Thermal hydraulic analyses of two fusion reactor first wall/blanket concepts

International Nuclear Information System (INIS)

Misra, B.; Maroni, V.A.

1977-01-01

A comparative study has been made of the thermal hydraulic performance of two liquid lithium blanket concepts for tokamak-type reactors. In one concept lithium is circulated through 60-cm deep cylindrical modules oriented so that the module axis is parallel to the reactor minor radius. In the other concept helium carrying channels oriented parallel to the first wall are used to cool a 60-cm thick stagnant lithium blanket. Paralleling studies were carried out wherein the thermal and structural properties of the construction materials were based on those projected for either solution-annealed 316-stainless steel or vanadium-base alloys. The effects of limitations on allowable peak structural temperature, material strength, thermal stress, coolant inlet temperature, and pumping power/thermal power ratio were evaluated. Consequences to thermal hydraulic performance resulting from the presence of or absence of a divertor were also investigated

Thermal hydraulic analyses of two fusion reactor first wall/blanket concepts

International Nuclear Information System (INIS)

Misra, B.; Maroni, V.A.

1978-01-01

A comparative study has been made of the thermal hydraulic performance of two liquid lithium blanket concepts for tokamak-type reactors. In one concept lithium is circulated through 60-cm deep cylindrical modules oriented so that the module axis is parallel to the reactor minor radius. In the other concept helium carrying channels oriented parallel to the first wall are used to cool a 60-cm thick stagnant lithium blanket. Paralleling studies were carried out wherein the thermal and structural properties of the construction materials were based on those projected for either solution-annealed 316-stainless steel or vanadium-base alloys. The effects of limitations on allowable peak structural temperature, material strength, thermal stress, coolant inlet temperature, and pumping power/thermal power ratio were evaluated. Consequences to thermal hydraulic performance resulting from the presence of or absence of a divertor were also investigated

Replacement of Ablators with Phase-Change Material for Thermal Protection of STS Elements

Science.gov (United States)

Kaul, Raj K.; Stuckey, Irvin; Munafo, Paul M. (Technical Monitor)

2002-01-01

As part of the research and development program to develop new Thermal Protection System (TPS) materials for aerospace applications at NASA's Marshall Space Flight Center (MSFC), an experimental study was conducted on a new concept for a non-ablative TPS material. Potential loss of TPS material and ablation by-products from the External Tank (ET) or Solid Rocket Booster (SRB) during Shuttle flight with the related Orbiter tile damage necessitates development of a non-ablative thermal protection system. The new Thermal Management Coating (TMC) consists of phase-change material encapsulated in micro spheres and a two-part resin system to adhere the coating to the structure material. The TMC uses a phase-change material to dissipate the heat produced during supersonic flight rather than an ablative material. This new material absorbs energy as it goes through a phase change during the heating portion of the flight profile and then the energy is slowly released as the phase-change material cools and returns to its solid state inside the micro spheres. The coating was subjected to different test conditions simulating design flight environments at the NASA/MSFC Improved Hot Gas Facility (IHGF) to study its performance.

Development, concept and scope of copyright protection in Nigeria ...

African Journals Online (AJOL)

Development, concept and scope of copyright protection in Nigeria: an overview. ... Nnamdi Azikiwe University Journal of International Law and Jurisprudence ... This forms the aim of this paper which focuses essentially on basic issues relating to the development, concept and the scope of protection afforded copyright in ...

Investigating the potential of a novel low-energy house concept with hybrid adaptable thermal storage

International Nuclear Information System (INIS)

Hoes, P.; Trcka, M.; Hensen, J.L.M.; Hoekstra Bonnema, B.

2011-01-01

Research highlights: → In conventional buildings thermal mass is a permanent building characteristic. → Permanent thermal mass concepts are not optimal in all operational conditions. → We propose a concept that combines the benefits of low and high thermal mass. → Building simulation shows the concept is able to reduce the energy demand with 35%. → Furthermore, the concept increases the performance robustness of the building. -- Abstract: In conventional buildings thermal mass is a permanent building characteristic depending on the building design. However, none of the permanent thermal mass concepts are optimal in all operational conditions. We propose a concept that combines the benefits of buildings with low and high thermal mass by applying hybrid adaptable thermal storage (HATS) systems and materials to a lightweight building. The HATS concept increases building performance and the robustness to changing user behavior, seasonal variations and future climate changes. Building performance simulation is used to investigate the potential of the novel concept for reducing heating energy demand and increasing thermal comfort. Simulation results of a case study in the Netherlands show that the optimal quantity of the thermal mass is sensitive to the change of seasons. This implies that the building performance will benefit from implementing HATS. Furthermore, the potential of HATS is quantified using a simplified HATS model. Calculations show heating energy demand reductions of up to 35% and increased thermal comfort compared to conventional thermal mass concepts.

EDV supported dynamic fire protection concept adaptation during dismantling of nuclear facilities

International Nuclear Information System (INIS)

Mummert, Maxi; Traichel, Anke; Dilger, Matthias

2013-01-01

Fire protection concepts are supposed to be a decision guide for the definition of measures and priorities in fire fighting and fire prevention. In case of reactor dismantling a fire protection concept for the actual status is required. Following the fuel removal from the reactor the protection goals are reduced to the safe confinement of radioactive materials and the restriction of radiation exposure. A dynamic fire protection concept was developed to allow the compliance with the required protection measures with respect to the protection targets. The implementation of the dynamic fire protection concept simplifies the planning of the dismantling steps and to adjust the fire protection measured in the frame of changes in the plant.

Thermal processing system concepts and considerations for RWMC buried waste

International Nuclear Information System (INIS)

Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

1992-02-01

This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided

Thermal processing system concepts and considerations for RWMC buried waste

Energy Technology Data Exchange (ETDEWEB)

Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

1992-02-01

This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided.

Basic Theoretical Principles Pertaining to Thermal Protection of Oil Transformer

Directory of Open Access Journals (Sweden)

O. G. Shirokov

2008-01-01

Full Text Available The paper contains formulation of basic theoretical principles pertaining to thermal protection of an oil transformer in accordance with classical theory of relay protection and theory of diagnostics with the purpose of unification of terminological and analytical information which is presently available in respect of this problem. Classification of abnormal thermal modes of an oil transformer and also algorithms and methods for operation of diagnostic thermal protection of a transformer have been proposed.

Ablative thermal protection systems

International Nuclear Information System (INIS)

Vaniman, J.; Fisher, R.; Wojciechowski, C.; Dean, W.

1983-01-01

The procedures used to establish the TPS (thermal protection system) design of the SRB (solid rocket booster) element of the Space Shuttle vehicle are discussed. A final evaluation of the adequacy of this design will be made from data obtained from the first five Shuttle flights. Temperature sensors installed at selected locations on the SRB structure covered by the TPS give information as a function of time throughout the flight. Anomalies are to be investigated and computer design thermal models adjusted if required. In addition, the actual TPS ablator material loss is to be measured after each flight and compared with analytically determined losses. The analytical methods of predicting ablator performance are surveyed. 5 references

Study of organic ablative thermal-protection coating for solid rocket motor

Science.gov (United States)

Hua, Zenggong

1992-06-01

A study is conducted to find a new interior thermal-protection material that possesses good thermal-protection performance and simple manufacturing possibilities. Quartz powder and Cr2O3 are investigated using epoxy resin as a binder and Al2O3 as the burning inhibitor. Results indicate that the developed thermal-protection coating is suitable as ablative insulation material for solid rocket motors.

Discussion of thermal extraction chamber concepts for Lunar ISRU

Science.gov (United States)

Pfeiffer, Matthias; Hager, Philipp; Parzinger, Stephan; Dirlich, Thomas; Spinnler, Markus; Sattelmayer, Thomas; Walter, Ulrich

The Exploration group of the Institute of Astronautics (LRT) of the Technische Universitüt a München focuses on long-term scenarios and sustainable human presence in space. One of the enabling technologies in this long-term perspective is in-situ resource utilization (ISRU). When dealing with the prospect of future manned missions to Moon and Mars the use of ISRU seems useful and intended. The activities presented in this paper focus on Lunar ISRU. This basically incorporates both the exploitation of Lunar oxygen from natural rock and the extraction of solar wind implanted particles (SWIP) from regolith dust. Presently the group at the LRT is examining possibilities for the extraction of SWIPs, which may provide several gaseous components (such as H2 and N2) valuable to a human presence on the Moon. As a major stepping stone in the near future a Lunar demonstrator/ verification experiment payload is being designed. This experiment, LUISE (LUnar ISru Experiment), will comprise a thermal process chamber for heating regolith dust (grain size below 500m), a solar thermal power supply, a sample distribution unit and a trace gas analysis. The first project stage includes the detailed design and analysis of the extraction chamber concepts and the thermal process involved in the removal of SWIP from Lunar Regolith dust. The technique of extracting Solar Wind volatiles from Regolith has been outlined by several sources. Heating the material to a threshold value seems to be the most reasonable approach. The present paper will give an overview over concepts for thermal extraction chambers to be used in the LUISE project and evaluate in detail the pros and cons of each concept. The special boundary conditions set by solar thermal heating of the chambers as well as the material properties of Regolith in a Lunar environment will be discussed. Both greatly influence the design of the extraction chamber. The performance of the chamber concepts is discussed with respect to the

Applying chemical engineering concepts to non-thermal plasma reactors

Science.gov (United States)

Pedro AFFONSO, NOBREGA; Alain, GAUNAND; Vandad, ROHANI; François, CAUNEAU; Laurent, FULCHERI

2018-06-01

Process scale-up remains a considerable challenge for environmental applications of non-thermal plasmas. Undersanding the impact of reactor hydrodynamics in the performance of the process is a key step to overcome this challenge. In this work, we apply chemical engineering concepts to analyse the impact that different non-thermal plasma reactor configurations and regimes, such as laminar or plug flow, may have on the reactor performance. We do this in the particular context of the removal of pollutants by non-thermal plasmas, for which a simplified model is available. We generalise this model to different reactor configurations and, under certain hypotheses, we show that a reactor in the laminar regime may have a behaviour significantly different from one in the plug flow regime, often assumed in the non-thermal plasma literature. On the other hand, we show that a packed-bed reactor behaves very similarly to one in the plug flow regime. Beyond those results, the reader will find in this work a quick introduction to chemical reaction engineering concepts.

Concepts in radiation protection

International Nuclear Information System (INIS)

Oncescu, M.

1996-01-01

This monograph provides basic notions and principles in dosimetry and radiation protection in compliance with two fundamental works: IAEA Safety Series No.115 - International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources - and Publication no. 60 of International Commission on Radiological Protection. After the review of quantities and units necessary in radiation protection, the book presents the new values of dose limits as well as the values of 'radiation weighting factor', 'tissue weighting factor' and 'conversion factor intake-dose' (committed effective dose per unit intake) by ingestion and inhalation for 30 most important radionuclides. The new values of dose limits, lower than the old values, are a challenge for the radiation protection, especially of the 'public' where the dose limit diminished by a factor of five relative to the earlier edition. The new value of dose limit for public, 1 mSv per year (obviously over the natural exposure of 2.4 mSv per year), imposes new action ways and levels in radiation protection, especially in some cases of exacerbated natural radioactivity. The book provides the calculus of external exposure with the Gamma constant expressed in adequate units, to make the calculation easier. In the calculus of protection shield for gamma sources one uses a method, which while approximate helps save time. The calculus of internal exposure is made using the conversion factor intake-dose. Finally, the 'dosimetric watch' of the natural and artificial radioactivity of the atmosphere, hydrosphere and biosphere is intended to comply with the International Basic Safety Standards. Each chapter ends with a set of illustrative problems which enhances the reader's understanding of underlying concepts and current methods used in the field

Environmental protection in thermal power plants

International Nuclear Information System (INIS)

1987-01-01

This workbook is a compilation of the most important facts and data that are relevant today for environmental protection in thermal power plants. Unlike the other issues the text is not in the form of a random collection of data but in the form of a complete presentation. Possible elaboration projects for pupils can be easily derived from the individual sections. These deal with: the discussion about environmental protection; forest decline; sources of emission; nuisances in the Federal Republic of Germany; environmental protection in fossil-fuel power plants - clean air - cooling water utilization and water protection - noise; environmental protection in nuclear power plants - radioactive material produced in nuclear reactors and the retention of such materials - radioactive waste materials - monitoring of radioactive emissions; accessory materials and hints. (orig./HSCH) [de

Development of a test device to characterize thermal protective performance of fabrics against hot steam and thermal radiation

International Nuclear Information System (INIS)

Su, Yun; Li, Jun

2016-01-01

Steam burns severely threaten the life of firefighters in the course of their fire-ground activities. The aim of this paper was to characterize thermal protective performance of flame-retardant fabrics exposed to hot steam and low-level thermal radiation. An improved testing apparatus based on ASTM F2731-11 was developed in order to simulate the routine fire-ground conditions by controlling steam pressure, flow rate and temperature of steam box. The thermal protective performance of single-layer and multi-layer fabric system with/without an air gap was studied based on the calibrated tester. It was indicated that the new testing apparatus effectively evaluated thermal properties of fabric in hot steam and thermal radiation. Hot steam significantly exacerbated the skin burn injuries while the condensed water on the skin’s surface contributed to cool down the skin tissues during the cooling. Also, the absorbed thermal energy during the exposure and the cooling was mainly determined by the fabric’s configuration, the air gap size, the exposure time and the existence of hot steam. The research provides a effective method to characterize the thermal protection of fabric in complex conditions, which will help in optimization of thermal protection performance of clothing and reduction of steam burn. (paper)

Active Wireless Temperature Sensors for Aerospace Thermal Protection Systems

Science.gov (United States)

Milos, Frank S.; Karunaratne, K.; Arnold, Jim (Technical Monitor)

2002-01-01

Health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles in order to reduce life-cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to advance inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and Korteks to develop active wireless sensors that can be embedded in the thermal protection system to monitor sub-surface temperature histories. These devices are thermocouples integrated with radio-frequency identification circuitry to enable acquisition and non-contact communication of temperature data through aerospace thermal protection materials. Two generations of prototype sensors are discussed. The advanced prototype collects data from three type-k thermocouples attached to a 2.54-cm square integrated circuit.

Thermal design, analysis and comparison on three concepts of space solar power satellite

Science.gov (United States)

Yang, Chen; Hou, Xinbin; Wang, Li

2017-08-01

Space solar power satellites (SSPS) have been widely studied as systems for collecting solar energy in space and transmitting it wirelessly to earth. A previously designed planar SSPS concept collects solar power in two huge arrays and then transmits it through one side of the power-conduction joint to the antenna. However, the system's one group of power-conduction joints may induce a single point of failure. As an SSPS concept, the module symmetrical concentrator (MSC) architecture has many advantages. This architecture can help avoid the need for a large, potentially failure-prone conductive rotating joint and limit wiring mass. However, the thermal control system has severely restricted the rapid development of MSC, especially in the sandwich module. Because of the synchronous existence of five suns concentration and solar external heat flux, the sandwich module will have a very high temperature, which will surpass the permissible temperature of the solar cells. Recently, an alternate multi-rotary joints (MR) SSPS concept was designed by the China Academy of Space Technology (CAST). This system has multiple joints to avoid the problem of a single point of failure. Meanwhile, this concept has another advantage for reducing the high power and heat removal in joints. It is well known to us that, because of the huge external flux in SSPS, the thermal management sub-system is an important component that cannot be neglected. Based on the three SSPS concepts, this study investigated the thermal design and analysis of a 1-km, gigawatt-level transmitting antenna in SSPS. This study compares the thermal management sub-systems of power-conduction joints in planar and MR SSPS. Moreover, the study considers three classic thermal control architectures of the MSC's sandwich module: tile, step, and separation. The study also presents an elaborate parameter design, analysis and discussion of step architecture. Finally, the results show the thermal characteristics of each SSPS

Preparation and thermal performance of paraffin/Nano-SiO2 nanocomposite for passive thermal protection of electronic devices

International Nuclear Information System (INIS)

Wang, Yaqin; Gao, Xuenong; Chen, Peng; Huang, Zhaowen; Xu, Tao; Fang, Yutang; Zhang, Zhengguo

2016-01-01

Highlights: • Three types of paraffin/nano-SiO 2 nanocomposites were prepared and characterized. • Thermo-physical properties of these composites were determined and compared. • One composite with lower thermal conductivity showed better thermal insulation properties. • This composite was identified as thermal insulation material for electronic components. - Abstract: In this paper, three grades of nano silicon dioxide (nano-SiO 2 ), NS1, NS2 and NS3, were mixed into paraffin to prepare nanocomposites as novel insulation materials for electronic passive thermal protection applications. The optimal mass percentages of paraffin for the three composites, NS1P, NS2P and NS3P, were determined to be 75%, 70% and 65%, respectively. Investigations by means of scanning electron micrographs (SEM), differential scanning calorimeter (DSC), thermogravimetric analysis (TG), hot disk analyzer and thermal protection performance tests were devoted to the morphology, thermal properties and thermal protection performance analysis of composites. Experimental results showed that paraffin uniformly distributed into the pores and on the surface of nano-SiO 2 . Melting points of composites declined and experimental latent heat became lower than the calculated values with the decrease of nano-SiO 2 pore size. The NS1P composite had larger thermal storage capacity, better reliability and stability compared with NS2P and NS3P. In addition, compared with 90% wt.% paraffin/EG composite, the incorporation of NS1 (25 wt.%) into paraffin caused not only 63.2% reduction in thermal conductivity, but also 21.8% increase in thermal protection time affected by the ambient temperature. Thus those good properties confirmed that NS1P (75 wt.%) composite was a viable candidate for protecting electronic devices under high temperature environment.

Investigating the potential of a novel low-energy house concept with hybrid adaptable thermal storage

NARCIS (Netherlands)

Hoes, P.; Trcka, M.; Hensen, J.L.M.; Hoekstra Bonnema, B.

2011-01-01

In conventional buildings thermal mass is a permanent building characteristic depending on the building design. However, none of the permanent thermal mass concepts are optimal in all operational conditions. We propose a concept that combines the benefits of buildings with low and high thermal mass

Investigating the potential of a novel low-energy house concept with hybrid adaptable thermal storage

NARCIS (Netherlands)

Hoes, P.; Trcka, M.; Hensen, J.L.M.; Hoekstra Bonnema, B.

2010-01-01

In conventional buildings thermal mass is a permanent building characteristic depending on the building design. However, none of the permanent thermal mass concepts are optimal in all operational conditions. We propose a concept that combines the benefits of buildings with low and high thermal mass

Kinetic Integrated Thermal Protection System (KnITPS)

Data.gov (United States)

National Aeronautics and Space Administration — Use the flexibility and shape formation possibilities inherent in knitting to form thermal protection systems that can be custom fitted to a heat shield carrier...

Fire protection concept for power stations

International Nuclear Information System (INIS)

Zitzmann, H.

The author shows how a systematic approach permits the design of a fire-protected power station. The special conditions of an individual power station are here treated as marginal conditions. The article describes how the concept is realized in the completed power station, taking account of the information provided by fire statistics. (orig.) [de

Public understanding of radiation protection concepts

International Nuclear Information System (INIS)

1988-01-01

The Chernobyl accident in April 1986 clearly showed that communication with the public was one of the areas where there was a strong need for improvement, particularly concerning the nature and extent of the information provided by national authorities. The countermeasures adopted by public health authorities also raised difficulties in terms of public understanding and acceptance due, in part, to the perception of discrepancies in national, regional or local response to the accident, but also to a more basic lack of comprehension of the complex radiation protection considerations involved. In an attempt to help improve the situation, the NEA Committee on Radiation Protection and Public Health decided to organise a Workshop on public communication in the event of a nuclear accident, centered on radiation protection issues. The purpose of this Workshop was to analyse appropriate methods and language to be used when explaining to the public the scientific concepts underlying radiation risks and radiation protection, and the technical rationale for the choice of protective actions in an emergency. Separate abstracts were prepared for individual papers presented at the meeting

GCD TechPort Data Sheets Thermal Protection System Materials (TPSM) Project

Science.gov (United States)

Chinnapongse, Ronald L.

2014-01-01

The Thermal Protection System Materials (TPSM) Project consists of three distinct project elements: the 3-Dimensional Multifunctional Ablative Thermal Protection System (3D MAT) project element; the Conformal Ablative Thermal Protection System (CA-TPS) project element; and the Heatshield for Extreme Entry Environment Technology (HEEET) project element. 3D MAT seeks to design, develop and deliver a game changing material solution based on 3-dimensional weaving and resin infusion approach for manufacturing a material that can function as a robust structure as well as a thermal protection system. CA-TPS seeks to develop and deliver a conformal ablative material designed to be efficient and capable of withstanding peak heat flux up to 500 W/ sq cm, peak pressure up to 0.4 atm, and shear up to 500 Pa. HEEET is developing a new ablative TPS that takes advantage of state-of-the-art 3D weaving technologies and traditional manufacturing processes to infuse woven preforms with a resin, machine them to shape, and assemble them as a tiled solution on the entry vehicle substructure or heatshield.

Application of waterproof breathable fabric in thermal protective clothing exposed to hot water and steam

Science.gov (United States)

Su, Y.; Li, R.; Song, G.; Li, J.

2017-10-01

A hot water and steam tester was used to examine thermal protective performance of waterproof and breathable fabric against hot water and steam hazards. Time to cause skin burn and thermal energy absorbed by skin during exposure and cooling phases was employed to characterize the effect of configuration, placing order and properties of waterproof and breathable fabric on the thermal protective performance. The difference of thermal protective performance due to hot water and steam hazards was discussed. The result showed that the configuration of waterproof and breathable fabric presented a significant effect on the thermal protective performance of single- and double-layer fabric system, while the difference between different configurations in steam hazard was greater than that in hot water hazard. The waterproof and breathable fabric as outer layer provided better protection than that as inner layer. Increasing thickness and moisture regain improved the thermal protective performance of fabric system. Additionally, the thermal energy absorbed by skin during the cooling phase was affected by configuration, thickness and moisture regain of fabric. The findings will provide technical data to improve performance of thermal protective clothing in hot water and steam hazards.

NDE for Ablative Thermal Protection Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This program addresses the need for non-destructive evaluation (NDE) methods for quality assessment and defect evaluation of thermal protection systems (TPS),...

NDE for Ablative Thermal Protection Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This program addresses the need for non-destructive evaluation (NDE) methods for quality assessment and defect evaluation of thermal protection systems (TPS). Novel...

Investigation for thermal stability of U3Si2 and protection methods

International Nuclear Information System (INIS)

Zhang Huiying; Sun Jichang; Sun Rongxian

1994-08-01

The thermal stability of U 3 Si 2 in Ar, N 2 and air, and the interaction between U 3 Si 2 and Al, Zr have been investigated by thermal analysis method. According to the results of thermal analysis, protection measures for various procedures have been improved. From the practice, it shows that the protection measures can ensure the safety of production and raise the product quality as well as reduce the cost effectively

Generic repository design concepts and thermal analysis (FY11)

International Nuclear Information System (INIS)

Howard, Robert; Dupont, Mark; Blink, James A.; Fratoni, Massimiliano; Greenberg, Harris; Carter, Joe; Hardin, Ernest L.; Sutton, Mark A.

2011-01-01

Reference concepts for geologic disposal of used nuclear fuel and high-level radioactive waste in the U.S. are developed, including geologic settings and engineered barriers. Repository thermal analysis is demonstrated for a range of waste types from projected future, advanced nuclear fuel cycles. The results show significant differences among geologic media considered (clay/shale, crystalline rock, salt), and also that waste package size and waste loading must be limited to meet targeted maximum temperature values. In this study, the UFD R and D Campaign has developed a set of reference geologic disposal concepts for a range of waste types that could potentially be generated in advanced nuclear FCs. A disposal concept consists of three components: waste inventory, geologic setting, and concept of operations. Mature repository concepts have been developed in other countries for disposal of spent LWR fuel and HLW from reprocessing UNF, and these serve as starting points for developing this set. Additional design details and EBS concepts will be considered as the reference disposal concepts evolve. The waste inventory considered in this study includes: (1) direct disposal of SNF from the LWR fleet, including Gen III+ advanced LWRs being developed through the Nuclear Power 2010 Program, operating in a once-through cycle; (2) waste generated from reprocessing of LWR UOX UNF to recover U and Pu, and subsequent direct disposal of used Pu-MOX fuel (also used in LWRs) in a modified-open cycle; and (3) waste generated by continuous recycling of metal fuel from fast reactors operating in a TRU burner configuration, with additional TRU material input supplied from reprocessing of LWR UOX fuel. The geologic setting provides the natural barriers, and establishes the boundary conditions for performance of engineered barriers. The composition and physical properties of the host medium dictate design and construction approaches, and determine hydrologic and thermal responses of

Generic repository design concepts and thermal analysis (FY11).

Energy Technology Data Exchange (ETDEWEB)

Howard, Robert (Oak Ridge National Laboratory, Oak Ridge, TN); Dupont, Mark (Savannah River Nuclear Solutions, Aiken, SC); Blink, James A. (Lawrence Livermore National Laboratory, Livermore, CA); Fratoni, Massimiliano (Lawrence Livermore National Laboratory, Livermore, CA); Greenberg, Harris (Lawrence Livermore National Laboratory, Livermore, CA); Carter, Joe (Savannah River Nuclear Solutions, Aiken, SC); Hardin, Ernest L.; Sutton, Mark A. (Lawrence Livermore National Laboratory, Livermore, CA)

2011-08-01

Reference concepts for geologic disposal of used nuclear fuel and high-level radioactive waste in the U.S. are developed, including geologic settings and engineered barriers. Repository thermal analysis is demonstrated for a range of waste types from projected future, advanced nuclear fuel cycles. The results show significant differences among geologic media considered (clay/shale, crystalline rock, salt), and also that waste package size and waste loading must be limited to meet targeted maximum temperature values. In this study, the UFD R&D Campaign has developed a set of reference geologic disposal concepts for a range of waste types that could potentially be generated in advanced nuclear FCs. A disposal concept consists of three components: waste inventory, geologic setting, and concept of operations. Mature repository concepts have been developed in other countries for disposal of spent LWR fuel and HLW from reprocessing UNF, and these serve as starting points for developing this set. Additional design details and EBS concepts will be considered as the reference disposal concepts evolve. The waste inventory considered in this study includes: (1) direct disposal of SNF from the LWR fleet, including Gen III+ advanced LWRs being developed through the Nuclear Power 2010 Program, operating in a once-through cycle; (2) waste generated from reprocessing of LWR UOX UNF to recover U and Pu, and subsequent direct disposal of used Pu-MOX fuel (also used in LWRs) in a modified-open cycle; and (3) waste generated by continuous recycling of metal fuel from fast reactors operating in a TRU burner configuration, with additional TRU material input supplied from reprocessing of LWR UOX fuel. The geologic setting provides the natural barriers, and establishes the boundary conditions for performance of engineered barriers. The composition and physical properties of the host medium dictate design and construction approaches, and determine hydrologic and thermal responses of the

The Wick-Concept for Thermal Insulation of Cold Piping

DEFF Research Database (Denmark)

Koverdynsky, Vit; Korsgaard, Vagn; Rode, Carsten

2006-01-01

the wick-concept in either of two variations: the self-drying or the self-sealing system. Experiments have been carried out using different variations of the two systems to investigate the conditions for exploiting the drying capabilities of the systems, and the results are presented. The results show......The wick-concept for thermal insulation of cold piping is based on capillary suction of a fiber fabric to remove excess water from the pipe surface by transporting it to the outer surface of the insulation. From the surface of the insulation jacket, the water will evaporate to the ambient air....... This will prevent long-term accumulation of moisture in the insulation material. The wick keeps the hydrophobic insulation dry, allowing it to maintain its thermal performance. The liquid moisture is kept only in the wick fabric. This article presents the principle of operation of cold pipe insulation using...

Concept for the Emergency Protection in the Vicinity of Nuclear Power Plants

International Nuclear Information System (INIS)

1998-03-01

In 1991, the Swiss Federal Nuclear Safety Inspectorate (HSK) issued a concept of the regulations for the cloud phase 1 of an nuclear power plant accident in Switzerland valid at that time in co-operation with the Federal Commission for AC Protection (KOMAC) and the Swiss Federal Nuclear Safety Commission (KSA). This concept replaced the version of 1977, which then formed the basis for emergency preparedness in Switzerland. Legal changes, such as the civil protection legislation and the ordinance on the distribution of iodine tablets to the population, as well as experience gained from the emergency exercises necessitated a revision of the existing concept. The present concept is issued by the Federal Commission for AC Protection (KOMAC) and deals with all phases of an accident sequence in a Swiss nuclear power plant focussing on the pre- and cloud phase. It also gives an overview of responsibilities and alert procedures for accidents at foreign nuclear power plants and other nuclear installations, as well as of accidents in connection with transportation of radioactive materials. The concept is designed to help the federal and cantonal authorities in the vicinity of nuclear power plants in charge of emergency protection in preparing their emergency procedure specifications, and in the realisation of the readiness for emergencies. Furthermore, it shall serve the cantons as a guideline for the preparation of emergency specifications for the communities. The concept is based on the assumption that the executive bodies and emergency forces provided for the general civil protection are employed in case of an accident at a nuclear power plant. (authors)

Application of the lines of protection concept to the HTGR-SC/C

International Nuclear Information System (INIS)

1981-09-01

This study of the application of the line of protection (LOP) concept to high temperature gas-cooled reactors (HTGRs) was motivated by a desire to develop a simple and straightforward HTGR safety concept that embodies many of the more complicated and seemingly conflicting concepts facing nuclear industry safety today. These concepts include: (1) defense in depth; (2) design basis events; (3) core damage events (degraded cores); (4) probabilistic analysis and risk assessment; (5) numerical safety goals; and (6) plant investment protection. The LOP concept described herein attempts to incorporate many of the important principles of each into a cohesive framework which provides an overall logic, meaning, and direction for conducting HTGR design and research activities

Thermal assault and polyurethane foam-evaluating protective mechanisms

International Nuclear Information System (INIS)

Williamson, C.L.; Iams, Z.L.

2004-01-01

Rigid polyurethane foam utilizes a variety of mechanisms to mitigate the thermal assault of a ''regulatory burn''. Polymer specific heat and foam k-factor are of limited usefulness in predicting payload protection. Properly formulated rigid polyurethane foam provides additional safeguards by employing ablative mechanisms which are effective even when the foam has been crushed or fractured as a result of trauma. The dissociative transitions from polymer to gas and char, and the gas transport of heat from inside the package out into the environment are also thermal mitigators. Additionally, the in-situ production of an intumescent, insulative, carbonaceous char, confers thermal protection even when a package's outer steel skin has been breached. In this test program, 19 liter, ''Five gallon'' steel pails are exposed on one end to the flame of an ''Oil Burner'' as described in the US Federal Aviation Administration (FAA) ''Aircraft Materials Fire Test Handbook''. When burning 2 diesel at a nominal rate of 8.39 kg (18.5 pounds)/hr, the burner generates a high emissivity flame that impinges on the pail face with the thermal intensity of a full scale pool-fire environment. Results of these tests, TGA and MDSC analysis on the subject foams are reported, and their relevance to full size packages and pool fires are discussed

Alternative High Performance Polymers for Ablative Thermal Protection Systems

Science.gov (United States)

Boghozian, Tane; Stackpoole, Mairead; Gonzales, Greg

2015-01-01

Ablative thermal protection systems are commonly used as protection from the intense heat during re-entry of a space vehicle and have been used successfully on many missions including Stardust and Mars Science Laboratory both of which used PICA - a phenolic based ablator. Historically, phenolic resin has served as the ablative polymer for many TPS systems. However, it has limitations in both processing and properties such as char yield, glass transition temperature and char stability. Therefore alternative high performance polymers are being considered including cyanate ester resin, polyimide, and polybenzoxazine. Thermal and mechanical properties of these resin systems were characterized and compared with phenolic resin.

Thermal Protection System Materials (TPSM): 3D MAT

Data.gov (United States)

National Aeronautics and Space Administration — The 3D MAT Project seeks to design and develop a game changing Woven Thermal Protection System (TPS) technology tailored to meet the needs of the Orion Multi-Purpose...

Advanced materials for thermal protection system

Science.gov (United States)

Heng, Sangvavann; Sherman, Andrew J.

1996-03-01

Reticulated open-cell ceramic foams (both vitreous carbon and silicon carbide) and ceramic composites (SiC-based, both monolithic and fiber-reinforced) were evaluated as candidate materials for use in a heat shield sandwich panel design as an advanced thermal protection system (TPS) for unmanned single-use hypersonic reentry vehicles. These materials were fabricated by chemical vapor deposition/infiltration (CVD/CVI) and evaluated extensively for their mechanical, thermal, and erosion/ablation performance. In the TPS, the ceramic foams were used as a structural core providing thermal insulation and mechanical load distribution, while the ceramic composites were used as facesheets providing resistance to aerodynamic, shear, and erosive forces. Tensile, compressive, and shear strength, elastic and shear modulus, fracture toughness, Poisson's ratio, and thermal conductivity were measured for the ceramic foams, while arcjet testing was conducted on the ceramic composites at heat flux levels up to 5.90 MW/m2 (520 Btu/ft2ṡsec). Two prototype test articles were fabricated and subjected to arcjet testing at heat flux levels of 1.70-3.40 MW/m2 (150-300 Btu/ft2ṡsec) under simulated reentry trajectories.

Low Pressure Nuclear Thermal Rocket (LPNTR) concept

International Nuclear Information System (INIS)

Ramsthaler, J.H.

1991-01-01

A background and a description of the low pressure nuclear thermal system are presented. Performance, mission analysis, development, critical issues, and some conclusions are discussed. The following subject areas are covered: LPNTR's inherent advantages in critical NTR requirement; reactor trade studies; reference LPNTR; internal configuration and flow of preliminary LPNTR; particle bed fuel assembly; preliminary LPNTR neutronic study results; multiple LPNTR engine concept; tank and engine configuration for mission analysis; LPNTR reliability potential; LPNTR development program; and LPNTR program costs

Adaptation of the present concept of dosimetric radiation protection quantities for external radiation to radiation protection practice

International Nuclear Information System (INIS)

Boehm, J.; Thompson, I. M. G.

2004-01-01

The present concept of dosimetric radiation protection quantities for external radiation is reviewed. For everyday application of the concept some adaptations are recommended. The check of the compliance with dose limits should be performed either by the comparison with values of the respective operational quantities directly or by the calculation of the protection quantity by means of the operational quantity, the appertaining conversion coefficient and additional information of the radiation field. Only four operational quantities are regarded to be sufficient for most applications in radiation protection practice. The term equivalent should be used in the connection dose equivalent only. Proposals are made for names of frequently used operational quantities which are denoted up to now by symbols only. (authors)

A Hybrid Power Control Concept for PV Inverters with Reduced Thermal Loading

DEFF Research Database (Denmark)

Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

2014-01-01

on a single-phase PV inverter under yearly operation is presented with analyses of the thermal loading, lifetime, and annual energy yield. It has revealed the trade-off factors to select the power limit and also verified the feasibility and the effectiveness of the proposed control concept.......This letter proposes a hybrid power control concept for grid-connected Photovoltaic (PV) inverters. The control strategy is based on either a Maximum Power Point Tracking (MPPT) control or a Constant Power Generation (CPG) control depending on the instantaneous available power from the PV panels....... The essence of the proposed concept lies in the selection of an appropriate power limit for the CPG control to achieve an improved thermal performance and an increased utilization factor of PV inverters,and thus to cater for a higher penetration level of PV systems with intermittent nature. A case study...

Thermal stress analysis of space shuttle orbiter wing skin panel and thermal protection system

Science.gov (United States)

Ko, William L.; Jenkins, Jerald M.

1987-01-01

Preflight thermal stress analysis of the space shuttle orbiter wing skin panel and the thermal protection system (TPS) was performed. The heated skin panel analyzed was rectangular in shape and contained a small square cool region at its center. The wing skin immediately outside the cool region was found to be close to the state of elastic instability in the chordwise direction based on the conservative temperature distribution. The wing skin was found to be quite stable in the spanwise direction. The potential wing skin thermal instability was not severe enough to tear apart the strain isolation pad (SIP) layer. Also, the preflight thermal stress analysis was performed on the TPS tile under the most severe temperature gradient during the simulated reentry heating. The tensile thermal stress induced in the TPS tile was found to be much lower than the tensile strength of the TPS material. The thermal bending of the TPS tile was not severe enough to cause tearing of the SIP layer.

The French fire protection concept. Vulnerability analysis

International Nuclear Information System (INIS)

Kaercher, M.

1998-01-01

The French fire protection concept is based on a principle of three levels of defence in depth: fire prevention, fire containing and fire controlling. Fire prevention is based on arrangements which prevent the fire from starting or which make difficult for the fire to start. Fire containing is based on design measures so that the fire will have no impact on the safety of the installation. For fire controlling, equipment nad personnel are on duty in order to detect, to fight and to gain control over the fire as early as possible. The French fire protection concept gives priority to fire containing based on passive structural measures. All buildings containing safety equipment are divided into fire compartments (or fire areas) and fire cells (or fire zones). Basically, a compartment houses safety equipment belonging to one division (or train) so that the other division is always available to reach the plant safe shut down or to mitigate an accident. Because there is a large number of fire compartments and fire cells, deviations from the general principle can be observed. To this reason the RCC-I (Design and Construction Rules applicable for fire protection) requires to implement an assessment of the principle of division. This assessment is called vulnerability analysis. The vulnerability analysis is usually performed at the end of the project, before erection. It is also possible to perform a vulnerability analysis in an operating nuclear power plant in the scope of a fire safety upgrading programme. In the vulnerability analysis, the functional failure of all the equipment (except for those protected by a qualified fire barrier, designed or able to withstand the fire consequences) within the fire compartment or cell, where the fire breaks out, is postulated. The potential consequences for the plant safety are analysed

THE INFLUENCE OF THERMAL EVOLUTION IN THE MAGNETIC PROTECTION OF TERRESTRIAL PLANETS

Energy Technology Data Exchange (ETDEWEB)

Zuluaga, Jorge I.; Bustamante, Sebastian; Cuartas, Pablo A. [Instituto de Fisica-FCEN, Universidad de Antioquia, Calle 67 No. 53-108, Medellin (Colombia); Hoyos, Jaime H., E-mail: jzuluaga@fisica.udea.edu.co, E-mail: sbustama@pegasus.udea.edu.co, E-mail: p.cuartas@fisica.udea.edu.co, E-mail: jhhoyos@udem.edu.co [Departamento de Ciencias Basicas, Universidad de Medellin, Carrera 87 No. 30-65, Medellin (Colombia)

2013-06-10

Magnetic protection of potentially habitable planets plays a central role in determining their actual habitability and/or the chances of detecting atmospheric biosignatures. Here we develop a thermal evolution model of potentially habitable Earth-like planets and super-Earths (SEs). Using up-to-date dynamo-scaling laws, we predict the properties of core dynamo magnetic fields and study the influence of thermal evolution on their properties. The level of magnetic protection of tidally locked and unlocked planets is estimated by combining simplified models of the planetary magnetosphere and a phenomenological description of the stellar wind. Thermal evolution introduces a strong dependence of magnetic protection on planetary mass and rotation rate. Tidally locked terrestrial planets with an Earth-like composition would have early dayside magnetopause distances between 1.5 and 4.0 R{sub p} , larger than previously estimated. Unlocked planets with periods of rotation {approx}1 day are protected by magnetospheres extending between 3 and 8 R{sub p} . Our results are robust in comparison with variations in planetary bulk composition and uncertainties in other critical model parameters. For illustration purposes, the thermal evolution and magnetic protection of the potentially habitable SEs GL 581d, GJ 667Cc, and HD 40307g were also studied. Assuming an Earth-like composition, we found that the dynamos of these planets are already extinct or close to being shut down. While GL 581d is the best protected, the protection of HD 40307g cannot be reliably estimated. GJ 667Cc, even under optimistic conditions, seems to be severely exposed to the stellar wind, and, under the conditions of our model, has probably suffered massive atmospheric losses.

Damage Detection/Locating System Providing Thermal Protection

Science.gov (United States)

Woodard, Stanley E. (Inventor); Jones, Thomas W. (Inventor); Taylor, Bryant D. (Inventor); Qamar, A. Shams (Inventor)

2010-01-01

A damage locating system also provides thermal protection. An array of sensors substantially tiles an area of interest. Each sensor is a reflective-surface conductor having operatively coupled inductance and capacitance. A magnetic field response recorder is provided to interrogate each sensor before and after a damage condition. Changes in response are indicative of damage and a corresponding location thereof.

Thermal-Acoustic Fatigue of a Multilayer Thermal Protection System in Combined Extreme Environments

Directory of Open Access Journals (Sweden)

Liu Liu

2014-06-01

Full Text Available In order to ensure integrity of thermal protection system (TPS structure for hypersonic vehicles exposed to severe operating environments, a study is undertaken to investigate the response and thermal-acoustic fatigue damage of a representative multilayer TPS structure under combined thermal and acoustic loads. An unsteady-state flight of a hypersonic vehicle is composed of a series of steady-state snapshots, and for each snapshot an acoustic load is imposed to a static steady-state TPS structure. A multistep thermal-acoustic fatigue damage intensity analysis procedure is given and consists of a heat transfer analysis, a nonlinear thermoelastic analysis, and a random response analysis under a combined loading environment and the fatigue damage intensity has been evaluated with two fatigue analysis techniques. The effects of thermally induced deterministic stress and nondeterministic dynamic stress due to the acoustic loading have been considered in the damage intensity estimation with a maximum stress fatigue model. The results show that the given thermal-acoustic fatigue intensity estimation procedure is a viable approach for life prediction of TPS structures under a typical mission cycle with combined loadings characterized by largely different time-scales. A discussion of the effects of the thermal load, the acoustic load, and fatigue analysis methodology on the fatigue damage intensity has been provided.

PLZT thermal/flash protective goggles: device concepts and constraints

International Nuclear Information System (INIS)

Cutchen, J.T.

1979-01-01

In 1975 Sandia Laboratories began the design and development of PLZT Goggles for the US Air Force to provide protection from temporary flashblindness and permanent retinal burns caused by the brilliant flash of nuclear explosions. The user requirements, system and physical constraints, and use/storage environments were all considered in arriving at the final design goals. When the program began, there was no industrial capability to manufacture large-aperture PLZT materials or bonded lens assemblies. The technology has been established from a laboratory baseline in a brief period, and operational testing and evaluation by the Air Force has been completed. The goggles, identified as the EEU-2/P,, are now in production

Concepts on integration of physical protection and material accounting functions in a safeguards system

International Nuclear Information System (INIS)

Reynolds, D.A.

1981-01-01

Concepts on integration of physical protection and material accounting systems to enhance overall safeguards capability are developed and presented. These concepts identify ways in which material accounting systems can be used to enable effective monitoring of authorized movement of nuclear material through physical protection boundaries. Concepts are also discussed for monitoring user access to nuclear material and for tagging user identification to material accounting transactions through physical protection functions. These result in benefits in detecting diversion and in positively tracing material movement. Finally, coordination of safeguards information from both subsystems in such an integrated system through a safeguards coordination center is addressed with emphasis on appropriate response in case of discrepancies

Power cables thermal protection by interval simulation of imprecise dynamical systems

Energy Technology Data Exchange (ETDEWEB)

Bontempi, G. [Universite Libre de Brussels (Belgium). Dept. d' Informatique; Vaccaro, A.; Villacci, D. [Universita del Sannio Benevento (Italy). Dept. of Engineering

2004-11-01

The embedding of advanced simulation techniques in power cables enables improved thermal protection because of higher accuracy, adaptiveness and. flexibility. In particular, they make possible (i) the accurate solution of differential equations describing the cables thermal dynamics and (ii) the adoption of the resulting solution in the accomplishment of dedicated protective functions. However, the use of model-based protective systems is exposed to the uncertainty affecting some model components (e.g. weather along the line route, thermophysical properties of the soil, cable parameters). When uncertainty can be described in terms of probability distribution, well-known techniques, such as Monte Carlo, are used to simulate the system behaviour. On the other hand, when the description of uncertainty in probabilistic terms is unfeasible or problematic, nonprobabilistic alternatives should be taken into consideration. This paper will discuss and compare three interval-based techniques as alternatives to probabilistic methods in the simulation of power cable dynamics. The experimental session will assess the interval-based approaches by simulating the thermal behaviour of medium voltage power cables.(author)

Thermal protection system gap analysis using a loosely coupled fluid-structural thermal numerical method

Science.gov (United States)

Huang, Jie; Li, Piao; Yao, Weixing

2018-05-01

A loosely coupled fluid-structural thermal numerical method is introduced for the thermal protection system (TPS) gap thermal control analysis in this paper. The aerodynamic heating and structural thermal are analyzed by computational fluid dynamics (CFD) and numerical heat transfer (NHT) methods respectively. An interpolation algorithm based on the control surface is adopted for the data exchanges on the coupled surface. In order to verify the analysis precision of the loosely coupled method, a circular tube example was analyzed, and the wall temperature agrees well with the test result. TPS gap thermal control performance was studied by the loosely coupled method successfully. The gap heat flux is mainly distributed in the small region at the top of the gap which is the high temperature region. Besides, TPS gap temperature and the power of the active cooling system (CCS) calculated by the traditional uncoupled method are higher than that calculated by the coupled method obviously. The reason is that the uncoupled method doesn't consider the coupled effect between the aerodynamic heating and structural thermal, however the coupled method considers it, so TPS gap thermal control performance can be analyzed more accurately by the coupled method.

Thermal Protection with 5% Dextrose Solution Blanket During Radiofrequency Ablation

International Nuclear Information System (INIS)

Chen, Enn Alexandria; Neeman, Ziv; Lee, Fred T.; Kam, Anthony; Wood, Brad

2006-01-01

A serious complication for any thermal radiofrequency ablation is thermal injury to adjacent structures, particularly the bowel, which can result in additional major surgery or death. Several methods using air, gas, fluid, or thermometry to protect adjacent structures from thermal injury have been reported. In the cases presented in this report, 5% dextrose water (D5W) was instilled to prevent injury to the bowel and diaphragm during radiofrequency ablation. Creating an Insulating envelope or moving organs with D5W might reduce risk for complications such as bowel perforation

Utilization of Self-Healing Materials in Thermal Protection System Applications

Data.gov (United States)

National Aeronautics and Space Administration — The proposed project is the Utilization of Self-Healing Materials for Thermal Protection System (TPS) Applications. Currently, the technology for repairing TPS from...

Concept of radiological, medical and social protection of the population of Russia affected by accidental exposure

International Nuclear Information System (INIS)

Osechinski, I.V.; Ivanov, E.V.; Ramzaev, P.V.; Balonov, M.I.; Tsyb, A.F.

1997-01-01

Main principles of population radiation protection from various accidental exposure, including the Chernobyl accident, have been implemented in officially approved Concept ''On radiological, medical, social protection and rehabilitation of the Russian Federation population affected by accidental radiation exposure''. The concept includes basic principles of radiation protection, designation of regional radionuclide contaminated territories, records and registers of exposed persons, health protection and rehabilitation, socio-economic and legal aspects

The nuclear thermal electric rocket: a proposed innovative propulsion concept for manned interplanetary missions

Science.gov (United States)

Dujarric, C.; Santovincenzo, A.; Summerer, L.

2013-03-01

Conventional propulsion technology (chemical and electric) currently limits the possibilities for human space exploration to the neighborhood of the Earth. If farther destinations (such as Mars) are to be reached with humans on board, a more capable interplanetary transfer engine featuring high thrust, high specific impulse is required. The source of energy which could in principle best meet these engine requirements is nuclear thermal. However, the nuclear thermal rocket technology is not yet ready for flight application. The development of new materials which is necessary for the nuclear core will require further testing on ground of full-scale nuclear rocket engines. Such testing is a powerful inhibitor to the nuclear rocket development, as the risks of nuclear contamination of the environment cannot be entirely avoided with current concepts. Alongside already further matured activities in the field of space nuclear power sources for generating on-board power, a low level investigation on nuclear propulsion has been running since long within ESA, and innovative concepts have already been proposed at an IAF conference in 1999 [1, 2]. Following a slow maturation process, a new concept was defined which was submitted to a concurrent design exercise in ESTEC in 2007. Great care was taken in the selection of the design parameters to ensure that this quite innovative concept would in all respects likely be feasible with margins. However, a thorough feasibility demonstration will require a more detailed design including the selection of appropriate materials and the verification that these can withstand the expected mechanical, thermal, and chemical environment. So far, the predefinition work made clear that, based on conservative technology assumptions, a specific impulse of 920 s could be obtained with a thrust of 110 kN. Despite the heavy engine dry mass, a preliminary mission analysis using conservative assumptions showed that the concept was reducing the required

Enabling Technology for Thermal Protection on HIAD and Other Hypersonic Missions, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — S. D. Miller and Associates proposes to investigate a new class of thermal insulations that will enable thermal protection systems (TPS) on ceramic matrix composite...

Smart thermal networks for smart cities - Introduction of concepts and measures

Science.gov (United States)

Schmidt, R. R.; Pol, O.; Basciotti, D.; Page, J.

