Journal articles on the topic 'Contact between a shell and a round plate'

In the bodies of cylindrical apparatuses that operate under pressure, one of the weak elements is a flat bottom whose thickness is increased by 4…5 times in comparison with the wall thickness. This is due to the fact that the bottom is exposed to a more unfavorable bending deformation compared to the wall that «works» on stretching. In order to reduce specific metal consumption for the bottom, we propose the optimization of the shape of a radial cross-section by a rational redistribution of the material: to increase thickness of the bottom in the region of its contact with the wall and to significantly reduce it in the central zone. To describe a variable thickness of the bottom, we applied the Gauss equation with an arbitrary parameter that determines the intensity of change in the thickness in radial direction. We have obtained a general solution to the differential equation of the problem on bending a bottom at a given law of change in its thickness, which is represented using the hypergeometric Kummer’s functions. A technique for concretizing the resulting solution was proposed and implemented, based on the application of conditions of contact between a cylindrical shell and a bottom. The solution derived was used to minimize the mass of the bottom. We have designed a zone of transition from the bottom to the wall whose strength was verified by the method of finite elements under actual conditions

Background. Rhinosinusitis, affecting both maxillary and other sinuses, is a multidisciplinary issue which otolaryngologists, dentists, neurologists and ophthalmologists are constantly dealing with. There is a remarkable diagnostic value of anthropometric indicators of maxillary sinuses of people of different genders, using CT scan images of mature age patients. Purpose – establish a relationship between the shape of the maxillary sinuses and possible contacts of the tooth roots of the maxillary dental arch in healthy mature men and women. Materials and methods. The study was performed based on the results of 102 CBCT with normal maxillary sinuses variations in adults in the frontal and sagittal plane. The examinations were performed on Point 3D Combi 500 cone-beam tomograph. The paper belongs to the «description of case series» category whis is a type of study recognized by evidence based medicine and does not claim statistical significance of the results. Results and discussion. When examining the computer tomograms of men and women in the study group, it has been found out how the shape of the maxillary sinuses (MS) affects the contact of the tooth roots with the cortical plate and the mucous membrane of the maxillary sinuses. Six main shapes of the MS are defined: trapezoidal, square, round, oval, rectangular and triangular. In the frontal plane of CBCT, the most frequent contact with the MS cortical plate is observed in the triangular and rectangular shape of the MS, that is: in the MS rectangular shape it is in contact with the 15th, 25th tooth root in 13 people (56.5% of cases) and in the triangular shape – with the 15th, 25th tooth root in 17 people (56.5% of cases). Analyzing CBCT in the sagittal plane, the most frequent contact with the cortical plate of the left MS is observed in the MS triangular shape, namely – the sinus is in contact with the 25th tooth root in 38 people (59.4% of cases). In the sagittal plane of CBCT, the contact with the tooth roots was rarely observed in the MS square and round shape. In the MS square shape, the 13th and 14th tooth roots do not come into contact with its cortical plate, and, with the mucous membrane, there is no contact of all the roots of the teeth except the 16th, in 1 person only. Conclusions. The results of the study have made it possible to trace a number of patterns of influence of the maxillary sinus shape on the tooth roots contacting it. The contact of the MS cortical plate is most often observed with 16th and 26th tooth roots, while the MS mucous membrane – with 17th and 27th tooth roots of the upper jaw. It was found that in any shape of sinus in the frontal plane, no contact of the 13th, 23rd and 24th tooth roots of the maxillary dental arch with the mucous membrane of the maxillary sinus was detected. In the CBCT frontal plane, it has been found that the most frequent contact with the MS cortical plate is observed in triangular, trapezoidal and rectangular form of the MS, and the rarest one – in oval, square and round form of MS. The study has established that in the sagittal plane of CBCT the most frequent contact with the MS cortical plate is observed in the MS triangular shape, and the rarest – in the round one.

The study introduces a concept of contact stress analysis to the local stress calculation of plate and shell structures in pressure vessels. A new computational method for local stresses is proposed in the light of the contact between pad and shell and the compatibility at the pad edges due to the fillet weld. Using the developed program of the contact stress analysis of plates and shells, which is based on the flexibility mixed FEM, the authors have studied the contact stresses of a saddle support model and local stresses of a suspended tower structure which cannot be achieved with old methods. The theoretical calculations coincide well with the experimental results.

The article presents the results of a study of the contact zone of a thin-walled cylindrical shell located between two parallel rigid plates. The shell under consideration was located with various gaps from the rigid plate and was subsequently subjected to internal pressure. In the course of such a study, experimental, numerical and analytical estimates of the contact zone width were obtained depending on the discharge pressure. The obtained numerical and analytical estimates are tested with experiment. To study the width of the contact zone, depending on the gap, a testing workbench was used. The problem of numerical and analytical modelling was solved by the finite element analysis in the Ansys Workbench system. The solution to transcendental equation was found numerically using the Newton-Raphson method. As a result of experimental, numerical and analytical studies, results were obtained for a plane-oval shell with gaps of 0.5 mm, 1 mm and 2 mm, depending on the applied pressure.

The profitability of walnut cultivation and processing was investigated in the paper, both on small farms and large agricultural enterprises. The demand for walnuts in Ukraine and abroad was investigated. Theoretical studies of the dynamics of nut crop growth in the territory of our country were conducted. The tendency to increase domestic production of walnuts in the future is established. Among the most important areas of the organization of the process of purification of this raw material is noted the process of chopping (crushing) of its shell. Applying a constructive implementation of a vibrating machine «GMK-350» for the process of mechanical cleavage of the shell of a walnut were carried out studies of the influence of the working body (plate and spherical insert) on the technological and energy parameters of the process taking into account the quality of the processed product (the integrity of the core). The article analyzes the process of shelling of walnuts between the plate and the spherical insert. Graphical correlations between the size of the shell deformation and the dynamics of change of the driving force of change at different nut humidity and shell thickness are analyzed. The scheme of driving forces in the area of contact between the nut and the ring is drawn up and analyzed. The graphical dependences of the maximum crushing force on the bevel of the rings according to different shell thickness are presented; variations of the maximum crushing force depending on the humidity of the nuts for different thicknesses of the nut shell. It is established that, theoretically, the coefficient of friction increases as the angle of inclination of the ring increases. It is established that the crushing force of a walnut shell depends less on the friction coefficient and more on the contact surface.

Abstract. On the basis of the nonlinear plate-shell and piezoelectric theory, the governing equations of motion for axisymmetrical piezoelectric delaminated cylindrical shell under hygrothermal conditions were derived. The governing equation of transverse motion was modified by contact force and thus the penetration between two delaminated layers could be avoided. The whole problem was resolved by using the finite difference method. In calculation examples, the effects of delamination length, depth and amplitude of load on the nonlinear dynamic response of the axisymmetrical piezoelectric delaminated shell under hygrothermal conditions were discussed in detail.

Abstract: Heat transfer is one of the most important processes in many industries. For this a heat exchanger is used. There are many different types of heat exchanger available that are double tube heat exchanger, Shell and Tube heat exchanger, tube in tube heat exchanger, Plate heat exchanger, Finned heat exchanger etc. In heat exchanger a fluid is used to cool another fluid which is a higher temperature, this is done either with direct contact between the fluids or indirect contact between the fluids with a surface in between. Most common type of heat exchanger used in industries is Shell and Tube heat exchanger due to its dimension flexibility which is it dose not have any dimension limit to it. As most of the Shell and Tube heat exchanger in the industries are of long lengths and also they are equipped with only single pass of the tube and with either parallel flow or counter flow. They are also equipped with different types of baffle plate at different angles and placing. In this project we have done construction and performance on Shell and Tube heat exchanger which is made in compact size and which is also equipped with parallel flow and counter flow. We have given multiple passing of the tube throughout the shell which results in better cooling of water. The cooling medium used in this project is water at normal room temperature. Because of the compact size of this heat exchanger it can be used in small spaces with availability of water like in small scale industries. Keywords: Shell and tube heat exchanger, heat transfer, multiple pass, compact size, rotameter, valves

A numerical simulation model of heat flux sensors embedded in a flat plate is established. Each sensor has four thermal couples and is inserted into the specified hole. The problem is defined as a steady heat conduction problem with specified boundary conditions and solved by the finite element method. The results of the simulation case demonstrate that the maximum heat flux appears near the sensor shell. The average heat flux of the plate is much smaller than the maximum. Due to exiting of the contact heat resistance, the temperature of the sensor is much lower than that of the plate at horizontal surface. The maximum temperature difference appears on the bottom shell of the sensor. The maximum temperature difference between the simulation results and the experimental data at test points is 1.5 K. The model is verified and could be accepted for the further errors analysis.

Abstract With the development trend of automobile lightweight, the continuous casting process of automobile slab is more and more demanding. In this paper, the stress conditions and boundary conditions in the deoxidizer of the continuous casting process were analyzed, and a contact mechanics model was established between the cast slab and the copper plate. The deformation laws of the slab shell under different amplitude and frequency were simulated and analyzed, and the amplitude and frequency parameters that minimize the impact of slag marks on the slab shell were determined, providing a basis for selecting reasonable vibration parameters.

An analysis to predict the transient response of a thin, curved laminated plate subjected to low velocity transverse impact by a rigid object is presented. The contact force history due to the impact phenomenon is assumed to be a known imput to the analysis. The coupled governing equations, in terms of the Airy stress function and shell deformation, are solved using Fourier series expansions for the variables. Closed-form analytical solutions for plate deflections and strains are compared with available impact test results for flat plates. Outer ply strains are used to predict fiber failures and matrix splitting between fibers in the impacted laminate.

AbstractThe motion of gravity-driven deformable drops (Bond number, $\mathit{Bo}\sim 0.8{-}11$) through a circular confining orifice (ratio of orifice diameter to drop diameter, $d/D<1$) was studied using high-speed imaging. Drops of water/glycerin, surrounded by silicone oil, fall toward and encounter the orifice plate after reaching terminal speed. The effects of surface wettability were investigated for both round-edged and sharp-edged orifices. For the round-edged case, a thin film of surrounding oil prevents the drop fluid from contacting the orifice surface, such that the flow outcomes of the drops are independent of surface wettability. For $d/D<0.8$, the boundary between drop capture and release depends on a modified Bond number relating drop gravitational time scale to orifice surface tension time scale and is independent of viscosity ratio. Drops that release break into multiple fragments for larger $\mathit{Bo}$ and smaller $d/D$. For the sharp-edged case, a contact is initiated at the orifice edge immediately upon impact, such that surface wettability influences the drop outcome. When the surface is hydrophobic, the contact line motion through the orifice enhances penetration of the drop fluid, but the trailing interface becomes pinned at the orifice edge, inhibiting drop release. When the surface is hydrophilic, a fraction of the drop fluid is always captured because the drop fluid spreads on both the upper and lower plate surfaces.

Bistable microstructures are promising for implementation in many mictroelectromechanical system (MEMS)-based applications due to their ability to stay in several equilibrium states, high tunability and unprecedented sensitivity to external stimuli. As opposed to the extensively investigated one-dimensional curved beam-type devices of this kind, microfabrication of non-planar two-dimensional bistable structures, such as plates or shells, represents a remarkable challenge. Recently reported by us, a new moldless stamping procedure, based on pressing a soft stamp over a thin suspended metallic film, was demonstrated to be a feasible direction for the fabrication of initially curved micro plates. However, reliable implementation of this fabrication paradigm and its further development requires better understanding of the role of the process parameters, and of the effect of both the plate and the stamp material properties on the shape of the formed shell and on the postfabrication residual stresses, and therefore on the shell behavior. The need for an appropriate choice of these parameters requires the development of a systematic modeling approach to the stamping process. Here, we report on a finite element (FE)-based methodology for modeling the processing sequences of a successfully fabricated aluminum (Al) micro shell of realistic geometry. The model accounts for the elasto-plastic behavior of the plate material, the nonlinear material behavior of the foam and the contact between them. It was found that the stamping pressure and the plate material parameters are the key parameters affecting the residual shell curvature as well as its shape. Consistently with previously presented experimental results, we show that the fabrication procedure partially relieves the prestresses emerging during preceding fabrication steps, leaving a nontrivial distribution of residual stresses in the formed shell. The presented analysis approach and results provide tools for designers and manufacturers of systems including micro structural elements of shell type.

