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1

Thermally activated (“thermal”) battery technology  

Microsoft Academic Search

In this paper, the history of anode materials developed for use in thermally activated (“thermal”) batteries is presented. The chemistries (phases) and electrochemical characteristics (discharge mechanisms) of these materials are described, along with general thermodynamic properties, where available. This paper is the last of a five-part series that presents a general review of thermal-battery technology.

Ronald A. Guidotti; Patrick J. Masset

2008-01-01

2

Solar Thermal Energy Technology.  

National Technical Information Service (NTIS)

Solar Thermal Energy Technology announces on a monthly semimonthly basis the current worldwide research and development information that would expand the technology base required or advancement of solar thermal systems as significant energy source. Solar ...

1995-01-01

3

Solar Thermal Energy Technology.  

National Technical Information Service (NTIS)

Solar Thermal Energy Technology announces on a monthly semimonthly basis the current worldwide research and development information that would expand the technology base required or advancement of solar thermal systems as significant energy source. Solar ...

1988-01-01

4

Solar Thermal Energy Technology.  

National Technical Information Service (NTIS)

Solar Thermal Energy Technology announces on a monthly semimonthly basis the current worldwide research and development information that would expand the technology base required for advancement of solar thermal systems as significant energy source. Solar...

1985-01-01

5

Solar Thermal Energy Technology  

SciTech Connect

Solar Thermal Energy Technology (PST) announces on a bimonthly basis the current worldwide research and development information that would expand the technology base required for the advancement of solar thermal systems as a significant energy resource.

Cason, D.L.; Pitsenbarger, J. [eds.

1996-02-01

6

Thermally activated (“thermal”) battery technology  

Microsoft Academic Search

Thermally activated (“thermal”) batteries are primary batteries that use molten salts as electrolytes and employ an internal pyrotechnic (heat) source to bring the battery stack to operating temperatures. They are primarily used for military applications, such as missiles and ordnance, and in nuclear weapons. This paper discusses the development history and presents a general overview of this technology.

Ronald A. Guidotti; Patrick Masset

2006-01-01

7

Heat pipe thermal conditioning panel  

NASA Technical Reports Server (NTRS)

The technology involved in designing and fabricating a heat pipe thermal conditioning panel to satisfy a broad range of thermal control system requirements on NASA spacecraft is discussed. The design specifications were developed for a 30 by 30 inch heat pipe panel. The fundamental constraint was a maximum of 15 gradient from source to sink at 300 watts input and a flux density of 2 watts per square inch. The results of the performance tests conducted on the panel are analyzed.

Saaski, E. W.

1973-01-01

8

Thermal condition of Surtsey  

NASA Astrophysics Data System (ADS)

The island Surtsey was created by a submarine volcanic eruption which started on the 14th of November 1963, 21 km southwest of the Westman Islands. Volcanic activity continued in this area for nearly 4 years. During the summer of 1979 a 181 m deep continuously cored borehole was drilled on the Surtsey island. Several temperature profiles have been measured in the hole since 1979. The results of these temperature measurements are used as the basis for a discussion of the thermal condition of Surtsey. The hypothesis that intrusions rather than pillow lavas are responsible for the excess heat content of Surtsey is favored. It is found that the 13 m thick discontinuous dike complex, observed in the drill core, is sufficient to explain the excess heat content in the vicinity of the borehole and the shape of the temperature profiles recorded. It is demonstrated that the heat transfer in Surtsey has been dominated by hydrothermal convection and that the system is vapor dominated above sea level. It is estimated that the permeability of a 40 m thick section of altered tuff below sea level is 4.1 × 10 -13 m 2, while the permeability of the unaltered tuff above sea level is estimated as 1.2 × 10 -10 m 2.

Stefansson, V.; Axelsson, G.; Sigurdsson, O.; Gudmundsson, G.; Steingrimsson, B.

1985-12-01

9

Thermal activated (thermal) battery technology  

Microsoft Academic Search

This article gives an overview of the important properties and design characteristics of electrolyte used in thermally activated (thermal) batteries. The basic physical properties of the main compositions are reviewed. The properties of electrolytes such as melting point, ionic conductivity, surface tension, density, thermal characteristics, and moisture sensitivity were analyzed in relation with the functioning of the batteries. Solubility data

Patrick Masset; Ronald A. Guidotti

2007-01-01

10

Thermal Desorption: A Technology Review.  

National Technical Information Service (NTIS)

New and innovative technologies have been developed to treat hazardous wastes because of the high costs of remediation. One such technology is thermal desorption, which heats soils, sediments, and sludges to volatilize any contaminants present. Thermal de...

T. P. Sullivan

1997-01-01

11

Thermal activated (“thermal”) battery technology  

Microsoft Academic Search

This article presents an overview of cathode materials (except the pyrite FeS2) used or envisaged in thermally activated (“thermal”) batteries. The physicochemical properties and electrochemical performance of different cathode families (oxides, sulfides) are reviewed, including discharge mechanisms, when known.

Patrick J. Masset; Ronald A. Guidotti

2008-01-01

12

Thermal activated (“thermal”) battery technology  

Microsoft Academic Search

This article presents an overview of the pyrite FeS2 used as cathode material in thermally activated (“thermal”) batteries. A large emphasis was placed on the physicochemical properties and electrochemical performance of the pyrite FeS2, including the discharge mechanisms, self-discharge phenomena, and recent developments.

Patrick J. Masset; Ronald A. Guidotti

2008-01-01

13

Thermal Trends in Emerging Technologies  

Microsoft Academic Search

In the future, the peak temperature of a chip will be a primary design constraint. In order to meet this constraint, temperature must be considered in the earliest phases of the design process. Using a newly developed thermal analysis tool, HS3d, this work explores the thermal profile of devices as technology varies. We show that as technology scales, the hotspot

Greg M. Link; Narayanan Vijaykrishnan

2006-01-01

14

Monitoring Thermal Conditions in Footwear  

NASA Astrophysics Data System (ADS)

Thermal conditions inside the foot were evaluated on a volunteer subject. We have designed and constructed an electronic system which can monitors temperature and humidity of the foot inside the shoe. The data is stored in a battery-powered device for later uploading to a host computer for data analysis. The apparatus potentially can be used to provide feedback to patients who are prone to having skin breakdowns.

Silva-Moreno, Alejandra. A.; Lopez Vela, Martín; Alcalá Ochoa, Noe

2006-09-01

15

Thermal Skin fabrication technology  

NASA Technical Reports Server (NTRS)

Advanced fabrication techniques applicable to Thermal Skin structures were investigated, including: (1) chemical machining; (2) braze bonding; (3) diffusion bonding; and (4) electron beam welding. Materials investigated were nickel and nickel alloys. Sample Thermal Skin panels were manufactured using the advanced fabrication techniques studied and were structurally tested. Results of the program included: (1) development of improved chemical machining processes for nickel and several nickel alloys; (2) identification of design geometry limits; (3) identification of diffusion bonding requirements; (4) development of a unique diffusion bonding tool; (5) identification of electron beam welding limits; and (6) identification of structural properties of Thermal Skin material.

Milam, T. B.

1972-01-01

16

Nuclear thermal propulsion technology overview  

NASA Technical Reports Server (NTRS)

Viewgraphs on nuclear thermal propulsion technology overview are presented. Topics covered include non-nuclear material; instrumentation, controls, and health monitoring; turbopumps; nozzle and extension; and exhaust plume characteristics.

Stone, James R.

1993-01-01

17

Solar Thermal Energy Technology.  

National Technical Information Service (NTIS)

Solar thermal systems providing medium- and high-temperature heat have a wide range of applications such as agricultural and industrial process heat, electric power generation, cogeneration, repowering of existing power plants, and production of fuels and...

1986-01-01

18

Thermal Treatment Technologies: Lessons Learned.  

National Technical Information Service (NTIS)

Contents: Critical Evaluation of State-of-the-Art In Situ Thermal Treatment Technologies for DNAPL Source Zone Treatment, ER-200314, by Jennifer Kingston, Paul Dahlen, and Paul Johnson (p5); Measuring and Modeling Thermal Treatment at Naval Air Warfare Ce...

2011-01-01

19

Rapid thermal conditioning of sewage sludge  

NASA Astrophysics Data System (ADS)

Rapid thermal conditioning (RTC) is a developing technology recently applied to sewage sludge treatment. Sludge is heated rapidly to a reaction temperature (up to about 220sp°C) under sufficient pressure to maintain the liquid phase. Reaction is quenched after 10 to 30 seconds when the mixture of sludge and steam pass through a pressure let-down valve. This process reduces the amount of sludge requiring land disposal, eliminates the need for polymer coagulant, improves dewaterability, increases methane production, and further reduces the concentration of pathogens. The odor problem associated with traditional thermal conditioning processes is largely minimized. Ammonia removal is readily integrated with the process. For this research, a pilot unit was constructed capable of processing 90 liters of sludge per hour. Over 22 runs were made with this unit using sludge from New York City Water Pollution Control Plants (WPCP). Sludges processed in this equipment were tested to determine the effect of RTC operating conditions on sludge dewaterability, biodegradability, and other factors affecting the incorporation of RTC into wastewater treatment plants. Dewaterability of thermally conditioned sludge was assessed for cetrifugeability and filterability. Bench scale centrifugation was used for evaluating centrifugeability, pressure filtration and capillary suction time (CST) for filterability. A mathematical model developed for centrifuge dewatering was used to predict the effect of RTC on full scale centrifuge performance. Particle size distribution and solids density of raw and treated PDS were also analyzed. An observed increase in sludge solids density at least partially explains its improved centrifugeability. An investigation of thermally conditioned amino acids showed that the L-isomer is highly biodegradable while the D-isomers are generally less so. Glucose is highly biodegradable, but rapidly becomes refractory as thermal conditioning time is lengthened. This shows the fundamental importance of rapid processing. Rapid thermal conditioning may be incorporated into a wastewater treatment plant where biological treatment is used. For purposes of a concrete example, flow-sheets for the incorporation of the RTC process into the New York City Wards Island WPCP were prepared, and experimental data from the laboratory scale RTC test facility were used to set design parameters. A design incorporating nitrogen removal into the RTC flow sheet was also examined. ASPEN software was used to design the proposed processes and perform economic analyses. Cost estimates for these alternatives show a substantial advantage to implement RTC in comparison to present plant operation. About one third of the current sludge processing cost can be saved by incorporation of RTC into the Wards Island Plant. With nitrogen removal, the economics are even more attractive.

Zheng, Jianhong

20

Overview of Thermal Desorption Technology.  

National Technical Information Service (NTIS)

This report is a summary and extension of the presentation on thermal desorption that formed a part of the 'Remediation Innovative Technology Seminar' presented by NFESC earlier this year. The presentation was intended primarily to benefit U.S. Naval fiel...

R. J. Feeney P. J. Nicotri D. S. Janke

1998-01-01

21

The thermal conditions of Venus  

NASA Technical Reports Server (NTRS)

Models of Venus' thermal evolution are examined. The following subject areas are covered: (1) modified approximation of parameterized convection; (2) description of the model; (3) numerical results and asymptotic solution of the MAPC equations; (4) magnetism and the thermal regime of the cores of Earth and Venus; and (5) the thermal regime of the Venusian crust.

Zharkov, Vladimir N.; Solomatov, V. S.

1991-01-01

22

Conceptual Thermal Treatment Technologies Feasibility Study  

SciTech Connect

This report presents a conceptual Thermal Treatment Technologies Feasibility Study (FS) for the Savannah River Site (SRS) focusing exclusively on thermal treatment technologies for contaminated soil, sediment, or sludge remediation projects.

Suer, A.

1996-02-28

23

Thermally-Choked Combustor Technology  

NASA Technical Reports Server (NTRS)

A program is underway to demonstrate the practical feasibility of thermally-choked combustor technology with particular emphasis on rocket propulsion applications. Rather than induce subsonic to supersonic flow transition in a geometric throat, the goal is to create a thermal throat by adding combustion heat in a diverging nozzle. Such a device would have certain advantages over conventional flow accelerators assuming that the pressure loss due to heat addition does not severely curtail propulsive efficiency. As an aid to evaluation, a generalized one-dimensional compressible flow analysis tool was constructed. Simplified calculations indicate that the process is fluid dynamically and thermodynamically feasible. Experimental work is also being carried out in an attempt to develop, assuming an array of practical issues are surmountable, a practical bench-scale demonstrator using high flame speed H2/O2 combustibles.

Knuth, William H.; Gloyer, P.; Goodman, J.; Litchford, R. J.

1993-01-01

24

JPL Advanced Thermal Control Technology Roadmap - 2012  

NASA Technical Reports Server (NTRS)

NASA's new emphasis on human exploration program for missions beyond LEO requires development of innovative and revolutionary technologies. Thermal control requirements of future NASA science instruments and missions are very challenging and require advanced thermal control technologies. Limited resources requires organizations to cooperate and collaborate; government, industry, universities all need to work together for the successful development of these technologies.

Birur, Gaj; Rodriguez, Jose I.

2012-01-01

25

Thermal comfort and sensation under transient conditions.  

National Technical Information Service (NTIS)

This thesis consists of a study of thermal comfort under transient conditions. A thermo-regulatory model originally developed by the author has been developed further. The model can predict whether a subject is in a state of thermal comfort under a given ...

X. Wang

1994-01-01

26

Evaluation and visualisation of perceived thermal conditions.  

PubMed

Investigations have been made on ways to evaluate and visualise the perceived thermal climate. Thermal interaction with windows, heating, ventilation and seating influence the occupant's thermal situation. When this information on the physical thermal climate is linked together with human thermal sensation in "comfort-zone diagrams", valuable knowledge about the thermal situation can be visualised. Thermal manikin measurements of local climate disturbances with two different thermal manikins are found to be well correlated with the thermal sensation experienced by panels of subjects exposed to the same conditions. Differences both in manikin shape and construction, as well as testing conditions and panel members, make limit lines differ at some points. Comfort diagrams can be defined by equivalent temperature (t(eq)) limit lines; however, a consequence of individual and experimental variations is that it is not an optimal solution to have diagrams with absolute limit lines, rather a range of t(eq) values, forming new "comfort-zone diagrams". This improvement provides a more appropriate base for assessment of a complex local thermal climate, and opens up the possibility of a general profile that can be used with different manikins, possibly also different methods, in a variety of environments. However, more data from validation experiments with subjects and different methods will contribute to the development of a more general evaluation concept. PMID:15098131

Nilsson, Hĺkan O

2004-09-01

27

NASA/Goddard Thermal Technology Overview 2012  

NASA Technical Reports Server (NTRS)

New Technology program is underway at NASA NASA/GSFC's primary mission of science satellite development is healthy and vibrant, although new missions are scarce Future mission applications promise to be thermally challenging Direct technology funding is still very restricted

Butler, Dan; Swanson, Ted

2012-01-01

28

Meaningful performance evaluation conditions for fire service thermal imaging cameras  

Microsoft Academic Search

Thermal imaging cameras (TIC) are rapidly becoming integral equipment for the fire service for use in structure fires and other emergencies. The Building and Fire Research Laboratory (BFRL) at the National Institute of Standards and Technology has conducted research to establish test conditions that best represent the environment in which TIC are used. Firefighters may use TIC for field operations

Francine Amon; Anthony Hamins; Nelson Bryner; Justin Rowe

2008-01-01

29

Advanced thermal management technologies for defense electronics  

NASA Astrophysics Data System (ADS)

Thermal management technology plays a key role in the continuing miniaturization, performance improvements, and higher reliability of electronic systems. For the past decade, and particularly, the past 4 years, the Defense Advanced Research Projects Agency (DARPA) has aggressively pursued the application of micro- and nano-technology to reduce or remove thermal constraints on the performance of defense electronic systems. The DARPA Thermal Management Technologies (TMT) portfolio is comprised of five technical thrust areas: Thermal Ground Plane (TGP), Microtechnologies for Air-Cooled Exchangers (MACE), NanoThermal Interfaces (NTI), Active Cooling Modules (ACM), and Near Junction Thermal Transport (NJTT). An overview of the TMT program will be presented with emphasis on the goals and status of these efforts relative to the current State-of-the-Art. The presentation will close with future challenges and opportunities in the thermal management of defense electronics.

Bloschock, Kristen P.; Bar-Cohen, Avram

2012-05-01

30

Status of thermal spray technology in Japan  

NASA Astrophysics Data System (ADS)

The paper summarizes the profile of the fundamental research, the developments in industrial applications, and the business in thermal spray technology in Japan and discusses prospects for future progress in this technology. Particular attention is given to the status of new process technologies (including reactive low-pressure spraying, RF plasma spraying, laser spray, and multielectrode spray) and the development of functional materials. It is noted that, although up to now the progress of thermal spraying in Japan depended on the technologies of the United States and Europe, the thermal spraying technologies in the steel making and automotive industry superseded the technologies of other countries. In the first half of 1992, the thermal spray market in Japan was estimated at more than 100 billion yen (770 million U.S. dollars) per year.

Tani, K.; Nakahira, H.

1992-12-01

31

Review on sustainable thermal energy storage technologies, Part II: cool thermal storage  

Microsoft Academic Search

This paper describes the inherent pros and cons of the two common (i.e. chilled water and ice storage) commercially available thermal energy storage (TES) technologies for off-peak air conditioning applications. Case studies on cool thermal storage have demonstrated not only savings in energy and other operation and maintenance costs but also significant savings in initial capital costs. This paper also

S. M. Hasnain

1998-01-01

32

NASA thermal control technologies for robotic spacecraft  

Microsoft Academic Search

Technology development is inevitably a dynamic process in search of an elusive goal. It is never truly clear whether the need for a particular technology drives its development, or the existence of a new capability initiates new applications. Technology development for the thermal control of spacecraft presents an excellent example of this situation. Nevertheless, it is imperative to have a

Theodore D. Swanson; Gajanana C. Birur

2003-01-01

33

Thermal Control Technologies for Complex Spacecraft  

NASA Technical Reports Server (NTRS)

Thermal control is a generic need for all spacecraft. In response to ever more demanding science and exploration requirements, spacecraft are becoming ever more complex, and hence their thermal control systems must evolve. This paper briefly discusses the process of technology development, the state-of-the-art in thermal control, recent experiences with on-orbit two-phase systems, and the emerging thermal control technologies to meet these evolving needs. Some "lessons learned" based on experience with on-orbit systems are also presented.

Swanson, Theodore D.

2004-01-01

34

High Spatial Resolution Thermal Satellite Technologies  

NASA Technical Reports Server (NTRS)

This document in the form of viewslides, reviews various low-cost alternatives to high spatial resolution thermal satellite technologies. There exists no follow-on to Landsat 7 or ASTER high spatial resolution thermal systems. This document reviews the results of the investigation in to the use of new technologies to create a low-cost useful alternative. Three suggested technologies are examined. 1. Conventional microbolometer pushbroom modes offers potential for low cost Landsat Data Continuity Mission (LDCM) thermal or ASTER capability with at least 60-120 ground sampling distance (GSD). 2. Backscanning could produce MultiSpectral Thermal Imager performance without cooled detectors. 3. Cooled detector could produce hyperspectral thermal class system or extremely high spatial resolution class instrument.

Ryan, Robert

2003-01-01

35

Air Conditioning and Heating Technology--II.  

ERIC Educational Resources Information Center

Twenty-eight chapters and numerous drawings provide information for instructors and students of air conditioning and heating technology. Chapter 1 lists the occupational opportunities in the field. Chapter 2 covers the background or development of the industry of air conditioning and heating technology. Chapter 3 includes some of the principle…

Gattone, Felix

36

NASA's nuclear thermal propulsion technology project  

Microsoft Academic Search

The nonnuclear subsystem technologies required for incorporating nuclear thermal propulsion (NTP) into space-exploration missions are discussed. Of particular interest to planned missions are such technologies as materials, instrumentation and controls, turbomachinery, CFD modeling, nozzle extension designs and models, and analyses of exhaust plumes. NASA studies are described and\\/or proposed for refractory metals and alloys, robotic NTP controls, and turbopump materials

Keith M. Peecook; James R. Stone

1992-01-01

37

Advanced thermal control technology for commercial applications  

NASA Technical Reports Server (NTRS)

A number of the technologies previously developed for the thermal control of spacecraft have found their way into commercial application. Specialized coatings and heat pipes are but two examples. The thermal control of current and future spacecraft is becoming increasingly more demanding, and a variety of new technologies are being developed to meet these needs. Closed two-phase loops are perceived to be the answer to many of the new requirements. All of these technologies are discussed, and their spacecraft and current terrestrial applications are summarized.

Swanson, Theodore D.

1991-01-01

38

Proceedings of the Solar Thermal Technology Conference  

NASA Astrophysics Data System (ADS)

The Solar Thermal Technology Conference was held on August 26 to 28, 1987, at the Marriott Hotel, Albuquerque, New Mexico. The meeting was sponsored by the United States Department of Energy and Sandia National Laboratories. Topics covered during the conference included a status summary of the Sandia Solar Thermal Development Project, perspectives on central and distributed receiver technology including energy collection and conversion technologies, systems analyses and applications experiments. The proceedings contain summaries (abstracts and principal visual aids) of the presentations made at the conference.

Tyner, C. E.

1987-08-01

39

Proceedings of the Solar Thermal Technology Conference  

NASA Astrophysics Data System (ADS)

The Solar Thermal Technology Conference was held on June 17 to 19, 1986 at the Marriott Hotel, Albuquerque, New Mexico. The meeting was sponsored by the United States Department of Energy and Sandia National Laboratories. Topics covered during the conference included a status summary of the Sandia Solar Thermal Development Project, perspectives on central and distributed receiver technology including energy collection and conversion technologies, systems analyses and applications experiments. The proceedings contain summaries (abstracts plus principal visual aids) of the presentations made at the conference.

Diver, R. B.

1986-06-01

40

MSFC nuclear thermal propulsion technology program  

NASA Technical Reports Server (NTRS)

Viewgraphs on non-nuclear materials assessment, nuclear thermal propulsion (NTP) turbomachinery technologies, and high temperature superconducting magnetic bearing technology are presented. The objective of the materials task is to identify and evaluate candidate materials for use in NTP turbomachinery and propellant feed system applications. The objective of the turbomachinery technology task is to develop and validate advanced turbomachinery technologies at the component and turbopump assembly levels. The objective of the high temperature superconductors (HTS) task is to develop and validate advanced technology for HTS passive magnetic/hydrostatic bearing.

Swint, Shane

1993-01-01

41

NASA/Goddard Thermal Technology Overview 2014  

NASA Technical Reports Server (NTRS)

This presentation summarizes the current plans and efforts at NASA Goddard to develop new thermal control technology for anticipated future missions. It will also address some of the programmatic developments currently underway at NASA, especially with respect to the Technology Development Program at NASA. While funding for basic technology development is still scarce, significant efforts are being made in direct support of flight programs. New technology development continues to be driven by the needs of future missions, and applications of these technologies to current Goddard programs will be addressed. Many of these technologies also have broad applicability to DOD, DOE, and commercial programs. Partnerships have been developed with the Air Force, Navy, and various universities to promote technology development. In addition, technology development activities supported by internal research and development (IRAD) program, the Small Business Innovative Research (SBIR) program, and the NASA Engineering and Safety Center (NESC), are reviewed in this presentation. Specific technologies addressed include; two-phase systems applications and issues on NASA missions, latest developments of electro-hydrodynamically pumped systems, development of high electrical conductivity coatings, and various other research activities. New Technology program underway at NASA, although funding is limited center dot NASA/GSFC's primary mission of science satellite development is healthy and vibrant, although new missions are scarce - now have people on overhead working new missions and proposals center dot Future mission applications promise to be thermally challenging center dot Direct technology funding is still very restricted - Projects are the best source for direct application of technology - SBIR thermal subtopic resurrected in FY 14 - Limited Technology development underway via IRAD, NESC, other sources - Administrator pushing to revive technology and educational programs at NASA - new HQ directorate established

Butler, Daniel; Swanson, Theodore D.

2014-01-01

42

Cost studies of thermally enhanced in situ soil remediation technologies  

SciTech Connect

This report describes five thermally enhanced technologies that may be used to remediate contaminated soil and water resources. The standard methods of treating these contaminated areas are Soil Vapor Extraction (SVE), Excavate & Treat (E&T), and Pump & Treat (P&T). Depending on the conditions at a given site, one or more of these conventional alternatives may be employed; however, several new thermally enhanced technologies for soil decontamination are emerging. These technologies are still in demonstration programs which generally are showing great success at achieving the expected remediation results. The cost savings reported in this work assume that the technologies will ultimately perform as anticipated by their developers in a normal environmental restoration work environment. The five technologies analyzed in this report are Low Frequency Heating (LF or Ohmic, both 3 and 6 phase AC), Dynamic Underground Stripping (DUS), Radio Frequency Heating (RF), Radio Frequency Heating using Dipole Antennae (RFD), and Thermally Enhanced Vapor Extraction System (TEVES). In all of these technologies the introduction of heat to the formation raises vapor pressures accelerating contaminant evaporation rates and increases soil permeability raising diffusion rates of contaminants. The physical process enhancements resulting from temperature elevations permit a greater percentage of volatile organic compound (VOC) or semi- volatile organic compound (SVOC) contaminants to be driven out of the soils for treatment or capture in a much shorter time period. This report presents the results of cost-comparative studies between these new thermally enhanced technologies and the conventional technologies, as applied to five specific scenarios.

Bremser, J.; Booth, S.R.

1996-05-01

43

Flameless thermal oxidation. Innovative technology summary report  

SciTech Connect

The Flameless Thermal Oxidizer (FTO) is a commercial technology offered by Thermatrix, Inc. The FTO has been demonstrated to be an effective destructive technology for process and waste stream off-gas treatment of volatile organic compounds (VOCs), and in the treatment of VOC and chlorinated volatile organic compounds (CVOCs) off-gases generated during site remediation using either baseline or innovative in situ environmental technologies. The FTO process efficiently converts VOCs and CVOCs to carbon dioxide, water, and hydrogen chloride. When FTO is coupled with a baseline technology, such as soil vapor extraction (SVE), an efficient in situ soil remediation system is produced. The innovation is in using a simple, reliable, scalable, and robust technology for the destruction of VOC and CVOC off-gases based on a design that generates a uniform thermal reaction zone that prevents flame propagation and efficiently oxidizes off-gases without forming products of incomplete combustion (PICs).

NONE

1995-09-01

44

NASA Thermal Control Technologies for Robotic Spacecraft  

NASA Technical Reports Server (NTRS)

Technology development is inevitably a dynamic process in search of an elusive goal. It is never truly clear whether the need for a particular technology drives its development, or the existence of a new capability initiates new applications. Technology development for the thermal control of spacecraft presents an excellent example of this situation. Nevertheless, it is imperative to have a basic plan to help guide and focus such an effort. Although this plan will be a living document that changes with time to reflect technological developments, perceived needs, perceived opportunities, and the ever-changing funding environment, it is still a very useful tool. This presentation summarizes the current efforts at NASA/Goddard and NASA/JPL to develop new thermal control technology for future NASA missions.

Swanson, Theodore D.; Biur, Gajanana C.

2002-01-01

45

NASA Thermal Control Technologies for Robotic Spacecraft  

NASA Technical Reports Server (NTRS)

Technology development is inevitably a dynamic process in search of an elusive goal. It is never truly clear whether the need for a particular technology drives its development, or the existence of a new capability initiates new applications. Technology development for the thermal control of spacecraft presents an excellent example of this situation. Nevertheless, it is imperative to have a basic plan to help guide and focus such an effort. Although this plan will be a living document that changes with time to reflect technological developments, perceived needs, perceived opportunities, and the ever-changing funding environment, it is still a very useful tool. This presentation summarizes the current efforts at NASA/Goddard and NASA/JPL to develop new thermal control technology for future robotic NASA missions.

Swanson, Theodore D.; Birur, Gajanana C.

2003-01-01

46

Comparison of solar thermal technologies for applications in seawater desalination  

Microsoft Academic Search

This paper deals with a global analysis of the use of solar energy in seawater distillation under Spanish climatic conditions. Static solar technologies as well as one-axis sun tracking were compared. Different temperature ranges of the thermal energy supply required for a desalination process were considered. At each temperature range, suitable solar collectors were compared in some aspects as: (1)

Lourdes García-Rodríguez; Ana I. Palmero-Marrero; Carlos Gómez-Camacho

2002-01-01

47

Thermal conditions of Warsaw botanical gardens  

NASA Astrophysics Data System (ADS)

The aim of the paper is to present the air temperature differences in Warsaw over the period 1951-1998 between different city structures: botanical gardens in the city centre and of suburban location, compact development in the city center and the suburbs. The trend of growing yearly mean air temperature in Warsaw was confirmed. The air temperature in the botanical garden in the city centre is of 0.4°C higher than outside the city. However, the thermal regime of the botanical garden in Powsin (which is of peripheral location) does not differ from rural conditions.

Baranowski, Jaros?aw; Adamczyk, Anna

2011-01-01

48

Marketing solar thermal technologies: strategies in Europe, experience in Greece  

Microsoft Academic Search

Solar thermal technologies (STTs) are mature in many EU Member States. However, in some EU regions solar applications, and especially the innovative ones (such as solar heating\\/cooling, solar drying, solar-powered desalination), remain at an early stage. The degree of development of each market does not depend on climate conditions (e.g., insolation) or on different technological developments. The major strengths, weaknesses,

Theocharis D Tsoutsos

2002-01-01

49

Development of Design Technology on Thermal-Hydraulic Performance in Tight-Lattice Rod Bundles: II - Rod Bowing Effect on Boiling Transition under Transient Conditions  

NASA Astrophysics Data System (ADS)

A thermal-hydraulic feasibility project for an Innovative Water Reactor for Flexible fuel cycle (FLWR) has been performed since 2002. In this R&D project, large-scale thermal-hydraulic tests, several model experiments and development of advanced numerical analysis codes have been carried out. In this paper, we describe the critical power characteristics in a 37-rod tight-lattice bundle with rod bowing under transient states. It is observed that transient Boiling Transition (BT) always occurs axially at exit elevation of upper high-heat-flux region and transversely in the central area of the bundle, which is same as that under steady state. For the postulated power increase and flow decrease cases that may be possibly met in a normal operation of the FLWR, it is confirmed that no BT occurs when Initial Critical Power Ratio (ICPR) is 1.3. Moreover, when the transients are run under severer ICPR that causes BT, the transient critical powers are generally same as the steady ones. The experiments are analyzed with a modified TRAC-BFI code, where Japan Atomic Energy Agency (JAEA) newest critical power correlation is implemented for the BT judgement. The code shows good prediction for the occurrence or the non occurrence of the BT and predicts the BT starting time conservatively. Traditional quasi-steady state prediction of the transient BT is confirmed being applicable for the postulated abnormal transient processes in the tight-lattice bundle with rod bowing.

Liu, Wei; Tamai, Hidesada; Kureta, Masatoshi; Ohnuki, Akira; Akimoto, Hajime

50

Thermal battery infrared monitoring system design based on virtual instrument technology  

NASA Astrophysics Data System (ADS)

This paper designs a thermal battery infrared monitoring system using FLUKE Ti45 Thermal Imagers and IMAQ Vision software of LabVIEW. The thermal battery infrared monitoring system uses infrared imaging technology to monitor the electrical property testing process. It can investigate and analyze the working performance of thermal batteries on different kinds of maximum conditions, and monitor the temperature variation tendency.

Qin, Qin; Liu, Zheng-Guo; Jiang, Li

2011-06-01

51

Uranium-mill-tailings conditioning technology  

Microsoft Academic Search

Conditioning of uranium mill tailings involves the physico-chemical alteration of tailings to remove or immobilize mobile radionuclides and toxic trace elements before disposal in a repository. The principal immobilization approach under investigation is sntering tailings at high temperatures (1100 to 1200°C) to radically alter the structure of tailings. This thermal stabilization at 1200°C reduced radon emanation power for tailings sands

D. R. Dreesen; E. J. Cokal; P. D. OBrien; E. F. Thode; L. E. Wangen; J. M. Williams

1982-01-01

52

An Experimental Study of Casing Performance Under Thermal Cycling Conditions  

Microsoft Academic Search

The authors have investigated the behavior of casing pipe body and connections under simulated thermal recovery conditions. The study, performed in a new computer-controlled thermal-well simulator, examined the thermal stress behavior and leak resistance of pipe and connections at temperatures up to 354°C (670°F) under severe loading conditions similar to those encountered in thermal wells. We also studied the biaxial

Kazushi Maruyama; Eiji Tsuru; Masao Ogasawara; Yasusuke Inoue; Ekwere Peters

1990-01-01

53

Latest research development of spacecraft thermal control technology  

Microsoft Academic Search

With the rapid development of space technology, special thermal design and proper thermal control technologies are essential for ensuring normal spacecraft operation and its instruments. The paper depicts latest research results and application occasion of spacecraft thermal control, especially introduces passive thermal control techniques in detailed, finally proposes current problems need to be solved. Furthermore, it has some reference values

Xiaoling Luo; Meijuan Wang

2010-01-01

54

NASA's nuclear thermal propulsion technology project  

NASA Technical Reports Server (NTRS)

The nonnuclear subsystem technologies required for incorporating nuclear thermal propulsion (NTP) into space-exploration missions are discussed. Of particular interest to planned missions are such technologies as materials, instrumentation and controls, turbomachinery, CFD modeling, nozzle extension designs and models, and analyses of exhaust plumes. NASA studies are described and/or proposed for refractory metals and alloys, robotic NTP controls, and turbopump materials candidates. Alternative nozzle concepts such as aerospikes and truncated plugs are proposed, and numerical simulations are set forth for studying heavy molecules and the backstreaming of highly reactive free-radical hydrogen in the exhaust plume. The critical technologies described in the paper are central to the development of NTP, and NTP has the potential to facilitate a range of space exploration activities.

Peecook, Keith M.; Stone, James R.

1992-01-01

55

NASA's nuclear thermal propulsion technology project  

SciTech Connect

The nonnuclear subsystem technologies required for incorporating nuclear thermal propulsion (NTP) into space-exploration missions are discussed. Of particular interest to planned missions are such technologies as materials, instrumentation and controls, turbomachinery, CFD modeling, nozzle extension designs and models, and analyses of exhaust plumes. NASA studies are described and/or proposed for refractory metals and alloys, robotic NTP controls, and turbopump materials candidates. Alternative nozzle concepts such as aerospikes and truncated plugs are proposed, and numerical simulations are set forth for studying heavy molecules and the backstreaming of highly reactive free-radical hydrogen in the exhaust plume. The critical technologies described in the paper are central to the development of NTP, and NTP has the potential to facilitate a range of space exploration activities. 3 refs.

Peecook, K.M.; Stone, J.R. (NASA, Lewis Research Center, Cleveland, OH (United States))

1992-07-01

56

Thermal Interface Comparisons Under Flight Like Conditions  

NASA Technical Reports Server (NTRS)

Thermal interface materials are used in bolted interfaces to promote good thermal conduction between the two. The mounting surface can include panels, heat pipes, electronics boxes, etc.. . On Lunar Reconnaissance Orbiter (LRO) project the results are directly applicable: a) Several high power avionics boxes b) Several interfaces from RWA to radiator through heat pipe network

Rodriquez-Ruiz, Juan

2008-01-01

57

Interconnect technologies and the thermal performance of MCM  

Microsoft Academic Search

The thermal performances of multichip modules (MCMs) are compared on the basis of their interconnection technologies. The comparisons are made for hermetic and conduction cooled use environments. The thermal performances of the chip-first-type high density interconnect (HDI) technology, the flipped chip (FCP) technology, and the flipped tape automated bond (FTAB) technology are analyzed and compared for the MCM applications. The

Burhan Ozmat

1992-01-01

58

Integrated Vehicle Thermal Management for Advanced Vehicle Propulsion Technologies  

SciTech Connect

A critical element to the success of new propulsion technologies that enable reductions in fuel use is the integration of component thermal management technologies within a viable vehicle package. Vehicle operation requires vehicle thermal management systems capable of balancing the needs of multiple vehicle systems that may require heat for operation, require cooling to reject heat, or require operation within specified temperature ranges. As vehicle propulsion transitions away from a single form of vehicle propulsion based solely on conventional internal combustion engines (ICEs) toward a wider array of choices including more electrically dominant systems such as plug-in hybrid electric vehicles (PHEVs), new challenges arise associated with vehicle thermal management. As the number of components that require active thermal management increase, so do the costs in terms of dollars, weight, and size. Integrated vehicle thermal management is one pathway to address the cost, weight, and size challenges. The integration of the power electronics and electric machine (PEEM) thermal management with other existing vehicle systems is one path for reducing the cost of electric drive systems. This work demonstrates techniques for evaluating and quantifying the integrated transient and continuous heat loads of combined systems incorporating electric drive systems that operate primarily under transient duty cycles, but the approach can be extended to include additional steady-state duty cycles typical for designing vehicle thermal management systems of conventional vehicles. The work compares opportunities to create an integrated low temperature coolant loop combining the power electronics and electric machine with the air conditioning system in contrast to a high temperature system integrated with the ICE cooling system.

Bennion, K.; Thornton, M.

2010-04-01

59

Behavior of materials under conditions of thermal stress  

NASA Technical Reports Server (NTRS)

A review is presented of available information on the behavior of brittle and ductile materials under conditions of thermal stress and thermal shock. For brittle materials, a simple formula relating physical properties to thermal-shock resistance is derived and used to determine the relative significance of two indices currently in use for rating materials. For ductile materials, thermal-shock resistance depends upon the complex interrelation among several metallurgical variables which seriously affect strength and ductility. These variables are briefly discussed and illustrated from literature sources. The importance of simulating operating conditions in tests for rating materials is especially to be emphasized because of the importance of testing conditions in metallurgy. A number of practical methods that have been used to minimize the deleterious effects of thermal stress and thermal shock are outlined.

Manson, S S

1954-01-01

60

Thermal batteries, their technologies and applications  

NASA Astrophysics Data System (ADS)

Thermal batteries, which from their inception have proven ideal for military applications requiring long shelf life, high power and reliability, and imperviousness to dynamic environmental conditions, are typically composed of an alkali metal and a transition metal chalcogenide electrochemical couple in a fused-salt electrolyte. The electrolyte, which is solid and nonconducting at ambient temperatures, melts after the ignition of integral pyrotechnic heat sources. Enough power is thus supplied for guidance and control of missiles and torpedoes, warhead fusing, and telemetry. Recent improvements have brought specific energies to the level of 70 W h/kg, and energy densities to 155 W h/l.

Press, Khushrow K.; Briscoe, J. Douglass

1990-04-01

61

APPLICATION OF THERMAL DESORPTION TECHNOLOGIES TO HAZARDOUS WASTE SITES  

EPA Science Inventory

Thermal desorption is a separation process frequently used to remediate many Superfund sites. Thermal desorption technologies are recommended and used because of (1) the wide range of organic contaminants effectively treated, (2) availability and mobility of commercial systems, ...

62

Status of solar-thermal electric technology  

SciTech Connect

This report summarizes an evaluation performed of solar thermal electric technology. The objective was to assess the technology as a future source of power for United States utilities. An experimental data base was used to the greatest extent possible. A representative configuration was selected for each of the main solar collector concepts: the central receiver, the parabolic dish and the parabolic trough. The ultimate energy costs that could be expected from these three concepts as mature, commercial systems were estimated. The estimates were in the form of upper and lower bounds to the expected energy costs, where the upper bound could be supported by the existing experimental data base and the lower bound represented the potential possible for the system if present uncertainties in costs and performance are resolved favorably. The development status for each of the three concepts was reviewed, and estimates were made of the costs and time that would be required to complete the development of a commercial version of the systems. The central receiver and the dish collector systems have potential energy costs as low as 5 cents per kilowatt hour, but the uncertainty of achieving this potential is high. The trough has higher potential energy costs but lower uncertainty. 132 refs., 72 figs., 47 tabs.

Holl, R.J. (HGH Enterprises, Inc., Laguna Hills, CA (USA))

1989-12-01

63

Thermal arcjet technology for space propulsion  

SciTech Connect

Advanced space propulsion systems are required to meet projected Air Force needs through the year 2000. Most of these missions require a large, on-orbit impulse capability. High specific impulse (I sub sp) electric engines can provide this impulse while consuming relatively little propellant. An arcjet engine system, which operates in the range of 800 to 2000 s I sub sp, is a promising candidate to meet these projected Air Force mission needs. This electric propulsion system is ideally suited to missions currently under consideration, such as the space-based radar and other space platforms, because sufficient power is already installed for other functions on the spacecraft. Also, arcjet systems are attractive for NASA near-term, low-cost Mariner Mark II missions to Saturn and Uranus. This paper describes thermal arcjet technology as it was developed over two decades ago and points to the direction this technology development should proceed in the future. In particular, operation with storable propellants such as ammonia and hydrazine are considered. The performance, applicability and advantages of these systems in terms of increased payload and/or decreased trip times are discussed.

Pivirotto, T.J.; King, D.Q.

1985-01-01

64

Comparison of Innovative Technology for Thermal Destruction of Hazardous Waste.  

National Technical Information Service (NTIS)

This paper briefly summaries and compares six technologies which are considered to be innovative to the thermal destruction of hazardous wastes. The six technologies are: Fluidized Bed, Molten Salt, High Temperature Fluid Wall, Plasma Arc, Wet Air Oxidati...

C. C. Lee

1984-01-01

65

Interconnect technologies and the thermal performance of MCM  

Microsoft Academic Search

The author compares the thermal performance of multi-chip modules (MCMs) based on their interconnection technology. The comparisons were made for hermetic and conduction cooled use environments. The thermal performances of the chip-first high-density interconnect (HDI) technology, the flipped-chip (FC) technology, and flipped-tape automated bonding (FTAB) technologies were analyzed and compared for MCM applications. The results of the study showed the

Burhan Ozmat

1992-01-01

66

Predicted sweat rate in fluctuating thermal conditions.  

PubMed

The ISO 7933 Required Sweat Rate Index is inappropriate under conditions of fluctuating exposure. Time weighted average values can introduce large underestimations as, for hot conditions, the relationship between physical stress and physiological strain is not linear. Mean skin temperature and sweat rate vary as a first order system, that is, according to an exponential averaging system, in response to a step function of the primary parameters. A very simple algorithm has been derived to take into account this exponential averaging and to predict the sweat rate at any time, taking into account the past exposure of the subject. It is based on time constants of 3 min for the mean skin temperature and of 25 min (up to a sweat rate of 50 W.m-2) and 10 min for the sweat rate. The correlation coefficient is 0.780 between observed and predicted sweat rates in independent experiments used for the validation of the model. This emphasises the necessity for exponential averaging as differences between individuals are very important and the precision of the observed data in these experiments was lower than for laboratory experimental data. PMID:1761022

Malchaire, J B

1991-01-01

67

Concepts of learning and experience in developing solar thermal technologies  

Microsoft Academic Search

This study presents a picture of development of solar thermal technology, using the learning and experience curve concepts. The cost estimates for solar thermal energy technologies are made assuming a fixed production process, characterized by standard capacity factors, overhead, and labor costs. The learning curve is suggested as a generalization of the costs of potential solar energy system. The concept

F Krawiec

1983-01-01

68

Treatment of organic waste using thermal plasma pyrolysis technology  

Microsoft Academic Search

This paper outlines the principles of thermal plasma pyrolysis processes and discusses recent research activities about organic waste treatment using thermal plasma pyrolysis technology. Different kinds of organic wastes, varying from plastic and used tires to agricultural residue and medical waste, have been subjected to thermal plasma pyrolysis tests in laboratory and pilot scale projects. Plasma pyrolysis of organic waste

H. Huang; L. Tang

2007-01-01

69

Nuclear vapor thermal reactor propulsion technology  

NASA Astrophysics Data System (ADS)

The conceptual design of a nuclear rocket based on the vapor core reactor is presented. The Nuclear Vapor Thermal Rocket (NVTR) offers the potential for a specific impulse of 1000 to 1200 s at thrust-to-weight ratios of 1 to 2. The design is based on NERVA geometry and systems with the solid fuel replaced by uranium tetrafluoride (UF4) vapor. The closed-loop core does not rely on hydrodynamic confinement of the fuel. The hydrogen propellant is separated from the UF4 fuel gas by graphite structure. The hydrogen is maintained at high pressure (~100 atm), and exits the core at 3,100 K to 3,500 K. Zirconium carbide and hafnium carbide coatings are used to protect the hot graphite from the hydrogen. The core is surrounded by beryllium oxide reflector. The nuclear reactor core has been integrated into a 75 klb engine design using an expander cycle and dual turbopumps. The NVTR offers the potential for an incremental technology development pathway to high performance gas core reactors. Since the fuel is readily available, it also offers advantages in the initial cost of development, as it will not require major expenditures for fuel development.

Maya, Isaac; Diaz, Nils J.; Dugan, Edward T.; Watanabe, Yoichi; McClanahan, James A.; Wen-Hsiung Tu; Carman, Robert L.

1993-01-01

70

ALTERNATIVE TECHNOLOGIES FOR REFRIGERATION AND AIR-CONDITIONING APPLICATIONS  

EPA Science Inventory

The report gives results of an assessment of refrigeration technologies that are alternatives to vapor compression refrigeration for use in five application categories: domestic air conditioning, commercial air conditioning, mobile air conditioning, domestic refrigeration, and co...

71

Boundary conditions of normal and anomalous diffusion from thermal equilibrium  

NASA Astrophysics Data System (ADS)

Infiltration of diffusing particles from one material to another, where the diffusion mechanism is either normal or anomalous, is a widely observed phenomenon. Starting with an underlying continuous-time random-walk model, we derive the boundary conditions for the diffusion equations describing this problem. We discuss a simple method showing how the boundary conditions can be determined from equilibrium experiments. When the diffusion processes are close to thermal equilibrium, the boundary conditions are determined by a thermal Boltzmann factor, which in turn controls the solution of the problem.