2012-10-01

In order to contribute to high living standards, climate mitigation and energy supply security, future urban energy systems require a holistic approach. In particular an intelligent integration of thermal networks is necessary. This paper will briefly present the "smart city" concept and introduce an associated definition for smart thermal networks defined on three levels: 1. the interaction with urban planning processes and the interface to the overall urban energy system, 2. the adaptation of the temperature level and 3. supply and demand-side management strategies.

Outer skin protection of columbium Thermal Protection System (TPS) panels

Science.gov (United States)

Culp, J. D.

1973-01-01

A coated columbium alloy material system 0.04 centimeter thick was developed which provides for increased reliability to the load bearing character of the system in the event of physical damage to and loss of the exterior protective coating. The increased reliability to the load bearing columbium alloy (FS-85) was achieved by interposing an oxidation resistant columbium alloy (B-1) between the FS-85 alloy and a fused slurry silicide coating. The B-1 alloy was applied as a cladding to the FS-85 and the composite was fused slurry silicide coated. Results of material evaluation testing included cyclic oxidation testing of specimens with intentional coating defects, tensile testing of several material combinations exposed to reentry profile conditions, and emittance testing after cycling of up to 100 simulated reentries. The clad material, which was shown to provide greater reliability than unclad materials, holds significant promise for use in the thermal protection system of hypersonic reentry vehicles.

An Approximate Ablative Thermal Protection System Sizing Tool for Entry System Design

Science.gov (United States)

Dec, John A.; Braun, Robert D.

2006-01-01

A computer tool to perform entry vehicle ablative thermal protection systems sizing has been developed. Two options for calculating the thermal response are incorporated into the tool. One, an industry-standard, high-fidelity ablation and thermal response program was integrated into the tool, making use of simulated trajectory data to calculate its boundary conditions at the ablating surface. Second, an approximate method that uses heat of ablation data to estimate heat shield recession during entry has been coupled to a one-dimensional finite-difference calculation that calculates the in-depth thermal response. The in-depth solution accounts for material decomposition, but does not account for pyrolysis gas energy absorption through the material. Engineering correlations are used to estimate stagnation point convective and radiative heating as a function of time. The sizing tool calculates recovery enthalpy, wall enthalpy, surface pressure, and heat transfer coefficient. Verification of this tool is performed by comparison to past thermal protection system sizings for the Mars Pathfinder and Stardust entry systems and calculations are performed for an Apollo capsule entering the atmosphere at lunar and Mars return speeds.

Multiscale Modeling of Carbon/Phenolic Composite Thermal Protection Materials: Atomistic to Effective Properties

Science.gov (United States)

Arnold, Steven M.; Murthy, Pappu L.; Bednarcyk, Brett A.; Lawson, John W.; Monk, Joshua D.; Bauschlicher, Charles W., Jr.

2016-01-01

Next generation ablative thermal protection systems are expected to consist of 3D woven composite architectures. It is well known that composites can be tailored to achieve desired mechanical and thermal properties in various directions and thus can be made fit-for-purpose if the proper combination of constituent materials and microstructures can be realized. In the present work, the first, multiscale, atomistically-informed, computational analysis of mechanical and thermal properties of a present day - Carbon/Phenolic composite Thermal Protection System (TPS) material is conducted. Model results are compared to measured in-plane and out-of-plane mechanical and thermal properties to validate the computational approach. Results indicate that given sufficient microstructural fidelity, along with lowerscale, constituent properties derived from molecular dynamics simulations, accurate composite level (effective) thermo-elastic properties can be obtained. This suggests that next generation TPS properties can be accurately estimated via atomistically informed multiscale analysis.

Feasibility study for an engineering concept of a stainless steel/copper divertor plate protected by W-5 Re alloy or graphite armor

International Nuclear Information System (INIS)

Renda, V.; Federici, G.; Papa, L.

1988-01-01

The latest Joint Research Centre (JRC)-Ispra proposal is presented to support the design of a divertor concept that has long been considered the most crucial component of the plasma impurity control system for the Next Europen Torus (NET) tokamak fusion reactor. Because of the harsh tokamak environment, the divertor panel is the plasma facing component that suffers the most severe loading conditions, such as high thermal stresses, thermal fatigue, severe erosion rates and neutron damage. An analysis of a new divertor panel concept has evolved from the previous studies carried out at JRC-Ispra. The materials considered in this study are AISI 316 stainless steel for the cooling tubes, pure copper for the heat sink, and W-5 Re alloy or graphite for the protective armor. The panel is cooled by pressurized water circulation in U-tubes. A preliminary thermo-hydraulic analysis has been carried out to evaluate a set of reference parameters, such as optimum coolant velocity, maximum outlet water temperature, convective heat exchange coefficient, and the expected pressure drops in the channels. Thermal and mechanical calculations, performed by using the finite element technique, showed encouraging results about the engineering feasibility of the pressure boundary of the divertor for loading conditions similar to those of NET double null, assumed as the reference mainframe

Generic Repository Concepts and Thermal Analysis for Advanced Fuel Cycles - 12477

Energy Technology Data Exchange (ETDEWEB)

Hardin, Ernest [Sandia National Laboratories, P.O. Box 5800 MS 0736, Albuquerque, NM 87185 (United States); Blink, James [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551-0808 (United States); Carter, Joe [Savannah River National Laboratory, Savannah River Site, Aiken, SC 29808 (United States); Fratoni, Massimiliano; Greenberg, Harris; Sutton, Mark [Lawrence Livermore National Laboratory (United States); Howard, Robert [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States)

2012-07-01

A geologic disposal concept for spent nuclear fuel (SNF) or high-level waste (HLW) consists of three components: waste inventory, geologic setting, and concept of operations. A set of reference geologic disposal concepts has been developed by the U.S. Department of Energy (DOE), Used Fuel Disposition campaign. Reference concepts are identified for crystalline rock, clay/shale, bedded salt, and deep borehole (crystalline basement) geologic settings. These were analyzed for waste inventory cases representing a range of waste types that could be produced by advanced nuclear fuel cycles. Concepts of operation consisting of emplacement mode, repository layout, and engineered barrier descriptions, were selected based on international progress. All of these disposal concepts are enclosed emplacement modes, whereby waste packages are in direct contact with encapsulating engineered or natural materials. Enclosed modes have less capacity to dissipate heat than open modes such as that proposed for a repository at Yucca Mountain. Thermal analysis has identified important relationships between waste package size and capacity, and the duration of surface decay storage needed to meet temperature limits for different disposal concepts. For the crystalline rock and clay/shale repository concepts, a waste package surface temperature limit of 100 deg. C was assumed to prevent changes in clay-based buffer material or clay-rich host rock. Surface decay storage of 50 to 100 years is needed for disposal of high-burnup LWR SNF in 4-PWR packages, or disposal of HLW glass from reprocessing LWR uranium oxide (UOX) fuel. High-level waste (HLW) from reprocessing of metal fuel used in a fast reactor could be disposed after decay storage of 50 years or less. For disposal in salt the rock thermal conductivity is significantly greater, and higher temperatures (200 deg. C) can be tolerated at the waste package surface. Decay storage of 10 years or less is needed for high-burnup LWR SNF in 4-PWR

Design concepts to enhance nuclear power plant protection

International Nuclear Information System (INIS)

Ericson, D.M. Jr.; Varnado, G.B.

1980-01-01

Using a modern design for a nuclear power plant as a point of departure, this study examines the enhancement of protection which may be achieved by changes to the design. These changes include concepts such as complete physical separation of redundant trains of safety equipment, hardened enclosures for water storage tanks, and hardened shutdown heat removal systems. The degree of enhancement (value) is examined in terms such as the potential reduction in the number of vital areas and the increase in probability of adversary sequence interruption. The impacts considered include constraints imposed upon operations and maintenance personnel and increased capital and operating costs. The study concludes that structural design changes alone do not provide significant increases in protection

Transpiration cooling assisted ablative thermal protection of aerospace substructures

International Nuclear Information System (INIS)

Khan, M.B.; Iqbal, N.; Haider, Z.

2009-01-01

Ablatives are heat-shielding materials used to protect aerospace substructures. These materials are sacrificial in nature and provide protection primarily through the large endothermic transformation during exposure to hyper thermal environment such as encountered in re-entry modules. The performance of certain ablatives was reported in terms of their TGA/DTA in Advanced Materials-97 (pp 57-65). The focus of this earlier research resided in the consolidation of interface between the refractory inclusion and the host polymeric matrix to improve thermal resistance. In the present work we explore the scope of transpiration cooling in ablative performance through flash evaporation of liquid incorporated in the host EPDM (Ethylene Propylene Diene Monomer) matrix. The compression-molded specimens were exposed separately to plasma flame (15000 C) and oxyacetylene torch (3000 C) and the back face transient temperature is recorded in situ employing a thermocouple/data logger system. Both head on impingement (HOI) and parallel flow (PF) through a central cavity in the ablator were used. It is observed that transpiration cooling is effective and yields (a) rapid thermal equilibrium in the specimen, (b) lower back face temperature and (c) lower ablation rate, compared to conventional ablatives. SEM/EDS analysis is presented to amplify the point. (author)

Thermal protection from a finite period of heat exposure – Heat survival of flight data recorders

International Nuclear Information System (INIS)

Rana, Ruhul Amin; Li, Ri

2015-01-01

This work relates to developing thermal protection for a finite period of exposure to a high temperature environment. This type of transient heat transfer problem starts with a heating period, which is then followed by a cooling period once the high temperature environment disappears. The study is particularly relevant to the thermal protection of flight data recorders from high temperature flame. In this work, transient heat conduction through a three-concentric-layer configuration is numerically studied, which includes a metal housing, a thermal insulation, and a phase change material. The thermal performance is evaluated using the center temperature changing with time. It is found that the center temperature reaches a peak during cooling period rather than heating period. Time taken to reach the peak and the peak value depend on the sizes and properties of the layers. The properties include latent heat of fusion, melting temperature, heat capacities, and thermal conductivities. Parametric study is conducted to analyze and distinguish the influence of these parameters. The study provides general guidance for determining sizes and selecting materials for the thermal design of flight data recorders. Additionally, the study is also useful for other similar applications, for which thermal management and protection over a period of time is needed. In this paper, analysis starts with a baseline configuration composed of specific materials and sizes. Finite changes are applied to sizes, properties of the materials, and the results are compared to understand the roles of the varied parameters in affecting the thermal protection performance. - Highlights: • We study the thermal design of flight data recorders for heat survival. • Consecutive heating and cooling of 3-layer configuration is investigated. • Influences of sizes and material properties on thermal protection are explored

Protected River. A new concept for conservation management of fluvial systems in Colombia

International Nuclear Information System (INIS)

Andrade; German I

2011-01-01

Based upon the concept of Ecological Integrity, relevant geophysical, bio- ecological and social attributes for river systems area identified. It is argued that current conservation and environmental management instruments in Colombia, do not take into account the identified IE attributes simultaneously. The concept of Protected River, PR, is then presented, as a necessary complement for conservation strategies. The PR concept would be defined for the maintenance of the attributes of EI in some representative river systems, as a part of the biodiversity conservation objectives within the Convention of Biological Diversity. Some attributes and indicators, and thresholds of undesired change are discussed. A typology for PR is proposed, following the international protected area management categories.

Protection Heater Design Validation for the LARP Magnets Using Thermal Imaging

CERN Document Server

Marchevsky, M; Cheng, D W; Felice, H; Sabbi, G; Salmi, T; Stenvall, A; Chlachidze, G; Ambrosio, G; Ferracin, P; Izquierdo Bermudez, S; Perez, J C; Todesco, E

2016-01-01

Protection heaters are essential elements of a quench protection scheme for high-field accelerator magnets. Various heater designs fabricated by LARP and CERN have been already tested in the LARP high-field quadrupole HQ and presently being built into the coils of the high-field quadrupole MQXF. In order to compare the heat flow characteristics and thermal diffusion timescales of different heater designs, we powered heaters of two different geometries in ambient conditions and imaged the resulting thermal distributions using a high-sensitivity thermal video camera. We observed a peculiar spatial periodicity in the temperature distribution maps potentially linked to the structure of the underlying cable. Two-dimensional numerical simulation of heat diffusion and spatial heat distribution have been conducted, and the results of simulation and experiment have been compared. Imaging revealed hot spots due to a current concentration around high curvature points of heater strip of varying cross sections and visuali...

Data fusion concept in multispectral system for perimeter protection of stationary and moving objects

Science.gov (United States)

Ciurapiński, Wieslaw; Dulski, Rafal; Kastek, Mariusz; Szustakowski, Mieczyslaw; Bieszczad, Grzegorz; Życzkowski, Marek; Trzaskawka, Piotr; Piszczek, Marek

2009-09-01

The paper presents the concept of multispectral protection system for perimeter protection for stationary and moving objects. The system consists of active ground radar, thermal and visible cameras. The radar allows the system to locate potential intruders and to control an observation area for system cameras. The multisensor construction of the system ensures significant improvement of detection probability of intruder and reduction of false alarms. A final decision from system is worked out using image data. The method of data fusion used in the system has been presented. The system is working under control of FLIR Nexus system. The Nexus offers complete technology and components to create network-based, high-end integrated systems for security and surveillance applications. Based on unique "plug and play" architecture, system provides unmatched flexibility and simplistic integration of sensors and devices in TCP/IP networks. Using a graphical user interface it is possible to control sensors and monitor streaming video and other data over the network, visualize the results of data fusion process and obtain detailed information about detected intruders over a digital map. System provides high-level applications and operator workload reduction with features such as sensor to sensor cueing from detection devices, automatic e-mail notification and alarm triggering.

An overview of recent projects to study thermal protection in life rafts, lifeboats and immersion suits

Energy Technology Data Exchange (ETDEWEB)

Mak, L.; DuCharme, M. B.; Farnworth, B.; Wissler, E. H.; Brown, R.; Kuczora, A. [Maritime and Arctic Survival Scientific and Engineering Ressearch Team (Canada)

2011-07-01

Survival during a marine evacuation in cold regions is very challenging. However international regulations do not require specific thermal protection or ventilation performance criteria for lifeboats. In the same way, the testing methods for approval testing of immersion suits are not standardised. This paper investigated recent projects completed or on-going to study thermal protection in life rafts, lifeboats and immersion suits. An overview of several projects from the Maritime and Arctic Survival Scientific and Engineering Research Team (MASSERT) was conducted. This review provided the necessary knowledge to advance international standards and develop the thermal protection requirements for survival in the Arctic. The results showed the MASSERT correlated thermal insulation values between human subjects and thermal manikins in life rafts and in immersion suits. It was found that the manikins are a valuable evaluation tool, as well as the computerised models used as prediction tools.

Fracture mechanics assessment of thermal aged nuclear piping based on the Leak-Before-Break concept

Energy Technology Data Exchange (ETDEWEB)

Chen, Mingya, E-mail: chenmingya@cgnpc.com.cn [Suzhou Nuclear Power Research Institute, Suzhou, Jiangsu Province (China); Yu, Weiwei [Suzhou Nuclear Power Research Institute, Suzhou, Jiangsu Province (China); Qian, Guian [Paul Scherrer Institute, Nuclear Energy and Safety Department, Villigen PSI (Switzerland); Wang, Rongshan; Lu, Feng; Zhang, Guodong; Xue, Fei; Chen, Zhilin [Suzhou Nuclear Power Research Institute, Suzhou, Jiangsu Province (China)

2016-05-15

Highlights: • The effects of thermal aging on crack unstable tearing are studied. • The critical size of crack unstable tearing is calculated by different methods. • The critical failure models are compared. • The conservatism of J–T diagram is shown. - Abstract: The Leak-Before-Break (LBB) concept has been accepted to design the primary piping system of the pressurized water reactor (PWR). Due to thermal aging of long term operation, the cast stainless steels (CSSs) which are used for the primary piping of PWR, suffer a significant loss of fracture toughness, and as a consequence the safety margin of the thermal aged pipe decreases. Therefore, the aged piping should be analyzed and validated by the LBB concept. In this paper, elastic–plastic fracture mechanics (EPFM) assessments of the thermal aged piping are presented according to the LBB concept. The critical break size of crack unstable tearing is calculated by the EPFM method. The crack driving force diagram (J–a diagram), the stability assessment diagram (J–T diagram) and a numerical method are applied to calculate the critical crack size of crack break. The effects of thermal aging on the plastic limit load, J–T diagram, critical crack size of the EPFM and the critical failure mode are studied. The results show that the thermal aging effect decreases the maximum allowed J-integral at a certain ductile tearing modulus by more than 50% and it increases the flow stress and plastic limit load by 11.78%. The results based on the J–T diagram are about 40% conservative than those based on the direct numerical method for the high loading case. For the thermal aged piping, it is important to consider the competition failure modes between plastic collapse and unstable ductile tearing.

Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

Directory of Open Access Journals (Sweden)

Kirpluks Mikelis

2014-12-01

Full Text Available One of the biggest disadvantages of rigid polyurethane (PU foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ, which at 18-28 mW/(m•K is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K. This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.

The Concept of Rights and Protection to Employees: A Comparative Overview

Directory of Open Access Journals (Sweden)

RAJA RAZIFF RAJA SHAHARUDDIN

2013-12-01

Full Text Available Issues relating to the rights and protection accorded to employees throughout their employment with the employers is a matter that has been given much attention and treated with utmost priority in any organization, be it in the public or the private sector. It is an undeniable fact that the success story of any organization in the generation of profits in its enterprise or the smooth running in achieving the organization's desired objectives is much attributed to having a reliable, skilled and efficient workforce. Today, employees have been regarded as one of the most valuable assets of any organization. In pursuant thereto, apart from having various employment packages, laws regulating employment were enacted as protective measures in guiding both employers and employees. At the international level, rights and protections to employees have been embedded in the Universal Declaration of Human Rights. Comparatively, under the Shariah, though a similar concept has been forwarded, the notion of employment has been elevated to the status of ‘ibadah. Islam places importance of adhering to the Shari`ah principles in dealing with protection accorded to employees. As employment is regarded as ‘ibadah’ the employees are required and enjoined to observe full dedication, sincerity and commitment to their tasks. It is the responsibility of the employers, on the other hand, to ensure that the welfare of their employees is well protected. This paper attempts to outline the concept of employment under the Shari’ah and civil perspectives and to provide a comparative understanding on the rights and protection accorded to employees.

Ocean thermal energy: concept and resources, history and perspectives

International Nuclear Information System (INIS)

Nihous, Gerard

2015-10-01

Two articles address the possibility of exploiting a higher than 20 degrees temperature difference between ocean surfaces and 1 km deep waters to produce electricity. The first article describes the operation principle in closed cycle and briefly presents the open cycle approach. The global energetic assessment is discussed. The author analyses available thermal resources in relationship with the main ocean streams. He outlines that the design of an ocean thermal energy project requires the acquisition and knowledge of a lot of data, modelling and simulations. In the second article, the author notices that past experiments highlighted the difficulties of implementation of the concept. He notably evokes works performed by Georges Claude during the 1920's, projects elaborated at the end of the 20. century, the realisation of a mini OTEC (Ocean Thermal Energy Conversion) station in Hawaii, the OTEC-1 project, a Japanese project in Nauru, the test of a suspended cold water duct, the net power producing experiment in the USA. Perspectives and costs are finally briefly discussed, and recent and promising projects briefly evoked (notably that by DCNS and Akuo Energy in Martinique)

Smart thermal networks for smart cities – Introduction of concepts and measures

Directory of Open Access Journals (Sweden)

Basciotti D.

2012-10-01

Full Text Available In order to contribute to high living standards, climate mitigation and energy supply security, future urban energy systems require a holistic approach. In particular an intelligent integration of thermal networks is necessary. This paper will briefly present the “smart city” concept and introduce an associated definition for smart thermal networks defined on three levels: 1. the interaction with urban planning processes and the interface to the overall urban energy system, 2. the adaptation of the temperature level and 3. supply and demand-side management strategies.

Thermal Protection Systems: Past, Present and Future

Science.gov (United States)

Johnson, Sylvia M.

2015-01-01

Thermal protection materials and systems (TPS) have been critical to fulfilling humankinds desire to explore space. Composite and ceramic materials have enabled the early missions to orbit, the moon, the space station, Mars with robots, and sample return. Crewed missions to Mars are being considered, and this places even more demands on TPS materials. This talk will give some history on the materials used for earth and planetary entry and the demands placed upon such materials. TPS needs for future missions, especially to Mars, will be identified and potential solutions discussed.

Effect of Air Gap Entrapped in Firefighter Protective Clothing on Thermal Resistance and Evaporative Resistance

Directory of Open Access Journals (Sweden)

He Hualing

2018-03-01

Full Text Available Heat and water vapor transfer behavior of thermal protective clothing is greatly influenced by the air gap entrapped in multilayer fabric system. In this study, a sweating hot plate method was used to investigate the effect of air gap position and size on thermal resistance and evaporative resistance of firefighter clothing under a range of ambient temperature and humidity. Results indicated that the presence of air gap in multilayer fabric system decreased heat and water vapor transfer abilities under normal wear. Moreover, the air gap position slightly influenced the thermal and evaporative performances of the firefighter clothing. In this study, the multilayer fabric system obtained the highest thermal resistance, when the air space was located at position B. Furthermore, the effect of ambient temperature on heat and water vapor transfer properties of the multilayer fabric system was also investigated in the presence of a specific air gap. It was indicated that ambient temperature did not influence the evaporative resistance of thermal protective clothing. A thermographic image was used to test the surface temperature of multilayer fabric system when an air gap was incorporated. These results suggested that a certain air gap entrapped in thermal protective clothing system could affect wear comfort.

Ballistic Performance of Porous-Ceramic, Thermal Protection Systems

Science.gov (United States)

Miller, J. E.; Bohl, W. E.; Christiansen, Eric C.; Davis, B. A.; Foreman, C. D.

2011-01-01

Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of US manned spacecraft, Orion. These systems insulate reentry critical components of a spacecraft against the intense thermal environments of atmospheric reentry. Additionally, these materials are highly exposed to space environment hazards like solid particle impacts. This paper discusses impact studies up to 10 km/s on 8 lb/cu ft alumina-fiber-enhanced-thermal-barrier (AETB8) tiles coated with a toughened-unipiece-fibrous-insulation/ reaction-cured-glass layer (TUFI/RCG). A semi-empirical, first principals impact model that describes projectile dispersion is described that provides excellent agreement with observations over a broad range of impact velocities, obliquities and projectile materials. Model extensions to look at the implications of greater than 10 GPa equation of state is also discussed. Predicted penetration probabilities for a vehicle visiting the International Space Station is 60% lower for orbital debris and 95% lower for meteoroids with this model compared to an energy scaled approach.

Ballistic Performance of Porous-Ceramic, Thermal-Protection-Systems

Science.gov (United States)

Christiansen, E. L.; Davis, B. A.; Miller, J. E.; Bohl, W. E.; Foreman, C. D.

2009-01-01

Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Space Shuttle and are currently being proposed for the next generation of manned spacecraft, Orion. These materials insulate the structural components of a spacecraft against the intense thermal environments of atmospheric reentry. Furthermore, these materials are also highly exposed to space environmental hazards like meteoroid and orbital debris impacts. This paper discusses recent impact testing up to 9 km/s, and the findings of the influence of material equation-of-state on the simulation of the impact event to characterize the ballistic performance of these materials. These results will be compared with heritage models1 for these materials developed from testing at lower velocities. Assessments of predicted spacecraft risk based upon these tests and simulations will also be discussed.

Comparative Analysis of the Thermal Insulation of Traditional and Newly Designed Protective Clothing for Foundry Workers

Directory of Open Access Journals (Sweden)

Iwona Frydrych

2016-09-01

Full Text Available An objective of the undertaken research was checking the applicability of aluminized basalt fabrics for the production of clothing for foundry workers. The results of flammability, the resistance to contact, convective and radiation heat, as well as the resistance to big molten metal splashes confirmed the thesis of applicability of the packages with the use of aluminized basalt fabric content for the assumed purpose; therefore, such protective clothing was produced. Thermal comfort of foundry workers is very important and related to many factors, i.e., the structure of the protective clothing package, the number of layers, their thickness, the distance between the body and appropriate underwear. In the paper, a comparison of the results of thermal insulation measurement of two kinds of protective clothing is presented: the traditional one made of aluminized glass fabrics and the new one made of aluminized basalt fabrics. Measurements of clothing thermal insulation were conducted using a thermal manikin dressed in the protective clothing and three kinds of underwear products covering the upper and lower part of the manikin.

The Development of HfO2-Rare Earth Based Oxide Materials and Barrier Coatings for Thermal Protection Systems

Science.gov (United States)

Zhu, Dongming; Harder, Bryan James

2014-01-01

Advanced hafnia-rare earth oxides, rare earth aluminates and silicates have been developed for thermal environmental barrier systems for aerospace propulsion engine and thermal protection applications. The high temperature stability, low thermal conductivity, excellent oxidation resistance and mechanical properties of these oxide material systems make them attractive and potentially viable for thermal protection systems. This paper will focus on the development of the high performance and high temperature capable ZrO2HfO2-rare earth based alloy and compound oxide materials, processed as protective coating systems using state-or-the-art processing techniques. The emphasis has been in particular placed on assessing their temperature capability, stability and suitability for advanced space vehicle entry thermal protection systems. Fundamental thermophysical and thermomechanical properties of the material systems have been investigated at high temperatures. Laser high-heat-flux testing has also been developed to validate the material systems, and demonstrating durability under space entry high heat flux conditions.

Impact Testing of Orbiter Thermal Protection System Materials

Science.gov (United States)

Kerr, Justin

2006-01-01

This viewgraph presentation reviews the impact testing of the materials used in designing the shuttle orbiter thermal protection system (TPS). Pursuant to the Columbia Accident Investigation Board recommendations a testing program of the TPS system was instituted. This involved using various types of impactors in different sizes shot from various sizes and strengths guns to impact the TPS tiles and the Leading Edge Structural Subsystem (LESS). The observed damage is shown, and the resultant lessons learned are reviewed.

Thermal imaging as a smartphone application: exploring and implementing a new concept

Science.gov (United States)

Yanai, Omer

2014-06-01

Today's world is going mobile. Smartphone devices have become an important part of everyday life for billions of people around the globe. Thermal imaging cameras have been around for half a century and are now making their way into our daily lives. Originally built for military applications, thermal cameras are starting to be considered for personal use, enabling enhanced vision and temperature mapping for different groups of professional individuals. Through a revolutionary concept that turns smartphones into fully functional thermal cameras, we have explored how these two worlds can converge by utilizing the best of each technology. We will present the thought process, design considerations and outcome of our development process, resulting in a low-power, high resolution, lightweight USB thermal imaging device that turns Android smartphones into thermal cameras. We will discuss the technological challenges that we faced during the development of the product, and what are the system design decisions taken during the implementation. We will provide some insights we came across during this development process. Finally, we will discuss the opportunities that this innovative technology brings to the market.

In-Situ Real-Time Temperature Monitoring of Thermal Protection Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This program addresses the need for interfacial and in-depth temperature monitoring of thermal protection systems (TPS). Novel, linear drive, eddy current methods...

Methods of evaluating protective clothing relative to heat and cold stress: thermal manikin, biomedical modeling, and human testing.

Science.gov (United States)

O'Brien, Catherine; Blanchard, Laurie A; Cadarette, Bruce S; Endrusick, Thomas L; Xu, Xiaojiang; Berglund, Larry G; Sawka, Michael N; Hoyt, Reed W

2011-10-01

Personal protective equipment (PPE) refers to clothing and equipment designed to protect individuals from chemical, biological, radiological, nuclear, and explosive hazards. The materials used to provide this protection may exacerbate thermal strain by limiting heat and water vapor transfer. Any new PPE must therefore be evaluated to ensure that it poses no greater thermal strain than the current standard for the same level of hazard protection. This review describes how such evaluations are typically conducted. Comprehensive evaluation of PPE begins with a biophysical assessment of materials using a guarded hot plate to determine the thermal characteristics (thermal resistance and water vapor permeability). These characteristics are then evaluated on a thermal manikin wearing the PPE, since thermal properties may change once the materials have been constructed into a garment. These data may be used in biomedical models to predict thermal strain under a variety of environmental and work conditions. When the biophysical data indicate that the evaporative resistance (ratio of permeability to insulation) is significantly better than the current standard, the PPE is evaluated through human testing in controlled laboratory conditions appropriate for the conditions under which the PPE would be used if fielded. Data from each phase of PPE evaluation are used in predictive models to determine user guidelines, such as maximal work time, work/rest cycles, and fluid intake requirements. By considering thermal stress early in the development process, health hazards related to temperature extremes can be mitigated while maintaining or improving the effectiveness of the PPE for protection from external hazards.

Heat Transfer Analysis of Thermal Protection Structures for Hypersonic Vehicles

Science.gov (United States)

Zhou, Chen; Wang, Zhijin; Hou, Tianjiao

2017-11-01

This research aims to develop an analytical approach to study the heat transfer problem of thermal protection systems (TPS) for hypersonic vehicles. Laplace transform and integral method are used to describe the temperature distribution through the TPS subject to aerodynamic heating during flight. Time-dependent incident heat flux is also taken into account. Two different cases with heat flux and radiation boundary conditions are studied and discussed. The results are compared with those obtained by finite element analyses and show a good agreement. Although temperature profiles of such problems can be readily accessed via numerical simulations, analytical solutions give a greater insight into the physical essence of the heat transfer problem. Furthermore, with the analytical approach, rapid thermal analyses and even thermal optimization can be achieved during the preliminary TPS design.

Entransy: A misleading concept for the analysis and optimization of thermal systems

International Nuclear Information System (INIS)

Sekulic, Dusan P.; Sciubba, Enrico; Moran, Michael J.

2015-01-01

The purpose of this article is to assess the value of entransy for use in the thermal system engineering domain and in particular for design. The conclusion is that use of entransy is not recommended. This finding is in keeping with increasing uneasiness that has emerged recently in the technical literature about this concept. Throughout this article emphasis is on concise discussions of salient entransy aspects and the presentation is shaped to reach a broad technical audience. Accordingly, because secondary entransy aspects do not play a central role in reaching the above recommendation, they are considered only in passing or deferred. - Highlights: • A methodology for analysis, design, and optimization of thermal systems. • Entransy is not recommended for use in thermal system engineering. • Components of actual thermal systems do not operate ideally on any basis. • Entropy and exergy rest firmly on the second law of thermodynamics. • Entransy arises by analogy

Characterization of solar thermal concepts for electricity generation: Volume 1, Analyses and evaluation

Energy Technology Data Exchange (ETDEWEB)

Williams, T.A.; Dirks, J.A.; Brown, D.R.; Drost, M.K.; Antoniac, Z.A.; Ross, B.A.

1987-03-01

This study is aimed at providing a relative comparison of the thermodynamic and economic performance in electric applications of several concepts that have been studied and developed in the DOE solar thermal program. Since the completion of earlier systems comparison studies in the late 1970's, there have been a number of years of progress in solar thermal technology. This progress has included development of new solar components, improvements in component and system design detail, construction of working systems, and collection of operating data on the systems. This study provides an updating of the expected performance and cost of the major components and the overall system energy cost for the concepts evaluated. The projections in this study are for the late 1990's time frame, based on the capabilities of the technologies that could be expected to be achieved with further technology development.

Concept of Educational Assistance to Health Protection of the Individual

Science.gov (United States)

Levanova, Elena Aleksandrovna; Kokorina, Olga Rafailovna; Nikitin, Yuriy Vladimirovich; Perepelkina, Tatiyna Vladislavovna; Segodina, Polina Anatolievna

2016-01-01

The article describes the theoretical and practical need for the development of the concept of assistance to health protection of the individual in order to address the problem of health protection of students and teachers in the conditions of a higher pedagogical education. The problem of studying human health, its entirety, systemacity and connection with the environment attracts particular attention in recent years. This was one of the reasons to study the problem of “healthy lifestyle” as the qualitative characteristic of a human life aimed at health, due to the fact that a healthy lifestyle is one of the determinants of health. This is made possible with the use of specific health-protecting technologies aimed at searching for ways and means of protection and conservation of health of students and teachers in the conditions of the educational process and using educational tools, which is currently included into the priorities of education. PMID:26493439

Protective Skins for Composite Airliners

Science.gov (United States)

Johnson, Vicki S.; Boone, Richard L.; Jones, Shannon; Pendse, Vandana; Hayward, Greg

2014-01-01

Traditional composite aircraft structures are designed for load bearing and then overdesigned for impact damage and hot humid environments. Seeking revolutionary improvement in the performance and weight of composite structures, Cessna Aircraft Company, with sponsorship from the NASA Fundamental Aeronautics Program/Subsonic Fixed Wing Project, has developed and tested a protective skin concept which would allow the primary composite structure to carry only load and would meet the impact, hot and humid, and other requirements through protective skins. A key requirement for the protective skins is to make any impact damage requiring repair visible. Testing from the first generation of skins helped identify the most promising materials which were used in a second generation of test articles. This report summarizes lessons learned from the first generation of protective skins, the design and construction of the second-generation test articles, test results from the second generation for impact, electromagnetic effects, aesthetics and smoothing, thermal, and acoustic (for the first time), and an assessment of the feasibility of the protective skin concept.

Robotic system for the servicing of the orbiter thermal protection system

Science.gov (United States)

Graham, Todd; Bennett, Richard; Dowling, Kevin; Manouchehri, Davoud; Cooper, Eric; Cowan, Cregg

1994-01-01

This paper describes the design and development of a mobile robotic system to process orbiter thermal protection system (TPS) tiles. This work was justified by a TPS automation study which identified tile rewaterproofing and visual inspection as excellent applications for robotic automation.

Management optimization in Thermal complex through water reuse

International Nuclear Information System (INIS)

De Souza, S.; Manganelli, A.; Bertolotto, J.; Leys, P.; Garcia, B.

2004-01-01

Water reuse involves the concept of the exploitation of a previously used water, for a new, beneficial purpose. Actually, in Uruguay, thermal water is just utilised for balneological purposes, in this paper is proposed the water reuse taking the excess of used swimming pool water, and using it for heating and greenhouse irrigation, and australian lobster breeding. An important aspect of sustainable thermal water management is the protection of the exploted thermal water resources, so water reuse plays an important role in water resource, and ecosystem management, because it reduces the volume discharged and also reduces the risk of thermal pollution [es

A new concept of hybrid photovoltaic thermal (PVT) collector with natural circulation

Science.gov (United States)

Lu, Longsheng; Wang, Xiaowu; Wang, Shuai; Liu, Xiaokang

2017-07-01

Hybrid photovoltaic thermal (PVT) technology refers to the integration of a photovoltaic module into a conventional solar thermal collector. Generally, the traditional design of a PVT collector has solar cells fixed on the top surface of an absorber in a flat-plate solar thermal collector. In this work, we presented a new concept of water-based PVT collector in which solar cells were directly placed on the bottom surface of its glass cover. A dynamic numerical model of this new PVT is developed and validated by experimental tests. With numerical analysis, it is found that at same covering factor, the electricity conversion efficiency of solar cells of the new PVT exceed that of the traditional PVT by nearly 10% while its thermal efficiency is approximately 30% lower than that of the traditional PVT. When the covering factor changes from 0.05 to 1, the thermal efficiency of the new PVT drops nearly 70%. The thermal efficiency of both the new PVT and the traditional PVT rise up as the water mass in tank increases. Meanwhile, the final water temperature in tank of the traditional PVT collector declines more than 17 °C, whereas that of the new PVT declines less than 6 °C, when the water mass increases from 100 to 300 kg.

Thermal spraying of corrosion protection layers in biogas plants; Erzeugung von Korrosionsschutzschichten fuer Bioenergieanlagen mittels Thermischen Spritzens

Energy Technology Data Exchange (ETDEWEB)

Crimmann, P.; Dimaczek, G.; Faulstich, M. [ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany)

2004-07-01

Corrosion in plants for the energetic conversion of biomass is a severe problem that often causes premature damage of components. Thermal spraying is a process for the creation of corrosion protection layer. An advantage of thermal spraying is that as well as each material can be used as layer material. First practical results demonstrated that thermal spraying has the potential to create coatings to protect components against high temperature corrosion as well as biocorrosion. Layer materials are for example nickel base alloys (high temperature corrosion) and titan alloys (biocorrosion). Further investigations are necessary in order to examine whether cost-efficient coatings also contribute to the corrosion protection (e.g. polymer materials against biocorrosion). (orig.)

Thermal analysis of W VII-AS limiter system and presentation of a graphite-block concept

International Nuclear Information System (INIS)

Mukherjee, S.; Grigull, P.

1989-01-01

A 2D-finite element thermal analysis of the initial W VII-AS limiter system has been performed and is discussed. Furhter to this analysis a graphite block concept is presented. This concept has been numerically analyzed for applications as a limiter in plasma and nuclear fusion experimental devices. The results are described in this paper. This block concept seems to be also applicable to first wall and divertor designs; the graphite elements could be replaced by ceramic ones. (author). 10 refs.; 13 figs

Lightweight Ablative and Ceramic Thermal Protection System Materials for NASA Exploration Systems Vehicles

Science.gov (United States)

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

2006-01-01

As a collaborative effort among NASA Centers, the "Lightweight Nonmetallic Thermal Protection Materials Technology" Project was set up to assist mission/vehicle design trade studies, to support risk reduction in thermal protection system (TPS) material selections, to facilitate vehicle mass optimization, and to aid development of human-rated TPS qualification and certification plans. Missions performing aerocapture, aerobraking, or direct aeroentry rely on advanced heatshields that allow reductions in spacecraft mass by minimizing propellant requirements. Information will be presented on candidate materials for such reentry approaches and on screening tests conducted (material property and space environmental effects tests) to evaluate viable candidates. Seventeen materials, in three classes (ablatives, tiles, and ceramic matrix composites), were studied. In additional to physical, mechanical, and thermal property tests, high heat flux laser tests and simulated-reentry oxidation tests were performed. Space environmental effects testing, which included exposures to electrons, atomic oxygen, and hypervelocity impacts, was also conducted.

Monitoring of Thermal Protection Systems using Robust Self-Organizing Optical Fiber Sensing Networks

Data.gov (United States)

National Aeronautics and Space Administration — Effective thermal protection systems are crucial for spacecraft or future hypersonic transports re-entering the atmosphere. Micro-meteoroids and orbital debris...

New radiation protection concept as important safety factor of industrial radiography

International Nuclear Information System (INIS)

Pavlovic, R.; Pavlovic, S.

1998-01-01

Industrial radiography is a method for non destructive testing of homogeneity of various materials based on different absorption of radiation in different material. X and γ radiation are the most often used. Detrimental effects of radiation are observed since its discovery. In order to prevent harmful effects of radiation without unduly limitations of its use, International Commission on Radiological Protection in collaboration with International Atomic Energy Agency have developed International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, Safety Series No 115, adopted in 1996. based on ICRP recommendations from 1991. Besides a lot of changes in radiation protection concept and philosophy, decrement of annual dose limits for occupational exposure from 50 to 20 mSv. (author)

A theoretical concept for a thermal-hydraulic 3D parallel channel core model

International Nuclear Information System (INIS)

Hoeld, A.

2004-01-01

A detailed description of the theoretical concept of the 3D thermal-hydraulic single- and two-phase flow phenomena is presented. The theoretical concept is based on important development lines such as separate treatment of the mass and energy from the momentum balance eqs. The other line is the establishment of a procedure for the calculation of the mass flow distributions into different parallel channels based on the fact that the sum of pressure decrease terms over a closed loop must stay, despite of un-symmetric perturbations, zero. The concept is realized in the experimental code HERO-X3D, concentrating in a first step on an artificial BWR or PWR core which may consist of a central channel, four quadrants, and a bypass channel. (authors)

On-Orbit Health Monitoring and Repair Assessment of Thermal Protection Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR project delivers On-orbit health MoNItoring and repair assessment of THERMal protection systems (OMNI_THERM). OMNI_THERM features impedance-based...

Landscape ecology: a concept for protecting park resources

Science.gov (United States)

Allen, Craig D.; Lissoway, John; Yarborough, Keith

1990-01-01

The Southwest Region has been supporting Resource Basic Inventory (RBI) efforts to establish baseline data for comparisons with long-term monitoring results to be conducted in the future. This “pulse taking” is a part of the Servicewide initiative being fostered so that resource managers, scientists, and park managers will be able to track the health of park resources by determining changes and trends. The RBI work is being linked with the development of Geographic Information Systems (GIS) at Bandelier, Big Thicket, Big Bend, Padre Island, and Guadalupe Mountains. Many of the parks in the southwest Region have only partially completed RBIs. This informational shortcoming is a pervasive threat to the parks because without detailed knowledge of the parks’ respective resources the Service cannot protect them adequately. To overcome this deficiency, the SWRO’s Division of Natural Resources Management and Science has fostered at Bandelier a pilot research effort, which started in FY ’87 and utilizes a landscape ecology paradigm. This concept links the RBI, GIS, and research activities in a park to present an overall picture of the park in its regional ecosystem setting. The flowchart diagrams this project’s concept. The results have been encouraging. A final report was recently completed (Allen 1989). This concept may now be applied to other Southwest Region parks.

Enabling Technology for Thermal Protection on HIAD and Other Hypersonic Missions, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Gas conduction and radiation are the two important heat transfer mechanisms in highly porous reusable thermal protection systems used for planetary entry of space...

Laying Stress on Energy-Saving and Environmental Protection of Thermal Generation

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

@@ The most attraetive spot of the 11th Five-Year Plan is to change China's present mode of cconomic growth and take a road of circulative cconomy based on effective utilization of resources and environmental protection. Electric power as a basic industry,energy conservation and environmental protection will become one of its working cmphases in a period of time to come. In this connection, the journalist (Zhao Ran) from China Electric Power has exclusively interviewed Tang Yunlin, the former president of the China Electric Power Planning and Engineering Institute. He thought that the most important thing for power industry to save energy and protect environment is to bring about the energy conservation and environmental protection in thermal power plants rather than first devclop hydropower, nuclear power and renewable energy. His viewpoints and suggestions have been recognized by many insiders.

A new approach to characterize the effect of fabric deformation on thermal protective performance

International Nuclear Information System (INIS)

Li, Jun; Li, Xiaohui; Lu, Yehu; Wang, Yunyi

2012-01-01

It is very important to evaluate thermal protective performance (TPP) in laboratory-simulated fire scenes as accurately as possible. For this paper, to thoroughly understand the effect of fabric deformation on basic physical properties and TPP of flame-retardant fabrics exposed to flash fire, a new modified TPP testing apparatus was developed. Different extensions were employed to simulate the various extensions displayed during different body motions. The tests were also carried out with different air gaps. The results showed a significant decrease in air permeability after deformation. However, the change of thickness was slight. The fabric deformation had a complicated effect on thermal protection with different air gaps. The change of TPP depended on the balance between the surface contact area and the thermal insulation. The newly developed testing apparatus could be well employed to evaluate the effect of deformation on TPP of flame-resistant fabrics. (paper)

A new approach to characterize the effect of fabric deformation on thermal protective performance

Science.gov (United States)

Li, Jun; Li, Xiaohui; Lu, Yehu; Wang, Yunyi

2012-04-01

It is very important to evaluate thermal protective performance (TPP) in laboratory-simulated fire scenes as accurately as possible. For this paper, to thoroughly understand the effect of fabric deformation on basic physical properties and TPP of flame-retardant fabrics exposed to flash fire, a new modified TPP testing apparatus was developed. Different extensions were employed to simulate the various extensions displayed during different body motions. The tests were also carried out with different air gaps. The results showed a significant decrease in air permeability after deformation. However, the change of thickness was slight. The fabric deformation had a complicated effect on thermal protection with different air gaps. The change of TPP depended on the balance between the surface contact area and the thermal insulation. The newly developed testing apparatus could be well employed to evaluate the effect of deformation on TPP of flame-resistant fabrics.

Effective evaluation of privacy protection techniques in visible and thermal imagery

Science.gov (United States)

Nawaz, Tahir; Berg, Amanda; Ferryman, James; Ahlberg, Jörgen; Felsberg, Michael

2017-09-01

Privacy protection may be defined as replacing the original content in an image region with a (less intrusive) content having modified target appearance information to make it less recognizable by applying a privacy protection technique. Indeed, the development of privacy protection techniques also needs to be complemented with an established objective evaluation method to facilitate their assessment and comparison. Generally, existing evaluation methods rely on the use of subjective judgments or assume a specific target type in image data and use target detection and recognition accuracies to assess privacy protection. An annotation-free evaluation method that is neither subjective nor assumes a specific target type is proposed. It assesses two key aspects of privacy protection: "protection" and "utility." Protection is quantified as an appearance similarity, and utility is measured as a structural similarity between original and privacy-protected image regions. We performed an extensive experimentation using six challenging datasets (having 12 video sequences), including a new dataset (having six sequences) that contains visible and thermal imagery. The new dataset is made available online for the community. We demonstrate effectiveness of the proposed method by evaluating six image-based privacy protection techniques and also show comparisons of the proposed method over existing methods.

Thermal overload protection for electric motors on safety-related motor-operated valves: Generic Issue II.E.6.1

International Nuclear Information System (INIS)

Rothberg, O.

1988-06-01

NRC regulatory positions, as stated in Regulatory Guide 1.106, Revision 1, have been identified by the Office for Analysis and Evaluation of Operational Data (AEOD) as potential contributors to valve motor burnout. AEOD is particularly concerned about the allowed policy of bypassing thermal overload devices during normal or accident conditions. Regulatory Guide 1.106 favors compromising the function of thermal overload devices in favor of completing the safety-related action of valves. The purpose of this study was to determine if the guidance contained in Regulatory Guide 1.106 is appropriate and, if not, to recommend the necessary changes. This report describes thermal overload devices commonly used to protect safety-related valve operator motors. The regulatory guidelines stated in Regulatory Guide 1.106 along with the limitations of thermal overload protection are discussed. Supplements and alternatives to thermal overload protection are also described. Findings and conclusions of several AEOD reports are discussed. Information obtained from the standard review plan, standard technical specifications, technical specifications from representative plants, and several papers are cited

Three-dimensional biomimetic head model as a platform for thermal testing of protective goggles for prevention of eye injuries.

Science.gov (United States)

Friedman, Rinat; Haimy, Ayelet; Gefen, Amit; Epstein, Yoram

2018-04-22

The rate of eye injury is steadily rising during military conflicts of the century, with thermal burns being the most common type of injury to the eyes. The present study focuses on assessing the heat resistance properties of military protective goggles using three-dimensional (3D) finite element head modeling fitted with the tested protective gear. A computational thermal impact was applied onto a 3D biomimetic human head model fitted with two goggle models - sports (Type 1) and square (Type 2). The resultant temperature of the eye tissues and the thermal injury thresholds were calculated by using the modeling, hence allowing to determine the protective efficacy of the goggles objectively, in a standardized, quantitative and cost-effective manner. Both types of goggles had a dramatic protective effect on the eyes. The specific goggle geometry had no notable effect on the level of protection to the inner tissues against the thermal insult. At the skin level goggles reduced temperatures by ~64% under the impact zone, with only a mild difference (10 °C) between the goggles. Little limitations on the shape and geometry of goggles were observed and any structure of goggles can provide an adequate protection against a thermal insult (per se) to inner cranial tissues, assuming the lenses are wide and thick enough to block direct skin contact of the heat insult. It was shown that our 3D biomimetic human head model provides a practical and cost-effective tool for determining the performance level of goggles with different attributed (i.e., shapes and thermal properties). Copyright © 2018 Elsevier Ltd. All rights reserved.

A new method of thermal protection by opposing jet for a hypersonic aeroheating strut

Science.gov (United States)

Qin, Jiang; Ning, Dongpo; Feng, Yu; Zhang, Junlong; Feng, Shuo; Bao, Wen

2017-06-01

This paper presents the numerical investigation of thermal protection of scramjet strut by opposing jet in supersonic stream of Mach number 6 with a hydrogen fueled scramjet strut model using CFD software. Simulation results indicate that when a small amount of fuel is injected from the nose of the strut, the bow shock is pushed away from the strut, and the heat flux is reduced in the strut, especially at the leading edge. Opposing jet forms a recirculation region near the nozzle so that the strut is covered with low temperature fuel and separated from free stream. An appropriate total pressure ratio can be used to reduce not only aerodynamic heating but also the drag of strut. It is therefore concluded that thermal protection of scramjet strut by opposing jet is one of the promising ways to protect scramjet strut in high enthalpy stream.

