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Sample records for advanced vehicular heat

  1. Advanced Extra-Vehicular Activity Pressure Garment Requirements Development

    NASA Technical Reports Server (NTRS)

    Ross, Amy; Aitchison, Lindsay; Rhodes, Richard

    2015-01-01

    The NASA Johnson Space Center advanced pressure garment technology development team is addressing requirements development for exploration missions. Lessons learned from the Z-2 high fidelity prototype development have reiterated that clear low-level requirements and verification methods reduce risk to the government, improve efficiency in pressure garment design efforts, and enable the government to be a smart buyer. The expectation is to provide requirements at the specification level that are validated so that their impact on pressure garment design is understood. Additionally, the team will provide defined verification protocols for the requirements. However, in reviewing exploration space suit high level requirements there are several gaps in the team's ability to define and verify related lower level requirements. This paper addresses the efforts in requirement areas such as mobility/fit/comfort and environmental protection (dust, radiation, plasma, secondary impacts) to determine the method by which the requirements can be defined and use of those methods for verification. Gaps exist at various stages. In some cases component level work is underway, but no system level effort has begun; in other cases no effort has been initiated to close the gap. Status of on-going efforts and potential approaches to open gaps are discussed.

  2. Advanced heat pump

    NASA Astrophysics Data System (ADS)

    Ashley, Joseph L.; Matthews, John D.

    1989-09-01

    This patent application discloses a heat pump which includes a first packed bed of liquid desiccant for removing moisture from outside air in the heating mode of operation, and a pump for transferring the moisture laden desiccant to a second packed bed which humidifies condenser heated inside air by adding water vapor to the air. The first packed bed, by removing moisture from the outside air before it passes through the heat pump's evaporator coils, prevents frost from forming on the coils. In the cooling mode of operation the second packed bed of liquid desiccant removes water vapor from the air inside of the building. The moisture laden desiccant is then transferred to the first packed bed by a second pump where condenser heat transfers the moisture from the desiccant to outside air.

  3. Life prediction methodology for ceramic components of advanced heat engines. Phase 1: Volume 2, Appendices

    SciTech Connect

    1995-03-01

    This volume presents the following appendices: ceramic test specimen drawings and schematics, mixed-mode and biaxial stress fracture of structural ceramics for advanced vehicular heat engines (U. Utah), mode I/mode II fracture toughness and tension/torsion fracture strength of NT154 Si nitride (Brown U.), summary of strength test results and fractography, fractography photographs, derivations of statistical models, Weibull strength plots for fast fracture test specimens, and size functions.

  4. Sensitivity of Solder Joint Fatigue to Sources of Variation in Advanced Vehicular Power Electronics Cooling

    SciTech Connect

    Vlahinos, A.; O'Keefe, M.

    2010-06-01

    This paper demonstrates a methodology for taking variation into account in thermal and fatigue analyses of the die attach for an inverter of an electric traction drive vehicle. This method can be used to understand how variation and mission profile affect parameters of interest in a design. Three parameters are varied to represent manufacturing, material, and loading variation: solder joint voiding, aluminum nitride substrate thermal conductivity, and heat generation at the integrated gate bipolar transistor. The influence of these parameters on temperature and solder fatigue life is presented. The heat generation loading variation shows the largest influence on the results for the assumptions used in this problem setup.

  5. Advanced high temperature heat flux sensors

    NASA Technical Reports Server (NTRS)

    Atkinson, W.; Hobart, H. F.; Strange, R. R.

    1983-01-01

    To fully characterize advanced high temperature heat flux sensors, calibration and testing is required at full engine temperature. This required the development of unique high temperature heat flux test facilities. These facilities were developed, are in place, and are being used for advanced heat flux sensor development.

  6. Advanced regenerative heat recovery system

    NASA Astrophysics Data System (ADS)

    Whitbeck, R. G.

    1984-08-01

    A new concept heat wheel regenerator was developed to recover heat from a wide range of industrial heating processes. The heat wheel design separates the heat transfer matrix from the areas to be sealed so that better sealing performance can be expected and ceramic heat transfer matrix materials can be used. The design is expected to make it possible to expand the usage of heat wheel regenerators to high temperature (2000F and higher), high flow industrial processes. Two proof of concept heat wheels were installed and laboratory tested.

  7. Heat and mass transfer considerations in advanced heat pump systems

    SciTech Connect

    Panchal, C.B.; Bell, K.J.

    1992-01-01

    Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

  8. Heat and mass transfer considerations in advanced heat pump systems

    SciTech Connect

    Panchal, C.B.; Bell, K.J.

    1992-08-01

    Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

  9. Plasma Heating: An Advanced Technology

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Mercury and Apollo spacecraft shields were designed to protect astronauts from high friction temperatures (well over 2,000 degrees Fahrenheit) when re-entering the Earth's atmosphere. It was necessary to test and verify the heat shield materials on Earth before space flight. After exhaustive research and testing, NASA decided to use plasma heating as a heat source. This technique involves passing a strong electric current through a rarefied gas to create a plasma (ionized gas) that produces an intensely hot flame. Although NASA did not invent the concept, its work expanded the market for commercial plasma heating systems. One company, Plasma Technology Corporation (PTC), was founded by a member of the team that developed the Re-entry Heating Simulator at Ames Research Center (ARC). Dr. Camacho, President of PTC, believes the technology has significant environmental applications. These include toxic waste disposal, hydrocarbon, decomposition, medical waste disposal, asbestos waste destruction, and chemical and radioactive waste disposal.

  10. Development and Evaluation of Active Thermal Management System for Lithium-Ion Batteries using Solid-State Thermoelectric Heat Pump and Heat Pipes with Electric Vehicular Applications

    NASA Astrophysics Data System (ADS)

    Parekh, Bhaumik Kamlesh

    Lithium-Ion batteries have become a popular choice for use in energy storage systems in electric vehicles (EV) and Hybrid electric vehicles (HEV) because of high power and high energy density. But the use of EV and HEV in all climates demands for a battery thermal management system (BTMS) since temperature effects their performance, cycle life and, safety. Hence the BTMS plays a crucial role in the performance of EV and HEV. In this paper, three thermal management systems are studied: (a) simple aluminum as heat spreader material, (b) heat pipes as heat spreader, and (c) advanced combined solid state thermoelectric heat pump (TE) and heat pipe system; these will be subsequently referred to as Design A, B and C, respectively. A detailed description of the designs and the experimental setup is presented. The experimental procedure is divided into two broad categories: Cooling mode and Warming-up mode. Cooling mode covers the conditions when a BTMS is responsible to cool the battery pack through heat dissipation and Warming-up mode covers the conditions when the BTMS is responsible to warm the battery pack in a low temperature ambient condition, maintaining a safe operating temperature of the battery pack in both modes. The experimental procedure analyzes the thermal management system by evaluating the effect of each variable like heat sink area, battery heat generation rate, cooling air temperature, air flow rate and TE power on parameters like maximum temperature of the battery pack (T max), maximum temperature difference (DeltaT) and, heat transfer through heat sink/cooling power of TE (Q c). The results show that Design C outperforms Design A and Design B in spite of design issues which reduce its efficiency, but can still be improved to achieve better performance.

  11. Advances in Solar Heating and Cooling Systems

    ERIC Educational Resources Information Center

    Ward, Dan S.

    1976-01-01

    Reports on technological advancements in the fields of solar collectors, thermal storage systems, and solar heating and cooling systems. Diagrams aid in the understanding of the thermodynamics of the systems. (CP)

  12. Advanced Gradient Heating Facility (AGHF)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This section of the publication includes papers entitled: (1) Coupled growth in hypermonotectics; (2) Directional solidification of refined Al-4 wt.% Cu alloys; (3) Effects of convection on interface curvature during growth of concentrated ternary compounds; (4) Directional solidification of Al-1.5 wt.% Ni alloys; (5) Interactive response of advancing phase boundaries to particles; (6) INTeractive Response of Advancing Phase boundaries to Particles-INTRAPP; and (7) Particle engulfment and pushing by solidifying interfaces.

  13. Advanced electric residential heat pump

    NASA Astrophysics Data System (ADS)

    Veyo, S. E.

    The heat pump concept developed uses the vapor compression refrigeration cycle with R22 as the working fluid. In order to achieve the target efficiency an improved reciprocating compressor with modulatable capacity was developed along with higher efficiency air movers, a breadboard microprocessor based control system and higher effectiveness heat exchangers. The relative proportions of the compressor, blower, fan, and heat exchangers are specified through system optimization to minimize annual ownership cost while constrained to provide comfort. The efficiency of this compressor is comparable to the best available while the ratio of minimum to maximum capacity can be selected as a parameter of optimization. The incremental cost of this compressor is estimated to be one third that of the compressor with two speed drive motor.

  14. Recent advances in coronal heating.

    PubMed

    De Moortel, Ineke; Browning, Philippa

    2015-05-28

    The solar corona, the tenuous outer atmosphere of the Sun, is orders of magnitude hotter than the solar surface. This 'coronal heating problem' requires the identification of a heat source to balance losses due to thermal conduction, radiation and (in some locations) convection. The review papers in this Theo Murphy meeting issue present an overview of recent observational findings, large- and small-scale numerical modelling of physical processes occurring in the solar atmosphere and other aspects which may affect our understanding of the proposed heating mechanisms. At the same time, they also set out the directions and challenges which must be tackled by future research. In this brief introduction, we summarize some of the issues and themes which reoccur throughout this issue. PMID:25897095

  15. Recent advances in coronal heating

    PubMed Central

    De Moortel, Ineke; Browning, Philippa

    2015-01-01

    The solar corona, the tenuous outer atmosphere of the Sun, is orders of magnitude hotter than the solar surface. This ‘coronal heating problem’ requires the identification of a heat source to balance losses due to thermal conduction, radiation and (in some locations) convection. The review papers in this Theo Murphy meeting issue present an overview of recent observational findings, large- and small-scale numerical modelling of physical processes occurring in the solar atmosphere and other aspects which may affect our understanding of the proposed heating mechanisms. At the same time, they also set out the directions and challenges which must be tackled by future research. In this brief introduction, we summarize some of the issues and themes which reoccur throughout this issue. PMID:25897095

  16. Life prediction methodology for ceramic components of advanced vehicular heat engines: Volume 1. Final report

    SciTech Connect

    Khandelwal, P.K.; Provenzano, N.J.; Schneider, W.E.

    1996-02-01

    One of the major challenges involved in the use of ceramic materials is ensuring adequate strength and durability. This activity has developed methodology which can be used during the design phase to predict the structural behavior of ceramic components. The effort involved the characterization of injection molded and hot isostatic pressed (HIPed) PY-6 silicon nitride, the development of nondestructive evaluation (NDE) technology, and the development of analytical life prediction methodology. Four failure modes are addressed: fast fracture, slow crack growth, creep, and oxidation. The techniques deal with failures initiating at the surface as well as internal to the component. The life prediction methodology for fast fracture and slow crack growth have been verified using a variety of confirmatory tests. The verification tests were conducted at room and elevated temperatures up to a maximum of 1371 {degrees}C. The tests involved (1) flat circular disks subjected to bending stresses and (2) high speed rotating spin disks. Reasonable correlation was achieved for a variety of test conditions and failure mechanisms. The predictions associated with surface failures proved to be optimistic, requiring re-evaluation of the components` initial fast fracture strengths. Correlation was achieved for the spin disks which failed in fast fracture from internal flaws. Time dependent elevated temperature slow crack growth spin disk failures were also successfully predicted.

  17. Advanced heat pump research and development

    NASA Astrophysics Data System (ADS)

    Kuliasha, M. A.

    The Office of Building Energy Research and Development of the U.S. Department of Energy (DOE), has been funding R&D in advanced heat pumps and appliances since 1976. Much of that research has been managed for DOE by the Oak Ridge National Laboratory (ORNL). The objective of the Building Equipment Research (BER) program at ORNL has been to generate new concepts and develop a technology base for improving the energy efficiency and load characteristics of energy conversion equipment used in residential and commercial buildings. The research being pursued to achieve these objectives falls under three general areas: thermally activated heat pumps (TAHP), refrigeration systems, and building equipment systems. The TAHP work is concentrated on three technologies: (1) absorption heat pumps; (2) Stirling engine-driven heat pumps; and (3) internal combustion (IC) engine-driven heat pumps. Major project areas in refrigeration systems research include electric heat pumps, ground-coupled heat pumps, and refigerant mixtures. In the building equipment systems areas, project areas include advanced distribution systems, advanced insulation for appliances, and commercial building equipment.

  18. "Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"

    SciTech Connect

    Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann

    2008-06-12

    ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids” Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers

  19. Ceramic Technology for Advanced Heat Engines Project

    SciTech Connect

    Not Available

    1990-08-01

    The Ceramic Technology For Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Advanced Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DOD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The objective of the project is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic hearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines.

  20. Advances in refrigeration and heat transfer engineering

    DOE PAGESBeta

    Bansal, Pradeep; Cremaschi, Prof. Lorenzo

    2015-05-13

    This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO2 may perhaps have been themore » most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

  1. Advances in refrigeration and heat transfer engineering

    SciTech Connect

    Bansal, Pradeep; Cremaschi, Prof. Lorenzo

    2015-05-13

    This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO2 may perhaps have been the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).

  2. Solar thermoelectricity via advanced latent heat storage

    NASA Astrophysics Data System (ADS)

    Olsen, M. L.; Rea, J.; Glatzmaier, G. C.; Hardin, C.; Oshman, C.; Vaughn, J.; Roark, T.; Raade, J. W.; Bradshaw, R. W.; Sharp, J.; Avery, A. D.; Bobela, D.; Bonner, R.; Weigand, R.; Campo, D.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

    2016-05-01

    We report on a new modular, dispatchable, and cost-effective solar electricity-generating technology. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) integrates several state-of-the-art technologies to provide electricity on demand. In the envisioned STEALS system, concentrated sunlight is converted to heat at a solar absorber. The heat is then delivered to either a thermoelectric (TE) module for direct electricity generation, or to charge a phase change material for thermal energy storage, enabling subsequent generation during off-sun hours, or both for simultaneous electricity production and energy storage. The key to making STEALS a dispatchable technology lies in the development of a "thermal valve," which controls when heat is allowed to flow through the TE module, thus controlling when electricity is generated. The current project addresses each of the three major subcomponents, (i) the TE module, (ii) the thermal energy storage system, and (iii) the thermal valve. The project also includes system-level and techno- economic modeling of the envisioned integrated system and will culminate in the demonstration of a laboratory-scale STEALS prototype capable of generating 3kWe.

  3. Improved silicon carbide for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.

    1988-01-01

    This is the third annual technical report for the program entitled, Improved Silicon Carbide for Advanced Heat Engines, for the period February 16, 1987 to February 15, 1988. The objective of the original program was the development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines. Injection molding is the forming method selected for the program because it is capable of forming complex parts adaptable for mass production on an economically sound basis. The goals of the revised program are to reach a Weibull characteristic strength of 550 MPa (80 ksi) and a Weibull modulus of 16 for bars tested in 4-point loading. Two tasks are discussed: Task 1 which involves materials and process improvements, and Task 2 which is a MOR bar matrix to improve strength and reliability. Many statistically designed experiments were completed under task 1 which improved the composition of the batches, the mixing of the powders, the sinter and anneal cycles. The best results were obtained by an attritor mixing process which yielded strengths in excess of 550 MPa (80 ksi) and an individual Weibull modulus of 16.8 for a 9-sample group. Strengths measured at 1200 and 1400 C were equal to the room temperature strength. Annealing of machined test bars significantly improved the strength. Molding yields were measured and flaw distributions were observed to follow a Poisson process. The second iteration of the Task 2 matrix experiment is described.

  4. Improved silicon carbide for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.

    1987-01-01

    This is the second annual technical report entitled, Improved Silicon Carbide for Advanced Heat Engines, and includes work performed during the period February 16, 1986 to February 15, 1987. The program is conducted for NASA under contract NAS3-24384. The objective is the development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines. The fabrication methods used are to be adaptable for mass production of such parts on an economically sound basis. Injection molding is the forming method selected. This objective is to be accomplished in a two-phase program: (1) to achieve a 20 percent improvement in strength and a 100 percent increase in Weibull modulus of the baseline material; and (2) to produce a complex shaped part, a gas turbine rotor, for example, with the improved mechanical properties attained in the first phase. Eight tasks are included in the first phase covering the characterization of the properties of a baseline material, the improvement of those properties and the fabrication of complex shaped parts. Activities during the first contract year concentrated on two of these areas: fabrication and characterization of the baseline material (Task 1) and improvement of material and processes (Task 7). Activities during the second contract year included an MOR bar matrix study to improve mechanical properties (Task 2), materials and process improvements (Task 7), and a Ford-funded task to mold a turbocharger rotor with an improved material (Task 8).

  5. Proceedings of the DOE/Advanced Heat Exchangers Program Review

    NASA Astrophysics Data System (ADS)

    1992-02-01

    Semiannual review meetings of the USDOE's Advanced Heat Exchanger Program with the objective of reviewing ongoing and recently completed project activities. Personnel from industrial contractors and National Laboratories present technical aspects of their projects. The projects deal with high temperature heat exchangers for waste heat recuperation and process heat exchange and other areas such as materials performance and heat transfer enhancement. Topics presented are high pressure heat exchangers, ceramic heat exchangers, enhanced tubes, and materials studies to include silicon carbide whiskers and alumina.

  6. Advanced heat receiver conceptual design study

    NASA Technical Reports Server (NTRS)

    Kesseli, James; Saunders, Roger; Batchelder, Gary

    1988-01-01

    Solar Dynamic space power systems are candidate electrical power generating systems for future NASA missions. One of the key components of the solar dynamic power system is the solar receiver/thermal energy storage (TES) subsystem. Receiver development was conducted by NASA in the late 1960's and since then a very limited amount of work has been done in this area. Consequently the state of the art (SOA) receivers designed for the IOC space station are large and massive. The objective of the Advanced Heat Receiver Conceptual Design Study is to conceive and analyze advanced high temperature solar dynamic Brayton and Stirling receivers. The goal is to generate innovative receiver concepts that are half of the mass, smaller, and more efficient than the SOA. It is also necessary that these innovative receivers offer ease of manufacturing, less structural complexity and fewer thermal stress problems. Advanced Brayton and Stirling receiver storage units are proposed and analyzed in this study which can potentially meet these goals.

  7. Ceramic technology for advanced heat engines project

    SciTech Connect

    Not Available

    1990-09-01

    The Ceramic Technology for Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems in Conservation and Renewable Energy. This project was developed to meet the ceramic technology requirements of the OTT's automotive technology programs. This project is managed by ORNL and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DoD, and industry. Research is discussed under the following topics; Turbomilling of SiC Whiskers; microwave sintering of silicon nitride; and milling characterization; processing of monolithics; silicon nitride matrix; oxide matrix; silicate matrix; thermal and wear coatings; joining; design; contact interfaces; time-dependent behavior; environmental effects; fracture mechanics; nondestructive evaluation; and technology transfer. References, figures, and tables are included with each topic.

  8. Ceramic technology for Advanced Heat Engines Project

    SciTech Connect

    Johnson, D.R.

    1991-07-01

    Significant accomplishments in fabricating ceramic components for advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and database and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. This project is managed by ORNL for the Office of Transportation Technologies, Office of Transportation Materials, and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DOD, and industry.

  9. Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)

    SciTech Connect

    Not Available

    2010-08-01

    Fact sheet describing NREL CSP Program capabilities in the area of thermal storage and advanced heat transfer fluids: measuring thermophysical properties, measuring fluid flow and heat transfer, and simulating flow of thermal energy and fluid.

  10. Advanced heat exchanger development for molten salts

    SciTech Connect

    Sabharwall, Piyush; Clark, Denis; Glazoff, Michael; Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark

    2014-12-01

    This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, which show corrosion resistance to molten salt at nominal operating temperatures up to 700°C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet material in Hastelloy N were corrosion tested in?58 mol% KF and 42 mol% ZrF4 at 650, 700, and 850°C for 200, 500, and 1,000 hours. Corrosion rates found were similar between welded and nonwelded materials, typically <10 mils per year. For materials of construction, nickel and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of contaminant type and alloy composition with respect to chromium and carbon to better define the optimal chromium and carbon composition, independent of galvanic or differential solubility effects. Also presented is the division of the nuclear reactor and high temperature components per ASME standards, along with design requirements for a subcritical Rankine power cycle heat exchanger that has to overcome pressure difference of about 17 MPa.

  11. Advanced heat exchanger development for molten salts

    DOE PAGESBeta

    Sabharwall, Piyush; Clark, Denis; Glazoff, Michael; Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark

    2014-12-01

    This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, which show corrosion resistance to molten salt at nominal operating temperatures up to 700°C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet materialmore » in Hastelloy N were corrosion tested in?58 mol% KF and 42 mol% ZrF4 at 650, 700, and 850°C for 200, 500, and 1,000 hours. Corrosion rates found were similar between welded and nonwelded materials, typically <10 mils per year. For materials of construction, nickel and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of contaminant type and alloy composition with respect to chromium and carbon to better define the optimal chromium and carbon composition, independent of galvanic or differential solubility effects. Also presented is the division of the nuclear reactor and high temperature components per ASME standards, along with design requirements for a subcritical Rankine power cycle heat exchanger that has to overcome pressure difference of about 17 MPa.« less

  12. Improved silicon carbide for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.

    1989-01-01

    The development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines is studied. Injection molding was the forming method selected for the program because it is capable of forming complex parts adaptable for mass production on an economically sound basis. The goals were to reach a Weibull characteristic strength of 550 MPa (80 ksi) and a Weibull modulus of 16 for bars tested in four-point loading. Statistically designed experiments were performed throughout the program and a fluid mixing process employing an attritor mixer was developed. Compositional improvements in the amounts and sources of boron and carbon used and a pressureless sintering cycle were developed which provided samples of about 99 percent of theoretical density. Strengths were found to improve significantly by annealing in air. Strengths in excess of 550 MPa (80 ksi) with Weibull modulus of about 9 were obtained. Further improvements in Weibull modulus to about 16 were realized by proof testing. This is an increase of 86 percent in strength and 100 percent in Weibull modulus over the baseline data generated at the beginning of the program. Molding yields were improved and flaw distributions were observed to follow a Poisson process. Magic angle spinning nuclear magnetic resonance spectra were found to be useful in characterizing the SiC powder and the sintered samples. Turbocharger rotors were molded and examined as an indication of the moldability of the mixes which were developed in this program.

  13. Improved silicon nitride for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Yeh, Hun C.; Fang, Ho T.

    1987-01-01

    The technology base required to fabricate silicon nitride components with the strength, reliability, and reproducibility necessary for actual heat engine applications is presented. Task 2 was set up to develop test bars with high Weibull slope and greater high temperature strength, and to conduct an initial net shape component fabrication evaluation. Screening experiments were performed in Task 7 on advanced materials and processing for input to Task 2. The technical efforts performed in the second year of a 5-yr program are covered. The first iteration of Task 2 was completed as planned. Two half-replicated, fractional factorial (2 sup 5), statistically designed matrix experiments were conducted. These experiments have identified Denka 9FW Si3N4 as an alternate raw material to GTE SN502 Si3N4 for subsequent process evaluation. A detailed statistical analysis was conducted to correlate processing conditions with as-processed test bar properties. One processing condition produced a material with a 97 ksi average room temperature MOR (100 percent of goal) with 13.2 Weibull slope (83 percent of goal); another condition produced 86 ksi (6 percent over baseline) room temperature strength with a Weibull slope of 20 (125 percent of goal).

  14. Hydrodynamical Approach to Vehicular Flow in the Urban Street Canyon

    NASA Astrophysics Data System (ADS)

    Duras, Maciej M.

    2001-06-01

    The vehicular flow in the urban street canyon is considered. The classical field description is used in the modelling of the vehicular movement and of gaseous mixture in generic urban street canyon. The dynamical variables include vehicular densities, velocities, and emissivities: of pollutants, heat and exhaust gases, as well as standard mixture components' variables: densities, velocities, temperature, pressures. The local balances' equations predict the dynamics of the complex system. The automatic control of the vehicular flow is attained by the sets of coordinated traffic lights. The automatic control is aimed at minimization of traffic ecological costs by the application of variational calculus (Lagrange's and Bolz's problems). The theoretical description is accompanied by numerical examples of computer fluid dynamics based on real traffic data.

  15. Advanced radioisotope heat source for Stirling Engines

    NASA Astrophysics Data System (ADS)

    Dobry, T. J.; Walberg, G.

    2001-02-01

    The heat exchanger on a Stirling Engine requires a thermal energy transfer from a heat source to the engine through a very limited area on the heater head circumference. Designing an effective means to assure maximum transfer efficiency is challenging. A single General Purpose Heat Source (GPHS), which has been qualified for space operations, would satisfy thermal requirements for a single Stirling Engine that would produce 55 electrical watts. However, it is not efficient to transfer its thermal energy to the engine heat exchanger from its rectangular geometry. This paper describes a conceptual design of a heat source to improve energy transfer for Stirling Engines that may be deployed to power instrumentation on space missions. .

  16. Life prediction methodology for ceramic components of advanced vehicular heat engines: Volume 2, Appendices 1 and 2. Final report

    SciTech Connect

    Khandelwal, P.K.; Provenzano, N.J.; Schneider, W.E.

    1996-02-01

    The two appendices are included: I. Fast fracture testing of MOR Type- B (3x4x50 mm) specimens in air at Allison from 25 to 1400 C. II. Fast fracture tensile testing of button-head specimens in air at Southern Research Institute from 25 to 1400 C. The material is silicon nitride.

  17. Batteries for Vehicular Applications

    NASA Astrophysics Data System (ADS)

    Srinivasan, Venkat

    2008-09-01

    This paper will describe battery technology as it relates to use in vehicular applications, including hybrid-electric vehicles (HEV), electric vehicles (EV), and plug-in-hybrid-electric vehicles (PHEV). The present status of rechargeable batteries, the requirements for each application, and the scientific stumbling blocks that stop batteries from being commercialized for these applications will be discussed. Focus will be on the class of batteries referred to as lithium batteries and the various chemistries that are the most promising for these applications. While Li-ion is expected in HEVs in the very near future, use in PHEVs are expected to be more gradual and dependent on solving the life, safety, and cost challenges. Finally, batteries for EVs remain problematic because of the range and charging-time issues.

  18. Advanced heat pump cycle for district heating and cooling systems

    SciTech Connect

    Radermacher, R.

    1991-07-01

    A bread board heat pump was designed and built to test the performance of a vapor compression heat pump with two stage ammonia-water solution circuits. The design was updated based on the experience gained with the single stage version of this heat pump. A major improvement was obtained by eliminating the rectifier. The new scheme was first investigated by computer simulation and then incorporated in the experimental setup. Water balance in the high and low temperature circuits is now maintained by bleeding up to 2.5% of the weak solution flow from one solution circuit to the other. The advantages of this scheme are reduced first cost, simplified design and control, 20--30% improvement in cooling coefficient of performance and 10--15% increase in cooling capacity as compared to the cycle with a rectifier. Coefficients of performance in the range of 0.84 to 1.03 were obtained experimentally for a temperature lift of 100-K. The pressure ratios encountered were in the range of 7.6 to 9.9, which are 35 to 50% of the pressure ratio expected for a conventional heat pump. Thus the results demonstrate that high temperature lifts can be achieved at pressure ratios which are less than half as large as for conventional systems. The cooling capacities were in the range of 2.79 to 4.21 kW. 13 refs., 5 figs., 2 tabs.

  19. Advances in induction-heated plasma torch technology

    NASA Technical Reports Server (NTRS)

    Poole, J. W.; Vogel, C. E.

    1972-01-01

    Continuing research has resulted in significant advances in induction-heated plasma torch technology which extend and enhance its potential for broad range of uses in chemical processing, materials development and testing, and development of large illumination sources. Summaries of these advances are briefly described.

  20. Advanced Heat Transfer and Thermal Storage Fluids

    SciTech Connect

    Moens, L.; Blake, D.

    2005-01-01

    The design of the next generation solar parabolic trough systems for power production will require the development of new thermal energy storage options with improved economics or operational characteristics. Current heat-transfer fluids such as VP-1?, which consists of a eutectic mixture of biphenyl and diphenyl oxide, allow a maximum operating temperature of ca. 300 C, a limit above which the vapor pressure would become too high and would require pressure-rated tanks. The use of VP-1? also suffers from a freezing point around 13 C that requires heating during cold periods. One of the goals for future trough systems is the use of heat-transfer fluids that can act as thermal storage media and that allow operating temperatures around 425 C combined with lower limits around 0 C. This paper presents an outline of our latest approach toward the development of such thermal storage fluids.

  1. Advanced two-phase heat transfer systems

    NASA Technical Reports Server (NTRS)

    Swanson, Theodore D.

    1992-01-01

    Future large spacecraft, such as the Earth Observing System (EOS) platforms, will require a significantly more capable thermal control system than is possible with current 'passive' technology. Temperatures must be controlled much more tightly over a larger surface area. Numerous heat load sources will often be located inside the body of the spacecraft without a good view to space. Power levels and flux densities may be higher than can be accommodated with traditional technology. Integration and ground testing will almost certainly be much more difficult with such larger, more complex spacecraft. For these and similar reasons, the Goddard Space Flight Center (GSFC) has been developing a new, more capable thermal control technology called capillary pumped loops (CPL's). CPL's represent an evolutionary improvement over heat pipes; they can transport much greater quantities of heat over much longer distances and can serve numerous heat load sources. In addition, CPL's can be fabricated into large cold plates that can be held to tight thermal gradients. Development of this technology began in the early 1980's and is now reaching maturity. CPL's have recently been baselined for the EOS-AM platform (1997 launch) and the COMET spacecraft (1992 launch). This presentation describes this new technology and its applications. Most of the viewgraphs are self descriptive. For those that are less clear additional comments are provided.

  2. NDE (nondestructive examination) development for ceramics for advanced heat engines

    SciTech Connect

    McClung, R.W. , Powell, TN ); Johnson, D.R. )

    1991-01-01

    The Department of Energy (DOE) Ceramic Technology for Advanced Heat Engines (CTAHE) project was initiated in 1983 to meet the ceramic technology needs of DOE's advanced heat engines programs (i.e., advanced gas turbines and low heat rejection diesels). The objective is to establish an industrial ceramic technology base for reliable and cost-effective high-temperature components. Reliability of ceramics was recognized as the major technology need. To increase the material reliability of current and new ceramics, advances were needed in component design methodology, materials processing technology, and data base/life prediction. Nondestructive examination (NDE) was identified as one of the key elements in the approach to high-reliability components. An assessment was made of the current status of NDE for structural ceramics, and a report was prepared containing the results and recommendations for needed development. Based on these recommendations, a long-range NDE development program has been established in the CTAHE project to address these needs.

  3. Heat pipe radiation cooling of advanced hypersonic propulsion system components

    NASA Technical Reports Server (NTRS)

    Martin, R. A.; Keddy, M.; Merrigan, M. A.; Silverstein, C. C.

    1991-01-01

    Heat transfer, heat pipe, and system studies were performed to assess the newly proposed heat pipe radiation cooling (HPRC) concept. With an HPRC system, heat is removed from the ramburner and nozzle of a hypersonic aircraft engine by a surrounding, high-temperature, heat pipe nacelle structure, transported to nearby external surfaces, and rejected to the environment by thermal radiation. With HPRC, the Mach number range available for using hydrocarbon fuels for aircraft operation extends into the Mach 4 to Mach 6 range, up from the current limit of about Mach 4. Heat transfer studies using a newly developed HPRC computer code determine cooling system and ramburner and nozzle temperatures, heat loads, and weights for a representative combined-cycle engine cruising at Mach 5 at 80,000 ft altitude. Heat pipe heat transport calculations, using the Los Alamos code HTPIPE, reveal that adequate heat trasport capability is available using molybdenum-lithium heat pipe technology. Results show that the HPRC system radiator area is limited in size to the ramburner-nozzle region of the engine nacelle; reasonable system weights are expected; hot section temperatures are consistent with advanced structural materials development goals; and system impact on engine performance is minimal.

  4. Improved silicon nitride for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Yeh, H. C.; Wimmer, J. M.

    1986-01-01

    Silicon nitride is a high temperature material currently under consideration for heat engine and other applications. The objective is to improve the net shape fabrication technology of Si3N4 by injection molding. This is to be accomplished by optimizing the process through a series of statistically designed matrix experiments. To provide input to the matrix experiments, a wide range of alternate materials and processing parameters was investigated throughout the whole program. The improvement in the processing is to be demonstrated by a 20 percent increase in strength and a 100 percent increase in the Weibull modulus over that of the baseline material. A full characterization of the baseline process was completed. Material properties were found to be highly dependent on each step of the process. Several important parameters identified thus far are the starting raw materials, sinter/hot isostatic pressing cycle, powder bed, mixing methods, and sintering aid levels.

  5. Recent advances in magnetic heat pump technology

    NASA Astrophysics Data System (ADS)

    Uherka, Kenneth L.; Hull, John R.; Scheihing, Paul E.

    Magnetic heat pump (MHP)/refrigeration systems, incorporating state-of-the-art superconducting magnet technology, were assessed for industrial applications ranging from the liquefaction of gases (20 K to 100 K range) to cold storage refrigeration for food preservation (250 K to 320 K range). Initial market penetration of MHP technology is anticipated to occur in the gas liquefaction sector, since the performance advantages of magnetic refrigeration cycles relative to gas compression cycles and other conventional systems are more pronounced in the lower temperature ranges. Design options for rotary MHP devices include alternative regeneration schemes to obtain the temperature spans necessary for industrial applications. The results of preliminary design assessment studies indicate that active magnetic regenerator concepts, in which the magnetic working material also serves as the regenerative medium, offer advantages over alternative MHP designs for industrial applications.

  6. Ceramic technology for advanced heat engines program data base

    SciTech Connect

    Booker, M.K.

    1987-12-01

    A large amount and wide variety of data on the behavior of advanced ceramic materials is currently being generated within the Ceramic Technology for Advanced Heat Engines Program. This paper summarizes efforts to date to develop a computer data base system for the management of those data. The system is based on the use of desktop microcomputers, which provides a maximum of efficiency, economy, and convenience in the operation of the system. 4 refs., 8 tabs.

  7. IEA Annex 26: Advanced Supermarket Refrigeration/Heat Recovery Systems

    SciTech Connect

    Baxter, VAN

    2003-05-19

    With increased concern about the impact of refrigerant leakage on global warming, a number of new supermarket refrigeration system configurations requiring significantly less refrigerant charge are being considered. In order to help promote the development of advanced systems and expand the knowledge base for energy-efficient supermarket technology, the International Energy Agency (IEA) established IEA Annex 26 (Advanced Supermarket Refrigeration/Heat Recovery Systems) under the ''IEA Implementing Agreement on Heat Pumping Technologies''. Annex 26 focuses on demonstrating and documenting the energy saving and environmental benefits of advanced systems design for food refrigeration and space heating and cooling for supermarkets. Advanced in this context means systems that use less energy, require less refrigerant and produce lower refrigerant emissions. Stated another way, the goal is to identify supermarket refrigeration and HVAC technology options that reduce the total equivalent warming impact (TEWI) of supermarkets by reducing both system energy use (increasing efficiency) and reducing total refrigerant charge. The Annex has five participating countries: Canada, Denmark, Sweden, the United Kingdom, and the United States. The working program of the Annex has involved analytical and experimental investigation of several candidate system design approaches to determine their potential to reduce refrigerant usage and energy consumption. Advanced refrigeration system types investigated include the following: distributed compressor systems--small parallel compressor racks are located in close proximity to the food display cases they serve thus significantly shortening the connecting refrigerant line lengths; secondary loop systems--one or more central chillers are used to refrigerate a secondary coolant (e.g. brine, ice slurry, or CO2) that is pumped to the food display cases on the sales floor; self-contained display cases--each food display case has its own

  8. Polymers Advance Heat Management Materials for Vehicles

    NASA Technical Reports Server (NTRS)

    2013-01-01

    For 6 years prior to the retirement of the Space Shuttle Program, the shuttles carried an onboard repair kit with a tool for emergency use: two tubes of NOAX, or "good goo," as some people called it. NOAX flew on all 22 flights following the Columbia accident, and was designed to repair damage that occurred on the exterior of the shuttle. Bill McMahon, a structural materials engineer at Marshall Space Flight Center says NASA needed a solution for the widest range of possible damage to the shuttle s exterior thermal protection system. "NASA looked at several options in early 2004 and decided on a sealant. Ultimately, NOAX performed the best and was selected," he says. To prove NOAX would work effectively required hundreds of samples manufactured at Marshall and Johnson, and a concerted effort from various NASA field centers. Johnson Space Center provided programmatic leadership, testing, tools, and crew training; Glenn Research Center provided materials analysis; Langley Research Center provided test support and led an effort to perform large patch repairs; Ames Research Center provided additional testing; and Marshall provided further testing and the site of NOAX manufacturing. Although the sealant never had to be used in an emergency situation, it was tested by astronauts on samples of reinforced carbon-carbon (RCC) during two shuttle missions. (RCC is the thermal material on areas of the shuttle that experience the most heat, such as the nose cone and wing leading edges.) The material handled well on orbit, and tests showed the NOAX patch held up well on RCC.

  9. Advanced Print Reading. Heating, Ventilation and Air Conditioning.

    ERIC Educational Resources Information Center

    Oregon State Dept. of Education, Salem.

    This is a workbook for students learning advanced blueprint reading for heating, ventilation, and air conditioning applications. The workbook contains eight units covering the following material: architectural working drawings; architectural symbols and dimensions; basic architectural electrical symbols; wiring symbols; basic piping symbols;…

  10. Kinetic theory of vehicular traffic

    NASA Astrophysics Data System (ADS)

    Iannini, M. L. L.; Dickman, Ronald

    2016-02-01

    We review the kinetic theory of traffic proposed by Prigogine and Herman in which the Boltzmann equation is adapted to vehicular traffic. The kinetic equation and its solution are discussed, and a novel distribution of desired velocities that is more suitable for describing real traffic conditions is analyzed. We also study the stationary velocity distribution at the transition between individual and collective flow patterns. At this transition, the distribution splits into a smoothly varying regular part, in which vehicles have nonzero velocities, and a singular one, corresponding to stopped vehicles. Computational methods for obtaining the stationary velocity distribution and the full space-time evolution of the vehicular distribution are explained.

  11. 49 CFR 177.810 - Vehicular tunnels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vehicular tunnels. 177.810 Section 177.810... Information and Regulations § 177.810 Vehicular tunnels. Except as regards Class 7 (radioactive) materials... through any urban vehicular tunnel used for mass transportation....

  12. 49 CFR 177.810 - Vehicular tunnels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Vehicular tunnels. 177.810 Section 177.810... Information and Regulations § 177.810 Vehicular tunnels. Except as regards Class 7 (radioactive) materials... through any urban vehicular tunnel used for mass transportation....

  13. Advanced Materials Development Program: Ceramic Technology for Advanced Heat Engines program plan, 1983--1993

    SciTech Connect

    Not Available

    1990-07-01

    The purpose of the Ceramic Technology for Advanced Heat Engines (CTAHE) Project is the development of an industrial technology base capable of providing reliable and cost-effective high temperature ceramic components for application in advanced heat engines. There is a deliberate emphasis on industrial'' in the purpose statement. The project is intended to support the US ceramic and engine industries by providing the needed ceramic materials technology. The heat engine programs have goals of component development and proof-of-concept. The CTAHE Project is aimed at developing generic basic ceramic technology and does not involve specific engine designs and components. The materials research and development efforts in the CTAHE Project are focused on the needs and general requirements of the advanced gas turbine and low heat rejection diesel engines. The CTAHE Project supports the DOE Office of Transportation Systems' heat engine programs, Advanced Turbine Technology Applications (ATTAP) and Heavy Duty Transport (HDT) by providing the basic technology required for development of reliable and cost-effective ceramic components. The heat engine programs provide the iterative component design, fabrication, and test development logic. 103 refs., 18 figs., 11 tabs.

  14. Advanced heat pump for the recovery of volatile organic compounds

    SciTech Connect

    Not Available

    1992-03-01

    Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total US VOC emissions. The Toxic-Release Inventory'' of The US Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing,refrigerant production, and wood products production. The US Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase I report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient and economically priced.

  15. Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids

    SciTech Connect

    Raade, Justin; Roark, Thomas; Vaughn, John; Bradshaw, Robert

    2013-07-22

    Concentrating solar power (CSP) facilities are comprised of many miles of fluid-filled pipes arranged in large grids with reflective mirrors used to capture radiation from the sun. Solar radiation heats the fluid which is used to produce steam necessary to power large electricity generation turbines. Currently, organic, oil-based fluid in the pipes has a maximum temperature threshold of 400 °C, allowing for the production of electricity at approximately 15 cents per kilowatt hour. The DOE hopes to foster the development of an advanced heat transfer fluid that can operate within higher temperature ranges. The new heat transfer fluid, when used with other advanced technologies, could significantly decrease solar electricity cost. Lower costs would make solar thermal electricity competitive with gas and coal and would offer a clean, renewable source of energy. Molten salts exhibit many desirable heat transfer qualities within the range of the project objectives. Halotechnics developed advanced heat transfer fluids (HTFs) for application in solar thermal power generation. This project focused on complex mixtures of inorganic salts that exhibited a high thermal stability, a low melting point, and other favorable characteristics. A high-throughput combinatorial research and development program was conducted in order to achieve the project objective. Over 19,000 candidate formulations were screened. The workflow developed to screen various chemical systems to discover salt formulations led to mixtures suitable for use as HTFs in both parabolic trough and heliostat CSP plants. Furthermore, salt mixtures which will not interfere with fertilizer based nitrates were discovered. In addition for use in CSP, the discovered salt mixtures can be applied to electricity storage, heat treatment of alloys and other industrial processes.

  16. Development of advanced high-temperature heat flux sensors

    NASA Technical Reports Server (NTRS)

    Atkinson, W. H.; Strange, R. R.

    1982-01-01

    Various configurations of high temperature, heat flux sensors were studied to determine their suitability for use in experimental combustor liners of advanced aircraft gas turbine engines. It was determined that embedded thermocouple sensors, laminated sensors, and Gardon gauge sensors, were the most viable candidates. Sensors of all three types were fabricated, calibrated, and endurance tested. All three types of sensors met the fabricability survivability, and accuracy requirements established for their application.

  17. Meetings to share advancements in heat pump technologies

    NASA Astrophysics Data System (ADS)

    Creswick, F. A.; Devault, R. C.; Fairchild, P. D.

    1990-04-01

    The Conference brought together researchers, engineers, managers, and government policy makers from the various participating countries and provided a forum to share information on heat pump technological advancements and related environmental issues. From interactions with the Japanese participants in various working meetings and site visits, it is clear that heat pumps represent a major technology emphasis in Japan for industry and utility supported R and D, as well as government sponsored programs. The Super Heat Pump (SHP) project sponsored by the Agency of Industrial Science and Technology (AIST), Ministry of International Trade and Industry (MITI) and aimed at leveling electric power demand in addition to higher heat pump performance, is a notable example of this emphasis and of the way in which industry, research institutes, and government are working together in Japan. A joint industry R and D association established for the SHP effort, for example, includes sixteen (16) major corporate members (Mitsubishi, Toshiba, etc.). Also, gas fired heat pumps have moved beyond laboratory prototypes and field tests and have emerged in Japan in production quantities. These first market entry products use near conventional small I.C. engines and are sized for residential and small commercial building applications. Sales are already in the ten thousands annually, and are increasing. Four major companies are already manufacturing and marketing such units (Yamaha, Yanmar, Aisin Seiki, and Sanyo). The Japanese companies and research organizations were much more open and frank about their research activities and progress than anticipated. The new Heat Pump Technology Center of Japan (HPTCJ) was an excellent host and established a positive atmosphere for international dialogue and cooperation.

  18. Comparative analysis of compact heat exchangers for application as the intermediate heat exchanger for advanced nuclear reactors

    SciTech Connect

    Bartel, N.; Chen, M.; Utgikar, V. P.; Sun, X.; Kim, I. -H.; Christensen, R.; Sabharwall, P.

    2015-04-04

    A comparative evaluation of alternative compact heat exchanger designs for use as the intermediate heat exchanger in advanced nuclear reactor systems is presented in this article. Candidate heat exchangers investigated included the Printed circuit heat exchanger (PCHE) and offset strip-fin heat exchanger (OSFHE). Both these heat exchangers offer high surface area to volume ratio (a measure of compactness [m2/m3]), high thermal effectiveness, and overall low pressure drop. Helium–helium heat exchanger designs for different heat exchanger types were developed for a 600 MW thermal advanced nuclear reactor. The wavy channel PCHE with a 15° pitch angle was found to offer optimum combination of heat transfer coefficient, compactness and pressure drop as compared to other alternatives. The principles of the comparative analysis presented here will be useful for heat exchanger evaluations in other applications as well.

  19. Comparative analysis of compact heat exchangers for application as the intermediate heat exchanger for advanced nuclear reactors

    DOE PAGESBeta

    Bartel, N.; Chen, M.; Utgikar, V. P.; Sun, X.; Kim, I. -H.; Christensen, R.; Sabharwall, P.

    2015-04-04

    A comparative evaluation of alternative compact heat exchanger designs for use as the intermediate heat exchanger in advanced nuclear reactor systems is presented in this article. Candidate heat exchangers investigated included the Printed circuit heat exchanger (PCHE) and offset strip-fin heat exchanger (OSFHE). Both these heat exchangers offer high surface area to volume ratio (a measure of compactness [m2/m3]), high thermal effectiveness, and overall low pressure drop. Helium–helium heat exchanger designs for different heat exchanger types were developed for a 600 MW thermal advanced nuclear reactor. The wavy channel PCHE with a 15° pitch angle was found to offer optimummore » combination of heat transfer coefficient, compactness and pressure drop as compared to other alternatives. The principles of the comparative analysis presented here will be useful for heat exchanger evaluations in other applications as well.« less

  20. Advanced control strategy for plant heat rate improvement

    SciTech Connect

    Schultz, P.; Frerichs, D.K.; Kyr, D.

    1995-12-31

    Florida Power & Light Company (FPL) supplies electricity to about half of the population of Florida, roughly 6.5 million people. The load base is largely residential/business with the obvious seasonal extremes due to the climate. FPL`s generating capacity is 16,320 MW composed of 70% traditional fossil cycle, 18% nuclear, and 12% gas turbine. The system load profile coupled with bulk power purchases is such that the 400 MW class units (9 Foster Wheeler drum type units comprising 24% of total capacity) are now forced to cycle daily all year, and to come off line on weekends during the winter months. The current economic realities of power generation force utility companies to seek methods to improve plant heat rate, and FPL is no exception. FPL believed it possible to achieve the goal of lower heat rate and follow the required load demand with the 400 MW class units through the use of an advanced control strategy implemented totally within the unit`s Distributed Control System (DCS). As of the writing of this paper, the project is still ongoing. This paper will present the theory and methodology of the advanced control strategy along with the current design and implementation status and results obtained to date.

  1. Studies of Vehicular Padding Materials

    PubMed Central

    Sances, Anthony; Carlin, Fred H.; Herbst, Brian; Forrest, Steve; Meyer, Steve; Khadilkar, Anil; Friedman, Keith; Bish, Jack

    2000-01-01

    The Federal Motor Vehicle Safety Standard 571.201 discusses occupant protection with interior impacts of vehicles. Rule making by the National Highway Traffic Safety Administration (NHTSA) has identified padding for potential injury reduction in vehicles. In these studies, head injury mitigation with padding on vehicular roll bars and brush bars was evaluated. Studies were conducted with free falling Hybrid 50% male head form drops on the fore head and side of the head and a 5% female head. Marked reductions in angular acceleration, as well as Head Injury Criterions (HIC), were observed when compared to unpadded roll bars and brush bars. PMID:11558079

  2. Advanced technology options for industrial heating equipment research

    SciTech Connect

    Jain, R.C.

    1992-10-01

    This document presents a strategy for a comprehensive program plan that is applicable to the Combustion Equipment Program of the DOE Office of Industrial Technologies (the program). The program seeks to develop improved heating equipment and advanced control techniques which, by improvements in combustion and beat transfer, will increase energy-use efficiency and productivity in industrial processes and allow the preferred use of abundant, low grade and waste domestic fuels. While the plan development strategy endeavors to be consistent with the programmatic goals and policies of the office, it is primarily governed by the needs and concerns of the US heating equipment industry. The program, by nature, focuses on energy intensive industrial processes. According to the DOE Manufacturing Energy Consumption Survey (MECS), the industrial sector in the US consumed about 21 quads of energy in 1988 in the form of coal, petroleum, natural gas and electricity. This energy was used as fuels for industrial boilers and furnaces, for agricultural uses, for construction, as feedstocks for chemicals and plastics, and for steel, mining, motors, engines and other industrial use over 75 percent of this energy was consumed to provide heat and power for manufacturing industries. The largest consumers of fuel energy were the primary metals, chemical and allied products, paper and allied products, and stone, clay and glass industry groups which accounted for about 60% of the total fuel energy consumed by the US manufacturing sector.

  3. 40 CFR 247.11 - Vehicular products.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Vehicular products. 247.11 Section 247.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES COMPREHENSIVE PROCUREMENT GUIDELINE FOR PRODUCTS CONTAINING RECOVERED MATERIALS Item Designations § 247.11 Vehicular products. (a) Lubricating oils...

  4. 40 CFR 247.11 - Vehicular products.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Vehicular products. 247.11 Section 247.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES COMPREHENSIVE PROCUREMENT GUIDELINE FOR PRODUCTS CONTAINING RECOVERED MATERIALS Item Designations § 247.11 Vehicular products. (a) Lubricating oils...

  5. Location-Based Services in Vehicular Networks

    ERIC Educational Resources Information Center

    Wu, Di

    2013-01-01

    Location-based services have been identified as a promising communication paradigm in highly mobile and dynamic vehicular networks. However, existing mobile ad hoc networking cannot be directly applied to vehicular networking due to differences in traffic conditions, mobility models and network topologies. On the other hand, hybrid architectures…

  6. The Vehicular Information Space Framework

    NASA Astrophysics Data System (ADS)

    Prinz, Vivian; Schlichter, Johann; Schweiger, Benno

    Vehicular networks are distributed, self-organizing and highly mobile ad hoc networks. They allow for providing drivers with up-to-the-minute information about their environment. Therefore, they are expected to be a decisive future enabler for enhancing driving comfort and safety. This article introduces the Vehicular Information Space framework (VIS). Vehicles running the VIS form a kind of distributed database. It enables them to provide information like existing hazards, parking spaces or traffic densities in a location aware and fully distributed manner. In addition, vehicles can retrieve, modify and delete these information items. The underlying algorithm is based on features derived from existing structured Peer-to-Peer algorithms and extended to suit the specific characteristics of highly mobile ad hoc networks. We present, implement and simulate the VIS using a motorway and an urban traffic environment. Simulation studies on VIS message occurrence show that the VIS implies reasonable traffic overhead. Also, overall VIS message traffic is independent from the number of information items provided.

  7. Advancements in Afterbody Radiative Heating Simulations for Earth Entry

    NASA Technical Reports Server (NTRS)

    Johnston, Christopher O.; Panesi, Marco; Brandis, Aaron M.

    2016-01-01

    Four advancements to the simulation of backshell radiative heating for Earth entry are presented. The first of these is the development of a flow field model that treats electronic levels of the dominant backshell radiator, N, as individual species. This is shown to allow improvements in the modeling of electron-ion recombination and two-temperature modeling, which are shown to increase backshell radiative heating by 10 to 40%. By computing the electronic state populations of N within the flow field solver, instead of through the quasi-steady state approximation in the radiation code, the coupling of radiative transition rates to the species continuity equations for the levels of N, including the impact of non-local absorption, becomes feasible. Implementation of this additional level of coupling between the flow field and radiation codes represents the second advancement presented in this work, which is shown to increase the backshell radiation by another 10 to 50%. The impact of radiative transition rates due to non-local absorption indicates the importance of accurate radiation transport in the relatively complex flow geometry of the backshell. This motivates the third advancement, which is the development of a ray-tracing radiation transport approach to compute the radiative transition rates and divergence of the radiative flux at every point for coupling to the flow field, therefore allowing the accuracy of the commonly applied tangent-slab approximation to be assessed for radiative source terms. For the sphere considered at lunar-return conditions, the tangent-slab approximation is shown to provide a sufficient level of accuracy for the radiative source terms, even for backshell cases. This is in contrast to the agreement between the two approaches for computing the radiative flux to the surface, which differ by up to 40%. The final advancement presented is the development of a nonequilibrium model for NO radiation, which provides significant backshell

  8. Survey of advanced-heat-pump developments for space conditioning

    SciTech Connect

    Fairchild, P.D.

    1981-01-01

    A survey of heat pump projects with special emphasis on those supported by DOE, EPRI, and the Gas Research Institute is presented. Some historical notes on heat pump development are discussed. Market and equipment trends, well water and ground-coupled heat pumps, heat-actuated heat pump development, and international interest in heat pumps are also discussed. 30 references.

  9. Reversible Discrete Event Formulation and Optimistic Parallel Execution of Vehicular Traffic Models

    SciTech Connect

    Yoginath, Srikanth B; Perumalla, Kalyan S

    2009-01-01

    Vehicular traffic simulations are useful in applications such as emergency planning and traffic management. High speed of traffic simulations translates to speed of response and level of resilience in those applications. Discrete event formulation of traffic flow at the level of individual vehicles affords both the flexibility of simulating complex scenarios of vehicular flow behavior as well as rapid simulation time advances. However, efficient parallel/distributed execution of the models becomes challenging due to synchronization overheads. Here, a parallel traffic simulation approach is presented that is aimed at reducing the time for simulating emergency vehicular traffic scenarios. Our approach resolves the challenges that arise in parallel execution of microscopic, vehicular-level models of traffic. We apply a reverse computation-based optimistic execution approach to address the parallel synchronization problem. This is achieved by formulating a reversible version of a discrete event model of vehicular traffic, and by utilizing this reversible model in an optimistic execution setting. Three unique aspects of this effort are: (1) exploration of optimistic simulation applied to vehicular traffic simulation (2) addressing reverse computation challenges specific to optimistic vehicular traffic simulation (3) achieving absolute (as opposed to self-relative) speedup with a sequential speed close to that of a fast, de facto standard sequential simulator for emergency traffic. The design and development of the parallel simulation system is presented, along with a performance study that demonstrates excellent sequential performance as well as parallel performance. The benefits of optimistic execution are demonstrated, including a speed up of nearly 20 on 32 processors observed on a vehicular network of over 65,000 intersections and over 13 million vehicles.

  10. Metabolic assessments during extra-vehicular activity

    NASA Astrophysics Data System (ADS)

    Osipov, Yu. Yu.; Spichkov, A. N.; Filipenkov, S. N.

    Extra-vehicular activity (EVA) has a significant role during extended space flights. It demonstrates that humans can survive and perform useful work outside the Orbital Space Stations (OSS) while wearing protective space suits (SS). When the International Space Station 'Alpha'(ISSA) is fully operational, EVA assembly, installation, maintenance and repair operations will become an everyday repetitive work activity in space. It needs new ergonomic evaluation of the work/rest schedule for an increasing of the labor amount per EVA hour. The metabolism assessment is a helpful method to control the productivity of the EVA astronaut and to optimize the work/rest regime. Three following methods were used in Russia to estimate real-time metabolic rates during EVA: 1. Oxygen consumption, computed from the pressure drop in a high pressure bottle per unit time (with actual thermodynamic oxygen properties under high pressure and oxygen leakage taken into account). 2. Carbon dioxide production, computed from CO 2 concentration at the contaminant control cartridge and gas flow rate in the life support subsystem closed loop (nominal mode) or gas leakage in the SS open loop (emergency mode). 3. Heat removal, computed from the difference between the temperatures of coolant water or gas and its flow rate in a unit of time (with assumed humidity and wet oxygen state taken into account). Comparison of heat removal values with metabolic rates enables us to determine the thermal balance during an operative medical control of EVA at "Salyut-6", "Salyut-7" and "Mir" OSS. Complex analysis of metabolism, body temperature and heat rate supports a differential diagnosis between emotional and thermal components of stress during EVA. It gives a prognosis of human homeostasis during EVA. Available information has been acquired into an EVA data base which is an effective tool for ergonomical optimization.

  11. Secondary heat exchanger design and comparison for advanced high temperature reactor

    SciTech Connect

    Sabharwall, P.; Kim, E. S.; Siahpush, A.; McKellar, M.; Patterson, M.

    2012-07-01

    Next generation nuclear reactors such as the advanced high temperature reactor (AHTR) are designed to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. This study considers two different types of heat exchangers - helical coiled heat exchanger and printed circuit heat exchanger - as possible options for the AHTR secondary heat exchangers with distributed load analysis and comparison. Comparison is provided for all different cases along with challenges and recommendations. (authors)

  12. Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer

    SciTech Connect

    Fleeter, S.; Lawless, P.B.

