WorldWideScience

Sample records for nonmetallic thermal protection

  1. Thermophysical Properties of Matter - the TPRC Data Series. Volume 13. Thermal Expansion - Nonmetallic Solids

    Science.gov (United States)

    1977-01-01

    Amer. Dental Assoc., 20, 108-19, 1933. 267 52429 Nielsen, T. H. and Leipold, M. H., "Thermal Expansion of Yttria-Stpbilized Zirconia , "J. Amer. Ceram...isotropic the coefficient of thermal Symmetres expansion is equal to three times the coefficient of linear thermal expansion; i.e., Cubic at a, a1 0 0 0...can Where sj (j = 4, 5, 6) = 0, as in cubic , hexagonal, happen in open-structure crystals, such as silicon orthorhombic, and some tetragonal crystals, a

  2. High-frequency electro-thermal processing of secondary nonmetallic raw materials

    Directory of Open Access Journals (Sweden)

    A. V. Livshits

    2014-01-01

    modified by waste of polyethylene. Using the authors’ snap enables producing the sawdust briquettes with enhanced heat of combustion.Using the waste of pulp and paper industry was successful in creating the arrays of hydrolytic lignin for their use as a fuel or an insulation material. The presence of temperature gradient contributed to the mass-transfer of low boiling and water-soluble compounds to the sample surface, and, thus, to its hardening. The thermal insulation properties of produced material are higher than those of wood, claydite-concrete, etc. thereby making it advanced for further research.The article draws a conclusion from the theoretical and experimental studies that the use of НF power for of waste processing has unconditional prospects.

  3. Thermal Management and Thermal Protection Systems

    Science.gov (United States)

    Hasnain, Aqib

    2016-01-01

    's rays directly impinging on the system. Heating rate of the lamps were calculated by knowing fraction of emitted energy in a wavelength interval and the filament temperature. This version of the model can be used to predict performance of the system under vacuum with extreme cold or hot conditions. Initial testing of the PTMS showed promise, and the thermal math model predicts even better performance in thermal vacuum testing. ii) Thermal Protection Systems (TPS) are required for vehicles which enter earth's atmosphere to protect from aerodynamic heating caused by the friction between the vehicle and atmospheric gases. Orion's heat shield design has two aspects which needed to be analyzed thermally: i) a small excess of adhesive used to bond the outer AVCOAT layer to the inner composite structure tends to seep from under the AVCOAT and form a small bead in between two bricks of AVCOAT, ii) a silicone rubber with different thermophysical properties than AVCOAT fills the gap between two bricks of AVCOAT. I created a thermal model using TD to determine temperature differences that are caused by these two features. To prevent false results, all TD models must be verified against something known. In this case, the TD model was correlated to CHAR, an ablation modelling software used to analyze TPS. Analyzing a node far from the concerning features, we saw that the TD model data match CHAR data, verifying the TD model. Next, the temperature of the silicone rubber as well as the bead of adhesive were analyzed to determine if they exceeded allowable temperatures. It was determined that these two features do not have a significant effect on the max temperature of the heat shield. This model can be modified to check temperatures at various locations of the heat shield where the composite thickness varies.

  4. Monte Carlo simulations as a feasibility tool for non-metallic land-mine detection by thermal-neutron backscattering

    NARCIS (Netherlands)

    Maucec, M; de Meijer, RJ

    2002-01-01

    The use of Monte Carlo simulations is presented for modelling a simplified land-mine detector system with thermal neutron backscattering (TNB) analysis based on a Cf-252-neutron source. Different aspects and a variety of external conditions, related to localisation and identification of a buried obj

  5. Aerogel Modified Structural Thermal Protection System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This program will mature and further develop structural syntactic foam insulated integral Thermal Protection System (TPS) designs and materials as an enabling...

  6. NDE for Ablative Thermal Protection Systems Project

    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),...

  7. NDE for Ablative Thermal Protection Systems Project

    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...

  8. Improved Thermal-Switch Disks Protect Batteries

    Science.gov (United States)

    Darcy, Eric; Bragg, Bobby

    1990-01-01

    Improved thermal-switch disks help protect electrical batteries against high currents like those due to short circuits or high demands for power in circuits supplied by batteries. Protects batteries against excessive temperatures. Centered by insulating fiberglass washer. Contains conductive polymer that undergoes abrupt increase in electrical resistance when excessive current raises its temperature above specific point. After cooling, polymer reverts to low resistance. Disks reusable.

  9. Electric mine motor thermal models aiding design and setting thermal protections

    National Research Council Canada - National Science Library

    R Krok

    2012-01-01

      Electric mine motor thermal models aiding design and setting thermal protections The paper presents original modified thermal networks for calculations of the temperature field in induction mine...

  10. Economic impact of using nonmetallic materials in low to intermediate temperature geothermal well construction

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    Four appendices are included. The first covers applications of low-temperature geothermal energy including industrial processes, agricultural and related processes, district heating and cooling, and miscellaneous. The second discusses hydrogeologic factors affecting the design and construction of low-temperature geothermal wells: water quality, withdrawal rate, water depth, water temperature, basic well designs, and hydrogeologic provinces. In the third appendix, properties of metallic and nonmetallic materials are described, including: specific gravity, mechanical strength properties, resistance to physical and biological attack, thermal properties of nonmetallics, fluid flow characteristics, corrosion resistance, scaling resistance, weathering resistance of nonmetallics, and hydrolysis resistance of nonmetallics. Finally, special considerations in the design and construction of low-temperature geothermal wells using nonmetallics materials are covered. These include; drilling methods, joining methods, methods of casing and screen installation, well cementing, and well development. (MHR)

  11. Modeling thermal protection outfits for fire exposures

    Science.gov (United States)

    Song, Guowen

    2002-01-01

    A numerical model has been developed that successfully predicts heat transfer through thermally protective clothing materials and garments exposed to intense heat. The model considers the effect of fire exposure to the thermophysical properties of materials as well as the air layers between the clothing material and skin surface. These experiments involved characterizing the flash fire surrounding the manikin by measuring the temperature of the flame above each thermal sensor in the manikin surface. An estimation method is used to calculate the heat transfer coefficient for each thermal sensor in a 4 second exposure to an average heat flux of 2.00cal/cm2sec. A parameter estimation method was used to estimate heat induced change in fabric thermophysical properties. The skin-clothe air gap distribution of different garments was determined using three-dimensional body scanning technology. Multi-layer skin model and a burn prediction method were used to predict second and third degree burns. The integrated generalized model developed was validated using the "Pyroman" Thermal Protective Clothing Analysis System with Kevlar/PBIRTM and NomexRTMIIIA coverall garments with different configuration and exposure time. A parametric study conducted using this numerical model indicated the influencing parameters on garment thermal protective performance in terms of skin burn damage subjected to 4 second flash fire exposure. The importance of these parameters is analyzed and distinguished. These parameters includes fabric thermophysical properties, PyromanRTM chamber flash fire characteristics, garment shrinkage and fit factors, as well as garment initial and test ambient temperature. Different skin models and their influence on burn prediction were also investigated using this model.

  12. Thermal Protection Materials: Development, Characterization and Evaluation

    Science.gov (United States)

    Johnson, Silvia M.

    2012-01-01

    Thermal protection materials and systems (TPS) are used to protect space vehicles from the heat experienced during entry into an atmosphere. The application for these materials is very specialized as are the materials. They must have specific properties to withstand conditions during specific entries. There is no one-size-fits-all TPS as the conditions experienced by a material are very dependent upon the atmosphere, the entry speed, the size and shape of the vehicle, and the location on the vehicle. However, all TPS must be reliable and efficient to ensure mission safety, that is to protect the vehicle while ensuring that payload is maximized. Types of TPS will be reviewed in relation to types of missions and applications. Both reusable and ablative materials will be discussed. Approaches to characterizing and evaluating these materials will be presented. The role of heritage versus new materials will be described.

  13. Thermal Vacuum Facility for Testing Thermal Protection Systems

    Science.gov (United States)

    Daryabeigi, Kamran; Knutson, Jeffrey R.; Sikora, Joseph G.

    2002-01-01

    A thermal vacuum facility for testing launch vehicle thermal protection systems by subjecting them to transient thermal conditions simulating re-entry aerodynamic heating is described. Re-entry heating is simulated by controlling the test specimen surface temperature and the environmental pressure in the chamber. Design requirements for simulating re-entry conditions are briefly described. A description of the thermal vacuum facility, the quartz lamp array and the control system is provided. The facility was evaluated by subjecting an 18 by 36 in. Inconel honeycomb panel to a typical re-entry pressure and surface temperature profile. For most of the test duration, the average difference between the measured and desired pressures was 1.6% of reading with a standard deviation of +/- 7.4%, while the average difference between measured and desired temperatures was 7.6% of reading with a standard deviation of +/- 6.5%. The temperature non-uniformity across the panel was 12% during the initial heating phase (t less than 500 sec.), and less than 2% during the remainder of the test.

  14. Electric mine motor thermal models aiding design and setting thermal protections

    National Research Council Canada - National Science Library

    Krok, R

    2012-01-01

    The paper presents original modified thermal networks for calculations of the temperature field in induction mine motors under steady and transient conditions aiding design and setting thermal protections...

  15. Thermal protection materials: Thermophysical property data

    Science.gov (United States)

    Williams, S. D.; Curry, Donald M.

    1992-01-01

    This publication presents a thermophysical property survey on materials that could potentially be used for future spacecraft thermal protection systems (TPS). This includes data that was reported in the 1960's as well as more current information reported through the 1980's. An attempt was made to cite the manufacturers as well as the data source in the bibliography. This volume represents an attempt to provide in a single source a complete set of thermophysical data on a large variety of materials used in spacecraft TPS analysis. The property data is divided into two categories: ablative and reusable. The ablative materials have been compiled into twelve categories that are descriptive of the material composition. An attempt was made to define the Arrhenius equation for each material although this data may not be available for some materials. In a similar manner, char data may not be available for some of the ablative materials. The reusable materials have been divided into three basic categories: thermal protection materials (such as insulators), adhesives, and structural materials.

  16. Effect of the conditions of REM microalloying of steel on the corrosion activity of nonmetallic inclusions

    Science.gov (United States)

    Movenko, D. A.; Kotel'nikov, G. I.; Pavlov, A. V.; Bytsenko, O. A.

    2015-11-01

    Experimental heats of low-alloy steel are performed under various conditions of rare-earth metal microalloying and aluminum and calcium deoxidation. Electron-probe microanalysis of nonmetallic inclusions and a metallographic investigation of a metal are used to show that, when interacting with water, nonmetallic cerium oxide inclusions do not form hydrates and, correspondingly, are not aggressive. When aluminum, calcium, and cerium additions are sequentially introduced into a melt, a continuous cerium oxide shell forms on calcium aluminates, protects corrosive nonmetallic inclusions against interaction with water, and weakens local metal corrosion.

  17. Determination of Health Protection Zone Standard for Nonmetallic Mineral Production%非金属矿物制品制造业卫生防护距离研制

    Institute of Scientific and Technical Information of China (English)

    黄婵; 张文勇; 郭嘉昒; 李举

    2012-01-01

    [目的]了解非金属矿物制品业无组织排放水平,制定非金属矿物制品业卫生防护距离标准.[方法]通过收集行业资料选择代表全国先进生产工艺水平的非金属矿物制品企业作为被测企业,选择工艺相似、原料相同、选址相近的可比性企业作为类比企业.现场监测无组织排放量(Qc),根据被测企业的特点分别选用地面浓度反推法计算水泥和石灰制品业的卫生防护距离,选用通量法计算石棉制造业的卫生防护距离,选用物料衡算法计算石墨炭素制品业的卫生防护距离,类比分析不同规模同类企业的卫生防护距离,结合被测企业周边人群健康状况流行病学调查统计学秩和检验结果,预测合理的卫生防护距离标准值.[结果]非金属矿物制品制造业卫生防护距离标准建议值按当地近五年平均风速分别为:水泥制造业300m、200m和200m;石灰制造业生产规模≤20×104t/a者分别为400m、300m和300m,生产规模> 20×104t/a者分别为500m、400m和300m;石棉制品制造业分别为400m、300m和200m;石墨炭素制品制造业超高功率石墨电极<3×104 t/a者分别为800m、700m和600 m;超高功率石墨电极≥3×104 t/a者分别为1 200m、1 200m和900m.人群健康状况流行病学调查回收有效问卷347份,秩和检验结果显示,人群出现的症状或体症例数总体分布在不同距离间的差异有统计学意义(P<0.05).[结论]设置卫生防护距离标准值应当综合考虑风速与规模的影响,分档给出标准建议值.以行业分类制定卫生防护距离标准具有可行性.%[ Objective ] To quantify the unorganized emission of nonmetallic mineral production and to propose the health protection zone standard for it. [ Methods ] The detected enterprises which represented the national advanced technology level of nonmetallic mineral production were selected through industry data. The analogic enterprises of similar production

  18. 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.

  19. Thermal protection using very high temperature ceramics

    Science.gov (United States)

    Adamczyk, George R.

    1992-01-01

    The purpose of the paper is to expose the reader to a technology that may solve some of the toughest materials problems facing thermal protection for use in aerospace. Supermaterials has created a system capable of producing unique material properties. Over 10 years and many man-hours have been invested in the development of this technology. Applications range from the food industry to the rigors of outer space. The flexibility of the system allows for customization not found in many other processes and at a reasonable cost. The ranges of materials and alloys that can be created are endless. Many cases with unique characteristics have been identified and we can expect even more with further development.

  20. 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.

  1. A study on non-metallic structure of heliostat

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiaobin; Zang Chuncheng; Zhang Xiliang; Wang Yangzhong; Du Fengli [Himin Solar Energy Group Co., Ltd, Dezhou City (China); Wang Zhifeng [Inst. of Electrical Engineering, CAS, BJ (China)

    2008-07-01

    Heliostat constitutes a very important component in the solar power tower system. Its importance derives from three aspects: one is the large proportion in the total cost, accounting for about 50% of the whole, the other is its concentration efficiency and reflectivity heavily determining the power conversion from solar thermal energy to electrical energy, another is itself power consumption amount highly expressing failure or success of the power plant. Therefore, serious efforts and considerations from the structure, motion and control mode to material selection have to be given in the design and optimization of heliostat. In the present paper, the mechanical and aging performance of non-metallic materials is investigated and compared. The possibility of these non-metallic materials in the application of heliostat structure is discussed. (orig.)

  2. Encapsulation of nonmetallic fractions recovered from printed circuit boards waste with thermoplastic.

    Science.gov (United States)

    Muniyandi, Shantha Kumari; Sohaili, Johan; Hassan, Azman

    2014-09-01

    The present work includes a process for encapsulation by combining substantially simultaneously dry nonmetallic printed circuit boards (PCBs) powder and recycled high-density polyethylene (rHDPE) in an extruder to form a homogenous matrix. The extruded materials were then molded into standard tensile, flexural, and impact properties testing specimens. Nonmetallic PCB mainly consists of large amount of glass fiber-reinforced epoxy resin materials. Incorporation of 50 wt% nonmetallic PCB in rHDPE matrix had increased the flexural strength and modulus by 35% and 130%, respectively. Tensile strength reported to be constant without much improvement. However, the Young's modulus has increased by 180%, with incorporation of 50 wt% nonmetallic PCB. The addition of 6 phr (parts per hundred) maleated polyethylene (MAPE) resulted in 2-fold increase in tensile and flexural strength. Regarding the leaching properties, Cu was identified as the metal that leached at the highest level from the raw nonmetallic PCB, at 59.09 mg/L. However, after the nonmetallic PCB was filled in rHDPE/PCB composites, the concentration of Cu was reduced far below the regulatory limit, to only 3 mg/L. Thermal properties of composites were studied, and it was found out that incorporation of nonmetallic PCB fillers in rHDPE resulted in low thermal conductivity, whereas mechanical strength of the composites showed maximum improvements at 220 degrees C. Overall, the encapsulation technique using nonmetallic PCB waste has formed a monolithic waste form that provides a barrier to the dispersion of wastes into the environment. Implications: Nonmetallic materials reclaimed from waste PCBs were used to analyze the chemical composition, and it was found that nonmetalllic PCBs mainly consist of glass fiber-reinforced epoxy resin materials. With such millions of glass fibers in nonmetallic PCBs, there are mass-excellent supporting bodies that enhance the mechanical properties of composites. In fact, utilization

  3. System definition study of deployable, non-metallic space structures

    Science.gov (United States)

    Stimler, F. J.

    1984-01-01

    The state of the art for nonmetallic materials and fabrication techniques suitable for future space structures are summarized. Typical subsystems and systems of interest to the space community that are reviewed include: (1) inflatable/rigidized space hangar; (2) flexible/storable acoustic barrier; (3) deployable fabric bulkhead in a space habitat; (4) extendible tunnel for soft docking; (5) deployable space recovery/re-entry systems for personnel or materials; (6) a manned habitat for a space station; (7) storage enclosures external to the space station habitat; (8) attachable work stations; and (9) safe haven structures. Performance parameters examined include micrometeoroid protection; leakage rate prediction and control; rigidization of flexible structures in the space environment; flammability and offgassing; lifetime for nonmetallic materials; crack propagation prevention; and the effects of atomic oxygen and space debris. An expandable airlock for shuttle flight experiments and potential tethered experiments from shuttle are discussed.

  4. THERMAL AND PHYSICAL FEATURES OF MAGNETIC AND ELECTRIC GRINDING PROCESS OF GAS AND THERMAL PROTECTIVE COATINGS

    OpenAIRE

    N. V. Spiridonov; I. O. Sokorov; M. V. Niaroda

    2008-01-01

    The paper reveals thermal zones of magnetic and electric grinding process. The influence of electric and physical parameters of magnetic and electric grinding on temperature in the zone of gas and thermal protective coatings has been established in the paper.

  5. In Situ Diagnostic Sensors for Thermal Protection Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Low-profile, embedded sensors are proposed for condition monitoring and health management (HM) of thermal protection systems. The sensors will be fabricated using a...

  6. Thermal Protection System Materials (TPSM): 3D MAT Project

    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...

  7. An empirical analysis of thermal protective performance of fabrics used in protective clothing.

    Science.gov (United States)

    Mandal, Sumit; Song, Guowen

    2014-10-01

    Fabric-based protective clothing is widely used for occupational safety of firefighters/industrial workers. The aim of this paper is to study thermal protective performance provided by fabric systems and to propose an effective model for predicting the thermal protective performance under various thermal exposures. Different fabric systems that are commonly used to manufacture thermal protective clothing were selected. Laboratory simulations of the various thermal exposures were created to evaluate the protective performance of the selected fabric systems in terms of time required to generate second-degree burns. Through the characterization of selected fabric systems in a particular thermal exposure, various factors affecting the performances were statistically analyzed. The key factors for a particular thermal exposure were recognized based on the t-test analysis. Using these key factors, the performance predictive multiple linear regression and artificial neural network (ANN) models were developed and compared. The identified best-fit ANN models provide a basic tool to study thermal protective performance of a fabric.

  8. Arcjet Testing of Micro-Meteoroid Impacted Thermal Protection Materials

    Science.gov (United States)

    Agrawal, Parul; Munk, Michelle M.; Glaab, Louis J.

    2013-01-01

    There are several harsh space environments that could affect thermal protection systems and in turn pose risks to the atmospheric entry vehicles. These environments include micrometeoroid impact, extreme cold temperatures, and ionizing radiation during deep space cruise, all followed by atmospheric entry heating. To mitigate these risks, different thermal protection material samples were subjected to multiple tests, including hyper velocity impact, cold soak, irradiation, and arcjet testing, at various NASA facilities that simulated these environments. The materials included a variety of honeycomb packed ablative materials as well as carbon-based non-ablative thermal protection systems. The present paper describes the results of the multiple test campaign with a focus on arcjet testing of thermal protection materials. The tests showed promising results for ablative materials. However, the carbon-based non-ablative system presented some concerns regarding the potential risks to an entry vehicle. This study provides valuable information regarding the capability of various thermal protection materials to withstand harsh space environments, which is critical to sample return and planetary entry missions.

  9. Electromagnetic shielding of thermal protection system for hypersonic vehicles

    Science.gov (United States)

    Albano, M.; Micheli, D.; Gradoni, G.; Morles, R. B.; Marchetti, M.; Moglie, F.; Mariani Primiani, V.

    2013-06-01

    The numerical simulation and the measurement of electromagnetic shielding at microwave frequencies of thermal protection system for hypersonic vehicles is presented using nested reverberation chamber. An example of a possible thermal protection system for a re-entry vehicle is presented. This system based on carbon material is electromagnetically characterized. The characterization takes into account not only the materials but also the final assembly configuration of the thermal protection system. The frequency range is 2-8 GHz. The results of measurements and simulations show that the microwave shielding effectiveness of carbon materials is above 60 dB for a single tile and that the tile inter-distance is able to downgrade the shielding effectiveness on the average to about 40 dB.

  10. A ceramic matrix composite thermal protection system for hypersonic vehicles

    Science.gov (United States)

    Riccitiello, Salvatore R.; Love, Wendell L.; Pitts, William C.

    1993-01-01

    The next generation of hypersonic vehicles (NASP, SSTO) that require reusable thermal protection systems will experience acreage surface temperatures in excess of 1100 C. More important, they will experience a more severe physical environment than the Space Shuttle due to non-pristine launching and landing conditions. As a result, maintenance, inspection, and replacement factors must be more thoroughly incorporated into the design of the TPS. To meet these requirements, an advanced thermal protection system was conceived, designated 'TOPHAT'. This system consists of a toughened outer ceramic matrix composite (CMC) attached to a rigid reusable surface insulator (RSI) which is directly bonded to the surface. The objective of this effort was to evaluate this concept in an aeroconvective environment, to determine the effect of impacts to the CMC material, and to compare the results with existing thermal protection systems.

  11. Numerical Simulation for Thermal Shock Resistance of Thermal Protection Materials Considering Different Operating Environments

    Directory of Open Access Journals (Sweden)

    Weiguo Li

    2013-01-01

    Full Text Available Based on the sensitivities of material properties to temperature and the complexity of service environment of thermal protection system on the spacecraft, ultrahigh-temperature ceramics (UHTCs, which are used as thermal protection materials, cannot simply consider thermal shock resistance (TSR of the material its own but need to take the external constraint conditions and the thermal environment into full account. With the thermal shock numerical simulation on hafnium diboride (HfB2, a detailed study of the effects of the different external constraints and thermal environments on the TSR of UHTCs had been made. The influences of different initial temperatures, constraint strengths, and temperature change rates on the TSR of UHTCs are discussed. This study can provide a more intuitively visual understanding of the evolution of the TSR of UHTCs during actual operation conditions.

  12. 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.