Synthesis and Characterization of Fibre Reinforced Silica Aerogel Blankets for Thermal Protection

Directory of Open Access Journals (Sweden)

S. Chakraborty

2016-01-01

Full Text Available Using tetraethoxysilane (TEOS as the source of silica, fibre reinforced silica aerogels were synthesized via fast ambient pressure drying using methanol (MeOH, trimethylchlorosilane (TMCS, ammonium fluoride (NH4F, and hexane. The molar ratio of TEOS/MeOH/(COOH2/NH4F was kept constant at 1 : 38 : 3.73 × 10−5 : 0.023 and the gel was allowed to form inside the highly porous meta-aramid fibrous batting. The wet gel surface was chemically modified (silylation process using various concentrations of TMCS in hexane in the range of 1 to 20% by volume. The fibre reinforced silica aerogel blanket was obtained subsequently through atmospheric pressure drying. The aerogel blanket samples were characterized by density, thermal conductivity, hydrophobicity (contact angle, and Scanning Electron Microscopy. The radiant heat resistance of the aerogel blankets was examined and compared with nonaerogel blankets. It has been observed that, compared to the ordinary nonaerogel blankets, the aerogel blankets showed a 58% increase in the estimated burn injury time and thus ensure a much better protection from heat and fire hazards. The effect of varying the concentration of TMCS on the estimated protection time has been examined. The improved thermal stability and the superior thermal insulation of the flexible aerogel blankets lead to applications being used for occupations that involve exposure to hazards of thermal radiation.

Preliminary design of the thermal protection system for solar probe

Science.gov (United States)

Dirling, R. B., Jr.; Loomis, W. C.; Heightland, C. N.

1982-01-01

A preliminary design of the thermal protection system for the NASA Solar Probe spacecraft is presented. As presently conceived, the spacecraft will be launched by the Space Shuttle on a Jovian swing-by trajectory and at perihelion approach to three solar radii of the surface of the Earth's sun. The system design satisfies maximum envelope, structural integrity, equipotential, and mass loss/contamination requirements by employing lightweight carbon-carbon emissive shields. The primary shield is a thin shell, 15.5-deg half-angle cone which absorbs direct solar flux at up to 10-deg off-nadir spacecraft pointing angles. Secondary shields of sandwich construction and low thickness-direction thermal conductivity are used to reduce the primary shield infrared radiation to the spacecraft payload.

Characterization of thermally sprayed coatings for high-temperature wear-protection applications

International Nuclear Information System (INIS)

Li, C.C.

1980-03-01

Under normal high-temperature gas-cooled reactor (HTGR) operating conditions, faying surfaces of metallic components under high contact pressure are prone to friction, wear, and self-welding damage. Component design calls for coatings for the protection of the mating surfaces. Anticipated operating temperatures up to 850 to 950 0 C (1562 to 1742 0 F) and a 40-y design life require coatings with excellent thermal stability and adequate wear and spallation resistance, and they must be compatible with the HTGR coolant helium environment. Plasma and detonation-gun (D-gun) deposited chromium carbide-base and stabilized zirconia coatings are under consideration for wear protection of reactor components such as the thermal barrier, heat exchangers, control rods, and turbomachinery. Programs are under way to address the structural integrity, helium compatibility, and tribological behavior of relevant sprayed coatings. In this paper, the need for protection of critical metallic components and the criteria for selection of coatings are discussed. The technical background to coating development and the experience with the steam cycle HTGR (HTGR-SC) are commented upon. Coating characterization techniques employed at General Atomic Company (GA) are presented, and the progress of the experimental programs is briefly reviewed. In characterizing the coatings for HTGR applications, it is concluded that a systems approach to establish correlation between coating process parameters and coating microstructural and tribological properties for design consideration is required

Risk concepts in various fields including radiation protection. A historical review and some recent topics

International Nuclear Information System (INIS)

Kai, Michiaki

2000-01-01

This is a review by the expert group concerning risks in radiation protection and in chemical management, recent state of protection and of health-risk assessment of low dose radiation, and risk concepts in other fields. Risk concepts in radiation protection are described mainly on ICRP: Its history leading to its Publication 1 (1958), Pub. 9 (1965), Pub. 26 (1977) and Pub. 60 (1990). In that recent publication, the term, risk, is used only for the established one like estimated risk or excess relative risk. Risk management of chemicals involves that against pollution from environmental and ecological aspects, and assessment of dioxin and chemicals from toxicology and carcinogenicity aspects. Recently, risks of low dose radiation have been actively discussed conceivably because of possible reduction of the exposure limit in ICRP Recommendation 1990, Chernobyl accident, advances of radiation biology and radiation protection problem in the radioactive waste disposition. Globally, many academic societies such as American Health-Physics Society published Position Statements and Reports and there are activities like the Research program plan for the risk and an international conference of bridging radiation policy and science. Risk concepts involve technological and ecological ones, insurance ones and health ones. Risk assessment or analysis is done through recognition, measurement and prediction, thus through the scientific process based on objective facts. (K.H.)

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining-a thermal manikin and questionnaire study.

Science.gov (United States)

Jussila, Kirsi; Rissanen, Sirkka; Aminoff, Anna; Wahlström, Jens; Vaktskjold, Arild; Talykova, Ljudmila; Remes, Jouko; Mänttäri, Satu; Rintamäki, Hannu

2017-12-07

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (I cl ) of the reported clothing was estimated (ISO 9920). The I cl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the I cl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The I cl of the clothing measured by thermal manikin was 1.9-2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C.

Ballistic Performance of Porous Ceramic Thermal Protection Systems at 9 km/s

Science.gov (United States)

Miller, Joshua E.; Bohl, W. E.; Foreman, C. D.; Christiansen, Eric L.; Davis, B. A.

2009-01-01

Porous-ceramic, thermal-protection-systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of manned spacecraft, Orion. These materials insulate the structural components and sensitive electronic components of a spacecraft against the intense thermal environments of atmospheric reentry. Furthermore, these materials are also highly exposed to space environmental hazards like meteoroid and orbital debris impacts. This paper discusses recent impact testing up to 9 km/s on ceramic tiles similar to those used on the Orbiter. These tiles have a porous-batting of nominally 8 lb/cubic ft alumina-fiber-enhanced-thermal-barrier (AETB8) insulating material coated with a damage-resistant, toughened-unipiece-fibrous-insulation (TUFI) layer.

Ballistic Performance of Porous-Ceramic, Thermal Protection Systems to 9 km/s

Science.gov (United States)

Miller, Joshua E.; Bohl, William E.; Foreman, Cory D.; Christiansen, Eric C.; Davis, Bruce A.

2010-01-01

Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of US manned spacecraft, Orion. These materials insulate the structural components and sensitive components of a spacecraft against the intense thermal environments of atmospheric reentry. These materials are also highly exposed to solid particle space environment hazards. This paper discusses recent impact testing up to 9.65 km/s on ceramic tiles similar to those used on the Orbiter. These tiles are a porous-ceramic insulator of nominally 8 lb/ft(exp 3) alumina-fiber-enhanced-thermal-barrier (AETB8) coated with a damage-resistant, toughened-unipiece-fibrous-insulation/reaction-cured-glass layer (TUFI/RCG).

Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Included among...

Ballistic Performance Model of Crater Formation in Monolithic, Porous Thermal Protection Systems

Science.gov (United States)

Miller, J. E.; Christiansen, E. L.; Deighton, K. D.

2014-01-01

Porous monolithic ablative systems insulate atmospheric reentry vehicles from reentry plasmas generated by atmospheric braking from orbital and exo-orbital velocities. Due to the necessity that these materials create a temperature gradient up to several thousand Kelvin over their thickness, it is important that these materials are near their pristine state prior to reentry. These materials may also be on exposed surfaces to space environment threats like orbital debris and meteoroids leaving a probability that these exposed surfaces will be below their prescribed values. Owing to the typical small size of impact craters in these materials, the local flow fields over these craters and the ablative process afford some margin in thermal protection designs for these locally reduced performance values. In this work, tests to develop ballistic performance models for thermal protection materials typical of those being used on Orion are discussed. A density profile as a function of depth of a typical monolithic ablator and substructure system is shown in Figure 1a.

Thermal-hydraulic limitations on water-cooled limiters

International Nuclear Information System (INIS)

Cha, Y.S.; Misra, B.

1984-08-01

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on current design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated conditions. Since the data presented herein concern primarily thermal protection, the final design should consider other factors such as thermal stresses, temperature limits, and fatigue

Mechanisms Underpinning Degradation of Protective Oxides and Thermal Barrier Coatings in High Hydrogen Content (HHC) - Fueled Turbines

Energy Technology Data Exchange (ETDEWEB)

Mumm, Daniel

2013-08-31

The overarching goal of this research program has been to evaluate the potential impacts of coal-derived syngas and high-hydrogen content fuels on the degradation of turbine hot-section components through attack of protective oxides and thermal barrier coatings. The primary focus of this research program has been to explore mechanisms underpinning the observed degradation processes, and connections to the combustion environments and characteristic non-combustible constituents. Based on the mechanistic understanding of how these emerging fuel streams affect materials degradation, the ultimate goal of the program is to advance the goals of the Advanced Turbine Program by developing materials design protocols leading to turbine hot-section components with improved resistance to service lifetime degradation under advanced fuels exposures. This research program has been focused on studying how: (1) differing combustion environments – relative to traditional natural gas fired systems – affect both the growth rate of thermally grown oxide (TGO) layers and the stability of these oxides and of protective thermal barrier coatings (TBCs); and (2) how low levels of fuel impurities and characteristic non-combustibles interact with surface oxides, for instance through the development of molten deposits that lead to hot corrosion of protective TBC coatings. The overall program has been comprised of six inter-related themes, each comprising a research thrust over the program period, including: (i) evaluating the role of syngas and high hydrogen content (HHC) combustion environments in modifying component surface temperatures, heat transfer to the TBC coatings, and thermal gradients within these coatings; (ii) understanding the instability of TBC coatings in the syngas and high hydrogen environment with regards to decomposition, phase changes and sintering; (iii) characterizing ash deposition, molten phase development and infiltration, and associated corrosive

Trade Study of System Level Ranked Radiation Protection Concepts for Deep Space Exploration

Science.gov (United States)

Cerro, Jeffrey A

2013-01-01

A strategic focus area for NASA is to pursue the development of technologies which support exploration in space beyond the current inhabited region of low earth orbit. An unresolved issue for crewed deep space exploration involves limiting crew radiation exposure to below acceptable levels, considering both solar particle events and galactic cosmic ray contributions to dosage. Galactic cosmic ray mitigation is not addressed in this paper, but by addressing credible, easily implemented, and mass efficient solutions for the possibility of solar particle events, additional margin is provided that can be used for cosmic ray dose accumulation. As a result, NASA s Advanced Engineering Systems project office initiated this Radiation Storm Shelter design activity. This paper reports on the first year results of an expected 3 year Storm Shelter study effort which will mature concepts and operational scenarios that protect exploration astronauts from solar particle radiation events. Large trade space definition, candidate concept ranking, and a planned demonstration comprised the majority of FY12 activities. A system key performance parameter is minimization of the required increase in mass needed to provide a safe environment. Total system mass along with operational assessments and other defined protection system metrics provide the guiding metrics to proceed with concept developments. After a downselect to four primary methods, the concepts were analyzed for dosage severity and the amount of shielding mass necessary to bring dosage to acceptable values. Besides analytical assessments, subscale models of several concepts and one full scale concept demonstrator were created. FY12 work terminated with a plan to demonstrate test articles of two selected approaches. The process of arriving at these selections and their current envisioned implementation are presented in this paper.

Development of High-Fidelity Material Response Modeling for Resin-Infused Woven Thermal Protection Systems

Data.gov (United States)

National Aeronautics and Space Administration — For future space exploration missions, it is essential for the thermal protection system (TPS) found on hypersonic vehicles or atmospheric entry probes to be...

Digital protection in power plants. Electrical unit and line protection. Digital protection systems for NPP

International Nuclear Information System (INIS)

Kaczmarek, A.

2000-01-01

In this presentation author deals with the digital protection systems for nuclear power plants. The evolution of protection devices, protection concept for power plants, concept of functional redundancy, references for digital protection, benefits for the customer well as concept fault recorder are presented. (author)

The Way Forward in Radiation Protection: New Concepts from the NEA Committee on Radiation Protection and Public Health

Energy Technology Data Exchange (ETDEWEB)

Lazo, T.; McHugh, J.

2004-07-01

Since the publication of the last main recommendations of the International Commission on Radiological Protection (ICRP Publication 60, 1990) experience has shown that in applying the system of radiological protection, whilst many aspects work reasonably well, some areas have been identified as being somewhat unclear, or seemingly incoherent. While the CRPPH has, in general, found the ICRP system to be robust, the Committee has continued to focus its attention on those aspects of the system that it judges would benefit from further refinement. Recognising the need for modernisation, Professor Roger Clarke, the Chair of the ICRP, has published several papers in the open literature (Clarke 2002) suggesting an evolutionary process that could be followed for the development of the next set of ICRP recommendations, due in the 2005 time frame, and has engaged with many in the radiation protection community to seek their comments. The CRPPH has been actively involved in developing its own consensus thoughts on how the system of radiation protection could be made more responsive to decision makers, regulators and practitioners, and has provided these directly to the ICRP and the international community for consideration. To further refine this work, the CRPPH commissioned the Expert Group on the Evolution of the System of Radiation Protection (EGRP) to produce a follow-up contribution, which has suggested specific modifications to the current system of radiological protection that, in the Group's view, would result in improvement and simplification. These suggestions include : the implementation of an umbrella concept of ''Authorisation''. based on a process of constrained optimisation with appropriate stakeholder input, and would supersede the concepts of exemption, exclusion, , and triviality; clear recognition of the boundaries between the scientific aspects of risk assessment, the social aspects of risk evaluation, management, and acceptance

The Way Forward in Radiation Protection: New Concepts from the NEA Committee on Radiation Protection and Public Health

International Nuclear Information System (INIS)

Lazo, T.; McHugh, J.

2004-01-01

Since the publication of the last main recommendations of the International Commission on Radiological Protection (ICRP Publication 60, 1990) experience has shown that in applying the system of radiological protection, whilst many aspects work reasonably well, some areas have been identified as being somewhat unclear, or seemingly incoherent. While the CRPPH has, in general, found the ICRP system to be robust, the Committee has continued to focus its attention on those aspects of the system that it judges would benefit from further refinement. Recognising the need for modernisation, Professor Roger Clarke, the Chair of the ICRP, has published several papers in the open literature (Clarke 2002) suggesting an evolutionary process that could be followed for the development of the next set of ICRP recommendations, due in the 2005 time frame, and has engaged with many in the radiation protection community to seek their comments. The CRPPH has been actively involved in developing its own consensus thoughts on how the system of radiation protection could be made more responsive to decision makers, regulators and practitioners, and has provided these directly to the ICRP and the international community for consideration. To further refine this work, the CRPPH commissioned the Expert Group on the Evolution of the System of Radiation Protection (EGRP) to produce a follow-up contribution, which has suggested specific modifications to the current system of radiological protection that, in the Group's view, would result in improvement and simplification. These suggestions include : the implementation of an umbrella concept of A uthorisation , based on a process of constrained optimisation with appropriate stakeholder input, and would supersede the concepts of exemption, exclusion, , and triviality; clear recognition of the boundaries between the scientific aspects of risk assessment, the social aspects of risk evaluation, management, and acceptance, and the regulatory aspects

New method for evaluating the kinetic constant of thermal protection materials

International Nuclear Information System (INIS)

Bae, Ji Yeul; Yi, Jong Ju; Park, Sul Ki; Cho, Hyung Hee; Bae, Ju Chan; Ham, Hee Cheol

2013-01-01

Thermal protection material (TPM) is used to protect rocket structures from extreme conditions created by the hot exhaust of the rocket. Designing TPM is an important step in the rocket design process. Considering that an increase in the system weight decreases the overall performance of a rocket, the amount of TPM is carefully determined during the design process. Therefore, the precise properties of TPM guarantee an accurate thermal analysis and the successful design of the rocket. Among the many properties of TPM, the kinetic constant and activation energy, which govern the thermochemical reaction of the TPM, are the most important. Thus, an experiment to measure the kinetic constant and activation energy is conducted as part of this research. A theoretical approach to deduce the properties from measured data is discussed, and a method to apply the theory to experimental data, termed the R 2 method, is developed. Compared to a previous method which was difficult to apply, the R 2 method reduces unclear selections of the reaction time and does not require intervention by an interpreter. The properties deduced by the R 2 method show good agreement with the other method despite the limited number of experimental results.

On protection and operation of home consumption of large thermal and nuclear power plants

International Nuclear Information System (INIS)

Pospisil, J.

1988-01-01

The operating reliability of the system of home consumption is affected not only by the operating reliability of the equipment but also by the system of home consumption protection. The existing system of protection in Czechoslovakia and elsewhere and new concepts in the GDR and in Poland are described. In order to improve protection redundancy in the home consumption system, distance protection can be used. The reliability of the home consumption power supply system can be improved by the use of low-ohm grounding of the home consumption transformer or by an additional transformer and a protection system with time-graded overcurrent protection devices to the zero component of the current. (M.D.). 2 figs., 8 refs

Flexible Transpiration Cooled Thermal Protection System for Inflatable Atmospheric Capture and Entry Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Andrews Space, Inc. proposes an innovative transpiration cooled aerobrake TPS design that is thermally protective, structurally flexible, and lightweight. This...

Flexible Transpiration Cooled Thermal Protection System for Inflatable Atmospheric Capture and Entry Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Andrews Space, Inc. proposes an innovative transpiration cooled aerobrake TPS design that is thermally protective, structurally flexible, and lightweight. This...

Innovative nuclear thermal rocket concept utilizing LEU fuel for space application

International Nuclear Information System (INIS)

Nam, Seung Hyun; Venneri, Paolo; Choi, Jae Young; Jeong, Yong Hoon; Chang, Soon Heung

2015-01-01

Space is one of the best places for humanity to turn to keep learning and exploiting. A Nuclear Thermal Rocket (NTR) is a viable and more efficient option for human space exploration than the existing Chemical Rockets (CRs) which are highly inefficient for long-term manned missions such as to Mars and its satellites. NERVA derived NTR engines have been studied for the human missions as a mainstream in the United States of America (USA). Actually, the NERVA technology has already been developed and successfully tested since 1950s. The state-of-the-art technology is based on a Hydrogen gas (H_2) cooled high temperature reactor with solid core utilizing High-Enriched Uranium (HEU) fuel to reduce heavy metal mass and to use fast or epithermal neutron spectrums enabling simple core designs. However, even though the NTR designs utilizing HEU is the best option in terms of rocket performance, they inevitably provoke nuclear proliferation obstacles on all Research and Development (R and D) activities by civilians and non-nuclear weapon states, and its eventual commercialization. To surmount the security issue to use HEU fuel for a NTR, a concept of the innovative NTR engine, Korea Advanced NUclear Thermal Engine Rocket utilizing Low-Enriched Uranium fuel (KANUTER-LEU) is presented in this paper. The design goal of KANUTER-LEU is to make use of a LEU fuel for its compact reactor, but does not sacrifice the rocket performance relative to the traditional NTRs utilizing HEU. KANUTER-LEU mainly consists of a fission reactor utilizing H_2 propellant, a propulsion system and an optional Electricity Generation System as a bimodal engine. To implement LEU fuel for the reactor, the innovative engine adopts W-UO_2 CERMET fuel to drastically increase uranium density and thermal neutron spectrum to improve neutron economy in the core. The moderator and structural material selections also consider neutronic and thermo-physical characteristics to reduce non-fission neutron loss and

Analysis of risk and dose when using thermal protection on non-fissile and fissile-excepted UF6 48-inch cylinder packages

International Nuclear Information System (INIS)

Chambers, D.B.; Lowe, L.M.; Elizabeth Darrough, M.; Jones, R.H.

2004-01-01

An industry consortium of owners of large (i.e., the 48-inch or 48X and 48Y) cylinders commissioned an independent study to evaluate the safety of using thermal protective covers on the cylinders and the likelihood that the cylinders would experience the regulations' hypothetical thermal accident. The study examined the demonstrable risks of the protective covers, i.e., increased dose to workers and the potential for accidents associated with the extra handling, vs. the theoretical risk of the UF 6 cylinders' encountering the hypothetical fire, to evaluate the appropriateness of using the thermal protective covers

Concept of assistance of the Federal Office for Rdiation Protection with regard to serious cases of prevention of nuclear hazards

International Nuclear Information System (INIS)

Becker, D.E.

1998-01-01

For the defence against the threats through radioactive substances, a general concept is presently being elaborated under the overall control of the Federal Government. A number of competent organisations are involved in this, for example the Federal Office of Criminal Investigation, the Federal Armed Forces, and the Federal Office for Radiation Protection. In Germany, the 16 Federal States are responsible for the prevention of nuclear hazards. In the case of hazards through radioactive material, experts from the competent radiation protection authorities are consulted. For serious cases of prevention of nuclear hazards (nuclear fuels, criticality, danger of dispersion), the Federal Office for Radiation Protection - a subordinate authority of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety responsible for radiation protection - was given order to elaborate a concept for assistance to those Federal States. This concept is presented in the following. (author)

Thermal buffering performance of composite phase change materials applied in low-temperature protective garments

Science.gov (United States)

Yang, Kai; Jiao, Mingli; Yu, Yuanyuan; Zhu, Xueying; Liu, Rangtong; Cao, Jian

2017-07-01

Phase change material (PCM) is increasingly being applied in the manufacturing of functional thermo-regulated textiles and garments. This paper investigated the thermal buffering performance of different composite PCMs which are suitable for the application in functional low-temperature protective garments. First, according to the criteria selecting PCM for functional textiles/garments, three kinds of pure PCM were selected as samples, which were n-hexadecane, n-octadecane and n-eicosane. To get the adjustable phase change temperature range and higher phase change enthalpy, three kinds of composite PCM were prepared using the above pure PCM. To evaluate the thermal buffering performance of different composite PCM samples, the simulated low-temperature experiments were performed in the climate chamber, and the skin temperature variation curves in three different low temperature conditions were obtained. Finally composite PCM samples’ thermal buffering time, thermal buffering capacity and thermal buffering efficiency were calculated. Results show that the comprehensive thermal buffering performance of n-octadecane and n-eicosane composite PCM is the best.

3D Multifunctional Ablative Thermal Protection System

Science.gov (United States)

Feldman, Jay; Venkatapathy, Ethiraj; Wilkinson, Curt; Mercer, Ken

2015-01-01

NASA is developing the Orion spacecraft to carry astronauts farther into the solar system than ever before, with human exploration of Mars as its ultimate goal. One of the technologies required to enable this advanced, Apollo-shaped capsule is a 3-dimensional quartz fiber composite for the vehicle's compression pad. During its mission, the compression pad serves first as a structural component and later as an ablative heat shield, partially consumed on Earth re-entry. This presentation will summarize the development of a new 3D quartz cyanate ester composite material, 3-Dimensional Multifunctional Ablative Thermal Protection System (3D-MAT), designed to meet the mission requirements for the Orion compression pad. Manufacturing development, aerothermal (arc-jet) testing, structural performance, and the overall status of material development for the 2018 EM-1 flight test will be discussed.

Heat Transfer and Failure Mode Analyses of Ultrahigh-Temperature Ceramic Thermal Protection System of Hypersonic Vehicles

Directory of Open Access Journals (Sweden)

Tianbao Cheng

2014-01-01

Full Text Available The transient temperature distribution of the ultrahigh-temperature ceramic (UHTC thermal protection system (TPS of hypersonic vehicles is calculated using finite volume method. Convective cooling enables a balance of heat increment and loss to be achieved. The temperature in the UHTC plate at the balance is approximately proportional to the surface heat flux and is approximately inversely proportional to the convective heat transfer coefficient. The failure modes of the UHTCs are presented by investigating the thermal stress field of the UHTC TPS under different thermal environments. The UHTCs which act as the thermal protection materials of hypersonic vehicles can fail because of the tensile stress at the lower surface, an area above the middle plane, and the upper surface as well as because of the compressive stress at the upper surface. However, the area between the lower surface and the middle plane and a small area near the upper surface are relatively safe. Neither the compressive stress nor the tensile stress will cause failure of these areas.

The monolithic carbon aerogels and aerogel composites for electronics and thermal protection applications

Science.gov (United States)

Lu, Sheng; Guo, Hui; Zhou, Yugui; Liu, Yuanyuan; Jin, Zhaoguo; Liu, Bin; Zhao, Yingmin

2017-09-01

Monolithic carbon aerogels have been prepared by condensation polymerization and high temperature pyrolysis. The morphology of carbon aerogels are characterized by SEM. The pore structure is characterized by N2 adsorption-desorption technique. Monolithic carbon aerogels are mesoporous nanomaterials. Carbon fiber reinforced carbon aerogel composites are prepared by in-situ sol-gel process. Fiber reinforced carbon aerogel composites are of high mechanical strength. The thermal response of the fiber reinforced aerogel composite samples are tested in an arc plasma wind tunnel. Carbon aerogel composites show good thermal insulation capability and high temperature resistance in inert atmosphere even at ultrahigh temperature up to 1800 °C. The results show that they are suitable for applications in electrodes for supercapacitors/ Lithium-ion batteries and aerospace thermal protection area.

77 FR 11598 - Thermal Overload Protection for Electric Motors on Motor-Operated Valves

Science.gov (United States)

2012-02-27

... application of thermal overload protection devices that are integral with the motor starter for electric... Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, telephone: 301-251-7455; email... Development Branch, Division of Engineering, Office of Nuclear Regulatory Research. [FR Doc. 2012-4552 Filed 2...

Atomistic study of a nanometer-scale pump based on the thermal ratchet concept

DEFF Research Database (Denmark)

Oyarzua, Elton; Walther, J. H.; Zambrano, Harvey

In this study, a novel concept of nanoscale pump fabricated using Carbon Nanotubes (CNTs) is presented. The development of nanofluidic systems provides unprecedented possibilities for the control of biology and chemistry at the molecular level with potential applications in low energy cost devices...... dynamics simulations, we explore the possibility to design thermophoretic pumping devices fabricated of CNTs for water transport in nanoconduits. The design of the nanopumps is based on the concept of the Feynman-Smoluchowski ratchet....... of great interest in nanofluidics. Thermophoresisis the phenomenon observed when a mixture of two or more types of motile objects experience a force induced by a thermal gradient and the different types of objects respond to it differently, inducing a motion and segregation of the objects. Using molecular...

Space Shuttle Thermal Protection System Repair Flight Experiment Induced Contamination Impacts

Science.gov (United States)

Smith, Kendall A.; Soares, Carlos E.; Mikatarian, Ron; Schmidl, Danny; Campbell, Colin; Koontz, Steven; Engle, Michael; McCroskey, Doug; Garrett, Jeff

2006-01-01

NASA s activities to prepare for Flight LF1 (STS-114) included development of a method to repair the Thermal Protection System (TPS) of the Orbiter s leading edge should it be damaged during ascent by impacts from foam, ice, etc . Reinforced Carbon-Carbon (RCC) is used for the leading edge TPS. The repair material that was developed is named Non- Oxide Adhesive eXperimental (NOAX). NOAX is an uncured adhesive material that acts as an ablative repair material. NOAX completes curing during the Orbiter s descent. The Thermal Protection System (TPS) Detailed Test Objective 848 (DTO 848) performed on Flight LF1 (STS-114) characterized the working life, porosity void size in a micro-gravity environment, and the on-orbit performance of the repairs to pre-damaged samples. DTO 848 is also scheduled for Flight ULF1.1 (STS-121) for further characterization of NOAX on-orbit performance. Due to the high material outgassing rates of the NOAX material and concerns with contamination impacts to optically sensitive surfaces, ASTM E 1559 outgassing tests were performed to determine NOAX condensable outgassing rates as a function of time and temperature. Sensitive surfaces of concern include the Extravehicular Mobility Unit (EMU) visor, cameras, and other sensors in proximity to the experiment during the initial time after application. This paper discusses NOAX outgassing characteristics, how the amount of deposition on optically sensitive surfaces while the NOAX is being manipulated on the pre-damaged RCC samples was determined by analysis, and how flight rules were developed to protect those optically sensitive surfaces from excessive contamination where necessary.

An assessment of thermal spray coating technologies for high temperature corrosion protection

International Nuclear Information System (INIS)

Heath, G.R.; Heimgartner, P.; Gustafsson, S.; Irons, G.; Miller, R.

1997-01-01

The use of thermally sprayed coatings in combating high temperature corrosion continues to grow in the major industries of chemical, waste incineration, power generation and pulp and paper. This has been driven partially by the development of corrosion resistant alloys, improved knowledge and quality in the thermal spray industry and continued innovation in thermal spray equipment. There exists today an extensive range of thermal spray process options, often with the same alloy solution. In demanding corrosion applications it is not sufficient to just specify alloy and coating method. For the production of reliable coatings the whole coating production envelope needs to be considered, including alloy selection, spray parameters, surface preparation, base metal properties, heat input etc. Combustion, arc-wire, plasma, HVOF and spray+fuse techniques are reviewed and compared in terms of their strengths and limitations to provide cost-effective solutions for high temperature corrosion protection. Arc wire spraying, HP/HVOF and spray+fuse are emerging as the most promising techniques to optimise both coating properties and economic/practical aspects. (orig.)

In-Space Repair of Reinforced Carbon-Carbon Thermal Protection System Structures

Science.gov (United States)

Singh, Mrityunjay

2006-01-01

Advanced repair and refurbishment technologies are critically needed for the thermal protection system of current space transportation system as well as for future Crew Exploration Vehicles (CEV). The damage to these components could be caused by impact during ground handling or due to falling of ice or other objects during launch. In addition, in-orbit damage includes micrometeoroid and orbital debris impact as well as different factors (weather, launch acoustics, shearing, etc.) during launch and re-entry. The GRC developed GRABER (Glenn Refractory Adhesive for Bonding and Exterior Repair) material has shown multiuse capability for repair of small cracks and damage in reinforced carbon-carbon (RCC) material. The concept consists of preparing an adhesive paste of desired ceramic with appropriate additives and then applying the paste to the damaged/cracked area of the RCC composites with adhesive delivery system. The adhesive paste cures at 100-120 C and transforms into a high temperature ceramic during simulated entry conditions. A number of plasma torch and ArcJet tests were carried out to evaluate the crack repair capability of GRABER materials for Reinforced Carbon-Carbon (RCC) composites. For the large area repair applications, integrated system for tile and leading edge repair (InSTALER) have been developed. In this presentation, critical in-space repair needs and technical challenges as well as various issues and complexities will be discussed along with the plasma performance and post test characterization of repaired RCC materials.

Small Scale Hydrocarbon Fire Test Concept

Directory of Open Access Journals (Sweden)

Joachim Søreng Bjørge

2017-11-01

Full Text Available In the oil and gas industry, hydrocarbon process equipment was previously often thermally insulated by applying insulation directly to the metal surface. Fire protective insulation was applied outside the thermal insulation. In some cases, severe corrosion attacks were observed due to ingress of humidity and condensation at cold surfaces. Introducing a 25 mm air gap to prevent wet thermal insulation and metal wall contact is expected to solve the corrosion issues. This improved insulation methodology does, however, require more space that may not be available when refurbishing older process plants. Relocating structural elements would introduce much hot work, which should be minimized in live plants. It is also costly. The aim of the present study is therefore to develop a test concept for testing fire resistance of equipment protected with only air-gap and thermal insulation, i.e., without the fire-protective insulation. The present work demonstrates a conceptual methodology for small scale fire testing of mockups resembling a section of a distillation column. The mockups were exposed to a small-scale propane flame in a test configuration where the flow rate and the flame zone were optimized to give heat flux levels in the range 250–350 kW/m2. Results are presented for a mockup resembling a 16 mm thick distillation column steel wall. It is demonstrated that the modern distance insulation in combination with the heat capacity of the column wall indicates 30+ minutes fire resistance. The results show that this methodology has great potentials for low cost fire testing of other configurations, and it may serve as a set-up for product development.

Use of thermal time constant concept in the analysis of reactivity induced accidents with feedback

International Nuclear Information System (INIS)

Narain, R.

1981-01-01

A simple heat transfer model based on the thermal time constant concept which leads to significant reduction in fuel temperature computing time and gives a physical insight of the phenomena is presented. The fuel temperatures can be used to estimate the reactivity feedback using the measured or calculated Doppler coefficients. (E.G.) [pt

Improvement of environmental aspects of thermal power plant operation by advanced control concepts

Directory of Open Access Journals (Sweden)

Mikulandrić Robert

2012-01-01

Full Text Available The necessity of the reduction of greenhouse gas emissions, as formulated in the Kyoto Protocol, imposes the need for improving environmental aspects of existing thermal power plants operation. Improvements can be reached either by efficiency increment or by implementation of emission reduction measures. Investments in refurbishment of existing plant components or in plant upgrading by flue gas desulphurization, by primary and secondary measures of nitrogen oxides reduction, or by biomass co-firing, are usually accompanied by modernisation of thermal power plant instrumentation and control system including sensors, equipment diagnostics and advanced controls. Impact of advanced control solutions implementation depends on technical characteristics and status of existing instrumentation and control systems as well as on design characteristics and actual conditions of installed plant components. Evaluation of adequacy of implementation of advanced control concepts is especially important in Western Balkan region where thermal power plants portfolio is rather diversified in terms of size, type and commissioning year and where generally poor maintenance and lack of investments in power generation sector resulted in high greenhouse gases emissions and low efficiency of plants in operation. This paper is intended to present possibilities of implementation of advanced control concepts, and particularly those based on artificial intelligence, in selected thermal power plants in order to increase plant efficiency and to lower pollutants emissions and to comply with environmental quality standards prescribed in large combustion plant directive. [Acknowledgements. This paper has been created within WBalkICT - Supporting Common RTD actions in WBCs for developing Low Cost and Low Risk ICT based solutions for TPPs Energy Efficiency increasing, SEE-ERA.NET plus project in cooperation among partners from IPA SA - Romania, University of Zagreb - Croatia and Vinca

New method for evaluating the kinetic constant of thermal protection materials

Energy Technology Data Exchange (ETDEWEB)

Bae, Ji Yeul; Yi, Jong Ju; Park, Sul Ki; Cho, Hyung Hee [Yonsei University, Seoul (Korea, Republic of); Bae, Ju Chan; Ham, Hee Cheol [Agency for Defense Development, Daegu (Korea, Republic of)

2013-06-15

Thermal protection material (TPM) is used to protect rocket structures from extreme conditions created by the hot exhaust of the rocket. Designing TPM is an important step in the rocket design process. Considering that an increase in the system weight decreases the overall performance of a rocket, the amount of TPM is carefully determined during the design process. Therefore, the precise properties of TPM guarantee an accurate thermal analysis and the successful design of the rocket. Among the many properties of TPM, the kinetic constant and activation energy, which govern the thermochemical reaction of the TPM, are the most important. Thus, an experiment to measure the kinetic constant and activation energy is conducted as part of this research. A theoretical approach to deduce the properties from measured data is discussed, and a method to apply the theory to experimental data, termed the R{sup 2} method, is developed. Compared to a previous method which was difficult to apply, the R{sup 2} method reduces unclear selections of the reaction time and does not require intervention by an interpreter. The properties deduced by the R{sup 2} method show good agreement with the other method despite the limited number of experimental results.

Development of a helmet-mounted PLZT thermal/flash protection system

International Nuclear Information System (INIS)

Harris, J.O. Jr.; Cutchen, J.T.; Pfoff, B.J.

1976-01-01

Sandia Laboratories is developing PLZT thermal/flash protective devices (TFPD's) goggles to prevent exposure and resultant eye damage from nuclear weapon detonations. The primary emphasis of the present program is to transfer technology and establish production capability for helmet-mounted PLZT/TFPD goggles for USAF flight crews, with a non-helmet-mounted configuration to follow. The first production units are anticipated in the fall of 1977. The operating principles of the PLZT/TFPD goggle device are briefly outlined, and the device configuration and operational characteristics are described

Detection of impact damage on thermal protection systems using thin-film piezoelectric sensors for integrated structural health monitoring

Science.gov (United States)

Na, Jeong K.; Kuhr, Samuel J.; Jata, Kumar V.

2008-03-01

Thermal Protection Systems (TPS) can be subjected to impact damage during flight and/or during ground maintenance and/or repair. AFRL/RXLP is developing a reliable and robust on-board sensing/monitoring capability for next generation thermal protection systems to detect and assess impact damage. This study was focused on two classes of metallic thermal protection tiles to determine threshold for impact damage and develop sensing capability of the impacts. Sensors made of PVDF piezoelectric film were employed and tested to evaluate the detectability of impact signals and assess the onset or threshold of impact damage. Testing was performed over a range of impact energy levels, where the sensors were adhered to the back of the specimens. The PVDF signal levels were analyzed and compared to assess damage, where digital microscopy, visual inspection, and white light interferometry were used for damage verification. Based on the impact test results, an assessment of the impact damage thresholds for each type of metallic TPS system was made.

Physical protection concepts of nuclear materials. The French experience

International Nuclear Information System (INIS)

Arnaud, G.; Artaud, R.

1995-01-01

As the nuclear energy was being developed, it appeared necessary to set up protections against its potential hazards, that should be more complete and elaborate than those implemented on the other industrial installations. This had to be done both in the safety field to prevent the environment and the populations from the consequences of severe casualties, and in the security field to avoid the risk of proliferation and limit to an acceptable level the results of voluntarily provoked accidents and sabotages. Taking advantage of the gathered experience, this document gives consideration to the concepts used in France in order to ensure the physical protection of the nuclear materials. The following topics are tackled: context inside which are envisaged the specific measures, coherence with the general dispositions taken to protect industrial installations, importance and limitations of the part played by the regulations, respective responsibilities of the plant operators and the public authorities, compromise between objectives in view and means to implement, adjustment between the physical protection system and the operating requirements. In addition, the ways in which these systems should be implemented are discussed, underlining the necessity to make progressive steps under a permanent will, in order, first, to update and bring under conformity the old installations, and second, to ensure the maintenance of the systems, taking account of the evolutions of needs and techniques. Those points are commented on examples taken among the different types of installations to be found in France, showing the differences in approach coming from the type and the age of the facilities, and giving the present trends for the new plants. (authors). 1 annexe

Analysis of risk and dose when using thermal protection on non-fissile and fissile-excepted UF{sub 6} 48-inch cylinder packages

Energy Technology Data Exchange (ETDEWEB)

Chambers, D.B.; Lowe, L.M. [SENES Consultants Ltd., Richmond Hill, ON (Canada); Elizabeth Darrough, M.; Jones, R.H.

2004-07-01

An industry consortium of owners of large (i.e., the 48-inch or 48X and 48Y) cylinders commissioned an independent study to evaluate the safety of using thermal protective covers on the cylinders and the likelihood that the cylinders would experience the regulations' hypothetical thermal accident. The study examined the demonstrable risks of the protective covers, i.e., increased dose to workers and the potential for accidents associated with the extra handling, vs. the theoretical risk of the UF{sub 6} cylinders' encountering the hypothetical fire, to evaluate the appropriateness of using the thermal protective covers.

Assessing energy and thermal comfort of different low-energy cooling concepts for non-residential buildings

International Nuclear Information System (INIS)

Salvalai, Graziano; Pfafferott, Jens; Sesana, Marta Maria

2013-01-01

Highlights: • Impact of five cooling technologies are simulated in six European climate zones with Trnsys 17. • The ventilation strategies reduce the cooling energy need even in South Europe climate. • Constant ventilation controller can lead to a poor cooling performance. • Comparing radiant strategies with air conditioning scenario, the energy saving is predicted to within 5–35%. - Abstract: Energy consumption for cooling is growing dramatically. In the last years, electricity peak consumption grew significantly, switching from winter to summer in many EU countries. This is endangering the stability of electricity grids. This article outlines a comprehensive analysis of an office building performances in terms of energy consumption and thermal comfort (in accordance with static – ISO 7730:2005 – and adaptive thermal comfort criteria – EN 15251:2007 –) related to different cooling concepts in six different European climate zones. The work is based on a series of dynamic simulations carried out in the Trnsys 17 environment for a typical office building. The simulation study was accomplished for five cooling technologies: natural ventilation (NV), mechanical night ventilation (MV), fan-coils (FC), suspended ceiling panels (SCP), and concrete core conditioning (CCC) applied in Stockholm, Hamburg, Stuttgart, Milan, Rome, and Palermo. Under this premise, the authors propose a methodology for the evaluation of the cooling concepts taking into account both, thermal comfort and energy consumption

Thermal characteristics of highly compressed bentonite

International Nuclear Information System (INIS)

Sueoka, Tooru; Kobayashi, Atsushi; Imamura, S.; Ogawa, Terushige; Murata, Shigemi.

1990-01-01

In the disposal of high level radioactive wastes in strata, it is planned to protect the canisters enclosing wastes with buffer materials such as overpacks and clay, therefore, the examination of artificial barrier materials is an important problem. The concept of the disposal in strata and the soil mechanics characteristics of highly compressed bentonite as an artificial barrier material were already reported. In this study, the basic experiment on the thermal characteristics of highly compressed bentonite was carried out, therefore, it is reported. The thermal conductivity of buffer materials is important because the possibility that it determines the temperature of solidified bodies and canisters is high, and the buffer materials may cause the thermal degeneration due to high temperature. Thermophysical properties are roughly divided into thermodynamic property, transport property and optical property. The basic principle of measured thermal conductivity and thermal diffusivity, the kinds of the measuring method and so on are explained. As for the measurement of the thermal conductivity of highly compressed bentonite, the experimental setup, the procedure, samples and the results are reported. (K.I.)

Special protective concretes

International Nuclear Information System (INIS)

Bouniol, P.

2001-01-01

Concrete is the most convenient material when large-scale radiation protection is needed. Thus, special concretes for nuclear purposes are used in various facilities like reactors, reprocessing centers, storage sites, accelerators, hospitals with nuclear medicine equipment, food ionization centers etc.. The recent advances made in civil engineering for the improvement of concrete durability and compactness are for a large part transposable to protection concretes. This article presents the basic knowledge about protection concretes with the associated typological and technological aspects. A large part is devoted to the intrinsic properties of concretes and to their behaviour in irradiation and temperature conditions: 1 - definition and field of application of special protective concretes; 2 - evolution of concepts and technologies (durability of structures, techniques of formulation, new additives, market evolution); 3 - design of protective structures (preliminary study, radiation characteristics, thermal constraints, damping and dimensioning, mechanical criteria); 4 - formulation of special concretes (general principles, granulates, hydraulic binders, pulverulent additives, water/cement ratio, reference composition of some special concretes); 5 - properties of special concretes (damping and thermo-mechanical properties); 6 - induced-irradiation and temperature phenomena (activation, radiolysis, mineralogical transformations, drying, shrinking, creep, corrosion of reinforcement). (J.S.)

A Numerical Proof of Concept for Thermal Flow Control

Directory of Open Access Journals (Sweden)

V. Dragan

2017-02-01

Full Text Available In this paper computational fluid dynamics is used to provide a proof of concept for controlled flow separation using thermal wall interactions with the velocity boundary layer. A 3D case study is presented, using a transition modeling Shear Stress Transport turbulence model. The highly loaded single slot flap airfoil was chosen to be representative for a light aircraft and the flow conditions were modeled after a typical landing speed. In the baseline case, adiabatic walls were considered while in the separation control case, the top surface of the flaps was heated to 500 K. This heating lead to flow separation on the flaps and a significant alteration of the flow pattern across all the elements of the wing. The findings indicate that this control method has potential, with implications in both aeronautical as well as sports and civil engineering applications.

Integrated Thermal Protection Systems and Heat Resistant Structures

Science.gov (United States)

Pichon, Thierry; Lacoste, Marc; Glass, David E.

2006-01-01

In the early stages of NASA's Exploration Initiative, Snecma Propulsion Solide was funded under the Exploration Systems Research & Technology program to develop integrated thermal protection systems and heat resistant structures for reentry vehicles. Due to changes within NASA's Exploration Initiative, this task was cancelled early. This presentation provides an overview of the work that was accomplished prior to cancellation. The Snecma team chose an Apollo-type capsule as the reference vehicle for the work. They began with the design of a ceramic aft heatshield (CAS) utilizing C/SiC panels as the capsule heatshield, a C/SiC deployable decelerator and several ablators. They additionally developed a health monitoring system, high temperature structures testing, and the insulation characterization. Though the task was pre-maturely cancelled, a significant quantity of work was accomplished.

Thermal Protection Test Bed Pathfinder Development Project

Science.gov (United States)

Snapp, Cooper

2015-01-01

In order to increase thermal protection capabilities for future reentry vehicles, a method to obtain relevant test data is required. Although arc jet testing can be used to obtain some data on materials, the best method to obtain these data is to actually expose them to an atmospheric reentry. The overprediction of the Orion EFT-1 flight data is an example of how the ground test to flight traceability is not fully understood. The RED-Data small reentry capsule developed by Terminal Velocity Aerospace is critical to understanding this traceability. In order to begin to utilize this technology, ES3 needs to be ready to build and integrate heat shields onto the RED-Data vehicle. Using a heritage Shuttle tile material for the heat shield will both allow valuable insight into the environment that the RED-Data vehicle can provide and give ES3 the knowledge and capability to build and integrate future heat shields for this vehicle.

A carbon-carbon panel design concept for the inboard limiter of the Compact Ignition Tokamak (CIT)

International Nuclear Information System (INIS)

Mantz, H.C.; Bowers, D.A.; Williams, F.R.; Witten, M.A.

1989-01-01

The inboard limiter of the Compact Ignition Tokamak (CIT) must protect the vacuum vessel from the plasma energy. This limiter region must withstand nominal heat fluxes in excess of 10 MW/m 2 and in addition it must be designed to be remotely maintained. Carbon-carbon composite material was selected over bulk graphite materials for the limiter design because of its ability to meet the thermal and structural requirements. The structural design concept consists of carbon-carbon composite panels attached to the vacuum vessel by a hinged rod/retainer concept. Results of the preliminary design study to define this inboard limiter are presented. The design concept is described along with the analyses of the thermal and structural response during nominal plasma operation and during plasma disruption events. 2 refs., 8 figs

Electric power from laser fusion: the HYLIFE concept

International Nuclear Information System (INIS)

Monsler, M.; Blink, J.; Hovingh, J.; Meier, W.; Walker, P.; Maniscalco, J.

1978-06-01

A high yield lithium injection fusion energy chamber is described which can conceptually be operated with pulsed yields of several thousand megajoules a few times a second, using less than one percent of the gross thermal power to circulate the lithium. Because a one meter thick blanket of lithium protects the structure, no first wall replacement is envisioned for the life of the power plant. The induced radioactivity is reduced by an order of magnitude over solid blanket concepts. The design calls for the use of common ferritic steels and a power density approaching that of a LWR, promising shortened development times over other fusion concepts and reactor vessel costs comparable to a LMFBR

The Relationship between Physical Activity and Thermal Protective Clothing on Functional Balance in Firefighters

Science.gov (United States)

Kong, Pui W.; Suyama, Joe; Cham, Rakie; Hostler, David

2012-01-01

We investigated the relationship between baseline physical training and the use of firefighting thermal protective clothing (TPC) with breathing apparatus on functional balance. Twenty-three male firefighters performed a functional balance test under four gear/clothing conditions. Participants were divided into groups by physical training status,…

Evaluation of antioxidants stability by thermal analysis and its protective effect in heated edible vegetable oil

Directory of Open Access Journals (Sweden)

Seme Youssef Reda

2011-06-01

Full Text Available In this work, through the use of thermal analysis techniques, the thermal stabilities of some antioxidants were investigated, in order to evaluate their resistance to thermal oxidation in oils, by heating canola vegetable oil, and to suggest that antioxidants would be more appropriate to increase the resistance of vegetable oils in the thermal degradation process in frying. The techniques used were: Thermal Gravimetric (TG and Differential Scanning Calorimetry (DSC analyses, as well as an allusion to a possible protective action of the vegetable oils, based on the thermal oxidation of canola vegetable oil in the laboratory under constant heating at 180 ºC/8 hours for 10 days. The studied antioxidants were: ascorbic acid, sorbic acid, citric acid, sodium erythorbate, BHT (3,5-di-tert-butyl-4-hydroxytoluene, BHA (2, 3-tert-butyl-4-methoxyphenol, TBHQ (tertiary butyl hydroquinone, PG (propyl gallate - described as antioxidants by ANVISA and the FDA; and also the phytic acid antioxidant and the SAIB (sucrose acetate isobutyrate additive, which is used in the food industry, in order to test its behavior as an antioxidant in vegetable oil. The following antioxidants: citric acid, sodium erythorbate, BHA, BHT, TBHQ and sorbic acid decompose at temperatures below 180 ºC, and therefore, have little protective action in vegetable oils undergoing frying processes. The antioxidants below: phytic acid, ascorbic acid and PG, are the most resistant and begin their decomposition processes at temperatures between 180 and 200 ºC. The thermal analytical techniques have also shown that the SAIB antioxidant is the most resistant to oxidative action, and it can be a useful choice in the thermal decomposition prevention of edible oils, improving stability regarding oxidative processes.

Equivalent Energy Density concept: A preliminary reexamination of a technique for equating thermal loads

International Nuclear Information System (INIS)

Ryder, E.E.