    1995-10-01

    The gas turbine has the potential for power production at the highest possible efficiency. The challenge is to ensure that gas turbines operate at the optimum efficiency so as to use the least fuel and produce minimum emissions. A key component to meeting this challenge is the turbine. Turbine performance, both aerodynamics and heat transfer, is one of the barrier advanced gas turbine development technologies. This is a result of the complex, highly three-dimensional and unsteady flow phenomena in the turbine. Improved turbine aerodynamic performance has been achieved with three-dimensional highly-loaded airfoil designs, accomplished utilizing Euler or Navier-Stokes Computational Fluid Dynamics (CFD) codes. These design codes consider steady flow through isolated blade rows. Thus they do not account for unsteady flow effects. However, unsteady flow effects have a significant impact on performance. Also, CFD codes predict the complete flow field. The experimental verification of these codes has traditionally been accomplished with point data - not corresponding plane field measurements. Thus, although advanced CFD predictions of the highly complex and three-dimensional turbine flow fields are available, corresponding data are not. To improve the design capability for high temperature turbines, a detailed understanding of the highly unsteady and three-dimensional flow through multi-stage turbines is necessary. Thus, unique data are required which quantify the unsteady three-dimensional flow through multi-stage turbine blade rows, including the effect of the film coolant flow. This requires experiments in appropriate research facilities in which complete flow field data, not only point measurements, are obtained and analyzed. Also, as design CFD codes do not account for unsteady flow effects, the next logical challenge and the current thrust in CFD code development is multiple-stage analyses that account for the interactions between neighboring blade rows.

  13. STS-109 Extra Vehicular Activity (EVA)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Inside the Space Shuttle Columbia's cabin, astronaut Nancy J. Currie, mission specialist, controlled the Remote Manipulator System (RMS) on the crew cabin's aft flight deck to assist fellow astronauts during the STS-109 mission Extra Vehicular Activities (EVA). The RMS was used to capture the telescope and secure it into Columbia's cargo bay. The Space Shuttle Columbia STS-109 mission lifted off March 1, 2002 with goals of repairing and upgrading the Hubble Space Telescope (HST). The Marshall Space Flight Center in Huntsville, Alabama had the responsibility for the design, development, and construction of the HST, which is the most powerful and sophisticated telescope ever built. STS-109 upgrades to the HST included: replacement of the solar array panels; replacement of the power control unit (PCU); replacement of the Faint Object Camera (FOC) with a new advanced camera for Surveys (ACS); and installation of the experimental cooling system for the Hubble's Near-Infrared Camera and Multi-object Spectrometer (NICMOS), which had been dormant since January 1999 when its original coolant ran out. Lasting 10 days, 22 hours, and 11 minutes, the STS-109 mission was the 108th flight overall in NASA's Space Shuttle Program.

  14. Energy Conversion Advanced Heat Transport Loop and Power Cycle

    SciTech Connect

    Oh, C. H.

    2006-08-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with 3 turbines and 4 compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with 3 stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and an 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to various

  15. Advanced thermoplastic materials for district heating piping systems

    SciTech Connect

    Raske, D.T.; Karvelas, D.E.

    1988-04-01

    The work described in this report represents research conducted in the first year of a three-year program to assess, characterize, and design thermoplastic piping for use in elevated-temperature district heating (DH) systems. The present report describes the results of a program to assess the potential usefulness of advanced thermoplastics as piping materials for use in DH systems. This includes the review of design rules for thermoplastic materials used as pipes, a survey of candidate materials and available mechanical properties data, and mechanical properties testing to obtain baseline data on a candidate thermoplastic material extruded as pipe. The candidate material studied in this phase of the research was a polyetherimide resin, Ultem 1000, which has a UL continuous service temperature rating of 338/degree/F (170/degree/C). The results of experiments to determine the mechanical properties between 68 and 350/degree/F (20 and 177/degree/C) were used to establish preliminary design values for this material. Because these prototypic pipes were extruded under less than optimal conditions, the mechanical properties obtained are inferior to those expected from typical production pipes. Nevertheless, the present material in the form of 2-in. SDR 11 pipe (2.375-in. O. D. by 0.216-in. wall) would have a saturated water design pressure rating of /approximately/34 psig at 280/degree/F. 16 refs., 6 figs., 8 tabs.

  16. Process Integration Study [Advanced Industrial Heat Pump Applications and Evaluations

    SciTech Connect

    Eastwood, A.

    1992-06-01

    This work was carried out in two phases: Phase 1; identification of opportunities for heat pumps in industrial applications and Phase 2; evaluation of heat pumps in industrial applications. In Phase 1, pinch analysis was applied to several industrial sites to identify the best opportunities for heat pumping and other forms of heat integration. In Phase 2, more detailed analyses were undertaken, including the evaluation of a heat pump installed as a recommendation of Phase 1.

  17. Modular Stirling Radioisotope Power System (SRPS) using an advanced heat source

    NASA Astrophysics Data System (ADS)

    Moul, David S.

    2001-02-01

    The advanced Stirling engine/alternator developed by Stirling Technology Company has potential for a wide range of space applications, at an efficiency comparable to solar cells and triple that of thermoelectric elements. However, the unique design of the Stirling engine requires a concentrated heat input in an annular band which would be optimized with an advanced heat source design. The concentrated heat rejection area of the Stirling engine would also be optimized with the use of a Capillary Pumped Loop to transport the waste heat from the engine. This advanced concept will explore using a Capillary Pumped Loop to transport the waste heat to the mission spacecraft for operational heating. Use of these advanced techniques will allow a specific power approaching 8 We/kg, compared to 5 We for a conventional RTG. .

  18. Process Heat Exchanger Options for the Advanced High Temperature Reactor

    SciTech Connect

    Piyush Sabharwall; Eung Soo Kim; Michael McKellar; Nolan Anderson

    2011-06-01

    The work reported herein is a significant intermediate step in reaching the final goal of commercial-scale deployment and usage of molten salt as the heat transport medium for process heat applications. The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production and process heat application, which would support large-scale deployment.

  19. Advanced oil burner for residential heating -- development report

    SciTech Connect

    Butcher, T.A.

    1995-07-01

    The development of advanced oil burner concepts has long been a part of Brookhaven National Laboratory`s (BNL) oil heat research program. Generally, goals of this work include: increased system efficiency, reduced emissions of soot and NO{sub x}, and the practical extension of the firing rate range of current burners to lower input rates. The report describes the results of a project at BNL aimed at the development of air atomized burners. Two concepts are discussed. The first is an air atomizer which uses air supplied at pressures ranging from 10 to 20 psi and requiring the integration of an air compressor in the system. The second, more novel, approach involves the use of a low-pressure air atomizing nozzle which requires only 8-14 inches of water air pressure for fuel atomization. This second approach requires the use of a fan in the burner instead of a compressor although the fan pressure is higher than with conventional, pressure atomized retention head burners. In testing the first concept, high pressure air atomization, a conventional retention head burner was modified to accept the new nozzle. In addition, the burner head was modified to reduce the flow area to maintain roughly 1 inch of water pressure drop across the head at a firing rate of 0.25 gallons of oil per hour. The burner ignited easily and could be operated at low excess air levels without smoke. The major disadvantage of this burner approach is the need for the air compressor as part of the system. In evaluating options, a vane-type compressor was selected although the use of a compressor of this type will lead to increased burner maintenance requirements.

  20. Life prediction methodology for ceramic components of advanced vehicular heat engines: Volume 3, Appendices 3, 4, 5, 6, and 7. Final report

    SciTech Connect

    Khandelwal, P.K.; Provenzano, N.J.; Schneider, W.E.

    1996-02-01

    The appendices contain: dynamic fatigue testing of MOR specimens in air at Allison from 1000 to 1400 C; dynamic fatigue testing of MOR specimens in air and Ar at ORNL from 1000-1400 C; dynamic fatigue testing of button-head tensile specimens in air at Southern Research Institute; tensile creep curves for dogbone specimens tested at the National Institute of Science and Technology; and oxidation behavior of PY-6 Si nitride between 1000-1400 C in air.

  1. Hollow fiber membrane systems for advanced life support systems

    NASA Technical Reports Server (NTRS)

    Roebelen, G. J., Jr.; Lysaght, M. J.

    1976-01-01

    The practicability of utilizing hollow fiber membranes in vehicular and portable life support system applications is described. A preliminary screening of potential advanced life support applications resulted in the selection of five applications for feasibility study and testing. As a result of the feasibility study and testing, three applications, heat rejection, deaeration, and bacteria filtration, were chosen for breadboard development testing; breadboard hardware was manufactured and tested, and the physical properties of the hollow fiber membrane assemblies are characterized.

  2. Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor

    SciTech Connect

    Piyush Sabharwall; Ali Siahpush; Michael McKellar; Michael Patterson; Eung Soo Kim

    2012-06-01

    The goals of next generation nuclear reactors, such as the high temperature gas-cooled reactor and advance high temperature reactor (AHTR), are to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. The need for efficiency, compactness, and safety challenge the boundaries of existing heat exchanger technology, giving rise to the following study. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more efficient conversion cycles, such as the Rankine super critical and subcritical cycles. This study considers two different types of heat exchangers—helical coiled heat exchanger and printed circuit heat exchanger—as possible options for the AHTR secondary heat exchangers with the following three different options: (1) A single heat exchanger transfers all the heat (3,400 MW(t)) from the intermediate heat transfer loop to the power conversion system or process plants; (2) Two heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants, each exchanger transfers 1,700 MW(t) with a parallel configuration; and (3) Three heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants. Each heat exchanger transfers 1,130 MW(t) with a parallel configuration. A preliminary cost comparison will be provided for all different cases along with challenges and recommendations.

  3. Heat pipe technology for advanced rocket thrust chambers

    NASA Technical Reports Server (NTRS)

    Rousar, D. C.

    1971-01-01

    The application of heat pipe technology to the design of rocket engine thrust chambers is discussed. Subjects presented are: (1) evaporator wick development, (2) specific heat pipe designs and test results, (3) injector design, fabrication, and cold flow testing, and (4) preliminary thrust chamber design.

  4. Testing of advanced ceramic fabric heat pipe for a Stirling engine

    SciTech Connect

    Antoniak, Z.I.; Webb, B.J.; Bates, J.M.

    1991-09-01

    The development and application of Stirling engines for space power production requires concomitant development of an advanced heat rejection system. We are currently involved in the design, development, and testing of advanced ceramic fabric (ACF) water heat pipes for optimal heat rejection from the Stirling cycle without the use of hazardous working fluids such as mercury. Our testing to-date has been with a 200-{mu}m thick titanium heat pipe utilizing Nextel {trademark} fabric as both the outer structural component and as a wick. This heat pipe has been successfully started up from a frozen condition against a negative 4 degree tilt (i.e., fluid return to evaporator was against gravity), with 75 W heat input, in ambient air. In a horizontal orientation, up to 100 W heat input was tolerated without experiencing dryout. 7 refs., 5 figs., 2 tabs.

  5. Radiative properties of advanced spacecraft heat shield materials

    NASA Technical Reports Server (NTRS)

    Cunnington, G. R.; Funai, A. I.; Mcnab, T. K.

    1983-01-01

    Experimental results are presented to show the effects of simulated reentry exposure by convective heating and by radiant heating on spectral and total emittance of statically oxidized Inconel 617 and Haynes HS188 superalloys to 1260 K and a silicide coatea (R512E) columbium 752 alloy to 1590 K. Convective heating exposures were conducted in a supersonic arc plasma wind tunnel using a wedge-shaped specimen configuration. Radiant tests were conducted at a pressure of .003 atmospheres of dry air at a flow velocity of several meters per second. Convective heating specimens were subjected to 8, 20, and 38 15-min heating cycles, and radiant heating specimens were tested for 10, 20, 50, and 100 30-min heating cycles. Changes in radiative properties are explained in terms of changes in composition resulting from simulated reentry tests. The methods used to evaluate morphological, compositional and crystallographic changes include: Auger electron spectroscopy; scanning electron microscopy; X-ray diffraction analysis; and electron microprobe analysis.

  6. Development and Analysis of Advanced High-Temperature Technology for Nuclear Heat Transport and Power Conversion

    SciTech Connect

    Per F. Peterson

    2010-03-01

    This project by the Thermal Hydraulics Research Laboratory at U.C. Berkeley Studied advanced high-temperature heat transport and power conversion technology, in support of the Nuclear Hydrogen Initiative and Generation IV.

  7. The Tensile Properties of Advanced Nickel-Base Disk Superalloys During Quenching Heat Treatments

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; Gayda, John; Kantzos, Pete T.; Biles, Tiffany; Konkel, William

    2001-01-01

    There is a need to increase the temperature capabilities of superalloy turbine disks. This would allow full utilization of higher temperature combustor and airfoil concepts under development. One approach to meet this goal is to modify the processing and chemistry of advanced alloys, while preserving the ability to use rapid cooling supersolvus heat treatments to achieve coarse grain, fine gamma prime microstructures. An important step in this effort is to understand the key high temperature tensile properties of advanced alloys as they exist during supersolvus heat treatments. This could help in projecting cracking tendencies of disks during quenches from supersolvus heat treatments. The objective of this study was to examine the tensile properties of two advanced disk superalloys during simulated quenching heat treatments. Specimens were cooled from the solution heat treatment temperatures at controlled rates, interrupted, and immediately tensile tested at various temperatures. The responses and failure modes were compared and related to the quench cracking tendencies of disk forgings.

  8. Kohlrausch Heat Conductivity Apparatus for Intermediate or Advanced Laboratory

    ERIC Educational Resources Information Center

    Jensen, H. G.

    1970-01-01

    Describes student experiment in measuring heat conductivity according to Kohlrausch's method. Theory, apparatus design, and experimental procedure is outlined. Results for copper are consistent to within 2 percent. (LC)

  9. Advanced turbine cooling, heat transfer, and aerodynamic studies

    SciTech Connect

    Je-Chin Han; Schobeiri, M.T.

    1995-10-01

    The contractual work is in three parts: Part I - Effect of rotation on enhanced cooling passage heat transfer, Part II - Effect on Thermal Barrier Coating (TBC) spallation on surface heat transfer, and Part III - Effect of surface roughness and trailing edge ejection on turbine efficiency under unsteady flow conditions. Each section of this paper has been divided into three parts to individually accommodate each part. Part III is further divided into Parts IIIa and IIIb.

  10. Advanced sensible heat solar receiver for space power

    NASA Technical Reports Server (NTRS)

    Bennett, Timothy J.; Lacy, Dovie E.

    1988-01-01

    NASA Lewis, through in-house efforts, has begun a study to generate a conceptual design of a sensible heat solar receiver and to determine the feasibility of such a system for space power applications. The sensible heat solar receiver generated in this study uses pure lithium as the thermal storage medium and was designed for a 7 kWe Brayton (PCS) operating at 1100 K. The receiver consists of two stages interconnected via temperature sensing variable conductance sodium heat pipes. The lithium is contained within a niobium vessel and the outer shell of the receiver is constructed of third generation rigid, fibrous ceramic insulation material. Reradiation losses are controlled with niobium and aluminum shields. By nature of design, the sensible heat receiver generated in this study is comparable in both size and mass to a latent heat system of similar thermal capacitance. The heat receiver design and thermal analysis was conducted through the combined use of PATRAN, SINDA, TRASYS, and NASTRAN software packages.

  11. Advanced sensible heat solar receiver for space power

    NASA Technical Reports Server (NTRS)

    Bennett, Timothy J.; Lacy, Dovie E.

    1988-01-01

    NASA Lewis, through in-house efforts, has begun a study to generate a conceptual design of a sensible heat solar receiver and to determine the feasibility of such a system for space power applications. The sensible heat solar receiver generated in this study uses pure lithium as the thermal storage medium and was designed for a 7 kWe Brayton (PCS) operating at 1100 K. The receiver consists of two stages interconnected via temperature sensing variable conductance sodium heat pipes. The lithium is contained within a niobium vessel and the outer shell of the receiver is constructed of third generation rigid, fibrous ceramic insulation material. Reradiation losses are controlled with niobium and aluminum shields. By nature of design, the sensible heat receiver generated in this study is comparable in both size and mass to a latent heat system of similar thermal capacitance. The heat receiver design and thermal analysis were conducted through the combined use of PATRAN, SINDA, TRASYS, and NASTRAN software packages.

  12. Assessment of Feasibility of the Beneficial Use of Waste Heat from the Advanced Test Reactor

    SciTech Connect

    Donna P. Guillen

    2012-07-01

    This report investigates the feasibility of using waste heat from the Advanced Test Reactor (ATR). A proposed glycol waste heat recovery system was assessed for technical and economic feasibility. The system under consideration would use waste heat from the ATR secondary coolant system to preheat air for space heating of TRA-670. A tertiary coolant stream would be extracted from the secondary coolant system loop and pumped to a new plate and frame heat exchanger, where heat would be transferred to a glycol loop for preheating outdoor air in the heating and ventilation system. Historical data from Advanced Test Reactor operations over the past 10 years indicates that heat from the reactor coolant was available (when needed for heating) for 43.5% of the year on average. Potential energy cost savings by using the waste heat to preheat intake air is $242K/yr. Technical, safety, and logistics considerations of the glycol waste heat recovery system are outlined. Other opportunities for using waste heat and reducing water usage at ATR are considered.

  13. Thermal Protection System (Heat Shield) Development - Advanced Development Project

    NASA Technical Reports Server (NTRS)

    Kowal, T. John

    2010-01-01

    The Orion Thermal Protection System (TPS) ADP was a 3 1/2 year effort to develop ablative TPS materials for the Orion crew capsule. The ADP was motivated by the lack of available ablative TPS's. The TPS ADP pursued a competitive phased development strategy with succeeding rounds of development, testing and down selections. The Project raised the technology readiness level (TRL) of 8 different TPS materials from 5 different commercial vendors, eventual down selecting to a single material system for the Orion heat shield. In addition to providing a heat shield material and design for Orion on time and on budget, the Project accomplished the following: 1) Re-invigorated TPS industry & re-established a NASA competency to respond to future TPS needs; 2) Identified a potentially catastrophic problem with the planned MSL heat shield, and provided a viable, high TRL alternate heat shield design option; and 3) Transferred mature heat shield material and design options to the commercial space industry, including TPS technology information for the SpaceX Dragon capsule.

  14. Privacy-Preserving Security for Vehicular Communications

    ERIC Educational Resources Information Center

    Weerasinghe, Hesiri Dhammika

    2011-01-01

    Because of the large number of deaths, severe injuries and huge financial loss due to auto accidents and poor traffic management, road safety and traffic management have become very important areas of interest among research community. As a result, Vehicular Ad-hoc Network (VANET) becomes a promising technology to improve road safety and quality…

  15. Advanced Design Heat PumpRadiator for EVA Suits

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Passow, Christian; Phillips, Scott; Trevino, Luis

    2009-01-01

    Absorption cooling using a LiCl/water heat pump can enable lightweight and effective thermal control for EVA suits without venting water to the environment. The key components in the system are an absorber/radiator that rejects heat to space and a flexible evaporation cooling garment that absorbs heat from the crew member. This paper describes progress in the design, development, and testing of the absorber/radiator and evaporation cooling garment. New design concepts and fabrication approaches will significantly reduce the mass of the absorber/radiator. We have also identified materials and demonstrated fabrication approaches for production of a flexible evaporation cooling garment. Data from tests of the absorber/radiator s modular components have validated the design models and allowed predictions of the size and weight of a complete system.

  16. ADVANCED HEAT EXCHANGERS USING TUNABLE NANOSCALE-MOLECULAR ASSEMBLY

    SciTech Connect

    Kwang J. Kim; Thomas W. Bell; Srinivas Vemuri; Sailaja Govindaraju

    2004-01-01

    Steam condensation heat transfer on smooth horizontal tubes and enhanced tubes (TURBO-CDI and TURBO-CSL) along with nanoscale hydrophobic coated tubes was studied experimentally. Hydrophobic coatings have been created through self-assembled mono layers (SAMs) on copper alloy (99.9% Cu, 0.1% P) surfaces to enhance steam condensation through dropwise condensation. In general, a SAM system with a long-chain, hydrophobic group is nano-resistant, meaning that such a system forms a protective hydrophobic layer with negligible heat transfer resistance but a much stronger bond. When compared to complete filmwise condensation, the SAM coating on a plain tube increased the condensation heat transfer rate by a factor of 3 for copper alloy surfaces, under vacuum pressure (33.86 kPa) and by a factor of about 8 times when operated at atmospheric pressure (101 kPa). Lifetime of maintaining dropwise condensation is greatly dependent on the processing conditions.

  17. Advanced radiator concepts utilizing honeycomb panel heat pipes (stainless steel)

    NASA Technical Reports Server (NTRS)

    Fleischman, G. L.; Tanzer, H. J.

    1985-01-01

    The feasibility of fabricating and processing moderate temperature range heat pipes in a low mass honeycomb sandwich panel configuration for highly efficient radiator fins for the NASA space station was investigated. A variety of honeycomb panel facesheet and core-ribbon wick concepts were evaluated within constraints dictated by existing manufacturing technology and equipment. Concepts evaluated include: type of material, material and panel thicknesses, wick type and manufacturability, liquid and vapor communication among honeycomb cells, and liquid flow return from condenser to evaporator facesheet areas. In addition, the overall performance of the honeycomb panel heat pipe was evaluated analytically.

  18. Advanced heat-pipe heat exchanger and microprocessor-based modulating burner controls development

    NASA Astrophysics Data System (ADS)

    Lowenstein, A.; Cohen, B.; Feldman, S.; Spatz, M.; Smith, E.

    1986-03-01

    The development of a novel condensing heat exchanger, a modulating gas burner, and a zone-controlled residential warm-air heating system is described. The condensing heat exchanger uses ten thermosyphons which are manifolded at both the condenser and evaporator ends to achieve a compact low-cost design. Initial tests have demonstrated a + 92 percent steady-state efficiency for a conventional clamshell furnace operating with the thermosyphon heat exchanger located outside the furnace cabinet. A 100,000 -Btu/hr modulating burner has also been developed. Comprehensive study of the burner's operating characteristics has produced guidelines for the design and application of the device. Finally, the modulating burner has been incorporated into a zone-controlled heating system. In parallel with the development of the preceding heating system components, the performance of thermosyphons over a wide range of operating conditions is being explored with the objective of improving design procedures for incorporating these devices into heat exchangers.

  19. A Course in Advanced Topics in Heat and Mass Transfer.

    ERIC Educational Resources Information Center

    Shaeiwitz, Joseph A.

    1983-01-01

    A three or four semester-hour graduate course was designed to provide basic instruction in heat/mass transfer topics relevant to chemical engineering problems and to train students to develop mathematical descriptions for new situations encountered in problem-solving. Course outline and list of references used in the course are provided. (JM)

  20. Advanced Thermoelectric Materials for Efficient Waste Heat Recovery in Process Industries

    SciTech Connect

    Adam Polcyn; Moe Khaleel

    2009-01-06

    The overall objective of the project was to integrate advanced thermoelectric materials into a power generation device that could convert waste heat from an industrial process to electricity with an efficiency approaching 20%. Advanced thermoelectric materials were developed with figure-of-merit ZT of 1.5 at 275 degrees C. These materials were not successfully integrated into a power generation device. However, waste heat recovery was demonstrated from an industrial process (the combustion exhaust gas stream of an oxyfuel-fired flat glass melting furnace) using a commercially available (5% efficiency) thermoelectric generator coupled to a heat pipe. It was concluded that significant improvements both in thermoelectric material figure-of-merit and in cost-effective methods for capturing heat would be required to make thermoelectric waste heat recovery viable for widespread industrial application.

  1. Low Temperature Heat Source Utilization Current and Advanced Technology

    SciTech Connect

    Anderson, James H. Jr.; Dambly, Benjamin W.

    1992-06-01

    Once a geothermal heat source has been identified as having the potential for development, and its thermal, physical, and chemical characteristics have been determined, a method of utilization must be decided upon. This compendium will touch upon some of these concerns, and hopefully will provide the reader with a better understanding of technologies being developed that will be applicable to geothermal development in East Africa, as well as other parts of the world. The appendices contain detailed reports on Down-the-Well Turbo Pump, The Vapor-Turbine Cycle for Geothermal Power Generation, Heat Exchanger Design for Geothermal Power Plants, and a Feasibility Study of Combined Power and Water Desalting Plant Using Hot Geothermal Water. [DJE-2005

  2. Proceedings of the 1987 coatings for advanced heat engines workshop

    SciTech Connect

    Not Available

    1987-01-01

    This Workshop was conducted to enhance communication among those involved in coating development for improved heat engine performance and durability. We were fortunate to have Bill Goward review the steady progress and problems encountered along the way in the use of thermal barrier coatings (TBC) in aircraft gas turbine engines. Navy contractors discussed their work toward the elusive goal of qualifying TBC for turbine airfoil applications. In the diesel community, Caterpillar and Cummins are developing TBC for combustion chamber components as part of the low heat rejection diesel engine concept. The diesel engine TBC work is based on gas turbine technology with a goal of more than twice the thickness used on gas turbine engine components. Adoption of TBC in production for diesel engines could justify a new generation of plasma spray coating equipment. Increasing interests in tribology were evident in this Workshop. Coatings have a significant role in reducing friction and wear under greater mechanical loadings at higher temperatures. The emergence of a high temperature synthetic lubricant could have an enormous impact on diesel engine design and operating conditions. The proven coating processes such as plasma spray, electron-beam physical vapor deposition, sputtering, and chemical vapor deposition have shown enhanced capabilities, particularly with microprocessor controls. Also, the newer coating schemes such as ion implantation and cathodic arc are demonstrating intriguing potential for engine applications. Coatings will play an expanding role in higher efficiency, more durable heat engines.

  3. Advanced k-epsilon modeling of heat transfer

    NASA Technical Reports Server (NTRS)

    Kwon, Okey; Ames, Forrest E.

    1995-01-01

    This report describes two approaches to low Reynolds-number k-epsilon turbulence modeling which formulate the eddy viscosity on the wall-normal component of turbulence and a length scale. The wall-normal component of turbulence is computed via integration of the energy spectrum based on the local dissipation rate and is bounded by the isotropic condition. The models account for the anisotropy of the dissipation and the reduced mixing length due to the high strain rates present in the near-wall region. The turbulent kinetic energy and its dissipation rate were computed from the k and epsilon transport equations of Durbin. The models were tested for a wide range of turbulent flows and proved to be superior to other k-epsilon models, especially for nonequilibrium anisotropic flows. For the prediction of airfoil heat transfer, the models included a set of empirical correlations for predicting laminar-turbulent transition and laminar heat transfer augmentation due to the presence of freestream turbulence. The predictions of surface heat transfer were generally satisfactory.

  4. Heat engine requirements for advanced solar thermal power systems

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.; Pham, H. Q.

    1981-01-01

    Requirements and constraints are established for power conversion subsystems, including heat engine, alternator and auxiliaries, of dish concentrator solar thermal power systems. In order to be competitive with conventional power systems, it is argued that the heat engine should be of less than 40 kW rated output, in a subsystem with an efficiency of at least 40% at rated output and at least 37% at half power. An interval between major overhauls of 50,000 hours is also desirable, along with minor maintenance and lubrication not more than four times a year requiring no more than one man-hour each time, and optimal reliability. Also found to be important are the capability for hybrid operation using heat from a solar receiver, fuel-fired combustor or both simultaneously, operation at any attitude, stability to transients in input power and output loading, operation at ambient temperatures from -30 to 50 C, and compatibility with environmental and safety requirements. Cost targets include a price of $180/kWe, and operation, maintenance and replacement costs averaging $0.001/kWh for 30 years of operation.

  5. Advanced simulation of electron heat transport in fusion plasmas

    SciTech Connect

    Lin, Zhihong; Xiao, Y.; Klasky, Scott A; Lofstead, J.

    2009-01-01

    Electron transport in burning plasmas is more important since fusion products first heat electrons. First-principles simulations of electron turbulence are much more challenging due to the multi-scale dynamics of the electron turbulence, and have been made possible by close collaborations between plasma physicists and computational scientists. The GTC simulations of collisionless trapped electron mode (CTEM) turbulence show that the electron heat transport exhibits a gradual transition from Bohm to gyroBohm scaling when the device size is increased. The deviation from the gyroBohm scaling can be induced by large turbulence eddies, turbulence spreading, and non-diffusive transport processes. Analysis of radial correlation function shows that CTEM turbulence eddies are predominantly microscopic but with a significant tail in the mesoscale. A comprehensive analysis of kinetic and fluid time scales shows that zonal flow shearing is the dominant decorrelation mechanism. The mesoscale eddies result from a dynamical process of linear streamers breaking by zonal flows and merging of microscopic eddies. The radial profile of the electron heat conductivity only follows the profile of fluctuation intensity on a global scale, whereas the ion transport tracks more sensitively the local fluctuation intensity. This suggests the existence of a nondiffusive component in the electron heat flux, which arises from the ballistic radial E x B drift of trapped electrons due to a combination of the presence of mesoscale eddies and the weak de-tuning of the toroidal precessional resonance that drives the CTEM instability. On the other hand, the ion radial excursion is not affected by the mesoscale eddies due to a parallel decorrelation, which is not operational for the trapped electrons because of a bounce averaging process associated with the electron fast motion along magnetic field lines. The presence of the nondiffusive component raises question on the applicability of the usual

  6. Advanced Simulation of Electron Heat Transport in Fusion Plasmas

    SciTech Connect

    Lin, Z.; Xiao, Y.; Holod, I.; Zhang, W. L.; Deng, Wenjun; Klasky, Scott A; Lofstead, J.; Kamath, Chandrika; Wichmann, Nathan

    2009-01-01

    Electron transport in burning plasmas is more important since fusion products first heat electrons. First-principles simulations of electron turbulence are much more challenging due to the multi-scale dynamics of the electron turbulence, and have been made possible by close collaborations between plasma physicists and computational scientists. The GTC simulations of collisionless trapped electron mode (CTEM) turbulence show that the electron heat transport exhibits a gradual transition from Bohm to gyroBohm scaling when the device size is increased. The deviation from the gyroBohm scaling can be induced by large turbulence eddies, turbulence spreading, and non-diffusive transport processes. Analysis of radial correlation function shows that CTEM turbulence eddies are predominantly microscopic but with a significant tail in the mesoscale. A comprehensive analysis of kinetic and fluid time scales shows that zonal flow shearing is the dominant decorrelation mechanism. The mesoscale eddies result from a dynamical process of linear streamers breaking by zonal flows and merging of microscopic eddies. The radial profile of the electron heat conductivity only follows the profile of fluctuation intensity on a global scale, whereas the ion transport tracks more sensitively the local fluctuation intensity. This suggests the existence of a nondiffusive component in the electron heat flux, which arises from the ballistic radial E x B drift of trapped electrons due to a combination of the presence of mesoscale eddies and the weak de-tuning of the toroidal precessional resonance that drives the CTEM instability. On the other hand, the ion radial excursion is not affected by the mesoscale eddies due to a parallel decorrelation, which is not operational for the trapped electrons because of a bounce averaging process associated with the electron fast motion along magnetic field lines. The presence of the nondiffusive component raises question on the applicability of the usual

  7. Development of advanced low-temperature heat transfer fluids for district heating and cooling, final report

    SciTech Connect

    Cho, Y.I.; Lorsch, H.G.

    1991-03-31

    The feasibility of adding phase change materials (PCMS) and surfactants to the heat transfer fluids in district cooling systems was investigated. It increases the thermal capacity of the heat transfer fluid and therefore decreases the volume that needs to be pumped. It also increases the heat transfer rate, resulting in smaller heat exchangers. The thermal behavior of two potential PCMS, hexadecane and tetradecane paraffin wax, was experimentally evaluated. The heat of fusion of these materials is approximately 60% of that of ice. They exhibit no supercooling and are stable under repeated thermal cycling. While test results for laboratory grade materials showed good agreement with data in the literature, both melting point and heat of fusion for commercial grade hexadecane were found to be considerably lower than literature values. PCM/water mixtures were tested in a laboratory-scale test loop to determine heat transfer and flow resistance properties. For 10% and 25% PCM/water slurries, the heat transfer enhancement was found to be approximately 18 and 30 percent above the value for water, respectively. Within the turbulent region, there is only a minor pumping penalty from the addition of up to 25% PCM to the water. Research is continuing on these fluids in order to determine their behavior in large-size loops and to arrive at optimum formulations.

  8. Development of advanced low-temperature heat transfer fluids for district heating and cooling

    SciTech Connect

    Not Available

    1991-09-30

    The feasibility of adding phase change materials (PCMs) and surfactants to the heat transfer fluids in district cooling systems was investigated. It increases the thermal capacity of the heat transfer fluid and therefore decreases the volume that needs to be pumped. It also increases the heat transfer rate, resulting in smaller heat exchangers. The thermal behavior of two potential PCMs, hexadecane and tetradecane paraffin wax, was experimentally evaluated. The heat of fusion of these materials is approximately 60% of that of ice. They exhibit no supercooling and are stable under repeated thermal cycling. While test results for laboratory grade materials showed good agreement with data in the literature, both melting point and heat of fusion for commercial grade hexadecane were found to be considerably lower than literaturevalues. PCM/water mixtures were tested in a laboratory-scale test loop to determine heat transfer and flow resistance properties. When using PCMs in district cooling systems, clogging of frozen PCM particles isone of the major problems to be overcome. In the present project it is proposed to minimize or prevent clogging by the addition of an emulsifier. Effects of the emulsifier on the mixture of water and hexadecane(a PCM) were studied. As the amount of the emulsifier was increased, the size of the solid PCM particles became smaller. When the size of the particles was small enough, they did not stick together or stick to the cold surface of a heat exchanger. The amount of emulsifier to produce this condition was determined.

  9. Advances in the application of in situ electrical resistance heating

    SciTech Connect

    Smith, Gregory J.; Beyke, Gregory

    2007-07-01

    Electrical Resistance Heating (ERH) is an aggressive in situ thermal remediation technology that was developed by the U.S. Department of Energy from the original oil production technology to enhance vapor extraction remediation technologies in low permeability soils. Soil and groundwater are heated by the passage of electrical current through saturated and unsaturated soil between electrodes, not by the electrodes themselves. It is the resistance to the flow of electrical current that results in increased subsurface temperatures, and this is typically applied to the boiling point of water. It is estimated that more than 75 ERH applications have been performed. Capacity to perform these projects has increased over the years, and as many as 15 to 20 of these applications now being performed at any given time, mainly in North America, with some European applications. While the main focus has been to vaporize volatile organic compounds, as one would expect other semi-volatile and non-volatile organic compounds have also been encountered, resulting in observations of chemical and physical reactions that have not been normally incorporated into environmental restoration projects. One such reaction is hydrolysis, which is slow under normal groundwater temperatures, becomes very rapid under temperatures that can easily be achieved using ERH. As a result, these chemical and physical reactions are increasing the applicability of ERH in environmental restoration projects, treating a wider variety of compounds and utilizing biotic and abiotic mechanisms to reduce energy costs. For the treatment of oil and coal tar residues from manufactured gas plants, a process TRS has called steam bubble floatation is used to physically remove the coal and oil tar from the soils for collection using conventional multi-phase collection methods. Heat-enhanced hydrolysis has been used to remediate dichloromethane from soils and groundwater at a site in Illinois, while heat-enhanced biotic and

  10. Thermal evaluation of advanced solar dynamic heat receiver performance

    NASA Technical Reports Server (NTRS)

    Crane, Roger A.

    1989-01-01

    The thermal performance of a variety of concepts for thermal energy storage as applied to solar dynamic applications is discussed. It is recognized that designs providing large thermal gradients or large temperature swings during orbit are susceptible to early mechanical failure. Concepts incorporating heat pipe technology may encounter operational limitations over sufficiently large ranges. By reviewing the thermal performance of basic designs, the relative merits of the basic concepts are compared. In addition the effect of thermal enhancement and metal utilization as applied to each design provides a partial characterization of the performance improvements to be achieved by developing these technologies.

  11. Advanced radiator concepts utilizing honeycomb panel heat pipes

    NASA Astrophysics Data System (ADS)

    Fleischman, G. L.; Peck, S. J.; Tanzer, H. J.

    1987-10-01

    The feasibility of fabricating and processing moderate temperature range vapor chamber type heat pipes in a low mass honeycomb panel configuration for highly efficient radiator fins for potential use on the space station was investigated. A variety of honeycomb panel facesheet and core-ribbon wick concepts were evaluated within constraints dictated by existing manufacturing technology and equipment. Concepts evaluated include type of material, material and panel thickness, wick type and manufacturability, liquid and vapor communication among honeycomb cells, and liquid flow return from condenser to evaporator facesheet areas. A thin-wall all-welded stainless steel design with methanol as the working fluid was the initial prototype unit. It was found that an aluminum panel could not be fabricated in the same manner as a stainless steel panel due to diffusion bonding and resistance welding considerations. Therefore, a formed and welded design was developed. The prototype consists of ten panels welded together into a large panel 122 by 24 by 0.15 in., with a heat rejection capability of 1000 watts and a fin efficiency of essentially 1.0.

  12. Cognitive disorders in children associated with urban vehicular emissions.

    PubMed

    Annavarapu, Ramesh Naidu; Kathi, Srujana

    2016-01-01

    This review introduces recent advances in an emerging research area that is focussed on studying the effect of exposure to vehicular emissions on cognition, with specific attention to children from urban environments. Today, air pollution is a global environmental issue, especially in urban environments, emitting particulate matter (PM), nitrogen dioxide (NO2), carbon monoxide (CO), volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) into the surroundings. The association of exposure to urban air pollution and cognitive disorders in children is a major cause of concern. We review recent findings associated with exposure to air pollutants and explained the potential mechanisms driving oxidative stress in living systems. An attempt has been made to investigate the cognitive effects of air pollutants leading to neurodegeneration, neurodysfunction, attention deficit/hypersensitivity deficiencies and autism in children. Accumulating evidence suggests that urban air pollution may have significant impact on central nervous system (CNS) of the developing brain. PMID:26476694

  13. Intra-Extra Vehicular Activity Apollo Spacesuits

    NASA Technical Reports Server (NTRS)

    Thomas, Kenneth S.

    2016-01-01

    Kenneth Thomas will discuss the Apollo Intra-Extra Vehicular Activity (IEVA) spacesuits, which supported launch and reentry and extra-vehicular activity. This program was NASA's first attempt to develop a new suit design from requirements and concepts. Mr. Thomas will chronicle the challenges, developments, struggles, and solutions that culminated in the system that allowed the first human exploration of the Moon and deep space (outside low-Earth orbit). Apollo pressure suit designs allowed the heroic repair of the Skylab space station and supported the first U.S. and Russian spacecraft docking during the Apollo Soyuz Test Project. Mr. Thomas will also discuss the IEVA suits' successes and challenges associated with the IEVA developments of the 1960s.

  14. Development of an Advanced Trapezoidal Axially Grooved (ATAG) heat pipe. [for Space Station

    NASA Technical Reports Server (NTRS)

    Richter, R. F. G.; Brennan, P. J.; Rankin, J. G.

    1986-01-01

    This paper discusses the breadboard development of an Advanced Trapezoidal Axially Grooved (ATAG) heat pipe, which will satisfy space constructible radiator heat rejection requirements for large space power systems. The ATAG heat pipe development program includes a technology demonstration of Space Station heat load and temperature requirements through the design, fabrication, and testing of breadboard and preprototype units. A parametric analysis was conducted to determine trapezoidal groove geometries that could meet the transport performance goal and could be fabricated by available extrusion technology for a diameter chosen to be compatible with an existing development test unit of a cylindrical, pressure-actuated contact heat exchanger. Performance test results for the breadboard heat pipes are presented.

  15. Passive magnetic bearings for vehicular electromechanical batteries

    SciTech Connect

    Post, R

    1996-03-01

    This report describes the design of a passive magnetic bearing system to be used in electromechanical batteries (flywheel energy storage modules) suitable for vehicular use. One or two such EMB modules might, for example, be employed in a hybrid-electric automobile, providing efficient means for power peaking, i.e., for handling acceleration and regenerative braking power demands at high power levels. The bearing design described herein will be based on a ''dual-mode'' operating regime.

  16. Heat Shock Proteins in Dermatophytes: Current Advances and Perspectives.

    PubMed

    Martinez-Rossi, Nilce M; Jacob, Tiago R; Sanches, Pablo R; Peres, Nalu T A; Lang, Elza A S; Martins, Maíra P; Rossi, Antonio

    2016-04-01

    Heat shock proteins (HSPs) are proteins whose transcription responds rapidly to temperature shifts. They constitute a family of molecular chaperones, involved in the proper folding and stabilisation of proteins under physiological and adverse conditions. HSPs also assist in the protection and recovery of cells exposed to a variety of stressful conditions, including heat. The role of HSPs extends beyond chaperoning proteins, as they also participate in diverse cellular functions, such as the assembly of macromolecular complexes, protein transport and sorting, dissociation of denatured protein aggregates, cell cycle control, and programmed cell death. They are also important antigens from a variety of pathogens, are able to stimulate innate immune cells, and are implicated in acquired immunity. In fungi, HSPs have been implicated in virulence, dimorphic transition, and drug resistance. Some HSPs are potential targets for therapeutic strategies. In this review, we discuss the current understanding of HSPs in dermatophytes, which are a group of keratinophilic fungi responsible for superficial mycoses in humans and animals. Computational analyses were performed to characterise the group of proteins in these dermatophytes, as well as to assess their conservation and to identify DNA-binding domains (5'-nGAAn-3') in the promoter regions of the hsp genes. In addition, the quantification of the transcript levels of few genes in a pacC background helped in the development of an extended model for the regulation of the expression of the hsp genes, which supports the participation of the pH-responsive transcriptional regulator PacC in this process. PMID:27226766

  17. The Effect of Solution Heat Treatment on an Advanced Nickel-Base Disk Alloy

    NASA Technical Reports Server (NTRS)

    Gayda, J.; Gabb, T. P.; Kantzos, P. T.

    2004-01-01

    Five heat treat options for an advanced nickel-base disk alloy, LSHR, have been investigated. These included two conventional solution heat treat cycles, subsolvus/oil quench and supersolvus/fan cool, which yield fine grain and coarse grain microstructure disks respectively, as well as three advanced dual microstructure heat treat (DMHT) options. The DMHT options produce disks with a fine grain bore and a coarse grain rim. Based on an overall evaluation of the mechanical property data, it was evident that the three DMHT options achieved a desirable balance of properties in comparison to the conventional solution heat treatments for the LSHR alloy. However, one of the DMHT options, SUB/DMHT, produced the best set of properties, largely based on dwell crack growth data. Further evaluation of the SUB/DMHT option in spin pit experiments on a generic disk shape demonstrated the advantages and reliability of a dual grain structure at the component level.

  18. Conventional and Advanced Silicagel-water Adsorption Cycles Driven by Near - environmental Temperature Heat

    NASA Astrophysics Data System (ADS)

    Boelman, Elisa; B. Saha, Bidyut; Tanaka, Aiharu; Kashiwagi, Takao

    This work aims at clarifying the possible operating temperature ranges for silica gel-water adsorption refrigeration cycles driven by near-environmental temperature heat sources (between 50°C and 85°C), with relatively small regenerating temperature lifts (10 K to 65 K). A newly developed three stage advanced silica gel-water cycle, which is operational with 50°C driving heat source and 30°C cooling source is introduced and compared with a conventional single stage cycle. The cycles are evaluated in terms of cooling capacity, COP and the viability of operation with near-environmental temperature driving heat sources. The analysis is based on experimental and cycle simulation work. The results showed the advanced three stage cycle to be particularly suited for operation with low grade waste heat driving sources, since it worked with small regenerating temperature lifts (ΔTregen)of 10K to 30K. Another significant advantage of operation with small ΔTregen is the possibility to reduce irreversible heat losses from batched cycle operation. Experiments carried out on full-size machine suggested that, even with smallΔTregen, adsorber /desorber heat exchanger improvements such as higher thermal conductance and smaller heat capacitance can contribute to reduce heat losses while improving cycle performance in terms of cooling capacity and COP.

  19. Numerical Study on Crossflow Printed Circuit Heat Exchanger for Advanced Small Modular Reactors

    SciTech Connect

    Yoon, Su-Jong; Sabharwall, Piyush; Kim, Eung-Soo

    2014-03-01

    Various fluids such as water, gases (helium), molten salts (FLiNaK, FLiBe) and liquid metal (sodium) are used as a coolant of advanced small modular reactors (SMRs). The printed circuit heat exchanger (PCHE) has been adopted as the intermediate and/or secondary heat exchanger of SMR systems because this heat exchanger is compact and effective. The size and cost of PCHE can be changed by the coolant type of each SMR. In this study, the crossflow PCHE analysis code for advanced small modular reactor has been developed for the thermal design and cost estimation of the heat exchanger. The analytical solution of single pass, both unmixed fluids crossflow heat exchanger model was employed to calculate a two dimensional temperature profile of a crossflow PCHE. The analytical solution of crossflow heat exchanger was simply implemented by using built in function of the MATLAB program. The effect of fluid property uncertainty on the calculation results was evaluated. In addition, the effect of heat transfer correlations on the calculated temperature profile was analyzed by taking into account possible combinations of primary and secondary coolants in the SMR systems. Size and cost of heat exchanger were evaluated for the given temperature requirement of each SMR.

  20. High temperature solid lubricant materials for heavy duty and advanced heat engines

    SciTech Connect

    DellaCorte, C.; Wood, J.C.

    1994-10-01

    Advanced engine designs incorporate higher mechanical and thermal loading to achieve efficiency improvements. This approach often leads to higher operating temperatures of critical sliding elements (e.g. piston ring/cylinder wall contacts and valve guides) which compromise the use of conventional and even advanced synthetic liquid lubricants. For these applications solid lubricants must be considered. Several novel solid lubricant composites and coatings designated PS/PM200 have been employed to dry and marginally oil lubricated contacts in advanced heat engines. These applications include cylinder kits of heavy duty diesels, and high temperature sterling engines, sidewall seals of rotary engines and various exhaust valve and exhaust component applications. The following paper describes the tribological and thermophysical properties of these tribomaterials and reviews the results of applying them to engine applications. Other potential tribological materials and applications are also discussed with particular emphasis to heavy duty and advanced heat engines.

  1. High Temperature Solid Lubricant Materials for Heavy Duty and Advanced Heat Engines

    NASA Technical Reports Server (NTRS)

    Dellacorte, C.; Wood, J. C.

    1994-01-01

    Advanced engine designs incorporate higher mechanical and thermal loading to achieve efficiency improvements. This approach often leads to higher operating temperatures of critical sliding elements (e.g. piston ring/cylinder wall contacts and valve guides) which compromise the use of conventional and even advanced synthetic liquid lubricants. For these applications solid lubricants must be considered. Several novel solid lubricant composites and coatings designated PS/PM200 have been employed to dry and marginally oil lubricated contacts in advanced heat engines. These applications include cylinder kits of heavy duty diesels, and high temperature Stirling engines, sidewall seals of rotary engines, and various exhaust valve and exhaust component applications. This paper describes the tribological and thermophysical properties of these tribomaterials and reviews the results of applying them to engine applications. Other potential tribological materials and applications are also discussed with particular emphasis on heavy duty and advanced heat engines.

  2. Ceramic Technology for Advanced Heat Engines Program data base: A summary report

    SciTech Connect

    Booker, M.K.

    1988-01-01

    A large amount and wide variety of data on the behavior of advanced ceramic materials is currently being generated within the Ceramic Technology for Advanced Heat Engines Program. This paper summarizes efforts to date to develop a computer data base system for the management of those data. The system is based on the use of desktop microcomputers, which provides a maximum of efficiency, economy, and convenience in the operation of the system.

  3. Ceramic Technology for Advanced Heat Engines Project data base: September 1988 summary report

    SciTech Connect

    Booker, B.L.P.

    1989-03-01

    A large volume and wide variety of data on the behavior of advanced ceramic materials are currently being generated within the Ceramic Technology for Advanced Heat Engines project (CTAHE). This is the second in a series of reports summarizing the data stored in the microcomputer-based CTAHE data base. Each report features a different class of ceramics, with as much information on materials in that class as has then been processed. This report concentrates on zirconia-based ceramics.

  4. Recent Advances in Combustion Technology for Heating Processes

    NASA Astrophysics Data System (ADS)

    Katsuki, Masashi

    Recent advancement in industrial furnaces brought by highly preheated air combustion is reviewed. Highly Preheated Air Combustion in regenerative furnaces has been paid much attention for its accomplishment in not only energy saving but also low nitric oxides emission. Characteristics of combustion with highly preheated air were studied to understand the change of combustion regime and the reason for the compatibility between high performance and low nitric oxides emission. It was found that combustion was sustained even in an extremely low concentration of oxygen if the temperature of oxidizer was higher than the auto-ignition temperature of the fuel. As an application of the principle, we can reduce nitric oxides emission by dilution of combustion air with plenty of recirculated burned gas in the furnace. Dilution makes the oxygen content of the oxidizer low, which decreases temperature fluctuations in flames as well as the mean temperature, hence low nitric oxides emission. Finally, the applicability of highly preheated air combustion to other fields than industrial furnaces has been discussed.

  5. Hot dry rock heat mining: An advanced geothermal energy technology

    SciTech Connect

    Duchane, D.V.

    1991-01-01

    The conventional geothermal industry relies on naturally occurring fluids, either liquids or gases to transport the internal heat of the earth to the surface where it is applied to useful purposes, but there are only a relatively few places where these hydrothermal resources exist at temperatures high enough to generate electric power. Over most of the world, the hot rock beneath the surface is relatively dry. Geothermal energy in the form of hot dry rock (HDR) is abundant, widely distributed, and accessible. Energy extraction from HDR promises to be economically competitive and can be accomplished with essentially no adverse environmental effects. The purpose of this paper is to describe the technology which is being developed to gain access to, mine, and utilize the thermal energy existing in HDR. For the last two decades, the Los Alamos National Laboratory has been working to develop techniques for mining HDR energy. Early worked proved that it is feasible to extract thermal energy using drilling and fracturing techniques adapted from the petroleum and geothermal industries. Recently, results have demonstrated that it should be possible to operate HDR plants in a closed-loop mode with minimal water use. Long-term testing is about to begin at the HDR facility operated by Los Alamos at Fenton Hill in the Mountains of northern New Mexico. The goal of this test will be to demonstrate that useful amounts of energy can be produced from HDR on a sustainable basis. Results of this work will form the basis for design, construction, and operation of economic HDR plants in the future. Significant HDR programs are now underway in a number of countries. As the technology matures, HDR should take its place as a clean, economically competitive energy source for the world. 11 refs., 7 figs., 2 tabs.

  6. Advanced interface heat exchangers for the Space Station main thermal bus

    NASA Astrophysics Data System (ADS)

    Valenzuela, Javier A.

    Future evolution and growth of the Space Station will place increasing demands on the thermal management system by the addition of new payloads and from increased activity in the habitat modules. To meet this need, Creare is developing advanced evaporators, condensors, and single-phase heat exchangers for operation in microgravity. The objective is to achieve a several-fold increase in the heat flux capability of these components, while operating at the same temperature difference as specified for the present interface heat exchangers. Two prototype interface heat exchangers are presently being developed: one to interface the main thermal bus to a payload two-phase ammonia bus, and the other, to interface with the crew module single-phase water loop. The results achieved to date in the development of these heat exchangers are reviewed.

  7. Advanced interface heat exchangers for the Space Station main thermal bus

    NASA Technical Reports Server (NTRS)

    Valenzuela, Javier A.

    1990-01-01

    Future evolution and growth of the Space Station will place increasing demands on the thermal management system by the addition of new payloads and from increased activity in the habitat modules. To meet this need, Creare is developing advanced evaporators, condensors, and single-phase heat exchangers for operation in microgravity. The objective is to achieve a several-fold increase in the heat flux capability of these components, while operating at the same temperature difference as specified for the present interface heat exchangers. Two prototype interface heat exchangers are presently being developed: one to interface the main thermal bus to a payload two-phase ammonia bus, and the other, to interface with the crew module single-phase water loop. The results achieved to date in the development of these heat exchangers are reviewed.

  8. Advanced thermal energy management: A thermal test bed and heat pipe simulation

    NASA Technical Reports Server (NTRS)

    Barile, Ronald G.

    1986-01-01

    Work initiated on a common-module thermal test simulation was continued, and a second project on heat pipe simulation was begun. The test bed, constructed from surplus Skylab equipment, was modeled and solved for various thermal load and flow conditions. Low thermal load caused the radiator fluid, Coolanol 25, to thicken due to its temperature avoided by using a regenerator-heat-exchanger. Other possible solutions modeled include a radiator heater and shunting heat from the central thermal bus to the radiator. Also, module air temperature can become excessive with high avionics load. A second preoject concerning advanced heat pipe concepts was initiated. A program was written which calculates fluid physical properties, liquid and vapor pressure in the evaporator and condenser, fluid flow rates, and thermal flux. The program is directed to evaluating newer heat pipe wicks and geometries, especially water in an artery surrounded by six vapor channels. Effects of temperature, groove and slot dimensions, and wick properties are reported.

  9. Advanced electric heat pump dual-stroke compressor and system development

    NASA Astrophysics Data System (ADS)

    Veyo, S. E.; Fagan, T. J.

    1983-12-01

    The development of an advanced electric heat pump is discussed. A two-capacity, residential, advanced electric heat pump utilizing a unique dual-stroke compressor was developed. Two nearly identical preprototype split systems of nominally 3.5 tons maximum cooling capacity were designed, built and laboratory tested. The estimated annual energy efficiency of this advanced system is 20 percent better than a two-speed electric heat pump available at contract inception in 1979. This superior performance is due to the synergism of a high-efficiency, dual-stroke reciprocating compressor, a dual-strength high-efficiency single-speed single-phase hermetic drive motor, a single-width, single-entry high-efficiency indoor blower with backward curved cambered plate blades, a high-efficiency multivane axial flow outdoor fan, high-efficiency two-speed air mover motors and a microprocessor control system. The relative proportions of heat exchangers, air flows and compressor size as well as the ratio between high and low capacity were optimized so as to minimize the annual cost of ownership in a northern climate. Constraints placed upon the optimization and design process to ensure comfort provide heating air with a temperature of at least 90(0)F and provide cooling with a sensible-to-total capacity ratio of not more than 0.7. System performance was measured in the laboratory in accordance with applicable codes and procedures. Performance data plus hardware details are provided.

  10. Overview of Heat Addition and Efficiency Predictions for an Advanced Stirling Convertor

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.; Reid, Terry V.; Schifer, Nicholas A.; Briggs, Maxwell H.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot end and cold end temperatures, and specified electrical power output for a given net heat input. Microporous bulk insulation is used in the ground support test hardware to minimize the loss of thermal energy from the electric heat source to the environment. The insulation package is characterized before operation to predict how much heat will be absorbed by the convertor and how much will be lost to the environment during operation. In an effort to validate these predictions, numerous tasks have been performed, which provided a more accurate value for net heat input into the ASCs. This test and modeling effort included: (a) making thermophysical property measurements of test setup materials to provide inputs to the numerical models, (b) acquiring additional test data that was collected during convertor tests to provide numerical models with temperature profiles of the test setup via thermocouple and infrared measurements, (c) using multidimensional numerical models (computational fluid dynamics code) to predict net heat input of an operating convertor, and (d) using validation test hardware to provide direct comparison of numerical results and validate the multidimensional numerical models used to predict convertor net heat input. This effort produced high fidelity ASC net heat input predictions, which were successfully validated using

  11. Evaluation of Advanced Stirling Convertor Net Heat Input Correlation Methods Using a Thermal Standard

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Schifer, Nicholas A.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot end and cold end temperatures, and specified electrical power output for a given net heat input. In an effort to improve net heat input predictions, numerous tasks have been performed which provided a more accurate value for net heat input into the ASCs, including testing validation hardware, known as the Thermal Standard, to provide a direct comparison to numerical and empirical models used to predict convertor net heat input. This validation hardware provided a comparison for scrutinizing and improving empirical correlations and numerical models of ASC-E2 net heat input. This hardware simulated the characteristics of an ASC-E2 convertor in both an operating and non-operating mode. This paper describes the Thermal Standard testing and the conclusions of the validation effort applied to the empirical correlation methods used by the Radioisotope Power System (RPS) team at NASA Glenn.

  12. Waste Heat Recovery from the Advanced Test Reactor Secondary Coolant Loop

    SciTech Connect

    Donna Post Guillen

    2012-11-01

    This study investigated the feasibility of using a waste heat recovery system (WHRS) to recover heat from the Advanced Test Reactor (ATR) secondary coolant system (SCS). This heat would be used to preheat air for space heating of the reactor building, thus reducing energy consumption, carbon footprint, and energy costs. Currently, the waste heat from the reactor is rejected to the atmosphere via a four-cell, induced-draft cooling tower. Potential energy and cost savings are 929 kW and $285K/yr. The WHRS would extract a tertiary coolant stream from the SCS loop and pump it to a new plate and frame heat exchanger, from which the heat would be transferred to a glycol loop for preheating outdoor air supplied to the heating and ventilation system. The use of glycol was proposed to avoid the freezing issues that plagued and ultimately caused the failure of a WHRS installed at the ATR in the 1980s. This study assessed the potential installation of a new WHRS for technical, logistical, and economic feasibility.

  13. 7 CFR 502.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Vehicular and pedestrian traffic. 502.12 Section 502.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.12 Vehicular and pedestrian...

  14. 4 CFR 25.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 4 Accounts 1 2012-01-01 2012-01-01 false Vehicular and pedestrian traffic. 25.13 Section 25.13... OFFICE BUILDING AND ON ITS GROUNDS § 25.13 Vehicular and pedestrian traffic. (a) Drivers of all vehicles... at all times and shall comply with all posted traffic signs and with the signals and directions...

  15. 4 CFR 25.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 4 Accounts 1 2014-01-01 2013-01-01 true Vehicular and pedestrian traffic. 25.13 Section 25.13... OFFICE BUILDING AND ON ITS GROUNDS § 25.13 Vehicular and pedestrian traffic. (a) Drivers of all vehicles... at all times and shall comply with all posted traffic signs and with the signals and directions...