For studying the vibration frequencies and modes of structural elements that operate in interaction with a liquid, an approach has been proposed. The approach is based on coupled usage of finite and boundary element methods. For description the motion of both structural elements and the fluid, the method deals with basic relations of the continuous medium mechanics. In the study of structural elements, the linear relations between stresses and strains have been accepted, i.e. elastic elements have been considered. The relations between the components of stress tensors and strain rates are used to describe the fluid motion. The fluid is considered to be ideal and incompressible. The Laplace equations have been obtained considering the fluid pressure on the wetted surfaces of structural elements. The corresponding boundary conditions have been formulated for one-sided and two-sided contact of a structural element with a liquid. Integral equations for pressure determination have been received. In the case of a two-sided contact of a structural element with a liquid, a hypersingular integral equation has been obtained. If the contact with the liquid is one-sided, then the indicated singular integral equations have logarithmic singularities and Cauchy-type singularities. In the presence of axial symmetry of the structure, these hypersingular integral equations are being reduced to one-dimensional ones. A round elastic plate under different fastening conditions has been considered. Modes of free oscillations of this structural element have been received; these ones serve as basic functions in the study of plate oscillations taking into account the added liquid masses. The finite element method was used. A one-dimensional hypersingular integral equation is implemented to find the fluid pressure on the plate. The frequencies and oscillation forms of the plate have been obtained with considering the attached masses of the liquid. Accuracy and reliability of the proposed method have been ascertained.

The paper examines the problems of calculating a beam slab axisymmetrically loaded with round and rectangular plates on an elastic Winkler foundation in the traditional formulation without taking into account shear stresses and one-sided connections in the contact zone between the structure and the elastic foundation. The deflections of the structure are represented as a series of eigenfunctions of the differential equation of bending vibrations of a structure with free edges. The external load is also arranged in a series according to its own functions. Substituting these expansions into the differential equation for the deflection of a structure on the Winkler base and equating the coefficients for the same eigenfunctions, we find an expression for the deflections of the structure. Next, the forces in the structure are determined from the deflections. Solutions are given to problems of bending of a beam slab axisymmetrically loaded with round and square plates partially loaded with a uniformly distributed load.

Tubes in shell-and-tube heat exchangers, including nuclear plant steam generators, derive their support from longitudinally positioned tube support plates (TSPs). Typically, there is a clearance between the tube and TSP hole. Depending on design and fabrication tolerances, the tube may or may not contact all of the TSPs. Non-contact results in an inactive TSP which can lead to detrimental flow-induced tube vibrations under certain conditions dependent on the resulting tube-TSP interaction dynamics and the fluid excitation forces. The purpose of this study is to investigate the tube-TSP interaction dynamics. Results of an experimental study of damping and natural frequency as functions of tube-TSP diametral clearance and TSP thickness are reported. Calculated values of damping ratio and frequency of a tube vibrating within an inactive TSP are also presented together with a comparison of calculated and experimental quantities.

In order to achieve high productivity of assembly blocks of hull structure, it is important to predict welding deformations accurately and to apply these data to the production planning. For this purpose the transient thermal-elastic-plastic analysis by FEM (finite-element method) may be utilized. However, this method is not a practical approach to analyze the deformation of large and complex structures, such as ship hull structures, in view of time and cost. Whereas the inherent strain method deals the residual strain near the weld line as the inherent strain, therefore the residual deformation can be simply calculated by elastic analysis. This method is much more practical and efficient than the transient thermal-elastic-plastic analysis. Thus, in this paper, the inherent strain method is used to predict the welding deformation of hull structures. Past research activities of the inherent strain method have been focused on the prediction of the welding deformation of small size specimens and simple shape specimens; however, very few of them treat the problem of large and complex structures. Hence, in this paper, prediction of welding deformation of curved shell plate, of which size is approximately full scale, is conducted by the inherent strain method. In applying elastic analysis to predict the welding deformation of actual hull blocks, contact condition between the plate and the positioning jig should be adequately realized in the analysis. Therefore, a practical solution is proposed to con- sider the contact condition between the plate and the jig by judging reaction forces of the jig at calculation steps. Furthermore, since the welded plates may slip on the positioning jig due to the welding deformation, rigid body motion of plates is caused. Hence this motion should be taken into account of the estimation of calculated results of FEM. In addition to the rigid body motion, coordinate system of the measured data is usually different from the calculated data, therefore, the deviation of the coordinate system must be involved. These calibrations to assess the calculated deformation by FEM are also discussed. The above prediction method is confirmed to be successful by comparing the calculated deformations and the measured ones of large size specimen of curved shell plates due to butt welding.

In the novel The English Patient, the Sri Lankan-born Canadian writer Michael Ondaatje projects his characters as the diasporic subjects performing their ambivalence regarding identity, culture and nationality. This research article, applying diasporic theories as a critical tool, aims to demonstrate the non-conformist cultural and national stand of the shell-shocked characters at the Italian villa of Girolamo as soon as the devastating Second World War has been over. The novelist Ondaatje and his fictional characters bear the fate of diasporic experience entangled between two cultures. Their divided loyalty demonstrates their fractured subjectivity as an outcome in the colonial and postcolonial setting where they come in contact with the people of the nationality and culture which are different from their own. Cultural mixing is a reality in today's world resulting from the transnational and cross-border migration. Such a mix-up phenomenon is not creating a one-way-traffic-like influence from the West to the Rest but it is other way round, too.

Abstract A computational procedure has been presented for the solution of frictional contact problems for aircraft tires. The Space Shuttle nose-gear tire was modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in material and geometric parameters, transverse shear deformation, and geometric non-linearities included. Contact conditions were incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact and friction conditions. The contact friction algorithm was based on a modified Coulomb friction law. Elemental arrays were obtained by using a modified two-field, mixed variational principle that was obtained by augmenting the functional of the variational principle by two terms: the Lagrange multiplier vector associated with nodal normal and tangential contact load intensities and a regularization term which is quadratic in the Lagrange multiplier vector. Experimental measurements were made to define the response of the Space Shuttle nose-gear tire to combined inflation pressure loads and static normal loads against a rigid flat plate. These experimental results describe the static load-deflection characteristics of the tire and the normal and tangential load intensity distributions in the tire footprint for the various static vertical loading conditions. Numerical results were obtained for the Space Shuttle nose-gear tire subjected to combined inflation pressure and contact loads against a rigid flat plate. Comparisons were made between the experimental measurements and the numerical results.

Sanitation standard operating procedures (SSOPs) are an integral component of process control and are often the first step in the implementation of food safety regulations. The objective of this study was to assess and compare the efficacies of sanitation programs used in a variety of shell egg processing facilities. In-line, off-line, and mixed operations were evaluated. Sixteen direct or indirect egg contact surfaces were sampled in various shell egg processing facilities in the southeast United States. Samples were collected at the end of a processing day (POST) and again the next morning before operations began (PRE). Total aerobic plate counts (APCs) were obtained and Enterobacteriacae were enumerated. No significant differences (P > 0.05) between POST and PRE bacterial counts were found for the 16 sampling sites. In general, high APCs were found on the wall of the recirculating water tank both POST and PRE. The APCs for the rewash belt were considerably high for all plants sampled. APCs were also high for the vacuum loaders. APCs for washers and washer brushes were relatively low for most plants sampled. PRE and POST levels of plant sanitation, as determined by direct microbial plating, did not differ significantly. At this point, it is difficult to draw definitive conclusions about how rigid SSOPs should be for the shell egg processing industry.

Air entrainment can become a significant problem in a web handling process line. The development of an air film between a roller and web can cause a reduction in traction. This can cause a velocity difference between the web and roller and may also cause guiding problems. Roller grooving is a common method to reduce the effects of the air entrainment to improve traction. A traction simulation model for circumferentially grooved rollers has been devised. The model is based on classical plate and shell theory, the Reynolds’ equation, and asperity contact theory. The governing equations are solved in an iterative scheme using a finite difference method with a variable mesh. Theoretical results are experimentally verified. [S0742-4787(00)02203-7]

This article investigates the forced oscillations of an incompressible liquid drop under the action of an inhomogeneous alternating electric field. The drop is surrounded by an incompressible fluid of a different density and is clamped between two inhomogeneous parallel plates. In equilibrium, the drop has the shape of a round cylinder bounded in the axial direction by these plates. The external electric field acts as an external force causing the contact line to move. To describe the motion of the contact line, a modified Hocking boundary condition is used: the velocity of the contact line is proportional to the deviation of the contact angle from its equilibrium value and the rate of fast relaxation processes, the frequency of which is proportional to the doubled frequency of the electric field. The use of this equation makes it possible to qualitatively describe the experimental dependence of the contact angle as a function of stress, in contrast to the Young-Lippmann equation. The solution of the problem is represented as a Fourier series in terms of eigenfunctions of the Laplace operator. The resulting system of inhomogeneous equations for unknown amplitudes is solved numerically. Graphs of the amplitude-frequency characteristics and the dynamic shape of the drop are plotted for various values of the problem parameters. The wetting parameter depends on the polar angle  , i.e. the coefficient of interaction between the plate and the fluid (contact line) is a function of the coordinates.

The response of the side shell to non-contact underwater explosion is of major concern in ship design. While extensive research is carried out on air-backed plates, relatively less attention is paid to water-backed plates. Nevertheless, the response of the water-backed plates becomes relevant when the water filled side shells are exposed to an underwater shock loading. Availability of scant information on the experimental results of water-backed plates is the primary motivating factor to make analytical estimates. These estimates are provided in comparison with an air-backed plate for identical attack geometry and target parameters. This work aims to bring out a comparative procedure for the damage assessment between air- and water-backed plates so that the response of the latter can be presented in terms of that of the former.

ABSTRACTIn this study, a spherical indenter mounted on an atomic force microscope (AFM) was used to compress a Nannochloropsis oculata (N. oculata) cell on a poly-l-lysine coated slide. A mathematical model of the cell, which was derived by considering a fluid-filled spherical shell with axisymmetric compression between a sphere and an infinite flat plate, is proposed. In the construction of this mathematical model, the spherical shell was assumed to be a homogenous, isotropic, and elastic material. Thin-film theory was applicable to the spherical shell because the thickness of the shell was nearly negligible compared with its diameter. The governing equations of the contact and noncontact regions were converted from a boundary condition problem to an initial value problem. Then, the fourth-order Runge–Kutta method was applied to solve the transformed governing equations. The force curve obtained from the compression experiment was compared with the theoretical results derived from the proposed model. Furthermore, the numerical solution of the proposed model was verified to be consistent with the experimental data. The mechanical properties of cell walls were confirmed by applying the least square error method. Subsequently, the contact radius, inner pressure and tension distribution of the cell wall could be determined using the proposed model. The models proposed in other studies are suitable for analyzing the compression characteristics of cells whose size is of the order of tens of micrometers and millimeters. By contrast, the model proposed in this study can analyze the compression characteristics of N. oculata, which is only a few micrometers in diameter. Furthermore, a force curve that accurately describes the deformation behavior of N. oculata under strain levels of 25% was established.

To successfully implement a hazard analysis critical control point plan, prerequisite programs are essential. Sanitation standard operating procedures are an important part of such a plan and can reduce contamination levels so that food safety and quality are not adversely affected. Noncontact surfaces in the shell egg processing plants can serve as a reservoir of cross-contamination. The objective of this study was to assess the efficacy of sanitation programs used in a variety of shell egg processing facilities (in-line, off-line, and mixed operations). Fourteen different noncontact surfaces were sampled in nine commercial facilities across the southeastern United States. Non–egg-contact surfaces were defined as those where the shell egg does not come into direct contact with the surface or with the fluid from that surface. Gauze pads soaked in sterile phosphate-buffered saline were used for sampling at the end of a processing day (POST) and again the next morning prior to operations (PRE). Aerobic plate counts (APCs) and numbers of Enterobacteriaceae were determined. No significant differences (P > 0.05) were found between POST and PRE counts for either population recovered from the 14 sampling sites. Only samples from the floor under the farm belts, nest-run loader, washers, and packer heads were reduced by 1 log CFU/ml of rinsate for APCs or Enterobacteriaceae counts. APCs of more than 104 CFU/ml of rinsate were recovered from many samples. Highest APCs were found on the floor under the farm belt and on shelves of the nest-run carts. High APCs were found on the wheel surface for off-line carts and on the loading dock floor. Highest Enterobacteriaceae counts were found in samples from the floor, drain, and nest-run egg cart shelves. A lack of significant difference between POST and PRE counts indicates that current sanitation programs could be improved. These data suggest that traffic patterns for the movement of eggs and materials through the plant should be reevaluated so that cross-contamination is reduced.

