Academic literature on the topic 'Air drop testing device'
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Journal articles on the topic "Air drop testing device"
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Palmiste, Ülar, Tauno Meier, Jarek Kurnitski, and Hendrik Voll. "Experimental testing of exterior wall mounted mechanical ventilation exhaust air outlet devices." E3S Web of Conferences 246 (2021): 02001. http://dx.doi.org/10.1051/e3sconf/202124602001.
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The purpose of the study was to experimentally test the performance of four types of wall-mounted mechanical ventilation exhaust air outlet devices. A full-scale mock-up of a segment of an external wall with an exhaust air outlet was constructed. The tested exhaust air devices include a gravity louver, fixed-blade louver, louver plate, and exhaust nozzle. The performance assessment included two types of experiments over the exhaust airflow rate range of 25–94 l/s at isothermal conditions with no influencing wind: (i) the particle tracer method with smoke to visualize the exhaust air jets from the outlets, and (ii) the tracer gas method to measure the dilution of CO2 concentration in the exhaust air jet. Furthermore, the aerodynamic performance was comparatively evaluated in terms of pressure drop and exhaust air face velocity at the outlet. The qualitative comparison of airflow patterns by smoke visualization showed notable differences between the tested device types. Concentration decrease evaluation indicated that the exhaust air pollutants are more efficiently transported away from the building wall by exhaust outlets that discharge at 0–45 degrees downwards from the horizontal plane. Discharge angles 60–90 degrees downwards produced a wall-attached jet and the pollutant tracer concentration remained relatively high in the vicinity of the wall.
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Kruk, I. S., Yu V. Chigarev, and V. Romanyuk. "Determination of kinematic parameters of falling drops of standard solution of pesticides during spraying, taking into account geometric dimensions variability." Proceedings of the National Academy of Sciences of Belarus. Agrarian Series 58, no. 3 (August 4, 2020): 352–63. http://dx.doi.org/10.29235/1817-7204-2020-58-3-352-363.
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Expansion of range of applied pesticides and liquid mineral fertilizers necessitates continuous improvement of spray nozzle design, allowing to create a monodisperse spray and ensure high-quality application of chemical agents at low doses and minimal losses. The issue of studying the process of falling drops with varying geometric dimensions remains sore. Studies of drop movement in air environment make it possible to determine the falling speed and coordinates on the treated surface, to substantiate the design, dimensions, optimal operating modes and parameters of sprayers and devices for protecting the spray cone from direct exposure to wind, which is especially important at the design stage of sprayer for field spraying machines. The paper presents simulation of process of falling drops of pesticide standard solution in resisting environment, considering geometric dimensions variability. An equation for drop radius variability depending on the unit motion horizontal transverse variability, formula for variability of intensity of drop decrease depending on the initial conditions and state of environment are obtained. Dependence between coefficients of drop displacement along the horizontal transverse to the unit movement axis and time is obtained, expressions for variability of drop radius depending on the horizontal displacement and the equation for variability of velocity and vertical coordinate of drop movement on time are presented. The coefficient of mass transfer from the drop surface is determined depending on the resistance coefficient, initial velocity, medium density at the border of drop and plant medium subjected to treatment. The results obtained can be used in mechanical engineering for design and testing of sprayers and nozzles, design of wind protection devices for spray cones of standard solutions of pesticides in field sprayers, in simulation of process of drop movement with varying mass.
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Yuan, Guo Zheng, Xia Chen, and Xue Feng Shu. "Failure Analysis of the Solder Joints in Flip-Chip BGA Packages under Free-Drop Test." Advanced Materials Research 936 (June 2014): 628–32. http://dx.doi.org/10.4028/www.scientific.net/amr.936.628.
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The failure of plastic ball grid array under intense dynamic loading was studied in the project. This paper presents the drop test reliability results of SnPb flip-chip on a standard JEDEC drop reliability test board. The failure mode and mechanism of planar array package in the drop test was comprehensively analyzed. High acceleration dropping test method was used to research the reliability of BGA (ball grid array) packages during the free-drop impact process. The model RS-DP-03A drop device was used to simulate the falling behavior of BGA chip packages under the real conditions, The drop condition meets the JEDEC22-B111 standards (pulse peak 1500g, pulse duration 0.5 ms) when dropping from the 650mm height . In the testing, according to the real-time changes of dynamic voltage, the relationship between drop times and different phases of package failure was analyzed. With the dye-penetrated method and optical microscopy, it was easy to observe the internal crack and failure locations. The growth mechanism of the cracks in solder joints under the condition of drop-free was analyzed and discussed.
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Shikani, Alan H., Elamin M. Elamin, and Andrew C. Miller. "The Shikani HME: A New Tracheostomy Heat and Moisture Exchanger." Journal of Speech, Language, and Hearing Research 63, no. 9 (September 15, 2020): 2921–29. http://dx.doi.org/10.1044/2020_jslhr-19-00107.