  13. THERMAL AND PHYSICAL FEATURES OF MAGNETIC AND ELECTRIC GRINDING PROCESS OF GAS AND THERMAL PROTECTIVE COATINGS

    Directory of Open Access Journals (Sweden)

    N. V. Spiridonov

    2008-01-01

    Full Text Available The paper reveals thermal zones of magnetic and electric grinding process. The influence of electric and physical parameters of magnetic and electric grinding on temperature in the zone of gas and thermal protective coatings has been established in the paper.

  14. 46 CFR 182.720 - Nonmetallic piping materials.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Nonmetallic piping materials. 182.720 Section 182.720... TONS) MACHINERY INSTALLATION Piping Systems § 182.720 Nonmetallic piping materials. (a) Rigid... systems where permitted by paragraph (e) of this section. (c) Nonmetallic piping must not be used...

  15. 46 CFR 119.720 - Nonmetallic piping materials.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Nonmetallic piping materials. 119.720 Section 119.720 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE... Piping Systems § 119.720 Nonmetallic piping materials. Nonmetallic piping materials,...

  16. 49 CFR 193.2187 - Nonmetallic membrane liner.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Nonmetallic membrane liner. 193.2187 Section 193... GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage tank....

  17. Arc Jet Testing of Thermal Protection Materials: 3 Case Studies

    Science.gov (United States)

    Johnson, Sylvia; Conley, Joe

    2015-01-01

    Arc jet testing is used to simulate entry to test thermal protection materials. This paper discusses the usefulness of arc jet testing for 3 cases. Case 1 is MSL and PICA, Case 2 is Advanced TUFROC, and Case 3 is conformable ablators.

  18. European Directions for Hypersonic Thermal Protection Systems and Hot Structures

    Science.gov (United States)

    Glass, David E.

    2007-01-01

    This presentation will overview European Thermal Protection Systems (TPS) and Hot Structures activities in Europe. The Europeans have a lot of very good work going on in the area. The presentation will discuss their emphasis on focused technology development for their flight vehicles.

  19. Interfacial Thermal Conductance of Thiolate-Protected Gold Nanospheres

    CERN Document Server

    Stocker, Kelsey M; Gezelter, J Daniel

    2016-01-01

    Molecular dynamics simulations of thiolate-protected and solvated gold nanoparticles were carried out in the presence of a non-equilibrium heat flux between the solvent and the core of the particle. The interfacial thermal conductance ($G$) was computed for these interfaces, and the behavior of the thermal conductance was studied as a function of particle size, ligand flexibility, and ligand chain length. In all cases, thermal conductance of the ligand-protected particles was higher than the bare metal-solvent interface. A number of mechanisms for the enhanced conductance were investigated, including thiolate-driven corrugation of the metal surface, solvent ordering at the interface, solvent-ligand interpenetration, and ligand ordering relative to the particle surface. Only the smallest particles exhibited significant corrugation. All ligands permitted substantial solvent-ligand interpenetration, and ligand chain length has a significant influence on the orientational ordering of interfacial solvent. Solvent-...

  20. Engineering Aerothermal Analysis for X-34 Thermal Protection System Design

    Science.gov (United States)

    Wurster, Kathryn E.; Riley, Christopher J.; Zoby, E. Vincent

    1998-01-01

    Design of the thermal protection system for any hypersonic flight vehicle requires determination of both the peak temperatures over the surface and the heating-rate history along the flight profile. In this paper, the process used to generate the aerothermal environments required for the X-34 Testbed Technology Demonstrator thermal protection system design is described as it has evolved from a relatively simplistic approach based on engineering methods applied to critical areas to one of detailed analyses over the entire vehicle. A brief description of the trajectory development leading to the selection of the thermal protection system design trajectory is included. Comparisons of engineering heating predictions with wind-tunnel test data and with results obtained using a Navier-Stokes flowfield code and an inviscid/boundary layer method are shown. Good agreement is demonstrated among all these methods for both the ground-test condition and the peak heating flight condition. Finally, the detailed analysis using engineering methods to interpolate the surface-heating-rate results from the inviscid/boundary layer method to predict the required thermal environments is described and results presented.

  1. Heat-balance Thermal Protection with Heat Pipes for Hypersonic Vehicle

    Directory of Open Access Journals (Sweden)

    Rong Yisheng

    2016-01-01

    Full Text Available Heat-balance thermal protection is non-ablating thermal protection for leading edge of hypersonic vehicle. Heat will be quickly transferred from high aerodynamic heating area to low aerodynamic heating area, where the energy will be released by radiation. The temperature of high aerodynamic heating area could be reduced to protect the designed structure from being burned down. Heat-balance thermal protection is summarized. The research on heat-pipe for heat-balance thermal protection is introduced.

  2. Heat-balance Thermal Protection with Heat Pipes for Hypersonic Vehicle

    OpenAIRE

    Rong Yisheng; Wei Yuechuan; Duan Dongli; Zhan Renjun

    2016-01-01

    Heat-balance thermal protection is non-ablating thermal protection for leading edge of hypersonic vehicle. Heat will be quickly transferred from high aerodynamic heating area to low aerodynamic heating area, where the energy will be released by radiation. The temperature of high aerodynamic heating area could be reduced to protect the designed structure from being burned down. Heat-balance thermal protection is summarized. The research on heat-pipe for heat-balance thermal protection is intro...

  3. Important Parameter Groups in Thermal Protection of Polymers

    Directory of Open Access Journals (Sweden)

    John Staggs

    2015-07-01

    Full Text Available The problem of thermal protection is explored for two idiosyncratic reactive systems, namely a sacrificial heat-sink material and an intumescent system where a dynamically evolving insulation layer is produced from an initially thin coating. Relatively simple mathematical models of both systems are proposed that encompass the important physical characteristics of each situation and these models are analysed using a mixture of numerical and analytical techniques. Important dimensionless parameter groups are identified and domains of parameter space where thermal performance is particularly good- or particularly bad- are identified.

  4. Quantitative thermal diffusivity imaging of disbonds in thermal protective coatings using inductive heating

    Science.gov (United States)

    Heath, D. M.; Winfree, William P.

    1990-01-01

    An inductive heating technique for making thermal diffusivity images of disbonds between thermal protective coatings and their substrates is presented. Any flaw in the bonding of the coating and the substrate shows as an area of lowered values in the diffusivity image. The benefits of the inductive heating approach lie in its ability to heat the conductive substrate without directly heating the dielectric coating. Results are provided for a series of samples with fabricated disbonds, for a range of coating thicknesses.

  5. 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.

  6. Thermal-Acoustic Analysis of a Metallic Integrated Thermal Protection System Structure

    Science.gov (United States)

    Behnke, Marlana N.; Sharma, Anurag; Przekop, Adam; Rizzi, Stephen A.

    2010-01-01

    A study is undertaken to investigate the response of a representative integrated thermal protection system structure under combined thermal, aerodynamic pressure, and acoustic loadings. A two-step procedure is offered and consists of a heat transfer analysis followed by a nonlinear dynamic analysis under a combined loading environment. Both analyses are carried out in physical degrees-of-freedom using implicit and explicit solution techniques available in the Abaqus commercial finite-element code. The initial study is conducted on a reduced-size structure to keep the computational effort contained while validating the procedure and exploring the effects of individual loadings. An analysis of a full size integrated thermal protection system structure, which is of ultimate interest, is subsequently presented. The procedure is demonstrated to be a viable approach for analysis of spacecraft and hypersonic vehicle structures under a typical mission cycle with combined loadings characterized by largely different time-scales.

  7. Inclusion of Thermal Protection Systems in Spacecraft Thermal-Stress Analysis using Concurrent Engineering Techniques

    Science.gov (United States)

    Rickman, Steven L.

    2002-07-01

    Creating compatible thermal and structural mathematical models is complicated by the different meshing requirements of the thermal and structural disciplines. Often times, the structural model is of significantly higher fidelity requiring the thermal model to grow to an intractable size if full compatibility is to be assured. Given that the structural finite element mesh can be transformed into a thermal model, the network description remains incomplete until the appropriate thermal protection system (TPS) features are added. For entry heating studies, a high fidelity TPS mesh is required to accurately predict structural temperatures. Additionally, local pressure, temperature and heating variations further complicate the analysis. A technique for the efficient extraction of thermal protection system thickness data from CAD geometry is presented. The technique allows for application of complicated TPS cross-sections consisting of different materials and permits local pressure and heating rate variations. The resulting process has been successfully demonstrated on the X-38 crew return vehicle configuration and serves as a prototype for concurrent engineering techniques using a combination of custom and commercial software tools.

  8. 46 CFR 199.214 - Immersion suits and thermal protective aids.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Immersion suits and thermal protective aids. 199.214... Passenger Vessels § 199.214 Immersion suits and thermal protective aids. (a) Each passenger vessel must... an immersion suit. (c) The immersion suits and thermal protective aids required under paragraphs...

  9. Ablation Modeling of Ares-I Upper State Thermal Protection System Using Thermal Desktop

    Science.gov (United States)

    Sharp, John R.; Page, Arthur T.

    2007-01-01

    The thermal protection system (TPS) for the Ares-I Upper Stage will be based on Space Transportation System External Tank (ET) and Solid Rocket Booster (SRB) heritage materials. These TPS materials were qualified via hot gas testing that simulated ascent and re-entry aerothermodynamic convective heating environments. From this data, the recession rates due to ablation were characterized and used in thermal modeling for sizing the thickness required to maintain structural substrate temperatures. At Marshall Space Flight Center (MSFC), the in-house code ABL is currently used to predict TPS ablation and substrate temperatures as a FORTRAN application integrated within SINDA/G. This paper describes a comparison of the new ablation utility in Thermal Desktop and SINDA/FLUINT with the heritage ABL code and empirical test data which serves as the validation of the Thermal Desktop software for use on the design of the Ares-I Upper Stage project.

  10. Thermal Protective Coating for High Temperature Polymer Composites

    Science.gov (United States)

    Barron, Andrew R.

    1999-01-01

    The central theme of this research is the application of carboxylate-alumoxane nanoparticles as precursors to thermally protective coatings for high temperature polymer composites. In addition, we will investigate the application of carboxylate-alumoxane nanoparticle as a component to polymer composites. The objective of this research was the high temperature protection of polymer composites via novel chemistry. The significance of this research is the development of a low cost and highly flexible synthetic methodology, with a compatible processing technique, for the fabrication of high temperature polymer composites. We proposed to accomplish this broad goal through the use of a class of ceramic precursor material, alumoxanes. Alumoxanes are nano-particles with a boehmite-like structure and an organic periphery. The technical goals of this program are to prepare and evaluate water soluble carboxylate-alumoxane for the preparation of ceramic coatings on polymer substrates. Our proposed approach is attractive since proof of concept has been demonstrated under the NRA 96-LeRC-1 Technology for Advanced High Temperature Gas Turbine Engines, HITEMP Program. For example, carbon and Kevlar(tm) fibers and matting have been successfully coated with ceramic thermally protective layers.

  11. 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.

  12. Fiber optic temperature profiling for thermal protection heat shields

    Science.gov (United States)

    Black, Richard J.; Costa, Joannes M.; Moslehi, Behzad; Zarnescu, Livia; Hackney, Drew; Peters, Kara

    2014-04-01

    Reliable Thermal Protection System (TPS) sensors are needed to achieve better designs for spacecraft (probe) heatshields for missions requiring atmospheric aero-capture or entry/reentry. In particular, they will allow both reduced risk and heat-shield mass minimization, which will facilitate more missions and allow increased payloads and returns. For thermal measurements, Intelligent Fiber Optic Systems Corporation (IFOS) is providing a temperature monitoring system involving innovative lightweight, EMI-immune, high-temperature resistant Fiber Bragg Grating (FBG) sensors with a thermal mass near that of TPS materials together with fast FBG sensor interrogation. The IFOS fiber optic sensing technology is highly sensitive and accurate. It is also low-cost and lends itself to high-volume production. Multiple sensing FBGs can be fabricated as arrays on a single fiber for simplified design and reduced cost. In this paper, we provide experimental results to demonstrate the temperature monitoring system using multi-sensor FBG arrays embedded in small-size Super-Light Ablator (SLA) coupon, which was thermally loaded to temperatures in the vicinity of the SLA charring temperature. In addition, a high temperature FBG array was fabricated and tested for 1000°C operation.

  13. The behavior of multilayer ceramic protections at quick thermal shock

    Directory of Open Access Journals (Sweden)

    Alexandru MIHAILESCU

    2013-06-01

    Full Text Available Protective layers of “hot parts” of the turbo engines as well as co-generative systems of energy industry are exposed to a combination of wear factors which may act together at high values.The main goal of the paper is the behavior of some advanced layers, duplex and triplex, multifunctional, ceramics in relation to the most complex wear factor and disturbing as well, the quick thermal shock.The quick thermal shock test installation designed and constructed by the INCAS covers the domain of some high gradients of heating/cooling and is currently integrated in a network of European infrastructure that evaluates the properties of functional layers for turbo engines.Micro-structure inter- and intra- facial changes gradually induced in ceramic structures are highlighted and on this basis their ranking and selection for application on physical parts are established.

  14. Thermal Protection System Aerothermal Screening Tests in HYMETS Facility

    Science.gov (United States)

    Szalai, Christine E.; Beck, Robin A. S.; Gasch, Matthew J.; Alumni, Antonella I.; Chavez-Garcia, Jose F.; Splinter, Scott C.; Gragg, Jeffrey G.; Brewer, Amy

    2011-01-01

    The Entry, Descent, and Landing (EDL) Technology Development Project has been tasked to develop Thermal Protection System (TPS) materials for insertion into future Mars Entry Systems. A screening arc jet test of seven rigid ablative TPS material candidates was performed in the Hypersonic Materials Environmental Test System (HYMETS) facility at NASA Langley Research Center, in both an air and carbon dioxide test environment. Recession, mass loss, surface temperature, and backface thermal response were measured for each test specimen. All material candidates survived the Mars aerocapture relevant heating condition, and some materials showed a clear increase in recession rate in the carbon dioxide test environment. These test results supported subsequent down-selection of the most promising material candidates for further development.

  15. Thermal Protection Materials and Systems: Past, Present, and Future

    Science.gov (United States)

    Johnson, Sylvia M.

    2013-01-01

    Thermal protection materials and systems (TPS) protect vehicles from the heat generated when entering a planetary atmosphere. NASA has developed many TPS systems over the years for vehicle ranging from planetary probes to crewed vehicles. The goal for all TPS is efficient and reliable performance. Efficient means using the right material for the environment and minimizing the mass of the heat shield without compromising safety. Efficiency is critical if the payload such as science experiments is to be maximized on a particular vehicle. Reliable means that we understand and can predict performance of the material. Although much characterization and testing of materials is performed to qualify and certify them for flight, it is not possible to completely recreate the reentry conditions in test facilities, and flight-testing

  16. Experimental study on a transpiration cooling thermal protection system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Transpiration cooling thermal protection systems (TPS) are investigated for potential applications in hypersonic and re-entry vehicles,which are subjected to the severe aerodynamic heating environment. In this paper a transpiration cooling thermal protection system was designed and manufactured,and an experiment platform with radiant heating at the bottom as heat source was developed. The cooling capacity of the transpiration cooling TPS was experimentally investigated. By combining transpiration cooling method with traditional TPS,the heat load capability of the TPS can be improved. The structure temperature with active cooling applied was much lower than that without active cooling applied under the same heat load as well as the heat load increased with active cooling than the one without active cooling for the same structure temperature. The experimental results showed that at 5800 s,the temperature of inner structure was 100°C with active cooling applied compared to 500°C without active cooling applied,then the temperature increased and reached to 360°C at 8300 s. Heat load of this transpiration cooling TPS can be increased by over 70% as compared to the passion one and the cooling capability of the transpiration TPS was about 1700 kJ/kg. The results can provide fundamental data for developing the transpiration cooling TPS.

  17. Ballistic performance of porous-ceramic, thermal protection systems

    Science.gov (United States)

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

    2012-03-01

    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/ft3 alumina-fiber-enhanced-thermal-barrier (AETB8) tiles coated with a toughened-unipiece-fibrousinsulation/ reaction-cured-glass layer (TUFI/RCG). A semi-empirical, first principles 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.

  18. Thermal Cycling Assessment of Steel-Based Thermal Barrier Coatings for Al Protection

    Science.gov (United States)

    Poirier, Dominique; Lamarre, Jean-Michel; Legoux, Jean-Gabriel

    2015-01-01

    There is a strong interest from the transportation industry to achieve vehicle weight reduction through the replacement of steel components by aluminum parts. For some applications, aluminum requires protective coatings due to its limited wear and lower temperature resistance compared to steel. The objective of this study was to assess the potential of amorphous-type plasma-sprayed steel coatings and conventional arc-sprayed steel coatings as thermal barrier coatings, mainly through the evaluation of their spalling resistance under thermal cycling. The microstructures of the different coatings were first compared via SEM. The amorphicity of the coatings produced via plasma spraying of specialized alloyed steel and the crystalline phases of the conventional arc-sprayed steel coatings were confirmed through x-ray diffraction. The thermal diffusivity of all coatings produced was measured to be about a third of that of bulk stainless steel. Conventional arc-sprayed steel coatings typically offered better spalling resistance under thermal cycling than steel-based amorphous coatings due probably to their higher initial bond strength. However, the presence of vertical cracks in the steel-based amorphous coatings was found to have a beneficial effect on their thermal cycling resistance. The amorphous plasma-sprayed steel coatings presented indications of recrystallization after their exposure to high temperature.

  19. Biologically-Derived Photonic Materials for Thermal Protection Systems

    Science.gov (United States)

    Johnson, Sylvia M.; Squire, Thomas H.; Lawson, John W.; Gusman, Michael; Lau, K.-H.; Sanjurjo, Angel

    2014-01-01

    Space vehicles entering a planetary atmosphere at high velocity can be subject to substantial radiative heating from the shock layer in addition to the convective heating caused by the flow of hot gas past the vehicle surface. The radiative component can be very high but of a short duration. Approaches to combat this effect include investigation of various materials to reflect the radiation. Photonic materials can be used to reflect radiation. The wavelengths reflected depend on the length scale of the ordered microstructure. Fabricating photonic structures, such as layers, can be time consuming and expensive. We have used a biologically-derived material as the template for forming a high temperature photonic material that could be incorporated into a heatshield thermal protection material.

  20. 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.

  1. Thermal decomposition of fullerene nanowhiskers protected by amorphous carbon mask

    Science.gov (United States)

    Guo, Hongxuan; Wang, Chengxiang; Miyazawa, Kun’Ichi; Wang, Hongxin; Masuda, Hideki; Fujita, Daisuke

    2016-12-01

    Fullerene nanostructures are well known for their unique morphology, physical and mechanical properties. The thermal stability of fullerene nanostructures, such as their sublimation at high temperature is also very important for studying their structures and applications. In this work, We observed fullerene nanowhiskers (FNWs) in situ with scanning helium ion microscopy (HIM) at elevated temperatures. The FNWs exhibited different stabilities with different thermal histories during the observation. The pristine FNWs were decomposed at the temperatures higher than 300 °C in a vacuum environment. Other FNWs were protected from decomposition with an amorphous carbon (aC) film deposited on the surface. Based on high spacial resolution, aC film with periodic structure was deposited by helium ion beam induced deposition (IBID) on the surface of FNWs. Annealed at the high temperature, the fullerene molecules were selectively sublimated from the FNWs. The periodic structure was formed on the surface of FNWs and observed by HIM. Monte Carlo simulation and Raman characterization proved that the morphology of the FNWs was changed by helium IBID at high temperature. This work provides a new method of fabricating artificial structure on the surface of FNWs with periodic aC film as a mask.

  2. Modern air protection technologies at thermal power plants (review)

    Science.gov (United States)

    Roslyakov, P. V.

    2016-07-01

    Realization of the ecologically safe technologies for fuel combustion in the steam boiler furnaces and the effective ways for treatment of flue gases at modern thermal power plants have been analyzed. The administrative and legal measures to stimulate introduction of the technologies for air protection at TPPs have been considered. It has been shown that both the primary intrafurnace measures for nitrogen oxide suppression and the secondary flue gas treatment methods are needed to meet the modern ecological standards. Examples of the environmentally safe methods for flame combustion of gas-oil and solid fuels in the boiler furnaces have been provided. The effective methods and units to treat flue gases from nitrogen and sulfur oxides and flue ash have been considered. It has been demonstrated that realization of the measures for air protection should be accompanied by introduction of the systems for continuous instrumentation control of the composition of combustion products in the gas path of boiler units and for monitoring of atmospheric emissions.

  3. Hypervelocity Impact Test Results for a Metallic Thermal Protection System

    Science.gov (United States)

    Karr, Katherine L.; Poteet, Carl C.; Blosser, Max L.

    2003-01-01

    Hypervelocity impact tests have been performed on specimens representing metallic thermal protection systems (TPS) developed at NASA Langley Research Center for use on next-generation reusable launch vehicles (RLV). The majority of the specimens tested consists of a foil gauge exterior honeycomb panel, composed of either Inconel 617 or Ti-6Al-4V, backed with 2.0 in. of fibrous insulation and a final Ti-6Al-4V foil layer. Other tested specimens include titanium multi-wall sandwich coupons as well as TPS using a second honeycomb sandwich in place of the foil backing. Hypervelocity impact tests were performed at the NASA Marshall Space Flight Center Orbital Debris Simulation Facility. An improved test fixture was designed and fabricated to hold specimens firmly in place during impact. Projectile diameter, honeycomb sandwich material, honeycomb sandwich facesheet thickness, and honeycomb core cell size were examined to determine the influence of TPS configuration on the level of protection provided to the substructure (crew, cabin, fuel tank, etc.) against micrometeoroid or orbit debris impacts. Pictures and descriptions of the damage to each specimen are included.

  4. Sustainable Non-Metallic Building Materials

    Directory of Open Access Journals (Sweden)

    Svetlana Tretsiakova-McNally

    2010-01-01

    Full Text Available Buildings are the largest energy consumers and greenhouse gases emitters, both in the developed and developing countries. In continental Europe, the energy use in buildings alone is responsible for up to 50% of carbon dioxide emission. Urgent changes are, therefore, required relating to energy saving, emissions control, production and application of materials, use of renewable resources, and to recycling and reuse of building materials. In addition, the development of new eco-friendly building materials and practices is of prime importance owing to the growing environmental concerns. This review reflects the key tendencies in the sector of sustainable building materials of a non-metallic nature that have occurred over the past decade or so.

  5. Flexible Transpiration Cooled Thermal Protection System for Inflatable Atmospheric Capture and Entry Systems Project

    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...

  6. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    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...

  7. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    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). Among the...

  8. Graded Density Carbon Bonded Carbon Fiber (CBCF) Preforms for Lightweight Ablative Thermal Protection Systems (TPS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FMI currently manufactures Phenolic Impregnated Carbon Ablator (PICA) material for Thermal Protection Systems (TPS) systems, such as the Stardust Sample Return...