Belt conveyors are widely used in mining industry in open-pit and underground mining for moving bulkload in horizontal and inclined directions to the sites of processing. In order to create the best conditions of frictional contact between a belt and a drum, various methods of drive drum lining are used. The main lining material is rubber of different grades, providing proper coefficient of friction of a belt with a drum (within the range of 0.6–0.62). A drive drum lining material must have high wear resistance, thermal resistance, mechanical strength, ability not to accumulate electric charges on the surface and not to generate dangerous concentrations of toxic components (for example, chlorine gases, carbon monoxide) when heated. The use of ceramic lining opens up great opportunities for increasing lining durability and useful life of high capacity heavy-duty conveyors. The paper presents the results of the study of stress-strain state of belt conveyor drive drum ceramic lining plates. We used Solid Work Simulation environment in the study on the basis of the accepted analytical model of plate-belt contact for drive drum with diameter D = 1250 mm, belt width L = 1000 mm, and the belt entering branch tension value Se = 25400 daN with regard to the value, direction, and nature of the acting loads. On the basis of stress-strain analysis of alumina ceramics lining plates, the favorable geometrical parameters of the plate cleats (projections) and the required properties of lining material ensuring the proper load-carrying capacity at the contact with the belt rubber facing were found. It was established that a plate cleat diameter for heavy duty conditions should be not less than 4.5 mm and its end round R should be within the limits of 0.5–0.6 mm, and, in the base, 0.3–0.4 mm at a cleat height of 1.0–1.4 mm in order to prevent stress concentration in hazardous sections. It was also established that alumina ceramics bending strength must be no less than 350 MPa for effective functioning of rubber-ceramic lining. Simulation of a plate stress-strain state on exposure to alternating loads made it possible to identify characteristic areas with maximum stress concentration, which were foci of crack nucleation. Thus, it became possible to predict lining useful life.

The paper deals with the analysis of reliability and safety of a welded tank for the storage of oil, which is located in the Czech Republic. The oil tank has a capacity of 125 thousand cubic meters. It is one of the largest tanks of its kind in the world. Safety is ensured by a steel outer intercepting shell and a double bottom. The tank was modelled in the programme ANSYS. The computational model was developed using the finite element method – elements SHELL181. A nonlinear contact problem was analysed for the simulation of the interaction between the bottom plate and foundation. The normative approach in design and check of tanks according to standards API 650, ČSN EN 14015, EEMUA 159 and API 653 is mentioned. The dominant loading of the filled tank is from oil. The normative solution is based on the shell theory, which considers constant wall thickness. For real tanks sheet thicknesses of individual courses increase with increasing depth. Stochastic sensitivity analysis was used to study the effect of the variability of the thickness of the ith course on the stress of adjacent courses. The Latin Hypercube Sampling method was implemented during analysis.

We present a facile approach to fabricate superamphiphobic surfaces by spray coating silica-fluoropolymer core-shell particles without substrate pretreatment with an additional binder resin. A series of SiO2@poly(1H,1H,2H,2H-heptadecafluorodecyl methacrylate) (SiO2@PFMA) core-shell particles with core particles of different sizes were prepared via thiol-lactam initiated radical polymerization (TLIRP). The surface of each SiO2 particle with an average particle size of 12, 80, 150, and 350 nm was modified with (3-mercaptopropyl) trimethoxysilane and used as a seed for TLIRP. The SiO2@PFMA particles with various SiO2 sizes and contents were coated on aluminum substrates by a spray gun and then thermally treated to form a stable, rough composite layer. During the spray coating, the core-shell particles were aggregated by rapid evaporation of the solvent and then irregularly adhered to the substrate resulting in hierarchical structures. In the case of SiO2@PFMAs with low SiO2 contents, the roughness created mainly by the polymer shell disappeared during heat treatment. However, the substrates coated with SiO2@PFMAs with high SiO2 contents maintained the roughness even after heat treatment. The core-shell particles prepared with 12 nm SiO2 formed a stable superamphiphobic surface. The water/hexadecane contact and sliding angles on an aluminum plate coated with SiO2@PFMA, prepared using 12 nm silica at 46 wt% silica content (12 nm-SiO2(46)@PFMA), were 178.5°/159.2° and 1°/7°, respectively. The cross-cut tape test showed that adhesion between the 12nm-SiO2(46)@PFMA and the aluminum substrate was classified as 5B. A glass surface spray-coated with the core-shell composite particles exhibited transparent superhydrophobicity and translucent superamphiphobicity by controlling the concentration of the coating solution.

Abstract The composite slabs behavior is governed by longitudinal shear at the interface between the steel deck and concrete, which is developed in slabs under simple bending. The m-k method and the partial connection method, that are used in the evaluation of shear strength at the steel-concrete interface of composite slabs, are based on expensive and long-term experimental tests. The main objective of this work is to implement a finite element model for nonlinear numerical analysis of concrete slabs with steel decking. For this, flat shell elements are implemented, considering Reissner-Mindlin and Kirchoff plate theories, bar elements, considering the beam theory of Tymoshenko, and interface elements. In the numerical analyzes presented in the present work, the steel deck and the concrete slab, of thickness given by the total height of the slab less the height of the steel deck, are modeled with flat shell elements. The concrete rib is modeled with bar elements. The contact between steel deck and concrete is modeled through interface elements. The geometric and material nonlinearities are considered in the numerical analysis. The analyzed examples validate the numerical model suggested in this work, presenting the advantage of using a two-dimensional discretization of the problem while in comparative numerical models are uses a three-dimensional discretization of the concrete slab.

Abstract The coconut shell charcoal industry is growing rapidly for export purpose, raw material for several industries, and as fuel on cooking stove or grill. In the other side, charcoal production activity causing negative impacts since the process produce smoke which can pollute the environment around production area. One of many efforts to reduce the negative impact of charcoal production activities is by condensing the smoke into liquid smoke. Liquid smoke has high economical value since it can be utilized as a natural pesticide, natural preservative, and also for medicine after a certain processing. Charcoal production is a carbonization process based on primary pyrolysis technology. A condenser system has been developed for carbonization process in a portable venturi kiln. The condenser system consists of the condenser itself as the main part of the system, piping unit to transfer the smoke from the kiln (carbonization reactor) to the condenser, connection port between kiln and the pipe, and connection port between pipe and the condenser. Several improvements have been done to the original design to get optimum performance of the overall system (both of kiln performance and the condenser system performance). Kiln performance was decline when condenser system applied since the smoke interrupted when release from the kiln and causing carbonization process getting slowly. In the other side, the smoke should be slowly entering the condenser system for good result of condensation. The lasted modification design of the system is a condenser with 11 vertical copper pipes with 0.5 cm diameter and 110 cm length, bounded by 20 round galvanic plate with 10 cm diameter and 0.4 mm thickness. The condenser connected to the kiln through the 210 cm pipe in a half circle form. The system performance successfully processing 12.45 kg coconut shell to produce good charcoal with yield around 24% in the average temperature of 260 °C in around 270 minutes. The system produce 1520 ml condensate with average distillation rate of 0.35lt/hour.

The paper presents an updated Lagrangian-type finite element procedure, formulated with reference to a surface embedded coordinated system. Membrane shell theory is employed, and an attempt is made to calculate the strain distribution incurred by a peripherally clamped square plate, when impressed by a rigid punch. Three different punch geometries were considered. The material is treated as a rate insentive, elastic work-hardening solid, which obeys the J2 flow theory; both finite deformation and normal anisotropy can be considered. A linear relationship between the Jaumann rate of Cauchy stress and the Eulerian rate of Green’s strain tensor is derived. A slip-stick model was adopted for the interfacial frictional conditions. This was achieved by considering the equilibrium of a constant strain-element node in contact with the tools, and deciding whether such a node would stick or slip under Coulomb friction conditions. It is demonstrated that the punch geometry and frictional conditions exert a strong influence on the deformation mode, and hence, upon the overall strain distribution. The predictions were checked against experimental observations when stretch-forming square plates of pure aluminum, 0.5-mm thick. Contours of equal height on the deforming blanks were determined using a Moir´e fringe technique. The agreement between theory and experiment was favorable.

[ID] Prinsip dasar pondasi terapung adalah keseimbangan antara berat struktur atas dan total berat tanah (termasuk didalamnya air tanah) yang dipindahkan oleh konstruksi pondasi tersebut sehingga tidak menghasilkan penurunan struktur. Pondasi terapung sangat baik digunakan pada daerah dengan daya dukung tanah yang rendah atau pada daerah yang memiliki tanah dengan derajat pemadatan yang bervariasi. Hal ini dikarenakan karakteristik pondasi terapung yang membagi gaya ke area kontak yang sangat besar sehingga seluruh area kontak tersebut hanya mengalami tegangan yang relatif kecil. Namun demikian, karena kapasitas dukung pondasi terapung sangat tergantung pada luasan area, maka pondasi terapung menjadi tidak efektif untuk diterapkan pada daerah yang kecil. Salah satu solusi yang dapat digunakan untuk mengatasi permasalahan ini adalah dengan penerapan struktur pelat cangkang (shell structure) pada pondasi terapung untuk meningkatkan luas area bidang kontak pondasi terapung dan tanah. Paper ini membahas optimasi bentuk pelat cangkang yang digunakan pada pondasi terapung agar memiliki daya dukung yang cukup untuk menahan gaya yang ditransferkan oleh struktur atas. Metode algoritma genetik digunakan dalam proses optimasi dimana koordinat dari titik yang menyusun bentuk (shape) struktur cangkang (cn) dipakai sebagai desain variabel. Pada penelitian ini, proses optimasi menggunakan pemodelan dengan 11, 13 dan 15 variabel desain untuk melihat sensitivitas desain variable tersebut terhadap hasil optimasi. Tegangan yang terjadi pada struktur cangkang tersebut di evaluasi dengan Analisa Elemen Hingga dengan perilaku element cangkang seperti model teory pelat Reissner-Midlin. Fungsi tujuan pada penelitian ini adalah meminimalkan penggunaan material untuk membentuk sebuah pondasi terapung dengan fungsi penalti tegangan pada elemen cangkang.
 [EN] The basic principle of floating foundation is counterforce balancing between the weight of the structure and thetotal weight of the soil (including groundwater) which is displaced by the structure. Floating foundation is effective in areas with low soil bearing capacity because the external load is widely spread that resulting lower stress level in contact area; Hence, it is necessary to design the shape of floating structure that provide adequate uplift whilst also create lower stress level by spreading the external load to wider contact area. This paper discusses the shape optimization of the floating foundations to have sufficient capacity to resist the force transferred by the upper structure whilst also minimize the use of material without resulting element overstress. Genetic algorithm method is used in the optimization process where the coordinates of the points that shape the shell structure (cn) are used as variable designs. In this study, the multivariable optimization using finite element model is investigated . The stress that occurs in the shell structure is evaluated by Finite Element Analysis with the behavior of shell elements based on Reissner-Mindlin plate theory.

The article discusses the results of thermal imaging monitoring of building structures with and without insulation. Research and thermal and physical calculations showed that heat loss from the premises is determined by two groups of factors: surface loss depending on thermal conductivity, as well as vapor and air permeability of enclosing elements and heat loss at all types of joints, fasteners, etc. Thermal insulation with plate materials significantly reduces heat losses, but at the same time, heat flows through the joints between the heat-insulating plates and in the areas of their contact with other structures, necessitating the use of steam and waterproof windproof roll materials. The usage of elastic and thermoplastic materials in the insulation circuit allows minimizing heat loss at the joints between the heat-insulating elements and along the smooth surface of the wall due to the low air and vapor permeability of the material. In the systems of frame cottages, when used as a thermal insulation of rolled foam-polyethylene, it becomes possible to form a seamless insulating shell of a building. This is made possible by connecting individual sheets of polyethylene foam into a lock, followed by hot air welding. Seamless insulation systems are used both in the construction of cottages and in the construction of frame and frameless logistic facilities and housing and communal services.

