, and despite the humour and invention, there is considerable ideologically driven passion, is reserved for her biologically based beliefs -- that physical difference should be no barrier to achievement. As is common in sf, race is incidental and not part of the argument (it is rare for any but black writers of sf to see race as a meaningful issue for the future), but sex and ability are primary. Thus Miles, whose bones were damaged while a foetus and who is short and hunched, Bel Thorne, the hermaphrodite, Taura, the genetically engineered 'perfect soldier' eight foot tall with claws and fangs, Mark, Miles's clone brother and many others who appear less frequently carry the story of difference that must not be allowed to make a difference. Where gender is concerned, the popular spread of feminism means that forceful statements of position are read as political, not as some more woolly bit of being 'nice to the afflicted'. Bujold's feminism may be old-fashioned liberal rather than radical or post-modern, but it doesn't operate by parachuting women in to narratively significant positions of power. You buy the book and you get the argument and with Cordelia, Miles's mother, inscribed as the figure of rationality, the bases are loaded. The machine around which the discourse of liberation is organised, Bujold's novum and the machine which is the focus of complaint, is the uterine replicator -- an artificial womb. In the Bujold universe this is the ultimate good machine. It was a replicator that enabled Miles to survive after teratogenic damage in utero; his first love and his mother both issued from them; and it seems like the key test of a man is his willingness or otherwise to have his wife reproduce in vitro. I suppose I can see why this offends those wedded to old-fashioned hard space opera. Traditionally, the machines that tell the men from the girls/boys/lesser beings are the ships and their weaponry, but here the machines that count replicate the uterus (ultimate squishiness) and so, far from delivering death, deliver babies. Furthermore, their entry into the narrative is almost always the cue for a disquisition on the inequities of the patriarchal society within which Bujold sets almost all her action. InMirror Dance Miles's clone brother Mark finally meets the senior Vorkosigans. He is taken to a court ball by his 'mother' who explains the dynamics of the evening in terms of the political agenda of the old men and the genetic one of the old women. The men imagine theirs is the only one but that's just an ego-serving self-delusion. ... The old men in government councils spend their lives arguing against or scheming to fund this or that piece of off-planet military hardware. Meanwhile the uterine replicator is creeping in past their guard. (296) In the most recent book,Komarr, the main female character is an abused wife with a young son and the fact that her husband required her to bear the child herself is presented as just one of the many abuses he subjects her to. When you read the various passages which discuss the uterine replicators across the books, it can be surprising to discover the insistence with which barbarity and male oppression are figured in the refusal to countenance the machine and good men are revealed by their regarding it as a valuable device. It seems almost to verge on the excessive (but then this is not how such ephemeral texts as popular space opera are read, and if one put together a collection of the passages of 'best bits of weapons admiration' that would look a bit strange too). One could, if so minded, easily dismiss the Vorkosigan adventures as a bit girly on the basis of their enjoyment of interpersonal relations, character development, or romance. If, though, one were willing to admit that only certain pieces of hardware had generically usable hardness, it might rather be possible to observe that the carping at the centrality of the wrong kind of machine identifies much more accurately what is really worrying about the whole popularity of the series -- that this machine is a Trojan Horse for the incorporation through hard technology of 'hard' feminist politics. References Bujold, Lois McMaster. Komarr. Earthlight, 1998. ---. Mirror Dance Riverdale: Baen, 1994. ---. The Vor Game. Riverdale: Baen, 1990. Delany, Samuel R. Silent Interviews: On Language, Race, Sex, Science Fiction and Some Comics. Hanover: Wesleyan UP, 1994. Suvin, Darko. Metamorphoses of Science Fiction. New Haven: Yale UP, 1979. Citation reference for this article MLA style: Frances Bonner. "The Hard Question of Squishy Machines." M/C: A Journal of Media and Culture 2.6 (1999). [your date of access] <http://www.uq.edu.au/mc/9909/bujold.php>. Chicago style: Frances Bonner, "The Hard Question of Squishy Machines," M/C: A Journal of Media and Culture 2, no. 6 (1999), <http://www.uq.edu.au/mc/9909/bujold.php> ([your date of access]). APA style: Frances Bonner. (1999) The hard question of squishy machines. M/C: A Journal of Media and Culture 2(6). <http://www.uq.edu.au/mc/9909/bujold.php> ([your date of access]).

IntroductionTraditionally, suburbs have been conceived as dormitory – in binary opposition to the inner-city (Powell). Supporting this stereotypical view have been gendered binaries between inner and outer city areas; densely populated vs. sprawl; gentrified terraces and apartment culture vs. new estates and first home buyers; zones of (male) production and creativity against (female) sedate, consumer territory. These binaries have for over a decade been thoroughly criticised by urban researchers, who have traced such representations and demonstrated how they are discriminatory and incorrect (see Powell; Mee; Dowling and Mee). And yet, such binaries persist in popular media commentaries and even in academic research (Gibson and Brennan-Horley). In creative city research, inner-city areas have been bestowed with the supposed correct mix of conditions that may lead to successful creative ventures. In part, this discursive positioning has been borne out of prior attempts to mapthe location of creativity in the city. Existing research on the geography of creativity in the city have relied on proxy data forms: mapping data on firms and/or employment in the creative industry sectors (e.g. Gibson, Murphy and Freestone; Markusen et al.; Watson). In doing so, the focus has rested on “winners” – i.e. headquarters of major arts and cultural institutions located in inner city/CBD locations, or by looking for concentrations of registered creative businesses. Such previous studies are useful because they give some indication of the geographical spread and significance of creative activities in cities, and help answer questions about the locational preferences of creative industries, including their gravitational pull towards each other in an agglomerative sense (Scott). However, such studies rely on (usually) one proxy data source to reveal the presence of creative activities, rather than detail how creativity is itself apparent in everyday working lives, or embedded in the spaces, networks and activities of the city. The latter, more qualitative aspects of the lived experience of creativity can only at best be inferred from proxy data such as employment numbers and firm location. In contrast, other researchers have promoted ethnographic methods (Drake; Shorthose; Felton, Collis and Graham) including interviewing, snowballing through contacts and participant observation, as means to get ‘inside’ creative industries and to better understand their embeddedness in place and networks of social relations. Such methods provide rich explanation of the internal dynamics and social logics of creative production, but having stemmed from text-based recorded interviews, they produce data without geographical co-ordinates necessary to be mapped in the manner of employment or business location data – and thus remain comparatively “aspatial”, with no georeferenced component. Furthermore, in such studies relational interactions with material spaces of home, work and city are at best conveyed in text form only – from recorded interviews – and thus cannot be aggregated easily as a mapped representation of city life. This analysis takes a different tack, by mapping responses from interviews, which were then analysed using methods more common in mapping and analysing proxy data sources. By taking a qualitative route toward data collection, this paper illustrates how suburbs can actually play a major role in creative city economies, expanding understandings of what constitutes a creative workplace and examining the resulting spatial distributions according to their function. Darwin and the Creative Tropical City Project This article draws on fieldwork carried out in Darwin, NT a small but important city in Australia’s tropical north. It is the government and administration capital of the sparsely populated Northern Territory and continues to grapple with its colonial past, a