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The thermodynamic simulation model for the performance of a 4-stroke, direct-injection (DI), variable compression ratio (rc), diesel engine, previously developed by the authors [1], is used to investigate the effect of varying compression ratio (rc) on engine brake power and torque and engine soot and NOx emissions. An optimization analysis is conducted to an engine with specifications similar to HELWAAN M114 under normal operating conditions to seek optimum rc variation to achieve some specific targets. For constant maximum brake power or constant minimum soot emission, the analysis shows an enormous increase in maximum cylinder pressure inside the variable rc engine reaching about 19.8 MPa compared to 10.7 MPa for constant rc engine, which means difficult practical applicability. For constant maximum brake torque, the optimized variation of rc lies within the range of 16.4 to 19.3.

This paper describes the thermal management and design challenges of testing packaged integrated circuit (IC) devices, specifically device thermal conditioning and device-under-test (DUT) temperature control. The approach taken is to discuss the individual thermal design issues as defined by the device type (e.g. memory, microcontroller) and tester capabilities. The influence of performance-parameter specifications, such as the DUT parallelism, test time, index time, test-temperature range and test-temperature tolerance are examined. An understanding of these performance requirements and design constraints enables consideration of existing test handler thermal processing systems (e.g., gravity feed, pick and place), future test handler thermal concepts, and future high-parallelism testing needs for high-wattage memory and microprocessor devices. New thermal designs in several of these areas are described.

Two alternative methods are currently under evaluation by the Department of Energy to handle high-level nuclear wastes: deep storage at Yucca Mountain and particle induced transmutation, typically utilizing neutrons via a proton accelerator-target facility [1]. While the transmutation approach is favored in that the net radioactivity is reduced in the process, the great expense involved in an accelerator facility forces consideration of the more economical storage approach. Consequently, alternative methods to carry out transmutation treatment are being sought. One novel alternative method involves an electrolytic process initially investigated by J. Patterson [2]. Other studies have also demonstrated the possibility of utilizing related electrolytic methods for conducting radioactive amelioration [3]. However, before a complete evaluation is possible, additional research is necessary to verify and optimize these previous experiments.

Hydrogen generation by water electrolysis was carried out using solar cells. As the electrolyte, sulfuric acid solution was used. As a reference, a single electrolyte cell of solid polymer membrane was used too. Mono- and poly-crystalline silicon solar cells were employed. The output of solar cells was connected to the electrolytic electrodes directly. The conversion efficiency of solar energy to generated hydrogen energy was evaluated. The hydrogen production for one year was estimated on the base of measured data of solar radiation, and the effect of reduction of CO2 production by exchanging fossil fuels (LPG and Town gas) with hydrogen was evaluated.

A characteristic of any electric or thermal storage technology is that it is easy to qualitatively describe the benefits, but it is very difficult to quantify the benefit and how a storage system should be best operated since operation is both site specific and requires forecasts of future electric, heating or cooling demand. Ice storage has the advantage of being able to absorb or release heat at a constant temperature of 32 F by using the abundant mass of water as the storage medium. There is no comparable substance that is available for constant temperature storage of space heat. Thus heat storage is typically done much less effectively by sensible heating or cooling of water. Thus, storing cold is more practical than strong heat. Thus, ice for air con-ditioning has been installed at several locations and has been proposed for the expansion of the chiller capacity at Union College to meet the increased demand from two new buildings.

Numerical solutions for steady laminar thermally developing flow in a rectangular duct with a sinusoidally corrugated surface are presented. All surfaces are under uniform heat flux conditions (circumferentially and axially). Comparisons are made with previously published results on steady laminar thermally developing flow in a horizontal square duct. In the present problem, a horizontal rectangular duct is obtained by setting the corrugation amplitude aspect ratio and orientation angle to zero. Significant differences in heat transfer rates and temperatures are observed through the ratio of curvature-assisted Nusselt number to flat surface Nusselt number in the developing flow regime.

Hydrogen has long been considered the fuel of the future. During this decade, significant resources have been invested in the development of advanced production, storage and utilization methods that hold the promise of moving society towards the use of this clean and renewable source of energy. One obstacle impeding the implementation of a hydrogen infrastructure is hydrogen compression. Large mechanical compressors have a high capital cost, consume substantial amounts of energy and require frequent maintenance. An economical alternative to mechanical compression is thermal compression of hydrogen using reversible metal hydride alloys. Recent developments in the areas of moisture tolerant hydride alloys and improved heat transfer will permit the application of thermal compressors to non-pure hydrogen streams likely to result from large scale advanced production methods.