1992-08-01

Historical and projected inventories of spent fuel from commercial light-water nuclear reactors exhibit diverse decay characteristics and ages. This report summarizes a preliminary reexamination of a method for determining equivalent thermal loads for the range of spent fuel expected at a potential underground repository. The method, known at the Equivalent Energy Density (EED) concept, bases its equivalence criteria on the assumption that a given waste will produce worst-case thermomechanical effects equal to worst-case thermomechanical effects produced by a baseline waste, provided that the thermal energy deposited in the host rock over a specified deposition period is the same for both waste descriptions. To test this assumption, temperature histories at representative locations within the host rock were calculated using layouts defined by the EED concept and four deposition periods (20, 50, 100, and 300 years). It was found that the peak temperatures at near-field locations were best matched by the shorter deposition periods of 20 and 50 years. However, due to the sensitivity of the near-field environment to short-term canister-to-canister interactions, caution,should be used when choosing a near-field deposition period. At the location chosen to represent the far-field, a 300-year deposition period provided reasonable correspondence of peak temperature responses for all waste descriptions examined

A Satellite-Based Imaging Instrumentation Concept for Hyperspectral Thermal Remote Sensing.

Science.gov (United States)

Udelhoven, Thomas; Schlerf, Martin; Segl, Karl; Mallick, Kaniska; Bossung, Christian; Retzlaff, Rebecca; Rock, Gilles; Fischer, Peter; Müller, Andreas; Storch, Tobias; Eisele, Andreas; Weise, Dennis; Hupfer, Werner; Knigge, Thiemo

2017-07-01

This paper describes the concept of the hyperspectral Earth-observing thermal infrared (TIR) satellite mission HiTeSEM (High-resolution Temperature and Spectral Emissivity Mapping). The scientific goal is to measure specific key variables from the biosphere, hydrosphere, pedosphere, and geosphere related to two global problems of significant societal relevance: food security and human health. The key variables comprise land and sea surface radiation temperature and emissivity, surface moisture, thermal inertia, evapotranspiration, soil minerals and grain size components, soil organic carbon, plant physiological variables, and heat fluxes. The retrieval of this information requires a TIR imaging system with adequate spatial and spectral resolutions and with day-night following observation capability. Another challenge is the monitoring of temporally high dynamic features like energy fluxes, which require adequate revisit time. The suggested solution is a sensor pointing concept to allow high revisit times for selected target regions (1-5 days at off-nadir). At the same time, global observations in the nadir direction are guaranteed with a lower temporal repeat cycle (>1 month). To account for the demand of a high spatial resolution for complex targets, it is suggested to combine in one optic (1) a hyperspectral TIR system with ~75 bands at 7.2-12.5 µm (instrument NEDT 0.05 K-0.1 K) and a ground sampling distance (GSD) of 60 m, and (2) a panchromatic high-resolution TIR-imager with two channels (8.0-10.25 µm and 10.25-12.5 µm) and a GSD of 20 m. The identified science case requires a good correlation of the instrument orbit with Sentinel-2 (maximum delay of 1-3 days) to combine data from the visible and near infrared (VNIR), the shortwave infrared (SWIR) and TIR spectral regions and to refine parameter retrieval.

A Satellite-Based Imaging Instrumentation Concept for Hyperspectral Thermal Remote Sensing

Directory of Open Access Journals (Sweden)

Thomas Udelhoven

2017-07-01

Full Text Available This paper describes the concept of the hyperspectral Earth-observing thermal infrared (TIR satellite mission HiTeSEM (High-resolution Temperature and Spectral Emissivity Mapping. The scientific goal is to measure specific key variables from the biosphere, hydrosphere, pedosphere, and geosphere related to two global problems of significant societal relevance: food security and human health. The key variables comprise land and sea surface radiation temperature and emissivity, surface moisture, thermal inertia, evapotranspiration, soil minerals and grain size components, soil organic carbon, plant physiological variables, and heat fluxes. The retrieval of this information requires a TIR imaging system with adequate spatial and spectral resolutions and with day-night following observation capability. Another challenge is the monitoring of temporally high dynamic features like energy fluxes, which require adequate revisit time. The suggested solution is a sensor pointing concept to allow high revisit times for selected target regions (1–5 days at off-nadir. At the same time, global observations in the nadir direction are guaranteed with a lower temporal repeat cycle (>1 month. To account for the demand of a high spatial resolution for complex targets, it is suggested to combine in one optic (1 a hyperspectral TIR system with ~75 bands at 7.2–12.5 µm (instrument NEDT 0.05 K–0.1 K and a ground sampling distance (GSD of 60 m, and (2 a panchromatic high-resolution TIR-imager with two channels (8.0–10.25 µm and 10.25–12.5 µm and a GSD of 20 m. The identified science case requires a good correlation of the instrument orbit with Sentinel-2 (maximum delay of 1–3 days to combine data from the visible and near infrared (VNIR, the shortwave infrared (SWIR and TIR spectral regions and to refine parameter retrieval.

Protection devices in the transmission grids, German practice. Typical protection concepts in Germany's power transmission lines; Schutzsysteme im Uebertragungsnetz, deutsche Praxis. Typische Schutzkonzepte im deutschen Uebertragungsnetz

Energy Technology Data Exchange (ETDEWEB)

Herrmann, Hans-Joachim [Siemens AG, Nuernberg (Germany). Sektor Energy, Energy Automation; Ludwig, Andrea [50 Hertz Transmission GmbH, Berlin (Germany). Schutztechnik, Anlagenmanagement; Kuehn, Holger [Tennet TSO GmbH, Bayreuth (Germany). Schutztechnik, Assetmanagement/Umspannwerke; Oechsle, Fred [EnBW Regional AG, Stuttgart (Germany). Netzschutz, Netzservice - Projekte Strom

2011-04-18

The contribution presents typical protection concepts for power grids. Solutions for power plant feed-in, bus bar, transmission lines and coupling transformer are explained. General information is provided on triggering concepts, on the design of d.c. power supply, selection of current inverters, and other subjects.

A Simplified Top-Oil Temperature Model for Transformers Based on the Pathway of Energy Transfer Concept and the Thermal-Electrical Analogy

Directory of Open Access Journals (Sweden)

Muhammad Hakirin Roslan

2017-11-01

Full Text Available This paper presents an alternative approach to determine the simplified top-oil temperature (TOT based on the pathway of energy transfer and thermal-electrical analogy concepts. The main contribution of this study is the redefinition of the nonlinear thermal resistance based on these concepts. An alternative approximation of convection coefficient, h, based on heat transfer theory was proposed which eliminated the requirement of viscosity. In addition, the lumped capacitance method was applied to the thermal-electrical analogy to derive the TOT thermal equivalent equation in differential form. The TOT thermal model was evaluated based on the measured TOT of seven transformers with either oil natural air natural (ONAN or oil natural air forced (ONAF cooling modes obtained from temperature rise tests. In addition, the performance of the TOT thermal model was tested on step-loading of a transformer with an ONAF cooling mode obtained from previous studies. A comparison between the TOT thermal model and the existing TOT Thermal-Electrical, Exponential (IEC 60076-7, and Clause 7 (IEEE C57.91-1995 models was also carried out. It was found that the measured TOT of seven transformers are well represented by the TOT thermal model where the highest maximum and root mean square (RMS errors are 6.66 °C and 2.76 °C, respectively. Based on the maximum and RMS errors, the TOT thermal model performs better than Exponential and Clause 7 models and it is comparable with the Thermal-Electrical 1 (TE1 and Thermal-Electrical 2 (TE2 models. The same pattern is found for the TOT thermal model under step-loading where the maximum and RMS errors are 5.77 °C and 2.02 °C.

Central unresolved issues in thermal energy storage for building heating and cooling

Energy Technology Data Exchange (ETDEWEB)

Swet, C.J.; Baylin, F.

1980-07-01

This document explores the frontier of the rapidly expanding field of thermal energy storage, investigates unresolved issues, outlines research aimed at finding solutions, and suggests avenues meriting future research. Issues related to applications include value-based ranking of storage concepts, temperature constraints, consistency of assumptions, nomenclature and taxonomy, and screening criteria for materials. Issues related to technologies include assessing seasonal storage concepts, diurnal coolness storage, selection of hot-side storage concepts for cooling-only systems, phase-change storage in building materials, freeze protection for solar water heating systems, and justification of phase-change storage for active solar space heating.

Thixoforming of Steel: New Tools Conception to Analyse Thermal Exchanges and Strain Rate Effects

International Nuclear Information System (INIS)

Cezard, P.; Bigot, R.; Becker, E.; Mathieu, S.; Pierret, J. C.; Rassili, A.

2007-01-01

Through different papers, authors shown that the influence of thermal exchanges was a first order parameter on the semi-solid steel behaviour, and certainly for every semi-solid metallic materials. These thermal exchanges hide other parameters effect like, for example, the strain rate influence. This paper tries to determine the influence of these two parameters by using a new extrusion device on a hydraulic press. This new tools conception annihilated the influence of the decrease of the punch speed before stopping and permitted to have a constant speed during the experiment. This work also deals with the homogeneous flow during thixoforming of steel and shows the importance to couple initial temperature of the slug with punch speed. This paper presents different conditions which permitted to have a homogeneous flow by keeping a low load

Theoretical prediction of thermal conductivity for thermal protection systems

International Nuclear Information System (INIS)

Gori, F.; Corasaniti, S.; Worek, W.M.; Minkowycz, W.J.

2012-01-01

The present work is aimed to evaluate the effective thermal conductivity of an ablative composite material in the state of virgin material and in three paths of degradation. The composite material is undergoing ablation with formation of void pores or char and void pores. The one dimensional effective thermal conductivity is evaluated theoretically by the solution of heat conduction under two assumptions, i.e. parallel isotherms and parallel heat fluxes. The paper presents the theoretical model applied to an elementary cubic cell of the composite material which is made of two crossed fibres and a matrix. A numerical simulation is carried out to compare the numerical results with the theoretical ones for different values of the filler volume fraction. - Highlights: ► Theoretical models of the thermal conductivity of an ablative composite. ► Composite material is made of two crossed fibres and a matrix. ► Three mechanisms of degradation are investigated. ► One dimensional thermal conductivity is evaluated by the heat conduction equation. ► Numerical simulations to be compared with the theoretical models.

The development of an environmental protection programme for the population based on concepts and standards inspired by radiological protection

International Nuclear Information System (INIS)

Recht, P.

1977-01-01

Following the United Nations Conference in Stockholm, 1972, on the protection of the environment a certain number of principles and methods have been put forward to national authorities which put into effect environmental protection programmes. Several of these principles have been taken directly from and inspired by the field of application of radiological protection; it is not without interest to draw comparisons between those which have been conceived and applied in health physics for the prevention of a radioactivity risk as it applies to the population, and those which already exist or which are envisaged vis-a-vis the risks from non radioactive pollutants. It is opportune to remember that the ICRP publications, in particular those published in and after 1958, included recommendations on radiological protection, and that these recommendations laid down the bases for both the theoretical steps and the practical methodology of which the main components are still in existence today; a remarkable achievement which merits emphasis. The ICRP recommendations included in publication 1 and more particularly publications 7, 9 and 22 introduced the basic concepts of a health physics policy which can be recognized as having been beneficial for the protection of man and his environment and which can be utilized as a basis for consideration, if not action, as it concerns the non-radioactive environmental pollutants [fr

Non-ionizing radiation and health protection problems

International Nuclear Information System (INIS)

Jammet, Henri.

1979-01-01

Wavelength and frequency are two closely related properties which determine the characteristics of any particular type of electromagnetic radiation and which can be used interchangeably to describe it. For protection purposes the determination of the energy absorbed (absorbed dose) and of its distribution within living systems, whatever the radiation concerned, is still one of the chief problems to be solved. Therefore, although thermal effects are often prevailing, no appropriate dose-effect relationships could be established in most cases and more particularly as far as non-thermal effects are concerned. The problems associated with the different types of NIR are briefly reviewed. An increasing number of countries is promulgating regulatory measures for limiting exposure to NIR of occupationally exposed individuals and of the general population. Harmonization of basic concepts and internationally acceptable protection standards are therefore urgently needed. IRPA is probably the only international, non-governmental scientific organization able to promote wide international and interdisciplinary cooperation in the field of health protection against NIR. Therefore, after having carefully considered the situation, IRPA felt that it was its responsibility to produce guidance on basic protection criteria and standards and created the International NIR-Committee with the objective of developing background documents and internationally accepted recommendations

Thermal-hydraulic limitations on water-cooled fusion reactor components

International Nuclear Information System (INIS)

Cha, Y.S.; Misra, B.

1986-01-01

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on conventional design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require unconventional shapes or heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated conditions. Since the data presented herein are concerned primarily with thermal protection of the reactor components, the final design should consider other factors such as thermal stresses, temperature limits, and fatigue

A new concept Tandem thermal dissociator/electron impact ion source for RIB generation

International Nuclear Information System (INIS)

Alton, G.D.; Williams, C.

1995-01-01

An innovative thermal dissociation/electron impact ionization positive ion source is presently under design at the Oak Ridge National Laboratory for potential use for generating RIBs at the Holifield Radioactive Ion Beam Facility (HRIBF). Because of the low probability of simultaneously dissociating and efficiently ionizing the individual atomic constituents with conventional, hot-cathode, electron-impact ion sources, the ion beams extracted from these sources often appear as a mixture of several molecular sideband beams. In this way, the intensity of the species of interest is diluted. We have conceived an Ion source that combines the excellent molecular dissociation properties of a thermal dissociator and the high efficiency characteristics of an electron impact ionization source. If the concept proves to be a viable option, the source will be used as a complement to the electron beam plasma ion sources already in use at the HRIBF. The design features and principles of operation of the source are described in this article

Concept of assistance of the Federal Office for Radiation Protection with regard to prevention of serious cases of nuclear hazards

Energy Technology Data Exchange (ETDEWEB)

Becker, D.E. [Federal Office for Radiation Protection, Salzgitter (Germany)

2000-05-01

For the defence against the threats caused by radioactive substances, a general concept was elaborated under the overall control of the Federal Government. A number of competent organisations are involved in this, for example the Federal Office of Criminal Investigation, the Federal Armed Forces, and the Federal Office for Radiation Protection. In Germany, the 16 Federal States are responsible for the prevention of nuclear hazards. In the case of hazards caused by radioactive material, experts from the competent radiation protection authorities are consulted. For the prevention of serious cases of nuclear hazards (nuclear fuels, criticality, danger of dispersion), the Federal Office for Radiation Protection - a subordinate authority of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety responsible for radiation protection, nuclear safety, and waste management - was given order to elaborate a concept for assistance to those Federal States. The field of prevention of nuclear hazards ranges from combatting illegal trade with radioactive test sources up to the defence of nuclear fuels with the possibility to construct critical assemblies or the threatening by the distribution of airborne material which might enter the lungs. The latter are considered as serious cases of nuclear hazards. Since the expenditures for devices and personal to be trained would be inadequately high, the Federal Office for Radiation Protection (BfS) is prepared to support the Federal States if it becomes necessary. The concept includes a stand-by service, the search for radioactive material by helicopter or a ground team, analysis of the activity and the type of nuclides, risk assessment, and also measures to steam the risk. This concept will be presented. (author)

Concept of assistance of the Federal Office for Radiation Protection with regard to prevention of serious cases of nuclear hazards

International Nuclear Information System (INIS)

Becker, D.E.

2000-01-01

For the defence against the threats caused by radioactive substances, a general concept was elaborated under the overall control of the Federal Government. A number of competent organisations are involved in this, for example the Federal Office of Criminal Investigation, the Federal Armed Forces, and the Federal Office for Radiation Protection. In Germany, the 16 Federal States are responsible for the prevention of nuclear hazards. In the case of hazards caused by radioactive material, experts from the competent radiation protection authorities are consulted. For the prevention of serious cases of nuclear hazards (nuclear fuels, criticality, danger of dispersion), the Federal Office for Radiation Protection - a subordinate authority of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety responsible for radiation protection, nuclear safety, and waste management - was given order to elaborate a concept for assistance to those Federal States. The field of prevention of nuclear hazards ranges from combatting illegal trade with radioactive test sources up to the defence of nuclear fuels with the possibility to construct critical assemblies or the threatening by the distribution of airborne material which might enter the lungs. The latter are considered as serious cases of nuclear hazards. Since the expenditures for devices and personal to be trained would be inadequately high, the Federal Office for Radiation Protection (BfS) is prepared to support the Federal States if it becomes necessary. The concept includes a stand-by service, the search for radioactive material by helicopter or a ground team, analysis of the activity and the type of nuclides, risk assessment, and also measures to steam the risk. This concept will be presented. (author)

Measuring the spectral emissivity of thermal protection materials during atmospheric reentry simulation

Science.gov (United States)

Marble, Elizabeth

1996-01-01

Hypersonic spacecraft reentering the earth's atmosphere encounter extreme heat due to atmospheric friction. Thermal Protection System (TPS) materials shield the craft from this searing heat, which can reach temperatures of 2900 F. Various thermophysical and optical properties of TPS materials are tested at the Johnson Space Center Atmospheric Reentry Materials and Structures Evaluation Facility, which has the capability to simulate critical environmental conditions associated with entry into the earth's atmosphere. Emissivity is an optical property that determines how well a material will reradiate incident heat back into the atmosphere upon reentry, thus protecting the spacecraft from the intense frictional heat. This report describes a method of measuring TPS emissivities using the SR5000 Scanning Spectroradiometer, and includes system characteristics, sample data, and operational procedures developed for arc-jet applications.

Surface Catalytic Efficiency of Advanced Carbon Carbon Candidate Thermal Protection Materials for SSTO Vehicles

Science.gov (United States)

Stewart, David A.

1996-01-01

The catalytic efficiency (atom recombination coefficients) for advanced ceramic thermal protection systems was calculated using arc-jet data. Coefficients for both oxygen and nitrogen atom recombination on the surfaces of these systems were obtained to temperatures of 1650 K. Optical and chemical stability of the candidate systems to the high energy hypersonic flow was also demonstrated during these tests.

Centralized coordinated control to protect the JET ITER-like wall

International Nuclear Information System (INIS)

Stephen, A.V.; Arnoux, G.; Budd, T.; Card, P.; Felton, R.; Goodyear, A.; Harling, J.; Kinna, D.; Lomas, P.; McCullen, P.; Thomas, P.; Young, I.; Zastrow, K.D.; Neto, A.; Alves, D.; Valcarcel, D.F.; Jachmich, S.; Devaux, S.

2012-01-01

The JET ITER-like wall project (ILW) replaces the first wall carbon fibre composite tiles with beryllium and tungsten tiles which should have improved fuel retention characteristics but are less thermally robust. An enhanced protection system using new control and diagnostic systems has been designed which can modify the pre-planned experimental control to protect the new wall. Key design challenges were to extend the Level-1 supervisory control system to allow configurable responses to thermal problems to be defined without introducing excessive complexity, and to integrate the new functionality with existing control and protection systems efficiently and reliably. Alarms are generated by the vessel thermal map (VTM) system if infra-red camera measurements of tile temperatures are too high and by the plasma wall load system (WALLS) if component power limits are exceeded. The design introduces two new concepts: local protection, which inhibits individual heating components but allows the discharge to proceed, and stop responses, which allow highly configurable early termination of the pulse in the safest way for the plasma conditions and type of alarm. These are implemented via the new real-time protection system (RTPS), a centralized controller which responds to the VTM and WALLS alarms by providing override commands to the plasma shape, current, density and heating controllers. This paper describes the design and implementation of the RTPS system which is built with the Multi-threaded Application Real-Time executor (MARTe) and will present results from initial operations. (authors)

Thermal stability and electrochemical properties of PVP-protected Ru nanoparticles synthesized at room temperature

Science.gov (United States)

Kumar, Manish; Devi, Pooja; Shivling, V. D.

2017-08-01

Stable ruthenium nanoparticles (RuNPs) have been synthesized by the chemical reduction of ruthenium trichloride trihydrate (RuCl3 · 3H2O) using sodium borohydride (NaBH4) as a reductant and polyvinylpyrrolidone (PVP) as a protecting agent in the aqueous medium at room temperature. The nanoparticles thus prepared were characterized by their morphology and structural analysis from transmission electron microscopy (TEM), X-ray powder diffraction (XRD), UV-vis spectroscopy, Fourier transformation infrared and thermogravimetric analysis (TGA) techniques. The TEM image suggested a homogeneous distribution of PVP-protected RuNPs having a small average diameter of 2-4 nm with a chain-like network structure. The XRD pattern also confirmed that a crystallite size is around 2 nm of PVP-protected RuNPs having a single broad peak. The thermal stability studied using TGA, indicated good stability and the electrochemical properties of these nanoparticles revealed that saturation current increases for PVP-protected RuNPs/GC.

Experimental and numerical thermal-hydraulics investigation of a molten salt reactor concept core

Energy Technology Data Exchange (ETDEWEB)

Yamaji, Bogdan; Aszodi, Attila [Budapest Univ. of Technology and Economics (Hungary). Inst. of Nuclear Techniques

2017-09-15

In the paper measurement results of experimental modelling of a molten salt fast reactor concept will be presented and compared with three-dimensional computational fluid dynamics (CFD) simulation results. Purpose of this article is twofold, on one hand to introduce a geometry modification in order to avoid the disadvantages of the original geometry and discuss new measurement results. On the other hand to present an analysis in order to suggest a method of proper numerical modelling of the problem based on the comparison of calculation results and measurement data for the new, modified geometry. The investigated concept has a homogeneous cylindrical core without any internal structures. Previous measurements on the scaled and segmented plexiglas model of the concept core and simulation results have shown that this core geometry could be optimized for better thermal-hydraulics characteristics. In case of the original geometry strong undesired flow separation could develop, that could negatively affect the characteristics of the core from neutronics point of view as well. An internal flow distributor plate was designed and installed with the purpose of optimizing the flow field in the core by enhancing its uniformity. Particle image velocimetry (PIV) measurement results of the modified experimental model will be presented and compared to numerical simulation results with the purpose of CFD model validation.

Flexible Thermal Protection System Development for Hypersonic Inflatable Aerodynamic Decelerators

Science.gov (United States)

DelCorso, Joseph A.; Bruce, Walter E., III; Hughes, Stephen J.; Dec, John A.; Rezin, Marc D.; Meador, Mary Ann B.; Guo, Haiquan; Fletcher, Douglas G.; Calomino, Anthony M.; Cheatwood, McNeil

2012-01-01

The Hypersonic Inflatable Aerodynamic Decelerators (HIAD) project has invested in development of multiple thermal protection system (TPS) candidates to be used in inflatable, high downmass, technology flight projects. Flexible TPS is one element of the HIAD project which is tasked with the research and development of the technology ranging from direct ground tests, modelling and simulation, characterization of TPS systems, manufacturing and handling, and standards and policy definition. The intent of flexible TPS is to enable large deployable aeroshell technologies, which increase the drag performance while significantly reducing the ballistic coefficient of high-mass entry vehicles. A HIAD requires a flexible TPS capable of surviving aerothermal loads, and durable enough to survive the rigors of construction, handling, high density packing, long duration exposure to extrinsic, in-situ environments, and deployment. This paper provides a comprehensive overview of key work being performed within the Flexible TPS element of the HIAD project. Included in this paper is an overview of, and results from, each Flexible TPS research and development activity, which includes ground testing, physics-based thermal modelling, age testing, margins policy, catalysis, materials characterization, and recent developments with new TPS materials.

A modernized high-pressure heater protection system for nuclear and thermal power stations

Science.gov (United States)

Svyatkin, F. A.; Trifonov, N. N.; Ukhanova, M. G.; Tren'kin, V. B.; Koltunov, V. A.; Borovkov, A. I.; Klyavin, O. I.

2013-09-01

Experience gained from operation of high-pressure heaters and their protection systems serving to exclude ingress of water into the turbine is analyzed. A formula for determining the time for which the high-pressure heater shell steam space is filled when a rupture of tubes in it occurs is analyzed, and conclusions regarding the high-pressure heater design most advisable from this point of view are drawn. A typical structure of protection from increase of water level in the shell of high-pressure heaters used in domestically produced turbines for thermal and nuclear power stations is described, and examples illustrating this structure are given. Shortcomings of components used in the existing protection systems that may lead to an accident at the power station are considered. A modernized protection system intended to exclude the above-mentioned shortcomings was developed at the NPO Central Boiler-Turbine Institute and ZioMAR Engineering Company, and the design solutions used in this system are described. A mathematical model of the protection system's main elements (the admission and check valves) has been developed with participation of specialists from the St. Petersburg Polytechnic University, and a numerical investigation of these elements is carried out. The design version of surge tanks developed by specialists of the Central Boiler-Turbine Institute for excluding false operation of the high-pressure heater protection system is proposed.

Fire protection concepts for Timber-Glass Composite façades

Directory of Open Access Journals (Sweden)

Schleicher Andreas

2016-01-01

The main objectives can be summarized as follows: Growth and densification in urban areas require the development of intelligent and resource-efficient building systems for “Smart Cities” of the future. By using timber-glass composites (TGC the primary energy demand of buildings can be reduced substantially. This research project examines the feasibility of applications of this new technology in multi-story and high-rise buildings. Critical aspects concerning fire protection such as flammability of timber elements, fire spread and failure of façade elements with bracing capacity will be analyzed. Different strategies will be developed in case studies and validated by structural analysis. Large scale mock ups of TGC façade elements will be checked on their suitability in fire tests. The findings of this research will lead to innovative fire safety concepts for building systems with TGC façades. Compliance with the high safety standards for multi-story buildings in urban areas like Vienna is one of the main objectives of this work. The adaptation of these fire safety concepts to the national standards of the neighboring countries will be continued subsequently. The gained knowledge should lead to further cooperation with companies for serial productions with TGC technology.

Thermal spray for commercial shipbuilding

Science.gov (United States)

Rogers, F. S.

1997-09-01

Thermal spraying of steel with aluminum to protect it from corrosion is a technology that has been proven to work in the marine environment. The thermal spray coating system includes a paint sealer that is applied over the thermally sprayed aluminum. This extends the service life of the coating and provides color to the end product. The thermal spray system protects steel both through the principle of isolation (as in painting) and galvanizing. With this dual protection mechanism, steel is protected from corrosion even when the coating is damaged. The thermal- sprayed aluminum coating system has proved the most cost- effective corrosion protection system for the marine environment. Until recently, however, the initial cost of application has limited its use for general application. Arc spray technology has reduced the application cost of thermal spraying of aluminum to below that of painting. Commercial shipbuilders could use this technology to enhance their market position in the marine industry.

Concepts on integration of physical protection and material accounting functions in a safeguards system

International Nuclear Information System (INIS)

Reynolds, D.A.

1981-01-01

Concepts on integration of physical protection and material accounting systems to enhance overall safeguards capability are developed and presented. Integration is approached by coordinating all safeguards information through a safeguards coordination center. This center represents a higher level in a communication, data-processing, and decision-making structure which is needed for efficient real-time operation of the integrated system. The safeguards coordination center functions to assess alarm and warning data required to resolve threats in the safeguards system, coordinate information and interaction involving the material accounting, physical protection, and facility monitoring and control systems, and present a single unified interface for interaction with facility management, facility operations, safeguards system personnel, and response forces

Thermal protection system for the concrete core support floor at Fort St. Vrain

International Nuclear Information System (INIS)

Jones, H.; Hedgecock, P.D.

1976-01-01

A unique feature of the Fort St. Vrain HTGR is its steel jacketed concrete core support floor. The construction of this floor generally resembles that of the prestressed concrete reactor vessel, but its location immediately below the core hot gas outlets generates some particularly severe thermal protection requirements. A thermal barrier is used over the entire outer surface of the floor and in the twelve hot gas ducts which convey the primary coolant through the floor to the steam generators. A cooling water system of square tubes welded to the inside of the steel jacket is used to remove that heat which does pass through the thermal barrier and to maintain the concrete at acceptable temperatures. The design approach to the floor itself and to the thermal barriers and cooling system will be described, but the main emphasis of the paper will be on the total experience gained during construction and pre-operational testing. A particular problem experienced during construction was leakage from some cooling tubes, after their embedment in concrete. The solution to that problem was to develop a method for injecting catalyzed epoxy into the leaking tube. This method, which has general usefulness for in-service repairs, will be described. (author)

Weapons-grade plutonium dispositioning. Volume 3: A new reactor concept without uranium or thorium for burning weapons-grade plutonium

International Nuclear Information System (INIS)

Ryskamp, J.M.; Schnitzler, B.G.; Fletcher, C.D.

1993-06-01

The National Academy of Sciences (NAS) requested that the Idaho National Engineering Laboratory (INEL) examine concepts that focus only on the destruction of 50,000 kg of weapons-grade plutonium. A concept has been developed by the INEL for a low-temperature, low-pressure, low-power density, low-coolant-flow-rate light water reactor that destroys plutonium quickly without using uranium or thorium. This concept is very safe and could be designed, constructed, and operated in a reasonable time frame. This concept does not produce electricity. Not considering other missions frees the design from the paradigms and constraints used by proponents of other dispositioning concepts. The plutonium destruction design goal is most easily achievable with a large, moderate power reactor that operates at a significantly lower thermal power density than is appropriate for reactors with multiple design goals. This volume presents the assumptions and requirements, a reactor concept overview, and a list of recommendations. The appendices contain detailed discussions on plutonium dispositioning, self-protection, fuel types, neutronics, thermal hydraulics, off-site radiation releases, and economics

Thermal Spray Applications in Electronics and Sensors: Past, Present, and Future

Science.gov (United States)

Sampath, Sanjay

2010-09-01

Thermal spray has enjoyed unprecedented growth and has emerged as an innovative and multifaceted deposition technology. Thermal spray coatings are crucial to the enhanced utilization of various engineering systems. Industries, in recognition of thermal spray's versatility and economics, have introduced it into manufacturing environments. The majority of modern thermal spray applications are "passive" protective coatings, and they rarely perform an electronic function. The ability to consolidate dissimilar material multilayers without substrate thermal loading has long been considered a virtue for thick-film electronics. However, the complexity of understanding/controlling materials functions especially those resulting from rapid solidification and layered assemblage has stymied expansion into electronics. That situation is changing: enhancements in process/material science are allowing reconsideration for novel electronic/sensor devices. This review critically examines past efforts in terms of materials functionality from a device perspective, along with ongoing/future concepts addressing the aforementioned deficiencies. The analysis points to intriguing future possibilities for thermal spray technology in the world of thick-film sensors.

Temperature-base and soma thermal for Zinnia ‘Profusion Cherry’ potted grown in protected environment

Directory of Open Access Journals (Sweden)

Charleston Gonçalves

2016-02-01

Full Text Available The growing of consumer market demands introduction of new species of flowers and cultivars primarily for production under protected cultivation. The zinnia by the quickness of production can be regarded as an alternative, however demand studies by the lack of information in the literature. We evaluated the duration of different periods, the base temperature and thermal accumulation, expressed as degree-days for the potted zinnia ‘Profusion Cherry’, conducted under protected cultivation for different phenological subperiods. The test was conducted in a greenhouse covered with plastic and closed laterally with shading-net and the duration of subperiods were made to twenty times after sowing. The base temperature was determined by relative development and values-based temperature and thermal time in degree-days (DD. The results for the different phases were, respectively: first open flower-planting: 4.1 °C and GD 838, first open flower - 50% of flowers open: 3.0 °C and 184 GD and 50% of flowers open - senescence: 6.9 °C and 238 GD.

A study of performance parameters on drag and heat flux reduction efficiency of combinational novel cavity and opposing jet concept in hypersonic flows

Science.gov (United States)

Sun, Xi-wan; Guo, Zhen-yun; Huang, Wei; Li, Shi-bin; Yan, Li

2017-02-01

The drag reduction and thermal protection system applied to hypersonic re-entry vehicles have attracted an increasing attention, and several novel concepts have been proposed by researchers. In the current study, the influences of performance parameters on drag and heat reduction efficiency of combinational novel cavity and opposing jet concept has been investigated numerically. The Reynolds-average Navier-Stokes (RANS) equations coupled with the SST k-ω turbulence model have been employed to calculate its surrounding flowfields, and the first-order spatially accurate upwind scheme appears to be more suitable for three-dimensional flowfields after grid independent analysis. Different cases of performance parameters, namely jet operating conditions, freestream angle of attack and physical dimensions, are simulated based on the verification of numerical method, and the effects on shock stand-off distance, drag force coefficient, surface pressure and heat flux distributions have been analyzed. This is the basic study for drag reduction and thermal protection by multi-objective optimization of the combinational novel cavity and opposing jet concept in hypersonic flows in the future.

Thermal Protection System Mass Estimating Relationships For Blunt-Body, Earth Entry Spacecraft

Science.gov (United States)

Sepka, Steven A.; Samareh, Jamshid A.

2015-01-01

Mass estimating relationships (MERs) are developed to predict the amount of thermal protection system (TPS) necessary for safe Earth entry for blunt-body spacecraft using simple correlations that are non-ITAR and closely match estimates from NASA's highfidelity ablation modeling tool, the Fully Implicit Ablation and Thermal Analysis Program (FIAT). These MERs provide a first order estimate for rapid feasibility studies. There are 840 different trajectories considered in this study, and each TPS MER has a peak heating limit. MERs for the vehicle forebody include the ablators Phenolic Impregnated Carbon Ablator (PICA) and Carbon Phenolic atop Advanced Carbon-Carbon. For the aftbody, the materials are Silicone Impregnated Reusable Ceramic Ablator (SIRCA), Acusil II, SLA- 561V, and LI-900. The MERs are accurate to within 14% (at one standard deviation) of FIAT prediction, and the most any MER can under predict FIAT TPS thickness is 18.7%. This work focuses on the development of these MERs, the resulting equations, model limitations, and model accuracy.

Realization of a thermal cloak-concentrator using a metamaterial transformer.

Science.gov (United States)

Liu, Ding-Peng; Chen, Po-Jung; Huang, Hsin-Haou

2018-02-06

By combining rotating squares with auxetic properties, we developed a metamaterial transformer capable of realizing metamaterials with tunable functionalities. We investigated the use of a metamaterial transformer-based thermal cloak-concentrator that can change from a cloak to a concentrator when the device configuration is transformed. We established that the proposed dual-functional metamaterial can either thermally protect a region (cloak) or focus heat flux in a small region (concentrator). The dual functionality was verified by finite element simulations and validated by experiments with a specimen composed of copper, epoxy, and rotating squares. This work provides an effective and efficient method for controlling the gradient of heat, in addition to providing a reference for other thermal metamaterials to possess such controllable functionalities by adapting the concept of a metamaterial transformer.

Radiation protection. Basic concepts of ICRP

International Nuclear Information System (INIS)

Saito, Tsutomu; Hirata, Hideki

2014-01-01

The title subject is easily explained. Main international organizations for radiation protection are United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), International Commission on Radiological Protection (ICRP) and International Atomic Energy Agency (IAEA). The UNSCEAR objectively summarizes and publishes scientific findings; ICRP, an NGO, takes part in recommending the radiological protection from the expertized aspect; and IAEA, a UN autonomy, aims at peaceful usage of atomic power. These organizations support the legal regulation and standard of nations. The purpose of the ICRP recommendation (Pub. 103, 2007) is to contribute to the appropriate protection of radiation hazardous effects, which are assumed to be linearly proportional (the model of linear no-threshold, LNT) that radiation risk exists even at the lowest dose. When a change in the single cell results in hazardous alteration, the causative effects are called stochastic effects, which include the mutation leading to cancer formation and genetic effect in offspring (not observed in man). ICRP says the validity of LNT for the stochastic effects essentially from the protective aspect, although epidemiological data support it at >100 mSv exposure. The deterministic effects are caused by loss of cell itself or of its function, where the threshold is defined to be the dose causing >1% of disorder or death. Radiation protective system against exposure is on the situation (programmed, emergent and natural), category (occupational, public and medical) and 3 principles of justification, optimization and application of dose limit. (T.T.)

Thermal Protection Performance of Phase Changing Material Based on Polyethylene Glycol

Directory of Open Access Journals (Sweden)

Leila Sadat Ahmadi

2012-12-01

Full Text Available Phase change materials (PCM are substances with a high heat of fusion which, through melting and solidifying at certain temperatures, are capable to store or release a large amount of energy. This phenomenon can be utilized in designing heat protective materials as well as in thermal energy storage systems. One of the approaches to avoid materials leaching from a structure, where PCMs are incorporated, is to blend them with suitable polymers. To have a proper blend it is necessary to choose a compatible polymer with a PCM. It is important to assess the optimized concentration of PCM in polymer matrix and the phase structure and morphology of the blend, which causes the best heat protection. In this work, the influence of polyethylene glycol (PEG as PCMs in epoxy resin matrix on heat protection was investigated. A special performance test was designed to study timetemperature behavior of the prepared samples and DSC and SEM tests to observe the melting point, heat of fusion and morphology of the samples. The results indicated that increases in PCM content led to better heat protection and the best concentration for PEG was found to be 60% wt. Time-temperature curves show that increases of temperature for PCM samples is very slow compared with net epoxy sample. PCM samples curves show plateau in melting region. In this region, they show nearly 15°C temperature lower than a net epoxy sample. The plateau region makes a delay time in temperature increment, which is about 22 min for PEG samples compared with a net epoxy.

Thermal Properties and Thermal Analysis:

Science.gov (United States)

Kasap, Safa; Tonchev, Dan

The chapter provides a summary of the fundamental concepts that are needed to understand the heat capacity C P, thermal conductivity κ, and thermal expansion coefficient α L of materials. The C P, κ, and α of various classes of materials, namely, semiconductors, polymers, and glasses, are reviewed, and various typical characteristics are summarized. A key concept in crystalline solids is the Debye theory of the heat capacity, which has been widely used for many decades for calculating the C P of crystals. The thermal properties are interrelated through Grüneisen's theorem. Various useful empirical rules for calculating C P and κ have been used, some of which are summarized. Conventional differential scanning calorimetry (DSC) is a powerful and convenient thermal analysis technique that allows various important physical and chemical transformations, such as the glass transition, crystallization, oxidation, melting etc. to be studied. DSC can also be used to obtain information on the kinetics of the transformations, and some of these thermal analysis techniques are summarized. Temperature-modulated DSC, TMDSC, is a relatively recent innovation in which the sample temperature is ramped slowly and, at the same time, sinusoidally modulated. TMDSC has a number of distinct advantages compared with the conventional DSC since it measures the complex heat capacity. For example, the glass-transition temperature T g measured by TMDSC has almost no dependence on the thermal history, and corresponds to an almost step life change in C P. The new Tzero DSC has an additional thermocouple to calibrate better for thermal lags inherent in the DSC measurement, and allows more accurate thermal analysis.

In-Space Repair and Refurbishment of Thermal Protection System Structures for Reusable Launch Vehicles

Science.gov (United States)

Singh, M.

2007-01-01

Advanced repair and refurbishment technologies are critically needed for the thermal protection system of current space transportation systems as well as for future launch and crew return vehicles. There is a history of damage to these systems from impact during ground handling or ice during launch. In addition, there exists the potential for in-orbit damage from micrometeoroid and orbital debris impact as well as different factors (weather, launch acoustics, shearing, etc.) during launch and re-entry. The GRC developed GRABER (Glenn Refractory Adhesive for Bonding and Exterior Repair) material has shown multiuse capability for repair of small cracks and damage in reinforced carbon-carbon (RCC) material. The concept consists of preparing an adhesive paste of desired ceramic with appropriate additives and then applying the paste to the damaged/cracked area of the RCC composites with an adhesive delivery system. The adhesive paste cures at 100-120 C and transforms into a high temperature ceramic during reentry conditions. A number of plasma torch and ArcJet tests were carried out to evaluate the crack repair capability of GRABER materials for Reinforced Carbon-Carbon (RCC) composites. For the large area repair applications, Integrated Systems for Tile and Leading Edge Repair (InSTALER) have been developed and evaluated under various ArcJet testing conditions. In this presentation, performance of the repair materials as applied to RCC is discussed. Additionally, critical in-space repair needs and technical challenges are reviewed.

Terahertz Computed Tomography of NASA Thermal Protection System Materials

Science.gov (United States)

Roth, D. J.; Reyes-Rodriguez, S.; Zimdars, D. A.; Rauser, R. W.; Ussery, W. W.

2011-01-01

A terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described.

Saturation of SERCA's lipid annulus may protect against its thermal inactivation

International Nuclear Information System (INIS)

Fajardo, Val Andrew; Trojanowski, Natalie; Castelli, Laura M.; Miotto, Paula M.; Amoye, Foyinsola; Ward, Wendy E.; Tupling, A. Russell; LeBlanc, Paul J.

2017-01-01

The sarco(endo)plasmic reticulum Ca 2+ -ATPase (SERCA) pumps are integral membrane proteins that catalyze the active transport of Ca 2+ into the sarcoplasmic reticulum, thereby eliciting muscle relaxation. SERCA pumps are highly susceptible to oxidative damage, and cytoprotection of SERCA dampens thermal inactivation and is a viable therapeutic strategy in combating diseases where SERCA activity is impaired, such as muscular dystrophy. Here, we sought to determine whether increasing the percent of saturated fatty acids (SFA) within SERCA's lipid annulus through diet could protect SERCA pumps from thermal inactivation. Female Wistar rats were fed either a semi-purified control diet (AIN93G, 7% soybean oil by weight) or a modified AIN93G diet containing high SFA (20% lard by weight) for 17 weeks. Soleus muscles were extracted and SERCA lipid annulus and activity under thermal stress were analyzed. Our results show that SERCA's lipid annulus is abundant with short-chain (12–14 carbon) fatty acids, which corresponds well with SERCA's predicted bilayer thickness of 21 Å. Under control-fed conditions, SERCA's lipid annulus was already highly saturated (79%), and high-fat feeding did not increase this any further. High-fat feeding did not mitigate the reductions in SERCA activity seen with thermal stress; however, correlational analyses revealed significant and strong associations between % SFA and thermal stability of SERCA activity with greater %SFA being associated with lower thermal inactivation and greater % polyunsaturation and unsaturation index being associated with increased thermal inactivation. Altogether, these findings show that SERCA's lipid annulus may influence its susceptibility to oxidative damage, which could have implications in muscular dystrophy and age-related muscle wasting. - Highlights: • SERCA's lipid annulus in rat soleus was measured after immunoconcentration. • Short fatty acid chains surround SERCA and

Investigation of the thermal behavior of 2 1/2 ton cylinder protective overpack

International Nuclear Information System (INIS)

Park, S.H.

1988-01-01

UF 6 cylinders containing reactor grade enriched uranium are transported in protective overpacks. Recently, the design of the 2 1/2 ton UF 6 cylinder overpack was modified to insure the safety of the cylinder inside the overpack. Modifications include a continuous stainless steel liner from the outer surface to the inner surface of the overpack and step joints between the upper and lower halves of the overpack. The effects of a continuous stainless steel liner and moisture in the insulation layer of a UF 6 cylinder protective overpack were investigated with a numerical code. Results were compared with limited available field data. The purpose of comparing the numerical results with field data is to insure the validity of the numerical analysis and the physical properties used in the analysis. The study indicates that the continuous stainless steel liner did not influence the heat transfer rate much from the outer surface of the overpack to the 30B cylinder inside. The effect of step joints was not modeled due to the difficulty of quantifying the leakage rate through the gap. With a continuous stainless steel liner from the outside of the overpack to the inside, the overpack satisfies the thermal design criteria of protecting the cylinder inside for a minimum of 30 minutes when the overpack is exposed to a fire. The effect of moisture inside the insulation layer in the overpack is to reduce the energy to the cylinder with its high thermal capacity. The high pressure steam generated from the moisture will be relieved externally through the vent holes on the outer surface of the overpack. Although these holes are sealed after the overpack is dried, the plug sealing the holes will melt when the overpack is exposed to a fire

Single-chip microcomputer based protection, diagnostic and recording system for longwall shearers

Energy Technology Data Exchange (ETDEWEB)

Heyduk, A.; Krasucki, F. (Politechnika Slaska, Gliwice (Poland). Katedra Elektryfikacji i Automatyzacji Gornictwa)

1993-05-01

Presents a concept of microcomputer-aided operation, protection, diagnostics and recording for shearer loaders. A two-stage mathematical model is suggested and explained. The model represents the thermal processes that determine the overcurrent protection of drive motors. Circuits for monitoring fuses, supply voltages, contacts, relays, contactors and electro-hydraulic distributors with the use of transoptors are shown. Recording characteristic operation parameters of a shearer loader during the 5 minutes before a failure is proposed. Protection, diagnosis and control functions are suggested as additional functions to the microcomputer-aided system of shearer loader control being developed at the Silesian Technical University. The system is based on the NECmicroPD 78310 microprocessor. 10 refs.

Design guide for fire protection of grouped electrical cables

International Nuclear Information System (INIS)

Dungan, K.W.

1991-05-01

This paper develops design guidance for fire protection of grouped electrical cables using previous research and the concept of design objectives based on damage limits. A quantitative approach is taken to establishing performance-oriented design objectives and addressing fires exposing cables as well as cable fires. A one-page Design Calculation Checklist is developed and examples are shown. In addition, testing was done for placement of linear thermal detection on cable trays and recommendations are given. 32 refs., 10 figs., 8 tabs

Aero-thermal optimization of in-flight electro-thermal ice protection systems in transient de-icing mode

International Nuclear Information System (INIS)

Pourbagian, Mahdi; Habashi, Wagdi G.

2015-01-01

Highlights: • We introduce an efficient methodology for the optimization of a de-icing system. • We can replace the expensive CHT simulation by ROM without loosing much accuracy. • We propose different criteria affecting the energy usage and aerodynamic performance. • These criteria can significantly improve the performance of the de-icing system. - Abstract: Even if electro-thermal ice protection systems (IPS) consume less energy when operating in de-icing mode than in anti-icing mode, they still need to be optimized for energy usage. The optimization, however, should also take into account the effect of the de-icing system on the aerodynamic performance. The present work offers an optimization framework in which both thermal and aerodynamic viewpoints are taken into account in formulating various objective and constraint functions by considering the energy consumption, the thickness, the volume, the shape and the location of the accreted ice on the surface as the key parameters affecting the energy usage and the aerodynamic performance. The design variables include the power density and the activation time of the electric heating blankets. A derivative-free technique, called the mesh adaptive direct search (MADS) method, is used to carry out the optimization process, which would normally need a large number of unsteady conjugate heat transfer (CHT) calculations for the IPS simulation. To avoid such prohibitive computations, reduced-order modeling (ROM) is used to construct simplified low-dimensional CHT models. The approach is illustrated through several test cases, in which different combinations of objective and constraint functions, design variables and cycling sequence patterns are examined. In these test cases, the energy consumption is significantly reduced compared to the experiments by improving the spatial and temporal distribution of the thermal energy usage. The results show the benefits of the approach in bringing energy, safety and

Thermal-hydraulics for space power, propulsion, and thermal management system design

International Nuclear Information System (INIS)

Krotiuk, W.J.

1990-01-01

The present volume discusses thermal-hydraulic aspects of current space projects, Space Station thermal management systems, the thermal design of the Space Station Free-Flying Platforms, the SP-100 Space Reactor Power System, advanced multi-MW space nuclear power concepts, chemical and electric propulsion systems, and such aspects of the Space Station two-phase thermal management system as its mechanical pumped loop and its capillary pumped loop's supporting technology. Also discussed are the startup thaw concept for the SP-100 Space Reactor Power System, calculational methods and experimental data for microgravity conditions, an isothermal gas-liquid flow at reduced gravity, low-gravity flow boiling, computations of Space Shuttle high pressure cryogenic turbopump ball bearing two-phase coolant flow, and reduced-gravity condensation

I/O Standard Based Thermal/Energy Efficient Green Communication For Wi-Fi Protected Access on FPGA

DEFF Research Database (Denmark)

Kumar, Tanesh; Pandey, Bishwajeet; Das, Teerath

2014-01-01

In this paper, we analyzed how does life and reliability of an integrated circuit is affected when it is operated in different regions under different temperatures. We have taken Fibonacci generator as our target circuit and LVCMOS as I/O standards. WPA and WPA2 (Wi-Fi Protected Access) key can...... be generated with Fibonacci generator. Here, thermal efficient green Fibonacci Generator is used to generate key for Wi-Fi Protected Access in order to make green communication possible under different room temperature. By analysis it is observed that at standard normal temperature (21degrees C), LVCMOS12 have...

Technology Development and Design of a Hybrid Mars Ascent Vehicle Concept

Science.gov (United States)

Karp, Ashley C.; Redmond, Matt; Nakazono, Barry; Vaughan, David; Shotwell, Robert; Story, George; Jackson, Dale; Young, David

2016-01-01

Hybrid propulsion has been investigated as an enhancing technology for a Mars Ascent Vehicle (MAV) concept as part of potential Mars Sample Return (MSR) because of its high specific impulse, restartability, and the ability to operate and survive at extremely low temperatures. A new wax-based hybrid fuel formulation has been developed that could withstand the harsh and variable Mars environment protected solely by a minimal layer of passive insulation. This formulation could provide substantial energy savings for a notional lander and is critical for rover mobility. Preliminary thermal cycle testing has determined that the formulation can survive the expected temperature extremes and lifetime thermal testing is currently underway. A complete preliminary design using this new fuel formulation combined with a low temperature oxidizer such as Mixed Oxides of Nitrogen (MON30) is presented. Several key features associated with a complete hybrid MAV concept are investigated to determine their mission suitability (e.g. Thrust Vector Control and restartable ignition options). Potential challenges along a path towards developing such a system are outlined and future work is suggested as a means of technology maturation. The hybrid design presented here was the lowest Gross Lift Off Mass (GLOM) result of a 2015 Jet Propulsion Laboratory (JPL) led MAV concept study.