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Purpose Tracheostomy patients face many adversities including loss of phonation and essential airway functions including air filtering, warming, and humidification. Heat and moisture exchangers (HMEs) facilitate humidification and filtering of inspired air. The Shikani HME (S-HME) is a novel turbulent airflow HME that may be used in-line with the Shikani Speaking Valve (SSV), allowing for uniquely preserved phonation during humidification. The aims of this study were to (a) compare the airflow resistance ( R airflow ) and humidification efficiency of the S-HME and the Mallinckrodt Tracheolife II tracheostomy HME (M-HME) when dry (time zero) and wet (after 24 hr) and (b) determine if in-line application of the S-HME with a tracheostomy speaking valve significantly increases R airflow over a tracheostomy speaking valve alone (whether SSV or Passy Muir Valve [PMV]). Method A prospective observational ex vivo study was conducted using a pneumotachometer lung simulation unit to measure airflow ( Q ) amplitude and R airflow , as indicated by a pressure drop ( P Drop ) across the device (S-HME, M-HME, SSV + S-HME, and PMV). Additionally, P Drop was studied for the S-HME and M-HME when dry at time zero (T 0 ) and after 24 hr of moisture testing (T 24 ) at Q of 0.5, 1, and 1.5 L/s. Results R airflow was significantly less for the S-HME than M-HME (T 0 and T 24 ). R airflow of the SSV + S-HME in series did not significant increase R airflow over the SSV or PMV alone. Moisture loss efficiency trended toward greater efficiency for the S-HME; however, the difference was not statistically significant. Conclusions The turbulent flow S-HME provides heat and moisture exchange with similar or greater efficacy than the widely used laminar airflow M-HME, but with significantly lower resistance. The S-HME also allows the innovative advantage of in-line use with the SSV, hence allowing concurrent humidification and phonation during application, without having to manipulate either device.
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Gorobey, V. P., V. Y. Moskalevich, and Z. A. Godzhaev. "Device Substantiation for Generating Artificial Rain Drops by Pneumohydraulic Liquid Spraying." Agricultural Machinery and Technologies 15, no. 2 (June 23, 2021): 53–60. http://dx.doi.org/10.22314/2073-7599-2021-15-2-53-60.
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The authors studied the pneumohydraulic device indicators for spraying liquids for irrigation, nutrition and protection of agricultural plants, taking into account the principles of water and energy conservation, based on preliminary gas saturation of sprayed water and the use of a cavitation effect in the design of the aerator unit during ejection and supply of air under pressure. (Research purpose) To determine the technological parameters of a pneumohydraulic device for spraying liquids to obtain controlled dispersive artificial rain and substantiate the choice of its optimal technical parameters depending on the operating modes. (Materials and methods) The authors used an algorithm for calculating parameters in EXCEL or WPS spreadsheet processor and mathematical expressions. (Results and discussion) The authors theoretically determined the minimum and maximum calculated parameters of the constructive solution geometry for spraying the liquid phase: water nozzle, air nozzle channel, mixing cell, middle annular gap, outlet nozzle. They changed indicators of operating water pressure – 0.20; 0.25; 0.30 and 0.35 megapascals; air – 0.25 and 0.30 megapascals, provided the water flow rate from 0.002 to 0.010 liter per second and air – from 0.0005 to 0.0090 kilogram per second. With an increase in the water flow rate within the specified limits and the ejection coefficient from 0.5 to 0.9, a linear increase in the average annular gap diameter from 2 to 15 millimetres was revealed, as well as a nonlinear dependence of the increase in the sprayer mixing cell diameter from 5 to 20 millimetres. The authors showed the possibility of reducing the mixing cell diameter if the water pressure was increased from 0.25 to 0.35 megapascal's and the air pressure was from 0.20 to 0.30 megapascals. They obtained the parameters values for the designed and experimental samples development, which turned out to be significantly less than when operating in the air ejection mode: the outlet nozzle and the middle annular gap – by 16 percent, the air nozzle – by 23, the diameter of the mixing cell – by 50 percent or more. (Conclusions) The authors obtained calculated data to optimize technological parameters and design solutions, which would speed up the manufacture of designed and model samples of the device and its experimental testing for the generation of dispersive artificial rain drops.
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Gradetsky, V. G., M. M. Knyazkov, E. A. Semenov, and A. N. Sukhanov. "Dynamic Processes in Vacuum Contact Devices of Robots for Vertical Motion in the Water Environment." Mekhatronika, Avtomatizatsiya, Upravlenie 20, no. 7 (July 4, 2019): 417–21. http://dx.doi.org/10.17587/mau.20.417-421.
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The results of experimental investigation intended to improve movement conditions for pneumatic robots on vertical surfaces under water are discussed. Features of the movement of vacuum contact devices for the simulation of mathematical model of the vacuum contact device with surfaces under water are presented. The experimental studies made it possible to obtain additional data on the dynamics of attachment, to obtain transient processes for air-water flow through ejector and to correct the results obtained earlier. For the purpose of analytical study of dynamic processes occurring in the system of vacuum contact devices, and taking into account the complexity of the description of nonlinearities, linearized simplified models of the system "air ejector — contact device — water environment" were developed. Vacuum contact devices are designed to provide guaranteed contact with vertical surfaces, plane slopes or horizontal surfaces on which the underwater robot performs its movement, carrying out the prescribed technological tasks, for example, in dry wells of nuclear power plants, on the surfaces of ship hulls, on the surfaces of underwater structures. The models took into account the forces of adhesion to the surfaces under water — the forces from the pressure drop, the friction force, the contact and vacuum interaction, the elasticity of suction caps. As a result of the solution of the model problem, the values of mechanical parameters, as well as the values of vacuum and flow in the cavity of variable volume as functions of changing the gap between the end of the corrugated membrane and the surfaces are obtained explicitly. As a result of the study of dynamic processes occurring in simplified models of vacuum contact devices "air ejector — contact surface — water environment", the transient characteristics of the change in the operating forces and pressures over time, as well as the dependence of the normal and tangential components of the forces on the depth of immersion in water were obtained. The variants of the designs of vacuum contact devices with surfaces in the water environment are investigated, and the modernization of the laboratory test bench for testing vacuum contact devices under water is carried out.