challenging climate, small population base and remoteness from southern centres. The city’s development pattern is relatively new, even in Australian terms, only dating back to the late 1970s. After wholesale destruction by Cyclone Tracy, Darwin was rebuilt displaying the hallmarks of post-1970 planning schemes: wide ring-roads and cul-de-sacs define its layout, its urban form dominated by stout single-story suburban dwellings built to withstand cyclonic activity. More recently, Darwin has experienced growth in residential tower block apartments, catering to the city’s high degree of fly-in, fly-out labour market of mining, military and public service workers. These high rise developments have been focussed unsurprisingly on coastal suburbs with ample sections of foreshore. Further adding to its peculiar layout, the geographic centre is occupied by Darwin Airport (a chief military base for Australia’s northern frontier) splitting the northern suburbs from those closer to its small CBD, itself jutting to the south on a peninsula. Lacking then in Darwin are those attributes so often heralded as the harbingers of a city’s creative success – density, walkability, tracts of ex-industrial brownfields sites ripe for reinvention as creative precincts. Darwin is a city dominated by its harsh tropical climate, decentralised and overtly dependant on private car transport. But, if one cares to look beyond the surface, Darwin is also a city punching above its weight on account of the unique possibilities enabled by transnational Asian proximity and its unique role as an outlet for indigenous creative work from across the top of the continent (Luckman, Gibson and Lea). Against this backdrop, Creative Tropical City: Mapping Darwin’s Creative Industries (CTC), a federally funded ARC project from 2006 to 2009, was envisaged to provide the evidential base needed to posit future directions for Darwin’s creative industries. City and Territory leaders had by 2004 become enchanted by the idea of ‘the creative city’ (Landry) – but it is questionable how well these policy discourses travel when applied to disparate examples such as Darwin (Luckman, Gibson and Lea). To provide an empirical grounding to creative city ideas and to ensure against policy fetishism the project was developed to map the nature, extent and change over time of Darwin’s creative industries and imagine alternate futures for the city based on a critical appraisal of the applicability of national and international creative industry policy frameworks to this remote, tropical location (Lea et al.). Toward a Typology of Darwin’s Creative Workplaces This article takes one data set gathered during the course of the CTC project, based around a participatory mapping exercise, where interviewees responded to questions about where creative industry activities took place in Darwin by drawing on paper maps. Known as mental maps, these were used to gather individual representations of place (Tuan), but in order to extend their applicability for spatial querying, responses were transferred to a Geographic Information System (GIS) for storage, collation and analysis (Matei et al.). During semi-structured interviews with 98 Darwin-based creative industry practitioners, participants were provided with a base map of Darwin displaying Statistical Local Area (SLA) boundaries and roads for mark up in response to specific questions about where creative activities occurred (for more in depth discussion of this method and its varied outputs, refer to Brennan-Horley and Gibson). The analysis discussed here only examines answers to one question: “Where do you work?” This question elicited a total of 473 work locations from 98 respondents – a fourfold increase over statistics gleaned from employment measures alone (Brennan-Horley). Such an increase resulted from participants identifying their everyday work practices which, by necessity, took place across multiple locations. When transferring the spatial location of workplaces into the GIS, each site was coded depending on whether it was cited by the interviewee as their “major” or primary place of work, or if the place being discussed played a secondary or “minor” role in their creative practice. For example, an artist’s studio was categorised as major, but other minor sites also featured in their mental maps, for example, galleries, supply locations and teaching sites. Each worksite was then assigned to one of four categories: Front, Back, Networking and Supply (Table 1). In a similar fashion to McCannell’s work on the “front and back regions” of tourist towns (597), the creative industries, predicated on the production and exchange of texts, objects and ideas also display front spaces of sorts – sites that facilitate interactions between practitioner and audiences, spaces for performance and consumption. Operating behind these front spaces, are sites where creative endeavours take place – perhaps not as so readily seen or engaged with by wider publics. For example, a rehearsal room, artist’s studio or a theatre company’s office may not be key sites of interaction between creator and audience but remain nonetheless important sites of creative work. However, a binary of Front versus Back could not encapsulate the variety of other everyday, prosaic work sites evident in the data. Participants indicated on their maps visits to the post office to send artworks, going to Bunnings to buy paint (and inadvertently networking with others), through to more fleeting spaces such as artist materials fossicked from parklands to photoshoot locations. These supply sites (each themselves positioned along a continuum of “creative” to “mundane”) were typified as supply locations: sites that act as places to gather inputs into the creative process. Finally, sites where meetings and networking took place (more often than not, these were indicated by participants as occurring away from their major work place) were assigned under a heading of networking spaces. Table 1: A typology of creative workplaces Space Definition Coded examples Front A space for consumption/exchange of creative goods, outputs or expertise. Performance space, Market, Gallery, Client Location, Shopfront, Cinema, Exhibition space, Museum, Festival space Back A site of production, practice or business management Office, Studio, Rehearsal Space, Teaching Space, Factory, Recording Studio Networking A space to meet clients or others involved in creative industries Meeting places Supply Spaces where supplies for creative work are sourced Supplier, Photoshoot Location, Story Location, Shoot Location, Storage Coding data into discrete units and formulating a typology is a reductive process, thus a number of caveats apply to this analysis. First there were numerous cases where worksites fell across multiple categories. This was particularly the case with practitioners from the music and performing arts sector whose works are created and consumed at the same location, or a clothing designer whose studio is also their shopfront. To avoid double counting, these cases were assigned to one category only, usually split in favour of the site’s main function (i.e. performance sites to Front spaces). During interviews, participants were asked to locate parts of Darwin they went to for work, rather than detail the exact role or name for each of those spaces. While most participants were forthcoming and descriptive in their responses, in two percent of cases (n=11) the role of that particular space was undefined. These spaces were placed into the “back” category. Additionally, the data was coded to refer to individual location instances aggregated to the SLA level, and does not take into account the role of specific facilities within suburbs, even though certain spaces were referred to regularly in the transcripts. It was often the case that a front space for one creative industry practitioner was a key production site for another, or operated simultaneously as a networking site for both. Future disaggregated analyses will tease out the important roles that individual venues play in Darwin’s creative economy, but are beyond this article’s scope. Finally, this analysis is only a snapshot in time, and captures some of the ephemeral and seasonal aspects of creative workplaces in Darwin that occurred around the time of interviewing. To illustrate, there are instances of photographers indicating photo shoot locations, sites that may only be used once, or may be returned to on multiple occasions. As such, if this exercise were to be carried out at another time, a different geography may result. Results A cross-tabulation of the workplace typology against major and minor locations is given in Table 2. Only 20 per cent of worksites were designated as major worksites with the remaining 80 per cent falling into the minor category. There was a noticeable split between Back and Front spaces and their Major/Minor designation. 