Korabel, Nickolay; Barkai, Eli

2011-05-01

72

MIUS technology evaluation: thermal energy conveyance. [Conduits  

Microsoft Academic Search

Thermal energy produced by a MIUS can be distributed at moderate temperatures, and low-pressure steam or water are most adaptable as energy-transfer media. This report discusses the types, cost, and performance of several types of conduits for thermal energy conveyance. Conduits applicable to water conveyance of thermal energy produced in a MIUS are evaluated from data on characteristics and economic

1976-01-01

73

Current Technology for Thermal Protection Systems  

NASA Technical Reports Server (NTRS)

Interest in thermal protection systems for high-speed vehicles is increasing because of the stringent requirements of such new projects as the Space Exploration Initiative, the National Aero-Space Plane, and the High-Speed Civil Transport, as well as the needs for improved capabilities in existing thermal protection systems in the Space Shuttle and in turbojet engines. This selection of 13 papers from NASA and industry summarizes the history and operational experience of thermal protection systems utilized in the national space program to date, and also covers recent development efforts in thermal insulation, refractory materials and coatings, actively cooled structures, and two-phase thermal control systems.

Scotti, Stephen J. (compiler)

1992-01-01

74

Thermal shock on interfacial adhesion of thermally conditioned glass fiber\\/epoxy composites  

Microsoft Academic Search

The fiber\\/matrix adhesion is most likely to control the overall mechanical behavior of fiber-reinforced composites. An interfacial reaction may result in various morphological modifications to polymer matrix microstructure in proximity to the fiber surface. The interactions between fiber and polymer matrix during thermal conditioning and thermal shock are important phenomena. Thermal stresses were built-up in glass fiber-reinforced epoxy composites by

B. C. Ray

2004-01-01

75

Long-term goals for solar thermal technology  

SciTech Connect

This document describes long-term performance and cost goals for three solar thermal technologies. Pacific Northwest Laboratory (PNL) developed these goals in support of the Draft Five Year Research and Development Plan for the National Solar Thermal Technology Program (DOE 1984b). These technology goals are intended to provide targets that, if met, will lead to the widespread use of solar thermal technologies in the marketplace. Goals were developed for three technologies and two applications: central receiver and dish technologies for utility-generated electricity applications, and central receiver, dish, and trough technologies for industrial process heat applications. These technologies and applications were chosen because they are the primary technologies and applications that have been researched by DOE in the past. System goals were developed through analysis of future price projections for energy sources competing with solar thermal in the middle-to-late 1990's time frame. The system goals selected were levelized energy costs of $0.05/kWh for electricity and $9/MBtu for industrial process heat (1984 $). Component goals established to meet system goals were developed based upon projections of solar thermal component performance and cost which could be achieved in the same time frame.

Williams, T.A.; Dirks, J.A.; Brown, D.R.

1985-05-01

76

Nanoparticle Pre-Conditioning for Enhanced Thermal Therapies in Cancer  

PubMed Central

Nanoparticles show tremendous promise in the safe and effective delivery of molecular adjuvants to enhance local cancer therapy. One important form of local cancer treatment that suffers from local recurrence and distant metastases is thermal therapy. Here we review a new concept involving the use of nanoparticle delivered adjuvants to “pre-condition” or alter the vascular and immunological biology of the tumor to enhance its susceptibility to thermal therapy. To this end, a number of opportunities to combine nanoparticles with vascular and immunologically active agents are reviewed. One specific example of pre-conditioning involves a gold nanoparticle tagged with a vascular targeting agent (i.e. TNF-?). This nanoparticle embodiment demonstrates pre-conditioning through a dramatic reduction in tumor blood flow and induction of vascular damage which recruits a strong and sustained inflammatory infiltrate in the tumor. The ability of this nanoparticle pre-conditioning to enhance subsequent heat or cold thermal therapy in a variety of tumor models is reviewed. Finally, the potential for future clinical imaging to judge the extent of pre-conditioning and thus the optimal timing and extent of combinatorial thermal therapy is discussed.

Shenoi, Mithun M.; Shah, Neha B.; Griffin, Robert J.; Vercellotti, Gregory M.; Bischof, John C.

2011-01-01

77

Overview of NASA's Thermal Control Technology Development Project  

NASA Technical Reports Server (NTRS)

NASA?s Constellation Program included the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, were planned to be manned space vehicles while the third element was much broader and included several sub-elements including Rovers and a Lunar Habitat. The planned missions involving these systems and vehicles included several risks and design challenges. Due to the unique thermal operating environment, many of these risks and challenges were associated with the vehicles? thermal control system. NASA?s Exploration Technology Development Program (ETDP) consisted of several technology development projects. The project chartered with mitigating the aforementioned thermal risks and design challenges was the Thermal Control System Development for Exploration Project. These risks and design challenges were being addressed through a rigorous technology development process that was planned to culminate with an integrated thermal control system test. Although these Constellation elements have been cancelled or significantly changed, the thermal technology development process is being continued within a new program entitled Enabling Technology Development and Demonstration (ETDD). The current paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing a material compatibility assessment for a promising thermal control system working fluid. The to-date progress and lessons-learned from these development efforts will be discussed throughout the paper.

Stephan, Ryan A.

2010-01-01

78

Demonstration of Passive Fuel Cell Thermal Management Technology  

NASA Technical Reports Server (NTRS)

The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates and integrated heat exchanger technology to collect the heat from the cooling plates (Ref. 1). The next step in the development of this passive thermal approach was the demonstration of the control of the heat removal process and the demonstration of the passive thermal control technology in actual fuel cell stacks. Tests were run with a simulated fuel cell stack passive thermal management system outfitted with passive cooling plates, an integrated heat exchanger and two types of cooling flow control valves. The tests were run to demonstrate the controllability of the passive thermal control approach. Finally, successful demonstrations of passive thermal control technology were conducted with fuel cell stacks from two fuel cell stack vendors.

Burke, Kenneth A.; Jakupca, Ian; Colozza, Anthony; Wynne, Robert; Miller, Michael; Meyer, Al; Smith, William

2012-01-01

79

Solar thermal technology evaluation, fiscal year 1982. Volume 2: Technical  

NASA Technical Reports Server (NTRS)

The technology base of solar thermal energy is investigated. The materials, components, subsystems, and processes capable of meeting specific energy cost targets are emphasized, as are system efficiency and reliability.

1983-01-01

80

Solar Thermal Technology Program Bibliography, 1973-1985.  

National Technical Information Service (NTIS)

This bibliography contains citations of technical publications that have emerged from the US Department of Energy's Solar Thermal Technology (STT) Program. The entries include research performed at the federal laboratories and at various universities and ...

1986-01-01

81

TREATMENT OF HAZARDOUS PETROLEUM CONTAMINATED SOILS BY THERMAL DESORPTION TECHNOLOGIES  

EPA Science Inventory

Spills, leaks, and accidental discharges of petroleum products have contaminated soil at thousands of sites in the United States. ne remedial action technique for treating petroleum contaminated soil is the use of thermal desorption technologies. his paper describes key elements ...

82

APPLICATION OF THERMAL DESORPTION TECHNOLOGIES TO HAZARDOUS WASTE SITES  

EPA Science Inventory

Thermal desorption is a separation process frequently used to remediate many Superfund sites. hermal desorption technologies are recommended and used because of (1) the wide range of organic contaminants effectively treated, (2) availability and mobility of commercial systems, an...

83

Influence of anomalous thermal losses of ignition conditions  

SciTech Connect

In the process of achieving ignition conditions, it is likely that microinstabilities, which lead to anomalous thermal transport of the fusing nuclei, will be present. When such phenomena are taken into account, an appropriate formulation of ignition criteria becomes necessary. In particular, a new type of plasma density limit is identified.

Coppi, B.; Tang, W.M.

1986-05-01

84

Hypothetical accident conditions thermal analysis of the 5320 package.  

National Technical Information Service (NTIS)

An axisymmetric model of the 5320 package was created to perform hypothetical accident conditions (HAC) thermal calculations. The analyses assume the 5320 package contains 359 grams of plutonium-238 (203 Watts) in the form of an oxide powder at a minimum ...

S. J. Hensel R. J. Gromada

1995-01-01

85

Treatment of Recycle Streams from Thermal Sludge Conditioning.  

National Technical Information Service (NTIS)

The thermal conditioning and dewatering of activated sludges in wastewater treatment plants results in decant and filtrate streams that are high in organic matter. Although the volume of the recycle flow is small, the high strength may add as much as 20% ...

R. R. Dague

1983-01-01

86

Estimating Thermal Inertia with a Maximum Entropy Boundary Condition  

NASA Astrophysics Data System (ADS)

Thermal inertia, P [Jm-2s-1/2K-1], is a physical property the land surface which determines resistance to temperature change under seasonal or diurnal heating. It is a function of volumetric heat capacity, c [Jm-3K-1], and thermal conductivity, k [Wm-1K-1] of the soil near the surface: P=?ck. Thermal inertia of soil varies with moisture content due the difference between thermal properties of water and air, and a number of studies have demonstrated that it is feasible to estimate soil moisture given thermal inertia (e.g. Lu et al, 2009, Murray and Verhoef, 2007). We take the common approach to estimating thermal inertia using measurements of surface temperature by modeling the Earth's surface as a 1-dimensional homogeneous diffusive half-space. In this case, surface temperature is a function of the ground heat flux (G) boundary condition and thermal inertia and a daily value of P was estimated by matching measured and modeled diurnal surface temperature fluctuations. The difficulty is in measuring G; we demonstrate that the new maximum entropy production (MEP) method for partitioning net radiation into surface energy fluxes (Wang and Bras, 2011) provides a suitable boundary condition for estimating P. Adding the diffusion representation of heat transfer in the soil reduces the number of free parameters in the MEP model from two to one, and we provided a sensitivity analysis which suggests that, for the purpose of estimating P, it is preferable to parameterize the coupled MEP-diffusion model by the ratio of thermal inertia of the soil to the effective thermal inertia of convective heat transfer to the atmosphere. We used this technique to estimate thermal inertia at two semiarid, non-vegetated locations in the Walnut Gulch Experimental Watershed in southeast AZ, USA and compared these estimates to estimates of P made using the Xue and Cracknell (1995) solution for a linearized ground heat flux boundary condition, and we found that the MEP-diffusion model produced superior thermal inertia estimates. The MEP-diffusion estimates also agreed well with P estimates made using a boundary condition measured with buried flux plates. We further demonstrated the new method using diurnal surface temperature fluctuations estimated from day/night MODIS image pairs and, excluding instances where the soil was extremely dry, found a strong relationship between estimated thermal inertia and measured 5 cm soil moisture. Lu, S., Ju, Z.Q., Ren, T.S. & Horton, R. (2009). A general approach to estimate soil water content from thermal inertia. Agricultural and Forest Meteorology, 149, 1693-1698. Murray, T. & Verhoef, A. (2007). Moving towards a more mechanistic approach in the determination of soil heat flux from remote measurements - I. A universal approach to calculate thermal inertia. Agricultural and Forest Meteorology, 147, 80-87. Wang, J.F. & Bras, R.L. (2011). A model of evapotranspiration based on the theory of maximum entropy production. Water Resources Research, 47. Xue, Y. & Cracknell, A.P. (1995). Advanced thermal inertia modeling. International Journal of Remote Sensing, 16, 431-446.

Nearing, G.; Moran, M. S.; Scott, R.; Ponce-Campos, G.

2012-04-01

87

Uranium-Mill-Tailings Conditioning Technology.  

National Technical Information Service (NTIS)

Conditioning of uranium mill tailings involves the physico-chemical alteration of tailings to remove or immobilize mobile radionuclides and toxic trace elements before disposal in a repository. The principal immobilization approach under investigation is ...

D. R. Dreesen E. J. Cokal P. D. O'Brien E. F. Thode L. E. Wangen

1982-01-01

88

Solar Thermal Energy: An Overview of One-Sun Solar Thermal Technology  

NSDL National Science Digital Library

This presentation from the Advanced Technology Environmental and Energy Center (ATEEC) provides an introduction to solar thermal energy. The presentation includes descriptions of solar basics, technology and future solar technology systems. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

Burch, Jay

2013-01-03

89

Sludge dewatering using centrifuge with thermal/polymer conditioning.  

PubMed

Sludge dewatering is preceded by a conditioning operation to enhance water removal efficiency. In the conditioning operation, chemical coagulants or polymers are added to promote sludge particle aggregation for easier dewatering. In this study, an alternative conditioning method for sludge thermal treatment at temperatures up to 80 degrees C was extensively investigated. Dewatering characteristics such as sludge capillary suction time and specific resistance to filtration, sludge viscosity and concentration of solid cakes were examined thoroughly. A good correlation between capillary suction time and specific resistance to filtration was established for sludges from water treatment, but not for biological sludge. Cationic polymer exhibits the best enhancement on sludge moisture removal. The sludge rheogram varies from 60 to 5 cP as temperature changes from 20 to 80 degrees C for sludges from water treatment plant. The dewatering ability of sludge can be greatly enhanced by thermal treatment in conjunction with the use of polymers. PMID:11794673

Lin, C F; Shien, Y

2001-01-01

90

Estimation of package temperatures during hypothetical accident thermal test conditions  

SciTech Connect

Knowledge of package maximum temperatures during normal transport and hypothetical accident thermal test conditions is required to ensure that a package for the transportation of radioactive materials is designed adequately to meet the requirements specified in the Code of Federal Regulations. The testing procedure for the hypothetical accident thermal event is to expose the whole package to a radiation environment of 800{degrees}C (1475{degrees}F) for a period of 30 minutes, with the ambient temperature before and after the 30-min test held constant at 38{degrees}C (100{degrees}F). To determine the temperatures of a package during the hypothetical accident thermal event, the designers and reviewers perform detailed analyses with computer codes. Because detailed modeling of the package and solving the thermal diffusion equation with computer codes require considerable time and effort, simple conservative estimating procedures are therefore preferred because the very detailed and time-consuming numerical computation can be avoided if the results of a simple conservative estimation can show that a package meets the requirements. The simple procedure presented in this paper provides quick and conservative estimation of package maximum temperatures, T{sub max}({times}), at a distance {times} from the surface, during hypothetical accident thermal test conditions. The analytical solutions for temperature in a semi-infinite solid and in an infinitely long circular cylinder, subjected to a step surface-temperature boundary condition, are applied to estimate the maximum temperature. The procedure is applicable to all packages, with or without an internal heat source, that have rectangular or cylindrical thermal insulating overpacks. Examples, mathematical proof, and qualitative arguments are presented to show that the proposed method is conservative and easy to use.

Shah, V.L.

1995-12-31

91

Thermal Cyclic Behavior of Thermal and Environmental Barrier Coatings Investigated Under High-Heat-Flux Conditions  

NASA Technical Reports Server (NTRS)

Environmental barrier coatings (EBC's) have been developed to protect silicon-carbide- (SiC) based ceramic components in gas turbine engines from high-temperature environmental attack. With continuously increasing demands for significantly higher engine operating temperature, future EBC systems must be designed for both thermal and environmental protection of the engine components in combustion gases. In particular, the thermal barrier functions of EBC's become a necessity for reducing the engine-component thermal loads and chemical reaction rates, thus maintaining the required mechanical properties and durability of these components. Advances in the development of thermal and environmental barrier coatings (TBC's and EBC's, respectively) will directly impact the successful use of ceramic components in advanced engines. To develop high-performance coating systems, researchers must establish advanced test approaches. In this study, a laser high-heat-flux technique was employed to investigate the thermal cyclic behavior of TBC's and EBC's on SiC-reinforced SiC ceramic matrix composite substrates (SiC/SiC) under high thermal gradient and thermal cycling conditions. Because the laser heat flux test approach can monitor the coating's real-time thermal conductivity variations at high temperature, the coating thermal insulation performance, sintering, and delamination can all be obtained during thermal cycling tests. Plasma-sprayed yttria-stabilized zirconia (ZrO2-8 wt% Y2O3) thermal barrier and barium strontium aluminosilicate-based environmental barrier coatings (BSAS/BSAS+mullite/Si) on SiC/SiC ceramic matrix composites were investigated in this study. These coatings were laser tested in air under thermal gradients (the surface and interface temperatures were approximately 1482 and 1300 C, respectively). Some coating specimens were also subject to alternating furnace cycling (in a 90-percent water vapor environment at 1300 C) and laser thermal gradient cycling tests (in air), to investigate the water vapor effect. All cyclic tests were conducted using a 60-min hot-time temperature.

Zhu, Dongming; Lee, Kang N.; Miller, Robert A.

2002-01-01

92

Boundary conditions for thermal lattice Boltzmann equation method  

NASA Astrophysics Data System (ADS)

We propose a thermal boundary condition treatment based on the "bounce-back" idea and interpolation of the distribution functions for both the Dirichlet and Neumann (normal derivative) conditions in the thermal lattice Boltzmann equation (TLBE) method. The coefficients for the distribution functions involved are determined to satisfy the Dirichlet or Neumann condition with second-order accuracy. For the Dirichlet condition there is an adjustable parameter in the treatment and three particular schemes are selected for demonstration, while for the Neumann condition the second-order accurate scheme is unique. When applied to inclined or curved boundaries, the Dirichlet condition treatment can be directly used, while the Neumann condition given in the normal direction of the boundary should be converted into derivative conditions in the discrete velocity directions of the TLBE model. A spatially coupled formula relating the boundary temperature, boundary normal heat flux, and the distribution functions near the boundary is thus derived for the Neumann problems on curved boundaries. The applicability and accuracy of the present boundary treatments are examined with several numerical tests for which analytical solutions are available, including the 2-dimensional (2-D) steady-state channel flow, the 1-D transient heat conduction in an inclined semi-infinite solid, the 2-D steady-state and transient heat conduction inside a circle and the 3-D steady-state circular pipe flow. While the Dirichlet condition treatment leads to second-order accuracy for the temperature field, it only gives a first-order accurate boundary heat flux because of the irregularity of the cuts by the curved boundary with the lattices. With the Neumann condition on the curved boundary, the accuracy for the temperature field obtained is first-order. When the tangential temperature gradient on the boundary is decoupled, second-order convergence of the temperature field can be obtained with Neumann conditions.

Li, Like; Mei, Renwei; Klausner, James F.

2013-03-01

93

Evaluation of airborne thermal, magnetic, and electromagnetic characterization technologies  

Microsoft Academic Search

The identification of Buried Structures (IBS) or Aerial Surveillance Project was initiated by the US Department of Energy (DOE) Office of Technology Development to demonstrate airborne methods for locating and identifying buried waste and ordnance at the Idaho National Engineering Laboratory (INEL). Two technologies were demonstrated: (a) a thermal infrared imaging system built by Martin Marietta Missile Systems and (b)

Josten

1992-01-01

94

Assessing condition of turbine engine ceramic components through NDE technology.  

SciTech Connect

Thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs) are under development for hot-gas path components to allow higher gas-firing temperatures in advanced (high-efficiency, low-emission) gas turbines. Increasing dependence on the reliability of TBC and EBC components has driven the need for nondestructive evaluation (NDE) methods to assess the condition, or ''health status,'' of these coatings. NDE methods based on elastic optical scatter and thermal imaging have been applied to TBC-coated test specimens that were thermally cycled and to EBC-coated SiC/SiC components that were run in 4.5 MW(e) field-test turbines. One primary interest is to develop NDE methods that can predict a prespall condition. Resulting data suggest a correlation between laser scatter data and thermal cycles for TBC-coated specimens, and thermal imaging results have demonstrated prespall detection for an EBC-coated SiC/SiC combustor liner.

Ellingson, W.A.; Sun, J.G.; Deemer, C.; Erdman, S.; Prested, C.

2002-04-12

95

Accepted practices of thermal spray technology  

NASA Astrophysics Data System (ADS)

This is the fourth and final article in a series of articles dealing with the metallographic preparation and evaluation of thermal spray coatings. Previous articles have covered variables and best practices for the sectioning, mounting, and coarse grinding of coated components. In this article, the relationship between fine grinding and polishing practices, consumables, and resultant plasma spray coating structure are discussed.

Sobota, Lori

2006-06-01

96

High-Temperature Adhesives for Thermally Stable Aero-Assist Technologies  

NASA Technical Reports Server (NTRS)

Aero-assist technologies are used to control the velocity of exploration vehicles (EVs) when entering Earth or other planetary atmospheres. Since entry of EVs in planetary atmospheres results in significant heating, thermally stable aero-assist technologies are required to avoid the high heating rates while maintaining low mass. Polymer adhesives are used in aero-assist structures because of the need for high flexibility and good bonding between layers of polymer films or fabrics. However, current polymer adhesives cannot withstand temperatures above 400 C. This innovation utilizes nanotechnology capabilities to address this need, leading to the development of high-temperature adhesives that exhibit high thermal conductivity in addition to increased thermal decomposition temperature. Enhanced thermal conductivity will help to dissipate heat quickly and effectively to avoid temperature rising to harmful levels. This, together with increased thermal decomposition temperature, will enable the adhesives to sustain transient high-temperature conditions.

Eberts, Kenneth; Ou, Runqing

2013-01-01

97

Thermal momentum distribution from path integrals with shifted boundary conditions.  

PubMed

For a thermal field theory formulated in the grand canonical ensemble, the distribution of the total momentum is an observable characterizing the thermal state. We show that its cumulants are related to thermodynamic potentials. In a relativistic system, for instance, the thermal variance of the total momentum is a direct measure of the enthalpy. We relate the generating function of the cumulants to the ratio of (a) a partition function expressed as a Matsubara path integral with shifted boundary conditions in the compact direction and (b) the ordinary partition function. In this form the generating function is well suited for Monte Carlo evaluation, and the cumulants can be extracted straightforwardly. We test the method in the SU(3) Yang-Mills theory and obtain the entropy density at three different temperatures. PMID:21517372

Giusti, Leonardo; Meyer, Harvey B

2011-04-01

98

Thermal and electrical conductivity of iron at Earth's core conditions  

NASA Astrophysics Data System (ADS)

The power supplied to the geodynamo, measured by the heat-flux at the core-mantle boundary (CMB), places constraints on the evolution of Earth's core. Estimates of CMB heat-flux depend on properties of iron mixtures under the extreme pressure and temperature conditions in the core, most critically on the thermal and electrical conductivities. Recently, we computed these conductivities at core conditions for liquid iron mixtures that fit the seismologically-determined core density and inner-core boundary density jump. Both conductivities were found to be 2-3 times higher than estimates in current use. Here we describe a reassessment of the power requirements for the geodynamo based on the revised conductivity values and new estimates of the mass diffusion coefficients for individual components of the mixtures. The adiabatic heat-flux at the CMB is found to be 15-16 TW at the CMB, higher than present estimates of CMB heat-flux based on mantle convection. A thermally stratified layer beneath the CMB appears unavoidable unless a very high present-day CMB heat-flux can be maintained, which requires a rapid CMB cooling rate and an inner core that is only a few hundred years old. We estimate stable layer thicknesses by computing the radial variation of thermal and compositional gradients for a range of plausible CMB heat-flux values and assuming that the base of the layer is defined by the condition for neutral buoyancy. Thermally stable layers spanning hundreds of kilometres are found for all cases except those where the inner core is very young. These calculations also suggest that compositional buoyancy may not be sufficient to overcome the large stabilising thermal gradient; any convection in the upper core must be driven by dynamical instabilities arising from convection deeper inside the core, or by lateral variations in CMB heat flow.

Davies, C. J.; Pozzo, M.; Gubbins, D.; Alfe, D.

2012-12-01

99

Thermal diffusivity measurements using insulating and isothermal boundary conditions  

NASA Astrophysics Data System (ADS)

Many methods exist to measure thermal diffusivity using either steady state or transient techniques. Steady state methods yield large experimental error and inaccuracies. Transient techniques, namely, the laser flash method, are expensive and require specialized equipment and advanced data analysis. In this paper, a novel experimental setup is devised to evaluate thermal diffusivity. In this experiment hot isothermal and insulating boundary conditions are imposed on a flat disk sample. The transient temperature profile of the insulated side of the sample is analytically similar to a classic time constant formulation. The thermal diffusivity is proportional to the inverse time constant. This method hosts a variety of advantages over other methods such as accuracy comparable to other methods, low cost, integrated modeling of interface effects, and small sample size. Several materials with low to medium thermal diffusivity (0.1 ? 3 mm2/s) have been measured. The diameter of the sample is 32 mm and its thickness ranges from 2 to 6.5 mm. The thermal diffusivity measurements in this experiment have an accuracy of 5% or better in comparison to the literature values.

Shekhani, H. N.; Uchino, K.

2014-01-01

100

Guidelines on Thermal Comfort of Air Conditioned Indoor Environment  

NASA Astrophysics Data System (ADS)

The thermal comfort of air conditioned indoor environment for workers depended, of course, on metabolic rate of work, race, sex, age, clothing, climate of the district and state of acclimatization. The attention of the author was directed to the seasonal variation and the sexual difference of comfortable temperature and a survey through a year was conducted on the thermal comfort, and health conditions of workers engaged in light work in a precision machine factory, in some office workers. Besides, a series of experiments were conducted for purpose of determinning the optimum temperature of cooling in summer time in relation to the outdoor temperature. It seemed that many of workers at present would prefer somewhat higher temperature than those before the World War II. Forty years ago the average homes and offices were not so well heated as today, and clothing worn on the average was considerably heavier.

Miura, Toyohiko

101

Electro Thermal Chemical Gun Technology Study.  

National Technical Information Service (NTIS)

This study of ETC gun technology was performed at the request of Dr. John Parmentola, Acting Director for Research and Lab Management, Office of the Secretary, U.S. Army. Funding for the study was provided by the Army Research Office under the guidance of...

P. Diamond P. Dimotakis D. Hammer J. Katz J. Sullivan

1999-01-01

102

Alternative technologies for refrigeration and air-conditioning applications. Final report, October 1991-December 1993  

SciTech Connect

The report gives results of an assessment of refrigeration technologies that are alternatives to vapor compression refrigeration for use in five application categories: domestic air conditioning, commercial air conditioning, mobile air conditioning, domestic refrigeration, and commercial refrigeration. A fundamental criterion for the selection of the alternative refrigeration technologies to be assessed was that they be environmentally safe. The study was conducted in three phases: a survey of U.S. patents, system modeling, and a technology assessment. Each refrigeration application was defined by a set of thermal source and sink temperatures. The U.S. patent survey was conducted from 1918 to the present. A method was developed for classifying refrigeration technologies found during the survey.

Gauger, D.C.; Shapiro, H.N.; Pate, M.B.

1995-05-01

103

Stability conditions, nonlinear dynamics, and thermal runaway in microbolometers  

SciTech Connect

The nonlinear dynamic behavior of microbolometers, operating at room temperature (300 K) under conditions of positive electrothermal feedback is investigated. An improved device model, based on the heat balance equation is developed. It takes into account the temperature dependence of the thermophysical parameters, such as thermal coupling coefficient between the sensor and its surroundings, and sensor heat capacity and its thermal resistance coefficient. Operational considerations for thermoresistive microbolometer with positive and negative temperature coefficient of resistance are discussed for both, constant current and constant voltage modes of operation. Analytical expressions are derived for predicting stable and unstable operation. Safety factors L{sub 0}, establishing the biasing conditions for stable device operation are proposed for the positive temperature coefficient of resistance and negative temperature coefficient of resistance type sensors. Limits for fast catastrophic destruction are provided, and the dynamic characteristics of the associated thermal runaway phenomenon is illustrated. This effect, as predicted by analysis and numerical simulation, was observed experimentally, confirming the validity of the proposed modeling approach for the microbolometer. {copyright} 2001 American Institute of Physics.

Brandao, G. B.; de Almeida, L. A. L.; Deep, G. S.; Lima, A. M. N.; Neff, H.

2001-08-15

104

Ceramic technology for solar thermal receivers  

NASA Technical Reports Server (NTRS)

The high-temperature capability, resistance to corrosive environments and non-strategic nature of ceramics have prompted applications in the solar thermal field whose advantages over metallic devices of comparable performance may begin to be assessed. It is shown by a survey of point-focusing receiver designs employing a variety of ceramic compositions and fabrication methods that the state-of-the-art in structural ceramics is not sufficiently advanced to fully realize the promised benefits of higher temperature capabilities at lower cost than metallic alternatives. The ceramics considered include alumina, berylia, magnesia, stabilized zirconia, fused silica, silicon nitride, silicon carbide, mullite and cordierite, processed by such methods as isostatic pressing, dry pressing, slip casting, extrusion, calendaring and injection molding.

Kudirka, A. A.; Smoak, R. H.

1981-01-01

105

Advancements in thermal spallation drilling technology  

SciTech Connect

Thermal spallation of hard rocks has been used commercially for many years to cut granite in quarries and to produce blasting holes in taconite mines. It is potentially an economic process for creating cavities in hard rocks that are difficult to drill or mine by conventional methods. These cavities might have application for storage of liquids and gases and of energy in several forms. They may also be used as high-pressure, naturally heated retorts for certain chemical processes. This report describes the spallation process, including the fluid dynamics and heat transfer from flame jets to the rock and subsequent rock failure. Our model of the spallation process predicts with good accuracy the surface temperatures and heat-transfer rates required to maintain desired drilling rates. Field tests, including site selection, equipment, field operations, and accomplishments, are also described in detail. 31 refs., 13 figs., 1 tab.

Williams, R.E.; Dey, T.; Rauenzahn, R.; Kranz, R.; Tester, J.; Potter, R.; Murphy, H.

1988-09-01

106

Lightweight Nonmetallic Thermal Protection Materials Technology  

NASA Technical Reports Server (NTRS)

To fulfill President George W. Bush's "Vision for Space Exploration" (2004) - successful human and robotic missions to and from other solar system bodies in order to explore their atmospheres and surfaces - the National Aeronautics and Space Administration (NASA) must reduce the trip time, cost, and vehicle weight so that the payload and scientific experiments' capabilities can be maximized. The new project described in this paper will generate thermal protection system (TPS) product that will enable greater fidelity in mission/vehicle design trade studies, support risk reduction for material selections, assist in the optimization of vehicle weights, and provide materials and processes templates for use in the development of human-rated TPS qualification and certification plans.

Valentine, Peter G.; Lawrence, Timothy W.; Gubert, Michael K.; Milos, Frank S.; Levine, Stanley R.; Ohlhorst, Craig W.; Koenig, John R.

2005-01-01

107

Heating, Ventilating, and Air Conditioning. Energy Technology Series.  

ERIC Educational Resources Information Center

This course in heating, ventilating, and air conditioning is one of 16 courses in the Energy Technology Series developed for an Energy Conservation-and-Use Technology curriculum. Intended for use in two-year postsecondary technical institutions to prepare technicians for employment, the courses are also useful in industry for updating employees in…

Center for Occupational Research and Development, Inc., Waco, TX.

108

Thermal batteries: A technology review and future directions  

SciTech Connect

Thermally activated (``thermal``) batteries have been used for ordnance applications (e.g., proximity fuzes) since World War II and, subsequent to that, in nuclear weapons. This technology was developed by the Germans as a power source for their V2 rockets. It was obtained by the Allies by interrogation of captured German scientists after the war. The technology developed rapidly from the initial primitive systems used by the Germans to one based on Ca/CaCrO{sub 4}. This system was used very successfully into the late 1970s, when it was replaced by the Li-alloy/FeS{sub 2} electrochemical system. This paper describes the predominant electrochemical couples that have been used in thermal batteries over the years. Major emphasis is placed on the chemistry and electrochemistry of the Ca/CaCrO{sub 4} and Li-alloy/FeS{sub 2} systems. The reason for this is to give the reader a better appreciation for the advances in thermal-battery technology for which these two systems are directly responsible. Improvements to date in the current Li-alloy/FeS{sub 2} and related systems are discussed and areas for possible future research and development involving anodes, cathodes, electrolytes, and insulations are outlined. New areas where thermal-battery technology has potential applications are also examined.

Guidotti, R.A.

1995-07-01

109

Validating an infrared thermal switch as a novel access technology  

PubMed Central

Background Recently, a novel single-switch access technology based on infrared thermography was proposed. The technology exploits the temperature differences between the inside and surrounding areas of the mouth as a switch trigger, thereby allowing voluntary switch activation upon mouth opening. However, for this technology to be clinically viable, it must be validated against a gold standard switch, such as a chin switch, that taps into the same voluntary motion. Methods In this study, we report an experiment designed to gauge the concurrent validity of the infrared thermal switch. Ten able-bodied adults participated in a series of 3 test sessions where they simultaneously used both an infrared thermal and conventional chin switch to perform multiple trials of a number identification task with visual, auditory and audiovisual stimuli. Participants also provided qualitative feedback about switch use. User performance with the two switches was quantified using an efficiency measure based on mutual information. Results User performance (p = 0.16) and response time (p = 0.25) with the infrared thermal switch were comparable to those of the gold standard. Users reported preference for the infrared thermal switch given its non-contact nature and robustness to changes in user posture. Conclusions Thermal infrared access technology appears to be a valid single switch alternative for individuals with disabilities who retain voluntary mouth opening and closing.

2010-01-01

110

Innovative site remediation technology: Thermal desorption. Volume 6  

SciTech Connect

The monograph on thermal desorption is one of a series of eight on innovative site and waste remediation technologies that are the culmination of a multiorganization effort involving more than 100 experts over a two-year period. The thermal desorption processes addressed in this monograph use heat, either direct or indirect, ex situ, as the principal means to physically separate and transfer contaminants from soils, sediments, sludges, filter cakes, or other media. Thermal desorption is part of a treatment train; some pre- and postprocessing is necessary.

Anderson, W.C.

1993-11-01

111

Active Dust Mitigation Technology for Thermal Radiators for Lunar Exploration  

NASA Technical Reports Server (NTRS)

Dust accumulation on thermal radiator surfaces planned for lunar exploration will significantly reduce their efficiency. Evidence from the Apollo missions shows that an insulating layer of dust accumulated on radiator surfaces could not be removed and caused serious thermal control problems. Temperatures measured at different locations in the magnetometer on Apollo 12 were 38 C warmer than expected due to lunar dust accumulation. In this paper, we report on the application of the Electrodynamic Dust Shield (EDS) technology being developed in our NASA laboratory and applied to thermal radiator surfaces. The EDS uses electrostatic and dielectrophoretic forces generated by a grid of electrodes running a 2 micro A electric current to remove dust particles from surfaces. Working prototypes of EDS systems on solar panels and on thermal radiators have been successfully developed and tested at vacuum with clearing efficiencies above 92%. For this work EDS prototypes on flexible and rigid thermal radiators were developed and tested at vacuum.

Calle, C. I.; Buhler, C. R.; Hogue, M. D.; Johansen, M. R.; Hopkins, J. W.; Holloway, N. M. H.; Connell, J. W.; Chen, A.; Irwin, S. A.; Case, S. O.; VanSuetendael, N. J.; Snyder, S. J.; Clements, J. S.

2010-01-01

112

Thermal and electrical conductivity of iron at Earth's core conditions.  

PubMed

The Earth acts as a gigantic heat engine driven by the decay of radiogenic isotopes and slow cooling, which gives rise to plate tectonics, volcanoes and mountain building. Another key product is the geomagnetic field, generated in the liquid iron core by a dynamo running on heat released by cooling and freezing (as the solid inner core grows), and on chemical convection (due to light elements expelled from the liquid on freezing). The power supplied to the geodynamo, measured by the heat flux across the core-mantle boundary (CMB), places constraints on Earth's evolution. Estimates of CMB heat flux depend on properties of iron mixtures under the extreme pressure and temperature conditions in the core, most critically on the thermal and electrical conductivities. These quantities remain poorly known because of inherent experimental and theoretical difficulties. Here we use density functional theory to compute these conductivities in liquid iron mixtures at core conditions from first principles--unlike previous estimates, which relied on extrapolations. The mixtures of iron, oxygen, sulphur and silicon are taken from earlier work and fit the seismologically determined core density and inner-core boundary density jump. We find both conductivities to be two to three times higher than estimates in current use. The changes are so large that core thermal histories and power requirements need to be reassessed. New estimates indicate that the adiabatic heat flux is 15 to 16 terawatts at the CMB, higher than present estimates of CMB heat flux based on mantle convection; the top of the core must be thermally stratified and any convection in the upper core must be driven by chemical convection against the adverse thermal buoyancy or lateral variations in CMB heat flow. Power for the geodynamo is greatly restricted, and future models of mantle evolution will need to incorporate a high CMB heat flux and explain the recent formation of the inner core. PMID:22495307

Pozzo, Monica; Davies, Chris; Gubbins, David; Alfč, Dario

2012-05-17

113

Low-thrust chemical propulsion system propellant expulsion and thermal conditioning study  

NASA Technical Reports Server (NTRS)

Thermal conditioning systems for satisfying engine net positive suction pressure (NPSP) requirements, and propellant expulsion systems for achieving propellant dump during a return-to-launch site (RTLS) abort were studied for LH2/LO2 and LCH4/LO2 upper stage propellant combinations. A state-of-the-art thermal conditioning system employing helium injection beneath the liquid surface shows the lowest weight penalty for LO2 and LCH4. A technology system incorporating a thermal subcooler (heat exchanger) for engine NPSP results in the lowest weight penalty for the LH2 tank. A preliminary design of two state-of-the-art and two new technology systems indicates a weight penalty difference too small to warrant development of a LH2 thermal subcooler. Analysis results showed that the LH2/LO2 propellant expulsion system is optimized for maximum dump line diameters, whereas the LCH4/LO2 system is optimized for minimum dump line diameter (LCH4) and maximum dump line diameter (LO2). The primary uncertainty is the accurate determination of two-phase flow rates through the dump system; experimentation is not recommended because this uncertainty is not considered significant.

Merino, F.; Wakabayashi, I.; Pleasant, R. L.; Hill, M.

1982-01-01

114

Generalized elastic model: Thermal vs. non-thermal initial conditions —Universal scaling, roughening, ageing and ergodicity  

NASA Astrophysics Data System (ADS)

We study correlation properties of the generalized elastic model which accounts for the dynamics of polymers, membranes, surfaces and fluctuating interfaces, among others. We develop a theoretical framework which leads to the emergence of universal scaling laws for systems starting from thermal (equilibrium) or non-thermal (non-equilibrium) initial conditions. Our analysis incorporates and broadens previous results such as observables' double scaling regimes, (super)roughening and anomalous diffusion, and furnishes a new scaling behavior for correlation functions at small times (long distances). We discuss ageing and ergodic properties of the generalized elastic model in non-equilibrium conditions, providing a comparison with the situation occurring in continuous time random walk. Our analysis also allows to assess which observable is able to distinguish whether the system is in or far from equilibrium conditions in an experimental set-up.

Taloni, A.; Chechkin, A.; Klafter, J.

2012-02-01

115

The thermal boundary condition for high speed seal flow  

SciTech Connect

Earlier derived relationships for Couette flow with thermoviscous fluids are adapted to accommodate thermal resistances between the bounding surfaces and the ambient. Recognizing that these equations are approximate, correction coefficients are included; and the magnitudes of these are evaluated to make the approximate predictions agree with accurate numerical calculations. The correction coefficients are shown to lie close to unity over most of the range of expected operating conditions. The establishment of these convenient representations provides a basis for examining the interactions of thermoviscous films with more complex bearing and seal geometries. 14 refs.

Burton, R.A. (Burton Technologies, Inc., Raleigh, NC (USA))

1991-04-01

116

Application of Database Technology in Bridge Condition Assessment  

Microsoft Academic Search

Huge number of testing data are needed to be handled in the bridge condition assessment. If there is not a good handled and archived method, these testing data will be omitted or lost since these testing data are extremely bulky. Database technology is adopted to deal with testing data in the bridge condition assessment. 84 data tables, 184 stored procedures

Deshan Shan; Chunyu Fu; Qiao Li

2010-01-01

117

Thermally Stable Mesoporous Silica Spheres synthesized under Mild Conditions  

NASA Astrophysics Data System (ADS)

Thermally stable, mesoporous silica spheres were synthesized using a one-pot technique under mild conditions. As-calcined silica spheres were shown to be highly porous with surface areas greater than 1000 m^2/g and pore volumes on the order of 1 cc/g. Pore walls were found to be highly resistant to collapse as a consequence of thermal treatment at temperatures exceeding 750 C or hydrothermal treatment in boiling water at temperatures exceeding 100 C for over 100 hours. ^29Si-^1H cross polarization NMR data indicate that the silica is highly condensed at the surface providing rationale for the exceptional pore wall stability observed. The mesoporous silica spheres were synthesized from tetraethyl orthosilicate (TEOS) at room temperature and near-neutral pH using cysteamine and cetyltrimethylammonium bromide (CTAB) in a mixed water and ethanol system. Sphere size was shown to be tunable by altering the relative amounts of ethanol, CTAB, or TEOS. Sphere diameters ranging from 30 nm to 560 nm were observed. The preparation method and characterization of these highly condensed, thermally stable, mesoporous silica spheres for applications including sensing, catalysis, purification, and payload encapsulation is presented.

Ziegler, Christopher; You, Eunyoung; Watkins, James

2009-03-01

118

Alternative energy sources session ocean thermal energy conversion: Technology development  

NASA Astrophysics Data System (ADS)

Four ocean-energy technologies with significant promise are explored: ocean thermal energy conversion; wave power; ocean currents; and salinity gradients. The major funding emphasis has been in OTEC. Technical developments, accomplishments and major findings, remaining problems, and proposed plans for the future are discussed.

Richards, W. E.; Vadus, J. R.

1980-03-01

119

Capital cost estimates of selected advanced thermal energy storage technologies  

Microsoft Academic Search

A method for evaluating the first cost of diverse advanced thermal energy storage (TES) concepts on a common basis is presented. For a total sample of at least 20 baseline and advanced TES technologies, the methodology developed was to be applied in the calculation of actual cost and performance measures. Work on the development of TES focused on 5 types

W. T. Lawrence

1980-01-01

120

Site technology capsule: Clean Berkshires, Inc. thermal desorption system  

SciTech Connect

The thermal desorption process devised by Clean Berkshires Inc. (CBI) uses standard rotary kiln technology to remove organic contaminants from excavated solid wastes. The process works by vaporizing and isolating the constituents in a gas stream and then destroying them in a high-efficiency afterburner. The processed solids are either reused or disposed of as nonhazardous, depending on applicable regulations.

Not Available

1994-08-01

121

Advances in NASA's Nuclear Thermal Propulsion Technology project  

NASA Technical Reports Server (NTRS)

The status of the Nuclear Thermal Propulsion (NTP) project for space exploration and the future plans for NTP technology are discussed. Current activities in the framework of the NTP project deal with nonnuclear material tests; instrumentation, controls, and health management; turbopumps; nozzles and nozzle extension; and an exhaust plume.

Peecook, Keith M.; Stone, James R.

1993-01-01

122

A review on photovoltaic\\/thermal hybrid solar technology  

Microsoft Academic Search

A significant amount of research and development work on the photovoltaic\\/thermal (PVT) technology has been done since the 1970s. Many innovative systems and products have been put forward and their quality evaluated by academics and professionals. A range of theoretical models has been introduced and their appropriateness validated by experimental data. Important design parameters are identified. Collaborations have been underway

T. T. Chow

2010-01-01

123

Thermal degradation of folates under varying oxygen conditions.  

PubMed

Folate losses in thermally treated foods are mainly due to oxidation. Other mechanisms and folate vitamers behaviour are poorly described. Our study evaluated oxygen impact on total folate degradation and derivatives' evolution during thermal treatments. Spinach and green bean purees were heated, in an instrumented reactor, in anaerobic conditions, under an oxygen partial pressure of 40kPa. Folates were stable in the absence of oxygen, whilst they were degraded under 40kPa of oxygen. Total folate showed a sharp decrease in the first hour driven by the degradation of 5-CH3-H4folate, followed by a plateau due to the formyl derivatives and minor compounds stability. The different evolution of the main derivatives was confirmed by the degradation of 5-CH3-H4folate and folic acid in solution, under the same conditions of oxygen concentrations. The stability of folic acid and the high susceptibility of 5-CH3-H4folate to degradation in the presence of oxygen were confirmed. PMID:25038652

Delchier, Nicolas; Ringling, Christiane; Cuvelier, Marie-Elisabeth; Courtois, Francis; Rychlik, Michael; Renard, Catherine M G C

2014-12-15

124

Numerical Determination of Critical Conditions for Thermal Ignition  

NASA Technical Reports Server (NTRS)

The determination of ignition or thermal explosion in an oxidizing porous body of material, as described by a dimensionless reaction-diffusion equation of the form .tu = .2u + .e-1/u over the bounded region O, is critically reexamined from a modern perspective using numerical methodologies. First, the classic stationary model is revisited to establish the proper reference frame for the steady-state solution space, and it is demonstrated how the resulting nonlinear two-point boundary value problem can be reexpressed as an initial value problem for a system of first-order differential equations, which may be readily solved using standard algorithms. Then, the numerical procedure is implemented and thoroughly validated against previous computational results based on sophisticated path-following techniques. Next, the transient nonstationary model is attacked, and the full nonlinear form of the reaction-diffusion equation, including a generalized convective boundary condition, is discretized and expressed as a system of linear algebraic equations. The numerical methodology is implemented as a computer algorithm, and validation computations are carried out as a prelude to a broad-ranging evaluation of the assembly problem and identification of the watershed critical initial temperature conditions for thermal ignition. This numerical methodology is then used as the basis for studying the relationship between the shape of the critical initial temperature distribution and the corresponding spatial moments of its energy content integral and an attempt to forge a fundamental conjecture governing this relation. Finally, the effects of dynamic boundary conditions on the classic storage problem are investigated and the groundwork is laid for the development of an approximate solution methodology based on adaptation of the standard stationary model.

Luo, W.; Wake, G. C.; Hawk, C. W.; Litchford, R. J.

2008-01-01

125

Experiments and models of active and thermal imaging under bad weather conditions  

NASA Astrophysics Data System (ADS)

Thermal imaging cameras are widely used in military contexts for their night vision capabilities and their observation range; there are based on passive infrared sensors (e.g. MWIR or LWIR range). Under bad weather conditions or when the target is partially hidden (e.g. foliage, military camouflage) they are more and more complemented by active imaging systems, a key technology to perform target identification at long range. The 2D flash imaging technique is based on a high powered pulsed laser source that illuminates the entire scene and a fast gated camera as the imaging system. Both technologies are well experienced under clear meteorological conditions; models including atmospheric effects such as turbulence are able to predict accurately their performances. However, under bad weather conditions such as rain, haze or snow, these models are not relevant. This paper introduces new models to predict performances under bad weather conditions for both active and infrared imaging systems. We point out their effects on controlled physical parameters (extinction, transmission, spatial resolution, thermal background, speckle, turbulence). Then we develop physical models to describe their intrinsic characteristics and their impact on the imaging system performances. Finally, we approximate these models to have a "first order" model easy to deploy for industrial applications. This theoretical work will be validated on real active and infrared data.