Large thermal protection system panel

Science.gov (United States)

Weinberg, David J. (Inventor); Myers, Franklin K. (Inventor); Tran, Tu T. (Inventor)

2003-01-01

A protective panel for a reusable launch vehicle provides enhanced moisture protection, simplified maintenance, and increased temperature resistance. The protective panel includes an outer ceramic matrix composite (CMC) panel, and an insulative bag assembly coupled to the outer CMC panel for isolating the launch vehicle from elevated temperatures and moisture. A standoff attachment system attaches the outer CMC panel and the bag assembly to the primary structure of the launch vehicle. The insulative bag assembly includes a foil bag having a first opening shrink fitted to the outer CMC panel such that the first opening and the outer CMC panel form a water tight seal at temperatures below a desired temperature threshold. Fibrous insulation is contained within the foil bag for protecting the launch vehicle from elevated temperatures. The insulative bag assembly further includes a back panel coupled to a second opening of the foil bag such that the fibrous insulation is encapsulated by the back panel, the foil bag, and the outer CMC panel. The use of a CMC material for the outer panel in conjunction with the insulative bag assembly eliminates the need for waterproofing processes, and ultimately allows for more efficient reentry profiles.

Heat transfer characteristics and limitations analysis of heat-pipe-cooled thermal protection structure

International Nuclear Information System (INIS)

Guangming, Xiao; Yanxia, Du; Yewei, Gui; Lei, Liu; Xiaofeng, Yang; Dong, Wei

2014-01-01

The theories of heat transfer, thermodynamics and fluid dynamics are employed to develop the coupled heat transfer analytical methods for the heat-pipe-cooled thermal protection structure (HPC TPS), and a three-dimensional numerical method considering the sonic limit of heat pipe is proposed. To verify the calculation correctness, computations are carried out for a typical heat pipe and the results agree well with experimental data. Then, the heat transfer characteristics and limitations of HPC TPS are mainly studied. The studies indicate that the use of heat pipe can reduce the temperature at high heat flux region of structure efficiently. However, there is a frozen startup period before the heat pipe reaching a steady operating state, and the sonic limit will be a restriction on the heat transfer capability. Thus, the effects of frozen startup must be considered for the design of HPC TPS. The simulation model and numerical method proposed in this paper can predict the heat transfer characteristics of HPC TPS quickly and exactly, and the results will provide important references for the design or performance evaluation of HPC TPS. - Highlights: • Numerical methods for the heat-pipe-cooled thermal protection structure are studied. • Three-dimensional simulation model considering sonic limit of heat pipe is proposed. • The frozen startup process of the embedded heat pipe can be predicted exactly. • Heat transfer characteristics of TPS and limitations of heat pipe are discussed

Effect of thermal protectants on the stability of bovine milk immunoglobulin G

Energy Technology Data Exchange (ETDEWEB)

Chen, C. C. [National Taiwan University, Taipei, Taiwan (China); Chang, H. M.

1998-09-15

pH stability, thermal stability, and the effect of homogenization and ultrasonic treatment on the stability of bovine milk immunoglobulin G (IgG) in model systems was studied. Separated IgG (0.02 mg/mL) was found to be unstable and susceptible to denaturation when incubated at pH 4 or 10 or thermally treated at temperature 75 degrees C. IgG in the colostrum, on the other hand, was found to be much more stable than in whey or in PBS when thermally treated at temperatures in the range of 75-100 degrees C. The residual IgC content reduced more sharply with increasing heating times, and almost no IgG content was detected when IgG in PBS (0.15 M NaCl/0.01 M phosphate buffer, pH 7.0) was heated at 95 degrees C for 15 s, whereas the corresponding residual IgG contents in whey and colostrum were found to be 42 and 59%, respectively. For IgG in PBS heated at 95 degrees C for 15 s, addition of 5% fructose or maltose displayed most remarkable protection effects by raising the residual IgG content to 31%, followed by sucrose, lactose, glucose, and galactose. However, extravagant addition ( 30%) to IgG in PBS led to a decline in residual IgG content. Addition of 0.4% glutamic acid and 2% glycine to IgG in PBS heated at 95 degrees C for 15 s also remarkably improved the residual IgG content by 13.5 and 26.7%, respectively. Glycerol and sugar alcohol, such as sorbitol, stabilized IgG during the thermal treatment.

Effect of thermal protectants on the stability of bovine milk immunoglobulin G

International Nuclear Information System (INIS)

Chen, C.C.; Chang, H.M.

1998-01-01

pH stability, thermal stability, and the effect of homogenization and ultrasonic treatment on the stability of bovine milk immunoglobulin G (IgG) in model systems was studied. Separated IgG (0.02 mg/mL) was found to be unstable and susceptible to denaturation when incubated at pH 4 or 10 or thermally treated at temperature 75 degrees C. IgG in the colostrum, on the other hand, was found to be much more stable than in whey or in PBS when thermally treated at temperatures in the range of 75-100 degrees C. The residual IgC content reduced more sharply with increasing heating times, and almost no IgG content was detected when IgG in PBS (0.15 M NaCl/0.01 M phosphate buffer, pH 7.0) was heated at 95 degrees C for 15 s, whereas the corresponding residual IgG contents in whey and colostrum were found to be 42 and 59%, respectively. For IgG in PBS heated at 95 degrees C for 15 s, addition of 5% fructose or maltose displayed most remarkable protection effects by raising the residual IgG content to 31%, followed by sucrose, lactose, glucose, and galactose. However, extravagant addition ( 30%) to IgG in PBS led to a decline in residual IgG content. Addition of 0.4% glutamic acid and 2% glycine to IgG in PBS heated at 95 degrees C for 15 s also remarkably improved the residual IgG content by 13.5 and 26.7%, respectively. Glycerol and sugar alcohol, such as sorbitol, stabilized IgG during the thermal treatment

Thermal Conductivity Measurement and Analysis of Fully Ceramic Microencapsulated fuel

International Nuclear Information System (INIS)

Lee, H. G.; Kim, D. J.; Park, J. Y.; Kim, W. J.; Lee, S. J.

2015-01-01

FCM nuclear fuel is composed of tristructural isotropic(TRISO) fuel particle and SiC ceramic matrix. SiC ceramic matrix play an essential part in protecting fission product. In the FCM fuel concept, fission product is doubly protected by TRISO coating layer and SiC ceramic matrix in comparison with the current commercial UO2 fuel system of LWR. In addition to a safety enhancement of FCM fuel, thermal conductivity of SiC ceramic matrix is better than that of UO2 fuel. Because the centerline temperature of FCM fuel is lower than that of the current UO2 fuel due to the difference of thermal conductivity of fuel, an operational release of fission products from the fuel can be reduced. SiC ceramic has attracted for nuclear fuel application due to its high thermal conductivity properties with good radiation tolerant properties, a low neutron absorption cross-section and a high corrosion resistance. Thermal conductivity of ceramic matrix composite depends on the thermal conductivity of each component and the morphology of reinforcement materials such as fibers and particles. There are many results about thermal conductivity of fiber-reinforced composite like as SiCf/SiC composite. Thermal conductivity of SiC ceramics and FCM pellets with the volume fraction of TRISO particles were measured and analyzed by analytical models. Polycrystalline SiC ceramics and FCM pellets with TRISO particles were fabricated by hot press sintering with sintering additives. Thermal conductivity of the FCM pellets with TRISO particles of 0 vol.%, 10 vol.%, 20 vol.%, 30 vol.% and 40 vol.% show 68.4, 52.3, 46.8, 43.0 and 34.5 W/mK, respectively. As the volume fraction of TRISO particles increased, the measured thermal conductivity values closely followed the prediction of Maxwell's equation

Monitoring of Thermal Protection Systems Using Robust Self-Organizing Optical Fiber Sensing Networks

Science.gov (United States)

Richards, Lance

2013-01-01

The general aim of this work is to develop and demonstrate a prototype structural health monitoring system for thermal protection systems that incorporates piezoelectric acoustic emission (AE) sensors to detect the occurrence and location of damaging impacts, and an optical fiber Bragg grating (FBG) sensor network to evaluate the effect of detected damage on the thermal conductivity of the TPS material. Following detection of an impact, the TPS would be exposed to a heat source, possibly the sun, and the temperature distribution on the inner surface in the vicinity of the impact measured by the FBG network. A similar procedure could also be carried out as a screening test immediately prior to re-entry. The implications of any detected anomalies in the measured temperature distribution will be evaluated for their significance in relation to the performance of the TPS during re-entry. Such a robust TPS health monitoring system would ensure overall crew safety throughout the mission, especially during reentry

Proof-of-Concept Testing of the Passive Cooling System (T-CLIP™) for Solar Thermal Applications at an Elevated Temperature

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Jun [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Quintana, Donald L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Vigil, Gabrielle M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Perraglio, Martin Juan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Farley, Cory Wayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Tafoya, Jose I. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Martinez, Adam L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology

2015-11-30

The Applied Engineering and Technology-1 group (AET-1) at Los Alamos National Laboratory (LANL) conducted the proof-of-concept tests of SolarSPOT LLC’s solar thermal Temperature- Clipper, or T-CLIP™ under controlled thermal conditions using a thermal conditioning unit (TCU) and a custom made environmental chamber. The passive T-CLIP™ is a plumbing apparatus that attaches to a solar thermal collector to limit working fluid temperature and to prevent overheating, since overheating may lead to various accident scenarios. The goal of the current research was to evaluate the ability of the T-CLIP™ to control the working fluid temperature by using its passive cooling mechanism (i.e. thermosiphon, or natural circulation) in a small-scale solar thermal system. The assembled environmental chamber that is thermally controlled with the TCU allows one to simulate the various possible weather conditions, which the solar system will encounter. The performance of the T-CLIP™ was tested at two different target temperatures: 1) room temperature (70 °F) and 2) an elevated temperature (130 °F). The current test campaign demonstrated that the T-CLIP™ was able to prevent overheating by thermosiphon induced cooling in a small-scale solar thermal system. This is an important safety feature in situations where the pump is turned off due to malfunction or power outages.

Solar-thermal jet pumping for irrigation

Science.gov (United States)

Clements, L. D.; Dellenback, P. A.; Bell, C. A.

1980-01-01

This paper describes a novel concept in solar powered irrigation pumping, gives measured performance data for the pump unit, and projected system performance. The solar-thermal jet pumping concept is centered around a conventional jet eductor pump which is commercially available at low cost. The jet eductor pump is powered by moderate temperature, moderate pressure Refrigerant-113 vapor supplied by a concentrating solar collector field. The R-113 vapor is direct condensed by the produced water and the two fluids are separated at the surface. The water goes on to use and the R-113 is repressurized and returned to the solar field. The key issue in the solar-thermal jet eductor concept is the efficiency of pump operation. Performance data from a small scale experimental unit which utilizes an electrically heated boiler in place of the solar field is presented. The solar-thermal jet eductor concept is compared with other solar irrigation concepts and optimal application situations are identified. Though having lower efficiencies than existing Rankine cycle solar-thermal irrigation systems, the mechanical and operational simplicity of this concept make it competitive with other solar powered irrigation schemes.

Combined Thermal Management and Power Generation Concept for the Spent Fuel Dry Storage Cask

International Nuclear Information System (INIS)

Kim, In Guk; Bang, In Cheol

2017-01-01

The management of the spent nuclear fuel generated by nuclear power plants is a major issue in Korea due to insufficient capacity of the wet storage pools. Therefore, it is considered that dry storage system is the one possible solution for storing spent fuel. A dual-purpose metal cask (transportation and storage) is currently developing in Korea. This cask has 21 of fuel assemblies and 16.8 kW of maximum decay heat. To evaluate the critical safety in normal/off normal and accident conditions, critical stabilities were conducted by using CSAS 6.0. The experimental investigation of heat removal of a concrete storage cask was also conducted under normal, off normal and accident conditions. The results of the evaluation showed a good safety of the dry storage cask. The results showed the enhanced thermal performance according to modification of flow rate. To verify combined thermal management and power generation concept, a new type of test facility for dry storage cask was designed in 1/10 scale of concrete dry storage cask. The experimental study involved the cooling methods that are an integrated system on the top of the dry cask and air flow path on the canister wall. The results showed the temperature distribution of the wall and inside of the dry cask at the normal condition. The influence of the change of the heat load and cooling system were investigated. The heat removal by the integrated system is approximately 20% of the total heat removal of the dry cask with reduced wall temperature. In these tests, economic analysis is conducted by applying the concept of the cost and efficiency. Under different decay power cases, the energy efficiency of the heat pipe and Stirling engine are determined and compared based on experimental results. The average efficiencies of the Stirling engine were the range of 2.375 to 3.247% under the power range of 35– 65W. These results showed that advanced dry storage concept had a better cooling performance in comparison with

Thermal Arc Spray Overview

Science.gov (United States)

Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

2013-06-01

Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

Thermal Arc Spray Overview

International Nuclear Information System (INIS)

Malek, Muhamad Hafiz Abd; Saad, Nor Hayati; Abas, Sunhaji Kiyai; Shah, Noriyati Mohd

2013-01-01

Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

Thermal performance and efficiency of supercritical nuclear reactors

International Nuclear Information System (INIS)

Romney Duffey; Tracy Zhou; Hussam Khartabil

2009-01-01

The paper reviews the major advances and innovative aspects of the thermal performance of recent concepts for super-critical water-cooled nuclear reactors (SCWR). The concepts are based on the extensive experience in the thermal power industry with super and ultra-supercritical boilers and turbines. The challenges and goals of increased efficiency, reduced cost, enhanced safety and co-generation have been pursued over the last ten years, and have resulted both in viable concepts and a vibrant defined R and D effort. The supercritical concept has wide acceptance among industry, as it reflects standard engineering practices and current thermal plant technology that is being already deployed. The SCWR concept represents a continuous development of water-cooled reactor technology, which utilizes the best and latest advances made in the thermal power industry. (author)

A Collaborative Analysis Tool for Thermal Protection Systems for Single Stage to Orbit Launch Vehicles

Science.gov (United States)

Alexander, Reginald; Stanley, Thomas Troy

2001-01-01

Presented is a design tool and process that connects several disciplines which are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to all other systems, as is the case with SSTO vehicles with air breathing propulsion, which is currently being studied by the National Aeronautics and Space Administration (NASA). In particular, the thermal protection system (TPS) is linked directly to almost every major system. The propulsion system pushes the vehicle to velocities on the order of 15 times the speed of sound in the atmosphere before pulling up to go to orbit which results in high temperatures on the external surfaces of the vehicle. Thermal protection systems to maintain the structural integrity of the vehicle must be able to mitigate the heat transfer to the structure and be lightweight. Herein lies the interdependency, in that as the vehicle's speed increases, the TPS requirements are increased. And as TPS masses increase the effect on the propulsion system and all other systems is compounded. To adequately calculate the TPS mass of this type of vehicle several engineering disciplines and analytical tools must be used preferably in an environment that data is easily transferred and multiple iterations are easily facilitated.

The effect of moisture content within multilayer protective clothing on protection from radiation and steam.

Science.gov (United States)

Su, Yun; Li, Jun; Song, Guowen

2018-06-01

The moisture from skin sweat and atmospheric water affects the thermal protective performance provided by multilayer protective clothing. Four levels of moisture content were selected to evaluate the impact of moisture on thermal protection under dry (thermal radiation) and wet (thermal radiation and low-pressure steam) heat exposure. Also, the role of moisture and its relationship with exposure time were analyzed based on skin heat flux and Henriques integral value. The addition of moisture to a fabric system was found to result in differences in second-degree and third-degree skin burn times. When moisture is added to a fabric system, it both acts as a thermal conductor to present a negative effect and provides a positive effect owing to thermal storage of water and evaporative heat loss. The positive or negative effects of moisture are mainly dependent on the thermal exposure time, the moisture content and the presence of hot steam.

SCWR Concepts in Japan

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-08-15

Two SCWR concepts are being developed in Japan, one corresponding to the thermal spectrum reactor and the other to the fast spectrum reactor. Yamada et al. described the thermal-spectrum reactor concept referred to as the Japan SCWR (or JSCWR). This concept was developed under the financial support of the Ministry of Economy, Trade and Industry (METI). The basic philosophy of the JSCWR development is to utilize proven light water reactor and supercritical fossil-fired power plant technologies as much as possible to minimize the R&D cost, time and risks. Therefore, the JSCWR is designed as a thermal neutron spectrum reactor using light water as moderator and reactor coolant. The JSCWR plant consists of a pressure-vessel type, once-through reactor and a direct Rankine cycle system. Reactor coolant fed through inlet nozzles is heated up in the core and flows through outlet nozzles with no recirculation in the vessel. Other options to the JSCWR core design are being investigated at the University of Tokyo. The electric output of the JSCWR is assumed to range from 600 MWe to 1700 MWe class to fulfill user’s requirements as much as possible. In this section, the reference value is selected to 1725 MWe, which corresponds to a reactor thermal output of 4039 MWth. Nakatsuka et al. described the core design for the fast-spectrum reactor, which is based on a similar plant system compared to that of the thermal-spectrum reactor. The fast-spectrum reactor, however, would produce higher power rating than the thermal-spectrum one of the same reactor pressure-vessel size. Since the fast-spectrum reactor does not require the moderator, its unit capital cost would be lower than the thermal-spectrum reactor.

Conceptual thermal design

NARCIS (Netherlands)

Strijk, R.

2008-01-01

Present thermal design tools and methods insufficiently support the development of structural concepts engaged by typical practicing designers. Research described in this thesis identifies the main thermal design problems in practice. In addition, models and methods are developed that support an

Superconducting Strips: A Concept in Thermal Neutron Detection

Directory of Open Access Journals (Sweden)

Vittorio Merlo

2018-03-01

Full Text Available In the never-ending quest for better detection efficiency and spatial resolution, various thermal neutron detection schemes have been proposed over the years. Given the presence of some converting layers (typically boron, but 6LiF is also widely used nowadays, the shift towards concepts based on solid state detectors has been steadily increasing and ingenious schemes thereby proposed. However, a trade-off has been always sought for between efficiency and spatial resolution; the problem can be (at least partially circumvented using more elaborate geometries, but this complicates the sample preparation and detector construction. Thus, viable alternatives must be found. What we proposed (and verified experimentally is a detection scheme based on the superconducting to normal transition. More precisely, using a boron converting layer, the α particles (generated in the (n, α reaction crossing a low critical temperature superconducting strip some 10 µm wide have been detected; the process, bolometric in nature and based on the ionization energy loss, is intrinsically fast and the spatial resolution very appealing. In this work, some of the work done so far will be illustrated, together with the principles of the measurement and various related problems. The realization of the detector is based on industrial deposition and photolitographic techniques well within the grasp of a condensed matter laboratory, so that there is substantial room for improvement over our elementary strip geometry. Some of the plans for future work will also be presented, together with some improvements both in the choice of the materials and the geometry of the detector.

STRUCTURAL SOLUTIONS AND SPECIAL FEATURES OF THE THERMAL PROTECTION ANALYSIS OF EXTERIOR WALLS OF BUILDINGS MADE OF AUTOCLAVED GAS-CONCRETE BLOCKS

Directory of Open Access Journals (Sweden)

Bedov Anatolij Ivanovich

2012-10-01

Full Text Available Relevant structural solutions, physical and mechanical characteristics, coefficients of thermal conductivity for exterior masonry walls made of autoclaved gas-concrete blocks are provided in the article. If a single-layer wall is under consideration, an autoclaved gas-concrete block is capable of performing the two principal functions of a shell structure, including the function of thermal protection and the bearing function. The functions are performed simultaneously. Therefore, the application of the above masonry material means the design development and erection of exterior walls of residential buildings noteworthy for their thermal efficiency. In the event of frameless structures, the height of the residential building in question may be up to 5 stories, while the use of a monolithic or a ready-made frame makes it possible to build high-rise buildings, and the number of stories is not limited in this case. If the average block density is equal to 400…500 kilograms per cubic meter, the designed wall thickness is to be equal to 400 mm. Its thermal resistance may be lower than the one set in the event of the per-element design of the thermal protection (Rreq = 3.41 м2 C/Watt, in Ufa, although it will meet the requirements of the applicable regulations if per-unit power consumption rate is considered.

Determination of Acreage Thermal Protection Foam Loss From Ice and Foam Impacts

Science.gov (United States)

Carney, Kelly S.; Lawrence, Charles

2015-01-01

A parametric study was conducted to establish Thermal Protection System (TPS) loss from foam and ice impact conditions similar to what might occur on the Space Launch System. This study was based upon the large amount of testing and analysis that was conducted with both ice and foam debris impacts on TPS acreage foam for the Space Shuttle Project External Tank. Test verified material models and modeling techniques that resulted from Space Shuttle related testing were utilized for this parametric study. Parameters varied include projectile mass, impact velocity and impact angle (5 degree and 10 degree impacts). The amount of TPS acreage foam loss as a result of the various impact conditions is presented.

Protecting agriculture against nuclear radiations: conception and measures

International Nuclear Information System (INIS)

Lehmann Hans-Joerg

1997-01-01

In case of atomic and chemical (AC) accident or attacks the agriculture is severely affected. This became clearly after the Chernobyl disaster, after which the authorities mobilized and increased the efforts to protect the agriculture. In Switzerland the Federal Commission for AC protection has undertaken the necessary actions in collaboration with the Federal Office for Agriculture. The protection of agriculture against radioactive fallout has many aspects. One of these concerns the requirement of informing farmers with all the necessary instruction to ensure the protection of rural population and animals, foods and forages, to make them able to take essential protection measures without exterior assistance, and to provide the agriculture buildings with simple and durable tools necessary in case of emergency intervention. To implement these requirements on Confederation level educational programs were developed to instruct agriculture agents and advisors on basic notions of radioactivity and radiation protection. These programs are thought to make the farmer aware with the implications of nuclear chemical and nuclear menace and the measures of protecting its enterprise by own means. Special instructions are to be applied by the enterprise chiefs to ensure first that the personnel protection is the top priority and then how to minimize and limit the damage produced by the radiation accident

Thermal Mapper (TMAP) concept to study volcanism on Io

OpenAIRE

Maturilli, A.; Helbert, J.; Walter, Ingo; Peter, Gisbert

2016-01-01

Thermal Mapper (TMAP) is part of the payload of the proposed Discovery mission IVO. TMAP will provide near-global coverage at 0.1–20 km/pixel to map heat flow and monitor volcanism. It is a high spatial- resolution thermal imaging system optimized for observing Io with heritage from the ESA AIDA mission’s Minaturized Asteroid infrared Imager (MAIR) and Radiometer instrument and the Bepi-Colombo mission’s MErcury Radiometer and Thermal Infrared Spectrometer (MERTIS). Minor modifications of the...

On the Thermal Protection Systems of Landers for Venus Exploration

Science.gov (United States)

Ekonomov, A. P.; Ksanfomality, L. V.

2018-01-01

The landers of the Soviet Venera series—from Venera-9 to Venera-14—designed at the Lavochkin Association are a man-made monument to spectacular achievements of Soviet space research. For more than 40 years, they have remained the uneclipsed Soviet results in space studies of the Solar System. Within the last almost half a century, the experiments carried out by the Venera-9 to Venera-14 probes for studying the surface of the planet have not been repeated by any space agency in the world, mainly due to quite substantial technical problems. Since that time, no Russian missions with landers have been sent to Venus either. On Venus, there is an anoxic carbon dioxide atmosphere, where the pressure is 9.2 MPa and the temperature is 735 K near the surface. A long-lived lander should experience these conditions for an appreciable length of time. What technical solutions could provide a longer operation time for a new probe investigating the surface of Venus, if its thermal scheme is constructed similar to that of the Venera series? Onboard new landers, there should be a sealed module, where the physical conditions required for operating scientific instruments are maintained for a long period. At the same time, new high-temperature electronic equipment that remains functional under the above-mentioned conditions have appeared. In this paper, we consider and discuss different variants of the system for a long-lived sealed lander, in particular, the absorption of the penetrating heat due to water evaporation and the thermal protection construction for the instruments with intermediate characteristics.

The system of protected areas in Bulgaria in terms of the implementation of the concepts of sustainable and alternative tourism

Directory of Open Access Journals (Sweden)

Georgiev Leonidov Georgi

2010-01-01

Full Text Available Protected areas hold a special position in terms of the sustainable socio-economic and tourism development of the planet. The International Union for Conservation of Nature has created a specific classifying system for cate­gorization of such areas depending on their nature-scientific and conservation value and significance. Except for preserving valuable biological species and their natural habitats, these areas could fulfill one more function. They can be integrated and contribute to the sustainable development of all spheres of socio-economic life of the com­munity. This paper sets the aim to determine to what extent and what categories of protected areas in Bulgaria could be integrated into the tourism sector of the country and to contribute that way to its sustainable development. Eco­tourism is considered as main tool to achieve this goal. Two concepts are laid upon its successful implementation. These are the concept for sustainable development and the one for development of alternative forms of tourism. The thesis that the concept for development of alternative forms of tourism is thought to compliment the one for development of sustainable tourism.

Thermal Shock Properties of Cladding with SiC{sub f}/SiC Composite Protective Films

Energy Technology Data Exchange (ETDEWEB)

Lee, Donghee; Park, Kwangheon [Kyunghee University, Yongin (Korea, Republic of); Kim, Weonju; Park, Jiyeon; Kim, Daejong; Lee, Hyeon Geun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

In general, Zr-4 alloy is used for such nuclear fuel cladding. Zr-4 possesses a very small thermal neutron absorption cross-section and has superior corrosion resistance in the normal operating conditions of a nuclear reactor. However, in the case of a critical accident such as a LOCA (loss-of-coolant accident) in the Fukushima disaster, the risk of hydrogen explosion becomes serious. That is, in the case of coolant leakage, a dramatic reaction between the nuclear fuel cladding and steam can cause a heating reaction accompanied by rapid high-temperature oxidation, while creating a huge amount of hydrogen. Hence, the search for an alternative material for nuclear fuel cladding is being actively undertaken. Ceramic-based nuclear fuel cladding is receiving much attention as a means of improving safety. SiC has excellent properties of resistance to high temperature and high exposure and superior mechanical properties, as well as a very small thermal neutron absorption cross-section (0.09 barns), which causes almost no decrease in mechanical strength or volume change following exposure. This experiment examined the thermal shock properties and microstructure of cladding that has SiCf/SiC composite protective film, using polycarbosilane preceramic polymer.

A new concept of submersed centrifugal pump protection

International Nuclear Information System (INIS)

Ribeiro, Fabiano U.; Aguiar, Jose Luiz de M.; Hamdan, Adel C.; Doerwald, Bruno K.; Dutra, Diogenes; Ghiotto, Edson Carlos da S.; Meira, Marco Antonio A. de

2000-01-01

The present article is related to the development of one motor protection relay, which features include the electrical and mechanical device protection of machine. The main focus the purpose of this development, was the monitoring of the phenomena called 'Back Spin', which is common in oil production plant where 'Electrical Submersible Pump' (ESP) Technologies is used. The final results of this job is to present one equipment which is capable to completely protect the ESP Set, electrically and mechanically, and with additional functions of monitoring the mechanical set, with graphic interface to set all protection and monitoring functions using 'windows based' tools. (author)

Thermal Expansion Behavior of Hot-Pressed Engineered Matrices

Science.gov (United States)

Raj, S. V.

2016-01-01

Advanced engineered matrix composites (EMCs) require that the coefficient of thermal expansion (CTE) of the engineered matrix (EM) matches those of the fiber reinforcements as closely as possible in order to reduce thermal compatibility strains during heating and cooling of the composites. The present paper proposes a general concept for designing suitable matrices for long fiber reinforced composites using a rule of mixtures (ROM) approach to minimize the global differences in the thermal expansion mismatches between the fibers and the engineered matrix. Proof-of-concept studies were conducted to demonstrate the validity of the concept.

An Overt Chemical Protective Garment Reduces Thermal Strain Compared with a Covert Garment in Warm-Wet but Not Hot-Dry Environments

Directory of Open Access Journals (Sweden)

Matthew J. Maley

2017-11-01

Full Text Available Objectives: A commercial chemical, biological, radiological and nuclear (CBRN protective covert garment has recently been developed with the aim of reducing thermal strain. A covert CBRN protective layer can be worn under other clothing, with equipment added for full chemical protection when needed. However, it is unknown whether the covert garment offers any alleviation to thermal strain during work compared with a traditional overt ensemble. Therefore, the aim of this study was to compare thermal strain and work tolerance times during work in an overt and covert ensemble offering the same level of CBRN protection.Methods: Eleven male participants wore an overt (OVERT or covert (COVERT CBRN ensemble and walked (4 km·h−1, 1% grade for a maximum of 120 min in either a wet bulb globe temperature [WBGT] of 21, 30, or 37°C (Neutral, WarmWet and HotDry, respectively. The trials were ceased if the participants' gastrointestinal temperature reached 39°C, heart rate reached 90% of maximum, walking time reached 120 min or due to self-termination.Results: All participants completed 120 min of walking in Neutral. Work tolerance time was greater in OVERT compared with COVERT in WarmWet (P < 0.001, 116.5[9.9] vs. 88.9[12.2] min, respectively, though this order was reversed in HotDry (P = 0.003, 37.3[5.3] vs. 48.4[4.6] min, respectively. The rate of change in mean body temperature and mean skin temperature was greater in COVERT (0.025[0.004] and 0.045[0.010]°C·min−1, respectively compared with OVERT (0.014[0.004] and 0.027[0.007]°C·min−1, respectively in WarmWet (P < 0.001 and P = 0.028, respectively. However, the rate of change in mean body temperature and mean skin temperature was greater in OVERT (0.068[0.010] and 0.170[0.026]°C·min−1, respectively compared with COVERT (0.059[0.004] and 0.120[0.017]°C·min−1, respectively in HotDry (P = 0.002 and P < 0.001, respectively. Thermal sensation, thermal comfort, and ratings of perceived

Mechanical Testing of Carbon Based Woven Thermal Protection Materials

Science.gov (United States)

Pham, John; Agrawal, Parul; Arnold, James O.; Peterson, Keith; Venkatapathy, Ethiraj

2013-01-01

Three Dimensional Woven thermal protection system (TPS) materials are one of the enabling technologies for mechanically deployable hypersonic decelerator systems. These materials have been shown capable of serving a dual purpose as TPS and as structural load bearing members during entry and descent operations. In order to ensure successful structural performance, it is important to characterize the mechanical properties of these materials prior to and post exposure to entry-like heating conditions. This research focuses on the changes in load bearing capacity of woven TPS materials after being subjected to arcjet simulations of entry heating. Preliminary testing of arcjet tested materials [1] has shown a mechanical degradation. However, their residual strength is significantly more than the requirements for a mission to Venus [2]. A systematic investigation at the macro and microstructural scales is reported here to explore the potential causes of this degradation. The effects of heating on the sizing (an epoxy resin coating used to reduce friction and wear during fiber handling) are discussed as one of the possible causes for the decrease in mechanical properties. This investigation also provides valuable guidelines for margin policies for future mechanically deployable entry systems.

Solar collector overheating protection

NARCIS (Netherlands)

Slaman, M.J.; Griessen, R.P.

Prismatic structures in a thermal solar collector are used as overheating protection. Such structures reflect incoming light efficiently back whenever less thermal power is extracted from the solar collector. Maximum thermal power is generated when the prismatic structure is surrounded by a

About properties of ZrO2 thermal protective coatings obtained from spherical powder mixtures

Science.gov (United States)

Berdnik, O. B.; Tsareva, I. N.; Tarasenko, Yu P.

2017-05-01

It is developed the technology of high-energy plasma spraying of the zirconium dioxide (ZrO2) thermal protective coating on the basis of ZrO2 tetragonal and cubic phases with the spheroidal grain shape and the columnar substructure, with the total porosity P = 4 %, the hardness HV = 12 GPa, the roughness parameter R a ˜ 6 μm, the thickness 0.3-3 mm. As a sublayer it is used the heat-resistant coating of “Ni-Co-Cr-Al-Y” system with an intermetallic phase composition and the layered microstructure of the grains.

German physical protection concept for the storage of spent fuel elements in transport and storage casks

International Nuclear Information System (INIS)

Weil, L.; Maier, R.

2005-01-01

Full text: In Germany, the legal regulations and requirements derived from rules and guidelines for the protection of storage facilities for spent fuel elements from disruptive action or other inference by third parties are structured hierarchically. The Atomic Energy Act constitutes the top level. It is supported by federal ordinances. The next level down is formed by the rules and guidelines. The storage of nuclear fuels may only be authorized, according to the provisions of the Atomic Energy Act, if the required protection from disruptive action or other interference by third parties can be guaranteed as following: it must be possible to prevent any danger to life and health due to a substantial amount of direct radiation or due to the release of a substantial amount of radioactive material; it must be possible to prevent singular or repeated acts of stealing nuclear fuels in such amounts that a critical accumulation can be produced directly without reprocessing and enrichment. Knowing that nuclear installations cannot be protected from every possible interference, physical protection is focused on basic security standards, the so-called design basic threat (DBT), departing from the assumed interference. DBT is regularly reviewed by the competent federal authorities and authorities of the states and are revised on the basis of newly gained knowledge, if necessary, such as in the wake of the terrorist attacks in the U.S. on September 11, 2001. The operator must guarantee and give proof of a sufficient level of physical protection of the plant. The sole physical protection measures implemented by the operator cannot ensure the required protection from other interference by third parties for an unlimited time span. The concept therefore requires additional physical protection measures by the police. (author)

Thermal management of space stations

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Thermal management aims at making full use of energy resources available in the space station to reduce energy consumption, waste heat rejection and the weight of the station. It is an extension of the thermal control. This discussion introduces the concept and development of thermal management, presents the aspects of thermal management and further extends its application to subsystems of the space station.

The Thermal Protection of a Specific Experimental Instrument for Monitoring of Combustion Conditions on the Grate of Municipal Solid Waste Incinerators

Czech Academy of Sciences Publication Activity Database

Martinec, J.; Šen, H.; Svoboda, Karel; Martincová, J.V.; Baxter, D.

2010-01-01

Roč. 30, 8-9 (2010), s. 1022-1028 ISSN 1359-4311 Institutional research plan: CEZ:AV0Z40720504 Keywords : waste incineration * thermal protection * gas composition Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.823, year: 2010

The preliminary thermal-hydraulic design of one superheated steam water cooled blanket concept based on RELAP5 and MELCOR codes - 15147

International Nuclear Information System (INIS)

Guo, Y.; Wang, G.; Cheng, Y.; Peng, C.

2015-01-01

Water Cooled Blanket (WCB) is very important in the concept design and energy transfer in future fusion power plant. One concept design of WCB is under computational testing. RELAP5 and MELCOR codes, which are mature and often used in nuclear engineering, are selected as simulation tools. The complex inner flow channels and heat sources are simplified according to its thermal-hydraulic characteristics. Then the nodal models for RELAP5 and MELCOR are built for approximating the concept design. The superheated steam scheme is analyzed by two codes separately under different power levels. After some adjustments of the inlet flow resistance coefficients of some flow channels, the reasonable stable conditions can be obtained. The stable fluid and wall temperature distributions and pressure drops are studied. The results of two codes are compared and some advices are given. (authors)

Mathematical Foundation Based Inter-Connectivity modelling of Thermal Image processing technique for Fire Protection

Directory of Open Access Journals (Sweden)

Sayantan Nath

2015-09-01

Full Text Available In this paper, integration between multiple functions of image processing and its statistical parameters for intelligent alarming series based fire detection system is presented. The proper inter-connectivity mapping between processing elements of imagery based on classification factor for temperature monitoring and multilevel intelligent alarm sequence is introduced by abstractive canonical approach. The flow of image processing components between core implementation of intelligent alarming system with temperature wise area segmentation as well as boundary detection technique is not yet fully explored in the present era of thermal imaging. In the light of analytical perspective of convolutive functionalism in thermal imaging, the abstract algebra based inter-mapping model between event-calculus supported DAGSVM classification for step-by-step generation of alarm series with gradual monitoring technique and segmentation of regions with its affected boundaries in thermographic image of coal with respect to temperature distinctions is discussed. The connectedness of the multifunctional operations of image processing based compatible fire protection system with proper monitoring sequence is presently investigated here. The mathematical models representing the relation between the temperature affected areas and its boundary in the obtained thermal image defined in partial derivative fashion is the core contribution of this study. The thermal image of coal sample is obtained in real-life scenario by self-assembled thermographic camera in this study. The amalgamation between area segmentation, boundary detection and alarm series are described in abstract algebra. The principal objective of this paper is to understand the dependency pattern and the principles of working of image processing components and structure an inter-connected modelling technique also for those components with the help of mathematical foundation.

Thermal Protection System Cavity Heating for Simplified and Actual Geometries Using Computational Fluid Dynamics Simulations with Unstructured Grids

Science.gov (United States)

McCloud, Peter L.

2010-01-01

Thermal Protection System (TPS) Cavity Heating is predicted using Computational Fluid Dynamics (CFD) on unstructured grids for both simplified cavities and actual cavity geometries. Validation was performed using comparisons to wind tunnel experimental results and CFD predictions using structured grids. Full-scale predictions were made for simplified and actual geometry configurations on the Space Shuttle Orbiter in a mission support timeframe.

Study on thermal wave based on the thermal mass theory

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

The conservation equations for heat conduction are established based on the concept of thermal mass.We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass.The general law introduces a damped thermal wave equation.It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected,which indicates that the CV model only considers the temporal inertia of heat flux.Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory.For larger thermal perturbation,however,the physically impossible phenomenon pre-dicted by CV model,i.e.the negative temperature induced by the thermal wave superposition,is eliminated by the general heat conduction law,which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.

Study on thermal wave based on the thermal mass theory

Institute of Scientific and Technical Information of China (English)

HU RuiFeng; CAO BingYang

2009-01-01

The conservation equations for heat conduction are established based on the concept of thermal mass. We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass. The general law introduces a damped thermal wave equation. It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected, which indicates that the CV model only considers the temporal inertia of heat flux. Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory. For larger thermal perturbation, however, the physically impossible phenomenon pre-dicted by CV model, i.e. the negative temperature induced by the thermal wave superposition, is eliminated by the general heat conduction law, which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.

Exotic power and propulsion concepts

International Nuclear Information System (INIS)

Forward, R.L.

1990-01-01

The status of some exotic physical phenomena and unconventional spacecraft concepts that might produce breakthroughs in power and propulsion in the 21st Century are reviewed. The subjects covered include: electric, nuclear fission, nuclear fusion, antimatter, high energy density materials, metallic hydrogen, laser thermal, solar thermal, solar sail, magnetic sail, and tether propulsion

Thermal-Insulation Properties of Multilayer Textile Packages

Directory of Open Access Journals (Sweden)

Matusiak Małgorzata

2014-12-01

Full Text Available Thermal-insulation properties of textile materials play a significant role in material engineering of protective clothing. Thermal-insulation properties are very important from the point of view of thermal comfort of the clothing user as well as the protective efficiency against low or high temperature. Thermal protective clothing usually is a multilayer construction. Its thermal insulation is a resultant of a number of layers and their order, as well as the thermalinsulation properties of a single textile material creating particular layers. The aim of the presented work was to investigate the relationships between the thermal-insulation properties of single materials and multilayer textile packages composed of these materials. Measurement of the thermal-insulation properties of single and multilayer textile materials has been performed with the Alambeta. The following properties have been investigated: thermal conductivity, resistance and absorptivity. Investigated textile packages were composed of two, three and four layers made of woven and knitted fabrics, as well as nonwovens. On the basis of the obtained results an analysis has been carried out in order to assess the dependency of the resultant values of the thermal-insulation properties of multilayer packages on the appropriate values of particular components.

Living closer to the environment: Housing design concept

Directory of Open Access Journals (Sweden)

Kosorić Vesna

2011-01-01

Full Text Available The main idea of this design concept is to strengthen the relationship and understanding between a man - resident and his environment. Residents are separated from the outdoor environment by glazing, which enables constant observation of environment from nearly all points of indoor space, encouraging positive feelings towards external world and understanding of the fragility of biosphere. Care for the environment should become a part of a man's nature and way of living, and it is the people who are expected to become the driving force of positive global changes towards sustainable development. The semisphere-like single family house of 14m in diameter has a multifunctional, multi-layer 'active' facade envelope. The envelope ensures constant visual contact of residents with the whole surroundings, while still providing comfort. The living space of the house reflects natural shapes which are organic rather than rectangular. Such indoor space becomes a part of the environment, rather than being protected, distanced and isolated from it. The house is designed to use solar energy 'passively' by absorption through insulated glazed envelope and 'actively' by outer skin layer on the first floor, made of stripes of flat semi-transparent polycrystalline photovoltaic (PV panels. In addition to its constructive role, the concrete core of the house acts as thermal mass and enables absorption and accumulation of thermal energy. The developed housing concept is applicable in different urban-design units and sets.

'THERMO-BRIDGE' between East and West for technology transfer and information exchange. 16. International conference on Thermal engineering and thermogrammetry (THERMO) with Exhibition and Pre-Session on Thermal Energy in Hungarian

International Nuclear Information System (INIS)

2009-01-01

It was already organized as the International Conference on Thermal Engineering and Thermogrammetry (THERMO) in 1987. This conference is a series of biennial meetings. The developments of measurement theory and technologies help the energy-conscious design of thermal engineering equipment and processes as well as the better understanding of thermal phenomena in living organism. The conference will cover topics both the field of theory and application including nem measurements concepts; transducer technique mapping; contact, optical and IR imaging; biomedical and biotechnological applications; thermal informatics, automatic methods and systems for industrial energy management and process control; heat loss detection and analysis; heat and mass transfer; utilization of alternative energy; thermophysical properties as well as the common practice of thermal engineering. The programme included more than 40 papers from 19 countries. On the three days of oral presentation and poster workshops are organized whose topics will cover the following fields: Heat and mass transfer, thermotechnics; combustion and environmental protection; thermogravimetry; thermomechanics and defectometry; Infrared imagery and analysis, thermodynamics; practice of thermal engineering; medicine and biology. During the conference there were an exhibition of scientific and industrial instrumentation in the conference hall. (S.I.)

Flutter Analysis of the Thermal Protection Layer on the NASA HIAD

Science.gov (United States)

Goldman, Benjamin D.; Dowell, Earl H.; Scott, Robert C.

2013-01-01

A combination of classical plate theory and a supersonic aerodynamic model is used to study the aeroelastic flutter behavior of a proposed thermal protection system (TPS) for the NASA HIAD. The analysis pertains to the rectangular configurations currently being tested in a NASA wind-tunnel facility, and may explain why oscillations of the articles could be observed. An analysis using a linear flat plate model indicated that flutter was possible well within the supersonic flow regime of the wind tunnel tests. A more complex nonlinear analysis of the TPS, taking into account any material curvature present due to the restraint system or substructure, indicated that significantly greater aerodynamic forcing is required for the onset of flutter. Chaotic and periodic limit cycle oscillations (LCOs) of the TPS are possible depending on how the curvature is imposed. When the pressure from the base substructure on the bottom of the TPS is used as the source of curvature, the flutter boundary increases rapidly and chaotic behavior is eliminated.

Minority Protection in the European Union: From Economic Rights to the Protection of European Values

NARCIS (Netherlands)

Versteegh, C.R.M.

2015-01-01

Minority protection did not receive attention in the original EC treaty of 1956. The concept of nondiscrimination of laborers and later of EU citizens became the cornerstone for minority protection. Gradually the EU became familiar with the concept of human rights because of judgments of the

Protecting-group-free synthesis of taiwaniaquinone H using a one-pot thermal ring expansion/4π-electrocyclization strategy.

Science.gov (United States)

Yan, Xiuxiang; Hu, Xiangdong

2014-06-06

A strategy to the 6-5-6 tricyclic scaffold of taiwaniaquinoids was established on the basis of a one-pot thermal ring expansion/4π-electrocyclization process. The efficiency of this methodology has been demonstrated through its application in the total synthesis of taiwaniaquinone H, which has been accomplished in three steps and 14% overall yield in a protecting-group-free manner starting from commercially available materials.

Development of Processing Techniques for Advanced Thermal Protection Materials

Science.gov (United States)

Selvaduray, Guna; Cox, Michael; Srinivasan, Vijayakumar

1997-01-01

Thermal Protection Materials Branch (TPMB) has been involved in various research programs to improve the properties and structural integrity of the existing aerospace high temperature materials. Specimens from various research programs were brought into the analytical laboratory for the purpose of obtaining and refining the material characterization. The analytical laboratory in TPMB has many different instruments which were utilized to determine the physical and chemical characteristics of materials. Some of the instruments that were utilized by the SJSU students are: Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), X-ray Diffraction Spectrometer (XRD), Fourier Transform-Infrared Spectroscopy (FTIR), Ultra Violet Spectroscopy/Visible Spectroscopy (UV/VIS), Particle Size Analyzer (PSA), and Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). The above mentioned analytical instruments were utilized in the material characterization process of the specimens from research programs such as: aerogel ceramics (I) and (II), X-33 Blankets, ARC-Jet specimens, QUICFIX specimens and gas permeability of lightweight ceramic ablators. In addition to analytical instruments in the analytical laboratory at TPMB, there are several on-going experiments. One particular experiment allows the measurement of permeability of ceramic ablators. From these measurements, physical characteristics of the ceramic ablators can be derived.

Radiation protection standards

International Nuclear Information System (INIS)

Koelzer, W.

1980-01-01

The present paper deals with: Objectives and basic concepts of radiation protection, basic radiobiological considerations, the ICRP system of dose limitation and with operational radiation protection (limits, reference levels, occupational exposure). (RW)

Thermally Sprayed Aluminum Coatings for the Protection of Subsea Risers and Pipelines Carrying Hot Fluids

Directory of Open Access Journals (Sweden)

Nataly Ce

2016-11-01

Full Text Available This paper reports the effect of boiling synthetic seawater on the performance of damaged Thermally Sprayed Aluminum (TSA on carbon steel. Small defects (4% of the sample’s geometric surface area were drilled, exposing the steel, and the performance of the coating was analyzed for corrosion potential for different exposure times (2 h, 335 h, and 5000 h. The samples were monitored using linear polarization resistance (LPR in order to obtain their corrosion rate. Scanning electron microscopy (SEM/energy dispersive X-ray spectroscopy (EDX and X-ray diffraction (XRD were used for post-test characterization. The results showed that a protective layer of Mg(OH2 formed in the damaged area, which protected the underlying steel. Additionally, no coating detachment from the steel near the defect region was observed. The corrosion rate was found to be 0.010–0.015 mm/year after 5000 h in boiling synthetic seawater.

Value and cost analyses for solar thermal-storage systems

Energy Technology Data Exchange (ETDEWEB)

Luft, W.; Copeland, R.J.

1983-04-01

Value and cost data for thermal energy storage are presented for solar thermal central receiver systems for which thermal energy storage appears to be attractive. Both solar thermal electric power and industrial process heat applications are evaluated. The value of storage is based on the cost for fossil fuel and solar thermal collector systems in 1990. The costing uses a standard lifetime methodology with the storage capacity as a parameter. Both value and costs are functions of storage capacity. However, the value function depends on the application. Value/cost analyses for first-generation storage concepts for five central receiver systems (molten salt, water/steam, organic fluid, air, and liquid metal) established the reference against which new systems were compared. Some promising second-generation energy storage concepts have been identified, and some more advanced concepts have also been evaluated.

Conventional and Bimodal Nuclear Thermal Rocket (NTR) Artificial Gravity Mars Transfer Vehicle Concepts

Science.gov (United States)

Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W.