77 per cent of back spaces were major locations, while the majority of Front spaces (92 per cent) fell into the minor category. The four most frequently occurring Minor Front spaces – client location, performance space, markets and gallery – collectively comprise one third of all workplaces for participants, pointing to their important role as interfacing spaces between creative output produced or worked on elsewhere, and wider publics/audiences. Understandably, all supply sites and networking places were categorised as minor, with each making up approximately 20 per cent of all workplaces. Table 2: creative workplaces cross tabulated against primary and secondary workplaces and divided by creative workplace typology. Major Minor Grand Total Back Office 44 1 45 Studio 22 - 22 Rehearsal Space 7 11 18 Undefined - 11 11 Teaching Space 3 1 4 Factory 1 - 1 Recording Studio 1 - 1 Leanyer Swamp 1 - 1 Back space total 79 24 103 Front Client Location - 70 70 Performance Space 2 67 69 Market 1 11 12 Gallery 3 8 11 Site - 8 8 Shopfront 1 3 4 Exhibition Space - 3 3 Cinema 2 1 3 Museum 1 1 2 Shop/Studio 1 - 1 Gallery and Office 1 - 1 NightClub 1 - 1 Festival space - 1 1 Library 1 - 1 Front Space total 14 173 187 Networking Meeting Place - 94 94 Networking space total - 94 94 Supply Supplier - 52 52 Photoshoot Location - 14 14 Story Location - 9 9 Shoot Location - 7 7 Storage - 4 4 Bank - 1 1 Printer - 1 1 Supply Space total - 88 88 Grand Total 93 379 472 The maps in Figures 1 through 4 analyse the results spatially, with individual SLA scores provided in Table 3. The maps use location quotients, representing the diversion of each SLA from the city-wide average. Values below one represent a less than average result, values greater than one reflecting higher results. The City-Inner SLA maintains the highest overall percentage of Darwin’s creative worksites (35 per cent of the total) across three categories, Front, Back and especially Networking sites (60 per cent). The concentration of key arts institutions, performance spaces and CBD office space is the primary reason for this finding. Additionally, the volume of hospitality venues in the CBD made it an amenable place to conduct meetings away from major back spaces. Figure 1: Back spaces by Statistical Local Areas Figure 2: Front spaces by Statistical Local Areas Figure 3: Networking sites, by Statistical Local Areas Figure 4: Supply sites by Statistical Local Areas However this should not deter from the fact that the majority of all worksites (65 per cent) indicated by participants actually reside in suburban locations. Numerically, the vast majority (70 per cent) of Darwin’s Front spaces are peppered across the suburbs, with agglomerations occurring in The Gardens, Fannie Bay, Nightcliff and Parap. The Gardens is the location for Darwin’s biggest weekly market (Mindl Beach night market), and a performance space for festivals and events during the city’s long dry season. Mirroring more the cultures of its neighbouring SE Asian counterparts, Darwin sustains a vibrant market culture unlike that of any other Australian capital city. As the top end region is monsoonal, six months of the year is guaranteed to be virtually rain free, allowing for outdoor activities such as markets and festivals to flourish. Markets in Darwin have a distinctly suburban geography with each of the three top suburban SLAs (as measured by Front spaces) hosting a regular market, each acting as temporary sites of networking and encounter for creative producers and audiences. Importantly, over half of the city’s production sites (Back spaces) were dispersed across the suburbs in two visible arcs, one extending from the city taking in Fannie Bay and across to Winnellie via Parap, and through the northern coastal SLAs from Coconut Grove to Brinkin (Figure 1). Interestingly, 85 per cent of all supply points were also in suburban locations. Figure 4 maps this suburban specialisation, with the light industrial suburb of Winnellie being the primary location for Darwin’s creative practitioners to source supplies. Table 3: Top ten suburbs by workplace mentions, tabulated by workplace type* SLA name Front Back Networking Supply Workplace total Inner City/CBD City - Inner 56 (29.9%) 35 (36%) 57 (60.6%) 13 (14.8%) 162 (34.3%) Inner City Total 56 (29.9%) 35 (36%) 57 (60.6%) 13 (14.8%) 162 (34.3%) Top 10 suburban The Gardens 30 (16%) 3 (2.9%) 6 (6.4%) 5 (5.7%) 44 (9.3%) Winnellie 3 (1.6%) 7 (6.8%) 1 (1.1%) 24 (27.3%) 35 (7.4%) Parap 14 (7.5%) 4 (3.9%) 6 (6.4%) 9 (10.2%) 33 (7%) Fannie Bay 17 (9.1%) 5 (4.9%) 4 (4.3%) 2 (2.3%) 28 (5.9%) Nightcliff 14 (7.5%) 7 (6.8%) 2 (2.1%) 4 (4.5%) 27 (5.7%) Stuart Park 4 (2.1%) 8 (7.8%) 4 (4.3%) 4 (4.5%) 20 (4.2%) Brinkin 1 (0.5%) 8 (7.8%) 9 (9.6%) 2 (2.3%) 20 (4.2%) Larrakeyah 5 (2.7%) 5 (4.9%) 1 (1.1%) 3 (3.4%) 14 (3%) City - Remainder 5 (2.7%) 2 (1.9%) 0 (0%) 6 (6.8%) 13 (2.8%) Coconut Grove 3 (1.6%) 4 (3.9%) 1 (1.1%) 4 (4.5%) 12 (2.5%) Rapid Creek 3 (1.6%) 6 (5.8%) 0 (0%) 0 (0%) 9 (1.9%) Suburban Total** 131 (70.1%) 67 (65%) 37 (39.4%) 75 (85%) 310 (65.7%) City-Wide Total 187 103 94 88 472 *All percentages calculated from city- wide total **Suburban total row includes all 27 suburbs, not just top tens Discussion There are two key points to take from this analysis. First, the results show the usefulness of combining in-depth qualitative research with GIS mapping methods. Interviewing creative workers about where activities in their working days (or nights) take place, rather than defaulting to incomplete industry statistics can reveal a more comprehensive view of where creative work manifests in the city. Second, the role that multiple, decentred and often suburban facilities played as sites of supply, production and consumption in Darwin’s creative economy leads theories about the spatiality of creativity in the city in new directions. These results clearly show that the cultural binaries that theorists have assumed shape perceptions of the city and its suburbs do not appear in this instance to be infusing the everyday nature of creative work in the city. What was revealed by this data is that creative work in the city creates a variegated city produced through practitioners’ ordinary daily activities. Creative workers are not necessarily resisting or reinventing ideas of what the suburbs mean, they are getting on with creative work in ways that connect suburbs and the city centre in complex – and yet sometimes quite prosaic – ways. This is not to say that the suburbs do not present challenges for the effective conduct of creative work in Darwin – transport availability and lack of facilities were consistently cited problems by practitioners – but instead what is argued here is that ways of understanding the suburbs (in popular discourse, and in response in critical cultural theory) that emanate from Sydney or Los Angeles do not provide a universal conceptual framework for a city like Darwin. By not presuming that there is a meta-discourse of suburbs and city centres that everyone in every city is bound to, this analysis captured a different geography. In conclusion, the case of Darwin displayed decentred and dispersed sites of creativity as the norm rather than the exception. Accordingly, creative city planning strategies should take into account that decentralised and varied creative work sites exist beyond the purview of flagship institutions and visible creative precincts. References Brennan-Horley, Chris. “Multiple Work Sites and City-Wide Networks: A Topological Approach to Understanding Creative Work.” Australian Geographer 41 (2010): 39-56. ———, and Chris Gibson. “Where Is Creativity in the City? Integrating Qualitative and GIS Methods.” Environment and Planning A 41 (2009): 2295–2614.Collis, Christy, Emma Felton, and Phil Graham. “Beyond the Inner City: Real and Imagined Places in Creative Place Policy and Practice.” The Information Society 26 (2010): 104-112. Dowling, Robyn, and Kathy Mee. “Tales of the City: Western Sydney at the End of the Millennium.” Sydney: The Emergence of a World City. Ed. John Connell. Melbourne: Oxford UP, 2000. Drake, Graham. “‘This Place Gives Me Space’: Place and Creativity in the Creative Industries.” Geoforum 34 (2003): 511–524. Felton, Emma, Christy Collis and Phil Graham. “Making Connections: Creative Industries Networks in Outer-Suburban Locations.” Australian Geographer 41 (2010): 57-70. Gibson, Chris, and Chris Brennan-Horley. “Goodbye Pram City: Beyond Inner/Outer Zone Binaries in Creative City Research.” Urban Policy and Research 24 (2006): 455–71. ———, Peter Murphy, and Robert Freestone. “Employment and Socio-Spatial Relations in Australia's Cultural Economy.” Australian Geographer 33 (2002): 173-189. Landry, Charles. The Creative City: A Toolkit for Urban Innovators. London: Comedia/Earthscan, 2000. Lea, Tess, Susan Luckman, Chris Gibson, Donal Fitzpatrick, Chris Brennan-Horley, Julie Willoughby-Smith, and Karen Hughes. Creative Tropical City: Mapping Darwin’s Creative Industries. Darwin: Charles Darwin University, 2009. Luckman, Sue, Chris Gibson, and Tess Lea. “Mosquitoes in the Mix: How Transferable Is Creative City Thinking?” Singapore Journal of Tropical Geography (2009): 30, 47-63. Markusen, Ann, Gregory Wassall, Douglas DeNatale, and Randy Cohen. “Defining the Creative Economy: Industry and Occupational Approaches.” Economic Development Quarterly 22 (2008): 24-45. Matei, Sorin, Sandra Ball-Rokeach, and Jack Qiu. “Fear and Misperception of Los Angeles Urban Space: A Spatial-Statistical Study of Communication-Shaped Mental Maps.” Communication Research 28 (2001): 429-463. McCannell, Dean. “Staged Authenticity: Arrangements of Social Space in Tourist Settings.” The American Journal of Sociology 79 (1973): 589-603. Mee, Kathy. “Dressing Up the Suburbs: Representations of Western Sydney.” Metropolis Now: Planning and the Urban in Contemporary Australia Eds. Katherine Gibson and Sophie Watson. Sydney: Pluto Press, 1994. 