  9. Novel Fabrication Approach for SiC/SiC Thermal Protection System Elements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Durable high temperature materials are required for structural thermal protection systems (TPS) that exhibit a structural load carrying capability at temperatures in...

  10. Evaluation of protective ensemble thermal characteristics through sweating hot plate, sweating thermal manikin, and human tests.

    Science.gov (United States)

    Kim, Jung-Hyun; Powell, Jeffery B; Roberge, Raymond J; Shepherd, Angie; Coca, Aitor

    2014-01-01

    The purpose of this study was to evaluate the predictive capability of fabric Total Heat Loss (THL) values on thermal stress that Personal Protective Equipment (PPE) ensemble wearers may encounter while performing work. A series of three tests, consisting of the Sweating Hot Plate (SHP) test on two sample fabrics and the Sweating Thermal Manikin (STM) and human performance tests on two single-layer encapsulating ensembles (fabric/ensemble A = low THL and B = high THL), was conducted to compare THL values between SHP and STM methods along with human thermophysiological responses to wearing the ensembles. In human testing, ten male subjects performed a treadmill exercise at 4.8 km and 3% incline for 60 min in two environmental conditions (mild = 22°C, 50% relative humidity (RH) and hot/humid = 35°C, 65% RH). The thermal and evaporative resistances were significantly higher on a fabric level as measured in the SHP test than on the ensemble level as measured in the STM test. Consequently the THL values were also significantly different for both fabric types (SHP vs. STM: 191.3 vs. 81.5 W/m(2) in fabric/ensemble A, and 909.3 vs. 149.9 W/m(2) in fabric/ensemble B (p values are significantly different from the actual THL potential of the PPE ensemble tested on STM, (2) physiological benefits from wearing a more breathable PPE ensemble may not be feasible with incremental THL values (SHP test) less than approximately 150-200 W·m(2), and (3) the effects of thermal environments on a level of heat stress in PPE ensemble wearers are greater than ensemble thermal characteristics.

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

    Science.gov (United States)

    Su, Yun; Li, Jun

    2016-12-01

    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.

  12. 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.

  13. Multifunctional Aerogel Thermal Protection Systems for Hypersonic Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The push to hypersonic flight regimes requires novel materials that are lightweight as well as thermally and structurally efficient for airframes and thermal...

  14. A computer controlled mass spectrometer system for investigating the decomposition of non-metallic materials under atmospheric conditions

    Science.gov (United States)

    Thompson, J. M.

    1985-01-01

    A PDP 11/23 quadrupole mass spectrometer system was coupled to a nondiscriminating gas inlet system permitting gases at atmospheric pressure to be admitted into a high vacuum chamber containing the ion source of the mass spectrometer without separation of the gaseous components. The resolution of related software problems has resulted in a convenient computer-mass spectrometer system capable of generating masses, relative intensities and related data on the gaseous products resulting from the atmospheric thermal decomposition of nonmetallic materials.

  15. A computer controlled mass spectrometer system for investigating the decomposition of non-metallic materials under atmospheric conditions

    Science.gov (United States)

    Thompson, J. M.

    1985-01-01

    A PDP 11/23 quadrupole mass spectrometer system was coupled to a nondiscriminating gas inlet system permitting gases at atmospheric pressure to be admitted into a high vacuum chamber containing the ion source of the mass spectrometer without separation of the gaseous components. The resolution of related software problems has resulted in a convenient computer-mass spectrometer system capable of generating masses, relative intensities and related data on the gaseous products resulting from the atmospheric thermal decomposition of nonmetallic materials.

  16. Thermal degradation study of silicon carbide threads developed for advanced flexible thermal protection systems

    Science.gov (United States)

    Tran, Huy Kim; Sawko, Paul M.

    1992-01-01

    Silicon carbide (SiC) fiber is a material that may be used in advanced thermal protection systems (TPS) for future aerospace vehicles. SiC fiber's mechanical properties depend greatly on the presence or absence of sizing and its microstructure. In this research, silicon dioxide is found to be present on the surface of the fiber. Electron Spectroscopy for Chemical Analysis (ESCA) and Scanning Electron Microscopy (SEM) show that a thin oxide layer (SiO2) exists on the as-received fibers, and the oxide thickness increases when the fibers are exposed to high temperature. ESCA also reveals no evidence of Si-C bonding on the fiber surface on both as-received and heat treated fibers. The silicon oxide layer is thought to signal the decomposition of SiC bonds and may be partially responsible for the degradation in the breaking strength observed at temperatures above 400 C. The variation in electrical resistivity of the fibers with increasing temperature indicates a transition to a higher band gap material at 350 to 600 C. This is consistent with a decomposition of SiC involving silicon oxide formation.

  17. On-Orbit Health Monitoring and Repair Assessment of Thermal Protection Systems Project

    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...

  18. Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability

    NARCIS (Netherlands)

    Bröde, P.; Kuklane, K.; Candas, V.; Hartog, E.A. den; Griefahn, B.; Holmér, I.; Meinander, H.; Nocker, W.; Richards, M.; Havenith, G.

    2010-01-01

    The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were

  19. In-Situ Real-Time Temperature Monitoring of Thermal Protection Systems Project

    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...

  20. Non-metallic inclusions in high manganese austenitic alloys

    OpenAIRE

    A. Grajcar; L. Bulkowski; U. Galisz

    2011-01-01

    Purpose: The aim of the paper is to identify the type, fraction and chemical composition of non-metallic inclusions modified by rare-earth elements in an advanced group of high-manganese austenitic C-Mn-Si-Al-type steels with Nb and Ti microadditions.Design/methodology/approach: The heats of 3 high-Mn steels of a various content of Si, Al and Ti were melted in a vacuum induction furnace and a modification of non-metallic inclusions was carried out by the mischmetal in the amount of 0.87 g or ...

  1. Uses of Advanced Ceramic Composites in the Thermal Protection Systems of Future Space Vehicles

    Science.gov (United States)

    Rasky, Daniel J.

    1994-01-01

    Current ceramic composites being developed and characterized for use in the thermal protection systems (TPS) of future space vehicles are reviewed. The composites discussed include new tough, low density ceramic insulation's, both rigid and flexible; ultra-high temperature ceramic composites; nano-ceramics; as well as new hybrid ceramic/metallic and ceramic/organic systems. Application and advantage of these new composites to the thermal protection systems of future reusable access to space vehicles and small spacecraft is reviewed.

  2. Orion Flight Test-1 Thermal Protection System Instrumentation

    Science.gov (United States)

    Kowal, T. John

    2011-01-01

    The Orion Crew Exploration Vehicle (CEV) was originally under development to provide crew transport to the International Space Station after the retirement of the Space Shuttle, and to provide a means for the eventual return of astronauts to the Moon. With the current changes in the future direction of the United States human exploration programs, the focus of the Orion project has shifted to the project s first orbital flight test, designated Orion Flight Test 1 (OFT-1). The OFT-1 is currently planned for launch in July 2013 and will demonstrate the Orion vehicle s capability for performing missions in low Earth orbit (LEO), as well as extensibility beyond LEO for select, critical areas. Among the key flight test objectives are those related to validation of the re-entry aerodynamic and aerothermal environments, and the performance of the thermal protection system (TPS) when exposed to these environments. A specific flight test trajectory has been selected to provide a high energy entry beyond that which would be experienced during a typical low Earth orbit return, given the constraints imposed by the possible launch vehicles. This trajectory resulted from a trade study that considered the relative benefit of conflicting objectives from multiple subsystems, and sought to provide the maximum integrated benefit to the re-entry state-of-the-art. In particular, the trajectory was designed to provide: a significant, measureable radiative heat flux to the windward surface; data on boundary transition from laminar to turbulent flow; and data on catalytic heating overshoot on non-ablating TPS. In order to obtain the necessary flight test data during OFT-1, the vehicle will need to have an adequate quantity of instrumentation. A collection of instrumentation is being developed for integration in the OFT-1 TPS. In part, this instrumentation builds upon the work performed for the Mars Science Laboratory Entry, Descent and Landing Instrument (MEDLI) suite to instrument the

  3. A radiant heating test facility for space shuttle orbiter thermal protection system certification

    Science.gov (United States)

    Sherborne, W. D.; Milhoan, J. D.

    1980-01-01

    A large scale radiant heating test facility was constructed so that thermal certification tests can be performed on the new generation of thermal protection systems developed for the space shuttle orbiter. This facility simulates surface thermal gradients, onorbit cold-soak temperatures down to 200 K, entry heating temperatures to 1710 K in an oxidizing environment, and the dynamic entry pressure environment. The capabilities of the facility and the development of new test equipment are presented.

  4. New technology for recovering residual metals from nonmetallic fractions of waste printed circuit boards.

    Science.gov (United States)

    Zhang, Guangwen; He, Yaqun; Wang, Haifeng; Zhang, Tao; Wang, Shuai; Yang, Xing; Xia, Wencheng

    2017-03-23

    Recycling of waste printed circuit boards is important for environmental protection and sustainable resource utilization. Corona electrostatic separation has been widely used to recycle metals from waste printed circuit boards, but it has poor separation efficiency for finer sized fractions. In this study, a new process of vibrated gas-solid fluidized bed was used to recycle residual metals from nonmetallic fractions, which were treated using the corona electrostatic separation technology. The effects of three main parameters, i.e., vibration frequency, superficial air flow velocity, and fluidizing time on gravity segregation, were investigated using a vibrating gas-solid fluidized bed. Each size fraction had its own optimum parameters. Corresponding to their optimal segregation performance, the products from each experiment were analyzed using an X-ray fluorescence (XRF) and a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). From the results, it can be seen that the metal recoveries of -1+0.5mm, -0.5+0.25mm, and -0.25mm size fractions were 86.39%, 82.22% and 76.63%, respectively. After separation, each metal content in the -1+0.5 or -0.5+0.25mm size fraction reduced to 1% or less, while the Fe and Cu contents are up to 2.57% and 1.50%, respectively, in the -0.25mm size fraction. Images of the nonmetallic fractions with a size of -0.25mm indicated that a considerable amount of clavate glass fibers existed in these nonmetallic fractions, which may explain why fine particles had the poorest segregation performance.

  5. Interaction mechanism of non-metallic particles with crystallization front

    Directory of Open Access Journals (Sweden)

    Żak P. L.

    2017-03-01

    Full Text Available The process of steel solidification in the CCS mould is accompanied by a number of phenomena relating to the formation of non-metallic phase, as well as the mechanism of its interaction with the existing precipitations and the advancing crystallization front. In the solidification process the non-metallic inclusions may be absorbed or repelled by the moving front. As a result a specific distribution of non-metallic inclusions is obtained in the solidified ingot, and their distribution is a consequence of these processes. The interaction of a non-metallic inclusion with the solidification front was analyzed for alumina, for different values of the particle radius. The simulation was performed with the use of own computer program. Each time a balance of forces acting on a particle in its specific position was calculated. On this basis the change of position of alumina particle in relation to the front was defined for a specific radius and original location of the particle with respect to the front.

  6. Test plan for the irradiation of nonmetallic materials.

    Energy Technology Data Exchange (ETDEWEB)

    Brush, Laurence H.; Farnum, Cathy Ottinger; Dahl, M.; Joslyn, C. C.; Venetz, T. J.

    2013-05-01

    A comprehensive test program to evaluate nonmetallic materials use in the Hanford tank farms is described in detail. This test program determines the effects of simultaneous multiple stressors at reasonable conditions on in-service configuration components by engineering performance testing.

  7. Test plan for the irradiation of nonmetallic materials.

    Energy Technology Data Exchange (ETDEWEB)

    Brush, Laurence H.; Farnum, Cathy Ottinger; Gelbard, Fred; Dahl, M.; Joslyn, C. C.; Venetz, T. J.

    2013-03-01

    A comprehensive test program to evaluate nonmetallic materials use in the Hanford Tank Farms is described in detail. This test program determines the effects of simultaneous multiple stressors at reasonable conditions on in-service configuration components by engineering performance testing.

  8. Coating effects on thermal properties of carbon carbon and carbon silicon carbide composites for space thermal protection systems

    Science.gov (United States)

    Albano, M.; Morles, R. B.; Cioeta, F.; Marchetti, M.

    2014-06-01

    Many are the materials for hot structures, but the most promising one are the carbon based composites nowadays. This is because they have good characteristics with a high stability at high temperatures, preserving their mechanical properties. Unfortunately, carbon reacts rapidly with oxygen and the composites are subjected to oxidation degradation. From this point of view CC has to be modified in order to improve its thermal and oxidative resistance. The most common solutions are the use of silicon carbide into the carbon composites matrix (SiC composites) to make the thermal properties increase and the use of coating on the surface in order to protect the composite from the space plasma effects. Here is presented an experimental study on coating effects on these composites. Thermal properties of coated and non coated materials have been studied and the thermal impact on the matrix and surface degradation is analyzed by a SEM analysis.

  9. 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.

  10. Solution behavior of hydrogen isotopes and other non-metallic elements in liquid lithium

    Energy Technology Data Exchange (ETDEWEB)

    Maroni, V.A.; Calaway, W.F.; Veleckis, E.; Yonco, R.M.

    1976-01-01

    Results of experimental studies to measure selected thermodynamic properties for systems of lithium with non-metallic elements are reported. Investigations of the Li-H, Li-D, and Li-T systems have led to the elucidation of the dilute solution behavior and the H/D/T isotope effects. In the case of the Li-H and Li-D systems, the principal features of the respective phase diagrams have been delineated. The solubility of Li-D in liquid lithium has been measured down to 200/sup 0/C. The solubility of Li/sub 3/N in liquid lithium and the thermal decomposition of Li/sub 3/N have also been studied. From these data, the free energy of formation of Li/sub 3/N and the Sieverts' constant for dissolution of nitrogen in lithium have been determined. Based on studies of the distribution of non-metallic elements between liquid lithium and selected molten salts, it appears that molten salt extraction offers promise as a means of removing these impurity elements (e.g., H, D, T, O, N, C) from liquid lithium.

  11. PVC-based composite material containing recycled non-metallic printed circuit board (PCB) powders.

    Science.gov (United States)

    Wang, Xinjie; Guo, Yuwen; Liu, Jingyang; Qiao, Qi; Liang, Jijun

    2010-12-01

    The study is directed to the use of non-metallic powders obtained from comminuted recycled paper-based printed circuit boards (PCBs) as an additive to polyvinyl chloride (PVC) substrate. The physical properties of the non-metallic PCB (NMPCB) powders were measured, and the morphological, mechanical and thermal properties of the NMPCB/PVC composite material were investigated. The results show that recycled NMPCB powders, when added below a threshold, tended to increase the tensile strength and bending strength of PVC. When 20 wt% NMPCB powders (relative to the substrate PVC) of an average diameter of 0.08 mm were added, the composite tensile strength and bending strength reached 22.6 MPa and 39.83 MPa, respectively, representing 107.2% and 123.1% improvement over pure PVC. The elongation at break of the composite material reached 151.94% of that of pure PVC, while the Vicat softening temperature of the composite material did not increase significantly compared to the pure PVC. The above results suggest that paper-based NMPCB powders, when used at appropriate amounts, can be effective for toughening PVC. Thus, this study suggests a new route for reusing paper-based NMPCB, which may have a significant beneficial environmental impact.

  12. Multidimensional Testing of Thermal Protection Materials in the Arcjet Test Facility

    Science.gov (United States)

    Agrawal, Parul; Ellerby, Donald T.; Switzer, Matt R.; Squire, Thomas Howard

    2010-01-01

    Many thermal protection system materials used for spacecraft heatshields have anisotropic thermal properties, causing them to display significantly different thermal characteristics in different directions, when subjected to a heating environment during flight or arcjet tests. The anisotropic effects are enhanced in the presence of sidewall heating. This paper investigates the effects of anisotropic thermal properties of thermal protection materials coupled with sidewall heating in the arcjet environment. Phenolic Impregnated Carbon Ablator (PICA) and LI-2200 materials (the insulation material of Shuttle tiles) were used for this study. First, conduction-based thermal response simulations were carried out, using the Marc.Mentat finite element solver, to study the effects of sidewall heating on PICA arcjet coupons. The simulation showed that sidewall heating plays a significant role in thermal response of these models. Arcjet tests at the Aerodynamic Heating Facility (AHF) at NASA Ames Research Center were performed later on instrumented coupons to obtain temperature history at sidewall and various radial locations. The details of instrumentation and experimental technique are the prime focus of this paper. The results obtained from testing confirmed that sidewall heating plays a significant role in thermal response of these models. The test results were later used to validate the two-dimensional ablation, thermal response, and sizing program, TITAN. The test data and model predictions were found to be in excellent agreement

  13. Multidimensional Tests of Thermal Protection Materials in the Arcjet Test Facility

    Science.gov (United States)

    Agrawal, Parul; Ellerby, Donald T.; Switzer, Mathew R.; Squire, Thomas H.

    2010-01-01

    Many thermal protection system materials used for spacecraft heatshields have anisotropic thermal properties, causing them to display significantly different thermal characteristics in different directions, when subjected to a heating environment during flight or arcjet tests. This paper investigates the effects of sidewall heating coupled with anisotropic thermal properties of thermal protection materials in the arcjet environment. Phenolic Impregnated Carbon Ablator (PICA) and LI-2200 materials (the insulation material of Shuttle tiles) were used for this study. First, conduction-based thermal response simulations were carried out, using the Marc.Mentat finite element solver, to study the effects of sidewall heating on PICA arcjet coupons. The simulation showed that sidewall heating plays a significant role in thermal response of these models. Arcjet tests at the Aerodynamic Heating Facility (AHF) at NASA Ames Research Center were performed later on instrumented coupons to obtain temperature history at sidewall and various radial locations. The details of instrumentation and experimental technique are the prime focus of this paper. The results obtained from testing confirmed that sidewall heating plays a significant role in thermal response of these models. The test results were later used to verify the two-dimensional ablation, thermal response, and sizing program, TITAN. The test data and model predictions were found to be in excellent agreement

  14. Transient thermal protection of film covering circular aperture by sublimation and weak decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Havstad, Mark A.; Miles, Robin R.; Hsieh, Henry, E-mail: hsieh6@llnl.gov

    2015-03-15

    Highlights: • Precise sublimating layers can provide protection in transient thermal environments. • Sensitivity analysis shows that the uncertainty in properties has modest influence. • It is likely that methane layers are a good choice for IFE targets. - Abstract: Unwanted heating of sensitive surfaces in harsh thermal environments can be prevented by precise application of sacrificial materials such as sublimation layers and pyrolyzing films. The use of sublimation for the protection of circular polyimide membranes subjected to brief (∼100 ms) heating by infrared radiation and hot (6000 K) inert gas convection is analyzed. Selection of sublimation material and sublimation layer and membrane thickness is considered with emphasis on providing sufficient thermal protection yet negligible unwanted material remaining at the end of a specified heating period. Though the analysis here is general, the motivation is protection of the polyimide films covering the laser entrance holes on IFE (inertial fusion energy) hohlraums being injected into the hot gas (xenon) protecting IFE reactor chambers. Both one and two dimensional thermal models are used to develop a robust thermal concept. Sensitivity analyses (SA) methods are exercised to show where the design may be vulnerable and which input parameters have the greatest effect on performance and likelihood of success. For the design and conditions considered, methane sublimating layers are probably preferred over xenon or pentane.

  15. The effect of various cosmetic pretreatments on protecting hair from thermal damage by hot flat ironing.

    Science.gov (United States)

    Zhou, Y; Rigoletto, R; Koelmel, D; Zhang, G; Gillece, T W; Foltis, L; Moore, D J; Qu, X; Sun, C

    2011-01-01

    Hot flat irons are used to create straight hair styles. As these devices operate at temperatures over 200 °C they can cause significant damage to hair keratin. In this study, hair thermal damage and the effect of various polymeric pretreatments were investigated using FTIR imaging spectroscopy, DSC, dynamic vapor sorption (DVS), AFM, SEM, and thermal image analysis. FTIR imaging spectroscopy of hair cross sections provides spatially resolved molecular information such as protein distribution and structure. This approach was used to monitor thermally induced modification of hair protein, including the conversion of α-helix to β-sheet and protein degradation. DSC measurements of thermally treated hair also demonstrated degradation of hair keratin. DVS of thermally treated hair shows the reduced water regain and lower water retention, compared to the non-thermally treated hair, which might be attributed to the protein conformation changes due to heat damage. The protection of native protein structure associated with selected polymer pretreatments leads to improved moisture restoration and water retention of hair. This contributes to heat control on repeated hot flat ironing. Thermally stressing hair led to significantly increased hair breakage when subjected to combing. These studies indicate that hair breakage can be reduced significantly when hair is pretreated with selected polymers such as VP/acrylates/lauryl methacrylate copolymer, polyquaternium-55, and a polyelectrolyte complex of PVM/MA copolymer and polyquaternium-28. In addition, polymeric pretreatments provide thermal protection against thermal degradation of keratin in the cortex as well as hair surface damage. The morphological improvement in cuticle integrity and smoothness with the polymer pretreatment plays an important role in their anti-breakage effect. Insights into structure-property relationships necessary to provide thermal protection to hair are presented.

  16. Thermal protection mechanism of heat pipe in leading edge under hypersonic conditions

    OpenAIRE

    Peng Wengen; He Yurong; Wang Xinzhi; Zhu Jiaqi; Han Jiecai

    2015-01-01

    Sharp local structure, like the leading edge of hypersonic aircraft, confronts a severe aerodynamic heating environment at a Mach number greater than 5. To eliminate the danger of a material failure, a semi-active thermal protection system is proposed by integrating a metallic heat pipe into the structure of the leading edge. An analytical heat-balance model is established from traditional aerodynamic theories, and then thermal and mechanical characteristics of the structure are studied at Ma...

  17. Thermal resistance testing of standard and protective filtering military garment on the burning napalm mixture

    Directory of Open Access Journals (Sweden)

    Rajić Dušan S.