Bernard, Erwan; Riviere, Nicolas; Renaudat, Mathieu; Guiset, Pierrick; Pealat, Michel; Zenou, Emmanuel

2013-10-01

126

Limiting factors to advancing thermal battery technology for naval applications  

NASA Astrophysics Data System (ADS)

Thermal batteries are primary reserve electrochemical power sources using molten salt electrolyte which experience little effective aging while in storage or dormant deployment. Thermal batteries are primarily used in military applications, and are currently used in a wide variety of Navy devices such as missiles, torpedoes, decays, and training targets, usually as power supplies in guidance, propulsion, and Safe/Arm applications. Technology developments have increased the available energy and power density ratings by an order of magnitude in the last ten years. Present thermal batteries, using lithium anodes and metal sulfide cathodes, are capable of performing applications where only less rugged and more expensive silver oxide/zinc or silver/magnesium chloride seawater batteries could serve previously. Additionally, these batteries are capable of supplanting lithium/thionyl chloride reserve batteries in a variety of specifically optimized designs. Increases in thermal battery energy and power density capabilities are not projected to continue with the current available technology. Several battery designs are now at the edge of feasibility and safety. Since future naval systems are likely to require continued growth of battery energy and power densities, there must be significant advances in battery technology. Specifically, anode alloy composition and new cathode materials must be investigated to allow for safe development and deployment of these high power, higher energy density batteries.

Davis, Patrick B.; Winchester, Clinton S.

1991-10-01

127

Chronic Heat Stress and Cognitive Development: An Example of Thermal Conditions Influencing Human Development  

ERIC Educational Resources Information Center

Although thermal conditions influence the development of living organisms in a wide variety of ways, this topic has been recently ignored in humans. This paper reintroduces thermal conditions as a topic of importance for developmentalists by presenting an example of how thermal conditions are hypothesized to influence a particular developmental…

Riniolo, Todd C.; Schmidt, Louis A.

2006-01-01

128

Peptide Formation Mechanism on Montmorillonite Under Thermal Conditions  

NASA Astrophysics Data System (ADS)

The oligomerization of amino acids is an essential process in the chemical evolution of proteins, which are precursors to life on Earth. Although some researchers have observed peptide formation on clay mineral surfaces, the mechanism of peptide bond formation on the clay mineral surface has not been clarified. In this study, the thermal behavior of glycine (Gly) adsorbed on montmorillonite was observed during heating experiments conducted at 150 °C for 336 h under dry, wet, and dry-wet conditions to clarify the mechanism. Approximately 13.9 % of the Gly monomers became peptides on montmorillonite under dry conditions, with diketopiperazine (cyclic dimer) being the main product. On the other hand, peptides were not synthesized in the absence of montmorillonite. Results of IR analysis showed that the Gly monomer was mainly adsorbed via hydrogen bonding between the positively charged amino groups and negatively charged surface sites (i.e., Lewis base sites) on the montmorillonite surface, indicating that the Lewis base site acts as a catalyst for peptide formation. In contrast, peptides were not detected on montmorillonite heated under wet conditions, since excess water shifted the equilibrium towards hydrolysis of the peptides. The presence of water is likely to control thermodynamic peptide production, and clay minerals, especially those with electrophilic defect sites, seem to act as a kinetic catalyst for the peptide formation reaction.

Fuchida, Shigeshi; Masuda, Harue; Shinoda, Keiji

2014-06-01

129

Thermal Plasma Technology: Where Do We Stand and Where Are We Going?  

Microsoft Academic Search

In this overview, an attempt is made to assess the present and future research and development in thermal plasma processing of materials restricted to (1) thermal plasma coating technologies, (2) thermal plasma synthesis of fine powders, (3) thermal plasma waste destruction, and (4) thermal plasma spheroidization and densification. Since thermal plasma processing is, in general, governed by a large number

E. Pfender

1999-01-01

130

Study of thermal management for space platform applications: Unmanned modular thermal management and radiator technologies  

NASA Technical Reports Server (NTRS)

Candidate techniques for thermal management of unmanned modules docked to a large 250 kW platform were evaluated. Both automatically deployed and space constructed radiator systems were studied to identify characteristics and potential problems. Radiator coating requirements and current state-of-the-art were identified. An assessment of the technology needs was made and advancements were recommended.

Oren, J. A.

1981-01-01

131

Condition Assessment Technologies for Water Transmission and Distribution Systems  

EPA Science Inventory

As part of the U.S. Environmental Protection Agency?s (EPA?s) Aging Water Infrastructure Research Program, this research was conducted to identify and characterize the state of the technology for structural condition assessment of drinking water transmission and distribution syst...

132

Nondestructive analysis of ultrashallow junctions using thermal wave technology  

NASA Astrophysics Data System (ADS)

It is shown that the thermal wave (TW) nondestructive technology widely used in semiconductor industry for ion-implant monitoring can also be used for characterization of ultrashallow junctions created as a result of thermal annealing of ion implanted wafers. A set of Si wafers implanted with boron at energies 0.2-0.5 keV and implantation doses in the range of 1014-1015 cm-2 thermally annealed at different temperatures (950-1100 °C) has been studied. For all samples, the TW signal is found to vary linearly with junction depth and is shown to exhibit a very good correlation with secondary ion mass spectrometry data. A special processing of experimental data using both the TW quadrature and in-phase signal components allowing for resolution of effects introduced by different implantation doses, energies, and annealing temperatures is discussed.

Nicolaides, Lena; Salnick, Alex; Opsal, Jon

2003-01-01

133

Facility level thermal systems for the Advanced Technology Solar Telescope  

NASA Astrophysics Data System (ADS)

The management and control of the local aero-thermal environment is critical for success of the Advanced Technology Solar Telescope (ATST). In addition to minimizing disturbances to local seeing, the facility thermal systems must meet stringent energy efficiency requirements to minimize impact on the surrounding environment and meet federal requirements along with operational budgetary constraints. This paper describes the major facility thermal equipment and systems to be implemented along with associated energy management features. The systems presented include the central plant, the climate control systems for the computer room and coudé laboratory, the carousel cooling system which actively controls the surface temperature of the rotating telescope enclosure, and the systems used for active and passive ventilation of the telescope chamber.

Phelps, LeEllen; Murga, Gaizka; Fraser, Mark; Climent, Tŕnia

2012-09-01

134

Dish concentrators for solar thermal energy: Status and technology development  

NASA Technical Reports Server (NTRS)

Point-focusing concentrators under consideration for solar thermal energy use are reviewed. These concentrators differ in such characteristics as optical configuration, optical materials, structure for support of the optical elements and of the receiver, mount, foundation, drive, controls and enclosure. Concentrator performance and cost are considered. Technology development is outlined, including wind loads and aerodynamics; precipitation, sand, and seismic considerations; and maintenance and cleaning.

Jaffe, L. D.

1982-01-01

135

Hydro-thermal Conditions for Paleopermafrost Distribution by Climate Modeling  

NASA Astrophysics Data System (ADS)

Near-surface conditions for the frozen ground distribution under the paleoclimate environments are investigated which were derived from the Paleoclimate Model Intercomparison Project II (PMIP2). Total of twenty-two realizations from ten participating climate models (CCSM, CNRM, CSIRO, ECBILTCLIO, ECHAM, FGOALS, HadCM, IPSL, MIROC, MRI) were used for the analysis. Freeze index (FI) and thaw index (TI) are calculated from the monthly near-surface air temperature field that was taken from Climate Research Unit dataset for the present-day condition, and from the model output for the pre-industrial (0K), Holocene Optimum (6K), and the Last Glacial Maximum (21K) conditions. When an model integration is longer than ten years, only the last ten years of the output were used for the calculation. A simple classification method for the frozen ground zones, namely, continuous/discontinuous permafrost (PF), seasonal frost (SF; excluding PF), and no frost (NF) zones, by use of FI and TI was constructed from the observation-based present-day frozen ground distribution compiled by International Permafrost Association (IPA). PF is the areas whose TI is less than the threshold TI0 (1700. in this study). Similarly, SF is the area whose FI is less than the threshold value FI0 (2625. in this study) and TI is less than TImax (7255). If the TI is greater than TImax it is NF. The overall misclassification rate, that is the ratio of the areas falsely classified to PF or SF compared to the original IPA map, was 19.1% in this methodology. The identical classification scheme was used to infer the paleopermafrost distribution for the three periods. For 0K, PF and SF zones occupy, in average and range in parentheses, respective 18.4% (14.1% - 26.0%) and 40.1% (31.4% - 52.2%) of the Northern Hemisphere ice-free land area, among the eight different realizations, whereas the observational counterparts are ca. 17.8% and 32.0%, respectively. Similarly, 18.8% (12.2% - 26.4%) and 38.4% (32.8% - 44.0%) of the ice-free land are underlain by respective PF and SF zones for the 6K simulation (with six realizations), and 24.1% (21.0% - 31.5%) and 34.4% (26.9% - 43.8%) for 21K (with six realizations). In addition to the thermally-based methodology, influence of precipitation and seasonal snow cover to the subsurface thermal regime will be discussed.

Saito, K.; Marchenko, S.; Romanovsky, V.; Bigelow, N.; Yoshikawa, K.; Walsh, J.

2009-04-01

136

CARBONACEOUS MATTER PRECURSORS AND METAMORPHIC CONDITIONS IN THERMALLY PROCESSED CHONDRITES  

NASA Astrophysics Data System (ADS)

Unravelling the origin of carbonaceous matter in pristine chondrites requires the understanding of the effect of post-accretion processes. In chondrites of petrologic type 3, thermal metamorphism modified to various extents the composition and structure of carbonaceous matter. Interestingly, this process controls the degree of structural order of carbonaceous matter, and clues on the thermal history of the parent body may be recovered from the physico-chemical study of carbonaceous matter. Following this framework, geothermometers based on Raman spectrometry of carbonaceous matter and covering a wide range of temperatures (100-650 °C) have been developed over recent years, both on terrestrial rocks and chondrites. While Raman data have been largely interpreted in terms of temperature, they are also the fingerprint of certain metamorphic conditions, especially in the low temperature range relevant to poorly ordered carbonaceous matter. This study investigates the Raman spectra of two series of chondritic carbonaceous matter and coal samples formed from different precursors and under different metamorphic conditions. The Raman spectra of Polyaromatic Carbonaceous Matter (PCM) from 42 chondrites and 27 coal samples, measured with visible (514 nm) and ultra-violet (244 nm) excitation wavelengths, are analyzed. The Raman spectra of low rank coals and chondrites of petrologic types 1 and 2, which contain the more disordered PCM, reflect the distinct carbon structures of their precursors. The 514 nm Raman spectra of high rank coals and chondrites of petrologic type 3 exhibit continuous and systematic spectral differences reflecting different carbon structures present during the metamorphism event. They result from differences in the chemical structures of the precursors concerning for instance the reticulation of polyaromatic units or an abundance of ether functional groups, or possibly from a lack of carbonization processes to efficiently expel oxygen heteroatoms, due to weak lithostatic pressure and confinement. These results suggest that the use of lowtemperature carbon thermometers should be restricted to a given geological context. At the same time, the sensitivity of Raman spectra to precursors and certain metamorphic conditions could be used to obtain information other than temperature. The analysis also provides evidence of the accretion of relatively homogeneous PCM precursors among ordinary CO and CV carbonaceous chondrite parent bodies, given that the 514nm Raman spectra of PCM efficiently trace the metamorphism grades. Looking closer, however, the 514 nm Raman data are more scattered in chondrites than in coals and the maturity tracers are less sensitive and miscorrelate with the atomic H/C ratio, suggesting slight compositional and structural differences among the PCM precursors accreted.

Quirico, E.; Montagnac, G.; Rouzaud, J.; Bonal, L.; Bourot-Denise, M.; Duber, S.; Reynard, B.

2009-12-01

137

Trend of Refrigeration and Air-Conditioning Technology in Korea  

NASA Astrophysics Data System (ADS)

It can be said that refrigeration and air-conditioning technology in Korea dates back to the ancient dynasty, all the way up to the Sokkuram(700s) and Seokbinggo(1700s), But modern refrigeration and air-conditioning technology was first developed in and introduced to Korea in the1960swith the modernization of Korea, Today it is at a level which meets that of advanced countries in both the industrial and domestic fields. As of 2003, there were about 700 companies that owned cold storage/freezing/refrigeration facilities, with cold storage capacity of about 2,000, 000tons and capacity per company of about 3,000 tons. These facilities most are continuously expanding and automating their facilities. 62 million units of refrigeration and air-conditioning machinery and equipment were produced in 2003, worth a total of 7.7 trillion won(about 7.7 thousand million US). On the academic side there are 9 universities and 12 junior colleges with courses in either refrigeration and air-conditioning or architectural equipment. Academic societies such as the Society of Air-conditioning and Refrigerating Engineers of Korea(SAREK), and industrial societies like the Korean Association of Refrigeration(KAR) are active members of the refrigeration and air-conditioning industry. The1eare also national/government-established research institutions such as the Korea Institute of Science and Technology(KIST), the Korea Institute of Machinery and Materials (KIMM), the Korea Institute of Energy Research(KIER), and the Korea Institute of Industrial Technology (KITECH).

Oh, Hoo-Kyu; Papk, Ki-Won

138

Development of Passive Fuel Cell Thermal Management Technology  

NASA Technical Reports Server (NTRS)

The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA exploration program. The passive thermal management system relies on heat conduction within the cooling plate to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack rather than using a pumped loop cooling system to convectively remove the heat. Using the passive approach eliminates the need for a coolant pump and other cooling loop components which reduces fuel cell system mass and improves overall system reliability. Previous analysis had identified that low density, ultra-high thermal conductivity materials would be needed for the cooling plates in order to achieve the desired reductions in mass and the highly uniform thermal heat sink for each cell within a fuel cell stack. A pyrolytic graphite material was identified and fabricated into a thin plate using different methods. Also a development project with Thermacore, Inc. resulted in a planar heat pipe. Thermal conductivity tests were done using these materials. The results indicated that lightweight passive fuel cell cooling is feasible.

Burke, Kenneth A.; Jakupca, Ian; Colozza, Anthony

2011-01-01

139

Evaluation Framework and Analyses for Thermal Energy Storage Integrated with Packaged Air Conditioning  

SciTech Connect

Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.

Kung, F.; Deru, M.; Bonnema, E.

2013-10-01

140

Balanced Flow Metering and Conditioning: Technology for Fluid Systems  

NASA Technical Reports Server (NTRS)

Revolutionary new technology that creates balanced conditions across the face of a multi-hole orifice plate has been developed, patented and exclusively licensed for commercialization. This balanced flow technology simultaneously measures mass flow rate, volumetric flow rate, and fluid density with little or no straight pipe run requirements. Initially, the balanced plate was a drop in replacement for a traditional orifice plate, but testing revealed substantially better performance as compared to the orifice plate such as, 10 times better accuracy, 2 times faster (shorter distance) pressure recovery, 15 times less acoustic noise energy generation, and 2.5 times less permanent pressure loss. During 2004 testing at MSFC, testing revealed several configurations of the balanced flow meter that match the accuracy of Venturi meters while having only slightly more permanent pressure loss. However, the balanced meter only requires a 0.25 inch plate and has no upstream or downstream straight pipe requirements. As a fluid conditioning device, the fluid usually reaches fully developed flow within 1 pipe diameter of the balanced conditioning plate. This paper will describe the basic balanced flow metering technology, provide performance details generated by testing to date and provide implementation details along with calculations required for differing degrees of flow metering accuracy.

Kelley, Anthony R.

2006-01-01

141

Solar Thermal Technology Program bibliography, 1973-1985  

NASA Astrophysics Data System (ADS)

This bibliography contains citations of technical publications that have emerged from the US Department of Energy's Solar Thermal Technology (STT) Program. The entries include research performed at the Federal laboratories and at various universities and other organizations under subcontract to the US Department of Energy or its laboratories from 1973 through 1985. The types of references include journal articles, papers presented in conference proceedings, monographs, chapters in monographs, technical reports, and patents. The citations are divided into chapters by federal laboratory where the research was performed or where the subcontract was monitored. Although there may be some crossover among the laboratories, each one has traditionally had certain areas of responsibility. The first chapter contains citations from the Jet Propulsion Laboratory, which directed most of the parabolic dish technology research. The second chapter, Sandia National Laboratory/Albuquerque, lists documents primarily for distributed receiver technology as well as documents pertaining to the Central Receiver Test Facility (CRTF), which is located in Albuquerque. The third chapter, Sandia National Laboratory/Livermore, contains references for central receiver technology. The documents on central receiver technology that resulted from contracts managed by the US Department of Energy San Francisco Operations Office are also included in the third chapter. The fourth chapter, Solar Energy Research Institute, contains citations documenting advanced research concepts.

1986-12-01

142

Thermo-Oxidative Stability of High Performance Composites under Thermal Cycling Conditions  

Microsoft Academic Search

Thermo-oxidative stability of high performance composites was investigated under thermal cycling conditions between room and 177°C curing temperature. For the analysis of thermal cycling experimental results, an equivalent cycle time (ECT) was developed by applying degradation-reaction kinetic theories to thermal-cycling conditions. Applying this methodology to the weight loss measurements of composite specimens, thermal cycling was found to exhibit a slower

Sang-Ho Lee; Jae-Do Nam; Kyujong Ahn; Ki-Mo Chung; James C. Seferis

2001-01-01

143

High temperature solar thermal technology: The North Africa Market  

SciTech Connect

High temperature solar thermal (HTST) technology offers an attractive option for both industrialized and non-industrialized countries to generate electricity and industrial process steam. The purpose of this report is to assess the potential market for solar thermal applications in the North African countries of Algeria, Egypt, Morocco and Tunisia. North Africa was selected because of its outstanding solar resource base and the variety of applications to be found there. Diminishing oil and gas resources, coupled with expanding energy needs, opens a large potential market for the US industry. The US high temperature solar trough industry has little competition globally and could build a large market in these areas. The US is already familiar with certain solar markets in North Africa due to the supplying of substantial quantities of US-manufactured flat plate collectors to this region.

Not Available

1990-12-01

144

NASA-EPA automotive thermal reactor technology program  

NASA Technical Reports Server (NTRS)

The status of the NASA-EPA automotive thermal reactor technology program is summarized. This program is concerned primarily with materials evaluation, reactor design, and combustion kinetics. From engine dynamometer tests of candidate metals and coatings, two ferritic iron alloys (GE 1541 and Armco 18-SR) and a nickel-base alloy (Inconel 601) offer promise for reactor use. None of the coatings evaluated warrant further consideration. Development studies on a ceramic thermal reactor appear promising based on initial vehicle road tests. A chemical kinetic study has shown that gas temperatures of at least 900 K to 1000 K are required for the effective cleanup of carbon monoxide and hydrocarbons, but that higher temperatures require shorter combustion times and thus may permit smaller reactors.

Blankenship, C. P.; Hibbard, R. R.

1972-01-01

145

Modeling of Subjective Responses to Indoor Air Quality and Thermal Conditions in Office Buildings  

Microsoft Academic Search

Air conditioning is used to control air quality and thermal environment and has a significant impact on perceived indoor air quality, thermal conditions, health symptoms, sick-building syndrome (SBS), task performance, and productivity. Building occupants provide a rich source of information about perceived indoor air. Could this information be used to teach and adapt the heating, ventilating, and air-conditioning system to

T. Kostiainen; I. Welling; M. Lahtinen; K. Salmi; E. Kähkönen; J. Lampinen

2008-01-01

146

Porous materials for thermal management under extreme conditions  

Microsoft Academic Search

A brief analysis is presented of how heat transfer takes place in porous materials of various types. The emphasis is on materials able to withstand extremes of temperature, gas pressure, irradiation, etc., i.e. metals and ceramics, rather than polymers. A primary aim is commonly to maximize either the thermal resistance (i.e. provide insulation) or the rate of thermal equilibration between

T. W. Clyne; I. O. G OLOSNOY; A. E. MARKAKI

2006-01-01

147

Poaceae pollen in the air depending on the thermal conditions.  

PubMed

The relationship between the meteorological elements, especially the thermal conditions and the Poaceae pollen appearance in the air, were analysed as a basis to construct a useful model predicting the grass season start. Poaceae pollen concentrations were monitored in 1991-2012 in Kraków using the volumetric method. Cumulative temperature and effective cumulative temperature significantly influenced the season start in this period. The strongest correlation was seen as the sum of mean daily temperature amplitudes from April 1 to April 14, with mean daily temperature >15 °C and effective cumulative temperature >3 °C during that period. The proposed model, based on multiple regression, explained 57 % of variation of the Poaceae season starts in 1991-2010. When cumulative mean daily temperature increased by 10 °C, the season start was accelerated by 1 day. The input of the interaction between these two independent variables into the factor regression model caused the increase in goodness of model fitting. In 2011 the season started 5 days earlier in comparison with the predicted value, while in 2012 the season start was observed 2 days later compared to the predicted day. Depending on the value of mean daily temperature from March 18th to the 31st and the sum of mean daily temperature amplitudes from April 1st to the 14th, the grass pollen seasons were divided into five groups referring to the time of season start occurrence, whereby the early and moderate season starts were the most frequent in the studied period and they were especially related to mean daily temperature in the second half of March. PMID:23793956

Myszkowska, Dorota

2014-07-01

148

Production of pig iron from red mud waste fines using thermal plasma technology  

NASA Astrophysics Data System (ADS)

Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite (fixed carbon, 99%) as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.

Jayasankar, K.; Ray, P. K.; Chaubey, A. K.; Padhi, A.; Satapathy, B. K.; Mukherjee, P. S.

2012-08-01

149

Induction of preset thermally stressed states in thermal fatigue tests: Choice of testing conditions and geometry of specimens  

Microsoft Academic Search

Two approaches to the choice of testing conditions with the effect of simultaneous control over thermal and thermally stressed\\u000a states of specimens which provide the induction of preset uniaxial and biaxial unsteady stressed states were analyzed and\\u000a developed. The first approach is based on inducing thermal stresses in a cyclically heated specimen by restraining force and\\u000a mechanical loads. The second

G. N. Tretyachenko; B. S. Karpinos; V. G. Barilo; N. G. Solovyeva

1997-01-01

150

Thermal conductivity measurements of particulate materials under Martian conditions  

NASA Technical Reports Server (NTRS)

The mean particle diameter of surficial units on Mars has been approximated by applying thermal inertia determinations from the Mariner 9 Infrared Radiometer and the Viking Infrared Thermal Mapper data together with thermal conductivity measurement. Several studies have used this approximation to characterize surficial units and infer their nature and possible origin. Such interpretations are possible because previous measurements of the thermal conductivity of particulate materials have shown that particle size significantly affects thermal conductivity under martian atmospheric pressures. The transfer of thermal energy due to collisions of gas molecules is the predominant mechanism of thermal conductivity in porous systems for gas pressures above about 0.01 torr. At martian atmospheric pressures the mean free path of the gas molecules becomes greater than the effective distance over which conduction takes place between the particles. Gas particles are then more likely to collide with the solid particles than they are with each other. The average heat transfer distance between particles, which is related to particle size, shape and packing, thus determines how fast heat will flow through a particulate material.The derived one-to-one correspondence of thermal inertia to mean particle diameter implies a certain homogeneity in the materials analyzed. Yet the samples used were often characterized by fairly wide ranges of particle sizes with little information about the possible distribution of sizes within those ranges. Interpretation of thermal inertia data is further limited by the lack of data on other effects on the interparticle spacing relative to particle size, such as particle shape, bimodal or polymodal mixtures of grain sizes and formation of salt cements between grains. To address these limitations and to provide a more comprehensive set of thermal conductivities vs. particle size a linear heat source apparatus, similar to that of Cremers, was assembled to provide a means of measuring the thermal conductivity of particulate samples. In order to concentrate on the dependence of the thermal conductivity on particle size, initial runs will use spherical glass beads that are precision sieved into relatively small size ranges and thoroughly washed.

Presley, M. A.; Christensen, P. R.

1993-01-01

151

Mercury emissions control technologies for mixed waste thermal treatment  

SciTech Connect

EPA has identified wet scrubbing at low mercury feedrates, as well as carbon adsorption via carbon injection into the offgas or via flow through fixed carbon beds, as control technologies that can be used to meet the proposed Maximum Achievable Control Technology (MACT) rule limit for mercury emissions from hazardous waste incinerators. DOE is currently funding demonstrations of gold amalgamation that may also control mercury to the desired levels. Performance data from a variety of sources was reviewed to determine ranges of achievable mercury control. Preliminary costs were estimated for using these technologies to control mercury emissions from mixed waste incineration. Mercury emissions control for mixed waste incineration may need to be more efficient than for incineration of other hazardous wastes because of higher mercury concentrations in some mixed waste streams. However, mercury control performance data for wet scrubbing and carbon adsorption is highly variable. More information is needed to demonstrate control efficiencies that are achievable under various design and operating conditions for wet scrubbing, carbon adsorption, and gold amalgamation technologies. Given certain assumptions made in this study, capital costs, operating costs, and lifecycle costs for carbon injection, carbon beds, and gold amalgamation generally vary for different assumed mercury feedrates and for different offgas flowrates. Assuming that these technologies can in fact provide the necessary mercury control performance, each of these technologies may be less costly than the others for certain mercury feedrates and the offgas flowrates.

Chambers, A.; Knecht, M.; Soelberg, N.; Eaton, D. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Roberts, D.; Broderick, T. [ADA Technologies, Englewood, CO (United States)

1997-12-31

152

Evaluation of airborne thermal, magnetic, and electromagnetic characterization technologies  

SciTech Connect

The identification of Buried Structures (IBS) or Aerial Surveillance Project was initiated by the US Department of Energy (DOE) Office of Technology Development to demonstrate airborne methods for locating and identifying buried waste and ordnance at the Idaho National Engineering Laboratory (INEL). Two technologies were demonstrated: (a) a thermal infrared imaging system built by Martin Marietta Missile Systems and (b) a magnetic and electromagnetic (EM) geophysical surveying system operated by EBASCO Environmental. The thermal system detects small differences in ground temperature caused by uneven heating and cooling of the ground by the sun. Waste materials on the ground can be detected when the temperature of the waste is different than the background temperature. The geophysical system uses conventional magnetic and EM sensors. These sensors detect disturbances caused by magnetic or conductive waste and naturally occurring magnetic or conductive features of subsurface soils and rock. Both systems are deployed by helicopter. Data were collected at four INEL sites. Tests at the Naval Ordnance Disposal Area (NODA) were made to evaluate capabilities for detecting ordnance on the ground surface. Tests at the Cold Simulated Waste Demonstration Pit were made to evaluate capabilities for detecting buried waste at a controlled site, where the location and depth of buried materials are known. Tests at the Subsurface Disposal Area and Stationary Low-Power Reactor-1 burial area were made to evaluate capabilities for characterizing hazardous waste at sites that are typical of DOE buried waste sites nationwide.

Josten, N.E.

1992-03-01

153

Emerging technologies in therapeutic ultrasound: thermal ablation to gene delivery.  

PubMed

Ultrasound is used today in medicine as a modality for diagnostic imaging. Recently, there have been numerous reports on the application of thermal and nonthermal ultrasound energy for treating various diseases. In addition to thermal ablation of tumors, non-thermal ultrasound combined with drugs and genes have led to much excitement especially for cancer treatment, vascular diseases, and regenerative medicine. Ultrasound energy can enhance the effects of thrombolytic agents such as urokinase for treatment of stroke and acute myocardial infarction. New ultrasound technologies have resulted in advanced devices such as a) ultrasound catheters, b) Non-invasive methods as high intensity focused ultrasound (HIFU) in conjunction with MRI and CT is already being applied in the clinical field, c) Chemical activation of drugs by ultrasound energy for treatment of tumors is another new field recently termed "Sonodynamic Therapy", and d) Combination of genes and microbubble have induced great hopes for ideal gene therapy (sonoporation). Various examples of ultrasound combined modalities are under investigation which could lead to revolutionary therapy. PMID:15369132

Tachibana, Katsuro

2004-03-01

154

Hydraulic fracturing theory for conditions of thermal stress  

Microsoft Academic Search

Thermal stresses associated with a temperature change of only 10°C are on the order of 10 to 100 bars. This illustrates the important influence thermal stresses can impose on the results of rock stress measurements by the hydraulic fracturing method. In order to examine the problem, expressions are derived to describe the stress field produced by non-steady state heat conduction

G. Stephens; B. Voight

1982-01-01

155

Advances in thermal interface technology: mono-metal interconnect formation, processing and characterisation  

Microsoft Academic Search

As the demand for new thermal technologies and materials has been increasing over the years to provide thermal solutions to the next generation of power electronics, microprocessors and high-power optical systems also thermal characterisation methods have to keep up with the pace of this development with respect to resolution and accuracy. We have developed both bulk and interface technologies to

B. Wunderle; M. Klein; L. Dietrich; M. Abo Ras; R. Mrossko; D. May; R. Schacht; H. Oppermann; B. Michel; H. Reichl

2010-01-01

156

Thermal conductivity and elastic modulus evolution of thermal barrier coatings under high heat flux conditions  

Microsoft Academic Search

Laser high heat flux test approaches have been established to obtain critical properties of ceramic thermal barrier coatings\\u000a (TBCs) under near-realistic temperature and thermal gradients that may be encountered in advanced engine systems. Thermal\\u000a conductivity change kinetics of a thin ceramic coating were continuously monitored in real time at various test temperatures.\\u000a A significant thermal conductivity increase was observed during

Dongming Zhu; Robert A. Miller

2000-01-01

157

Thermal-shock resistant refractories and ceramics under thermal-shock conditions  

Microsoft Academic Search

Conclusions We propose an approach to evaluating the thermal-shock resistance of solid bodies in a thermal-shock schedule based on the development of elastic waves of compression (expansion) and the final value of the velocity of the thermal waves.

V. V. Kolomeitsev; K. N. Dergunov

1988-01-01

158

Alternative Air Conditioning Technologies: Underfloor AirDistribution (UFAD)  

SciTech Connect

Recent trends in today's office environment make it increasingly more difficult for conventional centralized HVAC systems to satisfy the environmental preferences of individual officer workers using the standardized approach of providing a single uniform thermal and ventilation environment. Since its original introduction in West Germany during the 1950s, the open plan office containing modular workstation furniture and partitions is now the norm. Thermostatically controlled zones in open plan offices typically encompass relatively large numbers of workstations in which a diverse work population having a wide range of preferred temperatures must be accommodated. Modern office buildings are also being impacted by a large influx of heat-generating equipment (computers, printers, etc.) whose loads may vary considerably from workstation to workstation. Offices are often reconfigured during the building's lifetime to respond to changing tenant needs, affecting the distribution of within-space loads and the ventilation pathways among and over office partitions. Compounding this problem, there has been a growing awareness of the importance of the comfort, health, and productivity of individual office workers, giving rise to an increased demand among employers and employees for a high-quality work environment. During recent years an increasing amount of attention has been paid to air distribution systems that individually condition the immediate environments of office workers within their workstations to address the issues outlined above. As with task/ambient lighting systems, the controls for the ''task'' components of these systems are partially or entirely decentralized and under the control of the occupants. Typically, the occupant has control over the speed and direction, and in some cases the temperature, of the incoming air supply. Variously called ''task/ambient conditioning,'' ''localized thermal distribution,'' and ''personalized air conditioning'' systems, these systems have been most commonly installed in open-plan office buildings in which they provide supply air and (in some cases) radiant heating directly into workstations. TAC systems can be classified into the following two major categories: (1) furniture-based, and (2) floor-based, underfloor air distribution (UFAD). A large majority of these systems include a raised floor system with which underfloor plenums are used to deliver conditioned air to the space through floor grills, or in conjunction with the workstation furniture and partitions.

Webster, Tom

2004-06-01

159

Strength and Lifetime of a 15Kh11MFBl Structural Steel under Thermal Cycling Conditions  

Microsoft Academic Search

Results of experimental studies on the influence of different thermal loading conditions on the resistance of a 15Kh11MFBl structural steel to long-term static and cyclic thermal loading are presented as applied to operating conditions of mineral-processing equipment. It was experimentally established that upon thermal loading of the material, two damage accumulation processes took place: quasistatic associated with directed plastic deformation

A. P. Gopkalo

2001-01-01

160

History of Sulphur Content Effects on the Thermal Stability of RP-1 under Heated Conditions.  

National Technical Information Service (NTIS)

As technologies advance in the aerospace industry, a strong desire has emerged to design more efficient, longer life, reusable liquid hydrocarbon fueled rocket engines. To achieve this goal, a more complete understanding of the thermal stability and chemi...

S. A. Irvine A. K. Schoettmer R. W. Bates M. L. Meyer

2004-01-01

161

Thermal behaviour of compatibilised polypropylene nanocomposite: Effect of processing conditions  

Microsoft Academic Search

The thermal properties and fire behaviour of polypropylene (PP) nanocomposites were investigated using differential scanning calorimetry, dynamic-mechanical analysis, thermogravimetric analysis and glow wire test. In order to study the morphological structure of the materials obtained, TEM and XRD analyses were also carried out. The nanocomposites were prepared using the melt intercalation technique in a co-rotating intermeshing twin screw extruder. Particular

M. Modesti; A. Lorenzetti; D. Bon; S. Besco

2006-01-01

162

Status of reusable surface insulation thermal protection system technology programs  

NASA Technical Reports Server (NTRS)

The development of three low-density rigidized insulation materials for the shuttle TPS application is reported. These materials consist of one high purity silica system and two systems based on mullite, an aluminum silicate. Both systems consist of fibers joined together with appropriate binders to obtain a rigidized insulation composite. Both material systems require the application of a glassy coating to provide a wear resistant, high emittance surface and to prevent the absorption of water by the fiber matrix. The technology program has addressed the development of water impervious coatings, methods of assembling the materials in design concepts while minimizing the thermal stress in the insulation, achieving compatibility between the RSI material and the structural system, and test evaluations to demonstrate the feasibility of the surface insulation concept.

Greenshields, D. H.; Meyer, A. J.; Tillian, D. J.

1972-01-01

163

Treatment of Bone Waste Using Thermal Plasma Technology  

NASA Astrophysics Data System (ADS)

Daily meat consumption produces a lot of bone waste, and dumped bone waste without treatment would result in environmental hazards. Conventional treatment methods of waste bones have some disadvantages. Herein, an investigation of bone waste treated using thermal plasma technology is presented. A high-temperature plasma torch operated at 25.2 kW was used to treat bone waste for seven minutes. The bone waste was finally changed into vitric matter and lost 2/3 of its weight after the treatment. The process was highly efficient, economical, convenient, and fuel-free. This method could be used as an alternative for disposal of bone waste, small infectious animals, hazardous hospital waste, etc.

Ki, Ho Beom; Kim, Woo Hyung; Kim, Bong Soo; Koo, Hyung Joon; Li, Mingwei; Chae, Jae Ou

2007-10-01

164

Design, Manufacture and Qualification of Modular Power Conditioning Circuits for Space Application Using Thick Film Technology.  

National Technical Information Service (NTIS)

A study was performed on the use of thick film technology for spacecraft power conditioning circuits. Design rules and guidelines for adapting power conditioning units to thick film technology are outlined. Suitable thick film fabrication processes are se...

H. Kroeger J. Spencer A. Lewicki

1975-01-01

165

Field Demonstration of Multi-Sensor Technology for Condition Assessment of Wastewater Collection Systems (Abstract)  

EPA Science Inventory

The purpose of the field demonstration program is to gather technically reliable cost and performance information on selected condition assessment technologies under defined field conditions. The selected technologies include zoom camera, focused electrode leak location (FELL), ...

166

A technical and economic evaluation of thermal spallation drilling technology  

SciTech Connect

Thermal spallation of rock may be defined as a type of progressive rock failure caused by the creation of thermal stresses induced by a sudden application of heat from a high temperature source. This technology is applicable to only certain types of hard rock, such as dolomite, taconite, and granite. In 1981 and 1982, the deepest holes ever drilled by this process were drilled in granite to depths of 1086 feet and 425 feet respectively. Penetration rates at the bottom of the deeper hole reached a maximum of 100 ft/hr. Because of these high rates, considerable interest was generated concerning the use of this technology for the drilling of deep holes. Based on this interest, this study was undertaken to evaluate the technical and economic aspects of the technology in general. This methodology has been used for blasthole drilling, the cutting of chambers at the bottom of drilled holes, and the cutting of narrow grooves in rock. However, because of the very high temperatures generated by the flame jet and the application of the technology to only certain types of rock, other areas of use have been very limited. In this report, evaluation of the technology was performed by conceptually designing and costing a theoretical flame jet drilling rig. The design process reviews a number of different concepts of the various components needed, and then chooses those pieces of equipment that best suit the needs of the system and have the best chance of being properly developed. The final concept consists of a flexible umbilical hose containing several internal hoses for carrying the various required fluids. An evaluation of this system was then made to determine its operational characteristics. The drilling capabilities and the economics of this rig were then compared to a conventional rotary drilling rig by theoretically drilling two holes of approximately 15,000 feet in depth. This comparison was done by use of a spread sheet type computer program. The results of this study indicate that flame jet drilling performs significantly better in both time and cost. These results are due primarily to the high penetration rates, the reduced number of trips, and the decreased trip time due to the use of the umbilical. However, this significant time and cost advantage must be tempered by the fact that they are based on the assumption that the main components of the flame jet rig can be realistically and reliably built. Unfortunately, the use of an umbilical system presents very realistic and difficult design problems as hole depth extends beyond 7000 feet. Thus, unless a significant market for the use of this equipment can be found, further development of an umbilical type system is very questionable. An alternate system suggests by LASL may circumvent many of the problems stated. This concept consists of using concentric pipes and a down hole fluid separation system. Concentric pipe built by the Walker-Neer Manufacturing Company, Wichita Falls, Texas, has been used successfully in the drilling industry for years. Fluid separators have also been developed and used. Although this concept also presents problems, it may be worth investigating.

None

1984-07-10

167

Transient thermal modeling of permafrost conditions in Southern Norway  

NASA Astrophysics Data System (ADS)

Thermal modeling is a powerful tool to infer the temperature regime of the ground in permafrost areas. We present a transient permafrost model, CryoGrid 2, that calculates ground temperatures according to conductive heat transfer in the soil and in the snowpack. CryoGrid 2 is forced by operational air temperature and snow-depth products for potential permafrost areas in Southern Norway for the period 1958 to 2009 at 1 km2 spatial resolution. In total, an area of about 80 000 km2 is covered. The model results are validated against borehole temperatures, permafrost probability maps from "bottom temperature of snow" measurements and inventories of landforms indicative of permafrost occurrence. The validation demonstrates that CryoGrid 2 can reproduce the observed lower permafrost limit to within 100 m at all validation sites, while the agreement between simulated and measured borehole temperatures is within 1 K for most sites. The number of grid cells with simulated permafrost does not change significantly between the 1960s and 1990s. In the 2000s, a significant reduction of about 40% of the area with average 2 m ground temperatures below 0 °C is found, which mostly corresponds to degrading permafrost with still negative temperatures in deeper ground layers. The thermal conductivity of the snow is the largest source of uncertainty in CryoGrid 2, strongly affecting the simulated permafrost area. Finally, the prospects of employing CryoGrid 2 as an operational soil-temperature product for Norway are discussed.

Westermann, S.; Schuler, T. V.; Gisnĺs, K.; Etzelmüller, B.

2013-04-01

168

Energy efficient engine, high pressure turbine thermal barrier coating. Support technology report  

NASA Technical Reports Server (NTRS)

This report describes the work performed on a thermal barrier coating support technology task of the Energy Efficient Engine Component Development Program. A thermal barrier coating (TBC) system consisting of a Ni-Cr-Al-Y bond cost layer and ZrO2-Y2O3 ceramic layer was selected from eight candidate coating systems on the basis of laboratory tests. The selection was based on coating microstructure, crystallographic phase composition, tensile bond and bend test results, erosion and impact test results, furnace exposure, thermal cycle, and high velocity dynamic oxidation test results. Procedures were developed for applying the selected TBC to CF6-50, high pressure turbine blades and vanes. Coated HPT components were tested in three kinds of tests. Stage 1 blades were tested in a cascade cyclic test rig, Stage 2 blades were component high cycle fatigue tested to qualify thermal barrier coated blades for engine testing, and Stage 2 blades and Stage 1 and 2 vanes were run in factory engine tests. After completion of the 1000 cycle engine test, the TBC on the blades was in excellent condition over all of the platform and airfoil except at the leading edge above midspan on the suction side of the airfoil. The coating damage appeared to be caused by particle impingement; adjacent blades without TBC also showed evidence of particle impingement.

Duderstadt, E. C.; Agarwal, P.

1983-01-01

169

The DOE Solar Thermal Electric Program Concentrator Technology Project  

SciTech Connect

The project comprises the development of concentrating solar collectors, heliostats and dishes, and the development of optical materials. Because the solar concentrator represents from 40 to 60% of the cost of a solar thermal electric system, the continued development of high-performance concentrators is very important to the commercial viability of these systems. The project is currently testing two large area heliostats, the SPECO 200 m{sup 2} heliostat and the ATS 150 m{sup 2} heliostat and also trying to reduce the cost of the heliostats through the development of stretched-membrane heliostats. Stretched-membrane heliostats are made by attaching thin metal membranes to the two sides of a circular, metal ring. A slight vacuum in the plenum between the two membranes is used to focus the heliostat. The optical surface is provided by a silver-acrylic film, ECP 305. A prototype 100 m{sup 2} commercial unit has been built and is currently being tested. Parabolic dish concentrators are under development for use on dish-Stirling electric systems. The state-of-the-art dish is the McDAC/SCE faceted glass concentrator. Because of the success of stretched-membrane technology for heliostats, the project applied the technology to parabolic dish development and is currently designing a near-term, faceted, stretched-membrane dish. The current thrust of the program in optical materials development is the development of a low-cost, high-performance, silver-acrylic film. 3M's ECP 305 has demonstrated substantial improvement over previous films in its resistance to corrosion, longer life. An experimental film, developed at SERI, has promise for further improving the lifetime of the ECP 305. The project is currently investigating solutions to the problem of separation between the silver and acrylic layers of the film in the presence of water.

Mancini, T.R.

1991-01-01

170

A Study on the Thermal Fatigue Behavior of Solder Joints Under Power Cycling Conditions  

Microsoft Academic Search

Failure mechanisms exposed by environmental accelerating testing methods such as thermal cycling or thermal shock test, may differ from those at service operating conditions. While the device is heated up or cooled down evenly on its external surface during environmental testing, real operating powered devices experience temperature gradients caused by internal local heating, components' different heat dissipation capability, and ambient

Se Young Yang; Ilho Kim; Soon-Bok Lee

2008-01-01

171

Sweating Agile Thermal Manikin (SAM) Developed to Test Complete Clothing Systems Under Normal and Extreme Conditions.  

National Technical Information Service (NTIS)

Moisture transport, thermal insulation and their interaction influence both the comfort and protective properties of clothing systems. Depending on the environmental conditions and clothing design, wind and repetitive body movements can increase the trans...

M. G. Richards N. G. Mattle

2002-01-01

172

Hypothetical accident condition thermal analysis and testing of a Type B drum package.  

National Technical Information Service (NTIS)

A thermophysical property model developed to analytically determine the thermal response of cane fiberboard when exposed to temperatures and heat fluxes associated with the 10 CFR 71 hypothetical accident condition (HAC) has been benchmarked against two T...

S. J. Hensel M. N. Alstine R. J. Gromada

1995-01-01

173

Mechanical and thermal buckling analysis of rectangular sandwich panels under different edge conditions  

NASA Technical Reports Server (NTRS)

The combined load (mechanical or thermal load) buckling equations were established for orthotropic rectangular sandwich panels under four different edge conditions by using the Rayleigh-Ritz method of minimizing the total potential energy of a structural system. Two-dimensional buckling interaction curves and three-dimensional buckling interaction surfaces were constructed for high-temperature honeycomb-core sandwich panels supported under four different edge conditions. The interaction surfaces provide overall comparison of the panel buckling strengths and the domains of symmetrical and antisymmetrical buckling associated with the different edge conditions. In addition, thermal buckling curves of these sandwich panels are presented. The thermal buckling conditions for the cases with and without thermal moments were found to be identical for the small deformation theory.

Ko, William L.

1994-01-01

174

Thermal decomposition of hydroxylamine: isoperibolic calorimetric measurements at different conditions.  

PubMed

Thermal decomposition of hydroxylamine, NH2OH, was responsible for two serious accidents. However, its reactive behavior and the synergy of factors affecting its decomposition are not being understood. In this work, the global enthalpy of hydroxylamine decomposition has been measured in the temperature range of 130-150 °C employing isoperibolic calorimetry. Measurements were performed in a metal reactor, employing 30-80 ml solutions containing 1.4-20 g of pure hydroxylamine (2.8-40 g of the supplied reagent). The measurements showed that increased concentration or temperature, results in higher global enthalpies of reaction per unit mass of reactant. At 150 °C, specific enthalpies as high as 8 kJ per gram of hydroxylamine were measured, although in general they were in the range of 3-5 kJ g(-1). The accurate measurement of the generated heat was proven to be a cumbersome task as (a) it is difficult to identify the end of decomposition, which after a fast initial stage, proceeds very slowly, especially at lower temperatures and (b) the environment of gases affects the reaction rate. PMID:23644689

Adamopoulou, Theodora; Papadaki, Maria I; Kounalakis, Manolis; Vazquez-Carreto, Victor; Pineda-Solano, Alba; Wang, Qingsheng; Mannan, M Sam

2013-06-15

175

NASA Office of Aeronautics and Space Technology Summer Workshop. Volume 8: Thermal control panel  

NASA Technical Reports Server (NTRS)

Technology deficiencies in the area of thermal control for future space missions are identified with emphasis on large space structures and cold controlled environments. Thermal control surfaces, heat pipes, and contamination are considered along with cryogenics, insulation, and design techniques. Major directions forecast for thermal control technology development and space experiments are: (1) extend the useful lifetime of cryogenic systems for space, (2) reduce temperature gradients, and (3) improve temperature stability.

