No description available.

High Efficiency Particulate Air (HEPA) filters are defined as extended-medium, dry-type filters with: (1) a minimum particle removal efficiency of no less than 99.97 percent for 0.3 micrometer particles, (2) a maximum, clean resistance of 1.0 inch water column (in. WC) when operated at 1,000 cubic feet per minute (CFM), and (3) a rigid casing that extends the full depth of the medium. Specifically, ceramic media HEPA filters provide better performance at elevated temperatures, are moisture resistant and nonflammable, can perform their function if wetted and exposed to greater pressures, and can be cleaned and reused. This paper describes the modification and design of a large scale test stand which properly evaluates the filtration characteristics of a range of ceramic media filters challenged with a nuclear aerosol agent in order to develop Section FO of ASME AG-1.

The largest cost in manufacturing PEM fuel cells for automotive applications is due to the bipolar plate. The current graphite material used for the bipolar plate is very brittle and difficult to machine to the rigorous specifications needed for fuel cell stacks. This paper introduces the development of a fuel cell test stand for simultaneous testing of six individual fuel cells. To establish a long-term performance evaluation, the fuel cells incorporate a baseline graphite material that undergoes testing in the fuel cell environment. The graphite is an industry standard material that should not corrode when subjected to continual testing. The baseline model will be used in development of novel composite materials that will be tested under the same conditions for comparison to the graphite. Furthermore, the new materials and applied manufacturing methods could reduce the overall cost of fuel cell stacks in the future. Funding for this project was generously donated by the Virginia Center for Innovative Technology and the National Science Foundation. / Master of Science

No description available.

Propõe-se aqui uma metodologia de projeto aero-termo-estrutural de motores foguete a propelente sólido. O projeto de um motor foguete deve ser realizado com o objetivo de cumprir requisitos de uma missão. Para cada veículo espacial, com uma nova missão, um novo motor pode ser projetado, necessitando para isso de uma série de ferramentas robustas, capazes de compreender todas as combinações de esforços existentes no funcionamento de um motor, sob condições de altas pressões e temperaturas. A metodologia aqui proposta é testada e validada em bancada de ensaios desenvolvida para este fim. Os resultados obtidos mostram que a metodologia utilizada se aproxima bastante dos resultados teóricos e pode ser ajustada por coeficientes de eficiência com grande facilidade. / It is proposed here an aero-thermo-structural design methodology for solid propellant rocket motors. The design of a rocket motor must be carried out in order to fulfill requirements of a mission. For each new space vehicle, with a new mission, a new motor can be designed, requiring for it a variety of robust tools, able to comprise all combinations of load existing in the operation of a motor under high pressures and temperatures. The methodology proposed here is tested and validated in bank of tests developed for this purpose. The results show that the methodology is very close to the theoretical results and can be adjusted by coefficients of efficiency with great ease.

Spausdinimo įrenginys „CITIZEN MD-910“ naudojamas kasos aparatuose, kaip kliento ir kontrolinės juostų spausdintuvas. Šis spausdintuvas plačiai naudojamas šiuose kasos aparatuose: ELCOM EURO-2000M, CASIO FE-800, DATECS MP-500, KONIC SR508F. Šiuos spausdintuvus remontuojant kasos aparatuose, iškyla pavojus, panaikinti kasos aparato atmintį, kurioje saugomi programiniai ir apyvartų duomenys. Spausdinimo įrenginio „CITIZEN MD-910“ patikros stendas kuriamas, tam, kad palengvinti kasos aparatų remonto darbus, taip sumažinant tikimybę panaikinti remontuojamo kasos aparato atmintį. Darbo tikslas – išnagrinėti spausdinimo įrenginio „CITIZEN MD-910“ veikimo principą, elektrines bei mechanines charakteristikas. Taip pat, išsiaiškinti spausdintuvo dvigubos galvos adatų išsidėstymą, sukurti spausdinimo algoritmą, simbolių biblioteką ir valdymo programą. Spausdintuvas „CITIZEN MD-910“ bus dedamas į stendą ir pasiuntus į jį iš valdymo programos tekstą, tikrinamas jo veikimas. Stendas atitiks spausdintuvo realų darbinį režimą. Iš to, kaip vyks spausdinimas, ir iš atspausdinto teksto ant popieriaus juostos, bus sprendžiama apie spausdintuvo mechaninius ir elektronikos gedimus, adatų veikimą ir jų mušimo jėgą į popierių, bei tinkamumą tolesnei eksploatacijai. Spausdinimo įrenginio „CITIZEN MD-910“ patikros stendo pagrindinė kūrimo priežastis yra ta, jog nėra sukurtų panašių analogų, kurie palengvintų šių kasos aparatų spausdinimo įrenginių remonto darbus. / Dot impact printer mechanism “CITIZEN MD-910” is used in cash registers as a printer for customer receipts and journal paper ribbons. This printer is widely used in the cash registers such as ELCOM EURO-2000M, CASIO FE-800, DATECS MP-500, KONIC SR508F. Repairing these printers inside the cash registers there is a risk to delete the cash register’s memory in which programs and data of a turnover is stored. The dot impact printer mechanism “CITIZEN MD-910” test stand is being worked out to make the cash registers repairing easier and in this way to reduce the risk of deleting cash registers memory. The printer “CITIZEN MD-910” will be placed in the test stand and its work will be tested by sending text from the operating program into it. The stand will simulate real working conditions of the printer. Analyzing the printing process and the printed text on the paper ribbon it will be possible to decide on printer’s mechanical and electrical damage, work of wires and force they dot the paper, also, further usability. There are no similar analogues which could make the repairing of the cash registers dot impact printer mechanism “CITIZEN MD-910” easier and this is the main reason to work out the dot impact printer mechanism “CITIZEN MD-910” test stand.