  16. 4 CFR 25.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 4 Accounts 1 2013-01-01 2013-01-01 false Vehicular and pedestrian traffic. 25.13 Section 25.13... OFFICE BUILDING AND ON ITS GROUNDS § 25.13 Vehicular and pedestrian traffic. (a) Drivers of all vehicles... at all times and shall comply with all posted traffic signs and with the signals and directions...

  17. 4 CFR 25.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 4 Accounts 1 2011-01-01 2011-01-01 false Vehicular and pedestrian traffic. 25.13 Section 25.13... OFFICE BUILDING AND ON ITS GROUNDS § 25.13 Vehicular and pedestrian traffic. (a) Drivers of all vehicles... at all times and shall comply with all posted traffic signs and with the signals and directions...

  18. 7 CFR 500.11 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Vehicular and pedestrian traffic. 500.11 Section 500.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.11 Vehicular and pedestrian traffic. (a) Drivers...

  19. 7 CFR 502.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Vehicular and pedestrian traffic. 502.12 Section 502... § 502.12 Vehicular and pedestrian traffic. (a) Drivers of all vehicles whether or not motorized in or on... and directions of the security staff and all posted traffic signs; (b) The blocking of...

  20. 7 CFR 502.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Vehicular and pedestrian traffic. 502.12 Section 502... § 502.12 Vehicular and pedestrian traffic. (a) Drivers of all vehicles whether or not motorized in or on... and directions of the security staff and all posted traffic signs; (b) The blocking of...

  1. 7 CFR 502.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Vehicular and pedestrian traffic. 502.12 Section 502... § 502.12 Vehicular and pedestrian traffic. (a) Drivers of all vehicles whether or not motorized in or on... and directions of the security staff and all posted traffic signs; (b) The blocking of...

  2. 31 CFR 91.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Vehicular and pedestrian traffic. 91.12 Section 91.12 Money and Finance: Treasury Regulations Relating to Money and Finance REGULATIONS GOVERNING CONDUCT IN OR ON THE BUREAU OF THE MINT BUILDINGS AND GROUNDS § 91.12 Vehicular and...

  3. 7 CFR 503.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Vehicular and pedestrian traffic. 503.12 Section 503.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.12 Vehicular and...

  4. 7 CFR 503.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Vehicular and pedestrian traffic. 503.12 Section 503.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.12 Vehicular and...

  5. 7 CFR 503.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Vehicular and pedestrian traffic. 503.12 Section 503.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.12 Vehicular and...

  6. 7 CFR 503.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Vehicular and pedestrian traffic. 503.12 Section 503.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.12 Vehicular and...

  7. 7 CFR 503.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Vehicular and pedestrian traffic. 503.12 Section 503.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.12 Vehicular and...

  8. Advances in Transient Modeling of Loop Heat Pipe Systems with Multiple Components

    NASA Astrophysics Data System (ADS)

    Khrustalev, Dmitry

    2010-01-01

    Modeling of transient thermal-fluid phenomena, temperature control, and gravity effects for conventional and upgraded loop heat pipe (LHP) systems with complex radiators, multiple components, and varying environmental conditions, can be effectively accomplished using Thermal Desktop™. This paper outlines some recent advances in transient modeling of LHP systems with multiple components, such as a) one LHP with two parallel condensers on two orthogonal radiators with varying environmental heating loads, b) two LHPs sharing one radiator under heat loading and sink conditions changing in time, and c) a hybrid LHP with two main and one secondary evaporators undergoing transients due to the heat loads variation. Cleared for open publication, Oct. 29, 2009, OSR, DOD, 10-S-0170.

  9. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    SciTech Connect

    Swindeman, R.W.; Ren, W.

    1996-06-01

    The objective of the research is to provide databases and design criteria to assist in the selection of optimum alloys for construction of components needed to contain process streams in advanced heat recovery and hot-gas cleanup systems. Typical components include: steam line piping and superheater tubing for low emission boilers (600 to 700{degrees}C), heat exchanger tubing for advanced steam cycles and topping cycle systems (650 to 800{degrees}C), foil materials for recuperators, on advanced turbine systems (700 to 750{degrees}C), and tubesheets for barrier filters, liners for piping, cyclones, and blowback system tubing for hot-gas cleanup systems (850 to 1000{degrees}C). The materials being examined fall into several classes, depending on which of the advanced heat recovery concepts is of concern. These classes include martensitic steels for service to 650{degrees}C, lean stainless steels and modified 25Cr-30Ni steels for service to 700{degrees}C, modified 25Cr-20Ni steels for service to 900{degrees}C, and high Ni-Cr-Fe or Ni-Cr-Co-Fe alloys for service to 1000{degrees}C.

  10. Conductive heating and microwave hydrolysis under identical heating profiles for advanced anaerobic digestion of municipal sludge.

    PubMed

    Mehdizadeh, Seyedeh Neda; Eskicioglu, Cigdem; Bobowski, Jake; Johnson, Thomas

    2013-09-15

    Microwave (2.45 GHz, 1200 W) and conventional heating (custom pressure vessel) pretreatments were applied to dewatered municipal waste sludge (18% total solids) using identical heating profiles that span a wide range of temperatures (80-160 °C). Fourteen lab-scale semi-continuous digesters were set up to optimize the energy (methane) output and sludge retention time (SRT) requirements of untreated (control) and thermally pretreated anaerobic digesters operated under mesophilic and thermophilic temperatures. Both pretreatment methods indicated that in the pretreatment range of 80-160 °C, temperature was a statistically significant factor (p-value < 0.05) for increasing solubilization of chemical oxygen demand and biopolymers (proteins, sugars, humic acids) of the waste sludge. However, the type of pretreatment method, i.e. microwave versus conventional heating, had no statistically significant effect (p-value >0.05) on sludge solubilization. With the exception of the control digesters at a 5-d SRT, all control and pretreated digesters achieved steady state at all three SRTs, corresponding to volumetric organic loading rates of 1.74-6.96 g chemical oxygen demand/L/d. At an SRT of 5 d, both mesophilic and thermophilic controls stopped producing biogas after 20 d of operation with total volatile fatty acids concentrations exceeding 1818 mg/L at pH <5.64 for mesophilic and 2853 mg/L at pH <7.02 for thermophilic controls, while the pretreated digesters continued producing biogas. Furthermore, relative (to control) organic removal efficiencies dramatically increased as SRT was shortened from 20 to 10 and then 5 d, indicating that the control digesters were challenged as the organic loading rate was increased. Energy analysis showed that, at an elevated temperature of 160 °C, the amount of methane recovered was not enough to compensate for the energy input. Among the digesters with positive net energy productions, control and pretreated digesters at 80 °C were more

  11. A Review of Recent Advances in Research on Extreme Heat Events

    NASA Technical Reports Server (NTRS)

    Horton, Radley M.; Mankin, Justin S.; Lesk, Corey; Coffel, Ethan; Raymond, Colin

    2016-01-01

    Reviewing recent literature, we report that changes in extreme heat event characteristics such as magnitude, frequency, and duration are highly sensitive to changes in mean global-scale warming. Numerous studies have detected significant changes in the observed occurrence of extreme heat events, irrespective of how such events are defined. Further, a number of these studies have attributed present-day changes in the risk of individual heat events and the documented global-scale increase in such events to anthropogenic-driven warming. Advances in process-based studies of heat events have focused on the proximate land-atmosphere interactions through soil moisture anomalies, and changes in occurrence of the underlying atmospheric circulation associated with heat events in the mid-latitudes. While evidence for a number of hypotheses remains limited, climate change nevertheless points to tail risks of possible changes in heat extremes that could exceed estimates generated from model outputs of mean temperature. We also explore risks associated with compound extreme events and nonlinear impacts associated with extreme heat.

  12. Local Optimization Strategies in Urban Vehicular Mobility.

    PubMed

    Mastroianni, Pierpaolo; Monechi, Bernardo; Liberto, Carlo; Valenti, Gaetano; Servedio, Vito D P; Loreto, Vittorio

    2015-01-01

    The comprehension of vehicular traffic in urban environments is crucial to achieve a good management of the complex processes arising from people collective motion. Even allowing for the great complexity of human beings, human behavior turns out to be subject to strong constraints--physical, environmental, social, economic--that induce the emergence of common patterns. The observation and understanding of those patterns is key to setup effective strategies to optimize the quality of life in cities while not frustrating the natural need for mobility. In this paper we focus on vehicular mobility with the aim to reveal the underlying patterns and uncover the human strategies determining them. To this end we analyze a large dataset of GPS vehicles tracks collected in the Rome (Italy) district during a month. We demonstrate the existence of a local optimization of travel times that vehicle drivers perform while choosing their journey. This finding is mirrored by two additional important facts, i.e., the observation that the average vehicle velocity increases by increasing the travel length and the emergence of a universal scaling law for the distribution of travel times at fixed traveled length. A simple modeling scheme confirms this scenario opening the way to further predictions. PMID:26656106

  13. Local Optimization Strategies in Urban Vehicular Mobility

    PubMed Central

    Mastroianni, Pierpaolo; Monechi, Bernardo; Liberto, Carlo; Valenti, Gaetano; Servedio, Vito D. P.; Loreto, Vittorio

    2015-01-01

    The comprehension of vehicular traffic in urban environments is crucial to achieve a good management of the complex processes arising from people collective motion. Even allowing for the great complexity of human beings, human behavior turns out to be subject to strong constraints—physical, environmental, social, economic—that induce the emergence of common patterns. The observation and understanding of those patterns is key to setup effective strategies to optimize the quality of life in cities while not frustrating the natural need for mobility. In this paper we focus on vehicular mobility with the aim to reveal the underlying patterns and uncover the human strategies determining them. To this end we analyze a large dataset of GPS vehicles tracks collected in the Rome (Italy) district during a month. We demonstrate the existence of a local optimization of travel times that vehicle drivers perform while choosing their journey. This finding is mirrored by two additional important facts, i.e., the observation that the average vehicle velocity increases by increasing the travel length and the emergence of a universal scaling law for the distribution of travel times at fixed traveled length. A simple modeling scheme confirms this scenario opening the way to further predictions. PMID:26656106

  14. A superstatistical model of vehicular traffic flow

    NASA Astrophysics Data System (ADS)

    Kosun, Caglar; Ozdemir, Serhan

    2016-02-01

    In the analysis of vehicular traffic flow, a myriad of techniques have been implemented. In this study, superstatistics is used in modeling the traffic flow on a highway segment. Traffic variables such as vehicular speeds, volume, and headway were collected for three days. For the superstatistical approach, at least two distinct time scales must exist, so that a superposition of nonequilibrium systems assumption could hold. When the slow dynamics of the vehicle speeds exhibit a Gaussian distribution in between the fluctuations of the system at large, one speaks of a relaxation to a local equilibrium. These Gaussian distributions are found with corresponding standard deviations 1 /√{ β }. This translates into a series of fluctuating beta values, hence the statistics of statistics, superstatistics. The traffic flow model has generated an inverse temperature parameter (beta) distribution as well as the speed distribution. This beta distribution has shown that the fluctuations in beta are distributed with respect to a chi-square distribution. It must be mentioned that two distinct Tsallis q values are specified: one is time-dependent and the other is independent. A ramification of these q values is that the highway segment and the traffic flow generate separate characteristics. This highway segment in question is not only nonadditive in nature, but a nonequilibrium driven system, with frequent relaxations to a Gaussian.

  15. Performance of an Advanced Stirling Convertor Based on Heat Flux Sensor Measurements

    NASA Technical Reports Server (NTRS)

    Wilson, Dcott D.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two highefficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

  16. Performance of an Advanced Stirling Convertor Based on Heat Flux Sensor Measurements

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

  17. Towards energy efficient operation of Heating, Ventilation and Air Conditioning systems via advanced supervisory control design

    NASA Astrophysics Data System (ADS)

    Oswiecinska, A.; Hibbs, J.; Zajic, I.; Burnham, K. J.

    2015-11-01

    This paper presents conceptual control solution for reliable and energy efficient operation of heating, ventilation and air conditioning (HVAC) systems used in large volume building applications, e.g. warehouse facilities or exhibition centres. Advanced two-level scalable control solution, designed to extend capabilities of the existing low-level control strategies via remote internet connection, is presented. The high-level, supervisory controller is based on Model Predictive Control (MPC) architecture, which is the state-of-the-art for indoor climate control systems. The innovative approach benefits from using passive heating and cooling control strategies for reducing the HVAC system operational costs, while ensuring that required environmental conditions are met.

  18. Advanced Fuel Cycle Initiative - Projected Linear Heat Generation Rate and Burnup Calculations

    SciTech Connect

    Richard G. Ambrosek; Gray S. Chang; Debbie J. Utterbeck

    2005-02-01

    This report provides documentation of the physics analysis performed to determine the linear heat generation rate (LHGR) and burnup calculations for the Advanced Fuel Cycle Initiative (AFCI) tests, AFC-1D, AFC-1H, and AFC-1G. The AFC-1D and AFC-1H tests consists of low-fertile metallic fuel compositions and the AFC-1G test consists of non-fertile and low-fertile nitride compositions. These tests will be irradiated in the East Flux Trap (EFT) positions E1, E2, and E3, respectively, during Advanced Test Reactor (ATR) Cycle 135B.

  19. The development of an advanced generic solar dynamic heat receiver thermal model

    NASA Technical Reports Server (NTRS)

    Wu, Y. C.; Roschke, E. J.; Kohout, L.

    1988-01-01

    An advanced generic solar dynamic heat receiver thermal model under development which can analyze both orbital transient and orbital average conditions is discussed. This model can be used to study advanced receiver concepts, evaluate receiver concepts under development, analyze receiver thermal characteristics under various operational conditions, and evaluate solar dynamic system thermal performances in various orbit conditions. The model and the basic considerations that led to its creation are described, and results based on a set of baseline orbit, configuration, and operational conditions are presented to demonstrate the working of the receiver model.

  20. Vehicular hydrogen storage using lightweight tanks (regenerative fuel cell systems)

    SciTech Connect

    Mitlitsky, F; Myers, B; Weisberg, A H

    1999-06-01

    Energy storage systems with extremely high specific energy (>400 Wh/kg) have been designed that use lightweight tankage to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs). Lawrence Livermore National Laboratory (LLNL) will leverage work for aerospace applications supported by other sponsors (including BMDO, NASA, and USAF) to develop URFC systems for transportation and utility applications. Lightweight tankage is important for primary fuel cell powered vehicles that use on-board storage of hydrogen. Lightweight pressure vessels with state-of-the-art performance factors were designed, and prototypes are being fabricated to meet the DOE 2000 goals (4000 Wh/kg, 12% hydrogen by weight, 700 Wh/liter, and $20/kWh in high volume production). These pressure vessels use technologies that are easily adopted by industrial partners. Advanced liners provide permeation barriers for gas storage and are mandrels for composite overwrap. URFCs are important to the efficient use of hydrogen as a transportation fuel and enabler of renewable energy. H{sub 2}/halogen URFCs may be advantageous for stationary applications whereas H{sub 2}/O{sub 2} or H{sub 2}/air URFCs are advantageous for vehicular applications. URFC research and development is required to improve performance (efficiency), reduce catalyst loading, understand engineering operation, and integrate systems. LLNL has the experimental equipment and advanced URFC membrane electrode assemblies (some with reduced catalyst loading) for evaluating commercial hardware (not funded by DOE in FY1999).

  1. ECUT energy data reference series: high-temperature materials for advanced heat engines

    SciTech Connect

    Abarcar, R.B.; Hane, G.J.; Johnson, D.R.

    1984-07-01

    Information that describes the use of high-temperature materials in advanced heat engines for ground transportation applications is summarized. Applications discussed are: automobiles, light trucks, and medium and heavy trucks. The information provided on each of these modes includes descriptions of the average conversion efficiency of the engine, the capital stock, the amount of energy used, and the activity level as measured in ton-miles.

  2. ADVANCED HEAT TRANSFER TEST FACILITY, TRA666A. ELEVATIONS. ROOF FRAMING PLAN. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADVANCED HEAT TRANSFER TEST FACILITY, TRA-666A. ELEVATIONS. ROOF FRAMING PLAN. CONCRETE BLOCK SIDING. SLOPED ROOF. ROLL-UP DOOR. AIR INTAKE ENCLOSURE ON NORTH SIDE. F.C. TORKELSON 842-MTR-666-A5, 8/1966. INL INDEX NO. 531-0666-00-851-152258, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  3. Energy Savings and Economics of Advanced Control Strategies for Packaged Heat Pumps

    SciTech Connect

    Wang, Weimin; Huang, Yunzhi; Katipamula, Srinivas

    2012-10-31

    Pacific Northwest National Laboratory (PNNL), with funding from the U.S. Department of Energy’s (DOE’s) Building Technologies Program (BTP), evaluated a number of control strategies for packaged cooling equipment that can be implemented in an advanced controller, which can be retrofit into existing packaged heat pump units to improve their operational efficiency. This report documents the results of that analysis.

  4. Detailed heat load calculations for the conceptual design of the Advanced Neutron Source reactor

    SciTech Connect

    Wemple, C.A.

    1993-12-01

    A very detailed MCNP model of the Advanced Neutron Source reactor has been developed at Idaho National Engineering Laboratory. All reactor components inside the reflector vessel were included, and al components were highly segmented. Specific heat loads (watts per gram) have been calculated for each segment in the model, and system-integrated total powers are compared with the design value for the total reactor fission power. The calculated results agree very well with the design values. Axial profiles of the heat loads are provided for all components of the reactor. Individual segment statistical uncertainties were limited wherever possible, and the heat loads for all important reflector components have a standard deviation below 5%.

  5. The cryogenic cooling program in high-heat-load optics at the Advanced Photon Source

    SciTech Connect

    Rogers, C.S.

    1993-07-01

    This paper describes some of the aspects of the cryogenic optics program at the Advanced Photon Source (APS). A liquid-nitrogen-cooled, high-vacuum, double crystal monochromator is being fabricated at Argonne National Laboratory (ANL). A pumping system capable of delivering a variable flow rate of up to 10 gallons per minute of pressurized liquid nitrogen and removing 5 kilowatts of x-ray power is also being constructed. This specialized pumping system and monochromator will be used to test the viability of cryogenically cooled, high-heat-load synchrotron optics. It has been determined that heat transfer enhancement will be required for optics used with APS insertion devices. An analysis of a porous-matrix-enhanced monochromator crystal is presented. For the particular case investigated, a heat transfer enhancement factor of 5 to 6 was calculated.

  6. Energy-efficiency comparison of advanced ammonia heat-exchanger types

    SciTech Connect

    Panchal, C.; Rabas, T.

    1990-01-01

    Ammonia is the most cost-effective working fluid for many Rankine power cycles and is widely utilized in industrial refrigeration applications. For example, it was selected as the most advantageous working fluid for the comprehensive closed-cycle Ocean Thermal Energy Conversion investigations where the heat source and sink are the warm, surface seawater and the cold, deep seawater, respectively. An essential part of this investigation was to measure the performance of many advanced heat-exchanger types using ammonia as the working fluid and to compare these results with those for conventional shell-and-tube designs. This paper presents an overview of these experiments and their potential significance for improved energy efficiency for industrial refrigeration applications. The heat exchangers used for industrial refrigeration systems account for about 50% of the equipment cost. However, current practice is to use state-of-the-art designs -- the shell-and-tube type without enhanced tubes. Substantial energy savings are possible through the use of advanced ammonia evaporator and condenser heat-exchanger types. 31 refs., 10 figs., 6 tabs.

  7. Practical Considerations of Waste Heat Reuse for a Mars Mission Advanced Life Support System

    NASA Technical Reports Server (NTRS)

    Levri, Julie; Finn, Cory; Luna, Bernadette (Technical Monitor)

    2000-01-01

    Energy conservation is a key issue in design optimization of Advanced Life Support Systems (ALSS) for long-term space missions. By considering designs for conservation at the system level, energy saving opportunities arise that would otherwise go unnoticed. This paper builds on a steady-state investigation of system-level waste heat reuse in an ALSS with a low degree of crop growth for a Mars mission. In past studies, such a system has been defined in terms of technology types, hot and cold stream identification and stream energy content. The maximum steady-state potential for power and cooling savings within the system was computed via the Pinch Method. In this paper, several practical issues are considered for achieving a pragmatic estimate of total system savings in terms of equivalent system mass (ESM), rather than savings solely in terms of power and cooling. In this paper, more realistic ESM savings are computed by considering heat transfer inefficiencies during material transfer. An estimate of the steady-state mass, volume and crewtime requirements associated with heat exchange equipment is made by considering heat exchange equipment material type and configuration, stream flow characteristics and associated energy losses during the heat exchange process. Also, previously estimated power and cooling savings are adjusted to reflect the impact of such energy losses. This paper goes one step further than the traditional Pinch Method of considering waste heat reuse in heat exchangers to include ESM savings that occur with direct reuse of a stream. For example, rather than exchanging heat between crop growth lamp cooling air and air going to a clothes dryer, air used to cool crop lamps might be reused directly for clothes drying purposes. When thermodynamically feasible, such an approach may increase ESM savings by minimizing the mass, volume and crewtime requirements associated with stream routing equipment.

  8. Evaluation of H.264/AVC over IEEE 802.11p vehicular networks

    NASA Astrophysics Data System (ADS)

    Rozas-Ramallal, Ismael; Fernández-Caramés, Tiago M.; Dapena, Adriana; García-Naya, José Antonio

    2013-12-01

    The capacity of vehicular networks to offer non-safety services, like infotainment applications or the exchange of multimedia information between vehicles, have attracted a great deal of attention to the field of Intelligent Transport Systems (ITS). In particular, in this article we focus our attention on IEEE 802.11p which defines enhancements to IEEE 802.11 required to support ITS applications. We present an FPGA-based testbed developed to evaluate H.264/AVC (Advanced Video Coding) video transmission over vehicular networks. The testbed covers some of the most common situations in vehicle-to-vehicle and roadside-to-vehicle communications and it is highly flexible, allowing the performance evaluation of different vehicular standard configurations. We also show several experimental results to illustrate the quality obtained when H.264/AVC encoded video is transmitted over IEEE 802.11p networks. The quality is measured considering two important parameters: the percentage of recovered group of pictures and the frame quality. In order to improve performance, we propose to substitute the convolutional channel encoder used in IEEE 802.11p for a low-density parity-check code encoder. In addition, we suggest a simple strategy to decide the optimum number of iterations needed to decode each packet received.

  9. Low cost antennas for MSAT vehicular applications

    NASA Technical Reports Server (NTRS)

    Shafai, L.; Barakat, M.

    1993-01-01

    For Mobile MSAT applications a number of vehicular antennas have been developed that meet the program requirements. They are, however, costly to manufacture. Two antenna candidates are described here that provide adequate gain in the coverage zone and are also lower cost. One is the mast antenna that uses three or four element arrays of aquadrifilar helices. It generates omnidirectional pattern in azimuth and its beam is scanned in elevation. The second unit is a planar spiral antenna; it generates directional beams by a summation of the azimuthal modes. A variation of this antenna uses conical spirals to fulfill the same task. In both cases beam scanning is achieved by means of electronic switches rather than phase shifters, thus resulting in simpler configurations.

  10. Advanced Energy and Water Recovery Technology from Low Grade Waste Heat

    SciTech Connect

    Dexin Wang

    2011-12-19

    The project has developed a nanoporous membrane based water vapor separation technology that can be used for recovering energy and water from low-temperature industrial waste gas streams with high moisture contents. This kind of exhaust stream is widely present in many industrial processes including the forest products and paper industry, food industry, chemical industry, cement industry, metal industry, and petroleum industry. The technology can recover not only the sensible heat but also high-purity water along with its considerable latent heat. Waste heats from such streams are considered very difficult to recover by conventional technology because of poor heat transfer performance of heat-exchanger type equipment at low temperature and moisture-related corrosion issues. During the one-year Concept Definition stage of the project, the goal was to prove the concept and technology in the laboratory and identify any issues that need to be addressed in future development of this technology. In this project, computational modeling and simulation have been conducted to investigate the performance of a nanoporous material based technology, transport membrane condenser (TMC), for waste heat and water recovery from low grade industrial flue gases. A series of theoretical and computational analyses have provided insight and support in advanced TMC design and experiments. Experimental study revealed condensation and convection through the porous membrane bundle was greatly improved over an impermeable tube bundle, because of the membrane capillary condensation mechanism and the continuous evacuation of the condensate film or droplets through the membrane pores. Convection Nusselt number in flue gas side for the porous membrane tube bundle is 50% to 80% higher than those for the impermeable stainless steel tube bundle. The condensation rates for the porous membrane tube bundle also increase 60% to 80%. Parametric study for the porous membrane tube bundle heat transfer

  11. The Charlotte (TM) intra-vehicular robot

    NASA Technical Reports Server (NTRS)

    Swaim, Patrick L.; Thompson, Clark J.; Campbell, Perry D.

    1994-01-01

    NASA has identified telerobotics and telescience as essential technologies to reduce the crew extra-vehicular activity (EVA) and intra-vehicular activity (IVA) workloads. Under this project, we are developing and flight testing a novel IVA robot to relieve the crew of tedious and routine tasks. Through ground telerobotic control of this robot, we will enable ground researchers to routinely interact with experiments in space. Our approach is to develop an IVA robot system incrementally by employing a series of flight tests with increasing complexity. This approach has the advantages of providing an early IVA capability that can assist the crew, demonstrate capabilities that ground researchers can be confident of in planning for future experiments, and allow incremental refinement of system capabilities and insertion of new technology. In parallel with this approach to flight testing, we seek to establish ground test beds, in which the requirements of payload experimenters can be further investigated. In 1993 we reviewed manifested SpaceHab experiments and defined IVA robot requirements to assist in their operation. We also examined previous IVA robot designs and assessed them against flight requirements. We rejected previous design concepts on the basis of threat to crew safety, operability, and maintainability. Based on this insight, we developed an entirely new concept for IVA robotics, the CHARLOTTE robot system. Ground based testing of a prototype version of the system has already proven its ability to perform most common tasks demanded of the crew, including operation of switches, buttons, knobs, dials, and performing video surveys of experiments and switch panels.

  12. Development of Advanced Thermal and Environmental Barrier Coatings Using a High-Heat-Flux Testing Approach

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    2003-01-01

    The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 1700 C) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, high temperature capability thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity, which initially rises under the steady-state high temperature thermal gradient test due to coating sintering, and later drops under the cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on damage accumulation and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The external radiation resistance of the coating is assessed based on the measured specimen temperature response under a laser- heated intense radiation-flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature may be derived.

  13. EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF NEW POWER CYCLES AND ADVANCED FALLING FILM HEAT EXCHANGERS

    SciTech Connect

    Arsalan Razani; Kwang J. Kim

    2001-12-01

    The final report for the DOE/UNM grant number DE-FG26-98FT40148 discusses the accomplishments of both the theoretical analysis of advanced power cycles and experimental investigation of advanced falling film heat exchangers. This final report also includes the progress report for the third year (period of October 1, 2000 to September 30, 2001). Four new cycles were studied and two cycles were analyzed in detail based on the second law of thermodynamics. The first cycle uses a triple combined cycle, which consists of a topping cycle (Brayton/gas), an intermediate cycle (Rankine/steam), and a bottoming cycle (Rankine/ammonia). This cycle can produce high efficiency and reduces the irreversibility of the Heat Recovery Steam Generator (HRSC) of conventional combined power cycles. The effect of important system parameters on the irreversibility distribution of all components in the cycle under reasonable practical constraints was evaluated. The second cycle is a combined cycle, which consists of a topping cycle (Brayton/gas) and a bottoming cycle (Rankine/ammonia) with integrated compressor inlet air cooling. This innovative cycle can produce high power and efficiency. This cycle is also analyzed and optimized based on the second the second law to obtain the irreversibility distribution of all components in the cycle. The results of the studies have been published in peer reviewed journals and ASME conference proceeding. Experimental investigation of advanced falling film heat exchangers was conducted to find effective additives for steam condensation. Four additives have been selected and tested in a horizontal tube steam condensation facility. It has been observed that heat transfer additives have been shown to be an effective way to increase the efficiency of conventional tube bundle condenser heat exchangers. This increased condensation rate is due to the creation of a disturbance in the liquid condensate surround the film. The heat transfer through such a film has

  14. 10. Closeup view, looking east, of vehicular gates in closed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Close-up view, looking east, of vehicular gates in closed position and portal truss with knee bracing. (Nov. 30, 1988) - University Heights Bridge, Spanning Harlem River at 207th Street & West Harlem Road, New York County, NY

  15. 66. View from vehicular bridge southwest corner of Printz Basin, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    66. View from vehicular bridge southwest corner of Printz Basin, looking north. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  16. 67. View of old, abandoned vehicular bridge near entrance to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. View of old, abandoned vehicular bridge near entrance to Lake Trapps. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  17. 23. VIEW, LOOKING NORTH, SHOWING LOWER LEVEL OF VEHICULAR FERRY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. VIEW, LOOKING NORTH, SHOWING LOWER LEVEL OF VEHICULAR FERRY CONCOURSE, HEAD HOUSE ON LEFT AND FERRY SHEDS ON RIGHT - Central Railroad of New Jersey, Jersey City Ferry Terminal, Johnson Avenue at Hudson River, Jersey City, Hudson County, NJ

  18. 7. LESLIE WICKMAN, EVA (EXTRA VEHICULAR ACTIVITIES) SPECIALIST, IN SPACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. LESLIE WICKMAN, EVA (EXTRA VEHICULAR ACTIVITIES) SPECIALIST, IN SPACE SUIT AFTER TESTING IN NEUTRAL BUOYANCY TANK. AVERAGE COST OF SUIT IS $1,000,000. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

  19. 36 CFR 910.18 - Vehicular circulation and storage systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CORPORATION GENERAL GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE DEVELOPMENT AREA Urban Planning and Design Concerns § 910.18 Vehicular circulation...

  20. 36 CFR 910.18 - Vehicular circulation and storage systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CORPORATION GENERAL GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE DEVELOPMENT AREA Urban Planning and Design Concerns § 910.18 Vehicular circulation...

  1. 36 CFR 910.18 - Vehicular circulation and storage systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CORPORATION GENERAL GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE DEVELOPMENT AREA Urban Planning and Design Concerns § 910.18 Vehicular circulation...

  2. 36 CFR 910.18 - Vehicular circulation and storage systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CORPORATION GENERAL GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE DEVELOPMENT AREA Urban Planning and Design Concerns § 910.18 Vehicular circulation...

  3. 36 CFR 910.18 - Vehicular circulation and storage systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CORPORATION GENERAL GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE DEVELOPMENT AREA Urban Planning and Design Concerns § 910.18 Vehicular circulation...

  4. 35. VIEW TO NORTHWEST; DETAIL, VOLUTE AT BASE OF VEHICULAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. VIEW TO NORTHWEST; DETAIL, VOLUTE AT BASE OF VEHICULAR RAMP FROM LIGHTING PYLON (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  5. 34. VIEW TO EAST; DETAIL OF LAMP ON VEHICULAR RAMP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. VIEW TO EAST; DETAIL OF LAMP ON VEHICULAR RAMP LIGHTING PYLON (Dobson) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  6. 33. VIEW TO NORTHWEST; DETAIL OF VEHICULAR RAMP LIGHTING PYLON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. VIEW TO NORTHWEST; DETAIL OF VEHICULAR RAMP LIGHTING PYLON (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  7. View looking from the Tenth Street vehicular entrance to the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View looking from the Tenth Street vehicular entrance to the Justice Department Building to show the great court and fountain - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  8. Studies of dynamic contact of ceramics and alloys for advanced heat engines. Final report

    SciTech Connect

    Gaydos, P.A.; Dufrane, K.F.

    1993-06-01

    Advanced materials and coatings for low heat rejection engines have been investigated for almost a decade. Much of the work has concentrated on the critical wear interface between the piston ring and cylinder liner. Simplified bench tests have identified families of coatings with high temperature wear performance that could meet or exceed that of conventional engine materials at today`s operating temperatures. More recently, engine manufacturers have begun to optimize material combinations and manufacturing processes so that the materials not only have promising friction and wear performance but are practical replacements for current materials from a materials and manufacturing cost standpoint. In this study, the advanced materials supplied by major diesel engine manufacturers were evaluated in an experimental apparatus that simulates many of the in-cylinder conditions of a low heat rejection diesel engine. Results include ring wear factors and average dynamic friction coefficients measured at intervals during the test. These results are compared with other advanced materials tested in the past as well as the baseline wear of current engines. Both fabricated specimens and sections of actual ring and cylinder liners were used in the testing. Observations and relative friction and wear performance of the individual materials are provided.

  9. Field evaluation of advanced controls for the retrofit of packaged air conditioners and heat pumps

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Ngo, Hung; Underhill, Ronald M.; Taasevigen, Danny J.; Lutes, Robert G.

    2015-09-01

    This paper documents the magnitude of energy savings achievable in the field by retrofitting existing packaged rooftop units (RTUs) with advanced control strategies not ordinarily used for RTUs. A total of 66 RTUs on 8 different buildings were retrofitted with a commercially available advanced controller for improving RTU operational efficiency. The controller features enhanced air-side economizer control, multi-speed fan control, and demand controlled ventilation. Of the 66 RTUs, 18 are packaged heat pumps and the rest are packaged air conditioners with gas heat. The eight buildings cover four building types and four climate conditions. Based on the data collected for about a whole year, the advanced controller reduced the normalized annual RTU energy consumption between 22% and 90%, with an average of 57% for all RTUs. The average fractional savings uncertainty was 12% at 95% confidence level. Normalized annual electricity savings were in the range between 0.47 kWh/h (kWh per hour of RTU operation) and 7.21 kWh/h, with an average of 2.39 kWh/h. RTUs greater than 53 kW and runtime greater than 14 hours per day had payback periods less than 3 years even at $0.05/kWh.

  10. Pressure Build-Up in LNG and LH2 Vehicular Cryogenic Storage Tanks

    NASA Astrophysics Data System (ADS)

    Barclay, J. A.; Rowe, A. M.; Barclay, M. A.

    2004-06-01

    The use of LNG and LH2 as fuels in heavy duty vehicles is increasing steadily because cryogenic liquids provides superior volumetric and gravimetric energy densities compared to other means of on-board storage. Although several sizes and types of tanks exist, a typical vehicular storage tank has a volume of ˜400 liters (˜100 gallons). The pressure in the ullage space of a tank freshly filled is usually ˜0.25 MPa but may vary during use from ˜0.25 MPa (˜20 psig) to ˜0.92 MPa (˜120 psig). Cryogenic vehicular tanks are typically dual-walled, stainless steel vessels with vacuum and superinsulation isolation between the inner and outer vessel walls. The heat leaks into such tanks are measured as a percentage boil-off per day. For a storage tank of vehicular size range, the boil-off may be ˜ 1 % day, depending upon the cryogen and the quality of the tank. The corresponding heat leak into the cryogenic liquid vaporizes a certain amount of liquid that in turn increases the pressure in the tank which in turn significantly influences the properties of the cryogens. We have used a novel approach to calculate the increase in pressure of LNG and LH2 in a closed cryogenic vessel with a fixed heat leak as a function of time using real equations of state for the properties of the cryogens. The method and results for the time it takes for a freshly filled tank to increase in pressure from the filling pressure of ˜0.25 MPa to a venting pressure of ˜1.73 MPa are presented.

  11. Analysis of state of vehicular scars on Arctic Tundra, Alaska

    NASA Technical Reports Server (NTRS)

    Lathram, E. H.

    1974-01-01

    Identification on ERTS images of severe vehicular scars in the northern Alaska tundra suggests that, if such scars are of an intensity or have spread to a dimension such that they can be resolved by ERTS sensors (20 meters), they can be identified and their state monitored by the use of ERTS images. Field review of the state of vehicular scars in the Umiat area indicates that all are revegetating at varying rates and are approaching a stable state.

  12. Enskog-like kinetic models for vehicular traffic

    SciTech Connect

    Klar, A.; Wegener, R.

    1997-04-01

    In the present paper a general criticism of kinetic equations for vehicular traffic is given. The necessity of introducing an Enskog-type correction into these equations is shown. An Enskog-like kinetic traffic flow equation is presented and fluid dynamic equations are derived. This derivation yields new coefficients for the standard fluid dynamic equations of vehicular traffic. Numerical simulations for inhomogeneous traffic flow situations are shown together with a comparison between kinetic and fluid dynamics models.

  13. EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF NEW POWER CYCLES AND ADVANCED FALLING FILM HEAT EXCHANGERS

    SciTech Connect

    Arsalan Razani; Kwang J. Kim

    2000-10-28

    The annual progress report for the period of October 1, 1999 to September 30, 2000 on DOE/UNM grant number DE-FG26-98FT40148 discusses the progress on both the theoretical analysis of advanced power cycles and the experimental investigation of advanced falling film heat exchangers. The previously developed computer program for the triple cycle, based on the air standard cycle assumption, was modified to include actual air composition (%77.48 N{sub 2}, %20.59 O{sub 2}, %1.9 H{sub 2}O, and %0.03 CO{sub 2}). The actual combustion products were used in exergy analysis of the triple cycle. The effect of steam injection into the combustion chamber on its irreversibility, and the irreversibility of the entire cycle, was evaluated. A more practical fuel inlet condition and a better position of the feedwater heater in the steam cycle were used in the modified cycle. The effect of pinch point and the temperature difference between the combustion products, as well as the steam in the heat recovery steam generator on irreversibility of the cycle were evaluated. Design, construction, and testing of the multitube horizontal falling film condenser facility were completed. Two effective heat transfer additives (2-ethyl-1-hexanol and alkyl amine) were identified and tested for steam condensation. The test results are included. The condenser was designed with twelve tubes in an array of three horizontals and four verticals, with a 2-inch horizontal and 1.5-inch vertical in-line pitch. By using effective additives, the condensation heat transfer rate can be augmented as much as 30%, as compared to a heat transfer that operated without additives under the same operating condition. When heat transfer additives function effectively, the condensate-droplets become more dispersed and have a smaller shape than those produced without additives. These droplets, unlike traditional turbulence, start at the top portion of the condenser tubes and cover most of the tubes. Such a flow behavior can

  14. An Infrastructureless Approach to Estimate Vehicular Density in Urban Environments

    PubMed Central

    Sanguesa, Julio A.; Fogue, Manuel; Garrido, Piedad; Martinez, Francisco J.; Cano, Juan-Carlos; Calafate, Carlos T.; Manzoni, Pietro

    2013-01-01

    In Vehicular Networks, communication success usually depends on the density of vehicles, since a higher density allows having shorter and more reliable wireless links. Thus, knowing the density of vehicles in a vehicular communications environment is important, as better opportunities for wireless communication can show up. However, vehicle density is highly variable in time and space. This paper deals with the importance of predicting the density of vehicles in vehicular environments to take decisions for enhancing the dissemination of warning messages between vehicles. We propose a novel mechanism to estimate the vehicular density in urban environments. Our mechanism uses as input parameters the number of beacons received per vehicle, and the topological characteristics of the environment where the vehicles are located. Simulation results indicate that, unlike previous proposals solely based on the number of beacons received, our approach is able to accurately estimate the vehicular density, and therefore it could support more efficient dissemination protocols for vehicular environments, as well as improve previously proposed schemes. PMID:23435054

  15. Technology Development Roadmap for the Advanced High Temperature Reactor Secondary Heat Exchanger

    SciTech Connect

    P. Sabharwall; M. McCllar; A. Siahpush; D. Clark; M. Patterson; J. Collins

    2012-09-01

    This Technology Development Roadmap (TDRM) presents the path forward for deploying large-scale molten salt secondary heat exchangers (MS-SHX) and recognizing the benefits of using molten salt as the heat transport medium for advanced high temperature reactors (AHTR). This TDRM will aid in the development and selection of the required heat exchanger for: power production (the first anticipated process heat application), hydrogen production, steam methane reforming, methanol to gasoline production, or ammonia production. This TDRM (a) establishes the current state of molten salt SHX technology readiness, (b) defines a path forward that systematically and effectively tests this technology to overcome areas of uncertainty, (c) demonstrates the achievement of an appropriate level of maturity prior to construction and plant operation, and (d) identifies issues and prioritizes future work for maturing the state of SHX technology. This study discusses the results of a preliminary design analysis of the SHX and explains the evaluation and selection methodology. An important engineering challenge will be to prevent the molten salt from freezing during normal and off-normal operations because of its high melting temperature (390°C for KF ZrF4). The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The need for efficiency, compactness, and safety challenge the capabilities of existing heat exchanger technology. The description of potential heat exchanger configurations or designs (such as printed circuit, spiral or helical coiled, ceramic, plate and fin, and plate type) were covered in an earlier report (Sabharwall et al. 2011). Significant future work, much of which is suggested in this report, is needed before the benefits and full potential of the AHTR can be realized. The execution of this TDRM will focuses

  16. The study of heat flux for disruption on experimental advanced superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Yang, Zhendong; Fang, Jianan; Gong, Xianzu; Gan, Kaifu; Luo, Jiarong; Zhao, Hailin; Cui, Zhixue; Zhang, Bin; Chen, Meiwen

    2016-05-01

    Disruption of the plasma is one of the most dangerous instabilities in tokamak. During the disruption, most of the plasma thermal energy is lost, which causes damages to the plasma facing components. Infrared (IR) camera is an effective tool to detect the temperature distribution on the first wall, and the energy deposited on the first wall can be calculated from the surface temperature profile measured by the IR camera. This paper concentrates on the characteristics of heat flux distribution onto the first wall under different disruptions, including the minor disruption and the vertical displacement events (VDE) disruption. Several minor disruptions have been observed before the major disruption under the high plasma density in experimental advanced superconducting tokamak. During the minor disruption, the heat fluxes are mainly deposited on the upper/lower divertors. The magnetic configuration prior to the minor disruption is a lower single null with the radial distance between the two separatrices in the outer midplane dRsep = -2 cm, while it changes to upper single null (dRsep = 1.4 cm) during the minor disruption. As for the VDE disruption, the spatial distribution of heat flux exhibits strong toroidal and radial nonuniformity, and the maximum heat flux received on the dome plate can be up to 11 MW/m2.

  17. Studies of dynamic contact of ceramics and alloys for advanced heat engines: Final report

    SciTech Connect

    Dufrane, K.F.; Glaeser, W.A.; Rosenfield, A.R.

    1988-03-01

    In support of the efforts to apply ceramics in advanced heat engines, a study was made of the sliding performance of ceramics at the ring/cylinder interface of low heat rejection engines. The objective was to understand the basic mechanisms controlling the wear of candidate ceramics and thereby identify means for applying these ceramics effectively. Attempts to operate three different zirconias, silicon carbide, silicon nitride, and several plasma-sprayed ceramic coatings without lubrication were unsuccessful because of high friction and high wear rates. Experiments using a polyalphaolefin lubricant at temperatures to 260 C identified several combinations having wear rates in the general range likely to be acceptable for engines. Plasma-sprayed coatings of chromium oxide and hypersonic powder flame sprayed coatings of cobalt-bonded tungsten carbide performed particularly well as ring coatings. Similar performance was obtained with these ring coatings operating against silicon carbide, silicon nitride, silicon carbide whisker-reinforced alumina, and chromium oxide coatings. Zirconia experienced high wear rates because of thermal-shock-induced surface cracking. Low thermal conductivity of zirconia allows local areas to heat excessively from friction. Periodic heating induces thermal shock cracking and subsequent spalling. The study demonstrated the importance of lubrication to successful sliding of ceramics and the need for lubricants capable of operating at temperatures in the range of 250 to 650 C. 42 refs., 32 figs., 8 tabs.

  18. ATF (Advanced Toroidal Facility) ECH (Electron Cyclotron Heating) waveguide component development and testing

    SciTech Connect

    Bigelow, T.S.; White, T.L.; Kimrey, H.D.

    1987-01-01

    The Advanced Toroidal Facility (ATF) Electron Cyclotron Heating (ECH) system presently under construction will consist of two 53.2-GHz, 200-kW continuous-wave (cw) gyrotrons with a mode-controlled waveguide system and polarized launcher optimized for maximum power in the ATF plasma. Several components, such as a waveguide mode-analyzing directional coupler, a TiO/sub 2/ mode absorber, miter bends, and a polarization-selectable beamed launcher, have been developed and tested. Laboratory results and initial high-power operation of the system are presented. 2 refs., 2 figs.

  19. Development of electrical feedback controlled heat pipes and the advanced thermal control flight experiment

    NASA Technical Reports Server (NTRS)

    Bienert, W. B.

    1974-01-01

    The development and characteristics of electrical feedback controlled heat pipes (FCHP) are discussed. An analytical model was produced to describe the performance of the FCHP under steady state and transient conditions. An advanced thermal control flight experiment was designed to demonstrate the performance of the thermal control component in a space environment. The thermal control equipment was evaluated on the ATS-F satellite to provide performance data for the components and to act as a thermal control system which can be used to provide temperature stability of spacecraft components in future applications.

  20. Advanced Soldier Thermoelectric Power System for Power Generation from Battlefield Heat Sources

    SciTech Connect

    Hendricks, Terry J.; Hogan, Tim; Case, Eldon D.; Cauchy, Charles J.

    2010-09-01

    The U.S. military uses large amounts of fuel during deployments and battlefield operations. This project sought to develop a lightweight, small form-factor, soldier-portable advanced thermoelectric (TE) system prototype to recover and convert waste heat from various deployed military equipment (i.e., diesel generators/engines, incinerators, vehicles, and potentially mobile kitchens), with the ultimate purpose of producing power for soldier battery charging, advanced capacitor charging, and other battlefield power applications. The technical approach employed microchannel technology, a unique “power panel” approach to heat exchange/TE system integration, and newly-characterized LAST (lead-antimony-silver-telluride) and LASTT (lead-antimony-silver-tin-telluride) TE materials segmented with bismuth telluride TE materials in designing a segmented-element TE power module and system. This project researched never-before-addressed system integration challenges (thermal expansion, thermal diffusion, electrical interconnection, thermal and electrical interfaces) of designing thin “power panels” consisting of alternating layers of thin, microchannel heat exchangers (hot and cold) sandwiching thin, segmented-element TE power generators. The TE properties, structurally properties, and thermal fatigue behavior of LAST and LASTT materials were developed and characterized such that the first segmented-element TE modules using LAST / LASTT materials were fabricated and tested at hot-side temperatures = 400 °C and cold-side temperatures = 40 °C. LAST / LASTT materials were successfully segmented with bismuth telluride and electrically interconnected with diffusion barrier materials and copper strapping within the module electrical circuit. A TE system design was developed to produce 1.5-1.6 kW of electrical energy using these new TE modules from the exhaust waste heat of 60-kW Tactical Quiet Generators as demonstration vehicles.

  1. Regularization and control of irregular vehicular motion through a series of signals at disordered intervals

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2011-06-01

    We study the control and regularization of irregular motion of a vehicle moving through the series of traffic signals positioned at disordered intervals. All signals are controlled by both cycle time and phase shift. The nonlinear dynamic model of the vehicular motion controlled by signals is described in terms of the stochastic nonlinear map. The vehicle exhibits a very complex behavior with varying both cycle time and strength of disordered intervals. The delay or advance of tour time is compensated by synchronizing the phase shift with disordered intervals. The irregular motion induced by the disordered configuration of signals is regularized for various values of cycle time.

  2. Recent Advances in Regional Climate System Modeling and ClimateChange Analyses of Extreme Heat

    SciTech Connect

    Miller, Norman L.

    2004-09-24

    During the period May 2003 to May 2004, there were two CEC/PIER funded primary research activities by the Atmosphere and Ocean Sciences Group/Earth Science Division at LBNL. These activities are the implementation and testing of the National Center for Atmospheric Research Community Land Model (CLM) into MM5, and the analysis of extreme heat days under a new set of climate simulations. The new version of MM5,MM5-CLM, has been tested for a 90 day snowmelt period in the northwestern U.S. Results show that this new code upgrade, as compared to the MM5-NOAH, has improved snowmelt, temperature, and precipitation when compared to observations. These are due in part to a subgrid scheme,advanced snow processes, and advanced vegetation. The climate change analysis is the upper and lower IPCC Special Report on Emission Scenarios, representing fossil fuel intensive and energy conserving future emission scenarios, and medium and low sensitivity Global Climate Models. Results indicate that California cities will see increases in the number of heat wave and temperature threshold days from two to six times.These results may be viewed as potential outcomes based on today's decisions on emissions.

  3. Evaluation of Thermocompression Heat Pump Performance for American Maize, Decatur, AL [Advanced Industrial Heat Pump Applications and Evaluations

    SciTech Connect

    Eastwood, A.

    1993-06-01

    This work was carried out in two phases: Phase 1, identification of opportunities for heat pumps in industrial applications and Phase 2, evaluation of heat pumps in industrial applications. In Phase 1, pinch analysis was applied to several industrial sites to identify the best opportunities for heat pumping and other forms of heat integration. In Phase 2, more detailed analyses were undertaken, including the evaluation of a heat pump installed as a recommendation of Phase 1.

  4. Advances in the Lightweight Air-Liquid Composite Heat Exchanger Development for Space Exploration Applications

    NASA Technical Reports Server (NTRS)

    Shin, E. Eugene; Johnston, J. Chris; Haas, Daniel

    2011-01-01

    An advanced, lightweight composite modular Air/Liquid (A/L) Heat Exchanger (HX) Prototype for potential space exploration thermal management applications was successfully designed, manufactured, and tested. This full-scale Prototype consisting of 19 modules, based on recommendations from its predecessor Engineering Development unit (EDU) but with improved thermal characteristics and manufacturability, was 11.2 % lighter than the EDU and achieves potentially a 42.7% weight reduction from the existing state-of-the-art metallic HX demonstrator. However, its higher pressure drop (0.58 psid vs. 0.16 psid of the metal HX) has to be mitigated by foam material optimizations and design modifications including a more systematic air channel design. Scalability of the Prototype design was validated experimentally by comparing manufacturability and performance between the 2-module coupon and the 19-module Prototype. The Prototype utilized the thermally conductive open-cell carbon foam material but with lower density and adopted a novel high-efficiency cooling system with significantly increased heat transfer contact surface areas, improved fabricability and manufacturability compared to the EDU. Even though the Prototype was required to meet both the thermal and the structural specifications, accomplishing the thermal requirement was a higher priority goal for this first version. Overall, the Prototype outperformed both the EDU and the corresponding metal HX, particularly in terms of specific heat transfer, but achieved 93.4% of the target. The next generation Prototype to achieve the specification target, 3,450W would need 24 core modules based on the simple scaling factor. The scale-up Prototype will weigh about 14.7 Kg vs. 21.6 Kg for the metal counterpart. The advancement of this lightweight composite HX development from the original feasibility test coupons to EDU to Prototype is discussed in this paper.

  5. Advanced Multi-Effect Distillation System for Desalination Using Waste Heat fromGas Brayton Cycles

    SciTech Connect

    Haihua Zhao; Per F. Peterson

    2012-10-01

    Generation IV high temperature reactor systems use closed gas Brayton Cycles to realize high thermal efficiency in the range of 40% to 60%. The waste heat is removed through coolers by water at substantially greater average temperature than in conventional Rankine steam cycles. This paper introduces an innovative Advanced Multi-Effect Distillation (AMED) design that can enable the production of substantial quantities of low-cost desalinated water using waste heat from closed gas Brayton cycles. A reference AMED design configuration, optimization models, and simplified economics analysis are presented. By using an AMED distillation system the waste heat from closed gas Brayton cycles can be fully utilized to desalinate brackish water and seawater without affecting the cycle thermal efficiency. Analysis shows that cogeneration of electricity and desalinated water can increase net revenues for several Brayton cycles while generating large quantities of potable water. The AMED combining with closed gas Brayton cycles could significantly improve the sustainability and economics of Generation IV high temperature reactors.

  6. Advanced Synthesis of Spinnable MWCNT Forests by RF-Induction Heating Enhanced CVD Process

    NASA Astrophysics Data System (ADS)

    Zakhidov, Anvar; Holmes, William; UTD Solarno Team; Solarno UTD Team

    2015-03-01

    We demonstrate here an advanced method to effectively grow tall multi-wall carbon nanotubes (MWCNT) vertically oriented forests which are highly spinnable. Heating of the Fe catalyst is achieved extremely fast by RF induction heating using coils outside the quartz tube. This method and the new apparatus designed and presented in this paper allow separate control over the temperature of the substrate and the temperature of the incoming gases. In addition to temperature control, the fast T-ramping of the substrate preserves the catalyst nanoclusters from Ostwald ripening and other growth quenching effects such as carbon overgrowth of the catalyst. We show that the parametric sweet spot or bell curve of substrate spinnability can be increased significantly with this improved RF-CVD method. The catalyst nanoclusters also show a wide band of density arrangements that very positively effect spinnability and the drawing ratio. Drawing ratios can vary from 2 meters to 12 meters of sheets drawn from only 1cm of forest. RF-CVD method allows to grow fast (in several minuts) higher CNT forests at higher temperature of synthesis up to 800 K, and obtain dry-spinable CNTs, Characterization results of the samples created in the newRF-CVD system will be presented and compared to previous CNT sheet samples by conventional three-zone resistive heating CVD to measure the extent of property improvements of the CNT sheets and forests. Specifics of the experimental system will be addressed in detail and future property improvements and applications explored.

  7. Advanced heat receiver conceptual design study. Final report, May 1986-July 1988

    SciTech Connect

    Kesseli, J.; Saunders, R.; Batchelder, G.

    1988-10-01

    Solar dynamic space power systems are candidate electrical power generating systems for future NASA missions. One of the key components of the solar dynamic power system is the solar receiver/thermal energy storage (TES) subsystem. Receiver development was conducted by NASA in the late 1960's and since then a very limited amount of work has been done in this area. Consequently the state of the art (SOA) receivers designed for the IOC space station are large and massive. The objective of the Advanced Heat Receiver Conceptual Design Study is to conceive and analyze advanced high temperature solar dynamic Brayton and Stirling receivers. The goal is to generate innovative receiver concepts that are half of the mass, smaller, and more efficient than the SOA. It is also necessary that these innovative receivers offer ease of manufacturing, less structural complexity and fewer thermal stress problems. Advanced Brayton and Stirling receiver storage units are proposed and analyzed in this study which can potentially meet these goals.

  8. Investigation of Heat Transfer and Combustion in the Advanced Fluidized Bed Combustion.

    SciTech Connect

    Lee, S.W.

    1997-10-01

    This technical report summarizes the research conducted and progress achieved during the period from July 1, 1997 to September 30, 1997. In order to conduct the numerical modeling/simulation on the advanced swirling fluidized bed combustor (hot model), the basic governing equations are formulated based upon the continuity and momentum equations, and energy equations in the cylindrical coordinates. The chemical reaction and radiation heat transfer were considered in this modeling/simulation work. The chemical reaction and the diffusion due to concentration gradients and thermal effects are also included in the modeling for simulation. The flow system was configured in 3-D cylindrical coordinates with the uniform mesh grids. The calculation grid was set of orthogonal lines arranged in the cylindrical coordinates which includes three different directions: tangential direction (I), radial direction (i), and vertical direction (k). There are a total of 24192 grids in the system configuration including 14 slices of the tangential direction (I), 24 slices of the radial direction (j), and 72 slices of the vertical direction. Numerical simulation on the advanced swirling fluidized bed combustor is being conducted using computational fluid dynamics (CFD) code, Fluent. This code is loaded onto the supercomputer, CRAY J916 system of Morgan State University. Numerical modeling/simulation will be continued to determine the hot flow patterns, velocity profiles, static pressure profiles, and temperature profiles in the advanced swirling fluidized combustor.

  9. Colored three-dimensional reconstruction of vehicular thermal infrared images

    NASA Astrophysics Data System (ADS)

    Sun, Shaoyuan; Leung, Henry; Shen, Zhenyi

    2015-06-01

    Enhancement of vehicular night vision thermal infrared images is an important problem in intelligent vehicles. We propose to create a colorful three-dimensional (3-D) display of infrared images for the vehicular night vision assistant driving system. We combine the plane parameter Markov random field (PP-MRF) model-based depth estimation with classification-based infrared image colorization to perform colored 3-D reconstruction of vehicular thermal infrared images. We first train the PP-MRF model to learn the relationship between superpixel features and plane parameters. The infrared images are then colorized and we perform superpixel segmentation and feature extraction on the colorized images. The PP-MRF model is used to estimate the superpixel plane parameter and to analyze the structure of the superpixels according to the characteristics of vehicular thermal infrared images. Finally, we estimate the depth of each pixel to perform 3-D reconstruction. Experimental results demonstrate that the proposed method can give a visually pleasing and daytime-like colorful 3-D display from a monochromatic vehicular thermal infrared image, which can help drivers to have a better understanding of the environment.