1975-01-01

176

NON-THERMAL PLASMA TECHNOLOGY FOR DEGRADATION OF ORGANIC COMPOUNDS IN WASTEWATER CONTROL: A CRITICAL REVIEW  

Microsoft Academic Search

Non-thermal plasma is an emerging technique in environmental pollution control technology, produced by the high-voltage discharge processes and therefore a large amount of high energy electrons and active species are generated. The degradation of difficult-degraded organic pollutions will be greatly enhanced by the active species generated from non-thermal plasma process. However, research on non-thermal plasma technology on organic wastewater cleaning

Hsu-Hui Cheng; Shiao-Shing Chen; Yu-Chi Wu; Din-Lit Ho

177

Correlation between spraying conditions and microcrack density and their influence on thermal cycling life of thermal barrier coatings  

NASA Astrophysics Data System (ADS)

It is generally known that the porosity of thermal barrier coatings is essential to guarantee a sufficiently high strain tolerance of the coating during thermal cycling. However, much less is known about the influence of the specific morphology of porosity, such as microcracks and typically larger pores, on the performance of the coatings. Both features are usually formed during plasma spraying of yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs). In this investigation, the influence of microcracks on the thermal cycling behavior was studied. The amount of microcracks within YSZ thermal barrier coatings was changed by changing the powder-feeding rate. Only small changes of the total porosity were observed. Mercury porosimetry served as a tool to investigate both the amount of microcracks and pores in the coating. Additionally, microcrack densities were determined from metallographical investigations. A linear dependence between the amount of fine pores determined by Hg porosimetry and the crack density was obtained for one set of coatings. Thermal cycling TBC specimens with different microcrack densities were produced and tested in a gas burner test facility. At high surface temperatures (above 1300 °C), failure occurred in the ceramic close to the surface. Under these conditions, the samples with increased horizontal microcrack densities showed a significant increase of thermal cycling life.

Vaßen, Robert; Traeger, Franziska; Stöver, Detlev

2004-09-01

178

Strategy of analysis and interpretation of thermal working conditions.  

PubMed

This paper proposes a strategy for the management of heat problems at the workplace. This includes three steps of analysis: the first aims at recognizing the problem and classifying it under one of the categories--comfort, discomfort but no health risk, or health risk either in the long term or in the short term. The second is designed to evaluate the magnitude of the problem and to optimize the choice of solutions. The interpretation of the data is based on analytical indices: the PMV-PPD indices for heat discomfort conditions and the Required Sweat Rate index for heat stress conditions. The third step involves an in-depth analysis of the situation: this will be undertaken only if a major problem of heat stress has been detected at the previous stage and providing technical solutions cannot be immediately implemented. The advantages and possible limitations of this step-by-step approach are outlined and its cost effectiveness is discussed in the perspective of a true management of health and safety at work. PMID:1888099

Malchaire, J; Mairiaux, P

1991-06-01

179

Inverse Thermal Analysis of a Titanium Laser Weld Using Multiple Constraint Conditions  

NASA Astrophysics Data System (ADS)

Inverse thermal analysis of a titanium laser weld using multiple constraint conditions is presented. This analysis employs a methodology that is in terms of numerical-analytical basis functions for inverse thermal analysis of steady-state energy deposition in plate structures. The results of this type of analysis provide parametric representations of weld temperature histories that can be adopted as input data to various types of computational procedures, such as those for prediction of solid-state phase transformations. In addition, these temperature histories can be used to construct parametric-function representations for inverse thermal analysis of welds corresponding to other process parameters or welding processes whose process conditions are within similar regimes. The present study extends an inverse thermal analysis procedure applied in previous studies. This extension provides for the inclusion of constraint conditions associated with both solidification and phase transformation boundaries.

Lambrakos, S. G.; Shabaev, A.; Huang, L.

2014-04-01

180

Inverse Thermal Analysis of a Titanium Laser Weld Using Multiple Constraint Conditions  

NASA Astrophysics Data System (ADS)

Inverse thermal analysis of a titanium laser weld using multiple constraint conditions is presented. This analysis employs a methodology that is in terms of numerical-analytical basis functions for inverse thermal analysis of steady-state energy deposition in plate structures. The results of this type of analysis provide parametric representations of weld temperature histories that can be adopted as input data to various types of computational procedures, such as those for prediction of solid-state phase transformations. In addition, these temperature histories can be used to construct parametric-function representations for inverse thermal analysis of welds corresponding to other process parameters or welding processes whose process conditions are within similar regimes. The present study extends an inverse thermal analysis procedure applied in previous studies. This extension provides for the inclusion of constraint conditions associated with both solidification and phase transformation boundaries.

Lambrakos, S. G.; Shabaev, A.; Huang, L.

2014-06-01

181

Space-based hyperspectral technologies for the thermal infrared  

NASA Astrophysics Data System (ADS)

Various approaches now exist for obtaining spectral imagery over a broad range of infrared wavelengths. One approach involves the use of a single grating element in two grating orders with dualband focal plane array (FPA) technology. This approach offers greater efficiency over the mid-wave infrared and long-wave infrared and eliminates the need for separate FPAs, dispersing elements, and optical beamsplitters. Another approach achieves similar results by exploiting an FPA which has a broad wavelength response with an innovative grating which has useable efficiency that extends beyond the single octave limits of traditional gratings. Significant advantages result, in either case, for space-based hyperspectral imagers, for which a reduction in cryo-cooled mass translates into prodigious savings in overall payload mass, cryo-cooling requirements, and waste heat removal. By contrast, longer term approaches might realize infrared "hyperspectral pixels" in two-dimensional imaging FPAs. In this case, each pixel would detect different wavelengths of radiation, at different depths, and the resulting "spectral photocurrents" would be transported to read-out circuitry through a vertical grid of electrical contacts. Although not yet realized in practice, the conceptual basis for accomplishing this, with the widely available HgCdTe detector material, has been described. With regard to employment, space-based thermal hyperspectral imaging is characterized by coarser ground resolution as a result of aperture diameter limitations and diffraction considerations at the longer infrared wavelengths. The resulting subpixel detections, based on spectral signature, are often complementary with higher resolution, shorter wavelength, panchromatic imagery.

LeVan, Paul D.

2013-06-01

182

Comparative Study of Thermally Sprayed Coatings Under Different Types of Wear Conditions for Hard Chromium Replacement  

Microsoft Academic Search

The tribological properties of part surfaces, namely their wear resistance and friction properties, are decisive in many cases\\u000a for their proper function. To improve surface properties, it is possible to create hard, wear-resistant coatings by thermal\\u000a spray technologies. With these versatile coating preparation technologies, part lifetime, reliability, and safety can be improved.\\u000a In this study, the tribological properties of the

Š. Houdková; F. Zahálka; M. Kašparová; L.-M. Berger

183

A SINDA thermal model using CAD/CAE technologies  

NASA Technical Reports Server (NTRS)

The approach to thermal analysis described by this paper is a technique that incorporates Computer Aided Design (CAD) and Computer Aided Engineering (CAE) to develop a thermal model that has the advantages of Finite Element Methods (FEM) without abandoning the unique advantages of Finite Difference Methods (FDM) in the analysis of thermal systems. The incorporation of existing CAD geometry, the powerful use of a pre and post processor and the ability to do interdisciplinary analysis, will be described.

Rodriguez, Jose A.; Spencer, Steve

1992-01-01

184

187: Assessment and evaluation of the thermal and acoustical conditions in traditional bath buildings  

Microsoft Academic Search

This paper presents the results of a number of case studies concerning the thermal and acoustical behavior of traditional Islamic bath buildings (hammams). Within the framework of a long-term monitoring effort, we collected data on indoor environmental conditions and outdoor microclimatic conditions pertaining to hammams in Egypt, Turkey, Morocco, Syria, and Algeria. Moreover, short- term acoustical measurements were performed in

Ardeshir Mahdavi; Kristina Orehounig; Belinda Kainrath

2008-01-01

185

Experimental study of human thermal sensation under hypobaric conditions in winter clothes  

Microsoft Academic Search

Hypobaric conditions, with pressures about 20–30% below that at sea level, are often experienced at mountain resorts and plateau areas. The diffusive transfer of water evaporation increases at hypobaric conditions whereas dry heat loss by convection decreases. In order to clarify the effects of barometric on human thermal comfort, experiments are conducted in a decompression chamber where the air parameters

Haiying Wang; Songtao Hu; Guodan Liu; Angui Li

2010-01-01

186

Field Demonstration of Condition Assessment Technologies for Wastewater Collection Systems  

EPA Science Inventory

Reliable information on pipe condition is needed to accurately estimate the remaining service life of wastewater collection system assets. Although inspections with conventional closed-circuit television (CCTV) have been the mainstay of pipeline condition assessment for decades,...

187

Mechanically Pumped Fluid Loop (MPFL) Technologies for Thermal Control of Future Mars Rovers  

NASA Technical Reports Server (NTRS)

Mechanically pumped fluid loop has been the basis of thermal control architecture for the last two Mars lander and rover missions and is the key part of the MSL thermal architecture. Several MPFL technologies are being developed for the MSL rover include long-life pumps, thermal control valves, mechanical fittings for use with CFC-11 at elevated temperatures of approx.100 C. Over three years of life tests and chemical compatibility tests on these MPFL components show that MPFL technology is mature for use on MSL. The advances in MPFL technologies for MSL Rover will benefit any future MPFL applications on NASA s Moon, Mars and Beyond Program.

Birur, Gaj; Bhandari, Pradeep; Prina, Mauro; Bame, Dave; Yavrouian, Andre; Plett, Gary

2006-01-01

188

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions  

NASA Technical Reports Server (NTRS)

A thermal interface material is one of the many tools often used as part of the thermal control scheme for space-based applications. Historically, at Marshall Space Flight Center, CHO-THERM 1671 has primarily been used for applications where an interface material was deemed necessary. However, numerous alternatives have come on the market in recent years. It was decided that a number of these materials should be tested against each other to see if there were better performing alternatives. The tests were done strictly to compare the thermal performance of the materials relative to each other under repeatable conditions and do not take into consideration other design issues, such as off-gassing, electrical conduction, isolation, etc. The purpose of this Technical Memorandum is to detail the materials tested, test apparatus, procedures, and results of these tests. The results show that there are a number of better performing alternatives now available.

Glasgow, S. D.; Kittredge, K. B.

2003-01-01

189

Air Conditioning With Deep Seawater: A Reliable, Cost Effective Technology  

Microsoft Academic Search

Deep, cold seawater has long been recognized as a valuable energy resource, and early studies in the 1970's, motivated by the energy crisis, identified its advantages for coastal air conditioning.',' Air conditioning with seawater uses only a small fraction of the electrical power required for conventional air conditioning. At the time of these studies, however, the cost of the seawater

J. C. Van Ryzin; T. K. Leraand

1991-01-01

190

Thermal signature of fear conditioning in mild post traumatic stress disorder.  

PubMed

Fear conditioning has been proposed as an important factor involved in the etiology of posttraumatic stress disorder (PTSD). We examined fear processing in PTSD patients with mild symptoms and in individuals who did not develop symptoms (both groups consisting of victims of a bank robbery), through the study of fear-conditioned response. Conditioned responses were quantified by the skin conductance response (SCR) and the facial thermal response, the latter being measured by high-resolution functional thermal infrared (fIR) imaging. We found: (a) a change of the physiological parameters with respect to the baseline condition in both control subjects and PTSD patients during the conditioning phase; (b) the permanence of the conditioning effect in the maintenance phase in both control and PTSD patients; (c) patients and controls did differ for the variation across the phases of the physiological parameters rather than for their absolute values, showing that PTSD patients had a prolonged excitation and higher tonic component of autonomic activity. These results, although preliminary, indicate that the analysis of SCR and facial thermal response during the conditioning paradigm is a promising psychometric method of investigation, even in the case of low level of PTSD symptom severity. To the best of our knowledge, this study is the first attempt to discriminate between control subjects and PTSD patients with mild symptoms through infrared thermal imaging. It may suggest feasible approaches for diagnostic screening in the early phases of the disorder and in the assessment of preventive measures and therapies. PMID:24561216

Di Giacinto, A; Brunetti, M; Sepede, G; Ferretti, A; Merla, A

2014-04-25

191

CFD study of the thermal environment in an air-conditioned train station building  

Microsoft Academic Search

This study used the computational fluid dynamics (CFD) method to evaluate the indoor thermal environment of an air-conditioned train station building under three types of air-conditioning design schemes. The impacts of air-conditioning design parameters such as supply air temperature, velocity, altitude and angle of incidence were also investigated. The numerical results showed that if the waiting hall and entrance hall

Qiong Li; Hiroshi Yoshino; Akashi Mochida; Bo Lei; Qinglin Meng; Lihua Zhao; Yufat Lun

2009-01-01

192

Apparent thermal resistance of Bacillus stearothermophilus spores recovered under anaerobic conditions  

Microsoft Academic Search

The effect of recovering Bacillus stearothermophilus spores under anaerobic conditions on their apparent thermal resistance was studied. Spores were suspended in bidistilled\\u000a water as a reference medium, heated at 115, 117, 119, 121, 123 and 125°C and recovered under aerobic and anaerobic conditions.\\u000a D values (decimal reduction time) obtained following recovery under anaerobic conditions were lower than those obtained under

Paula María Periago; P. S. Fernández; María José Ocio; A. Martínez

1998-01-01

193

A review of the combined effects of thermal and noise conditions on human performance  

NASA Astrophysics Data System (ADS)

Human perception and annoyance due to background noise has been the subject of much research. A great deal of work has also been done to identify conditions that produce an acceptable thermal environment for building occupants. The experience of occupants in indoor environments, however, is much more complex than can be represented by thermal comfort or the acoustic environment in isolation. Occupants normally experience a mix of thermal, auditory, visual, and olfactory stimuli that combines to form an impression of the environment. This paper is specifically interested in how building occupants trade off between acoustic and thermal comfort. Heating, ventilation, and air-conditioning systems in buildings are often adjusted by building users to arrive at a more comfortable temperature, but this change may also produce more noise. Previous studies on the interaction effects between temperature and noise on human performance are reviewed in this presentation, followed by a discussion of the authors' current work in this area.

Moscoso, Richard A.; Wang, Lily M.; Musser, Amy

2001-05-01

194

Fuel Savings and Emission Reductions from Next-Generation Mobile Air Conditioning Technology in India  

SciTech Connect

Up to 19.4% of vehicle fuel consumption in India is devoted to air conditioning (A/C). Indian A/C fuel consumption is almost four times the fuel penalty in the United States and close to six times that in the European Union because India's temperature and humidity are higher and because road congestion forces vehicles to operate inefficiently. Car A/C efficiency in India is an issue worthy of national attention considering the rate of increase of A/C penetration into the new car market, India's hot climatic conditions and high fuel costs. Car A/C systems originally posed an ozone layer depletion concern. Now that industrialized and many developing countries have moved away from ozone-depleting substances per Montreal Protocol obligations, car A/C impact on climate has captured the attention of policy makers and corporate leaders. Car A/C systems have a climate impact from potent global warming potential gas emissions and from fuel used to power the car A/Cs. This paper focuses on car A/C fuel consumption in the context of the rapidly expanding Indian car market and how new technological improvements can result in significant fuel savings and consequently, emission reductions. A 19.4% fuel penalty is associated with A/C use in the typical Indian passenger car. Car A/C fuel use and associated tailpipe emissions are strong functions of vehicle design, vehicle use, and climate conditions. Several techniques: reducing thermal load, improving vehicle design, improving occupants thermal comfort design, improving equipment, educating consumers on impacts of driver behaviour on MAC fuel use, and others - can lead to reduced A/C fuel consumption.

Chaney, L.; Thundiyil, K.; Andersen, S.; Chidambaram, S.; Abbi, Y. P.

2007-01-01

195

Hydrazine-hydrate intercalated halloysite under controlled-rate thermal analysis conditions  

Microsoft Academic Search

The thermal behaviour of halloysite fully expanded with hydrazine-hydrate has been investigated in nitrogen atmosphere under\\u000a dynamic heating and at a constant, pre-set decomposition rate of 0.15 mg min-1. Under controlled-rate thermal analysis (CRTA) conditions it was possible to resolve the closely overlapping decomposition\\u000a stages and to distinguish between adsorbed and bonded reagent. Three types of bonded reagent could be

E. Horváth; J. Kristóf; R. L. Frost; Á. Rédey; V. Vágvölgyi; T. Cseh

2003-01-01

196

The thermal degradation of acrylonitrile-butadiene-styrene terpolymer under various gas conditions  

Microsoft Academic Search

In this paper, the thermal degradation of (acrylonitrile-butadiene-styrene) terpolymer (ABS) was studied under various gas conditions as used by the thermogravimetry analyzer. The activation energies of thermal decomposition were evaluated by using Flynn's and Freeman's models. The experimental results showed that the activation energy of isothermal heating of ABS resin were 32.0, 34.4, and 42.7kcal\\/mole under oxygen, air, and nitrogen,

Mu-Hoe Yang

2000-01-01

197

Study of the performance of TBC under thermal cycling conditions using an acoustic emission rig  

Microsoft Academic Search

An experimental rig based on the use of infrared quartz lamps has been developed to monitor the degradation mechanisms causing\\u000a failure of thermal barrier coatings (TBC) under thermal-cycling conditions. An acoustic emission (AE) technique monitored\\u000a these degradation mechanisms, and advanced signals processing identified the key parameters that classify the AE signals according\\u000a to the long-term behavior of the TBC. The

J. Voyer; F. Gitzhofer; M. I. Boulos

1998-01-01

198

Nuclear thermal propulsion technology: Results of an interagency panel in FY 1991  

NASA Technical Reports Server (NTRS)

NASA LeRC was selected to lead nuclear propulsion technology development for NASA. Also participating in the project are NASA MSFC and JPL. The U.S. Department of Energy will develop nuclear technology and will conduct nuclear component, subsystem, and system testing at appropriate DOE test facilities. NASA program management is the responsibility of NASA/RP. The project includes both nuclear electric propulsion (NEP) and nuclear thermal propulsion (NTP) technology development. This report summarizes the efforts of an interagency panel that evaluated NTP technology in 1991. Other panels were also at work in 1991 on other aspects of nuclear propulsion, and the six panels worked closely together. The charters for the other panels and some of their results are also discussed. Important collaborative efforts with other panels are highlighted. The interagency (NASA/DOE/DOD) NTP Technology Panel worked in 1991 to evaluate nuclear thermal propulsion concepts on a consistent basis. Additionally, the panel worked to continue technology development project planning for a joint project in nuclear propulsion for the Space Exploration Initiative (SEI). Five meetings of the panel were held in 1991 to continue the planning for technology development of nuclear thermal propulsion systems. The state-of-the-art of the NTP technologies was reviewed in some detail. The major technologies identified were as follows: fuels, coatings, and other reactor technologies; materials; instrumentation, controls, health monitoring and management, and associated technologies; nozzles; and feed system technology, including turbopump assemblies.

Clark, John S.; Mcdaniel, Patrick; Howe, Steven; Helms, Ira; Stanley, Marland

1993-01-01

199

LOW TEMPERATURE THERMAL TREATMENT (LT3®) TECHNOLOGY - ROY F. WESTON, INC. - APPLICATIONS ANALYSIS REPORT  

EPA Science Inventory

This report evaluates the Low Temperature Thermal Treatment (LT3®) system's ability to remove VOC and SVOC compounds from solid wastes. This evaluation is based on treatment performance and cost data from the Superfund Innovative Technology (SITE) demonstration and fi...

200

Thermal plasma technology for the treatment of wastes: a critical review.  

PubMed

This review describes the current status of waste treatment using thermal plasma technology. A comprehensive analysis of the available scientific and technical literature on waste plasma treatment is presented, including the treatment of a variety of hazardous wastes, such as residues from municipal solid waste incineration, slag and dust from steel production, asbestos-containing wastes, health care wastes and organic liquid wastes. The principles of thermal plasma generation and the technologies available are outlined, together with potential applications for plasma vitrified products. There have been continued advances in the application of plasma technology for waste treatment, and this is now a viable alternative to other potential treatment/disposal options. Regulatory, economic and socio-political drivers are promoting adoption of advanced thermal conversion techniques such as thermal plasma technology and these are expected to become increasingly commercially viable in the future. PMID:18499345

Gomez, E; Rani, D Amutha; Cheeseman, C R; Deegan, D; Wise, M; Boccaccini, A R

2009-01-30

201

Non-Thermal Plasma Decontamination Technology for Forward-Deployed Forces.  

National Technical Information Service (NTIS)

Non-thermal plasma processing is an emerging advanced oxidation technology for oxidation of hazardous microorganisms and compounds at low temperature. The plasma generated during an electrical discharge or when an energetic particle beam is injected into ...

C. Golkowski

2004-01-01

202

OVERVIEW OF CONVENTIONAL AND INNOVATIVE LAND-BASED THERMAL TECHNOLOGIES FOR WASTE DISPOSAL  

EPA Science Inventory

For more than the past two decades, the USEPA has been aggressive in its research, development, performance testing, and in encouragement of the regulated use of proven thermal destruction (or incineration) technologies for the environmentally acceptable treatment and disposal of...

203

Applications of cogeneration with thermal energy storage technologies.  

National Technical Information Service (NTIS)

The Pacific Northwest Laboratory (PNL) leads the U.S. Department of Energy's Thermal Energy Storage (TES) Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility-scale applications...

S. Somasundaram S. Katipamula H. R. Williams

1995-01-01

204

Dish Concentrators for Solar Thermal Energy: Status and Technology Development.  

National Technical Information Service (NTIS)

A wide variety of point-focusing concentrators are under consideration for solar thermal energy use. They are reviewed briefly in this paper. These concentrators differ in such characteristics as optical configuration, optical materials, structure for sup...

L. D. Jaffe

1982-01-01

205

Thermal plasma waste remediation technology: Historical perspective and current trends. Final report  

SciTech Connect

The idea of utilizing thermal plasma technology for waste processing goes back to the mid-1970`s during the energy crisis. Since then, more interest has been shown by universities, industry, and government in developing thermal plasma waste processing technology for hazardous and non-hazardous waste treatment. Much of the development has occurred outside of the United States, most significantly in Japan and France, while the market growth for thermal plasma waste treatment technology has remained slow in the United States. Despite the slow expansion of the market in the United States, since the early 1990`s there has been an increase in interest in utilizing thermal plasma technology for environmental remediation and treatment in lieu of the more historical methods of incineration and landfilling. Currently within the Department of Defense there are several demonstration projects underway, and details of some of these projects are provided. Prior to these efforts by the U.S. Government, the State of New York had investigated the use of thermal plasma technology for treating PCB contaminated solvent wastes from the Love Canal cleanup. As interest continues to expand in the application of thermal plasma technology for waste treatment and remediation, more and more personnel are becoming involved with treatment, regulation, monitoring, and commercial operations and many have little understanding of this emerging technology. To address these needs, this report will describe: (1) characteristics of plasmas; (2) methods for generating sustained thermal plasmas; (3) types of thermal plasma sources for waste processing; (4) the development of thermal plasma waste treatment systems; and (5) Department of Defense plasma arc waste treatment demonstration projects.

Counts, D.A.; Sartwell, B.D.; Peterson, S.H.; Kirkland, R.; Kolak, N.P.

1999-01-29

206

Likely near-term solar-thermal water splitting technologies  

Microsoft Academic Search

Thermodynamic and materials considerations were made for some two- and three-step thermochemical cycles to split water using solar-thermal processing. The direct thermolysis of water to produce H2 using solar-thermal processing is unlikely in the near term due to ultra-high-temperature requirements exceeding 3000K and the need to separate H2 from O2 at these temperatures. However, several lower temperature (<2500K) thermochemical cycles

Christopher Perkins; Alan W. Weimer

2004-01-01

207

Report on Condition Assessment Technology of Wastewater Collection Systems  

EPA Science Inventory

The wastewater collection system infrastructure in the United States is recognized as being in poor condition and in urgent need of condition assessment and rehabilitation. As part of an effort to address aging infrastructure needs, the U.S. Environmental Protection Agency (USEP...

208

Evaluation of thermal comfort conditions in a classroom equipped with radiant cooling systems and subjected to uniform convective environment  

Microsoft Academic Search

The aim of this work is to evaluate numerically the human thermal response that 24 students and 1 teacher feel in a classroom equipped with radiant cooling systems and subjected to uniform convective environments, in lightly warm conditions. The evolution of thermal comfort conditions, using the PMV index, is made by the multi-nodal human thermal comfort model.In this numerical model,

Eusébio Z. E. Conceiçăo; M Lúcio

2011-01-01

209

Advanced Thermal Control Technologies for "CEV" (New Name: ORION)  

NASA Technical Reports Server (NTRS)

NASA is currently investigating several technology options for advanced human spaceflight. This presentation covers some recent developments that relate to NASA's Orion spacecraft and future Lunar missions.

Golliher, Eric; Westheimer, David; Ewert, Michael; Hasan, Mojib; Anderson, Molly; Tuan, George; Beach, Duane

2007-01-01

210

Thermal Energy for Space Cooling--Federal Technology Alert  

SciTech Connect

Cool storage technology can be used to significantly reduce energy costs by allowing energy-intensive, electrically driven cooling equipment to be predominantly operated during off peak hours when electricity rates are lower. This Federal Technology Alert, which is sponsored by DOE's Federal Energy Management Program (FEMP), describes the basic types of cool storage technologies and cooling system integration options. In addition, it defines the savings potential in the federal sector, presents application advice, and describes the performance experience of specific federal users. The results of a case study of a GSA building using cool storage technology are also provided.

Brown, Daryl R.

2000-12-31

211

Thermal Energy Storage for Space Cooling--Federal Technology Alert  

SciTech Connect

Cool storage technology can be used to significantly reduce energy costs by allowing energy-intensive, electrically driven cooling equipment to be predominantly operated during off peak hours when electricity rates are lower. This Federal Technology Alert, which is sponsored by DOE's Federal Energy Management Program (FEMP), describes the basic types of cool storage technologies and cooling system integration options. In addition, it defines the savings potential in the federal sector, presents application advice, and describes the performance experience of specific federal users. The results of a case study of a GSA building using cool storage technology are also provided.

Brown, Daryl R

2000-12-31

212

Indium solder as a thermal interface material using fluxless bonding technology  

Microsoft Academic Search

The capability and diversity of high performance microprocessors is increasing with each process technology generation in order to meet increasing application demand. The cooling designs for these electronic chips have to deal with larger temperature gradients across the die than previously. The key to thermal management is to dissipate the thermal energy from a heat-generating device to a heat sink

Tanawan Chaowasakoo; Teng Hoon Ng; Jinda Songninluck; Margaret B. Stern; Sai Ankireddi

2009-01-01

213

Non-thermal plasma technologies: New tools for bio-decontamination  

Microsoft Academic Search

Bacterial control and decontamination are crucial to industrial safety assessments. However, most recently developed materials are not compatible with standard heat sterilization treatments. Advanced oxidation processes, and particularly non-thermal plasmas, are emerging and promising technologies for sanitation because they are both efficient and cheap. The applications of non-thermal plasma to bacterial control remain poorly known for several reasons: this technique

M. Moreau; N. Orange; M. G. J. Feuilloley

2008-01-01

214

Degradation of different photovoltaic technologies under field conditions  

Microsoft Academic Search

Over the past years a number of testing facilities have been monitoring the performance and degradation of PV systems according to the established standards of indoor and outdoor testing. The objective of this paper is to present the initial first year and longer-term rate of degradation of different PV technologies installed at the testing facility of the University of Cyprus,

George Makrides; Bastian Zinsser; George E. Georghiou; Markus Schubert; Jürgen H. Werner

2010-01-01

215

Optical coating for thermofluidodynamic experiments cuvettes in microgravity conditions: the technology and performances  

NASA Astrophysics Data System (ADS)

The aim of the present paper is to present the results of a research, developed in Officine Galileo, on a special coating that is used on cuvettes for thermofluidodynamic experiments in Microgravity as on the BDPU (Bubbles Drops and Particles Unit), which will flight on the IML2 in June 1994, and on the Inex-Mam (Interactive Experiment on Marangoni Migration) module that has been launched with a Maser Sounding Rocket in November 1993. The very stringent optical and thermal requirements and the Microgravity environmental conditions led to the development of a multilayer coating on a quartz covette with a low reflectivity in the visible (< 1.5% at 633 nm and < 4.0% in the range 400-800 nm), a good reflectivity (> 80.0%) in the IR above 3.7 micrometers (this is the upper cut wavelength of Suprasil 300 Quartz, the cuvette materials), and an average transparency > 20.0% in the range of 0.8-3.7 micrometers . These performances allow to reach an extremely low IR emissivity (< 0.1 above 5.0 micrometers ) of the external cuvettes surfaces, but simultaneously allow a partial thermal images acquisition of the fluid surface within the cuvette (in the range 0.8-3.7 micrometers ) and the application of interferometric diagnostic systems in the visible range (PDI: Point Diffraction Interferometer at 633 nm). In the paper the achieved performances in the visible and thermal ranges are discussed with respect to the experiments cuvettes requirements, and a description of the used technology is given.

Tacconi, M.; Dionisio, Germano; Simoncini, M.; Falciani, P. G.

1994-09-01

216

Real-time condition monitoring of thermal power plants feed-pumps by rolling bearings supports vibration  

NASA Astrophysics Data System (ADS)

The report addresses the real-time condition monitoring of technical state and automatic diagnosis of auxiliary equipment for bearings supports vibration, for example, control of the feed-pump operating modes of thermal power stations. The causes that lead to premature birth and development of defects in rolling bearings are identified and the development of activities ensuring safe and continuous operation of the auxiliary equipment of thermal power stations is carried out. Collection and analysis of vibration parameters of pumping units during their operation at the operating modes of the technological process are realized by means of real-time technical condition monitoring. Spectral analysis of vibration parameters of one of the pumps showed the presence of frequency components, which mark violations in the operating practices of the pump, the imbalance development and, as a consequence, the development of defects in the bearings by long-term operation of the unit. Timely warning of the personnel on the operation of the unit with the "INTOLERABLE" technical state and automatic warning issuance of the need to change the technological process allowed to recover the estimated pump operation mode in due time and prevent further development of defects in equipment.

Kostyukov, V. N.; Tarasov, E. V.

2012-05-01

217

Aquatic ecotoxicity of the fungicide pyrimethanil: effect profile under optimal and thermal stress conditions.  

PubMed

The aquatic ecotoxic profile of the fungicide pyrimethanil and its acute and chronic thermal dependence in two aquatic invertebrates Chironomus riparius and Daphnia magna were investigated. The ecotoxicity of pyrimethanil at optimal thermal conditions did not depend on the trophic level, but was species-specific. The acute pyrimethanil-toxicity on C. riparius increased with higher temperature. The chronic response of Daphnia magna to the NOEC of the fungicide was examined in a multigenerational experiment under three near-natural temperature regimes. A pyrimethanil-induced increase of total mortality was buffered by the strongly related increase of the general reproductive capacity, while population growth was stronger influenced by temperature than by the fungicide. At a LOEC, however, a second generation could not be established with D. magna at all thermal regimes. This clearly shows that thermal and multigenerational effects should be considered when appraising the ecotoxicity of pesticides and assessing their future risk for the environment. PMID:22622013

Seeland, Anne; Oehlmann, Jörg; Müller, Ruth

2012-09-01

218

A study on oscillating second-kind boundary condition for Pennes equation considering thermal relaxation  

NASA Astrophysics Data System (ADS)

To study the effects of the thermal relaxation, the blood perfusion and the oscillating of ambient heat flux on the living tissue temperature in detail, we analytically investigated the one-dimensional CV model, a thermal wave model presented by Cattaneo and Vernott, for Pennes' bio-heat transfer equation under oscillating second-kind boundary condition. The results showed that the blood perfusion has the effect of maintaining the tissue's temperature. The heat propagation velocity decreases with the thermal relaxation time, while the absolute value of tissue's mean excess temperature at steady state increases with the thermal relaxation time. When the ambient heat flux oscillates, the tissue's temperature oscillates in the same period with a lag time. The results obtained in this paper are valuable for the research reference on the topic of tumor hyperthermia, heat injury, etc.

Zhu, Weiping; Xu, Peng; Xu, Dong; Zhang, Meimei; Liu, Huiming; Gong, Linghui; Lu, Junfeng

2014-05-01

219

The effect of atmospheric thermal conditions and urban thermal pollution on all-cause and cardiovascular mortality in Bangladesh.  

PubMed

This study assessed the effect of temperature and thermal atmospheric conditions on all-cause and cardiovascular mortality in Bangladesh. In particular, differences in the response to elevated temperatures between urban and rural areas were investigated. Generalized additive models (GAMs) for daily death counts, adjusted for trend, season, day of the month and age were separately fitted for urban and rural areas. Breakpoint models were applied for determining the increase in mortality above and below a threshold (equivalent) temperature. Generally, a 'V'-shaped (equivalent) temperature-mortality curve with increasing mortality at low and high temperatures was observed. Particularly, urban areas suffered from heat-related mortality with a steep increase above a specific threshold. This adverse heat effect may well increase with ongoing urbanization and the intensification of the urban heat island due to the densification of building structures. Moreover, rising temperatures due to climate change could aggravate thermal stress. PMID:21377776

Burkart, Katrin; Schneider, Alexandra; Breitner, Susanne; Khan, Mobarak Hossain; Krämer, Alexander; Endlicher, Wilfried

2011-01-01

220

A Rubric for Self-Assessment of Essential Technology Conditions in Schools  

ERIC Educational Resources Information Center

This article describes the development of a Web-based instrument that is part of a strategic planning initiative in technology in K-12 schools in Nebraska. The instrument provides rubrics for self-assessment of essential conditions necessary for integrating and adopting of technology. Essential conditions were defined by an extended panel of…

Steckelberg, Allen L.; Li, Lan; Liu, Xiongyi; Kozak, Mike

2008-01-01

221

Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems  

EPA Science Inventory

The purpose of the field demonstration program is to gather technically reliable cost and performance information on selected condition assessment technologies under defined field conditions. The selected technologies include zoom camera, electro-scan (FELL-41), and a multi-sens...

222

Solar thermal power systems point-focusing distributed receiver \\/PFDR\\/ technology - A project description  

Microsoft Academic Search

The goal of the Project is to support the industrial development of PFDR technology that will provide favorable life-cycle costs per unit of electrical or thermal energy produced. The technology will be made available in the early 1980s for applications project experiments. PFDR systems utilize concentrator dishes to furnish energy to their own individual receivers and power conversion subsystems. Initial

J. W. Lucas; E. J. Roschke

1978-01-01

223

Thermal comfort of an air-conditioned office through different windows-door opening arrangements  

Microsoft Academic Search

This paper investigates the thermal comfort level of an office room through various windows-door opening arrangements in hot and humid climate. To determine the windows-door opening performance, 14 opening configurations have been considered and the combination of opening arrangements was carried out in an air-conditioned office at UPM, Malaysia. After conducting objective measurement for each condition, Predicted Mean Vote (PMV)

R. Daghigh; NM Adam; K. Sopian; BB Sahari

2009-01-01

224

Evaluation of airborne thermal, magnetic, and electromagnetic characterization technologies.  

National Technical Information Service (NTIS)

The identification of Buried Structures (IBS) or Aerial Surveillance Project was initiated by the US Department of Energy (DOE) Office of Technology Development to demonstrate airborne methods for locating and identifying buried waste and ordnance at the ...

N. E. Josten

1992-01-01

225

Application of CFD Technology to electronic thermal management  

Microsoft Academic Search

Application of a Computational Fluids Dynamics (CFD) tool to the thermal modeling of free convection cooled handheld\\/portable products and component level products is assessed. The results of two case studies are reviewed. The first case focuses on a sealed, system level enclosure typical of portable consumer products; while the second case looks at a component level analysis of a sealed

Tom Lee; Ben Chambers; Mali Mahalingam

1994-01-01

226

Application of CFD technology to electronic thermal management  

Microsoft Academic Search

Application of a computational fluid dynamics (CFD) tool to the thermal modeling of free convection cooled handheld\\/portable products and component level products is assessed. The results of two case studies are reviewed. The first case focuses on a sealed, system level enclosure typical of portable consumer products; while the second case looks at a component level analysis of a sealed

T.-Y. T. L. Lee; B. Chambers; M. Mahalingam

1995-01-01

227

Thermal neutral format based on the step technology  

NASA Technical Reports Server (NTRS)

The exchange of models is one of the most serious problems currently encountered in the practice of spacecraft thermal analysis. Essentially, the problem originates in the diversity of computing environments that are used across different sites, and the consequent proliferation of native tool formats. Furthermore, increasing pressure to reduce the development's life cycle time has originated a growing interest in the so-called spacecraft concurrent engineering. In this context, the realization of the interdependencies between different disciplines and the proper communication between them become critical issues. The use of a neutral format represents a step forward in addressing these problems. Such a means of communication is adopted by consensus. A neutral format is not directly tied to any specific tool and it is kept under stringent change control. Currently, most of the groups promoting exchange formats are contributing with their experience to STEP, the Standard for Exchange of Product Model Data, which is being developed under the auspices of the International Standards Organization (ISO 10303). This paper presents the different efforts made in Europe to provide the spacecraft thermal analysis community with a Thermal Neutral Format (TNF) based on STEP. Following an introduction with some background information, the paper presents the characteristics of the STEP standard. Later, the first efforts to produce a STEP Spacecraft Thermal Application Protocol are described. Finally, the paper presents the currently harmonized European activities that follow up and extend earlier work on the area.

Almazan, P. Planas; Legal, J. L.

1995-01-01

228

TECHNOLOGY ASSESSMENT OF SOLAR THERMAL ENERGY APPLICATIONS IN WASTEWATER TREATMENT  

EPA Science Inventory

Three major areas were identified for which solar thermal energy usage has potential applicability in Publicly Owned Treatment Works. These areas include space and domestic water heating, anaerobic digester heating, and sludge drying. The report contains a detailed analysis of so...

229

SITE TECHNOLOGY CAPSULE: CLEAN BERKSHIRES, INC. THERMAL DESORPTION SYSTEM  

EPA Science Inventory

The thermal desorption process devised by Clean Berkshires, Inc., works by vaporizing the organic contaminants from the soil with heat, isolating the contaminant! in a gas stream, and then destroying them in a high efficiency afterburner. The processed solids are either replaced ...

230

SITE TECHNOLOGY CAPSULE: CLEAN BERKSHIRES, INC. - THERMAL DESORPTION SYSTEM  

EPA Science Inventory

The thermal desorption process devised by Clean Berkshires, Inc., works by vaporizing the organic contaminants from the soil with heat, isolating the contaminant! in a gas stream, and then destroying them in a high efficiency afterburner. he processed solids are either replaced f...

231

Supporting technology for enhanced oil recovery for thermal processes.  

National Technical Information Service (NTIS)

This report contains the results of efforts under the six tasks of the Ninth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections (for each of the 6 tasks) and eac...

J. Bolivar T. B. Reid

1997-01-01

232

Porous materials produced from incineration ash using thermal plasma technology.  

PubMed

This study presents a novel thermal plasma melting technique for neutralizing and recycling municipal solid waste incinerator (MSWI) ash residues. MSWI ash residues were converted into water-quenched vitrified slag using plasma vitrification, which is environmentally benign. Slag is adopted as a raw material in producing porous materials for architectural and decorative applications, eliminating the problem of its disposal. Porous materials are produced using water-quenched vitrified slag with Portland cement and foaming agent. The true density, bulk density, porosity and water absorption ratio of the foamed specimens are studied here by varying the size of the slag particles, the water-to-solid ratio, and the ratio of the weights of the core materials, including the water-quenched vitrified slag and cement. The thermal conductivity and flexural strength of porous panels are also determined. The experimental results show the bulk density and the porosity of the porous materials are 0.9-1.2gcm(-3) and 50-60%, respectively, and the pore structure has a closed form. The thermal conductivity of the porous material is 0.1946Wm(-1)K(-1). Therefore, the slag composite materials are lightweight and thermal insulators having considerable potential for building applications. PMID:23948051

Yang, Sheng-Fu; Chiu, Wen-Tung; Wang, To-Mai; Chen, Ching-Ting; Tzeng, Chin-Ching

2014-06-01

233

Solid phase synthesis of hydantoins by thermal cyclization and screening of reaction conditions using APOS 1200.  

PubMed

A novel strategy for solid-phase synthesis of hydantoins with high optical purity is described using a thermal pH-neutral cyclization and simultaneous release from resin. Hereby even hydantoins bearing a pH-sensitive side chain (protection) are available. The reaction conditions are well screened applying the parallel organic synthesizer APOS 1200. PMID:10729901

Karnbrock, W; Deeg, M; Gerhardt, J; Rapp, W

1998-01-01

234

Mechanical and thermal buckling analysis of sandwich panels under different edge conditions  

NASA Technical Reports Server (NTRS)

By using the Rayleigh-Ritz method of minimizing the total potential energy of a structural system, combined load (mechanical or thermal load) buckling equations are established for orthotropic rectangular sandwich panels supported under four different edge conditions. Two-dimensional buckling interaction curves and three dimensional buckling interaction surfaces are constructed for high-temperature honeycomb-core sandwich panels supported under four different edge conditions. The interaction surfaces provide easy comparison of the panel buckling strengths and the domains of symmetrical and antisymmetrical buckling associated with the different edge conditions. Thermal buckling curves of the sandwich panels also are presented. The thermal buckling conditions for the cases with and without thermal moments were found to be identical for the small deformation theory. In sandwich panels, the effect of transverse shear is quite large, and by neglecting the transverse shear effect, the buckling loads could be overpredicted considerably. Clamping of the edges could greatly increase buckling strength more in compression than in shear.

Ko, William L.

1993-01-01

235

Thermal Comfort and Indoor Air Quality of Task Ambient Air Conditioning in Modern Office Buildings  

Microsoft Academic Search

Energy and environmental sustainability is a major global trend for the 21st century. Thermal discomfort and poor air quality in office buildings can result in loss of productivity, absenteeism and medical problems. The most frequently identified causes are related to inadequate ventilation and contaminants from indoor sources. Task ambient air conditioning aims to provide each occupant with personalized clean air

Guozhong Zheng; Youyin Jing; Hongxia Huang; Puzhao Ma

2009-01-01

236

Low-Thrust Chemical Propulsion System Propellant Expulsion and Thermal Conditioning Study.  

National Technical Information Service (NTIS)

Thermal conditioning systems for satisfying engine net positive suction pressure (NPSP) requirements, and propellant expulsion systems for achieving propellant dump during a return-to-launch site (RTLS) abort were studied for LH2/LO2 and LCH4/LO2 upper st...

F. Merino I. Wakabayashi R. L. Pleasant M. Hill

1982-01-01

237

Building envelope design with the objective to ensure thermal, visual and acoustic comfort conditions  

Microsoft Academic Search

To ensure conditions of thermal, visual and acoustic comfort in rooms with a minimum of energy consumption is of great importance for the health of the user and the energy conservation. One of the most important functions of the building envelope is, therefore, to control physical environmental factors such as heat, light and sound in order to realise defined comfort

Gül Koçlar Oral; Alpin Köknel Yener; Nurgün Tamer Bayazit

2004-01-01

238

Real-time bicycle detection at signalized intersections using thermal imaging technology  

NASA Astrophysics Data System (ADS)

More and more governments and authorities around the world are promoting the use of bicycles in cities, as this is healthy for the bicyclist and improves the quality of life in general. Safety and efficiency of bicyclists has become a major focus. To achieve this, there is a need for a smarter approach towards the control of signalized intersections. Various traditional detection technologies, such as video, microwave radar and electromagnetic loops, can be used to detect vehicles at signalized intersections, but none of these can consistently separate bikes from other traffic, day and night and in various weather conditions. As bikes should get a higher priority and also require longer green time to safely cross the signalized intersection, traffic managers are looking for alternative detection systems that can make the distinction between bicycles and other vehicles near the stop bar. In this paper, the drawbacks of a video-based approach are presented, next to the benefits of a thermal-video-based approach for vehicle presence detection with separation of bicycles. Also, the specific technical challenges are highlighted in developing a system that combines thermal image capturing, image processing and output triggering to the traffic light controller in near real-time and in a single housing.

Collaert, Robin

2013-02-01

239

Optimization of Remediation Conditions using Vadose Zone Monitoring Technology  

NASA Astrophysics Data System (ADS)

Success of in-situ bio-remediation of the vadose zone depends mainly on the ability to change and control hydrological, physical and chemical conditions of subsurface. These manipulations enables the development of specific, indigenous, pollutants degrading bacteria or set the environmental conditions for seeded bacteria. As such, the remediation efficiency is dependent on the ability to implement optimal hydraulic and chemical conditions in deep sections of the vadose zone. Enhanced bioremediation of the vadose zone is achieved under field conditions through infiltration of water enriched with chemical additives. Yet, water percolation and solute transport in unsaturated conditions is a complex process and application of water with specific chemical conditions near land surface dose not necessarily result in promoting of desired chemical and hydraulic conditions in deeper sections of the vadose zone. A newly developed vadose-zone monitoring system (VMS) allows continuous monitoring of the hydrological and chemical properties of the percolating water along deep sections of the vadose zone. Implementation of the VMS at sites that undergoes active remediation provides real time information on the chemical and hydrological conditions in the vadose zone as the remediation process progresses. Manipulating subsurface conditions for optimal biodegradation of hydrocarbons is demonstrated through enhanced bio-remediation of the vadose zone at a site that has been contaminated with gasoline products in Tel Aviv. The vadose zone at the site is composed of 6 m clay layer overlying a sandy formation extending to the water table at depth of 20 m bls. The upper 5 m of contaminated soil were removed for ex-situ treatment, and the remaining 15 m vadose zone is treated in-situ through enhanced bioremedaition. Underground drip irrigation system was installed below the surface on the bottom of the excavation. Oxygen and nutrients releasing powder (EHCO, Adventus) was spread below the irrigation system to enrich the percolating water. The vadose zone monitoring system that was installed at the site allowed accurate monitoring of the wetting cycles, including: (1) wetting front propagation velocities, (2) temporal variation of the sediment water content, (2) chemical composition of the percolating water, (3) isotopic composition of BTEX compounds, (4) variations in nutrient concentration, and (5) variations in the vadose zone redox potential. Preliminary results showed that the wetting front crossed the entire vadose zone in four days reaching maximum water content values of 12 to 18 %. Temporal variation in the sediment BTEX concentrations indicated significant reduction in highly soluble and mobile compounds such as MTBE. Yet the chemical composition of the water samples through the first sampling campaign indicated that the limiting factor for biodegradation at the first wetting cycle was insufficient nitrogen. Results from each wetting cycles were used to improve the following wetting cycles in order to optimize the vadose zone conditions for microbial activity while minimizing leaching of contaminants to the groundwater.