We studied the effect of energy mechanical pre-treatment (EMT) of the initial (Co – Cr – Mo) alloy powders in a vortex layer of ferromagnetic bodies on the structural-mechanical properties of products obtained by spark plasma sintering (SPS). To study the properties of powder and compact samples, the methods of scanning electron microscopy (SEM), optical microscopy, determining the bending strength and microhardness on the Vickers scale were used. It was shown that the EMT of powders for a short time (1 – 3 min) leads to intense plastic deformation of a large part of the initial rounded particles, forming irregular- and plate-shaped particles with high surface roughness. As a result, EMT has a positive effect on spark plasma sintering process of powder, makes it possible to obtain a densely sintered material with a low-porous structure. It was found that the sample pre-treated under EMT for 3 min is compacted during sintering process to a high level (relative density reached 98.3 %) and its mechanical properties has greatly improved (microhardness and bending strength are 16 % and 14 % respectively higher than the sample without pre-treatment). The improvement of structural and mechanical properties of sintered specimens pre-treated under EMT is a result of intensification of diffusion mass transfer processes during sintering due to the plastic deformation of material, change in the shape, surface state of the powder particles and an increase in the total contact area between them. High surface roughness and deviation of particles from the round form lead to a decrease in the radii of curvature of their contact surfaces and, consequently, to an increase in the Laplace forces value, which play a dominant role in the diffusion mass transfer processes during sintering.

To address the problems of threshing loss and high impurity rate during sunflower oil harvesting, a vertical axial flow sunflower oil threshing device was designed. To reduce severe breakage of the sunflower plate and high entrainment loss rate when threshing by the traditional grating gravure sieve, a circular tube-type gravure screen was designed, and a contact model describing the grain rod, sunflower pan, and gravure screen was analyzed. The results show that reducing the diameter of the gravure screen round tubes can effectively reduce breakage of the sunflower pan. The range of the threshing gap, drum speed, and feed amount were determined by a single-factor test. Design-Expert software was used to design a response surface experiment: threshing gap, drum rotation speed, and feed amount were used as test factors, and the threshing loss rate of grains and the grain mass ratio of undersize grains were used as evaluation indicators. A regression model between test factors and evaluation indexes was established by variance analysis of the test results. A software-based numerical optimization function was used to reduce the loss rate of grains and increase the grain mass ratio of undersize grains. The optimal parameters of the threshing device were obtained by multi-objective optimization of all factors: the separation gap was 24.90 mm, drum speed was 244.14 r/min, feed amount was 2.95 kg/s, the threshing loss rate grains was 2.35%, and the grain mass ratio of undersized grains was 81.34%. This study can provide a reference for the design of a combined sunflower oil harvester threshing device.

The purpose of the study is to study the features of the macro- and microscopic structure of the avian uterus in the hen of the Haysex white cross. The objects of the study were 10 carcasses of adult hens, cross-hysex white, aged 160-180 days. To study the structure of the oviduct, the method of conventional and fine dissection was used. For histological examination, the material was fixed in a 10% aqueous solution of neutral formalin, followed by pouring into paraffin. As a result of our research, we noted that the avian uterus of the oviduct is a sac-like expansion of the oviduct, where the process of mineralization and egg shell coating is carried out. The mucous membrane of the bird's uterus in a chicken is assembled into primary, secondary and tertiary folds covered with a multi-row ciliated epithelium, with the presence of cambial, ciliated and goblet-shaped cells with densely arranged tubular glands. The nuclei of round-oval cells are compressed from the sides, located at different levels. The ducts of the tubular glands open to the surface of the folds. On the mucous membrane there are folds in the form of leaf-shaped plates, which are located longitudinally, covered with columnar ciliated epithelium. The mucous membrane of the avian uterus occupies 61.9% of the wall thickness, is represented by a multi-row ciliated epithelium. At the heart of its own plate of the mucous membrane of the avian uterus lies a large number of tubular glands. Due to the active secreting function, the mucous membrane of the avian uterus is 2.4 times larger than the thickness of the muscular membrane. The muscle membrane, occupying 26.3% of the wall thickness, consists of 5 -6 layers of longitudinal 4 layers of circular bundles of smooth muscle fibers, between which bundles of collagen and elastic fibers are located. The serous membrane accounts for 13.4% of the entire thickness of the uterine wall.

A heat exchanger is a device used to transfer heat between two or more fluids. The fluids can be single or two phases depending on the exchanger type and may be separated by in -direct contact (the two most common kinds of heat exchanger are the shell-and-tube and plate/fin). In this research work double pipe heat exchanger was used to analyze the performance of water coolant for industrial applications. In Heat Exchanger the water coolant temperature increases due to increase in the temperature of oil in the tubes. Therefore, it may decrease the overall efficiency of the equipment resulting from degradation of the lubricant oil. In this regard, it is required some additives to be mixed with water coolant so that to enhance the heat transfer rate of the unit. Due to the excessive heating of the hydraulic oil in the turbine bearings, the material of the bearing found damage and deteriorate. Therefore, the aim of this study was to remove the heat from bearing oil, so that overall efficiency of heating equipment could be increased. In this research work Hydraulic oil was heated at 600C and 700C as per requirements of the industry. The experiments were conducted at both parallel and counter flow directions. Initially, a baseline experiment was carried out between hot oil and water coolant (without additives or nanoparticles). Besides the heat transfer rate between hot oil and water coolant with the additives (CuO and Al2O3) were observed at 1-3% proportion. It was concluded that the heat transfer rate of CuO was increased more than Al2O3 and plain water coolant due to more uniform temperature difference maintained between the inlet and outlet of cold and hot fluids due to the higher thermal conductivity of CuO. The maximum heat transfer rate was found to be 36.6 % at 60℃ and 38% at 70℃ with 3% of CuO additive in water coolant in the counter-flow condition.

Valaris Adds Fresh Rig Contracts to Backlog Valaris has scooped a number of new contracts and contract extensions, adding an associated $466 million to its contract backlog. The company received a 540-day contract with Equinor offshore Brazil for use of drillship Valaris DS-17. The rig will be reactivated for this contract, which is expected to begin in mid-2023. The total contract value is around $327 million, including an upfront payment totaling $86 million for mobilization costs, a contribution toward reactivation costs, and capital upgrades. The remaining contract value relates to the operating day rate and additional services. Also in Brazil, Valaris received a contract extension with TotalEnergies EP Brasil offshore Brazil for the use of drillship Valaris DS-15. The option is in direct continuation of the current firm program. “We are particularly pleased to have been awarded another contract for one of our preservation stacked drillships, Valaris DS-17, and look forward to partnering with Equinor on their flagship Bacalhau project in Brazil,” said Valaris Chief Executive Anton Dibowitz. “We expect Brazil to be a significant growth market for high-specification floaters over the next several years, and we are well positioned to benefit by now adding a third rig to this strategic basin.” The contractor also was awarded a two-well contract extension with Woodside offshore Australia for semisubmersible Valaris DPS-1. The two-well extension has an estimated duration of 38 days and will be in direct continuation of the existing firm program for Woodside’s Enfield plug-and-abandonment (P&A) campaign. The P&A work covers 18 wells in total. Woodside also awarded Valaris a separate one-well extension for the rig. The work has an estimated duration of 60 days with Woodside’s Scarborough development campaign. Elsewhere, Shell awarded a 4-year contract for heavy-duty modern jackup Valaris 115 offshore Brunei. The $159-million contract is expected to begin in April 2023. The contract was also awarded various short-term deals for jackups with Shell in the UK, an undisclosed operator in the Gulf of Mexico (GOM), Cantium in the GOM, and GB Energy offshore Australia. Shell Joins Equinor in GOM Sparta Development Shell has agreed to purchase 51% of Equinor’s interest in the North Platte deepwater development project in the US Gulf of Mexico (GOM). Equinor will retain 49% interest in the project, and Shell will become the new operator of the field. The new partners also have agreed to rename North Platte to Sparta. Sparta straddles four blocks of the Garden Banks area, 275 km off the coast of Louisiana in approximately 1300 m of water depth. Front-end engineering and design has been matured for the project. Equinor and Shell will review the work that has been completed and update the development plan. Shell said that Sparta aligns with its strategy to pursue upstream investments that can remain competitive over time, both from a financial and environmental-intensity perspective. North Platte was discovered by Cobalt Energy and Total in 2012. The partners said the Wilcox-aged discovery would require 20K-psi technology to develop. Cobalt went bankrupt in 2017 and its stake in the asset was sold to Equinor and Total. In early 2022, TotalEnergies walked away from the project and its operatorship to focus on other projects, leaving Equinor with 100% interest. BP Awarded King Mariout Block in Egypt’s West Med BP has been awarded the King Mariout exploration block offshore Egypt following its participation last year in the limited bid round organized by the Egyptian Natural Gas Holding Company. The King Mariout Offshore area is located 20 km west of the Raven field in the Mediterranean Sea and covers 2600 km2 with water depths ranging between 500 and 2100 m. The block is within the West Nile Delta area, for which material gas discoveries could be developed using existing infrastructure. BP holds a 100% stake in the block. BP is a major player in Egypt investing more than $35 billion in the area over the past 60 years. LLOG Begins Production From Spruance in GOM LLOG has kicked off production from its operated Spruance Field located in Ewing Bank Blocks 877 and 921 in the US GOM. The two-well subsea development is producing, in combination, approximately 16,000 B/D of oil and 13 MMcf/D via a 14-mile subsea tieback to the EnVen-operated Lobster platform in nearby Block 873. The Spruance Field was initially discovered by LLOG and its partners in mid-2019 via a subsalt exploratory well, the Ewing Bank 877 #1, which was drilled in 1,570 ft to a total depth of 17,000 ft and logged around 150 net ft of oil pay in multiple high-quality Miocene sands. A second well, the Ewing Bank 921 #1, was drilled from the same surface location as the discovery well to a total depth of 16,600 ft in early October 2020. The well delineated the main field pays and logged additional oil pay in the exploratory portion of the well, finding a total of more than 200 net ft of oil. LLOG is the operator of the Spruance Field and owns a 22.64% working interest with partners Ridgewood Energy (23.89%), EnVen (13.5%), Beacon Asset Holdings (11.61%), Houston Energy (11.2%), Red Willow (11.15%), and CL&F (6%). Egypt Signs Agreement With Chevron To Drill First Exploration Well in East Med Chevron is planning to drill the first exploration well in its concession area in the Eastern Mediterranean this September. The well plans come as Egyptian Natural Gas Holding signed a memorandum of understanding with the US-based producer to cooperate in transporting, importing, and exporting natural gas from the area. Chevron expanded its presence in the area following its $5-billion acquisition of Noble Energy in 2020. The two companies will evaluate options for natural gas transmission from the East Mediterranean to Egypt to optimize its value through liquefaction before re-exporting and selling it, according to the memorandum. In addition, the two firms will perform research on low-carbon natural gas. APA Suriname Campaign Offers Mixed Results APA Corporation successfully flow tested its Krabdagu exploration well (KBD-1) on Block 58 offshore Suriname, while its Rasper exploration well on Block 53 offered disappointing results. Flow-test data collected in the two lower intervals, the Upper Campanian (32 m of net oil pay) and Lower Campanian (32 m of net oil pay), indicate oil-in-place resources of approximately 100 million bbl and 80 million bbl, respectively, connected to the KBD-1 well. Appraisal drilling will be necessary to confirm additional resource and development-well locations, according to APA. The exploration well encountered another high-quality interval in the Upper Campanian that was not in a location suitable for flow testing. This shallower Campanian zone will need to be flow tested in the appraisal stage from a better location. The APA-TotalEnergies joint venture is currently drilling the Dikkop exploration well in the central portion of Block 58 with drilling rig Maersk Valiant. Following completion of operations at Dikkop, the rig is expected to continue exploration and appraisal activities in the central portion of Block 58. APA Suriname and operator TotalEnergies each hold a 50% working interest in the block. Meanwhile, APA’s Rasper well in Block 53 off Suriname encountered water-bearing reservoirs in the Campanian and Santonian intervals. The Noble Gerry de Souza drillship has been mobilized to the next exploration prospect, Baja, in the southwestern corner of Block 53. Baja lies 11 km northeast of the recently announced Block 58 discovery at Krabdagu and will test Maastrichtian and Campanian targets. APA Suriname, the operator, holds a 45% working interest in the block, Petronas holds a 30% working interest, and CEPSA a 25% working interest. Novatek JV Wins North Yarudeyskoye License Novatek’s Yargeo joint venture has won the license to survey, explore, and develop production at the North Yarudeyskoye oil and gas condensate field over the next 27 years. The license area is in the Yamal-Nenets autonomous region in the Arctic, Russia’s principal gas-producing area. North Yarudeyskoye holds an estimated hydrocarbon resource potential of 93.5 million BOE. The greater Yarudeyskoye field began producing in 2015 and by 2017 was responsible for nearly a third of Novatek’s liquids production. The company, Russia’s largest private natural gas producer, noted that it had participated in the recent auction to explore and develop North Yarudeyskoye through Gazprom Bank’s Electronic Trading Platform and that the win was Novatek’s first on that platform. PDC Energy Gets Green Light for Kenosha, Broe Developments The Colorado Oil and Gas Conservation Commission has approved PDC Energy’s Kenosha and Broe developments’ permit applications. The Kenosha development, which encompasses 69 wells on three pads in rural Weld County, Colorado, further increases PDC’s permitted inventory by another rig year and solidifies drilling and completion activity well into 2024. The Broe permit encompasses 30 wells in rural Weld County. The Broe plan was initiated by Great Western Petroleum, which was acquired by PDC in May 2022 and represents PDC’s first development plan approval on Great Western acreage. Combined with the Kenosha plan approval, PDC added 99 new wells to its inventory in June and will soon have more than 675 permits and drilled and uncompleted wells. Both fields are in the greater Wattenberg area. The new permits add to an already-established multiyear inventory of projects in the DJ Basin. Kenosha is the second oil and gas development plan to be approved, and the company anticipates further approvals with its Guanella area plan and others. PDC’s operations in the Wattenberg field are focused in the horizontal Niobrara and Codell plays. The Wattenberg represents PDC Energy’s largest asset with more than 85% of its 2021 production and 90% of its year-end 2021 proved reserves.