    2013-01-01

    Full Text Available Fires are an accompanying manifestation in modern weaponry use and in case of different accidents in peacetime. The standard military uniform is a primary barrier in protection of a soldier’s body from all external influences, including the thermal ones which can cause burns. The minimum thermal resistance to the effect of burning napalm mixture (BNM in individual uniform garment materials has been determined, and is higher at simultaneous use of more materials one over another (the so-called sandwich materials, where the best thermal protection give sandwich materials with an air interspace. The requirement for the thermal resistance of the material of the filtrating protective suit (FPS to the effect of BNM (≥ 15 s has been fully met. The highest thermal resistance has been demonstrated by the FPS whose inner layer is made of polyurethane foam with active carbon. A proportional dependence between the thermal resistance of FPS to the effect of BNM and water vapor permeability through this garment mean has been determined, and reversed in respect to air permeability. [Projekat Ministarstva nauke Republike Srbije, br. TR34034

  18. Cutting of nonmetallic materials using Nd:YAG laser beam

    Institute of Scientific and Technical Information of China (English)

    Bashir Ahmed Tahir; Rashid Ahmed; M. G. B. Ashiq; Afaq Ahmed; M. A. Saeed

    2012-01-01

    This study deals with Nd:YAG laser cutting nonmetallic materials,which is one of the most important and popular industrial applications of laser.The main theme is to evaluate the effects of Nd:YAG laser beam power besides work piece scanning speed.For approximate cutting depth,a theoretical study is conducted in terms of material property and cutting speed.Results show a nonlinear relation between the cutting depth and input energy.There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s.An extra energy is utilized in the deep cutting.It is inferred that as the laser power increases,cutting depth increases.The experimental outcomes are in good agreement with theoretical results.This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting,scribing,trimming,engraving,and marking nonmetallic materials.

  19. Synthesis of aromatic nitriles using nonmetallic cyano-group sources.

    Science.gov (United States)

    Kim, Jinho; Kim, Hyun Jin; Chang, Sukbok

    2012-11-26

    Aromatic nitriles are prepared efficiently through transition-metal-mediated cyanation of aryl (pseudo)halides with metallic cyano-group sources, such as CuCN, KCN, NaCN, Zn(CN)(2), TMSCN, or K(4) [Fe(CN)(6)]. However, this approach often suffers from drawbacks, such as the formation of stoichiometric amounts of metal waste, the poisoning of the metal catalysts, or the generation of toxic HCN gas. As a result, a range of "nonmetallic" organic cyano-group sources have been explored for the cyanation of aryl halides and arene C-H bonds. This Minireview summarizes types of nonmetallic cyano-group sources and their applications in the preparation of aryl nitriles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Earth Entry Requirements for Mars, Europa and Enceladus Sample Return Missions: A Thermal Protection System Perspective

    Science.gov (United States)

    Venkatapathy, Ethiraj; Gage, Peter; Ellerby, Don; Mahzari, Milad; Peterson, Keith; Stackpoole, Mairead; Young, Zion

    2016-01-01

    This oral presentation will be given at the 13th International Planetary Probe Workshop on June 14th, 2016 and will cover the drivers for reliability and the challenges faced in selecting and designing the thermal protection system (TPS). In addition, an assessment is made on new emerging TPS related technologies that could help with designs to meet the planetary protection requirements to prevent backward (Earth) contamination by biohazardous samples.

  1. Design of a Protection Thermal Energy Storage Using Phase Change Material Coupled to a Solar Receiver

    Science.gov (United States)

    Verdier, D.; Falcoz, Q.; Ferrière, A.

    2014-12-01

    Thermal Energy Storage (TES) is the key for a stable electricity production in future Concentrated Solar Power (CSP) plants. This work presents a study on the thermal protection of the central receiver of CSP plant using a tower which is subject to considerable thermal stresses in case of cloudy events. The very high temperatures, 800 °C at design point, impose the use of special materials which are able to resist at high temperature and high mechanical constraints and high level of concentrated solar flux. In this paper we investigate a TES coupling a metallic matrix drilled with tubes of Phase Change Material (PCM) in order to store a large amount of thermal energy and release it in a short time. A numerical model is developed to optimize the arrangement of tubes into the TES. Then a methodology is given, based from the need in terms of thermal capacity, in order to help the choice of the geometry.

  2. 77 FR 11598 - Thermal Overload Protection for Electric Motors on Motor-Operated Valves

    Science.gov (United States)

    2012-02-27

    ... COMMISSION Thermal Overload Protection for Electric Motors on Motor-Operated Valves AGENCY: Nuclear... for Electric Motors on Motor-Operated Valves.'' This regulatory guide describes a method acceptable to... devices that are integral with the motor starter for electric motors on motor-operated valves....

  3. Development of a Sheathed Miniature Aerothermal Reentry Thermocouple for Thermal Protection System Materials

    Science.gov (United States)

    Martinez, Edward R.; Weber, Carissa Tudryn; Oishi, Tomo; Santos, Jose; Mach, Joseph

    2011-01-01

    The Sheathed Miniature Aerothermal Reentry Thermocouple is a micro-miniature thermocouple for high temperature measurement in extreme environments. It is available for use in Thermal Protection System materials for ground testing and flight. This paper discusses the heritage, and design of the instrument. Experimental and analytical methods used to verify its performance and limitations are described.

  4. Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability

    NARCIS (Netherlands)

    Bröde, P.; Kuklane, K.; Candas, V.; Hartog, E.A. den; Griefahn, B.; Holmér, I.; Meinander, H.; Nocker, W.; Richards, M.; Havenith, G.

    2010-01-01

    The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considere

  5. 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.

  6. Self-Protection of Electrochemical Storage Devices via a Thermal Reversible Sol-Gel Transition.

    Science.gov (United States)

    Yang, Hui; Liu, Zhiyuan; Chandran, Bevita K; Deng, Jiyang; Yu, Jiancan; Qi, Dianpeng; Li, Wenlong; Tang, Yuxin; Zhang, Chenguang; Chen, Xiaodong

    2015-10-07

    Thermal self-protected intelligent electrochemical storage devices are fabricated using a reversible sol-gel transition of the electrolyte, which can decrease the specific capacitance and increase and enable temperature-dependent charging and discharging rates in the device. This work represents proof of a simple and useful concept, which shows tremendous promise for the safe and controlled power delivery in electrochemical devices.

  7. 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,…

  8. Advances in hypersonic vehicle synthesis with application to studies of advanced thermal protection system

    Science.gov (United States)

    Ardema, Mark D.

    1995-01-01

    This report summarizes the work entitled 'Advances in Hypersonic Vehicle Synthesis with Application to Studies of Advanced Thermal Protection Systems.' The effort was in two areas: (1) development of advanced methods of trajectory and propulsion system optimization; and (2) development of advanced methods of structural weight estimation. The majority of the effort was spent in the trajectory area.

  9. 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.

  10. On the development of a cooled metallic thermal protection system for spacecraft

    NARCIS (Netherlands)

    Buursink, J.

    2005-01-01

    To achieve a significant cost reduction for launch of payloads to space, it is essential that the launcher is reused to the largest possible extent, and that the maintenance and operations cost of this launcher are minimised. To achieve this, work is ongoing on metallic thermal protection systems (T

  11. Wireless Subsurface Microsensors for Health Monitoring of Thermal Protection Systems on Hypersonic Vehicles

    Science.gov (United States)

    Milos, Frank S.; Watters, David G.; Pallix, Joan B.; Bahr, Alfred J.; Huestis, David L.; Arnold, Jim (Technical Monitor)

    2001-01-01

    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 develop inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and SRI International to develop 'SensorTags,' radio frequency identification devices coupled with event-recording sensors, that can be embedded in the thermal protection system to monitor temperature or other quantities of interest. Two prototype SensorTag designs containing thermal fuses to indicate a temperature overlimit are presented and discussed.

  12. Woven Thermal Protection System (WTPS) a Novel Approach to Meet NASA's Most Demanding Reentry Missions

    Science.gov (United States)

    Stackpoole, Mairead

    2014-01-01

    NASA's future robotic missions to Venus and outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of current mid-density ablators (PICA or Avcoat). Therefore mission planners assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust Thermal Protection System (TPS) however its high density and thermal conductivity constrain mission planners to steep entries, high heat fluxes, pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose certification challenges in existing ground based test facilities. In 2012 the Game Changing Development Program in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This presentation will summarize maturation of the WTPS project.

  13. 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...

  14. 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.

  15. Performance of thermal-sprayed zinc anodes treated with humectants in cathodic protection systems

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Sophie J.; Covino, Bernard S., Jr.; Cramer, Stephen D.; Holcomb, Gordon R.; Russell, James H.; Bennett, John E. (JE Bennett Consulting Inc.); Milius, John K. (Corrosion Restoration Tech.); Cryer, Curtis B. (Oregon Dept. of Transportation); Soltesz, Steven M. (Oregon Dept. of Transportation)

    2001-01-01

    Thermal-sprayed Zn anodes are used for impressed current cathodic protection (ICCP) systems in Oregon's reinforced concrete coastal bridges to minimize corrosion damage. Thermal-sprayed Zn performs well as an ICCP anode but the voltage requirement can increase with increasing electrochemical age. It also performs well as a galvanic (GCP) anode but current output can decrease with increasing electrochemical age. Past research has shown that increasing moisture at the Zn anode-concrete interface improves the operation of the thermal-sprayed Zn anode. Humectants, hygroscopic materials that are applied to the surface of the Zn-anode, can increase the moisture at the zinc-concrete interface, thereby improving the performance and extending the anode service life. Results are given for humectant-treated (LiBr and LiNO3) thermal-sprayed Zn anodes used in the laboratory electrochemical aging studies and in field studies on the Yaquina Bay Bridge, Oregon, USA.

  16. Analytic estimation and numerical modeling of actively cooled thermal protection systems with nickel alloys

    Institute of Scientific and Technical Information of China (English)

    Wang Xinzhi; He Yurong; Zheng Yan; Ma Junju; H. Inaki Schlaberg

    2014-01-01

    Actively cooled thermal protection system has great influence on the engine of a hyper-sonic vehicle, and it is significant to obtain the thermal and stress distribution in the system. So an analytic estimation and numerical modeling are performed in this paper to investigate the behavior of an actively cooled thermal protection system. The analytic estimation is based on the electric analogy method and finite element analysis (FEA) is applied to the numerical simulation. Temper-ature and stress distributions are obtained for the actively cooled channel walls with three kinds of nickel alloys with or with no thermal barrier coating (TBC). The temperature of the channel wall with coating has no obvious difference from the one with no coating, but the stress with coating on the channel wall is much smaller than that with no coating. Inconel X-750 has the best charac-teristics among the three Ni-based materials due to its higher thermal conductivity, lower elasticity module and greater allowable stress. Analytic estimation and numerical modeling results are com-pared with each other and a reasonable agreement is obtained.

  17. Analytic estimation and numerical modeling of actively cooled thermal protection systems with nickel alloys

    Directory of Open Access Journals (Sweden)

    Wang Xinzhi

    2014-12-01

    Full Text Available Actively cooled thermal protection system has great influence on the engine of a hypersonic vehicle, and it is significant to obtain the thermal and stress distribution in the system. So an analytic estimation and numerical modeling are performed in this paper to investigate the behavior of an actively cooled thermal protection system. The analytic estimation is based on the electric analogy method and finite element analysis (FEA is applied to the numerical simulation. Temperature and stress distributions are obtained for the actively cooled channel walls with three kinds of nickel alloys with or with no thermal barrier coating (TBC. The temperature of the channel wall with coating has no obvious difference from the one with no coating, but the stress with coating on the channel wall is much smaller than that with no coating. Inconel X-750 has the best characteristics among the three Ni-based materials due to its higher thermal conductivity, lower elasticity module and greater allowable stress. Analytic estimation and numerical modeling results are compared with each other and a reasonable agreement is obtained.

  18. Ceramic-ceramic shell tile thermal protection system and method thereof

    Science.gov (United States)

    Riccitiello, Salvatore R. (Inventor); Smith, Marnell (Inventor); Goldstein, Howard E. (Inventor); Zimmerman, Norman B. (Inventor)

    1986-01-01

    A ceramic reusable, externally applied composite thermal protection system (TPS) is proposed. The system functions by utilizing a ceramic/ceramic upper shell structure which effectively separates its primary functions as a thermal insulator and as a load carrier to transmit loads to the cold structure. The composite tile system also prevents impact damage to the atmospheric entry vehicle thermal protection system. The composite tile comprises a structurally strong upper ceramic/ceramic shell manufactured from ceramic fibers and ceramic matrix meeting the thermal and structural requirements of a tile used on a re-entry aerospace vehicle. In addition, a lightweight high temperature ceramic lower temperature base tile is used. The upper shell and lower tile are attached by means effective to withstand the extreme temperatures (3000 to 3200F) and stress conditions. The composite tile may include one or more layers of variable density rigid or flexible thermal insulation. The assembly of the overall tile is facilitated by two or more locking mechanisms on opposing sides of the overall tile assembly. The assembly may occur subsequent to the installation of the lower shell tile on the spacecraft structural skin.

  19. Chemically modified thermal-spray zinc anodes for galvanic cathodic protection

    Energy Technology Data Exchange (ETDEWEB)

    Covino, B.S. Jr.; Bullard, S.J.; Holcomb, G.R.; Russell, J.H.; Cramer, S.D.; Bennett, J.E.; Laylor, H.M.

    1999-12-01

    Humectants, substances that promote the retention of moisture, were applied to new and previously aged thermal-sprayed Zn anodes to improve the performance of galvanic cathodic protection systems. Anodes on steel-reinforced concrete were treated with aqueous solutions of the humectants lithium nitrate (LiNO{sub 3}) and lithium bromide (LiBr). LiBr was the most beneficial humectant, increasing the average galvanic current density of new thermal-sprayed Zn anodes by as much as a factor of six.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Characterization of Textiles Used in Chefs' Uniforms for Protection Against Thermal Hazards Encountered in the Kitchen Environment.

    Science.gov (United States)

    Zhang, Han; McQueen, Rachel H; Batcheller, Jane C; Ehnes, Briana L; Paskaluk, Stephen A

    2015-10-01

    Within the kitchen the potential for burn injuries arising from contact with hot surfaces, flames, hot liquid, and steam hazards is high. The chef's uniform can potentially offer some protection against such burns by providing a protective barrier between the skin and the thermal hazard, although the extent to which can provide some protection is unknown. The purpose of this study was to examine whether fabrics used in chefs' uniforms were able to provide some protection against thermal hazards encountered in the kitchen. Fabrics from chefs' jackets and aprons were selected. Flammability of single- and multiple-layered fabrics was measured. Effect of jacket type, apron and number of layers on hot surface, hot water, and steam exposure was also measured. Findings showed that all of the jacket and apron fabrics rapidly ignited when exposed to a flame. Thermal protection against hot surfaces increased as layers increased due to more insulation. Protection against steam and hot water improved with an impermeable apron in the system. For wet thermal hazards increasing the number of permeable layers can decrease the level of protection due to stored thermal energy. As the hands and arms are most at risk of burn injury increased insulation and water-impermeable barrier in the sleeves would improve thermal protection with minimal compromise to overall thermal comfort.

  2. Phonon thermal transport in metallic glasses below 100 K

    Energy Technology Data Exchange (ETDEWEB)

    Matey, James Regis

    1978-01-01

    Measurements of the phonon thermal conductivity of a variety of metallic glasses were made. In each case, the temperature dependence and magnitude of the phonon thermal conductivity of the glassy metal was very similar to that characteristic of nonmetallic glasses. Variation of sound velocity measurements were made on a glassy palladium silicon alloy and a qualitative similarity was found between its behavior and the behavior of nonmetallic glasses. These findings and results from other laboratories have led to the conclusion that the localized excitations responsible for the anomalous behavior of nonmetallic glasses are also present in the metallic glasses.

  3. Non-metallic Inclusions in Continuously Cast Aluminum Killed Steels

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In aluminum killed steels, the size, shape, quantity and formation of non-metallic inclusions in ladle steel (before and after RH vacuum treatment) and in tundish as well as in slabs were studied by EPMA (Electron Probe Microanalysis) and by analyzing the total oxygen. The results showed that in the slabs the total oxygen was quite low and the inclusions discovered were mainly small-sized angular alumina inclusions. This indicates that most inclusions have been removed by floating out during the continuous casting process. In addition, the countermeasures were discussed to decrease the alumina inclusions in the slabs further.

  4. Testing theOdour Quality of Non-Metallic Materials

    Directory of Open Access Journals (Sweden)

    AVIJIT SINGH GANGWAR

    2014-10-01

    Full Text Available This report has been compiled on the completion of 3 week summer training at ICAT. It discusses about a very necessary and least popular part of the Automotive Industry i.e. Testing and Certification. It discusses about one of the government notified Testing body ICAT which is one of just 6 such organisations in India.This report deals with the odour quality testing of non-metallic materials that are used for automobile compartment and parts associated with the compartment.

  5. Research progress on thermal protection materials and structures of hypersonic vehicles

    Institute of Scientific and Technical Information of China (English)

    YANG Ya-zheng; YANG Jia-ling; FANG Dai-ning

    2008-01-01

    Hypersonic vehicles represent future trends of military equipments and play an important role in future war. Thermal protection materials and structures, which relate to the safety of hypersonic vehicles, are one of the most key techniques in design and manufacture of hypersonic vehicles. Among these materials and structures, such as metallic temperature protection structure, the temperature ceramics and carbon/carbon composites are usually adopted in design. The recent progresses of research and applica- tion of ultra-high temperature materials in preparation, oxidation resistance, mechanical and physical characterization are summarized.

  6. 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.

  7. Hybrid Carbon-Carbon Ablative Composites for Thermal Protection in Aerospace

    Directory of Open Access Journals (Sweden)

    P. Sanoj

    2014-01-01

    Full Text Available Composite materials have been steadily substituting metals and alloys due to their better thermomechanical properties. The successful application of composite materials for high temperature zones in aerospace applications has resulted in extensive exploration of cost effective ablative materials. High temperature heat shielding to body, be it external or internal, has become essential in the space vehicles. The heat shielding primarily protects the substrate material from external kinetic heating and the internal insulation protects the subsystems and helps to keep coefficient of thermal expansion low. The external temperature due to kinetic heating may increase to about maximum of 500°C for hypersonic reentry space vehicles while the combustion chamber temperatures in case of rocket and missile engines range between 2000°C and 3000°C. Composite materials of which carbon-carbon composites or the carbon allotropes are the most preferred material for heat shielding applications due to their exceptional chemical and thermal resistance.

  8. Multi-tube thermal fuse for nozzle protection from a flame holding or flashback event

    Science.gov (United States)

    Lacy, Benjamin Paul; Davis, Jr., Lewis Berkley; Johnson, Thomas Edward; York, William David

    2012-07-03

    A protection system for a pre-mixing apparatus for a turbine engine, includes: a main body having an inlet portion, an outlet portion and an exterior wall that collectively establish a fuel delivery plenum; and a plurality of fuel mixing tubes that extend through at least a portion of the fuel delivery plenum, each of the plurality of fuel mixing tubes including at least one fuel feed opening fluidly connected to the fuel delivery plenum; at least one thermal fuse disposed on an exterior surface of at least one tube, the at least one thermal fuse including a material that will melt upon ignition of fuel within the at least one tube and cause a diversion of fuel from the fuel feed opening to at least one bypass opening. A method and a turbine engine in accordance with the protection system are also provided.

  9. Thermal and Electrodynamic Risk of Residual Current Devices in the Case of Back-Up Protection by Overcurrent Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Stanisław Czapp

    2014-12-01

    Full Text Available Residual current operated circuit breakers without integral overcurrent protection should be back-up protected. As back-up protection devices, overcurrent circuit breakers are used. The maximum let-through energy and let-through current of the overcurrent devices were evaluated under laboratory conditions. The thermal and electrodynamic risk of residual current devices was analyzed.

  10. The Measurement of Hardness and Elastic Modulus of non-Metallic Inclusions in Steely Welding Joints

    Directory of Open Access Journals (Sweden)

    Ignatova Anna

    2015-08-01

    Full Text Available Trunk pipelines work under a cyclic dynamical mechanical load because when oil or gas is pumped, the pressure constantly changes - pulsates. Therefore, the fatigue phenomenon is a common reason of accidents. The fatigue phenomenon more often happens in the zone of non-metallic inclusions concentration. To know how the characteristics of nonmetallic inclusions influence the probability of an accident the most modern research methods should be used. It is determined with the help of the modern research methods that the accident rate of welded joints of pipelines is mostly influenced by their morphological type, composition and size of nonmetallic inclusions, this effect is more important than the common level of pollution by non-metallic inclusions. The article presents the results of the investigations of welded joints, obtained after the use of different common welding materials. We used the methods, described in the state standards: scanning electronic microscopy, spectral microprobe analysis and nano-indentation. We found out that non-metallic inclusions act like stress concentrators because they shrink, forming a blank space between metal and nonmetallic inclusions; it strengthens the differential properties on this boundary. Nonmetallic inclusion is not fixed, it can move. The data that we have received mean that during welded joints’ contamination (with non-metallic inclusions monitoring process, more attention should be paid to the content of definite inclusions, but not to total contamination.

  11. Analysis of gap heating due to stepped tiles in the shuttle thermal protection system

    Science.gov (United States)

    Petley, D. H.; Smith, D. M.; Edwards, C. L. W.; Carlson, A. B.

    1983-01-01

    Analytical methods used to investigate entry gap heating in the Shuttle orbiter thermal protection system are described. Analytical results are given for a fuselage lower-surface location and a wing lower-surface location. These are locations where excessive gap heating occurred on the first flight of the Shuttle. The results of a study to determine the effectiveness of a half-height ceramic fiber gap filler in preventing hot-gas flow in the tile gaps are also given.

  12. 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.

  13. 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).

  14. Impact of cabin environment on thermal protection system of crew hypersonic vehicle

    Science.gov (United States)

    Zhu, Xiao Wei; Zhao, Jing Quan; Zhu, Lei; Yu, Xi Kui

    2016-05-01

    Hypersonic crew vehicles need reliable thermal protection systems (TPS) to ensure their safety. Since there exists relative large temperature difference between cabin airflow and TPS structure, the TPS shield that covers the cabin is always subjected to a non-adiabatic inner boundary condition, which may influence the heat transfer characteristic of the TPS. However, previous literatures always neglected the influence of the inner boundary by assuming that it was perfectly adiabatic. The present work focuses on studying the impact of cabin environment on the thermal performance. A modified TPS model is created with a mixed thermal boundary condition to connect the cabin environment with the TPS. This helps make the simulation closer to the real situation. The results stress that cabin environment greatly influences the temperature profile inside the TPS, which should not be neglected in practice. Moreover, the TPS size can be optimized during the design procedure if taking the effect of cabin environment into account.

  15. Development of thermal protective seal for hot structure control surface actuator rod

    Science.gov (United States)

    Infed, F.; Handrick, K.; Lange, H.; Steinacher, A.; Weiland, S.; Wegmann, C.

    2012-01-01

    For the Intermediate eXperimental Vehicle (IXV) the deflection of the highly loaded body flap is performed by an actuator system which is connected to the body flap by a rod. Besides the thermal and mechanical loads the sealing of the inner vehicle against the possible leaking hot plasma is an important issue whereby the special challenge for the design results from the spatial movement of the rod. This requires a design consisting of different parts and various materials in order to satisfy the mechanical flexibility and the resistance to the thermal and mechanical loads under the aspect of reusability. This paper describes the MT Aerospace approach for the thermal protection system for the actuator as presented for the critical design review of IXV. The design is presented and described including all necessary performed analysis steps toward such a design.