60–77. Powell, Diane. Out West: Perceptions of Sydney’s Western Suburbs. Sydney: Allen and Unwin, 1993. Shorthose, Jim. “Accounting for Independent Creativity in the New Cultural Economy.” Media International Australia 112 (2004): 150-161. Scott, Allen J. The Cultural Economy of Cities. London: Sage, 2000. Tuan, Yi-Fu. “Images and Mental Maps.” Annals of the Association of American Geographers 65 (1975): 205-213. Watson, Allan. “Global Music City: Knowledge and Geographical Proximity in London’s Recorded Music Industry.” Area 40 (2008): 12–23.

Troubled visions of white ash and concrete-grey powder water-logged my mind. Just as I had ‘understood’ and ‘contextualised’ the events of September 11, I witnessed Jules and Gedeon Naudet’s 9/11, the documentary of the events, as they followed the firefighters into Tower One. Their cameras witness death, dense panic and ashen fear. I did not need to see this – it was too intimate and shocking. But it was the drained, grey visage – where the New York streets and people appeared like injured ghosts walking through the falling ruins of a paper mill – that will always stay with me. Not surprisingly I was drawn (safely?) back in time, away from the grey-stained New York streets, when another series of images seismically shifted by memory palate. Aberfan was the archetypal coal mining town, but what made it distinct was tragedy. On the hill above the village, coal waste from the mining process was dumped on water-filled slurry. Heavy rain on October 20, 1966 made way for a better day to follow. The dense rain dislodged the coal tip, and at 9:15, the slurry became a black tidal wave, overwhelming people and buildings in the past. There have been worse tragedies than Aberfan, if there are degrees of suffering. In the stark grey iconography of September 11, there was an odd photocopy of Aberfan, but in the negative. Coal replaced paper. My short piece explores the notion of shared tragedy and media-ted grief, utilising the Welsh mining disaster as a bloodied gauze through which to theorise collective memory and social change. Tragedy on the television A disaster, by definition, is a tragic, unexpected circumstance. Its etymology ties it to astrology and fate. Too often, free flowing emotions of sympathy dissipate with the initial fascination, without confronting the long-term consequences of misfortune. When coal slurry engulfed the school and houses in Aberfan, a small working class community gleaned attention from the London-based media. The Prime Minister and royalty all traveled to Aberfan. Through the medium of television, grief and confusion were conveyed to a viewing public. For the first time, cameras gathered live footage of the trauma as it overwhelmed the Taff Valley. The sludge propelled from the Valley and into the newspapers of the day. A rescue worker remembers, “I was helping to dig the children out when I heard a photographer tell a kiddie to cry for her dear friends, so that he could get a good picture – that taught me silence.” (“The last day before half-term.”) Similarly, a bereaved father remembers that, during that period the only thing I didn’t like was the press. If you told them something, when the paper came out your words were all the wrong way round. (“The last day before half-term.”) When analyzed as a whole, the concerns of the journalists – about intense emotion and (alternatively) censorship of emotion - blocked a discussion of the reasons and meaning of the tragedy, instead concentrating on the form of the news broadcasts. Debates about censorship and journalistic ethics prevented an interpretative, critical investigation of the disaster. The events in Aberfan were not created by a natural catastrophe or an unpredictable or blameless ‘act of God.’ Aberfan’s disaster was preventable, but it became explainable within a coal industry village accustomed to unemployment and work-related ‘accidents.’ Aberfan was not merely a disaster that cost life. It represented a two-fold decline of Britain: industrially and socially. Coal built the industrial matrix of Britain. Perhaps this cost has created what Dean MacCannell described as “the collective guilt of modernised people” (23). Aberfan was distinct from the other great national tragedies in the manner the public perceived the events unfolding in the village. It was the disaster where cameras recorded the unerring screams of grief, the desperate search for a lost – presumed dead – child, and the building anger of a community suffering through a completely preventable ‘accident.’ The cameras – in true A Current Affair style – intruded on grief and privacy. A bereaved father stated that “I’ve got to say this again, if the papers and the press and the television were to leave us alone in the very beginning I think we could have settled down a lot quicker than what we did” (“The last day before half-term.”). This breach of grieving space also allowed those outside the community to share a memory, create a unifying historical bond, and raised some sympathy-triggered money. To actually ‘share’ death and grief at Aberfan through the medium of television led to a reappraisal, however temporary, about the value and costs of industrialisation. The long-term consequences of these revelations are more difficult to monitor. A question I have always asked – and the events of September 11, Bali and the second Gulf War have not helped me – is if a community or nation personally untouched by tragic events experience grief. Sympathy and perhaps empathy are obvious, as is voyeurism and curiosity. But when the bodies are simply unidentified corpses and a saddened community as indistinguishable from any other town, then viewers needs to ponder the rationale and depth of personal feelings. Through the window of television, onlookers become Peeping Toms, perhaps saturated with sympathy and tears, but still Peeping Toms. How has this semiotic synergy continued through popular memory? Too often we sap the feelings of disasters at a distance, and then withdraw when it is no longer fashionable, relevant or in the news. Notions about Wales, the working class and coal mining communities existed in journalists’ minds before they arrived in the village, opened their notebook or spoke to camera. They mobilised ‘the facts’ that suited a pre-existing interpretation. Bereaved parents digging into the dirt for lost children, provide great photographs and footage. This material was ideologically shaped to infantilise the community of Aberfan and, indirectly, the working class. They were exoticised and othered. It is clear from testimony recorded since the event that the pain felt by parents was compounded by television and newspaper reportage. Television allowed “a collective witnessing” (McLean and Johnes, “Remembering Aberfan”) of the disaster. Whether these televisual bystanders actually contributed anything to the healing of the tragedy, or forged an understanding of the brutal work involved in extracting coal, is less clear. There is not a natural, intrinsic sense of community created through television. Actually, it can establish boundaries of difference. Television has provided a record of exploitation, dissent and struggle. Whether an event or programme is read as an expression of unequal power relations or justifiable treatment of the ‘unworthy poor’ is in the hands of the viewer. Class-based inequalities and consciousness are not blinked out with the operation of a remote control. Intervention When I first researched Aberfan in the 1980s, the story was patchy and incomplete. The initial events left journalistic traces of the horror and – later – boredom with the Aberfan tragedy. Because of the thirty year rule on the release of government documents, the cause, motivation and rationale of many decisions from the Aberfan disaster appeared illogical or without context. When searching for new material and interpretations on Aberfan between 1968 and 1996, little exists. The release of documents in January 1997 triggered a wave of changing interpretations. Two committed