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Cordes, A. Laura, B. Tim Pychynski, C. Corina Schwitzke, D. Hans-Jörg Bauer, A. Thiago P. de Carvalho, and B. Hervé P. Morvan. "Experimental study of the pressure loss in aero-engine air-oil separators." Aeronautical Journal 121, no. 1242 (June 21, 2017): 1147–61. http://dx.doi.org/10.1017/aer.2017.41.
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ABSTRACTThe results of extensive experimental testing of an aero-engine air-oil separator are presented and discussed. The study focuses on the pressure loss of the system. Oil enters the device in the form of dispersed droplets. Subsequently, separation occurs by centrifuging larger droplets towards the outer walls and by film formation at the inner surface of a rotating porous material, namely an open-cell metal foam. The work described here is part of a study led jointly by the Karlsruhe Institute of Technology (KIT) and the University of Nottingham (UNott) within a recent EU project.The goal of the research is to increase the separation efficiency to mitigate oil consumption and emissions, while keeping the pressure loss as low as possible. The aim is to determine the influencing factors on pressure loss and separation efficiency. With this knowledge, a correlation can eventually be derived. Experiments were conducted for three different separator configurations, one without a metal foam and two with metal foams of different pore sizes. For each configuration, a variety of engine-like conditions of air mass flow rate, rotational speed and droplet size was investigated. The experimental results were used to validate and improve the numerical modelling.Results for the pressure drop and its dependencies on air mass flow rate and the rotational speed were analysed. It is shown that the swirling flow and the dissipation of angular momentum are the most important contributors to the pressure drop, besides the losses due to friction and dissipation caused by the flow passing the metal foam. It was found that the ratio of the rotor speed and the tangential velocity of the fluid is an important parameter to describe the influence of rotation on the pressure loss. Contrary to expectations, the pressure loss is not necessarily increased with a metal foam installed.
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Amaluddin, Fitroh, and Andy Haryoko. "ANALISA SENSOR SUHU DAN TEKANAN UDARA TERHADAP KETINGGIAN AIR LAUT BERBASIS MIKROKONTROLER." Antivirus : Jurnal Ilmiah Teknik Informatika 13, no. 2 (November 30, 2019): 98–104. http://dx.doi.org/10.35457/antivirus.v13i2.843.
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Tsunamis are natural events that can occur any time without prior warning. Some mitigation efforts both through physical construction consist of sea wave height detection sensors such as DT-Sense Barometric Pressure & Temperature sensors, Infrared sensors, and ultrasonic sensors. However, the sensors have a low accuration and difficult installation. Therefore a device designed to provide temperature and air pressure data based on a microcontroller with higher accuracy, and easier installation. The device are made using a DS18B20 temperature sensor, then air pressure using BMP180 sensor. Sea wave height measurement system based on the working principle of air pressure at sea level. This tool is able to work well at altitudes with a minimum temperature of 25 degrees Celsius. Based on the results of air trials on water levels obtained every 0.1 meter increase in sea air, air pressure increases by 0.02 mb (millibar) or 0.12 mb / meter. While testing the air pressure against the temperature obtained is higher, the air temperature at sea level will increase. Each time the air pressure changes by 1.00 mb, the air temperature at sea level will change an average of around 0.46 degrees Celsius. In other words if the temperature decreases around 1 degree Celsius, then the air pressure also drops by 2.00 mb or around 16.67 meters.
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Alexander, A. Michel, and Richard W. Haskins. "New Field System for Measuring Degree of Consolidation of Concrete During Vibration." Transportation Research Record: Journal of the Transportation Research Board 1574, no. 1 (January 1997): 116–22. http://dx.doi.org/10.3141/1574-16.
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Significant progress has been made in the development of a field prototype device for slipform pavers to measure the degree of consolidation of concrete during vibration. The device operates on the principle that since air is an insulator and fresh concrete is a conductor, electrical impedance measurements can indicate the release of air during the consolidation of fresh concrete. When the air is released from the fresh concrete through the process of vibration, the electrical impedance of the concrete drops in value. The device, which is based on the impedance bridge, is portable, battery-powered, noise resistant, and easy to operate. Fresh concrete has been found to be equivalent to an RC (resistor and capacitor in parallel) circuit in terms of its electrical response. Limited tests indicate that the entrapped air is released at a faster rate than entrained air, creating two distinct parts to the AC-resistance curve against time of vibration. The intersection of these two curves represents the point at which consolidation is complete. The system has a 0- to 15-V analog meter to indicate that point of completion. Project constraints did not permit the research to be completed by testing its performance on a slipform paver. However, the likelihood of commercialization has been augmented since a prototype and specifications now exist for a portable field meter.
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Bakar, Noor Haznida, Koay Mei Hyie, A. Jumahat, Eli Nadia A. Latip, Anizah Kalam, and Z. Salleh. "Influence of Different Matrices on the Tensile and Impact Properties of Treated Kenaf Composites." Advanced Materials Research 1133 (January 2016): 136–40. http://dx.doi.org/10.4028/www.scientific.net/amr.1133.136.