Dahan, O.; Mandelbaum, R.; Ronen, Z.

2010-12-01

240

Proceedings of the Annual Solar Thermal Technology Research and Development Conference  

NASA Astrophysics Data System (ADS)

The Annual Solar Thermal Technology Research and Development Conference is being held at the Holiday Inn Crowne Plaza in Arlington, Virgina, March 8 and 9, 1989. This year the conference is meeting in conjunction with SOLTECH '89. SOLTECH '89 is a jointly sponsored meeting of the Solar Energy Industries Association, Interstate Solar Coordination Council, Sandia National Laboratories and the Solar Energy Research Institute. This report contains the agenda, extended abstracts and most significant visual aids used by the speakers during the Solar Thermal Technology research and development sessions. The program is divided into three sessions: Solar Electric Technology, Non-Electric Research and Development and Applications, and Concentrators.

Couch, W. A.

1989-02-01

241

Heat Transfer and Thermal Stability Research for Advanced Hydrocarbon Fuel Technologies  

NASA Technical Reports Server (NTRS)

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 used the Heated Tube Facility at the NASA Glenn Research Center to perform a thermal stability and heat transfer characterization of RP-1 in an environment simulating that of a high chamber pressure, regenerative cooled rocket engine. The first step in the research was to investigate the carbon deposition process of previous heated tube experiments by performing scanning electron microscopic analysis in conjunction with energy dispersive spectroscopy on the tube sections. This analysis gave insight into the carbon deposition process and the effect that test conditions played in the formation of deleterious coke. Furthermore, several different formations were observed and noted. One other crucial finding of this investigation was that in sulfur containing hydrocarbon fuels, the interaction of the sulfur components with copper based wall materials presented a significant corrosion problem. This problem in many cases was more life limiting than those posed by the carbon deposition process. The results of this microscopic analysis was detailed and presented at the December 2003 JANNAF Air-Breathing Propulsion Meeting as a Materials Compatibility and Thermal Stability Analysis of common Hydrocarbon Fuels (reference 1).

DeWitt, Kenneth; Stiegemeier, Benjamin

2005-01-01

242

Effect of soil water content on soil thermal conductivity under field conditions  

NASA Astrophysics Data System (ADS)

Knowledge of the thermal properties of soils is required in many areas of engineering, meteorology, agronomy, and ecosystem and soil science. Soil thermal conductivity varies in time and space, since it is influenced by soil properties as well as soil temperature and moisture conditions. We use the one dimensional heat conduction equation in conjunction with two-year data measured in a grass-covered field in North Carolina Piedmont to estimate soil thermal conductivity and to investigate how it is impacted by water content. In agreement with laboratory experiments reported in the literature, our results suggest that under dry conditions soil thermal conductivity increases across a relatively narrow range of soil water contents, above which a further increase in water content does not significantly change thermal conductivity. However, when soil approaches saturation, heat transfer is further improved, a fact not previously noted. This nonlinear behavior is consistent with the formation at high water contents of a continuous film of liquid water in soil aggregates of mineral and organic matter.

Vico, G.; Daly, E.; Manzoni, S.; Porporato, A.

2008-12-01

243

Structural health monitoring technology for bolted carbon-carbon thermal protection panels  

NASA Astrophysics Data System (ADS)

The research in this dissertation is motivated by the need for reliable inspection technologies for the detection of bolt loosening in Carbon-Carbon (C-C) Thermal Protection System (TPS) panels on Space Operation Vehicles (SOV) using minimal human intervention. A concept demonstrator of the Structural Health Monitoring (SHM) system was developed to autonomously detect the degradation of the mechanical integrity of the standoff C-C TPS panels. This system assesses the torque levels of the loosened bolts in the C-C TPS panel, as well as identifies the location of those bolts accordingly. During the course of building the proposed SHM prototype, efforts have been focused primarily on developing a trustworthy diagnostic scheme and a responsive sensor suite. Based on the microcontact conditions and damping phenomena of ultrasonic waves across the bolted joints, an Attenuation-based Diagnostic Method was proposed to assess the fastener integrity by observing the attenuation patterns of the resultant sensor signals. Parametric model studies and prototype testing validated the theoretical explanation of the attenuation-based method. Once the diagnostic scheme was determined, the implementation of a sensor suite was the next step. A new PZT-embedded sensor washer was developed to enhance remote sensing capability and achieve sufficient sensitivity by guiding diagnostic waves primarily through the inspection areas. The sensor-embedded washers replace the existing washers to constitute the sensor network, as well as to avoid jeopardizing the integrity of the original fastener components. After sensor design evolution and appropriate algorithm development, verification tests were conducted using a shaker and a full-scale oven, which simulated the acoustic and thermal environments during the re-entry process, respectively. The test results revealed that the proposed system successfully identifies the loss of the preload for the bolted joints that were loosened. The sensors were also found to be durable under the cyclic mechanical and thermal loads without major failures.

Yang, Jinkyu

2005-12-01

244

Supporting technology for enhanced oil recovery - EOR thermal processes  

SciTech Connect

This report contains the results of efforts under the six tasks of the Eighth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section.

NONE

1995-03-01

245

Bayesian Framework Approach for Prognostic Studies in Electrolytic Capacitor under Thermal Overstress Conditions  

NASA Technical Reports Server (NTRS)

Electrolytic capacitors are used in several applications ranging from power supplies for safety critical avionics equipment to power drivers for electro-mechanical actuator. Past experiences show that capacitors tend to degrade and fail faster when subjected to high electrical or thermal stress conditions during operations. This makes them good candidates for prognostics and health management. Model-based prognostics captures system knowledge in the form of physics-based models of components in order to obtain accurate predictions of end of life based on their current state of heal th and their anticipated future use and operational conditions. The focus of this paper is on deriving first principles degradation models for thermal stress conditions and implementing Bayesian framework for making remaining useful life predictions. Data collected from simultaneous experiments are used to validate the models. Our overall goal is to derive accurate models of capacitor degradation, and use them to remaining useful life in DC-DC converters.

Kulkarni, Chetan S.; Celaya, Jose R.; Goebel, Kai; Biswas, Gautam

2012-01-01

246

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions  

NASA Technical Reports Server (NTRS)

A thermal interface material is one of the many tools that are often used as part of the thermal control scheme for space-based applications. These materials are placed between, for example, an avionics box and a cold plate, in order to improve the conduction heat transfer so that proper temperatures can be maintained. Historically at Marshall Space Flight Center, CHO-THERM@ 1671 has primarily been used for applications where an interface material was deemed necessary. However, there have been numerous alternatives come on the market in recent years. It was decided that a number of these materials should be tested against each other to see if there were better performing alternatives. The tests were done strictly to compare the thermal performance of the materials relative to each other under repeatable conditions and they do not take into consideration other design issues such as off-gassing, electrical conduction or isolation, etc. This paper details the materials tested, test apparatus, procedures, and results of these tests.

Glasgow, Shaun; Kittredge, Ken

2003-01-01

247

The OTEC (Ocean Thermal Energy Conversion) mooring technology  

NASA Astrophysics Data System (ADS)

Existing technology for mooring components which may be suitable for OTEC use is summarized. Due to the platform size, depth of water, and length of design life required for an operational OTEC plant, only large and high capacity mooring components were investigated. Engineering, test, and manufacturer's data on wire rope, synthetic rope (nylon, polyester and Kevlar), anchors, deck fittings and machinery, and design concepts for tension leg platform mooring systems are included. A significant portion of the effort was directed to the assessment of synthetic rope technology and its application to moorings.

Shields, D. R.; Wendt, R. L.; Johnson, B. A.

1982-12-01

248

Magnetic Refrigeration Technology for High Efficiency Air Conditioning  

SciTech Connect

Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate heat exchangers or oil distribution issues found in traditional vapor compression systems.

Boeder, A; Zimm, C

2006-09-30

249

REVIEW OF MOBILE THERMAL TECHNOLOGIES FOR SOLID WASTE DESTRUCTION  

EPA Science Inventory

Incineration has been dopted as a proven technology to dispose of: azardous waste regulated under the Resource Conservation and Recovery Act (RCRA); Toxic substances under the Toxic Substances Control Act (TSCA); Sludge waste under the Clean Water Act; Hazardous substances under ...

250

Comparison of Dynamic Characteristics for an Inflatable Solar Concentrator in Atmospheric and Thermal Vacuum Conditions  

NASA Technical Reports Server (NTRS)

Dynamic testing of an inflatable solar concentrator structure in a thermal vacuum chamber as well as in ambient laboratory conditions is described in detail. Unique aspects of modal testing for the extremely lightweight inflatable are identified, including the use of a noncontacting laser vibrometer measurement system. For the thermal vacuum environment, mode shapes and frequency response functions are compared for three different test article inflation pressures at room temperature. Modes that persist through all the inflation pressure regimes are identified, as well as modes that are unique for each pressure. In atmospheric pressure and room temperature conditions, dynamic measurements were obtained for the expected operational inflation pressure of 0.5 psig. Experimental mode shapes and frequency response functions for ambient conditions are described and compared to the 0.5 psig results from the thermal vacuum tests. Only a few mode shapes were identified that occurred in both vacuum and atmospheric environments. This somewhat surprising result is discussed in detail, and attributed at least partly to 1.) large differences in modal damping, and 2.) significant differences in the mass of air contained by the structure, in the two environments. Results of this investigation point out the necessity of testing inflatable space structures in vacuum conditions before they can be launched. Ground testing in atmospheric pressure is not sufficient for predicting on-orbit dynamics of non-rigidized inflatable systems.

Slade, Kara N.; Tinker, Michael L.; Lassiter, John O.; Engberg, Robert

2000-01-01

251

Formation of separating layers under conditions of the thermal aging of sorbents modified by fluorinated polyimide  

NASA Astrophysics Data System (ADS)

Thermogravimetry, elemental analysis, low-temperature nitrogen adsorption, high-resolution electron microscopy, and gas chromatography are used to study the effect of the content of perfluorinated polyimide when used as a stationary phase for modifying Chromosorb P NAW diatomite supports and aluminum oxide, and the effect of thermal aging conditions on changes in their texture and chromatographic characteristics. It is shown that Chromosorb P NAW + 5 wt % of polyimide (PI) adsorbent thermally aged at 700°C in a flow of inert gas exhibits properties of carbon molecular sieves, while aluminum oxide impregnated with 10 wt % of PI and thermally aged at 250°C allows us to selectively separate permanent and organic gases, as well separate saturated and unsaturated hydrocarbons.

Yakovleva, E. Yu.; Shundrina, I. K.; Gerasimov, E. Yu.; Vaganova, T. A.

2014-03-01

252

Development of the Variable Emittance Thermal Suite for the Space Technology 5 Microsatellite  

NASA Technical Reports Server (NTRS)

The advent of very small satellites, such as nano and microsatellites, logically leads to a requirement for smaller thermal control subsystems. In addition, the thermal control needs of the smaller spacecraft/instrument may well be different from more traditional situations. For example, power for traditional heaters may be very limited or unavailable, mass allocations may be severely limited, and fleets of nano/microsatellites will require a generic thermal design as the cost of unique designs will be prohibitive. Some applications may require significantly increased power levels while others may require extremely low heat loss for extended periods. Small spacecraft will have low thermal capacitance thus subjecting them to large temperature swings when either the heat generation rate changes or the thermal sink temperature changes. This situation, combined with the need for tighter temperature control, will present a challenging situation during transient operation. The use of "off-the-shelf" commercial spacecraft buses for science instruments will also present challenges. Older thermal technology, such as heaters, thermostats, and heat pipes, will almost certainly not be sufficient to meet the requirements of these new spacecraft/instruments. They are generally too heavy, not scalable to very small sizes, and may consume inordinate amounts of power. Hence there is a strong driver to develop new technology to meet these emerging needs. Variable emittance coatings offer an exciting alternative to traditional control methodologies and are one of the technologies that will be flown on Space Technology 5, a mission of three microsatellites designed to validate "enabling" technologies. Several studies have identified variable emittance coatings as applicable to a wide range of spacecraft, and to potentially offer substantial savings in mass and/or power over traditional approaches. This paper discusses the development of the variable emittance thermal suite for ST-5. More specifically, it provides a description of and the infusion and validation plans for the variable emittance coatings.

Douglas, Donya M.; Swanson, Theodore; Osiander, Robert; Champion, John; Darrin, Ann Garrison; Biter, William; Chandrasekhar, Prasanna; Obenschain, Arthur (Technical Monitor)

2001-01-01

253

A simple capacitive cell for the measurement of liquids dielectric constant under transient thermal conditions.  

PubMed

A simple device for the measurement of the complex dielectric permittivity of liquids in various thermodynamic states has been developed. It uses a cylindrical aluminium capacitor of a type currently applied in tuning antenna circuits. The capacitor is filled with the liquid solution under study. A comparison of its capacity is made with that of the nitrogen filled capacitor tested under the same thermal conditions. This comparison allows the determination of the real and imaginary part of the solutions permittivity as a function of temperature (between 150 and 300 K) and frequency (between 100 Hz to 2 MHz). After validating the technique with pure glycerol and pure 1,2-propanediol, spectroscopic measurements have been undertaken on pure and diluted 1,2-propanediol in water. Due to the low heat capacity and the high thermal conductivity of the capacitor, cooling rates of 40 K/min have been achieved inside the solution, allowing measurements in the supercooled liquid and vitreous states. Results are presented and discussed in terms of relaxation and the physical states of the sample. By selecting the required thermal conditions, this device permits the observation of thermal transitions, such as ice crystallisation, and measurements to be conducted in the unstable supercooled liquid state. These measurements are necessary in the development of an effective electromagnetic warming device for vitrified cryoprotective solutions. PMID:12644848

Baudot, A; Bret, J L

2003-01-01

254

Graphite Ablation and Thermal Response Simulation Under Arc-Jet Flow Conditions  

NASA Technical Reports Server (NTRS)

The Two-dimensional Implicit Thermal Response and Ablation program, TITAN, was developed and integrated with a Navier-Stokes solver, GIANTS, for multidimensional ablation and shape change simulation of thermal protection systems in hypersonic flow environments. The governing equations in both codes are demoralized using the same finite-volume approximation with a general body-fitted coordinate system. Time-dependent solutions are achieved by an implicit time marching technique using Gauess-Siedel line relaxation with alternating sweeps. As the first part of a code validation study, this paper compares TITAN-GIANTS predictions with thermal response and recession data obtained from arc-jet tests recently conducted in the Interaction Heating Facility (IHF) at NASA Ames Research Center. The test models are graphite sphere-cones. Graphite was selected as a test material to minimize the uncertainties from material properties. Recession and thermal response data were obtained from two separate arc-jet test series. The first series was at a heat flux where graphite ablation is mainly due to sublimation, and the second series was at a relatively low heat flux where recession is the result of diffusion-controlled oxidation. Ablation and thermal response solutions for both sets of conditions, as calculated by TITAN-GIANTS, are presented and discussed in detail. Predicted shape change and temperature histories generally agree well with the data obtained from the arc-jet tests.

Chen, Y.-K.; Milos, F. S.; Reda, D. C.; Stewart, D. A.; Venkatapathy, Ethiraj (Technical Monitor)

2002-01-01

255

Overview of Altair's Thermal Control System and the Associated Technology Development Efforts  

NASA Technical Reports Server (NTRS)

Abstract In early 2004, President Bush announced a bold vision for space exploration. One of the goals included in this vision is a return to the moon by 2020. In response to this vision, NASA established the Constellation Program, which includes several project offices. One of the Constellation projects is Altair, which is the next generation Lunar Lander. The future Altair missions are very different than the Lunar missions accomplished during the Apollo era. As such, there are several project risks and design challenges that have never before been addressed. Due to the unique thermal environment associated with this mission, many of these risks and design challenges are associated with the vehicle's thermal control system. NASA's Exploration Systems Mission Directorate (ESMD) includes the Exploration Technology Development Program (ETDP). ETDP consists of several technology development projects. The project chartered with mitigating the aforementioned risks and design challenges is the Thermal Control System Development for Exploration Project. The current paper will summarize the Altair mission profile, the operational phases, and the thermal design challenges unique to this particular vehicle. The paper will also describe the technology development efforts being performed to mitigate the risks and design challenges. The technology development project is performing a rigorous development effort that includes thermal control system fluids, evaporators, heat exchangers, and Lunar surface radiators. Constellation Program, there are several project offices. One of these projects includes the development of NASA's new lunar lander vehicle. The overall mission architecture for this vehicle, Altair, is very similar to Apollo's architecture. This paper will provide the reader with an overview of the Altair vehicle. In addition, Altair's thermal control system, including the functionality and the hardware, will be discussed. The paper will also describe the technology development process and the various technology developments currently underway.

Stephan, Ryan A.

2009-01-01

256

Thermal Stability and Hydrogen Release Kinetics of Ammonia Borane Under Vehicle Storage Conditions  

SciTech Connect

Ammonia borane (AB) is a promising chemical hydrogen storage material for H2 powered fuel-cell vehicles (FCVs) owing to its considerable hydrogen density and stability under typical ambient conditions. U.S. Department of Energy (DOE) Technical Targets for on-board hydrogen storage systems in 2015 provide a requirement for operating temperatures in full-sun exposure as high as 60°C (50°C by 2010) [1]. The purpose of this work is to investigate the thermal stability of solid AB during storage on-board a FCV at 40 to 60°C. Calorimeter measurements and calculation models are used to estimate AB thermal stability and H2 release kinetics under isothermal, adiabatic, and cooled storage conditions as a function of storage time, temperature, and AB purity.

Rassat, Scot D.; Smith, R. Scott; Aardahl, Christopher L.; Autrey, Thomas; Chin, Arthur A.; Magee, Joseph W.; VanSciver, Gary R.; Lipiecki, Frank J.

2006-09-01

257

(Thermal energy storage technologies for heating and cooling applications)  

SciTech Connect

Recent results from selected TES research activities in Germany and Sweden under an associated IEA annex are discussed. In addition, several new technologies for heating and cooling of buildings and automobiles were reviewed and found to benefit similar efforts in the United states. Details of a meeting with Didier-Werke AG, a leading German ceramics manufacturer who will provide TES media necessary for the United States to complete field tests of an advanced high temperature latent heat storage material, are presented. Finally, an overview of the December 1990 IEA Executive Committee deliberations on TES is presented.

Tomlinson, J.J.

1990-12-19

258

Variation in cooling load of a moving air-conditioned train compartment under the effects of ambient conditions and body thermal storage  

Microsoft Academic Search

A mathematic model was built to simulate dynamic cooling load of an air-conditioned train compartment. Using the model, the dynamic cooling loads of YZ25G train compartment were investigated under the average ambient conditions during the hottest month July, when it travels in three main railway lines of China. The effects of ambient conditions and body thermal storage on the variation

Weiwei Liu; Qihong Deng; Wenjie Huang; Rui Liu

2011-01-01

259

Changes induced in the thermal properties of Galizian soils by the heating in laboratory conditions  

Microsoft Academic Search

The soil properties can be strongly affected by wildfires, causing direct effects on ecosystem productivity and sustainability.\\u000a These effects depend, among other things, on the soil type and on the temperature reached during the fire. The variations\\u000a of thermal properties of several Galizian soils heated in an oven in laboratory conditions at different temperatures (200–500 °C)\\u000a during 15 min have been examined

P. V. Verdes; J. Salgado

2011-01-01

260

Thermal-stress analysis of a Fort St. Vrain core-support block under accident conditions  

SciTech Connect

A thermoelastic stress analysis of a graphite core support block in the Fort St. Vrain High Temperature Gas Cooled Reactor is described. The support block is subjected to thermal stresses caused by a loss of forced circulation accident of the reactor system. Two- and three-dimensional finite element models of the core support block are analyzed using the ADINAT and ADINA codes, and results are given that verify the integrity of this structural component under the given accident condition.

Carruthers, L.M.; Butler, T.A.; Anderson, C.A.

1982-01-01

261

Influence of thermal boundary conditions on stress-strain distribution generated in blade-shaped samples  

Microsoft Academic Search

Cyclic thermal fatigue experiments have been performed on a single-edge wedge specimen of the polycrystalline nickel-based superalloy INI00 to simulate the conditions experienced by a turbine blade during operation. Induction heating and forced-air cooling of the wedge tip was used. The temperature at the leading edge was cycled between 200 and 1100 °C and the surface temperature distribution was measured

O. Mallet; H. Kaguchi; B. Ilschner; F. Meyer-Olbersleben; K. Nikbin; F. Rézaď-Aria; G. A. Webster

1995-01-01

262

Chemiluminescence as a condition monitoring method for thermal aging and lifetime prediction of an HTPB elastomer  

Microsoft Academic Search

Chemiluminescence (CL) has been applied as a condition monitoring technique to assess aging related changes in a hydroxyl-terminated-polybutadiene based polyurethane elastomer. Initial thermal aging of this polymer was conducted between 110 and 50°C. Two CL methods were applied to examine the degradative changes that had occurred in these aged samples: isothermal “wear-out” experiments under oxygen yielding initial CL intensity and

M. Celina; A. B. Trujillo; K. T. Gillen; L. M. Minier

2006-01-01

263

Evaluation of performance of thermal barrier coatings under simulated industrial\\/utility gas turbine conditions  

Microsoft Academic Search

Corrosion tests were performed on state-of-the-art yttria-stabilized zirconia Thermal Barrier Coatings (TBC), under development for cleanfueled aircraft gas turbine service, applied to IN-738 substrates. Small burner rig tests with NaâSOâ condensate were conducted on coated disc specimens to simulate present industrial\\/utility gas turbine operating conditions in an accelerated manner. Specimens were evaluated with appropriate techniques to establish specific corrosion effects

J. E. Palko; K. L. Luthra; D. W. McKee

1978-01-01

264

Distribution of coral reefs in the Pearl Islands (Gulf of Panama) in relation to thermal conditions  

Microsoft Academic Search

The hypothesis that coral reefs are largely confined to the north and east sides of islands because of favorable thermal conditions was tested and confirmed in the Pearl Islands, Panama. The growth rate of Pocillopom dumicornis, the chief reef-building species, declined mark- edly or ceased on shores exposed to temperatures in the range 2%21°C when median growth rates dropped to

PETER W. GLYNN; ROBERT H. STEWART

1973-01-01

265

Two-dimensional heat transfer from a rectangular fin with asymmetrical thermal boundary conditions  

NASA Astrophysics Data System (ADS)

An example of a heat-transfer fin that extends between two surfaces at different temperatures, so that the fin operates at asymmetric thermal boundary conditions, is found in a compact heat exchanger design whose core consists of finned passages between parallel plates at different temperatures. Attention is given to the results obtained for this configuration's two-dimensional fin unequal base temperature effects, fin heat dissipation effects, and total convection heat losses.

Aziz, A.; Tesarik, D. R.

1992-04-01

266

Effects of Starch Properties and Thermal-processing Conditions on Surimi–Starch Gels  

Microsoft Academic Search

Effects of starch and thermal-processing conditions on texture, microstructure, and color of surimi–starch gels were investigated by measuring shear stress, shear strain and color values, as well as microstructure. The influences of starch on texture of surimi–starch gels depended on the concentration and modification of starch as well as the ratio of amylose and amylopectin. Starch increased the gel strength

Hong Yang; Jae W. Park

1998-01-01

267

Numerical Investigation of Thermal Stress Convention in Nonisothermal Gases Under Microgravity Conditions  

NASA Technical Reports Server (NTRS)

Reported here are our results of our numerical/theoretical investigation into the effects of thermal stress in nonisothermal gases under microgravity conditions. The first part of the report consists of a brief summary of the accomplishments and conclusions of our work. The second part consists of two manuscripts, one being a paper presented at the 1998 MSAD Fluid Physics workshop, and the other to appear in Physics of Fluids.

Mackowski, D. W.

1999-01-01

268

Power Conditioning Hardware for AC Traction Based on Utilization of TLRV Hardware and Technology.  

National Technical Information Service (NTIS)

This final report records the findings of an application study that investigated the feasibility of hardware and technology transfer to railroad traction of a multimegawatt power conditioning unit previously developed under sponsorship of the Department o...

G. W. McLean

1982-01-01

269

General Programmatic Terms and Conditions for the Science and Technology Center (STC) Cooperative Agreements  

NSF Publications Database

... and Technology Centers Program (STC) Cooperative Agreements (NSF 03-550) 1. Key Personnel: Except ... Terms and Conditions for NSF 03-550 Cooperative Agreements 1 of 4 statements about the vision ...

270

Thermal Properties of Methane Hydrate by Experiment and Modeling and Impacts on Technology  

SciTech Connect

Thermal properties of pure methane hydrate, under conditions similar to naturally occurring hydrate-bearing sediments being considered for potential production, have been determined both by a new experimental technique and by advanced molecular dynamics simulation (MDS). A novel single-sided, Transient Plane Source (TPS) technique has been developed and used to measure thermal conductivity and thermal diffusivity values of low-porosity methane hydrate formed in the laboratory. The experimental thermal conductivity data are closely matched by results from an equilibrium MDS method using in-plane polarization of the water molecules. MDS was also performed using a non-equilibrium model with a fully polarizable force field for water. The calculated thermal conductivity values from this latter approach were similar to the experimental data. The impact of thermal conductivity on gas production from a hydrate-bearing reservoir was also evaluated using the Tough+/Hydrate reservoir simulator.

Warzinski, R.P.; Gamwo, I.K.; Rosenbaum, E.M.; Jiang, Hao; Jordan, K.D.; English, N.J. (Univ. College Dublin, IRELAND); Shaw, D.W. (Geneva College, Beaver Falls, PA)

2008-07-01

271

Integration of Thermal Indoor Conditions into Operational Heat Health Warning Systems  

NASA Astrophysics Data System (ADS)

The 2003 heat wave in Western Europe with altogether 35,000 to 50,000 deaths in Europe, several thousands of which occurred in Germany, has clearly pointed out the danger arising from long periods with high heat load. As a consequence, Germany, as many other European countries, has started to implement a Heat Health Warning System (HHWS). The German HHWS is based on the ‘Perceived Temperature'. The 'Perceived Temperature' is determined through a heat budget model of the human organism which includes the main thermophysiologically relevant mechanisms of heat exchange with the atmosphere. The most important meteorological ambience parameters included in the model are air temperature, humidity, wind speed and radiation fluxes in the short-wave and long-wave ranges. In addition to using a heat budget model for the assessment of the thermal load, the German HHWS also takes into account that the human body reacts in different ways to its thermal environment due to physiological adaptation (short-term acclimatisation) and short-term behavioural adaptation. The restriction of such an approach, like the majority of approaches used to issue heat warnings, is that the threshold for a warning is generally derived from meteorological observations and that warnings are issued on the basis of weather forecasts. Both, the observed data and the weather forecasts are only available for outside conditions. The group of people who are most at risk of suffering from a heat wave, however, are the elderly and frail who mainly stay inside. The indoor situation, which varies largely from the conditions outside, is not taken into account by most of the warning systems. To overcome this limitation the DWD, in co-operation with the Fraunhofer Institute for Solar Energy Systems, has developed a model which simulates the thermal conditions in the indoor environment. As air-conditioning in private housing in Germany is not very common, the thermal indoor conditions depend on the outside conditions, on the building characteristics, and on the inhabitants' behaviour. The thermal building simulation model estimates the indoor heat load based of the predicted meteorological outside conditions by calculating the operative indoor temperature. The building types prevailing in Germany are quite heterogeneous. It was therefore decided to use for the thermal simulation a so-called "realistic worst-case” building type. In addition, a differentiation is made between two types of user behaviour: the active user opens the windows during the cold hours of the day and uses shading devices whereas the passive user does nothing to keep the heat outside. Since 2007, the DWD has been using the simulation of the indoor thermal conditions as an additional source of information for heat warnings. The information on the indoor conditions has proved very valuable for the decision whether to issue a heat warning or not.

Koppe, C.; Becker, P.; Pfafferott, J.

2009-09-01

272

Suitable features selection for monitoring thermal condition of electrical equipment using infrared thermography  

NASA Astrophysics Data System (ADS)

Monitoring the thermal condition of electrical equipment is necessary for maintaining the reliability of electrical system. The degradation of electrical equipment can cause excessive overheating, which can lead to the eventual failure of the equipment. Additionally, failure of equipment requires a lot of maintenance cost, manpower and can also be catastrophic- causing injuries or even deaths. Therefore, the recognition processof equipment conditions as normal and defective is an essential step towards maintaining reliability and stability of the system. The study introduces infrared thermography based condition monitoring of electrical equipment. Manual analysis of thermal image for detecting defects and classifying the status of equipment take a lot of time, efforts and can also lead to incorrect diagnosis results. An intelligent system that can separate the equipment automatically could help to overcome these problems. This paper discusses an intelligent classification system for the conditions of equipment using neural networks. Three sets of features namely first order histogram based statistical, grey level co-occurrence matrix and component based intensity features are extracted by image analysis, which are used as input data for the neural networks. The multilayered perceptron networks are trained using four different training algorithms namely Resilient back propagation, Bayesian Regulazation, Levenberg-Marquardt and Scale conjugate gradient. The experimental results show that the component based intensity features perform better compared to other two sets of features. Finally, after selecting the best features, multilayered perceptron network trained using Levenberg-Marquardt algorithm achieved the best results to classify the conditions of electrical equipment.

Huda, A. S. N.; Taib, S.

2013-11-01

273

Proceedings of the 1993 non-fluorocarbon insulation, refrigeration and air conditioning technology workshop  

SciTech Connect

Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

Not Available

1994-09-01

274

Fast access to the CMS detector condition data employing HTML5 technologies  

Microsoft Academic Search

This paper focuses on using HTML version 5 (HTML5) for accessing condition data for the CMS experiment, evaluating the benefits and risks posed by the use of this technology. According to the authors of HTML5, this technology attempts to solve issues found in previous iterations of HTML and addresses the needs of web applications, an area previously not adequately covered

Giuseppe Antonio Pierro; Francesca Cavallari; Salvatore Di Guida; Vincenzo Innocente

2011-01-01

275

Supporting technology for enhanced oil recovery for thermal processes  

SciTech Connect

This report contains the results of efforts under the six tasks of the Ninth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections (for each of the 6 tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section. The tasks are numbered 62 through 67. The first, second, third, fourth fifth, sixth, seventh, eighth, and ninth reports on Annex IV, [Venezuela MEM/USA-DOE Fossil Energy Report IV-1, IV-2, IV-3, IV-4, IV-5, IV-6, IV-7, and IV-8 (DOE/BETC/SP-83/15, DOE/BC-84/6/SP, DOE/BC-86/2/SP, DOE/BC-87/2/SP, DOE/BC-90/1/SP, DOE/BC-90/1/SP) (DOE/BC-92/1/SP, DOE/BC-93/3/SP, and DOE/BC-95/3/SP)] contain the results from the first 61 tasks. Those reports are dated April 1983, August 1984, March 1986, July 1987, November 1988, October 1991, February 1993, and March 1995 respectively.

Reid, T.B.; Bolivar, J.

1997-12-01

276

Critical Evaluation of State-of-the-Art In Situ Thermal Treatment Technologies for DNAPL Source Zone Treatment.  

National Technical Information Service (NTIS)

In-situ thermal soil and aquifer remediation technologies (e.g., electrical resistance heating, conductive heating, steam-based heating, etc.) have undergone rapid development and application in recent years. These technologies offer the promise of more r...

E. Foote J. T. Kingston P. C. Johnson P. R. Dahlen S. Williams

2010-01-01

277

solar thermal power systems advanced solar thermal technology project, advanced subsystems development  

NASA Technical Reports Server (NTRS)

The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities.

1979-01-01

278

A review of imperative technologies for wastewater treatment I: oxidation technologies at ambient conditions  

Microsoft Academic Search

Nowadays, due to the increasing presence of molecules, refractory to the microorganisms in the wastewater streams, the conventional biological methods cannot be used for complete treatment of the effluent and hence, introduction of newer technologies to degrade these refractory molecules into smaller molecules, which can be further oxidized by biological methods, has become imperative. The present work aims at highlighting

Parag R Gogate; Aniruddha B Pandit

2004-01-01

279

Thermal and electrical conductivity of solid iron and iron-silicon mixtures at Earth's core conditions  

NASA Astrophysics Data System (ADS)

We report on the thermal and electrical conductivities of solid iron and iron-silicon mixtures (Fe0.92Si0.08 and Fe0.93Si0.07), representative of the composition of the Earth's solid inner core at the relevant pressure-temperature conditions, obtained from density functional theory calculations with the Kubo-Greenwood formulation. We find thermal conductivities k =232 (237) W m-1 K-1, and electrical conductivities ? = 1.5 (1.6) × 106~? -1m-1 at the top of the inner core (centre of the Earth).These values are respectively about 45-56 % and 18-25% higher than the corresponding conductivities in the liquid outer core. The higher conductivities are due to the solid structure and to the lower concentration of light impurities. These values are much higher than those in use for previous inner core studies, k by a factor of four and ? by a factor of three. The high thermal conductivity means that heat leaks out by conduction almost as quickly as the inner core forms, making thermal convection unlikely. The high electrical conductivity increases the magnetic decay time of the inner core by a factor of more than three, lengthening the magnetic diffusion time to 10~kyr and making it more likely that the inner core stabilises the geodynamo and reduces the frequency of reversals.

Pozzo, M.; Alfe, D.; Gubbins, D.; Davies, C. J.

2013-12-01

280

Thermal and electrical conductivity of solid iron and iron–silicon mixtures at Earth's core conditions  

NASA Astrophysics Data System (ADS)

We report on the thermal and electrical conductivities of solid iron and iron-silicon mixtures (Fe0.92Si0.08 and Fe0.93Si0.07), representative of the composition of the Earth's solid inner core at the relevant pressure-temperature conditions, obtained from density functional theory calculations with the Kubo-Greenwood formulation. We find thermal conductivities k=232 (237) W m K, and electrical conductivities ?=1.5 (1.6)×106 ?-1 m at the top of the inner core (centre of the Earth). These values are respectively about 45-56% and 18-25% higher than the corresponding conductivities in the liquid outer core. The higher conductivities are due to the solid structure and to the lower concentration of light impurities. These values are much higher than those in use for previous inner core studies, k by a factor of four and ? by a factor of three. The high thermal conductivity means that heat leaks out by conduction almost as quickly as the inner core forms, making thermal convection unlikely. The high electrical conductivity increases the magnetic decay time of the inner core by a factor of more than three, lengthening the magnetic diffusion time to 10 kyr and making it more likely that the inner core stabilises the geodynamo and reduces the frequency of reversals.

Pozzo, Monica; Davies, Chris; Gubbins, David; Alfč, Dario

2014-05-01

281

Heart Rate Variability in Sleeping Preterm Neonates Exposed to Cool and Warm Thermal Conditions  

PubMed Central

Sudden infant death syndrome (SIDS) remains the main cause of postneonatal infant death. Thermal stress is a major risk factor and makes infants more vulnerable to SIDS. Although it has been suggested that thermal stress could lead to SIDS by disrupting autonomic functions, clinical and physiopathological data on this hypothesis are scarce. We evaluated the influence of ambient temperature on autonomic nervous activity during sleep in thirty-four preterm neonates (mean ± SD gestational age: 31.4±1.5 weeks, postmenstrual age: 36.2±0.9 weeks). Heart rate variability was assessed as a function of the sleep stage at three different ambient temperatures (thermoneutrality and warm and cool thermal conditions). An elevated ambient temperature was associated with a higher basal heart rate and lower short- and long-term variability in all sleep stages, together with higher sympathetic activity and lower parasympathetic activity. Our study results showed that modification of the ambient temperature led to significant changes in autonomic nervous system control in sleeping preterm neonates. The latter changes are very similar to those observed in infants at risk of SIDS. Our findings may provide greater insight into the thermally-induced disease mechanisms related to SIDS and may help improve prevention strategies.

Stephan-Blanchard, Erwan; Chardon, Karen; Leke, Andre; Delanaud, Stephane; Bach, Veronique; Telliez, Frederic

2013-01-01

282

Heart rate variability in sleeping preterm neonates exposed to cool and warm thermal conditions.  

PubMed

Sudden infant death syndrome (SIDS) remains the main cause of postneonatal infant death. Thermal stress is a major risk factor and makes infants more vulnerable to SIDS. Although it has been suggested that thermal stress could lead to SIDS by disrupting autonomic functions, clinical and physiopathological data on this hypothesis are scarce. We evaluated the influence of ambient temperature on autonomic nervous activity during sleep in thirty-four preterm neonates (mean ± SD gestational age: 31.4±1.5 weeks, postmenstrual age: 36.2±0.9 weeks). Heart rate variability was assessed as a function of the sleep stage at three different ambient temperatures (thermoneutrality and warm and cool thermal conditions). An elevated ambient temperature was associated with a higher basal heart rate and lower short- and long-term variability in all sleep stages, together with higher sympathetic activity and lower parasympathetic activity. Our study results showed that modification of the ambient temperature led to significant changes in autonomic nervous system control in sleeping preterm neonates. The latter changes are very similar to those observed in infants at risk of SIDS. Our findings may provide greater insight into the thermally-induced disease mechanisms related to SIDS and may help improve prevention strategies. PMID:23840888

Stéphan-Blanchard, Erwan; Chardon, Karen; Léké, André; Delanaud, Stéphane; Bach, Véronique; Telliez, Frédéric

2013-01-01

283

Diurnal cool thermal energy storage: Research programs, technological developments, and commercial status  

NASA Astrophysics Data System (ADS)

This report presents an overview of the major federal and private research and development efforts in diurnal cool thermal energy storage for electric load management in buildings. Included are brief technical descriptions and research histories of the technologies and applications of cool thermal storage. The goals, accomplishments, and funding levels of major thermal storage research programs also are summarized. The report concludes with the results of recent field performance evaluations of cool thermal storage installations and a discussion of the current commercial status of thermal storage equipment, including utility participation programs. This report was sponsored by the Technology and Consumer Products (TCP) Division within the Office of Conservation of the U.S. Department of Energy. This report is part of TCP's ongoing effort to examine and evaluate technology developments and research efforts in the areas of lighting, space heating and cooling, water heating, refrigeration, and other building energy conversion equipment. Information obtained through this effort is used as an input in developing the U.S. research agenda in these areas.

Wise, M. A.

1992-01-01

284

Mathematical Modelling of Thermal Process to Aquatic Environment with Different Hydrometeorological Conditions  

PubMed Central

This paper presents the mathematical model of the thermal process from thermal power plant to aquatic environment of the reservoir-cooler, which is located in the Pavlodar region, 17?Km to the north-east of Ekibastuz town. The thermal process in reservoir-cooler with different hydrometeorological conditions is considered, which is solved by three-dimensional Navier-Stokes equations and temperature equation for an incompressible flow in a stratified medium. A numerical method based on the projection method, divides the problem into three stages. At the first stage, it is assumed that the transfer of momentum occurs only by convection and diffusion. Intermediate velocity field is solved by fractional steps method. At the second stage, three-dimensional Poisson equation is solved by the Fourier method in combination with tridiagonal matrix method (Thomas algorithm). Finally, at the third stage, it is expected that the transfer is only due to the pressure gradient. Numerical method determines the basic laws of the hydrothermal processes that qualitatively and quantitatively are approximated depending on different hydrometeorological conditions.

Issakhov, Alibek

2014-01-01

285

Mathematical modelling of thermal process to aquatic environment with different hydrometeorological conditions.  

PubMed

This paper presents the mathematical model of the thermal process from thermal power plant to aquatic environment of the reservoir-cooler, which is located in the Pavlodar region, 17?Km to the north-east of Ekibastuz town. The thermal process in reservoir-cooler with different hydrometeorological conditions is considered, which is solved by three-dimensional Navier-Stokes equations and temperature equation for an incompressible flow in a stratified medium. A numerical method based on the projection method, divides the problem into three stages. At the first stage, it is assumed that the transfer of momentum occurs only by convection and diffusion. Intermediate velocity field is solved by fractional steps method. At the second stage, three-dimensional Poisson equation is solved by the Fourier method in combination with tridiagonal matrix method (Thomas algorithm). Finally, at the third stage, it is expected that the transfer is only due to the pressure gradient. Numerical method determines the basic laws of the hydrothermal processes that qualitatively and quantitatively are approximated depending on different hydrometeorological conditions. PMID:24991644

Issakhov, Alibek

2014-01-01

286

LOW THERMAL TREATMENT (LT3) TECHNOLOGY, ROY F. WESTON, INC. - APPLICATIONS ANALYSIS REPORT  

EPA Science Inventory

This report evaluates the Low Temperature Thermal Treatment (LT3) system's ability to remove VOC and SVOC compounds from solid wastes. his evaluation is based on treatment performance and cost data from the Superfund Innovative Technology (SITE) demonstration and five other case ...

287

Review on sustainable thermal energy storage technologies, Part I: heat storage materials and techniques  

Microsoft Academic Search

This paper reviews the development of available thermal energy storage (TES) technologies and their individual pros and cons for space and water heating applications. Traditionally, available heat has been stored in the form of sensible heat (typically by raising the temperature of water, rocks, etc.) for later use. In most of the low temperature applications, water is being used as

S. M. Hasnain

1998-01-01

288

Thermal plasma technology for the treatment of wastes: A critical review  

Microsoft Academic Search

This review describes the current status of waste treatment using thermal plasma technology. A comprehensive analysis of the available scientific and technical literature on waste plasma treatment is presented, including the treatment of a variety of hazardous wastes, such as residues from municipal solid waste incineration, slag and dust from steel production, asbestos-containing wastes, health care wastes and organic liquid

E. Gomez; D. Amutha Rani; C. R. Cheeseman; D. Deegan; M. Wise; A. R. Boccaccini

2009-01-01

289

Structural health monitoring technology for bolted carbon-carbon thermal protection panels  

Microsoft Academic Search

The research in this dissertation is motivated by the need for reliable inspection technologies for the detection of bolt loosening in Carbon-Carbon (C-C) Thermal Protection System (TPS) panels on Space Operation Vehicles (SOV) using minimal human intervention. A concept demonstrator of the Structural Health Monitoring (SHM) system was developed to autonomously detect the degradation of the mechanical integrity of the

Jinkyu Yang

2005-01-01

290

Solar Thermal Technology. Annual Evaluation Report, Fiscal Year 1982. Volume I. Executive Summary.  

National Technical Information Service (NTIS)

This report, which is divided into two volumes, documents the accomplishments and progress of the US Department of Energy Solar Thermal Technology (STT) Program during FY 1982, covering the period from October 1, 1981 to September 30, 1982. The focus of t...

1983-01-01

291

Multi-criteria decision aid to assess concentrated solar thermal technologies  

Microsoft Academic Search

There are now several concentrated solar thermal technologies (CSP), such as parabolic troughs and central receivers using various heat transfer media, that have reached the phase of initial commercial deployment for large-scale power production. Information about cost, performance and impact on the environment of the systems being analyzed is currently affected by uncertainty. In many cases, traditional evaluation methods such

Fausto Cavallaro

2009-01-01

292

Thermal Analysis Of The NASA Integrated Vehicle Health Monitoring Experiment Technology For X-Vehicles (NITEX)  

NASA Technical Reports Server (NTRS)

The purpose of this project was to perform a thermal analysis for the NASA Integrated Vehicle Health Monitoring (IVHM) Technology Experiment for X-vehicles (NITEX). This electronics package monitors vehicle sensor information in flight and downlinks vehicle health summary information via telemetry. The experiment will be tested on the X-34 in an unpressurized compartment, in the vicinity of one of the vehicle's liquid oxygen tanks. The transient temperature profile for the electronics package has been determined using finite element analysis for possible mission profiles that will most likely expose the package to the most extreme hot and cold environmental conditions. From the analyses, it was determined that temperature limits for the electronics would be exceeded for the worst case cold environment mission profile. The finite element model used for the analyses was modified to examine the use of insulation to address this problem. Recommendations for insulating the experiment for the cold environment are presented, and were analyzed to determine their effect on a nominal mission profile.

Hegab, Hisham E.

2001-01-01

293

Heavy oil reservoirs recoverable by thermal technology. Annual report  

SciTech Connect

The purpose of this study was to compile data on reservoirs that contain heavy oil in the 8 to 25/sup 0/ API gravity range, contain at least ten million barrels of oil currently in place, and are non-carbonate in lithology. The reservoirs within these constraints were then analyzed in light of applicable recovery technology, either steam-drive or in situ combustion, and then ranked hierarchically as candidate reservoirs. The study is presented in three volumes. Volume I presents the project background and approach, the screening analysis, ranking criteria, and listing of candidate reservoirs. The economic and environmental aspects of heavy oil recovery are included in appendices to this volume. This study provides an extensive basis for heavy oil development, but should be extended to include carbonate reservoirs and tar sands. It is imperative to look at heavy oil reservoirs and projects on an individual basis; it was discovered that operators, and industrial and government analysts will lump heavy oil reservoirs as poor producers, however, it was found that upon detailed analysis, a large number, so categorized, were producing very well. A study also should be conducted on abandoned reservoirs. To utilize heavy oil, refiners will have to add various unit operations to their processes, such as hydrotreaters and hydrodesulfurizers and will require, in most cases, a lighter blending stock. A big problem in producing heavy oil is that of regulation; specifically, it was found that the regulatory constraints are so fluid and changing that one cannot settle on a favorable recovery and production plan with enough confidence in the regulatory requirements to commit capital to the project.