Purpose. It is development of a numerical algorithm for solving a wide range of stationary dynamics problems on the interaction of plates and cylindrical shells with elastic inertial foundations, the mechanical parameters of which vary in thickness according to arbitrary continuous or discrete laws. Solution of specific problems by the obtained algorithm and assessment of the influence of the variability of the medium characteristics on the main dynamic characteristics using three stationary dynamics problems as an example. Research methods. Timoshenko-type equations and equations based on the Kirchhoff-Love hypothesis are used to describe the motion of plates and shells. The behavior of the foundation is described by dynamic equations of elasticity theory in stresses, from which, taking into account the changeability of Young's modulus and density, equations in displacements with variable coefficients are derived, which in the general case cannot be integrated analytically. For the boundary value problem for a system of ordinary differential equations obtained as a result of the transition to amplitudes and recording the contact conditions between a thin-walled structure and a non-uniform foundation, the orthogonal differential sweep method is used, which uses the Runge-Kutta method at each orthogonalization step to solve the problem. Thus, in problems of free waves and natural frequencies, the eigenvalue problem is solved, and in problems of moving loads, it is necessary to use the reverse move and then apply the superposition method. To assess the accuracy, as well as the optimal choice of orthogonalization nodes in the limiting cases of all the considered problems with a homogeneous foundation, analytical solutions are found and a comparison of the results is carried out. Results. A software package for numerical solution of homogeneous and heterogeneous boundary value problems for systems of ordinary differential equations with variable coefficients based on the orthogonal differential sweep method has been developed. In this study, this software package is used for problems from three main classes of stationary dynamics problems: propagation of free waves in a cylindrical shell – heterogeneous elastic filler system, determination of natural frequencies in a three-layer cylindrical shell with a heterogeneous middle layer, and motion of a normal load along a plate on a foundation heterogeneous in thickness. Each problem shows the influence of the foundation heterogeneity on phase velocities, natural frequencies, and plate displacement. The efficiency of the developed program for more complex practical problems has been tested using boundary transitions to corresponding homogeneous materials, and recommendations have been made on the use of this algorithm for media with a significant number of layers. Scientific novelty. An algorithm based on the orthogonal differential sweep method has been developed for problems of stationary dynamics of plates and shells interacting with a three-dimensional heterogeneous inertial medium. Three problems from three different classes of this section of solid mechanics have been solved with its help. The ways of further use of the developed package for problems of such classes are indicated. Practical value. The developed software package and the results obtained with its help can be used in the practice of design organizations engaged in the development of elements of new technology, construction, and the construction of modern highways. In addition, the mathematical part of this publication can be useful not only in the mechanics of a deformable solid, but also in those sections of science where boundary value problems arise for systems of ordinary differential equations.

Sonadrill Lands Contract for Drillship Seadrill confirmed a new contract has been secured by Sonadrill Holding, Seadrill’s 50:50 joint venture with an affiliate of Sonangol for the drillship West Gemini. Sonadrill has secured a 10‑well contract with options for up to eight additional wells in Angola for an unknown operator. Total contract value for the firm portion of the deal is expected to be around $161 million, with further revenue potential from a performance bonus. The rig is expected to begin the work in the fourth quarter of this year with a firm term of about 18 months, in direct continuation of the West Gemini’s existing contract. The West Gemini is the third drillship to be bareboat chartered into Sonadrill, along with two Sonangol‑owned units, the Sonangol Quenguela and Sonangol Libongos. Seadrill will manage and operate the units on behalf of Sonadrill. Together, the three units position the Seadrill joint venture as an active rig operator in Angola, furthering the goal of building an ultradeepwater franchise in the Golden Triangle and driving efficiencies from rig clustering in the region. Petrobras Receives TotalEnergies, Shell Payments for Atapu TotalEnergies and Shell have formalized payments to Petrobras for separate, minority stakes in the pre‑salt Atapu field in the Santos Basin. TotalEnergies paid $4.7 billion reais ($940 million) while Shell paid closer to $1.1 billion. The Atapu block was acquired by the consortium comprising Petrobras (52.5%), Shell (25%), and TotalEnergies (22.5%) in the Second Bidding Round for the Transfer of Rights auction held 17 December 2021. The payments are compensation for monies spent thus far by Petrobras, which was granted contractual rights to produce 550 million BOE from Atapu in 2010. The partners will now work together to produce additional volumes from the field. Production at Atapu started in June 2020 via the P-70 FPSO. The unit is in about 2000 m of water and has the capacity to produce 150,000 BOED. CNOOC Brings New Bohai Sea Discoveries On Stream CNOOC Limited has kicked off production from its Luda 5‑2 oil field North Phase I project and Kenli 6‑1 oil field 4‑1 Block development project. Luda 5‑2 is in the Liaodong Bay of Bohai Sea, with average water depth of about 32 m and utilizes a thermal recovery wellhead platform and production platform tied into the Suizhong 36‑1 oil field. A total of 28 development wells are planned, including 26 production wells and two water‑source wells. The project is expected to reach its peak production of 8,200 B/D of oil in 2024. Kenli 6‑1 is in the south of Bohai Sea, with average water depth of about 17 m. The resource is being developed by a wellhead platform in addition to fully utilizing the existing processing facilities of the Bozhong 34‑9 oil field. A total of 12 development wells are planned, including seven production wells and five water‑injection wells. The field is expected to reach its peak production of 4,000 B/D of oil later this year. CNOOC Limited is operator and sole owner of the Luda 5‑2 oil field North and the Kenli 6‑1 oil field 4‑1 Block. Stabroek Block Bounty Off Guyana Gets Bigger The partners in the prolific Stabroek Block have again increased the gross discovered recoverable resource estimate for the area offshore Guyana. The owners now believe they have discovered reserves of at least 11 billion BOE, up from the previous estimate of more than 10 billion BOE. The updated resource estimate includes three new discoveries on the block at Barreleye, Lukanani, and Patwa in addition to the Fangtooth and Lau Lau discoveries announced earlier this year. The Barreleye‑1 well encountered approximately 70 m of hydrocarbon‑bearing sandstone reservoirs of which 16 m is high‑quality oil‑bearing. The well was drilled in 1170 m of water and is located 32 km southeast of the Liza field. The Lukanani‑1 well encountered 35 m of hydrocarbon‑bearing sandstone reservoirs of which approximately 23 m is high‑quality oil‑ bearing. The well was drilled in water depth of 1240 m and is in the southeastern part of the block, approximately 3 km west of the Pluma discovery. The Patwa‑1 well encountered 33 m of hydrocarbon‑bearing sandstone reservoirs. The well was drilled in 1925 m of water and is located approximately 5 km northwest of the Cataback‑1 discovery. “These new discoveries further demonstrate the extraordinary resource density of the Stabroek Block and will underpin our queue of future development opportunities,” said John Hess, chief executive of Hess and a partner in Stabroek. The co‑venturers have sanctioned four developments to date on Stabroek with both Liza and Liza Phase 2 on stream. The third planned development at Payara is ahead of schedule and is now expected to come on line in late 2023; it will utilize the Prosperity FPSO with a production capacity of 220,000 BOPD. The fourth development, Yellowtail, is expected to come on line in 2025, utilizing the ONE GUYANA FPSO with a production capacity of 250,000 BOPD of oil. At least six FPSOs with a production capacity of more than 1 million gross BOPD are expected to be on line on the Stabroek Block in 2027, with the potential for up to ten FPSOs to develop gross discovered recoverable resources. The Stabroek Block is 6.6 million acres. ExxonMobil affiliate Esso Exploration and Production Guyana Limited is operator and holds 45% interest; Hess Guyana Exploration holds 30% interest; and CNOOC Petroleum Guyana Limited holds 25%. ConocoPhillips Gets Ekofisk License Extension Norway’s Ministry of Petroleum and Energy (MPE) has extended production licenses in the Greater Ekofisk Area from 2028 to 2048 with ConocoPhillips as operator. The company said the license extension provides long‑term operations and resource management aligned with the company’s long‑term perspective on the Norwegian continental shelf. Fields on the shelf are required to operate with a valid production license where the operator and licensees enter into an agreement with the authorities, including relevant field activities. The authorities may require commitments, leading to increased oil recovery. The existing production licenses 018, 018 B, and 275 in the Greater Ekofisk Area were set to expire on 31 December 2028; however, the MPE approved an extension through 2048. The new terms provide a potential for extending Ekofisk’s lifetime to nearly 80 years. The license partners are ConocoPhillips (operator, 35.11%), TotalEnergies EP Norge (39.896%), Vår Energi (12.388%), Equinor (7.604%), and Petoro (5%). BHP’s Wasabi Disappoints in US GOM Australian operator BHP encountered noncommercial hydrocarbons with its Wasabi‑2 well in the US Gulf of Mexico. BHP said the well in Green Canyon Block 124 was plugged and abandoned following the disappointing results. “This completes the Wasabi exploration program, with results under evaluation to determine next steps,” the company said. The well was targeting oil in an early Miocene reservoir. Transocean drillship Deepwater Invictus spudded the well in 764 m of water in November 2021. The previous Wasabi‑1 well had a mechanical problem and was plugged and abandoned 4 days earlier, prior to reaching its prospective targets. BHP operates Wasabi with a 75% interest. Lukoil Says Titonskaya Holds 150 Million BOE Russia’s Lukoil believes it has discovered around 150 million BOE following analysis of the two wells it drilled at the Titonskaya structure on the Caspian Sea shelf. Work is now underway to refine the seismic models of productive deposits and study deep samples of formation fluids. The results of the assessment will be submitted to the State Reserves Commission of the Russian Federation. The structure is in the central part of the Caspian Sea, not far from the Khazri field. Lukoil drilled the first well at the Titonskaya structure in 2020 and announced the new discovery in April 2021. According to that assessment, the probable geological resources of the Titonskaya are 130.4 million tons. In 2021, drilling of the second prospecting and appraisal well began to identify oil and gas deposits in the terrigenous‑carbonate deposits of the Jurassic‑ Cretaceous age. The well was drilled using the Neptune jackup drilling rig. The new find at Titonskaya will likely be tied into Khazri infrastructure. Petrobras’ Roncador IOR Project Comes On Line Petrobras has successfully started production from the first two wells of the improved oil recovery (IOR) project at the Roncador field in the Campos Basin offshore Brazil. The two wells are the first of a series of IOR wells to reach production. Startup is almost 5 months ahead of schedule and at half of the planned cost, according to partner Equinor. The wells will add a combined 20,000 BOED to Roncador, bringing daily production to around 150,000 bbl and reducing the carbon intensity (emissions per barrel produced) of the field. Through this first IOR project, the partnership will drill 18 wells that are expected to provide additional recoverable resources of 160 million bbl. Improvements in well design and the partners’ combined technological experience are the main drivers behind the 50% cost reduction across the first six wells, including the two in production. Roncador is Brazil’s fifth‑largest producing asset and has been in production since 1999. Petrobras operates the field and holds a 75% stake. In 2018, Equinor entered the project as a strategic partner with the remaining 25% interest. In addition to the planned 18 IOR wells, the partnership believes it can further improve recovery and aims to increase recoverable resources by a total of 1 billion BOE. The field has more than 10 billion BOE in place under a license lasting until 2052. The strategic alliance agreement also includes an energy‑efficiency and CO2‑emissions‑reduction program for Roncador. Gazania-1 To Spud Off South Africa Africa Energy will move ahead with its planned Gazania‑1 wildcat well offshore South Africa after securing partner Eco Atlantic’s $20 million in capital requirements for its portion of the probe. The well will be drilled in Block 2B. Island Drilling semisubmersible Island Innovator has been contracted for the work and is expected to mobilize from its current location in the North Sea for the 45‑day trip to South Africa. The Block 2B joint venture plans to spud the well by October with drilling expected to last 30 days, including a full set of logs if the well is successful. The block has significant contingent and prospective resources in relatively shallow water and contains the A‑J1 discovery that flowed light sweet crude oil to surface. Gazania‑1 will target two large prospects 7 km updip from A‑J1 in the same region as the recent Venus and Graff discoveries. Block 2B is located offshore South Africa in the Orange Basin where both TotalEnergies and Shell recently announced significant oil and gas discoveries offshore Namibia. The block covers 3062 km2 approximately 25 km off the west coast of South Africa near the border with Namibia in water depths ranging from 50 m to 200 m. The Southern Oil Exploration Corp. (Soekor) discovered and tested oil on Block 2B in 1988 with the A‑J1 borehole, which intersected thick reservoir sandstones between 2985 m and 3350 m. The well flowed 191 B/D of 36 °API oil from a 10‑m sandstone interval at around 3250 m. Africa Energy has a 27.5% interest in Block 2B offshore South Africa. The block is operated by a subsidiary of Eco Atlantic which holds a 50% interest. A subsidiary of Panoro Energy holds a 12.5% stake, and Crown Energy AB indirectly holds the remaining 10%. Brazil Grants New Exploration Blocks Brazil’s National Agency of Petroleum, Natural Gas, and Biofuels (ANP) has granted 59 exploratory blocks of oil and natural gas to 13 companies, including Shell, TotalEnergies, and 3R Petroleum. The awards were part of a permanent bid offer round held in Rio de Janiero in April. The auction totaled 422.4 million reais in signature bonuses with leases granted in six Brazilian states: Rio Grande do Norte, Alagoas, Bahia, Espírito Santo, Santa Catarina, and Paraná. The awards will result in investments of 406.3 million reais in the exploratory phase of the contracts. Shell Brazil (70%) was granted six blocks in the Santos Basin in a consortium with the Colombian Ecopetrol (30%). The blocks leases were SM‑1599, SM‑1601, SM‑1713, SM‑1817, SM‑1908, and SM‑1910. TotalEnergies won two areas in the same basin while Brazilian company 3R Petroleum received six areas in the Potiguar Basin. Petro‑Victory was also awarded 19 new blocks in Potiguar, increasing its holdings in Brazil to 38 blocks (37 in Potiguar). The new blocks are nearby Petro‑Victory infrastructure at the Andorinha, Alto Alegre, and Trapia oil fields. Eni Finds More Oil in Egypt’s Western Desert Eni struck new oil and gas reserves with a trio of discoveries in the Meleiha concessions of Egypt’s Western Desert. The finds have already been tied into existing infrastructure in the region and have added around 8,500 BOED to overall production from the area. The operator drilled the Nada E Deep 1X well, which encountered 60 m of net hydrocarbon pay in the Cretaceous‑Jurassic Alam El Bueib and Khatatba formations Meleiha SE Deep 1X well, which found 30 m of net hydrocarbon pay in the Cretaceous‑Jurassic sands of the Matruh Khatatba formations, and the Emry Deep 21 well, which encountered 35 m of net hydrocarbon pay in the massive cretaceous sandstones of Alam El Bueib. The results, added to the discoveries of 2021 for a total of eight exploration wells, give Eni a 75% success rate in the region. The company added that additional exploration activities in the concession are ongoing with “promising indications.” With these discoveries, Eni, through AGIBA, a joint venture between Eni and EGPC, continues to pursue its near‑field strategy in the mature basin of the Western Desert, aimed at maximizing production by containing development costs and minimizing time to market. Eni is planning a new high‑resolution 3D seismic survey in the Meleiha concession this year to investigate the gas potential of the area. Eni is currently the leading producer in Egypt with an equity production of around 360,000 BOED.