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This study investigated the mechanical behavior of the treated and untreated kenaf with different matrix resin (epoxy and polyester) using the tensile and low velocity test. The long kenaf fibre was treated with 6% of sodium hydroxide (NaOH) solution for twelve hours in room temperature. The tensile properties of composites at different weight percentage (10,15,20 and 25%) were studied by using Instron Universal Testing Machine according to the standard ASTM D638. Impact test was conducted using an instrumented drop tower device at 10J incident energy level according to the standard ASTM D3763. The results of the study indicated that the epoxy resin reinforced with treated kenaf fibre exhibited higher tensile properties. On the other hand, the impact properties of polyester resin reinforced with treated kenaf fibre show better matrix bonding compared to those with epoxy resin matrices.
Dissertations / Theses on the topic "Air drop testing device"
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Chadima, Bedřich. "Návrh shozové laboratoře pro testy balistických záchranných systémů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232089.
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This thesis is focussed on designing of the air drop labradory for testing the balistic recovery systems. The first part of the thesis describes balistic recovery systems, their parts as well as methods of testing this devices. In the second charter there is a description of older vision of a testing device and simple test with the electronics of the testing device. The next step is designing of the new koncept of testing device and the structure analysis of the frame. The product of the thesis is a modular automated testing device, which is able to test balistic recovery systems for aicrafts with the weights between 230 and 1700 kilograms.
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Bizzarri, Didier. "Compact air separation system for space launcher." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210488.
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A compact air separator demonstrator based on centrifugally enhanced distillation has been studied. The full size device is meant to be used on board of a Two Stage To Orbit vehicle launcher. The air separation system must be able to extract oxygen in highly concentrated liquid form (LEA, Liquid Enriched Air) from atmospheric air. The LEA is stored before being used in a subsequent rocket propulsion phase by the second stage of the launcher. Two reference vehicles are defined, one with a subsonic first stage and one with a supersonic first stage. In both cases, oxygen collection is performed during a cruise phase (M 0.7 and M 2.5 respectively). The aim of the project is to demonstrate the feasibility of the air separation system, investigate the separation cycle design, and assess that the separator design selected is suitable for the reference vehicles.The project is described from original base ideas to design, construction, extended testing and analysis of experimental results. Preliminary computations for a realistic layout have been performed and the motivations for the choices made during the process are explained. Test rig design, separator design and technical discussion are provided for a subscale pilot unit. Mass transport parameters and flooding limits have been estimated and experimentally measured. Performance has been assessed and shown to be sufficient for the reference Two Stage To Orbit vehicles. The technology developed is found suitable without further optimization, although some volume and mass reduction would be desirable for the supersonic first stage concept. There are many ways of optimisation that can be further investigated. The aim of this program, however, is not to fully optimize the device, but to demonstrate that a device based on a simple, robust, low-risk design is already suitable for the launch vehicles. On top of that analysis, directions for improvements are suggested and their potentials estimated. A complete assessment of those improvements requires further maturation of the technological concept through further testing and practical implementations.
Directions for future work, general conclusions and a vehicle development roadmap have also been provided.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Books on the topic "Air drop testing device"
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Mulroy, William J. Evaluation of a standard device for calibrating calorimeter test rooms. Gaithersburg, MD: U.S. Dept. of Commerce, National Bureau of Standards, 1986.
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Mulroy, William J. Evaluation of a standard device for calibrating calorimeter test rooms. Gaithersburg, MD: U.S. Dept. of Commerce, National Bureau of Standards, 1986.
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Branch, Ontario Water Resources. The design and testing of a large propeller driven aeration device for reservoir use. [Toronto?]: Queen's Printer, 1991.
Find full textBook chapters on the topic "Air drop testing device"
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Herkersdorf, Andreas, Michael Engel, Michael Glaß, Jörg Henkel, Veit B. Kleeberger, Johannes M. Kühn, Peter Marwedel, et al. "RAP Model—Enabling Cross-Layer Analysis and Optimization for System-on-Chip Resilience." In Dependable Embedded Systems, 1–27. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-52017-5_1.
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AbstractThe Resilience Articulation Point (RAP) model aims to provision a probabilistic fault abstraction and error propagation concept for various forms of variability related faults in deep sub-micron CMOS technologies at the semiconductor material or device levels. RAP assumes that each of such physical faults will eventually manifest as a single- or multi-bit binary signal inversion or out-of-specification delay in a signal transition between bit values. When probabilistic error functions for specific fault origins are known at the bit or signal level, knowledge about the unit of design and its environment allow the transformation of the bit-related error functions into characteristic higher layer representations, such as error functions for data words, finite state machine (FSM) states, IP macro-interfaces, or software variables. Thus, design concerns can be investigated at higher abstraction layers without the necessity to further consider the full details of lower levels of design. This chapter introduces the ideas of RAP based on examples of particle strike, noise and voltage drop induced bit errors in SRAM cells. Furthermore, we show by different examples how probabilistic bit flips are systematically abstracted and propagated towards instruction and data vulnerability at MPSoC architecture level, and how RAP can be applied for dynamic testing and application-level optimizations in an autonomous robot scenario.
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Rehding, Alexander. "Opelt’s Siren and the Technologies of Musical Hearing." In Testing Hearing, 131–58. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780197511121.003.0006.