Propõe-se aqui uma metodologia de projeto aero-termo-estrutural de motores foguete a propelente sólido. O projeto de um motor foguete deve ser realizado com o objetivo de cumprir requisitos de uma missão. Para cada veículo espacial, com uma nova missão, um novo motor pode ser projetado, necessitando para isso de uma série de ferramentas robustas, capazes de compreender todas as combinações de esforços existentes no funcionamento de um motor, sob condições de altas pressões e temperaturas. A metodologia aqui proposta é testada e validada em bancada de ensaios desenvolvida para este fim. Os resultados obtidos mostram que a metodologia utilizada se aproxima bastante dos resultados teóricos e pode ser ajustada por coeficientes de eficiência com grande facilidade. / It is proposed here an aero-thermo-structural design methodology for solid propellant rocket motors. The design of a rocket motor must be carried out in order to fulfill requirements of a mission. For each new space vehicle, with a new mission, a new motor can be designed, requiring for it a variety of robust tools, able to comprise all combinations of load existing in the operation of a motor under high pressures and temperatures. The methodology proposed here is tested and validated in bank of tests developed for this purpose. The results show that the methodology is very close to the theoretical results and can be adjusted by coefficients of efficiency with great ease.

This Master’s thesis deals with measuring of acting forces from rider to footbike during the ride, followed by the construction of test stand to draw an equivalent load. Measurements and subsequent analysis of acting forces from the rider to the footbike were made. These results were then used for complete design of the test stand. The frame of the test stand was subdued to a stress analysis. A complete automatic control system, including a pneumatic control circuit, was also designed. The proposed automatic test stand was then manufactured and put into operation.

The theses presented proposes an innovation of load test stand for electric drives. It begins with a general overview of load test stand types, their manufacturers and measurement methods in load and no-load situations. Next part analyses current circuit diagram of the load test stand and its risks. This is followed by a proposal for innovation of the circuit diagram which is divided into electrical and control part using current load test stand and its mechanical parts. A wiring diagram is created, the control part is processed by the Logosoft program. The design is evaluated from the safety point of view and modified to meet applicable technical standards.

Thermoelectric generators (TEGs) are currently a topic of interest in the field of energy harvesting for automobiles. In applying TEGs to the outside of the exhaust tailpipe of a vehicle, the difference in temperature between the hot exhaust gases and the automobile coolant can be used to generate a small amount of electrical power to be used in the vehicle. The amount of power is anticipated to be a few hundred watts based on the temperatures expected and the properties of the materials for the TEG. This study focuses on developing efficient heat exchanger modules for the cold side of the TEG through the analysis of experimental data. The experimental set up mimics conditions that were previously used in a computational fluid dynamics (CFD) model. This model tested several different geometries of cold side sections for the heat exchanger at standard coolant and exhaust temperatures for a typical car. The test section uses the same temperatures as the CFD model, but the geometry is a 1/5th scaled down model compared to an full-size engine and was fabricated using a metal-based rapid prototyping process. The temperatures from the CFD model are validated through thermocouple measurements, which provide the distribution of the temperatures across the TEG. All of these measurements are compared to the CFD model for trends and temperatures to ensure that the model is accurate. Two cold side geometries, a baseline geometry and an impingement geometry, are compared to determine which will produce the greater temperature gradient across the TEG. / Master of Science