ExxonMobil, Partners Tout New Angola Block 15 Discovery ExxonMobil has made a new oil discovery with the Bavuca South-1 exploration well in Block 15 offshore Angola. The well is part of the Angola Block 15 redevelopment project targeting to deliver around 40,000 B/D of new oil production. According to ExxonMobil, the well encountered 30 m of hydrocarbon-bearing sandstone. The probe is located approximately 365 km northwest of Luanda and was drilled in 1100 m of water by the Valaris DS-9 rig. As the block’s operator, ExxonMobil is leading the installation of new technology and a multiyear drilling program aimed at adding new production volumes to help offset natural production declines. There have been 17 previous discoveries on Block 15: Hungo, Kissanje, Marimba, and Dikanza in 1998; Chocalho and Xikomba in 1999; Mondo, Saxi, and Batuque in 2000; Mbulumbumba, Vicango, and Mavacola in 2001; Reco Reco in 2002; and Clochas, Kakocha, Tchihumba, and Bavuca in 2003. ExxonMobil affiliate Esso Exploration Angola (Block 15) Limited is the operator of Block 15 and holds a 36% interest. BP Exploration (Angola) Limited holds 24%, ENI Angola Exploration BV holds 18%, Equinor Angola Block 15 AS holds 12%, and Sonangol P&P holds 10%. The National Agency for Petroleum, Gas, and Biofuels (ANPG) is the Block 15 concessionaire. Neptune Energy Begins Drilling Calypso Exploration Well Neptune Energy has spudded its Calypso exploration well 6407/88 S in the Norwegian Sea utilizing semisubmersible Deepsea Yantai. The Calypso prospect is located 14 km northwest of the Draugen field and 22 km northeast of the Njord A platform, within the Neptune-operated PL938 license. Calypso is positioned within one of Neptune’s core areas on the Norwegian Continental Shelf. In the event of a commercial discovery, Calypso could potentially be tied back to existing infrastructure. The reservoir target is the middle and lower Jurassic formations and is expected to be reached at a depth of approximately 2960 m. The drilling program comprises a main bore (6407/8-8 A) with an optional sidetrack (6407/8-8 S) based on the outcome of the exploration well. Neptune Energy operates the well with a 30% working interest. Partners include OKEA ASA, 30%; Pandion Energy AS, 20%; and Vår Energi ASA, 20%. Petrobras Strikes Oil Near Sepia Field Petrobras has a new oil find at its 4-BRSA-1386D-RJS (Pedunculo) well in the extreme northwest of the Sépia field in Brazil’s Santos Basin. The well spud in late July in a water depth of 2200 m, and the oil-bearing interval was verified by logs and fluid samples. According to Petrobras, the effective thickness of the oil column is one of the largest ever recorded in Brazil. The discovery is in the Sepia coparticipation area and comprises the Sepia block acquired by Petrobras (100%), and the Sépia-ECO block, which was acquired in December 2021 in the ANP’s second bidding round of surplus volumes. Petrobras (operator) was awarded Sépia-ECO along with partners TotalEnergies, QatarEnergy, and Petronas Petróleo Brasil Ltda., with Pré-Sal Petróleo SA as manager. The Sépia shared reservoir is currently producing 170,000 B/D. Petrobras also successfully completed the test at the pioneer well 1-BRSA-1381-SPS (Curaçao) in the pre-salt of the southwestern part of the Santos Basin. The new discovery is located 240 km from the city of Santos-SP, at a depth of 1905 m, in the Aram Block. The test evaluated a thick range of pre-salt carbonate reservoirs, in which it was possible to know its productivity through dynamic production data, according to Petrobras. During the test, oil samples were collected that will be characterized by laboratory analyses. The consortium will continue its activities in the Aram Block, aiming to evaluate the dimensions and commerciality of the new accumulation. The block was acquired in March 2020, in the sixth bidding round of the ANP, under the production-sharing regime, with Pré-Sal Petróleo SA as manager. Petrobras is the operator of the block (80% interest) in partnership with CNPC 20%. Shell, Murphy Eye Fresh Mexican Gulf Wildcats Shell is preparing to drill an exploration test in the Salina basin in offshore Mexico. According to Mexican hydrocarbons regulator CNH, the supermajor intends to spud the Jokol-1EXP wildcat in Block 28 starting in January 2023. The operator plans to use drillship Maersk Voyager for the work. The rig has been drilling the Zanderij-1 probe in Block 42 offshore Suriname and is expected to depart for Mexico soon. The Jokol-1EXP well is set to test a prospective light-oil reservoir at final depth of around 5586 m. The wellsite is roughly 40 km southwest of the Tamha-1EXP well. Meanwhile, Murphy Oil is drilling ahead on the deepwater Tulum-1EXP, where it hopes to tap 150 million BOE in reserves off the coast of Tabasco. The operator’s Mexican subsidiary, Murphy Sur, received authorization from CNH earlier this year. Murphy will use the Valaris DPS-5 semisubmersible to target lower Miocene and Oligocene formations and is drilling Tulum-1EXP as a deviated well to a depth of 5569 m. Tulum-1EXP is the second exploratory well of the Block 5 consortium led by Murphy Sur (40%), with partners PC Carigali Mexico Operations, Petronas’ Mexican subsidiary, and Wintershall Dea holding 30% each. Block 5 is in the center of the highly touted Salina Basin, a deepwater area in Mexico with significant hydrocarbon potential. CNOOC Has Certified Gas Find With Baodao 21-1 The proved gas-in-place of CNOOC’s Baodao 21-1 gas field has been certified at 50 billion m3 by the Chinese government. Baodao 21-1 gas field is in Baodao Sag, Qiongdongnan Basin, Western South China Sea in water depths ranging from 660 to 1570 m. The main gas-bearing zone is the Paleogene Lingshui formation, and the discovery is in condensate gas reservoirs. The discovery well Baodao 21-1 completed at a total depth of 5188 m, encountering 113 m of gas pay. The well is tested to produce an average of 587,000 m3 of natural gas per day. Baodao 21-1 is the first deepwater, deep-stratum large gas field in the South China Sea, realizing the biggest discovery in more than half a century in Songnan-Baodao Sag, according to CNOOC. ADNOC Sets Well-Length Record Abu Dhabi National Oil Company (ADNOC) said it set a new world record for the longest oil and gas well at its Upper Zakum Concession. Stretching 50,000 ft, the well is around 800 ft longer than the previous world record set in 2017. ADNOC Drilling drilled the well from Umm Al Anbar, one of ADNOC Offshore’s artificial islands. The extended-reach wells will tap into an undeveloped part of the giant Upper Zakum reservoir with the potential to increase the field’s production capacity by 15,000 B/D. Umm Al Anbar is one of Upper Zakum’s four artificial islands, serving as a hub for offshore drilling and operations. The producer added that its use of the artificial island concept has resulted in cost savings and environmental benefits compared to conventional approaches that traditionally require more offshore installations and infrastructure. New Tampen Area Wells Planned The Norwegian Petroleum Directorate issued to Equinor, Aker BP, and Var Energi a pair of drilling permits for exploration wells in the Tampen area of the Norwegian North Sea. The partnership has applied to drill the 34/6-6A wildcat in PL-554 using drilling rig Transocean Spitsbergen. The well is located to the northeast of the Visund field. Equinor will operate the well with a 40% working interest. Aker BP and Var Energi each hold a 30% stake. The second probe, 34/6-6S, was also permitted by the same partnership in the same license. Petronas Strengthens Partnership With TotalEnergies and Shell Through New PSC Petronas has signed a production-sharing contract (PSC) with TotalEnergies EP Malaysia, Petronas Carigali Sdn Bhd (PCSB), Sabah Shell Petroleum Company Limited (SSPC), and Shell Sabah Selatan Sdn Bhd (SSS) for Block 2K, an ultradeepwater block located off the coast of Sabah. Block SB 2K, with depths up to 3000 m, covering 1952 km2, is in the northwest ultradeepwater area within a proven hydrocarbon basin. Under the PSC terms, TotalEnergies will be the operator with a 34.9% participating interest. PCSB holds a 40% participating interest while the remaining 25.1% is equally split between the other two partners, SSPC and SSS. The signing of the PSC for Block 2K completes the licensing of the five ultradeepwater blocks off the coast of Sabah, along the newly identified Oligo-Miocene carbonate trend proven by Tepat-1 oil discovery in Block N in 2018. Block 2V was signed last year followed by Blocks 2W and X early this year. A total of four wells are expected to be drilled in these blocks in 2022 and 2023.