Kujawa, P.

1981-02-01

294

Nuclear Thermal Propulsion Technology - Summary of FY 1991 Interagency Panel Planning  

NASA Technical Reports Server (NTRS)

An Interagency (NASA/DOE/DOD) technical panel has been working in 1991 to evaluate nuclear thermal propulsion (NTP) concepts on a consistent basis, and to continue technology development project planning for a joint project in nuclear propulsion for Space Exploration Initiative (SEI). This paper summarizes the efforts of the panel to date and summarizes the technology plans defined for NTP. Concepts were categorized based on probable technology readiness data, and innovative 'proof-of-concept' tests and analyses were defined. While further studies will be required to provide a consistent comparison of all of the NTP concepts, the current status of the studies is presented.

Clark, John S.; Mcdaniel, Patrick; Howe, Steven; Stanley, Marland

1991-01-01

295

Non-thermal plasma technologies: new tools for bio-decontamination.  

PubMed

Bacterial control and decontamination are crucial to industrial safety assessments. However, most recently developed materials are not compatible with standard heat sterilization treatments. Advanced oxidation processes, and particularly non-thermal plasmas, are emerging and promising technologies for sanitation because they are both efficient and cheap. The applications of non-thermal plasma to bacterial control remain poorly known for several reasons: this technique was not developed for biological applications and most of the literature is in the fields of physics and chemistry. Moreover, the diversity of the devices and complexity of the plasmas made any general evaluation of the potential of the technique difficult. Finally, no experimental equipment for non-thermal plasma sterilization is commercially available and reference articles for microbiologists are rare. The present review aims to give an overview of the principles of action and applications of plasma technologies in biodecontamination. PMID:18775485

Moreau, M; Orange, N; Feuilloley, M G J

2008-01-01

296

Numerical and experimental analysis of inhomogeneities in SMA wires induced by thermal boundary conditions  

NASA Astrophysics Data System (ADS)

Published data on NiTi wire tensile tests display a surprising variety of results even though the same material has been studied. Hysteresis shapes can be observed that range from box- to cigar-like. In some cases, the variation may be the result of different post-fabrication treatment, such as annealing or cold working procedures. However, oftentimes local data are generated from average stress/strain concepts on the basis of global force and end displacement measurements. It is well known among experimentalists that this has a smoothening effect on data, but there is an additional, less well-known mechanism at work as well. This effect is due to thermomechanical coupling and the thermal boundary condition at the ends of the wires, and it manifests itself in a strong data dependence on the length of the employed specimen. This paper illustrates the effects of a thermal boundary layer in a 1D wire by means of an experimental study combined with a simulation based on the fully coupled momentum and energy balance equations. The system is modeled using COMSOL FEA software to simulate the distribution of strain, temperature, resistivity, and phase fractions. The local behavior is then integrated over the length of the wire to predict the expected behavior of the bulk wire as observed at its endpoints. Then, simulations are compared with results from a tensile test of a 100 mum diameter Dynalloy Flexinol wire between two large, steel clamps. Each step of the tensile test experiment is carefully controlled and then simulated via the boundary and initial conditions of the model. The simulated and experimental results show how the thermal boundary layer affects different length SMA wires and how the inhomogeneity prevents transition to austenite at the wire endpoints. Accordingly, shorter wires tend to be softer (more martensitic) than longer wires and exhibit a large reduction in recoverable strain because a larger percentage of their total length is impacted by the thermal boundary.

Furst, Stephen J.; Crews, John H.; Seelecke, Stefan

2012-11-01

297

Thermalization, isotropization, and elliptic flow from nonequilibrium initial conditions with a saturation scale  

NASA Astrophysics Data System (ADS)

In this article we report on our results about the computation of the elliptic flow of the quark-gluon plasma produced in relativistic heavy-ion collisions, simulating the expansion of the fireball by solving the relativistic Boltzmann equation for the parton distribution function tuned at a fixed shear-viscosity to entropy-density ratio ? /s. Our main goal is to put emphasis on the role of a saturation scale in the initial gluon spectrum, which makes the initial distribution far from a thermalized one. We find that the presence of the saturation scale reduces the efficiency in building up the elliptic flow, even if the thermalization process is quite fast ?therm?0.8fm/c and the pressure isotropization is even faster ?isotr?0.5fm/c. The impact of the nonequilibrium implied by the saturation scale manifests for noncentral collisions and can modify the estimate of the viscosity with respect to the assumption of full thermalization in pT space. We find that the estimate of ? /s is modified from ? /s?2/4? to ? /s?1/4? at the Relativistic Heavy-Ion Collider and from ? /s?3/4? to ? /s?2/4? at the Large Hadron Collider. We complete our investigation with a study of the thermalization and isotropization times of the fireball for different initial conditions and values of ? /s showing how the latter affects both isotropization and thermalization. Last, we have seen that the range of values explored by the phase-space distribution function f is such that at pT<0.5GeV the inner part of the fireball stays with occupation number significantly larger than unity despite the fast longitudinal expansion, which might suggest the possibility of the formation of a transient Bose-Einstein condensate.

Ruggieri, M.; Scardina, F.; Plumari, S.; Greco, V.

2014-05-01

298

Multi-alkali photocathode thermal performance analysis of image intensifier based on low-high temperature environment testing conditions  

NASA Astrophysics Data System (ADS)

Low-level-light (LLL) weapon sight measurement technologies based on Low-high temperature environments testing conditions are always concerned by military equipments manufacturers. Because low-high temperature environment, etc. are under loaded function, the electric performance parameter change to make LLL weapon sight, causing the LLL weapon sight can't be worked and used normally while taking aim. Generally believed that many photocathode is n-type and p-type doping of the inner surface layer comprising more photocathode not light sensitive, but also sensitive to temperature. To image intensifier is non-working state at the temperature 70°C +/-2°C test boxes and thermostats time one hour, five minutes to image intensifier into -50°C+/-2°C Test Box temperature one hour, then five minutes again placed 70°C +/-2°C high temperature test box for three cycle question image intensifier restore normal temperature after the test. The experiments show that, when the temperature rises, the heat semiconductor photocathode current density, thermal current rise in the temperature range 0 to 70°C, 4°C temperature is increased, almost twice its current heat. Of course, image intensifier imported the equivalent background illumination will also increase, resulting in night vision systems observed at the scene image contrast and differential rates were lowered, target detection system performance last night caused the decline. A study of the reasons is the photo-cathode materials and fabrication of thermal electron emission standards restricting the ability.

Gao, Youtang; Tian, Si; Chang, Benkang; Qiu, Yafeng; Qiao, Jianliang

2008-03-01

299

Thermal Analysis of the Advanced Technology Large Aperture Space Telescope (ATLAST) 8 Meter Primary Mirror  

NASA Technical Reports Server (NTRS)

The Advanced Technology Large Aperture Space Telescope (ATLAST) preliminary design concept consists of an 8 meter diameter monolithic primary mirror enclosed in an insulated, optical tube with stray light baffles and a sunshade. ATLAST will be placed in orbit about the Sun-Earth L2 and will experience constant exposure to the sun. The insulation on the optical tube and sunshade serve to cold bias the telescope which helps to minimize thermal gradients. The primary mirror will be maintained at 280K with an active thermal control system. The geometric model of the primary mirror, optical tube, sun baffles, and sunshade was developed using Thermal Desktop(R) SINDA/FLUINT(R) was used for the thermal analysis and the radiation environment was analyzed using RADCAD(R). A XX node model was executed in order to characterize the static performance and thermal stability of the mirror during maneuvers. This is important because long exposure observations, such as extra-solar terrestrial planet finding and characterization, require a very stable observatory wave front. Steady state thermal analyses served to predict mirror temperatures for several different sun angles. Transient analyses were performed in order to predict thermal time constant of the primary mirror for a 20 degree slew or 30 degree roll maneuver. This paper describes the thermal model and provides details of the geometry, thermo-optical properties, and the environment which influences the thermal performance. All assumptions that were used in the analysis are also documented. Parametric analyses are summarized for design parameters including primary mirror coatings and sunshade configuration. Estimates of mirror heater power requirements are reported. The thermal model demonstrates results for the primary mirror heated from the back side and edges using a heater system with multiple independently controlled zones.

Hornsby, Linda; Stahl, H. Philip; Hopkins, Randall C.

2010-01-01

300

Modeling of Thermal Performance of Multiphase Nuclear Fuel Cell Under Variable Gravity Conditions  

NASA Technical Reports Server (NTRS)

A unique numerical method has been developed to model the dynamic processes of bulk evaporation and condensation processes, associated with internal heat generation and natural convection under different gravity levels. The internal energy formulation, for the bulk liquid-vapor phase change problems in an encapsulated container, was employed. The equations, governing the conservation of mass, momentum and energy for both phases involved in phase change, were solved. The thermal performance of a multiphase uranium tetra-fluoride fuel element under zero gravity, micro-gravity and normal gravity conditions has been investigated. The modeling yielded results including the evolution of the bulk liquid-vapor phase change process, the evolution of the liquid-vapor interface, the formation and development of the liquid film covering the side wall surface, the temperature distribution and the convection flow field in the fuel element. The strong dependence of the thermal performance of such multiphase nuclear fuel cell on the gravity condition has been revealed. Under all three gravity conditions, 0-g, 10(exp -3)-g, and 1-g, the liquid film is formed and covers the entire side wall. The liquid film covering the side wall is more isothermalized at the wall surface, which can prevent the side wall from being over-heated. As the gravity increases, the liquid film is thinner, the temperature gradient is larger across the liquid film and smaller across the vapor phase. This investigation provides valuable information about the thermal performance of multi-phase nuclear fuel element for the potential space and ground applications.

Ding, Z.; Anghaie, S.

1996-01-01

301

The optimum levels of the thermal protection of residential buildings under climatic conditions of Russia  

NASA Astrophysics Data System (ADS)

The present paper reports the results of determining the optimum values of the resistance of building envelopes to heat transfer for both existing and newly constructed buildings for regions of Russia with different climatic conditions. An analysis for the sensitivity of obtained optimum solutions to changes in external factors has been made. The potential of energy saving in both the existing housing stock and in newly constructed buildings due to the improvement of thermal protection performance of buildings to the optimum level has been determined.

Filippov, S. P.; Dil'man, M. D.; Ionov, M. S.

2013-11-01

302

Thermal conditions during juvenile development affect adult dispersal in a spider  

PubMed Central

Understanding the causes and consequences of dispersal is a prerequisite for the effective management of natural populations. Rather than treating dispersal as a fixed trait, it should be considered a plastic process that responds to both genetic and environmental conditions. Here, we consider how the ambient temperature experienced by juvenile Erigone atra, a spider inhabiting crop habitat, influences adult dispersal. This species exhibits 2 distinct forms of dispersal, ballooning (long distance) and rappelling (short distance). Using a half-sib design we raised individuals under 4 different temperature regimes and quantified the spiders' propensity to balloon and to rappel. Additionally, as an indicator of investment in settlement, we determined the size of the webs build by the spiders following dispersal. The optimal temperature regimes for reproduction and overall dispersal investment were 20 °C and 25 °C. Propensity to perform short-distance movements was lowest at 15 °C, whereas for long-distance dispersal it was lowest at 30 °C. Plasticity in dispersal was in the direction predicted on the basis of the risks associated with seasonal changes in habitat availability; long-distance ballooning occurred more frequently under cooler, spring-like conditions and short-distance rappelling under warmer, summer-like conditions. Based on these findings, we conclude that thermal conditions during development provide juvenile spiders with information about the environmental conditions they are likely to encounter as adults and that this information influences the spider's dispersal strategy. Climate change may result in suboptimal adult dispersal behavior, with potentially deleterious population level consequences.

Bonte, Dries; Travis, Justin M. J.; De Clercq, Nele; Zwertvaegher, Ingrid; Lens, Luc

2008-01-01

303

Genotypic Influence on Aversive Conditioning in Honeybees, Using a Novel Thermal Reinforcement Procedure  

PubMed Central

In Pavlovian conditioning, animals learn to associate initially neutral stimuli with positive or negative outcomes, leading to appetitive and aversive learning respectively. The honeybee (Apis mellifera) is a prominent invertebrate model for studying both versions of olfactory learning and for unraveling the influence of genotype. As a queen bee mates with about 15 males, her worker offspring belong to as many, genetically-different patrilines. While the genetic dependency of appetitive learning is well established in bees, it is not the case for aversive learning, as a robust protocol was only developed recently. In the original conditioning of the sting extension response (SER), bees learn to associate an odor (conditioned stimulus - CS) with an electric shock (unconditioned stimulus - US). This US is however not a natural stimulus for bees, which may represent a potential caveat for dissecting the genetics underlying aversive learning. We thus first tested heat as a potential new US for SER conditioning. We show that thermal stimulation of several sensory structures on the bee’s body triggers the SER, in a temperature-dependent manner. Moreover, heat applied to the antennae, mouthparts or legs is an efficient US for SER conditioning. Then, using microsatellite analysis, we analyzed heat sensitivity and aversive learning performances in ten worker patrilines issued from a naturally inseminated queen. We demonstrate a strong influence of genotype on aversive learning, possibly indicating the existence of a genetic determinism of this capacity. Such determinism could be instrumental for efficient task partitioning within the hive.

Junca, Pierre; Carcaud, Julie; Moulin, Sibyle; Garnery, Lionel; Sandoz, Jean-Christophe

2014-01-01

304

TEM Observations of Corrosion Behaviors of Platinized Carbon Blacks under Thermal and Electrochemical Conditions  

SciTech Connect

Carbon blacks such as Vulcan XC-72 are widely used to support platinum (Pt) or Pt alloy catalysts in proton exchange membrane fuel cells. Despite their widespread use, carbon blacks are susceptible to corrosion during fuel cell operations. In this work, the corrosion behaviors of platinized Vulcan XC-72 nanoparticles under thermal and electrochemical conditions were monitored by transmission electron microscopy (TEM). The thermal corrosion experiment was carried out in a gas-cell TEM, which allows for a direct observation of the thermal oxidation behavior of the nanoparticles. The electrochemical corrosion experiment was performed outside of the TEM by loading the nanoparticles on a TEM grid and then electrochemically corroding them step by step followed by taking TEM images from exactly the same nanoparticles after each step. This work revealed four types of structural changes: (i) total removal of structurally weak aggregates, (ii) breakdown of aggregates via neck-breaking, (iii) center-hollowed primary particles caused by an inside-out corrosion starting from the center to outer region, and (iv) gradual decrease in the size of primary particles caused by a uniform removal of material from the surface. These structural changes took place in sequence or simultaneously depending on the competition of carbon corrosion dynamical processes. The results obtained from this work provide insight on carbon corrosion and its effects on fuel cells' long-term performance and durability.

Liu, Z.Y. [General Motors Corporation; Zhang, J.L. [General Motors Corporation; Yu, P.T. [General Motors Corporation; Zhang, J.X. [General Motors Corporation; Makharia, R. [General Motors Corporation; More, Karren Leslie [ORNL; Stach, Eric [Brookhaven National Laboratory (BNL)

2010-01-01

305

Three-Dimensional Mixed Convection Flow of Viscoelastic Fluid with Thermal Radiation and Convective Conditions  

PubMed Central

The objective of present research is to examine the thermal radiation effect in three-dimensional mixed convection flow of viscoelastic fluid. The boundary layer analysis has been discussed for flow by an exponentially stretching surface with convective conditions. The resulting partial differential equations are reduced into a system of nonlinear ordinary differential equations using appropriate transformations. The series solutions are developed through a modern technique known as the homotopy analysis method. The convergent expressions of velocity components and temperature are derived. The solutions obtained are dependent on seven sundry parameters including the viscoelastic parameter, mixed convection parameter, ratio parameter, temperature exponent, Prandtl number, Biot number and radiation parameter. A systematic study is performed to analyze the impacts of these influential parameters on the velocity and temperature, the skin friction coefficients and the local Nusselt number. It is observed that mixed convection parameter in momentum and thermal boundary layers has opposite role. Thermal boundary layer is found to decrease when ratio parameter, Prandtl number and temperature exponent are increased. Local Nusselt number is increasing function of viscoelastic parameter and Biot number. Radiation parameter on the Nusselt number has opposite effects when compared with viscoelastic parameter.

Hayat, Tasawar; Ashraf, Muhammad Bilal; Alsulami, Hamed H.; Alhuthali, Muhammad Shahab

2014-01-01

306

Three-dimensional mixed convection flow of viscoelastic fluid with thermal radiation and convective conditions.  

PubMed

The objective of present research is to examine the thermal radiation effect in three-dimensional mixed convection flow of viscoelastic fluid. The boundary layer analysis has been discussed for flow by an exponentially stretching surface with convective conditions. The resulting partial differential equations are reduced into a system of nonlinear ordinary differential equations using appropriate transformations. The series solutions are developed through a modern technique known as the homotopy analysis method. The convergent expressions of velocity components and temperature are derived. The solutions obtained are dependent on seven sundry parameters including the viscoelastic parameter, mixed convection parameter, ratio parameter, temperature exponent, Prandtl number, Biot number and radiation parameter. A systematic study is performed to analyze the impacts of these influential parameters on the velocity and temperature, the skin friction coefficients and the local Nusselt number. It is observed that mixed convection parameter in momentum and thermal boundary layers has opposite role. Thermal boundary layer is found to decrease when ratio parameter, Prandtl number and temperature exponent are increased. Local Nusselt number is increasing function of viscoelastic parameter and Biot number. Radiation parameter on the Nusselt number has opposite effects when compared with viscoelastic parameter. PMID:24608594

Hayat, Tasawar; Ashraf, Muhammad Bilal; Alsulami, Hamed H; Alhuthali, Muhammad Shahab

2014-01-01

307

Infrared survey of 50 buildings constructed during 100 years: thermal performances and damage conditions  

NASA Astrophysics Data System (ADS)

Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this study is to be incorporated in planning of short- and long term maintenance programs of the Swedish Defence. In general the military buildings are expected to have better status than civilian buildings, due to the more rigorous control during the building process, performed by military building authorities.

Ljungberg, Sven-Ake

1995-03-01

308

Hypothetical accident conditions free drop and thermal tests USA/5791/BLF (ERDA-AL)  

SciTech Connect

The USA/5791/BLF (ERDA-AL) shipping container with rolled-top food pack cans as inner containers is evaluated under conditions required by 10 CFR 71.42. One kilogram of depleted uranium as UO/sub 2/ was packaged in each of the inner containers. After completion of a free drop test and a simulated thermal test, the maximum observed leakage of UO/sub 2/ for the following week was 3.0 ..mu..g. This leakage is well below the allowable leakage per week for most plutonium isotopic mixtures. Using the examples provided, any plutonium isotopic mixture can be easily compared with the allowable leakage per week. Test conditions and results are reported.

Blankenship, R.W.

1980-05-01

309

Hypothetical accident conditions, free drop and thermal tests: Specification 6M  

SciTech Connect

The 30 gallon Specification 6M shipping container with rolled-top food pack cans as inner containers is evaluated under conditions required by 10 CFR 71.42. One kilogram of depleted uranium as UO/sub 2/ was packaged in each of the inner containers. After completion of a free drop test and a simulated thermal test, the maximum observed leakage of UO/sub 2/ for the following week was 3.2 ..mu..g. This leakage is well below the allowable leakage per week for most plutonium isotopic mixtures. Using the examples provided, any plutonium isotopic mixture can be easily compared with the allowable leakage per week. Test conditions and results are reported.

Blankenship, R.W.

1980-05-01

310

Line-focus solar thermal energy technology development. FY 79 annual report for Department 4720  

SciTech Connect

The primary role of the Solar Energy Projects Department II (4720) is the development, evaluation, and testing of line-focus solar thermal technology. This report of FY 79 progress and accomplishments is divided into two parts: (1) Component and Subsystem Development including the design and analysis of collector modules, their components, and associated materials and processes, and (2) Systems and Applications Development, involving larger configurations of solar thermal line-focus systems. The emphasis is on parabolic troughs, but significant efforts on hemispherical bowls, compound parabolic collectors, and dishes for the Solar Total Energy Project are also described.

Bergeron, K D; Champion, R L; Hunke, R W [eds.

1980-04-01

311

Line-focus solar thermal energy technology development. Report for Department 4720  

NASA Astrophysics Data System (ADS)

The primary role of the Solar Energy Projects Department 2 is the development, evaluation, and testing of lime focus solar thermal technology. This report is divided into two parts: (1) component and subsystem development including the design and analysis of collector modules, their components, and associated materials and processes; and (2) systems and applications development, involving larger configurations of solar thermal line focus systems. The emphasis is on parabolic troughs, but significant efforts on hemispherical bowls, compound parabolic collectors, and dishes for the Solar Total Energy Project are also described.

Bergeron, K. D.; Champion, R. L.; Hunke, R. W.

1980-04-01

312

A novel underground solar thermal heat storage unit cum heat exchanger for non air-conditioned buildings  

Microsoft Academic Search

A novel passive space conditioning configuration is presented, integrating a Solar Collector System, Underground Storage Tank and Novel Heat Exchanger. This Underground Solar Thermal Heat Exchanger (USTHE) provided improved sensible heating\\/cooling of air by employing a Novel Heat Exchanger (NHX). The dynamic performance of the storage tank in USTHE is modelled using the finite difference method accounting thermal stratification of

Rakesh Kumar; S. C. Kaushik

2003-01-01

313

Thermal resistance of attic loose-fill insulations decreases under simulated winter conditions  

SciTech Connect

Two absolute techniques were used to measure the thermal resistance of attic loose-fill insulations: the Large Scale Climate Simulator (LSCS) and the Unguarded Thin-Heater Apparatus (UTHA). Two types of attic loose-fill insulations (unbonded and bonded/cubed) were tested under simulated winter conditions. To simulate winter conditions for an attic insulation, the specimens were tested with heat flow up, large temperature differences, and an air gap. The specimens were tested either with a constant mean temperature (30 or 21{degrees}C) and an increasing temperature difference or with a constant base temperature (21{degrees}C) and an increasing temperature difference (i.e., a decreasing mean temperature). The UTHA test specimens had a nominal thickness of 0.2 m of loose-fill insulation. The LSCS test specimens had a nominal thickness of 0.3 m of loose-fill insulation contained in a 4.2 by 5 m attic test module with a gypsum board base. The module had a gabled attic with a 5 in 12 slope roof. The tests yielded the surface-to-surface thermal resistance, R, which includes the thermal resistance due to gypsum, insulation, and any wood joists. Tests with and without an air gap were conducted in the UTHA. Surface-to-surface thermal resistance results from the LSCS and the UTHA show similar trends for these two types of loose-fill insulation when tested under simulated winter conditions. Tests with no air gap gave values of R that agreed with the bag label R-value for the insulations; R increased with lower mean temperatures. These no-gap values of R were 2 to 5% greater than the values of R obtained with an air gap for temperature differences of less than 22{degrees}C. For larger temperature differences R decreased, and at temperature differences of over 40{degrees}C, the R values were 50% less than those at small temperature differences.

Graves, R.S.; Wilkes, K.E.; McElroy, D.L.

1994-05-01

314

Chemiluminescence as a condition monitoring method for thermal aging and lifetime prediction of an HTPB elastomer.  

SciTech Connect

Chemiluminescence (CL) has been applied as a condition monitoring technique to assess aging related changes in a hydroxyl-terminated-polybutadiene based polyurethane elastomer. Initial thermal aging of this polymer was conducted between 110 and 50 C. Two CL methods were applied to examine the degradative changes that had occurred in these aged samples: isothermal 'wear-out' experiments under oxygen yielding initial CL intensity and 'wear-out' time data, and temperature ramp experiments under inert conditions as a measure of previously accumulated hydroperoxides or other reactive species. The sensitivities of these CL features to prior aging exposure of the polymer were evaluated on the basis of qualifying this method as a quick screening technique for quantification of degradation levels. Both the techniques yielded data representing the aging trends in this material via correlation with mechanical property changes. Initial CL rates from the isothermal experiments are the most sensitive and suitable approach for documenting material changes during the early part of thermal aging.

Gillen, Kenneth Todd; Minier, Leanna M. G.; Celina, Mathias Christopher; Trujillo, Ana B.

2007-03-01

315

Numerical simulation of the thermal conditions in a sea bay water area used for water supply to nuclear power plants  

SciTech Connect

Consideration is given to the numerical simulation of the thermal conditions in sea water areas used for both water supply to and dissipation of low-grade heat from a nuclear power plant on the shore of a sea bay.

Sokolov, A. S. [JSC 'B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering (VNIIG)' (Russian Federation)] [JSC 'B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering (VNIIG)' (Russian Federation)

2013-07-15

316

Study Task for Determining the Effects of Boost-Phase Environments on Densified Propellants Thermal Conditions for Expendable Launch Vehicles.  

National Technical Information Service (NTIS)

A thermodynamic study has been conducted that investigated the effects of the boost-phase environment on densified propellant thermal conditions for expendable launch vehicles. Two thermodynamic models were developed and utilized to bound the expected the...

M. S. Haberbusch

2002-01-01

317

History of Sulphur Content Effects on the Thermal Stability of RP-1 under Heated Conditions  

NASA Technical Reports Server (NTRS)

As technologies advance in the aerospace industry, a strong desire has emerged to design more efficient, longer life, reusable liquid hydrocarbon fueled rocket engines. To achieve this goal, a more complete understanding of the thermal stability and chemical makeup of the hydrocarbon propellant is needed. Since the main fuel used in modern liquid hydrocarbon systems is RP-1, there is concern that Standard Grade RP-1 may not be a suitable propellant for future-generation rocket engines due to concern over the outdated Mil-Specification for the fuel. This current specification allows high valued limits on contaminants such as sulfur compounds, and also lacks specification of required thermal stability qualifications for the fuel. Previous studies have highlighted the detrimental effect of high levels of mercaptan sulfur content (^50 ppm) on copper rocket engine materials, but the fuel itself has not been studied. While the role of sulfur in other fuels (e.g., aviation, diesel, and automotive fuels) has been extensively studied, little has been reported on the effects of sulfur levels in rocket fuels. Lower RP-1 sulfur concentrations need to be evaluated and an acceptable sulfur limit established before RP-1 can be recommended for use as the propellant for future launch vehicles. (5 tables, 8 figures, 9 refs.)

Irvine, Solveig A.; Schoettmer, Amanda K.; Bates, Ronald W.; Meyer, Michael L.

2004-01-01

318

Thermal Fatigue Testing of Plasma Transfer Arc Stellite Coatings on Hot Work Tool Steels under Steel Thixoforming Conditions  

Microsoft Academic Search

The thermal fatigue performance of Stellite 12 coating deposited on X32CrMoV33 hot work tool steel via the plasma transfer arc (PTA) process was investigated under steel thixoforming conditions. Stellite 12 coating has made\\u000a a favorable impact on the thermal fatigue performance of the X32CrMoV33 hot work tool steel. The latter survived steel thixoforming\\u000a conditions lasting much longer, for a total

Yucel Birol; Agca B. Kayihan

2011-01-01

319

Effects of Boundary Conditions on Thermal Response of a Cellulose Acetate Layer Using Hottel's Zonal Method  

NASA Astrophysics Data System (ADS)

Energy can transfer internally by radiation in addition to conduction in translucent polymers. Since radiant propagation is very rapid, it can provide energy within the layer more quickly than diffusion by heat conduction. Thus, the transient thermal response of a layer for combined radiative and conduction may be extremely different from that of conduction alone. In this paper, the behavior of a heat conducting, absorbing, and emitting layer of Cellulose Acetate layer is investigated during the transient interval when both conductive and radiative heat transfer are considered. Specifically, the effects of boundary conditions on the response of the layer are considered here. These boundary conditions include both conductive boundary conditions, such as convection coefficient and convective fluid temperature, and radiation boundary conditions, like radiation surrounding temperature and specular reflectivity. To this end, the governing differential equations including the equation of radiative heat transfer within the material coupled to the transient energy equation with radiative terms are presented. The solution procedure is based on nodal analysis and Hottel's zonal method extended by the ray tracing method. The transient energy equation including the radiative internal energy source is solved using a time marching finite difference procedure with variable space and time increments.

Safavisohi, Babak; Sharbati, Ehsan; Aghanajafi, Cyrus; Firoozabadi, Seyed Reza Khatami

2006-12-01

320

Fast access to the CMS detector condition data employing HTML5 technologies  

NASA Astrophysics Data System (ADS)

This paper focuses on using HTML version 5 (HTML5) for accessing condition data for the CMS experiment, evaluating the benefits and risks posed by the use of this technology. According to the authors of HTML5, this technology attempts to solve issues found in previous iterations of HTML and addresses the needs of web applications, an area previously not adequately covered by HTML. We demonstrate that employing HTML5 brings important benefits in terms of access performance to the CMS condition data. The combined use of web storage and web sockets allows increasing the performance and reducing the costs in term of computation power, memory usage and network bandwidth for client and server. Above all, the web workers allow creating different scripts that can be executed using multi-thread mode, exploiting multi-core microprocessors. Web workers have been employed in order to substantially decrease the web page rendering time to display the condition data stored in the CMS condition database.

Pierro, Giuseppe Antonio; Cavallari, Francesca; Di Guida, Salvatore; Innocente, Vincenzo

2011-12-01

321

Effect of thermal shock on the decomposition of rocks under controlled laboratory conditions  

NASA Astrophysics Data System (ADS)

The major factor determining the rate of weathering of a given rock are the climatic conditions of the surrounding environment, most notably type and amount of precipitation and temperature. For the latter, average annual temperature and where applicable, the frequency of freezing and thawing are often considered to be relevant for weathering. The rate of temperature change is mostly ignored. However, a rapid change in temperature, referred to as thermal shock could have more severe consequences of rock deterioration then gradual heating and cooling of rocks is gradual. Thermal shock induces a stress of such a magnitude that the material is unable to adjust fast enough and so it breaks down. The aim of this study is to examine the importance of mechanical decomposition of rocks when treated with thermal shock by freezing. The rate of decomposition of rocks of various sizes was measured based on their weight loss. In addition, they were immersed in water after freezing and the electrical conductivity and pH of the water were measured as an index for thermal-shock induced micro-fracturing. Samples of three rock types were chosen for the experiment: limestone, tuffaceous rock and basalt. Samples were examined in two separate cycles: (i) 24h immersion in ultra-clean water followed by 24h drying at 30o and (ii) 24h immersion, 24h temperature shock by freezing at -20?C and 6h thawing. Each cycle was repeated approximately 20 times. In each cycle three different sizes of rock were examined: <16mm, 16-8mm and 8-5mm. Limestone mass decreased for both cycles, although more distinctly after repeated thermal shocks. Furthermore, the rate of decay decreased with increasing rock size. Tuffaceous rock exposed to cycle (i) also showed a significant weight loss. Somewhat surprisingly, the mass of the tuffaceous rock exposed to thermal shock increased by about 13% in all sample size groups. It is possible that pore volume increased during experiment and that the rocks became capable of absorbing more water, but the rock was elastic enough not to break under stress. On the basalt, as expected, the rate of weight loss was the smallest. Cylce (ii) samples also showed more intensive mass reduction. Electrical conductivity and pH of the immersion water were constant throughout the experiment and did not change with the number of cycles. This implies that no significant chemical disintegration occurred. The results show that thermal shock can have a rock type-specific effect on physical weathering. The lacking effect on chemical weathering is expected due to the design of the experiment. Under natural conditions, with non-pH neutral water, the declining rock stability, indicated by the loss of mass, especially of the limestone, will mostly likely also enhance leaching and thus chemical weathering.

Kasanin-Grubin, Milica; Vezmar, Tijuana; Kuhn, Nikolaus J.

2013-04-01

322

Innovative nuclear thermal propulsion technology evaluation - Results of the NASA/DOE task team study  

NASA Technical Reports Server (NTRS)

In response to findings from two NASA/DOE nuclear propulsion workshops, six task teams were created to continue evaluation of various propulsion concepts, from which evolved an innovative concepts subpanel to evaluate thermal propulsion concepts which did not utilize solid fuel. This subpanel endeavored to evaluate each concept on a level technology basis, and to identify critical issues, technologies, and early proof-of-concept experiments. Results of the concept studies including the liquid core fission, the gas core fission, the fission foil reactors, explosively driven systems, fusion, and antimatter are presented.

Howe, Steven D.; Borowski, Stanley; Motloch, Chet; Helms, Ira; Diaz, Nils; Anghaie, Samim; Latham, Thomas

1991-01-01

323

Design Factors for Applying Cryogen Storage and Delivery Technology to Solar Thermal Propulsion  

NASA Technical Reports Server (NTRS)

Thermodynamic Vent System (TVS) and Multilayer Insulation (MLI) technology, originally developed for long term storage of cryogen propellants in microgravity, is ideally suited for propellant storage and delivery systems for solar thermal propulsion. With this technology the heat-induced pressure rise in the tank provides the propellant delivery pressure without the need for an auxiliary pressurant system, and propellant delivery is used to remove the excess heat to control tank pressure. The factors to consider in designing such a balanced system, are presented. An example of a minimum system design is presented along with examples of laboratory-tested hardware.

Millis, Marc G.

1996-01-01

324

Thermal power systems, point-focusing distributed receiver technology project. Volume 2: Detailed report  

NASA Technical Reports Server (NTRS)

Thermal or electrical power from the sun's radiated energy through Point-Focusing Distributed Receiver technology is the goal of this Project. The energy thus produced must be economically competitive with other sources. The Project supports the industrial development of technology and hardware for extracting energy from solar power to achieve the stated goal. Present studies are working to concentrate the solar energy through mirrors or lenses, to a working fluid or gas, and through a power converter change to an energy source useful to man. Rankine-cycle and Brayton-cycle engines are currently being developed as the most promising energy converters for our near future needs.

Lucas, J.

1979-01-01

325

Thermal performance of a scramjet combustor operating at Mach 5.6 flight conditions. Final report, May 1996--May 1997  

SciTech Connect

This report describes the experimental data and the procedures used in acquiring and reducing the thermal loads data during tests of a hydrocarbon-fueled scramjet combustor at United Technologies Research Center (UTRC). This research effort is part of the UTRC effort to develop dual-mode scramjet combustor technology to support the development of Mach S missile technology. The objective of the thermal loads testing was to map the thermal and mechanical loads, including heat transfer, dynamic and static pressures, and skin friction in a scramjet combustor during direct-connect scramjet tests. The tests were conducted at the UTRC Ramject/Scramjet direct-connect combustor test facility in East Hartford, CT.

Stouffer, S.D.; Neumann, R.D.; Emmer, D.S.

1997-10-01

326

Innovative nuclear thermal propulsion technology evaluation: Results of the NASA/DOE Task Team study  

SciTech Connect

In response to findings from two NASA/DOE nuclear propulsion workshops held in the summer of 1990, six task teams were formed to continue evaluation of various nuclear propulsion concepts. The Task Team on Nuclear Thermal Propulsion (NTP) created the Innovative Concepts Subpanel to evaluate thermal propulsion concepts which did not utilize solid fuel. The Subpanel endeavored to evaluate each of the concepts on a level technological playing field,'' and to identify critical technologies, issues, and early proof-of-concept experiments. The concepts included the liquid core fission, the gas core fission, the fission foil reactors, explosively driven systems, fusion, and antimatter. The results of the studies by the panel will be provided. 13 refs., 6 figs., 2 tabs.

Howe, S. (Los Alamos National Lab., NM (United States)); Borowski, S. (National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center); Motloch, C. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Helms, I. (Nuclear Utility Services, Damascus, MD (United States)); Diaz, N.; Anghaie, S. (Florida Univ., Gainesville, FL (United States)); Latham, T. (United

1991-01-01

327

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions.  

National Technical Information Service (NTIS)

A thermal interface material is one of the many tools that are often used as part of the thermal control scheme for space-based applications. These materials are placed between, for example, an avionics box and a cold plate, in order to improve the conduc...

S. Glasgow K. Kittredge

2003-01-01

328

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions.  

National Technical Information Service (NTIS)

A thermal interface material is one of the many tools often used as part of the thermal control scheme for space-based applications. Historically, at Marshall Space Flight Center, CHO-THERM 1671 has primarily been used for applications where an interface ...

S. D. Glasgow K. B. Kittredge

2003-01-01

329

Active infrared thermal imaging technology to detect the corrosion defects in aircraft cargo door  

NASA Astrophysics Data System (ADS)

Aircraft fuselage material corrosion problems have been major aviation security issues, which hinder the development of aviation industry. How can we use non-destructive testing methods to detect the internal corrosion defects from the outside of the fuselage, to find the hidden safety problems in advance and update the defective equipment and materials, has great significance for the prevention of accidents. Nowadays, the active infrared thermal imaging technology as a new nondestructive technology has been gradually used on a wide variety of materials, such as composite, metal and so on. This article makes use of this technology on an aircraft cargo door specimen to detect the corrosion defects. Firstly, use High-energy flash pulse to excite the specimen, and use the thermal image processing software to splice the thermal images, so the thermal images of the overall specimen can be showed. Then, heat the defects by ultrasonic excitation, this will cause vibration and friction or thermoelastic effects in the places of defects, so the ultrasonic energy will dissipate into heat and manifested in the uneven temperature of surface. An Infrared camera to capture the changes of temperature of material surface, send data to the computer and records the thermal information of the defects. Finally, extracting data and drawing infrared radiation-time curve of some selected points of interest to analyze the signal changes in heat of defects further more. The results of the experiments show that both of the two ways of heat excitation show a clear position and shape of defects, and the ultrasonic method has more obvious effect of excitation to the defects, and a higher signal to noise ratio than the flash pulse excitation, but flash pulse method do not contact the specimen in the process of excitation, and shows the location and shape of defects in the overall of the specimen has its advantages.

Chen, Dapeng; Zhang, Cunlin; Zeng, Zhi; Xing, Chunfei; Li, Yanhong

2009-11-01

330

Focusing on the future: Solar thermal energy systems emerge as competitive technologies with major economic potential  

NASA Astrophysics Data System (ADS)

Hundreds of thousands of U.S. citizens are now receiving a portion of their daily demand for electricity from large-scale solar thermal electric generating stations-power plants that use concentrated solar energy to drive electric power generators. Just as with coal, fuel oil, natural gas, and nuclear energy, concentrated solar energy can create working temperatures of around 600C and much higher. Also, solar power plants contribute almost nothing to the atmospheric greenhouse effect and pose few, if any, of the other environmental problems associated with conventional energy sources. As a result of research and development within the national Solar Thermal Technology Program of the U.S. Department of Energy (DOE), solar thermal energy is on the threshold of competing economically with conventional power plants and is now viable for international markets. Its potential for spurring American economic growth and exports is significant.

1989-03-01

331

Improvements in Li(Si)\\/FeS2 thermal battery technology  

Microsoft Academic Search

Potential improvements in Li(Si)\\/FeS2 thermal battery technology were evaluated using as the test vehicle a 28 +-4-V, 400 cu cm battery discharged through a 28 omega load. Successful improvements included incorporating a catholyte additive to improve voltage regulation during discharge, changing the catholyte composition and blending procedure to increase life and current carrying capability, changing the anode composition to obtain

J. Q. Searcy; J. R. Armijo

1982-01-01

332

Recent developments in Li(Si)FeS2 thermal battery technology  

Microsoft Academic Search

The Li(Si)\\/FeS2 electrochemical system has been under development for thermal battery applications as an alternative to Ca\\/CaCrO4 for several years at Sandia National Laboratories (SNL). The new technology differs from the old in that the anode is a pressed powder (44 wt % lithium in Li(Si) alloy) as opposed to sheet calcium or bimetal; and a separator composed of LiCl.KCl

J. Q. Searcy; R. K. Quinn; H. J. Saxton

1982-01-01

333

Thermal Analysis of a New High Density Package Cooling Technology Using Low Melting Point Alloys  

Microsoft Academic Search

This paper describes one of the new package cooling technology concepts using a phase changing material (PCM) which would help develop high density packaging. A low cost alloy, composed of Bi\\/Pb\\/Sn\\/In whose melting point is 57°C, was used as the PCM. Thermal experiments using the abovementioned alloy had been studied by the authors. It was confirmed that the substrate back

Yoshitaka Fukuoka; Masaru Ishizuka

1991-01-01

334

Thermal stability of iron nitrides prepared by mixing laser and plasma beam nitriding technology  

Microsoft Academic Search

Thermal stability of iron nitrides prepared by mixing laser and plasma beam nitriding (LPN) technology was studied. The treated samples were annealed in vacuum at different temperature from 473K to 1273K. The phases were detected by X-ray diffraction (XRD), the nitride’s contents were calculated from the patterns of XRD, and the microstructures were analyzed by scanning electron microscope (SEM). Three

Junyou Liu; Fengjiu Sun; Hanjiang Yu; Aidang Shan

2008-01-01

335

In-Flight Thermal Performance of the Lidar In-Space Technology Experiment  

NASA Technical Reports Server (NTRS)

The Lidar In-Space Technology Experiment (LITE) was developed at NASA s Langley Research Center to explore the applications of lidar operated from an orbital platform. As a technology demonstration experiment, LITE was developed to gain experience designing and building future operational orbiting lidar systems. Since LITE was the first lidar system to be flown in space, an important objective was to validate instrument design principles in such areas as thermal control, laser performance, instrument alignment and control, and autonomous operations. Thermal and structural analysis models of the instrument were developed during the design process to predict the behavior of the instrument during its mission. In order to validate those mathematical models, extensive engineering data was recorded during all phases of LITE's mission. This inflight engineering data was compared with preflight predictions and, when required, adjustments to the thermal and structural models were made to more accurately match the instrument s actual behavior. The results of this process for the thermal analysis and design of LITE are presented in this paper.

Roettker, William

1995-01-01

336

Condition Assessment of Ferrous Water Transmission and Distribution Systems State of Technology Review Report  

EPA Science Inventory

This White Paper was developed to serve as the basis for discussion at a Technology Forum on Condition Assessment of Water Transmission and Distribution Systems that was held on September 9 and 10, 2008, at Edison, NJ. It was distributed to the Forum participants for review in a...

337

Thermal conditions during juvenile development affect adult dispersal in a spider.  

PubMed

Understanding the causes and consequences of dispersal is a prerequisite for the effective management of natural populations. Rather than treating dispersal as a fixed trait, it should be considered a plastic process that responds to both genetic and environmental conditions. Here, we consider how the ambient temperature experienced by juvenile Erigone atra, a spider inhabiting crop habitat, influences adult dispersal. This species exhibits 2 distinct forms of dispersal, ballooning (long distance) and rappelling (short distance). Using a half-sib design we raised individuals under 4 different temperature regimes and quantified the spiders' propensity to balloon and to rappel. Additionally, as an indicator of investment in settlement, we determined the size of the webs build by the spiders following dispersal. The optimal temperature regimes for reproduction and overall dispersal investment were 20 degrees C and 25 degrees C. Propensity to perform short-distance movements was lowest at 15 degrees C, whereas for long-distance dispersal it was lowest at 30 degrees C. Plasticity in dispersal was in the direction predicted on the basis of the risks associated with seasonal changes in habitat availability; long-distance ballooning occurred more frequently under cooler, spring-like conditions and short-distance rappelling under warmer, summer-like conditions. Based on these findings, we conclude that thermal conditions during development provide juvenile spiders with information about the environmental conditions they are likely to encounter as adults and that this information influences the spider's dispersal strategy. Climate change may result in suboptimal adult dispersal behavior, with potentially deleterious population level consequences. PMID:18974219

Bonte, Dries; Travis, Justin M J; De Clercq, Nele; Zwertvaegher, Ingrid; Lens, Luc

2008-11-01

338

Anaerobic digestion of raw and thermally hydrolyzed wastewater solids under various operational conditions.  

PubMed

In this study, high-solids anaerobic digestion of thermally pretreated wastewater solids (THD) was compared with conventional mesophilic anaerobic digestion (MAD). Operational conditions, such as pretreatment temperature (150 to 170 degrees C), solids retention time (15 to 20 days), and digestion temperature (37 to 42 degrees C), were varied for the seven THD systems operated. Volatile solids reduction (VSR) by THD ranged from 56 to 62%, compared with approximately 50% for MAD. Higher VSR contributed to 24 to 59% increased biogas production (m3/kg VSR-d) from THD relative to MAD. The high-solids conditions of the THD feed resulted in high total ammonia-nitrogen (proportional to solids loading) and total alkalinity concentrations in excess of 14 g/L as calcium carbonate (CaCO3). Increased pH in THD reactors caused 5 to 8 times more un-ionized ammonia to be present than in MAD, and this likely led to inhibition of aceticlastic methanogens, resulting in accumulation of residual volatile fatty acids between 2 and 6 g/L as acetic acid. The THD produced biosolids cake that possessed low organic sulfur-based biosolids odor and dewatered to between 33 and 39% total solids. Dual conditioning with cationic polymer and ferric chloride was shown to be an effective strategy for mitigating dissolved organic nitrogen and UV-quenching compounds in the return stream following centrifugal dewatering of THD biosolids. PMID:22073729

Wilson, Christopher A; Tanneru, Charan T; Banjade, Sarita; Murthy, Sudhir N; Novak, John T

2011-09-01

339

Thermal traction contact performance evaluation under fully flooded and starved conditions  

NASA Technical Reports Server (NTRS)

Ultra high speed traction tests were performed on two traction fluids commonly employed. Traction data on these fluids is required for purposes of traction drive design optimization techniques. To obtain the traction data, an existing twin disc traction test machine was employed. This machine was modified to accommodate the range of test variables. All the data reported was obtained under conditions of side slip, a technique whereby only low power levels are required to simulate real traction drive contacts. Theoretical traction predictions were performed for a representative number of curves that showed the influence of rolling velocity, of contact pressure and of aspect ratio. To establish the accuracy of the thermal model the predictions were performed ith increasing levels of independence of experimentally determined parameters. In the final resulting prediction only two non linear thermal parameters were used for the prediction of 15 different traction curves covering the entire range of variables as used in the investigation, with the exception of the influence of asperity traction. Comparison of these theoretical curves and corresponding experimental traces show very good agreement.

Tevaarwerk, J. L.