and outstanding scholars, upon the release of governmental materials, uncovered the excesses and inequalities, demonstrating how historical research can overcome past injustice, and the necessity for recompense in the present. Iain McLean and Martin Johnes claimed a media profile and role in influencing public opinion and changing the earlier interpretations of the tragedy. On BBC radio, Professor McLean stated I think people in the government, people in the Coal Board were extremely insensitive. They treated the people of Aberfan as trouble makers. They had no conception of the depth of trauma suffered (“Aberfan”). McLean and Johnes also created from 1997-2001 a remarkable, well structured and comprehensive website featuring interview material, a database of archival collections and interpretations of the newly-released governmental documents. The Website possessed an agenda of conservation, cataloguing the sources held at the Merthyr Tydfil and Dowlais libraries. These documents hold a crucial function: to ensure that the community of Aberfan is rarely bothered for interviews or morbid tourists returning to the site. The Aberfan disaster has been included in the UK School curriculum and to avoid the small libraries and the Community Centre being overstretched, the Website possesses a gatekeepping function. The cataloguing work by the project’s research officer Martin Johnes has produced something important. He has aligned scholarly, political and social goals with care and success. Iain McLean’s proactive political work also took another direction. While the new governmental papers were released in January 1997, he wrote an article based on the Press Preview of December 1996. This article appeared in The Observer on January 5, 1997. From this strong and timely intervention, The Times Higher Education Supplement commissioned another article on January 17, 1997. Through both the articles and the Web work, McLean and Johnes did not name the individual victims or their parents, and testimony appears anonymously in the Website and their publications. They – unlike the journalists of the time – respected the community of Aberfan, their privacy and their grief. These scholars intervened in the easy ‘sharing’ of the tragedy. They built the first academic study of the Aberfan Disaster, released on the anniversary of the landslide: Aberfan, Government and Disasters. Through this book and their wide-ranging research, it becomes clear that the Labour Government failed to protect the citizens of a safe Labour seat. A bereaved husband and parent stated that I was tormented by the fact that the people I was seeking justice from were my people – a Labour Government, a Labour council, a Labour-nationalised Coal Board (“The last day before half-term”). There is a rationale for this attitude towards the tragedy. The Harold Wilson Labour Governments of 1964-70 were faced with severe balance of payments difficulties. Also, they only held a majority in the house of five, which they were to build to 96 in the 1966 election. While the Welfare State was a construction ‘for’ the working class after the war, the ‘permissive society’ – and resultant social reforms – of the 1960s was ‘for’ middle class consumers. It appeared that the industrial working class was paying for the new white heat of technology. This paradox not only provides a context for the Aberfan disaster but a space for media and cultural studies commentary. Perhaps the most difficult task for those of us working in cultural and media studies is to understand the citizens of history, not only as consumers, spectators or an audience, but how they behave and what they may feel. We need to ask what values and ideas do we share with the ‘audiences,’ ‘citizens’ and ‘spectators’ in our theoretical matrix. At times we do hide behind our Foucaults and Kristevas, our epistemologies and etymology. Raw, jagged emotion is difficult to theorise, and even more complex to commit to the page. To summon any mode of resistive or progressivist politics, requires capturing tone, texture and feeling. This type of writing is hard to achieve from a survey of records. A public intellectual role is rare these days. The conservative media invariably summon pundits with whom they can either agree or pillory. The dissenting intellectual, the diffident voice, is far more difficult to find. Edward Said is one contemporary example. But for every Said, there is a Kissinger. McLean and Johnes, during a time of the Blair Government, reminded a liberal-leaning Labour of earlier mistakes in the handling of a working-class community. In finding origins, causes and effects, the politicisation of history is at its most overt. Path of the slag The coal slurry rolled onto the Welsh village nearly thirty-seven years ago. Aberfan represents more than a symbol of decline or of burgeoning televisual literacy. It demonstrates how we accept mediated death. A ‘disaster’ exposes a moment of insight, a transitory glimpse into other people’s lives. It composes a mobile, dynamic photograph: the viewer is aware that life has existed before the tragedy and will continue after it. The link between popular and collective memory is not as obvious as it appears. All memory is mediated – there is a limit to the sharing. Collective memory seems more organic, connected with an authentic experience of events. Popular memory is not necessarily contextually grounded in social, historical or economic formations but networks diverse times and spaces without an origin or ending. This is a post-authentic memory that is not tethered to the intentions, ideologies or origins of a sender, town or community. To argue that all who have seen photographs or televisual footage of Aberfan ‘share’ an equivalent collective memory to those directly touched by the event, place, family or industry is not only naïve, but initiates a troubling humanism which suggests that we all ‘share’ a common bank of experience. The literacy of tragedy and its reportage was different after October 1966. When reading the historical material from the disaster, it appears that grieving parents are simply devastated puppets lashing out at their puppeteers. Their arguments and interpretation were molded for other agendas. Big business, big government and big unions colluded to displace the voices of citizens (McLean and Johnes “Summary”). Harold Wilson came to office in 1964 with the slogan “13 wasted years.” He promised that – through economic growth – consensus could be established. Affluence through consumer goods was to signal the end of a polarisation between worker and management. These new world symbols, fed by skilled scientific workers and a new ‘technological revolution,’ were – like the industrial revolution – uneven in its application. The Aberfan disaster is situated on the fault line of this transformation. A Welsh working class community seemed out of time and space in 1960s Britain. The scarved women and stocky, strong men appeared to emerge from a different period. The television nation did not share a unified grief, but performed the gulf between England and Wales, centre and periphery, middle and working class, white collar and black collar. Politics saturates television, so that it is no longer possible to see the join. Aberfan’s television coverage is important, because the mend scar was still visible. Literacy in televisual grief was being formed through the event. But if Aberfan did change the ‘national consciousness’ of coal then why did so few southern English citizens support the miners trying to keep open the Welsh pits? The few industries currently operating in this region outside of Cardiff means that the economic clock has stopped. The Beveridge Report in 1943 declared that the great achievement of the Second World War was the sharing of experience, a unity that would achieve victory. The People’s War would create a People’s Peace. Aberfan, mining closures and economic decline destroyed this New Jerusalem. The green and pleasant land was built on black coal. Aberfan is an historical translator of these iconographies. Works Cited Bereaved father. “The last day before half-term.” 1999. 6 April 2003 <http://www.nuff.ox.ac.uk/politics/aberfan/chap1.htm>. Bereaved husband and parent. “The last day before half-term.” 1999. 6 April 2003 <http://www.nuff.ox.ac.uk/politics/aberfan/chap1.htm>. MacCannell, Dean. Empty Meeting Grounds. London: Routledge, 1992. McLean, Iain. “Aberfan.” 6 April 2003 <http://news.bbc.co.uk/olmedia/980000/audio/_983056_mclean_ab... ...erfan_21oct_0800.ram>. McLean, Iain, and Martin Johnes. Aberfan: Government and Disasters. Cardiff: Welsh Academic Press, 2000. McLean, Iain, and Martin Johnes. “Remembering Aberfan.” 1999. 6 April 2003 <http://www.nuff.ox.ac.uk/politics/aberfan/remem.htm>. McLean, Iain, and Martin Johnes. “Summary of Research Results.” 1999. 6 April 2003 <http://www.nuff.ox.ac.uk/politics/aberfan/eoafinal.htm>. Naudet, Jules, Gedeon Naudet, and James Hanlon. 9/11. New York: Goldfish Pictures and Silverstar Productions, 2001. Rescue worker. “The last day before half-term.” 1999. 6 April 2003 <http://www.nuff.ox.ac.uk/politics/aberfan/chap1.htm>. Links http://news.bbc.co.uk/olmedia/980000/audio/_983056_mclean_aberfan_21oct_0800.ram http://www.nuff.ox.ac.uk/politics/aberfan/chap1.htm http://www.nuff.ox.ac.uk/politics/aberfan/chap1.htm.(1999 http://www.nuff.ox.ac.uk/politics/aberfan/eoafinal.htm http://www.nuff.ox.ac.uk/politics/aberfan/home.htm http://www.nuff.ox.ac.uk/politics/aberfan/remem.htm Citation reference for this article Substitute your date of access for Dn Month Year etc... MLA Style Brabazon, Tara. "Black and Grey" M/C: A Journal of Media and Culture< http://www.media-culture.org.au/0304/07-blackandgrey.php>. APA Style Brabazon, T. (2003, Apr 23). Black and Grey. M/C: A Journal of Media and Culture, 6,< http://www.media-culture.org.au/0304/07-blackandgrey.php>