»My name is Boye, I dig carins and old mounds«The archaeologist Vilhelm Christian BoyeThe story of Vilhelm Boye is the history of one man’s passionate and insightful involvement in archaeology, which from the first was directed solely towards the Bronze Age. His involvement led to an academic disaster in his youth, but left behind it a developed skill in field archaeology. Despite his problems he persisted with what most obsessed him, namely the preservation of Denmark’s oak coffin graves. His multi-facetted personality and his more popular approach to archaeology may have challenged his contemporaries, and certainly contributed to his more or less deliberate exclusion from a permanent appointment at the Museum of Northern Antiquities in Copenhagen. Even though he was opposed by powerful people within the Copenhagen museum establishment for nearly twenty years, he had the natural facility of easily winning the trust of others. This enabled him to cope with the situation and turn it to his advantage wherever he found himself. His marriage to Mimi Drachmann brought a welcome stability to his life, but his lack of professional recognition and his exclusion from a place at the top of archaeology continued. Time was running out for Boye, but he managed to leave an impressive body of published work behind him.Vilhelm Christian Boye was the son of the Norwegian-born priest and writer of hymns Caspar Johannes Boye. In 1848 his father was moved to the garrison church in Copenhagen, where the family lived at 29 Bredgade until his father’s death from cholera in 1853. This was a fashionable part of town, its residents including both the composer Niels W. Gade and Professor Adam Oehlenschläger, and even more notably J.J.A. Worsaae lived in the same property as the Boye family from 1850 to 1852. It was probably through his neighbour Worsaae that Boye later became a member of the circle around C.J. Thomsen. We may therefore assume that Boye visited and spent many after-school hours at the Museum of Northern Antiquities, and soon became an assistant during the public tours.Early in the 1840s tension arose between Worsaae and Thomsen, because Thomsen did not want to make Worsaae a junior museum inspector. Worsaae had not hitherto received any stipend or official position, and with some justice felt himself hard done by. Thomsen however did not respond to his request, so he left the Museum, later to be made Director for the Preservation of Ancient monuments. At the same time he taught at Copenhagen University, where Boye from time to time came to his lectures. There is no doubt that Boye wanted an academic career, and presumably hoped that his involvement with the Museum of Northern Antiquities would allow him to complete a study of Scandinavian archaeology. In the meantime Boye studied at the Museum under the direction of both Thomsen and Herbst.In early October 1857 Boye undertook one of his first excavations of a Bronze Age mound, the so-called Loholm barrow at Snørumnedre Mark (fig. 1). The dating of the grave however caused problems for him, but through a comparative study of Bronze Age burial rituals he concluded that the grave had close parallels within this period.The following year three funerary urns and some bronze objects were found in Hullehøj barrow, near Kjeldbymagle on the island of Møn. The barrow was going to be blown up, but the local judge had the work stopped and sent Boye to lead the excavation in May 1859. As the excavation progressed, Boye was able to ascertain that there were both cremations and inhumations in one and the same barrow. The inhumations were surrounded by fist-sized stones and placed at the bottom of the barrow, the cremations higher up within the mound. In comparison with his earlier barrow excavations it is worth noting Boye’s stratigraphic observations, which for the first time supported the division of the Bronze Age into an earlier and a later section. This hypothesis had been suggested earlier, but not hitherto adequately demonstrated. In 1859 Boye published the results of his excavations of 1857-8, as well as those of his recently completed excavation of Aasehøj barrow at Raklev, in the periodical Annaler for Nordisk Oldkyndighed og Historie for 1858. This article is his first independent scientific publication, and should have attracted greater attention than it in fact did. In modern perspective the article is a perfectly competent archaeological publication, in which Boye solely through field observations reaches the conclusion that the Bronze Age could be divided into two periods, each with its own burial ritual. Even though Boye had been close to understanding why both cremations and inhumations occurred in the same barrow as early as 1857, he did not reach his final understanding this early. In November 1857 Worsaae had in fact given lectures at the university in which he suggested a division of the Bronze Age, but it is noteworthy that he had not earlier published any or all of his conclusions. His work on the subdivision of the Stone Age was probably more important to Worsaae, while the subdivision of the Bronze Age was more of a footnote, a natural outgrowth of the idea that there was continuous development from one stage to the next. Boye’s article in Annaler thus inevitably supported Worsaae’s hypothesis, although this was presumably not the intention. On the contrary, Boye merely intended to publish his own conclusions. Boye cannot therefore be said to be the sole originator of the subdivision of the Bronze Age, but apart his barrow investigations there was nobody else who reached the same conclusion at the time independently of Worsaae.In 1860 Boye took part in the first major bog excavations, at Vimose and then at Thorsbjerg with Engelhardt. Despite adverse circumstances and appalling weather, the Thorsbjerg excavations produced several important finds including Roman coins, a gilt breastplate, and also a very unusual face mask of silver with gilt (fig. 2). Although Engelhardt did not publish the full excavation report until 1863-69, Boye presented his observations in Annaler as early as 1860, where he discussed earlier interpretations of the many weapons found in bogs. Boye observed that the universal destruction of these weapons did not happen by chance, but was deliberate. Furthermore, the weapons lay in groups of one type, and the shields were pierced by spear points to pin them to the bottom of the bog. Boye’s interpretation of the finds was thus remarkably accurate, because he regarded them as votive offerings of the spoils of war.When Prussian and Austrian troops crossed the Ejder River on 1st February 1864, Boye volunteered within the month and was promoted to lance corporal (fig. 3). In May he was landed to take part in the defence of the island of Als along with the other Danish forces. On his return home in August Boye continued his work at the Museum of Northern Antiquities, but Thomsen’s health was failing, and after a long illness he died on 21st May 1865. The question of who was to succeed Thomsen had long been discussed, and it was indeed Worsaae who was appointed. Although Herbst had been groomed for the job by Thomsen, he found himself outmanouevred. Boye probably already knew by then that he would not be given a position at the Museum. Herbst, his confidant, could no longer help him, and Thomsen’s awareness of his archaeological skills was of no use either. Circumstances thus forced Boye to leave the Museum.Boye’s relationship with the family friend and poet H.C. Andersen resulted in the latter recommending Boye in December 1867 as a Danish tutor to the Brandt family in Amsterdam (fig. 4). On Wednesday 22nd January 1868 Boye departed for Amsterdam via Kiel. During his stay Boye wrote regularly to Andersen, who also travelled to Amsterdam to visit him. His stay in Amsterdam was evidently good for Boye, and contributed to the fact that he never lost his love for archaeology. As early as late August of the same year, Boye travelled to southern Halland in Sweden at the request of Ritmester Peter von Möller, to examine and excavate a large group of barrows known as the Ätterhögar on the Drömmestrup estate, the excavation of which was concluded in early July 1869. Boye thus returned home just in time to take part as a member of the Danish Committee in the International Congress of Archaeology and Anthropology that was held in Copenhagen from 25th August to 5th September. But his love of Schleswig and the old borderland called him, and soon Boye moved permanently to Haderslev to work as a freelance writer on the daily paper Dannevirke under the editorship of H.R. Hiort-Lorenzen.His coverage of the International Congress of Archaeology and Anthropology meeting in Copenhagen is the most extensive of Boye’s writings in Dannevirke. He also wrote a series of articles with a marked archaeological-ethnographic content, for example on the antiquities of Brazil, and the discovery of ­Australia.Although Boye supported himself as a writer for Dannevirke, his main occupation seems rather to have been the investigation of the burial mounds of Schleswig, which before 1864 had only been intermittently examined by amateurs. Boye began an extensive programme, and without his efforts and initiative, knowledge of many Schleswig barrows would have been lost. Although the information he recorded was not particularly satisfactory, in that it was mostly based on the memory of local people, his efforts should be seen as a precursor, because the work of protection went slowly at the time. In his search for lost information, in 1875 Boye considered the barrow at Dybvadgård north of Åbenrå, which had been partially excavated by Prince Carl of Prussia in 1864. During the excavations the Prince’s soldiers found an oak coffin, which was despatched to the Museum für Völkerkunde in Berlin. Boye therefore wrote direct to the Prince, who in reply sent a photograph and description of the coffin. During the next eight years Boye managed to accumulate a great deal of information about the barrows of Schleswig, but his work was not without risk, because several of his “missions” involved evading the Prussian authorities and their power to confiscate the antiquities which Boye from time to time illegally sent to the Museum in Copenhagen.In 1874 the Principal of Herlufsholm School, C. Hall, engaged Vilhelm Boye to organise the school’s collection of antiquities, which had been in store for nearly twenty years. In addition to this reorganisation, funds were also made available for the systematic excavation of a nearby barrow at Grimstrup (fig. 5). The barrow however contained very little, mainly urns full of cremated bone, but the excavation was thoroughly recorded and a series of drawings was produced by R. Bertelsen, the school’s teacher of drawing. After this Boye set to work to display the collection in the six cases that were made available. The greater part of the collection came from the Stone Age, filling no fewer than five cases, giving an impression both of coastal finds from shell middens, and grave finds. The Bronze Age display contained only a few bronzes, but rather more pots. Iron Age artifacts were hardly represented at all, and consisted mostly of whetstones, a bowl-shaped buckle, and a pot burnt black.In November of the same year Boye was working at Herlufsholm, he produced his remarkable work Vejledning til Udgravning af Oldsager og deres foreløbige Behandling [Guide to the Excavation of Antiquities and their Initial Study], published under the auspices of the Society for the Historical-Antiquarian Collection in Århus. Boye’s Guide is the first of its type, and one can clearly detect his close association with Herbst, who had contributed to the scientific content of the work.Boye’s link with the antiquarian collection in Århus had not come about by chance. During his time at the Museum of Northern Antiquities he had early on made contact with the person mainly responsible for the establishment of the Århus collection, Edvard Erslev. Boye joined the museum in 1871, re-arranged the collection, and produced a guide for visitors. For the first time the museum acquired a new and professional look. Boye thus functioned as part of the leadership until 1876, when he gave up his museum post in favour of the schoolteacher Emmerik Høegh-Guldberg. The continued problems facing Dannevirke and Hiort-Lorenzen’s mounting confrontation with the judicial authorities in Flensborg probably caused Boye to consider his position with the newspaper. This culminated with the expulsion of Hiort-Lorenzen, who then took up the post of chief editor of Nationaltidende in Copenhagen. Boye also travelled to Copenhagen in early 1878, and on 15th November the year after he married Mimi Drachmann, sister of the poet Holger Drachmann (fig. 6 ). Not suprisingly, Boye got a job at the Nationaltidende, where he edited the newspaper’s Archaeological and Ethnographic Communications until 1885. In the seven years Boye worked at the paper, no fewer than 150 numbers of the Communications appeared, Boye writing more than 400 pages of them himself. The articles include a multiplicity of archaeological and ethnographic topics such as “Egypt’s Ancient Cultures” and “A Copper Age in Scandinavia”.In 1882 Count Emil Frijs of Frijsenborg commissioned Boye to catalogue and organise his estate’s collection of prehistoric and medieval objects, which came from the area round the lake and castle ruin at Søborg in northern Zealand. Attempts had been made to drain the lake since 1793, and several antiquities had been found at various times during the work. The recording project culminated in the publication of a small book, Fund af Gjenstande fra Oldtiden og Middelalderen i og ved Søborg Sø [Finds of Objects from the Prehistoric and Medieval Periods in and around Søborg Lake], which among other things contains some of the first photographic illustrations of Danish antiquities (fig. 7).Worsaae’s death in 1885 inaugurated a new era, and Herbst was finally able to take over the post of head of the Museum (fig. 8). Boye’s long friendship with Herbst had in the previous years resulted in him becoming a regional inspector for the Museum. Herbst was probably even then considering Boye for a future post in the Museum, and was indicating that he himself could not be overlooked when it became time to nominate a successor to Worsaae. After his appointment to the Museum of Northern Antiquities in 1885, Boye continued his activities as inspector in northern Zealand, and was frequently called when new finds were recovered from Bronze Age barrows.In contrast to Herbst, Boye rapidly fell in with the group of younger workers, particularly Henry Petersen (fig. 9). Over the years they became close friends with a common interest in new finds, as during the excavation of Guldhøj in 1891. Boye had no draftsman at the excavation, but he did have a local photographer who recorded some aspects of the opening of the first oak coffin. These are the first photographs ever to be taken during an excavation, even though photography by then was nothing new (fig. 10).With the reorganising of the National Museum, Boye was made senior assistant of the historical section on 1st April 1892, under Henry Petersen. He was responsible for the Museum’s archive and library, but fieldwork and travels are what particularly characterise his work in these years. When the small Bronze Age barrow on which the Glavendrup rune stone had been erected in 1864 was nearly completely destroyed by ploughing, Boye undertook a restoration of the barrow itself and the associated ship-shaped arrangement of stones in 1892 (fig. 11). The restoration’s outcome was the construction of a new barrow on which was placed the rune stone, and the re-erection of the stones in the ship arrangement.At the same time, chamberlain A. Oxholm undertook a small excavation of the Bronze Age barrow at Tårnholm, and recovered an oak coffin containing the remains of a woman, a fine necklace, a belt plate, and a small bronze dagger. Boye was immediately informed, and in connection with his investigations at Tårnborg was able to go to Tårnholm and lead a new excavation of the barrow, in which A.P. Madsen was also involved, and recover two more oak coffins (fig. 12).If we now consider Boye’s last major work, the publication of the major volume Fund af Egekister fra Bronzealderen i Danmark [Finds of Oak Coffins from the Danish Bronze Age], there are several indications that suggest that Boye began the work with the early intention that its coverage should be wide, and contain his long-term investigations into and knowledge of the country’s oak coffin graves. It is particularly noteworthy that his work as an archaeological journalist and with the Archaeological and Ethnographic Communications seems to have been a kind of precursor to this, as the last chapters contain sections that are clearly derived from his contributions to the Communications. The manuscript was completed in April 1896, and A.P. Madsen prepared for it no fewer than 27 full-page folio sized copperplates. The work was dedicated to “the veterans of Danish archaeology”, C.F. Herbst the museum director, and Japetus Steenstrup, with whom Boye had first collaborated more recently.His many years of a wandering existence and work-related disruptions had however told on him, and soon after the book was published Boye became ill. From his private correspondence from 1896 it emerges that Boye often had insufficient time to be with his nearest and dearest. Despite his illness he travelled one last time to visit relatives at Viken, but his illness worsened and he had to travel rapidly to Lund and on to Copenhagen. Boye died on 22nd September apparently as the result of a stroke, and was buried in Søllerød churchyard north of Copenhagen.Boye’s potential as a researcher was noticed early on by Thomsen, but just as quickly suppressed by Worsaae, who may more or less deliberately have sought to out-manoeuvre his colleague. Boye’s character and energy may have seemed a threat, and although he never finished an academic education he nevertheless displayed a remarkable archaeological acuity, but was unable to bolster his own reputation. Some of the blame for this must rest with the Museum’s aged leaders, who never supported or developed Boye’s evident skills to any great extent. It must also be stressed that some of Boye’s earlier career problems are closely connected to the lack of vision and jealousy of these same leaders. When he departed for Amsterdam Boye had no expectation of a Museum post, but despite this he intelligently kept up his contacts with Copenhagen, particularly with Herbst, knowing full well that Worsaae’s leadership would one day end. This somewhat bold presumption turned out to be correct, and helped his archaeological career.There is no doubt that Boye in his later years tried hard to recover his lost reputation and save his career from the disaster it suffered when he was younger, but the price was high and it also affected his health. We must today recognise that his reputation was restored to the highest level, and we must thank him for the fact that, through him, a uniquely detailed knowledge of the Bronze Age people themselves was preserved for Danish archaeology, as well as of their most prominent contribution to the Danish landscape: the barrows.Anders Otte StensagerInstitut for forhistorisk arkæologiKøbenhavns UniversitetTranslated by Peter Rowley-Conwy