  10. Grassland plant composition alters vehicular disturbance effects in Kansas, USA.

    PubMed

    Dickson, Timothy L; Wilsey, Brian J; Busby, Ryan R; Gebhart, Dick L

    2008-05-01

    Many "natural" areas are exposed to military or recreational off-road vehicles. The interactive effects of different types of vehicular disturbance on vegetation have rarely been examined, and it has been proposed that some vegetation types are less susceptible to vehicular disturbance than others. At Fort Riley, Kansas, we experimentally tested how different plant community types changed after disturbance from an M1A1 Abrams tank driven at different speeds and turning angles during different seasons. The greatest vegetation change was observed because of driving in the spring in wet soils and the interaction of turning while driving fast (vegetation change was measured with Bray-Curtis dissimilarity). We found that less vegetation change occurred in communities with high amounts of native prairie vegetation than in communities with high amounts of introduced C(3) grasses, which is the first experimental evidence we are aware of that suggests plant communities dominated by introduced C(3) grasses changed more because of vehicular disturbance than communities dominated by native prairie grasses. We also found that vegetation changed linearly with vehicular disturbance intensity, suggesting that at least initially there was no catastrophic shift in vegetation beyond a certain disturbance intensity threshold. Overall, the intensity of vehicular disturbance appeared to play the greatest role in vegetation change, but the plant community type also played a strong role and this should be considered in land use planning. The reasons for greater vegetation change in introduced C(3) grass dominated areas deserve further study. PMID:18204985

  11. 75 FR 78269 - Vehicular Digital Multimedia Evidence Recording System (VDMERS) Standard for Law Enforcement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Office of Justice Programs Vehicular Digital Multimedia Evidence Recording System (VDMERS) Standard for Law... the general public the draft ``Vehicular Digital Multimedia Evidence Recording System Standard for...

  12. 76 FR 19128 - Extension of Time for Comments on NIJ Draft Vehicular Digital Multimedia Evidence Recording...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... of Justice Programs Extension of Time for Comments on NIJ Draft Vehicular Digital Multimedia Evidence... Enforcement Vehicular Digital Multimedia Evidence Recording System Selection and Application Guide AGENCY... Digital Multimedia Evidence Recording System Certification Program Requirements for Law...

  13. 76 FR 27355 - Law Enforcement Vehicular Digital Multimedia Evidence Recording System Selection and Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Office of Justice Programs Law Enforcement Vehicular Digital Multimedia Evidence Recording System Selection... public, the ``Law Enforcement Vehicular Digital Multimedia Evidence Recording System Selection...

  14. Advanced heat-pipe heat exchanger and microprocessor-based modulating burner controls development. Final report, January 1985-December 1987

    SciTech Connect

    Lowenstein, A.; Cohen, B.; Feldman, S.; Marsala, J.; Spatz, M.

    1988-02-01

    The work presented in the report includes: (1) the development of a heat-pipe condensing heat exchanger; (2) the development of a nominal 100,000-Btu/hr modulating air/gas valve; (3) the experimental performance studies of water/copper thermosyphons; (4) the field operation of a six-zone warm-air heating system; (5) the adaptation of a conventional venturi-type burner to modulation; and (6) the results of a one-day workshop for manufacturers of HVAC equipment on heat-pipe heat exchangers. Several of the accomplishments of the project included: A unique air/gas valve was adapted to furnaces with heat-pipe and drum-type heat exchangers, providing these furnaces with over a 5-to-1 turndown capability. A six-zone warm-air heating system was tested for two winters with the modulating furnaces previously described. A data base for the application of copper/water thermosyphons was started. A ten-tube heat-pipe heat exchanger was incorporated into a conventional clam-shell furnace as its second-stage condensing heat exchanger with only a small increase in the furnace's dimensions.

  15. Characteristics of vehicular traffic flow at a roundabout

    NASA Astrophysics Data System (ADS)

    Ebrahim Fouladvand, M.; Sadjadi, Zeinab; Reza Shaebani, M.

    2004-10-01

    We construct a stochastic cellular automata model for the description of vehicular traffic at a roundabout designed at the intersection of two perpendicular streets. The vehicular traffic is controlled by a self-organized scheme in which traffic lights are absent. This controlling method incorporates a yield-at-entry strategy for the approaching vehicles to the circulating traffic flow in the roundabout. Vehicular dynamics is simulated and the delay experienced by the traffic at each individual street is evaluated. We discuss the impact of the geometrical properties of the roundabout on the total delay. We compare our results with traffic-light signalization schemes, and obtain the critical traffic volume over which the intersection is optimally controlled through traffic-light signalization schemes.

  16. Effect of vehicular size on chain-reaction crash

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2015-11-01

    We present the dynamic model of the chain-reaction crash to take account of the vehicular size. Drivers brake according to taillights of the forward vehicle. We investigate the effect of the vehicular size on the chain-reaction crash (multiple-vehicle collision) in the traffic flow controlled by taillights. In the multiple-vehicle collision, the first crash induces more collisions. We investigate how the first collision induces the chain-reaction crash numerically. We derive, analytically, the transition points and the region maps for the chain-reaction crash in the traffic flow of vehicles with finite sizes. We clarify the effect of the vehicular size on the multiple-vehicle collision.

  17. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    SciTech Connect

    Swindeman, R.W.; Ren, W.

    1996-08-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, modified alloy 800, and two sulfidation resistant alloys: HR160 and HR120. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700{degrees}C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925{degrees}C with good weldability and ductility.

  18. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    SciTech Connect

    Swindeman, R.W.; Ren, W.

    1995-08-01

    Alloys for design and construction of structural components needed to contain process streams and provide internal structures in advanced heat recovery and hot gas cleanup systems were examined. Emphasis was placed on high-strength, corrosion-resistant alloys for service at temperatures above 1000 {degrees}F (540{degrees}C). Data were collected that related to fabrication, joining, corrosion protection, and failure criteria. Alloys systems include modified type 310 and 20Cr-25Ni-Nb steels and sulfidation-resistance alloys HR120 and HR160. Types of testing include creep, stress-rupture, creep crack growth, fatigue, and post-exposure short-time tensile. Because of the interest in relatively inexpensive alloys for high temperature service, a modified type 310 stainless steel was developed with a target strength of twice that for standard type 310 stainless steel.

  19. Investigation of austenitic alloys for advanced heat recovery and hot-gas cleanup systems

    SciTech Connect

    Swindeman, R.W.

    1997-12-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, and modified alloy 800. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700 C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925 C with good weldability and ductility.

  20. Heat-transfer characteristics of a dry and wet/dry advanced condenser for cooling towers

    NASA Astrophysics Data System (ADS)

    Fricke, H. D.; McIlroy, K.; Webster, D. J.

    1982-06-01

    An experimental evaluation of two types of advanced, air cooled ammonia condensers for a phase change dry/wet cooling system for electric power plants is described. Condensers of similar design, but much bigger, are being tested in a 15 MWe demonstration plant. These condensers, featuring different air side augmentation, were tested in an ammonia phase change pilot plant (0.3 MWe). The first unit consisted of the integral shaved fin extruded aluminum tubing designed for dry operation. Heat transfer and air side pressure loss characteristics were measured under varying air face velocities (600 to 1000 FPM) and initial temperature differences, ITD (20 to 60 F). Overall heat transfer coefficients (based on air side surface), U, ranged between 7.0 to 8.6 Btu/hr sq ft. F. The second configuration constituted the Hoterv aluminum plate fin/tube assembly of which two different sizes (5 sq ft and 58 sq ft frontal area) were performance tested; in both dry and wet modes at 200 to 800 FPM air face velocities, ITD's of 10 to 60 F and at water deluge rates up to 3.0 gpm/ft. of core width.

  1. Advanced development of the boundary element method for steady-state heat conduction

    NASA Technical Reports Server (NTRS)

    Dargush, G. F.; Banerjee, Prasanta K.

    1989-01-01

    Considerable progress has been made in recent years toward advancing the state-of-the-art in solid mechanics boundary element technology. In the present work, much of this new technology is applied in the development of a general-purpose boundary element method (BEM) for steady-state heat conduction. In particular, the BEM implementation involves the use of higher-order conforming elements, self-adaptive integration and multi-region capability. Two- and three-dimensional, as well as axisymmetric analysis, are incorporated within a unified framework. In addition, techniques are introduced for the calculation of boundary flux, and for the inclusion of thermal resistance across interfaces. As a final extension, an efficient formulation is developed for the analysis of solid three-dimensional bodies with embedded holes. For this last class of problems, the new BEM formulation is particularly attractive, since use of the alternatives (i.e. finite element or finite difference methods) is not practical. A number of detailed examples illustrate the suitability and robustness of the present approach for steady-state heat conduction.

  2. Initial high-power testing of the ATF (Advanced Toroidal Facility) ECH (electron cyclotron heating) system

    SciTech Connect

    White, T.L.; Bigelow, T.S.; Kimrey, H.D. Jr.

    1987-01-01

    The Advanced Toroidal Facility (ATF) is a moderate aspect ratio torsatron that will utilize 53.2 GHz 200 kW Electron Cyclotron Heating (ECH) to produce nearly current-free target plasmas suitable for subsequent heating by strong neutral beam injection. The initial configuration of the ECH system from the gyrotron to ATF consists of an optical arc detector, three bellows, a waveguide mode analyzer, two TiO/sub 2/ mode absorbers, two 90/sup 0/ miter bends, two waveguide pumpouts, an insulating break, a gate valve, and miscellaneous straight waveguide sections feeding a launcher radiating in the TE/sub 02/ mode. Later, a focusing Vlasov launcher will be added to beam the ECH power to the saddle point in ATF magnetic geometry for optimum power deposition. The ECH system has several unique features; namely, the entire ECH system is evacuated, the ECH system is broadband, forward power is monitored by a newly developed waveguide mode analyzer, phase correcting miter bends will be employed, and the ECH system will be capable of operating short pulse to cw. Initial high-power tests show that the overall system efficiency is 87%. The waveguide mode analyzer shows that the gyrotron mode output consists of 13% TE/sub 01/, 82.6% TE/sub 02/, 2.5% TE/sub 03/, and 1.9% TE/sub 04/. 4 refs.

  3. Heat Transfer and Thermal Stability Research for Advanced Hydrocarbon Fuel Technologies

    NASA Technical Reports Server (NTRS)

    DeWitt, Kenneth; Stiegemeier, Benjamin

    2005-01-01

    In recent years there has been increased interest in the development of a new generation of high performance boost rocket engines. These efforts, which will represent a substantial advancement in boost engine technology over that developed for the Space Shuttle Main Engines in the early 1970s, are being pursued both at NASA and the United States Air Force. NASA, under its Space Launch Initiative s Next Generation Launch Technology Program, is investigating the feasibility of developing a highly reliable, long-life, liquid oxygen/kerosene (RP-1) rocket engine for launch vehicles. One of the top technical risks to any engine program employing hydrocarbon fuels is the potential for fuel thermal stability and material compatibility problems to occur under the high-pressure, high-temperature conditions required for regenerative fuel cooling of the engine combustion chamber and nozzle. Decreased heat transfer due to carbon deposits forming on wetted fuel components, corrosion of materials common in engine construction (copper based alloys), and corrosion induced pressure drop increases have all been observed in laboratory tests simulating rocket engine cooling channels. To mitigate these risks, the knowledge of how these fuels behave in high temperature environments must be obtained. Currently, due to the complexity of the physical and chemical process occurring, the only way to accomplish this is empirically. Heated tube testing is a well-established method of experimentally determining the thermal stability and heat transfer characteristics of hydrocarbon fuels. The popularity of this method stems from the low cost incurred in testing when compared to hot fire engine tests, the ability to have greater control over experimental conditions, and the accessibility of the test section, facilitating easy instrumentation. These benefits make heated tube testing the best alternative to hot fire engine testing for thermal stability and heat transfer research. This investigation

  4. Heritability and genetic advance among chili pepper genotypes for heat tolerance and morphophysiological characteristics.

    PubMed

    Usman, Magaji G; Rafii, M Y; Ismail, M R; Malek, M A; Abdul Latif, Mohammad

    2014-01-01

    High temperature tolerance is an important component of adaptation to arid and semiarid cropping environment in chili pepper. Two experiments were carried out to study the genetic variability among chili pepper for heat tolerance and morphophysiological traits and to estimate heritability and genetic advance expected from selection. There was a highly significant variation among the genotypes in response to high temperature (CMT), photosynthesis rate, plant height, disease incidence, fruit length, fruit weight, number of fruits, and yield per plant. At 5% selection intensity, high genetic advance as percent of the mean (>20%) was observed for CMT, photosynthesis rate, fruit length, fruit weight, number of fruits, and yield per plant. Similarly, high heritability (>60%) was also observed indicating the substantial effect of additive gene more than the environmental effect. Yield per plant showed strong to moderately positive correlations (r = 0.23-0.56) at phenotypic level while at genotypic level correlation coefficient ranged from 0.16 to 0.72 for CMT, plant height, fruit length, and number of fruits. Cluster analysis revealed eight groups and Group VIII recorded the highest CMT and yield. Group IV recorded 13 genotypes while Groups II, VII, and VIII recorded one each. The results showed that the availability of genetic variance could be useful for exploitation through selection for further breeding purposes. PMID:25478590

  5. High temperature tribology for piston ring and cylinder liner in advanced low heat rejection engines

    SciTech Connect

    Kamo, L.S.; Kleyman, A.S.; Bryzik, W.; Mekari, M.

    1996-12-31

    High temperature tribology research efforts being pursued at Adiabatics are directed in the area of post treatment densified plasma sprayed coatings. Previous work has yielded good results for laboratory bench tests using no liquid lubrication. The process infiltrates a thermal sprayed coating layer with Chrome Oxide and Phosphate Glass compounds which serve to enhance the mechanical bond of a thermal sprayed layer, while improving its internal integrity, and sealing off open porosity. It has been applied to over 150 different wear combinations. Of these tests, Iron Oxide based coatings versus Molybdenum alloy materials provide the best results. Testing in a modified Low Heat Rejection (LHR) single cylinder diesel engine proved this wear combination superior to the state of the art materials available today. These data show improvement over past research efforts directed at developing solid lubricants, but they do not achieve goals set for operation in future advanced military LHR diesel powerplants. Through involvement with the support of the US Army Tank Automotive Research Development and Engineering Center (TARDEC) the authors have predetermined a goal of attaining bench test friction coefficients of {mu}{sub f} < 0.10, and material wear rates {le}1.0 mg/hr, at a temperature of 540 C. The research efforts discussed in this paper, focus on optimizing material friction and wear combinations and their interaction with liquid lubricants to generate boundary lubrication effects noted in previous studies and their correlation to advanced diesel engine design.

  6. Heritability and Genetic Advance among Chili Pepper Genotypes for Heat Tolerance and Morphophysiological Characteristics

    PubMed Central

    Usman, Magaji G.; Rafii, M. Y.; Ismail, M. R.; Malek, M. A.; Abdul Latif, Mohammad

    2014-01-01

    High temperature tolerance is an important component of adaptation to arid and semiarid cropping environment in chili pepper. Two experiments were carried out to study the genetic variability among chili pepper for heat tolerance and morphophysiological traits and to estimate heritability and genetic advance expected from selection. There was a highly significant variation among the genotypes in response to high temperature (CMT), photosynthesis rate, plant height, disease incidence, fruit length, fruit weight, number of fruits, and yield per plant. At 5% selection intensity, high genetic advance as percent of the mean (>20%) was observed for CMT, photosynthesis rate, fruit length, fruit weight, number of fruits, and yield per plant. Similarly, high heritability (>60%) was also observed indicating the substantial effect of additive gene more than the environmental effect. Yield per plant showed strong to moderately positive correlations (r = 0.23–0.56) at phenotypic level while at genotypic level correlation coefficient ranged from 0.16 to 0.72 for CMT, plant height, fruit length, and number of fruits. Cluster analysis revealed eight groups and Group VIII recorded the highest CMT and yield. Group IV recorded 13 genotypes while Groups II, VII, and VIII recorded one each. The results showed that the availability of genetic variance could be useful for exploitation through selection for further breeding purposes. PMID:25478590

  7. Pressure drop and heat transfer in turbulent non-Newtonian pipe flow of advanced energy transmission fluids

    NASA Astrophysics Data System (ADS)

    Choi, U. S.; Liu, K. V.; Kasza, K. E.

    1988-03-01

    Argonne National Laboratory (ANL), under sponsorship of the U.S. Department of Energy, is making significant progress on the development of advanced energy transmission fluids for thermal systems, in particular district heating and cooling systems. ANL has identified two concepts for developing advanced energy transmission fluids. Tests have been conducted at ANL to prove these concepts. This paper presents experimental results and discusses the degradation behavior of linear polymer additives and the flow and heat transfer characteristics of non-melting slurry flows. The experimental data obtained in this study provide support for the use of friction reducing additives and slurries in thermal system applications.

  8. Assessment and development of an advanced heat pump for recovery of volatile organic compounds. Final report

    SciTech Connect

    Not Available

    1992-06-01

    This report documents Phase 1 of a project conducted by Mechanical Technology Incorporated (MTI) for the assessment and development of an advanced heat pump for recovery of VOC solvents from process gas streams. In Phase 1, MTI has evaluated solvent recovery applications within New York State (NYS), identified host sites willing to implement their application, and conducted a preliminary design of the equipment required. The design and applications were evaluated for technical and economic feasibility. The solvent recovery heat pump system concept resulting from the Phase 1 work is one of a mobile unit that would service multiple stationary adsorbers. A large percentage of solvent recovery applications within the state can be serviced by on-site carbon bed adsorbers that are desorbed at frequencies ranging from once per to once per month. In this way, many users can effectively ``share`` the substantial capital investment associated with the system`s reverse Brayton hardware, providing it can be packaged as a mobile unit. In a typical operating scenario, a carbon adsorption module will be located permanently at the industrial site. The SLA will be ducted through the adsorber and the solvents removed, thus eliminating an air emission problem. Prior to VOC breakthrough, by schedule or by request, the mobile unit would arrive at the site to recover the concentrated solvent. An engine driven, natural gas fueled system, the mobile unit utilizes conditioned engine exhaust gases as the inert gas for desorption. Hot inert gas is directed through the carbon bed, heating it and volatilizing the adsorbed solvent. Using a revere Brayton-cycle refrigeration system to create low temperatures, the solvent vapors are condensed and collected from the inert gas stream. The solvent can then be recycled to the production process or sold for other uses and the adsorber returned to service.

  9. Assessment and development of an advanced heat pump for recovery of volatile organic compounds

    SciTech Connect

    Not Available

    1992-06-01

    This report documents Phase 1 of a project conducted by Mechanical Technology Incorporated (MTI) for the assessment and development of an advanced heat pump for recovery of VOC solvents from process gas streams. In Phase 1, MTI has evaluated solvent recovery applications within New York State (NYS), identified host sites willing to implement their application, and conducted a preliminary design of the equipment required. The design and applications were evaluated for technical and economic feasibility. The solvent recovery heat pump system concept resulting from the Phase 1 work is one of a mobile unit that would service multiple stationary adsorbers. A large percentage of solvent recovery applications within the state can be serviced by on-site carbon bed adsorbers that are desorbed at frequencies ranging from once per to once per month. In this way, many users can effectively share'' the substantial capital investment associated with the system's reverse Brayton hardware, providing it can be packaged as a mobile unit. In a typical operating scenario, a carbon adsorption module will be located permanently at the industrial site. The SLA will be ducted through the adsorber and the solvents removed, thus eliminating an air emission problem. Prior to VOC breakthrough, by schedule or by request, the mobile unit would arrive at the site to recover the concentrated solvent. An engine driven, natural gas fueled system, the mobile unit utilizes conditioned engine exhaust gases as the inert gas for desorption. Hot inert gas is directed through the carbon bed, heating it and volatilizing the adsorbed solvent. Using a revere Brayton-cycle refrigeration system to create low temperatures, the solvent vapors are condensed and collected from the inert gas stream. The solvent can then be recycled to the production process or sold for other uses and the adsorber returned to service.

  10. 47 CFR 15.515 - Technical requirements for vehicular radar systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Technical requirements for vehicular radar... DEVICES Ultra-Wideband Operation § 15.515 Technical requirements for vehicular radar systems. (a..., changing gears, or engaging a turn signal. (b) The UWB bandwidth of a vehicular radar system...

  11. 47 CFR 15.515 - Technical requirements for vehicular radar systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Technical requirements for vehicular radar... DEVICES Ultra-Wideband Operation § 15.515 Technical requirements for vehicular radar systems. (a..., changing gears, or engaging a turn signal. (b) The UWB bandwidth of a vehicular radar system...

  12. 47 CFR 15.515 - Technical requirements for vehicular radar systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Technical requirements for vehicular radar... DEVICES Ultra-Wideband Operation § 15.515 Technical requirements for vehicular radar systems. (a..., changing gears, or engaging a turn signal. (b) The UWB bandwidth of a vehicular radar system...

  13. 47 CFR 15.515 - Technical requirements for vehicular radar systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Technical requirements for vehicular radar... DEVICES Ultra-Wideband Operation § 15.515 Technical requirements for vehicular radar systems. (a..., changing gears, or engaging a turn signal. (b) The UWB bandwidth of a vehicular radar system...

  14. 47 CFR 15.515 - Technical requirements for vehicular radar systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Technical requirements for vehicular radar... DEVICES Ultra-Wideband Operation § 15.515 Technical requirements for vehicular radar systems. (a..., changing gears, or engaging a turn signal. (b) The UWB bandwidth of a vehicular radar system...

  15. Design of a pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Astrophysics Data System (ADS)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.; Kesseli, J.

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding a heat transport system to more uniformly supply heat to the heater head tubes. One heat transport system with favorable characteristics is an alkali metal pool boiler. An alkali metal pool boiler heat transport system was designed for a 25-kW advanced Stirling conversion system (ASCS). Solar energy concentrated on the absorber dome boils a eutectic mixture of sodium and potassium. The alkali metal vapors condense on the heater head tubes, supplying the Stirling engine with a uniform heat flux at a constant temperature. Boiling stability is achieved with the use of an enhanced boiling surface and noncondensible gas.

  16. Heat-Pipe Development for Advanced Energy Transport Concepts Final Report Covering the Period January 1999 through September 2001

    SciTech Connect

    R.S.Reid; J.F.Sena; A.L.Martinez

    2002-10-01

    This report summarizes work in the Heat-pipe Technology Development for the Advanced Energy Transport Concepts program for the period January 1999 through September 2001. A gas-loaded molybdenum-sodium heat pipe was built to demonstrate the active pressure-control principle applied to a refractory metal heat pipe. Other work during the period included the development of processing procedures for and fabrication and testing of three types of sodium heat pipes using Haynes 230, MA 754, and MA 956 wall materials to assess the compatibility of these materials with sodium. Also during this period, tests were executed to measure the response of a sodium heat pipe to the penetration of water.

  17. Observations of compound sawteeth in ion cyclotron resonant heating plasma using ECE imaging on experimental advanced superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Hussain, Azam; Zhao, Zhenling; Xie, Jinlin; Zhu, Ping; Liu, Wandong; Ti, Ang

    2016-04-01

    The spatial and temporal evolutions of compound sawteeth were directly observed using 2D electron cyclotron emission imaging on experimental advanced superconducting tokamak. The compound sawtooth consists of partial and full collapses. After partial collapse, the hot core survives as only a small amount of heat disperses outwards, whereas in the following full collapse a large amount of heat is released and the hot core dissipates. The presence of two q = 1 surfaces was not observed. Instead, the compound sawtooth occurs mainly at the beginning of an ion cyclotron resonant frequency heating pulse and during the L-H transition phase, which may be related to heat transport suppression caused by a decrease in electron heat diffusivity.

  18. Design of a pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Technical Reports Server (NTRS)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.; Kesseli, J.

    1991-01-01

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding a heat transport system to more uniformly supply heat to the heater head tubes. One heat transport system with favorable characteristics is an alkali metal pool boiler. An alkali metal pool boiler heat transport system was designed for a 25-kW advanced Stirling conversion system (ASCS). Solar energy concentrated on the absorber dome boils a eutectic mixture of sodium and potassium. The alkali metal vapors condense on the heater head tubes, supplying the Stirling engine with a uniform heat flux at a constant temperature. Boiling stability is achieved with the use of an enhanced boiling surface and noncondensible gas.

  19. Statistical physics of vehicular traffic and some related systems

    NASA Astrophysics Data System (ADS)

    Chowdhury, Debashish; Santen, Ludger; Schadschneider, Andreas

    2000-05-01

    In the so-called “microscopic” models of vehicular traffic, attention is paid explicitly to each individual vehicle each of which is represented by a “particle”; the nature of the “interactions” among these particles is determined by the way the vehicles influence each others’ movement. Therefore, vehicular traffic, modeled as a system of interacting “particles” driven far from equilibrium, offers the possibility to study various fundamental aspects of truly nonequilibrium systems which are of current interest in statistical physics. Analytical as well as numerical techniques of statistical physics are being used to study these models to understand rich variety of physical phenomena exhibited by vehicular traffic. Some of these phenomena, observed in vehicular traffic under different circumstances, include transitions from one dynamical phase to another, criticality and self-organized criticality, metastability and hysteresis, phase-segregation, etc. In this critical review, written from the perspective of statistical physics, we explain the guiding principles behind all the main theoretical approaches. But we present detailed discussions on the results obtained mainly from the so-called “particle-hopping” models, particularly emphasizing those which have been formulated in recent years using the language of cellular automata.

  20. 7 CFR 500.11 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Vehicular and pedestrian traffic. 500.11 Section 500... and pedestrian traffic. (a) Drivers of all vehicles in or on USNA property shall drive only on... and directions of the Security Staff and all posted traffic signs. (b) The blocking of...

  1. 36 CFR 504.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... traffic. 504.13 Section 504.13 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND REGULATIONS GOVERNING SMITHSONIAN INSTITUTION BUILDINGS AND GROUNDS § 504.13 Vehicular and pedestrian traffic... times and shall comply with the signals and directions of the guards and all posted traffic signs....

  2. 36 CFR 504.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... traffic. 504.13 Section 504.13 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND REGULATIONS GOVERNING SMITHSONIAN INSTITUTION BUILDINGS AND GROUNDS § 504.13 Vehicular and pedestrian traffic... times and shall comply with the signals and directions of the guards and all posted traffic signs....

  3. 31 CFR 700.10 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Vehicular and pedestrian traffic. 700... pedestrian traffic. (a) Drivers of all vehicles on the property shall drive in a careful and safe manner at all times and shall comply with the signals and directions of security officers and all posted...

  4. 7 CFR 500.11 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Vehicular and pedestrian traffic. 500.11 Section 500... and pedestrian traffic. (a) Drivers of all vehicles in or on USNA property shall drive only on... and directions of the Security Staff and all posted traffic signs. (b) The blocking of...

  5. 31 CFR 700.10 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Vehicular and pedestrian traffic. 700... pedestrian traffic. (a) Drivers of all vehicles on the property shall drive in a careful and safe manner at all times and shall comply with the signals and directions of security officers and all posted...

  6. 36 CFR 504.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... traffic. 504.13 Section 504.13 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND REGULATIONS GOVERNING SMITHSONIAN INSTITUTION BUILDINGS AND GROUNDS § 504.13 Vehicular and pedestrian traffic... times and shall comply with the signals and directions of the guards and all posted traffic signs....

  7. 36 CFR 520.14 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... traffic. 520.14 Section 520.14 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND... § 520.14 Vehicular and pedestrian traffic. (a) Drivers of all vehicles in or on the premises shall drive... police and all posted traffic signs. (b) The blocking of entrances, driveways, walks, loading...

  8. 7 CFR 500.11 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Vehicular and pedestrian traffic. 500.11 Section 500... and pedestrian traffic. (a) Drivers of all vehicles in or on USNA property shall drive only on... and directions of the Security Staff and all posted traffic signs. (b) The blocking of...

  9. 36 CFR 504.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... traffic. 504.13 Section 504.13 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND REGULATIONS GOVERNING SMITHSONIAN INSTITUTION BUILDINGS AND GROUNDS § 504.13 Vehicular and pedestrian traffic... times and shall comply with the signals and directions of the guards and all posted traffic signs....

  10. 31 CFR 700.10 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Vehicular and pedestrian traffic. 700... pedestrian traffic. (a) Drivers of all vehicles on the property shall drive in a careful and safe manner at all times and shall comply with the signals and directions of security officers and all posted...

  11. 7 CFR 500.11 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Vehicular and pedestrian traffic. 500.11 Section 500... and pedestrian traffic. (a) Drivers of all vehicles in or on USNA property shall drive only on... and directions of the Security Staff and all posted traffic signs. (b) The blocking of...

  12. 36 CFR 504.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... traffic. 504.13 Section 504.13 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND REGULATIONS GOVERNING SMITHSONIAN INSTITUTION BUILDINGS AND GROUNDS § 504.13 Vehicular and pedestrian traffic... times and shall comply with the signals and directions of the guards and all posted traffic signs....

  13. 36 CFR 520.14 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... traffic. 520.14 Section 520.14 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND... § 520.14 Vehicular and pedestrian traffic. (a) Drivers of all vehicles in or on the premises shall drive... police and all posted traffic signs. (b) The blocking of entrances, driveways, walks, loading...

  14. 31 CFR 700.10 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Vehicular and pedestrian traffic. 700... pedestrian traffic. (a) Drivers of all vehicles on the property shall drive in a careful and safe manner at all times and shall comply with the signals and directions of security officers and all posted...

  15. 31 CFR 700.10 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Vehicular and pedestrian traffic. 700... pedestrian traffic. (a) Drivers of all vehicles on the property shall drive in a careful and safe manner at all times and shall comply with the signals and directions of security officers and all posted...

  16. 31 CFR 407.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false Vehicular and pedestrian traffic. 407.12 Section 407.12 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) SECRET SERVICE, DEPARTMENT OF THE TREASURY REGULATIONS GOVERNING CONDUCT IN THE TREASURY BUILDING AND...

  17. 31 CFR 407.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Vehicular and pedestrian traffic. 407.12 Section 407.12 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) SECRET SERVICE, DEPARTMENT OF THE TREASURY REGULATIONS GOVERNING CONDUCT IN THE TREASURY BUILDING AND...

  18. 31 CFR 407.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Vehicular and pedestrian traffic. 407.12 Section 407.12 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) SECRET SERVICE, DEPARTMENT OF THE TREASURY REGULATIONS GOVERNING CONDUCT IN THE TREASURY BUILDING AND...

  19. 31 CFR 407.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Vehicular and pedestrian traffic. 407.12 Section 407.12 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) SECRET SERVICE, DEPARTMENT OF THE TREASURY REGULATIONS GOVERNING CONDUCT IN THE TREASURY BUILDING AND...

  20. 31 CFR 407.12 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 2 2013-07-01 2013-07-01 false Vehicular and pedestrian traffic. 407.12 Section 407.12 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) SECRET SERVICE, DEPARTMENT OF THE TREASURY REGULATIONS GOVERNING CONDUCT IN THE TREASURY BUILDING AND...

  1. Providing Location Security in Vehicular Ad Hoc Networks

    ERIC Educational Resources Information Center

    Yan, Gongjun

    2010-01-01

    Location is fundamental information in Vehicular Ad-hoc Networks (VANETs). Almost all VANET applications rely on location information. Therefore it is of importance to ensure location information integrity, meaning that location information is original (from the generator), correct (not bogus or fabricated) and unmodified (value not changed). We…

  2. 33. General view of flume from vehicular bridge crossing the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. General view of flume from vehicular bridge crossing the flume, just west of lumber storage shed, looking west. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  3. 8. LESLIE WICKMAN, EVA (EXTRA VEHICULAR ACTIVITIES) SPECIALIST, GETTING OUT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. LESLIE WICKMAN, EVA (EXTRA VEHICULAR ACTIVITIES) SPECIALIST, GETTING OUT OF SPACE SUIT AFTER TESTING IN NEUTRAL BUOYANCY TANK. AVERAGE COST OF SUIT $1,000,000. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

  4. Hollow fiber membranes for advanced life support systems. [permeable capillaries for medical filtration

    NASA Technical Reports Server (NTRS)

    Roebelen, G. J., Jr.; Lysaght, M. J.

    1977-01-01

    This paper describes an investigation of the practicability of utilizing hollow fiber membranes in vehicular and portable life support system applications. A preliminary screening of potential advanced life support applications resulted in the selection of five applications for feasibility study and testing. As a result of the feasibility study and testing, three applications, heat rejection, deaeration, and bacteria filtration, were chosen for breadboard development testing. Breadboard hardware has been manufactured and tested, and the physical properties of the three hollow fiber membrane assemblies applicable to use aboard future spacecraft have been characterized.

  5. Evaluation of Advanced Stirling Convertor Net Heat Input Correlation Methods Using a Thermal Standard

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell; Schifer, Nicholas

    2011-01-01

    Test hardware used to validate net heat prediction models. Problem: Net Heat Input cannot be measured directly during operation. Net heat input is a key parameter needed in prediction of efficiency for convertor performance. Efficiency = Electrical Power Output (Measured) divided by Net Heat Input (Calculated). Efficiency is used to compare convertor designs and trade technology advantages for mission planning.

  6. Advanced heat pump for the recovery of volatile organic compounds. Phase 1, Conceptual design of an advanced Brayton cycle heat pump for the recovery of volatile organic compounds: Final report

    SciTech Connect

    Not Available

    1992-03-01

    Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total US VOC emissions. The ``Toxic-Release Inventory`` of The US Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing,refrigerant production, and wood products production. The US Department of Energy`s (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase I report documents 3M`s work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient and economically priced.

  7. Process Integration Study of Cache Valley Cheese Plant [Advanced Industrial Heat Pump Applications and Evaluations

    SciTech Connect

    Eastwood, A.

    1991-10-01

    This work has carried out in two phases: Phase 1; identification of opportunities for heat pumps in industrial applications and Phase 2; evaluation of heat pumps in industrial applications. In Phase 1, pinch analysis was applied to several industrial sites to identify the best opportunities for heat pumping and other forms of heat integration. In Phase 2, more detailed analyses were undertaken, including the evaluation of a heat pump installed as a recommendation of Phase 1.

  8. Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady-state Laser Heat-flux Approach

    NASA Technical Reports Server (NTRS)

    Zhu, Dong-Ming; Miller, Robert A.

    2004-01-01

    The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine heat-flux conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) heat-flux approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and radiation conductivities as a function of heat flux and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser heat-flux conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications.

  9. Materials considerations in the design of a metal-hydride heat pump for an advanced extravehicular mobility unit

    NASA Technical Reports Server (NTRS)

    Liebert, B. E.

    1986-01-01

    A metal-hydride heat pump (HHP) has been proposed to provide an advanced regenerable nonventing thermal sink for the liquid-cooled garment worn during an extravehicular activity (EVA). The conceptual design indicates that there is a potential for significant advantages over the one presently being used by shuttle crew personnel as well as those that have been proposed for future use with the space station. Compared to other heat pump designs, a HHP offers the potential for extended use with no electrical power requirements during the EVA. In addition, a reliable, compact design is possible due to the absence of moving parts other than high-reliability check valves. Because there are many subtleties in the properties of metal hydrides for heat pump applications, it is essential that a prototype hydride heat pump be constructed with the selected materials before a committment is made for the final design. Particular care must be given to the evaporator heat exchanger worn by the astronaut since the performance of hydride heat pumps is generally heat transfer limited.

  10. Materials considerations in the design of a metal-hydride heat pump for an advanced extravehicular mobility unit

    NASA Astrophysics Data System (ADS)

    Liebert, B. E.

    1986-07-01

    A metal-hydride heat pump (HHP) has been proposed to provide an advanced regenerable nonventing thermal sink for the liquid-cooled garment worn during an extravehicular activity (EVA). The conceptual design indicates that there is a potential for significant advantages over the one presently being used by shuttle crew personnel as well as those that have been proposed for future use with the space station. Compared to other heat pump designs, a HHP offers the potential for extended use with no electrical power requirements during the EVA. In addition, a reliable, compact design is possible due to the absence of moving parts other than high-reliability check valves. Because there are many subtleties in the properties of metal hydrides for heat pump applications, it is essential that a prototype hydride heat pump be constructed with the selected materials before a committment is made for the final design. Particular care must be given to the evaporator heat exchanger worn by the astronaut since the performance of hydride heat pumps is generally heat transfer limited.

  11. The Synergism Between Heat and Mass Transfer Additive and Advanced Surfaces in Aqueous LiBr Horizontal Tube Absorbers

    SciTech Connect

    Miller, W.A.

    1999-03-24

    Experiments were conducted in a laboratory to investigate the absorption of water vapor into a falling-film of aqueous lithium bromide (LiBr). A mini-absorber test stand was used to test smooth tubes and a variety of advanced tube surfaces placed horizontally in a single-row bundle. The bundle had six copper tubes; each tube had an outside diameter of 15.9-mm and a length of 0.32-m. A unique feature of the stand is its ability to operate continuously and support testing of LiBr brine at mass fractions {ge} 0.62. The test stand can also support testing to study the effect of the failing film mass flow rate, the coolant mass flow rate, the coolant temperature, the absorber pressure and the tube spacing. Manufacturers of absorption chillers add small quantities of a heat and mass transfer additive to improve the performance of the absorbers. The additive causes surface stirring which enhances the transport of absorbate into the bulk of the film. Absorption may also be enhanced with advanced tube surfaces that mechanically induce secondary flows in the falling film without increasing the thickness of the film. Several tube geometry's were identified and tested with the intent of mixing the film and renewing the interface with fresh solution from the tube wall. Testing was completed on a smooth tube and several different externally enhanced tube surfaces. Experiments were conducted over the operating conditions of 6.5 mm Hg absorber pressure, coolant temperatures ranging from 20 to 35 C and LiBr mass fractions ranging from 0.60 through 0.62. Initially the effect of tube spacing was investigated for the smooth tube surface, tested with no heat and mass transfer additive. Test results showed the absorber load and the mass absorbed increased as the tube spacing increased because of the improved wetting of the tube bundle. However, tube spacing was not a critical factor if heat and mass transfer additive was active in the mini-absorber. The additive dramatically affected

  12. Development of a modular room-temperature hydride storage system for vehicular applications

    NASA Astrophysics Data System (ADS)

    Capurso, Giovanni; Schiavo, Benedetto; Jepsen, Julian; Lozano, Gustavo; Metz, Oliver; Saccone, Adriana; De Negri, Serena; Bellosta von Colbe, José M.; Klassen, Thomas; Dornheim, Martin

    2016-03-01

    The subject of this paper concerns the development of a vehicular hydrogen tank system, using a commercial interstitial metal hydride as storage material. The design of the tank was intended to feed a fuel cell in a light prototype vehicle, and the chosen hydride material, Hydralloy C5 by GfE, was expected to be able to absorb and desorb hydrogen in a range of pressure suitable for this purpose. A systematic analysis of the material in laboratory scale allows an extrapolation of the thermodynamic and reaction kinetics data. The following development of the modular tank was done according to the requirements of the prototype vehicle propulsion system and led to promising intermediate results. The modular approach granted flexibility in the design, allowing both to reach carefully the design goals and to learn the limiting factors in the sorption process. Proper heat management and suitable equipment remain key factors in order to achieve the best performances.

  13. Design of high heat load white-beam slits for wiggler/undulator beamlines at the Advanced Photon Source

    SciTech Connect

    Shu, D.; Tcheskidov, V.; Nian, T.; Haeffner, D.R.; Alp, E.E.; Ryding, D.; Collins, J.; Li, Y.; Kuzay, T.M.

    1994-12-01

    A set of horizontal and vertical white-beam slits has been designed for the Advanced Photon Source wiggler/undulator beamlines at Argonne National Laboratory. While this slit set can handle the high heat flux from on e APS undulator source, it has large enough aperture to be compatible with a wiggler source also. A grazing-incidence, knife-edge configuration has been used in the design to eliminate downstream X-ray scattering. Enhanced heat transfer technology has been used in the water-cooling system. A unique stepping parallelogram driving structure provides precise vertical slit motion with large optical aperture. The full design detail is presented in this paper.

  14. Development of heat transfer enhancement techniques for external cooling of an advanced reactor vessel

    NASA Astrophysics Data System (ADS)

    Yang, Jun

    Nucleate boiling is a well-recognized means for passively removing high heat loads (up to ˜106 W/m2) generated by a molten reactor core under severe accident conditions while maintaining relatively low reactor vessel temperature (<800 °C). With the upgrade and development of advanced power reactors, however, enhancing the nucleate boiling rate and its upper limit, Critical Heat Flux (CHF), becomes the key to the success of external passive cooling of reactor vessel undergoing core disrupture accidents. In the present study, two boiling heat transfer enhancement methods have been proposed, experimentally investigated and theoretically modelled. The first method involves the use of a suitable surface coating to enhance downward-facing boiling rate and CHF limit so as to substantially increase the possibility of reactor vessel surviving high thermal load attack. The second method involves the use of an enhanced vessel/insulation design to facilitate the process of steam venting through the annular channel formed between the reactor vessel and the insulation structure, which in turn would further enhance both the boiling rate and CHF limit. Among the various available surface coating techniques, metallic micro-porous layer surface coating has been identified as an appropriate coating material for use in External Reactor Vessel Cooling (ERVC) based on the overall consideration of enhanced performance, durability, the ease of manufacturing and application. Since no previous research work had explored the feasibility of applying such a metallic micro-porous layer surface coating on a large, downward facing and curved surface such as the bottom head of a reactor vessel, a series of characterization tests and experiments were performed in the present study to determine a suitable coating material composition and application method. Using the optimized metallic micro-porous surface coatings, quenching and steady-state boiling experiments were conducted in the Sub

  15. Intrusion-Tolerant Location Information Services in Intelligent Vehicular Networks

    NASA Astrophysics Data System (ADS)

    Yan, Gongjun; Yang, Weiming; Shaner, Earl F.; Rawat, Danda B.

    Intelligent Vehicular Networks, known as Vehicle-to-Vehicle and Vehicle-to-Roadside wireless communications (also called Vehicular Ad hoc Networks), are revolutionizing our daily driving with better safety and more infortainment. Most, if not all, applications will depend on accurate location information. Thus, it is of importance to provide intrusion-tolerant location information services. In this paper, we describe an adaptive algorithm that detects and filters the false location information injected by intruders. Given a noisy environment of mobile vehicles, the algorithm estimates the high resolution location of a vehicle by refining low resolution location input. We also investigate results of simulations and evaluate the quality of the intrusion-tolerant location service.

  16. Conventional heating vs. microwave sludge pretreatment comparison under identical heating/cooling profiles for thermophilic advanced anaerobic digestion.

    PubMed

    Hosseini Koupaie, E; Eskicioglu, C

    2016-07-01

    This research evaluates whether there is any advantage of selecting one of the thermal methods of sludge pretreatment, conventional heating (CH) and microwave hydrolysis (MW), over another to enhance municipal sludge disintegration and performance of thermophilic anaerobic digestion (AD). For this purpose, a custom-built CH system simulating MW hydrolysis under identical heating and cooling profiles was used. The effects of three main pretreatment parameters including pretreatment method (CH and MW), heating ramp rate (3, 6 and 11°C/min) and final temperature (80, 120 and 160°C) on sludge solubilization and performance of thermophilic batch AD were evaluated. The effects of CH and MW hydrolysis were observed to be similar for sludge disintegration and digester performance (p-value>0.05), while the effects of final temperature and heating ramp rate were proven to be different (p-value<0.05). According to the results, it is essential to apply MW and CH pretreatments under identical experimental condition for an unbiased comparison which supports the findings of the author's earlier study under mesophilic condition. Failing to address this issue explains the significant inconsistency observed among the findings of the previous CH vs. MW comparison studies that were unable to implement identical thermal profiles (between CH and MW) during sludge pretreatment. In comparison with mesophilic AD, thermophilic AD revealed lower biodegradation rate constant at the highest pretreatment temperature tested (160°C), suggesting its higher sensitivity to the inhibitory effects of thermal pretreatment at the elevated temperatures. PMID:27160636

  17. 17. NBS TOOL ROOM. MISCELLANEOUS TOOLS USED DURING EXTRA VEHICULAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. NBS TOOL ROOM. MISCELLANEOUS TOOLS USED DURING EXTRA VEHICULAR ACTIVITY (EVA) MISSIONS AND NBS TRAINING. FROM LEFT TO RIGHT THE TOOLS ARE: SHUTTLE TRANSPORTATION SYSTEM (STS) PORTABLE FOOT RESTRAINT (PFR), ESSEX WRENCH, SOCKET WRENCH, SAFETY TETHER REEL (LEFT REAR), MINI WORKSTATION (CENTER REAR), TETHERS (FRONT CENTER), HUBBLE SPACE TELESCOPE (HST) POWER TOOL (FRONT RIGHT), HUBBLE SPACE TELESCOPE & PORTABLE FOOT RESTRAINT (REAR RIGHT). - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

  18. Development of advanced high-temperature heat flux sensors. Phase 2: Verification testing

    NASA Technical Reports Server (NTRS)

    Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

    1985-01-01

    A two-phase program is conducted to develop heat flux sensors capable of making heat flux measurements throughout the hot section of gas turbine engines. In Phase 1, three types of heat flux sensors are selected; embedded thermocouple, laminated, and Gardon gauge sensors. A demonstration of the ability of these sensors to operate in an actual engine environment is reported. A segmented liner of each of two combustors being used in the Broad Specification Fuels Combustor program is instrumented with the three types of heat flux sensors then tested in a high pressure combustor rig. Radiometer probes are also used to measure the radiant heat loads to more fully characterize the combustor environment. Test results show the heat flux sensors to be in good agreement with radiometer probes and the predicted data trends. In general, heat flux sensors have strong potential for use in combustor development programs.

  19. UWB technology for safety-oriented vehicular communications

    NASA Astrophysics Data System (ADS)

    Llorente, Roberto; Morant, Maria

    2016-03-01

    Ultra-Wide Band (UWB) technology for wireless multiple access communications are receiving great interest for the last five years due to its unique features such as spectrum coexistence with other wireless services, RF front-end simplicity (enabling potential low cost terminals), good radio wave propagation (robust against multi-path fading, material penetration) and high bitrate. Low-cost UWB technology can be employed to provide simultaneous communications and vehicular radar capabilities. In this paper, the application of vehicle-to-vehicle (C2C), infrastructure-to-vehicle (I2C), communication and vehicular radar (VRAD) based on UWB technology are proposed altogether the required fiber-optics infrastructure, with the advantage of being flexible, cost-effective, reliable, fast and secure. The experimental validation and comparison for the optical generation of UWB signals combined with radio-over-fiber transmission is also reported in this work applied to vehicular communications. Both impulse-radio (IR-UWB) and orthogonal frequency division multiplexing (OFDM-UWB) signals are generated and their performance are evaluated experimentally in the 3.1-10.6 GHz frequency range. Up-conversion in the 60 GHz wireless band is also herein reported.

  20. Investigation of relativistic runaway electrons in electron cyclotron resonance heating discharges on Korea Superconducting Tokamak Advanced Research

    SciTech Connect

    Kang, C. S.; Lee, S. G.

    2014-07-15

    The behavior of relativistic runaway electrons during Electron Cyclotron Resonance Heating (ECRH) discharges is investigated in the Korea Superconducting Tokamak Advanced Research device. The effect of the ECRH on the runaway electron population is discussed. Observations on the generation of superthermal electrons during ECRH will be reported, which will be shown to be consistent with existing theory for the development of a superthermal electron avalanche during ECRH [A. Lazaros, Phys. Plasmas 8, 1263 (2001)].

  1. Fast wave direct electron heating in advanced inductive and ITER baseline scenario discharges in DIII-D

    SciTech Connect

    Pinsker, R. I.; Jackson, G. L.; Luce, T. C.; Politzer, P. A.; Austin, M. E.; Diem, S. J.; Kaufman, M. C.; Ryan, P. M.; Doyle, E. J.; Zeng, L.; Grierson, B. A.; Hosea, J. C.; Nagy, A.; Perkins, R.; Solomon, W. M.; Taylor, G.; Maggiora, R.; Milanesio, D.; Porkolab, M.; Turco, F.

    2014-02-12

    Fast Wave (FW) heating and electron cyclotron heating (ECH) are used in the DIII-D tokamak to study plasmas with low applied torque and dominant electron heating characteristic of burning plasmas. FW heating via direct electron damping has reached the 2.5 MW level in high performance ELMy H-mode plasmas. In Advanced Inductive (AI) plasmas, core FW heating was found to be comparable to that of ECH, consistent with the excellent first-pass absorption of FWs predicted by ray-tracing models at high electron beta. FW heating at the ∼2 MW level to ELMy H-mode discharges in the ITER Baseline Scenario (IBS) showed unexpectedly strong absorption of FW power by injected neutral beam (NB) ions, indicated by significant enhancement of the D-D neutron rate, while the intended absorption on core electrons appeared rather weak. The AI and IBS discharges are compared in an effort to identify the causes of the different response to FWs.

  2. Minimum Heating Re-Entry Trajectories for Advanced Hypersonic Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Windhorst, Robert

    1997-01-01

    Optimal re-entry trajectories are generated for reusable launch vehicles which minimize: (1) the heat absorbed at the vehicle surface, (2) the lower surface temperature, and (3) the heat absorbed by the internal structure. The approach uses the energy state approximation technique and a finite control volume heat transfer code coupled to a flight path integration code. These trajectories are compared to the optimal re-entry trajectory minimizing the integrated convective heat rate to determine which trajectory produces the minimum internal structural temperatures for a given thermal protection system. Three different thermal protection systems are considered: tile, blanket, and metallic.

  3. Coated Particles Fuel Compact-General Purpose Heat Source for Advanced Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2003-01-01

    Coated Particles Fuel Compacts (CPFC) have recently been shown to offer performance advantage for use in Radioisotope Heater Units (RHUs) and design flexibility for integrating at high thermal efficiency with Stirling Engine converters, currently being considered for 100 We. Advanced Radioisotope Power Systems (ARPS). The particles in the compact consist of 238PuO2 fuel kernels with 5-μm thick PyC inner coating and a strong ZrC outer coating, whose thickness depends on the maximum fuel temperature during reentry, the fuel kernel diameter, and the fraction of helium gas released from the kernels and fully contained by the ZrC coating. In addition to containing the helium generated by radioactive decay of 238Pu for up to 10 years before launch and 10-15 years mission lifetime, the kernels are intentionally sized (>= 300 μm in diameter) to prevent any adverse radiological effects on reentry. This paper investigates the advantage of replacing the four iridium-clad 238PuO2 fuel pellets, the two floating graphite membranes, and the two graphite impact shells in current State-Of-The-Art (SOA) General Purpose Heat Source (GPHS) with CPFC. The total mass, thermal power, and specific power of the CPFC-GPHS are calculated as functions of the helium release fraction from the fuel kernels and maximum fuel temperature during reentry from 1500 K to 2400 K. For the same total mass and volume as SOA GPHS, the generated thermal power by single-size particles CPFC-GPHS is 260 W at Beginning-Of-Mission (BOM), versus 231 W for the GPHS. For an additional 10% increase in total mass, the CPFC-GPHS could generate 340 W BOM; 48% higher than SOA GPHS. The corresponding specific thermal power is 214 W/kg, versus 160 W/kg for SOA GPHS; a 34% increase. Therefore, for the same thermal power, the CPFC-GPHS is lighter than SOA GPHS, while it uses the same amount of 238PuO2 fuel and same aeroshell. For the same helium release fraction and fuel temperature, binary-size particles CPFC-GPHS could

  4. STS-109 Extra Vehicular Activity (EVA)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronaut James H. Newman, mission specialist, floats about in the Space Shuttle Columbia's cargo bay while working in tandem with astronaut Michael J. Massimino (out of frame),mission specialist, during the STS-109 mission's second day of extravehicular activity (EVA). Inside Columbia's cabin, astronaut Nancy J. Currie, mission specialist, controlled the Remote Manipulator System (RMS) to assist the two in their work on the Hubble Space Telescope (HST). The RMS was used to capture the telescope and secure it into Columbia's cargo bay.Part of the giant telescope's base, latched down in the payload bay, can be seen behind Newman. The Space Shuttle Columbia STS-109 mission lifted off March 1, 2002 with goals of repairing and upgrading the HST. The Marshall Space Flight Center in Huntsville, Alabama had responsibility for the design, development, and contruction of the HST, which is the most powerful and sophisticated telescope ever built. STS-109 upgrades to the HST included: replacement of the solar array panels; replacement of the power control unit (PCU); replacement of the Faint Object Camera (FOC) with a new advanced camera for Surveys (ACS); and installation of the experimental cooling system for the Hubble's Near-Infrared Camera and Multi-object Spectrometer (NICMOS), which had been dormant since January 1999 when its original coolant ran out. Lasting 10 days, 22 hours, and 11 minutes, the STS-109 mission was the 108th flight overall in NASA's Space Shuttle Program.

  5. Automotive Air Conditioning and Heating; Automotive Mechanics (Advanced): 9047.04.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to provide the student with all the foundations necessary to become employable in the automotive air conditioning and heating trade. The course of study includes an orientation to the world of work, the elementary physics of air conditioning and heating, and laboratory experiments…

  6. Comparison of Advanced Residential Water Heating Technologies in the United States

    SciTech Connect

    Maguire, J.; Fang, X.; Wilson, E.

    2013-05-01

    Gas storage, gas tankless, condensing, electric storage, heat pump, and solar water heaters were simulated in several different climates across the US installed in both conditioned and unconditioned space and subjected to several different draw profiles. While many preexisting models were used, new models of condensing and heat pump water heaters were created specifically for this work.

  7. Feasibility Study of Secondary Heat Exchanger Concepts for the Advanced High Temperature Reactor

    SciTech Connect

    Piyush Sabharwall

    2011-09-01

    The work reported herein represents a significant step in the preliminary design of heat exchanger options (material options, thermal design, selection and evaluation methodology with existing challenges). The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production using either a subcritical or supercritical Rankine cycle.

  8. Heat Mining or Replenishable Geothermal Energy? A Project for Advanced-Level Physics Students

    ERIC Educational Resources Information Center

    Dugdale, Pam

    2014-01-01

    There is growing interest in the use of low enthalpy geothermal (LEG) energy schemes, whereby heated water is extracted from sandstone aquifers for civic heating projects. While prevalent in countries with volcanic activity, a recently proposed scheme for Manchester offered the perfect opportunity to engage students in the viability of this form…

  9. The Effect of Heat Treatment on Residual Stress and Machining Distortions in Advanced Nickel Base Disk Alloys

    NASA Technical Reports Server (NTRS)

    Gayda, John

    2001-01-01

    This paper describes an extension of NASA's AST and IDPAT Programs which sought to predict the effect of stabilization heat treatments on residual stress and subsequent machining distortions in the advanced disk alloy, ME-209. Simple "pancake" forgings of ME-209 were produced and given four heat treats: 2075F(SUBSOLVUS)/OIL QUENCH/NO AGE; 2075F/OIL QUENCH/1400F@8HR;2075F/OIL QUENCH/1550F@3HR/l400F@8HR; and 2160F(SUPERSOLVUS)/OIL QUENCH/1550F@3HR/ 1400F@8HR. The forgings were then measured to obtain surface profiles in the heat treated condition. A simple machining plan consisting of face cuts from the top surface followed by measurements of the surface profile opposite the cut were made. This data provided warpage maps which were compared with analytical results. The analysis followed the IDPAT methodology and utilized a 2-D axisymmetric, viscoplastic FEA code. The analytical results accurately tracked the experimental data for each of the four heat treatments. The 1550F stabilization heat treatment was found to significantly reduce residual stresses and subsequent machining distortions for fine grain (subsolvus) ME209, while coarse grain (supersolvus) ME209 would require additional time or higher stabilization temperatures to attain the same degree of stress relief.

  10. Parametric Evaluation of Large-Scale High-Temperature Electrolysis Hydrogen Production Using Different Advanced Nuclear Reactor Heat Sources

    SciTech Connect

    Edwin A. Harvego; Michael G. McKellar; James E. O'Brien; J. Stephen Herring

    2009-09-01

    High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 °C to 950 °C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the sweep gas loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycles producing the highest efficiencies varied depending on the temperature range considered.

  11. Molten Glass for Thermal Storage: Advanced Molten Glass for Heat Transfer and Thermal Energy Storage

    SciTech Connect

    2012-01-01

    HEATS Project: Halotechnics is developing a high-temperature thermal energy storage system using a new thermal-storage and heat-transfer material: earth-abundant and low-melting-point molten glass. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Halotechnics new thermal storage material targets a price that is potentially cheaper than the molten salt used in most commercial solar thermal storage systems today. It is also extremely stable at temperatures up to 1200°C—hundreds of degrees hotter than the highest temperature molten salt can handle. Being able to function at high temperatures will significantly increase the efficiency of turning heat into electricity. Halotechnics is developing a scalable system to pump, heat, store, and discharge the molten glass. The company is leveraging technology used in the modern glass industry, which has decades of experience handling molten glass.