'He did what the cipher could not, he rescued himself.' -- Alfred Bester, The Stars My Destination (23) On many levels, the new Nine Inch Nails album The Fragile is a gritty meditation about different types of End: the eternal relationship cycle of 'fragility, tension, ordeal, fragmentation' (adapted, with apologies to Wilhelm Reich); fin-de-siècle anxiety; post-millennium foreboding; a spectre of the alien discontinuity that heralds an on-rushing future vastly different from the one envisaged by Enlightenment Project architects. In retrospect, it's easy for this perspective to be dismissed as jargon-filled cyber-crit hyperbole. Cyber-crit has always been at its best too when it invents pre-histories and finds hidden connections between different phenomena (like the work of Greil Marcus and early Mark Dery), and not when it is closer to Chinese Water Torture, name-checking the canon's icons (the 'Deleuze/Guattari' tag-team), texts and key terms. "The organization of sound is interpreted historically, politically, socially ... . It subdues music's ambition, reins it in, restores it to its proper place, reconciles it to its naturally belated fate", comments imagineer Kodwo Eshun (4) on how cyber-crit destroys albums and the innocence of the listening experience. This is how official histories are constructed a priori and freeze-dried according to personal tastes and prior memes: sometimes the most interesting experiments are Darwinian dead-ends that fail to make the canon, or don't register on the radar. Anyone approaching The Fragile must also contend with the music industry's harsh realities. For every 10 000 Goth fans who moshed to the primal 'kill-fuck-dance' rhythms of the hit single "Closer" (heeding its siren-call to fulfil basic physiological needs and build niche-space), maybe 20 noted that the same riff returned with a darker edge in the title track to The Downward Spiral, undermining the glorification of Indulgent hedonism. "The problem with such alternative audiences," notes Disinformation Creative Director Richard Metzger, "is that they are trying to be different -- just like everyone else." According to author Don Webb, "some mature Chaos and Black Magicians reject their earlier Nine Inch Nails-inspired Goth beginnings and are extremely critical towards new adopters because they are uncomfortable with the subculture's growing popularity, which threatens to taint their meticulously constructed 'mysterious' worlds. But by doing so, they are also rejecting their symbolic imprinting and some powerful Keys to unlocking their personal history." It is also difficult to separate Nine Inch Nails from the commercialisation and colossal money-making machine that inevitably ensued on the MTV tour circuit: do we blame Michael Trent Reznor because most of his audience are unlikely to be familiar with 'first-wave' industrial bands including Cabaret Voltaire and the experiments of Genesis P. Orridge in Throbbing Gristle? Do we accuse Reznor of being a plagiarist just because he wears some of his influences -- Dr. Dre, Daft Punk, Atari Teenage Riot, Pink Floyd's The Wall (1979), Tom Waits's Bone Machine (1992), David Bowie's Low (1977) -- on his sleeve? And do we accept no-brain rock critic album reviews who quote lines like 'All the pieces didn't fit/Though I really didn't give a shit' ("Where Is Everybody?") or 'And when I suck you off/Not a drop will go to waste' ("Starfuckers Inc") as representative of his true personality? Reznor evidently has his own thoughts on this subject, but we should let the music speak for itself. The album's epic production and technical complexity turned into a post-modern studio Vision Quest, assisted by producer Alan Moulder, eleventh-hour saviour Bob Ezrin (brought in by Reznor to 'block-out' conceptual and sonic continuity), and a group of assault-technicians. The fruit of these collaborations is an album where Reznor is playing with our organism's time-binding sense, modulating strange emotions through deeply embedded tonal angularities. During his five-year absence, Trent Reznor fought diverse forms of repetitious trauma, from endogenous depression caused by endless touring to the death of his beloved grandmother (who raised him throughout childhood). An end signals a new beginning, a spiral is an open-ended and ever-shifting structure, and so Reznor sought to re-discover the Elder Gods within, a shamanic approach to renewal and secular salvation utilised most effectively by music PR luminary and scientist Howard Bloom. Concerned with healing the human animal through Ordeals that hard-wire the physiological baselines of Love, Hate and Fear, Reznor also focusses on what happens when 'meaning-making' collapses and hope for the future cannot easily be found. He accurately captures the confusion that such dissolution of meaning and decline of social institutions brings to the world -- Francis Fukuyama calls this bifurcation 'The Great Disruption'. For a generation who experienced their late childhood and early adolescence in Reagan's America, Reznor and his influences (Marilyn Manson and Filter) capture the Dark Side of recent history, unleashed at Altamont and mutating into the Apocalyptic style of American politics (evident in the 'Star Wars'/SDI fascination). The personal 'psychotic core' that was crystallised by the collapse of the nuclear family unit and supportive social institutions has returned to haunt us with dystopian fantasies that are played out across Internet streaming media and visceral MTV film-clips. That such cathartic releases are useful -- and even necessary (to those whose lives have been formed by socio-economic 'life conditions') is a point that escapes critics like Roger Scruton, some Christian Evangelists and the New Right. The 'escapist' quality of early 1980s 'Rapture' and 'Cosmocide' (Hal Lindsey) prophecies has yielded strange fruit for the Children of Ezekiel, whom Reznor and Marilyn Manson are unofficial spokes-persons for. From a macro perspective, Reznor's post-human evolutionary nexus lies, like J.G. Ballard's tales, in a mythical near-future built upon past memory-shards. It is the kind of worldview that fuses organic and morphogenetic structures with industrial machines run amok, thus The Fragile is an artefact that captures the subjective contents of the different mind produced by different times. Sonic events are in-synch but out of phase. Samples subtly trigger and then scramble kinaesthetic-visceral and kinaesthetic-tactile memories, suggestive of dissociated affective states or body memories that are incapable of being retrieved (van der Kolk 294). Perhaps this is why after a Century of Identity Confusion some fans find it impossible to listen to a 102-minute album in one sitting. No wonder then that the double album is divided into 'left' and 'right' discs (a reference to split-brain research?). The real-time track-by-track interpretation below is necessarily subjective, and is intended to serve as a provisional listener's guide to the aural ur-text of 1999. The Fragile is full of encrypted tones and garbled frequencies that capture a world where the future is always bleeding into a non-recoverable past. Turbulent wave-forms fight for the listener's attention with prolonged static lulls. This does not make for comfortable or even 'nice' listening. The music's mind is a snapshot, a critical indicator, of the deep structures brewing within the Weltanschauung that could erupt at any moment. "Somewhat Damaged" opens the album's 'Left' disc with an oscillating acoustic strum that anchor's the listener's attention. Offset by pulsing beats and mallet percussion, Reznor builds up sound layers that contrast with lyrical epitaphs like 'Everything that swore it wouldn't change is different now'. Icarus iconography is invoked, but perhaps a more fitting mythopoeic symbol of the journey that lies ahead would be Nietzsche's pursuit of his Ariadne through the labyrinth of life, during which the hero is steadily consumed by his numbing psychosis. Reznor fittingly comments: 'Didn't quite/Fell Apart/Where were you?' If we consider that Reznor has been repeating the same cycle with different variations throughout all of his music to date, retro-fitting each new album into a seamless tapestry, then this track signals that he has begun to finally climb out of self-imposed exile in the Underworld. "The Day the World Went Away" has a tremendously eerie opening, with plucked mandolin effects entering at 0:40. The main slashing guitar riff was interpreted by some critics as Reznor's attempt to parody himself. For some reason, the eerie backdrop and fragmented acoustic guitar strums recalls to my mind civil defence nuclear war films. Reznor, like William S. Burroughs, has some powerful obsessions. The track builds up in intensity, with a 'Chorus of the Damned' singing 'na na nah' over apocalyptic end-times imagery. At 4:22 the track ends with an echo that loops and repeats. "The Frail" signals a shift to mournful introspectiveness with piano: a soundtrack to faded 8 mm films and dying memories. The piano builds up slowly with background echo, holds and segues into ... "The Wretched", beginning with a savage downbeat that recalls earlier material from Pretty Hate Machine. 