AbstractInterference fit couplings between a perforated finite plate and a round pin are widely used mechanical systems in several industrial applications. Only a few works in the literature investigate the coupling contact pressure due to interference in the absence of an external load, and these works are limited to a few specific configurations. To overcome this limitation, this work performs a numerical systematic investigation of the pin-plate coupling for a wide range of configurations that can be encountered in practice. Three are the variables investigated: the pin diameter, the plate length, and the pin offset in the longitudinal direction, all of them normalized over plate width, for a total of 18 configurations. The work provides a detailed prediction of the contact pressure and equivalent von Mises stress along the contact surface and compares the results with photoelastic investigations retrieved from the literature. For design purposes, the results are synthesized through two stress concentration factors, one referring to the peak contact pressure, and the second one to the peak von Mises stress.

Abstract Liquid-based battery thermal management system (BTMS) is commonly applied to commercial electric vehicles (EVs). Current research on the liquid cooling structure of prismatic batteries is generally focused on microchannel cooling plates, while studies on the discrete tubes are limited. In this paper, a parallel liquid cooling structure based on heat-conducting plates and cooling tubes is proposed, with computational fluid dynamics used to investigate the cooling performance of the structure. Two different optimization schemes are then put forward, and the effects of the coolant inlet velocity and temperature on the thermal management performance of the optimized structures are explored. Compared with the previous series structures for the same battery module, the parallel structure can significantly reduce the pressure drop and the flow resistance loss. The gradient structures increasing the parallel round tube inner diameters were able to reduce the pressure drop, while the heat transfer was slightly enhanced. Changing the contact mode between the heat-conducting plates and the square cooling tubes could effectively improve the temperature uniformity of the battery module, particularly for structures with no contact between the lower region of the first plate and the cooling square tube. Based on the gradual increase in the inner diameter of the round tubes, the structure of breaking the contact between the lower region of the first plate and the cooling square tube was able to reduce the maximum temperature difference in the battery module within 3 °C by 41.12% and the pressure drop by 26.28% compared with the original structure.

AbstractMicrobubbles have potential applications as drug and gene carriers, and drug release can be triggered by externally applied ultrasound irradiation while inside blood vessels. Desorption of molecules forming the microbubble shell can be observed under ultrasound irradiation of a single isolated microbubble, and the volume of desorbed molecules can be quantitatively estimated from the contact angle between the bubble and a glass plate. Microbubbles composed of a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) shell and a poorly-soluble gas are created. When the microbubbles are exposed to a pulsed ultrasound, the contact angles increase dramatically; the percentage of DMPC molecules desorbed from the bubble surface reaches 70%. Vibration of a single bubble in the radial direction is measured using a laser Doppler vibrometer. The relationship between the vibrational characteristics and the amount of molecular desorption reveals that a larger vibrational amplitude of the bubble around the resonance size induces a larger amount of molecular desorption. These results support the possibility of controlling molecular desorption with pulsed ultrasound.

AbstractThe importance of the subchondral bone plate of the acetabulum when preparing the pelvis for a cemented acetabular cup during total hip arthroplasty (THA) has been investigated using finite element analysis. The effect of retaining or removing the subchondral bone plate and the use of anchoring holes are compared. Loading was applied via both hip joint contact force and the activity of up to 22 muscles at five stages through the load bearing phase of the gait cycle. Removing the subchondral bone plate leads to decreased stresses in the cancellous bone and slightly increased stresses in the cortical shell superior to the acetabulum. The differences between the two cases are small, nevertheless there are indications that removal of the subchondral bone plate reduces the stresses. Increasing the cement penetration depth leads to a slightly more rigid structure, due to cement penetrating the cancellous bone. Adding anchoring holes moves the position of the highest cancellous bone strains from the bone-cement interface into the cancellous bone. Thus removal of the subchondral bone plate should lead to an increased potential for cement penetration into the cancellous bone which should be beneficial for cup fixation and thus improve long term implant survival.

AbstractSeismic structural fuses such as buckling restrained braces (BRBs) are highly nonlinear members that need a detailed finite element model (FEM) to represent their actual behavior. On the other hand, making detailed model for the whole building from solid or shell elements to be consistent with the model of BRBs would require expensive computational time and large storage space especially when performing nonlinear time history analysis (NTHA). Therefore, a mixed FEM is developed in this research so that the solid elements are used for the core plate and the restraining system only. The non-yielding segments of the BRBs and the conjoined girders and columns are simulated using beam elements with nonlinear material properties while the effect of large deformations is taken during analysis and this was able to represent plastic hinge formation, plastic rotations and residual displacements in such members. A beam-solid transfer mechanism is developed to properly transfer forces between the non-yielding segments of BRB and the inner solid plate. The core plate is connected to the surrounding restraining system with contact elements to simulate the normal and frictional forces generated upon contact based on the penalty algorithm. This model was validated using the data and the results of an experimental work mentioned in the literature where very good agreement was achieved. Thereafter, a rehabilitation study for the SAC 9-storey building was performed. The results showed how the BRBs work as structural fuses during earthquakes and confirmed the ability of the model to represent inelastic behavior of multi-story BRBFs.

Abstract To fully investigate the polishing performance of the Fe3O4@SiO2 core-shell abrasive for TC4 titanium alloy plate and solve the problem of uneven distribution of abrasive particles in magnetic compound fluid polishing (MCFP) and obtain ultra-smooth titanium alloy surface. In this paper, the functional Fe3O4@SiO2 core-shell abrasives were prepared and characterized by XRD, FTIR, VSM and TEM to demonstrate the successful encapsulation of SiO2 in Fe3O4 first. Second, a new polishing device was built to perform polishing experiments. Four different fractions of Magnetic compound fluid (MCF) were configured and utilized in polishing experiments for MCFP of TC4 titanium alloy to verify the polishing properties. Finally, the contact model between abrasive particles and workpiece is established and the material removal mechanism is discussed. The results show that SiO2 was successfully coated on Fe3O4. The polishing results show that the MCF containing the core-shell structure had the best polishing effect. The surface roughness Ra decreased from 0.201μm to 0.025μm after 20 min of polishing. The surface roughness of TC4 titanium alloy with an initial roughness Sa of 0.248μm is reduced to 0.023μm after polishing by Fe3O4@SiO2 core-shell abrasive. It is shown that the application of core-shell abrasive to process titanium alloys can obtain smooth and defect-free surfaces with good polishing performance. The surface quality of titanium alloy can be improved effectively by using core-shell abrasive, and a new idea for polishing titanium alloy is proposed. This study plays an important role in solving the problem of uneven particle distribution in MCFP. These results pave the way for further research into the application of core-shell abrasives in precision machining and expand the application scope of particles with core-shell structure.

Abstract Traditional bump foil bearing, though widely used, is considered to have the problem of inadequate load capacity due to the effect of foil sag between adjacent bumps. In this paper, the thick top foil is applied to cope with the heavy load conditions, which has one order of magnitude larger top foil thickness than traditional top foil. Thick plate and curve shell models are developed to calculate the load carrying performance of thick top foil bearing based on contact mechanics, and the sag ratio is introduced to describe the degree of foil sag and estimate the bearing load capacity. The impacts of top foil thickness on the stiffness of bearings in different sizes as well on the adaptability to rotor tilt are discussed. The results indicate that the thick top foil (tt=2mm) bearing performs a nearly 100% enhanced load capacity at small gas film thickness whether rotor tilts or not. Thick top foil will increase the bearing stiffness of small size (d=35 mm) and tends to has little influence on large size bearing stiffness (d=70 mm).

Majority of braking systems work on the principle of dissipation of kinetic energy to heatenergy. This method has its own drawbacks and must be replaced with a more reliable brakingsystem that is quick in response, doesn’t heat up and is maintenance free. In this project thedesign of an electro-magnetic braking system and optimization for various operationalparameters has been done and the advantage of using the electromagnetic braking system inautomobile is studied. These parameters have been previously iterated in cited projects andpapers and also in the simulation models and are to be cross-checked with the experimentalsetup. An Electromagnetic Braking system uses Magnetic force to engage the brake, but thepower required for braking is transmitted manually. The wheel is connected to a shaft and theelectromagnet braking unit is attached to one side of the wheel. Here the braking unit consistsof a hollow circular steel plate and a stator which has 3 spokes made of iron wounded withcopper wire (or) magnetic wire. Here the round steel plate which is attached to the wheel rotateswhen wheel rotates with the help of motor. when current is supplied to the stator the spokes getmagnetized and creates a magnetic field which tries to attract or oppose the motion of rotatingcircular plate with the help of magnetic field created. In these brakes there is no contact betweenthe electro-magnetic coils and rotating circular plate (i.e 2mm gap between coil and circularplate) so this is also called as contactless braking system which is a main advantage in usingthese brakes. In this these brakes can be incorporated in heavy vehicles as an auxiliary brake.