  12. Road Accident Prevention with Instant Emergency Warning Message Dissemination in Vehicular Ad-Hoc Network

    PubMed Central

    P, Gokulakrishnan; P, Ganeshkumar

    2015-01-01

    A Road Accident Prevention (RAP) scheme based on Vehicular Backbone Network (VBN) structure is proposed in this paper for Vehicular Ad-hoc Network (VANET). The RAP scheme attempts to prevent vehicles from highway road traffic accidents and thereby reduces death and injury rates. Once the possibility of an emergency situation (i.e. an accident) is predicted in advance, instantly RAP initiates a highway road traffic accident prevention scheme. The RAP scheme constitutes the following activities: (i) the Road Side Unit (RSU) constructs a Prediction Report (PR) based on the status of the vehicles and traffic in the highway roads, (ii) the RSU generates an Emergency Warning Message (EWM) based on an abnormal PR, (iii) the RSU forms a VBN structure and (iv) the RSU disseminates the EWM to the vehicles that holds the high Risk Factor (RF) and travels in High Risk Zone (HRZ). These vehicles might reside either within the RSU’s coverage area or outside RSU’s coverage area (reached using VBN structure). The RAP scheme improves the performance of EWM dissemination in terms of increase in notification and decrease in end-to-end delay. The RAP scheme also reduces infrastructure cost (number of RSUs) by formulating and deploying the VBN structure. The RAP scheme with VBN structure improves notification by 19 percent and end-to-end delay by 14.38 percent for a vehicle density of 160 vehicles. It is also proved from the simulation experiment that the performance of RAP scheme is promising in 4-lane highway roads. PMID:26636576

  13. Road Accident Prevention with Instant Emergency Warning Message Dissemination in Vehicular Ad-Hoc Network.

    PubMed

    Gokulakrishnan, P; Ganeshkumar, P

    2015-01-01

    A Road Accident Prevention (RAP) scheme based on Vehicular Backbone Network (VBN) structure is proposed in this paper for Vehicular Ad-hoc Network (VANET). The RAP scheme attempts to prevent vehicles from highway road traffic accidents and thereby reduces death and injury rates. Once the possibility of an emergency situation (i.e. an accident) is predicted in advance, instantly RAP initiates a highway road traffic accident prevention scheme. The RAP scheme constitutes the following activities: (i) the Road Side Unit (RSU) constructs a Prediction Report (PR) based on the status of the vehicles and traffic in the highway roads, (ii) the RSU generates an Emergency Warning Message (EWM) based on an abnormal PR, (iii) the RSU forms a VBN structure and (iv) the RSU disseminates the EWM to the vehicles that holds the high Risk Factor (RF) and travels in High Risk Zone (HRZ). These vehicles might reside either within the RSU's coverage area or outside RSU's coverage area (reached using VBN structure). The RAP scheme improves the performance of EWM dissemination in terms of increase in notification and decrease in end-to-end delay. The RAP scheme also reduces infrastructure cost (number of RSUs) by formulating and deploying the VBN structure. The RAP scheme with VBN structure improves notification by 19 percent and end-to-end delay by 14.38 percent for a vehicle density of 160 vehicles. It is also proved from the simulation experiment that the performance of RAP scheme is promising in 4-lane highway roads. PMID:26636576

  14. Overview of Heat Addition and Efficiency Predictions for an Advanced Stirling Convertor

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.; Reid, Terry; Schifer, Nicholas; Briggs, Maxwell

    2011-01-01

    Past methods of predicting net heat input needed to be validated. Validation effort pursued with several paths including improving model inputs, using test hardware to provide validation data, and validating high fidelity models. Validation test hardware provided direct measurement of net heat input for comparison to predicted values. Predicted value of net heat input was 1.7 percent less than measured value and initial calculations of measurement uncertainty were 2.1 percent (under review). Lessons learned during validation effort were incorporated into convertor modeling approach which improved predictions of convertor efficiency.

  15. Evaluation Methodology for Advance Heat Exchanger Concepts Using Analytical Hierarchy Process

    SciTech Connect

    Piyush Sabharwall; Eung Soo Kim

    2012-07-01

    The primary purpose of this study is to aid in the development and selection of the secondary/process heat exchanger (SHX) for power production and process heat application for a Next Generation Nuclear Reactors (NGNR). The potential options for use as an SHX are explored such as shell and tube, printed circuit heat exchanger. A shell and tube (helical coiled) heat exchanger is a recommended for a demonstration reactor because of its reliability while the reactor design is being further developed. The basic setup for the selection of the SHX has been established with evaluation goals, alternatives, and criteria. This study describes how these criteria and the alternatives are evaluated using the analytical hierarchy process (AHP).

  16. A preliminary design and analysis of an advanced heat-rejection system for an extreme altitude advanced variable cycle diesel engine installed in a high-altitude advanced research platform

    NASA Technical Reports Server (NTRS)

    Johnston, Richard P.

    1992-01-01

    Satellite surveillance in such areas as the Antarctic indicates that from time to time concentration of ozone grows and shrinks. An effort to obtain useful atmospheric data for determining the causes of ozone depletion would require a flight capable of reaching altitudes of at least 100,000 ft and flying subsonically during the sampling portion of the mission. A study of a heat rejection system for an advanced variable cycle diesel (AVCD) engine was conducted. The engine was installed in an extreme altitude, high altitude advanced research platform. Results indicate that the waste heat from an AVCD engine propulsion system can be rejected at the maximum cruise altitude of 120,000 ft. Fifteen performance points, reflecting the behavior of the engine as the vehicle proceeded through the mission, were used to characterize the heat exchanger operation. That portion of the study is described in a appendix titled, 'A Detailed Study of the Heat Rejection System for an Extreme Altitude Atmospheric Sampling Aircraft,' by a consultant, Mr. James Bourne, Lytron, Incorporated.

  17. Vehicular emission inventory of criteria pollutants in Delhi.

    PubMed

    Goyal, Pramila; Mishra, Dhirendra; Kumar, Anikender

    2013-12-01

    The rapid urbanization in Delhi has resulted in a tremendous increase in the number of motor vehicles with the increase in population and urban mobilization. The vehicular traffic is now recognized as one of the main sources of air pollution in Delhi and has noticeable impact on air quality. The emission of criteria pollutants namely Carbon Monoxide (CO), Nitrogen Oxide (NOx) and Particulate Matter (PM) due to vehicles is estimated through the International Vehicle Emission (IVE) model, which includes the different driving modes of vehicles and meteorological parameters. The estimated emissions of Carbon Monoxide (CO), Nitrogen Oxides (NOx) and Particulate Matter (PM) due to different types of vehicles in the year 2008-09 are found to be 509, 194 and 15 tons/day respectively. The diurnal variation of emissions of air pollutants shows two peaks, which are fortunately matching with the morning and evening office hours. The emissions of CO and NOx due to personal cars (PCs) are found to be about 34% and 50% respectively, and the emission of CO due to 2 W (2- Wheeler) is about 61%. Similarly, the Heavy Commercial Vehicles (HCVs) are contributing PM about 92%. The analysis of fuel-wise emission of pollutants reveals that CO is mainly contributed by petrol, and NOx and PM are contributed by diesel. It is also noticeable that CO, NOx and PM emissions at ITO, one of the busiest traffic intersections of Delhi, are approximately 15, 6 and 0.5 tons/day respectively, which are found to be the maximum followed by Kashmiri Gate (ISBT), Nizamuddin etc. The present vehicular emissions inventory has been compared quantitatively with previous studies of Delhi. The present vehicular emission inventory has also validated using US environmental protection agency's (USEPA's) AERMOD model with observed concentration at different locations in Delhi. However, the present study shows that the air quality of Delhi has been degraded due to high level emissions of criteria pollutants. PMID

  18. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect

    Lee, S.W.

    1999-09-01

    This technical report summarizes the research conducted and progress achieved during the period from April 1, 1998 to June 30, 1998. The numerical simulation was continued to determine the concentration distribution of the gas species, heat flux and heat transfer coefficients in the hot combustor model. The different gas concentration profiles showed the gas mixing characteristics along the combustor height. The center zone of the combustor has a relatively high methane mass concentration. The injection of secondary air squeezes the uprising flue gas and methane that causes the fuel-lean zone near the secondary air nozzles. The carbon dioxide concentration increased with the increasing of the combustor height. The peak concentration of oxygen remains at the combustor wall because of the secondary injection. The heat flux on the wall of the upper chamber is much higher than that of the lower chamber. It is believed that the heat flux is affected by the designed strong swirl and secondary air injection. The heat transfer coefficient changes along the combustor height were also affected by the multiple secondary air injection. The numerical simulation results could verify the predictions of the experimental results. It is a quite similar trend of the heat transfer coefficient changes based on the combustion test results.

  19. Life prediction methodology for ceramic components of advanced heat engines. Phase 1: Volume 1, Final report

    SciTech Connect

    Cuccio, J.C.; Brehm, P.; Fang, H.T.

    1995-03-01

    Emphasis of this program is to develop and demonstrate ceramics life prediction methods, including fast fracture, stress rupture, creep, oxidation, and nondestructive evaluation. Significant advancements were made in these methods and their predictive capabilities successfully demonstrated.

  20. Inner structure of vehicular ensembles and random matrix theory

    NASA Astrophysics Data System (ADS)

    Krbálek, Milan; Hobza, Tomáš

    2016-05-01

    We introduce a special class of random matrices (DUE) whose spectral statistics corresponds to statistics of microscopical quantities detected in vehicular flows. Comparing the level spacing distribution (for ordered eigenvalues in unfolded spectra of DUE matrices) with the time-clearance distribution extracted from various areas of the flux-density diagram (evaluated from original traffic data measured on Czech expressways with high occupancies) we demonstrate that the set of classical systems showing an universality associated with Random Matrix Ensembles can be extended by traffic systems.

  1. Vehicular headways on signalized intersections: theory, models, and reality

    NASA Astrophysics Data System (ADS)

    Krbálek, Milan; Šleis, Jiří

    2015-01-01

    We discuss statistical properties of vehicular headways measured on signalized crossroads. On the basis of mathematical approaches, we formulate theoretical and empirically inspired criteria for the acceptability of theoretical headway distributions. Sequentially, the multifarious families of statistical distributions (commonly used to fit real-road headway statistics) are confronted with these criteria, and with original empirical time clearances gauged among neighboring vehicles leaving signal-controlled crossroads after a green signal appears. Using three different numerical schemes, we demonstrate that an arrangement of vehicles on an intersection is a consequence of the general stochastic nature of queueing systems, rather than a consequence of traffic rules, driver estimation processes, or decision-making procedures.

  2. APOLLO 9: Dave scott performs Extra Vehicular Activities

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Dave Scott performs Extra Vehicular Activities around the Command Module 'Gumdrop'. From the film documentary 'APOLLO 9: The Duet of Spider & Gumdrop': part of a documentary series made in the early 70's on the APOLLO missions, and narrated by Burgess Meredith. (Actual date created is not known at this time) Mission: APOLLO 9: Earth orbital flight with James A. McDivitt, David R. Scott, and Russell Schweickart. First flight of the Lunar Module. Performed rendezvous, docking and E.V.A..Mission Duration 241hrs 0m 54s.

  3. Routing Protocol of Sparse Urban Vehicular Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Li, Huxiong

    Vehicular ad hoc network (VANET) is an application of mobile ad hoc technology in transportation systems, it has become an important part of ITS. Since multi-hop link is hard to set up in sparse VANET, a traffic-aware routing (TAR) protocol is proposed which estimates vehicle average neighbors (VAN) of roads by exchanging beacon messages between encounter vehicles. Road with high VAN is preferred to be selected as part of forwarding path at intersection. Packets are forwarded to the next intersection in road in a greedy manner. Simulations show that TAR outperforms the compared protocols in terms of both packet delivery ratio and average end-to-end delay.

  4. Emerging technology for vehicular safety and emergency response to roadway crashes.

    PubMed

    Champion, H R; Cushing, B

    1999-12-01

    Emerging technology for vehicular safety and emergency response to roadway crashes is the topic of this article. Reduction in emergency medical services system notification time, improvements in vehicular safety, crash avoidance and protection, post-crash injury control, triage, national automatic crash notification systems, and technologic improvements in emergency diagnostics and treatment during the past year are discussed. PMID:10625974

  5. OLEDs: light-emitting thin film thermistors revealing advanced self-heating effects

    NASA Astrophysics Data System (ADS)

    Fischer, Axel; Koprucki, Thomas; Glitzky, Annegret; Liero, Matthias; Gärtner, Klaus; Hauptmann, Jacqueline; Reineke, Sebastian; Kasemann, Daniel; Lüssem, Björn; Leo, Karl; Scholz, Reinhard

    2015-09-01

    Large area OLEDs show pronounced Joule self-heating at high brightness. This heating induces brightness inhomogeneities, drastically increasing beyond a certain current level. We discuss this behavior considering 'S'-shaped negative differential resistance upon self-heating, even allowing for 'switched-back' regions where the luminance finally decreases (Fischer et al., Adv. Funct. Mater. 2014, 24, 3367). By using a multi-physics simulation the device characteristics can be modeled, resulting in a comprehensive understanding of the problem. Here, we present results for an OLED lighting panel considered for commercial application. It turns out that the strong electrothermal feedback in OLEDs prevents high luminance combined with a high degree of homogeneity unless new optimization strategies are considered.

  6. Recent Advances in Power Conversion and Heat Rejection Technology for Fission Surface Power

    NASA Technical Reports Server (NTRS)

    Mason, Lee

    2010-01-01

    Under the Exploration Technology Development Program, the National Aeronautics and Space Administration (NASA) and the Department of Energy (DOE) are jointly developing Fission Surface Power (FSP) technology for possible use in human missions to the Moon and Mars. A preliminary reference concept was generated to guide FSP technology development. The concept consists of a liquid-metal-cooled reactor, Stirling power conversion, and water heat rejection, with Brayton power conversion as a backup option. The FSP project has begun risk reduction activities on some key components with the eventual goal of conducting an end-to-end, non-nuclear, integrated system test. Several power conversion and heat rejection hardware prototypes have been built and tested. These include multi-kilowatt Stirling and Brayton power conversion units, titanium-water heat pipes, and composite radiator panels.

  7. Comparison of Advanced Residential Water Heating Technologies in the United States

    SciTech Connect

    Maguire, Jeff; Fang, Xia; Wilson, Eric

    2013-05-01

    In this study, gas storage, gas tankless, condensing, electric storage, heat pump, and solar water heaters were simulated in several different climates across the United States, installed in both conditioned and unconditioned space and subjected to several different draw profiles. While many pre-existing models were used, new models of condensing and heat pump water heaters were created specifically for this work. In each case modeled, the whole house was simulated along with the water heater to capture any interactions between the water heater and the space conditioning equipment.

  8. Soil Cation Status in Southern California: Interactions of Vehicular Emissions

    NASA Astrophysics Data System (ADS)

    Rossi, R.; Bain, D. J.; Jenerette, D.; Clarke, L. W.

    2012-12-01

    Roadside soils are often enriched in trace metals due to vehicular deposition. However, less attention is given to base cation pools in roadside soils. Relatively high loadings of nitrate from vehicular exhaust should acidify roadside soils, potentially mobilizing cationic species by displacing them from soil exchange sites. In contrast, weathering of road materials can contribute substantial amounts of these cations to the same soils, potentially replenishing cation pools. Base cations are essential nutrients and these dynamics may alter ecosystem processes in near-road environments. Metal concentrations in park and garden soils collected from Southern California (Los Angeles and Riverside Counties) were examined across gradients of road network intensity, climate and geology. In these samples, base cation concentrations decrease in areas of denser road networks. Base cation concentrations also decrease with distance from the road, with near-road samples relatively depleted in base cation concentrations. In addition, base cation concentrations are associated with traffic flux density, with exchange pools decreasing near heavily trafficked areas. These relationships suggest road activity is mobilizing cations, depleting near-road soils of essential nutrient pools, despite road material weathering. This depletion of soil nutrients from exchange pools in roadside soils likely influences local ecological function in unpredictable ways. This observation lays the groundwork for continued characterization of soil metal processes in the increasingly common roadside environment.

  9. A cooperative positioning algorithm for DSRC enabled vehicular networks

    NASA Astrophysics Data System (ADS)

    Efatmaneshnik, M.; Kealy, A.; Alam, N.; Dempster, A. G.

    2011-12-01

    Many of the safety related applications that can be facilitated by Dedicated Short Range Communications (DSRC), such as vehicle proximity warnings, automated braking (e.g. at level crossings), speed advisories, pedestrian alerts etc., rely on a robust vehicle positioning capability such as that provided by a Global Navigation Satellite System (GNSS). Vehicles in remote areas, entering tunnels, high rise areas or any high multipath/ weak signal environment will challenge the integrity of GNSS position solutions, and ultimately the safety application it underpins. To address this challenge, this paper presents an innovative application of Cooperative Positioning techniques within vehicular networks. CP refers to any method of integrating measurements from different positioning systems and sensors in order to improve the overall quality (accuracy and reliability) of the final position solution. This paper investigates the potential of the DSRC infrastructure itself to provide an inter-vehicular ranging signal that can be used as a measurement within the CP algorithm. In this paper, time-based techniques of ranging are introduced and bandwidth requirements are investigated and presented. The robustness of the CP algorithm to inter-vehicle connection failure as well as GNSS dropouts is also demonstrated using simulation studies. Finally, the performance of the Constrained Kalman Filter used to integrate GNSS measurements with DSRC derived range estimates within a typical VANET is described and evaluated.

  10. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect

    Dr. Seong W. Lee

    1998-10-01

    The objective of this project is to predict the heat transfer and combustion performance in newly-designed fluidized bed combustor (FBC) and to provide the design guide lines and innovative concept for small-scale boiler and furnace. The major accomplishments are summarized.

  11. Results of On-Orbit Testing of an Extra-Vehicular Infrared Camera Inspection System

    NASA Technical Reports Server (NTRS)

    Howell, Patricia A.; Cramer, K. Elliott

    2007-01-01

    This paper will discuss an infrared camera inspection system that has been developed to allow astronauts to demonstrate the ability to inspect reinforced carbon-carbon (RCC) components on the space shuttle as part of extra-vehicular activities (EVA) while in orbit. Presented will be the performance of the EVA camera system coupled with solar heating for inspection of damaged RCC specimens and NDE standards. The data presented was acquired during space shuttle flights STS-121 and STS-115 as well during a staged EVA from the ISS. The EVA camera system was able to detect flatbottom holes as small as 2.54cm in diameter with 25% material loss. Results obtained are shown to be comparable to ground-based thermal inspections performed in the laboratory using the same camera and simulated solar heating. Data on both the time history of the specimen temperature and the ability of the inspection system to image defects due to impact will likewise be presented.

  12. The Effect of Stabilization Heat Treatments on the Tensile and Creep Behavior of an Advanced Nickel-Based Disk Alloy

    NASA Technical Reports Server (NTRS)

    Gayda, John

    2003-01-01

    As part of NASA s Advanced Subsonic Technology Program, a study of stabilization heat treatment options for an advanced nickel-base disk alloy, ME 209, was performed. Using a simple, physically based approach, the effect of stabilization heat treatments on tensile and creep properties was analyzed in this paper. Solutions temperature, solution cooling rate, and stabilization temperature/time were found to have a significant impact on tensile and creep properties. These effects were readily quantified using the following methodology. First, the effect of solution cooling rate was assessed to determine its impact on a given property. The as-cooled property was then modified by using two multiplicative factors which assess the impact of solution temperature and stabilization parameters. Comparison of experimental data with predicted values showed this physically based analysis produced good results that rivaled the statistical analysis employed, which required numerous changes in the form of the regression equation depending on the property and temperature in question. As this physically based analysis uses the data for input, it should be noted that predictions which attempt to extrapolate beyond the bounds of the data must be viewed with skepticism. Future work aimed at expanding the range of the stabilization/aging parameters explored in this study would be highly desirable, especially at the higher solution cooling rates.

  13. Analytical and experimental evaluation of joining silicon nitride to metal and silicon carbide to metal for advanced heat engine applications

    SciTech Connect

    Kang, S.; Selverian, J.H.; Kim, H.; O'Niel, D.; Kim, K. )

    1990-04-01

    This report summarizes the results of Phase I of Analytical and Experimental Evaluation of Joining Silicon Nitride to Metal and Silicon Carbide to Metal and Silicon Carbide to Metal for Advanced Heat Engine Applications. A general methodology was developed to optimize the joint geometry and material systems for 650 and 950{degree}C applications. Failure criteria were derived to predict the fracture of the braze and ceramic. Extensive finite element analyses (FEA), using ABAQUS code, were performed to examine various joint geometries and to evaluate the affect of different interlayers on the residual stress state. Also, material systems composed of coating materials, interlayers, and braze alloys were developed for the program based on the chemical stability and strength of the joints during processing and service. Finally, the FEA results were compared with experiments using an idealized strength relationship. The results showed that the measured strength of the joint reached 30--90% of the strength by predicted by FEA. Overall results demonstrated that FEA is an effective tool for designing the geometries of ceramic-metal joints and that joining by brazing is a relevant method for advanced heat engine applications. 33 refs., 54 figs., 36 tabs.

  14. Emergency Situation Prediction Mechanism: A Novel Approach for Intelligent Transportation System Using Vehicular Ad Hoc Networks

    PubMed Central

    Gokulakrishnan, P.

    2015-01-01

    In Indian four-lane express highway, millions of vehicles are travelling every day. Accidents are unfortunate and frequently occurring in these highways causing deaths, increase in death toll, and damage to infrastructure. A mechanism is required to avoid such road accidents at the maximum to reduce the death toll. An Emergency Situation Prediction Mechanism, a novel and proactive approach, is proposed in this paper for achieving the best of Intelligent Transportation System using Vehicular Ad Hoc Network. ESPM intends to predict the possibility of occurrence of an accident in an Indian four-lane express highway. In ESPM, the emergency situation prediction is done by the Road Side Unit based on (i) the Status Report sent by the vehicles in the range of RSU and (ii) the road traffic flow analysis done by the RSU. Once the emergency situation or accident is predicted in advance, an Emergency Warning Message is constructed and disseminated to all vehicles in the area of RSU to alert and prevent the vehicles from accidents. ESPM performs well in emergency situation prediction in advance to the occurrence of an accident. ESPM predicts the emergency situation within 0.20 seconds which is comparatively less than the statistical value. The prediction accuracy of ESPM against vehicle density is found better in different traffic scenarios. PMID:26065014

  15. Use of Multiple Reheat Helium Brayton Cycles to Eliminate the Intermediate Heat Transfer Loop for Advanced Loop Type SFRs

    SciTech Connect

    Haihua Zhao; Hongbin Zhang; Samuel E. Bays

    2009-05-01

    The sodium intermediate heat transfer loop is used in existing sodium cooled fast reactor (SFR) plant design as a necessary safety measure to separate the radioactive primary loop sodium from the water of the steam Rankine power cycle. However, the intermediate heat transfer loop significantly increases the SFR plant cost and decreases the plant reliability due to the relatively high possibility of sodium leakage. A previous study shows that helium Brayton cycles with multiple reheat and intercooling for SFRs with reactor outlet temperature in the range of 510°C to 650°C can achieve thermal efficiencies comparable to or higher than steam cycles or recently proposed supercritical CO2 cycles. Use of inert helium as the power conversion working fluid provides major advantages over steam or CO2 by removing the requirement for safety systems to prevent and mitigate the sodium-water or sodium-CO2 reactions. A helium Brayton cycle power conversion system therefore makes the elimination of the intermediate heat transfer loop possible. This paper presents a pre-conceptual design of multiple reheat helium Brayton cycle for an advanced loop type SFR. This design widely refers the new horizontal shaft distributed PBMR helium power conversion design features. For a loop type SFR with reactor outlet temperature 550°C, the design achieves 42.4% thermal efficiency with favorable power density comparing with high temperature gas cooled reactors.

  16. Electron heating in superconducting cuprate heterostructures and its application for advanced sensing

    NASA Astrophysics Data System (ADS)

    Sergeev, Andrei; Wen, Bo; Yakobov, Roman; Vitkalov, Sergey; Karasik, Boris

    2014-03-01

    Low electron density in superconducting LaSrCuO heterostructures containing quasi-two dimensional CuO layers leads to strong reduction of the interaction between electrons and thermal phonons and simultaneously to substantial enhancement of the electron-electron interaction. This hierarchy of kinetic processes provides very effective quasiparticle multiplication and slow quasiparticle relaxation and recombination. Strong heating of quasiparticles in the superconducting and resistive states makes these superconducting nanomaterials to be very attractive for various sensing applications based on electron heating. These nanostructures allow for the managing of quasiparticle relaxation rate from low values determined by the electron-phonon relaxation to high values in short devices with out-diffusion electron cooling. Therefore, LSCO heterostructures are very interesting for applications in sensitive resistive detectors, kinetic inductance detectors, and wideband mixers. We experimentally determined key material parameters, design corresponding sensors and evaluated their parameters. Work is supported by NSF.

  17. Advanced Exploration Systems Logistics Reduction and Repurposing Trash-to-Gas and Heat Melt Compactor KSC

    NASA Technical Reports Server (NTRS)

    Caraccio, Anne J.; Layne, Andrew; Hummerick, Mary

    2013-01-01

    Topics covered: 1. Project Structure 2. "Trash to Gas" 3. "Smashing Trash! The Heat Melt Compactor" 4. "Heat Melt Compaction as an Effective Treatment for Eliminating Microorganisms from Solid Waste" Thermal degradation of trash reduces volume while creating water, carbon dioxide and ash. CO2 can be fed to Sabatier reactor for CH4 production to fuel LOX/LCH4 ascent vehicle. Optimal performance: HFWS, full temperature ramp to 500-600 C. Tar challenges exist. Catalysis: Dolomag did eliminate allene byproducts from the product stream. 2nd Gen Reactor Studies. Targeting power, mass, time efficiency. Gas separation, Catalysis to reduce tar formation. Microgravity effects. Downselect in August will determine where we should spend time optimizing the technology.

  18. Space Station heat pipe advanced radiator element (SHARE) flight test results and analysis

    NASA Technical Reports Server (NTRS)

    Kosson, Robert; Brown, Richard; Ungar, Eugene

    1990-01-01

    The SHARE experiment, which consisted of a single 51 ft long by 1 ft wide prototypical Space Station heat pipe radiator panel, was flown aboard STS-29 in March 1989. Several problems were uncovered during the flight which limited performance. Extensive post-flight analysis has revealed that the manifold connecting the evaporator and condenser sections did not prime properly in 0-g, and that a mismatch in hydraulic diameters between the evaporator and condenser caused large bubbles to be present in the liquid channel at startup. These bubbles subsequently became trapped at the evaporator entrance, halting liquid flow and causing premature dryout of the evaporator wall grooves. The experiment did demonstrate heat pipe transport capability of up to 1572 W with near isothermality in both the evaporator and condenser for short periods of time.

  19. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    NASA Astrophysics Data System (ADS)

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P.

    2014-01-01

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  20. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    SciTech Connect

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P.

    2014-01-29

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  1. Technical assessment of the Office of Industrial Programs' Advanced Heat Exchanger Program

    SciTech Connect

    Rinker, F.G.; Bergles, A.E.; Marciniak, T.J.; Batman, J.

    1987-02-01

    The DOE's AHX Program is an integral part of the OIP's Waste Heat Recovery Program whose goals are to increase the end-use energy efficiency of industry and agricultural operations, and to expand the energy options for manufacturing processes by providing technologies which use various fuels including coal, renewables, oil, and natural gas. The OIP and PNL convened a panel of industry experts to conduct a technical assessment of OIP's AHX program. This report documents the results of the panel's assessment.

  2. Advanced gas heating systems for high temperature furnaces for refractories firing

    SciTech Connect

    Zvyaghintsev, K.N.; Sinitsyn, E.A.; Verozub, E.Y.

    1988-01-01

    In this paper the results of investigations are presented. On the basis of these results the heating systems and burner arrangements with the adjustment of flame parameters for rotary furnaces and tunnel kilns for refractories production are developed. It is shown that the realization of results makes it possible to reduce the specific consumption of fuel, to increase the quality of fired products together with furnaces output and to assimilate now technological processes.

  3. Pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Astrophysics Data System (ADS)

    Anderson, W. G.; Rosenfeld, J. H.; Saaski, E. L.; Noble, J.; Tower, L.

    Experiments to determine alkali metal/enhanced surface combinations that have stable boiling at the temperatures and heat fluxes that occur in the Stirling engine are reported. Two enhanced surfaces and two alkali metal working fluids were evaluated. The enhanced surfaces were an EDM hole covered surface and a sintered-powder-metal porous layer surface. The working fluids tested were potassium and eutectic sodium-potasium alloy (NaK), both with and without undissolved noncondensible gas. Noncondensible gas (He and Xe) was added to the system to provide gas in the nucleation sites, preventing quenching of the sites. The experiments demonstrated the potential of an alkali metal pool boiler heat transport system for use in a solar-powered Stirling engine. The most favorable fluid/surface combination tested was NaK boiling on a -100 +140 mesh 304L stainless steel sintered porous layer with no undissolved noncondensible gas. This combination provided stable, high-performance boiling at the operating temperature of 700 C. Heat fluxes into the system ranged from 10 to 50 W/sq cm. The transition from free convection to nucleate boiling occurred at temperatures near 540 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

  4. Low Cost Advanced Thermoelectric (TE) Technology for Automotive Waste Heat Recovery

    NASA Astrophysics Data System (ADS)

    Meisner, G. P.

    2014-03-01

    Low cost, fully integrated TE generators (TEGs) to recover waste heat from vehicle exhaust will reduce transportation sector energy consumption and emissions. TEGs will be the first application of high-temperature TE materials for high-volume use and establish new industrial sectors with scaled up production capability of TEG materials and components. We will create a potential supply chain for practical automotive TEGs and identify manufacturing and assembly processes for large scale production of TEG materials and components. Our work focusses on several innovative R&D paths: (1) enhanced TE material performance by doping and compositional tuning, (2) optimized TE material fabrication and processing to reduce thermal conductivity and improve fracture strength, (3) high volume production for successful skutterudite commercialization, (4) new material, nanostructure, and nanoscale approaches to reduce thermal interface and electrical contact resistances, (5) innovative heat exchangers for high efficiency heat flows and optimum temperature profiles despite highly variable exhaust gas operating conditions, (6) new modeling and simulation tools, and (7) inexpensive materials for thermal insulation and coatings for TE encapsulation. Recent results will be presented. Supported by the U.S. DOE Vehicle Technology Program.

  5. Performance of advanced automotive fuel cell systems with heat rejection constraint

    NASA Astrophysics Data System (ADS)

    Ahluwalia, R. K.; Wang, X.; Steinbach, A. J.

    2016-03-01

    Although maintaining polymer electrolyte fuel cells (PEFC) at temperatures below 80 °C is desirable for extended durability and enhanced performance, the automotive application also requires the PEFC stacks to operate at elevated temperatures and meet the heat rejection constraint, stated as Q/ΔT < 1.45 kW/°C, where Q is the stack heat load for an 80-kWe net power PEFC system and ΔT is the difference between the stack coolant temperature and 40 °C ambient temperature. We have developed a method to determine the optimum design and operating conditions for an automotive stack subject to this Q/ΔT constraint, and illustrate it by applying it to a state-of-the-art stack with nano-structured thin film ternary catalysts in the membrane electrode assemblies. In the illustrative example, stack coolant temperatures >90 °C, stack inlet pressures >2 atm, and cathode stoichiometries <2 are needed to satisfy the Q/ΔT constraint in a cost effective manner. The reference PEFC stack with 0.1 mg/cm2 Pt loading in the cathode achieves 753 mW cm-2 power density at the optimum conditions for heat rejection, compared to 964 mW cm-2 in the laboratory cell at the same cell voltage (663 mV) and pressure (2.5 atm) but lower temperature (85 °C), higher cathode stoichiometry (2), and 100% relative humidity.

  6. High temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers. Final report

    SciTech Connect

    Kupp, E.R.; Trubelja, K.E.; Spear, K.E.; Tressler, R.E.

    1995-08-01

    Experimental corrosion studies of hot gas filter materials and heat exchanger materials in oxidizing combustion environments have been initiated. Filter materials from 3M Co. and DuPont Lanxide Composites Inc. are being tested over a range of temperatures, times and gas flows. It has been demonstrated that morphological and phase changes due to corrosive effects occur after exposure of these materials to a simulated coal combustion environment for relatively short periods of time (10-50 hours). Heat exchanger tubes from DuPont Lanxide Composite Inc. were cut and infiltrated with Cr by heating in a Cr{sub 2}O{sub 3} powder bed. This resulted in continuous Cr-rich layers with thicknesses ranging from 20 to 250 {mu}m. The Cr-free and the Cr-infiltrated specimens were reacted with the molten Illinois No. 6 slag for 2 and 20 h at 1260{degrees}C, and the reaction layers examined with SEM and EDX. In the Cr-free specimens, the segregation of Fe and the precipitation of Fe{sub 2}O{sub 3} were detected near the liquid/gas interface, but no evidence of corrosion was present. In the Cr-infiltrate specimens, corrosion was evident, since a rearrangement and segregation of the Cr-rich grains occurred toward the surface of the molten slag. In addition, evidence of the diffusion of major quantities of Fe was observed from the liquid slag into the Cr-rich layer formed by infiltration.

  7. Pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Technical Reports Server (NTRS)

    Anderson, W. G.; Rosenfeld, J. H.; Saaski, E. L.; Noble, J.; Tower, L.

    1990-01-01

    Experiments to determine alkali metal/enhanced surface combinations that have stable boiling at the temperatures and heat fluxes that occur in the Stirling engine are reported. Two enhanced surfaces and two alkali metal working fluids were evaluated. The enhanced surfaces were an EDM hole covered surface and a sintered-powder-metal porous layer surface. The working fluids tested were potassium and eutectic sodium-potasium alloy (NaK), both with and without undissolved noncondensible gas. Noncondensible gas (He and Xe) was added to the system to provide gas in the nucleation sites, preventing quenching of the sites. The experiments demonstrated the potential of an alkali metal pool boiler heat transport system for use in a solar-powered Stirling engine. The most favorable fluid/surface combination tested was NaK boiling on a -100 +140 mesh 304L stainless steel sintered porous layer with no undissolved noncondensible gas. This combination provided stable, high-performance boiling at the operating temperature of 700 C. Heat fluxes into the system ranged from 10 to 50 W/sq cm. The transition from free convection to nucleate boiling occurred at temperatures near 540 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

  8. High temperature corrosion of advanced ceramic materials for hot-gas filters and heat exchangers

    SciTech Connect

    Kupp, E.R.; Trubelja, M.F.; Spear, K.E.; Tressler, R.E.

    1995-08-01

    Experimental corrosion studies of hot gas filter materials and heat exchanger materials in oxidizing combustion environments have been initiated. Filter materials from 3M Co. and DuPont Lanxide Composites Inc. are being tested over a range of temperatures, times and gas flows. It has been demonstrated that morphological and phase changes due to corrosive effects occur after exposure of the 3M material to a combustion environment for as little as 25 hours at 800{degrees}C. The study of heat exchanger materials has focused on enhancing the corrosion resistance of DuPont Lanxide Dimox{trademark} composite tubes by adding chromium to its surfaces by (1) heat treatments in a Cr{sub 2}O{sub 3} powder bed, or (2) infiltrating surface porosity with molten chromium nitrate. Each process is followed by a surface homogenization at 1500{degrees}C. The powder bed method has been most successful, producing continuous Cr-rich layers with thicknesses ranging from 20 to 250 {mu}m. As-received and Cr-modified DuPont Lanxide Dimox{trademark} samples will be reacted with commonly encountered coal-ash slags to determine the Cr effects on corrosion resistance.

  9. Energy savings and economics of advanced control strategies for packaged air conditioners with gas heat

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

    2013-10-01

    This paper presents an evaluation of the potential energy savings from adding advanced control to existing packaged air conditioners. Advanced control options include air-side economizer, multi-speed fan control, demand control ventilation and staged cooling. The energy and cost savings from the different control strategies individually and in combination are estimated using the EnergyPlus detailed energy simulation program for four building types, namely, a small office building, a stand-alone retail building, a strip mall building and a supermarket building. For each of the four building types, the simulation was run for 16 locations covering all 15 climate zones in the U.S. The maximum installed cost of a replacement controller that provides acceptable payback periods to owners is estimated.

  10. An advanced Thermal-FSI approach to flow heating/cooling

    NASA Astrophysics Data System (ADS)

    Badur, J.; Ziółkowski, P.; Zakrzewski, W.; Sławiński, D.; Kornet, S.; Kowalczyk, T.; Hernet, J.; Piotrowski, R.; Felincjancik, J.; Ziółkowski, P. J.

    2014-08-01

    Actually, two-way thermal-energy exchange between working fluid and solid material of a casing is a leading problem for modern - semi automatic - design techniques. Many questions should be solved, especially, the turbulent mode of thermal energy transport both in fluid and solid, should be re-examined and reformulated from the primary principles. In the present paper, a group of researchers from Energy Conversion Department of IMP PAN at Gdańsk, tries to summarise a last three-years efforts towards to mathematical modelling of advanced models of thermal energy transport. This extremely difficult problem in "thermal-FSI" ("Fluid Solid Interaction") means that the both for solid and fluid mathematical model of a surface layer should be self-equilibrated and self-concise. Taking these requirements into account, an advanced Reynolds-Stanton analogy has been discussed and implemented. Some numerical examples concerning of the benchmarks experiments and industrial applications have also been developed and presented.

  11. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    SciTech Connect

    Swindeman, R.W.

    1993-07-01

    Commercial and developmental alloys were evaluated in support of advanced steam cycle and combined cycle technology. Working with industrial groups, Grade 91 steel, which is a candidate for main steam line piping and superheater tubing in advanced steam cycle plants, was re-evaluated to examine metallurgical factors that influence long-time performance to 600{degree}C. Deformation models and aging effect models were developed. Testing of corrosion-resistant filler metals for tubing was extended to times approaching 30,000 h. Good strengths were observed. Modified Type 310 stainless steels were examined to 927{degree}C. It was found that these steels had up to twice the strength of standard Type 310H stainless steel. The behavior of aluminum-bearing, alloys and high chromium alloys was examined for potential applications to 870{degree}C. Thermal cycling of clad tubing was undertaken, and good performance was found.

  12. Advanced variable speed air source integrated heat pump (AS-IHP) development - CRADA final report

    SciTech Connect

    Baxter, Van D.; Rice, C. Keith; Munk, Jeffrey D.; Ally, Moonis Raza; Shen, Bo

    2015-09-30

    Between August 2011 and September 2015, Oak Ridge National Laboratory (ORNL) and Nordyne, LLC (now Nortek Global HVAC LLC, NGHVAC) engaged in a Cooperative Research and Development Agreement (CRADA) to develop an air-source integrated heat pump (AS-IHP) system for the US residential market. Two generations of laboratory prototype systems were designed, fabricated, and lab-tested during 2011-2013. Performance maps for the system were developed using the latest research version of the DOE/ORNL Heat Pump Design Model, or HPDM, (Rice 1991; Rice and Jackson 2005; Shen et al 2012) as calibrated against the lab test data. These maps were the input to the TRNSYS (SOLAR Energy Laboratory, et al, 2010) system to predict annual performance relative to a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of 13 SEER air-source heat pump (ASHP) and resistance water heater with Energy Factor (EF) of 0.9). Predicted total annual energy savings, while providing space conditioning and water heating for a tight, well insulated 2600 ft2 (242 m2) house at 5 U.S. locations, ranged from 46 to 61%, averaging 52%, relative to the baseline system (lowest savings at the cold-climate Chicago location). Predicted energy use for water heating was reduced 62 to 76% relative to resistance WH. Based on these lab prototype test and analyses results a field test prototype was designed and fabricated by NGHVAC. The unit was installed in a 2400 ft2 (223 m2) research house in Knoxville, TN and field tested from May 2014 to April 2015. Based on the demonstrated field performance of the AS-IHP prototype and estimated performance of a baseline system operating under the same loads and weather conditions, it was estimated that the prototype would achieve ~40% energy savings relative to the minimum efficiency suite. The estimated WH savings were >60% and SC mode savings were >50%. But estimated SH savings were only about 20%. It is believed that had the test

  13. Advances in High Harmonic Fast Wave Heating of NSTX H-mode Plasmas

    SciTech Connect

    Ryan, Philip Michael; Ahn, Joonwook; Bell, R. E.; Bonoli, P.; Chen, Guangye; Green, David L; Harvey, R. W.; Hosea, J.; Jaeger, Erwin Frederick; Kaye, S.; LeBlanc, B; Maingi, Rajesh; Phillips, Cynthia; Podesta, M.; Taylor, G.; Wilgen, John B; Wilson, J. R.

    2010-01-01

    High-harmonic fast wave (HHFW) heating and current drive is being developed in NSTX to provide bulk electron heating and q(0) control during non-inductively sustained Hmode plasmas fuelled by deuterium neutral-beam injection (NBI). In addition, it is used to assist the plasma current ramp-up. A major modification to increase the RF power limit was made in 2009; the original end-grounded, single end-powered current straps of the 12- element array were replaced with center-grounded, double end-powered straps. Greater than 3 MW have been coupled into NBI-driven, ELMy H-mode plasmas with this upgraded antenna. Improved core HHFW heating, particularly at longer wavelengths and during low-density start-up and plasma current ramp-up, has been obtained by lowering the edge density with lithium wall conditioning, thereby moving the critical density for fast-wave propagation away from the vessel wall [1]. Significant core electron heating of NBI-fuelled H-modes has been observed for the first time over a range of launched wavelengths and H-modes can be accessed by HHFW alone. Visible and IR camera images of the antenna and divertor indicate that fast wave interactions can deposit considerable RF energy on the outboard divertor plate, especially at longer wavelengths that begin to propagate closer to the vessel walls. Edge power loss can also arise from HHFWgenerated parametric decay instabilities; edge ion heating is observed that is wavelength dependent. During plasmas where HHFW is combined with NBI, there is a significant enhancement in neutron rate, and fast-ion D-alpha (FIDA) emission measurements clearly show broadening of the fast-ion profile in the plasma core. Large edge localized modes (ELMs) have been observed immediately following the termination of RF power, whether the power turn off is programmed or due to antenna arcing. Causality has not been established but new experiments are planned and will be reported. Fast digitization of the reflected power signal

  14. THE POTENTIAL OF NANOPARTICLE ENHANCED IONIC LIQUIDS (NEILS) AS ADVANCED HEAT TRANSFER FLUIDS

    SciTech Connect

    Fox, E.; Bridges, N.; Visser, A.

    2011-09-14

    Interest in capturing the energy of the sun is rising as demands for renewable energy sources increase. One area of developing research is the use of concentrating solar power (CSP), where the solar energy is concentrated by using mirrors to direct the sunlight towards a collector filled with a heat transfer fluid (HTF). The HTF transfers the collected energy into pressurized steam, which is used to generate energy. The greater the energy collected by the HTF, the more efficent the electrical energy production is, thus the overall efficiency is controlled by the thermal fluid. Commercial HTFs such as Therminol{reg_sign} (VP-1), which is a blend of biphenyl and diphenyl oxide, have a significant vapor pressure, especially at elevated temperatures. In order for these volatile compounds to be used in CSP systems, the system either has to be engineered to prevent the phase change (i.e., volatilization and condensation) through pressurization of the system, or operate across the phase change. Over thirty years ago, a class of low-melting organic compounds were developed with negligible vapor pressure. These compounds are referred to as ionic liquids (ILs), which are organic-based compounds with discrete charges that cause a significant decrease in their vapor pressure. As a class, ILs are molten salts with a melting point below 100 C and can have a liquidus range approaching 400 C, and in several cases freezing points being below 0 C. Due to the lack of an appreciable vapor pressure, volatilization of an IL is not possible at atmospheric pressure, which would lead to a simplification of the design if used as a thermal fluid and for energy storage materials. Though the lack of a vapor pressure does not make the use of ILs a better HTF, the lack of a vapor pressure is a compliment to their higher heat capacity, higher volummetric density, and thus higher volumetric heat capacity. These favorable physical properties give ILs a pontential advantage over the current

  15. Performance demonstration of hydrogen advanced loop heat pipe for 20-30K cryocooling of far infrared sensors

    NASA Astrophysics Data System (ADS)

    Hoang, Triem T.; O'Connell, Tamara A.; Ku, Jentung; Butler, C. D.; Swanson, Theodore D.

    2005-08-01

    The James Webb Space Telescope (JWST) program have identified the need for cryogenic cooling transport devices that (i) provide robust/reliable thermal management for Infrared (IR) sensors/detectors in the temperature range of 20-30K, (ii) minimize vibration effects of mechanical cryocoolers on the instruments, (iii) reduce spatial temperature gradients in cryogenic components, and (iv) afford long continuous service life of the telescope. Passive two-phase capillary cooling technologies such as heat pipes, Loop Heat Pipes (LHPs), and Capillary pumped Loops (CPLs) have proven themselves capable of performing necessary thermal control functions for room temperature applications. They have no mechanical moving part to wear out or to introduce unwanted vibration to the instruments and, hence, are reliable and maintenancefree. However, utilizing these capillary devices for cryogenic cooling still remains a challenge because of difficulties involving the system start-up and operation in a warm environment. An advanced concept of LHP using Hydrogen as the working fluid was recently developed to demonstrate the cryocooling transport capabilities in the temperature range of 20-30K. A full-size demonstration test loop - appropriately called H2-ALHP_2 - was constructed and performance tested extensively in a thermal vacuum chamber. It was designed specifically to manage "heat parasitics" from a warm surrounding, enabling it to start up from an initially supercritical state and operate without requiring a rigid heat shield. Like room temperature LHPs, the H2-ALHP transport lines were made of small-diameter stainless steel tubing that are flexible enough to isolate the cryocooler-induced vibration from the IR instruments. In addition, focus of the H2-ALHP research and development effort was also placed on the system weight saving for space-based applications.

  16. Distributed Task Offloading in Heterogeneous Vehicular Crowd Sensing.

    PubMed

    Liu, Yazhi; Wang, Wendong; Ma, Yuekun; Yang, Zhigang; Yu, Fuxing

    2016-01-01

    The ability of road vehicles to efficiently execute different sensing tasks varies because of the heterogeneity in their sensing ability and trajectories. Therefore, the data collection sensing task, which requires tempo-spatial sensing data, becomes a serious problem in vehicular sensing systems, particularly those with limited sensing capabilities. A utility-based sensing task decomposition and offloading algorithm is proposed in this paper. The utility function for a task executed by a certain vehicle is built according to the mobility traces and sensing interfaces of the vehicle, as well as the sensing data type and tempo-spatial coverage requirements of the sensing task. Then, the sensing tasks are decomposed and offloaded to neighboring vehicles according to the utilities of the neighboring vehicles to the decomposed sensing tasks. Real trace-driven simulation shows that the proposed task offloading is able to collect much more comprehensive and uniformly distributed sensing data than other algorithms. PMID:27428967

  17. Distributed Task Offloading in Heterogeneous Vehicular Crowd Sensing

    PubMed Central

    Liu, Yazhi; Wang, Wendong; Ma, Yuekun; Yang, Zhigang; Yu, Fuxing

    2016-01-01

    The ability of road vehicles to efficiently execute different sensing tasks varies because of the heterogeneity in their sensing ability and trajectories. Therefore, the data collection sensing task, which requires tempo-spatial sensing data, becomes a serious problem in vehicular sensing systems, particularly those with limited sensing capabilities. A utility-based sensing task decomposition and offloading algorithm is proposed in this paper. The utility function for a task executed by a certain vehicle is built according to the mobility traces and sensing interfaces of the vehicle, as well as the sensing data type and tempo-spatial coverage requirements of the sensing task. Then, the sensing tasks are decomposed and offloaded to neighboring vehicles according to the utilities of the neighboring vehicles to the decomposed sensing tasks. Real trace-driven simulation shows that the proposed task offloading is able to collect much more comprehensive and uniformly distributed sensing data than other algorithms. PMID:27428967

  18. Realistic Mobility Modeling for Vehicular Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Akay, Hilal; Tugcu, Tuna

    2009-08-01

    Simulations used for evaluating the performance of routing protocols for Vehicular Ad Hoc Networks (VANET) are mostly based on random mobility and fail to consider individual behaviors of the vehicles. Unrealistic assumptions about mobility produce misleading results about the behavior of routing protocols in real deployments. In this paper, a realistic mobility modeling tool, Mobility for Vehicles (MOVE), which considers the basic mobility behaviors of vehicles, is proposed for a more accurate evaluation. The proposed model is tested against the Random Waypoint (RWP) model using AODV and OLSR protocols. The results show that the mobility model significantly affects the number of nodes within the transmission range of a node, the volume of control traffic, and the number of collisions. It is shown that number of intersections, grid size, and node density are important parameters when dealing with VANET performance.

  19. Distributed Reinforcement Learning Approach for Vehicular Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Wu, Celimuge; Kumekawa, Kazuya; Kato, Toshihiko

    In Vehicular Ad hoc Networks (VANETs), general purpose ad hoc routing protocols such as AODV cannot work efficiently due to the frequent changes in network topology caused by vehicle movement. This paper proposes a VANET routing protocol QLAODV (Q-Learning AODV) which suits unicast applications in high mobility scenarios. QLAODV is a distributed reinforcement learning routing protocol, which uses a Q-Learning algorithm to infer network state information and uses unicast control packets to check the path availability in a real time manner in order to allow Q-Learning to work efficiently in a highly dynamic network environment. QLAODV is favored by its dynamic route change mechanism, which makes it capable of reacting quickly to network topology changes. We present an analysis of the performance of QLAODV by simulation using different mobility models. The simulation results show that QLAODV can efficiently handle unicast applications in VANETs.

  20. Analysis of the development and the prospects about vehicular infrared night vision system

    NASA Astrophysics Data System (ADS)

    Li, Jing; Fan, Hua-ping; Xie, Zu-yun; Zhou, Xiao-hong; Yu, Hong-qiang; Huang, Hui

    2013-08-01

    Through the classification of vehicular infrared night vision system and comparing the mainstream vehicle infrared night vision products, we summarized the functions of vehicular infrared night vision system which conclude night vision, defogging , strong-light resistance and biological recognition. At the same time , the vehicular infrared night vision system's markets of senior car and fire protection industry were analyzed。Finally, the conclusion was given that vehicle infrared night vision system would be used as a safety essential active safety equipment to promote the night vision photoelectric industry and automobile industry.

  1. Advanced phase change materials and systems for solar passive heating and cooling of residential buildings

    SciTech Connect

    Salyer, I.O.; Sircar, A.K.; Dantiki, S.

    1988-01-01

    During the last three years under the sponsorship of the DOE Solar Passive Division, the University of Dayton Research Institute (UDRI) has investigated four phase change material (PCM) systems for utility in thermal energy storage for solar passive heating and cooling applications. From this research on the basis of cost, performance, containment, and environmental acceptability, we have selected as our current and most promising series of candidate phase change materials, C-15 to C-24 linear crystalline alkyl hydrocarbons. The major part of the research during this contract period was directed toward the following three objectives. Find, test, and develop low-cost effective phase change materials (PCM) that melt and freeze sharply in the comfort temperature range of 73--77{degree}F for use in solar passive heating and cooling of buildings. Define practical materials and processes for fire retarding plasterboard/PCM building products. Develop cost-effective methods for incorporating PCM into building construction materials (concrete, plasterboard, etc.) which will lead to the commercial manufacture and sale of PCM-containing products resulting in significant energy conservation.

  2. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC). Technical progress report

    SciTech Connect

    Lee, S.W.

    1998-01-01

    Numerical simulation on the flow patterns/the velocity profiles was conducted and predicted. The test conditions and input boundary conditions are summarized. The flow patterns of the side view/top view are predicted along with stream lines. When the flow reached to the secondary air input of the lower air injection nozzles, the flow pattern was changed from a laminar flow to a turbulent flow. The velocity profiles at various locations of the combustor chamber was predicted. The velocity at the center of the combustor is greater than that of the wall region. The velocity of the top section is also greater than that of the lower section. The swirling velocity is reduced in both directions of the wall and the center of the combustor chamber. The velocity increased from the wall region to the center region at the top section of the secondary air injectors. Numerical modeling/simulation will be continued to determine the species profiles, temperature profiles, mass fraction profiles, and heat flux and heat transfer coefficient profiles. In addition, experimental test on the hot combustor model will be conducted and analyzed to compare with the numerical simulation results.

  3. Production of general purpose heat source (GPHS) using advanced manufacturing methods

    NASA Astrophysics Data System (ADS)

    Miller, Roger G.

    1996-03-01

    Mankind will continue to explore the stars through the use of unmanned space craft until the technology and costs are compatible with sending travelers to the outer planets of our solar system and beyond. Unmanned probes of the present and future will be necessary to develop the necessary technologies and obtain information that will make this travel possible. Because of the significant costs incurred, the use of modern manufacturing technologies must be used to lower the investment needed even when shared by international partnerships. For over the last 30 years, radioisotopes have provided the heat from which electrical power is extracted. Electric power for future spacecraft will be provided by either Radioisotope Thermoelectric Generators (RTG), Radioisotopic Thermophotovoltaic systems (RTPV), radioisotope Stirling systems, or a combination of these. All of these systems will be thermally driven by General Purpose Heat Source (GPHS) fueled clad in some configuration. The GPHS clad contains a 238PuO2 pellet encapsulated in an iridium alloy container. Historically, the fabrication of the iridium alloy shells has been performed at EG&G Mound and Oak Ridge National Laboratory (ORNL), and girth welding at Westinghouse Savannah River Corporation (WSRC) and Los Alamos National Laboratory (LANL). This paper will describe the use of laser processing for welding, drilling, cutting, and machining with other manufacturing methods to reduce the costs of producing GPHS fueled clad components and compléted assemblies. Incorporation of new quality technologies will compliment these manufacturing methods to reduce cost.

  4. Health benefit modelling and optimization of vehicular pollution control strategies

    NASA Astrophysics Data System (ADS)

    Sonawane, Nayan V.; Patil, Rashmi S.; Sethi, Virendra

    2012-12-01

    This study asserts that the evaluation of pollution reduction strategies should be approached on the basis of health benefits. The framework presented could be used for decision making on the basis of cost effectiveness when the strategies are applied concurrently. Several vehicular pollution control strategies have been proposed in literature for effective management of urban air pollution. The effectiveness of these strategies has been mostly studied as a one at a time approach on the basis of change in pollution concentration. The adequacy and practicality of such an approach is studied in the present work. Also, the assessment of respective benefits of these strategies has been carried out when they are implemented simultaneously. An integrated model has been developed which can be used as a tool for optimal prioritization of various pollution management strategies. The model estimates health benefits associated with specific control strategies. ISC-AERMOD View has been used to provide the cause-effect relation between control options and change in ambient air quality. BenMAP, developed by U.S. EPA, has been applied for estimation of health and economic benefits associated with various management strategies. Valuation of health benefits has been done for impact indicators of premature mortality, hospital admissions and respiratory syndrome. An optimization model has been developed to maximize overall social benefits with determination of optimized percentage implementations for multiple strategies. The model has been applied for sub-urban region of Mumbai city for vehicular sector. Several control scenarios have been considered like revised emission standards, electric, CNG, LPG and hybrid vehicles. Reduction in concentration and resultant health benefits for the pollutants CO, NOx and particulate matter are estimated for different control scenarios. Finally, an optimization model has been applied to determine optimized percentage implementation of specific

  5. Development of a thermal diode heat pipe for the advanced thermal control flight experiment /ATFE/.

    NASA Technical Reports Server (NTRS)

    Swerdling, B.; Kosson, R.; Urkowitz, M.; Kirkpatrick, J.

    1972-01-01

    Description of the analysis, design, fabrication, and test of the engineering model of the ATFE diode. Included is a review of several diode concepts that led to selection of the liquid blockage technique for shut-off. The diode is made of stainless steel, 26 in. long, 0.375-in. nominal OD, with self-filling spiral artery wick and ammonia working fluid. In the normal heat pipe mode, at ambient temperatures, the diode capacity is 85 W. For flight, the pipe will deliver 20 W with a 9 F temperature difference between the external evaporator and condenser surfaces. Reverse mode conduction is less than 1.5 W with a 260 F temperature difference.

  6. High temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    SciTech Connect

    Crossland, C.E.; Shelleman, D.L.; Spear, K.E.

    1996-08-01

    A vertical flow-through furnace has been built to study the effect of corrosion on the morphology and mechanical properties of ceramic hot gas filters. Sections of 3M Type 203 and DuPont Lanxide SiC-SiC filter tubes were sealed at one end and suspended in the furnace while being subjected to a simulated coal combustion environment at 870{degrees}C. X-ray diffraction and electron microscopy is used to identify phase and morphology changes due to corrosion while burst testing determines the loss of mechanical strength after exposure to the combustion gases. Additionally, a thermodynamic database of gaseous silicon compounds is currently being established so that calculations can be made to predict important products of the reaction of the environment with the ceramics. These thermodynamic calculations provide useful information concerning the regimes where the ceramic may be degraded by material vaporization. To verify the durability and predict lifetime performance of ceramic heat exchangers in coal combustion environments, long-term exposure testing of stressed (internally pressurized) tubes must be performed in actual coal combustion environments. The authors have designed a system that will internally pressurize 2 inch OD by 48 inch long ceramic heat exchanger tubes to a maximum pressure of 200 psi while exposing the outer surface of the tubes to coal combustion gas at the Combustion and Environmental Research Facility (CERF) at the Pittsburgh Energy and Technology Center. Water-cooled, internal o-ring pressure seals were designed to accommodate the existing 6 inch by 6 inch access panels of the CERF. Tubes will be exposed for up to a maximum of 500 hours at temperatures of 2500 and 2600{degrees}F with an internal pressure of 200 psi. If the tubes survive, their retained strength will be measured using the high temperature tube burst test facility at Penn State University. Fractographic analysis will be performed to identify the failure source(s) for the tubes.