1985-01-01

340

On the thermal annealing conditions for self-synthesis of tungsten carbide nanowires from WCx films  

NASA Astrophysics Data System (ADS)

The thermal annealing conditions in nitrogen ambient for the self-synthesis of tungsten carbide nanowires from sputter-deposited WCx films were investigated. Experimental results show that the temperature window for the growth of nanowires lies in the range of 500-750 °C with the corresponding annealing time interval ranging from 2.5 to 0.25 h. The diameter, length, and density of the grown nanowires are in the range of 10-15 nm, 0.1-0.3 µm, and 210-410 µm-2, respectively. The degree of carbon depletion in the annealed WCx films plays a crucial role in determining both the shape and density of the self-synthesized nanowires. Nanowires synthesized at lower temperatures were seen to be smaller in dimension but higher in density. Material analysis reveals that the phase transition from WC to W2C arising from decarburization of the WCx film during thermal annealing should be responsible for the self-synthesis of nanowires.

Wang, Shui-Jinn; Chen, Chao-Hsuing; Chang, Shu-Cheng; Wong, Chin-Hong; Uang, Kai-Ming; Chen, Tron-Min; Ko, Rong-Ming; Liou, Bor-Wien

2005-02-01

341

Photopyroelectric Monitoring of Olive's Ripening Conditions and Olive Oil Quality Using Pulsed Wideband IR Thermal Source  

NASA Astrophysics Data System (ADS)

The present study is based on band absorption of radiation from pulsed wideband infrared (IR) thermal source (PWBS) in conjunction with polyvinylidene fluoride film (PVDF). It is the first time to be employed to monitor the ripening state of olive fruit. Olive's characteristics vary at different stages of ripening, and hence, cultivation of olives at the right time is important in ensuring the best oil quality and maximizes the harvest yield. The photopyroelectric (PPE) signal resulting from absorption of wideband infrared (IR) radiation by fresh olive juice indicates the ripening stage of olives, i.e., allows an estimate of the suitable harvest time. The technique was found to be very useful in discriminating between olive oil samples according to geographical region, shelf life, some storage conditions, and deliberate adulteration. Our results for monitoring oil accumulation in olives during the ripening season agree well with the complicated analytical studies carried out by other researchers.

Abu-Taha, M. I.; Sarahneh, Y.; Saleh, A. M.

342

Numerical simulations of thermal convection in rotating spherical shells under laboratory conditions  

NASA Astrophysics Data System (ADS)

An exhaustive study, based on numerical three-dimensional simulations, of the Boussinesq thermal convection of a fluid confined in a rotating spherical shell is presented. A moderately low Prandtl number fluid (?=0.1) bounded by differentially-heated solid spherical shells is mainly considered. Asymptotic power laws for the mean physical properties of the flows are obtained in the limit of low Rossby number and compared with laboratory experiments and with previous numerical results computed by taking either stress-free boundary conditions or quasi-geostrophic restrictions, and with geodynamo models. Finally, using parameters as close as possible to those of the Earth's outer core, some estimations of the characteristic time and length scales of convection are given.

Garcia, Ferran; Sánchez, Juan; Net, Marta

2014-05-01

343

Mineralization behavior of fluorine in perfluorooctanesulfonate (PFOS) during thermal treatment of lime-conditioned sludge.  

PubMed

The fate and transport of the fluorine in perfluorooctanesulfonate (PFOS) during the thermal treatment of lime-conditioned sludge were observed using both qualitative and quantitative X-ray diffraction techniques. Two main fluorine mineralization mechanisms leading to the substantial formation of CaF2 and Ca5(PO4)3F phases were observed. They had a close relationship with the thermal treatment condition and the PFOS content of the sludge. At low temperatures (300-600 °C), CaF2 dominated in the product and increases in treatment time and temperature generally enhanced the fluorine transformation. However, at higher temperatures (700-900 °C), increases in treatment time and temperature had a negative effect on the overall efficiency of the fluorine crystallization. The results suggest that in the high temperature environment there were greater losses of gaseous products such as HF and SiF4 in the transformation of CaF2 to Ca5(PO4)3F, the hydrolysis of CaF2, and the reaction with SiO2. The quantitative analysis also showed that when treating sludge with low PFOS content at high temperatures, the formation of Ca5(PO4)3F may be the primary mechanism for the mineralization of the fluorine in PFOS. The overall results clearly indicate the variations in the fate and transport of fluorine in PFOS when the sludge is subject to different PFOS contents and treatment types, such as heat drying or incineration. PMID:23360134

Wang, Fei; Shih, Kaimin; Lu, Xingwen; Liu, Chengshuai

2013-03-19

344

Correlation between spraying conditions and microcrack density and their influence on thermal cycling life of thermal barrier coatings  

Microsoft Academic Search

It is generally known that the porosity of thermal barrier coatings is essential to guarantee a sufficiently high strain tolerance\\u000a of the coating during thermal cycling. However, much less is known about the influence of the specific morphology of porosity,\\u000a such as microcracks and typically larger pores, on the performance of the coatings. Both features are usually formed during\\u000a plasma

Robert Vaßen; Franziska Traeger; Detlev Stöver

2004-01-01

345

Effect of fee-for-service air-conditioning management in balancing thermal comfort and energy usage  

NASA Astrophysics Data System (ADS)

Balancing thermal comfort with the requirement of energy conservation presents a challenge in hot and humid areas where air-conditioning (AC) is frequently used in cooling indoor air. A field survey was conducted in Taiwan to demonstrate the adaptive behaviors of occupants in relation to the use of fans and AC in a school building employing mixed-mode ventilation where AC use was managed under a fee-for-service mechanism. The patterns of using windows, fans, and AC as well as the perceptions of students toward the thermal environment were examined. The results of thermal perception evaluation in relation to the indoor thermal conditions were compared to the levels of thermal comfort predicted by the adaptive models described in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 55 and EN 15251 and to that of a local model for evaluating thermal adaption in naturally ventilated buildings. A thermal comfort-driven adaptive behavior model was established to illustrate the probability of fans/AC use at specific temperature and compared to the temperature threshold approach to illustrate the potential energy saving the fee-for-service mechanism provided. The findings of this study may be applied as a reference for regulating the operation of AC in school buildings of subtropical regions.

Chen, Chen-Peng; Hwang, Ruey-Lung; Shih, Wen-Mei

2014-02-01

346

A comparative analysis of human thermal conditions in outdoor urban spaces in the summer season in Singapore and Changsha, China  

NASA Astrophysics Data System (ADS)

This paper presents the comparative analysis between the findings from two field surveys of human thermal conditions in outdoor urban spaces during the summer season. The first survey was carried out from August 2010 to May 2011 in Singapore and the second survey was carried out from June 2010 to August 2010 in Changsha, China. The physiologically equivalent temperature (PET) was utilized as the thermal index to assess the thermal conditions. Differences were found between the two city respondents in terms of thermal sensation, humidity sensation, and wind speed sensation. No big difference was found between the two city respondents regarding the sun sensation. The two city respondents had similar neutral PET of 28.1 °C for Singapore and 27.9 °C for Changsha, respectively. However, Singapore respondents were more sensitive to PET change than Changsha respondents and the acceptable PET range for Changsha respondents was wider than that for Singapore respondents. Besides, the two city respondents had different thermal expectations with the preferred PET of 25.2 °C and 22.1 °C for Singapore and Changsha, respectively. The results also reveal that Changsha respondents were more tolerant than Singapore respondents under hot conditions. Finally, two regression models were proposed for Singapore and Changsha to predict the human thermal sensation in a given outdoor thermal environment.

Yang, Wei; Wong, Nyuk Hien; Zhang, Guoqiang

2013-11-01

347

Thermal-hydraulic instabilities in natural circulation flow loops under supercritical conditions  

NASA Astrophysics Data System (ADS)

In recent years, a growing interest has been generated in investigating the thermal hydraulics and flow stability phenomenon in supercritical natural circulation loops. These flow conditions are relevant to some of the innovative passive safety designs proposed for the Gen-IV Supercritical Water Reactor (SCWR) concepts. A computational model has been developed at UW Madison which provides a good basic simulation tool for the steady state and transient analysis of one dimensional natural circulation flow, and can be applied to conduct stability analysis. Several modifications and improvements were incorporated in an earlier numerical scheme before applying it to investigate the transient behavior of two experimental loops, namely, the supercritical water loop at UW-Madison and the supercritical carbon-dioxide (SCCO2) loop at Argonne National Laboratories. Although the model predicted development of instabilities for both SCW and SCCO2 loop which agrees with some previous work, the experiments conducted at SCCO2 loop exhibited stable behavior under similar conditions. To distinguish between numerical effects and physical processes, a linear stability approach has also been developed to investigate the stability characteristics associated with the natural circulation loop systems for various inlet conditions, input powers and geometries. The linear stability results for the SCW and SCCO2 loops exhibited differences with the corresponding transient simulations. This linear model also predicted the presence of instability in the SCCO 2 loop for certain high input powers contradictory to the experimental findings. Dimensionless parameters were proposed which would generalize the stability characteristics of the natural circulation flow loops under supercritical conditions.

Jain, Rachna

348

Clinical Trial on the Characteristics of Zheng Classification of Pulmonary Diseases Based on Infrared Thermal Imaging Technology  

PubMed Central

Zheng classification study based on infrared thermal imaging technology has not been reported before. To detect the relative temperature of viscera and bowels of different syndromes patients with pulmonary disease and to summarize the characteristics of different Zheng classifications, the infrared thermal imaging technology was used in the clinical trial. The results showed that the infrared thermal images characteristics of different Zheng classifications of pulmonary disease were distinctly different. The influence on viscera and bowels was deeper in phlegm-heat obstructing lung syndrome group than in cold-phlegm obstructing lung syndrome group. It is helpful to diagnose Zheng classification and to improve the diagnosis rate by analyzing the infrared thermal images of patients. The application of infrared thermal imaging technology provided objective measures for medical diagnosis and treatment in the field of Zheng studies and provided a new methodology for Zheng classification.

Ni, Jin-xia; Gao, Si-hua; Li, Yu-hang; Ma, Shi-lei; Tian, Tian; Mo, Fang-fang; Wang, Liu-qing; Zhu, Wen-zeng

2013-01-01

349

The deformation and cooling of ceramic particles sprayed with a thermal radio-frequency plasma under atmospheric conditions  

NASA Astrophysics Data System (ADS)

Common thermal-spray techniques use the strong acceleration of powder particles to produce dense ceramic coatings with high bond strength. The residence time of the powder particles within the plasma jet is correspondingly low, and only relatively small particles can be molten. In this work, on the contrary, an inductively coupled radio-frequency (RF) inductively coupled plasma (ICP) torch was used to spray large oxide-ceramic powder particles under atmospheric conditions. The slow plasma flow of a RF plasma leads to large residence times of the powder particles, so that the powder size of the feedstock can be 100 µm and more. It was observed that these particles will not be strongly accelerated in the plasma and that their velocity at the moment of impact is in the range of 10 to 20 m/s. Ceramic coatings were ICP sprayed with a low porosity and a high bond strength, similar to direct current (DC) or high-velocity-oxygen-fuel (HVOF) sprayed coatings. The morphology of ICP-sprayed particles on smooth steel surfaces, as a function of the surface temperature, is described and compared with DC plasma-sprayed splats. Furthermore, the degree of deformation was measured and determined by different models, and the pronounced contact zones formed between the pancake and the substrate were investigated. The ICP-sprayed ceramic coatings show some special properties, such as the absence of metastable crystalline phases, which are common in other spray technologies.

Dzur, B.; Wilhelmi, H.; Nutsch, G.

2001-12-01

350

Preliminary Safety Analysis of Conceptual Hybrid, Repowering, and Retrofit Applications of Solar-Thermal Central-Receiver Technology.  

National Technical Information Service (NTIS)

A preliminary safety analysis was undertaken for fifteen conceptual designs of hybrid, repowering/retrofit applications of solar thermal central receiver technology. The approach was generic in nature and focused on safety concerns associated with the phy...

P. R. Hurt R. G. Lindberg

1982-01-01

351

Engine Operating Conditions that Cause Thermal-Fatigue Cracks in Turbojet-Engine Buckets  

NASA Technical Reports Server (NTRS)

Five engine tests were conducted to definitely establish the failure mechanism of leading-edge cracking and to determine which conditions of engine operation cause the failures. Five groups of S-616 and M-252 buckets from master lots were run consecutively in the same J47-25 engine. The tests included a steady-state run at full-power conditions, rapid cycling between idle and rated speed, and three different start-stop tests. The first start-stop test consisted of cycles of start and stop with 5 minutes of idle speed before each stop; the second included cycles of start and stop but with 15 minutes of rated speed before each stop; the third consisted of cycles of gradual starts and normal stops with 5 minutes at idle speed before each stop. The test results demonstrated that the primary cause of leading-edge cracking was thermal fatigue produced by repeated engine starts. The leading edge of the bucket experiences plastic flow in compression during starts and consequently is subjected to a tensile stress when the remainder of the bucket becomes heated and expands. Crack initiation was accelerated when rated-speed operation was added to each normal start-stop cycle. This acceleration of crack formation was attributed to localized creep damage and perhaps to embrittlement resulting from overaging. It was demonstrated that leading-edge cracking can be prevented simply by starting the engine gradually.

Johnston, James R.; Weeton, John W.; Signorelli, Robert A.

1959-01-01

352

Determination of the Thermal Properties of Sands as Affected by Water Content, Drainage/Wetting, and Porosity Conditions for Sands With Different Grain Sizes  

NASA Astrophysics Data System (ADS)

It is widely recognized that liquid water, water vapor and temperature movement in the subsurface near the land/atmosphere interface are strongly coupled, influencing many agricultural, biological and engineering applications such as irrigation practices, the assessment of contaminant transport and the detection of buried landmines. In these systems, a clear understanding of how variations in water content, soil drainage/wetting history, porosity conditions and grain size affect the soil's thermal behavior is needed, however, the consideration of all factors is rare as very few experimental data showing the effects of these variations are available. In this study, the effect of soil moisture, drainage/wetting history, and porosity on the thermal conductivity of sandy soils with different grain sizes was investigated. For this experimental investigation, several recent sensor based technologies were compiled into a Tempe cell modified to have a network of sampling ports, continuously monitoring water saturation, capillary pressure, temperature, and soil thermal properties. The water table was established at mid elevation of the cell and then lowered slowly. The initially saturated soil sample was subjected to slow drainage, wetting, and secondary drainage cycles. After liquid water drainage ceased, evaporation was induced at the surface to remove soil moisture from the sample to obtain thermal conductivity data below the residual saturation. For the test soils studied, thermal conductivity increased with increasing moisture content, soil density and grain size while thermal conductivity values were similar for soil drying/wetting behavior. Thermal properties measured in this study were then compared with independent estimates made using empirical models from literature. These soils will be used in a proposed set of experiments in intermediate scale test tanks to obtain data to validate methods and modeling tools used for landmine detection.

Smits, K. M.; Sakaki, T.; Limsuwat, A.; Illangasekare, T. H.

2009-05-01

353

Multi-Evaporator Miniature Loop Heat Pipe for Small Spacecraft Thermal Control. Part 1; New Technologies and Validation Approach  

NASA Technical Reports Server (NTRS)

Under NASA s New Millennium Program Space Technology 8 (ST 8) Project, four experiments Thermal Loop, Dependable Microprocessor, SAILMAST, and UltraFlex - were conducted to advance the maturity of individual technologies from proof of concept to prototype demonstration in a relevant environment , i.e. from a technology readiness level (TRL) of 3 to a level of 6. This paper presents the new technologies and validation approach of the Thermal Loop experiment. The Thermal Loop is an advanced thermal control system consisting of a miniature loop heat pipe (MLHP) with multiple evaporators and multiple condensers designed for future small system applications requiring low mass, low power, and compactness. The MLHP retains all features of state-of-the-art loop heat pipes (LHPs) and offers additional advantages to enhance the functionality, performance, versatility, and reliability of the system. Details of the thermal loop concept, technical advances, benefits, objectives, level 1 requirements, and performance characteristics are described. Also included in the paper are descriptions of the test articles and mathematical modeling used for the technology validation. An MLHP breadboard was built and tested in the laboratory and thermal vacuum environments for TRL 4 and TRL 5 validations, and an MLHP proto-flight unit was built and tested in a thermal vacuum chamber for the TRL 6 validation. In addition, an analytical model was developed to simulate the steady state and transient behaviors of the MLHP during various validation tests. Capabilities and limitations of the analytical model are also addressed.

Ku, Jentung; Ottenstein, Laura; Douglas, Donya; Hoang, Triem

2010-01-01

354

Medium-density ablative composites: processing, characterisation and thermal response under moderate atmospheric re-entry heating conditions  

Microsoft Academic Search

Medium-density foam composites based on silica fibre-filled phenolic syntactic foams were processed and characterised for\\u000a mechanical, dynamic mechanical and thermophysical properties, and they were evaluated as Thermal Protection Systems (TPSs)\\u000a materials by way of experiment and simulated thermal response studies under atmospheric re-entry conditions. Ablative composites\\u000a with different specific gravities were processed by varying the volume fraction of the constituents.

Bibin John; Dona Mathew; B. Deependran; George Joseph; C. P. Reghunadhan Nair; K. N. Ninan

2011-01-01

355

Studies in biogas technology. Part III. Thermal analysis of biogas plants  

Microsoft Academic Search

A thermal model for a conventional biogas plant has been developed in order to understand the heat transfer from the slurry\\u000a and the gas holder to the surrounding earth and air respectively. The computations have been performed for two conditions\\u000a : (i) when the slurry is at an ambient temperature of 20°C, and (ii) when it is at 35°C, the

C. R. Prasad; S. R. C. Sathyanarayan

1979-01-01

356

Development of air conditioning technologies to reduce CO2 emissions in the commercial sector  

PubMed Central

Background Architectural methods that take into account global environmental conservation generally concentrate on mitigating the heat load of buildings. Here, we evaluate the reduction of carbon dioxide (CO2) emissions that can be achieved by improving heating, ventilating, and air conditioning (HVAC) technologies. Results The Climate Change Research Hall (CCRH) of the National Institute for Environmental Studies (NIES) is used as a case study. CCRH was built in line with the "Green Government Buildings" program of the Government Buildings Department at the Ministry of Land, Infrastructure and Transport in Japan. We have assessed the technology used in this building, and found that there is a possibility to reduce energy consumption in the HVAC system by 30%. Conclusion Saving energy reduces CO2 emissions in the commercial sector, although emission factors depend on the country or region. Consequently, energy savings potential may serve as a criterion in selecting HVAC technologies with respect to emission reduction targets.

Yoshida, Yukiko

2006-01-01

357

Determination of office building shapes for the optimization of thermal conditioning and daylighting  

SciTech Connect

Rising energy costs, especially for electricity, have forced designers to rediscover energy-conscious design that passively utilizes building form as an element of environmental control for energy conservation. Significant reductions in consumption are possible when the interrelationships of climate, building geometry and envelope, and internal loads are well understood. A building's energy use is considerably influenced by early decisions on such design issues as site development and building shape, which can rarely be reconsidered close to or at the end of the design process. A building type with rather large energy consumption is office buildings. This study is concerned with decision techniques resulting in optimum energy use in office buildings. Its main concern is linking of daylighting, artificial lighting, and thermal analyses. The prime aim of this research is the development of a computer model which provides quantitative information on resolving the optimization problem between cooling, heating, and lighting energy usages. The model assists designers in determining overall office building aspect ratios, perimeter zone depths, and interior zone size and orientation of parallelepiped open plan office buildings at early stages of the design process. This study produces via computer simulation the balance point locations of perimeter zones; that is, the depth of space from facades toward the inside of the building at which external and internal factors result in the lowest overall energy cost depending on facade orientation, envelope design, indoor thermal and luminous conditions, and climate. Such distances from the facades, together with the energy costs can serve as information for decisions toward optimum building shapes.

Lee, Hyunwoo.

1990-01-01

358

Discrimination techniques employing both reflective and thermal multispectral signals. [for remote sensor technology  

NASA Technical Reports Server (NTRS)

Recent improvements in remote sensor technology carry implications for data processing. Multispectral line scanners now exist that can collect data simultaneously and in registration in multiple channels at both reflective and thermal (emissive) wavelengths. Progress in dealing with two resultant recognition processing problems is discussed: (1) More channels mean higher processing costs; to combat these costs, a new and faster procedure for selecting subsets of channels has been developed. (2) Differences between thermal and reflective characteristics influence recognition processing; to illustrate the magnitude of these differences, some explanatory calculations are presented. Also introduced, is a different way to process multispectral scanner data, namely, radiation balance mapping and related procedures. Techniques and potentials are discussed and examples presented.

Malila, W. A.; Crane, R. B.; Richardson, W.

1973-01-01

359

Thermal and Structural Performance of Woven Carbon Cloth For Adaptive Deployable Entry and Placement Technology  

NASA Technical Reports Server (NTRS)

Arcjet testing and analysis of a three-dimensional (3D) woven carbon fabric has shown that it can be used as a thermal protection system and as a load bearing structural component for a low ballistic coefficient hypersonic decelerator called ADEPT (Adaptive Deployable Entry and Placement Technology). Results of arcjet tests proved that the 3D woven carbon fabric can withstand flight-like heating while under flight-like biaxial mechanical loads representative of those encountered during shallow entry flight path angles into the atmosphere of Venus. Importantly, the arcjet test results have been used to extend a preliminary material thermal response model based on previous testing of the same 3D woven carbon fabric under uni-axial mechanical loading.

Arnold, James O.; Peterson, Keith H.; Yount, Bryan C.; Schneider, Nigel; Chavez-Garcia, Jose

2013-01-01

360

A study of the thermal shock resistance of coke-oven dinas under laboratory conditions  

Microsoft Academic Search

The authors present the results of investigations on the thermal shock resistance of the dinas specimens having different values of porosity, density, and refractory clay content. The authors employed the direct method of evaluating the thermal shock resistance as well as the indirect method. It was concluded that the effect of the porosity of dinas on its thermal shock resistance

E. K. Akselrod; A. I. Portrova

1986-01-01

361

Energy and global warming impacts of next generation refrigeration and air conditioning technologies  

SciTech Connect

Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1996-10-01

362

A machine for thermal fatigue testing of materials in the nonuniform thermally stressed condition with cooling to cryogenic temperatures  

Microsoft Academic Search

This paper describes a machine that makes it possible to thermal-fatigue-test materials on the gas flow of the combustion products of kerosene in the 80 to 1500 degrees K temperature range. The combination of systems and units of the gasdynamic stand makes it possible to generate and form a flow of gases, the combustion products of kerosene in air, and

G. N. Tretyachenko; L. U. Kravchuk; G. R. Semenov

1986-01-01

363

A machine for thermal fatigue testing of materials in the nonuniform thermally stressed condition with cooling to cryogenic temperatures  

Microsoft Academic Search

This article describes a machine developed on the basis of the basic systems of the gasdynamic stands of the Institute of Strength Problems of the Academy of Sciences of the Ukrainian SSR [I] making it possible to thermal-fatiEue-test materials on the gas flow of the combustion products of kerosene in the 80 to 1500~ temperature range. The combination of systems

G. N. Tret'yachenko; L. V. Kravchuk; G. R. Semenov

1985-01-01

364

Remote Sensing of In-Flight Icing Conditions: Operational, Meteorological, and Technological Considerations  

NASA Technical Reports Server (NTRS)

Remote-sensing systems that map aircraft icing conditions in the flight path from airports or aircraft would allow icing to be avoided and exited. Icing remote-sensing system development requires consideration of the operational environment, the meteorological environment, and the technology available. Operationally, pilots need unambiguous cockpit icing displays for risk management decision-making. Human factors, aircraft integration, integration of remotely sensed icing information into the weather system infrastructures, and avoid-and-exit issues need resolution. Cost, maintenance, power, weight, and space concern manufacturers, operators, and regulators. An icing remote-sensing system detects cloud and precipitation liquid water, drop size, and temperature. An algorithm is needed to convert these conditions into icing potential estimates for cockpit display. Specification development requires that magnitudes of cloud microphysical conditions and their spatial and temporal variability be understood at multiple scales. The core of an icing remote-sensing system is the technology that senses icing microphysical conditions. Radar and microwave radiometers penetrate clouds and can estimate liquid water and drop size. Retrieval development is needed; differential attenuation and neural network assessment of multiple-band radar returns are most promising to date. Airport-based radar or radiometers are the most viable near-term technologies. A radiometer that profiles cloud liquid water, and experimental techniques to use radiometers horizontally, are promising. The most critical operational research needs are to assess cockpit and aircraft system integration, develop avoid-and-exit protocols, assess human factors, and integrate remote-sensing information into weather and air traffic control infrastructures. Improved spatial characterization of cloud and precipitation liquid-water content, drop-size spectra, and temperature are needed, as well as an algorithm to convert sensed conditions into a measure of icing potential. Technology development also requires refinement of inversion techniques. These goals can be accomplished with collaboration among federal agencies including NASA, the FAA, the National Center for Atmospheric Research, NOAA, and the Department of Defense. This report reviews operational, meteorological, and technological considerations in developing the capability to remotely map in-flight icing conditions from the ground and from the air.

Ryerson, Charles C.

2000-01-01

365

Experimental investigation on the photovoltaic-thermal solar heat pump air-conditioning system on water-heating mode  

SciTech Connect

An experimental study on operation performance of photovoltaic-thermal solar heat pump air-conditioning system was conducted in this paper. The experimental system of photovoltaic-thermal solar heat pump air-conditioning system was set up. The performance parameters such as the evaporation pressure, the condensation pressure and the coefficient of performance (COP) of heat pump air-conditioning system, the water temperature and receiving heat capacity in water heater, the photovoltaic (PV) module temperature and the photovoltaic efficiency were investigated. The experimental results show that the mean photovoltaic efficiency of photovoltaic-thermal (PV/T) solar heat pump air-conditioning system reaches 10.4%, and can improve 23.8% in comparison with that of the conventional photovoltaic module, the mean COP of heat pump air-conditioning system may attain 2.88 and the water temperature in water heater can increase to 42 C. These results indicate that the photovoltaic-thermal solar heat pump air-conditioning system has better performances and can stably work. (author)

Fang, Guiyin; Hu, Hainan; Liu, Xu [Department of Physics, Nanjing University, Nanjing 210093 (China)

2010-09-15

366

Thermal non-Newtonian elastohydrodynamic lubrication of line contacts under sliding-rolling and simple sliding conditions  

NASA Astrophysics Data System (ADS)

A thermal Reynolds-Erying equation is derived to study the elastohydrodynamic lubrication of line contacts. This lubrication condition is usually found in spur gears, roller bearings, and cams. The inlet region with back-flow is treated with a control volume scheme to obtain the temperature solution. A computationally-simple formulation for the stationary surface temperature is developed for simple sliding conditions. The most influential dimensionless groups are identified from the complete sets of dimensionless groups. Numerical results obtained for sliding and rolling and for simple sliding conditions are used to develop formulas for the thermal and non-Newtonian (Ree-Eyring) film thickness reduction factor. Even when thermal effects are small, these formulas can still give a film thickness reduction due to the non-Newtonian effects. Results for the maximum temperatures and traction coefficient are also presented. The pressure dependence of lubricant thermal conductivity is found to significantly affect the maximum lubricant temperature. The thermal effects on film thickness and traction are found to be more pronounced for simple sliding than for combined sliding and rolling conditions. Under simple sliding, the heat transferred to the stationary surface is found to be very small compared to that transferred to the moving surface and lubricating fluid.

Wang, Shao

1991-02-01

367

B10 finding and correlation to thermal neutron soft error rate sensitivity for SRAMs in the sub-micron technology  

Microsoft Academic Search

In this paper, we report the presence of B10 based on SIMS analysis in SRAM arrays in the 90nm to 45nm technology nodes. The physical presence of B10 correlated very well with the thermal neutron soft error rate (SER) sensitivity of SRAM cells. This result confirmed that without BPSG layer in advanced Si technologies, there is still a high possibility

Shi-Jie Wen; S. Y. Pai; R. Wong; M. Romain; N. Tam

2010-01-01

368

Thermal stabilities of drops of burning thermoplastics under the UL 94 vertical test conditions.  

PubMed

The properties of polymer melts will strongly affect the fire hazard of the pool induced by polymer melt flow. In this study the thermal stabilities of eight thermoplastic polymers as well as their melting drops generated under the UL 94 vertical burning test conditions were investigated by thermogravimetric experiments. It was found that the kinetic compensation effect existed for the decomposition reactions of the polymers and their drops. For polymethylmethacrylate (PMMA), high impact polystyrene (HIPS), poly(acrylonitrile-butadiene-styrene) (ABS), polyamide 6 (PA6), polypropylene (PP) and low density polyethylene (LDPE), the onset decomposition temperature and the two decomposition kinetic parameters (the pre-exponential factor and the activation energy) of the drop were less than those of the polymer. However, the onset decomposition temperature and the two kinetic parameters of PC's drop were greater than those of polycarbonate (PC). Interestingly, for polyethylenevinylacetate (EVA18) the drop hardly contained the vinyl acetate chain segments. Similarly, for the PMMA/LDPE blends and the PMMA/PP blends, when the volume fraction of PMMA was less than 50% the drop hardly contained PMMA, implying that the blend would not drip until PMMA burned away and its surface temperature approached the decomposition temperature of the continuous phase composed of LDPE or PP. PMID:23298738

Wang, Yong; Zhang, Jun

2013-02-15

369

Scar prevention by laser-assisted scar healing (LASH) using thermal post-conditioning  

NASA Astrophysics Data System (ADS)

An 810-nm diode laser system was developed to accelerate and improve the healing process in surgical scars. Using thermal post-conditioning, the laser system provides a localised moderate heating whose maximum temperature is controlled to prevent tissue damage and stimulate the heat shock proteins (HSP) synthesis. The 810-nm wavelength allows a deep penetration of the light into the dermis, without damaging the epidermis. The time along which surgical incision is treated (continuous wave) must therefore be selected carefully with respect to the temperature precision achieved within the heated volume. A top-hat profile is preferred to a Gaussian profile in order to ensure the skin surface temperature is homogenised, as is the temperature of the heated volume. The spot shape will depend on the medical indication. The treatment should be made safe and controlled by means of a safety strip containing an RFID chip which will transmit the various operating settings to the laser device. A clinical trial aims at evaluating the 810 nm-diode laser in surgical incisions, with only one laser treatment immediately after skin closure, of patients with Fitzpatrick skin types I to IV. Surgical incisions were divided into two fields, with only portions randomly selected receiving laser treatment. At the final scar analysis (12 months) of the pilot study, the treated portion scored significantly better for both surgeon (P = 0.046) and patients (P = 0.025). Further studies may be warranted to better understand the cellular mechanisms leading to Laser-Assisted Skin Healing (LASH).

Gossé, Alban; Iarmarcovai, Gwen; Capon, Alexandre; Cornil, Alain; Mordon, Serge

2009-02-01

370

Predicting worker exposure--the effect of ventilation velocity, free-stream turbulence and thermal condition.  

PubMed

Three-dimensional computational fluid dynamics (CFD) simulations were used to predict the flow field and resulting worker exposures when toxic airborne contaminants were released into the wake region of a mannequin that had its back to the airflow while holding the source of airborne contaminants. The effects of ventilation velocity, free-stream turbulence, and various thermal conditions on fluid flow and exposure levels were evaluated. The results showed good agreement between predicted and experimental concentrations at the mouth at a broad range of airflow velocities when the mannequin was both heated and unheated. When the mannequin was unheated, the exposure level decreased as the ventilation velocity increased. The expectation that buoyancy provided by the heat from the mannequin would be most important at very low velocities and decreasingly important at high velocities was proved true for both the predicted and observed exposures. The result was that when the mannequin was heated to normal human body temperatures, exposure levels had an inverted V relationship with velocity. These findings are important, since they call into question the common practice of modeling human exposures with mannequins at ambient temperatures. In addition, free-stream turbulence could be used to reduce worker exposure to airborne pollutants as suggested by the simulations. CFD enabled a detailed investigation of the effect of particular factors for exposure predictions in a cost-effective way. PMID:17917950

Li, Jun; Yavuz, Ibrahim; Celik, Ismail; Guffey, Steve

2007-11-01

371

Optical stimulation of the hearing and deaf cochlea under thermal and stress confinement condition  

NASA Astrophysics Data System (ADS)

There is a controversy, to which extend cochlear stimulation with near infrared laser pulses at a wavelength of 1860 nm is based on optoacoustic stimulation of intact hair cells or -in contrast- is based on direct stimulation of the nerve cells in absence of functional hair cells. Thermal and stress confinement conditions apply, because of the pulse duration range (5 ns, 10 ?s-20 ms) of the two lasers used. The dependency of the signal characteristics on pulse peak power and pulse duration was investigated in this study. The compound action potential (CAP) was measured during stimulation of the cochlea of four anaesthetized guinea pigs, which were hearing at first and afterwards acutely deafened using intracochlear neomycin-rinsing. For comparison hydrophone measurements in a water tank were performed to investigate the optoacoustic signals at different laser interaction regimes. With rising pulse peak power CAPs of the hearing animals showed first a threshold, then a positively correlated and finally a saturating dependency. CAPs also showed distinct responses at laser onset and offset separated with the pulse duration. At pulse durations shorter than physiological response times the signals merged. Basically the same signal characteristics were observed in the optoacoustic hydrophone measurements, scaled with the sensitivity and response time of the hydrophone. Taking together the qualitative correspondence in the signal response and the absence of any CAPs in deafened animals our results speak in favor of an optoacoustic stimulation of intact hair cells rather than a direct stimulation of nerve cells.

Schultz, M.; Baumhoff, P.; Kallweit, N.; Sato, M.; Krüger, A.; Ripken, T.; Lenarz, T.; Kral, A.

2014-03-01

372

Seasonal flows on dark martian slopes, thermal condition for liquescence of salts  

NASA Astrophysics Data System (ADS)

RSLs are narrow, dark albedo features on relatively steep slopes that appear during warm seasons and fade in the cold ones. So far they have only been observed in mid-latitudes where surface temperature is too high, periodically exceeding 300 K, for the presence of shallow ground ice. We attempt to determine what conditions are needed for the liquescence of salt to occur exactly when the RSLs are observed. If the eutectic temperature is exceeded, and humidity is high enough, salts may produce liquid brines through absorption of water vapor and liquescence. We calculate regolith temperature as a function of time and depth, for different macroscopic distributions of salt, for two different microphysical models of the distribution of salt on the regolith grains. Model parameters which are varied include surface albedo, thermal inertia of the dry regolith, the depths at which salt is present, and the salt content. We find that it is possible, for liquescence of magnesium perchlorate to occur where and when RSLs have been observed, but only within a very narrow range of parameters.

Kossacki, Konrad J.; Markiewicz, Wojciech J.

2014-05-01

373

Laser-induced damage in optical coatings and laser condition technology  

NASA Astrophysics Data System (ADS)

Laser-induced damages in several reflection coatings that are prepared with variant materials and technologies are investigated. It is found that the damage thresholds of the coatings are very different depending on the impurity absorption. We proved this conclusion by applying Auger Electron Spectroscopy to determine the surface composition of the coatings and measuring of the absorption of these coating. Laser condition of a large size coating is realized through scanning of a smaller laser spot. The condition is achieved through roistering at ten steps increasing from 5 to 80 percent of the zero probability damage threshold of the coating. The effect of the laser condition is directly related to the preparation process and the materials of the coating.

Fan, Zhengxiu; Zhao, Qiang; Qiu, Hong; Fan, Rui-Ying

1998-04-01

374

Study on the Technology and Method of Land Cover Classification for Geographic National Conditions Surveying  

NASA Astrophysics Data System (ADS)

Land Cover is the basis of geographic national conditions monitoring, extracting land cover information timely and accurately has become one of important tasks in the geographic national conditions surveying project. For the current situation of complex land cover type and large amount of data, there has emerged various new classification techniques and methods. However, the big difficult of classification?the large amount of data, the heavy workload of post-editing and other factors have seriously hampered the progress of the project. In this paper, it chooses high-resolution remote sensing image as original data, comprehensivly elaborates present research situation of oriented land cover classification. By the systematical analysis and summary of the basic and key problems of the land cover classification technology, relying on the geographic national information classification and standard system, discusses the available methods preliminarily to improve the accuracy of land cover classification which based on geographic national conditions surveying.

Jia, Y.; Li, H. T.; Gu, H. Y.; Han, Y. S.

2013-07-01

375

Research on the Characterization and Conditioning of Uranium Mill Tailings. II. Thermal Stabilization of Uranium Mill Tailings: Technical and Economic Evaluation. Volume 2.  

National Technical Information Service (NTIS)

A method of conditioning uranium mill tailings has been devised to greatly reduce radon emanation and contaminant leachability by using high-temperature treatments, i.e., thermal stabilization. The thermally stabilized products appear resistant to weather...

D. R. Dreesen E. J. Cokal E. F. Thode L. E. Wangen J. M. Williams

1983-01-01

376

Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies, Class III  

SciTech Connect

The objective of this project was to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California through the testing and application of advanced reservoir characterization and thermal production technologies. It was hoped that the successful application of these technologies would result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs.

City of Long Beach; Tidelands Oil Production Company; University of Southern California; David K. Davies and Associates

2002-09-30

377

Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies, Class III  

SciTech Connect

The objective of this project was to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California through the testing and application of advanced reservoir characterization and thermal production technologies. The successful application of these technologies would result in expanding their implementation throughout the Wilmington Field and, through technology transfer, to other slope and basin clastic (SBC) reservoirs.

City of Long Beach; Tidelands Oil Production Company; University of Southern California; David K. Davies and Associates

2002-09-30

378

Thermal Fatigue Testing of Plasma Transfer Arc Stellite Coatings on Hot Work Tool Steels under Steel Thixoforming Conditions  

NASA Astrophysics Data System (ADS)

The thermal fatigue performance of Stellite 12 coating deposited on X32CrMoV33 hot work tool steel via the plasma transfer arc (PTA) process was investigated under steel thixoforming conditions. Stellite 12 coating has made a favorable impact on the thermal fatigue performance of the X32CrMoV33 hot work tool steel. The latter survived steel thixoforming conditions lasting much longer, for a total of 5000 cycles, when coated with a PTA Stellite 12 layer. This marked improvement is attributed to the higher resistance to oxidation and to temper softening of the Stellite 12 alloy. The Cr-rich oxides, which form during thermal cycling, provide adequate protection to high-temperature oxidation. In contrast to hot work tool steel, Stellite 12 alloy enjoys hardening upon thermal exposure under steel thixoforming conditions. This increase in the strength of the coating is produced by the formation of carbides and contributes to the superior thermal fatigue resistance of the Stellite 12 alloy. When the crack finally initiates, it propagates via the fracture of hard interdendritic carbides. The transformation of M7C3 to M23C6, which is more voluminous than M7C3, promotes crack propagation.

Birol, Yucel; Kayihan, Agca B.

2011-11-01

379

Thermal analysis of hermetically sealed electromagnetic relay in high and low temperature condition  

Microsoft Academic Search

Hermetically sealed structure is the optimal style to protect electromagnetic relay (EMR) from formidable working environment. Each product shall be subjected to thermal environment shock in accordance with MIL-STD-202 from -65degC to +125degC temperature, so it is of great importance for thermal analysis of EMR to increase the thermal stability and reliability requirement. In this paper, special finite element analysis

Ren Wanbin; Liang Huimin; Zhai Guofu

2006-01-01

380

Miniature turbo-Brayton technologies for space-borne thermal-to-electric power converters  

NASA Astrophysics Data System (ADS)

Preliminary design studies show that a low-power, turbomachine-based, Brayton-cycle power unit is an extremely attractive option for thermal-to-electric power conversion on long-duration, deep-space missions. A 100 We power unit promises to achieve a thermal efficiency of 38% and weigh only 2.4 kg while requiring a single general-purpose heat source. The design of this unit is based on miniature, high-performance components that have been developed by Creare Inc. for space-borne, Brayton-cycle refrigerators. The components include high-speed, high-efficiency rotors and alternators: high-speed, precision gas bearings, and high-performance, compact recuperators. Miniaturization and performance goals for these components have been achieved through unique microscale fabrication techniques that have enabled high precision in miniature components. The resulting refrigerators are lightweight, highly efficient, vibration-free, highly reliable, and have long, maintenance-free life (greater than 5 years). These refrigerators and their components have been demonstrated to meet rigorous requirements for vibration emittance and susceptibility, acoustic susceptibility, electromagnetic interference and susceptibility, environmental cycling and endurance. A Creare Brayton-cycle refrigerator has been successfully space flight qualified and tested. The application of the underlying turbo-Brayton technologies to thermal-to-electric power conversion is the subject of this paper. .

Zagarola, Mark V.; Swift, Walter L.; McCormick, John A.; Izenson, Michael G.

2002-01-01

381

Hafnia-Based Nanostructured Thermal Barrier Coatings for Advanced Hydrogen Turbine Technology  

SciTech Connect

Thermal barrier coatings (TBCs) are critical technologies for future gas turbine engines of advanced coal based power generation systems. TBCs protect engine components and allow further increase in engine temperatures for higher efficiency. In this work, nanostructured HfO{sub 2}-based coatings, namely Y{sub 2}O{sub 3}-stabilized HfO{sub 2} (YSH), Gd{sub 2}O{sub 3}-stabilized HfO{sub 2} (GSH) and Y{sub 2}O{sub 3}-stabilized ZrO{sub 2}-HfO{sub 2} (YSZH) were investigated for potential TBC applications in hydrogen turbines. Experimental efforts are aimed at creating a fundamental understanding of these TBC materials. Nanostructured ceramic coatings of YSH, GSH and YSZH were grown by physical vapor deposition methods. The effects of processing parameters and ceramic composition on the microstructural evolution of YSH, GSH and YSZH nanostructured coatings was studied using combined X-ray diffraction (XRD) and Electron microscopy analyses. Efforts were directed to derive a detailed understanding of crystal-structure, morphology, and stability of the coatings. In addition, thermal conductivity as a function of composition in YSH, YSZH and GSH coatings was determined. Laboratory experiments using accelerated test environments were used to investigate the relative importance of various thermo-mechanical and thermo-chemical failure modes of TBCs. Effects of thermal cycling, oxidation and their complex interactions were evaluated using a syngas combustor rig.

Ramana, Chintalapalle; Choudhuri, Ahsan

2013-01-31

382

A novel test approach for plasma-sprayed coatings tested simultaneously under CMAS and thermal gradient cycling conditions  

Microsoft Academic Search

Plasma-sprayed ceramic coatings, used as thermal barrier or abradable coatings in high-pressure stages of gas turbines, are exposed to high thermo-mechanical loading due to harsh operating conditions. Under certain conditions they also have to withstand attack by calcium-magnesium-alumino-silicate (CMAS) deposits resulting from the ingestion of siliceous minerals with the intake air.Resistance to this kind of attack becomes more important at

Tanja Steinke; Doris Sebold; Daniel E. Mack; Robert Vaßen; Detlev Stöver

2010-01-01

383

Steady and Unsteady Heat Transfer in a Channel Partially Filled with Porous Media Under Thermal Non-Equilibrium Condition  

Microsoft Academic Search

Steady and pulsatile flow and heat transfer in a channel lined with two porous layers subject to constant wall heat flux under\\u000a local thermal non-equilibrium (LTNE) condition is numerically investigated. To do this, a physical boundary condition in the\\u000a interface of porous media and clear region of the channel is derived. The objective of this work is, first, to assess

Pourya Forooghi; Mahdi Abkar; Majid Saffar-Avval

2011-01-01

384

Calculation and visual displaying of the water chemistry conditions in return cooling systems at thermal power stations  

NASA Astrophysics Data System (ADS)

Matters concerned with treatment of cooling water at thermal power stations are addressed. Problems arising during operation of return cooling systems equipped with cooling towers are analyzed. The software used for monitoring, control, and indication of the hydraulic and water chemistry operating conditions of the circulation system at the Yaivinsk district power station is considered.

Ochkov, V. F.; Orlov, K. A.; Ivanov, E. N.; Makushin, A. A.

2013-07-01

385

Analysis of viscous dissipation effect on thermal entrance heat transfer in laminar pipe flows with convective boundary conditions  

Microsoft Academic Search

Consideration is given to the influence of viscous dissipation on the thermal entrance region laminar pipe flow heat transfer with convective boundary condition. The Eigenfunction series expansion technique is employed to solve the governing energy equation. The results for axial distributions of dimensionless bulk and wall temperatures, local Nusselt number as well as modified local Nusselt number are presented graphically

T. F. Lin; K. H. Hawks; W. Leidenfrost

1983-01-01

386

The Potential of Heavily And Severely Biodegraded Oils to be Partly Upgraded During High Temperature Thermal Recovery Conditions  

Microsoft Academic Search

Summary Upgrading of heavy oil and oil sands under simulated high temperature thermal recovery conditions was conducted to evaluate mechanisms and sources of the produced light hydrocarbon compounds that directly affect oil fluid properties. The main results suggest that the asphaltene fraction is the main source of the light hydrocarbons produced during the upgrading process. Comparing results from oils with

Norka Marcano; Barry Bennett; Thomas Oldenburg; Haiping Huang; Steve Larter

387

On the thermal stability of Co 2Z hexagonal ferrites for low-temperature ceramic cofiring technologies  

NASA Astrophysics Data System (ADS)

Co 2Z hexaferrite Ba 3Co 2Fe 24O 41 was prepared by a mixed oxalate co-precipitation route and the standard ceramic technology. XRD studies show that at T<1300 °C different ferrite phases coexist with the M-type hexaferrite as majority phase between 1000 and 1100 °C and the Y-type ferrite at 1230 °C. The Z-type material has its stability interval between 1300 and 1350 °C. Both synthesis routes result in almost single-phase Z-type ferrites after calcination at 1330 °C, intermediate grinding and sintering at 1330 °C. The permeability of Co 2Z-type ferrite of about ?=20 is stable up to several 100 MHz, with maximum losses ?'' around 700 MHz. Addition of 3 wt% Bi 2O 3 as sintering aid shifts the temperature of maximum shrinkage down to 950 °C and enables sintering of Z-type ferrite powders at 950 °C. However, the permeability is reduced to ?=3. It is shown here for the first time that Co 2Z ferrite is not stable under these conditions; partial thermal decomposition into other hexagonal ferrites is found by XRD studies. This is accompanied by a significant decrease of permeability. This shows that Co 2Z hexagonal ferrite is not suitable for the fabrication of multilayer inductors for high-frequency applications via the low-temperature ceramic cofiring technology since the material is not compatible with the typical process cofiring temperature of 950 °C.