  16. Electrochemical aging of humectant-treated thermal-sprayed zinc anodes for cathodic protection

    Energy Technology Data Exchange (ETDEWEB)

    Covino, B.S. Jr.; Holcomb, G.R.; Bullard, S.J.; Russell, J.H.; Cramer, S.D.; Bennett, J.E.; Laylor, H.M.

    1999-07-01

    Humectants, substances that promote the retention of moisture, were studied to determine their effectiveness in improving the performance and extending the service life of both new and previously-aged thermal-sprayed Zn anodes used in impressed current (ICCP) and galvanic cathodic protection (GCP) systems for steel-reinforced concrete structures. Potassium acetate, lithium nitrate, and lithium bromide were applied to a series of thermal-sprayed Zn-coated concrete slabs before starting the ICCP or GCP experiment. All of the humectants altered the behavior of the thermal-sprayed Zn anodes. LiNO{sub 3} was the most beneficial for ICCP anodes and LiBr was the most beneficial for GCP anodes. Circuit resistances for ICCP anodes and galvanic current density for GCP anodes are compared on the basis of electrochemical aging, humidity, and type of humectant.

  17. Protection of alodine coatings from thermal aging by removable polymer coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Wagstaff, Brett R. (.); Bradshaw, Robert W.; Whinnery, LeRoy L., Jr. (.,; .)

    2006-12-01

    Removable polymer coatings were evaluated as a means to suppress dehydration of Alodine chromate conversion coatings during thermal aging and thereby retain the corrosion protection afforded by Alodine. Two types of polymer coatings were applied to Alodine-treated panels of aluminum alloys 7075-T73 and 6061-T6 that were subsequently aged for 15 to 50 hours at temperatures between 135 F to 200 F. The corrosion resistance of the thermally aged panels was evaluated, after stripping the polymer coatings, by exposure to a standard salt-fog corrosion test and the extent of pitting of the polymer-coated and untreated panels compared. Removable polymer coatings mitigated the loss of corrosion resistance due to thermal aging experienced by the untreated alloys. An epoxide coating was more effective than a fluorosilicone coating as a dehydration barrier.

  18. Wireless Subsurface Sensors for Health Monitoring of Thermal Protection Systems on Hypersonic Vehicles

    Science.gov (United States)

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

    2001-01-01

    Health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles (RLVs) in order to reduce life cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to develop inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and industry partners to develop "wireless" devices that can be embedded in the thermal protection system to monitor temperature or other quantities of interest. These devices are sensors integrated with radio-frequency identification (RFID) microchips to enable non-contact communication of sensor data to an external reader that may be a hand-held scanner or a large portal. Both passive and active prototype devices have been developed. The passive device uses a thermal fuse to indicate the occurrence of excessive temperature. This device has a diameter under 0.13 cm. (suitable for placement in gaps between ceramic TPS tiles on an RLV) and can withstand 370 C for 15 minutes. The active device contains a small battery to provide power to a thermocouple for recording a temperature history during flight. The bulk of the device must be placed beneath the TPS for protection from high temperature, but the thermocouple can be placed in a hot location such as near the external surface.

  19. Analysis of thermal protection characteristics of a rectangular cell filled with PCM/air layer

    Energy Technology Data Exchange (ETDEWEB)

    Ho, C.J.; Chu, C.H. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Mechanical Engineering

    1995-12-31

    The present paper presents a numerical analysis concerning thermal protection characteristics of a rectangular composite cell filled with a solid-liquid phase change material (PCM) and air layer. Inside the composite cell the PCM layer is separated from air layer by a solid partition of negligible thickness. The buoyancy-induced flows developed in both the air-filled layer and the molten PCM zone inside the PCM layer were modeled as two-dimensional laminar Newtonian fluid flow adhering to the Boussinesq approximation. Meanwhile, two-dimensional conduction heat transfer was accounted for the unmelted solid PCM region. Delineation is made via a parametric simulation of the effects of the pertinent parameters: Ste (Stefan number), Sc (subcooling factor), Ra (Rayleigh number), aspect ratio of composite cell, A, and relative thickness ratio A{sub p}/A{sub a}, on the transient thermal protection performance of the composite cell. Results demonstrate that by means of the latent-heat absorption inside the PCM layer, heat penetration across the composite cell can be greatly retarded over an effective duration until a critical instant until the melting front of PCM reaches the partition wall. Such an effective thermal protection duration is found to be a strong function of Ra, Ste, A{sub p}/A{sub a}, and A.

  20. 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.

  1. Transient Analysis of Thermal Protection System for X-33 Aircraft using MSC/NASTRAN

    Science.gov (United States)

    Miura, Hirokazu; Chargin, M. K.; Bowles, J.; Tam, T.; Chu, D.; Chainyk, M.; Green, Michael J. (Technical Monitor)

    1997-01-01

    X-33 is an advanced technology demonstrator vehicle for the Reusable Launch Vehicle (RLV) program. The thermal protection system (TPS) for the X-33 is composed of complex layers of materials to protect internal components, while withstanding severe external temperatures induced by aerodynamic heating during high speed flight. It also serves as the vehicle aeroshell in some regions using a stand-off design. MSC/NASTRAN thermal analysis capability was used to predict transient temperature distribution (within the TPS) throughout a mission, from launch through the cool-off period after landing. In this paper, a typical analysis model, representing a point on the vehicle where the liquid oxygen tank is closest to the outer mold line, is described. The maximum temperature difference between the outer mold line and the internal surface of the liquid oxygen tank can exceed 1500 F. One dimensional thermal models are used to select the materials and determine the thickness of each layer for minimum weight while insuring that all materials remain within the allowable temperature range. The purpose of working with three dimensional (3D) comprehensive models using MSC/NASTRAN is to assess the 3D radiation effects and the thermal conduction heat shorts of the support fixtures.

  2. Deformability of plastering compositions in design solutions of modern thermal protective exterior walls

    Directory of Open Access Journals (Sweden)

    R.R. Vakhitov

    2013-04-01

    Full Text Available In recent years, appearance of new constructive decisions for multilayer thermal efficient walls in the practice of design and construction caused the increasing use of protective and decorative plaster compositions. Comprehensive protective plaster systems nowadays are used in the facade insulation systems as a protective layer on the surface of polystyrene foam or mineral wool boards, forming the insulating layer to the outer walls of concrete blocks. They are also used for exterior finish of walls made of gas-concrete blocks, plastering the brickwork of the buildings operated by rehabilitation, in particular, apartment houses of old mass series. The problem of ensuring durability of thermal efficient external walls with the use of protective and decorative plaster systems were identified in this article. The factors, affecting the resistance of facade plasters to the action of external conditions in operating process were considered. The weaknesses in the necessary characteristics of plaster mixtures provided by material manufacturers are revealed. The existing methods for determining crack resistance of plaster compositions are monitored. The author's method of determining the maximum stretch of plaster compositions is given. The article presents tests results of various plaster compositions, confirming the effectiveness of the proposed method.

  3. 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.

  4. Transient loads identification for a standoff metallic thermal protection system panel.

    Energy Technology Data Exchange (ETDEWEB)

    Hundhausen, R. J. (Roy Jason); Adams, Douglas E.; Derriso, Mark; Kukuchek, Paul; Alloway, Richard

    2004-01-01

    Standoff thermal protection system (TPS) panels are critical structural components in future aerospace vehicles because they protect the vehicle from the hostile environment encountered during space launch and reentry. Consequently, the panels are exposed to a variety of loads including high temperature thermal stresses, thermal shock, acoustic pressure, and foreign object impacts. Transient impacts are especially detrimental because they can cause immediate and severe degradation of the panel in the form of, for example, debonding and buckling of the face sheet, cracking of the fasteners, or deformation of the standoffs. Loads identification methods for determining the magnitude and location of impact loads provide an indication of TPS components that may be more susceptible to failure. Furthermore, a historical database of impact loads encountered can be retained for use in the development of statistical models that relate impact loading to panel life. In this work, simulated inservice transient loads are identified experimentally using two methods: a physics-based approach and an inverse Frequency Response Function (FRF) approach. It is shown that by applying the inverse FRF method, the location and magnitude of these simulated impacts can be identified with a high degree of accuracy. The identified force levels vary significantly with impact location due to the differences in panel deformation at the impact site indicating that resultant damage due to impacts would vary with location as well.

  5. A RISK MANAGEMENT METHODOLOGY FOR NON-METALLIC PROCESS EQUIPMENT

    Directory of Open Access Journals (Sweden)

    J.J. Viviers

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Many companies in South Africa have implemented the risk-based inspection (RBI methodology as a maintenance strategy. The risk involved in operating a piece of equipment, past history, non-destructive examination techniques, failure modes, and many other aspects determine the frequency of inspections required to meet legislation. The main purpose of the RBI methodology is to prevent failures of process equipment. The methodology for risk-based inspection for metal equipment is well-established and has been proven in industry, becoming the norm nationally and internationally. However, it is not possible to apply all the techniques to nonmetallic equipment owing to vast differences between the two types of materials. This paper discusses the results of data gathered on the RBI methodology for nonmetallic equipment, and proposes a risk-based model that can be used to perform a risk assessment for non-metallic equipment in a process plant. The risk assessment can be used to formulate the next inspection interval for the asset.

    AFRIKAANSE OPSOMMING: Verskeie maatskappye in Suid-Afrika het reeds die metodologie van risikogebaseeerde inspeksie (RBI geïmplementeer as deel van ‘n omvattende instandhoudingstrategie. Die risiko betrokke by ‘n fisiese item, bedryfsgeskiedenis, nie-vernietigende toetstegnieke, falingsmodusse, en vele ander aspekte bepaal die frekwensie van inspeksies wat benodig word om aan wetlike vereistes te voldoen. Die hoofdoel van die risiko-gebaseerde metodologie is om faling van prosestoerusting te verhinder. Die metodologie vir risiko-gebaseerde inspeksie van metaaltoerusting is goed bekend en word suksesvol toegepas in die industrie. Dis is egter nie moontlik om al die tegnieke toe te pas op nie-metaaltoerusting nie weens die groot verskeidenheid van materiaaltipes. Hierdie artikel bespreek die data wat ingewin is op die risiko-gebaseerde metodologie vir nie-metaaltipeprosestoerusting, en stel

  6. Thermal tolerance affects mutualist attendance in an ant-plant protection mutualism.

    Science.gov (United States)

    Fitzpatrick, Ginny; Lanan, Michele C; Bronstein, Judith L

    2014-09-01

    Mutualism is an often complex interaction among multiple species, each of which may respond differently to abiotic conditions. The effects of temperature on the formation, dissolution, and success of these and other species interactions remain poorly understood. We studied the thermal ecology of the mutualism between the cactus Ferocactus wislizeni and its ant defenders (Forelius pruinosus, Crematogaster opuntiae, Solenopsis aurea, and Solenopsis xyloni) in the Sonoran Desert, USA. The ants are attracted to extrafloral nectar produced by the plants and, in exchange, protect the plants from herbivores; there is a hierarchy of mutualist effectiveness based on aggression toward herbivores. We determined the relationship between temperature and ant activity on plants, the thermal tolerance of each ant species, and ant activity in relation to the thermal environment of plants. Temperature played a role in determining which species interact as mutualists. Three of the four ant species abandoned the plants during the hottest part of the day (up to 40 °C), returning when surface temperature began to decrease in the afternoon. The least effective ant mutualist, F. pruinosus, had a significantly higher critical thermal maximum than the other three species, was active across the entire range of plant surface temperatures observed (13.8-57.0 °C), and visited plants that reached the highest temperatures. F. pruinosus occupied some plants full-time and invaded plants occupied by more dominant species when those species were thermally excluded. Combining data on thermal tolerance and mutualist effectiveness provides a potentially powerful tool for predicting the effects of temperature on mutualisms and mutualistic species.

  7. Interaction effects of radiation and convection measured by a thermal manikin wearing protective clothing with different radiant properties

    NARCIS (Netherlands)

    Havenith, G.; Wang, X.; Candas, V.; Hartog, E. den; Griefahn, B.; Holmér, I.; Meinander, H.; Richards, M.

    2005-01-01

    As part of the EU funded research project THERMPROTECT ('Thermal properties of protective clothing and their use') this paper deals with manikin experiments on the effects of heat radiation at different wind speeds, considering aspects related to the reflectivity of the clothing. A heated thermal

  8. Study of heat sink thermal protection systems for hypersonic research aircraft

    Science.gov (United States)

    Vahl, W. A.; Edwards, C. L. W.

    1978-01-01

    The feasibility of using a single metallic heat sink thermal protection system (TPS) over a projected flight test program for a hypersonic research vehicle was studied using transient thermal analyses and mission performance calculations. Four materials, aluminum, titanium, Lockalloy, and beryllium, as well as several combinations, were evaluated. Influence of trajectory parameters were considered on TPS and mission performance for both the clean vehicle configuration as well as with an experimental scramjet mounted. From this study it was concluded that a metallic heat sink TPS can be effectively employed for a hypersonic research airplane flight envelope which includes dash missions in excess of Mach 8 and 60 seconds of cruise at Mach numbers greater than 6. For best heat sink TPS match over the flight envelope, Lockalloy and titanium appear to be the most promising candidates

  9. 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

  10. Radiation damage in nonmetallic solids under dense electronic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Noriaki; Tanimura, Katsumi; Nakai, Yasuo (Dept. of Physics, Nagoya Univ. (Japan))

    1992-03-01

    Basic processes of radiation damage of insulators by dense electronic excitation are reviewed. First it is pointed out that electronic excitation of nonmetallic solids produces the self-trapped excitons and defect-related metastable states having relatively long lifetimes, and that the excitation of these metastable states, produces stable defects. The effects of irradiation with heavy ions, including track registration, are surveyed on the basis of the microscopic studies. It is pointed out also that the excitation of the metastable states plays a role in laser-induced damage at relatively low fluences, while the laser damage has been reported to be governed by heating of free electrons produced by multiphoton excitation. Difference in the contributions of the excitation of metastable defects to laser-induced damage of surfaces, or laser ablation, and laser-induced bulk damage is stressed. (orig.).

  11. CFD Analysis of Flexible Thermal Protection System Shear Configuration Testing in the LCAT Facility

    Science.gov (United States)

    Ferlemann, Paul G.

    2014-01-01

    This paper documents results of computational analysis performed after flexible thermal protection system shear configuration testing in the LCAT facility. The primary objectives were to predict the shear force on the sample and the sensitivity of all surface properties to the shape of the sample. Bumps of 0.05, 0.10,and 0.15 inches were created to approximate the shape of some fabric samples during testing. A large amount of information was extracted from the CFD solutions for comparison between runs and also current or future flight simulations.

  12. 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.

  13. Conversion of hydrocarbon fuel in thermal protection reactors of hypersonic aircraft

    Science.gov (United States)

    Kuranov, A. L.; Mikhaylov, A. M.; Korabelnikov, A. V.

    2016-07-01

    Thermal protection of heat-stressed surfaces of a high-speed vehicle flying in dense layers of atmosphere is one of the topical issues. Not of a less importance is also the problem of hydrocarbon fuel combustion in a supersonic air flow. In the concept under development, it is supposed that in the most high-stressed parts of airframe and engine, catalytic thermochemical reactors will be installed, wherein highly endothermic processes of steam conversion of hydrocarbon fuel take place. Simultaneously with heat absorption, hydrogen generation will occur in the reactors. This paper presents the results of a study of conversion of hydrocarbon fuel in a slit reactor.

  14. 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.

  15. Corrosion protection of Mg/Al alloys by thermal sprayed aluminium coatings

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, A., E-mail: anpardo@quim.ucm.es [Departamento de Ciencia de Materiales, Facultad de Quimicas, Universidad Complutense, 28040 Madrid (Spain); Casajus, P.; Mohedano, M.; Coy, A.E.; Viejo, F. [Departamento de Ciencia de Materiales, Facultad de Quimicas, Universidad Complutense, 28040 Madrid (Spain); Torres, B. [Departamento de Ciencia e Ingenieria de Materiales, ESCET, Universidad Rey Juan Carlos, 28933 Mostoles, Madrid (Spain); Matykina, E. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Sackville Street, Manchester M60 1QD (United Kingdom)

    2009-05-15

    The protective features of thermal sprayed Al-coatings applied on AZ31, AZ80 and AZ91D magnesium/aluminium alloys were evaluated in 3.5 wt.% NaCl solution by electrochemical and gravimetric measurements. The changes in the morphology and corrosion behaviour of the Al-coatings induced by a cold-pressing post-treatment were also examined. The specimens were characterized by scanning electron microscopy, energy dispersive X-ray analysis and low-angle X-ray diffraction. The as-sprayed Al-coatings revealed a high degree of porosity and poor corrosion protection, which resulted in galvanic acceleration of the corrosion of the magnesium substrates. The application of a cold-pressing post-treatment produced more compact Al-coatings with better bonding at the substrate/coating interface and higher corrosion resistance regardless of the nature of the magnesium alloy.

  16. Personal, closed-cycle cooling and protective apparatus and thermal battery therefor

    Energy Technology Data Exchange (ETDEWEB)

    Klett, James W.; Klett, Lynn B.

    2004-07-20

    A closed-cycle apparatus for cooling a living body includes a heat pickup body or garment which permits evaporation of an evaporating fluid, transmission of the vapor to a condenser, and return of the condensate to the heat pickup body. A thermal battery cooling source is provided for removing heat from the condenser. The apparatus requires no external power and provides a cooling system for soldiers, race car drivers, police officers, firefighters, bomb squad technicians, and other personnel who may utilize protective clothing to work in hostile environments. An additional shield layer may simultaneously provide protection from discomfort, illness or injury due to harmful atmospheres, projectiles, edged weapons, impacts, explosions, heat, poisons, microbes, corrosive agents, or radiation, while simultaneously removing body heat from the wearer.

  17. Experimental demonstration of a new concept of drag reduction and thermal protection for hypersonic vehicles

    Institute of Scientific and Technical Information of China (English)

    Zonglin Jiang; Yunfeng Liu; Guilai Han; Wei Zhao

    2009-01-01

    A new idea of drag reduction and thermal protection for hypersonic vehicles is proposed based on the combination of a physical spike and lateral jets for shock-reconstruction. The spike recasts the bow shock in front of a blunt body into a conical shock, and the lateral jets work to protect the spike tip from overheating and to push the conical shock away from the blunt body when a pitching angle exists during flight. Experiments are conducted in a hypersonic wind tunnel at a nominal Math number of 6. It is demonstrated that the shock/shock interaction on the blunt body is avoided due to injection and the peak pressure at the reattachment point is reduced by 70% under a 4°attack angle.

  18. Development and flight qualification of the C-SiC thermal protection systems for the IXV

    Science.gov (United States)

    Buffenoir, François; Zeppa, Céline; Pichon, Thierry; Girard, Florent

    2016-07-01

    The Intermediate experimental Vehicle (IXV) atmospheric re-entry demonstrator, developed within the FLPP (Future Launcher Preparatory Programme) and funded by ESA, aimed at developing a demonstration vehicle that gave Europe a unique opportunity to increase its knowledge in the field of advanced atmospheric re-entry technologies. A key technology that has been demonstrated in real conditions through the flight of this ambitious vehicle is the thermal protection system (TPS) of the Vehicle. Within this programme, HERAKLES, Safran Group, has been in charge of the TPS of the windward and nose assemblies of the vehicle, and has developed and manufactured SepcarbInox® ceramic matrix composite (CMC) protection systems that provided a high temperature resistant non ablative outer mould line (OML) for enhanced aerodynamic control. The design and flight justification of these TPS has been achieved through extensive analysis and testing:

  19. 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.

  20. Quantitative assessment of the relationship between radiant heat exposure and protective performance of multilayer thermal protective clothing during dry and wet conditions.

    Science.gov (United States)

    Fu, M; Weng, W G; Yuan, H Y

    2014-07-15

    The beneficial effect of clothing on a person is important to the criteria for people exposure to radiant heat flux from fires. The thermal protective performance of multilayer thermal protective clothing exposed to low heat fluxes during dry and wet conditions was studied using two designed bench-scale test apparatus. The protective clothing with four fabric layers (outer shell, moisture barrier, thermal linear and inner layer) was exposed to six levels of thermal radiation (1, 2, 3, 5, 7 and 10kW/m(2)). Two kinds of the moisture barrier (PTFE and GoreTex) with different vapor permeability were compared. The outside and inside surface temperatures of each fabric layer were measured. The fitting analysis was used to quantitatively assess the relationship between the temperature of each layer during thermal exposure and the level of external heat flux. It is indicated that there is a linear correlation between the temperature of each layer and the radiant level. Therefore, a predicted equation is developed to calculate the thermal insulation of the multilayer clothing from the external heat flux. It can also provide some useful information on the beneficial effects of clothing for the exposure criteria of radiant heat flux from fire.

  1. Sustainably Sourced, Thermally Resistant, Radiation Hard Biopolymer

    Science.gov (United States)

    Pugel, Diane

    2011-01-01

    This material represents a breakthrough in the production, manufacturing, and application of thermal protection system (TPS) materials and radiation shielding, as this represents the first effort to develop a non-metallic, non-ceramic, biomaterial-based, sustainable TPS with the capability to also act as radiation shielding. Until now, the standing philosophy for radiation shielding involved carrying the shielding at liftoff or utilizing onboard water sources. This shielding material could be grown onboard and applied as needed prior to different radiation landscapes (commonly seen during missions involving gravitational assists). The material is a bioplastic material. Bioplastics are any combination of a biopolymer and a plasticizer. In this case, the biopolymer is a starch-based material and a commonly accessible plasticizer. Starch molecules are composed of two major polymers: amylase and amylopectin. The biopolymer phenolic compounds are common to the ablative thermal protection system family of materials. With similar constituents come similar chemical ablation processes, with the potential to have comparable, if not better, ablation characteristics. It can also be used as a flame-resistant barrier for commercial applications in buildings, homes, cars, and heater firewall material. The biopolymer is observed to undergo chemical transformations (oxidative and structural degradation) at radiation doses that are 1,000 times the maximum dose of an unmanned mission (10-25 Mrad), indicating that it would be a viable candidate for robust radiation shielding. As a comparison, the total integrated radiation dose for a three-year manned mission to Mars is 0.1 krad, far below the radiation limit at which starch molecules degrade. For electron radiation, the biopolymer starches show minimal deterioration when exposed to energies greater than 180 keV. This flame-resistant, thermal-insulating material is non-hazardous and may be sustainably sourced. It poses no hazardous

  2. Survey of the supporting research and technology for the thermal protection of the Galileo Probe

    Science.gov (United States)

    Howe, J. T.; Pitts, W. C.; Lundell, J. H.