  7. Benefits of Combined GPS/GLONASS with Low-Cost MEMS IMUs for Vehicular Urban Navigation

    PubMed Central

    Angrisano, Antonio; Petovello, Mark; Pugliano, Giovanni

    2012-01-01

    The integration of Global Navigation Satellite Systems (GNSS) with Inertial Navigation Systems (INS) has been very actively researched for many years due to the complementary nature of the two systems. In particular, during the last few years the integration with micro-electromechanical system (MEMS) inertial measurement units (IMUs) has been investigated. In fact, recent advances in MEMS technology have made possible the development of a new generation of low cost inertial sensors characterized by small size and light weight, which represents an attractive option for mass-market applications such as vehicular and pedestrian navigation. However, whereas there has been much interest in the integration of GPS with a MEMS-based INS, few research studies have been conducted on expanding this application to the revitalized GLONASS system. This paper looks at the benefits of adding GLONASS to existing GPS/INS(MEMS) systems using loose and tight integration strategies. The relative benefits of various constraints are also assessed. Results show that when satellite visibility is poor (approximately 50% solution availability) the benefits of GLONASS are only seen with tight integration algorithms. For more benign environments, a loosely coupled GPS/GLONASS/INS system offers performance comparable to that of a tightly coupled GPS/INS system, but with reduced complexity and development time. PMID:22666079

  8. SVANET: A smart vehicular ad hoc network for efficient data transmission with wireless sensors.

    PubMed

    Sahoo, Prasan Kumar; Chiang, Ming-Jer; Wu, Shih-Lin

    2014-01-01

    Wireless sensors can sense any event, such as accidents, as well as icy roads, and can forward the rescue/warning messages through intermediate vehicles for any necessary help. In this paper, we propose a smart vehicular ad hoc network (SVANET) architecture that uses wireless sensors to detect events and vehicles to transmit the safety and non-safety messages efficiently by using different service channels and one control channel with different priorities. We have developed a data transmission protocol for the vehicles in the highway, in which data can be forwarded with the help of vehicles if they are connected with each other or data can be forwarded with the help of nearby wireless sensors. Our data transmission protocol is designed to increase the driving safety, to prevent accidents and to utilize channels efficiently by adjusting the control and service channel time intervals dynamically. Besides, our protocol can transmit information to vehicles in advance, so that drivers can decide an alternate route in case of traffic congestion. For various data sharing, we design a method that can select a few leader nodes among vehicles running along a highway to broadcast data efficiently. Simulation results show that our protocol can outperform the existing standard in terms of the end to end packet delivery ratio and latency. PMID:25429409

  9. SVANET: A Smart Vehicular Ad Hoc Network for Efficient Data Transmission with Wireless Sensors

    PubMed Central

    Sahoo, Prasan Kumar; Chiang, Ming-Jer; Wu, Shih-Lin

    2014-01-01

    Wireless sensors can sense any event, such as accidents, as well as icy roads, and can forward the rescue/warning messages through intermediate vehicles for any necessary help. In this paper, we propose a smart vehicular ad hoc network (SVANET) architecture that uses wireless sensors to detect events and vehicles to transmit the safety and non-safety messages efficiently by using different service channels and one control channel with different priorities. We have developed a data transmission protocol for the vehicles in the highway, in which data can be forwarded with the help of vehicles if they are connected with each other or data can be forwarded with the help of nearby wireless sensors. Our data transmission protocol is designed to increase the driving safety, to prevent accidents and to utilize channels efficiently by adjusting the control and service channel time intervals dynamically. Besides, our protocol can transmit information to vehicles in advance, so that drivers can decide an alternate route in case of traffic congestion. For various data sharing, we design a method that can select a few leader nodes among vehicles running along a highway to broadcast data efficiently. Simulation results show that our protocol can outperform the existing standard in terms of the end to end packet delivery ratio and latency. PMID:25429409

  10. A compact dual-band RF front-end and board design for vehicular platforms

    NASA Astrophysics Data System (ADS)

    Sharawi, Mohammad S.; Aloi, Daniel N.

    2012-03-01

    Modern vehicular platforms include several wireless systems that provide navigation, entertainment and road side assistance, among other services. These systems operate at different frequency bands and thus careful system-level design should be followed to minimise the interference between them. In this study, we present a compact dual-band RF front-end module for global positioning system (GPS) operating in the L1-band (1574.42-1576.42 MHz) and satellite digital audio radio system (SDARS) operating in the S-band (2320-2345 MHz). The module provides more than 26 dB of measured gain in both bands and low noise figure values of 0.9 and 1.2 dB in SDARS and GPS bands, respectively. The front-end has interference suppression capability from the advanced mobile phone system and personal communication service cellular bands. The module is designed on a low-cost FR-4 substrate material and occupies a small size of 62 × 29 × 1.3 mm3. It dissipates 235 mW in the SDARS section and 100 mW in the GPS section. Three prototypes have been built to verify a repeatable performance.

  11. Robonaut 2 - Preparing for Intra-Vehicular Mobility on the International Space Station

    NASA Technical Reports Server (NTRS)

    Badger, Julia; Diftler, Myron; Hulse, Aaron; Taylor, Ross

    2013-01-01

    Robonaut 2 (R2) has been undergoing experimental trials on board the International Space Station (ISS) for more than a year. This upper-body anthropomorphic robotic system shown in Figure 1 has been making steady progress after completing its initial checkout. R2 demonstrated free space motion, physically interacted with its human crew mates, manipulated interfaces on its task board and has even used its first tool. This steady growth in capability will lead R2 to its next watershed milestone. Developers are currently testing prototype robotic climbing appendages and a battery backpack in preparation of sending flight versions of both subsystems to the ISS in late 2013. Upon integration of its new components, R2 will be able to go mobile inside the space station with a twofold agenda. First, R2 will learn to maneuver in microgravity in the best possible laboratory for such a task. Second, it will start providing early payback to the ISS program by helping with intra-vehicular (IVA) maintenance tasks. The experience gained inside the ISS will be invaluable in reducing risk when R2 moves to its next stage and is deployed as an extra-vehicular (EVA) tool. Even on its current fixed base stanchion, R2 has already shown its capability of performing several maintenance tasks on the ISS. It has measured the air flow through one of the stations vents and provided previously unavailable real time flow data to ground operators. R2 has cleaned its first handrail, exciting some crew members that perhaps Saturday morning housekeeping on the station may someday become a task they can hand off to their robotic colleague. Other tasks, including using radio frequency identification (RFID) tools for inventory tasks or vacuuming air filters, have also been suggested and will be explored. Once mobile, R2 will take on these tasks and more to free up crew time for more important science and exploration pursuits. In addition to task exploration, research and testing is happening on orbit

  12. 76 FR 52350 - Vehicular Digital Multimedia Evidence Recording System (VDMERS) Standard, Certification Program...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Office of Justice Programs Vehicular Digital Multimedia Evidence Recording System (VDMERS) Standard... Evidence Recording Systems (VDMERSs) used by law enforcement agencies: 1. Draft VDMERS Standard for...

  13. 76 FR 13436 - NIJ Request for Comments on Draft Vehicular Digital Multimedia Evidence Recording System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-11

    ... Office of Justice Programs NIJ Request for Comments on Draft Vehicular Digital Multimedia Evidence... Digital Multimedia Evidence Recording System Selection and Application Guide AGENCY: National Institute of... Evidence Recording System Certification Program Requirements for Law Enforcement'' ``Law...

  14. Low Emissions and Delay Optimization for an Isolated Signalized Intersection Based on Vehicular Trajectories

    PubMed Central

    2015-01-01

    A traditional traffic signal control system is established based on vehicular delay, queue length, saturation and other indicators. However, due to the increasing severity of urban environmental pollution issues and the development of a resource-saving and environmentally friendly social philosophy, the development of low-carbon and energy-efficient urban transport is required. This paper first defines vehicular trajectories and the calculation of vehicular emissions based on VSP. Next, a regression analysis method is used to quantify the relationship between vehicular emissions and delay, and a traffic signal control model is established to reduce emissions and delay using the enumeration method combined with saturation constraints. Finally, one typical intersection of Changchun is selected to verify the model proposed in this paper; its performance efficiency is also compared using simulations in VISSIM. The results of this study show that the proposed model can significantly reduce vehicle delay and traffic emissions simultaneously. PMID:26720095

  15. Parallel Vehicular Traffic Simulation using Reverse Computation-based Optimistic Execution

    SciTech Connect

    Yoginath, Srikanth B; Perumalla, Kalyan S

    2008-01-01

    Vehicular traffic simulations are useful in applications such as emergency management and homeland security planning tools. High speed of traffic simulations translates directly to speed of response and level of resilience in those applications. Here, a parallel traffic simulation approach is presented that is aimed at reducing the time for simulating emergency vehicular traffic scenarios. Three unique aspects of this effort are: (1) exploration of optimistic simulation applied to vehicular traffic simulation (2) addressing reverse computation challenges specific to optimistic vehicular traffic simulation (3) achieving absolute (as opposed to self-relative) speedup with a sequential speed equal to that of a fast, de facto standard sequential simulator for emergency traffic. The design and development of the parallel simulation system is presented, along with a performance study that demonstrates excellent sequential performance as well as parallel performance.

  16. Advanced Ultrasonic Inspection Techniques for General Purpose Heat Source Fueled Clad Closure Welds

    SciTech Connect

    Moyer, M.W.

    2001-01-11

    A radioisotope thermoelectric generator is used to provide a power source for long-term deep space missions. This General Purpose Heat Source (GPHS) is fabricated using iridium clad vent sets to contain the plutonium oxide fuel pellets. Integrity of the closure weld is essential to ensure containment of the plutonium. The Oak Ridge Y-12 Plant took the lead role in developing the ultrasonic inspection for the closure weld and transferring the inspection to Los Alamos National Laboratory for use in fueled clad inspection for the Cassini mission. Initially only amplitude and time-of-flight data were recorded. However, a number of benign geometric conditions produced signals that were larger than the acceptance threshold. To identify these conditions, a B-scan inspection was developed that acquired full ultrasonic waveforms. Using a test protocol the B-scan inspection was able to identify benign conditions such as weld shield fusion and internal mismatch. Tangential radiography was used to confirm the ultrasonic results. All but two of 29 fueled clads for which ultrasonic B-scan data was evaluated appeared to have signals that could be attributed to benign geometric conditions. This report describes the ultrasonic inspection developed at Y-12 for the Cassini mission.

  17. Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines

    NASA Technical Reports Server (NTRS)

    Yonushonis, T. M.; Wiczynski, P. D.; Myers, M. R.; Anderson, D. D.; McDonald, A. C.; Weber, H. G.; Richardson, D. E.; Stafford, R. J.; Naylor, M. G.

    1999-01-01

    In-cylinder components and tribological system concepts were designed, fabricated and tested at conditions anticipated for a 55% thermal efficiency heavy duty diesel engine for the year 2000 and beyond. A Cummins L10 single cylinder research engine was used to evaluate a spherical joint piston and connecting rod with 19.3 MPa (2800 psi) peak cylinder pressure capability, a thermal fatigue resistant insulated cylinder head, radial combustion seal cylinder liners, a highly compliant steel top compression ring, a variable geometry turbocharger, and a microwave heated particulate trap. Components successfully demonstrated in the final test included spherical joint connecting rod with a fiber reinforced piston, high conformability steel top rings with wear resistant coatings, ceramic exhaust ports with strategic oil cooling and radial combustion seal cylinder liner with cooling jacket transfer fins. A Cummins 6B diesel was used to develop the analytical methods, materials, manufacturing technology and engine components for lighter weight diesel engines without sacrificing performance or durability. A 6B diesel engine was built and tested to calibrate analytical models for the aluminum cylinder head and aluminum block.

  18. Recent advances in stimulated radiation studies during radiowave heating the near earth space environment

    NASA Astrophysics Data System (ADS)

    Scales, W. A.

    2016-02-01

    Investigation of stimulated radiation, commonly known as stimulated electromagnetic emissions (SEE), produced by the interaction of high-power, high-frequency HF radiowaves with the ionospheric plasma has been a vibrant area of research since the early 1980s. Substantial diagnostic information about ionospheric plasma characteristics, dynamics, and turbulence can be obtained from the frequency spectrum of the stimulated radiation. During the past several decades, so-called wideband SEE which exists in a frequency band of ±100 kHz or so of the transmit wave frequency (which is several MHz) has been investigated relatively thoroughly. Recent upgrades both in transmitter power and diagnostic receiver frequency sensitivity at major ionosphere interaction facilities in Alaska and Norway have allowed new breakthroughs in the ability to study a plethora of processes associated with the ionospheric plasma during these experiments. A primary advance is in observations of so-called narrowband SEE (NSEE) which exists roughly within ±1 kHz of the transmit wave frequency. An overview of several important new results associated with NSEE are discussed as well as implications to new diagnostics of space plasma physics occurring during ionospheric interaction experiments.

  19. Cryogenic high-heat-load optics at the advanced photon source

    SciTech Connect

    Rogers, C.S.

    1997-06-01

    Cryogenically cooled silicon monochromators have found wide application at the Advanced Photon Source (APS) and other third-generation synchrotron radiation facilities. Currently, 17 insertion device beamlines at the APS are implementing cryogenic, silicon double-crystal monochromators (DCM) at the first optical element. Recently, several silicon crystal monochromators internally cooled with liquid nitrogen have been tested on the sector 1-ID undulator beamline at the APS. Rocking curves at various energies were measured simultaneously in first and third order from a Si(111) DCM in the Bragg reflection geometry at a fixed undulator gap of 11.1 mm. The crystal exhibited a sub-arc second thermal broadening of the rocking curve over a first order energy range from 6.0 to 17.0 keV up to a maximum incident power of 561 W in a 2.5 V x 2.0 H mm{sup 2} beam. It has been demonstrated that cryogenic silicon monochromators can handle the highest power beams from hard x-ray undulators at the APS without significant thermo-mechanical distortion.

  20. Questions and Answers for Ken Thomas' "Intra-Extra Vehicular Activity Russian and Gemini Spacesuits" Presentation

    NASA Technical Reports Server (NTRS)

    Thomas, Kenneth S.

    2016-01-01

    Kenneth Thomas will discuss the Intra-Extra Vehicular Activity Russian & Gemini spacesuits. While the United States and Russia adapted to existing launch- and reentry-type suits to allow the first human ventures into the vacuum of space, there were differences in execution and capabilities. Mr. Thomas will discuss the advantages and disadvantages of this approach compared to exclusively intravehicular or extra-vehicular suit systems.

  1. Multibody instantly centered moving Lagrangian observer schemes. I - Formulation. II - Application to vehicular simulations

    NASA Technical Reports Server (NTRS)

    Padovan, Joseph; Kazempour, Amir

    1989-01-01

    A finite element modeling method employing an instantly centered moving Lagrangian observer is proposed to solve multibody problems involving several rotating components, each with its own rotational history. The present technique allows the steady-state behavior of the problem simulation to be rendered stationary and time independent. In the second part, the method is extended to model the steady and transient response of ground-based automotive-type vehicular systems, including the modeling of vehicular obstruction rollover events.

  2. K- and Ka-band mobile-vehicular satellite-tracking reflector antenna system for the NASA ACTS mobile terminal

    NASA Technical Reports Server (NTRS)

    Densmore, Art; Jamnejad, Vahraz; Wu, T. K.; Woo, Ken

    1993-01-01

    This paper describes the development of the K- and Ka-band mobile-vehicular satellite-tracking reflector antenna system for NASA's ACTS Mobile Terminal (AMT) project. ACTS is NASA's Advanced Communications Technology Satellites. The AMT project will make the first experimental use of ACTS soon after the satellite is operational, to demonstrate mobile communications via the satellite from a van on the road. The AMT antenna system consists of a mechanically steered small reflector antenna, using a shared aperture for both frequency bands and fitting under a radome of 23 cm diameter and 10 cm height, and a microprocessor controlled antenna controller that tracks the satellite as the vehicle moves about. The RF and mechanical characteristics of the antenna and the antenna tracking control system are discussed. Measurements of the antenna performance are presented.

  3. Vehicular emissions of organic particulate matter in Sao Paulo, Brazil

    NASA Astrophysics Data System (ADS)

    Oyama, B. S.; Andrade, M. F.; Herckes, P.; Dusek, U.; Röckmann, T.; Holzinger, R.

    2015-12-01

    Vehicular emissions have a strong impact on air pollution in big cities. Many factors affect these emissions: type of vehicle, type of fuel, cruising velocity, and brake use. This study focused on emissions of organic compounds by Light (LDV) and Heavy (HDV) duty vehicle exhaust. The study was performed in the city of Sao Paulo, Brazil, where vehicles run on different fuels: gasoline with 25 % ethanol (called gasohol), hydrated ethanol, and diesel (with 5 % of biodiesel). The vehicular emissions are an important source of pollutants and the principal contribution to fine particulate matter (smaller than 2.5 μm, PM2.5) in Sao Paulo. The experiments were performed in two tunnels: Janio Quadros (TJQ) where 99 % of the vehicles are LDV, and Rodoanel Mario Covas (TRA) where up to 30 % of the fleet was HDV. The PM2.5 samples were collected on quartz filters in May and July 2011 at TJQ and TRA, respectively, using two samplers operating in parallel. The samples were analyzed by Thermal-Desorption Proton-Transfer-Reaction Mass-Spectrometry (TD-PTR-MS), and by Thermal-Optical Transmittance (TOT). The organic aerosol (OA) desorbed at TD-PTR-MS represented around 30 % of the OA estimated by the TOT method, mainly due to the different desorption temperatures, with a maximum of 870 and 350 °C for TOT and TD-PTR-MS, respectively. Average emission factors (EF) organic aerosol (OA) and organic carbon (OC) were calculated for HDV and LDV fleet. We found that HDV emitted more OA and OC than LDV, and that OC emissions represented 36 and 43 % of total PM2.5 emissions from LDV and HDV, respectively. More than 700 ions were identified by TD-PTR-MS and the EF profiles obtained from HDV and LDV exhibited distinct features. Nitrogen-containing compounds measured in the desorbed material up to 350 °C contributed around 20 % to the EF values for both types of vehicles, possibly associated with incomplete fuel burning. Additionally, 70 % of the organic compounds measured from the aerosol

  4. Proceedings of the joint contractors meeting: FE/EE Advanced Turbine Systems conference FE fuel cells and coal-fired heat engines conference

    SciTech Connect

    Geiling, D.W.

    1993-08-01

    The joint contractors meeting: FE/EE Advanced Turbine Systems conference FEE fuel cells and coal-fired heat engines conference; was sponsored by the US Department of Energy Office of Fossil Energy and held at the Morgantown Energy Technology Center, P.O. Box 880, Morgantown, West Virginia 26507-0880, August 3--5, 1993. Individual papers have been entered separately.

  5. Description of TASHA: Thermal Analysis of Steady-State-Heat Transfer for the Advanced Neutron Source Reactor

    SciTech Connect

    Morris, D.G.; Chen, N.C.; Nelson, W.R.; Yoder, G.L.

    1996-10-01

    This document describes the code used to perform Thermal Analysis of Steady-State-Heat-Transfer for the Advanced Neutron Source (ANS) Reactor (TASHA). More specifically, the code is designed for thermal analysis of the fuel elements. The new code reflects changes to the High Flux Isotope Reactor steady-state thermal-hydraulics code. These changes were aimed at both improving the code`s predictive ability and allowing statistical thermal-hydraulic uncertainty analysis to be performed. A significant portion of the changes were aimed at improving the correlation package in the code. This involved incorporating more recent correlations for both single-phase flow and two-phase flow thermal limits, including the addition of correlations to predict the phenomenon of flow excursion. Since the code was to be used in the design of the ANS, changes were made to allow the code to predict limiting powers for a variety of thermal limits, including critical heat flux, flow excursion, incipient boiling, oxide spallation, maximum centerline temperature, and surface temperature equal to the saturation temperature. Statistical uncertainty analysis also required several changes to the code itself as well as changes to the code input format. This report describes these changes in enough detail to allow the reader to interpret code results and also to understand where the changes were made in the code programming. This report is not intended to be a stand alone report for running the code, however, and should be used in concert with the two previous reports published on the original code. Sample input and output files are also included to help accomplish these goals. In addition, a section is included that describes requirements for a new, more modem code that the project planned to develop.

  6. Zeolite Y adsorbents with high vapor uptake capacity and robust cycling stability for potential applications in advanced adsorption heat pumps

    SciTech Connect

    Li, XS; Narayanan, S; Michaelis, VK; Ong, TC; Keeler, EG; Kim, H; Mckay, IS; Griffin, RG; Wang, EN

    2015-01-01

    Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg2+ ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg, Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the lab-scale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N-2 sorption, Al-27/Si-29 MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick's 2nd law and D-R equation regressions. Among these, close examination of sorption isotherms for H2O and N-2 adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications. (C) 2014 Elsevier Inc. All rights reserved.

  7. Zeolite Y Adsorbents with High Vapor Uptake Capacity and Robust Cycling Stability for Potential Applications in Advanced Adsorption Heat Pumps

    PubMed Central

    Li, Xiansen; Narayanan, Shankar; Michaelis, Vladimir K.; Ong, Ta-Chung; Keeler, Eric G.; Kim, Hyunho; McKay, Ian S.; Griffin, Robert G.; Wang, Evelyn N.

    2014-01-01

    Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg2+ ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg,Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the labscale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N2 sorption, 27Al/29Si MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick’s 2nd law and D-R equation regressions. Among these, close examination of sorption isotherms for H2O and N2 adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications. PMID:25395877

  8. Zeolite Y Adsorbents with High Vapor Uptake Capacity and Robust Cycling Stability for Potential Applications in Advanced Adsorption Heat Pumps.

    PubMed

    Li, Xiansen; Narayanan, Shankar; Michaelis, Vladimir K; Ong, Ta-Chung; Keeler, Eric G; Kim, Hyunho; McKay, Ian S; Griffin, Robert G; Wang, Evelyn N

    2015-01-01

    Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg(2+) ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg,Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the labscale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N2 sorption, (27)Al/(29)Si MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick's 2(nd) law and D-R equation regressions. Among these, close examination of sorption isotherms for H2O and N2 adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications. PMID:25395877

  9. Optimizing the mix of strategies for control of vehicular emissions

    SciTech Connect

    Lejano, R.P.; Ayala, P.M.; Gonzales, E.A.

    1997-01-01

    A number of strategies for the control of vehicular emissions are being considered by the Philippine government to address Metropolitan Manila`s air quality problem. An analytical tool is needed for optimizing criteria pollutant reductions given the budgetary constraints. The simplest approach is to take costs and pollutant removals to be linear with each strategy`s scale of activity, and this is readily solved as a linear programming problem. Another approach is to use a dynamic system of weights which shift with progressive improvements in pollutant emissions. The two approaches yield somewhat different results, suggesting the sensitivity of the solution to the assumed weights. The study also illustrates the importance of a sound methodology for evaluating priorities given to different air quality goals. One such methodology may involve a polling of expert panels and the public to gain insight into the relative importance given to competing emissions reduction goals. An informal polling of resource agency staff was conducted and discussed in this paper. The authors take the position that proper planning involves tracing intermediate steps to the final outcome and not just focusing on the latter. 17 refs., 1 fig., 8 tabs.

  10. Vehicular Storage of Hydrogen in Insulated Pressure Vessels

    SciTech Connect

    Aceves, S M; Berry, G D; Martinez-Frias, J; Espinosa-Loza, F

    2005-01-03

    This paper describes the development of an alternative technology for storing hydrogen fuel onboard automobiles. Insulated pressure vessels are cryogenic-capable pressure vessels that can accept cryogenic liquid fuel, cryogenic compressed gas or compressed gas at ambient temperature. Insulated pressure vessels offer advantages over conventional H{sub 2} storage approaches. Insulated pressure vessels are more compact and require less carbon fiber than GH{sub 2} vessels. They have lower evaporative losses than LH{sub 2} tanks, and are much lighter than metal hydrides. After outlining the advantages of hydrogen fuel and insulated pressure vessels, the paper describes the experimental and analytical work conducted to verify that insulated pressure vessels can be used safely for vehicular H{sub 2} storage. The paper describes tests that have been conducted to evaluate the safety of insulated pressure vessels. Insulated pressure vessels have successfully completed a series of DOT, ISO and SAE certification tests. A draft procedure for insulated pressure vessel certification has been generated to assist in a future commercialization of this technology. An insulated pressure vessel has been installed in a hydrogen fueled truck and it is currently being subjected to extensive testing.

  11. Autonomous Motion Learning for Intra-Vehicular Activity Space Robot

    NASA Astrophysics Data System (ADS)

    Watanabe, Yutaka; Yairi, Takehisa; Machida, Kazuo

    Space robots will be needed in the future space missions. So far, many types of space robots have been developed, but in particular, Intra-Vehicular Activity (IVA) space robots that support human activities should be developed to reduce human-risks in space. In this paper, we study the motion learning method of an IVA space robot with the multi-link mechanism. The advantage point is that this space robot moves using reaction force of the multi-link mechanism and contact forces from the wall as space walking of an astronaut, not to use a propulsion. The control approach is determined based on a reinforcement learning with the actor-critic algorithm. We demonstrate to clear effectiveness of this approach using a 5-link space robot model by simulation. First, we simulate that a space robot learn the motion control including contact phase in two dimensional case. Next, we simulate that a space robot learn the motion control changing base attitude in three dimensional case.

  12. VOC from Vehicular Evaporation Emissions: Status and Control Strategy.

    PubMed

    Liu, Huan; Man, Hanyang; Tschantz, Michael; Wu, Ye; He, Kebin; Hao, Jiming

    2015-12-15

    Vehicular evaporative emissions is an important source of volatile organic carbon (VOC), however, accurate estimation of emission amounts and scientific evaluation of control strategy for these emissions have been neglected outside of the United States. This study provides four kinds of basic emission factors: diurnal, hot soak, permeation, and refueling. Evaporative emissions from the Euro 4 vehicles (1.6 kg/year/car) are about four times those of U.S. vehicles (0.4 kg/year/car). Closing this emissions gap would have a larger impact than the progression from Euro 3 to Euro 6 tailpipe HC emission controls. Even in the first 24 h of parking, China's current reliance upon the European 24 h diurnal standard results in 508 g/vehicle/year emissions, higher than 32 g/vehicle/year from Tier 2 vehicles. The U.S. driving cycle matches Beijing real-world conditions much better on both typical trip length and average speed than current European driving cycles. At least two requirements should be added to the Chinese emissions standards: an onboard refueling vapor recovery to force the canister to be sized sufficiently large, and a 48-h evaporation test requirement to ensure that adequate purging occurs over a shorter drive sequence. PMID:26599318

  13. Monitoring of atmospheric behaviour of NOx from vehicular traffic.

    PubMed

    Lal, S; Patil, R S

    2001-04-01

    In recent years the concern about the behaviour of oxides of nitrogen (NOx: NO, NO2) in atmosphere has increased considerably. NOx undergoes various complex atmospheric reactions to generate secondary pollutants which are known to cause severe adverse effects on human health. This work focuses on the study of physical and chemical fate of NOx released in the atmosphere from vehicles, which are the main sources of atmospheric NOx. Keeping the objective and standard guidelines for monitoring in view, two typical sites near the road with high vehicular density were chosen for the study. One site was a relatively cleaner area with only vehicles as major source of pollution, and the second site was a traffic junction in an industrial region, where pollution levels are amongst the highest in Mumbai. Ambient monitoring of NOx was done for 24 hr continuously using chemiluminescent NOx analyser. The data was used to analyse temporal and spatial variation of NO, NO2 and NOx and their atmospheric chemical reactions. The monitoring results show that at larger distance from the road the level of NO decreases but the concentration of NO2 which is very harmful remains the same. Statistical analysis is conducted to establish the relationship between likely change in NO2 concentration as a result of NOx emission changes. PMID:11336410

  14. Evaluating vehicular-induced bridge vibrations for energy harvesting applications

    NASA Astrophysics Data System (ADS)

    Reichenbach, Matthew; Fasl, Jeremiah; Samaras, Vasilis A.; Wood, Sharon; Helwig, Todd; Lindenberg, Richard

    2012-04-01

    Highway bridges are vital links in the transportation network in the United States. Identifying possible safety problems in the approximately 600,000 bridges across the country is generally accomplished through labor-intensive, visual inspections. Ongoing research sponsored by NIST seeks to improve inspection practices by providing real-time, continuous monitoring technology for steel bridges. A wireless sensor network with a service life of ten years that is powered by an integrated energy harvester is targeted. In order to achieve the target ten-year life for the monitoring system, novel approaches to energy harvesting for use in recharging batteries are investigated. Three main sources of energy are evaluated: (a) vibrational energy, (b) solar energy, and (c) wind energy. Assessing the energy produced from vehicular-induced vibrations and converted through electromagnetic induction is the focus of this paper. The goal of the study is to process acceleration data and analyze the vibrational response of steel bridges to moving truck loads. Through spectral analysis and harvester modeling, the feasibility of vibration-based energy harvesting for longterm monitoring can be assessed. The effects of bridge conditions, ambient temperature, truck traffic patterns, and harvester position on the power content of the vibrations are investigated. With sensor nodes continually recharged, the proposed real-time monitoring system will operate off the power grid, thus reducing life cycle costs and enhancing inspection practices for state DOTs. This paper will present the results of estimating the vibration energy of a steel bridge in Texas.

  15. Performance Improvement in Geographic Routing for Vehicular Ad Hoc Networks

    PubMed Central

    Kaiwartya, Omprakash; Kumar, Sushil; Lobiyal, D. K.; Abdullah, Abdul Hanan; Hassan, Ahmed Nazar

    2014-01-01

    Geographic routing is one of the most investigated themes by researchers for reliable and efficient dissemination of information in Vehicular Ad Hoc Networks (VANETs). Recently, different Geographic Distance Routing (GEDIR) protocols have been suggested in the literature. These protocols focus on reducing the forwarding region towards destination to select the Next Hop Vehicles (NHV). Most of these protocols suffer from the problem of elevated one-hop link disconnection, high end-to-end delay and low throughput even at normal vehicle speed in high vehicle density environment. This paper proposes a Geographic Distance Routing protocol based on Segment vehicle, Link quality and Degree of connectivity (SLD-GEDIR). The protocol selects a reliable NHV using the criteria segment vehicles, one-hop link quality and degree of connectivity. The proposed protocol has been simulated in NS-2 and its performance has been compared with the state-of-the-art protocols: P-GEDIR, J-GEDIR and V-GEDIR. The empirical results clearly reveal that SLD-GEDIR has lower link disconnection and end-to-end delay, and higher throughput as compared to the state-of-the-art protocols. It should be noted that the performance of the proposed protocol is preserved irrespective of vehicle density and speed. PMID:25429415

  16. Anthropogenic heat flux estimation from space: first results

    NASA Astrophysics Data System (ADS)

    Chrysoulakis, Nektarios; Heldens, Wieke; Gastellu-Etchegorry, Jean-Philippe; Grimmond, Sue; Feigenwinter, Christian; Lindberg, Fredrik; Del Frate, Fabio; Klostermann, Judith; Mitraka, Zina; Esch, Thomas; Albitar, Ahmad; Gabey, Andrew; Parlow, Eberhard; Olofson, Frans

    2016-04-01

    While Earth Observation (EO) has made significant advances in the study of urban areas, there are several unanswered science and policy questions to which it could contribute. To this aim the recently launched Horizon 2020 project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of EO to retrieve anthropogenic heat flux, as a key component in the urban energy budget. The anthropogenic heat flux is the heat flux resulting from vehicular emissions, space heating and cooling of buildings, industrial processing and the metabolic heat release by people. Optical, thermal and SAR data from existing satellite sensors are used to improve the accuracy of the radiation balance spatial distribution calculation, using also in-situ reflectance measurements of urban materials are for calibration. EO-based methods are developed for estimating turbulent sensible and latent heat fluxes, as well as urban heat storage flux and anthropogenic heat flux spatial patterns at city scale and local scale by employing an energy budget closure approach. Independent methods and models are engaged to evaluate the derived products and statistical analyses provide uncertainty measures as well. Ultimate goal of the URBANFLUXES is to develop a highly automated method for estimating urban energy budget components to use with Copernicus Sentinel data, enabling its integration into applications and operational services. Thus, URBANFLUXES prepares the ground for further innovative exploitation of European space data in scientific activities (i.e. Earth system modelling and climate change studies in cities) and future and emerging applications (i.e. sustainable urban planning) by exploiting the improved data quality, coverage and revisit times of the Copernicus data. The URBANFLUXES products will therefore have the potential to support both sustainable planning strategies to improve the quality of life in cities, as well as Earth system models to

  17. Advanced control strategies for heating, ventilation, air-conditioning, and refrigeration systems—An overview: Part I: Hard control

    SciTech Connect

    D. Subbaram Naidu; Craig G. Rieger

    2011-02-01

    A chronological overview of the advanced control strategies for heating, ventilation, air-conditioning, and refrigeration (HVAC&R) is presented in this article. The overview focuses on hard-computing or control techniques, such as proportional-integral-derivative, optimal, nonlinear, adaptive, and robust; soft-computing or control techniques, such as neural networks, fuzzy logic, genetic algorithms; and on the fusion or hybrid of hard- and soft-control techniques. Thus, it is to be noted that the terminology “hard” and “soft” computing/control has nothing to do with the “hardware” and “software” that is being generally used. Part I of a two-part series focuses on hard-control strategies, and Part II focuses on softand fusion-control in addition to some future directions in HVAC&R research. This overview is not intended to be an exhaustive survey on this topic, and any omission of other works is purely unintentional.

  18. Comparison of the PLTEMP code flow instability predictions with measurements made with electrically heated channels for the advanced test reactor.

    SciTech Connect

    Feldman, E.

    2011-06-09

    When the University of Missouri Research Reactor (MURR) was designed in the 1960s the potential for fuel element burnout by a phenomenon referred to at that time as 'autocatalytic vapor binding' was of serious concern. This type of burnout was observed to occur at power levels considerably lower than those that were known to cause critical heat flux. The conversion of the MURR from HEU fuel to LEU fuel will probably require significant design changes, such as changes in coolant channel thicknesses, that could affect the thermal-hydraulic behavior of the reactor core. Therefore, the redesign of the MURR to accommodate an LEU core must address the same issues of fuel element burnout that were of concern in the 1960s. The Advanced Test Reactor (ATR) was designed at about the same time as the MURR and had similar concerns with regard to fuel element burnout. These concerns were addressed in the ATR by two groups of thermal-hydraulic tests that employed electrically heated simulated fuel channels. The Croft (1964), Reference 1, tests were performed at ANL. The Waters (1966), Reference 2, tests were performed at Hanford Laboratories in Richland Washington. Since fuel element surface temperatures rise rapidly as burnout conditions are approached, channel surface temperatures were carefully monitored in these experiments. For self-protection, the experimental facilities were designed to cut off the electric power when rapidly increasing surface temperatures were detected. In both the ATR reactor and in the tests with electrically heated channels, the heated length of the fuel plate was 48 inches, which is about twice that of the MURR. Whittle and Forgan (1967) independently conducted tests with electrically heated rectangular channels that were similar to the tests by Croft and by Walters. In the Whittle and Forgan tests the heated length of the channel varied among the tests and was between 16 and 24 inches. Both Waters and Whittle and Forgan show that the cause of the

  19. DEVELOPMENT OF A MULTI-LOOP FLOW AND HEAT TRANSFER FACILITY FOR ADVANCED NUCLEAR REACTOR THERMAL HYDRAULIC AND HYBRID ENERGY SYSTEM STUDIES

    SciTech Connect

    James E. O'Brien; Piyush Sabharwall; SuJong Yoon

    2001-09-01

    A new high-temperature multi-fluid, multi-loop test facility for advanced nuclear applications is under development at the Idaho National Laboratory. The facility will include three flow loops: high-temperature helium, molten salt, and steam/water. Molten salts have been identified as excellent candidate heat transport fluids for primary or secondary coolant loops, supporting advanced high temperature and small modular reactors (SMRs). Details of some of the design aspects and challenges of this facility, which is currently in the conceptual design phase, are discussed. A preliminary design configuration will be presented, with the required characteristics of the various components. The loop will utilize advanced high-temperature compact printed-circuit heat exchangers (PCHEs) operating at prototypic intermediate heat exchanger (IHX) conditions. The initial configuration will include a high-temperature (750°C), high-pressure (7 MPa) helium loop thermally integrated with a molten fluoride salt (KF-ZrF4) flow loop operating at low pressure (0.2 MPa) at a temperature of ~450°C. Experiment design challenges include identification of suitable materials and components that will withstand the required loop operating conditions. Corrosion and high temperature creep behavior are major considerations. The facility will include a thermal energy storage capability designed to support scaled process heat delivery for a variety of hybrid energy systems and grid stabilization strategies. Experimental results obtained from this research will also provide important data for code ve

  20. Recent advances and current status of the use of heat treatments in postharvest disease management systems: Is it time to turn up the heat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eco-friendly approaches to postharvest disease management in harvested commodities, such as heat treatments and biological control utilizing antagonistic yeasts, is an active research field. The current review focuses on the physiological and molecular aspects of heat treatment on all the major par...

  1. Development of advanced low-temperature heat transfer fluids for district heating and cooling. Final report, September 25, 1990--September 24, 1991

    SciTech Connect

    Not Available

    1991-09-30

    The feasibility of adding phase change materials (PCMs) and surfactants to the heat transfer fluids in district cooling systems was investigated. It increases the thermal capacity of the heat transfer fluid and therefore decreases the volume that needs to be pumped. It also increases the heat transfer rate, resulting in smaller heat exchangers. The thermal behavior of two potential PCMs, hexadecane and tetradecane paraffin wax, was experimentally evaluated. The heat of fusion of these materials is approximately 60% of that of ice. They exhibit no supercooling and are stable under repeated thermal cycling. While test results for laboratory grade materials showed good agreement with data in the literature, both melting point and heat of fusion for commercial grade hexadecane were found to be considerably lower than literaturevalues. PCM/water mixtures were tested in a laboratory-scale test loop to determine heat transfer and flow resistance properties. When using PCMs in district cooling systems, clogging of frozen PCM particles isone of the major problems to be overcome. In the present project it is proposed to minimize or prevent clogging by the addition of an emulsifier. Effects of the emulsifier on the mixture of water and hexadecane(a PCM) were studied. As the amount of the emulsifier was increased, the size of the solid PCM particles became smaller. When the size of the particles was small enough, they did not stick together or stick to the cold surface of a heat exchanger. The amount of emulsifier to produce this condition was determined.

  2. Application environmental epidemiology to vehicular air pollution and health effects research.

    PubMed

    Patil, Rajan R; Chetlapally, Satish Kumar; Bagvandas, M

    2015-01-01

    Vehicular pollution is one of the major contributors to the air pollution in urban areas and perhaps and accounts for the major share of anthropogenic green-house gases such as carbon dioxide, carbon monoxide, nitrogen oxides. Knowledge of human health risks related to environmental exposure to vehicular pollution is a current concern. Analyze the range health effects are attributed varied constituents of vehicular air pollution examine evidence for a causal association to specific health effect. In many instances scenario involves exposure to very low doses of putative agents for extended periods, sometimes the period could mean over a lifetime of an individual and yet may result in small increase in health risk that may be imperceptible. Secondary data analysis and literature review. In environmental exposures, traditional epidemiological approaches evaluating mortality and morbidity indicators display many limiting factors such as nonspecificity of biological effects latency time between exposure and magnitude of the effect. Long latency period between exposure and resultant disease, principally for carcinogenic effects and limitation of epidemiological studies for detecting small risk increments. The present paper discusses the methodological challenges in studying vehicular epidemiology and highlights issues that affect the validity of epidemiological studies in vehicular pollution. PMID:26023265

  3. Application environmental epidemiology to vehicular air pollution and health effects research

    PubMed Central

    Patil, Rajan R.; Chetlapally, Satish Kumar; Bagvandas, M.

    2015-01-01

    Vehicular pollution is one of the major contributors to the air pollution in urban areas and perhaps and accounts for the major share of anthropogenic green-house gases such as carbon dioxide, carbon monoxide, nitrogen oxides. Knowledge of human health risks related to environmental exposure to vehicular pollution is a current concern. Analyze the range health effects are attributed varied constituents of vehicular air pollution examine evidence for a causal association to specific health effect. In many instances scenario involves exposure to very low doses of putative agents for extended periods, sometimes the period could mean over a lifetime of an individual and yet may result in small increase in health risk that may be imperceptible. Secondary data analysis and literature review. In environmental exposures, traditional epidemiological approaches evaluating mortality and morbidity indicators display many limiting factors such as nonspecificity of biological effects latency time between exposure and magnitude of the effect. Long latency period between exposure and resultant disease, principally for carcinogenic effects and limitation of epidemiological studies for detecting small risk increments. The present paper discusses the methodological challenges in studying vehicular epidemiology and highlights issues that affect the validity of epidemiological studies in vehicular pollution. PMID:26023265

  4. Carbonyl emissions from vehicular exhausts sources in Hong Kong.

    PubMed

    Ho, Steven Sai Hang; Ho, Kin Fai; Lee, Shun Cheng; Cheng, Yan; Yu, Jian Zhen; Lam, Ka Man; Feng, Natale Sin Yau; Huang, Yu

    2012-02-01

    Vehicular emission (VE) is one of the important anthropogenic sources for airborne carbonyls in urban area. Six types of VE-dominated samples were collected at representative locations in Hong Kong where polluted by a particular fueled type of vehicles, including (i) a gas refilling taxis station (liquefied petroleum gas [LPG] emission); (ii) a light-duty passenger car park (gasoline emission); (iii) a minibus station (diesel emission); (iv) a single-deck-bus depot (diesel emission); (v) a double-deck-bus depot (diesel emission); and (vi) a whole-food market entrance for light- and heavy-duty vehicles (diesel emission). A total of 15 carbonyls in the samples were quantified. Formaldehyde was the most abundant carbonyl among the VE-dominated samples, and its contribution to the total quantified amount on a molar basis ranged from 54.8% to 60.8%. Acetaldehyde and acetone were the next two abundant carbonyls. The carbonyls were quantified at three roadside locations in Hong Kong. The highest concentrations of formaldehyde and acetaldehyde, 22.7 +/- 8.4 and 6.0 +/- 2.8 microg/m3, respectively, were determined in the samples collected at a main transportation gate for goods between Hong Kong and Mainland China. The total quantified carbonyl concentration, 37.9 +/- 9.3 microg/m3, was the highest at an entrance of a cross-harbor tunnel in downtown area. The theoretical carbonyls compositions of the three roadside locations were estimated according to the VE-dominated sample profiles and the statistics on vehicle numbers and types during the sampling period. The measured compositions of formaldehyde were much higher than the theoretical compositions in summer, demonstrating that photochemical reactions significantly contributed to the formaldehyde production in the roadsides. PMID:22442938

  5. Degree of Urbanization and Mortality From Motor Vehicular Crashes

    PubMed Central

    Ryb, Gabriel E; Dischinger, Patricia C; McGwin, Gerald; Griffin, Russell L

    2012-01-01

    Purpose: The purpose of this study is to establish whether motor vehicular crash (MVC) case fatality varies across different urbanization levels in the USA using a representative sample of crashes. Methods: Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between urbanization level [i.e., central city (CC), suburban (SU) and others (OT)] and mortality were estimated in the 1997 - 2010 National Automotive Sampling System Crashworthiness Data System. Multiple logistic regression was used to adjust for confounders. Analysis was repeated for the occurrence of pre-hospital and hospital deaths. Results: 49,040,520 weighted occupants were included in the study. The distribution of occupants by urbanization categories was: SU 45%, OT 42%, and CC 13%. Case fatality was higher among OT occupants (0.81%) than among SU (0.51%) and CC (0.37%) occupants. Similar findings were present for pre-hospital deaths (OT 0.52%, SU 0.30%, and CC 0.21%) and hospital deaths (OT 0.29%, SU 0.21%, and CC 0.16%). Multivariate analysis revealed that adjusted odds of death were higher for OT cases [OR=1.55 (1.05–2.30)] than the CC. Adjusted odds of death for SU (OR=1.05 (0.81–1.37) were not different than CCs. Similar but accentuated findings were found for pre-hospital deaths. In contrast, adjusted odds of hospital death were not different among the 3 groups. Conclusion: Occupants of vehicles crashing in OT (i.e., rural areas and small cities) experience a higher likelihood of dying after MVCs than those in CC and SU. Pre-hospital deaths, not hospital deaths, are responsible for this disparity. PMID:23169128

  6. A novel isolation curtain to reduce turbine ingress heating and an advanced model for honeycomb labyrinth seals

    NASA Astrophysics Data System (ADS)

    Choi, Dong Chun

    A combination of 3-D and 2-D computational fluid dynamics (CFD) modeling as well as experimental testing of the labyrinth seal with hexagonal honeycomb cells on the stator wall was performed. For the 3-D and 2-D CFD models, the hexagonal honeycomb structure was modeled using the concept of the baffle (zero-thickness wall) and the simplified 2-D fin, respectively. The 3-D model showed that even a small axial change of the tooth (or honeycomb wall) location, or a small circumferential change of the honeycomb wall location significantly affected the flow patterns and leakage characteristics especially for small tooth tip clearance. Also, the local details of the flow field were investigated. The seven basic procedural steps to develop a 2-D axisymmetric honeycomb labyrinth seal leakage model were shown. Clearly demonstrated for varying test conditions was the 2-D model capability to predict the 3-D honeycomb labyrinth flow that had been measured at different operating conditions from that used in developing the 2-D model. Specifically, the 2-D model showed very close agreement with measurements. In addition, the 2-D model greatly reduced the computer resource requirement needed to obtain a solution of the 3-D honeycomb labyrinth seal leakage. The novel and advanced strategy to reduce the turbine ingress heating, and thus the coolant requirement, by injecting a "coolant isolation curtain" was developed numerically using a 3-D CFD model. The coolant isolation curtain was applied under the nozzle guide vane platform for the forward cavity of a turbine stage. Specifically, the isolation curtain serves to isolate the hot mainstream gas from the turbine outer region. The effect of the geometry change, the outer cavity axial gap clearance, the circumferential location of the injection curtain slot and the injection fluid angle on the ingress heating was investigated. Adding the chamfer to the baseline design gave a similar or higher maximum temperature T*max than did the

  7. Protection of HEVC Video Delivery in Vehicular Networks with RaptorQ Codes

    PubMed Central

    Martínez-Rach, Miguel; López, Otoniel; Malumbres, Manuel Pérez

    2014-01-01

    With future vehicles equipped with processing capability, storage, and communications, vehicular networks will become a reality. A vast number of applications will arise that will make use of this connectivity. Some of them will be based on video streaming. In this paper we focus on HEVC video coding standard streaming in vehicular networks and how it deals with packet losses with the aid of RaptorQ, a Forward Error Correction scheme. As vehicular networks are packet loss prone networks, protection mechanisms are necessary if we want to guarantee a minimum level of quality of experience to the final user. We have run simulations to evaluate which configurations fit better in this type of scenarios. PMID:25136675

  8. Vehicular motion in 2D city traffic network with signals controlled by phase shift

    NASA Astrophysics Data System (ADS)

    Komada, Kazuhito; Kojima, Kengo; Nagatani, Takashi

    2011-03-01

    We study the dynamic behavior of vehicular traffic through the series of traffic lights controlled by phase shift in two-dimensional (2D) city traffic network. The nonlinear-map model is presented for the vehicular traffic. The city traffic network is made of one-way perpendicular streets arranged in a square lattice with traffic signals where vertical streets are oriented upwards and horizontal streets are oriented rightwards. There are two traffic lights for the movement to north or that to east at each crossing. The traffic lights are controlled by the cycle time, split, and phase shift. The vehicle moves through the series of signals on a path selected by the driver. The city traffic with a heterogeneous density distribution is also studied. The dependence of the arrival time on cycle time, split, phase shift, selected path, and density is clarified for 2D city traffic. It is shown that the vehicular traffic is efficiently controlled by the phase shift.

  9. Clustering and maximal flow in vehicular traffic through a sequence of traffic lights

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2007-04-01

    We study the maximal current (maximum traffic capacity) of vehicular traffic through a sequence of traffic lights on a highway, where all signals turn on and off synchronously. The dynamical model of vehicular traffic controlled by signals is expressed in terms of a nonlinear map, where the excluded-volume effect is taken into account. The dynamical behaviors of vehicles are clarified by analyzing traffic patterns. The clustering of vehicles varies with the cycle time of signals. The maximum current is closely connected to vehicular clustering. Clustering of vehicles is controlled by varying both split and cycle time of signals. The dependence of the maximal current on both split and cycle time is derived.

  10. Application of a stochastic vehicular wake erosion model to determine PM2.5 exposure

    NASA Astrophysics Data System (ADS)

    Jazcilevich, Aron; Wellens, Ann; Siebe, Christina; Rosas, Irma; Bornstein, Robert D.; Riojas-Rodríguez, Horacio

    2012-06-01

    A stochastic model based on empirical probability distribution functions has been applied to estimate human exposure to emissions from the resuspension of road dust due to isolated wakes from moving vehicles. The model incorporates the turbulent nature of resuspension due to vehicular wake erosion phenomena, and is tested by in situ measurements. It statistically estimates exposure as a function of ambient temperature, traffic activity, human height, and breathe intake rates as a function of age and activity. The model is applied to evaluate whether communities in the Molango region in Mexico are affected by vehicular resuspension of Manganese (Mn) contaminated soil from on-road activities related to mining. Results showed that six and 10 year old children are at higher risk to vehicular resuspended dust exposure than adults, due to their lower height and higher respiratory intake rates during periods of light and moderate activity.

  11. 75 FR 52557 - Limiting of Vehicular Use of a Portion of Battery Caulfield Road; Extension of Comment Period

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-26

    ... of Vehicular Use of a Portion of Battery Caulfield Road; Extension of Comment Period SUMMARY: By Federal Register notice of July 29, 2010 (75 FR 44820), the Presidio Trust (Trust) announced its... portion of Battery Caulfield Road in the Presidio of San Francisco: (1) Limitation of vehicular use...

  12. On KLJN-based Secure Key Distribution in Vehicular Communication Networks

    NASA Astrophysics Data System (ADS)

    Cao, X.; Saez, Y.; Pesti, G.; Kish, L. B.

    2015-12-01

    In a former paper [Fluct. Noise Lett. 13 (2014) 1450020] we introduced a vehicular communication system with unconditionally secure key exchange based on the Kirchhoff-Law-Johnson-Noise (KLJN) key distribution scheme. In this paper, we address the secure KLJN key donation to vehicles. This KLJN key donation solution is performed lane-by-lane by using roadside key provider equipment embedded in the pavement. A method to compute the lifetime of the KLJN key is also given. This key lifetime depends on the car density and gives an upper limit of the lifetime of the KLJN key for vehicular communication networks.

  13. Lower hybrid current drive and ion cyclotron range of frequencies heating experiments in H-mode plasmas in Experimental Advanced Superconducting Tokomak

    SciTech Connect

    Zhang, X. J.; Wan, B. N. Zhao, Y. P.; Ding, B. J.; Xu, G. S.; Gong, X. Z.; Li, J. G.; Lin, Y.; Wukitch, S.; Taylor, G.; Noterdaeme, J. M.; Braun, F.; Magne, R.; Litaudon, X.; Kumazawa, R.; Kasahara, H.

    2014-06-15

    An ion cyclotron range of frequencies (ICRF) system with power up to 6.0 MW and a lower hybrid current drive (LHCD) system up to 4 MW have been applied for heating and current drive experiments in Experimental Advanced Superconducting Tokomak (EAST). Significant progress has been made with ICRF heating and LHCD for realizing the H-mode plasma operation in EAST. During 2010 and 2012 experimental campaigns, ICRF heating experiments were carried out at the fixed frequency of 27MHz, achieving effective ions and electrons heating with the H minority heating (H-MH) mode. The H-MH mode produced good plasma performance, and realized H-mode using ICRF power alone in 2012. In 2010, H-modes were generated and sustained by LHCD alone, where lithium coating and gas puffing near the mouth of the LH launcher were applied to improve the LHCD power coupling and penetration into the core plasmas of H-modes. In 2012, the combination of LHCD and ICRH power extended the H-mode duration up to over 30 s. H-modes with various types of edge localized modes (ELMs) have been achieved with H{sub IPB98}(y, 2) ranging from 0.7 to over unity. A brief overview of LHCD and ICRF Heating experiment and their application in achieving H-mode operation during these two campaigns will be presented.

  14. Effects of heating power on divertor in-out asymmetry and scrape-off layer flow in reversed field on Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Liu, S. C. Wang, H. Q.; Gan, K. F.; Xia, T. Y.; Xu, G. S.; Liu, Z. X.; Chen, L.; Zhang, W.; Chen, R.; Shao, L. M.; Ding, S.; Hu, G. H.; Liu, Y. L.; Zhao, N.; Li, Y. L.; Gong, X. Z.; Gao, X.; Guo, H. Y.; Wang, L.; Xu, X. Q.; and others

    2014-12-15

    The dependence of divertor asymmetry and scrape-off layer (SOL) flow on heating power has been investigated in the Experimental Advanced Superconducting Tokamak (EAST). Divertor plasma exhibits an outboard-enhanced in-out asymmetry in heat flux in lower single null configuration for in reversed (ion ∇B drift direction toward the upper X-point) field directions. Upper single null exhibits an inboard-favored asymmetry in low heating power condition, while exhibits an outboard-favored asymmetry when increasing the heating power. Double null has the strongest in-out asymmetry in heat flux, favoring the outer divertor. The in-out asymmetry ratios of q{sub t,out}/q{sub t,in} and P{sub out}/P{sub total} increase with the power across the separatrix P{sub loss}, which is probably induced by the enhanced radial particle transport due to a large pressure gradient. The characteristics of the measured SOL parallel flow under various discharge conditions are consistent with the Pfirsch-Schlüter (PS) flow with the parallel Mach number M{sub ∥} decreasing with the line averaged density but increasing with P{sub loss}, in the same direction as the PS flow. The contributions of both poloidal E×B drift and parallel flow on poloidal particle transport in SOL on EAST are also assessed.

  15. Multimodal Perception and Multicriterion Control of Nested Systems. 1; Coordination of Postural Control and Vehicular Control

    NASA Technical Reports Server (NTRS)

    Riccio, Gary E.; McDonald, P. Vernon

    1998-01-01

    The purpose of this report is to identify the essential characteristics of goal-directed whole-body motion. The report is organized into three major sections (Sections 2, 3, and 4). Section 2 reviews general themes from ecological psychology and control-systems engineering that are relevant to the perception and control of whole-body motion. These themes provide an organizational framework for analyzing the complex and interrelated phenomena that are the defining characteristics of whole-body motion. Section 3 of this report applies the organization framework from the first section to the problem of perception and control of aircraft motion. This is a familiar problem in control-systems engineering and ecological psychology. Section 4 examines an essential but generally neglected aspect of vehicular control: coordination of postural control and vehicular control. To facilitate presentation of this new idea, postural control and its coordination with vehicular control are analyzed in terms of conceptual categories that are familiar in the analysis of vehicular control.

  16. Alcohol-Related Vehicular Death Rates for College Students in the Commonwealth of Virginia

    ERIC Educational Resources Information Center

    Turner, James; Bauerle, Jennifer; Keller, Adrienne

    2011-01-01

    Objective: Determine rate of college student alcohol-related vehicular traffic fatalities in Virginia during 2007. Participants: Undergraduates at colleges and universities in Virginia. Methods: Institutions with membership in the American College Health Association were invited to participate in a survey. Data collected from institutional reports…

  17. The Structure and Tra c Flow Anatomy of the Planet-Scale Urban Vehicular Mobility

    SciTech Connect

    Thakur, Gautam

    2013-01-01

    A data-driven realistic design and evalua- tion of vehicular mobility has been particularly chal- lenging due to a lack of large-scale real-world mea- surements in the research community. Current research methodologies rely on articial scenarios, random con- nectivity, and use small and biased samples. In this pa- per, we perform a combined study to learn the struc- ture and connectivity of urban streets and modeling and characterization of vehicular trac densities on them. Our dataset is a collection of more than 222 thousand routes and 25 million vehicular mobility images from 1091 online web cameras located in six dierent re- gions of the world. Our results centered around four major observations: i. study shows that driving routes and visiting locations of regions demonstrate power-law distribution, indicating a planned or recently designed road infrastructure; ii. we represent regions by network graphs in which nodes are camera locations and edges are urban streets that connect the nodes. Such represen- tation exhibits small world properties with short path lengths and large clustering coecient; iii. trac densi- ties show 80% temporal correlation during several hours of a day; iv. modeling trac densities against known theoretical distributions show less than 5% deviation for heavy-trailed models such as log-logistic and log- gamma distributions. We believe this work will provide a much-needed contribution to the research community for design and evaluation of future vehicular networks and smart cities.

  18. Infotainment and road safety service support in vehicular networking: From a communication perspective

    NASA Astrophysics Data System (ADS)

    Cheng, Ho Ting; Shan, Hangguan; Zhuang, Weihua

    2011-08-01

    Vehicular ad hoc networking is an emerging technology for future on-the-road communications. Due to the virtue of vehicle-to-vehicle and vehicle-to-infrastructure communications, vehicular ad hoc networks (VANETs) are expected to enable a plethora of communication-based automotive applications including diverse in-vehicle infotainment applications and road safety services. Even though vehicles are organized mostly in an ad hoc manner in the network topology, directly applying the existing communication approaches designed for traditional mobile ad hoc networks to large-scale VANETs with fast-moving vehicles can be ineffective and inefficient. To achieve success in a vehicular environment, VANET-specific communication solutions are imperative. In this paper, we provide a comprehensive overview of various radio channel access protocols and resource management approaches, and discuss their suitability for infotainment and safety service support in VANETs. Further, we present recent research activities and related projects on vehicular communications. Potential challenges and open research issues are also discussed.

  19. FINAL Report on Analysis and direct numerical simulation of RF heating processes and advanced computational methods for fusion application

    SciTech Connect

    Cary, John R

    2015-02-23

    This completes the description of the work done under the above referenced grant. In brief, we have discovered many nonlinear effects, frequency doubling, nonlinear decays, that can prevent effective use of EBWs for plasma heating.