Kra?unovska, S.; Töpfer, J.

388

Measurement of single and double glazing thermal performance under realistic conditions using the mobile window thermal test (MoWiTT) facility  

Microsoft Academic Search

The thermal performance of single glazing, clear double glazing, and double glazing with a low-emissivity coating was measured in both south-facing and north-facing orientations under realistic field conditions using the new MoWiTT field test facility. The time-dependent net heat flow through each fenestration was found to be consistent with the predictions of the standard simplified heat transfer model, provided that

J. Klems; H. Keller

1986-01-01

389

Ground thermal conditions and active layer processes within two glacier forefields with heterogeneous permafrost occurrence  

NASA Astrophysics Data System (ADS)

The patchy occurrence of frozen ground in the alpine discontinuous permafrost zone is well known and often restricted to block fields and areas with coarse surface substrate. External factors that account for this heterogeneous distribution on a local scale are snow depth, snow cover evolution, local topography, nature of substrate and glacial history. We present temperature and geoelectrical monitoring data from two glacier forefields in the Swiss Alps, both deglaciated since the Little Ice Age. Two boreholes were drilled in 2006 at Val Murgal (8 m) and another two in 2008 within glacier forefield Vadret dal Murtčl (10 m) each equipped with temperature sensors in variable depths. Additionally, temperature data loggers were placed at both sites. Boreholes and miniloggers were installed at locations with different substrate to cover the range in grain sizes from sand to boulders that dominate in this kind of alpine environment. Geoelectrical measurements were conducted across the boreholes to correlate thermal conditions with physical properties of the near surface layer. Whereas in Val Muragl measurements were repeated several times a year since 2005, an automatic monitoring was installed in March 2011 in glacier forefield Murtčl. With the monitoring system changes in subsurface electrical resistivity can be resolved on a diurnal scale. Together with borehole temperatures these data enhance the understanding of processes during snow melt in spring and freeze-back in autumn within the active layer. Temperature data show a constant depth of the active layer for the 6-year record of Val Muragl. While the blocky debris thaws down to 2 m during summer, the active layer is 5 m at the site with finer till. A contrary trend is visible at the lowermost sensor in 8 m depth that indicates a slight warming at the coarse site. Within the fine debris temperatures dropped from -0.3 °C to -0.7 °C since 2009 and at the same time the annual signal diminished. The 3-year record from Murtčl site shows a constant temperature slightly below the freezing point at the 10 m sensor without any trend at the blocky site. The second borehole in morainic till has seasonal frost conditions. Data from miniloggers document a strong heterogeneity in the thermal regime at the ground surface on a local scale. Mean annual ground surface temperatures differ by more than 3 °C within short distances and show a correlation with grain size. However, outliers with cold MAGST indicate that permafrost may exist even at sites with finer debris. Results from geoelectrical measurements indicate a fast reduction in ground resistivity within the active layer that occurs immediately when the snow cover gets isothermal and snow melt sets in. Resistivity values decreased by more than 60 per cent during a 6 day period in May 2011.

Rödder, T.; Kneisel, C.

2012-04-01

390

Development of Boundary Condition Independent Reduced Order Thermal Models using Proper Orthogonal Decomposition  

Microsoft Academic Search

Compact Thermal Models (CTM) to represent IC packages has been traditionally developed using the DELPHI-based (DEvelopment of Libraries of PHysical models for an Integrated design) methodology. The drawbacks of this method are presented, and an alternative method is proposed. A reduced-order model that provides the complete thermal information accurately with less computational resources can be effectively used in system level

Arun Raghupathy; Karman Ghia; Urmila Ghia

2008-01-01

391

Power conditioning subsystems for photovoltaic central-station power plants - Technology and performance  

NASA Technical Reports Server (NTRS)

Central-Station (CS) Photovoltaic (PV) systems have the potential of economically displacing significant amounts of centrally generated electricity. However, the technical viability and, to some extent, the economic viability of central-station PV generation technology will depend upon the availability of large power conditioners that are efficient, safe, reliable, and economical. This paper is an overview of the technical and cost requirements that must be met to develop economically viable power conditioning subsystems (PCS) for central-station power plants. The paper also examines various already commercially available PCS hardware that may be suitable for use in today's central PV power stations.

Krauthamer, S.; Das, R.; Bulawka, A.

1985-01-01

392

Direct chemical oxidation: a non-thermal technology for the destruction of organic wastes  

SciTech Connect

Direct Chemical Oxidation (DCO) is a non-thermal, ambient pressure, aqueous-based technology for the oxidative destruction of the organic components of hazardous or mixed waste streams. The process has been developed for applications in waste treatment and chemical demilitarization and decontamination at LLNL since 1992, and is applicable to the destruction of virtually all solid or liquid organics, including: chlorosolvents, oils and greases, detergents, organic-contaminated soils or sludges, explosives, chemical and biological warfare agents, and PCB's. [1-15] The process normally operates at 80-100 C, a heating requirement which increases the difficulty of surface decontamination of large objects or, for example, treatment of a wide area contaminated soil site. The driver for DCO work in FY98 was thus to investigate the use of catalysts to demonstrate the effectiveness of the technology for organics destruction at temperatures closer to ambient. In addition, DCO is at a sufficiently mature stage of development that technology transfer to a commercial entity was a logical next step, and was thus included in FY98 tasks.

Balazs, G.B.; Cooper, J. F.; Lewis, P. R.; Adamson, M. G.

1998-02-01

393

Assessment of Technologies for the Space Shuttle External Tank Thermal Protection System and Recommendations for Technology Improvement. Part 2; Structural Analysis Technologies and Modeling Practices  

NASA Technical Reports Server (NTRS)

A technology review and assessment of modeling and analysis efforts underway in support of a safe return to flight of the thermal protection system (TPS) for the Space Shuttle external tank (ET) are summarized. This review and assessment effort focuses on the structural modeling and analysis practices employed for ET TPS foam design and analysis and on identifying analysis capabilities needed in the short-term and long-term. The current understanding of the relationship between complex flight environments and ET TPS foam failure modes are reviewed as they relate to modeling and analysis. A literature review on modeling and analysis of TPS foam material systems is also presented. Finally, a review of modeling and analysis tools employed in the Space Shuttle Program is presented for the ET TPS acreage and close-out foam regions. This review includes existing simplified engineering analysis tools are well as finite element analysis procedures.

Knight, Norman F., Jr.; Nemeth, Michael P.; Hilburger, Mark W.

2004-01-01

394

Analytical Solution of Thermal Wave Models on Skin Tissue Under Arbitrary Periodic Boundary Conditions  

NASA Astrophysics Data System (ADS)

Modeling and understanding the heat transfer in biological tissues is important in medical thermal therapeutic applications. The biothermomechanics of skin involves interdisciplinary features, such as bioheat transfer, biomechanics, and burn damage. The hyperbolic thermal wave model of bioheat transfer and the parabolic Pennes bioheat transfer equations with blood perfusion and metabolic heat generation are applied for the skin tissue as a finite and semi-infinite domain when the skin surface temperature is suddenly exposed to a source of an arbitrary periodic temperature. These equations are solved analytically by Laplace transform methods. The thermal wave model results indicate that a non-Fourier model has predicted the thermal behavior correctly, compared to that of previous experiments. The results of the thermal wave model show that when the first thermal wave moves from the first boundary, the temperature profiles for finite and semi-infinite domains of skin become separated for these phenomena; the discrepancy between these profiles is negligible. The accuracy of the obtained results is validated through comparisons with existing numerical results. The results demonstrate that the non-Fourier model is significant in describing the thermal behavior of skin tissue.

Fazlali, R.; Ahmadikia, H.

2013-01-01

395

Metallurgical properties of reduced activation martensitic steel Eurofer'97 in the as-received condition and after thermal ageing  

NASA Astrophysics Data System (ADS)

This paper describes the microstructural studies and the mechanical testing (hardness, tensile and charpy tests) performed on the Eurofer'97 steel in the as-received condition and after thermal ageing treatments up to 600 °C. In addition, fracture toughness tests on the as-received condition have been carried out in order to determine the Master Curve. During the thermal ageing treatments studied (500 °C/5000 h and 600 °C/1000 h) the general microstructure of the steel (tempered martensite with M 23C 6 and MX precipitates) remained stable. Only a slight growth of the particles has been observed. In terms of mechanical properties, the Eurofer'97 steel exhibited similar values of tensile properties (tensile and yield strength) and ductile-brittle transition temperature regardless of the material condition studied.

Fernández, P.; Lancha, A. M.; Lapeńa, J.; Serrano, M.; Hernández-Mayoral, M.

2002-12-01

396

Investigation of Thermal Stress Convection in Nonisothermal Gases under Microgravity Conditions  

NASA Technical Reports Server (NTRS)

The project has sought to ascertain the veracity of the Burnett relations, as applied to slow moving, highly nonisothermal gases, by comparison of convection and stress predictions with those generated by the DSMC method. The Burnett equations were found to provide reasonable descriptions of the pressure distribution and normal stress in stationary gases with a 1-D temperature gradient. Continuum/Burnett predictions of thermal stress convection in 2-D heated enclosures, however, are not quantitatively supported by DSMC results. For such situations, it appears that thermal creep flows, generated at the boundaries of the enclosure, will be significantly larger than the flows resulting from thermal stress in the gas.

Mackowski, Daniel W.

1999-01-01

397

Turonian Ultra-thermal Conditions as Recorded in the High Canadian Arctic: Faunal Controls and Tectomagmatic Boundary Conditions  

NASA Astrophysics Data System (ADS)

Fossil vertebrate discoveries in the High Canadian Arctic over the last decade are reviewed here. These have defined an interval of extreme climatic warmth in the Arctic region during Turonian (ca 90 Ma) times. The discussion is broadened to include a review of Arctic tectonic and magmatic conditions during the Late Cretaceous, and will include an outline of work to further refine paleotemperature estimates. The discovery of fossil champsosaurs from sedimentary rocks of Axel Heiberg Island suggested a minimum mean annual temperature of 14 degrees C (Tarduno et. al., 1998) when paleomagnetic data indicate that the site was at Arctic paleolatitudes (Tarduno et al., 2002). Work conducted on several faunal groups support the initial report of warm conditions. Fish fossils record an expansion of ranges toward the poles (Friedman et al., 2003), whereas turtle diversity is unusually high, consistent with warm temperatures (Brinkman and Tarduno, 2005). The fossil champsosaurs define a population dominated by juveniles, incompatible with cold conditions (Vandermark et al., 2007). Aurorachelys gaffneyi, a large macrobaenid fossil turtle with affinities to Asia, suggests the possibility of migration over a warm brackish Arctic Ocean, possibly dotted with islands related to unusually vigorous magmatic activity (Vandermark et al., 2009). The fossil vertebrates were found in sedimentary rocks overlying continental flood basalts of the Strand Fiord Formation, which may be the onland expression of magmatism that formed Alpha Ridge of the Arctic Ocean. If correct, CO2 outgassing related to this volcanism, together with outgassing at several other sites of coeval magmatism, may have been responsible for the interval of extreme climatic warmth.

Bono, R.; Tarduno, J. A.; Cottrell, R. D.; Higgins, P.; Brinkman, D. B.

2010-12-01

398

Robust Vehicle Detection under Various Environmental Conditions Using an Infrared Thermal Camera and Its Application to Road Traffic Flow Monitoring  

PubMed Central

We have already proposed a method for detecting vehicle positions and their movements (henceforth referred to as “our previous method”) using thermal images taken with an infrared thermal camera. Our experiments have shown that our previous method detects vehicles robustly under four different environmental conditions which involve poor visibility conditions in snow and thick fog. Our previous method uses the windshield and its surroundings as the target of the Viola-Jones detector. Some experiments in winter show that the vehicle detection accuracy decreases because the temperatures of many windshields approximate those of the exterior of the windshields. In this paper, we propose a new vehicle detection method (henceforth referred to as “our new method”). Our new method detects vehicles based on tires' thermal energy reflection. We have done experiments using three series of thermal images for which the vehicle detection accuracies of our previous method are low. Our new method detects 1,417 vehicles (92.8%) out of 1,527 vehicles, and the number of false detection is 52 in total. Therefore, by combining our two methods, high vehicle detection accuracies are maintained under various environmental conditions. Finally, we apply the traffic information obtained by our two methods to traffic flow automatic monitoring, and show the effectiveness of our proposal.

Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

2013-01-01

399

Robust vehicle detection under various environmental conditions using an infrared thermal camera and its application to road traffic flow monitoring.  

PubMed

We have already proposed a method for detecting vehicle positions and their movements (henceforth referred to as "our previous method") using thermal images taken with an infrared thermal camera. Our experiments have shown that our previous method detects vehicles robustly under four different environmental conditions which involve poor visibility conditions in snow and thick fog. Our previous method uses the windshield and its surroundings as the target of the Viola-Jones detector. Some experiments in winter show that the vehicle detection accuracy decreases because the temperatures of many windshields approximate those of the exterior of the windshields. In this paper, we propose a new vehicle detection method (henceforth referred to as "our new method"). Our new method detects vehicles based on tires' thermal energy reflection. We have done experiments using three series of thermal images for which the vehicle detection accuracies of our previous method are low. Our new method detects 1,417 vehicles (92.8%) out of 1,527 vehicles, and the number of false detection is 52 in total. Therefore, by combining our two methods, high vehicle detection accuracies are maintained under various environmental conditions. Finally, we apply the traffic information obtained by our two methods to traffic flow automatic monitoring, and show the effectiveness of our proposal. PMID:23774988

Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

2013-01-01

400

Cobalt basic salts as inorganic precursors of cobalt oxides and cobalt metal: Thermal behaviour dependence on experimental conditions  

Microsoft Academic Search

The influence of heating rates and environment conditions on the thermal behaviour of two cobalt basic salts,ß-Co2(OH)3Cl and Co5(OH)8.5Cl1.5 · 2.5H2O, have been studied. The processes were followed using thermogravimetric and differential thermal analysis, X-ray diffraction, and infrared spectroscopy. When decomposition reactions are carried out in a nitrogen atmosphere, Co3O4 is always formed in quantities that seem to depend on

O. García-Martínez; P. Millán; R. M. Rojas; M. J. Torralvo

1988-01-01

401

The liquid pressure amplifier: Controversial technology can boost efficiency of refrigeration and air conditioning systems  

SciTech Connect

A device to reduce energy use in commercial refrigeration and air conditioning systems has generated some controversy in engineering and utility circles. The liquid pressure amplifier (LPA) is a pump that provides extra pressure in the liquid line of refrigeration and air conditioning systems, allowing the system head pressure to be lowered without creating liquid line flash gas. Thousands of LPAs have been installed, users generally report good results, and over two dozen utilities offer rebates for the technology. Some analysts question whether the device is effective, however, and the authors are aware of no testing that adequately isolated the performance of the LPA from other system tune-ups or measured all of the relevant energy impacts. After careful review, they believe that the liquid pressure amplifier is based on sound engineering principles and has the potential to yield cost-effective energy savings in appropriate applications. This report presents results of their analysis, as well as guidelines for further independent testing and field evaluation that should be conducted to more accurately quantify the benefits and limitations of this technology. Because savings will be site-specific, the authors believe that the LPA is better suited to custom DSM [Demand Side Management] incentive programs than to a fixed rebate per installation.

Hibberd, D.

1993-12-31

402

Sensing technologies to measure metabolic activities in soil and assess its health conditions  

NASA Astrophysics Data System (ADS)

Soil is a complex ecosystem comprised of several and mutually interacting components, both abiotic (organo-mineral associations) and biotic (microbial and pedofaunal populations and plants), where a single parameter depends on other factors and affects the same and other factors, so that a network of influences among organisms coexists with the reciprocal actions between organisms and their environment. Therefore, it is difficult to undoubtedly determine what is the cause and what the effect within relationships between factors and processes. Soil is commonly studied through the evaluation and measurement of single parameters (e.g. the content of soil organic matter (SOM), microbial biomass, enzyme activities, pH, etc.), events (e.g. soil erosion, compaction, etc.) and processes (e.g. soil respiration, carbon fluxes, nitrification/denitrification, etc.), often carried out in laboratory conditions in order to limit the number of factors acting within the ecosystem under study, but missing the information about the global soil environment that way. In the last decade, several scientists have proposed and suggested the need for a holistic approach to soil ecosystems in different contexts. Recently, we have applied a sensing system developed in the last decades and capable of analysing complex mixtures of gases and volatiles (odours or aromas) in atmospheres, namely called electronic nose (EN). Typically, ENs are devices consisting of an array of differentially and partially specific, despite selective, sensors upon diverse coatings of sensitive films, i.e. interacting with single analytes of the same chemical class, despite not highly specific for a single substance, only, but showing also lower extent of cross-selectivity towards compounds of other chemical classes. ENs can be used in the classifications of odours by processing the collected responses of all sensors in the array through pattern recognition analyses, in order to obtain a chemical fingerprint (olfactory fingerprint) typical of the analysed air sample. Due to these features, we decided to apply such a sensing technology to the analyses of soil atmospheres, because several processes in soil, both abiotic and biotic, result in gas and/or volatile production and the dynamics of such releases may also be affected by several additional environmental factors, such as soil moisture, temperature, gas exchange rates with outer atmosphere, adsorption/desorption processes, etc. Then, the analysis of soil atmosphere may provide information about global soil conditions (e.g. soil quality and health), according to a holistic approach, where several factors are contemporarily taken into account. At the same time, the use of such a technology, if adequately trained on purpose, can supply information about a single or a pool of processes sharing similar features, which occur in soil over a certain period of time and mostly affecting soil atmosphere. According to these premises and hypotheses, we demonstrated that EN is an useful technology to measure soil microbial activity, through its correlation to specific metabolic activities occurring in soil (i.e. global and specific respiration and some enzyme activities), but also soil microbial biomass. On the basis of such evidences, we also were able to use this technology to assess the quality and health conditions of soil ecosystems in terms of metabolic indices previously identified, according to some metabolic parameters and biomass quantification of microbial populations. In other studies, we also applied EN technology, despite using a different set of sensors in the array, to analyse the atmosphere of soil ecosystems in order to assess their environmental conditions after contamination with polycyclic aromatic hydrocarbons (PAHs) (i.e. semivolatile - SVOCs - organic pollutants). In this case, EN technology resulted capable of distinguishing between contaminated and uncontaminated soils, according to the differences in a list of substances, occurring in the atmospheres of differently treated soils, which were identified throu

De Cesare, Fabrizio; Macagnano, Antonella

2013-04-01

403

The U.S. Department of Energy`s role in commercialization of solar thermal electric technology  

SciTech Connect

The U.S. Department of Energy (DOE) has supported the development of solar thermal electric (STE) technology since the early 1970s. From its inception, the program has held a long-term goal of nurturing STE technologies from the research and development (R&D) stage through technology development, ultimately leading to commercialization. Within the last few years, the focus of this work -has shifted from R&D to cost-shared cooperative projects with industry. These projects are targeted not just at component development, but at complete systems, marketing approaches, and commercialization plans. This changing emphasis has brought new industry into the program and is significantly accelerating solar thermal`s entry into the marketplace. Projects such as Solar Two in the power tower area, a number of dish/Stirling joint ventures in the modular power area, and operations and maintenance (O&M) cost reduction studies will be discussed as examples of this new focus.

Burch, G.D. [United States Dept. of Energy, Washington, DC (United States); Tyner, C.E. [Sandia National Labs., Albuquerque, NM (United States)

1994-10-01

404

Thermal Stability of Beta-Alumina Solid Electrolyte Under AMTEC Operating Conditions  

NASA Technical Reports Server (NTRS)

A critical component of alkali metal thermal-to electric converter (AMTEC) devices for long duration space missions is the sodium beta-alumina solid electrolyte ceramic (BASE), for which there exists no substitute.

Williams, R.; Homer, M.; Kulleck, J.; Lara, L.; Kisor, A.; Cortez, R.; Shields, V.; Ryan, M.

1999-01-01

405

A novel test method for measuring the thermal properties of clothing ensembles under dynamic conditions  

NASA Astrophysics Data System (ADS)

The dynamic thermal properties of clothing ensembles are important to thermal transient comfort, but have so far not been properly quantified. In this paper, a novel test procedure and new index based on measurements on the sweating fabric manikin-Walter are proposed to quantify and measure the dynamic thermal properties of clothing ensembles. Experiments showed that the new index is correlated to the changing rate of the body temperature of the wearer, which is an important indicator of thermal transient comfort. Clothing ensembles having higher values of the index means the wearer will have a faster changing rate of body temperature and shorter duration before approaching a dangerous thermo-physiological state, when he changes from 'resting' to 'exercising' mode. Clothing should therefore be designed to reduce the value of the index.

Wan, X.; Fan, J.

2008-06-01

406

K-West and K-East basin thermal analyses for dry conditions  

SciTech Connect

Detailed 3 dimensional thermal analyses of the 100K East and 100 K West basins were conducted to determine the peak fuel temperature for intact fuel in the event of a complete loss of water from the basins. Thermal models for the building, an array of fuel encapsulation canisters on the basin floor, and the fuel within a single canister are described along with conservative predictions for the maximum expected temperatures for the loss of water event.

Beaver, T.R.; Cramer, E.R.; Hinman, C.A.

1994-09-29

407

Building America Best Practices Series, Volume 6: High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems  

SciTech Connect

This guide is was written by PNNL for the US Department of Energy's Building America program to provide information for residential production builders interested in building near zero energy homes. The guide provides indepth descriptions of various roof-top photovoltaic power generating systems for homes. The guide also provides extensive information on various designs of solar thermal water heating systems for homes. The guide also provides construction company owners and managers with an understanding of how solar technologies can be added to their homes in a way that is cost effective, practical, and marketable. Twelve case studies provide examples of production builders across the United States who are building energy-efficient homes with photovoltaic or solar water heating systems.

Baechler, Michael C.; Gilbride, Theresa L.; Ruiz, Kathleen A.; Steward, Heidi E.; Love, Pat M.

2007-06-04

408

Solar thermal technology development: Estimated market size and energy cost savings. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

Estimated future energy cost savings associated with the development of cost-competitive solar thermal technologies (STT) are discussed. Analysis is restricted to STT in electric applications for 16 high-insolation/high-energy-price states. The fuel price scenarios and three 1990 STT system costs are considered, reflecting uncertainty over future fuel prices and STT cost projections. STT R&D is found to be unacceptably risky for private industry in the absence of federal support. Energy cost savings were projected to range from $0 to $10 billion (1990 values in 1981 dollars), dependng on the system cost and fuel price scenario. Normal R&D investment risks are accentuated because the Organization of Petroleum Exporting Countries (OPEC) cartel can artificially manipulate oil prices and undercut growth of alternative energy sources. Federal participation in STT R&D to help capture the potential benefits of developing cost-competitive STT was found to be in the national interest.

Gates, W. R.

1983-01-01

409

A new 3He-free thermal neutrons detector concept based on the GEM technology  

NASA Astrophysics Data System (ADS)

A thermal neutron detector based on the Gas Electron Multiplier technology is presented. It is configured to let a neutron beam interact with a series of borated glass layers placed in sequence along the neutron path inside the device. The detector has been tested on beam both at the ISIS (UK) spallation neutron source and at the TRIGA reactor of ENEA, at the Casaccia Research Center, near Rome in Italy. For a complete characterization and description of the physical mechanism underlying the detector operation, several Monte Carlo simulations were performed using both Fluka and Geant4 code. These simulations are intended to help in seeking the optimal geometrical set-up and material thickness (converter layer, gas gap, sheet substrate) to improve the final detector design in terms of achieving the best detector efficiency possible.

Pietropaolo, A.; Murtas, F.; Claps, G.; Quintieri, L.; Raspino, D.; Celentano, G.; Vannozzi, A.; Frasciello, O.

2013-11-01

410

Current Development of Nuclear Thermal Propulsion technologies at the Center for Space Nuclear Research  

SciTech Connect

Nuclear power and propulsion has been considered for space applications since the 1950s. Between 1955 and 1972 the US built and tested over twenty nuclear reactors / rocket engines in the Rover/NERVA programs1. The Aerojet Corporation was the prime contractor for the NERVA program. Modern changes in environmental laws present challenges for the redevelopment of the nuclear rocket. Recent advances in fuel fabrication and testing options indicate that a nuclear rocket with a fuel composition that is significantly different from those of the NERVA project can be engineered; this may be needed to ensure public support and compliance with safety requirements. The Center for Space Nuclear Research (CSNR) is pursuing a number of technologies, modeling and testing processes to further the development of safe, practical and affordable nuclear thermal propulsion systems.

Robert C. O'Brien; Steven K. Cook; Nathan D. Jerred; Steven D. Howe; Ronald Samborsky; Daniel Brasuell

2012-09-01

411

Improvements in Li(Si)/FeS2 thermal battery technology  

NASA Astrophysics Data System (ADS)

Potential improvements in Li(Si)/FeS2 thermal battery technology were evaluated using as the test vehicle a 28 +-4-V, 400 cu cm battery discharged through a 28 omega load. Successful improvements included incorporating a catholyte additive to improve voltage regulation during discharge, changing the catholyte composition and blending procedure to increase life and current carrying capability, changing the anode composition to obtain better voltage regulation, and optimizing the heat and mass input. One end of life mechanism for higher current drain batteries was determined to be electrolytic freeze-out at the anode at temperatures that increase as the current density increases. The increase in freezing temperature was caused by a change in the K(+)li(+) ratio in the electrolyte near the anode as the anode discharged. A balanced ratio of cathode to anode weight was determined for the two catholytes and anode powders considered. The balance was based on electrode polarization at various resistive loads.

Searcy, J. Q.; Armijo, J. R.

1982-06-01

412

Recent developments in Li(Si)FeS2 thermal battery technology  

NASA Astrophysics Data System (ADS)

The Li(Si)/FeS2 electrochemical system has been under development for thermal battery applications as an alternative to Ca/CaCrO4 for several years at Sandia National Laboratories (SNL). The new technology differs from the old in that the anode is a pressed powder (44 wt % lithium in Li(Si) alloy) as opposed to sheet calcium or bimetal; and a separator composed of LiCl.KCl eutectic electrolyte and MgO binder is required with a separate cathode pellet composed of FeS2 and electrolyte to replace the DEB pellet; and current collectors which may actually function as temperature moderators are always used. The applications require high reliability (typically, a success probability of 0.995) and a twenty-five year shelf-life. Consequently, a substantial materials effort has been necessary to assess degradation and deleterious reactions during storage and to determine necessary production specifications and controls.

Searcy, J. Q.; Quinn, R. K.; Saxton, H. J.

413

Application of In-Flight Melting Technology by RF Induction Thermal Plasmas to Glass Production  

NASA Astrophysics Data System (ADS)

An innovative in-flight glass melting technology with induced thermal plasmas was developed for the purpose of energy conservation and environmental protection. Two-dimensional modeling was used to simulate the thermofluid fields in the plasma torch. The in-flight melting behavior of glass raw material was investigated by various analysis methods. Results showed that the plasma temperature was up to 10000 K with a maximum velocity over 30 m/s, which made it possible to melt the granulated glass raw material within milliseconds. The carbonates in the raw material decomposed completely and the compounds in the raw material attainted 100% vitrification during the in-flight time from the nozzle exit to substrate. The particle melting process is similar to the unreacted-core shrinking model.

Yao, Yaochun; M. Hossain, M.; Watanabe, T.; Funabiki, F.; Yano, T.

2008-06-01

414

Potential effect of fracture technology on IPTS (Integrated Pressurized Thermal Shock) analysis (Fracture toughness: K sub la and K sub lc and warm prestressing)  

SciTech Connect

A major nuclear plant life extension issue to be confronted in the 1990's is pressure vessel integrity for the pressurized thermal shock (PTS) loading condition. Governing criteria associated with PTS are included in The PTS Rule'' (10 CFR 50.61) and Regulatory Guide 1.154: Format and Content of Plant-Specific Pressurized Thermal Shock Safety Analysis Reports for Pressurized Water Reactors. The results of the Integrated Pressurized Water Reactors. The results of the Integrated Pressurized Thermal Shock (IPTS) Program, along with risk assessments and fracture analyses performed by the NRC and reactor system vendors, contributed to the derivation of the PTS Rule. Over the last several years, the Heavy Section Steel Technology (HSST) Program at the Oak Ridge National Laboratory (ORNL) has performed a series of large-scale fracture-mechanics experiments. The Thermal Shock Experiments (TSE), Pressurized Thermal Shock Experiments (PTSE), and Wide Plate Experiments (WPE) produced K{sub IC} and K{sub Ia} data that suggest increased mean K{sub IC} and K{sub Ia} curves relative to the ones used in the IPTS study. Also, the PTSE and WPE have demonstrated that prototypical nuclear reactor pressure vessel steels are capable of arresting a propagating crack at K{sub I} values considerably above 220 MPa{radical}m, the implicit limit of the ASME Code and the limit used in the IPTS studies. This document provides a discussion of the results of these experiments.

Dickson, T.L.

1990-01-01

415

Survey of the supporting research and technology for the thermal protection of the Galileo Probe  

NASA Technical Reports Server (NTRS)

The Galileo Probe, which is scheduled to be launched in 1985 and to enter the hydrogen-helium atmosphere of Jupiter up to 1,475 days later, presents thermal protection problems that are far more difficult than those experienced in previous planetary entry missions. The high entry speed of the Probe will cause forebody heating rates orders of magnitude greater than those encountered in the Apollo and Pioneer Venus missions, severe afterbody heating from base-flow radiation, and thermochemical ablation rates for carbon phenolic that rival the free-stream mass flux. This paper presents a comprehensive survey of the experimental work and computational research that provide technological support for the Probe's heat-shield design effort. The survey includes atmospheric modeling; both approximate and first-principle computations of flow fields and heat-shield material response; base heating; turbulence modelling; new computational techniques; experimental heating and materials studies; code validation efforts; and a set of 'consensus' first-principle flow-field solutions through the entry maneuver, with predictions of the corresponding thermal protection requirements.

Howe, J. T.; Pitts, W. C.; Lundell, J. H.

1981-01-01

416

Applying infrared thermal wave technology to study the bonding structure defects of steel shell/insulation  

NASA Astrophysics Data System (ADS)

Infrared thermal wave technology has gained widely adopted as a nondestructive method in many fields, especially in the aerospace, manufacturing industries, etc. In this paper, pulsed thermography method was used to detect a structure with big curvature. The structure, in which there are five pre-designed debonding defects, is steel shell / insulation bonding structure. However, the characteristics of large curvature and complex surface will lead to uneven heat loading and serious non-uniformity of the thermograms. In order to solve the problem, oblique segment detection method was used. Watershed method was adopted to process the acquired thermograms for noise reduction, enhancement and segmentation. Eventually, the size of the defect has been identified. Through the experiment we concluded that, in the same depth, a larger defect is more easily to be identified, and the recognition accuracy is higher; Compared with conventional nondestructive testing methods, infrared thermal wave nondestructive testing is a better curvature tolerant method; For thin specimens, small defects can be well identified; When curvature specimen is in parallel with the pulsed flash tube, there would be a serious reflection phenomenon on the surface. By using the method of surface treatment and oblique segment detection, the results have been greatly improved.

Zhang, Wei; Luo, Wenyuan; Wu, Cuiqin; Song, Yuanjia; Jin, Guofeng; Li, Qike; Tian, Lu

2012-10-01

417

Infrared thermal wave nondestructive technology on the defect in the shell of solid rocket motor  

NASA Astrophysics Data System (ADS)

Based on the active infrared thermography nondestructive testing (NDT) technology, which is an emerging method and developed in the areas of aviation, spaceflight and national defence, the samples including glass fiber flat bottom hole sample, glass fiber inclusion sample and steel flat bottom hole sample that the shell materials of Solid Rocket Motor (SRM) were heated by a high energy flash lamp. The subsurface flaws can be detected through measuring temperature difference between flaws and materials. The results of the experiments show that: 1) the technique is a fast and effective inspection method, which is used for detecting the composites more easily than the metals. And it also can primarily identify the defect position and size according to the thermal image maps. 2) A best inspection time at when the area of hot spot is the same with that of defect is exited, which can be used to estimate the defect size. The bigger the defect area, the easier it could be detected and also the less of the error for estimating defect area. 3). The infrared thermal images obtained from experiments always have high noise, especially for metal materials due to high reflectivity and environmental factors, which need to be further processed.

Zhang, Wei; Song, Yuanjia; Yang, Zhengwei; Li, Ming; Tian, Gan

2010-05-01

418

Large-scale Experiments As A Tool For The Development of An Enhanced Remediation Technology With Thermal Wells  

NASA Astrophysics Data System (ADS)

The "cold"soil vapour extraction (SVE) is a state-of-the-art technology to remove volatile non- aqueous phase liquids from the unsaturated zone. This technology is most efficient for contaminants with low boiling points and soils with high to medium permeability. To increase phase transition from liquid to gas, thermal enhancement has been developed. Temperatures greater than 100oC are required to vaporize contami- nants with low vapour pressures in low permeable soils. This means, such that steam injection is inadequate. Thermal wells are the alternative remediation option.

Hiester, U.; Theurer, T.; Winkler, A.; Koschitzky, H.-P.; Färber, A.

419

Review of second law analysis techniques applicable to the Energy Conversion and Utilization Technologies Thermal Sciences Program  

SciTech Connect

This report describes a review of second law analysis emphasizing techniques applicable to basic research in the thermal sciences. Second law analysis is a class of thermodynamic analysis techniques that has become increasingly popular in the design of thermal systems. Pacific Northwest Laboratory conducted this review in l987 for the US Department of Energy's (DOE) Energy Conversion and Utilization Technologies (ECUT) Program. The primary goal is to determine whether second law techniques can be used in guiding or contributing to basic research in the thermal sciences. 35 refs.

Drost, M.K.; Zaworski, J.R.

1989-06-01

420

Critical analysis of the thermal inertia approach to map soil water content under sparse vegetation and changeable sky conditions  

NASA Astrophysics Data System (ADS)

The paper reports a critical analysis of the thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data. The study area is an experimental area located in Barrax (Spain). Field data were acquired within the Barrax 2011 research project. AHS airborne images including VIS/NIR and TIR bands were acquired both day and night time by the INTA (Instituto Nacional de Técnica Aeroespacial) between the 11th and 13rd of June 2011. Images cover a corn pivot surrounded by bare soil, where a set of in situ data have been collected previously and simultaneously to overpasses. To validate remotely sensed estimations, a preliminary proximity sensing set up has been arranged, measuring spectra and surface temperatures on transects by means of ASD hand-held spectroradiometer and an Everest Interscience radiometric thermometer respectively. These data were collected on two transects: the first one on bare soil and the second from bare to sparsely vegetated soil; soil water content in both transects ranged approximately between field and saturation values. Furthermore thermal inertia was measured using a KD2Pro probe, and surface water content of soil was measured using FDR and TDR probes. This ground dataset was used: 1) to verify if the thermal inertia method can be applied to map water content also on soil covered by sparse vegetation, and 2) to quantify a correction factor of the downwelling shortwave radiation taking into account sky cloudiness effects on thermal inertia assessment. The experiment tests both Xue and Cracknell approximation to retrieve the thermal inertia from a dumped value of the phase difference and the three-temperature approach of Sobrino to estimate the phase difference spatial distribution. Both methods were then applied on the remotely sensed airborne images collected during the following days, in order to obtain the spatial distribution of the surface soil moisture on bare soils and sparse vegetation coverage. Results verify that the thermal inertia method can be applied on sparsely vegetated soil characterized by fractional cover up to ~0.25 (maximum value within this experiment); a lumped value of the phase difference allows a good estimate of the thermal inertia, whereas the comparison with the three-temperature approach did not give conclusive responses because ground radiometric temperatures were not acquired in optimal conditions. Results also show that clear sky only at the time of the remote sensing acquisitions is not a sufficient condition to apply the thermal inertia method. A corrective coefficient taking into account the actual sky cloudiness throughout the day allows accurate estimates of the spatial distribution of the thermal inertia (r2 ~ 0.9) and soil water content (r2 ~ 0.7).

Maltese, Antonino; Capodici, Fulvio; Corbari, Chiara; Ciraolo, Giuseppe; La Loggia, Goffredo; Sobrino, José Antonio

2012-09-01

421

Assessment of thermal load on transported goats administered with ascorbic acid during the hot-dry conditions  

NASA Astrophysics Data System (ADS)

The major factor in the induction of physiological stress during road transportation of livestock is the complex fluctuations of the thermal transport microenvironment, encountered when animals are transported across different ecological zones. Recommended guidelines on optimum "on-board" conditions in which goats should be transported are lacking, and there are no acceptable ranges and limits for the thermal loads to which goats may be subjected during long-distance road transportation in hot-dry conditions. Panting score (PS), rectal temperature (RT), heart rate (HR) and respiratory rate (RR) were employed as reliable stress indices to assess the effects of different thermal loads, measured as temperature humidity index (THI), encountered in the vehicle during 12 h of road transportation of 40 goats, and to suggest the administration of 100 mg/kg body weight of ascorbic acid (AA) as an ameliorating agent. The results obtained showed that the PS, RT, HR and RR rose above normal reference values with increase in the THI and journey duration. The rise in PS value, which is a visual indicator of the severity of thermal load, was the most pronounced. The results suggest that values of THI in the vehicle up to 94.6 constitute no risk, while at of 100 it presents a moderate risk and above 100 may result in severe stress. The relationships between the thermal load and the physiological variables were positive and significant ( P < 0.05). They reflect the degree of stress imposed by each THI value during the transportation, and may be used as recommended ranges and limit thermal load values in transported goats. The results demonstrated that administration of 100 mg/kg body weight of AA before road transportation mitigated the risk of adverse effects of high THI values and other stress factors due to road transportation in goats.

Minka, N. S.; Ayo, J. O.

2012-03-01

422

Summary assessment of solar thermal parabolic dish technology for electrical power generation  

NASA Technical Reports Server (NTRS)

An assessment is provided of solar thermal parabolic dish technology for electrical power generation. The assessment is based on the development program undertaken by the Jet Propulsion Laboratory for the U.S. Department of Energy and covers the period from the initiation of the program in 1976 through mid-1984. The program was founded on developing components and subsystems that are integrated into parabolic dish power modules for test and evaluation. The status of the project is summarized in terms of results obtained through testing of modules, and the implications of these findings are assessed in terms of techno-economic projections and market potential. The techno-economic projections are based on continuation of an evolutionary technological development program and are related to the accomplishments of the program as of mid-1984. The accomplishments of the development effort are summarized for each major subsystem including concentrators, receivers, and engines. The ramifications of these accomplishments are assessed in the context of developmental objectives and strategies.

Penda, P. L.; Fujita, T.; Lucas, J. W.

1985-01-01

423

Solar thermal technologies - Potential benefits to U.S. utilities and industry  

NASA Technical Reports Server (NTRS)

Solar energy systems were investigated which complement nuclear and coal technologies as a means of reducing the U.S. dependence on imported petroleum. Solar Thermal Energy Systems (STES) represents an important category of solar energy technologies. STES can be utilized in a broad range of applications servicing a variety of economic sectors, and they can be deployed in both near-term and long-term markets. The net present value of the energy cost savings attributable to electric utility and IPH applications of STES were estimated for a variety of future energy cost scenarios and levels of R&D success. This analysis indicated that the expected net benefits of developing an STES option are significantly greater than the expected costs of completing the required R&D. In addition, transportable fuels and chemical feedstocks represent a substantial future potential market for STES. Due to the basic nature of this R&D activity, however, it is currently impossible to estimate the value of STES in these markets. Despite this fact, private investment in STES R&D is not anticipated due to the high level of uncertainty characterizing the expected payoffs. Previously announced in STAR as N83-10547

Terasawa, K. L.; Gates, W. R.

1983-01-01

424

Nuclear power plant accident simulations of gasket materials under simultaneous radiation plus thermal plus mechanical stress conditions  

SciTech Connect

In order to probe the response of silicone door gasket materials to a postulated severe accident in an Italian nuclear power plant, compression stress relaxation (CSR) and compression set (CS) measurements were conducted under combined radiation (approximately 6 kGy/h) and temperature (up to 230{degrees}C) conditions. By making some reasonable initial assumptions, simplified constant temperature and dose rates were derived that should do a reasonable job of simulating the complex environments for worst-case severe events that combine overall aging plus accidents. Further simplification coupled with thermal-only experiments allowed us to derive thermal-only conditions that can be used to achieve CSR and CS responses similar to those expected from the combined environments that are more difficult to simulate. Although the thermal-only simulations should lead to sealing forces similar to those expected during a severe accident, modulus and density results indicate that significant differences in underlying chemistry are expected for the thermal-only and the combined environment simulations. 15 refs., 31 figs., 15 tabs.

Gillen, K.T.; Malone, G.M.

1997-07-01

425

Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems - Paper  

EPA Science Inventory

A USEPA-sponsored field demonstration program was conducted to gather technically reliable cost and performance information on the electro-scan (FELL -41) pipeline condition assessment technology. Electro-scan technology can be used to estimate the magnitude and location of pote...

426

Development of Predictable Technology for Thermal\\/Hydraulic Performance of Reduced-Moderation Water Reactors (1) - Master Plan -  

Microsoft Academic Search

We start R and D project to develop the predictable technology for thermal-hydraulic performance of Reduced-Moderation Water Reactor (RMWR) in collaboration with power company\\/ reactor vendor\\/ university since 2002. The RMWR can attain the favorable characteristics such as effective utilization of uranium resources, multiple recycling of plutonium, high burn-up and long operation cycle, based on matured BWR technologies. MOX fuel

Akira Ohnuki; Kazuyuki Takase; Masatoshi Kureta; Hiroyuki Yoshida; Hidesada Tamai; Wei Liu; Hajime Akimoto

2004-01-01

427

Finding the organizational sources of technological breakthroughs: the story of Hewlett-Packard's thermal ink-jet  

Microsoft Academic Search

Which firms are more likely to invent technological breakthroughs, such as Hewlett-Packard's invention of the thermal ink-jet? I induct theory for this question by interpreting the history of the breakthrough as a recombinant and boundedly rational search process. The firm increased its odds of success by generating many high-variance inventive trials; it mixed and juxtaposed diverse technologies, professions and experience,

Lee Fleming

2002-01-01

428

The reuse of spent mushroom compost and coal tailings for energy recovery: Comparison of thermal treatment technologies  

Microsoft Academic Search

Thermal treatment technologies were compared to determine an appropriate method of recovering energy from two wastes – spent mushroom compost and coal tailings. The raw compost and pellets of these wastes were combusted in a fluidised-bed and a packed-bed, and contrasted to pyrolysis and gasification. Quantitative combustion parameters were compared to assess the differences in efficiency between the technologies. Fluidised-bed

Karen N. Finney; Changkook Ryu; Vida N. Sharifi; Jim Swithenbank

2009-01-01

429

Statistical optimization of thermal pretreatment conditions for enhanced biomethane production from defatted algal biomass.  

PubMed

The present study analyzes the effect of thermal pretreatment for enhancing the biomethane potential of defatted algal biomass of Scenedesmus dimorphus through statistically guided experimental design. To this end, defatted microalgal biomass at various concentrations (1, 3 and 5gL(-1)) was pretreated at elevated temperatures (100, 120 and 150°C) for 20, 40 and 60min. The solubilised TOC was favourably enhanced up to 71mgL(-1) after pretreatment at a temperature of 150°C for reaction time of 60min. The methane yield was substantially enhanced (up to 60%) and could be correlated with an increase in organic matter solubilisation and enhanced biodegradability via thermal pretreatment. The optimisation of the integrated thermal pretreatment-biomethanation process resulted in up to 1.6-fold increase in methane yield. PMID:24747395

Sarat Chandra, T; Suvidha, G; Mukherji, S; Chauhan, V S; Vidyashankar, S; Krishnamurthi, K; Sarada, R; Mudliar, S N

2014-06-01

430

Critical Evaluation of State-of-the-Art In Situ Thermal Treatment Technologies for DNAPL Source Zone Treatment. State-of-the-Practice Overview.  

National Technical Information Service (NTIS)

In situ thermal technologies have undergone rapid development and application in recent years as they promise the potential of quicker and more thorough treatment of nonaqueous phase liquid (NAPL) source zones. These technologies include electrical resist...

E. Foote J. T. Kingston P. Dahlen P. Johnson S. Williams

2009-01-01

431

Influence of EB-PVD TBC Microstructure on Thermal Barrier Coating System Performance Under Cyclic Conditions  

Microsoft Academic Search

The lifetimes of electron beam physical vapor deposited (EB-PVD) thermal barrier;\\u000acoating systems (TBCs) with three different microstructures of the Y2<\\/sub>O3<\\/sub>-stabilized ZrO, YSZ) ceramic top layer were investigated in lh thermal cycles at 1100 and 1150°C in flowing oxygen. Single crystal alloys CMSX-4 and Rene N5 that had been coated with an EB-PVD NiCoCrAlY bond coat were chosen as substrate

C. Leyens; B. A. Pint; U. Schulz; I. G. Wright

1999-01-01

432

On the influence of process variables on the thermal conditions and properties of high pressure die-cast magnesium alloys  

Microsoft Academic Search

The influence of pressure and velocity in high-pressure magnesium die casting on the thermal conditions and on the casting properties is studied. Specimens with the shape of a tensile test plate with a thickness of 12 mm and a length of 295 mm were cast using the alloys AM20HP, AM50HP, AS41, AE42, AZ91HP. Two gate velocities of the liquid metal

Nahed A. El-Mahallawy; Mohamed A Taha; Engenius Pokora; Friedrich Klein

1998-01-01

433

Advances in lectin microarray technology: optimized protocols for piezoelectric print conditions.  

PubMed

Lectin microarray technology has been used to profile the glycosylation of a multitude of biological and cli