2016-01-01

A variety of countermeasures have been developed to address the debilitating physiological effects of zero-gravity (0-g) experienced by cosmonauts and astronauts during their approximately 0.5 to 1.2 year long stays in low Earth orbit (LEO). Longer interplanetary flights, combined with possible prolonged stays in Mars orbit, could subject crewmembers to up to approximately 2.5 years of weightlessness. In view of known and recently diagnosed problems associated with 0-g, an artificial gravity (AG) spacecraft offers many advantages and may indeed be an enabling technology for human flights to Mars. A number of important human factors must be taken into account in selecting the rotation radius, rotation rate, and orientation of the habitation module or modules. These factors include the gravity gradient effect, radial and tangential Coriolis forces, along with cross-coupled acceleration effects. Artificial gravity Mars transfer vehicle (MTV) concepts are presented that utilize both conventional NTR, as well as, enhanced bimodal nuclear thermal rocket (BNTR) propulsion. The NTR is a proven technology that generates high thrust and has a specific impulse (Isp) capability of approximately 900 s-twice that of today's best chemical rockets. The AG/MTV concepts using conventional Nuclear Thermal Propulsion (NTP) carry twin cylindrical International Space Station (ISS)- type habitation modules with their long axes oriented either perpendicular or parallel to the longitudinal spin axis of the MTV and utilize photovoltaic arrays (PVAs) for spacecraft power. The twin habitat modules are connected to a central operations hub located at the front of the MTV via two pressurized tunnels that provide the rotation radius for the habitat modules. For the BNTR AG/MTV option, each engine has its own closed secondary helium(He)-xenon (Xe) gas loop and Brayton Rotating Unit (BRU) that can generate 10s of kilowatts (kWe) of spacecraft electrical power during the mission coast phase

Revisiting the thermal-spike concept in ion-surface interactions

Science.gov (United States)

Miotello, Antonio; Kelly, Roger

1997-02-01

In recent years many groups have advocated a thermal-spike model to explain a variety of experimental results in ion-irradiation of solids, as for example sputtering, mixing, compositional change, structural change, and track formation. The latter include crystal-to-amorphous transitions as well as track formation due to MeV/u particles. In this paper we reconsider the phenomena occurring during ion impact of solids looking at the time scale generally indicated as relevant for thermal-spike effects, namely a picosecond scale as shown by molecular dynamics. Sputtering, mixing, and track formation, however, will be analyzed in more detail. We consider first ion-beam sputtering and reiterate (as is already well-known) that yields which increase with the bulk temperature most often indicate merely the onset of normal vaporization. Indeed, only simulations appear to be capable of giving insight even if the information is sometimes tentative. In mixing, ballistic transport is important but not dominant. It is often argued that the additional transport is provided by thermal spikes but it is noted that such an assumption is normally not required by the experimental results. What is more relevant is a role for residual defects such that the total diffusion flux includes (if the defects are chemically guided) a modified Darken factor, or (if the defects are not chemically guided) simply an increased diffusivity. The time scale (min), distances (well beyond the collision cascade), temperature sensitivity (changes of as little as 75 K are relevant), and correlation with vacancy properties (thence with the solid rather than liquid state) which are relevant to these residual defects are not understandable in terms of thermal spikes. We finally consider track formation. Recent work claiming that track formation in solids, irradiated with heavy ions, may be understood in terms of thermal spikes is reconsidered to show that the thermal-spike model is utilized without considering

Thermal design trades for SAFIR architecture concepts

Science.gov (United States)

Yorke, Harold W.; Paine, Christopher; Bradford, Matt; Dragovan, Mark; Nash, Al; Dooley, Jennifer; Lawrence, Charles

2004-01-01

SAFIR is a IO-meter, 4 K space telescope optimized for wavelengths between 20 microns and 1 mm. The combination of aperture diameter and telescope temperature will provide a raw sensitivity improvement of more than a factor of 1000 over presently-planned missions. The sensitivity will be comparable to that of the JWST and ALMA, but at the critical far-IR wavelengths where much of the universe's radiative energy has emerged since the origin of stars and galaxies. We examine several of the critical technologies for SAFIR which enable the large cold aperture, and present results of studies examining the telescope optics and the spacecraft thermal architecture. Both the method by which the aperture is filled, and the overall optical design for the telescope can impact the potential scientific return of SAFIR. Thermal architecture that goes far beyond the sunshades developed for the James Webb Space Telescope will be necessary to achieve the desired sensitivity of SAFIR. By combining active and passive cooling at critical points within the observatory, a significant reduction of the required level of active cooling can be obtained.

Transient stress control of aeroengine disks based on active thermal management

International Nuclear Information System (INIS)

Ding, Shuiting; Wang, Ziyao; Li, Guo; Liu, Chuankai; Yang, Liu

2016-01-01

Highlights: • The essence of cooling in turbine system is a process of thermal management. • Active thermal management is proposed to control transient stress of disks. • The correlation between thermal load and transient stress of disks is built. • Stress level can be declined by actively adjusting the thermal load distribution. • Artificial temperature gradient can be used to counteract stress from rotating. - Abstract: The physical essence of cooling in the turbine system is a process of thermal management. In order to overcome the limits of passive thermal management based on thermal protection, the concept of active thermal management based on thermal load redistribution has been proposed. On this basis, this paper focuses on a near real aeroengine disk during a transient process and studies the stress control mechanism of active thermal management in transient conditions by a semi-analytical method. Active thermal management is conducted by imposing extra heating energy on the disk hub, which is represented by the coefficient of extra heat flow η. The results show that the transient stress level can be effectively controlled by actively adjusting the thermal load distribution. The decline ratio of the peak equivalent stress of the disk hub can be 9.0% for active thermal management load condition (η = 0.2) compared with passive condition (η = 0), even at a rotation speed of 10,000 r/min. The reason may be that the temperature distribution of the disk turns into an artificial V-shape because of the extra heating energy on the hub, and the resulting thermal stresses induced by the negative temperature gradients counteract parts of the stress from rotating.

Evaluation of an optimized coolant circuit conception in a thermal whole vehicle environment with respect to the consumption of primary energy; Bewertung eines optimierten Kuehlmittelkreislaufkonzeptes in einer thermischen Gesamtfahrzeugumgebung hinsichtlich des Primaerenergieverbrauchs

Energy Technology Data Exchange (ETDEWEB)

Schulze, Mirko; Neumann, Alexander; Tilch, Benjamin; Eilts, Peter [Technische Univ. Braunschweig (Germany). Inst. fuer Verbrennungskraftmaschinen; Niedersaechsisches Forschungszentrum Fahrzeugtechnik (NFF), Braunschweig (Germany)

2012-11-01

This work deals with a co-simulation vehicle environment developed by the institute of internal combustion engines (ivb) of the Technical University Braunschweig as a tool to analyze the thermal effects in the power train during the warm-up phase, especially on the fuel consumption. This allows evaluating new drive train concepts in early stages of development by using power train thermal management techniques (TMM). Therefore you are able to give an objective statement for these techniques by analyzing the changes in fuel consumption. The used simulation models will be introduced and the mechanical and thermal behavior is verified using test bench data. An optimized coolant circuit concept in GT Suite {sup registered}, developed at the institute is identified and coupled to a thermal engine model. In this paper, the potentials for reducing primary energy consumption in the New European Driving Cycle (NEDC) are presented. (orig.)

Thermal Protection Performance of Carbon Aerogels Filled with Magnesium Chloride Hexahydrate as a Phase Change Material

Directory of Open Access Journals (Sweden)

Ali Kazemi

2014-02-01

Full Text Available Carbon aerogels are comprised of a class of low density open-cell foams with large void space, nanometer pore size and composed of sparsely semi-colloidal nanometer sized particles forming an open porous structure. Phase change materials are those with high heat of fusion that could absorb and release a large amount of energy at the time of phase transition. These materials are mostly used as thermal energy storage materials but in addition they could serve as an obstacle for passage of heat during phase changes and this has led to their use in thermal protection systems. In this study, the effect of magnesium chloride hexahydrate, as a phase change material (melting point 115°C, on thermal properties of carbon aerogels is investigated. Thermal performance tests are designed and used for comparing the temperature-time behavior of the samples. DSC is applied to obtain the latent heat of melting of the phase change materials and the SEM tests are used to analyze the microstructure and morphology of carbon aerogels. The results show that the low percentage of phase change materials in carbon aerogels does not have any significant positive effect on carbon aerogels thermal properties. However, these properties are improved by increasing the percentage of phase change materials. With high percentage of phase change materials, a sample surface at 300°C would display an opposite surface with a significant drop in temperature increases, while at 115-200°C, with carbon aerogels, having no phase change materials, there is a severe reduction in the rate of temperature increase of the sample.

CONCEPTS OF IMPROVING CURRENT PROTECTION OF POWER-GRID LINES

Directory of Open Access Journals (Sweden)

F. A. Romaniuk

2015-01-01

Full Text Available The  6–35  kV  power-grid  current  protection  serves  to  protect  the  transmission  lines against phase-to-phase short-circuits. The major disadvantage of it lies in the relatively large time delays of the last stages especially in the main sections of the grid owing to the stepped relay characteristics as well as a large number of the steps. A full-fledged protection of the 6–35 kV lines against inter-phase short circuits can be provided by the two-stage current protection: the first stage being the current cutoff without any time delay and the second stage – the maximum current protection where the time delay is linear contingent on the distance between the protection placement and the fault-point location. The article introduces the rating formulae for the time delays of the second-stage and their exemplary graphic presentation. The authors offer a variant for solving the problem with computation of the second-stage time delays in those instances where several feeders diverge from the bus bars of the substation located in the end of the protected line.Improving current protections for the 6–35 kV transmission lines with one-end power supply against interphase short-circuits can be based on the collective application of the following principles: accounting for the type and location of the short-circuit which provides for the high-performance cutoff zone instantaneous expansion and its independence on the mode of failure and the grid operation mode. It also allows increase of the last stage sensitiveness towards asymmetrical short-circuits; detection of the short-circuit location only on the results of fault currents measurement which simplifies the protection implementation; realization of the last (second protection stage with linear-dependent time delay which ensures potentiality of its operation speed increase.

Definition of Turbulent Boundary-Layer with Entropy Concept

Directory of Open Access Journals (Sweden)

Zhao Rui

2016-01-01

Full Text Available The relationship between the entropy increment and the viscosity dissipation in turbulent boundary-layer is systematically investigated. Through theoretical analysis and direct numerical simulation (DNS, an entropy function fs is proposed to distinguish the turbulent boundary-layer from the external flow. This approach is proved to be reliable after comparing its performance in the following complex flows, namely, low-speed airfoil flows with different wall temperature, supersonic cavity-ramp flow dominated by the combination of free-shear layer, larger recirculation and shocks, and the hypersonic flow past an aeroplane configuration. Moreover, fs is deduced from the point of energy, independent of any particular turbulent quantities. That is, this entropy concept could be utilized by other engineering applications related with turbulent boundary-layer, such as turbulence modelling transition prediction and engineering thermal protection.

The second advanced lead lithium blanket concept using ODS steel as structural material and SiCf/SiC flow channel inserts as electrical and thermal insulators (Task PPA 2.5). Final report

International Nuclear Information System (INIS)

Norajitra, P.; Buehler, L.; Fischer, U.

1999-12-01

Preparatory work on the advanced dual coolant (A-DCL) blanket concept using SiC f /SiC flow channel inserts as electrical and thermal insulators has been carried out at the Forschungszentrum Karlsruhe in co-operation with CEA as a conceptual design proposal to the EU fusion power plant study planned to be launched in 2000 within the framework of the EU fusion programme with the main objective of specifying the characteristics of an attractive and viable commercial D-T fusion power plant. The basic principles and design characteristics of this A-DCL blanket concept are presented and its potential with regard to performance (neutron wall load, lifetime, availability) is discussed in this report. The results of this study show that the A-DCL blanket concept has a high potential for further development due to its high thermal efficiency and its simple concept solution. (orig.) [de

Micro- and Nano-Scale Electrically Driven Two-Phase Thermal Management

Science.gov (United States)

Didion, Jeffrey R.

2016-01-01

This presentation discusses ground based proof of concept hardware under development at NASA GSFC to address high heat flux thermal management in silicon substrates. The goal is to develop proof of concept hardware for space flight validation. The space flight hardware will provide gravity insensitive thermal management for electronics applications such as transmit receive modules that are severely limited by thermal concerns.

Radiation protection seminar

International Nuclear Information System (INIS)

2012-01-01

The Radiation Protection Seminar, was organized by the Argentina Association of Biology and Nuclear Medicine, and Bacon Laboratory, the 20 june 2012, in the Buenos Aires city of Argentina. In this event were presented some papers on the following topics: methods of decontamination, radiation protection of patients; concepts of radiation protection and dosimetry.

Investigation of Post-Flight Solid Rocket Booster Thermal Protection System

Science.gov (United States)

Nelson, Linda A.

2006-01-01

After every Shuttle mission, the Solid Rocket Boosters (SRBs) are recovered and observed for missing material. Most of the SRB is covered with a cork-based thermal protection material (MCC-l). After the most recent shuttle mission, STS-114, the forward section of the booster appeared to have been impacted during flight. The darkened fracture surfaces indicated that this might have occurred early in flight. The scope of the analysis included microscopic observations to assess the degree of heat effects and locate evidence of the impact source as well as chemical analysis of the fracture surfaces and recovered foreign material using Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy/Energy Dispersive Spectroscopy. The amount of heat effects and presence of soot products on the fracture surface indicated that the material was impacted prior to SRB re-entry into the atmosphere. Fragments of graphite fibers found on these fracture surfaces were traced to slag inside the Solid Rocket Motor (SRM) that forms during flight as the propellant is spent and is ejected throughout the descent of the SRB after separation. The direction of the impact mark matches with the likely trajectory of SRBs tumbling prior to re-entry.

Monitoring of Thermal Protection Systems and MMOD using Robust Self-Organizing Optical Fiber Sensing Networks

Science.gov (United States)

Richards, Lance

2014-01-01

The general aim of this work is to develop and demonstrate a prototype structural health monitoring system for thermal protection systems that incorporates piezoelectric acoustic emission (AE) sensors to detect the occurrence and location of damaging impacts, such as those from Micrometeoroid Orbital Debris (MMOD). The approach uses an optical fiber Bragg grating (FBG) sensor network to evaluate the effect of detected damage on the thermal conductivity of the TPS material. Following detection of an impact, the TPS would be exposed to a heat source, possibly the sun, and the temperature distribution on the inner surface in the vicinity of the impact measured by the FBG network. A similar procedure could also be carried out as a screening test immediately prior to re-entry. The implications of any detected anomalies in the measured temperature distribution will be evaluated for their significance in relation to the performance of the TPS during reentry. Such a robust TPS health monitoring system would ensure overall crew safety throughout the mission, especially during reentry.

A review of the concepts of exclusion and exemption

International Nuclear Information System (INIS)

Wrixon, A.D.

2004-01-01

The concept of exemption has been widely used in radiological protection. It is part of the regulator's arsenal for applying legislative requirements in a graded fashion, to avoid the expenditure of effort on situations where the return in terms of improvement in protection would otherwise be trivial. Nevertheless, it still remains a controversial matter. Perhaps somewhat surprisingly, it is not so much the dosimetric criteria for exemption that cause debate; it is more the way in which the concept is used; the scenarios employed to calculate derived activity concentrations, and its relationship to the somewhat analogous concept of exclusion. Much of the debate regarding the use of the concept and its relationship with exclusion finds its origin in the national legislative culture that has developed over the years in various countries and the inevitable resistance to keep pace with the evolution of the system of radiological protection as recommended by the International Commission on Radiological Protection and implemented through the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. A particular problem has been the full integration into the legislative system of protection of exposures to radiation from sources of natural origin and the degree to which exemption is a relevant concept for dealing with such situations. The purpose of this paper is to attempt to provide some clarity on the two concepts and their practical implementation with a view to encouraging international harmonization and avoiding further unnecessary debate. (author)

Study of elevated temperature design standard against thermal loads

International Nuclear Information System (INIS)

Kasahara, Naoto; Asayama, Tai; Morishita, Masaki

2001-01-01

Elevated temperature components must be designed against both pressure and thermal loads. In the case of sodium circuits of fast breeder reactors, a restriction from the pressure load becomes small because of the high boiling point of sodium. Design approaches for thermal loads (displacement-controlled) are compared with those against pressure loads (load-controlled). Considering differences between those two approaches, a concept of the elevated temperature design standard that takes the nature of thermal loads fully into account is proposed. This concept is a basis of load evaluation techniques and an inelastic analysis guide, that are being developed. Finally, problems and plans to realize the above concept are discussed. (author)

Protecting traditional knowledge of Chinese medicine: concepts and proposals.

Science.gov (United States)

Liu, Changhua; Gu, Man

2011-06-01

With the development of the knowledge economy, knowledge has become one of the most important resources for social progress and economic development. Some countries have proposed measures for the protection of their own traditional knowledge. Traditional Chinese medicine belongs to the category of intangible cultural heritage because it is an important part of Chinese cultural heritage. Today the value of traditional knowledge of Chinese medicine has been widely recognized by the domestic and international public. This paper discusses the definition of traditional knowledge of Chinese medicine and its protection, and evaluates research on its classification. We review the present status of the protection of traditional knowledge of Chinese medicine and tentatively put forward some possible ideas and methods for the protection of traditional knowledge of Chinese medicine. Our goal is to find a way to strengthen the vitality of traditional Chinese medicine and consolidate its foundation. We believe that if we could establish a suitable sui generis(sui generis is a Latin term meaning "of its own kind" and is often used in discussions about protecting the rights of indigenous peoples. Here we use it to emphasize the fact that protection of traditional knowledge of Chinese medicine cannot be achieved through existing legal means of protection alone due to its unique characteristics) system for traditional knowledge, a more favorable environment for the preservation and development of traditional Chinese medicine will ultimately be created.

Preliminary ALARA design concept for SMART

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyo Youn; Kim, Seung Nam; Kim, Ha Yong; Zee, Sung Quun; Chang, Moon Hee

1999-03-01

SMART(System-integrated Modular Advanced ReacTor) is a space saving integral type nuclear rector with the thermal power of 330 MW. This report provides general design guide and authority in NSSS designs for SMART needed to maintain the occupational doses and doses to members of public ALARA to meet the regulatory requirements. Paragraph 20.1 of 10 CFR 20, ''Standards for Protection Against Radiation'', states that licensee should make every reasonable effort to maintain exposures to radiation as far below the limits specified in Part 20 as is reasonably achievable. The ALARA (as low as is reasonably achievable) principle is incorporated into Korean radiation protection law as paragraph one Article 97 of the Atomic Energy Act. (Jan. 1995). This ALARA Design Concept for SMART provides 1) description of the organization and responsibilities needed for upper level management support and authority in order for the implementation of ALARA, 2) guidance and procedures for design, review, and evaluation needed for SMART ALARA program implementation, 3) general design guidelines for SMART NSSS and BOP designers to implement ALARA principles in design stage, and 4) training and instruction requirement of SMART NSSS and BOP designers for the familiarization of ALARA principles to be implemented in NSSS designs. (Author). 4 refs., 1 tabs.

Preliminary ALARA design concept for SMART

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyo Youn; Kim, Seung Nam; Kim, Ha Yong; Zee, Sung Quun; Chang, Moon Hee

1999-03-01

SMART(System-integrated Modular Advanced ReacTor) is a space saving integral type nuclear rector with the thermal power of 330 MW. This report provides general design guide and authority in NSSS designs for SMART needed to maintain the occupational doses and doses to members of public ALARA to meet the regulatory requirements. Paragraph 20.1 of 10 CFR 20, ''Standards for Protection Against Radiation'', states that licensee should make every reasonable effort to maintain exposures to radiation as far below the limits specified in Part 20 as is reasonably achievable. The ALARA (as low as is reasonably achievable) principle is incorporated into Korean radiation protection law as paragraph one Article 97 of the Atomic Energy Act. (Jan. 1995). This ALARA Design Concept for SMART provides 1) description of the organization and responsibilities needed for upper level management support and authority in order for the implementation of ALARA, 2) guidance and procedures for design, review, and evaluation needed for SMART ALARA program implementation, 3) general design guidelines for SMART NSSS and BOP designers to implement ALARA principles in design stage, and 4) training and instruction requirement of SMART NSSS and BOP designers for the familiarization of ALARA principles to be implemented in NSSS designs. (Author). 4 refs., 1 tabs.

Preliminary ALARA design concept for SMART

International Nuclear Information System (INIS)

Kim, Kyo Youn; Kim, Seung Nam; Kim, Ha Yong; Zee, Sung Quun; Chang, Moon Hee

1999-03-01

SMART(System-integrated Modular Advanced ReacTor) is a space saving integral type nuclear rector with the thermal power of 330 MW. This report provides general design guide and authority in NSSS designs for SMART needed to maintain the occupational doses and doses to members of public ALARA to meet the regulatory requirements. Paragraph 20.1 of 10 CFR 20, ''Standards for Protection Against Radiation'', states that licensee should make every reasonable effort to maintain exposures to radiation as far below the limits specified in Part 20 as is reasonably achievable. The ALARA (as low as is reasonably achievable) principle is incorporated into Korean radiation protection law as paragraph one Article 97 of the Atomic Energy Act. (Jan. 1995). This ALARA Design Concept for SMART provides 1) description of the organization and responsibilities needed for upper level management support and authority in order for the implementation of ALARA, 2) guidance and procedures for design, review, and evaluation needed for SMART ALARA program implementation, 3) general design guidelines for SMART NSSS and BOP designers to implement ALARA principles in design stage, and 4) training and instruction requirement of SMART NSSS and BOP designers for the familiarization of ALARA principles to be implemented in NSSS designs. (Author). 4 refs., 1 tabs

The role of the protected area concept in protecting the world’s largest natural reserve: Antarctica

Directory of Open Access Journals (Sweden)

Kees Bastmeijer

2009-06-01

Full Text Available Should the entire Antarctic continent and the surrounding islands be recognised as a ‘protected area’ or as a continent where certain areas, just like anywhere else, may be designated as protected areas? To find an answer to this question, this paper first discusses the most important agreements and declarations on environmental protection in Antarctica. Next, these instruments are compared with the components of IUCN’s ‘protected area’ definition (2008. In the light of this overall protection of Antarctica, the instrument of designating areas as Antarctic Specially Protected Areas (ASPAs is discussed on the basis of a quick scan of 42 management plans for existing ASPAs. It is concluded that Antarctica could indeed be considered as a protected area and that the ASPA instrument is so shaped to provide specific areas with ‘extra protection’ by regulating human activities in those areas with a high level of detail. However, the continuous increase in human activities in Antarctica raises concerns with respect to the scope and completeness of the existing legal instruments. These concerns regarding the overall protection of Antarctica could become an argument for applying the ASPA instrument in respect of larger areas to ensure the comprehensive protection of at least certain parts of Antarctica. This would make the ASPA system more comparable with protected area systems in other parts of the world; however, strengthening the overall protection of Antarctica – parallel to the further development of the ‘specially’ protected area system - would be more consistent with Antarctica’s protected status as has developed since the Antarctic Treaty was signed 50 years ago.

Study of thermal conductivity and thermal rectification in exponential mass graded lattices

Energy Technology Data Exchange (ETDEWEB)

Shah, Tejal N. [Bhavan' s Sheth R.A. College of Science, Khanpur, Ahmedabad 380 001, Gujarat (India); Gajjar, P.N., E-mail: pngajjar@rediffmail.com [Department of Physics, University School of Sciences, Gujarat University, Ahmedabad 380 009, Gujarat (India)

2012-01-09

Concept of exponential mass variation of oscillators along the chain length of N oscillators is proposed in the present Letter. The temperature profile and thermal conductivity of one-dimensional (1D) exponential mass graded harmonic and anharmonic lattices are studied on the basis of Fermi–Pasta–Ulam (FPU) β model. Present findings conclude that the exponential mass graded chain provide higher conductivity than that of linear mass graded chain. The exponential mass graded anharmonic chain generates the thermal rectification of 70–75% which is better than linear mass graded materials, so far. Thus instead of using linear mass graded material, the use of exponential mass graded material will be a better and genuine choice for controlling the heat flow at nano-scale. -- Highlights: ► In PRE 82 (2010) 040101, use of mass graded material as a thermal devices is explored. ► Concept of exponential mass graded material is proposed. ► The rectification obtained is about 70–75% which is better than linear mass graded materials. ► The exponential mass graded material will be a better choice for the thermal devices at nano-scale.

Commercial Aircraft Protection

Energy Technology Data Exchange (ETDEWEB)

Ehst, David A. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-10-26

This report summarizes the results of theoretical research performed during 3 years of P371 Project implementation. In results of such research a new scientific conceptual technology of quasi-passive individual infrared protection of heat-generating objects – Spatial Displacement of Thermal Image (SDTI technology) was developed. Theoretical substantiation and description of working processes of civil aircraft individual IR-protection system were conducted. The mathematical models and methodology were presented, there were obtained the analytical dependencies which allow performing theoretical research of the affect of intentionally arranged dynamic field of the artificial thermal interferences with variable contrast onto main parameters of optic-electronic tracking and homing systems.

Mini-chamber, an advanced protection concept for NIF

International Nuclear Information System (INIS)

Peterson, P.F.; Scott, J.M.

1996-01-01

Inertial confinement fusion (ICF) target debris and ablated near-target materials pose the primary threat to the National Ignition Facility (NIF) final optics debris shields, as well as a major challenge in future inertial fusion energy (IFE) power plants. This work discusses a NIF 'mini-chamber,' designed to mitigate the debris threat. Although the NIF base-line design protects against debris using a frost-protected target positioner and refractory first-wall coatings, the mini-chamber provides important flexibility in three areas: debris-shield protection from beyond-design basis shots (i.e. heavy hohlraums, special diagnostics, shields); fielding of large experiments with significant surface ablation; and studying key ablation and gas-dynamics issues for liquid-wall IFE power plants. Key mini-chamber modeling results are presented, followed by discussion of equipment requirements for fielding a NIF mini-chamber. 7 refs., 3 figs

Optimization and radiation protection culture

International Nuclear Information System (INIS)

Jeon, In Young; Shin, Hyeong Ki; Lee, Chan Mi

2013-01-01

Safety culture or radiation protection culture is based in common on the term, 'culture'. Culture is defined as the learned, shared set of symbols and patterns of basic assumptions, which is invented, discovered, or developed by a given group as it learns to cope with its problem of external adaptation and internal integration. Safety culture generally refers to the attitude and behaviors affecting safety performance. The concept of 'Safety Culture' was introduced after the Chernobyl accident in 1986. For the accident, nuclear society reached the conclusion that the cause was the wrong management attitude of the NPP, that is, deficient 'Safety Culture'. Recently, 'Radiation Protection Culture' was introduced as the core concept of nuclear safety culture. There have been many efforts to establish definition and develop assessment tool for radiation protection culture in international level such as ICRP and IRPA as well as NRC. In the same context with the safety culture, radiation protection culture is defined as 'the core values and behaviors resulting from a collective commitment by leaders and individual's to emphasize safety over competing goals to ensure protection of people and the environment.' It is worthwhile to recognize that regulatory enforcement in establishing healthy radiation protection culture of operators should be minimized because culture is not in the domain of regulatory enforcement. However, as 'ALARA', the most important concept in radiation protection, may be successfully achieved only in well established radiation protection culture, the least regulatory intervention would be needed in promoting and nurturing radiation protection culture in licensee. In addition, the concept of radiation protection culture should be addressed in plant operational policy to achieve the goals of ALARA. The pre-condition of the successful radiation protection culture is a healthy organizational

Optimization and radiation protection culture

Energy Technology Data Exchange (ETDEWEB)

Jeon, In Young; Shin, Hyeong Ki; Lee, Chan Mi [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2013-04-15

Safety culture or radiation protection culture is based in common on the term, 'culture'. Culture is defined as the learned, shared set of symbols and patterns of basic assumptions, which is invented, discovered, or developed by a given group as it learns to cope with its problem of external adaptation and internal integration. Safety culture generally refers to the attitude and behaviors affecting safety performance. The concept of 'Safety Culture' was introduced after the Chernobyl accident in 1986. For the accident, nuclear society reached the conclusion that the cause was the wrong management attitude of the NPP, that is, deficient 'Safety Culture'. Recently, 'Radiation Protection Culture' was introduced as the core concept of nuclear safety culture. There have been many efforts to establish definition and develop assessment tool for radiation protection culture in international level such as ICRP and IRPA as well as NRC. In the same context with the safety culture, radiation protection culture is defined as 'the core values and behaviors resulting from a collective commitment by leaders and individual's to emphasize safety over competing goals to ensure protection of people and the environment.' It is worthwhile to recognize that regulatory enforcement in establishing healthy radiation protection culture of operators should be minimized because culture is not in the domain of regulatory enforcement. However, as 'ALARA', the most important concept in radiation protection, may be successfully achieved only in well established radiation protection culture, the least regulatory intervention would be needed in promoting and nurturing radiation protection culture in licensee. In addition, the concept of radiation protection culture should be addressed in plant operational policy to achieve the goals of ALARA. The pre-condition of the successful radiation protection culture is a healthy organizational

Moisture absorption characteristics of the Orbiter thermal protection system and methods used to prevent water ingestion

Science.gov (United States)

Schomburg, C.; Dotts, R. L.; Tillian, D. J.

1983-01-01

The Space Shuttle Orbiter's silica tile Thermal Protection System (TPS) is beset by the moisture absorption problems inherently associated with low density, highly porous insulation systems. Attention is presently given to the comparative success of methods for the minimization and/or prevention of water ingestion by the TPS tiles, covering the development of water-repellent agents and their tile application techniques, flight test program results, and materials improvements. The use of external films for rewaterproofing of the TPS tiles after each mission have demonstrated marginal to unacceptable performance. By contrast, a tile interior waterproofing agent has shown promise.

Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

Science.gov (United States)

Glass, David E.

2008-01-01

Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this paper is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

Thermal Design and Thermal Behaviour of Radio Telescopes and their Enclosures

CERN Document Server

Greve, Albert

2010-01-01

Radio telescopes as well as communication antennas operate under the influence of gravity, temperature and wind. Among those, temperature influences may degrade the performance of a radio telescope through transient changes of the focus, pointing, path length and sensitivity, often in an unpredictable way. Thermal Design and Thermal Behaviour of Radio Telescopes and their Enclosures reviews the design and construction principles of radio telescopes in view of thermal aspects and heat transfer with the variable thermal environment; it explains supporting thermal model calculations and the application and efficiency of thermal protection and temperature control; it presents many measurements illustrating the thermal behaviour of telescopes in the environment of their observatory sites. The book benefits scientists and radio/communication engineers, telescope designers and construction firms as well as telescope operators, observatory staff, but also the observing astronomer who is directly confronted with the t...

Operational quantities for use in external radiation protection measurements. An investigation of concepts and principles

International Nuclear Information System (INIS)

1983-01-01

Under the terms of the Euratom Treaty the Commission of the European Communities is required to draw up basic standards for the health protection of the general public and workers against the dangers arising from ionizing radiation. The basic standards lay down reference values for particular quantities; these values are required to be measured, and appropriate steps taken to ensure that they are not exceeded. To ensure that the basic standards are applied uniformly in the Member States, it is necessary to harmonize not only national laws but also measurement and recording techniques. As a practical contribution towards this objective, the Commission has since 1964 been conducting intercomparison programmes on operational radiation protection dosimetry. Effective monitoring against the dangers of ionizing radiation cannot be guaranteed unless the measuring instruments meet the necessary requirements, the quantities measured are those for which limit values have been laid down, and the instruments can be calibrated unequivocally. The differences between the concepts of quantity and unit of measurement in radiation protection were often unclear. In the light of developments at international level, the introduction of the international system of units of measurements (SI units) and the contents of ICRP Publication No 26, the services of the European Community responsible for radiation protection decided to review the whole question of quantities. The introduction of the 'index' quantities (absorbed dose index and dose equivalent index) was greeted with initial enthusiasm, but it soon became clear, on closer critical examination, that these too had major shortcomings. The Commission, in collaboration with experts from the Member States of the European Community, has therefore set out in this publication the various considerations and points of view concerning the use of these quantities in practical dosimetry. It is hoped that this publication will be of use to all

Outdoor thermal comfort.

Science.gov (United States)

Nikolopoulou, Marialena

2011-06-01

A review of the various approaches in understanding outdoor thermal comfort is presented. The emphasis on field surveys from around the world, particularly across Europe, enables us to understand thermal perception and evaluate outdoor thermal comfort conditions. The consistent low correlations between objective microclimatic variables, subjective thermal sensation and comfort outdoors, internationally, suggest that thermophysiology alone does not adequate describe these relationships. Focusing on the concept of adaptation, it tries to explain how this influences outdoor comfort, enabling us to inhabit and get satisfaction from outdoor spaces throughout the year. Beyond acclimatization and behavioral adaptation, through adjustments in clothing and changes to the metabolic heat, psychological adaptation plays a critical role to ensure thermal comfort and satisfaction with the outdoor environment. Such parameters include recent experiences and expectations; personal choice and perceived control, more important than whether that control is actually exercised; and the need for positive environmental stimulation suggesting that thermal neutrality is not a pre-requisite for thermal comfort. Ultimately, enhancing environmental diversity can influence thermal perception and experience of open spaces.

Rethinking basic concepts in ICRP's system of dose limitation

International Nuclear Information System (INIS)

Mills, W.A.; Mossman, K.L.

1991-01-01

The present criterion for radiation protection appears to be exposure reduction rather than adequate protection of health. The 1990 ICRP draft recommendations for a system of dose limitation would further implement this more restrictive criterion by implementing certain academic concepts and assumptions. These concepts and assumptions are discussed and the suggestion is made that the radiation protection community needs to carefully examine the need for the complex system proposed

Thorium utilisation in thermal reactors

International Nuclear Information System (INIS)

Balakrishnan, K.

1997-01-01

It is now more or less accepted that the best way to use thorium is in thermal reactors. This is due to the fact that U233 is a good material in the thermal spectrum. Studies of different thorium cycles in various reactor concepts had been carried out in the early days of nuclear power. After three decades of neglect, the world is once again looking at thorium with some interest. We in India have been studying thorium cycles in most of the existing thermal reactor concepts, with greater emphasis on heavy water reactors. In this paper, we report some of the work done in India on different thorium cycles in the Indian pressurized heavy water reactor (PHWR), and also give a description of the design of the advanced heavy water reactor (AHWR). (author). 1 ref., 2 tabs., 5 figs

Ablation, Thermal Response, and Chemistry Program for Analysis of Thermal Protection Systems

Science.gov (United States)

Milos, Frank S.; Chen, Yih-Kanq

2010-01-01

In previous work, the authors documented the Multicomponent Ablation Thermochemistry (MAT) and Fully Implicit Ablation and Thermal response (FIAT) programs. In this work, key features from MAT and FIAT were combined to create the new Fully Implicit Ablation, Thermal response, and Chemistry (FIATC) program. FIATC is fully compatible with FIAT (version 2.5) but has expanded capabilities to compute the multispecies surface chemistry and ablation rate as part of the surface energy balance. This new methodology eliminates B' tables, provides blown species fractions as a function of time, and enables calculations that would otherwise be impractical (e.g. 4+ dimensional tables) such as pyrolysis and ablation with kinetic rates or unequal diffusion coefficients. Equations and solution procedures are presented, then representative calculations of equilibrium and finite-rate ablation in flight and ground-test environments are discussed.

Effects of alpha-zirconium phosphate on thermal degradation and flame retardancy of transparent intumescent fire protective coating

International Nuclear Information System (INIS)

Xing, Weiyi; Zhang, Ping; Song, Lei; Wang, Xin; Hu, Yuan

2014-01-01

Graphical abstract: - Highlights: • A transparent intumescent fire protective coating was obtained by UV-cured technology. • OZrP could enhance the thermal stability and anti-oxidation of the coating. • OZrP could reduce the combustion properties of the coatings. - Abstract: Organophilic alpha-zirconium phosphate (OZrP) was used to improve the thermal and fire retardant behaviors of the phenyl di(acryloyloxyethyl)phosphate (PDHA)-triglycidyl isocyanurate acrylate (TGICA)-2-phenoxyethyl acrylate (PHEA) (PDHA-TGICA-PHEA) coating. The morphology of nanocomposite coating was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effect of OZrP on the flame retardancy, thermal stability, fireproofing time and char formation of the coatings was investigated by microscale combustion calorimeter (MCC), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), laser Raman spectroscopy (LRS) and scanning electric microscope (SEM). The results showed that by adding OZrP, the peak heat release rate and total heat of combustion were significantly reduced. The highest improvement was achieved with 0.5 wt% OZrP. XPS analysis indicated that the performance of anti-oxidation of the coating was improved with the addition of OZrP, and SEM images showed that a good synergistic effect was obtained through a ceramic-like layer produced by OZrP covered on the surface of char

Effects of alpha-zirconium phosphate on thermal degradation and flame retardancy of transparent intumescent fire protective coating

Energy Technology Data Exchange (ETDEWEB)

Xing, Weiyi [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzai Road, Hefei, Anhui 230026 (China); Zhang, Ping [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010 (China); Song, Lei; Wang, Xin [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzai Road, Hefei, Anhui 230026 (China)

2014-01-01

Graphical abstract: - Highlights: • A transparent intumescent fire protective coating was obtained by UV-cured technology. • OZrP could enhance the thermal stability and anti-oxidation of the coating. • OZrP could reduce the combustion properties of the coatings. - Abstract: Organophilic alpha-zirconium phosphate (OZrP) was used to improve the thermal and fire retardant behaviors of the phenyl di(acryloyloxyethyl)phosphate (PDHA)-triglycidyl isocyanurate acrylate (TGICA)-2-phenoxyethyl acrylate (PHEA) (PDHA-TGICA-PHEA) coating. The morphology of nanocomposite coating was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effect of OZrP on the flame retardancy, thermal stability, fireproofing time and char formation of the coatings was investigated by microscale combustion calorimeter (MCC), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), laser Raman spectroscopy (LRS) and scanning electric microscope (SEM). The results showed that by adding OZrP, the peak heat release rate and total heat of combustion were significantly reduced. The highest improvement was achieved with 0.5 wt% OZrP. XPS analysis indicated that the performance of anti-oxidation of the coating was improved with the addition of OZrP, and SEM images showed that a good synergistic effect was obtained through a ceramic-like layer produced by OZrP covered on the surface of char.

Thermal physics kinetic theory and thermodynamics

CERN Document Server

Singh, Devraj; Yadav, Raja Ram

2016-01-01

THERMAL PHYSICS: Kinetic Theory and Thermodynamics is designed for undergraduate course in Thermal Physics and Thermodynamics. The book provides thorough understanding of the fundamental principles of the concepts in Thermal Physics. The book begins with kinetic theory, then moves on liquefaction, transport phenomena, the zeroth, first, second and third laws, thermodynamics relations and thermal conduction. The book concluded with radiation phenomenon. KEY FEATURES: * Include exercises * Short Answer Type Questions * Long Answer Type Questions * Numerical Problems * Multiple Choice Questions

Radiation protection of the environment: anthropocentric and eco-centric principles

International Nuclear Information System (INIS)

Alexakhin, R.M.; Fesenko, S.V.

2004-01-01

The second half of the 20. century was dominated in the field of radiation protection by the anthropocentric concept stated by the International Commission on Radiological Protection (ICRP). According to this concept 'if radiation standards protect man then biota are also adequately protected from ionizing radiation'. At the end of the 20. beginning of the 21. centuries in the area of radiation protection of nature an eco-centric strategy is beginning to develop where emphasis has swung to the protection of biota in their environment. Inadequacy of ICRP's anthropocentric concept is reported. Issues are discussed such as ecological dosimetry, non-equi-dose irradiation of man and biota, criteria for estimating radiation induced changes in biota and man, as well as the need to harmonize permissible exposure doses to man and biota. An urgent need is stressed to develop a single (synthetic) concept of radiation protection which simultaneously ensures protection of human health and biota well-being in their environment. This concept is to be based on the recognition of the integrity of socio-natural ecosystems where man and biota are considered as a unity. (author)

Lightning Protection for Composite Aircraft Structures

Science.gov (United States)

Olson, G. O.

1985-01-01

Lightning protection system consisting of two layers of aluminum foil separated by layer of dielectric material protects graphite/epoxy composite structures on aircraft. Protective layer is secondarily applied lightning protection system, prime advantage of which is nullification of thermal and right angle effect of lightning arc attachment to graphite/epoxy laminate.

Fire suppression as a thermal implosion

Science.gov (United States)

Novozhilov, Vasily

2017-01-01

The present paper discusses the possibility of the thermal implosion scenario. This process would be a reverse of the well known thermal explosion (autoignition) phenomenon. The mechanism for thermal implosion scenario is proposed which involves quick suppression of the turbulent diffusion flame. Classical concept of the thermal explosion is discussed first. Then a possible scenario for the reverse process (thermal implosion) is discussed and illustrated by a relevant mathematical model. Based on the arguments presented in the paper, thermal implosion may be observed as an unstable equilibrium point on the generalized Semenov diagram for turbulent flame, however this hypothesis requires ultimate experimental confirmation.

Novel Concept of an Installation for Sustainable Thermal Utilization of Sewage Sludge

Directory of Open Access Journals (Sweden)

Wilhelm Jan Tic

2018-03-01

Full Text Available This study proposes an innovative installation concept for the sustainable utilization of sewage sludge. The aim of the study is to prove that existing devices and technologies allow construction of such an installation by integration of a dryer, torrefaction reactor and gasifier with engine, thus maximizing recovery of the waste heat by the installation. This study also presents the results of drying tests, performed at a commercial scale paddle dryer as well as detailed analysis of the torrefaction process of dried sewage sludge. Both tests aim to identify potential problems that could occur during the operation. The scarce literature studies published so far on the torrefaction of sewage sludge presents results from batch reactors, thus giving very limited data of the composition of the torgas. This study aims to cover that gap by presenting results from the torrefaction of sewage sludge in a continuously working, laboratory scale, isothermal rotary reactor. The study confirmed the feasibility of a self-sustaining installation of thermal utilization of sewage sludge using low quality heat. Performed study pointed out the most favorable way to use limited amounts of high temperature heat. Plasma gasification of the torrefied sewage sludge has been identified that requires further studies.

The Evolution of Nondestructive Evaluation Methods for the Space Shuttle External Tank Thermal Protection System

Science.gov (United States)

Walker, James L.; Richter, Joel D.

2006-01-01

Three nondestructive evaluation methods are being developed to identify defects in the foam thermal protection system (TPS) of the Space Shuttle External Tank (ET). Shearography is being developed to identify shallow delaminations, shallow voids and crush damage in the foam while terahertz imaging and backscatter radiography are being developed to identify voids and cracks in thick foam regions. The basic theory of operation along with factors affecting the results of these methods will be described. Also, the evolution of these methods from lab tools to implementation on the ET will be discussed. Results from both test panels and flight tank inspections will be provided to show the range in defect sizes and types that can be readily detected.

Understanding Thermal Equilibrium through Activities

Science.gov (United States)

Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura; Ladage, Savita; Pradhan, Hemachandra

2015-01-01

Thermal equilibrium is a basic concept in thermodynamics. In India, this concept is generally introduced at the first year of undergraduate education in physics and chemistry. In our earlier studies (Pathare and Pradhan 2011 "Proc. episteme-4 Int. Conf. to Review Research on Science Technology and Mathematics Education" pp 169-72) we…

Small Scale Hydrocarbon Fire Test Concept

OpenAIRE

Joachim Søreng Bjørge; Maria-Monika Metallinou; Arjen Kraaijeveld; Torgrim Log

2017-01-01

In the oil and gas industry, hydrocarbon process equipment was previously often thermally insulated by applying insulation directly to the metal surface. Fire protective insulation was applied outside the thermal insulation. In some cases, severe corrosion attacks were observed due to ingress of humidity and condensation at cold surfaces. Introducing a 25 mm air gap to prevent wet thermal insulation and metal wall contact is expected to solve the corrosion issues. This improved insulation met...

Trauma and traumatic neurosis: Freud's concepts revisited.

Science.gov (United States)

Zepf, Siegfried; Zepf, Florian D

2008-04-01

The authors examine Freud 's concepts of 'trauma', 'protective shield against stimuli ' and 'traumatic neurosis' in the light of recent findings. 'Protective shield against stimuli' is regarded as a biological concept which appears in mental life as the striving to avoid unpleasant affects. 'Trauma' is a twofold concept in that it relates to mental experience and links an external event with the specific after-effects on an individual 's psychic reality. A distinction needs to be made between mentally destructive trauma and affective trauma. A destructive trauma does not break through the protective shield but does breach the pleasure-unpleasure principle, so that in the course of its subsequent mastery it leads to a traumatic neurosis. An affective trauma can be warded off under the rule of the pleasure-unpleasure principle and leads to a psychoneurosis.

Handling effluent from nuclear thermal propulsion system ground tests

International Nuclear Information System (INIS)

Shipers, L.R.; Allen, G.C.

1992-01-01

A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the different methods to handle effluent from nuclear thermal propulsion system ground tests

PLAY HANDS PROTECTIVE GLOVES: TECHNICAL NOTE ON DESIGN AND CONCEPT.

Science.gov (United States)

Houston-Hicks, Michele; Lura, Derek J; Highsmith, M Jason

2016-09-01

Cerebral Palsy (CP) is the leading cause of childhood motor disability, with a global incidence of 1.6 to 2.5/1,000 live births. Approximately 23% of children with CP are dependent upon assistive technologies. Some children with developmental disabilities have self-injurious behaviors such as finger biting but also have therapeutic needs. The purpose of this technical note is to describe design considerations for a protective glove and finger covering that maintains finger dexterity for children who exhibit finger and hand chewing (dermatophagia) and require therapeutic range of motion and may benefit from sensory stimulation resulting from constant contact between glove and skin. Protecting Little and Adolescent Youth (PLAY) Hands are protective gloves for children with developmental disorders such as CP who injure themselves by biting their hands due to pain or sensory issues. PLAY Hands will be cosmetically appealing gloves that provide therapeutic warmth, tactile sensory feedback, range of motion for donning/ doffing, and protection to maximize function and quality of life for families of children with developmental disorders. The technology is either a per-finger protective orthosis or an entire glove solution designed from durable 3D-printed biodegradable/bioabsorbable materials such as thermoplastics. PLAY Hands represent a series of protective hand wear interventions in the areas of self-mutilating behavior, kinematics, and sensation. They will be made available in a range of protective iterations from single- or multi-digit finger orthoses to a basic glove design to a more structurally robust and protective iteration. To improve the quality of life for patients and caregivers, they are conceptualized to be cosmetically appealing, protective, and therapeutic.

Photovoltaic thermal module concepts and their performance analysis: A review

International Nuclear Information System (INIS)

Hasan, M. Arif; Sumathy, K.

2010-01-01

This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

Photovoltaic thermal module concepts and their performance analysis: A review

Energy Technology Data Exchange (ETDEWEB)

Hasan, M. Arif; Sumathy, K. [Department of Mechanical Engineering, North Dakota State University, Fargo, ND (United States)

2010-09-15

This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

ULTRA SCWR+: Practical advanced water reactor concepts

International Nuclear Information System (INIS)

Duffey, Romney; Khartabil, Hussam; Kuran, Sermet; Zhou, Tracy; Pioro, Igor

2008-01-01

Modern thermal power plants now utilize supercritical steam cycles with thermal efficiencies of over 45%. Recent developments have lead to Ultra-SuperCritical (USC) systems, which adopt reheat turbines that can attain efficiencies of over 50%. Because these turbines are already developed, demonstrated and deployed worldwide, and use existing and traditional steam cycle technology, the simplest nuclear advance is to utilize these proven thermal cycle conditions by coupling this turbine type to a reactor. This development direction is fundamentally counter to the usual approach of adopting high-temperature gas-cooled (helium-cooled) reactor cycles, for which turbines have yet to be demonstrated on commercial scale unlike the supercritical steam turbines. The ULTRA (Ultra-supercritical Light water Thermal ReActor) SCWR+ concept adopts the fundamental design approach of matching a water and steam-cooled reactor to the ultra-supercritical steam cycle, adopting the existing and planned thermal power plant turbines. The HP and IP sections are fed with conditions of 25 MPa/625degC and 7 MPa/700degC, respectively, to achieve operating plant thermal efficiencies in excess of 50%, with a direct turbine cycle. By using such low-pressure reheated steam, this concept also adopts technology that was explored and used many years ago in existing water reactors, with the potential to produce large quantities of low cost heat, which can be used for other industrial and district processes. Pressure-Tube (PT) reactors are suitable for adoption of this design approach and, in addition, have other advantages that will significantly improve water-cooled reactor technology. These additional advantages include enhanced safety and improved resource utilization and proliferation resistance. This paper describes the PT-SCWR+ concept and its potential enhancements. (author)

Ingredients of protection engineering

International Nuclear Information System (INIS)

Latorre, V.R.; Spogen, L.R. Jr.

1974-01-01

The protection of an electronic/electrical system from an electromagnetic environment requires a systematic approach and a clear and concise identification of the data requirements and tools (analytical and experimental) for the vulnerability assessment. In this paper, a basic protection engineering concept is developed. The concept is general and therefore applicable to many systems. It consists of five stages: (1) systems analysis, (2) subsystem degradation, (3) interaction and coupling, (4) protection trade-off analysis, and (5) fabrication and operation. A detailed discussion of all functions performed in each stage is described; the input data to these functions identified; and means (tools) by which the functional operations are satisfied are summarized. Simple examples are used throughout the paper to illustrate the definitions of various functions and to emphasize the iterative process required in arriving at a protection scheme. (U.S.)

Concept of a utility scale dispatch able solar thermal electricity plant with an indirect particle receiver in a single tower layout

Science.gov (United States)

Schwaiger, Karl; Haider, Markus; Haemmerle, Martin; Steiner, Peter; Obermaier, Michael-Dario

2016-05-01

Flexible dispatch able solar thermal electricity plants applying state of the art power cycles have the potential of playing a vital role in modern electricity systems and even participating in the ancillary market. By replacing molten salt via particles, operation temperatures can be increased and plant efficiencies of over 45 % can be reached. In this work the concept for a utility scale plant using corundum as storage/heat transfer material is thermodynamically modeled and its key performance data are cited. A novel indirect fluidized bed particle receiver concept is presented, profiting from a near black body behavior being able to heat up large particle flows by realizing temperature cycles over 500°C. Specialized fluidized bed steam-generators are applied with negligible auxiliary power demand. The performance of the key components is discussed and a rough sketch of the plant is provided.