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Friedrich Wilhelm Opelt (1794–1863) proposed a revolutionary music theory based on the recursive features of human hearing. Opelt based his theory on a recent invention, Charles Cagniard de la Tour’s mechanical siren (1819), which he expanded and improved. Cagniard’s model consists of a metal disk with holes in regular intervals that, when set in rotation and with air blown through them, produce a series of air puffs. Once their pulsation increases above 20Hz, this pulse is heard as a continuous, rising pitch. Opelt employed this device to test the properties of hearing against the parameters of music: he noted that more complex patterns of holes translate into intervals, chords, and harmonies and showed that every pitch event can be translated into a corresponding rhythmic event. Pitch and rhythm may be different perceptual parameters, but physically, they are both temporal events, which merely inhabit different dimensions of the time axis.
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Tena Sánchez, Rubén, Lars Jacob Foged, and Manuel Sierra Castañer. "EMC Measurement Setup Based on Near-Field Multiprobe System." In Electromagnetic Compatibility [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99604.
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Multiprobe spherical near-field measurement is a potent tool for fast and accurate characterization of electrical properties of antennas. The use of fast switching in one axis, an azimuth positioner, and a near- to far-field transformation allows a substantial time reduction in antenna measurements while maintaining high-quality results. On the other hand, conventional emissions EMC measurement systems are typically based on detecting the radiated spurious emissions by a device at different frequencies. The systems usually work in far-field (or quasi-far-field conditions), performing the measurements either at 3 or 10 meters. Measurements under these conditions take space and time. Moreover, the systems are not cost-effective for pre-compliance purposes where pre-testing of the device should provide valuable information and confidence about the DUT before performing a compliance test. This chapter analyzes the possibility of cost and space reduction for EMC systems based on multiprobe near-field measurement systems in combination with OTA (over the air measurements), reference-less systems, spherical near-field transformation, phase reconstruction, modal filtering, source reconstruction, and software-defined radio receivers.
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Hilt, Robert, and Alison Leary. "Asthma and Cystic Fibrosis." In Cognitive and Behavioral Abnormalities of Pediatric Diseases. Oxford University Press, 2010. http://dx.doi.org/10.1093/oso/9780195342680.003.0059.
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Asthma and cystic fibrosis (CF) are examples of childhood pulmonary illnesses with significant psychological impacts. These disorders have in common an induced difficulty with a primal drive, the drive to breathe. Acute impairment with the drive to breathe is highly anxiety provoking, and chronic impairment is life-altering. Pulmonary illnesses like asthma and CF can have direct impacts on brain functioning through systemic hypoxia (low blood oxygen [O2] level) or hypercapnia (high blood carbon dioxide [CO2] level) due to poor respiratory gas exchange. With chronic respiratory problems in children, hypoxia is the more clinically pertinent issue in that hypoxia seems to produce developmental impacts. Studies that have looked at the outcomes of pulmonary hypoxia have found associations with adverse effects even from oxygen levels that were just slightly below the normal range (Bass et al. 2004). A drop of only 4% O2 saturation from baseline is associated with attentiondeficit hyperactivity (ADHD)-like symptoms. Persistent oxygen saturation levels that are even lower than this have been associated with decreased IQ and delays in motor development (Bass et al. 2004). Negative neurobehavioral effects of the hypercapnia side of impaired respiratory status are less well documented. In fact, hypercapnia, besides triggering an increase in cerebral blood flow and driving a sense of air hunger particularly in people with trait anxiety, seems to have no lasting neurocognitive impact (Wan et al. 2008). Research on the use of intentional ‘‘permissive’’ hypercapnia when using mechanical ventilation assistance (allowing higher blood carbon dioxide levels to minimize barotrauma from the assist device) has shown no common neurocognitive complications from this strategy. There are even suggestions of some improved neurocognitive outcomes for neonates managed in this manner (Miller and Carlo 2007). These results are tempered by a higher reported frequency of intraventricular hemorrhage in hypercapnic very-low-birth-weight infants, and there is at least one case report of subarachnoid hemorrhage in a child ventilated with permissive hypercapnia for an asthma episode (Edmunds and Harrison 2003; Kaiser et al. 2006). The severe hypercapnia of complete respiratory failure goes hand in hand with hypoxia, so the effects of each in that potentially fatal scenario are difficult to separate.
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Chilinski, Bogumil, and Anna Mackojc. "Proposal of the Coupled Thermomechanical Model of a Crank Mechanism." In Advances in Transdisciplinary Engineering. IOS Press, 2020. http://dx.doi.org/10.3233/atde200098.
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The aim of the paper is to propose analytical coupled thermomechanical model of the crankshaft system, which includes the mutual interaction between thermodynamic and mechanical phenomena occurring in engines. The most relevant dynamic effects observable in the crank system are connected with its kinematics. When the mechanism operates there are also additional effects corresponding with stress, strain and thermal fields. Elastic properties of the system parts and changeable stiffness of the fuel-air mixture cause different dynamics of the entire device. The authors assumed that rigid motion of the crank mechanism, parts deformation and thermodynamic effects and their mutual dependencies will be included in the modelling process. Elasticity of the crankshaft system components is the reason for the difference between a rigid ’ideal’ motion and the real movement of crankshaft elements. In most cases, it is enough to assume linear elastic material features based on the relatively high stiffness of the system preventing big deformations. This ensures small displacements and the correctness of the applied model. The performed investigations have shown an influence of the crank system flexibility on the overall device response. Moreover, the parameters that change due to thermodynamic and mechanical properties of the working medium were taken into account. The authors have applied simple engine cycles (Otto, Diesel or combined model) for determining engine load including the connection between mechanical and thermodynamic state variables. This caused another decrease of the total system stiffness. Further numerical testing proved a visible effect of the applied approach in the global system response. The main discrepancies are observable in natural frequencies and vibration modes. It can also be stated that the utilization of different engine cycles results in different engine features. The paper is concluded with an analysis of the existing systems and mutual reactions from the assumed phenomena. The authors have shown the necessity to take a transdisciplinary approach into account in order to model complex systems.