'The Far Aways/Forget It' intones Reznor -- it's becoming clear that despite some claims to the contrary, there is redemption in this album, but it is one borne out of a relentless move forward, a strive-drive. 'You're finally free/You could be' suggest Reznor studied Existentialism during his psychotherapy visits. This song contains perhaps the ultimate post-relationship line: 'It didn't turn out the way you wanted it to, did it?' It's over, just not the way you wanted; you can always leave the partner you're with, but the ones you have already left will always stain your memories. The lines 'Back at the beginning/Sinking/Spinning' recall the claustrophobic trapped world and 'eternal Now' dislocation of Post-Traumatic Stress Disorder victims. At 3:44 a plucked cello riff, filtered, segues into a sludge buzz-saw guitar solo. At 5:18 the cello riff loops and repeats. "We're in This Together Now" uses static as percussion, highlighting the influence of electricity flows instead of traditional rock instrument configurations. At 0:34 vocals enter, at 1:15 Reznor wails 'I'm impossible', showing he is the heir to Roger Waters's self-reflective rock-star angst. 'Until the very end of me, until the very end of you' reverts the traditional marriage vow, whilst 'You're the Queen and I'm the King' quotes David Bowie's "Heroes". Unlike earlier tracks like "Reptile", this track is far more positive about relationships, which have previously resembled toxic-dyads. Reznor signals a delta surge (breaking through barriers at any cost), despite a time-line morphing between present-past-future. At 5:30 synths and piano signal a shift, at 5:49 the outgoing piano riff begins. The film-clip is filled with redemptive water imagery. The soundtrack gradually gets more murky and at 7:05 a subterranean note signals closure. "The Fragile" is even more hopeful and life-affirming (some may even interpret it as devotional), but this love -- representative of the End-Times, alludes to the 'Glamour of Evil' (Nico) in the line 'Fragile/She doesn't see her beauty'. The fusion of synths and atonal guitars beginning at 2:13 summons forth film-clip imagery -- mazes, pageants, bald eagles, found sounds, cloaked figures, ruined statues, enveloping darkness. "Just like You Imagined" opens with Soundscapes worthy of Robert Fripp, doubled by piano and guitar at 0:39. Drums and muffled voices enter at 0:54 -- are we seeing a pattern to Reznor's writing here? Sonic debris guitar enters at 1:08, bringing forth intensities from white noise. This track is full of subtle joys like the 1:23-1:36 solo by David Bowie pianist Mike Garson and guitarist Adrian Belew's outgoing guitar solo at 2:43, shifting back to the underlying soundscapes at 3:07. The sounds are always on the dissipative edge of chaos. "Just like You Imagined" opens with Soundscapes worthy of Robert Fripp, doubled by piano and guitar at 0:39. Drums and muffled voices enter at 0:54 -- are we seeing a pattern to Reznor's writing here? Sonic debris guitar enters at 1:08, bringing forth intensities from white noise. This track is full of subtle joys like the 1:23-1:36 solo by David Bowie pianist Mike Garson and guitarist Adrian Belew's outgoing guitar solo at 2:43, shifting back to the underlying soundscapes at 3:07. The sounds are always on the dissipative edge of chaos. "Pilgrimage" utilises a persistent ostinato and beat, with a driving guitar overlay at 0:18. This is perhaps the most familiar track, using Reznor motifs like the doubling of the riff with acoustic guitars between 1:12-1:20, march cries, and pitch-shift effects on a 3:18 drumbeat/cymbal. Or at least I could claim it was familiar, if it were not that legendary hip-hop producer and 'edge-of-panic' tactilist Dr. Dre helped assemble the final track mix. "No, You Don't" has been interpreted as an attack on Marilyn Manson and Hole's Courntey Love, particularly the 0:47 line 'Got to keep it all on the outside/Because everything is dead on the inside' and the 2:33 final verse 'Just so you know, I did not believe you could sink so low'. The song's structure is familiar: a basic beat at 0:16, guitars building from 0:31 to sneering vocals, a 2:03 counter-riff that merges at 2:19 with vocals and ascending to the final verse and 3:26 final distortion... "La Mer" is the first major surprise, a beautiful and sweeping fusion of piano, keyboard and cello, reminiscent of Symbolist composer Debussy. At 1:07 Denise Milfort whispers, setting the stage for sometime Ministry drummer Bill Reiflin's jazz drumming at 1:22, and a funky 1:32 guitar/bass line. The pulsing synth guitar at 2:04 serves as anchoring percussion for a cinematic electronica mindscape, filtered through new layers of sonic chiaroscuro at 2:51. 3:06 phase shifting, 3:22 layer doubling, 3:37 outgoing solo, 3:50-3:54 more swirling vocal fragments, seguing into a fading cello quartet as shadows creep. David Carson's moody film-clip captures the end more ominously, depicting the beauty of drowning. This track contains the line 'Nothing can stop me now', which appears to be Reznor's personal mantra. This track rivals 'Hurt' and 'A Warm Place' from The Downward Spiral and 'Something I Can Never Have' from Pretty Hate Machine as perhaps the most emotionally revealing and delicate material that Reznor has written. "The Great Below" ends the first disc with more multi-layered textures fusing nostalgia and reverie: a twelve-second cello riff is counter-pointed by a plucked overlay, which builds to a 0:43 washed pulse effect, transformed by six second pulses between 1:04-1:19 and a further effects layer at 1:24. E-bow effects underscore lyrics like 'Currents have their say' (2:33) and 'Washes me away' (2:44), which a 3:33 sitar riff answers. These complexities are further transmuted by seemingly random events -- a 4:06 doubling of the sitar riff which 'glitches' and a 4:32 backbeat echo that drifts for four bars. While Reznor's lyrics suggest that he is unable to control subjective time-states (like The Joker in the Batman: Dark Knight series of Kali-yuga comic-books), the track constructions show that the Key to his hold over the listener is very carefully constructed songs whose spaces resemble Pythagorean mathematical formulas. Misdirecting the audience is the secret of many magicians. "The Way Out Is Through" opens the 'Right' disc with an industrial riff that builds at 0:19 to click-track and rhythm, the equivalent of a weaving spiral. Whispering 'All I've undergone/I will keep on' at 1:24, Reznor is backed at 1:38 by synths and drums coalescing into guitars, which take shape at 1:46 and turn into a torrential electrical current. The models are clearly natural morphogenetic structures. The track twists through inner storms and torments from 2:42 to 2:48, mirrored by vocal shards at 2:59 and soundscapes at 3:45, before piano fades in and out at 4:12. The title references peri-natal theories of development (particularly those of Stanislav Grof), which is the source of much of the album's imagery. "Into the Void" is not the Black Sabbath song of the same name, but a catchy track that uses the same unfolding formula (opening static, cello at 0:18, guitars at 0:31, drums and backbeat at 1:02, trademark industrial vocals and synth at 1:02, verse at 1:23), and would not appear out of place in a Survival Research Laboratories exhibition. At 3:42 Reznor plays with the edge of synth soundscapes, merging vocals at 4:02 and ending the track nicely at 4:44 alone. "Where Is Everybody?" emulates earlier structures, but relies from 2:01 on whirring effects and organic rhythms, including a flurry of eight beat pulses between 2:40-2:46 and a 3:33 spiralling guitar solo. The 4:26 guitar solo is pure Adrian Belew, and is suddenly ended by spluttering static and white