The thermal relay design to improve power system security for the HTS cables in Icheon substation

International Nuclear Information System (INIS)

Lee, Hansang; Yang, Byeong-Mo; Jang, Gilsoo

2013-01-01

Highlights: •It is important to study thermal characteristics of the HTS cable. •The thermal relay in the Icheon substation has been developed. •Well-designed thermal relay has been verified through PSCAD/EMTDC simulations. -- Abstract: This paper proposes a model for thermal protection relay for the high temperature superconducting (HTS) cables and thermal protection scheme in Icheon substation in Korea. The thermal protection is one of the most important factors to guarantee the reliability of the HTS cable as well as power system security. The superconductivity of the HTS cables, which can be guaranteed by the liquid nitrogen near 70 K, can be threatened by the large fault current. To avoid the overheating in HTS cable and to secure the power system operation with the HTS cable, the thermal protection relay should be considered. To find the optimal thermal-protection scheme, the model for the superconducting power system has been achieved in Icheon substation and the thermal protection scheme has been verified through PSCAD/EMTDC simulation

The thermal relay design to improve power system security for the HTS cables in Icheon substation

Energy Technology Data Exchange (ETDEWEB)

Lee, Hansang, E-mail: hslee80@kiu.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Yang, Byeong-Mo [Korea Electric Power Research Institute, Munji-dong, Yuseong-gu, Daejeon 305-760 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-713 (Korea, Republic of)

2013-11-15

Highlights: •It is important to study thermal characteristics of the HTS cable. •The thermal relay in the Icheon substation has been developed. •Well-designed thermal relay has been verified through PSCAD/EMTDC simulations. -- Abstract: This paper proposes a model for thermal protection relay for the high temperature superconducting (HTS) cables and thermal protection scheme in Icheon substation in Korea. The thermal protection is one of the most important factors to guarantee the reliability of the HTS cable as well as power system security. The superconductivity of the HTS cables, which can be guaranteed by the liquid nitrogen near 70 K, can be threatened by the large fault current. To avoid the overheating in HTS cable and to secure the power system operation with the HTS cable, the thermal protection relay should be considered. To find the optimal thermal-protection scheme, the model for the superconducting power system has been achieved in Icheon substation and the thermal protection scheme has been verified through PSCAD/EMTDC simulation.

Stirling converters for space dynamic power concepts with 2 to 130 We output

International Nuclear Information System (INIS)

Ross, B.A.

1995-01-01

Three innovative Stirling converter concepts are described. Two concepts are based on Pluto Fast Flyby (PFF) mission requirements, where two General Purpose Heat Source (GPHS) modules provide the thermal input. The first concept (PFF2) considers a power system with two opposed Stirling converters; the second concept (PFF4) considers four opposed Stirling converters. For both concepts the Stirling converters are designed to vary their power production capability to compensate for the failure of one Stirling converter. While the net thermal efficiency of PFF4 is a few percentage points lower than PFF2, the total Stirling converter mass of PFF4 is half that for PFF2. The third concept (ITTI) is designed to supply 2 watts of power for weather stations on the Martian surface. The predicted thermal performance of the ITTI is low compared to PFF2 and PFF4, yet the ITTI concept offers significant advantages compared to currently available power systems at the 2-watt power level. All three concepts are based on long-life technology demonstrated by an 11-watt output Stirling generator that as of March 1995 has accumulated over 15,000 operating hours without maintenance

32 CFR 989.2 - Concept.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Concept. 989.2 Section 989.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ENVIRONMENTAL PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.2 Concept. (a) This part provides a framework on how to comply with NEPA and...

Thermal insulation properties of walls

Directory of Open Access Journals (Sweden)

Zhukov Aleksey Dmitrievich

2014-05-01

Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

Environmental protection

International Nuclear Information System (INIS)

Martinez, A.S.

1987-01-01

The question of environment protection related to the use of nuclear energy aiming to power generation, based on the harmonic concept of economic and industrial development, preserving the environment, is discussed. A brief study of environmental impacts for some energy sources, including nuclear energy, to present the systems of a nuclear power plant which aim at environmental protection, is done. (M.C.K.) [pt

Concept of protection of food of animal origin

Directory of Open Access Journals (Sweden)

Mijačević Zora M.

2005-01-01

Full Text Available The currently valid regulations (Official Gazette 26/2002 define the requirements for the quality of milk and milk products. The same legislature defines also the concept of composite products, that is, products in which part of the fat or proteins have been substituted with fat or proteins of different origin. A composite product must include the term composite in its name, and the part of the declaration which lists the contents of total proteins and fat must specify the part of plant proteins and fat in total proteins and fat of milk products. With the growth of the population and the concern for health, new requirements have been set, and consumers expect a food article to meet not only the nutritive requirements, but also to have certain functional characteristics, or that it is not burdened with components which have a negative effect on health (the presence of cholesterol, sodium chloride, a high percentage of saturated fatty acids. The complete substitution of one milk component results in a completely new product. A change in the traditional composition of a certain food article must be clearly declared, so as not to confuse consumers and to provide them with the possibility of choice. In our market, there have lately appeared products that are marked as imitations, alternatives, diet cheese, vegetable cheese. Modified products which do not meet the traditional identity standards must be marked as imitations, in case they are nutritionally inferior with respect to the traditionally standardized food articles, or as substitutes or alternatives, in the event that they are a nutritive equivalent to the traditional food articles. The lack of legal regulations for this category of product leads to the irregular declaration of such products, and consequently provides false information about the characteristics of such articles to the consumer. It is necessary to regulate this area with the respective laws in order to protect the consumer.

Final analysis and design of a thermal protection system for 8-foot HTST combustor

Science.gov (United States)

Moskowitz, S.

1973-01-01

The cylindrical shell combustor with T-bar supports in the 8-foot HTST at the NASA-Langley Research Center encountered vibratory fatigue cracking over a period of 50-250 tunnel tests within a limited range of the required operating envelope. A preliminary design study provided several suitable thermal protection system designs for the combustor, one of which was a two-pass regenerative type air-cooled omega-shaped segment liner. A final design layout of the omega segment liner was prepared and analyzed for steady-state and transient conditions. The design of a support system for the fuel spray bar assembly was also included. Detail drawings suitable for fabrication purposes were also prepared. Liner design problems defined during the preliminary study included (1) the ingress of gas into the attachment bulb section of the omega segment, (2) the large thermal gradient along the leg of the omega bulb attachment section and, (3) the local peak metal temperature at the radius between the liner ID and the leg of the bulb attachment. These were resolved during the final design task. Analyses of the final design of the omega segment liner indicated that all design goals were met and the design provided the capability of operating over the required test envelope with a life expectancy substantially above the goal of 1500 cycles.

The relationship between psychological adjustment and social protection with academic self-concept and academic achievement among high school female students in Rasht

Directory of Open Access Journals (Sweden)

Kobra Dadarigashti

2016-07-01

Full Text Available The study conducted to examine the relationship between psychological adjustment and social protection with academic self-concept and academic achievement among high school female students in Rasht. The research is descriptive correlational. The target population includes all female students studying in Rasht in 2015. By random cluster sampling method and based on the variables, 180 subjects selected. In this study, to collect data, psychological adjustment and social support, academic self-concept and academic achievement questionnaire are used. To test the hypothesis of this research, the parametric statistical Pearson correlation and regression tests are used. Moreover, all statistical operations were analyzed by using SPSS software. The research results showed that the correlation values between psychological adjustment and social support with academic self-concept and academic achievement of high school female students is statistically significant ( 01/0 > p.

Analysis of molten salt thermal-hydraulics using computational fluid dynamics

International Nuclear Information System (INIS)

Yamaji, B.; Csom, G.; Aszodi, A.

2003-01-01

To give a good solution for the problem of high level radioactive waste partitioning and transmutation is expected to be a pro missing option. Application of this technology also could extend the possibilities of nuclear energy. Large number of liquid-fuelled reactor concepts or accelerator driven subcritical systems was proposed as transmutors. Several of these consider fluoride based molten salts as the liquid fuel and coolant medium. The thermal-hydraulic behaviour of these systems is expected to be fundamentally different than the behaviour of widely used water-cooled reactors with solid fuel. Considering large flow domains three-dimensional thermal-hydraulic analysis is the method seeming to be applicable. Since the fuel is the coolant medium as well, one can expect a strong coupling between neutronics and thermal-hydraulics too. In the present paper the application of Computational Fluid Dynamics for three-dimensional thermal-hydraulics simulations of molten salt reactor concepts is introduced. In our past and recent works several calculations were carried out to investigate the capabilities of Computational Fluid Dynamics through the analysis of different molten salt reactor concepts. Homogenous single region molten salt reactor concept is studied and optimised. Another single region reactor concept is introduced also. This concept has internal heat exchanges in the flow domain and the molten salt is circulated by natural convection. The analysis of the MSRE experiment is also a part of our work since it may form a good background from the validation point of view. In the paper the results of the Computational Fluid Dynamics calculations with these concepts are presented. In the further work our objective is to investigate the thermal-hydraulics of the multi-region molten salt reactor (Authors)

The advanced MAPLE reactor concept

International Nuclear Information System (INIS)

Lidstone, R.F.; Lee, A.G.; Gillespie, G.E.; Smith, H.J.

1989-01-01

During the past several years, Atomic Energy of Canada Limited (AECL) has been developing the new MAPLE multipurpose reactor concept, which is capable of generating peak thermal neutron fluxes of up to 3 x 10 18 n/m 2 s in its heavy water reflector at a nominal thermal power level of 15MW. An assessment of the MAPLE-D 2 O reactor has shown that it could also be used as a high-flux neutron source. it could be developed to be used for several applications if a 12-site annular core is used. Thermal fluxes several times greater than in existing facilities would be available (author)

Experimentally Studied Thermal Piston-head State of the Internal-Combustion Engine with a Thermal Layer Formed by Micro-Arc Oxidation Method

Directory of Open Access Journals (Sweden)

N. Yu. Dudareva

2015-01-01

Full Text Available The paper presents results of experimental study to show the efficiency of reducing thermal tension of internal combustion engine (ICE pistons through forming a thermal barrier coating on the piston-head. During the engine operation the piston is under the most thermal stress. High temperatures in the combustion chamber may lead to the piston-head burnout and destruction and engine failure.Micro-arc oxidation (MAO method was selected as the technology to create a thermal barrier coating. MAO technology allows us to form the ceramic coating with a thickness of 400μm on the surface of aluminum alloy, which have high heat resistance, and have good adhesion to the substrate even under thermal cycling stresses.Deliverables of MAO method used to protect pistons described in the scientific literature are insufficient, as they are either calculated or experimentally obtained at the special plants (units, which do not reproduce piston operation in a real engine. This work aims to fill this gap. The aim of the work is an experimental study of the thermal protective ability of MAO-layer formed on the piston-head with simulation of thermal processes of the real engine.The tests were performed on a specially designed and manufactured stand free of motor, which reproduces operation conditions maximum close to those of the real engine. The piston is heated by a fire source - gas burner with isobutene balloon, cooling is carried out by the water circulation system through the water-cooling jacket.Tests have been conducted to compare the thermal state of the regular engine piston without thermal protection and the piston with a heat layer formed on the piston-head by MAO method. The study findings show that the thermal protective MAO-layer with thickness of 100μm allows us to reduce thermal tension of piston on average by 8,5 %. Thus at high temperatures there is the most pronounced effect that is important for the uprated engines.The obtained findings can

NanoSatellite Thermal Overload Protection System (nSTOPS)

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop and demonstrate a laboratory version of a means to electrically dissipate excess thermal energy from 3-cube (and larger) nanosatellites:...

Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

Directory of Open Access Journals (Sweden)

Smajo Sulejmanovic

2014-11-01

Full Text Available This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.

Methane Lunar Surface Thermal Control Test

Science.gov (United States)

Plachta, David W.; Sutherlin, Steven G.; Johnson, Wesley L.; Feller, Jeffrey R.; Jurns, John M.

2012-01-01

NASA is considering propulsion system concepts for future missions including human return to the lunar surface. Studies have identified cryogenic methane (LCH4) and oxygen (LO2) as a desirable propellant combination for the lunar surface ascent propulsion system, and they point to a surface stay requirement of 180 days. To meet this requirement, a test article was prepared with state-of-the-art insulation and tested in simulated lunar mission environments at NASA GRC. The primary goals were to validate design and models of the key thermal control technologies to store unvented methane for long durations, with a low-density high-performing Multi-layer Insulation (MLI) system to protect the propellant tanks from the environmental heat of low Earth orbit (LEO), Earth to Moon transit, lunar surface, and with the LCH4 initially densified. The data and accompanying analysis shows this storage design would have fallen well short of the unvented 180 day storage requirement, due to the MLI density being much higher than intended, its substructure collapse, and blanket separation during depressurization. Despite the performance issue, insight into analytical models and MLI construction was gained. Such modeling is important for the effective design of flight vehicle concepts, such as in-space cryogenic depots or in-space cryogenic propulsion stages.

Analysis and evaluation of the Dual Fluid Reactor concept

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiang

2017-06-27

The Dual Fluid Reactor is a molten salt fast reactor developed by IFK in Berlin based on the Gen-IV Molten-Salt Reactor concept and the Liquid-Metal Cooled Reactor. The design aims to combine these two concepts to improve these two concepts. The Dissertation focuses on the concept and performs diverse calculations and estimations on the subjects of neutron physics, depletion and thermal-hydraulic behaviors to validate the new features of the concept. Based on the results it is concluded that this concept is feasible to its desired purpose and with great potential.

A Thermal Physiological Comparison of Two HazMat Protective Ensembles With and Without Active Convective Cooling

Science.gov (United States)

Williamson, Rebecca; Carbo, Jorge; Luna, Bernadette; Webbon, Bruce W.

1998-01-01

Wearing impermeable garments for hazardous materials clean up can often present a health and safety problem for the wearer. Even short duration clean up activities can produce heat stress injuries in hazardous materials workers. It was hypothesized that an internal cooling system might increase worker productivity and decrease likelihood of heat stress injuries in typical HazMat operations. Two HazMat protective ensembles were compared during treadmill exercise. The different ensembles were created using two different suits: a Trelleborg VPS suit representative of current HazMat suits and a prototype suit developed by NASA engineers. The two life support systems used were a current technology Interspiro Spirolite breathing apparatus and a liquid air breathing system that also provided convective cooling. Twelve local members of a HazMat team served as test subjects. They were fully instrumented to allow a complete physiological comparison of their thermal responses to the different ensembles. Results showed that cooling from the liquid air system significantly decreased thermal stress. The results of the subjective evaluations of new design features in the prototype suit were also highly favorable. Incorporation of these new design features could lead to significant operational advantages in the future.

Effluent treatment options for nuclear thermal propulsion system ground tests

International Nuclear Information System (INIS)

Shipers, L.R.; Brockmann, J.E.

1992-01-01

A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the strengths and weaknesses of different methods to handle effluent from nuclear thermal propulsion system ground tests

Parameter Uncertainty for Repository Thermal Analysis

Energy Technology Data Exchange (ETDEWEB)

Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Greenberg, Harris [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dupont, Mark [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-10-01

This report is one follow-on to a study of reference geologic disposal design concepts (Hardin et al. 2011a). Based on an analysis of maximum temperatures, that study concluded that certain disposal concepts would require extended decay storage prior to emplacement, or the use of small waste packages, or both. The study used nominal values for thermal properties of host geologic media and engineered materials, demonstrating the need for uncertainty analysis to support the conclusions. This report is a first step that identifies the input parameters of the maximum temperature calculation, surveys published data on measured values, uses an analytical approach to determine which parameters are most important, and performs an example sensitivity analysis. Using results from this first step, temperature calculations planned for FY12 can focus on only the important parameters, and can use the uncertainty ranges reported here. The survey of published information on thermal properties of geologic media and engineered materials, is intended to be sufficient for use in generic calculations to evaluate the feasibility of reference disposal concepts. A full compendium of literature data is beyond the scope of this report. The term “uncertainty” is used here to represent both measurement uncertainty and spatial variability, or variability across host geologic units. For the most important parameters (e.g., buffer thermal conductivity) the extent of literature data surveyed samples these different forms of uncertainty and variability. Finally, this report is intended to be one chapter or section of a larger FY12 deliverable summarizing all the work on design concepts and thermal load management for geologic disposal (M3FT-12SN0804032, due 15Aug2012).

Role of the protected area concept in protecting the world’s largest natural reserve : Antarctica

NARCIS (Netherlands)

Bastmeijer, C.J.; van Hengel, Steven

2009-01-01

Should the entire Antarctic continent and the surrounding islands be recognised as a ‘protected area’ or as a continent where certain areas, just like anywhere else, may be designated as protected areas? To find an answer to this question, this paper first discusses the most important agreements and

German emergency management concept

International Nuclear Information System (INIS)

Burkart, K.

1993-01-01

The advantages and disadvantages of the margin and start-up value concepts (according to ICRP 40 and EU-ordinances) are explained, and it is demonstrated that the two concepts are combinable. The combined concept has the advantage of immediately providing, if required, intervention levels for the various measures to be taken, and of obliging those persons concerned with emergency protection to study and quantify, already at the planning stage, the influence of a range of accident conditions on the decision on measures. In this context, the use of computerized decision support systems which are currently being developed is indispensable. (orig./DG) [de

Experiences with using a concept of organ-dose combination as a basis for practical measures in radiation protection

International Nuclear Information System (INIS)

Wernli, C.

1977-01-01

The concept of organ-dose combination is presented and its practical consequences for working-place and personnel monitoring and for the improvement of working methods are shown. Two years of practical experience have demonstrated the applicability and usefullness of the concept and have resulted in a better concentration and economization of the monitoring and protection efforts. The values for external total body dose and skin dose, in special cases also those for hand dose and internal contamination, are combined to form a criterion for the total radiation detriment which is easy to use and interpret: each measured external or internal exposure is registered as a fraction of the appropriate maximum permissible annual limit (expressed as dose for external exposures and as activity for incorporations). This fraction is called 'exposure index'. Over one year the sum of all registered 'exposure index' values for an employee must not exceed one. This 'total exposure index' values can also be expressed as an 'effective dose' if its value is multiplied by five rem. While the external body exposures clearly dominate in most departments of EIR, the 'effective doses' in the isotope production department are combinations of different organ doses. 'Low' and 'high risk' groups of employee differ by the relative importance of the four 'effective dose' components: 'low risk group' (effective dose 2 rem): (hand dose, total body dose, incorporation, skin dose). The total value of the 'effective dose' and the relative importance of its components determine the practical radiation protection measures and the appropriate combination and frequency of personnel monitoring for each employee

Concept of safety related I and C and power supply systems in the passive safety concept of the HTR-module

International Nuclear Information System (INIS)

Juengst, U.

1990-01-01

The main motivation for the passive safety concepts is to gain a better quality of safety or at least to achieve higher public acceptance for nuclear power plants. This strategy has been introduced into the European Fast Reactor (EER), a common project of France, UK and Germany is applied stringently to the German high-temperature gas-cooled reactor ''HTR - Module''. The following fields are briefly described in the paper: Safety design features of the HTR - Module, overview of I and C concept, reactor protection system, emergency control room, power supply concept, system arrangement and protection against external hazards, accidents sequence of station black-out. (author). 3 figs

Special problems: LBB, thermal effects

International Nuclear Information System (INIS)

Lin Chiwen

2001-01-01

This section presents the discussion of special problems in the reactor coolant system design, including LBB and thermal effects. First, the categories of fracture mechanics technology applicable to LBB is discussed. Two categories of fracture mechanics, namely: linear-elastic fracture mechanics (LEFM) and elastic-plastic fracture mechanics (EPFM) are discussed specifically. Next, basic concepts of LEFM are discussed. This will be followed by a discussion of EPFM, with more specific discussion of the methodology currently acceptable to NRC, with the emphasis on the J-integral approach. This is followed by a discussion of the NRC position and recommendations and basic requirements laid out by NRC. A specific example of LBB application to WPWR piping is used to identify the key steps to be followed, in order to satisfy the recommendations and requirements of NRC. An application of LBB to the WPWR reactor coolant loop piping is provided as further illustration of the methodology. This section focuses on the thermal effects which have not been addressed earlier, and the thermal effects which have caused particular concerns on potential reactor degradations, such as pressurized thermal shocks. The organization of this section is divided into the following subsections: linear-elastic fracture mechanics (LEFM); elastic-plastic fracture mechanics (EPFM); J concepts; NRC recommendations and requirements on the application of LBB; two specific applications of LBB to WPWR piping; PWR internals degradation; thermal fatigue considerations; a case study of pressurized thermal shock

Novel Voltage limiting concept for avalance breakdown protection

NARCIS (Netherlands)

Ruijs, L.C.H.; Bezooijen, van A.; Mahmoudi, R.; Roermund, van A.H.M.

2006-01-01

Destructive over-voltage breakdown of cellular phone power transistors is prevented by using a new voltage-limiting concept. The output voltage is detected by an avalanche-based detector, and limited by decreasing the output power when needed. The voltage detector contains a low voltage bipolar NPN

Advanced high-temperature thermal energy storage media for industrial applications

Science.gov (United States)

Claar, T. D.; Waibel, R. T.

1982-02-01

An advanced thermal energy storage media concept based on use of carbonate salt/ceramic composite materials is being developed for industrial process and reject heat applications. The composite latent/sensible media concept and its potential advantages over state of the art latent heat systems is described. Media stability requirements, on-going materials development efforts, and planned thermal energy storage (TES) performance evaluation tests are discussed.

High thermal load structure

International Nuclear Information System (INIS)

Tsujimura, Seiichi; Toyota, Masahiko.

1995-01-01

A highly thermal load structure applied to a plasma-opposed equipment of a thermonuclear device comprises heat resistant protection tiles and a cooling tube disposed in the protection tiles. As the protection tiles, a carbon/carbon composite material is used. The carbon/carbon composite material on the heat receiving surface comprises carbon fibers disposed in one direction (one dimensionally) arranged from the heat receiving surface toward the cooling tube. The carbon/carbon composite material on the side opposite to the heat receiving surface comprises carbon fibers arranged two-dimensionally in the direction perpendicular to the longitudinal direction of the cooling tube. Then, the cooling tube is interposed between the one-dimensional carbon/carbon composite material and the two-dimensional carbon/carbon composite material, and they are joined with each other by vacuum brazing. This can improve heat removing performance. In addition, thermal stresses at the joined portion is reduced. Further, electromagnetic force generated in the thermonuclear device is reduced. (I.N.)

High thermal load structure

Energy Technology Data Exchange (ETDEWEB)

Tsujimura, Seiichi; Toyota, Masahiko

1995-06-16

A highly thermal load structure applied to a plasma-opposed equipment of a thermonuclear device comprises heat resistant protection tiles and a cooling tube disposed in the protection tiles. As the protection tiles, a carbon/carbon composite material is used. The carbon/carbon composite material on the heat receiving surface comprises carbon fibers disposed in one direction (one dimensionally) arranged from the heat receiving surface toward the cooling tube. The carbon/carbon composite material on the side opposite to the heat receiving surface comprises carbon fibers arranged two-dimensionally in the direction perpendicular to the longitudinal direction of the cooling tube. Then, the cooling tube is interposed between the one-dimensional carbon/carbon composite material and the two-dimensional carbon/carbon composite material, and they are joined with each other by vacuum brazing. This can improve heat removing performance. In addition, thermal stresses at the joined portion is reduced. Further, electromagnetic force generated in the thermonuclear device is reduced. (I.N.).

Sandia Laboratories plutonium protection system

International Nuclear Information System (INIS)

Bernard, E.A.; Miyoshi, D.S.; Gutierrez, F.D.

1977-01-01

Sandia Laboratories is developing an improved plutonium protection system (PPS) to demonstrate new concepts for enhancing special nuclear materials safeguards. PPS concepts include separation of functions, real-time item accountability and improved means for control of materials, activities and personnel access. Physical barriers and a secure communications network are designed into the system to offer greater protection against sabotage, diversion and theft attempts. Prototype systems are being constructed at Hanford, Washington and Albuquerque, New Mexico and will be subjected to a comprehensive testing and evaluation program

From photoluminescence to thermal emission: Thermally-enhanced PL (TEPL) for efficient PV (Conference Presentation)

Science.gov (United States)

Manor, Assaf; Kruger, Nimrod; Martin, Leopoldo L.; Rotschild, Carmel

2016-09-01

The Shockley-Queisser efficiency limit of 40% for single-junction photovoltaic (PV) cells is mainly caused by the heat dissipation accompanying the process of electro-chemical potential generation. Concepts such as solar thermo-photovoltaics (STPV) aim to harvest this heat loss by the use of a primary absorber which acts as a mediator between the sun and the PV, spectrally shaping the light impinging on the cell. However, this approach is challenging to realize due to the high operating temperatures of above 2000K required in order to generate high thermal emission fluxes. After over thirty years of STPV research, the record conversion efficiency for STPV device stands at 3.2% for 1285K operating temperature. In contrast, we recently demonstrated how thermally-enhanced photoluminescence (TEPL) is an optical heat-pump, in which photoluminescence is thermally blue-shifted upon heating while the number of emitted photons is conserved. This process generates energetic photon-rates which are comparable to thermal emission in significantly reduced temperatures, opening the way for a TEPL based energy converter. In such a device, a photoluminescent low bandgap absorber replaces the STPV thermal absorber. The thermalization heat induces a temperature rise and a blue-shifted emission, which is efficiently harvested by a higher bandgap PV. We show that such an approach can yield ideal efficiencies of 70% at 1140K, and realistic efficiencies of almost 50% at moderate concentration levels. As an experimental proof-of-concept, we demonstrate 1.4% efficient TEPL energy conversion of an Nd3+ system coupled to a GaAs cell, at 600K.

Variable Thermal Conductivity on Compressible Boundary Layer ...

African Journals Online (AJOL)

In this paper, variable thermal conductivity on heat transfer over a circular cylinder is presented. The concept of assuming constant thermal conductivity on materials is however not efficient. Hence, the governing partial differential equation is reduced using non-dimensionless variables into a system of coupled non-linear ...

THERMAL PROTECTION AND THERMAL STABILIZATION OF FIBER-OPTICAL GYROSCOPE INCLUDED IN STRAPDOWN INERTIAL NAVIGATION SYSTEM

Directory of Open Access Journals (Sweden)

D. S. Gromov

2014-03-01

Full Text Available It is known, that temperature perturbations and thermal modes have significant influence on the accuracy of a fiber-optical gyroscope. Nowadays, thermal perturbations are among the main problems in the field of navigation accuracy. Review of existing methods for decrease of temperature influences on the accuracy of a strapdown inertial navigation system with fiberoptical gyros showed, that the usage of constructive and compensation methods only is insufficient and, therefore, thermostabilization is required. Reversible thermostabilization system is offered, its main executive elements are thermoelectric modules (Peltier’s modules, heat transfer from which is provided by heatsinks at work surfaces of modules. This variant of thermostabilization maintenance is considered; Peltier’s modules and temperature sensors for the system are chosen. Parameters of heatsinks for heat transfer intensification are calculated. Fans for necessary air circulation in the device are chosen and thickness of thermal isolation is calculated. Calculations of thermal modes of navigation system with thermostabilization are made in modern software Autodesk Simulation CFD. Comparison of results for present and previous researches and calculations shows essential decrease in gradients of temperature on gyro surfaces and better uniformity of temperature field in the whole device. Conclusions about efficiency of the given method usage in view of accuracy improvement of navigation system are made. Thermostabilization provision of a strapdown inertial navigation system with fiberoptical gyros is proved. Thermostabilization application in combination with compensational methods can reach a necessary accuracy of navigation system.

New concept of critical infrastructure strengthening

International Nuclear Information System (INIS)

Gazizov, Talgat R.; Orlov, Pavel E.; Zabolotsky, Alexander M.; Kuksenko, Sergey P.

2016-01-01

Strengthening of critical infrastructure is considered. Modal reservation of electronics is proposed as a new concept of the strengthening. The concept combines a widely used cold backup and a recently proposed modal filtration. It makes electronics reliable as well as protected against electromagnetic interference, especially the ultra-wide band pulses. New printed circuit board structure is suggested for implementation of the proposed concept. Results of simulation in time and frequency domains are presented for the suggested structures. Considerable attenuation of dangerous excitations shows that the new concept and structure are promising.

New concept of critical infrastructure strengthening

Energy Technology Data Exchange (ETDEWEB)

Gazizov, Talgat R.; Orlov, Pavel E.; Zabolotsky, Alexander M.; Kuksenko, Sergey P. [Tomsk State University of Control Systems and Radioelectronics, 634050, Lenin Ave., Tomsk (Russian Federation)

2016-06-08

Strengthening of critical infrastructure is considered. Modal reservation of electronics is proposed as a new concept of the strengthening. The concept combines a widely used cold backup and a recently proposed modal filtration. It makes electronics reliable as well as protected against electromagnetic interference, especially the ultra-wide band pulses. New printed circuit board structure is suggested for implementation of the proposed concept. Results of simulation in time and frequency domains are presented for the suggested structures. Considerable attenuation of dangerous excitations shows that the new concept and structure are promising.

Development of concepts for the management of thermal resources in urban areas - Assessment of transferability from the Basel (Switzerland) and Zaragoza (Spain) case studies

Science.gov (United States)

Epting, Jannis; García-Gil, Alejandro; Huggenberger, Peter; Vázquez-Suñe, Enric; Mueller, Matthias H.

2017-05-01

concept of the "relaxation factor", which is a first approach to overcome the present policy of "first come, first served". Remediation measures to regenerate overheated urban aquifers are also introduced. The transferability of the applied methods to other urban areas is discussed. It is shown that an appropriate selection of locations for monitoring hydraulic and thermal boundary conditions make it possible to implement representative interpretations of groundwater flow and thermal regimes as well as to set up high-resolution numerical flow- and heat-transport models. Those models are the basis for the sustainable management of thermal resources.

Concepts of Urban Drainage and Flood Protection

DEFF Research Database (Denmark)

Harremoës, Poul

1990-01-01

The significance of the introduction of modern computer technology to design, analysis, operation and control of sewer systems during rain is analyzed. With new tools come new basic concepts and new engineering criteria for performance. The most significant developments are: the capability...... to calculate surcharging and flooding, rather than just relating to pipe capacity performance criteria; the capability of calculating long series of rain record in order to derive proper statistics on the pollutional load on the environment; and finally the capability of dynamically controlling the system...

Study of workplace: concept and practical application

International Nuclear Information System (INIS)

Varin, J.C.; Casanova, P.; Benjamin, P.; Rey, M.

2006-01-01

The order in council published in March 2003 deals with the radiation protection of workers. It completes the French regulation of risks prevention. In this text appears a new item called 'study of workplace'. This new concept does not deal only with radiation risks: in a risks management organization, this concept must be a complementary disposition of the existing procedures. In the La Hague plant, a risks management policy has been developed for many years in respect with OHSAS 18001 referential. This risks management system involves all the departments which work in the risks prevention field: safety department, radiation protection department, health department. Many procedures and quality assurance tools have been crated which comply with the concept of 'work place study'. (author)

To a question on thermal protection of constructional elements of vacuum-plasma devices

International Nuclear Information System (INIS)

Borisko, V.N.; Borisko, S.V.; Zinovev, D.V.; Lapshin, V.I.; Tselujko, A.F.

2005-01-01

The progress in development of vacuum-plasma devices is connected with the design and creation of constructional elements from materials, which have a high erosion resistance and can maintain the large specific flux of energy per effective area. Recently as the materials of such constructional elements it was offered to use the reversible sorbents of hydrogen of Zr-V system, which have high-rates of sorption-desorption and large thermal effect of the hydride phases decomposition. In the paper an experimental research of the thermal conditions features of the metal-hydride electrodes, which subjected of the energy loads in the vacuum-plasma devices, are given. The simulation of the energy loads on the electrodes was carried out with the help of gas discharge plasma as there is an possibility to vary the energy spectrum of the bombarding particles and to gather a necessary radiation dose to the material surface. For comparative examinations of various materials under the irradiation by high-energy heavy particles it is the most convenient to use the Penning discharge. In this case, the cathodes made of different materials are under the identical conditions even at the change of working discharge modes. Therefore in the device on the basis of the Penning discharge the cathodes of metal-hydride and stainless steel were set. It was detected, that the increase of the temperature gradient of metal-hydride cathode goes down with the increase of discharge current value. The dependence of operating temperatures difference of cathodes from exposure time has shown that the temperature of the metal-hydride cathode is sufficiently lower than the temperature of the stainless steel cathode. Such a softening of the thermal operation conditions of the metal hydride cathode is caused by thermal decomposition of hydride phases. Besides there is the energy flow dissipation of bombarding particles on the protective gas target formed by desorbed hydrogen. The considerable decrease of

New concept of microprocessor protective devices design

Directory of Open Access Journals (Sweden)

Gurevich Vladimir

2010-01-01

Full Text Available Transition from electromechanical to digital protective relays is accompanied with serious technical problems. The author offers a new approach in designing the digital relays capable of solving these problems. It is proposed to construct digital relays in the form of standard modules from which it would be possible to assemble the digital relay in the same way as now a personal computer.

Study of workplace: concept and practical application; Etude de postes de travail: le concept et sa traduction en pratique

Energy Technology Data Exchange (ETDEWEB)

Varin, J.C.; Casanova, P.; Benjamin, P.; Rey, M. [COGEMA La Hague, 50 - Beaumont Hague (France)

2006-04-15

The order in council published in March 2003 deals with the radiation protection of workers. It completes the French regulation of risks prevention. In this text appears a new item called 'study of workplace'. This new concept does not deal only with radiation risks: in a risks management organization, this concept must be a complementary disposition of the existing procedures. In the La Hague plant, a risks management policy has been developed for many years in respect with OHSAS 18001 referential. This risks management system involves all the departments which work in the risks prevention field: safety department, radiation protection department, health department. Many procedures and quality assurance tools have been crated which comply with the concept of 'work place study'. (author)

Design concept of the HPLWR moderator flow path

International Nuclear Information System (INIS)

Koehly, Christina; Schulenberg, Thomas; Starflinger, Joerg

2009-01-01

The latest design concept of the High Performance Light Water Reactor (HPLWR) includes a thermal core in which supercritical water at 25 MPa inlet pressure is heated up from 280degC reactor inlet temperature to 500degC core exit temperature in three steps with intermediate coolant mixing to minimize peak cladding temperatures of the fuel rods. Prior to entering the first fuel assemblies, the coolant is used as moderator in water rods inside assemblies, in the gap volume between assembly boxes, as well as in the surrounding axial or radial reflectors. Even though assembly boxes and moderator rods are designed with a certain thermal insulation, heat is generated in the moderator water or transferred to it from the superheated steam inside assemblies, causing concern of natural convection phenomena with uncontrolled neutronic feedback on the core power distribution. Moreover, bypass flows of the moderator water need to be minimized at any thermal expansion of the reactor internal structures to avoid an unpredictable moderator mass flow. The design concept of the moderator flow path described in this paper is trying to overcome these problems. Downward flow of moderator water is limited to sub-cooled conditions, well below the pseudo-critical point of supercritical water. Dedicated orifices are foreseen to allow later correction of the mass flow split. The sealing concept accounts for larger thermal expansions of reactor components by using C-rings or bellows. A welded construction is preferred wherever possible to minimize leakage. The removable steam plenum is aligned at the extractable steam pipes to minimize thermal displacements at the sealing positions. The paper is showing several design details to illustrate the technical solutions. (author)

Radiation protection concepts review with an adapted quiz commercial game

International Nuclear Information System (INIS)

Rodrigues Junior, Ary de Araujo

2002-01-01

Before a new employee starts working at EMBRARAD under a large irradiation operator supervision, he has to attend the first radiation protection training. After that all radiation protection subjects are revised every six months. In that half-yearly training the employees are chosen randomly to explain radiation protection subjects to other participants under an instructor supervision. After some years attending the same training, employees do not have motivation to participate in this kind of periodic event due to the same issues covered. Therefore something should be made to revival their interest and motivation to take part in this periodic training. The way chose was adapted a commercial game to revised radiation protection subjects and included it in the periodic training. The game was well accepted by the employees, it caused a competition among them because everybody wanted to win the game and consequently stimulated them to study. (author)

Metal hydrides based high energy density thermal battery

International Nuclear Information System (INIS)

Fang, Zhigang Zak; Zhou, Chengshang; Fan, Peng; Udell, Kent S.; Bowman, Robert C.; Vajo, John J.; Purewal, Justin J.; Kekelia, Bidzina

2015-01-01

Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH 2 and TiMnV as a working pair. • High energy density can be achieved by the use of MgH 2 to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH 2 as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV 0.62 Mn 1.5 alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles

Core/Shell Structure of TiO2-Coated MWCNTs for Thermal Protection for High-Temperature Processing of Metal Matrix Composites

Directory of Open Access Journals (Sweden)

Laura Angélica Ardila Rodriguez

2018-01-01

Full Text Available The production of metal matrix composites with elevated mechanical properties depends largely on the reinforcing phase properties. Due to the poor oxidation resistance of multiwalled carbon nanotubes (MWCNTs as well as their high reactivity with molten metal, the processing conditions for the production of MWCNT-reinforced metal matrix composites may be an obstacle to their successful use as reinforcement. Coating MWCNTs with a ceramic material that acts as a thermal protection would be an alternative to improve oxidation stability. In this work, MWCNTs previously functionalized were coated with titanium dioxide (TiO2 layers of different thicknesses, producing a core-shell structure. Heat treatments at three different temperatures (500°C, 750°C, and 1000°C were performed on coated nanotubes in order to form a stable metal oxide structure. The MWCNT/TiO2 hybrids produced were evaluated in terms of thermal stability. Thermogravimetric analysis (TGA, X-ray diffraction (XRD, scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, Raman spectroscopy (RS, and X-ray photoelectron spectroscopy (XPS were performed in order to investigate TiO2-coated MWCNT structure and thermal stability under oxidative atmosphere. It was found that the thermal stability of the TiO2-coated MWCNTs was dependent of the TiO2 layer morphology that in turn depends on the heat treatment temperature.

Copyright protection

OpenAIRE

Plchotová, Gabriela

2011-01-01

The aim of this thesis is to offer a straightforward manual to anyone who authors their own original work or who utilises the original work of other creators. As such, it is necessary to briefly and clearly explain the historical development and essential terms of authorship as a concept and the origin of the need for copyright protection. Furthermore, this thesis includes chapters on copyright protection development specifically in the Czech Republic and the current definition of related law...

New economical concept of maritime terminal for LNG; Nouveau concept de terminal maritime a cout reduit pour le GNL

Energy Technology Data Exchange (ETDEWEB)

Dupont, B. [EURODIM S.A. (France)

2000-07-01

This series of slides present a new concept of marine terminal for LNG tanker-ships that requires less investments and offers a better adaptability to loading/unloading sites with a bad accessibility. This concept uses flexible cryogenic flow-lines developed by Coflexip Stena Offshore, double-envelope submarine pipes with a reinforced thermal insulation and the multi-purpose cryogenic connection module developed by Eurodim S.A. (J.S.)

Adaptive electrothermal protection of power converters

Directory of Open Access Journals (Sweden)

Baraniuk G. A.

2017-06-01

Full Text Available Thermal management for power converters during normal operation and transient modes when electrical components are warmed up is an actual problem. This can be particularly important for converters with intermittent duty operation, e.g. power supplies for resistance welding. According to some research, nearly 60% of failures are temperature-induced, and for every 10°C temperature rise in operating environment the failure rate nearly doubles. In this paper, thermal motion of state equations eigenvalue is analysed. It is shown, that in semiconductor converters with an output smoothing filter it is appropriate to use thermal protection devices based on thermal normalisation of the converter filter and, while for cases when short circuits are possible it is appropriate to use a soft start system with thermal adaptation for soft start time factor. Based on these results, two systems of thermal protections operating for semiconductor power converters are introduced. Simulation of combined electromagnetic and thermal processes in buck converter operating with both thermal management systems in overlapping environments MATLAB/Simulink and PLECS showed the possibility to significantly reduce thermal shock on semiconductor components. Using the system of filter parameters normalisation decreases the temperature of the crystal from 210°C to 85°C, using the adaptive soft start system decreases the temperature from 180°C to 80°C. The simulation results are confirmed by tests on real devices.

A thermal ground cloak

International Nuclear Information System (INIS)

Yang, Tianzhi; Wu, Qinghe; Xu, Weikai; Liu, Di; Huang, Lujun; Chen, Fei

2016-01-01

The thermal cloak has been a long-standing scientific dream of researchers and engineers. Recently thermal metamaterials with man-made micro-structure have been presented based on the principle of transformation optics (TO). This new concept has received considerable attention, which is a powerful tool for manipulating heat flux in thermal imaging systems. However, the inherent material singularity has long been a captivation of experimental realization. As an alternative method, the scattering-cancellation-based cloak (or bi-layer thermal cloak) has been presented to remove the singularity for achieving the same cloaking performance. Nevertheless, such strategy needs prerequisite knowledge (geometry and conductivity) of the object to be cloaked. In this paper, a new thermal ground cloak is presented to overcome the limitations. The device is designed, fabricated and measured to verify the thermal cloaking performance. We experimentally show that the remarkably low complexity of the device can fully and effectively be manipulated using realizable transformation thermal devices. More importantly, this thermal ground cloak is designed to exclude heat flux without knowing the information of the cloaked object. - Highlights: • We present the first thermal carpet cloak. • The carpet can thermally cloak any shaped object without knowing the properties of the object to be cloaked. • Excellent agreements between simulation and experiment are observed.

Advancement of the climate dual strategy. New concepts for a globally effective climate protection; Weiterentwicklung der baden-wuerttembergischen Klimadoppelstrategie. Neue Konzepte fuer einen global wirksamen Klimaschutz

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-10-15

The Baden-Wuerttemberg Council on Sustainable Development (Stuttgart, Federal Republic of Germany) presents a climate expert report with new concepts for a globally effective climate protection. First of all, the development of the global emissions of carbon dioxide since 1990 is described. The development of the global emissions of carbon dioxide up to 2050 is forecasted. Four general criteria (effectiveness, efficiency, fairness and acceptance) for a comparative evaluation of climate protection concepts are introduced. A proposal for solution on the basis of a globally effective cap-and-trade system as well as an identical scenario as an alternative with respect to the implementation are described. This alternative scenario is based on a cap-and-trade system but it develops on the basis of national self-commitment in accordance with an incentive and sanctionative system. Both implementation proposals are compared. Recommendations of the national government Baden-Wuerttemberg are given.

Bimodal Nuclear Thermal Rocket Analysis Developments

Science.gov (United States)

Belair, Michael; Lavelle, Thomas; Saimento, Charles; Juhasz, Albert; Stewart, Mark

2014-01-01

Nuclear thermal propulsion has long been considered an enabling technology for human missions to Mars and beyond. One concept of operations for these missions utilizes the nuclear reactor to generate electrical power during coast phases, known as bimodal operation. This presentation focuses on the systems modeling and analysis efforts for a NERVA derived concept. The NERVA bimodal operation derives the thermal energy from the core tie tube elements. Recent analysis has shown potential temperature distributions in the tie tube elements that may limit the thermodynamic efficiency of the closed Brayton cycle used to generate electricity with the current design. The results of this analysis are discussed as well as the potential implications to a bimodal NERVA type reactor.

Cooling concepts for HTS components

International Nuclear Information System (INIS)

Binneberg, A.; Buschmann, H.; Neubert, J.

1993-01-01

HTS components require that low-cost, reliable cooling systems be used. There are no general solutions to such systems. Any cooling concept has to be tailored to the specific requirements of a system. The following has to he taken into consideration when designing cooling concepts: - cooling temperature - constancy and controllability of the cooling temperature - cooling load and refrigerating capacity - continuous or discontinuous mode - degree of automation - full serviceability or availability before evacuation -malfunctions caused by microphonic, thermal or electromagnetic effects -stationary or mobile application - investment and operating costs (orig.)

Application of radiological protection measures to meet different environmental protection criteria

International Nuclear Information System (INIS)

Copplestone, D.

2012-01-01

The International Commission on Radiological Protection (ICRP) recognises that there is no simple or single universal definition of ‘environmental protection’, and that the concept differs from country to country and from one circumstance to another. However, there is an increasing need to be able to demonstrate that the environment is protected from radioactive substances released under authorisation for various reasons, such as for wildlife conservation requirements, or wildlife management for commercial reasons, or simply as part of pollution control. The Commission is developing the concept of Representative Organisms, which may be identified from any specific legal requirements or from more general requirements to protect local habitats or ecosystems. Such organisms may be the actual objects of protection or they may be hypothetical, depending on the objectives of the assessment. They may be similar to, or even congruent with, one or more of the Reference Animals and Plants (RAPs). Where this is not the case, attempts can be made to consider the extent to which the Representative Organisms differ from the nearest RAP in terms of known radiation effects upon it, basic biology, radiation dosimetry, and pathways of exposure. This paper discusses the practical implications of such an approach.

Thermal Stabilization of Biologics with Photoresponsive Hydrogels.

Science.gov (United States)

Sridhar, Balaji V; Janczy, John R; Hatlevik, Øyvind; Wolfson, Gabriel; Anseth, Kristi S; Tibbitt, Mark W

2018-03-12

Modern medicine, biological research, and clinical diagnostics depend on the reliable supply and storage of complex biomolecules. However, biomolecules are inherently susceptible to thermal stress and the global distribution of value-added biologics, including vaccines, biotherapeutics, and Research Use Only (RUO) proteins, requires an integrated cold chain from point of manufacture to point of use. To mitigate reliance on the cold chain, formulations have been engineered to protect biologics from thermal stress, including materials-based strategies that impart thermal stability via direct encapsulation of the molecule. While direct encapsulation has demonstrated pronounced stabilization of proteins and complex biological fluids, no solution offers thermal stability while enabling facile and on-demand release from the encapsulating material, a critical feature for broad use. Here we show that direct encapsulation within synthetic, photoresponsive hydrogels protected biologics from thermal stress and afforded user-defined release at the point of use. The poly(ethylene glycol) (PEG)-based hydrogel was formed via a bioorthogonal, click reaction in the presence of biologics without impact on biologic activity. Cleavage of the installed photolabile moiety enabled subsequent dissolution of the network with light and release of the encapsulated biologic. Hydrogel encapsulation improved stability for encapsulated enzymes commonly used in molecular biology (β-galactosidase, alkaline phosphatase, and T4 DNA ligase) following thermal stress. β-galactosidase and alkaline phosphatase were stabilized for 4 weeks at temperatures up to 60 °C, and for 60 min at 85 °C for alkaline phosphatase. T4 DNA ligase, which loses activity rapidly at moderately elevated temperatures, was protected during thermal stress of 40 °C for 24 h and 60 °C for 30 min. These data demonstrate a general method to employ reversible polymer networks as robust excipients for thermal stability of complex

Identifying and Investigating Difficult Concepts in Engineering Mechanics and Electric Circuits. Research Brief

Science.gov (United States)

Streveler, Ruth; Geist, Monica; Ammerman, Ravel; Sulzbach, Candace; Miller, Ronald; Olds, Barbara; Nelson, Mary

2007-01-01

This study extends ongoing work to identify difficult concepts in thermal and transport science and measure students' understanding of those concepts via a concept inventory. Two research questions provided the focal point: "What important concepts in electric circuits and engineering mechanics do students find difficult to learn?" and…

Technical guide to thermal processes

International Nuclear Information System (INIS)

Gosse, J.

1986-01-01

This book is an attempt to present the necessary formulae and numerical data for research programs. The most recent data have been used wherever possible. The work is not limited merely to statements of thermal laws; emphasis has been given to the important thermodynamic ideas and to the thermophysical properties of the working fluids. It discusses the thermodynamic concepts which govern the amount of energy transferred to, or from, a system undergoing any process as well as those concepts which allow rates of heat transfer to be predicted. In the same way, mass, momentum and energy balances are presented in a single section to emphasize that the three balances must always be considered together in the analysis of a system. It has been necessary to select the information to be presented in order to provide the essential ideas of thermal analysis. This technical guide summarises the fundamental laws and the experimental data on which the engineer can base his methods of calculation in order to provide an optimum thermal design

Can Nature Protection be Unsustainable? Models Behind Nature Protection in New Zealands National Parks

Science.gov (United States)

Hauhs, Michael; Bogner, Christina

2013-04-01

Nature protection can be justified by intrinsic values of life. Western culture sees nature as an autonomous system. Thus, nature protection is often synonymous with refraining from human interference as much as possible. This, however, can pose at least technical problems. Indeed, historical human impacts such as introduced species are often irreversible. In such cases refraining from human interference to protect threatened species is not an adequate management response. Nature protection in New Zealand is a prominent example. Many introduced species make a non-interventionist attitude infeasible to protect endemic species such as kiwis. Actually, active human interference is necessary to attain this goal. Therefore, one may consider nature protection as another form of land use. As any other form of land use, it needs standards of proper management (i.e. explicit goals, assessment, intervention etc.). In other words, it has to be shown to be sustainable. However, sustainability may rigorously be defined as an attribute of past land use only. Instantaneous positive indicators of sustainability may be elusive. At best it can be decided by observation whether or not a land use has been (not) sustainable until now. Stakeholders of nature protection have often different (implicit) concepts or models of nature in mind. This can lead to conflicts when it comes to management decisions. For example, the methods by which conservationists in New Zealand seek to re-establish historical species assemblages (e.g. aerial drop of poison into national parks) have come under criticism of animal rights groups as non-humane. We propose to use abstract modelling language to classify these concepts of nature protection and related issues. We show that from modelling perspective these conflicts pose a basic science problem rather than an applied science problem. This makes the delegation into existing disciplines so hard. We discuss possible implications for nature protection

Basic concepts and assumptions behind the ICRP recommendations

International Nuclear Information System (INIS)

Lindell, B.