Conference papers on the topic "Air drop testing device"
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Chan, Mark Aaron, Christopher R. Yap, and Kim Choon Ng. "Modeling and Testing of an Integrated Evaporator-Condenser Device for CPU Cooling." In ASME 2008 Heat Transfer Summer Conference collocated with the Fluids Engineering, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/ht2008-56187.
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CPUs with high clock rates can dramatically increase heat dissipation within their encapsulation due to internal Joule heat from the transistors. The conventionally used air cooling systems for CPUs, such as the aluminum or copper extruded heat sink types, have severe heat transfer “bottlenecks” due to high thermal resistances and they easily reach their thermal design limits (TDL). Alternative cooling devices such as heat pipes and liquid cooling tends to have externally attached radiator/condenser and/or pump and such designs are cumbersome. This paper describes the modeling, design, and testing of a compact (about the size of the Intel stock cooler, diameter: 96mm, height: 50mm), fully integrated, orientation-free, evaporator-condenser device for CPU cooling, with excellent attributes of low thermal resistance from phase change phenomena and minimal vapor pressure drop. The prototype fabricated is designed to reject 200 W (twice the capacity of conventional heat sinks). It is made of copper and uses distilled water as the working fluid. The working fluid boils inside a porous structure clad evaporator and is transported radially to nearby air-cooled condenser sections; this unique arrangement minimizes space while providing adequate area for air convection. Testing was done by subjecting it to varying heat loads and air flow rates. A best performance of 0.206 K/W of the device’s thermal resistance was achieved at a fan air flow rate of 34.5 CFM under 203 W of cooling load, and moreover, these results are in good agreement with the simulation. Further improvement of the current design could yield significantly better performance as the device has yet to reach its full potential, especially with regard to the design of its air-cooled curvilinear fins and boiling enhancement.
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TeGrotenhuis, Ward E., and Victoria S. Stenkamp. "Testing of a Microchannel Partial Condenser and Phase Separator in Reduced Gravity." In ASME 2003 1st International Conference on Microchannels and Minichannels. ASMEDC, 2003. http://dx.doi.org/10.1115/icmm2003-1089.
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Heat exchange has been successfully integrated with microchannel phase separation concepts to produce devices capable of simultaneous partial condensation and phase separation in reduced gravity. An air-cooled microchannel condenser has been tested on NASA’s KC-135 reduced gravity aircraft. The condenser was fed a mixture of air and water vapor at 70–95°C, which was cooled to below 40°C thereby generating water condensate. The condensate was successfully collected and removed as a separate stream over a range of operating conditions, thereby achieving simultaneous condensation and phase separation. Ambient air was used to cool in cross-flow with inches of water pressure drop. The microchannel device is presented along with an explanation of the principles of operation. Phase separation effectiveness and heat exchanger performance are reported for reduced gravity testing. Heat fluxes, effectiveness, and overall heat transfer coefficients are reported.
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Nezym, Vitaliy Yu. "Use of Turning Additional Blades in Compressor Rotor." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68069.
Full textAbstract:
An application of tip devices in the form of turning (adjustable) tip additional blades is rather effective means of influence on compressor performance due to change of fluid conditions in the region of rotating blade tips. The paper presents main results of tests of turning tip additional blades of two types. Firstly tip elements of rotating blades were substituted for turning tip additional blades at full length of the blade chord projection. While testing of these “large” additional blades with variable stagger angles, a significant shift of rotor performance curve to lower values of flow coefficients was observed, but this positive effect was accompanied by a great rotor peak efficiency drop. Then the similar turning tip additional blades were arranged only in the inlet part of rotating blades (“short” additional blades). Testing was done under condition of variable stagger angles in common with change of axial clearance between blade elements. As a result of these two parameters combination, maximum extension of stable operating range was found. And the important fact is that the rotor efficiency drop was relatively small after sharpening the inlet edges of the succeeding elements of rotating blades.
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ZINKEVIČIUS, Remigijus, and Sigitas ČEKANAUSKAS. "TESTING THE QUALITY OF SPRAYING FLUID BY USING VARIOUS NOZZLES IN SPECIAL DEVICES LECHLER DROPLEGUL." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.187.