  20. CFD Simulations of a Flow Mixing and Heat Transfer Enhancement in an Advanced LWR Nuclear Fuel Assembly

    SciTech Connect

    In, Wang-Kee; Chun, Tae-Hyun; Shin, Chang-Hwan; Oh, Dong-Seok

    2007-07-01

    A computational fluid dynamics (CFD) analysis has been performed to investigate a flow-mixing and heat-transfer enhancement caused by a mixing-vane spacer in a LWR fuel assembly which is a rod bundle. This paper presents the CFD simulations of a flow mixing and heat transfer in a fully heated 5x5 array of a rod bundle with a split-vane and hybrid-vane spacer. The CFD prediction at a low Reynolds number of 42,000 showed a reasonably good agreement of the initial heat transfer enhancement with the measured one for a partially heated experiment using a similar spacer structure. The CFD simulation also predicted the decay rate of a normalized Nusselt number downstream of the split-vane spacer which agrees fairly well with those of the experiment and the correlation. The CFD calculations for the split vane and hybrid vane at the LWR operating conditions(Re = 500,000) predicted hot fuel spots in a streaky structure downstream of the spacer, which occurs due to the secondary flow occurring in an opposite direction near the fuel rod. However, the split-vane and hybrid-vane spacers are predicted to significantly enhance the overall heat transfer of a LWR nuclear fuel assembly. (authors)

  1. Support of NASA ADR/ Cross-Enterprise NRA Advanced Adiabatic Demagnetization Refrigerators for Continuous Cooling from 10K to 50mK, Development of a Heat Switch

    NASA Technical Reports Server (NTRS)

    Richards, Paul L.

    2005-01-01

    Mechanical heat switches are used in conjunction with sorption refrigerators, adiabatic demagnetization refrigerators and for other cryogenic tasks including the pre-cooling cryogenic systems. They use a mechanical actuator which closes Au plated Cu jaws on an Au plated Cu bar. The thermal conductance in the closed position is essentially independent of the area of the jaws and proportional to the force applied. It varies linearly with T. It is approximately 10mW/K for 200 N at 1.5K. In some applications, the heat switch can be driven from outside the cryostat by a rotating rod and a screw. Such heat switches are available commercially from several sources. In other applications, including systems for space, it is desirable to drive the switch using a cold linear motor, or solenoid. Superconducting windings are used at temperatures s 4.2K to minimize power dissipation, but are not appropriate for pre-cooling a system at higher temperatures. This project was intended to improve the design of solenoid activated mechanical heat switches and to provide such switches as required to support the development of Advanced Adiabatic Demagnetization Refrigerators for Continuous Cooling from 10 K to 50 mK at GSFC. By the time funding began in 5/1/01, the immediate need for mechanical heat switches at GSFC had subsided but, at the same time, the opportunity had arisen to improve the design of mechanical heat switching by incorporating a "latching solenoid". In this device, the solenoid current is required only for changing the state of the switch and not during the whole time that the switch is closed.

  2. Feasibility study for an advanced coal fired heat exchanger/gas turbine topping cycle for a high efficiency power plant. Final report

    SciTech Connect

    Solomon, P.R.; Zhao, Y.; Pines, D.; Buggeln, R.C.; Shamroth, S.J.

    1993-11-01

    Significant improvements in efficiency for the conversion of coal into electricity can be achieved by cycles which employ a high temperature gas turbine topping cycle. The objective of this project is the development of an externally fired gas turbine system. The project computationally tested a new concept for a High Temperature Advanced Furnace (HITAF) and high temperature heat exchanger with a proprietary design to reduce the problems associated with the harsh coal environment. The program addressed two key technology issues: (1) the HITAF/heat exchanger heat transfer through a 2-D computer analysis of the HITAF configuration; (2) 3-D Computational Fluid Dynamics (CFD) model application to simulate the exclusion of particles and corrosive gases from the heat exchanger surface. The basic concept of this new combustor design was verified through the 2D and 3D modeling. It demonstrated that the corrosion and erosion of the exchanger material caused by coal and ash particles can be largely reduced by employing a specially designed firing scheme. It also suggested that a proper combustion geometry design is necessary to maximize the cleaning effect.

  3. Advanced flat top laser heating system for high pressure research at GSECARS: application to the melting behavior of germanium

    SciTech Connect

    Prakapenka, V.B.; Kubo, A.; Kuznetzov, A.; Laskin, A.; Shkurkhin, O.; Dera, P.; Rivers, M.L.; Sutton, S.R.

    2008-09-29

    Laser heating plays an essential role for in-situ high pressure high temperature studies into the physical and chemical properties of materials in the diamond anvil cell (DAC) and minerals at conditions relevant to the Earth's deep interior. High temperature experiments in the multi-Mbar (over 100 GPa) pressure range require the use of very small samples and consequently the utmost stability and controllability of the laser heating is crucial. To accomplish this, we have modified the laser heating system at GSECARS employing newly developed beam shaping optics combined with two diode-pumped, single mode fiber lasers. Varying the settings of the laser heating system, we were able to shape the beam to almost any desired intensity profile and size on the surface of the sample in the DAC, including tight focus, flat top, trident and doughnut types. The advantages and excellent performance of the flat top laser heating (FTLH) technique were demonstrated in melting experiments on germanium in the DAC at pressures up to 40 GPa.

  4. Integrated Combined Heat and Power/Advanced Reciprocating Internal Combustion Engine System for Landfill Gas to Power Applications

    SciTech Connect

    2009-02-01

    Gas Technology Institute will collaborate with Integrated CHP Systems Corporation, West Virginia University, Vronay Engineering Services, KAR Engineering Associates, Pioneer Air Systems, and Energy Concepts Company to recover waste heat from reciprocating engines. The project will integrate waste heat recovery along with gas clean-up technology system improvements. This will address fuel quality issues that have hampered expanded use of opportunity fuels such as landfill gas, digester biogas, and coal mine methane. This will enable increased application of CHP using renewable and domestically derived opportunity fuels.

  5. Development of sensors for ceramic components in advanced propulsion systems: Survey and evaluation of measurement techniques for temperature, strain and heat flux for ceramic components in advanced propulsion systems

    NASA Technical Reports Server (NTRS)

    Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

    1988-01-01

    The report presents the final results of Tasks 1 and 2, Development of Sensors for Ceramic Components in Advanced Propulsion Systems (NASA program NAS3-25141). During Task 1, an extensive survey was conducted of sensor concepts which have the potential for measuring surface temperature, strain and heat flux on ceramic components for advanced propulsion systems. Each sensor concept was analyzed and evaluated under Task 2; sensor concepts were then recommended for further development. For temperature measurement, both pyrometry and thermographic phosphors are recommended for measurements up to and beyond the melting point of ceramic materials. For lower temperature test programs, the thin-film techniques offer advantages in the installation of temperature sensors. Optical strain measurement techniques are recommended because they offer the possibility of being useful at very high temperature levels. Techniques for the measurement of heat flux are recommended for development based on both a surface mounted sensor and the measurement of the temperature differential across a portion of a ceramic component or metallic substrate.

  6. Strategic Coupling of Advanced Induction Heating with Magnetic Field Processing Technologies Provides Innovative Solutions for Elevated Industries Demands

    SciTech Connect

    Ludtka, Mackiewicz-Ludtka; Pfaffmann, George; Ludtka, Gerard Michael

    2013-01-01

    Industry s relentless pursuit of product performance improvements is now challenging the capability of available/existing Thermal processing technologies, i.e., Heat Treating. In fact, the EPA-mandated requirement for light-weighting vehicles underscores the urgent US need for achieving higher product strength improvements.

  7. Analytical and experimental evaluation of joining silicon carbide to silicon carbide and silicon nitride to silicon nitride for advanced heat engine applications, phase 2

    NASA Astrophysics Data System (ADS)

    Sundberg, G. J.; Vartabedian, A. M.; Wade, J. A.; White, C. S.

    1994-10-01

    The purpose of joining, Phase 2 was to develop joining technologies for HIP'ed Si3N4 with 4wt% Y2O3 (NCX-5101) and for a siliconized SiC (NT230) for various geometries including: butt joins, curved joins and shaft to disk joins. In addition, more extensive mechanical characterization of silicon nitride joins to enhance the predictive capabilities of the analytical/numerical models for structural components in advanced heat engines was provided. Mechanical evaluation were performed by: flexure strength at 22 C and 1,370 C, stress rupture at 1,370 C, high temperature creep, 22 C tensile testing and spin tests. While the silicon nitride joins were produced with sufficient integrity for many applications, the lower join strength would limit its use in the more severe structural applications. Thus, the silicon carbide join quality was deemed unsatisfactory to advance to more complex, curved geometries. The silicon carbide joining methods covered within this contract, although not entirely successful, have emphasized the need to focus future efforts upon ways to obtain a homogeneous, well sintered parent/join interface prior to siliconization. In conclusion, the improved definition of the silicon carbide joining problem obtained by efforts during this contract have provided avenues for future work that could successfully obtain heat engine quality joins.

  8. Analytical and experimental evaluation of joining silicon carbide to silicon carbide and silicon nitride to silicon nitride for advanced heat engine applications Phase 2. Final report

    SciTech Connect

    Sundberg, G.J.; Vartabedian, A.M.; Wade, J.A.; White, C.S.

    1994-10-01

    The purpose of joining, Phase 2 was to develop joining technologies for HIP`ed Si{sub 3}N{sub 4} with 4wt% Y{sub 2}O{sub 3} (NCX-5101) and for a siliconized SiC (NT230) for various geometries including: butt joins, curved joins and shaft to disk joins. In addition, more extensive mechanical characterization of silicon nitride joins to enhance the predictive capabilities of the analytical/numerical models for structural components in advanced heat engines was provided. Mechanical evaluation were performed by: flexure strength at 22 C and 1,370 C, stress rupture at 1,370 C, high temperature creep, 22 C tensile testing and spin tests. While the silicon nitride joins were produced with sufficient integrity for many applications, the lower join strength would limit its use in the more severe structural applications. Thus, the silicon carbide join quality was deemed unsatisfactory to advance to more complex, curved geometries. The silicon carbide joining methods covered within this contract, although not entirely successful, have emphasized the need to focus future efforts upon ways to obtain a homogeneous, well sintered parent/join interface prior to siliconization. In conclusion, the improved definition of the silicon carbide joining problem obtained by efforts during this contract have provided avenues for future work that could successfully obtain heat engine quality joins.

  9. Investigating the Effect of Different Verbal Formats of Advance Organizers on Third Graders' Understanding of Heat Transfer Concept

    ERIC Educational Resources Information Center

    Chuang, Hsueh-Hua; Liu, Han-Chin

    2014-01-01

    The emergence of computer and multimedia technology change the forms of instructional materials and instructional design plays an important role on student learning outcome in multimedia learning. Research has found that using advance organizers has the potential for achieving learning objectives. Thus, this study investigated how using different…

  10. Investigating the Effect of Different Verbal Formats of Advance Organizers on Third Graders' Understanding of Heat Transfer Concept

    ERIC Educational Resources Information Center

    Chuang, Hsueh-Hua; Liu, Han-Chin

    2014-01-01

    The emergence of computer and multimedia technology change the forms of instructional materials and instructional design plays an important role on student learning outcome in multimedia learning. Research has found that using advance organizers has the potential for achieving learning objectives. Thus, this study investigated how using different…

  11. The Local Integrity Approach for Urban Contexts: Definition and Vehicular Experimental Assessment.

    PubMed

    Margaria, Davide; Falletti, Emanuela

    2016-01-01

    A novel cooperative integrity monitoring concept, called "local integrity", suitable to automotive applications in urban scenarios, is discussed in this paper. The idea is to take advantage of a collaborative Vehicular Ad hoc NETwork (VANET) architecture in order to perform a spatial/temporal characterization of possible degradations of Global Navigation Satellite System (GNSS) signals. Such characterization enables the computation of the so-called "Local Protection Levels", taking into account local impairments to the received signals. Starting from theoretical concepts, this paper describes the experimental validation by means of a measurement campaign and the real-time implementation of the algorithm on a vehicular prototype. A live demonstration in a real scenario has been successfully carried out, highlighting effectiveness and performance of the proposed approach. PMID:26821028

  12. The Local Integrity Approach for Urban Contexts: Definition and Vehicular Experimental Assessment

    PubMed Central

    Margaria, Davide; Falletti, Emanuela

    2016-01-01

    A novel cooperative integrity monitoring concept, called “local integrity”, suitable to automotive applications in urban scenarios, is discussed in this paper. The idea is to take advantage of a collaborative Vehicular Ad hoc NETwork (VANET) architecture in order to perform a spatial/temporal characterization of possible degradations of Global Navigation Satellite System (GNSS) signals. Such characterization enables the computation of the so-called “Local Protection Levels”, taking into account local impairments to the received signals. Starting from theoretical concepts, this paper describes the experimental validation by means of a measurement campaign and the real-time implementation of the algorithm on a vehicular prototype. A live demonstration in a real scenario has been successfully carried out, highlighting effectiveness and performance of the proposed approach. PMID:26821028

  13. Lightweight cryogenic-compatible pressure vessels for vehicular fuel storage

    DOEpatents

    Aceves, Salvador; Berry, Gene; Weisberg, Andrew H.

    2004-03-23

    A lightweight, cryogenic-compatible pressure vessel for flexibly storing cryogenic liquid fuels or compressed gas fuels at cryogenic or ambient temperatures. The pressure vessel has an inner pressure container enclosing a fuel storage volume, an outer container surrounding the inner pressure container to form an evacuated space therebetween, and a thermal insulator surrounding the inner pressure container in the evacuated space to inhibit heat transfer. Additionally, vacuum loss from fuel permeation is substantially inhibited in the evacuated space by, for example, lining the container liner with a layer of fuel-impermeable material, capturing the permeated fuel in the evacuated space, or purging the permeated fuel from the evacuated space.

  14. EGPS: An Efficient Privacy Preserving Scheme for Vehicular ad hoc Networks

    NASA Astrophysics Data System (ADS)

    Zhao, Baokang; Su, Xiangyu; Su, Jinshu; Song, Ziming; Sun, Yipin; Tao, Jing; Tang, Yong; Chen, Shuhui; Zhao, Guohong; Chen, Yijiao

    2010-09-01

    In this paper, we propose EGPS, an efficient privacy preserving scheme for vehicular ad hoc networks. The EGPS scheme is based on a very efficient group signature and Identity Based Cryptography(IBC) techniques. Several security properties of EGPS, including the correctness and unforgeability have been proved. Furthermore, EGPS is also proved to be more efficient than GSIS, which is currently one of the best state-of-the-art VANET privacy preserving schemes.

  15. Waste Classification based on Waste Form Heat Generation in Advanced Nuclear Fuel Cycles Using the Fuel-Cycle Integration and Tradeoffs (FIT) Model

    SciTech Connect

    Denia Djokic; Steven J. Piet; Layne F. Pincock; Nick R. Soelberg

    2013-02-01

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. This analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. The value of separation of heat-generating fission products and actinides in different fuel cycles is discussed. It was shown that the benefits of reducing the short-term fission-product heat load of waste destined for geologic disposal are neglected under the current source-based radioactive waste classification system , and that it is useful to classify waste streams based on how favorable the impact of interim storage is in increasing repository capacity.

  16. Waste Classification based on Waste Form Heat Generation in Advanced Nuclear Fuel Cycles Using the Fuel-Cycle Integration and Tradeoffs (FIT) Model - 13413

    SciTech Connect

    Djokic, Denia; Piet, Steven J.; Pincock, Layne F.; Soelberg, Nick R.

    2013-07-01

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. This analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. The value of separation of heat-generating fission products and actinides in different fuel cycles is discussed. It was shown that the benefits of reducing the short-term fission-product heat load of waste destined for geologic disposal are neglected under the current source-based radioactive waste classification system, and that it is useful to classify waste streams based on how favorable the impact of interim storage is in increasing repository capacity. (authors)

  17. Development of advanced high temperature in-cylinder components and tribological systems for low heat rejection diesel engines, phase 1

    NASA Astrophysics Data System (ADS)

    Kroeger, C. A.; Larson, H. J.

    1992-03-01

    Analysis and concept design work completed in Phase 1 have identified a low heat rejection engine configuration with the potential to meet the Heavy Duty Transport Technology program specific fuel consumption goal of 152 g/kW-hr. The proposed engine configuration incorporates low heat rejection, in-cylinder components designed for operation at 24 MPa peak cylinder pressure. Water cooling is eliminated by selective oil cooling of the components. A high temperature lubricant will be required due to increased in-cylinder operating temperatures. A two-stage turbocharger air system with intercooling and aftercooling was selected to meet engine boost and BMEP requirements. A turbocompound turbine stage is incorporated for exhaust energy recovery. The concept engine cost was estimated to be 43 percent higher compared to a Caterpillar 3176 engine. The higher initial engine cost is predicted to be offset by reduced operating costs due the lower fuel consumption.

  18. Development of advanced high temperature in-cylinder components and tribological systems for low heat rejection diesel engines, phase 1

    NASA Technical Reports Server (NTRS)

    Kroeger, C. A.; Larson, H. J.

    1992-01-01

    Analysis and concept design work completed in Phase 1 have identified a low heat rejection engine configuration with the potential to meet the Heavy Duty Transport Technology program specific fuel consumption goal of 152 g/kW-hr. The proposed engine configuration incorporates low heat rejection, in-cylinder components designed for operation at 24 MPa peak cylinder pressure. Water cooling is eliminated by selective oil cooling of the components. A high temperature lubricant will be required due to increased in-cylinder operating temperatures. A two-stage turbocharger air system with intercooling and aftercooling was selected to meet engine boost and BMEP requirements. A turbocompound turbine stage is incorporated for exhaust energy recovery. The concept engine cost was estimated to be 43 percent higher compared to a Caterpillar 3176 engine. The higher initial engine cost is predicted to be offset by reduced operating costs due the lower fuel consumption.

  19. Building SDN-Based Agricultural Vehicular Sensor Networks Based on Extended Open vSwitch.

    PubMed

    Huang, Tao; Yan, Siyu; Yang, Fan; Pan, Tian; Liu, Jiang

    2016-01-01

    Software-defined vehicular sensor networks in agriculture, such as autonomous vehicle navigation based on wireless multi-sensor networks, can lead to more efficient precision agriculture. In SDN-based vehicle sensor networks, the data plane is simplified and becomes more efficient by introducing a centralized controller. However, in a wireless environment, the main controller node may leave the sensor network due to the dynamic topology change or the unstable wireless signal, leaving the rest of network devices without control, e.g., a sensor node as a switch may forward packets according to stale rules until the controller updates the flow table entries. To solve this problem, this paper proposes a novel SDN-based vehicular sensor networks architecture which can minimize the performance penalty of controller connection loss. We achieve this by designing a connection state detection and self-learning mechanism. We build prototypes based on extended Open vSwitch and Ryu. The experimental results show that the recovery time from controller connection loss is under 100 ms and it keeps rule updating in real time with a stable throughput. This architecture enhances the survivability and stability of SDN-based vehicular sensor networks in precision agriculture. PMID:26797616

  20. A reinforcement sensor embedded vertical handoff controller for vehicular heterogeneous wireless networks.

    PubMed

    Li, Limin; Xu, Yubin; Soong, Boon-Hee; Ma, Lin

    2013-01-01

    Vehicular communication platforms that provide real-time access to wireless networks have drawn more and more attention in recent years. IEEE 802.11p is the main radio access technology that supports communication for high mobility terminals, however, due to its limited coverage, IEEE 802.11p is usually deployed by coupling with cellular networks to achieve seamless mobility. In a heterogeneous cellular/802.11p network, vehicular communication is characterized by its short time span in association with a wireless local area network (WLAN). Moreover, for the media access control (MAC) scheme used for WLAN, the network throughput dramatically decreases with increasing user quantity. In response to these compelling problems, we propose a reinforcement sensor (RFS) embedded vertical handoff control strategy to support mobility management. The RFS has online learning capability and can provide optimal handoff decisions in an adaptive fashion without prior knowledge. The algorithm integrates considerations including vehicular mobility, traffic load, handoff latency, and network status. Simulation results verify that the proposed algorithm can adaptively adjust the handoff strategy, allowing users to stay connected to the best network. Furthermore, the algorithm can ensure that RSUs are adequate, thereby guaranteeing a high quality user experience. PMID:24193101

  1. Traffic stress, vehicular burden and well-being: a multilevel analysis.

    PubMed

    Gee, Gilbert C; Takeuchi, David T

    2004-07-01

    This study examined whether health is associated with individually perceived traffic stress and as well as ecologically measured vehicular burden using multi-level analysis. Data from the Chinese American psychiatric epidemiologic study (N = 1503) are linked to data from the 1990 Census in the United States. Hierarchical linear modeling was used to analyze the cross-sectional relationship between traffic stress, neighborhood conditions, depression and health status. Perceived traffic stress is associated with both general health status and depression in multivariate multilevel models, such that persons reporting traffic stress had lower health status and more depressive symptoms. Further, there is an interaction between vehicular burden and traffic stress for both health outcomes. Persons who lived in areas with greater vehicular burden and who reported the most traffic stress also had the lowest health status and greatest depressive symptoms. These findings suggest that traffic stress may represent an important factor that influences the well-being of urban populations, and that studies which examine factors at only one level (either individual level only or ecological level only) may underestimate the effect of the social environment. PMID:15110429

  2. Building SDN-Based Agricultural Vehicular Sensor Networks Based on Extended Open vSwitch

    PubMed Central

    Huang, Tao; Yan, Siyu; Yang, Fan; Pan, Tian; Liu, Jiang

    2016-01-01

    Software-defined vehicular sensor networks in agriculture, such as autonomous vehicle navigation based on wireless multi-sensor networks, can lead to more efficient precision agriculture. In SDN-based vehicle sensor networks, the data plane is simplified and becomes more efficient by introducing a centralized controller. However, in a wireless environment, the main controller node may leave the sensor network due to the dynamic topology change or the unstable wireless signal, leaving the rest of network devices without control, e.g., a sensor node as a switch may forward packets according to stale rules until the controller updates the flow table entries. To solve this problem, this paper proposes a novel SDN-based vehicular sensor networks architecture which can minimize the performance penalty of controller connection loss. We achieve this by designing a connection state detection and self-learning mechanism. We build prototypes based on extended Open vSwitch and Ryu. The experimental results show that the recovery time from controller connection loss is under 100 ms and it keeps rule updating in real time with a stable throughput. This architecture enhances the survivability and stability of SDN-based vehicular sensor networks in precision agriculture. PMID:26797616

  3. Vehicular emission exposure of bicycle commuters in the urban area of Guangzhou, South China (PRC)

    SciTech Connect

    Chan, L.Y.; Hung, W.T. ); Qin, Y. )

    1994-01-01

    Guangzhou is a major city in South China and is at the forefront of economic reform since 1978. The population of Guangzhou is rapidly increasing and most people either walk or cycle to and from work. These commuters are highly vulnerable to vehicular emissions. An indirect approach was adopted to estimate vehicular emission exposure to Guangzhou bicycle commuters. Four bus routes were selected as typical commuting routes. Concentrations of NO[sub x] and CO as well as traffic volume, vehicle speed, ground-level wind speed, and direction were measured at monitoring points set up along the routes of typical street links passing through areas of various land uses. CO and NO[sub x] were recognized to be two major vehicular emission pollutants. The average CO exposure levels of Guangzhou bicycle commuters ranged from 3.7 [mu]L/L to 8.2 [mu]L/L. Few CO samples exceeded the Chinese national assessment standard. No adverse effect on health was expected. The average NO[sub x] exposure levels of Guangzhou bicycle commuters ranged from 0.13 [mu]L/L to 0.26 [mu]L/L. More than half of the NO[sub x] samples exceeded the Chinese national assessment standard. Adverse effects on the health of bicycle commuters might result. Other factors such as street configurations and land uses were also analyzed. 15 refs., 5 figs., 4 tabs.

  4. A Reinforcement Sensor Embedded Vertical Handoff Controller for Vehicular Heterogeneous Wireless Networks

    PubMed Central

    Li, Limin; Xu, Yubin; Soong, Boon-Hee; Ma, Lin

    2013-01-01

    Vehicular communication platforms that provide real-time access to wireless networks have drawn more and more attention in recent years. IEEE 802.11p is the main radio access technology that supports communication for high mobility terminals, however, due to its limited coverage, IEEE 802.11p is usually deployed by coupling with cellular networks to achieve seamless mobility. In a heterogeneous cellular/802.11p network, vehicular communication is characterized by its short time span in association with a wireless local area network (WLAN). Moreover, for the media access control (MAC) scheme used for WLAN, the network throughput dramatically decreases with increasing user quantity. In response to these compelling problems, we propose a reinforcement sensor (RFS) embedded vertical handoff control strategy to support mobility management. The RFS has online learning capability and can provide optimal handoff decisions in an adaptive fashion without prior knowledge. The algorithm integrates considerations including vehicular mobility, traffic load, handoff latency, and network status. Simulation results verify that the proposed algorithm can adaptively adjust the handoff strategy, allowing users to stay connected to the best network. Furthermore, the algorithm can ensure that RSUs are adequate, thereby guaranteeing a high quality user experience. PMID:24193101

  5. Decadal change in carbon monoxide to nitrogen oxide ratio in U.S. vehicular emissions

    NASA Astrophysics Data System (ADS)

    Parrish, D. D.; Trainer, M.; Hereid, D.; Williams, E. J.; Olszyna, K. J.; Harley, R. A.; Meagher, J. F.; Fehsenfeld, F. C.

    2002-06-01

    Accurate emission inventories and their temporal trends must be incorporated into pollutant inventories to allow for reliable modeling of the country's past, present, and future air quality. Measured carbon monoxide (CO) and nitrogen oxide (NOx) concentrations from two urban areas show that the CO/NOx vehicular emission ratio has decreased at an average rate of 7-9% per year from 1987 to 1999. This amounts to a factor of nearly 3 over the 12 years. The current U.S. Environmental Protection Agency tabulations of estimated pollutant emission trends indicate a rate of decrease smaller by a factor of 2-3. The trend in maximum ambient CO levels in U.S. cities suggests a 5.2 +/- 0.8% per year average annual decrease in CO vehicular emissions, which implies a 2-3% annual increase in NOx emissions from vehicles. Thus over the decade of the 1990s, annual U.S. CO emissions from vehicles have decreased from ~65 to ~38 Tg, representing approximate decreases of 6 and 3% in the annual global fuel-use CO emissions and in total global anthropogenic CO emissions, respectively. It is expected that the volatile organic compound (VOC)/NOx vehicular exhaust emission ratio has decreased similarly, implying that the character of atmospheric photochemistry in U.S. urban areas has changed significantly over the decade.

  6. The Development of an INL Capability for High Temperature Flow, Heat Transfer, and Thermal Energy Storage with Applications in Advanced Small Modular Reactors, High Temperature Heat Exchangers, Hybrid Energy Systems, and Dynamic Grid Energy Storage C

    SciTech Connect

    Sun, Xiaodong; Zhang, Xiaoqin; Kim, Inhun; O'Brien, James; Sabharwall, Piyush

    2014-10-01

    The overall goal of this project is to support Idaho National Laboratory in developing a new advanced high temperature multi fluid multi loop test facility that is aimed at investigating fluid flow and heat transfer, material corrosion, heat exchanger characteristics and instrumentation performance, among others, for nuclear applications. Specifically, preliminary research has been performed at The Ohio State University in the following areas: 1. A review of fluoride molten salts’ characteristics in thermal, corrosive, and compatibility performances. A recommendation for a salt selection is provided. Material candidates for both molten salt and helium flow loop have been identified. 2. A conceptual facility design that satisfies the multi loop (two coolant loops [i.e., fluoride molten salts and helium]) multi purpose (two operation modes [i.e., forced and natural circulation]) requirements. Schematic models are presented. The thermal hydraulic performances in a preliminary printed circuit heat exchanger (PCHE) design have been estimated. 3. An introduction of computational methods and models for pipe heat loss analysis and cases studies. Recommendations on insulation material selection have been provided. 4. An analysis of pipe pressure rating and sizing. Preliminary recommendations on pipe size selection have been provided. 5. A review of molten fluoride salt preparation and chemistry control. An introduction to the experience from the Molten Salt Reactor Experiment at Oak Ridge National Laboratory has been provided. 6. A review of some instruments and components to be used in the facility. Flowmeters and Grayloc connectors have been included. This report primarily presents the conclusions drawn from the extensive review of literatures in material selections and the facility design progress at the current stage. It provides some useful guidelines in insulation material and pipe size selection, as well as an introductory review of facility process and components.

  7. Cost benefits from applying advanced heat rejection concepts to a wet/dry-cooled binary geothermal plant

    SciTech Connect

    Faletti, D.W.

    1981-03-01

    Optimized ammonia heat rejection system designs were carried out for three water allocations equivalent to 9, 20, and 31% of that of a 100% wet-cooled plant. The Holt/Procon design of a 50-MWe binary geothermal plant for the Heber site was used as a design basis. The optimization process took into account the penalties for replacement power, gas turbine capital, and lost capacity due to increased heat rejection temperature, as well as added base plant capacity and fuel to provide fan and pump power to the heat rejection system. Descriptions of the three plant designs are presented. For comparison, a wet tower loop was costed out for a 100% wet-cooled plant using the parameters of the Holt/Procon design. Wet/dry cooling was found to increase the cost of electricity by 28% above that of a 100% wet-cooled plant for all three of the water allocations studied (9, 20, and 31%). The application selected for a preconceptual evaluation of the BCT (binary cooling tower) system was the use of agricultural waste water from the New River, located in California's Imperial Valley, to cool a 50-MWe binary geothermal plant. Technical and cost evaluations at the preconceptual level indicated that performance estimates provided by Tower Systems Incorporated (TSI) were reasonable and that TSI's tower cost, although 2 to 19% lower than PNL estimates, was also reasonable. Electrical cost comparisonswere made among the BCT system, a conventional 100% wet system, and a 9% wet/dry ammonia system, all using agricultural waste water with solar pond disposal. The BCT system cost the least, yielding a cost of electricity only 13% above that of a conventional wet system using high quality water and 14% less than either the conventional 100% wet or the 9% wet/dry ammonia system.

  8. Improved silicon carbide for advanced heat engines. II - Pressureless sintering and mechanical properties of injection molded silicon carbide

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.; Baer, J. R.

    1989-01-01

    The influence on density and strength of pressureless sintering in vacuum and argon environments has been evaluated with injection molded SiC materials. Main effects and two factor interactions of sintering (cycle variables temperature, time, heating rate, and atmosphere) were assessed. An improved understanding of the influence of the processing flaws and sintering conditions has been obtained. Strength and density have improved from a baseline level of 299 MPa (43.3 Ksi) and 94 pct of theoretical density to values greater than 483 MPa (70 Ksi) and 97 pct.

  9. Investigation of Advanced Counterrotation Blade Configuration Concepts for High Speed Turboprop Systems. Task 8: Cooling Flow/heat Transfer Analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Topp, David A.; Heidegger, Nathan J.; Delaney, Robert A.

    1994-01-01

    The focus of this task was to validate the ADPAC code for heat transfer calculations. To accomplish this goal, the ADPAC code was modified to allow for a Cartesian coordinate system capability and to add boundary conditions to handle spanwise periodicity and transpiration boundaries. The primary validation case was the film cooled C3X vane. The cooling hole modeling included both a porous region and grid in each discrete hold. Predictions for these models as well as smooth wall compared well with the experimental data.

  10. Energy Savings and Economics of Advanced Control Strategies for Packaged Air-Conditioning Units with Gas Heat

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

    2011-12-31

    Pacific Northwest National Laboratory (PNNL) with funding from the U.S. Department of Energy's Building Technologies Program (BTP) evaluated a number of control strategies that can be implemented in a controller, to improve the operational efficiency of the packaged air conditioning units. The two primary objectives of this research project are: (1) determine the magnitude of energy savings achievable by retrofitting existing packaged air conditioning units with advanced control strategies not ordinarily used for packaged units and (2) estimating what the installed cost of a replacement control with the desired features should be in various regions of the U.S. This document reports results of the study.

  11. High temperature corrosion of advanced ceramic materials for hot gas filters. Topical report for part 1 of high temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    SciTech Connect

    Spear, K.E.; Crossland, C.E.; Shelleman, D.L.; Tressler, R.E.

    1997-12-11

    This program consists of two separate research areas. Part 1, for which this report is written, studied the high temperature corrosion of advanced ceramic hot gas filters, while Part 2 studied the long-term durability of ceramic heat exchangers to coal combustion environments. The objectives of Part 1 were to select two candidate ceramic filter materials for flow-through hot corrosion studies and subsequent corrosion and mechanical properties characterization. In addition, a thermodynamic database was developed so that thermochemical modeling studies could be performed to simulate operating conditions of laboratory reactors and existing coal combustion power plants, and to predict the reactions of new filter materials with coal combustion environments. The latter would make it possible to gain insight into problems that could develop during actual operation of filters in coal combustion power plants so that potential problems could be addressed before they arise.

  12. STS-109 Onboard Photo of Extra-Vehicular Activity (EVA)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is an onboard photo of the Hubble Space Telescope (HST) power control unit (PCU), the heart of the HST's power system. STS-109 payload commander John M. Grunsfeld, joined by Astronaut Richard M. Lirnehan, turned off the telescope in order to replace its PCU while participating in the third of five spacewalks dedicated to servicing and upgrading the HST. Other upgrades performed were: replacement of the solar array panels; replacement of the Faint Object Camera (FOC) with a new advanced camera for Surveys (ACS); and installation of the experimental cooling system for the Hubble's Near-Infrared Camera and Multi-Object Spectrometer (NICMOS), which had been dormant since January 1999 when its original coolant ran out. The telescope was captured and secured on a work stand in Columbia's payload bay using Columbia's robotic arm, where crew members completed the system upgrades. The Marshall Space Flight Center had the responsibility for the design, development, and construction of the HST, which is the most complex and sensitive optical telescope ever made, to study the cosmos from a low-Earth orbit. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. Launched March 1, 2002 the STS-109 HST servicing mission lasted 10 days, 22 hours, and 11 minutes. It was the 108th flight overall in NASA's Space Shuttle Program.

  13. Hands-Free Control Interfaces for an Extra Vehicular Jetpack

    NASA Technical Reports Server (NTRS)

    Zumbado, Jennifer Rochlis; Curiel, Pedro H.; Schreiner, Sam

    2012-01-01

    The National Aeronautics and Space Administration (NASA) strategic vision includes, as part of its long-term goals, the exploration of deep space and Near Earth Asteroids (NEA). To support these endeavors, funds have been invested in research to develop advanced exploration capabilities. To enable the human mobility necessary to effectively explore NEA and deep space, a new extravehicular activity (EVA) Jetpack is under development at the Johnson Space Center. The new design leverages knowledge and experience gained from the current astronaut rescue device, the Simplified Aid for EVA Rescue (SAFER). Whereas the primary goal for a rescue device is to return the crew to a safe haven, in-space exploration and navigation requires an expanded set of capabilities. To accommodate the range of tasks astronauts may be expected to perform while utilizing the Jetpack, it was desired to offer a hands-free method of control. This paper describes the development and innovations involved in creating two hands-free control interfaces and an experimental test platform for a suited astronaut flying the Jetpack during an EVA.

  14. Hands-Free Control Interfaces for an Extra Vehicular Jetpack

    NASA Astrophysics Data System (ADS)

    Zumbado, J. R.; Curiel, P. H.; Schreiner, S.

    The National Aeronautics and Space Administration (NASA) strategic vision includes, as part of its long-term goals, the exploration of deep space and Near Earth Asteroids (NEA). To support these endeavors, funds have been invested in research to develop advanced exploration capabilities. To enable the human mobility necessary to effectively explore NEA and deep space, a new extravehicular activity (EVA) Jetpack is under development at the Johnson Space Center. The new design leverages knowledge and experience gained from the current astronaut rescue device, the Simplified Aid for EVA Rescue (SAFER). Whereas the primary goal for a rescue device is to return the crew to a safe haven, in-space exploration and navigation requires an expanded set of capabilities. To accommodate the range of tasks astronauts may be expected to perform while utilizing the Jetpack, it was desired to offer a hands-free method of control. This paper describes the development and innovations involved in creating two hands-free control interfaces and an experimental test platform for a suited astronaut flying the Jetpack during an EVA.

  15. STS-109 Onboard Photo of Extra-Vehicular Activity (EVA)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is an onboard photo of Astronaut John M. Grunsfield, STS-109 payload commander, participating in the third of five spacewalks to perform work on the Hubble Space Telescope (HST). On this particular walk, Grunsfield, joined by Astronaut Richard M. Lirnehan, turned off the telescope in order to replace its power control unit (PCU), the heart of the HST's power system. The telescope was captured and secured on a work stand in Columbia's payload bay using Columbia's robotic arm, where crew members completed system upgrades to the HST. Included in those upgrades were: replacement of the solar array panels; replacement of the power control unit (PCU); replacement of the Faint Object Camera (FOC) with a new advanced camera for Surveys (ACS); and installation of the experimental cooling system for the Hubble's Near-Infrared Camera and Multi-object Spectrometer (NICMOS), which had been dormant since January 1999 when its original coolant ran out. The Marshall Space Flight Center had the responsibility for the design, development, and construction of the HST, which is the most complex and sensitive optical telescope ever made, to study the cosmos from a low-Earth orbit. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. Launched March 1, 2002 the STS-109 HST servicing mission lasted 10 days, 22 hours, and 11 minutes. It was the 108th flight overall in NASA's Space Shuttle Program.

  16. Heat stroke.

    PubMed

    Leon, Lisa R; Bouchama, Abderrezak

    2015-04-01

    Heat stroke is a life-threatening condition clinically diagnosed as a severe elevation in body temperature with central nervous system dysfunction that often includes combativeness, delirium, seizures, and coma. Classic heat stroke primarily occurs in immunocompromised individuals during annual heat waves. Exertional heat stroke is observed in young fit individuals performing strenuous physical activity in hot or temperature environments. Long-term consequences of heat stroke are thought to be due to a systemic inflammatory response syndrome. This article provides a comprehensive review of recent advances in the identification of risk factors that predispose to heat stroke, the role of endotoxin and cytokines in mediation of multi-organ damage, the incidence of hypothermia and fever during heat stroke recovery, clinical biomarkers of organ damage severity, and protective cooling strategies. Risk factors include environmental factors, medications, drug use, compromised health status, and genetic conditions. The role of endotoxin and cytokines is discussed in the framework of research conducted over 30 years ago that requires reassessment to more clearly identify the role of these factors in the systemic inflammatory response syndrome. We challenge the notion that hypothalamic damage is responsible for thermoregulatory disturbances during heat stroke recovery and highlight recent advances in our understanding of the regulated nature of these responses. The need for more sensitive clinical biomarkers of organ damage is examined. Conventional and emerging cooling methods are discussed with reference to protection against peripheral organ damage and selective brain cooling. PMID:25880507

  17. Heat pipe systems using new working fluids

    NASA Technical Reports Server (NTRS)

    Chao, David F. (Inventor); Zhang, Nengli (Inventor)

    2004-01-01

    The performance of a heat pipe system is greatly improved by the use of a dilute aqueous solution of about 0.0005 and about 0.005 moles per liter of a long chain alcohol as the working fluid. The surface tension-temperature gradient of the long-chain alcohol solutions turns positive as the temperature exceeds a certain value, for example about 40.degree. C. for n-heptanol solutions. Consequently, the Marangoni effect does not impede, but rather aids in bubble departure from the heating surface. Thus, the bubble size at departure is substantially reduced at higher frequencies and, therefore, increases the boiling limit of heat pipes. This feature is useful in microgravity conditions. In addition to microgravity applications, the heat pipe system may be used for commercial, residential and vehicular air conditioning systems, micro heat pipes for electronic devices, refrigeration and heat exchangers, and chemistry and cryogenics.

  18. A study on the trends of vehicular emissions in the Beijing-Tianjin-Hebei (BTH) region, China

    NASA Astrophysics Data System (ADS)

    Lang, Jianlei; Cheng, Shuiyuan; Wei, Wei; Zhou, Ying; Wei, Xiao; Chen, Dongsheng

    2012-12-01

    This paper aims to study the vehicular emissions trends in the Beijing-Tianjin-Hebei (BTH) region, located in northern China. The multiyear emission inventories of NOX, CO, VOC and PM10 from road vehicles in the period 1999-2010 were developed by the COPERT IV model. Results show that vehicular emissions of CO and VOC have decreased by annual average change rates (AACR) of -3.1% to -5.2% and -4.4% to -6.9% in the study area, respectively. However, due to the rapid development of freight traffic, emissions of NOX and PM10 have kept increasing in Tianjin and Hebei. Based on the vehicular emission inventories, trends of emission levels for vehicles with different standards, as well as the overall effects of implementing vehicular emission mitigation strategies were assessed. It is suggested that passenger cars (PC) with Euro 0 and Euro I standards, which were at higher emission level in the PC fleet, should be gradually eliminated. Although the increasing rates (IR) of emissions from PC were lower than those of the PC population, the sharp growth of PC population in recent years contributed to a remarkable increase of emissions, weakening the overall mitigation effect. Total vehicle population capacity and other mitigation measures should be studied in China in order to develop new and more effective vehicular emission control strategies.

  19. Factors contributing to the amount of vehicular damage resulting from collisions between four-wheel drive vehicles and passenger cars.

    PubMed

    Broyles, R W; Clarke, S R; Narine, L; Baker, D R

    2001-09-01

    This study examines the vehicular damage resulting from motor vehicle crashes involving four-wheel drive vehicles and passenger cars in the state of Oklahoma. In particular, the focus of the analysis is on differences in vehicular damage to passenger cars and four-wheel drive vehicles. Results indicate that passenger cars sustain significantly greater vehicular damage than four-wheel drive vehicles. In addition, several other factors significantly influence the level of damage resulting from collisions between four-wheel drive vehicles and passenger cars. Driver behavior or unsafe acts, represented by the rate of travel prior to the collision, failure to yield, failure to obey a stoplight or a stop sign, the consumption of alcohol and the use of drugs, also contributed to the amount of vehicular damage. In addition, results also indicate that the level of damage was influenced significantly by environmental factors, represented by a reduced intensity of light, wet or slippery roadways and the type of collision. The findings reinforce the importance of a number of policy initiatives that may reduce the vehicular damage resulting from collisions involving four-wheel drive vehicles and passenger cars. For example, the study indicates a need to initiate legislation that lowers the speed limit during dark and twilight hours, commits additional resources to road maintenance to reduce unsafe road conditions, and stimulates improvements in automotive design that provide better lateral protection to vehicles. PMID:11491248

  20. Analysis and recent advances in gamma heating measurements in MINERVE facility by using TLD and OSLD techniques

    SciTech Connect

    Amharrak, H.; Di Salvo, J.; Lyoussi, A.; Roche, A.; Masson-Fauchier, M.; Bosq, J. C.

    2011-07-01

    The objective of this study is to develop nuclear heating measurement methods in Zero Power experimental reactors. This paper presents the analysis of Thermo-Luminescent Detector (TLD) and Optically Stimulated Luminescent Detectors (OSLD) experiments in the UO{sub 2} core of the MINERVE research reactor at the CEA Cadarache. The experimental sources of uncertainties on the gamma dose have been reduced by improving the conditions, as well as the repeatability, of the calibration step for each individual TLD. The interpretation of these measurements needs to take into account calculation of cavity correction factors, related to calibration and irradiation configurations, as well as neutron corrections calculations. These calculations are based on Monte Carlo simulations of neutron-gamma and gamma-electron transport coupled particles. TLD and OSLD are positioned inside aluminum pillboxes. The comparison between calculated and measured integral gamma-ray absorbed doses using TLD, shows that calculation slightly overestimates the measurement with a C/E value equal to 1.05 {+-} 5.3 % (k = 2). By using OSLD, the calculation slightly underestimates the measurement with a C/E value equal to 0.96 {+-} 7.0% (k = 2. (authors)

  1. Differential exposure of the urban population to vehicular air pollution in Hong Kong.

    PubMed

    Fan, Xiaopeng; Lam, Kin-che; Yu, Qi

    2012-06-01

    This study aims to characterize the spatial variations in, and examine the influence of socio-economic class on, the exposure of urban population of Hong Kong to air pollution from vehicular sources. Hong Kong provides a unique and interesting case for an in-depth study of environmental inequality because of its dense environment and housing provision mechanism through which about half of the population is accommodated in public housing estates provided by the government. To estimate the exposure of the urban population to vehicular air pollution, the IMMIS(net) air dispersion model developed for city-wide air quality assessment was used. The annual mean concentrations of CO, NO(x), SO(2) and PM(10) were estimated for various assessment points of 275 public and 295 private building groups. The results show more pronounced inequality among residents living in private than in public housing estates. Elderly people and those of lower socio-economic status were found to be exposed to relatively higher levels of vehicular air pollution compared with groups of higher socio-economic status. However, when all the residents in Hong Kong were pooled together for analysis, no distinct class-biased patterns were found. This could be ascribed to the housing provision mechanism, in which less well-off people are accommodated in public housing estates where the air quality is relatively better. This study highlights the importance of government intervention in housing provision, through which the deprived groups in Hong Kong are inadvertently more protected from air pollution exposure. PMID:22542227

  2. Vehicular particulate matter emissions in road tunnels in Sao Paulo, Brazil.

    PubMed

    Sánchez-Ccoyllo, Odón R; Ynoue, Rita Y; Martins, Leila D; Astolfo, Rosana; Miranda, Regina M; Freitas, Edmilson D; Borges, Alessandro S; Fornaro, Adalgiza; Freitas, Helber; Moreira, Andréa; Andrade, Maria F

    2009-02-01

    In the metropolitan area of São Paulo, Brazil, ozone and particulate matter (PM) are the air pollutants that pose the greatest threat to air quality, since the PM and the ozone precursors (nitrogen oxides and volatile organic compounds) are the main source of air pollution from vehicular emissions. Vehicular emissions can be measured inside road tunnels, and those measurements can provide information about emission factors of in-use vehicles. Emission factors are used to estimate vehicular emissions and are described as the amount of species emitted per vehicle distance driven or per volume of fuel consumed. This study presents emission factor data for fine particles, coarse particles, inhalable particulate matter and black carbon, as well as size distribution data for inhalable particulate matter, as measured in March and May of 2004, respectively, in the Jânio Quadros and Maria Maluf road tunnels, both located in São Paulo. The Jânio Quadros tunnel carries mainly light-duty vehicles, whereas the Maria Maluf tunnel carries light-duty and heavy-duty vehicles. In the Jânio Quadros tunnel, the estimated light-duty vehicle emission factors for the trace elements copper and bromine were 261 and 220 microg km(-1), respectively, and 16, 197, 127 and 92 mg km(-1), respectively, for black carbon, inhalable particulate matter, coarse particles and fine particles. The mean contribution of heavy-duty vehicles to the emissions of black carbon, inhalable particulate matter, coarse particles and fine particles was, respectively 29, 4, 6 and 6 times higher than that of light-duty vehicles. The inhalable particulate matter emission factor for heavy-duty vehicles was 1.2 times higher than that found during dynamometer testing. In general, the particle emissions in São Paulo tunnels are higher than those found in other cities of the world. PMID:18228152

  3. General Motors LLC Final Project Report: Improving Energy Efficiency by Developing Components for Distributed Cooling and Heating Based on Thermal Comfort Modeling

    SciTech Connect

    Bozeman, Jeffrey; Chen, Kuo-Huey

    2014-12-09

    On November 3, 2009, General Motors (GM) accepted U.S. Department of Energy (DOE) Cooperative Agreement award number DE-EE0000014 from the National Energy Technology Laboratory (NETL). GM was selected to execute a three-year cost shared research and development project on Solid State Energy Conversion for Vehicular Heating, Ventilation & Air Conditioning (HVAC) and for Waste Heat Recovery.

  4. Effects of lead pollution from vehicular exhaust fumes against sentinel juvenile Achatina achatina.

    PubMed

    Ebenso, I E; Ologhobo, A D

    2008-11-01

    We investigated lead metal pollution induced by traffic fumes along roads with differing traffic intensity near abandoned battery factory (Niger Delta, Nigeria). Juvenile Achatina achatina were positioned as sentinels in plastic snaileries 2 m on road sides. Lead contamination in snail tissue by atomic absorption spectrophotometer increased with increasing vehicular traffic intensity. Snails showed low positive (r (2) = 0.40) relationship and significant (p < 0.05) accumulation of atmospheric lead pollution. Edible snails sold along road sides are prone to lead contamination. PMID:18784896

  5. Quantifying impacts on air quality of vehicular emissions in Sao Paulo and Rio de Janeiro

    NASA Astrophysics Data System (ADS)

    Artaxo, Paulo; Ferreira de Brito, Joel; Godoy, José Marcus; Luiza Godoy, Maria; Junior, Djacinto

    2016-04-01

    Vehicular emissions in megacities such as Sao Paulo and Rio de Janeiro are increasingly becoming a global issue. The São Paulo Metropolitan Area (SPMA), located in Southeast of Brazil, is a megacity with a population of 18 million people, with 7 million cars and large-scale industrial emissions. Rio de Janeiro is also a large city with different meteorology than São Paulo. All cars in Brazil runs gasohol, with 23% ethanol in gasoline, and for the last 10 years, flex cars that can run on gasohol, ethanol or any mixture dominate the market. Overall ethanol accounts for about 30-40% of fuel burned in both cities. To improve the understanding of vehicular emission impacts on aerosol composition and life cycle in these two large megacities a source apportionment study, combining online and offline measurements, was performed. Aerosols were collected for one year to capture seasonal variability at 4 sites in each city, with inorganic and organic aerosol component being sampled. Organic and elemental carbon were measured using a Sunset Laboratory Dual Optics (transmission and reflectance) Carbon Analyzer and about 22 trace elements has been measured using polarized X-Ray Fluorescence (XRF). Aerosol mass and black carbon were also measured, as well as trace gases to help in aerosol source apportionment. In Sao Paulo, the average PM2.5 mass concentration obtained varied from 9.6 to 12.2 μg m-3 for the several sites, and similar concentrations were measured in Rio de Janeiro. At all sites, organic matter (OM) has dominated fine mode aerosol concentration with 42 to 60% of the aerosol mass. EC accounted for 21 to 31% of fine mode aerosol mass concentration. Sulfate accounted for 21 to 26% of PM2.5 for the sites. Aerosol source apportionment was done with receptor analysis and integration with online data such as PTR-MS, Aethalometers, Nephelometers and ACSM helped to apportion vehicular emissions. For the 8 sites operated in Sao Paulo and Rio de Janeiro, vehicular

  6. AGT (Advanced Gas Turbine) technology project

    NASA Technical Reports Server (NTRS)

    1988-01-01

    An overall summary documentation is provided for the Advanced Gas Turbine Technology Project conducted by the Allison Gas Turbine Division of General Motors. This advanced, high risk work was initiated in October 1979 under charter from the U.S. Congress to promote an engine for transportation that would provide an alternate to reciprocating spark ignition (SI) engines for the U.S. automotive industry and simultaneously establish the feasibility of advanced ceramic materials for hot section components to be used in an automotive gas turbine. As this program evolved, dictates of available funding, Government charter, and technical developments caused program emphases to focus on the development and demonstration of the ceramic turbine hot section and away from the development of engine and powertrain technologies and subsequent vehicular demonstrations. Program technical performance concluded in June 1987. The AGT 100 program successfully achieved project objectives with significant technology advances. Specific AGT 100 program achievements are: (1) Ceramic component feasibility for use in gas turbine engines has been demonstrated; (2) A new, 100 hp engine was designed, fabricated, and tested for 572 hour at operating temperatures to 2200 F, uncooled; (3) Statistical design methodology has been applied and correlated to experimental data acquired from over 5500 hour of rig and engine testing; (4) Ceramic component processing capability has progressed from a rudimentary level able to fabricate simple parts to a sophisticated level able to provide complex geometries such as rotors and scrolls; (5) Required improvements for monolithic and composite ceramic gas turbine components to meet automotive reliability, performance, and cost goals have been identified; (6) The combustor design demonstrated lower emissions than 1986 Federal Standards on methanol, JP-5, and diesel fuel. Thus, the potential for meeting emission standards and multifuel capability has been initiated

  7. VehiHealth: An Emergency Routing Protocol for Vehicular Ad Hoc Network to Support Healthcare System.

    PubMed

    Bhoi, S K; Khilar, P M

    2016-03-01

    Survival of a patient depends on effective data communication in healthcare system. In this paper, an emergency routing protocol for Vehicular Ad hoc Network (VANET) is proposed to quickly forward the current patient status information from the ambulance to the hospital to provide pre-medical treatment. As the ambulance takes time to reach the hospital, ambulance doctor can provide sudden treatment to the patient in emergency by sending patient status information to the hospital through the vehicles using vehicular communication. Secondly, the experienced doctors respond to the information by quickly sending a treatment information to the ambulance. In this protocol, data is forwarded through that path which has less link breakage problem between the vehicles. This is done by calculating an intersection value I v a l u e for the neighboring intersections by using the current traffic information. Then the data is forwarded through that intersection which has minimum I v a l u e . Simulation results show VehiHealth performs better than P-GEDIR, GyTAR, A-STAR and GSR routing protocols in terms of average end-to-end delay, number of link breakage, path length, and average response time. PMID:26696419

  8. A Timing Estimation Method Based-on Skewness Analysis in Vehicular Wireless Networks

    PubMed Central

    Cui, Xuerong; Li, Juan; Wu, Chunlei; Liu, Jian-Hang

    2015-01-01

    Vehicle positioning technology has drawn more and more attention in vehicular wireless networks to reduce transportation time and traffic accidents. Nowadays, global navigation satellite systems (GNSS) are widely used in land vehicle positioning, but most of them are lack precision and reliability in situations where their signals are blocked. Positioning systems base-on short range wireless communication are another effective way that can be used in vehicle positioning or vehicle ranging. IEEE 802.11p is a new real-time short range wireless communication standard for vehicles, so a new method is proposed to estimate the time delay or ranges between vehicles based on the IEEE 802.11p standard which includes three main steps: cross-correlation between the received signal and the short preamble, summing up the correlated results in groups, and finding the maximum peak using a dynamic threshold based on the skewness analysis. With the range between each vehicle or road-side infrastructure, the position of neighboring vehicles can be estimated correctly. Simulation results were presented in the International Telecommunications Union (ITU) vehicular multipath channel, which show that the proposed method provides better precision than some well-known timing estimation techniques, especially in low signal to noise ratio (SNR) environments. PMID:26580628

  9. Development and Demonstration of Insulated Pressure Vessels for Vehicular Hydrogen Storage

    SciTech Connect

    Berry, G D; Aceves, S M

    2004-02-26

    This paper describes the development of an alternative technology for vehicular storage of hydrogen. Insulated pressure vessels are cryogenic-capable pressure vessels that can accept cryogenic liquid fuel, cryogenic compressed gas or compressed gas at ambient temperature. Insulated pressure vessels offer advantages over alternative hydrogen storage technologies. Insulated pressure vessels are more compact and less expensive than compressed hydrogen vessels. They have lower evaporative losses and lower energy requirement for fuel liquefaction than liquid hydrogen tanks, and they are lighter than hydrides. The work described in this paper is directed at verifying that insulated pressure vessels can be used safely for vehicular hydrogen storage. The paper describes multiple tests and analyses that have been conducted to evaluate the safety of insulated pressure vessels. Insulated pressure vessels have been subjected to multiple DOT, ISO and SAE certification tests, and the vessels have always been successful in meeting the passing criteria for the different tests. A draft procedure for insulated pressure vessel certification has been generated to assist in a future commercialization of this technology. Ongoing work includes the demonstration of this technology in a vehicle.

  10. Vehicular volatile organic compounds losses due to refueling and diurnal process in China: 2010-2050.

    PubMed

    Yang, Xiaofan; Liu, Huan; Cui, Hongyang; Man, Hanyang; Fu, Mingliang; Hao, Jiming; He, Kebin

    2015-07-01

    Volatile organic compounds (VOCs) are crucial to control air pollution in major Chinese cities since VOCs are the dominant factor influencing ambient ozone level, and also an important precursor of secondary organic aerosols. Vehicular evaporative emissions have become a major and growing source of VOC emissions in China. This study consists of lab tests, technology evaluation, emissions modeling, policy projections and cost-benefit analysis to draw a roadmap for China for controlling vehicular evaporative emissions. The analysis suggests that evaporative VOC emissions from China's light-duty gasoline vehicles were approximately 185,000 ton in 2010 and would peak at 1,200,000 ton in 2040 without control. The current control strategy implemented in China, as shown in business as usual (BAU) scenario, will barely reduce the long-term growth in emissions. Even if Stage II gasoline station vapor control policies were extended national wide (BAU+extended Stage II), there would still be over 400,000 ton fuel loss in 2050. In contrast, the implementation of on-board refueling vapor recovery (ORVR) on new cars could reduce 97.5% of evaporative VOCs by 2050 (BAU+ORVR/BAU+delayed ORVR). According to the results, a combined Stage II and ORVR program is a comprehensive solution that provides both short-term and long-term benefits. The net cost to achieve the optimal total evaporative VOC control is approximately 62 billion CNY in 2025 and 149 billion CNY in 2050. PMID:26141881

  11. Developing Singapore Driving Cycle for passenger cars to estimate fuel consumption and vehicular emissions

    NASA Astrophysics Data System (ADS)

    Ho, Sze-Hwee; Wong, Yiik-Diew; Chang, Victor Wei-Chung

    2014-11-01

    Singapore has pledged to attain 7-11% Business-As-Usual carbon emissions reduction by 2020. Road transport sector is a significant source of carbon emissions, estimated to be the third largest sector in Singapore. A current gap in environmental evaluation for road transport activities in Singapore is the lack of a representative driving cycle for passenger cars (64% of the total population of 974,170 vehicles). This Singapore Driving Cycle (SDC) is hence developed for Singapore roads and traffic conditions. A chase-car (instrumented vehicle) was used to collect on-road data along 12 designed routes, and circulation driving on highly utilized arterial roads (including those in Central Business District (CBD) and both inner and outer ring roads fringing the CBD area). The SDC was thus hence constructed, with consideration of road type proportions, time periods and desired distance, duration and peak-lull proportion. In essence, the SDC is a 2400-s speed-time profile to represent the driving pattern for passenger car in Singapore. Microscopic estimation model (CMEM) shows that, as compared to SDC, the New European Driving Cycle (NEDC) underestimates most of the vehicular emissions (fuel, CO2, HC and NOx by 5%, 5%, 22% and 47%, respectively) and overestimates CO by 8%. The SDC is thus more suitable than the NEDC that is currently in use in Singapore; the SDC can be used to generate more accurate fuel consumption and emissions ratings for various uses (for example, inventory of vehicular emissions and fuel economy labelling).