1981-03-01

The paper gives a review of the current radiation protection recommendations by the International Commission on Radiological Protection (ICRP). It discusses concepts like stochastic effects, radiation detriments, collective dose, dose equivalent and dose limits. (G.B.)

Thermal Conductivity and Thermal Gradient Cyclic Behavior of Refractory Silicate Coatings on SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

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

2001-01-01

Plasma-sprayed mullite and BSAS coatings have been developed to protect SiC/SiC ceramic matrix composites from high temperature environmental attack. In this study, thermal conductivity and thermal barrier functions of these coating systems are evaluated using a laser high-heat-flux test rig. The effects of water vapor on coating thermal conductivity and durability are studied by using alternating furnace and laser thermal gradient cyclic tests. The influence of laser high thermal-gradient cycling on coating failure modes is also investigated.

VIP protection from CBRN hazards

International Nuclear Information System (INIS)

Kaszeta, D.

2009-01-01

Protection of heads of state/government from CBRN threats requires flexibility and advanced planning. The best approach to CBRN countermeasures in a close protection context combine traditional close protection techniques, sound security practices, and a good understanding of the technical nature of the threat. Poor general security practices make for poor CBRN protection. This paper addresses a methodology for assessing the viability of threats to protected persons/VIPs and provides an overview of close protection in the CBRN environment. It is important to define the scope of CBRN response in the close protection context. Some threat agents are more applicable to a military environment than to the type of attack consistent with assassination. By focussing the scope of CBRN close protection more specifically on the more technically viable threats, appropriate concepts of operation can be developed. Concepts of operation, developed with an understanding of the threat, determine the requirement for advanced preparation and the training and equipping of protective details. Most of the responses required in CBRN incidents are well served by tactically sound close protection procedures. The fundamental principles are: rapid identification of hazard, speed, use of protective technology, and medical interventions, including rapid decontamination and basic and advanced life support measures. This paper does not contain confidential or classified information and represents only the opinion of its author. It does not represent any official policy or opinion of the authors present or previous employers.(author)

State of the art of the fluidized bed nuclear reactor concept

International Nuclear Information System (INIS)

Sefidvash, F.; Vilhena, M.T.M.B. de; Streck, E.; Borges, V.; Johansson, M.

1987-01-01

A small and simple nuclear reactors with inherent safety using the fluidized bed concept is under research and study. In this paper a brief study neutronics and thermal hydraulics of this reactor concept is presented. (Author) [pt

Thermal effects in concrete members

International Nuclear Information System (INIS)

Kar, A.K.

1977-01-01

When subjected to temperature changes and restrained from free movement, a member develops stresses. Restrained members are sometimes assumed to act independently of other members. A method of analysis and design for thermal stresses in such members is provided. The method of analysis, based on the ultimate strength concept, greatly reduces the computational efforts for determining thermal effects in concrete members. Available charts and tables and the recommendations given herein simplify the design. (Auth.)

Fracture Toughness Evaluation of Space Shuttle External Tank Thermal Protection System Polyurethane Foam Insulation Materials

Science.gov (United States)

McGill, Preston; Wells, Doug; Morgan, Kristin

2006-01-01

Experimental evaluation of the basic fracture properties of Thermal Protection System (TPS) polyurethane foam insulation materials was conducted to validate the methodology used in estimating critical defect sizes in TPS applications on the Space Shuttle External Fuel Tank. The polyurethane foam found on the External Tank (ET) is manufactured by mixing liquid constituents and allowing them to react and expand upwards - a process which creates component cells that are generally elongated in the foam rise direction and gives rise to mechanical anisotropy. Similarly, the application of successive foam layers to the ET produces cohesive foam interfaces (knitlines) which may lead to local variations in mechanical properties. This study reports the fracture toughness of BX-265, NCFI 24-124, and PDL-1034 closed-cell polyurethane foam as a function of ambient and cryogenic temperatures and knitline/cellular orientation at ambient pressure.

To MARS and Beyond with Nuclear Power - Design Concept of Korea Advanced Nuclear Thermal Engine Rocket

Energy Technology Data Exchange (ETDEWEB)

Nam, Seung Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2013-05-15

The President Park of ROK has also expressed support for space program promotion, praising the success of NARO as evidence of a positive outlook. These events hint a strong signal that ROK's space program will be accelerated by the national eager desire. In this national eager desire for space program, the policymakers and the aerospace engineers need to pay attention to the advanced nuclear technology of ROK that is set to a major world nuclear energy country, even exporting the technology. The space nuclear application is a very much attractive option because its energy density is the most enormous among available energy sources in space. This paper presents the design concept of Korea Advanced Nuclear Thermal Engine Rocket (KANuTER) that is one of the advanced nuclear thermal rocket engine developing in Korea Advanced Institute of Science and Technology (KAIST) for space application. Solar system exploration relying on CRs suffers from long trip time and high cost. In this regard, nuclear propulsion is a very attractive option for that because of higher performance and already demonstrated technology. Although ROK was a late entrant into elite global space club, its prospect as a space racer is very bright because of the national eager desire and its advanced technology. Especially it is greatly meaningful that ROK has potential capability to launch its nuclear technology into space as a global nuclear energy leader and a soaring space adventurer. In this regard, KANuTER will be a kind of bridgehead for Korean space nuclear application.

To MARS and Beyond with Nuclear Power - Design Concept of Korea Advanced Nuclear Thermal Engine Rocket

International Nuclear Information System (INIS)

Nam, Seung Hyun; Chang, Soon Heung

2013-01-01

The President Park of ROK has also expressed support for space program promotion, praising the success of NARO as evidence of a positive outlook. These events hint a strong signal that ROK's space program will be accelerated by the national eager desire. In this national eager desire for space program, the policymakers and the aerospace engineers need to pay attention to the advanced nuclear technology of ROK that is set to a major world nuclear energy country, even exporting the technology. The space nuclear application is a very much attractive option because its energy density is the most enormous among available energy sources in space. This paper presents the design concept of Korea Advanced Nuclear Thermal Engine Rocket (KANuTER) that is one of the advanced nuclear thermal rocket engine developing in Korea Advanced Institute of Science and Technology (KAIST) for space application. Solar system exploration relying on CRs suffers from long trip time and high cost. In this regard, nuclear propulsion is a very attractive option for that because of higher performance and already demonstrated technology. Although ROK was a late entrant into elite global space club, its prospect as a space racer is very bright because of the national eager desire and its advanced technology. Especially it is greatly meaningful that ROK has potential capability to launch its nuclear technology into space as a global nuclear energy leader and a soaring space adventurer. In this regard, KANuTER will be a kind of bridgehead for Korean space nuclear application

Core concept for long operating cycle simplified BWR (LSBWR)

International Nuclear Information System (INIS)

Kouji, Hiraiwa; Noriyuki, Yoshida; Mikihide, Nakamaru; Hideaki, Heki; Masanori, Aritomi

2002-01-01

An innovative core concept for a long operating cycle simplified BWR (LSBWR) is currently being developed under a Toshiba Corporation and Tokyo Institute of Technology joint study. In this core concept, the combination of enriched uranium oxide fuels and loose-pitched lattice is adopted for an easy application of natural circulation. A combination of enriched gadolinium and 0.7-times sized small bundle with peripheral-positioned gadolinium rod is also adopted as a key design concept for 15-year cycle operation. Based on three-dimensional nuclear and thermal hydraulic calculation, a nuclear design for fuel bundle has been determined. Core performance has been evaluated based on this bundle design and shows that thermal performance and reactivity characteristics meet core design criteria. Additionally, a control rod operation plan for an extension of control rod life has been successfully determined. (author)

The role of ductile ligaments and warm prestress on the re-initiation of fracture from a crack arrested during thermal shock

International Nuclear Information System (INIS)

Smith, E.

1982-01-01

The protection offered by warm prestress can be important for preserving a nuclear pressure vessel's integrity during a postulated emergency condition involving a loss of coolant, when the emergency core cooling water subjects the pressure vessel to a thermal shock. There are two aspects to the problem: (a) the initial extension of a defect into the vessel wall, and (b) the subsequent re-initiation of fracture at an arrested crack tip. This note considers the effect of warm prestress on the re-initiation of fracture from an arrested crack, and emphasizes the role of ductile ligaments. It is argued that the warm prestress concept is applicable, thus complementing the limited experimental results provided by the HSST Thermal Shock experimental programme. (orig.)

The use of numerical technology for protection, control and automation - a concept description

International Nuclear Information System (INIS)

Gjerde, Oddbjoern; Langdal, Bjoern Inge; Kjoelle, Gerd H.; Aaboe, Yngve

2005-06-01

In the regulation of network companies of today there is a great focus on supplier reliability and the demands on the use of existing networks increase. Protection, control and automation (PCA) have a central role both with respect to supplier reliability and network utilization. The supplier reliability is also dependent on the installed equipment and the chosen conditions. This also applies to the use of the network that largely depend on the operational margins. This implies that the network company costs will depend on disruptions, maintenance and investments and would be influenced by the chosen protection, control and automation solutions. In the report the concept or the ideas for the use of information from numerical technology in connection with maintenance and handling of supply reliability are described. In operation the focus is on supply reliability and handling of operation disruptions through 1) prevention of faults and avoid disruptions and 2) reduce the consequences of operation disruptions. Examples show that costs in the central network could be reduced with about 60 %. In a selection of regional and distribution networks the costs could be reduced with about 70 %. The maintenance of the primary plant and the PCA equipment may be implemented based on systems and risk considerations. A consequence analysis with respect to economy, availability in the system, the system conditions, the equipment condition and consequences for customers is included. Examples show that the methodology is at best when applied to networks with little redundancy and that the method is applicable in new constructions or refinancing. It is then believed that the network (technical solutions) may be simplified and that necessary security may be obtained at risk based maintenance more than by a high degree of redundancy

Thermal aspects of a superconducting coil for fusion reactor

International Nuclear Information System (INIS)

Yeh, H.T.

1975-01-01

Computer models are used to simulate both localized and extensive thermal excursions in a large superconducting magnet for fusion reactor. Conditions for the failure of fusion magnet due to thermal excursion are delineated. Designs to protect the magnet against such thermal excursion are evaluated

Thermal Management and Analysis for a Potential Yucca Mountain Repository

International Nuclear Information System (INIS)

Dr. A. Van Luik

2004-01-01

In the current Yucca Mountain repository design concept, heat from the emplaced waste (mostly from spent nuclear fuel) would keep the temperature of the rock around the waste packages higher than the boiling point of water for hundreds to thousands of years after the repository is closed. The design concept allows below-boiling portions of the pillars between drifts to serve as pathways for the drainage of thermally mobilized water and percolating groundwater by limiting the distance that boiling temperatures extend into the surrounding rock. This design concept takes advantage of host rock dry out, which would create a dry environment within the emplacement drifts and reduce the amount of water that might otherwise be available to enter the drifts and contact the waste packages during this thermal pulse. Table 1 provides an overview of design constraints related to thermal management after repository closure. The Yucca Mountain repository design concept also provides flexibility to allow for operation over a range of lower thermal operating conditions. The thermal conditions within the emplacement drifts can be varied, along with the relative humidity, by modifying operational parameters such as the thermal output of the waste packages, the spacing of the waste packages in the emplacement drifts, and the duration and rate of active and passive ventilation. A lower range has been examined to quantify lower-temperature thermal conditions (temperatures and associated humidity conditions) in the emplacement drifts and to quantify impacts to the required emplacement area and excavated drift length. This information has been used to evaluate the potential long-term performance of a lower-temperature repository and to estimate the increase in costs associated with operating a lower-temperature repository. This presentation provides an overview of the thermal management evaluations that have been conducted to investigate a range of repository thermal conditions and

Environmental protection in the frame of radiation protection. Recommendation of the Commission on radiological protection including justification and explanation; Schutz der Umwelt im Strahlenschutz. Empfehlung der Strahlenschutzkommission mit Begruendung und Erlaeuterung

Energy Technology Data Exchange (ETDEWEB)

NONE

2017-01-15

The environmental protection is part of the radiation protection but without defined regulations concerning the protection of non-human species and the ecological systems. In 2008 the SSK (Strahlenschutzkommission) was asked to elaborate measures for environmental radiation protection. Part of the recommendation was the application of sustainability concepts on radioactive materials.

Particular features of fire protection in nuclear power plants

International Nuclear Information System (INIS)

Krueger, W.

1985-01-01

The particular features of fire protection in nuclear power plants that are connected with the need to ensure nuclear and radiation safety even during an emergency are outlined followed by the recommendation to lay them down in special fire protection standards. These, in conjunction with comprehensive fire hazard analyses, could serve to work out complex concepts for the fire protection of individual nuclear power plants. Such concepts would be very useful for review and assessment of the fire protection design during the licensing process and for later inspections. (author)

Metal hydrides based high energy density thermal battery

Energy Technology Data Exchange (ETDEWEB)

Fang, Zhigang Zak, E-mail: zak.fang@utah.edu [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Zhou, Chengshang; Fan, Peng [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Udell, Kent S. [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States); Bowman, Robert C. [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Vajo, John J.; Purewal, Justin J. [HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA 90265 (United States); Kekelia, Bidzina [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States)

2015-10-05

Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH{sub 2} and TiMnV as a working pair. • High energy density can be achieved by the use of MgH{sub 2} to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH{sub 2} as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV{sub 0.62}Mn{sub 1.5} alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles.

Thermal barrier coatings application in diesel engines

Science.gov (United States)

Fairbanks, J. W.

1995-01-01

Commercial use of thermal barrier coatings in diesel engines began in the mid 70's by Dr. Ingard Kvernes at the Central Institute for Industrial Research in Oslo, Norway. Dr. Kvernes attributed attack on diesel engine valves and piston crowns encountered in marine diesel engines in Norwegian ships as hot-corrosion attributed to a reduced quality of residual fuel. His solution was to coat these components to reduce metal temperature below the threshold of aggressive hot-corrosion and also provide protection. Roy Kamo introduced thermal barrier coatings in his 'Adiabatic Diesel Engine' in the late 70's. Kamo's concept was to eliminate the engine block water cooling system and reduce heat losses. Roy reported significant performance improvements in his thermally insulated engine at the SAE Congress in 1982. Kamo's work stimulates major programs with insulated engines, particularly in Europe. Most of the major diesel engine manufacturers conducted some level of test with insulated combustion chamber components. They initially ran into increased fuel consumption. The German engine consortium had Prof. Woschni of the Technical Institute in Munich. Woschni conducted testing with pistons with air gaps to provide the insulation effects. Woschni indicated the hot walls of the insulated engine created a major increase in heat transfer he refers to as 'convection vive.' Woschni's work was a major factor in the abrupt curtailment of insulated diesel engine work in continental Europe. Ricardo in the UK suggested that combustion should be reoptimized for the hot-wall effects of the insulated combustion chamber and showed under a narrow range of conditions fuel economy could be improved. The Department of Energy has supported thermal barrier coating development for diesel engine applications. In the Clean Diesel - 50 Percent Efficient (CD-50) engine for the year 2000, thermal barrier coatings will be used on piston crowns and possibly other components. The primary purpose of the

Environmental/Thermal Barrier Coatings for Ceramic Matrix Composites: Thermal Tradeoff Studies

Science.gov (United States)

Murthy, Pappu L. M.; Brewer, David; Shah, Ashwin R.

2007-01-01

Recent interest in environmental/thermal barrier coatings (EBC/TBCs) has prompted research to develop life-prediction methodologies for the coating systems of advanced high-temperature ceramic matrix composites (CMCs). Heat-transfer analysis of EBC/TBCs for CMCs is an essential part of the effort. It helps establish the resulting thermal profile through the thickness of the CMC that is protected by the EBC/TBC system. This report documents the results of a one-dimensional analysis of an advanced high-temperature CMC system protected with an EBC/TBC system. The one-dimensional analysis was used for tradeoff studies involving parametric variation of the conductivity; the thickness of the EBC/TBCs, bond coat, and CMC substrate; and the cooling requirements. The insight gained from the results will be used to configure a viable EBC/TBC system for CMC liners that meet the desired hot surface, cold surface, and substrate temperature requirements.

Extensive feedwater quality control and monitoring concept for preventing chemistry-related failures of boiler tubes in a subcritical thermal power plant

International Nuclear Information System (INIS)

Vidojkovic, Sonja; Onjia, Antonije; Matovic, Branko; Grahovac, Nebojsa; Maksimovic, Vesna; Nastasovic, Aleksandra

2013-01-01

Prevention and minimizing corrosion processes on steam generating equipment is highly important in the thermal power industry. The maintenance of feedwater quality at a level corresponding to the standards of technological designing, followed by timely respond to the fluctuation of measured parameters, has a decisive role in corrosion prevention. In this study, the comprehensive chemical control of feedwater quality in 210 MW Thermal Power Plant (TPP) was carried out in order to evaluate its potentiality to assure reliable function of the boiler and discover possible irregularity that might be responsible for frequent boiler tube failures. Sensitive on-line and off-line analytical instruments were used for measuring key and diagnostic parameters considered to be crucial for boiler safety and performances. Obtained results provided evidences for exceeded levels of oxygen, silica, sodium, chloride, sulfate, copper, and conductivity what distinctly demonstrated necessity of feedwater control improvement. Consequently, more effective feedwater quality monitoring concept was recommended. In this paper, the explanation of presumable root causes of corrosive contaminants was given including basic directions for their maintenance in proscribed limits. -- Highlights: • Feedwater quality monitoring practice in a thermal power plant has been evaluated. • The more efficient feedwater quality control have been applied. • Analysis of feedwater quality parameters has been performed. • Exceeded levels of corrosive contaminants were found. • Recommendations for their maintenance at proscribed values were given

Thermal modeling and design of the anisogrid morphing structure for a modular optical telescope concept

Science.gov (United States)

Phoenix, Austin A.

2017-10-01

To meet the requirements for the next generation of optical space telescopes, a paradigm shift is required from current structures that are static, heavy, and stiff toward innovative structures that are adaptive, lightweight, versatile, and intelligent. A morphing or adaptive structure, the thermally actuated anisogrid morphing boom, can be used to meet the design requirements by making the primary structure actively adapt to the on-orbit environment. The adaptive anisogrid structure is actuated through the intelligent application of thermal gradients. This active primary structure improves structural and thermal stability performance, reduces mass, and enables mission architectures. This effort expands on the author's previous work by incorporating the impact of thermal coupling and demonstrating an updated architecture. This paper introduces a thermally isolated version of the thermal morphing anisogrid structure to enable control of the thermal losses between active members. To evaluate the isolation design, the stiffness and thermal conductivity of these isolating interfaces is addressed. This paper determines that the applied morphing error remains below 5% across all stiffnesses if the joint thermal conductivity is below 0.2 W/(mK). This paper investigates the performance of the thermal morphing system under a variety of structural and thermal isolation interface properties and determines the linear operational regime.

Alkali metal protective garment and composite material

Science.gov (United States)

Ballif, III, John L.; Yuan, Wei W.

1980-01-01

A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

Relationships between stratigraphy, deformation and thermal history in sedimentary basins. Impact of geodynamic concepts in petroleum exploration

International Nuclear Information System (INIS)

Sarmiento, Luis Fernando

2002-01-01

The natural processes that generate petroleum accumulations in a sedimentary basin require several ingredients: (1) the petroleum system elements: source, reservoir, seal and overburden rocks, which are the result of sedimentation processes in a subsiding basin; (2) petroleum traps, which in many cases are the result of deformation and (3) heat to convert suitable organic matter into petroleum. Although these different phenomena are considered independent at the scale of an oil field, at the lithosphere scale thermal phenomena, (2) vertical movements of the earth surface responsible for sedimentation and erosion and (3) tectonic deformation are not independent phenomena, physical quantitative laws intimately relate them. These mutual inter relationships are useful in petroleum exploration to predict one factor having knowledge of the others. Applications of these concepts can contribute to understand the tectonic history of complex areas, such as the Colombian sedimentary basins and reduce exploration risk

Development of Thermally Actuated, High Temperature Composite Morphing Concepts

Science.gov (United States)

2016-03-31

set of applications exists in gas turbine engines, which stand to benefit greatly from aerodynamic control in their combustors, turbines, and nozzles...Modelling Development 27 3.1 Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.1.1 Achieving Snap-Through Behaviour ...Fabrication of Hybrid Laminate Shell and Strip Specimens . . . . . . 35 3.3.2 Measurement of Thermal Curvatures and Snap-Through Behaviour of Hybrid

Development of Thermally Actuated, High-Temperature Composite Morphing Concepts

Science.gov (United States)

2016-05-11

set of applications exists in gas turbine engines, which stand to benefit greatly from aerodynamic control in their combustors, turbines, and nozzles...Modelling Development 27 3.1 Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.1.1 Achieving Snap-Through Behaviour ...Fabrication of Hybrid Laminate Shell and Strip Specimens . . . . . . 35 3.3.2 Measurement of Thermal Curvatures and Snap-Through Behaviour of Hybrid

Practical applications of the exemption principle in radiation protection

International Nuclear Information System (INIS)

Wrixon, A.D.

2004-01-01

The concept of exemption has been widely used in radiological protection. It is part of the regulator's arsenal for applying legislative requirements in a graded fashion, to avoid the expenditure of effort on situations where the return in terms of improvement in protection would otherwise be trivial. Nevertheless, it still remains a controversial matter. It is not so much the dosimetric criteria for exemption that cause debate; it is more the way in which the concept is used; the scenarios employed to calculate derived activity concentrations, and its relationship to the somewhat analogous concept of exclusion. A particular problem has been the full integration into the legislative system of protection of exposures to radiation from sources of natural origin and the degree to which exemption is a relevant concept for dealing with such situations. The purpose of this paper is to attempt to provide some clarity on the two concepts and their practical implementation with a view to encouraging international harmonization and avoiding further unnecessary debate. (orig.)

Transient thermal analysis of Vega launcher structures

Energy Technology Data Exchange (ETDEWEB)

Gori, F. [University of Rome ' Tor Vergata' , Rome (Italy); De Stefanis, M. [Thales Alenia Space Italia, Rome (Italy); Worek, W.M. [University of Illinois at Chicago, Chicago (United States)], E-mail: wworek@uic.edu; Minkowycz, W.J. [University of Illinois at Chicago, Chicago (United States)

2008-12-15

A transient thermal analysis is carried out to verify the base cover thermal protection system of Vega 2nd stage Solid Rocket Motor (SRM) and the flange coupling of the inter-stage 2/3. The analysis is performed with a finite element code. The work has developed suitable numerical Fortran subroutines to assign radiation and convection boundary conditions. The thermal behaviour of the structures is presented.

Child Protection and the Conception of Parental Responsibility

NARCIS (Netherlands)

Mass, M.; Nijnatten, C.H.C.J. van

2005-01-01

The legal discourse on child protection that is characterized by the normalization-moralization paradigm focuses more on society's response to parental failure than on the predicament of the child. Findings from texts of legal discourse in Israel and in Holland portray an alliance between the

Macroscopic dynamics of thermal nuclear excitations

International Nuclear Information System (INIS)

Bastrukov, S.I.; Deak, F.; Kiss, A.; Seres, Z.

1989-11-01

The concept of kinetic temperature as a local dynamical variable of thermal nuclear collective motion is formulated using long-mean-free-path approach based on the Landau-Vlasov kinetic equation. In the Fermi drop model the thermal fluid dynamics of the spherical nucleus is analyzed. It is shown that in a compressible Fermi liquid the temperature pulses propagate in the form of spherical wave in phase with the acoustic wave. The thermal and compressional excitations are caused by the isotropic harmonic oscillations of the Fermi sphere in momentum space. (author) 25 refs.; 2 figs

Alternate Propellant Thermal Rocket, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Alternate Propellant Thermal Rocket (APTR) is a novel concept for propulsion of space exploration or orbit transfer vehicles. APTR propulsion is provided by...

Illusion thermal device based on material with constant anisotropic thermal conductivity for location camouflage

Science.gov (United States)

Hou, Quanwen; Zhao, Xiaopeng; Meng, Tong; Liu, Cunliang

2016-09-01

Thermal metamaterials and devices based on transformation thermodynamics often require materials with anisotropic and inhomogeneous thermal conductivities. In this study, still based on the concept of transformation thermodynamics, we designed a planar illusion thermal device, which can delocalize a heat source in the device such that the temperature profile outside the device appears to be produced by a virtual source at another position. This device can be constructed by only one kind of material with constant anisotropic thermal conductivity. The condition which should be satisfied by the device is provided, and the required anisotropic thermal conductivity is then deduced theoretically. This study may be useful for the designs of metamaterials or devices since materials with constant anisotropic parameters have great facility in fabrication. A prototype device has been fabricated based on a composite composed by two naturally occurring materials. The experimental results validate the effectiveness of the device.

Soft Thermal Sensor with Mechanical Adaptability.

Science.gov (United States)

Yang, Hui; Qi, Dianpeng; Liu, Zhiyuan; Chandran, Bevita K; Wang, Ting; Yu, Jiancan; Chen, Xiaodong

2016-11-01

A soft thermal sensor with mechanical adaptability is fabricated by the combination of single-wall carbon nanotubes with carboxyl groups and self-healing polymers. This study demonstrates that this soft sensor has excellent thermal response and mechanical adaptability. It shows tremendous promise for improving the service life of soft artificial-intelligence robots and protecting thermally sensitive electronics from the risk of damage by high temperature. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermal analysis of charring materials based on pyrolysis interface model

Directory of Open Access Journals (Sweden)

Huang Hai-Ming

2014-01-01

Full Text Available Charring thermal protection systems have been used to protect hypersonic vehicles from high heat loads. The pyrolysis of charring materials is a complicated physical and chemical phenomenon. Based on the pyrolysis interface model, a simulating approach for charring ablation has been designed in order to obtain one dimensional transient thermal behavior of homogeneous charring materials in reentry capsules. As the numerical results indicate, the pyrolysis rate and the surface temperature under a given heat flux rise abruptly in the beginning, then reach a plateau, but the temperature at the bottom rises very slowly to prevent the structural materials from being heated seriously. Pyrolysis mechanism can play an important role in thermal protection systems subjected to serious aerodynamic heat.

40 CFR 90.329 - Catalyst thermal stress test.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress test. 90.329... Equipment Provisions § 90.329 Catalyst thermal stress test. (a) Oven characteristics. The oven used for thermally stressing the test catalyst must be capable of maintaining a temperature of 500 ±5 °C and 1000 ±10...

40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress resistance... Procedures § 91.427 Catalyst thermal stress resistance evaluation. (a)(1) The purpose of the evaluation procedure specified in this section is to determine the effect of thermal stress on catalyst conversion...

40 CFR 90.427 - Catalyst thermal stress resistance evaluation.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress resistance... Gaseous Exhaust Test Procedures § 90.427 Catalyst thermal stress resistance evaluation. (a) The purpose of... catalyst conversion efficiency for Phase 1 engines. The thermal stress is imposed on the test catalyst by...

Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems

International Nuclear Information System (INIS)

Song, C. H.; Baek, W. P.; Chung, M. K.

2007-06-01

The objectives of the project are to study thermal hydraulic characteristics of advanced nuclear reactor system for evaluating key thermal-hydraulic phenomena relevant to new safety concepts. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. The Followings are main research topics: - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation-induced Thermal Mixing in a Pool - Development of Thermal-Hydraulic Models for Two-Phase Flow - Construction of T-H Data Base

Thermal Analysis of the Fastrac Chamber/Nozzle

Science.gov (United States)

Davis, Darrell

2001-01-01

This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the Fastrac 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed.

Pre-test analysis of protected loss of primary pump transients in CIRCE-HERO facility

Science.gov (United States)

Narcisi, V.; Giannetti, F.; Del Nevo, A.; Tarantino, M.; Caruso, G.

2017-11-01

In the frame of LEADER project (Lead-cooled European Advanced Demonstration Reactor), a new configuration of the steam generator for ALFRED (Advanced Lead Fast Reactor European Demonstrator) was proposed. The new concept is a super-heated steam generator, double wall bayonet tube type with leakage monitoring [1]. In order to support the new steam generator concept, in the framework of Horizon 2020 SESAME project (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors), the ENEA CIRCE pool facility will be refurbished to host the HERO (Heavy liquid mEtal pRessurized water cOoled tubes) test section to investigate a bundle of seven full scale bayonet tubes in ALFRED-like thermal hydraulics conditions. The aim of this work is to verify thermo-fluid dynamic performance of HERO during the transition from nominal to natural circulation condition. The simulations have been performed with RELAP5-3D© by using the validated geometrical model of the previous CIRCE-ICE test section [2], in which the preceding heat exchanger has been replaced by the new bayonet bundle model. Several calculations have been carried out to identify thermal hydraulics performance in different steady state conditions. The previous calculations represent the starting points of transient tests aimed at investigating the operation in natural circulation. The transient tests consist of the protected loss of primary pump, obtained by reducing feed-water mass flow to simulate the activation of DHR (Decay Heat Removal) system, and of the loss of DHR function in hot conditions, where feed-water mass flow rate is absent. According to simulations, in nominal conditions, HERO bayonet bundle offers excellent thermal hydraulic behavior and, moreover, it allows the operation in natural circulation.

Procedure and methodology of Radiation Protection optimization

International Nuclear Information System (INIS)

Wang Hengde

1995-01-01

Optimization of Radiation Protection is one of the most important principles in the system of radiation protection. The paper introduces the basic principles of radiation protection optimization in general, and the procedure of implementing radiation protection optimization and methods of selecting the optimized radiation protection option in details, in accordance with ICRP 55. Finally, some economic concepts relating to estimation of costs are discussed briefly

Study on the effect of shape-stabilized phase change materials on spacecraft thermal control in extreme thermal environment

International Nuclear Information System (INIS)

Wu, Wan-fan; Liu, Na; Cheng, Wen-long; Liu, Yi

2013-01-01

Highlights: ► A shape-stabilized PCM is used to protect the spacecraft attacked by high energy. ► Taking a satellite as example, it proves the solution given in the work is feasible. ► Low thermal conductivity makes the material above its thermal stability limit. ► It provides guidance on how to choose the shape-stabilized PCM for similar problems. - Abstract: In space, the emergencies such as short-term high heat flux is prone to cause spacecraft thermal control system faults, resulting in temperature anomalies of electronic equipment of the spacecraft and even failures in them. In order to protect the spacecraft attacked by the high energy, a new guard method is proposed. A shape-stabilized phase change material (PCM), which has high thermal conductivity and does not require being tightly packaged, is proposed to be used on the spacecraft. To prove the feasibility of using the material on spacecraft attacked by high energy, the thermal responses for spacecraft with shape-stabilized PCM are investigated in situations of normal and short-term high heat flux, in contrast to that with conventional thermal control system. The results indicate that the shape-stabilized PCM can effectively absorb the heat to prevent the thermal control system faults when the spacecraft’s outer heat flux changes dramatically and has no negative effect on spacecraft in normal heat flux. Additionally the effect of thermal conductivity of PCM on its application effectiveness is discussed

Thermal processing systems for TRU mixed waste

International Nuclear Information System (INIS)

Eddy, T.L.; Raivo, B.D.; Anderson, G.L.

1992-01-01

This paper presents preliminary ex situ thermal processing system concepts and related processing considerations for remediation of transuranic (TRU)-contaminated wastes (TRUW) buried at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Anticipated waste stream components and problems are considered. Thermal processing conditions required to obtain a high-integrity, low-leachability glass/ceramic final waste form are considered. Five practical thermal process system designs are compared. Thermal processing of mixed waste and soils with essentially no presorting and using incineration followed by high temperature melting is recommended. Applied research and development necessary for demonstration is also recommended

Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort

Energy Technology Data Exchange (ETDEWEB)

Regnier, Cindy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-08-01

Historically thermal comfort in buildings has been controlled by simple dry bulb temperature settings. As we move into more sophisticated low energy building systems that make use of alternate systems such as natural ventilation, mixed mode system and radiant thermal conditioning strategies, a more complete understanding of human comfort is needed for both design and control. This guide will support building designers, owners, operators and other stakeholders in defining quantifiable thermal comfort parameters?these can be used to support design, energy analysis and the evaluation of the thermal comfort benefits of design strategies. This guide also contains information that building owners and operators will find helpful for understanding the core concepts of thermal comfort. Whether for one building, or for a portfolio of buildings, this guide will also assist owners and designers in how to identify the mechanisms of thermal comfort and space conditioning strategies most important for their building and climate, and provide guidance towards low energy design options and operations that can successfully address thermal comfort. An example of low energy design options for thermal comfort is presented in some detail for cooling, while the fundamentals to follow a similar approach for heating are presented.

Protection by high velocity thermal spraying coatings on thick walled permanent and interim store components for the diminution of repairs, corrosion and costs 'SHARK'. Overview at the end of the project

International Nuclear Information System (INIS)

Behrens, Sabine; Hassel, Thomas; Bach, Friedrich-Wilhelm

2012-01-01

The corrosion protection of the internal space of thick-walled interim and permanent storage facility components, such as Castor copyright containers, are ensured nowadays by a galvanic nickel layer. The method has proved itself and protects the base material of the containers at the underwater loading in the Nuclear power station from a corrosive attack. Although, the galvanic nickel plating is a relatively time consuming method, it lasts for several days for each container, and is with a layer thickness of 1,000 μm also expensive. To develop an alternative, faster and more economical method, a BMBF research project named - 'SHARK - protection by high velocity thermal spraying layers on thick-walled permanent and interim store components for the diminution of repairs, corrosion and costs' in cooperation between Siempelkamp Nukleartechnik GmbH and the Institute of Materials Science of the Leibniz University of Hanover was established to investigate the suitability of the high velocity oxy fuel spraying technology (HVOF) for the corrosion protective coating of thickwalled interim and permanent storage facility components. Since the permanent storage depot components are manufactured from cast iron with globular graphite, this material was exclusively used as a base material in this project. The evaluation of the economical features of the application of different nickel base spraying materials on cast iron substratum was in focus, as well as the scientific characterization of the coating systems with regard to the corrosion protective properties. Furthermore, the feasibility of the transfer of the laboratory results on a large industrial setup as well as a general suitability of the coating process for a required repair procedure was to be investigated. The preliminary examination program identified chromium containing spraying materials as successful. Results of the preliminary examination program have been used for investigations with the CASOIK demonstration

Energy, Entropy and Exergy Concepts and Their Roles in Thermal Engineering

OpenAIRE

Dincer, Ibrahim; Cengel, Yunus A.

2001-01-01

Abstract: Energy, entropy and exergy concepts come from thermodynamics and are applicable to all fields of science and engineering. Therefore, this article intends to provide background for better understanding of these concepts and their differences among various classes of life support systems with a diverse coverage. It also covers the basic principles, general definitions and practical applications and implications. Some illustrative examples are presented to highlight the importance of t...

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

International Nuclear Information System (INIS)

Howe, S.; Borowski, S.; Helms, I.; Diaz, N.; Anghaie, S.; Latham, T.

1991-01-01

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

Thermal management and analysis for a potential yucca mountain repository

International Nuclear Information System (INIS)

Van Luik, A.

2005-01-01

In the current Yucca Mountain repository design concept, heat from the emplaced. waste (mostly from spent nuclear fuel.) would keep the temperature of the rock around the waste packages higher than the boiling point of water for hundreds to thousands of years after the repository is closed. The design concept allows below-boiling portions of the pillars between drifts to serve as pathways for the drainage of thermally mobilized water and percolating groundwater by limiting the distance that boiling temperatures extend into the surrounding rock. This design concept takes advantage of host rock dry out, which would create a dry environment within the emplacement drifts and reduce the amount of water that might otherwise be available to enter the drifts and contact the waste packages during this thermal pulse. The Yucca Mountain repository design concept also provides flexibility to allow for operation over a range of lower thermal operating conditions. The thermal conditions within the emplacement drifts can be varied, along with the relative humidity, by modifying operational parameters such as the thermal output of the waste packages, the spacing of the waste packages in the emplacement drifts, and. the duration and rate of active and passive ventilation. A lower range has been examined to quantify lower-temperature thermal conditions (temperatures and associated humidity conditions) in the emplacement drifts and to quantify impacts to the required emplacement area and excavated drift length. This information has been used to evaluate the potential long-term performance of a lower-temperature repository and to estimate the increase in costs associated with operating a lower-temperature repository. This presentation provides an overview of the thermal management evaluations that have been conducted to investigate a range of repository thermal conditions and includes a summary of the technical basis that supports these evaluations. The majority of the material

Impact of the probability of causation on the radiation protection program

International Nuclear Information System (INIS)

Meinhold, C.B.

1988-01-01

Although the probability of causation approach is the only scientific basis on which a given cancer can be judged to be causally related to a given exposure, the impact of this concept on the radiation safety program could be counter-productive. As health physicists, the practices and the concepts we employ have been developed to protect the worker. Effective dose equivalent and committed dose equivalent are protective concepts but useless for probability of causation analysis. Perhaps extensive records will be the only way that good radiation protection and probability of causation analysis can coexist

A practical threshold concept for simple and reasonable radiation protection

International Nuclear Information System (INIS)

Kaneko, Masahito

2002-01-01

A half century ago it was assumed for the purpose of protection that radiation risks are linearly proportional at all levels of dose. Linear No-Threshold (LNT) hypothesis has greatly contributed to the minimization of doses received by workers and members of the public, while it has brought about 'radiophobia' and unnecessary over-regulation. Now that the existence of bio-defensive mechanisms such as DNA repair, apoptosis and adaptive response are well recognized, the linearity assumption can be said 'unscientific'. Evidences increasingly imply that there are threshold effects in risk of radiation. A concept of 'practical' thresholds is proposed and the classification of 'stochastic' and 'deterministic' radiation effects should be abandoned. 'Practical' thresholds are dose levels below which induction of detectable radiogenic cancers or hereditary effects are not expected. There seems to be no evidence of deleterious health effects from radiation exposures at the current dose limits (50 mSv/y for workers and 5 mSv/y for members of the public), which have been adopted worldwide in the latter half of the 20th century. Those limits are assumed to have been set below certain 'practical' thresholds. As any workers and members of the public do not gain benefits from being exposed, excepting intentional irradiation for medical purposes, their radiation exposures should be kept below 'practical' thresholds. There is no use of 'justification' and 'optimization' (ALARA) principles, because there are no 'radiation detriments' as far as exposures are maintained below 'practical' thresholds. Accordingly the ethical issue of 'justification' to allow benefit to society to offset radiation detriments to individuals can be resolved. And also the ethical issue of 'optimization' to exchange health or safety for economical gain can be resolved. The ALARA principle should be applied to the probability (risk) of exceeding relevant dose limits instead of applying to normal exposures

Solar thermal power systems point-focusing thermal and electric applications projects. Volume 1: Executive summary

Science.gov (United States)

Marriott, A.

1980-01-01

The activities of the Point-Focusing Thermal and Electric Applications (PETEA) project for the fiscal year 1979 are summarized. The main thrust of the PFTEA Project, the small community solar thermal power experiment, was completed. Concept definition studies included a small central receiver approach, a point-focusing distributed receiver system with central power generation, and a point-focusing distributed receiver concept with distributed power generation. The first experiment in the Isolated Application Series was initiated. Planning for the third engineering experiment series, which addresses the industrial market sector, was also initiated. In addition to the experiment-related activities, several contracts to industry were let and studies were conducted to explore the market potential for point-focusing distributed receiver (PFDR) systems. System analysis studies were completed that looked at PFDR technology relative to other small power system technology candidates for the utility market sector.

Relay protection coordination with generator capability curve, excitation system limiters and power system relay protections settings

OpenAIRE

Buha Danilo; Buha Boško; Jačić Dušan; Gligorov Saša; Božilov Marko; Marinković Savo; Milosavljević Srđan

2016-01-01

The relay protection settings performed in the largest thermal powerplant (TE "Nikola Tesla B") are reffered and explained in this paper. The first calculation step is related to the coordination of the maximum stator current limiter settings, the overcurrent protection with inverse characteristics settings and the permitted overload of the generator stator B1. In the second calculation step the settings of impedance generator protection are determined, and the methods and criteria according ...

A new approach to authorization in the field of radiological protection

International Nuclear Information System (INIS)

2003-01-01

Approaches to radiological protection have been evolving, particularly over the past several years. This has been driven by the emergence of modern concepts of and approaches to risk governance, and by calls from within the radiological protection community for the simplification and clarification of the existing system of protection, as based on the Recommendations of the International Commission on Radiological Protection (ICRP). The NEA Committee on Radiation Protection and Public Health (CRPPH) has been very active in developing its own suggestions as to how the system of radiological protection should evolve to better meet the needs of policy makers, regulators and practitioners. One of those suggestions is that a generic concept of 'regulatory authorization' of certain levels and types of exposure to radiation should replace the current and somewhat complicated concepts of exclusion, exemption and clearance. It has also been suggested that by characterising emerging sources and exposures in a screening process leading into the authorization process, regulatory authorities could develop a better feeling for the type and scale of stakeholder involvement that would be necessary to reach a widely accepted approach to radiological protection. In order to verify that these suggestions would make the system of radiological protection more understandable, easy to apply, and acceptable, independent consultants have 'road tested' the CRPPH concepts of authorization and characterisation. Their findings, which show that applying these concepts would represent significant improvement, are reproduced herein. Specific approaches for the application of the new CRPPH ideas are also illustrated in this report. (author)

De minimis concept from a regulatory standpoint

International Nuclear Information System (INIS)

Cunningham, G.H. III.

1983-01-01

The author maintains that the de minimis concept does not have the same legal connotations as a license exemption or a general license, nor is it the same concept as ALARA (as low as reasonably achievable), and to equate this concept with any of the three is erroneous. He discusses the concept with regard to the revision of 10 CFR Part 20 regulations and concludes that incorporating de minimis into Part 20 is preferable to including it in other parts, that legal precedents for doing so exist, and that coordinating with the Environmental Protection Agency is expected in formulating the concept for inclusion in Part 20

Solar thermal aided power generation

International Nuclear Information System (INIS)

Hu, Eric; Yang, YongPing; Nishimura, Akira; Yilmaz, Ferdi; Kouzani, Abbas

2010-01-01

Fossil fuel based power generation is and will still be the back bone of our world economy, albeit such form of power generation significantly contributes to global CO 2 emissions. Solar energy is a clean, environmental friendly energy source for power generation, however solar photovoltaic electricity generation is not practical for large commercial scales due to its cost and high-tech nature. Solar thermal is another way to use solar energy to generate power. Many attempts to establish solar (solo) thermal power stations have been practiced all over the world. Although there are some advantages in solo solar thermal power systems, the efficiencies and costs of these systems are not so attractive. Alternately by modifying, if possible, the existing coal-fired power stations to generate green sustainable power, a much more efficient means of power generation can be reached. This paper presents the concept of solar aided power generation in conventional coal-fired power stations, i.e., integrating solar (thermal) energy into conventional fossil fuelled power generation cycles (termed as solar aided thermal power). The solar aided power generation (SAPG) concept has technically been derived to use the strong points of the two technologies (traditional regenerative Rankine cycle with relatively higher efficiency and solar heating at relatively low temperature range). The SAPG does not only contribute to increase the efficiencies of the conventional power station and reduce its emission of the greenhouse gases, but also provides a better way to use solar heat to generate the power. This paper presents the advantages of the SAPG at conceptual level.

Health and thermal comfort: From WHO guidance to housing strategies

International Nuclear Information System (INIS)

Ormandy, David; Ezratty, Véronique

2012-01-01

There are many references to the WHO guidance on thermal comfort in housing, but not to the original source material. Based on archive material, this paper gives the evidential basis for the WHO guidance. It then reports on evidence that some groups may be more susceptible to high or low indoor temperatures than others. It examines different methods for measuring thermal comfort, such as air temperature measurement, assessing residents' perception, and predicting satisfaction. Resident's perception was used effectively in the WHO LARES project, showing that self-reported poor health was significantly associated with poor thermal comfort. Tools to inform strategies directed at dealing with cold homes and fuel poverty are considered, including Energy Performance Certificates, Fuel Poverty Indicators, and the English Housing Health and Safety Rating System. Conclusions from a WHO Workshop on Housing, Energy and Thermal Comfort are also summarised. The WHO view of thermal comfort, which is driven by protecting health from both high and low indoor temperatures, should be recognised in energy efficiency, fuel poverty and climate change strategies. While this is a major challenge, it could provide both health gains for individuals, and economic benefits for society. - Highlights: ► WHO guidance on thermal comfort is directed to protecting health in the home environment. ► In particular, the WHO guidance aims to protect the health of the most susceptible and fragile. ► Housing energy efficiency strategies protect health, and attack inequities. ► Housing energy efficiency strategies also have economic benefits for society.

Protection of Reinforced Concrete Structures of Waste Water Treatment Reservoirs with Stainless Steel Coating Using Arc Thermal Spraying Technique in Acidified Water

Directory of Open Access Journals (Sweden)

Han-Seung Lee

2016-09-01

Full Text Available Waste water treatment reservoirs are contaminated with many hazardous chemicals and acids. Reservoirs typically comprise concrete and reinforcement steel bars, and the main elements responsible for their deterioration are hazardous chemicals, acids, and ozone. Currently, a variety of techniques are being used to protect reservoirs from exposure to these elements. The most widely used techniques are stainless steel plating and polymeric coating. In this study, a technique known as arc thermal spraying was used. It is a more convenient and economical method for protecting both concrete and reinforcement steel bar from deterioration in waste water treatment reservoirs. In this study, 316L stainless steel coating was applied to a concrete surface, and different electrochemical experiments were performed to evaluate the performance of coatings in different acidic pH solutions. The coating generated from the arc thermal spraying process significantly protected the concrete surface from corrosion in acidic pH solutions, owing to the formation of a double layer capacitance—a mixture of Cr3+ enriched with Cr2O3 and Cr-hydroxide in inner and Fe3+ oxide on the outer layer of the coating. The formation of this passive film is defective owing to the non-homogeneous 316L stainless steel coating surface. In the pH 5 solution, the growth of a passive film is adequate due to the presence of un-dissociated water molecules in the aqueous sulfuric acid solution. The coated surface is sealed with alkyl epoxide, which acts as a barrier against the penetration of acidic solutions. This coating exhibits higher impedance values among the three studied acidic pH solutions.

Advanced Carbon Fabric/Phenolics for Thermal Protection Applications.

Science.gov (United States)

1982-02-01

structural properties are lower than rayon-based carbon fabriL analogues, they appear to be adequate for most ablative heat- shielding applications...34Development of Ablative Nozzles. Part II Ablative Nozzle Concept, Scaling Law , and Test Results," IAS Mtg. on Large Rockets, Sacramento, CA., Oct. 30

Design Concept of the Thermal Flux Island in MYRRHA for LLFP Transmutation. Present Status

International Nuclear Information System (INIS)

Aoust, Th.; De Raedt, Ch.; Malambu, E.; Ait Abderrahim, H.

2002-01-01

MYRRHA is an ADS aimed at providing protons and neutrons for various R and D applications. It consists of a proton accelerator coupled to a sub-critical fast core. While the fast neutron spectrum, obtaining in the MYRRHA core, allows the transmutation of minor actinides (MAs), the transmutation of long lived fission products (LLFPs) in MYRRHA requires the utilisation of a thermal spectrum in order to take profit of the fact that the capture cross-sections of the LLFPs are much larger in the thermal-energy domain than in the high-energy domain. A high thermal flux island inside MYRRHA is therefore being developed, consisting of an irradiation device for LLFPs (or other irradiation target material needing a thermal neutron spectrum), surrounded by assemblies filled with a lattice of ZrH 2 moderator pins, cooled by the same coolant (Pb-Bi) as the MYRRHA fuel assemblies. Thermal neutron absorbers at the periphery of the neutron island are used to minimise the influence of the thermal flux on the fast core. The study of the performances of MYRRHA, including the transmutation of the LLFPs in such a thermal island, is carried out with the aid of the code MCNPX. The transmutation performances of LLFPs are assessed by coupling the code MCNPX to an evolution calculation. The LLFPs studied are Tc-99 and I-129. (authors)