    1981-01-01

    The Galileo Probe, which is scheduled to be launched in 1985 and to enter the hydrogen-helium atmosphere of Jupiter up to 1,475 days later, presents thermal protection problems that are far more difficult than those experienced in previous planetary entry missions. The high entry speed of the Probe will cause forebody heating rates orders of magnitude greater than those encountered in the Apollo and Pioneer Venus missions, severe afterbody heating from base-flow radiation, and thermochemical ablation rates for carbon phenolic that rival the free-stream mass flux. This paper presents a comprehensive survey of the experimental work and computational research that provide technological support for the Probe's heat-shield design effort. The survey includes atmospheric modeling; both approximate and first-principle computations of flow fields and heat-shield material response; base heating; turbulence modelling; new computational techniques; experimental heating and materials studies; code validation efforts; and a set of 'consensus' first-principle flow-field solutions through the entry maneuver, with predictions of the corresponding thermal protection requirements.

  3. The Langley thermal protection system test facility: A description including design operating boundaries

    Science.gov (United States)

    Klich, G. F.

    1976-01-01

    A description of the Langley thermal protection system test facility is presented. This facility was designed to provide realistic environments and times for testing thermal protection systems proposed for use on high speed vehicles such as the space shuttle. Products from the combustion of methane-air-oxygen mixtures, having a maximum total enthalpy of 10.3 MJ/kg, are used as a test medium. Test panels with maximum dimensions of 61 cm x 91.4 cm are mounted in the side wall of the test region. Static pressures in the test region can range from .005 to .1 atm and calculated equilibrium temperatures of test panels range from 700 K to 1700 K. Test times can be as long as 1800 sec. Some experimental data obtained while using combustion products of methane-air mixtures are compared with theory, and calibration of the facility is being continued to verify calculated values of parameters which are within the design operating boundaries.

  4. Design of Inorganic Water Repellent Coatings for Thermal Protection Insulation on an Aerospace Vehicle

    Science.gov (United States)

    Fuerstenau, D. W.; Ravikumar, R.

    1997-01-01

    In this report, thin film deposition of one of the model candidate materials for use as water repellent coating on the thermal protection systems (TPS) of an aerospace vehicle was investigated. The material tested was boron nitride (BN), the water-repellent properties of which was detailed in our other investigation. Two different methods, chemical vapor deposition (CVD) and pulsed laser deposition (PLD), were used to prepare the BN films on a fused quartz substrate (one of the components of thermal protection systems on aerospace vehicles). The deposited films were characterized by a variety of techniques including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The BN films were observed to be amorphous in nature, and a CVD-deposited film yielded a contact angle of 60 degrees with water, similar to the pellet BN samples investigated previously. This demonstrates that it is possible to use the bulk sample wetting properties as a guideline to determine the candidate waterproofing material for the TPS.

  5. Electro-thermal protection system design against atmospheric frost on turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Noui, M.A.; Perron, J.; Fortin, G. [Quebec Univ., Chicoutimi, PQ (Canada). Anti-Icing Materials International Laboratory

    2010-07-01

    This presentation discussed a research program developed to adapt de-icing thermal heating systems for use in wind turbines. The presence of ice on turbine blades can significantly deteriorate rotor performance. Accumulations of ice can increase the radial load on the turbine blades. The uneven formations of ice can lead to vibrations and the expulsion of pieces of ice into surrounding areas. Ice can also reduce the accuracy of various wind measuring devices. A recent study in Finland showed that turbine heating systems consume 3.6 per cent of annual wind production energy. De-icing systems include protective covers; air inlets; sealing systems; inflation tubes; elastomeric ply; and bond ply. The systems also include blade trailing and loading edges, and blade roots. The energy dissipated by the system's heating element is lost by conduction to the interior of the profile. The research program is now developing a system to improve electrothermal protection against frost that is suitable for turbine blades, as well as a thermal model for simulating its operation in a wind turbine. tabs., figs.

  6. Cyclitols protect glutamine synthetase and malate dehydrogenase against heat induced deactivation and thermal denaturation.

    Science.gov (United States)

    Jaindl, Martina; Popp, Marianne

    2006-06-30

    The accumulation of cyclitols in plants is a widespread response that provides protection against various environmental stresses. The capacity of myo-Inositol, pinitol, quercitol, and other compatible solutes (i.e., sorbitol, proline, and glycinebetaine) to protect proteins against thermally induced denaturation and deactivation was examined. Enzymatic activity measurements of L-glutamine synthetase from Escherichia coli and Hordeum vulgare showed that the presence of cyclitols during heat treatment resulted in a significantly higher percentage of residual activity. CD spectroscopy experiments were used to study thermal stabilities of protein secondary structures upon the addition of myo-Inositol, pinitol, and glucose. 0.4 M myo-Inositol was observed to raise the melting temperature (Tm) of GS from E. coli by 3.9 degrees C and MDH from pig heart by 3.4 degrees C, respectively. Pinitol showed an increase in Tm of MDH by 3.8 degrees C, whereas glucose was not effective. Our results show a great potential of stabilizing proteins by the addition of cyclitols.

  7. Thermal protection mechanism of heat pipe in leading edge under hypersonic conditions

    Institute of Scientific and Technical Information of China (English)

    Peng Wengen; He Yurong; Wang Xinzhi; Zhu Jiaqi; Han Jiecai

    2015-01-01

    Sharp local structure, like the leading edge of hypersonic aircraft, confronts a severe aerodynamic heating environment at a Mach number greater than 5. To eliminate the danger of a material failure, a semi-active thermal protection system is proposed by integrating a metallic heat pipe into the structure of the leading edge. An analytical heat-balance model is established from tra-ditional aerodynamic theories, and then thermal and mechanical characteristics of the structure are studied at Mach number 6–8 for three refractory alloys, Inconel 625, C-103, and T-111. The feasi-bility of this simple analytical method as an initial design tool for hypersonic aircraft is assessed through numerical simulations using a finite element method. The results indicate that both the iso-thermal and the maximum temperatures fall but the von Mises stress increases with a longer design length of the leading edge. These two temperatures and the stress rise remarkably at a higher Mach number. Under all investigated hypersonic conditions, with a 3 mm leading edge radius and a 0.15 m design length, the maximum stress exceeds the yield strength of Inconel 625 at Mach num-bers greater than 6, which means a material failure. Moreover, both C-103 and T-111 meet all requirements at Mach number 6–8.

  8. A high precision high PSRR bandgap reference with thermal hysteresis protection

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yintang; Li Yani; Zhu Zhangming, E-mail: yanili@mail.xidian.edu.c [Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of the Ministry of Education, Institute of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-09-15

    To meet the accuracy requirement for the bandgap voltage reference by the increasing data conversion precision of integrated circuits, a high-order curvature-compensated bandgap voltage reference is presented employing the characteristic of bipolar transistor current gain exponentially changing with temperature variations. In addition, an over-temperature protection circuit with a thermal hysteresis function to prevent thermal oscillation is proposed. Based on the CSMC 0.5 {mu}m 20 V BCD process, the designed circuit is implemented; the active die area is 0.17 x 0.20 mm{sup 2}. Simulation and testing results show that the temperature coefficient is 13.7ppm/K with temperature ranging from -40 to 150 {sup 0}C, the power supply rejection ratio is -98.2 dB, the line regulation is 0.3 mV/V, and the power consumption is only 0.38 mW. The proposed bandgap voltage reference has good characteristics such as small area, low power consumption, good temperature stability, high power supply rejection ratio, as well as low line regulation. This circuit can effectively prevent thermal oscillation and is suitable for on-chip voltage reference in high precision analog, digital and mixed systems. (semiconductor integrated circuits)

  9. Crossing the Traditional Boundaries: Salen-Based Schiff Bases for Thermal Protective Applications.

    Science.gov (United States)

    Naik, Anil D; Fontaine, Gaëlle; Bellayer, Séverine; Bourbigot, Serge

    2015-09-30

    A broad spectrum of applications of "Salen"-based Schiff bases tagged them as versatile multifunctional materials. However, their applicability is often bounded by a temperature threshold and, thus, they have rarely been used for high temperature applications. Our investigation of a classical Schiff base, N,N'-bis(4-hydroxysalicylidene)ethylenediamine (L2), reveals that it displays an intriguingly combative response to an elevated temperature/fire scenario. L2 resists and regulates thermal degradation by forming an ablative surface, and acts as a thermal shield. A polycondensation via covalent cross-linking, which forms a hyperbranched cross-linked resin is found to constitute the origin of the ablative surface. This is a unique example of a resin formation produced with a Schiff base, that mimicks the operational strategy of a high-heat resistant phenolic resin. Further applicability of L2, as a flame retardant, was tested in an engineering polymer, polyamide-6. It was found that it reinforces the polymer against fire risks by the formation of an intumescent coating. This paves the way for a new strategic avenue in safeguarding polymeric materials toward fire risks. Further, this material represents a promising start for thermal protective applications.

  10. SEMICONDUCTOR INTEGRATED CIRCUITS: A high precision high PSRR bandgap reference with thermal hysteresis protection

    Science.gov (United States)

    Yintang, Yang; Yani, Li; Zhangming, Zhu

    2010-09-01

    To meet the accuracy requirement for the bandgap voltage reference by the increasing data conversion precision of integrated circuits, a high-order curvature-compensated bandgap voltage reference is presented employing the characteristic of bipolar transistor current gain exponentially changing with temperature variations. In addition, an over-temperature protection circuit with a thermal hysteresis function to prevent thermal oscillation is proposed. Based on the CSMC 0.5 μm 20 V BCD process, the designed circuit is implemented; the active die area is 0.17 × 0.20 mm2. Simulation and testing results show that the temperature coefficient is 13.7ppm/K with temperature ranging from -40 to 150 °C, the power supply rejection ratio is -98.2 dB, the line regulation is 0.3 mV/V, and the power consumption is only 0.38 mW. The proposed bandgap voltage reference has good characteristics such as small area, low power consumption, good temperature stability, high power supply rejection ratio, as well as low line regulation. This circuit can effectively prevent thermal oscillation and is suitable for on-chip voltage reference in high precision analog, digital and mixed systems.

  11. Converting non-metallic printed circuit boards waste into a value added product

    OpenAIRE

    Shantha Kumari Muniyandi; Johan Sohaili; Azman Hassan; Siti Suhaila Mohamad

    2013-01-01

    The aim of this study was to investigate the feasibility of using nonmetallic printed circuit board (PCB) waste as filler in recycled HDPE (rHDPE) in production of rHDPE/PCB composites. Maleic anhydride modified linear low-density polyethylene (MAPE) was used as compatibilizer. In particular, the effects of nonmetallic PCB and MAPE on mechanical properties of the composites were assessed through tensile, flexural and impact testing. Scanning electron microscope (SEM) was used to study the dis...

  12. Size of Non-Metallic Inclusions in High-Grade Medium Carbon Steel

    OpenAIRE

    Lipiński T.; Wach A.

    2014-01-01

    Non-metallic inclusions found in steel can affect its performance characteristics. Their impact depends not only on their quality, but also, among others, on their size and distribution in the steel volume. The literature mainly describes the results of tests on hard steels, particularly bearing steels. The amount of non-metallic inclusions found in steel with a medium carbon content melted under industrial conditions is rarely presented in the literature. The tested steel was melted in an el...

  13. The Effect of Different Non-Metallic Inclusions on the Machinability of Steel

    OpenAIRE

    Niclas Ånmark; Andrey Karasev; Pär Göran Jönsson

    2015-01-01

    Considerable research has been conducted over recent decades on the role of non-metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, ...

  14. 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.

  15. ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Dennis H. LeMieux

    2003-10-01

    Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.

  16. On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

    Energy Technology Data Exchange (ETDEWEB)

    Dennis H. LeMieux

    2005-04-01

    Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.

  17. On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

    Energy Technology Data Exchange (ETDEWEB)

    Dennis H. LeMieux

    2004-10-01

    Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land -based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems; a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization.

  18. ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Dennis H. LeMieux

    2003-07-01

    Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.

  19. Evaluation of Alternative Altitude Scaling Methods for Thermal Ice Protection System in NASA Icing Research Tunnel

    Science.gov (United States)

    Lee, Sam; Addy, Harold E. Jr.; Broeren, Andy P.; Orchard, David M.

    2017-01-01

    A test was conducted at NASA Icing Research Tunnel to evaluate altitude scaling methods for thermal ice protection system. Two new scaling methods based on Weber number were compared against a method based on Reynolds number. The results generally agreed with the previous set of tests conducted in NRCC Altitude Icing Wind Tunnel where the three methods of scaling were also tested and compared along with reference (altitude) icing conditions. In those tests, the Weber number-based scaling methods yielded results much closer to those observed at the reference icing conditions than the Reynolds number-based icing conditions. The test in the NASA IRT used a much larger, asymmetric airfoil with an ice protection system that more closely resembled designs used in commercial aircraft. Following the trends observed during the AIWT tests, the Weber number based scaling methods resulted in smaller runback ice than the Reynolds number based scaling, and the ice formed farther upstream. The results show that the new Weber number based scaling methods, particularly the Weber number with water loading scaling, continue to show promise for ice protection system development and evaluation in atmospheric icing tunnels.

  20. On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

    Energy Technology Data Exchange (ETDEWEB)

    Dennis H. LeMieux

    2005-10-01

    Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Power Generation, Inc proposed a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Power Generation, Inc. has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.

  1. International Space Station (ISS) Soyuz Vehicle Descent Module Evaluation of Thermal Protection System (TPS) Penetration Characteristics

    Science.gov (United States)

    Davis, Bruce A.; Christiansen, Eric L.; Lear, Dana M.; Prior, Tom

    2013-01-01

    The descent module (DM) of the ISS Soyuz vehicle is covered by thermal protection system (TPS) materials that provide protection from heating conditions experienced during reentry. Damage and penetration of these materials by micrometeoroid and orbital debris (MMOD) impacts could result in loss of vehicle during return phases of the mission. The descent module heat shield has relatively thick TPS and is protected by the instrument-service module. The TPS materials on the conical sides of the descent module (referred to as backshell in this test plan) are exposed to more MMOD impacts and are relatively thin compared to the heat shield. This test program provides hypervelocity impact (HVI) data on materials similar in composition and density to the Soyuz TPS on the backshell of the vehicle. Data from this test program was used to update ballistic limit equations used in Soyuz TPS penetration risk assessments. The impact testing was coordinated by the NASA Johnson Space Center (JSC) Hypervelocity Impact Technology (HVIT) Group [1] in Houston, Texas. The HVI testing was conducted at the NASA-JSC White Sands Hypervelocity Impact Test Facility (WSTF) at Las Cruces, New Mexico. Figure

  2. Minerogenic System of Magnesian Nonmetallic Deposits in Early Proterozoic Mg-rich Carbonate Formations in Eastern Liaoning Province

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the early Proterozoic the Liryu Formation and Dashiqiao Formation of eastern Liaoning province, China, there are distributed Mg-rich carbonate rock formations, in which large to superlarge deposits of boron, magnesite, talc, Xiuyan jade etc. occur. The formation of these magnesian nonmetallic deposits was related to early Proterozoic evaporates; then these deposits underwent reworking of regional metamorphism and hydrothermal metasomatism during the Lüliang orogeny and tectono-magmatism during the Indosinian-Yanshanian. Among other things, the Mg-rich carbonates formations, minerogenetic structures and ore-forming fluids played a controlling role in the formation of the mineral deposits. The refore, it can be concluded that the mineral deposits are products of combined processes of the coupling of ore source field, fluid field, thermal field (energy field) and stress field under certain time-space conditions in the early Proterozoic and the late-stage superimposed reworking of tectono-magmatism.

  3. Evaluation of protective coatings under thermal insulation at high temperatures by the use of an innovative design

    Energy Technology Data Exchange (ETDEWEB)

    Lasarte, C. [PEQUIVEN, S.A., Maracaibo (Venezuela); Rincon, O.T. de; Montiel, A. [Univ. del Zulia, Maracaibo (Venezuela). Centro de Estudios de Corrosion

    1994-12-31

    In order to disseminate the existing information on protective systems that have given good performance results, NACE published Document 6H-189 through its technical groups working on coatings for carbon and stainless steels under insulation and corrosion under thermal insulation. This report is unique in its kind and, in the opinion of the authors of this paper, the next step should be the characterization of each of these systems in combination with different insulating materials. Based on NACE Document No. 6H-189, the design of a probe was developed to evaluate, in a salt chamber, the protective coatings which were supposed to work under thermal insulation at high temperatures (30--1,500 C) . This paper describes the results obtained with different combinations of protective coatings (Silicone-Aluminum, Zinc-Rich and Aluminum Metallizing), and thermal insulators (mineral wool, fiber glass and calcium silicate).

  4. 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.)

  5. 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.

  6. Investigation of thermal protection system by forward-facing cavity and opposing jet combinatorial configuration

    Institute of Scientific and Technical Information of China (English)

    Lu Haibo; Liu Weiqiang

    2013-01-01

    This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system (TPS) for hypersonic vehicles.A hemispherecone nose-tip with the combinatorial configuration is investigated numerically in hypersonic free stream.Some numerical results are validated by experiments.The flow field parameters,aerodynamic force and surface heat flux distribution are obtained.The influence of the opposing jet stagnation pressure on cooling efficiency of the combinatorial TPS is discussed.The detailed numerical results show that the aerodynamic heating is reduced remarkably by the combinatorial system.The recirculation region plays a pivotal role for the reduction of heat flux.The larger the stagnation pressure of opposing jet is,the more the heating reduction is.This kind of combinatorial system is suitable to be the TPS for the high-speed vehicles which need long-range and long time flight.

  7. Computer program for nonlinear static stress analysis of shuttle thermal protection system: User's manual

    Science.gov (United States)

    Giles, G. L.; Wallas, M.

    1981-01-01

    User documentation is presented for a computer program which considers the nonlinear properties of the strain isolator pad (SIP) in the static stress analysis of the shuttle thermal protection system. This program is generalized to handle an arbitrary SIP footprint including cutouts for instrumentation and filler bar. Multiple SIP surfaces are defined to model tiles in unique locations such as leading edges, intersections, and penetrations. The nonlinearity of the SIP is characterized by experimental stress displacement data for both normal and shear behavior. Stresses in the SIP are calculated using a Newton iteration procedure to determine the six rigid body displacements of the tile which develop reaction forces in the SIP to equilibrate the externally applied loads. This user documentation gives an overview of the analysis capabilities, a detailed description of required input data and an example to illustrate use of the program.

  8. High Temperature Damping Behavior of Plasma-Sprayed Thermal Barrier and Protective Coatings

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.; Duffy, Kirsten P.; Ghosn, Louis J.

    2010-01-01

    A high temperature damping test apparatus has been developed using a high heat flux CO 2 laser rig in conjunction with a TIRA S540 25 kHz Shaker and Polytec OFV 5000 Vibrometer system. The test rig has been successfully used to determine the damping performance of metallic and ceramic protective coating systems at high temperature for turbine engine applications. The initial work has been primarily focused on the microstructure and processing effects on the coating temperature-dependence damping behavior. Advanced ceramic coatings, including multicomponent tetragonal and cubic phase thermal barrier coatings, along with composite bond coats, have also been investigated. The coating high temperature damping mechanisms will also be discussed.

  9. Flow through the tile gaps in the Space Shuttle Thermal Protection System

    Science.gov (United States)

    Dwoyer, D. L.; Newman, P. A.; Thames, F. C.; Melson, N. D.

    1982-01-01

    The problem of predicting aerodynamic loads on the insulating tiles of the Space Shuttle Thermal Protection System (TPS) is discussed and seen to require a method for predicting pressure and mass flux in the gaps between tiles. A mathematical model of the tile-gap flow is developed based upon a slow viscous (Stokes) flow analysis and is verified against available experimental data. This model derives the tile-gap pressure field from a solution of the two-dimensional Laplace equation; the mass flux vector is then calculated from the pressure gradient. The means for incorporating this model into a lumped-parameter network analogy for porous-media flow is also given. The flow model shows tile-gap mass flux to be very sensitive to the gap width indicating a need for coupling the TPS flow and tile displacement calculations. Finally recommendations are made concerning additional analytical and experimental work to improve TPS flow predictions.

  10. Interaction of silicene and germanene with non-metallic substrates

    Science.gov (United States)

    Houssa, M.; Scalise, E.; van den Broek, B.; Lu, A.; Pourtois, G.; Afanas'ev, V. V.; Stesmans, A.

    2015-01-01

    By using first-principles simulations, we investigate the interaction of silicene and germanene with various non-metallic substrates. We first consider weak van der Waals interactions between the 2D layers and dichalcogenide substrates, like MoX2 (X=S, Se, Te). The buckling of the silicene or germanene layer is correlated to the lattice mismatch between the 2D material and the MoX2 template. The electronic properties of silicene or germanene on these different templates then largely depend on the buckling of the 2D material layer: highly buckled silicene or germanene on MoS2 are predicted to be metallic, while low buckled silicene on MoTe2 is predicted to be semi-metallic, with preserved Dirac cones at the K points. We next study the covalent bonding of silicene and germanene on (0001) ZnS and ZnSe surfaces. On these substrates, silicene or germanene are found to be semiconducting. Remarkably, the nature and magnitude of their energy band gap can be controlled by an out-of-plane electric field.

  11. Peat and its modification products as sorbents for remeval of metals, metalloids and nonmetallic elements

    Science.gov (United States)

    Klavins, Maris; Ansone, Linda; Robalds, Artis; Dudare, Diana

    2013-04-01

    For remediation of soils and purification of waters biosorbents might be considered as an prospective group of materials and amongst them peat have a special role due to low cost, biodegradability, high number of functional groups, well developed surface area and combination of hydrophilic/hydrophobic structural elements. We have demonstrated the possibilities to use peat and its thermal treatment products for oil sorption. Peat as an oil sorbent has poor buoyancy characteristics, relatively low oil sorption capacity and low hydrophobicity. However, thermal treatment (low-temperature pyrolysis and synthesis of peat-based active coal) helps to significantly improve its sorptive characteristics. The processes and structural changes taking place during low-temperature pyrolysis have been studied by means of IR spectroscopy, thermogravimetry and scanning electron microscopy. Peat can be used also as an efficient sorbent for sorption of metallic elements as it has been demonstrated on example of Tl+, Cu2+, Cr3+, however sorption capacity in respect to nonmetallic (anionic species) elements is low. To develop such application possibilities peat, peat modified with iron compounds, iron humates were prepared and tested for sorption of arsenic and phosphorous compounds in comparison with weakly basic anionites. The highest sorption capacity was observed when peat sorbents modified with iron compounds were used. Sorption of different arsenic speciation forms onto iron-modified peat sorbents was investigated as a function of pH and temperature. It was established that sorption capacity increases with a rise in temperature, and the calculation of sorption process thermodynamic parameters indicates the spontaneity of sorption process and its endothermic nature.