Full textAbstract:
A variety of devices that help to prevent drops of spayed pesticides from getting into places that are difficult to reach (e. g. under the leaves of cultural plants of on the stem), is offered. Special devices Lechler DroplegUL are designed in a way that nozzles that are embedded in the end of the spraying pipe which is bended backwards, spray diagonally upwards. Data of the quality of spraying fluid by using various sprinklers in special devices Lechler DroplegUL is provided in the article. Two hydraulic flood nozzles Lechler 684.356.30X, mounted in a special holder TwinSprayCap were examined: pneumohydraulic twin flat spray air-injector nozzle Lechler DF 120-03 and hydraulic twin flat spray nozzle Lechler DF 120-02. A transverse repartition and a process of the formation of fluid drops, sprayed using different nozzles were examined. The results revealed that while spraying with a lower working pressure (e.g. 1.5 bar) with two hydraulic flood nozzles Lechler 684.356.30X that are placed in a special holder TwinSprayCap and embedded on a device Lechler DroplegUL, a majority of drops (evenly around 40 ml) get into stand trays that are in a setting place situated 70–110 cm behind the device Lechler DroplegUL, whereas at the approximate 40 cm area away from the setting place there are no drops of sprayed fluid at all. Having the working pressure increased to 3–4 bar, majority of drops (around 60 ml) get into the stend trays that are in a setting place situated 70–110 cm behind the device Lechler DroplegUL. Having the working pressure increased, an unsprayed area, which is situated around the setting place of the device Lechler DroplegUL, gets narrowed: a width of unsprayed area when spraying at the pressure of 2 bar was around 60 cm, whereas when the pressure was 3 bar and 4 bar, the area appeared to be only 20 cm. Circularly sprayed drops, depending on the working pressure, spread around in two strips of width from 1.4 to 1.8 m. An oblong flat flow of the sprayed fluid forms nearby the deflector and the maximum height of the rise of sprayed drops reaches 1.3–1.4 m.
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Weiland, Nathan T., Todd G. Sidwell, and Peter A. Strakey. "Testing of a Hydrogen Dilute Diffusion Array Injector at Gas Turbine Conditions." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46596.
Full textAbstract:
The U.S. Department of Energy’s Turbines Program is developing advanced technology for high-hydrogen gas turbines to enable integration of carbon sequestration technology into coal-gasifying power plants. Program goals include aggressive reductions in gas turbine NOx emissions: less than 2 ppmv NOx at 15% oxygen and 1750 K firing temperature. The approach explored in this work involves nitrogen dilution of hydrogen diffusion flames, which avoids problems with premixing hydrogen at gas turbine pressures and temperatures. Thermal NOx emissions are partially reduced through peak flame temperature control provided by nitrogen dilution, while further reductions are attained by minimizing flame size and residence time. The injector design includes high-velocity coaxial air injection from lobes surrounding the central fuel tube in each of the 48 array units. This configuration strikes a balance between stability and ignition performance, combustor pressure drop, and flame residence time. Array injector test conditions in the optically accessible Low Emissions Combustor Test & Research (LECTR) facility include air preheat temperatures of 500 K, combustor pressures of 4, 8 and 16 atm, equivalence ratios of 0.3 to 0.7, and three hydrogen/nitrogen fuel blend ratios. Test results show that NOx emissions increase with pressure and decrease with increasing fuel and air jet velocities, as expected. The magnitude of these emissions changes deviate from expected NOx scaling relationships, however, due to active combustor cooling and array spacing effects. At 16 atm and 1750 K firing temperature, the lowest NOx emissions obtained is 4.4 ppmv at 15% O2 equivalent (3.0 ppmv if diluent nitrogen is not considered), with a corresponding pressure drop of 7.7%. While these results demonstrate that nitrogen dilution in combination with high strain rates provides a reliable solution to low NOx hydrogen combustion at gas turbine conditions, the injector’s performance can still be improved significantly through suggested design changes.
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Muley, Arun, and Bengt Sunde´n. "Advances in Recuperator Technology for Gas Turbine Systems." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-43294.
Full textAbstract:
For high-speed micro gas turbine plants for electrical power and heat generation, a recuperator is needed to obtain a high thermal efficiency. The recuperator receives heat from the exhaust gas and preheats the compressor discharge air before it enters the combustion chamber. Such plants contribute to an ecological and environmentally friendly energy production. This paper considers recent advances in recuperator technology. Recent investigations have shown that with prime surfaces like corrugated wavy channels ones, it would be possible to attain high heat exchanger effectiveness without added weight penalty. However, with efficient heat transfer surfaces, the inlet/outlet manifolds design also become more important for the overall performance of the recuperator. Usually customers require recuperator with high effectiveness and low total pressure drop (within certain design requirements). Also, a request on compactness is commonly at hand. All these matters make recuperator an interesting and challenging device for thermal science investigation. A brief introduction and literature review is presented followed by discussion of recuperator thermal-hydraulic performance modeling and testing. Also surface selection procedure to achieve good balance between heat transfer and pressure drop is described. Other important topics such as material aspect and fabrication methods are also delineated.
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David, Milnes P., Tarun Khurana, Carlos Hidrovo, Beth L. Pruitt, and Kenneth E. Goodson. "Vapor-Venting, Micromachined Heat Exchanger for Electronics Cooling." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42553.
Full textAbstract:
The increasing complexity of modern integrated circuits and need for high-heat flux removal with low junction temperatures motivates research in a wide variety of cooling and refrigeration technologies. Two-phase liquid cooling is especially attractive due to high efficiency and low thermal resistances. While two-phase microfluidic cooling offers important benefits in required flow rate and pump size, there are substantial challenges related to flow stability and effective superheating. This work investigates the use of hydrophobic membrane to locally vent the vapor phase in microfluidic heat exchangers. Previous work has demonstrated selective venting of gas in microstructures and we extend this concept to two-phase heat exchangers. This paper details the design, fabrication and preliminary testing of the novel heat exchanger. Proof-of-concept of the device, carried out using an isothermal air-water mixture, found the air-mass venting efficiency exceeding 95%. Two-phase, thermal operation of the heat exchanger found the pressure-drop to be smaller compared to a two-phase, non-venting model. The paper also includes a discussion of design challenges such as membrane leakage and optical inaccessibility. The favorable results demonstrated in this first-generation, vapor-venting, micromachined, heat exchanger motivates further study of this and other novel microstructures aimed at mitigating the negative effects of phase-change. With continued research and optimization, we believe two-phase cooling is a viable solution for high heat flux generating electronics.