  12. A Timing Estimation Method Based-on Skewness Analysis in Vehicular Wireless Networks.

    PubMed

    Cui, Xuerong; Li, Juan; Wu, Chunlei; Liu, Jian-Hang

    2015-01-01

    Vehicle positioning technology has drawn more and more attention in vehicular wireless networks to reduce transportation time and traffic accidents. Nowadays, global navigation satellite systems (GNSS) are widely used in land vehicle positioning, but most of them are lack precision and reliability in situations where their signals are blocked. Positioning systems base-on short range wireless communication are another effective way that can be used in vehicle positioning or vehicle ranging. IEEE 802.11p is a new real-time short range wireless communication standard for vehicles, so a new method is proposed to estimate the time delay or ranges between vehicles based on the IEEE 802.11p standard which includes three main steps: cross-correlation between the received signal and the short preamble, summing up the correlated results in groups, and finding the maximum peak using a dynamic threshold based on the skewness analysis. With the range between each vehicle or road-side infrastructure, the position of neighboring vehicles can be estimated correctly. Simulation results were presented in the International Telecommunications Union (ITU) vehicular multipath channel, which show that the proposed method provides better precision than some well-known timing estimation techniques, especially in low signal to noise ratio (SNR) environments. PMID:26580628

  13. A Lightweight Radio Propagation Model for Vehicular Communication in Road Tunnels

    PubMed Central

    Shamim, Azra; Shamshirband, Shahaboddin; Raymond Choo, Kim-Kwang

    2016-01-01

    Radio propagation models (RPMs) are generally employed in Vehicular Ad Hoc Networks (VANETs) to predict path loss in multiple operating environments (e.g. modern road infrastructure such as flyovers, underpasses and road tunnels). For example, different RPMs have been developed to predict propagation behaviour in road tunnels. However, most existing RPMs for road tunnels are computationally complex and are based on field measurements in frequency band not suitable for VANET deployment. Furthermore, in tunnel applications, consequences of moving radio obstacles, such as large buses and delivery trucks, are generally not considered in existing RPMs. This paper proposes a computationally inexpensive RPM with minimal set of parameters to predict path loss in an acceptable range for road tunnels. The proposed RPM utilizes geometric properties of the tunnel, such as height and width along with the distance between sender and receiver, to predict the path loss. The proposed RPM also considers the additional attenuation caused by the moving radio obstacles in road tunnels, while requiring a negligible overhead in terms of computational complexity. To demonstrate the utility of our proposed RPM, we conduct a comparative summary and evaluate its performance. Specifically, an extensive data gathering campaign is carried out in order to evaluate the proposed RPM. The field measurements use the 5 GHz frequency band, which is suitable for vehicular communication. The results demonstrate that a close match exists between the predicted values and measured values of path loss. In particular, an average accuracy of 94% is found with R2 = 0.86. PMID:27031989

  14. A Lightweight Radio Propagation Model for Vehicular Communication in Road Tunnels.

    PubMed

    Qureshi, Muhammad Ahsan; Noor, Rafidah Md; Shamim, Azra; Shamshirband, Shahaboddin; Raymond Choo, Kim-Kwang

    2016-01-01

    Radio propagation models (RPMs) are generally employed in Vehicular Ad Hoc Networks (VANETs) to predict path loss in multiple operating environments (e.g. modern road infrastructure such as flyovers, underpasses and road tunnels). For example, different RPMs have been developed to predict propagation behaviour in road tunnels. However, most existing RPMs for road tunnels are computationally complex and are based on field measurements in frequency band not suitable for VANET deployment. Furthermore, in tunnel applications, consequences of moving radio obstacles, such as large buses and delivery trucks, are generally not considered in existing RPMs. This paper proposes a computationally inexpensive RPM with minimal set of parameters to predict path loss in an acceptable range for road tunnels. The proposed RPM utilizes geometric properties of the tunnel, such as height and width along with the distance between sender and receiver, to predict the path loss. The proposed RPM also considers the additional attenuation caused by the moving radio obstacles in road tunnels, while requiring a negligible overhead in terms of computational complexity. To demonstrate the utility of our proposed RPM, we conduct a comparative summary and evaluate its performance. Specifically, an extensive data gathering campaign is carried out in order to evaluate the proposed RPM. The field measurements use the 5 GHz frequency band, which is suitable for vehicular communication. The results demonstrate that a close match exists between the predicted values and measured values of path loss. In particular, an average accuracy of 94% is found with R2 = 0.86. PMID:27031989

  15. Development of improved processing and evaluation methods for high reliability structural ceramics for advanced heat engine applications Phase II. Final report

    SciTech Connect

    Pujari, V.J.; Tracey, D.M.; Foley, M.R.

    1996-02-01

    The research program had as goals the development and demonstration of significant improvements in processing methods, process controls, and nondestructive evaluation (NDE) which can be commercially implemented to produce high reliability silicon nitride components for advanced heat engine applications at temperatures to 1370{degrees}C. In Phase I of the program a process was developed that resulted in a silicon nitride - 4 w% yttria HIP`ed material (NCX 5102) that displayed unprecedented strength and reliability. An average tensile strength of 1 GPa and a strength distribution following a 3-parameter Weibull distribution were demonstrated by testing several hundred buttonhead tensile specimens. The Phase II program focused on the development of methodology for colloidal consolidation producing green microstructure which minimizes downstream process problems such as drying, shrinkage, cracking, and part distortion during densification. Furthermore, the program focused on the extension of the process to gas pressure sinterable (GPS) compositions. Excellent results were obtained for the HIP composition processed for minimal density gradients, both with respect to room-temperature strength and high-temperature creep resistance. Complex component fabricability of this material was demonstrated by producing engine-vane prototypes. Strength data for the GPS material (NCX-5400) suggest that it ranks very high relative to other silicon nitride materials in terms of tensile/flexure strength ratio, a measure of volume quality. This high quality was derived from the closed-loop colloidal process employed in the program.

  16. Analytical and experimental evaluation of joining silicon nitride to metal and silicon carbide to metal for advanced heat engine applications. Final report

    SciTech Connect

    Kang, S.; Selverian, J.H.; O`Neil, D.; Kim, H.; Kim, K.

    1993-05-01

    This report summarizes the results of Phase 2 of Analytical and Experimental Evaluation of Joining Silicon Nitride to Metal and Silicon Carbide to Metal for Advanced Heat Engine Applications. A general methodology was developed to optimize the joint geometry and material systems for 650{degrees}C applications. Failure criteria were derived to predict the fracture of the braze and ceramic. Extensive finite element analyses (FEA) were performed to examine various joint geometries and to evaluate the affect of different interlayers on the residual stress state. Also, material systems composed of coating materials, interlayers, and braze alloys were developed for the program based on the chemical stability and strength of the joints during processing, and service. The FEA results were compared with experiments using two methods: (1) an idealized strength relationship of the ceramic, and (2) a probabilistic analysis of the ceramic strength (NASA CARES). The results showed that the measured strength of the joint reached 30--80% of the strength predicted by FEA. Also, potential high-temperature braze alloys were developed and evaluated for the high-temperature application of ceramic-metal joints. 38 tabs, 29 figs, 20 refs.

  17. Process Integration Study of the Decatur HFCS Plant for American Fructose Company, Decatur, AL [Advanced Industrial Heat Pump Applications and Evaluations

    SciTech Connect

    Eastwood, A.

    1989-11-10

    This work has carried out in two phases: Phase 1, identification of opportunities for heat pumps in industrial applications and Phase 2; evaluation of heat pumps in industrial applications. In Phase 1, pinch analysis was applied to several industrial sites to identify the best opportunities for heat pumping and other forms of heat integration. In Phase 2, more detailed analyses were undertaken, including the evaluation of a heat pump installed as a recommendation of Phase 1.

  18. 41 CFR 102-74.430 - What is the policy concerning vehicular and pedestrian traffic on Federal property?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What is the policy concerning vehicular and pedestrian traffic on Federal property? 102-74.430 Section 102-74.430 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY...

  19. Contributions of vehicular carbonaceous aerosols to PM2.5 in a roadside environment in Hong Kong

    NASA Astrophysics Data System (ADS)

    Huang, X. H. H.; Bian, Q. J.; Louie, P. K. K.; Yu, J. Z.

    2014-09-01

    Hourly measurements of elemental carbon (EC) and organic carbon (OC) were made at Mong Kok, a roadside air quality monitoring station in Hong Kong, for a year, from May 2011 to April 2012. The monthly average EC concentrations were 3.8-4.9 μg C m-3, accounting for 9.2-17.7% of the PM2.5 mass (21.5-49.7 μg m-3). The EC concentrations showed little seasonal variation and peaked twice daily, coinciding with the traffic rush hours of a day. Strong correlations were found between EC and NOx concentrations, especially during the rush hours in the morning, confirming vehicular emissions as the dominant source of EC at this site. The analysis by means of the minimum OC / EC ratio approach to determine the OC / EC ratio representative of primary vehicular emissions yields a value of 0.5 for (OC / EC)vehicle. By applying the derived (OC / EC)vehicle ratio to the data set, the monthly average vehicle-related OC was estimated to account for 17-64% of the measured OC throughout the year. Vehicle-related OC was also estimated using receptor modeling of a combined data set of hourly NOx, OC, EC and volatile organic compounds characteristic of different types of vehicular emissions. The OCvehicle estimations by the two different approaches were in good agreement. When both EC and vehicle-derived organic matter (OM) (assuming an OM-to-OC ratio of 1.4) are considered, vehicular carbonaceous aerosols contributed ~ 7.3 μg m-3 to PM2.5, accounting for ~ 20% of PM2.5 mass (38.3 μg m-3) during winter, when Hong Kong received significant influence of air pollutants transported from outside, and ~ 30% of PM2.5 mass (28.2 μg m-3) during summertime, when local emission sources were dominant. A reduction of 3.8 μg m-3 in vehicular carbonaceous aerosols was estimated during 07:00-11:00 (i.e., rush hours on weekdays) on Sundays and public holidays. This could mainly be attributed to less on-road public transportation (e.g., diesel-powered buses) in comparison with non-holidays. These

  20. Air quality modelling of vehicular emissions under GIS environment, for Coimbatore Corporation (west zone).

    PubMed

    Meenambal, T; Palani, P K; Dhandapani, N; Manikumar, R

    2005-07-01

    Environment pollution is simply a consequence of the anthropogenic activities of mankind. Emissions from the motor vehicles have been shown to be the major contribution to air pollution in the urban environment. The major pollutants are SO2, No(x) and CO. Of these pollutants carbon monoxide is of utmost importance as the pollutant has serious toxicological effects and proves fatal on mankind. In this study, the concentration of Carbon-Monoxide (CO) along and near the major roads at Coimbatore west zone due to vehicular emission is predicted using the Air Quality Modelling Software Called CALINE4 model. Using MAPINFO GIS environment, thematic maps of the CO pollution at different receptor heights were prepared. Also, the concentration of CO for the year 2004 at 1.8 m height and 5 m height were predicted. In addition, to create awareness about the air quality, suggestions had been given to take suitable measures from engineering and environmental point of view. PMID:16841458

  1. Marvin: MARtian Vehicular INvestigator A Proposal for a Long-Range Pressurized Rover

    NASA Astrophysics Data System (ADS)

    1999-01-01

    NASA is planning manned missions to Mars in the near future. In order to fully exploit the available time on the surface for exploration, a roving vehicle is necessary. A nine-member student design team from the Wichita State University Department of Aerospace Engineering developed the MARtian Vehicular INvestigator (MARVIN) a manned, pressurized, long distance rover. In order to meet the unique requirements for successful operation in the harsh Martian environment a four wheeled, rover was designed with a composite pressure vessel six meters long and 2.5 meters in diameter. The rover is powered by twin proton exchange membrane fuel cells which provide electricity to the drive motors and onboard systems. The MARVIN concept is expected to have a 1500 km range with a maximum speed of 25 km/hr and a 14-day endurance.

  2. QoS-Oriented High Dynamic Resource Allocation in Vehicular Communication Networks

    PubMed Central

    2014-01-01

    Vehicular ad hoc networks (VANETs) are emerging as new research area and attracting an increasing attention from both industry and research communities. In this context, a dynamic resource allocation policy that maximizes the use of available resources and meets the quality of service (QoS) requirement of constraining applications is proposed. It is a combination of a fair packet scheduling policy and a new adaptive QoS oriented call admission control (CAC) scheme based on the vehicle density variation. This scheme decides whether the connection request is to be admitted into the system, while providing fair access and guaranteeing the desired throughput. The proposed algorithm showed good performance in testing in real world environment. PMID:24616639

  3. QoS-oriented high dynamic resource allocation in vehicular communication networks.

    PubMed

    Bejaoui, Tarek

    2014-01-01

    Vehicular ad hoc networks (VANETs) are emerging as new research area and attracting an increasing attention from both industry and research communities. In this context, a dynamic resource allocation policy that maximizes the use of available resources and meets the quality of service (QoS) requirement of constraining applications is proposed. It is a combination of a fair packet scheduling policy and a new adaptive QoS oriented call admission control (CAC) scheme based on the vehicle density variation. This scheme decides whether the connection request is to be admitted into the system, while providing fair access and guaranteeing the desired throughput. The proposed algorithm showed good performance in testing in real world environment. PMID:24616639

  4. Vehicular Traffic Flow Controlled by Traffic Light on a Street with Open Boundaries

    NASA Astrophysics Data System (ADS)

    Mhirech, Abdelaziz; Ismaili, Assia Alaoui

    2013-08-01

    The Nagel-Schreckenberg (NS) cellular automata (CA) model for describing the vehicular traffic flow in a street with open boundaries is studied. To control the traffic flow, a traffic signalization light operating for a fixed-time scheme is placed in the middle of the street. Extensive Monte Carlo simulations are carried out to calculate various model characteristics. Essentially, we investigate the formation of the cars queue behind traffic light dependence on the duration of green light Tg, injecting and extracting probabilities α and β, respectively. Two phases of average training queues were found. Besides, the dependence of car accident probability per site and per time step on Tg, α and β is computed.

  5. Vehicular traffic flow at an intersection with the possibility of turning

    NASA Astrophysics Data System (ADS)

    Ebrahim Foulaadvand, M.; Belbasi, Somayyeh

    2011-03-01

    We have developed a Nagel-Schreckenberg cellular automata model for describing a vehicular traffic flow at a single intersection. A set of traffic lights operating in a fixed-time scheme controls the traffic flow. An open boundary condition is applied to the streets each of which conducts a unidirectional flow. Streets are single lane and cars can turn upon reaching to the intersection with prescribed probabilities. Extensive Monte Carlo simulations are carried out to find the model flow characteristics. In particular, we investigate the flow dependence on signalization parameters, turning probabilities and input rates. It is shown that for each set of parameters, there exists a plateau region inside which the total outflow from the intersection remains almost constant. We also compute total waiting time of vehicles per cycle behind red lights for various control parameters.

  6. An Autonomous Control System for an Intra-Vehicular Spacecraft Mobile Monitor Prototype

    NASA Technical Reports Server (NTRS)

    Dorais, Gregory A.; Desiano, Salvatore D.; Gawdiak, Yuri; Nicewarner, Keith

    2003-01-01

    This paper presents an overview of an ongoing research and development effort at the NASA Ames Research Center to create an autonomous control system for an internal spacecraft autonomous mobile monitor. It primary functions are to provide crew support and perform intra- vehicular sensing activities by autonomously navigating onboard the International Space Station. We describe the mission roles and high-level functional requirements for an autonomous mobile monitor. The mobile monitor prototypes, of which two are operational and one is actively being designed, physical test facilities used to perform ground testing, including a 3D micro-gravity test facility, and simulators are briefly described. We provide an overview of the autonomy framework and describe each of its components, including those used for automated planning, goal-oriented task execution, diagnosis, and fault recovery. A sample mission test scenario is also described.

  7. Predicting Fatigue for Isolated Joints While Wearing an Extra-Vehicular Mobility Unit (EMU)

    NASA Technical Reports Server (NTRS)

    Maida, James C.; Gonzalez, L. Javier; Rajulu, Sudhaker; Miles, Erica

    2001-01-01

    To work outside a space craft, humans must wear a protective suit. The required suit pressurization creates additional resistance for the wearer while performing work. How much does the suit effect work and fatigue? To answer these questions, dynamic torque was collected for the shoulder, elbow and wrist for six subjects in an Extra-vehicular Mobility Unit (EMU). In order to quantify fatigue, the subjects were to exert maximum voluntary torque for five minutes or until their maximum fell below 50% of their initial maximum for three consecutive repetitions. Using the collected torque and time data, logarithmic based functions were derived to estimate torque decay to within an absolute error of 20%. These results will be used in the development of a generalized tool for prediction of maximum available torque over time for humans using the current EMU.

  8. Impact of Texting Laws on Motor Vehicular Fatalities in the United States

    PubMed Central

    Ferdinand, Alva O.; Blackburn, Justin L.; Morrisey, Michael; Nelson, Leonard

    2014-01-01

    Using a panel study design, we examined the effects of different types of texting bans on motor vehicular fatalities. We used the Fatality Analysis Reporting System and a difference-in-differences approach to examine the incidence of fatal crashes in 2000 through 2010 in 48 US states with and without texting bans. Age cohorts were constructed to examine the impact of these bans on age-specific traffic fatalities. Primarily enforced laws banning all drivers from texting were significantly associated with a 3% reduction in traffic fatalities in all age groups, and those banning only young drivers from texting had the greatest impact on reducing deaths among those aged 15 to 21 years. Secondarily enforced restrictions were not associated with traffic fatality reductions in any of our analyses. PMID:24922151

  9. A modal approach to vehicular emissions and fuel consumption model development.

    PubMed

    Hung, Wing-Tat; Tong, Hing-Yan; Cheung, Chun-Shun

    2005-10-01

    This study reports on the analysis of emissions and fuel consumption from motor vehicles using a modal approach. The four standard driving modes are idling, accelerating, cruising, and decelerating. On-road data were collected using instrumented test vehicles traveling many times through the urban areas of Hong Kong. A model was developed for estimating vehicular fuel consumption and emissions as a function of instantaneous speed and driving mode. Piecewise interpolation functions were proposed for each nonidling driving mode. Idling emission and fuel consumption rates were estimated as negative exponential functions of idling time. Preliminary modeling results showed good agreements for the test vehicles and indicated that the on-road measurements are feasible for the development of modal emission and fuel consumption models. PMID:16295267

  10. Evaluating the performance of vehicular platoon control under different network topologies of initial states

    NASA Astrophysics Data System (ADS)

    Li, Yongfu; Li, Kezhi; Zheng, Taixiong; Hu, Xiangdong; Feng, Huizong; Li, Yinguo

    2016-05-01

    This study proposes a feedback-based platoon control protocol for connected autonomous vehicles (CAVs) under different network topologies of initial states. In particularly, algebraic graph theory is used to describe the network topology. Then, the leader-follower approach is used to model the interactions between CAVs. In addition, feedback-based protocol is designed to control the platoon considering the longitudinal and lateral gaps simultaneously as well as different network topologies. The stability and consensus of the vehicular platoon is analyzed using the Lyapunov technique. Effects of different network topologies of initial states on convergence time and robustness of platoon control are investigated. Results from numerical experiments demonstrate the effectiveness of the proposed protocol with respect to the position and velocity consensus in terms of the convergence time and robustness. Also, the findings of this study illustrate the convergence time of the control protocol is associated with the initial states, while the robustness is not affected by the initial states significantly.

  11. Power management strategy for vehicular-applied hybrid fuel cell/battery power system

    NASA Astrophysics Data System (ADS)

    Li, Xiangjun; Xu, Liangfei; Hua, Jianfeng; Lin, Xinfan; Li, Jianqiu; Ouyang, Minggao

    In this paper, a control strategy for a hybrid PEM (proton exchange membrane) fuel cell/BES (battery energy system) vehicular power system is presented. The strategy, based on fuzzy logic control, incorporates the slow dynamics of fuel cells and the state of charge (SOC) of the BES. Fuel cell output power was determined according to the driving load requirement and the SOC, using fuzzy dynamic decision-making and fuzzy self-organizing concepts. An analysis of the simulation results was conducted using Matlab/Simulink/Stateflow software in order to verify the effectiveness of the proposed control strategy. It was confirmed that the control scheme can be used to improve the operational efficiency of the hybrid power system.

  12. When You Smoke, They Smoke: Children's Rights and Opinions about Vehicular Smoking Bans

    NASA Astrophysics Data System (ADS)

    Tymko, Morgan Anne

    International law guarantees every person the highest attainable standard of health, and this should include protection from the health risks of environmental tobacco smoke. As knowledge of these risks has increased, there has been an incremental expansion of smoking bans in public space. Since 2007, they have extended to the private space of the motor vehicle in an attempt to protect child passengers. This thesis aimed to understand the views and interests of children and youth on vehicular smoking bans, and the extent to which these have been sought after and considered in previous discussions of this policy initiative in Canada. A print media analysis found a lack of concern for children's perspectives. Rights, when considered, were generally those of adults. In focus groups, children discussed the unfairness of exposure to smoke in any space, but especially within the motor vehicle, and articulated a desire for increased participation in decision-making. Keywords: Smoking, smoking bans, rights, children's opinions, vehicles, Canada.

  13. An examination of the environmental attributes associated with pedestrian-vehicular crashes near public schools.

    PubMed

    Clifton, Kelly J; Kreamer-Fults, Kandice

    2007-07-01

    This paper examines pedestrian-vehicular crashes in the vicinity of public schools, the severity of injuries sustained, and their relationship to the physical and social attributes near the schools. Multivariate models of crash severity and crash risk exposure were estimated as a function of social and physical characteristics of the area immediately surrounding schools in Baltimore City, Maryland. Results show that the presence of a driveway or turning bay on the school entrance decreases both crash occurrence and injury severity. Conversely, the presence of recreational facilities on the school site is positively associated with crash occurrence and injury severity of crashes. Findings related to neighborhood characteristics were mixed but the significant variables - transit access, commercial access, and population density - are generally associated with increased pedestrian demand and should be interpreted with care. The results of this study are relevant for Safe Routes to School projects and point to areas meriting further study. PMID:17174259

  14. Automatic antenna switching design for Extra Vehicular Activity (EVA) communication system

    NASA Technical Reports Server (NTRS)

    Randhawa, Manjit S.

    1987-01-01

    An Extra Vehicular Activity (EVA) crewmember had two-way communications with the space station in the Ku-band frequency (12 to 18 GHz). The maximum range of the EVA communications link with the space station is approximately one kilometer for nominal values for transmitter power, antenna gains, and receiver noise figure. The EVA Communications System, that will continue to function regardless of the astronaut's position and orientation, requires an antenna system that has full spherical coverage. Three or more antennas that can be flush mounted on the astronaut's space suit (EMU) and/or his propulsive backpack (MMU), will be needed to provide the desired coverage. As the astronaut moves in the space station, the signal received by a given EVA antenna changes. An automatic antenna switching system is needed that will switch the communication system to the antenna with the largest signal strength. A design for automatic antenna switching is presented and discussed.

  15. RSSI-Based User Centric Anonymization for Location Privacy in Vehicular Networks

    NASA Astrophysics Data System (ADS)

    Wei, Yu-Chih; Chen, Yi-Ming; Shan, Hwai-Ling

    In Vehicular Networks, for enhancing driving safety as well as supporting other applications, vehicles periodically broadcast safety messages with their precise position information to neighbors. However, these broadcast messages make it easy to track specific vehicles and will likely lead to compromise of personal privacy. Unfortunately, current location privacy enhancement methodologies in VANET, including Pseudonymization, K-anonymity, Random silent period, Mix-zones and path confusion, all suffer some shortcomings. In this paper, we propose a RSSI (Received Signal Strength Indicator)-based user centric anonymization model, which can significantly enhance the location privacy and at the same time ensure traffic safety. Simulations are performed to show the advantages of the proposed method. In comparison with traditional random silent period method, our method can increase at least 47% of anonymity in both simple and correlation tracking.

  16. Analysis and Proposal of Position-Based Routing Protocols for Vehicular Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Okada, Hiraku; Takano, Akira; Mase, Kenichi

    One of the most promising applications of a mobile ad hoc network is a vehicular ad hoc network (VANET). Each vehicle is aware of its position information by GPS or other methods, so position-based routing is a useful approach in VANET. The position-based routing protocol can be classified roughly into a next-hop forwarding method and a directed flooding method. We evaluate performance of both methods by analytic approach and compare them in this paper. From the evaluation results, we conclude that it is effective for the position-based routing to choose either the next-hop forwarding method or the directed flooding method according to the environment. Then we propose the hybrid transmission method which can select one of them according to the environment, and clarify that the proposed method can keep the packet delivery ratio at a high level and reduce the delay time.

  17. A Group Based Key Sharing and Management Algorithm for Vehicular Ad Hoc Networks

    PubMed Central

    Moharram, Mohammed Morsi; Azam, Farzana

    2014-01-01

    Vehicular ad hoc networks (VANETs) are one special type of ad hoc networks that involves vehicles on roads. Typically like ad hoc networks, broadcast approach is used for data dissemination. Blind broadcast to each and every node results in exchange of useless and irrelevant messages and hence creates an overhead. Unicasting is not preferred in ad-hoc networks due to the dynamic topology and the resource requirements as compared to broadcasting. Simple broadcasting techniques create several problems on privacy, disturbance, and resource utilization. In this paper, we propose media mixing algorithm to decide what information should be provided to each user and how to provide such information. Results obtained through simulation show that fewer number of keys are needed to share compared to simple broadcasting. Privacy is also enhanced through this approach. PMID:24587749

  18. Vehicular ad hoc network for a surveillance system using multifrequency band enhancement

    NASA Astrophysics Data System (ADS)

    Bunruangses, Montree; Sunat, Khamron; Mitatha, Somsak; Yupapin, Preecha P.

    2010-09-01

    We present a new design of a surveillance system via a vehicular ad hoc network (VANET) integrated by a 3-G or 4-G cellular wireless network. We propose dense wavelength division multiplexing wavelength enhancement for increasing the channel capacity and signal security. Increase in the number of channels can be obtained by increasing the wavelength density. Signal security is introduced by a specific wavelength filter controlled by the central operator. Optical communication wavelength enhancement is reviewed. The advantage of this proposed system is that it can easily be implemented and incorporated into the existing communication link in either a cellular or ad hoc wireless system, where signal security and hence privacy can be provided.

  19. Vehicular emissions and fuel consumption estimation in passer IV. Research report

    SciTech Connect

    Chaudhary, N.A.

    1995-04-01

    Gasoline consumed by vehicles traveling within urban signalized networks constitutes a large portion of the total fuel usage in the United States. In addition, pollutants emitted by these vehicles degrade urban air quality. It is well known that the optimal coordination of traffic signals on urban signalized arterials improves traffic flow and reduces gasoline consumption and vehicular emissions. The research performed in this project incorporated fuel consumption and emissions estimation procedures into PASSER IV, a program for optimizing bandwidth-based signal timings in traffic networks. The enhanced PASSER IV software will allow Traffic Engineers to better assess the impacts of alternate signal timing plans on fuel consumption and emissions of vehicles traveling in a signalized network.

  20. Plant-Damage Assessment Technique for Evaluating Military Vehicular Impacts to Vegetation in the Mojave Desert

    SciTech Connect

    D. J. Hansen; W. K. Ostler

    2001-09-01

    A new plant damage assessment technique was developed by plant ecologists from Bechtel Nevada at the U.S. Department of Energy's National Security Administration Nevada Operations Office and funded by the Strategic Environmental Research and Development Program Project CS-1131 in cooperation with the U.S. Army's National Training Center (NTC) at Fort Irwin, California. The technique establishes linear transects the width of vehicle tracts from evidence of vehicle tracks in the soil (usually during a prior training rotation period of 30 days or since the last rain or wind storm), and measures vegetation within the tracks to determine the area of plant parts being run over, the percent of the impacted parts damaged, and the percent of impacted parts expected to recover. It documents prior-damage classes based on estimated of damage that plants have apparently experienced previously (as assessed from field indicators of damage such as plant shape and height). The technique was used to evaluate different vehicle types (rubber-tire wheels vs. tracks) in six area at the NTC with different soils and training intensity levels. The technique provides tabular data that can be sorted and queried to show a variety of trends related to military vehicular impacts. The technique also appears suitable for assessing other non-military off-road traffic impacts. Findings report: (1) differences in plant sensitivity of different vehicular impacts, (2) plant cover and density by species and training area, (3) the degree to which wheels have less impact than tracks, and (4) the mean percent survival is inversely proportional to the degree of prior damage received by the vegetation (i.e., plants previously impacted have lower survival than plants not previously impacted).

  1. Estimation of vehicular emissions using dynamic emission factors: A case study of Delhi, India

    NASA Astrophysics Data System (ADS)

    Mishra, Dhirendra; Goyal, P.

    2014-12-01

    The estimation of vehicular emissions depends mainly on the values of emission factors, which are used for the development of a comprehensive emission inventory of vehicles. In this study the variations of emission factors as well as the emission rates have been studied in Delhi. The implementation of compressed natural gas (CNG), in the diesel and petrol, public vehicles in the year 2001 has changed the complete air quality scenario of Delhi. The dynamic emission factors of criteria pollutants viz. carbon monoxide (CO), nitrogen oxide (NOx) and particulate matter (PM10) for all types of vehicles have been developed after, which are based on the several factors such as regulated emission limits, number of vehicle deterioration, vehicle increment, vehicle age etc. These emission factors are found to be decreased continuously throughout the study years 2003-2012. The International Vehicle Emissions (IVE) model is used to estimate the emissions of criteria pollutants by utilizing a dataset available from field observations at different traffic intersections in Delhi. Thus the vehicular emissions, based on dynamic emission factors have been estimated for the years 2003-2012, which are found to be comparable with the monitored concentrations at different locations in Delhi. It is noticed that the total emissions of CO, NOx, and PM10 are increased by 45.63%, 68.88% and 17.92%, respectively up to the year 2012 and the emissions of NOx and PM10 are grown continuously with an annual average growth rate of 5.4% and 1.7% respectively.

  2. Estimation of vehicular emission inventories in China from 1980 to 2005

    NASA Astrophysics Data System (ADS)

    Cai, Hao; Xie, Shaodong

    Multi-year inventories of vehicular emissions at a high spatial resolution of 40 km×40 km were established in China using the GIS methodology for the period 1980-2005, based on provincial statistical data from yearbooks regarding vehicles and roads, and on the emission factors for each vehicle category in each province calculated by COPERT III program. Results showed that the emissions of CH 4, CO, CO 2, NMVOC, NO x, PM 10, and SO 2 increased from 5, 1066, 19 893, 169, 174, 26, and 16 thousand tons in 1980 to 377, 36 197, 674 629, 5911, 4539, 983, and 484 thousand tons in 2005 at an annual average rate of 19%, 15%, 15%, 15%, 14%, 16%, and 15%, respectively. Statistical analysis of vehicular emissions and GDP showed that they were well positively correlated, which revealed that increase of pollutant emissions has been accompanying the growth of GDP. Spatial distribution of pollutant emissions was rather unbalanced: over three-quarters of the total emissions concentrated in developed regions of China's southeastern, northern and central areas covering only 35.2% of China's territory, while the remaining emissions were distributed over the southwestern, northwestern and northeastern regions covering as much as 64.8% of the territory. In 2005, the Beijing-Tianjin-Hebei region, the Yangtze River Delta, and the Pearl River Delta covering only 2.3%, 2.2%, and 1.9%, respectively, of the territory, generated about 10%, 19%, and 12%, respectively, of the total emissions. Since 1990, motorcycles have been the major contributors to the CH 4, CO, NMVOC, and PM 10 emissions, due to the large population. Heavy-duty vans were the major contributors to the NO x and SO 2 emissions because of high emission factors. Passenger cars contributed about one third of the emissions of each pollutant. Contributions of vehicle categories to emissions varied from province to province, due to the diversity of vehicle compositions among provinces.

  3. The effects of vehicular exhaust buoyancy during worst case pollution scenarios near roadways

    SciTech Connect

    Held, A.E.; Chang, D.P.Y.; Carroll, J.J.

    1998-12-31

    The California Department of Transportation (CALTRANS) has been using CALINE4, a gaussian finite line-source dispersion model, to estimate air pollutant concentrations near roadways given an estimate of traffic flow rates, vehicular emission factors, roadway geometry, and local meteorology. Modelers have typically used CALINE4 to simulate low wind near parallel thermally stable conditions to estimate a worst case pollution scenario (i.e., highest predicted pollutant concentrations) for a proposed roadway. In October 1995, the University of California, Davis (UCD), in conjunction with the CALTRANS Environmental Program, began a two-year investigation to determine if CALINE4 was adequately predicting CO concentrations during worst case meteorological conditions. Based on physical reasoning and a literature review of several highway dispersion studies conducted in the late 1970`s, it was reasoned that gaussian models may over-predict CO concentrations during worst case scenarios because these models do not adequately parameterize the increased vertical dispersion of pollutants due to vehicular emission buoyancy. To explore the role that exhaust buoyancy plays in roadway pollutant dispersion, a series of experiments were conducted on I-80 (near Sacramento) during winter pre-dawn commute hours. Results of the dispersion studies were inconclusive due to difficulty in capturing sufficiently low wind speed conditions during the sampling effort, however, in a compare-contrast study of field measurements versus CALINE4 predictions it was verified that CALINE4 adequately predicts both the magnitude and qualitative shape of non-worst case pollution scenarios. In addition, based on integrated mass flux from downwind CO concentration and wind profiles it was found that the use of CT-EMFAC, a regional scale emission factor model, overpredicted observed modal emissions by as much as 250 to 480%.

  4. Impact of vehicular traffic emissions on particulate-bound PAHs: Levels and associated health risks

    NASA Astrophysics Data System (ADS)

    Slezakova, Klara; Castro, Dionísia; Delerue–Matos, Cristina; Alvim–Ferraz, Maria da Conceição; Morais, Simone; Pereira, Maria do Carmo

    2013-06-01

    Considering vehicular transport as one of the most health-relevant emission sources of urban air, and with aim to further understand its negative impact on human health, the objective of this work was to study its influence on levels of particulate-bound PAHs and to evaluate associated health risks. The 16 PAHs considered by USEPA as priority pollutants, and dibenzo[a,l]pyrene associated with fine (PM2.5) and coarse (PM2.5-10) particles were determined. The samples were collected at one urban site, as well as at a reference place for comparison. The results showed that the air of the urban site was more seriously polluted than at the reference one, with total concentrations of 17 PAHs being 2240% and 640% higher for PM2.5 and PM2.5-10, respectively; vehicular traffic was the major emission source at the urban site. PAHs were predominantly associated with PM2.5 (83% to 94% of ΣPAHs at urban and reference site, respectively) with 5 rings PAHs being the most abundant groups of compounds at both sites. The risks associated with exposure to particulate PAHs were evaluated using the TEF approach. The estimated value of lifetime lung cancer risks exceeded the health-based guideline levels, thus demonstrating that exposure to PM2.5-bound PAHs at levels found at urban site might cause potential health risks. Furthermore, the results showed that evaluation of benzo[a]pyrene (regarded as a marker of the genotoxic and carcinogenic PAHs) alone would probably underestimate the carcinogenic potential of the studied PAH mixtures.

  5. Development of improved processing and evaluation methods for high reliability structural ceramics for advanced heat engine applications, Phase 1. Final report

    SciTech Connect

    Pujari, V.K.; Tracey, D.M.; Foley, M.R.; Paille, N.I.; Pelletier, P.J.; Sales, L.C.; Wilkens, C.A.; Yeckley, R.L.

    1993-08-01

    The program goals were to develop and demonstrate significant improvements in processing methods, process controls and non-destructive evaluation (NDE) which can be commercially implemented to produce high reliability silicon nitride components for advanced heat engine applications at temperatures to 1,370{degrees}C. The program focused on a Si{sub 3}N{sub 4}-4% Y{sub 2}O{sub 3} high temperature ceramic composition and hot-isostatic-pressing as the method of densification. Stage I had as major objectives: (1) comparing injection molding and colloidal consolidation process routes, and selecting one route for subsequent optimization, (2) comparing the performance of water milled and alcohol milled powder and selecting one on the basis of performance data, and (3) adapting several NDE methods to the needs of ceramic processing. The NDE methods considered were microfocus X-ray radiography, computed tomography, ultrasonics, NMR imaging, NMR spectroscopy, fluorescent liquid dye penetrant and X-ray diffraction residual stress analysis. The colloidal consolidation process route was selected and approved as the forming technique for the remainder of the program. The material produced by the final Stage II optimized process has been given the designation NCX 5102 silicon nitride. According to plan, a large number of specimens were produced and tested during Stage III to establish a statistically robust room temperature tensile strength database for this material. Highlights of the Stage III process demonstration and resultant database are included in the main text of the report, along with a synopsis of the NCX-5102 aqueous based colloidal process. The R and D accomplishments for Stage I are discussed in Appendices 1--4, while the tensile strength-fractography database for the Stage III NCX-5102 process demonstration is provided in Appendix 5. 4 refs., 108 figs., 23 tabs.

  6. Generation of Soluble Advanced Glycation End Products Receptor (sRAGE)-Binding Ligands during Extensive Heat Treatment of Whey Protein/Lactose Mixtures Is Dependent on Glycation and Aggregation.

    PubMed

    Liu, Fahui; Teodorowicz, Małgorzata; Wichers, Harry J; van Boekel, Martinus A J S; Hettinga, Kasper A

    2016-08-24

    Heating of protein- and sugar-containing materials is considered the primary factor affecting the formation of advanced glycation end products (AGEs). This study aimed to investigate the influence of heating conditions, digestion, and aggregation on the binding capacity of AGEs to the soluble AGE receptor (sRAGE). Samples consisting of mixtures of whey protein and lactose were heated at 130 °C. An in vitro infant digestion model was used to study the influence of heat treatment on the digestibility of whey proteins. The amount of sRAGE-binding ligands before and after digestion was measured by an ELISA-based sRAGE-binding assay. Water activity did not significantly affect the extent of digestibility of whey proteins dry heated at pH 5 (ranging from 3.3 ± 0.2 to 3.6 ± 0.1% for gastric digestion and from 53.5 ± 1.5 to 64.7 ± 1.1% for duodenal digestion), but there were differences in cleavage patterns of peptides among the samples heated at different pH values. Formation of sRAGE-binding ligands depended on the formation of aggregates and was limited in the samples heated at pH 5. Moreover, the sRAGE-binding activity of digested sample was changed by protease degradation and correlated with the digestibility of samples. In conclusion, generation of sRAGE-binding ligands during extensive heat treatment of whey protein/lactose mixtures is limited in acidic heating condition and dependent on glycation and aggregation. PMID:27460534

  7. Vehicular Traffic–Related Polycyclic Aromatic Hydrocarbon Exposure and Breast Cancer Incidence: The Long Island Breast Cancer Study Project (LIBCSP)

    PubMed Central

    Mordukhovich, Irina; Beyea, Jan; Herring, Amy H.; Hatch, Maureen; Stellman, Steven D.; Teitelbaum, Susan L.; Richardson, David B.; Millikan, Robert C.; Engel, Lawrence S.; Shantakumar, Sumitra; Steck, Susan E.; Neugut, Alfred I.; Rossner, Pavel; Santella, Regina M.; Gammon, Marilie D.

    2015-01-01

    Background Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants, known human lung carcinogens, and potent mammary carcinogens in laboratory animals. However, the association between PAHs and breast cancer in women is unclear. Vehicular traffic is a major ambient source of PAH exposure. Objectives Our study aim was to evaluate the association between residential exposure to vehicular traffic and breast cancer incidence. Methods Residential histories of 1,508 participants with breast cancer (case participants) and 1,556 particpants with no breast cancer (control participants) were assessed in a population-based investigation conducted in 1996–1997. Traffic exposure estimates of benzo[a]pyrene (B[a]P), as a proxy for traffic-related PAHs, for the years 1960–1995 were reconstructed using a model previously shown to generate estimates consistent with measured soil PAHs, PAH–DNA adducts, and CO readings. Associations between vehicular traffic exposure estimates and breast cancer incidence were evaluated using unconditional logistic regression. Results The odds ratio (95% CI) was modestly elevated by 1.44 (0.78, 2.68) for the association between breast cancer and long-term 1960–1990 vehicular traffic estimates in the top 5%, compared with below the median. The association with recent 1995 traffic exposure was elevated by 1.14 (0.80, 1.64) for the top 5%, compared with below the median, which was stronger among women with low fruit/vegetable intake [1.46 (0.89, 2.40)], but not among those with high fruit/vegetable intake [0.92 (0.53, 1.60)]. Among the subset of women with information regarding traffic exposure and tumor hormone receptor subtype, the traffic–breast cancer association was higher for those with estrogen/progesterone-negative tumors [1.67 (0.91, 3.05) relative to control participants], but lower among all other tumor subtypes [0.80 (0.50, 1.27) compared with control participants]. Conclusions In our population-based study

  8. Experimental investigations on decay heat removal in advanced nuclear reactors using single heater rod test facility: Air alone in the annular gap

    SciTech Connect

    Bopche, Santosh B.; Sridharan, Arunkumar

    2010-11-15

    During a loss of coolant accident in nuclear reactors, radiation heat transfer accounts for a significant amount of the total heat transfer in the fuel bundle. In case of heavy water moderator nuclear reactors, the decay heat of a fuel bundle enclosed in the pressure tube and outer concentric calandria tube can be transferred to the moderator. Radiation heat transfer plays a significant role in removal of decay heat from the fuel rods to the moderator, which is available outside the calandria tube. A single heater rod test facility is designed and fabricated as a part of preliminary investigations. The objective is to anticipate the capability of moderator to remove decay heat, from the reactor core, generated after shut down. The present paper focuses mainly on the role of moderator in removal of decay heat, for situation with air alone in the annular gap of pressure tube and calandria tube. It is seen that the naturally aspirated air is capable of removing the heat generated in the system compared to the standstill air or stagnant water situations. It is also seen that the flowing moderator is capable of removing a greater fraction of heat generated by the heater rod compared to a stagnant pool of boiling moderator. (author)

  9. A multiclass vehicular dynamic traffic flow model for main roads and dedicated lanes/roads of multimodal transport network

    SciTech Connect

    Sossoe, K.S.; Lebacque, J-P.

    2015-03-10

    We present in this paper a model of vehicular traffic flow for a multimodal transportation road network. We introduce the notion of class of vehicles to refer to vehicles of different transport modes. Our model describes the traffic on highways (which may contain several lanes) and network transit for pubic transportation. The model is drafted with Eulerian and Lagrangian coordinates and uses a Logit model to describe the traffic assignment of our multiclass vehicular flow description on shared roads. The paper also discusses traffic streams on dedicated lanes for specific class of vehicles with event-based traffic laws. An Euler-Lagrangian-remap scheme is introduced to numerically approximate the model’s flow equations.

  10. Wireless Video System for Extra Vehicular Activity in the International Space Station and Space Shuttle Orbiter Environment

    NASA Technical Reports Server (NTRS)

    Loh, Yin C.; Boster, John; Hwu, Shian; Watson, John C.; deSilva, Kanishka; Piatek, Irene (Technical Monitor)

    1999-01-01

    The Wireless Video System (WVS) provides real-time video coverage of astronaut extra vehicular activities during International Space Station (ISS) assembly. The ISS wireless environment is unique due to the nature of the ISS structure and multiple RF interference sources. This paper describes how the system was developed to combat multipath, blockage, and interference using an automatic antenna switching system. Critical to system performance is the selection of receiver antenna installation locations determined using Uniform Geometrical Theory of Diffraction (GTD) techniques.

  11. Experiences with Extra-Vehicular Activities in Response to Critical ISS Contingencies

    NASA Technical Reports Server (NTRS)

    Van Cise, E. A.; Kelly, B. J.; Radigan, J. P.; Cranmer, C. W.

    2016-01-01

    The maturation of the International Space Station (ISS) design from the proposed Space Station Freedom to today's current implementation resulted in external hardware redundancy vulnerabilities in the final design. Failure to compensate for or respond to these vulnerabilities could put the ISS in a posture to where it could no longer function as a habitable space station. In the first years of ISS assembly, these responses were to largely be addressed by the continued resupply and Extra-Vehicular Activity (EVA) capabilities of the Space Shuttle. Even prior to the decision to retire the Space Shuttle, it was realized that ISS needed to have its own capability to be able to rapidly repair or replace external hardware without needing to wait for the next cargo resupply mission. As documented in a previous publicatoin5, in 2006 development was started to baseline Extra- Vehicular Activity (EVA, or spacewalk) procedures to replace hardware components whose failure would expose some of the ISS vulnerabilities should a second failure occur. This development work laid the groundwork for the onboard crews and the ground operations and engineering teams to be ready to replace any of this failed hardware. In 2010, this development work was put to the test when one of these pieces of hardware failed. This paper will provide a brief summary of the planning and processes established in the original Contingency EVA development phase. It will then review how those plans and processes were implemented in 2010, highlighting what went well as well as where there were deficiencies between theory and reality. This paper will show that the original approach and analyses, though sound, were not as thorough as they should have been in the realm of planning for next worse failures, for documenting Programmatic approval of key assumptions, and not pursuing sufficient engineering analysis prior to the failure of the hardware. The paper will further highlight the changes made to the

  12. Experiences with Extra-Vehicular Activities in Response to Critical ISS Contingencies

    NASA Technical Reports Server (NTRS)

    Van Cise, E. A.; Kelly, B. J.; Radigan, J. P.; Cranmer, C. W.

    2016-01-01

    The maturation of the International Space Station (ISS) design from the proposed Space Station Freedom to today's current implementation resulted in external hardware redundancy vulnerabilities in the final design. Failure to compensate for or respond to these vulnerabilities could put the ISS in a posture where it could no longer function as a habitable space station. In the first years of ISS assembly, these responses were to largely be addressed by the continued resupply and Extra-Vehicular Activity (EVA) capabilities of the Space Shuttle. Even prior to the decision to retire the Space Shuttle, it was realized that ISS needed to have its own capability to be able to rapidly repair or replace external hardware without needing to wait for the next cargo resupply mission. As documented in a previous publication, in 2006 development was started to baseline Extra-Vehicular Activity (EVA, or spacewalk) procedures to replace hardware components whose failure would expose some of the ISS vulnerabilities should a second failure occur. This development work laid the groundwork for the onboard crews and the ground operations and engineering teams to be ready to replace any of this failed hardware. In 2010, this development work was put to the test when one of these pieces of hardware failed. This paper will provide a brief summary of the planning and processes established in the original Contingency EVA development phase. It will then review how those plans and processes were implemented in 2010, highlighting what went well as well as where there were deficiencies between theory and reality. This paper will show that the original approach and analyses, though sound, were not as thorough as they should have been in the realm of planning for next worse failures, for documenting Programmatic approval of key assumptions, and not pursuing sufficient engineering analysis prior to the failure of the hardware. The paper will further highlight the changes made to the Contingency

  13. [Study on on-board measurements and modeling of vehicular emissions].

    PubMed

    Hu, Jing-nan; Hao, Ji-ming; Fu, Li-xin; Wu, Ye; Wang, Zhi-shi; Tang, U-wa

    2004-05-01

    It's a basic work to study the characteristics of vehicular emissions and give emission factors for development of vehicular emission inventory and decision-making of the control strategies. On-board emission measurements of on-road vehicles are regarded as important complementary to emission laboratory dynamometer tests. On-board exhaust emission measurements were conducted on seven samples of gasoline cars in a typical road in Macao, using AVL DiGas 4000 light five-gas analyzer. It was found that there was an obvious reduction of gaseous pollutant emissions from cars equipped with electronic fuel injection and three-way catalytic converter system (referred to as EFI cars in the following), compared to old carburetor cars. The average volume concentrations of CO, HC and NO of carburetor cars were 227 x 10(-6), 1.57% and 1477 x 10(-6), respectively, while those of EFI cars were 33 x 10(-6), 0.21% and 131 x 10(-6), which were about 1/11 through 1/7 of the former. However, there were high emissions during the cold start of EFI cars. The arithmetical mean concentrations of CO and NO emissions of EFI cars were calculated and their absolute values were predominantly contributed by high concentrations with low frequency. Furthermore, the emission factors of gasoline cars were estimated by test data, and at the same time, MOBILES model was used to calculate average emission factors of gasoline cars in Macao in 2000. The ratios between the results calculated by model and estimated by experiment data were in the range of 59%-139%, which would narrow into 68%-132% if only annual average emission factors were compared. The results suggest that EFI + TWC systems equipped in vehicles have good effect on the emission reduction, but catalytic converters are not activated during the cold start. Technical improvement of EFI cars, which could reduce the occurrence of high emissions with low frequency during the operation, would decrease their average level on exhaust emissions a lot

  14. Minimizing human health effects of urban air pollution through quantification and control of motor vehicular carbon monoxide (CO) in Lahore.

    PubMed

    Aziz, Amer; Bajwa, Ihsan Ullah

    2007-12-01

    Impact of urban air pollution has variety of focuses such as urban ecology, human health, economy, etc. But human health is always given priority. Air pollution is threat to the lives of people living in big cities of Pakistan. In Lahore only there die 1,250 people annually because of air pollution. A strong correlation exists between urban air pollution and human health in Lahore. Growth of COPD is highest among other air pollution borne diseases. Existing mass transit system (one of driving forces behind motor vehicular emission) in Lahore due to frequent stoppages, entering and exit in flow of traffic causes excess discharge of motor vehicular carbon monoxide (CO) which is a hazardous to human health. Quantification and enumeration of this discharge is essential for environmental management. The paper is an attempt to highlight human health effects of urban air pollution through correlation and regression analysis. Further it is focused upon quantifying excess motor vehicular carbon monoxide through application of simplified mobile emission model. In light of results emission control measures are recommended. PMID:17380418

  15. Metal accumulation in roadside soil in Melbourne, Australia: Effect of road age, traffic density and vehicular speed.

    PubMed

    De Silva, Shamali; Ball, Andrew S; Huynh, Trang; Reichman, Suzie M

    2016-01-01

    Concentrations of vehicular emitted heavy metals in roadside soils result in long term environmental damage. This study assessed the relationships between traffic characteristics (traffic density, road age and vehicular speed) and roadside soil heavy metals. Significant levels were recorded for Cd (0.06-0.59 mg/kg), Cr (18-29 mg/kg), Cu (4-12 mg/kg), Ni (7-20 mg/kg), Mn (92-599 mg/kg), Pb (16-144 mg/kg) and Zn (10.36-88.75 mg/kg), with Mn concentrations exceeding the Ecological Investigation Level. Significant correlations were found between roadside soil metal concentration and vehicular speed (R = 0.90), road age (R = 0.82) and traffic density (R = 0.68). Recently introduced metals in automotive technology (e.g. Mn and Sb) were higher in younger roads, while the metals present for many years (e.g. Cd, Cu, Pb, Zn) were higher in medium and old age roads confirming the risk of significant metal deposition and soil metal retention in roadside soils. PMID:26603093

  16. Provisioning Vehicular Services and Communications Based on a Bluetooth Sensor Network Deployment

    PubMed Central

    Perez-Diaz de Cerio, David; Valenzuela, José Luis

    2015-01-01

    It is very common to rule out Bluetooth as a suitable technology for vehicular communications. The reasons behind this decision usually result from misconceptions such as accepting that Bluetooth has a short application range, or assuming its connection setup is not fast enough to allow communication which involves high speed moving nodes. This paper refutes those assertions and proposes the use of Bluetooth not only for Infrastructure-to-Vehicle (I2V) or Road-to-Vehicle (R2V) communications, but also for Vehicle-to-Vehicle (V2V) or Vehicle-to-Infrastructure (V2I) communications. This novel proposal is based on using the remote name request procedure of the standard, combined with an adjustment and optimization of the parameters present in the inquiry and page procedures. The proposed modifications reduce the information exchange delay, thus making Bluetooth a suitable technology for high-speed vehicle communications. The feasibility of the proposed scheme has been validated through experimental tests conducted in different scenarios: laboratory, a real highway and a racing test circuit. There, the communication system was installed in a vehicle circulating at speeds of up to 250 km/h, whereas autonomous devices were disseminated throughout the road path to communicate with the on board devices obtaining satisfying results. PMID:26035350

  17. Impact of Vehicular Networks on Emergency Medical Services in Urban Areas

    PubMed Central

    Lee, Chun-Liang; Huang, Chung-Yuan; Hsiao, Tzu-Chien; Wu, Chun-Yen; Chen, Yaw-Chung; Wang, I.-Cheng

    2014-01-01

    The speed with which emergency personnel can provide emergency treatment is crucial to reducing death and disability among acute and critically ill patients. Unfortunately, the rapid development of cities and increased numbers of vehicles are preventing emergency vehicles from easily reaching locations where they are needed. A significant number of researchers are experimenting with vehicular networks to address this issue, but in most studies the focus has been on communication technologies and protocols, with few efforts to assess how network applications actually support emergency medical care. Our motivation was to search the literature for suggested methods for assisting emergency vehicles, and to use simulations to evaluate them. Our results and evidence-based studies were cross-referenced to assess each method in terms of cumulative survival ratio (CSR) gains for acute and critically ill patients. Simulation results indicate that traffic light preemption resulted in significant CSR increases of between 32.4% and 90.2%. Route guidance was found to increase CSRs from 14.1% to 57.8%, while path clearing increased CSRs by 15.5% or less. It is our hope that this data will support the efforts of emergency medical technicians, traffic managers, and policy makers. PMID:25365059

  18. Vehicular crash data used to rank intersections by injury crash frequency and severity.

    PubMed

    Liu, Yi; Li, Zongzhi; Liu, Jingxian; Patel, Harshingar

    2016-09-01

    This article contains data on research conducted in "A double standard model for allocating limited emergency medical service vehicle resources ensuring service reliability" (Liu et al., 2016) [1]. The crash counts were sorted out from comprehensive crash records of over one thousand major signalized intersections in the city of Chicago from 2004 to 2010. For each intersection, vehicular crashes were counted by crash severity levels, including fatal, injury Types A, B, and C for major, moderate, and minor injury levels, property damage only (PDO), and unknown. The crash data was further used to rank intersections by equivalent injury crash frequency. The top 200 intersections with the highest number of crash occurrences identified based on crash frequency- and severity-based scenarios are shared in this brief. The provided data would be a valuable source for research in urban traffic safety analysis and could also be utilized to examine the effectiveness of traffic safety improvement planning and programming, intersection design enhancement, incident and emergency management, and law enforcement strategies. PMID:27508245

  19. Characterization of VOC Emission from Materials in Vehicular Environment at Varied Temperatures: Correlation Development and Validation.

    PubMed

    Xiong, Jianyin; Yang, Tao; Tan, Jianwei; Li, Lan; Ge, Yunshan

    2015-01-01

    The steady state VOC concentration in automobile cabin is taken as a good indicator to characterize the material emission behaviors and evaluate the vehicular air quality. Most studies in this field focus on experimental investigation while theoretical analysis is lacking. In this paper we firstly develop a simplified physical model to describe the VOC emission from automobile materials, and then derive a theoretical correlation between the steady state cabin VOC concentration (Ca) and temperature (T), which indicates that the logarithm of Ca/T0.75 is in a linear relationship with 1/T. Experiments of chemical emissions in three car cabins at different temperatures (24°C, 29°C, 35°C) were conducted. Eight VOCs specified in the Chinese National Standard GB/T 27630-2011 were taken for analysis. The good agreement between the correlation and experimental results from our tests, as well as the data taken from literature demonstrates the effectiveness of the derived correlation. Further study indicates that the slope and intercept of the correlation follows linear association. With the derived correlation, the steady state cabin VOC concentration different from the test conditions can be conveniently obtained. This study should be helpful for analyzing temperature-dependent emission phenomena in automobiles and predicting associated health risks. PMID:26452146

  20. Vehicular motion in counter traffic flow through a series of signals controlled by a phase shift

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi; Tobita, Kazuhiro

    2012-10-01

    We study the dynamical behavior of counter traffic flow through a sequence of signals (traffic lights) controlled by a phase shift. There are two lanes for the counter traffic flow: the first lane is for east-bound vehicles and the second lane is for west-bound vehicles. The green-wave strategy is studied in the counter traffic flow where the phase shift of signals in the second lane has opposite sign to that in the first lane. A nonlinear dynamic model of the vehicular motion is presented by nonlinear maps at a low density. There is a distinct difference between the traffic flow in the first lane and that in the second lane. The counter traffic flow exhibits very complex behavior on varying the cycle time, the phase difference, and the split. Also, the fundamental diagram is derived by the use of the cellular automaton (CA) model. The dependence of east-bound and west-bound vehicles on cycle time, phase difference, and density is clarified.