  12. Minimalistic details in face of thermal protection requirements with lightweight concrete

    Directory of Open Access Journals (Sweden)

    Tim Lueking

    2014-10-01

    Full Text Available In the 1970s governments in Central and Northern Europe established thermal protection requirements, leading to the reduction of heat transfer through the building envelope. Subsequently, two different strategies were employed to decline the heat loss of exterior walls: the first relied on new or modified building materials that possessed decreased thermal conductivity than previously used materials; the second provided a special insulating layer. Concerning detail design, constructions with specialized layers still might appear to be simple but they are complex and fragile on construction level. This leads to the question: Is it possible to design details, which are simple concerning both appearance and construction? In this article I begin with the advantages and constraints of different exterior wall typologies within today’s legal restrictions in Central Europe. After that I focus on to the material lightweight concrete. As a key issue the analysis of different window positions within the wall (flush to the inside/outside wall or in the middle is presented. Since the source of the investigation has architectural roots, constructive capabilities and design constraints are regarded, too. In the conclusion, future prospects of material development and the consequences for the detail design is given.

  13. Thermal protection mechanism of heat pipe in leading edge under hypersonic conditions

    Directory of Open Access Journals (Sweden)

    Peng Wengen

    2015-02-01

    Full Text Available Sharp local structure, like the leading edge of hypersonic aircraft, confronts a severe aerodynamic heating environment at a Mach number greater than 5. To eliminate the danger of a material failure, a semi-active thermal protection system is proposed by integrating a metallic heat pipe into the structure of the leading edge. An analytical heat-balance model is established from traditional aerodynamic theories, and then thermal and mechanical characteristics of the structure are studied at Mach number 6–8 for three refractory alloys, Inconel 625, C-103, and T-111. The feasibility of this simple analytical method as an initial design tool for hypersonic aircraft is assessed through numerical simulations using a finite element method. The results indicate that both the isothermal and the maximum temperatures fall but the von Mises stress increases with a longer design length of the leading edge. These two temperatures and the stress rise remarkably at a higher Mach number. Under all investigated hypersonic conditions, with a 3 mm leading edge radius and a 0.15 m design length, the maximum stress exceeds the yield strength of Inconel 625 at Mach numbers greater than 6, which means a material failure. Moreover, both C-103 and T-111 meet all requirements at Mach number 6–8.

  14. 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.

  15. 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.

  16. Improving Metallic Thermal Protection System Hypervelocity Impact Resistance Through Design of Experiments Approach

    Science.gov (United States)

    Poteet, Carl C.; Blosser, Max L.

    2001-01-01

    A design of experiments approach has been implemented using computational hypervelocity impact simulations to determine the most effective place to add mass to an existing metallic Thermal Protection System (TPS) to improve hypervelocity impact protection. Simulations were performed using axisymmetric models in CTH, a shock-physics code developed by Sandia National Laboratories, and validated by comparison with existing test data. The axisymmetric models were then used in a statistical sensitivity analysis to determine the influence of five design parameters on degree of hypervelocity particle dispersion. Several damage metrics were identified and evaluated. Damage metrics related to the extent of substructure damage were seen to produce misleading results, however damage metrics related to the degree of dispersion of the hypervelocity particle produced results that corresponded to physical intuition. Based on analysis of variance results it was concluded that the most effective way to increase hypervelocity impact resistance is to increase the thickness of the outer foil layer. Increasing the spacing between the outer surface and the substructure is also very effective at increasing dispersion.

  17. Design of an integral thermal protection system for future space vehicles

    Science.gov (United States)

    Bapanapalli, Satish Kumar

    Thermal protection systems (TPS) are the features incorporated into a spacecraft's design to protect it from severe aerodynamic heating during high-speed travel through planetary atmospheres. The ablative TPS on the space capsule Apollo and ceramic tiles and blankets on the Space Shuttle Orbiter were designed as add-ons to the main load-bearing structure of the vehicles. They are usually incompatible with the structure due to mismatch in coefficient of thermal expansion and as a result the robustness of the external surface of the spacecraft is compromised. This could potentially lead to catastrophic consequences because the TPS forms the external surface of the vehicle and is subjected to numerous other loads like aerodynamic pressure loads, small object high-speed impacts and handling damages during maintenance. In order to make the spacecraft external surface robust, an Integral Thermal Protection System (ITPS) concept has been proposed in this research in which the load-bearing structure and the TPS are combined into one single structure. The design of an ITPS is a formidable task because the requirement of a load-bearing structure and a TPS are often contradictory to one another. The design process has been formulated as an optimization problem with mass per unit area of the ITPS as the objective function and the various functions of the ITPS were formulated as constraints. This is a multidisciplinary design optimization problem involving heat transfer and structural analysis fields. The constraints were expressed as response surface approximations obtained from a large number of finite element analyses, which were carried out with combinations of design variables obtained from an optimized Latin-Hypercube sampling scheme. A MATLABRTM code has been developed to carry out these FE analyses automatically in conjunction with ABAQUSRTM . Corrugated-core structures were designed for ITPS applications with loads and boundary conditions similar to that of a Space

  18. Thermomechanical response of metal foam sandwich panels for structural thermal protection systems in hypersonic vehicles

    Science.gov (United States)

    Rakow, Joseph F.

    Sandwich panels with metal foam cores are proposed for load-bearing structural components in actively cooled thermal protection systems for aerospace vehicles. Prototype acreage metal foam sandwich panels (MFSP's) are constructed and analyzed with the central goal of characterizing the thermomechanical response of the system. MFSP's are subjected to uniform temperature fields and equibiaxial loading in a novel experimental load frame. The load frame exploits the mismatch of coefficients of thermal expansion and allows for thermostructural experimentation without the endemic conflict of thermal and mechanical boundary conditions. Back-to-back strain gages and distributed thermocouples capture the in-plane response of the panels, including buckling and elastic-plastic post-buckling. The out-of-plane response is captured via moire interferometry, which provides a visualization of evolving mode shapes throughout the post-buckling regime. The experimental results agree with an analytical prediction for critical temperatures in sandwich panels based on a Rayleigh-Ritz minimization of the energy functional for a Reissner-Mindlin plate. In addition, a three-dimensional finite element model of the non-linear thermomechanical response of the panel-frame experimental system is developed and the results are shown to agree well with the experimentally identified response of MFSP's. Central to analytical and numerical characterization of MFSP's is an understanding of the response of metal foam under shear loading. The shear response of metal foam is captured experimentally, providing density-dependent relationships for material stiffness, strength, and energy absorption. Speckle photography is employed to identify microstructural size effects in the distribution of strain throughout metal foam under shear loading. In addition, a micromechanical model is established for the density-dependent shear modulus of metal foam, which allows for the coupling of cell-level imperfections

  19. Research development of thermal protection techniques for textile%纺织品热防护技术研究现状

    Institute of Scientific and Technical Information of China (English)

    马新安; 张莹

    2012-01-01

    综述了国内外纺织品热防护的研究现状,主要介绍了国内外可用于热防护的纤维材料、织物热防护技术与产品开发和织物热防护评价方法与标准。综述表明,国外在耐热材料的开发利用,热防护产品的设计、生产和标准的制定,检测仪器的研制等方面处于领先地位,而我国处于模仿阶段的较低水平。指出应加快对织物热防护的研究,尽快缩小我国与国际热防护方面的技术差距,打破国外标准和材料对我国高档防护装备的垄断。%This paper describes the current development in research thermal protection for textile all of the world,and reviews the research progress of thermal protection techniques,the evaluating methods for thermal protection fabric and text standards are also introduced in detail.The review showed that the foreign research are on the dominating position in the fields of the development and utilization of the heat-resistant material,the design and production of thermal protection products,formulation of standards and the development of testing instruments,but China is in the lower level of imitation stage.That we should accelerate the study on the fabric thermal protection,and to narrow the technology gap between home and abroad,as soon as possible to break the monopoly of foreign standard and materials for China’s high-grade protective equipment.

  20. Converting non-metallic printed circuit boards waste into a value added product.

    Science.gov (United States)

    Muniyandi, Shantha Kumari; Sohaili, Johan; Hassan, Azman; Mohamad, Siti Suhaila

    2013-01-01

    The aim of this study was to investigate the feasibility of using nonmetallic printed circuit board (PCB) waste as filler in recycled HDPE (rHDPE) in production of rHDPE/PCB composites. Maleic anhydride modified linear low-density polyethylene (MAPE) was used as compatibilizer. In particular, the effects of nonmetallic PCB and MAPE on mechanical properties of the composites were assessed through tensile, flexural and impact testing. Scanning electron microscope (SEM) was used to study the dispersion of nonmetallic PCB and MAPE in the matrix. Nonmetallic PCB was blended with rHDPE from 0-30 wt% and prepared by counter-rotating twin screw extruder followed by molding into test samples via hot press for analysis. A good balance between stiffness, strength and toughness was achieved for the system containing 30 wt% PCB. Thus, this system was chosen in order to investigate the effect of the compatibilizer on the mechanical properties of the composites. The results indicate that MAPE as a compatiblizer can effectively promote the interfacial adhesion between nonmetallic PCB and rHDPE. The addition of 6 phr MAPE increased the flexural strength, tensile strength and impact strength by 71%, 98% and 44% respectively compared to the uncompatibilized composites.

  1. Modification of Non-Metallic Inclusions by Rare-Earth Elements in Microalloyed Steels

    Directory of Open Access Journals (Sweden)

    M. Opiela

    2012-04-01

    Full Text Available The modification of the chemical composition of non-metallic inclusions by rare-earth elements in the new-developed microalloyed steels was discussed in the paper. The investigated steels are assigned to production of forged elements by thermo- mechanical treatment. The steels were melted in a vaccum induction furnace and modification of non-metallic inclusions was carried out by the michmetal in the amount of 2.0 g per 1 kg of steel. It was found that using material charge of high purity and a realization of metallurgical process in vacuous conditions result in a low concentration of sulfur (0.004%, phosphorus (from 0.006 to 0.008% and oxygen (6 ppm. The high metallurgical purity is confirmed by a small fraction of non-metallic inclusions averaging 0.075%. A large majority of non-metallic inclusions are fine, globular oxide-sulfide or sulfide particles with a mean size 17m2. The chemical composition and morphology of non-metallic inclusions was modified by Ce, La and Nd, what results a small deformability of non- metallic inclusions during hot-working.

  2. Converting Non-Metallic Printed Circuit Boards Waste Into A Value Added Product

    Directory of Open Access Journals (Sweden)

    Shantha Kumari Muniyandi

    2013-05-01

    Full Text Available The aim of this study was to investigate the feasibility of using nonmetallic printed circuit board (PCB waste as filler in recycled HDPE (rHDPE in production of rHDPE/PCB composites. Maleic anhydride modified linear low-density polyethylene (MAPE was used as compatibilizer. In particular, the effects of nonmetallic PCB and MAPE on mechanical properties of the composites were assessed through tensile, flexural and impact testing. Scanning electron microscope (SEM was used to study the dispersion of nonmetallic PCB and MAPE in the matrix. Nonmetallic PCB was blended with rHDPE from 0--30 wt% and prepared by counter-rotating twin screw extruder followed by molding into test samples via hot press for analysis. A good balance between stiffness, strength and toughness was achieved for the system containing 30 wt% PCB. Thus, this system was chosen in order to investigate the effect of the compatibilizer on the mechanical properties of the composites. The results indicate that MAPE as a compatiblizer can effectively promote the interfacial adhesion between nonmetallic PCB and rHDPE. The addition of 6 phr MAPE increased the flexural strength, tensile strength and impact strength by 71%, 98% and 44% respectively compared to the uncompatibilized composites.

  3. Extravehicular Activity Probabilistic Risk Assessment Overview for Thermal Protection System Repair on the Hubble Space Telescope Servicing Mission

    Science.gov (United States)

    Bigler, Mark; Canga, Michael A.; Duncan, Gary

    2010-01-01

    The Shuttle Program initiated an Extravehicular Activity (EVA) Probabilistic Risk Assessment (PRA) to assess the risks associated with performing a Shuttle Thermal Protection System (TPS) repair during the Space Transportation System (STS)-125 Hubble repair mission as part of risk trades between TPS repair and crew rescue.

  4. 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

    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...

  5. 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.

  6. Woven Thermal Protection System Based Heat-shield for Extreme Entry Environments Technology (HEEET)

    Science.gov (United States)

    Ellerby, Donald; Venkatapathy, Ethiraj; Stackpoole, Margaret; Chinnapongse, Ronald; Munk, Michelle; Dillman, Robert; Feldman, Jay; Prabhu, Dinesh; Beerman, Adam

    2013-01-01

    NASA's future robotic missions utilizing an entry system into Venus and the outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of state of the art low to mid density ablators such as PICA or Avcoat. Therefore mission planners typically assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic is a robust TPS material however its high density and relatively high thermal conductivity constrain mission planners to steep entries, with high heat fluxes and pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose challenges for certification in existing ground based test facilities and the longer-term sustainability of CP will continue to pose challenges. In 2012 the Game Changing Development Program (GCDP) in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This project was highly successful demonstrating that a Woven TPS solution compares favorably to CP in performance in simulated reentry environments and provides the opportunity to manufacture graded materials that should result in overall reduced mass solutions and enable a much broader set of missions than does CP. Building off the success of the WTPS project GCDP has funded a follow on project to further mature and scale up the WTPS concept for insertion into future NASA robotic missions. The matured WTPS will address the CP concerns associated with ground based test limitations and sustainability. This presentation will briefly discuss results from the WTPS Project and the plans for WTPS maturation into a heat-shield for extreme entry environment.

  7. Coating Layer and Corrosion Protection Characteristics in Sea Water with Various Thermal Spray Coating Materials for STS304

    Science.gov (United States)

    Kim, Seong-Jong; Woo, Yong-Bin

    We investigated the optimal method of application and the anticorrosive abilities of Zn, Al, and Zn + 15%Al spray coatings in protecting stainless steel 304 (STS304) in sea water. If a defect such as porosity or an oxide layer, causes STS304 to be exposed to sea water, and the thermal spray coating material will act as the cathode and anode, respectively. The Tafel experiments revealed that Al-coated specimens among applied coating methods had the lowest corrosion current densities. As the corrosion potential decreases with increasing corrosion current density, we estimated the characteristics and lifetime of the protective thermal spray coating layer in the galvanic cell formed by the thermal spray coating layer and STS304.

  8. Fatigue Strength Prediction of Drilling Materials Based on the Maximum Non-metallic Inclusion Size

    Science.gov (United States)

    Zeng, Dezhi; Tian, Gang; Liu, Fei; Shi, Taihe; Zhang, Zhi; Hu, Junying; Liu, Wanying; Ouyang, Zhiying

    2015-12-01

    In this paper, the statistics of the size distribution of non-metallic inclusions in five drilling materials were performed. Based on the maximum non-metallic inclusion size, the fatigue strength of the drilling material was predicted. The sizes of non-metallic inclusions in drilling materials were observed to follow the inclusion size distribution rule. Then the maximum inclusion size in the fatigue specimens was deduced. According to the prediction equation of the maximum inclusion size and fatigue strength proposed by Murakami, fatigue strength of drilling materials was obtained. Moreover, fatigue strength was also measured through rotating bending tests. The predicted fatigue strength was significantly lower than the measured one. Therefore, according to the comparison results, the coefficients in the prediction equation were revised. The revised equation allowed the satisfactory prediction results of fatigue strength of drilling materials at the fatigue life of 107 rotations and could be used in the fast prediction of fatigue strength of drilling materials.

  9. Modelling of non-metallic particles motion process in foundry alloys

    Directory of Open Access Journals (Sweden)

    P. L. Żak

    2015-04-01

    Full Text Available The behaviour of non-metallic particles in the selected composites was analysed, in the current study. The calculations of particles floating in liquids differing in viscosity were performed. Simulations based on the Stokes equation were made for spherical SiC particles and additionally the particle size influence on Reynolds number was analysed.The movement of the particles in the liquid metal matrix is strictly connected with the agglomerate formation problem.Some of collisions between non-metallic particles lead to a permanent connection between them. Creation of the two spherical particles and a metallic phase system generates the adhesion force. It was found that the adhesion force mainly depends on the surface tension of the liquid alloy and radius of non-metallic particles.

  10. Products Made from Nonmetallic Materials Reclaimed from Waste Printed Circuit Boards

    Institute of Scientific and Technical Information of China (English)

    MOU Peng; XIANG Dong; DUAN Guanghong

    2007-01-01

    Printed circuit boards (PCBs) are in all electronic equipment, so with the sharp increase of electronic waste, the recovery of PCB components has become a critical research field. This paper presents a study of the reclaimation and reuse of nonmetallic materials recovered from waste PCBs. Mechanical processes, such as crushing, milling, and separation, were used to process waste PCBs. Nonmetallic materials in the PCBs were separated using density-based separation with separation rates in excess of 95%. The recovered nonmetals were used to make models, construction materials, composite boards, sewer grates,and amusement park boats. The PCB nonmetal products have better mechanical characteristics and durability than traditional materials and fillers. The flexural strength of the PCB nonmetallic material composite boards is 30% greater than that of standard products. Products derived from PCB waste processing have been brought into industrial production. The study shows that PCB nonmetals can be reused in profitable and environmentally friendly ways.

  11. Methodology for Flight Relevant Arc-Jet Testing of Flexible Thermal Protection Systems

    Science.gov (United States)

    Mazaheri, Alireza; Bruce, Walter E., III; Mesick, Nathaniel J.; Sutton, Kenneth

    2013-01-01

    A methodology to correlate flight aeroheating environments to the arc-jet environment is presented. For a desired hot-wall flight heating rate, the methodology provides the arcjet bulk enthalpy for the corresponding cold-wall heating rate. A series of analyses were conducted to examine the effects of the test sample model holder geometry to the overall performance of the test sample. The analyses were compared with arc-jet test samples and challenges and issues are presented. The transient flight environment was calculated for the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) Earth Atmospheric Reentry Test (HEART) vehicle, which is a planned demonstration vehicle using a large inflatable, flexible thermal protection system to reenter the Earth's atmosphere from the International Space Station. A series of correlations were developed to define the relevant arc-jet test environment to properly approximate the HEART flight environment. The computed arcjet environments were compared with the measured arc-jet values to define the uncertainty of the correlated environment. The results show that for a given flight surface heat flux and a fully-catalytic TPS, the flight relevant arc-jet heat flux increases with the arc-jet bulk enthalpy while for a non-catalytic TPS the arc-jet heat flux decreases with the bulk enthalpy.

  12. Multi-phase flow effect on SRM nozzle flow field and thermal protection materials

    Institute of Scientific and Technical Information of China (English)

    SHAFQAT Wahab; XIE Kan; LIU Yu

    2009-01-01

    Multi-phase flow effect generated from the combustion of aluminum based com-posite propellant was performed on the thermal protection material of solid rocket motor (SRM) nozzle. Injection of alumina (Al2O3) particles from 5% to 10% was tried on SRM nozzle flow field to see the influence of multiphase flow on heat transfer computations. A coupled, time resolved CFD (computational fluid dynamics) approach was adopted to solve the conjugate problem of multi-phase fluid flow and heat transfer in the solid rocket motor nozzle. The governing equations are discretized by using the finite volume method. Spalart-Allmaras (S-A) turbulence model was employed. The computation was executed on the dif-ferent models selected for the analysis to validate the temperature variation in the throat in-serts and baking material of SRM nozzle. Comparison for temperatures variations were also carried out at different expansion ratios of nozzle. This paper also characterized the advanced SRM nozzle composites material for their high thermo stability and their high thermo me-chanical capabilities to make it more reliable simpler and lighter.

  13. A new surface catalytic model for silica-based thermal protection material for hypersonic vehicles

    Directory of Open Access Journals (Sweden)

    Li Kai

    2015-10-01

    Full Text Available Silica-based materials are widely employed in the thermal protection system for hypersonic vehicles, and the investigation of their catalytic characteristics is crucially important for accurate aerothermal heating prediction. By analyzing the disadvantages of Norman’s high and low temperature models, this paper combines the two models and proposes an eight-reaction combined surface catalytic model to describe the catalysis between oxygen and silica surface. Given proper evaluation of the parameters according to many references, the recombination coefficient obtained shows good agreement with experimental data. The catalytic mechanisms between oxygen and silica surface are then analyzed. Results show that with the increase of the wall temperature, the dominant reaction contributing to catalytic coefficient varies from Langmuir–Hinshelwood (LH recombination (TW  1350 K. The surface coverage of chemisorption areas varies evidently with the dominant reactions in the high temperature (HT range, while the surface coverage of physisorption areas varies within quite low temperature (LT range (TW < 250 K. Recommended evaluation of partial parameters is also given.

  14. Estimation of surface heat flux for ablation and charring of thermal protection material

    Science.gov (United States)

    Qian, Wei-qi; He, Kai-feng; Zhou, Yu

    2016-07-01

    Ablation of the thermal protection material of the reentry hypersonic flight vehicle is a complex physical and chemical process. To estimate the surface heat flux from internal temperature measurement is much more complex than the conventional inverse heat conduction problem case. In the paper, by utilizing a two-layer pyrogeneration-plane ablation model to model the ablation and charring of the material, modifying the finite control volume method to suit for the numerical simulation of the heat conduction equation with variable-geometry, the CGM along with the associated adjoint problem is developed to estimate the surface heat flux. This estimation method is verified with a numerical example at first, the results show that the estimation method is feasible and robust. The larger is the measurement noise, the greater is the deviation of the estimated result from the exact value, and the measurement noise of ablated surface position has a significant and more direct influence on the estimated result of surface heat flux. Furthermore, the estimation method is used to analyze the experimental data of ablation of blunt Carbon-phenolic material Narmco4028 in an arc-heater. It is shown that the estimated surface heat flux agrees with the heating power value of the arc-heater, and the estimation method is basically effective and potential to treat the engineering heat conduction problem with ablation.

  15. Health Monitoring Technology for Thermal Protection Systems on Reusable Hypersonic Vehicles

    Science.gov (United States)

    Milos, Frank S.; Watters, D. G.; Heinemann, J. M.; Karunaratne, K. S.; Arnold, Jim (Technical Monitor)

    2001-01-01

    Integrated subsystem health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles (RLVs) in order to reduce life cycle costs, to increase safety margins, and to improve mission reliability. This talk summarizes a joint effort between NASA Ames and industry partners to develop rapid non-contact diagnostic tools for health and performance monitoring of thermal protection systems (TPS) on future RLVs. The specific goals for TPS health monitoring are to increase the speed and reliability of TPS inspections for improved operability at lower cost. The technology being developed includes a 3-D laser scanner for examining the exterior surface of the TPS, and a subsurface microsensor suite for monitoring the health and performance of the TPS. The sensor suite consists of passive overlimit sensors and sensors for continuous parameter monitoring in flight. The sensors are integrated with radio-frequency identification (RFID) microchips to enable wireless communication of-the sensor data to an external reader that may be a hand-held scanner or a large portal. Prototypes of the laser system and both types of subsurface sensors have been developed. The laser scanner was tested on Shuttle Orbiter Columbia and was able to dimension surface chips and holes on a variety of TPS materials. The temperature-overlimit microsensor has a diameter under 0.05 inch (suitable for placement in gaps between ceramic TPS tiles) and can withstand 700 F for 15 minutes.