We have reported that Euglena, a photosynthetic alga, has the ability to grow in a high CO2 atmosphere and yield great biomass due to the induction of chlorophyll biosynthesis under high CO2 conditions. In the present study, we investigated some microalgal culturing systems for CO2 elimination and O2 regeneration in closed air on the ground by using the photosynthetic alga, Euglena gracilis. z. In the first part of our experiments, we focused on the effects of CO2 and light intensity in the present culture system. We investigated to determine the optimum culture conditions for a microalgal culture system that functions effectively in the controlled ecological life support systems (CELSS). We determined the maximum elimination rate under a high concentration of CO2 with stirring of the supply gas by bubbling. We found that the maximum CO2 elimination rate or gas exchange performance under a 10 % concentration of CO2 was about 2.3 times higher than its low concentration of CO2 (0.04 %).

A regenerable carbon dioxide (CO2) removal system has been certified for use with the Extravehicular Mobility Unit (EMU), or space suit. The new system, nicknamed “Metox” to reflect its use of metal-oxide as the CO2 sor-bent material, was designed and developed by Hamilton Standard Space Systems International (HSSSI), Inc., under contract1 to the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC). As a part of the certification process, one hundred (100) operating cycles were accumulated on the certification canister and sixteen (16) regeneration cycles on the certification regenerator. This paper presents a summary of those tests. The results characterize canister performance for a wide range of temperatures, pressures and metabolic rates. It also presents regenerator performance under nominal and worst case operating conditions.

The existing Shuttle Extravehicular Mobility Unit (EMU) has served NASA well for sometime, however, it uses a large amount of consumables including water, O2 and lithium hydroxide. In order for extended missions to the Moon and Mars to be successful, two new portable life support systems (PLSS) designs have been proposed that will minimize the amount of consumables used and will be more reliable due to simplified designs. This paper considers one such PLSS, currently designated the Cryogenic-PLSS (CPLSS). The reason for this designation is because it uses liquid O2 to provide the breathing gas for the astronaut and to provide backup cooling for the astronaut. In order to understand how the system will function in space and to evaluate final design parameters, a transient thermal model has been developed using the software package MATLAB/Simulink.

The ISS resource Node 3 consists of a pressurized module, which provides passageway among habitable elements, distributes electrical energy and commands, collects and distributes thermal energy by rejecting waste heat to ISS radiators. This paper presents an overview of the Node 3 passive and active thermal control design and reports the most significant analysis results to evidence how the thermal and hydraulic requirements are satisfied. The Node 3 is being designed by Alenia Aerospazio following the know-how experienced on the Node 2, COF, MPLM and Cupolas Projects developed in the frame of a collaboration with ASI, NASA and ESA. Fig.1 shows a schematic representation of the ISS docked modules space configuration. The Node 3 TCS has two main sections, the PTCS and the ATCS.

The International Space Station (ISS) Trace Contaminant Control Subassembly (TCCS) design is based upon proven, highly reliable technology. However, because its core unit operations rely upon expendable activated charcoal and an indirectly heated high temperature catalyst, annual logistics mass, crew time, and power consumption requirements are significant. To address this situation, a unique catalytic reactor design has been developed which is suitable for retrofit into the TCCS’s high temperature catalytic oxidizer (HTCO) assembly. The unique design, which employs a metallic, ultra-short channel length monolith (USCM) catalyst substrate, was tested in a flight-like TCCS HTCO assembly to investigate its performance characteristics. Test results indicate that retrofitting the TCCS with a USCM-based catalytic reactor is feasible and that it may provide significant reductions in logistics mass, crew time, and power consumption.

The intent of a Reliability Development Growth Test (RDGT) is to maximize the initial reliability of newly designed equipment so that fewer failures occur in the field, and design changes to fielded equipment are averted. This improvement in initial fielded reliability is accomplished by revealing and eliminating core design flaws which result in failures normally distributed over the entire system life. To accelerate the exposure of faults, equipment is exposed to rapid cycling through severe conditions and environments, customized for the anticipated equipment application. Once revealed, rigorous pursuit and follow through in correcting a fault is applied to ensure that future failures due to the same design flaw do not occur. A perfect RDGT is impossible to implement when real world constraints such as space, funding, and time are included in the mix. This is especially true for large, distributed systems operating under extreme conditions.