noise at 5:13. "The Mark Has Been Made" signals another downshift into introspectiveness with 0:32 ghostly synth shimmers, echoed by cello at 1:04 which is the doubled at 1:55 by guitar. At 2:08 industrial riffs suddenly build up, weaving between 3:28 distorted guitars and the return of the repressed original layer at 4:16. The surprise is a mystery 32 second soundscape at the end with Reznor crooning 'I'm getting closer, all the time' like a zombie devil Elvis. "Please" highlights spacious noise at 0:48, and signals a central album motif at 1:04 with the line 'Time starts slowing down/Sink until I drown'. The psychic mood of the album shifts with the discovery of Imagination as a liberating force against oppression. The synth sound again is remarkably organic for an industrial album. "Starfuckers Inc" is the now infamous sneering attack on rock-stardom, perhaps at Marilyn Manson (at 3:08 Reznor quotes Carly Simon's 'You're So Vain'). Jungle beats and pulsing synths open the track, which features the sound-sculpting talent of Pop Will Eat Itself member Clint Mansell. Beginning at 0:26, Reznor's vocals appear to have been sampled, looped and cut up (apologies to Brion Gysin and William S. Burroughs). The lines 'I have arrived and this time you should believe the hype/I listened to everyone now I know everyone was right' is a very savage and funny exposure of Manson's constant references to Friedrich Nietzsche's Herd-mentality: the Herd needs a bogey-man to whip it into submission, and Manson comes dangerous close to fulfilling this potential, thus becoming trapped by a 'Stacked Deck' paradox. The 4:08 lyric line 'Now I belong I'm one of the Chosen Ones/Now I belong I'm one of the Beautiful Ones' highlights the problem of being Elect and becoming intertwined with institutionalised group-think. The album version ditches the closing sample of Gene Simmons screaming "Thankyou and goodnight!" to an enraptured audience on the single from KISS Alive (1975), which was appropriately over-the-top (the alternate quiet version is worth hearing also). "The danger Marilyn Manson faces", notes Don Webb (current High Priest of the Temple of Set), "is that he may end up in twenty years time on the 'Tonight Show' safely singing our favourite songs like a Goth Frank Sinatra, and will have gradually lost his antinomian power. It's much harder to maintain the enigmatic aura of an Evil villain than it is to play the clown with society". Reznor's superior musicianship and sense of irony should keep him from falling into the same trap. "Complication" juggernauts in at 0:57 with screaming vocals and a barrage of white noise at 1:56. It's clear by now that Reznor has read his psychological operations (PSYOP) manuals pertaining to blasting the hell out of his audiences' psyche by any means necessary. Computer blip noise and black light flotation tank memories. Dislocating pauses and time-bends. The aural equivalent of Klein bottles. "Complication" juggernauts in at 0:57 with screaming vocals and a barrage of white noise at 1:56. It's clear by now that Reznor has read his psychological operations (PSYOP) manuals pertaining to blasting the hell out of his audiences' psyche by any means necessary. Computer blip noise and black light flotation tank memories. Dislocating pauses and time-bends. The aural equivalent of Klein bottles. "The Big Come Down" begins with a four-second synth/static intro that is smashed apart by a hard beat at 0:05 and kaleidoscope guitars at 0:16. Critics refer to the song's lyrics in an attempt to project a narcissistic Reznor personality, but don't comment on stylistic tweaks like the AM radio influenced backing vocals at 1:02 and 1:19, or the use of guitars as a percussion layer at 1:51. A further intriguing element is the return of the fly samples at 2:38, an effect heard on previous releases and a possible post-human sub-text. The alien mythos will eventually reign over the banal and empty human. At 3:07 the synths return with static, a further overlay adds more synths at 3:45 as the track spirals to its peak, before dissipating at 3:1 in a mesh of percussion and guitars. "Underneath It All" opens with a riff that signals we have reached the album's climatic turning point, with the recurring theme of fragmenting body-memories returning at 0:23 with the line 'All I can do/I can still feel you', and being echoed by pulsing static at 0:42 as electric percussion. A 'Messiah Complex' appears at 1:34 with the line 'Crucify/After all I've died/After all I've tried/You are still inside', or at least it appears to be that on the surface. This is the kind of line that typical rock critics will quote, but a careful re-reading suggests that Reznor is pointing to the painful nature of remanifesting. Our past shapes us more than we would like to admit particularly our first relationships. "Ripe (With Decay)" is the album's final statement, a complex weaving of passages over a repetitive mesh of guitars, pulsing echoes, back-beats, soundscapes, and a powerful Mike Garson piano solo (2:26). Earlier motifs including fly samples (3:00), mournful funeral violas (3:36) and slowing time effects (4:28) recur throughout the track. Having finally reached the psychotic core, Reznor is not content to let us rest, mixing funk bass riffs (4:46), vocal snatches (5:23) and oscillating guitars (5:39) that drag the listener forever onwards towards the edge of the abyss (5:58). The final sequence begins at 6:22, loses fidelity at 6:28, and ends abruptly at 6:35. At millennium's end there is a common-held perception that the world is in an irreversible state of decay, and that Culture is just a wafer-thin veneer over anarchy. Music like The Fragile suggests that we are still trying to assimilate into popular culture the 'war-on-Self' worldviews unleashed by the nineteenth-century 'Masters of Suspicion' (Charles Darwin, Sigmund Freud, Friedrich Nietzsche). This 'assimilation gap' is evident in industrial music, which in the late 1970s was struggling to capture the mood of the Industrial Revolution and Charles Dickens, so the genre is ripe for further exploration of the scarred psyche. What the self-appointed moral guardians of the Herd fail to appreciate is that as the imprint baseline rises (reflective of socio-political realities), the kind of imagery prevalent throughout The Fragile and in films like Strange Days (1995), The Matrix (1999) and eXistenZ (1999) is going to get even darker. The solution is not censorship or repression in the name of pleasing an all-saving surrogate god-figure. No, these things have to be faced and embraced somehow. Such a process can only occur if there is space within for the Sadeian aesthetic that Nine Inch Nails embodies, and not a denial of Dark Eros. "We need a second Renaissance", notes Don Webb, "a rejuvenation of Culture on a significant scale". In other words, a global culture-shift of quantum (aeon or epoch-changing) proportions. The tools required will probably not come just from the over-wordy criticism of Cyber-culture and Cultural Studies or the logical-negative feeding frenzy of most Music Journalism. They will come from a dynamic synthesis of disciplines striving toward a unity of knowledge -- what socio-biologist Edward O. Wilson has described as 'Consilience'. Liberating tools and ideas will be conveyed to a wider public audience unfamiliar with such principles through predominantly science fiction visual imagery and industrial/electronica music. The Fragile serves as an invaluable model for how such artefacts could transmit their dreams and propagate their messages. For the hyper-alert listener, it will be the first step on a new journey. But sadly for the majority, it will be just another hysterical industrial album promoted as selection of the month. References Bester, Alfred. The Stars My Destination. London: Millennium Books, 1999. Eshun, Kodwo. More Brilliant than the Sun: Adventures in Sonic Fiction. London: Quartet Books, 1998. Van der Kolk, Bessel A. "Trauma and Memory." Traumatic Stress: The Effects of Overwhelming Experience on Mind, Body, and Society. Eds. Bessel A. van der Kolk et al. New York: Guilford Press, 1996. Nine Inch Nails. Downward Spiral. Nothing/Interscope, 1994. ---. The Fragile. Nothing, 1999. ---. Pretty Hate Machine. TVT, 1989. Citation reference for this article MLA style: Alex Burns. "'This Machine Is Obsolete': A Listeners' Guide to Nine Inch Nails' The Fragile." M/C: A Journal of Media and Culture 2.8 (1999). [your date of access] <http://www.uq.edu.au/mc/9912/nine.php>. Chicago style: Alex Burns, "'This Machine Is Obsolete': A Listeners' Guide to Nine Inch Nails' The Fragile," M/C: A Journal of Media and Culture 2, no. 8 (1999), <http://www.uq.edu.au/mc/9912/nine.php> ([your date of access]). APA style: Alex Burns. (1999) 'This machine is obsolete': a listeners' guide to Nine Inch Nails' The fragile. M/C: A Journal of Media and Culture 2(8). <http://www.uq.edu.au/mc/9912/nine.php> ([your date of access]).