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Hashim, Hafiz M., Baris Dogruoz, Mehmet Arik, and Murat Parlak. "An Investigation Into Performance Characteristics of an Axial Flow Fan Using CFD for Electronic Devices." In ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ipack2015-48024.
Full textAbstract:
Rotating fans are widely utilized in thermal management applications and their accurate characterization has recently become even a more critical issue for thermofluids engineers. The present study investigates the characterization of an axial fan computationally and experimentally. Using the three-dimensional CAD models of the fan, a series of computational fluid dynamics (CFD) simulations were performed to determine the flow and pressure fields produced by the axial mover over a range of flow rates. In order to validate the computational model findings, experiments were conducted to obtain the pressure drop values at different flow rates in an AMCA (Air Movement and Control Association) standard 210-99, 1999 wind tunnel. These data sets were also compared with the fan vendor’s published testing data. A reasonably good agreement was obtained among the data from these three separate sources. Furthermore, an attempt was made to understand the overall fan efficiency as a function of the volumetric flow rate. It was determined that the maximum overall fan efficiency was less than 27% correlating well with the computational results.
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Combs, Matthew J., S. Manian Ramkumar, and Satish Kandlikar. "Thermal Conductivity Performance Modeling and Characterization of a Novel Anisotropic Conductive Adhesive Used in Lead-Free Electronics Packaging." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89672.
Full textAbstract:
The continued desire to utilize an alternative to lead-based solder materials for electrical interconnections has led to significant research interest in Anisotropic Conductive Adhesives (ACAs). The use of ACAs in electrical connections creates bonds using a combination of metal particles and epoxies to replace solder. The novel ACA discussed in this paper allows for bonds to be created through aligning columns of conductive particles along the Z-axis. These columns are formed by the application of a magnetic field, during the curing process. The benefit of this novel ACA is that it does not require precise printing of the adhesive on pads and also enables the mass curing without creating shorts in the circuitry. This paper will present the findings of the thermal conductivity performance tests using the novel ACA and its applicability as a thermal interface material and for assembling bottom termination components, power devices, etc. The columns that act as electrical conduction paths also contribute towards the thermal conductivity. The thermal conductivity of the novel ACA was measured utilizing a system that is similar to that in ASTM (American Society of Testing Materials) D5470 standard. The goal was to examine the influence of Bond Line Thickness (BLT), particle loading densities, particle diameters and adhesive matrix curing conditions on the electrical and thermal performance of the novel ACA. This paper will also present a numerical model to describe the thermal behavior of the novel ACA. The novel ACA’s applicability for PCB-level assembly has also been successfully demonstrated by RIT, including base material characterization, effect of process parameters, failures, and long-term reliability. Reliability testing included the investigation of the assembly performance in temperature and humidity aging, thermal aging, air-to-air thermal cycling, and drop testing.
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Gorelchenko, Petr, Bin Zhang, and Guangli Hu. "Cover glass behavior in handheld device drop: modeling; validation and design evaluation." In 2016 IEEE Accelerated Stress Testing & Reliability Conference (ASTR). IEEE, 2016. http://dx.doi.org/10.1109/astr.2016.7762266.
Full textReports on the topic "Air drop testing device"
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Baral, Aniruddha, Jeffrey Roesler, M. Ley, Shinhyu Kang, Loren Emerson, Zane Lloyd, Braden Boyd, and Marllon Cook. High-volume Fly Ash Concrete for Pavements Findings: Volume 1. Illinois Center for Transportation, September 2021. http://dx.doi.org/10.36501/0197-9191/21-030.
Full textAbstract:
High-volume fly ash concrete (HVFAC) has improved durability and sustainability properties at a lower cost than conventional concrete, but its early-age properties like strength gain, setting time, and air entrainment can present challenges for application to concrete pavements. This research report helps with the implementation of HVFAC for pavement applications by providing guidelines for HVFAC mix design, testing protocols, and new tools for better quality control of HVFAC properties. Calorimeter tests were performed to evaluate the effects of fly ash sources, cement–fly ash interactions, chemical admixtures, and limestone replacement on the setting times and hydration reaction of HVFAC. To better target the initial air-entraining agent dosage for HVFAC, a calibration curve between air-entraining dosage for achieving 6% air content and fly ash foam index test has been developed. Further, a digital foam index test was developed to make this test more consistent across different labs and operators. For a more rapid prediction of hardened HVFAC properties, such as compressive strength, resistivity, and diffusion coefficient, an oxide-based particle model was developed. An HVFAC field test section was also constructed to demonstrate the implementation of a noncontact ultrasonic device for determining the final set time and ideal time to initiate saw cutting. Additionally, a maturity method was successfully implemented that estimates the in-place compressive strength of HVFAC through wireless thermal sensors. An HVFAC mix design procedure using the tools developed in this project such as the calorimeter test, foam index test, and particle-based model was proposed to assist engineers in implementing HVFAC pavements.