Parallel kinematics are on their way to the market. Different parallel and hybrid systems were proposed and realized in recent years. Due to the different structures and drive principles design possibilities are numerous. In order to be able to compare the different systems, both among each other and with conventional systems, there is a need to establish comparison criteria. In this paper different characteristics such as workspace, stiffness and isotropy are used to evaluate the most used strut arrangements and drive types. Based on the three different drive principles, several systems and their properties are introduced. Thereby different boundary conditions (joint angles, strut arrangement) are taken into account and their influence on the system characteristics is examined. Resulting workspace and stiffness were chosen as comparison criteria.

A stiffness requirement for high speed milling machines is determined by examining the stiffness of current generation high speed spindles. The desire for stability against chatter dictates that the stiffness of the machine structure and drives, when reflected to the tool tip exceed the spindle/tool holder/tool stiffness. The stiffness characteristics of a classical serial machine tool designed expressly for high speed milling are shown. Another potential design for high speed machining applications, the parallel kinematic or hexapod structure is also examined. It is found that hexapod structures exhibit lower structural stiffness than can be achieved in serial machines when using the same drive components. Furthermore, the stiffness of the hexapod structure varies widely across the workspace, leading to difficulties in control and limiting the achievable accuracy.

The design of fast machine tools which offer high manufacturing accuracy by employing high performance axis drives requires careful design not only of the individual components of the machine but of the entire machine structure. The overall consideration of the machine tool with its critical components, such as structure, frame and drives, represents a viable approach to achieving a qualitative improvement with regard to increased dynamics and accuracy. During the conceptual design phase of a machine tool for high-speed machining, special attention has to be given to its structure and frame, since very high inertia loads occur as a result of high accelerations caused by the feed drives. In the case of conventional machines these forces play a secondary role.

The theoretical development of a hybrid finite element method is presented. It combines conventional Finite Element Analysis (FEA) with Energy Finite Element Analysis (EFEA) in order to achieve a numerical solution to mid-frequency vibrations. In the mid-frequency range a system is comprised by some members that contain several wavelengths and some members that contain a small number of wavelengths. The former are considered long members and they are modeled by the EFEA. The latter are considered short and they are modeled by the FEA. The new formulation is based on deriving appropriate interface conditions at the joints between sections modeled by the EFEA and the FEA methods. Since the work presented in this paper constitutes a fundamental step in the development of a hybrid method for mid-frequency analysis, the formulation for one flexural degree of freedom in co-linear beams is presented.

A CAE procedure for modeling the aerodynamic excitation of greenhouse surface vibration and its reradiation as noise is described. The procedure begins with a description of the steady flow over the surfaces. This is used as a basis for estimating the spatially varying unsteady pressure loading. The approach is semi-empirical, utilizing normalized pressure data collected through wind tunnel testing of production vehicles. The unsteady pressures are utilized within a normal mode analysis to predict vibration of the greenhouse panels. Interior noise associated with the panel vibration is estimated from a statistical energy analysis model. We show that contributions of multiple surfaces can be significant.

Over the past two decades, significant work has been accomplished in the development and commercial applications of powertrains fueled by alternate fuels like compressed natural gas, hydrogen, liquefied petroleum gas, and alcohol, etc. These fuels have been proven to be very promising in terms of fuel economy and clean emissions. However, almost no work has been done or reported in terms of the noise and vibration aspects of powertrains being powered by these fuels. In this paper, an attempt has been made to elaborate the noise and vibration behavior of powertrains fueled by various alternate fuels. Some distinct powertrain NVH features due to alternate fuel combustion have been portrayed in detail.*

Brake related warranty costs are a major concern to the automotive industry. Large part of these costs are due to noise, more particularly due to the brake squeal complaints. Computer-aided engineering solutions have attracted a lot of attention from the engineering and development community for more effective brake product development. Recently, three brake squeal analysis methods were implemented on disc type brakes in a vehicle program at Ford. This paper summarizes the results and documents the experience obtained during implementation in the vehicle CAE process.