  16. 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.

  17. 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.

  18. Parametric Weight Comparison of Advanced Metallic, Ceramic Tile, and Ceramic Blanket Thermal Protection Systems

    Science.gov (United States)

    Myers, David E.; Martin, Carl J.; Blosser, Max L.

    2000-01-01

    A parametric weight assessment of advanced metallic panel, ceramic blanket, and ceramic tile thermal protection systems (TPS) was conducted using an implicit, one-dimensional (I-D) finite element sizing code. This sizing code contained models to account for coatings fasteners, adhesives, and strain isolation pads. Atmospheric entry heating profiles for two vehicles, the Access to Space (ATS) vehicle and a proposed Reusable Launch Vehicle (RLV), were used to ensure that the trends were not unique to a certain trajectory. Ten TPS concepts were compared for a range of applied heat loads and substructural heat capacities to identify general trends. This study found the blanket TPS concepts have the lightest weights over the majority of their applicable ranges, and current technology ceramic tiles and metallic TPS concepts have similar weights. A proposed, state-of-the-art metallic system which uses a higher temperature alloy and efficient multilayer insulation was predicted to be significantly lighter than the ceramic tile stems and approaches blanket TPS weights for higher integrated heat loads.

  19. Metallic Thermal Protection System Technology Development: Concepts, Requirements and Assessment Overview

    Science.gov (United States)

    Dorsey, John T.; Poteet, Carl C.; Chen, Roger R.; Wurster, Kathryn E.

    2002-01-01

    A technology development program was conducted to evolve an earlier metallic thermal protection system (TPS) panel design, with the goals of: improving operations features, increasing adaptability (ease of attaching to a variety of tank shapes and structural concepts), and reducing weight. The resulting Adaptable Robust Metallic Operable Reusable (ARMOR) TPS system incorporates a high degree of design flexibility (allowing weight and operability to be traded and balanced) and can also be easily integrated with a large variety of tank shapes, airframe structural arrangements and airframe structure/material concepts. An initial attempt has been made to establish a set of performance based TPS design requirements. A set of general (FARtype) requirements have been proposed, focusing on defining categories that must be included for a comprehensive design. Load cases required for TPS design must reflect the full flight envelope, including a comprehensive set of limit loads, However, including additional loads. such as ascent abort trajectories, as ultimate load cases, and on-orbit debris/micro-meteoroid hypervelocity impact, as one of the discrete -source -damage load cases, will have a significant impact on system design and resulting performance, reliability and operability. Although these load cases have not been established, they are of paramount importance for reusable vehicles, and until properly included, all sizing results and assessments of reliability and operability must be considered optimistic at a minimum.

  20. The Effect of Different Non-Metallic Inclusions on the Machinability of Steels.

    Science.gov (United States)

    Ånmark, Niclas; Karasev, Andrey; Jönsson, Pär Göran

    2015-02-16

    Considerable research has been conducted over recent decades on the role of non‑metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, etc.) are discussed and summarized. Finally, some methods for modification of non-metallic inclusions in the liquid steel are considered to obtain a desired balance between mechanical properties and machinability of various steel grades.

  1. Modification of Non-Metallic Inclusions by Rare-Earth Elements in Microalloyed Steels

    OpenAIRE

    Opiela M.; Grajcar A.

    2012-01-01

    The modification of the chemical composition of non-metallic inclusions by rare-earth elements in the new-developed microalloyed steels was discussed in the paper. The investigated steels are assigned to production of forged elements by thermo- mechanical treatment. The steels were melted in a vaccum induction furnace and modification of non-metallic inclusions was carried out by the michmetal in the amount of 2.0 g per 1 kg of steel. It was found that using material charge of high purity and...

  2. The Effect of Different Non-Metallic Inclusions on the Machinability of Steels

    Directory of Open Access Journals (Sweden)

    Niclas Ånmark

    2015-02-01

    Full Text Available Considerable research has been conducted over recent decades on the role of non‑metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, etc. are discussed and summarized. Finally, some methods for modification of non-metallic inclusions in the liquid steel are considered to obtain a desired balance between mechanical properties and machinability of various steel grades.

  3. Recycling of non-metallic fractions from waste electrical and electronic equipment (WEEE): a review.

    Science.gov (United States)

    Wang, Ruixue; Xu, Zhenming

    2014-08-01

    The world's waste electrical and electronic equipment (WEEE) consumption has increased incredibly in recent decades, which have drawn much attention from the public. However, the major economic driving force for recycling of WEEE is the value of the metallic fractions (MFs). The non-metallic fractions (NMFs), which take up a large proportion of E-wastes, were treated by incineration or landfill in the past. NMFs from WEEE contain heavy metals, brominated flame retardant (BFRs) and other toxic and hazardous substances. Combustion as well as landfill may cause serious environmental problems. Therefore, research on resource reutilization and safe disposal of the NMFs from WEEE has a great significance from the viewpoint of environmental protection. Among the enormous variety of NMFs from WEEE, some of them are quite easy to recycle while others are difficult, such as plastics, glass and NMFs from waste printed circuit boards (WPCBs). In this paper, we mainly focus on the intractable NMFs from WEEE. Methods and technologies of recycling the two types of NMFs from WEEE, plastics, glass are reviewed in this paper. For WEEE plastics, the pyrolysis technology has the lowest energy consumption and the pyrolysis oil could be obtained, but the containing of BFRs makes the pyrolysis recycling process problematic. Supercritical fluids (SCF) and gasification technology have a potentially smaller environmental impact than pyrolysis process, but the energy consumption is higher. With regard to WEEE glass, lead removing is requisite before the reutilization of the cathode ray tube (CRT) funnel glass, and the recycling of liquid crystal display (LCD) glass is economically viable for the containing of precious metals (indium and tin). However, the environmental assessment of the recycling process is essential and important before the industrialized production stage. For example, noise and dust should be evaluated during the glass cutting process. This study could contribute

  4. High-Temperature Structures, Adhesives, and Advanced Thermal Protection Materials for Next-Generation Aeroshell Design

    Science.gov (United States)

    Collins, Timothy J.; Congdon, William M.; Smeltzer, Stanley S.; Whitley, Karen S.

    2005-01-01

    The next generation of planetary exploration vehicles will rely heavily on robust aero-assist technologies, especially those that include aerocapture. This paper provides an overview of an ongoing development program, led by NASA Langley Research Center (LaRC) and aimed at introducing high-temperature structures, adhesives, and advanced thermal protection system (TPS) materials into the aeroshell design process. The purpose of this work is to demonstrate TPS materials that can withstand the higher heating rates of NASA's next generation planetary missions, and to validate high-temperature structures and adhesives that can reduce required TPS thickness and total aeroshell mass, thus allowing for larger science payloads. The effort described consists of parallel work in several advanced aeroshell technology areas. The areas of work include high-temperature adhesives, high-temperature composite materials, advanced ablator (TPS) materials, sub-scale demonstration test articles, and aeroshell modeling and analysis. The status of screening test results for a broad selection of available higher-temperature adhesives is presented. It appears that at least one (and perhaps a few) adhesives have working temperatures ranging from 315-400 C (600-750 F), and are suitable for TPS-to-structure bondline temperatures that are significantly above the traditional allowable of 250 C (482 F). The status of mechanical testing of advanced high-temperature composite materials is also summarized. To date, these tests indicate the potential for good material performance at temperatures of at least 600 F. Application of these materials and adhesives to aeroshell systems that incorporate advanced TPS materials may reduce aeroshell TPS mass by 15% - 30%. A brief outline is given of work scheduled for completion in 2006 that will include fabrication and testing of large panels and subscale aeroshell test articles at the Solar-Tower Test Facility located at Kirtland AFB and operated by Sandia

  5. Post-Flight Assessment of Avcoat Thermal Protection System for the Exploration Flight Test-1

    Science.gov (United States)

    Bose, Deepak; Santos, Jose; Rodriguez, Erika; Mahzari, Milad; Remark, Brian; Muppidi, Suman

    2016-01-01

    On December 5, 2014 NASA conducted the first flight test of its next generation human-class Orion spacecraft. The flight was called the Exploration Flight Test -1 (EFT-1) which lasted for 4 hours and culminated into a re-entry trajectory at 9 km/s. This flight test of the 5-meter Orion Crew Module demonstrated various sub-systems including the Avcoat ablative thermal protection system (TPS) on the heat shield. The Avcoat TPS had been developed from the Apollo-era recipe with a few key modifications. The engineering for thermal sizing was supported by modeling, analysis, and ground tests in arc jet facilities. This paper will describe a postlfight analysis plan and present results from post-recovery inspections, data analysis from embedded sensors, TPS sample extraction and characterization in the laboratory. After the recovery of the vehicle, a full photographic survey and surface scans of the TPS were performed. The recovered vehicle showed physical evidence of flow disturbances, varying degrees of surface roughness, and excessive recession downstream of compression pads. The TPS recession was measured at more than 200 locations of interest on the Avcoat surface. The heat shield was then processed for sample extraction prior to TPS removal using the 7-Axis Milling machine at Marshall Space Flight Center. Around 182 rectangular TPS samples were extracted for subsequent analysis and investigation. The final paper will also present results of sample analysis. The planned investigation includes sidewall imaging, followed by image analysis to characterize TPS response by quantifying different layers in the char and pyrolysis zones. A full postmortem of the instrumentation and sensor ports will also be performed to confirm no adverse effects due to the sensors themselves. A subset of the samples will undergo structural testing and perform detailed characterization of any cracks and integrity of gore seams. Finally, the material will be characterized with layer

  6. Modeling of ultrasonic and terahertz radiations in defective tiles for condition monitoring of thermal protection systems

    Science.gov (United States)

    Kabiri Rahani, Ehsan

    Condition based monitoring of Thermal Protection Systems (TPS) is necessary for safe operations of space shuttles when quick turn-around time is desired. In the current research Terahertz radiation (T-ray) has been used to detect mechanical and heat induced damages in TPS tiles. Voids and cracks inside the foam tile are denoted as mechanical damage while property changes due to long and short term exposures of tiles to high heat are denoted as heat induced damage. Ultrasonic waves cannot detect cracks and voids inside the tile because the tile material (silica foam) has high attenuation for ultrasonic energy. Instead, electromagnetic terahertz radiation can easily penetrate into the foam material and detect the internal voids although this electromagnetic radiation finds it difficult to detect delaminations between the foam tile and the substrate plate. Thus these two technologies are complementary to each other for TPS inspection. Ultrasonic and T-ray field modeling in free and mounted tiles with different types of mechanical and thermal damages has been the focus of this research. Shortcomings and limitations of FEM method in modeling 3D problems especially at high-frequencies has been discussed and a newly developed semi-analytical technique called Distributed Point Source Method (DPSM) has been used for this purpose. A FORTRAN code called DPSM3D has been developed to model both ultrasonic and electromagnetic problems using the conventional DPSM method. This code is designed in a general form capable of modeling a variety of geometries. DPSM has been extended from ultrasonic applications to electromagnetic to model THz Gaussian beams, multilayered dielectrics and Gaussian beam-scatterer interaction problems. Since the conventional DPSM has some drawbacks, to overcome it two modification methods called G-DPSM and ESM have been proposed. The conventional DPSM in the past was only capable of solving time harmonic (frequency domain) problems. Time history was

  7. Experimental investigation of technologie of pipelines thermal protection by monolithiс foam concrete

    Directory of Open Access Journals (Sweden)

    I.A. Lundyshev

    2010-08-01

    Full Text Available As the technology of heat insulation with using monolithic foam concrete is relatively new, after preliminary calculations, and before mass use by a group of scientists and engineers, which included the author of articles, under the guidance of Ph. D. V.D. Vasiliev< in 2007-2008 were conducted field experiments. According to the proposed technology, the insulated pipe centralizers are installed on which is mounted a removable or fixed timbering. The ends are sealed, and through technological holes in the formwork is filled with solid foam concrete. The technique is to perform a thermal finite linear and curved sections of the pipeline monolithic foam concrete of different densities using different materials and permanent form of various materials centralizers. At the same time ease the implementation rated insulation antivandal shuttering its strength and quality. This series of experiments, was and is far from the latest experiments in this field. However, it was after these experiments revealed the following, the most popular combinations of formwork and centralizers:- Combination of steel centralizers and steel formwork provides the best protection functions, long service life, very fast and technically easy going on the pipeline is suitable for reconstruction, and for the construction of new pipelines. - Combination of steel centralizers and design of metal mesh and tar paper provides good protective function, long service life, quickly installed on the pipeline is suitable for reconstruction, and for the construction of new pipelines. - Construction of centralizers of hollow PVC products can not be used to heating mains and steam but may find its application in the insulation of pipeline with the temperature of the working body is not more than 50 C. - Construction of centralizers of SPE disks have shown themselves well in the course of the experiments, and during follow-up within 180 days showed no changes in the geometry of centralizers

  8. A low noise and high precision linear power supply with thermal foldback protection

    Science.gov (United States)

    Carniti, P.; Cassina, L.; Gotti, C.; Maino, M.; Pessina, G.

    2016-05-01

    A low noise and high precision linear power supply was designed for use in rare event search experiments with macrobolometers. The circuit accepts at the input a "noisy" dual supply voltage up to ±15 V and gives at the output precise, low noise, and stable voltages that can be set between ±3.75 V and ±12.5 V in eight 1.25 V steps. Particular care in circuit design, component selection, and proper filtering results in a noise spectral density of 50 nV / √{ Hz } at 1 Hz and 20 nV / √{ Hz } white when the output is set to ±5 V. This corresponds to 125 nV RMS (0.8 μV peak to peak) between 0.1 Hz and 10 Hz, and 240 nV RMS (1.6 μV peak to peak) between 0.1 Hz and 100 Hz. The power supply rejection ratio (PSRR) of the circuit is 100 dB at low frequency, and larger than 40 dB up to high frequency, thanks to a proper compensation design. Calibration allows to reach a precision in the absolute value of the output voltage of ±70 ppm, or ±350 μV at ±5 V, and to reduce thermal drifts below ±1 ppm/∘C in the expected operating range. The maximum peak output current is about 6 A from each output. An original foldback protection scheme was developed that dynamically limits the maximum output current to keep the temperature of the output transistors within their safe operating range. An add-on card based on an ARM Cortex-M3 microcontroller is devoted to the monitoring and control of all circuit functionalities and provides remote communication via CAN bus.

  9. Simultaneously Harvesting Thermal and Mechanical Energies based on Flexible Hybrid Nanogenerator for Self-Powered Cathodic Protection.

    Science.gov (United States)

    Zhang, Hulin; Zhang, Shangjie; Yao, Guang; Huang, Zhenlong; Xie, Yuhang; Su, Yuanjie; Yang, Weiqing; Zheng, Chunhua; Lin, Yuan

    2015-12-30

    Metal corrosion occurs anytime and anywhere in nature and the corrosion prevention has a great significance everywhere in national economic development and daily life. Here, we demonstrate a flexible hybrid nanogenerator (NG) that is capable of simultaneously or individually harvesting ambient thermal and mechanical energies and used for a self-powered cathodic protection (CP) system without using an external power source. Because of its double peculiarities of both pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based NG was constructed to scavenge both thermal and mechanical energies. As a supplementary, a triboelectric NG was constructed below the pyro/piezoelectric NG to grab ambient mechanical energy. The output power of the fabricated hybrid NG can be directly used to protect the metal surface from the chemical corrosion. Our results not only verify the feasibility of self-powered CP-based NGs, but also expand potential self-powered applications.

  10. The C-terminal domain of human grp94 protects the catalytic subunit of protein kinase CK2 (CK2alpha) against thermal aggregation. Role of disulfide bonds

    DEFF Research Database (Denmark)

    Roher, N; Miró, F; Boldyreff, B

    2001-01-01

    with dithiothreitol. Grp94-CT conferred protection against aggregation on the catalytic subunit of protein kinase CK2 (CK2alpha), although it did not protect against thermal inactivation. This anti-aggregation effect of grp94-CT was concentration dependent, with full protection achieved at grp94-CT/CK2alpha molar...

  11. Stepped-Frequency Ground-Penetrating Radar for Detection of Small Non-metallic Buried Objects

    DEFF Research Database (Denmark)

    Jakobsen, Kaj Bjarne; Sørensen, Helge Bjarup Dissing; Nymann, Ole

    1997-01-01

    A monostatic amplitude and phase stepped-frequency radar approach have been proposed to detect small non-metallic buried anti-personnel (AP) mines. An M-56 AP-mine with a diameter of 54 mm and height of 40 mm, only, has been successfully detected and located in addition to small metallic mine...

  12. CHARACTERIZATION OF EMISSIONS FROM THE SIMULATED OPEN-BURNING OF NON-METALLIC AUTOMOBILE SHREDDER RESIDUE

    Science.gov (United States)

    The report gives results of a study in which the open combustion of a nonmetallic waste product called "fluff" was simulated and the resulting emissions collected and characterized to gain insight into the types and quantities of these air pollutants. (NOTE: The reclamation proce...

  13. Soil effects on GPR detection of buried non-metallic mines

    NARCIS (Netherlands)

    Hendrickx, J.M.H.; Hong, S.H.; Miller, T.; Borchers, B.; Rhebergen, J.B.

    2003-01-01

    Landmines are a major problem in many areas of the world. In spite of the fact that many different types of landmine sensors have been developed, the detection of non-metallic landmines remains very difficult. The objective of this contribution is to synthesize our work related to the effects of soi

  14. Economic impact of using nonmetallic materials in low to intermediate temperature geothermal well construction. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    The results are presented of an exhaustive literature search and evaluation concerning the properties and economics of commercially available nonmetallic well casing and screens. These materials were studied in terms of their use in low to intermediate temperature geothermal well construction.

  15. Size of Non-Metallic Inclusions in High-Grade Medium Carbon Steel

    Directory of Open Access Journals (Sweden)

    Lipiński T.

    2014-12-01

    Full Text Available Non-metallic inclusions found in steel can affect its performance characteristics. Their impact depends not only on their quality, but also, among others, on their size and distribution in the steel volume. The literature mainly describes the results of tests on hard steels, particularly bearing steels. The amount of non-metallic inclusions found in steel with a medium carbon content melted under industrial conditions is rarely presented in the literature. The tested steel was melted in an electric arc furnace and then desulfurized and argonrefined. Seven typical industrial melts were analyzed, in which ca. 75% secondary raw materials were used. The amount of non-metallic inclusions was determined by optical and extraction methods. The test results are presented using stereometric indices. Inclusions are characterized by measuring ranges. The chemical composition of steel and contents of inclusions in every melts are presented. The results are shown in graphical form. The presented analysis of the tests results on the amount and size of non-metallic inclusions can be used to assess them operational strength and durability of steel melted and refined in the desulfurization and argon refining processes.

  16. Elementary stage rate coefficients of heterogeneous catalytic recombination of dissociated air on thermal protective surfaces from ab initio approach

    Science.gov (United States)

    Buchachenko, A. A.; Kroupnov, A. A.; Kovalev, V. L.

    2015-08-01

    Elementary stage rate coefficients of the full system of kinetic equations describing heterogeneous catalytic recombination of the dissociated air on the surfaces of thermal protective ceramic coatings of β-cristobalite and α-Al2O3 are determined using the quantum-mechanical calculations within the framework of cluster models and literature data. Both the impact and associative recombination processes of adsorbed oxygen and nitrogen atoms are taken into account.

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

    OpenAIRE

    Tianbao Cheng; Weiguo Li; Wei Lu; Yushan Shi

    2014-01-01

    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...

  18. Thermo-mechanical performance of an ablative/ceramic composite hybrid thermal protection structure for re-entry applications

    OpenAIRE

    Triantou, K.; Mergia, K; Florez, S.; Perez, B.; Bárcena, Jorge; Rotärmel, W.; Pinaud, G.; Fischer, W.P.P.

    2015-01-01

    Hybrid thermal protection systems for aerospace applications based on ablative material (ASTERM (TM)) and ceramic matrix composite (SICARBON (TM)) have been investigated. The ablative material and the ceramic matrix composite were joined using graphite and zirconia zirconium silicate based commercial high temperature adhesives. The thermo-mechanical performance of the structures was assessed from room temperature up to 900 degrees C. In all the joints there is a decrease of shear strength wit...

  19. 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.

  20. Preparation and Properties of Smart Thermal Control and Radiation Protection Materials for Multi-functional Structure of Small Spacecraft

    Institute of Scientific and Technical Information of China (English)

    shijie Zhang; Xibin Cao; Yingqiang Luan; Xinxin Ma; Xiaohui Lin; Xianren Kong

    2011-01-01

    Considering the unique properties of small spacecraft, such as light weight, low power-consumption and high heat flux density, a new kind of lightweight boron carbide (B4C) radiation-protection coating material was proposed. New techniques for preparing LSMO thermal control coating and B4C radiation-protection coating were developed. The sample piece of multi-functional structure was manufactured by using the proposed materials, and a series of performance tests, such as thermal control and radiation-protection behaviors were evaluated. Test results show that: the emissivity of the multi-functional structure varies from 0.42 to 0.86 at 240 K to 353 K and the phase transition temperature is about 260 K. The electron radiation-protection ability of the multi-functional structure is 3.3 times better than that of Al material. The performance index of this multi-functional structure can meet the requirements for space application in on-board electronic equipment.

  1. The influence of the free space environment on the superlight-weight thermal protection system: conception, methods, and risk analysis

    Science.gov (United States)

    Yatsenko, Vitaliy; Falchenko, Iurii; Fedorchuk, Viktor; Petrushynets, Lidiia

    2016-07-01

    This report focuses on the results of the EU project "Superlight-weight thermal protection system for space application (LIGHT-TPS)". The bottom line is an analysis of influence of the free space environment on the superlight-weight thermal protection system (TPS). This report focuses on new methods that based on the following models: synergetic, physical, and computational. This report concentrates on four approaches. The first concerns the synergetic approach. The synergetic approach to the solution of problems of self-controlled synthesis of structures and creation of self-organizing technologies is considered in connection with the super-problem of creation of materials with new functional properties. Synergetics methods and mathematical design are considered according to actual problems of material science. The second approach describes how the optimization methods can be used to determine material microstructures with optimized or targeted properties. This technique enables one to find unexpected microstructures with exotic behavior (e.g., negative thermal expansion coefficients). The third approach concerns the dynamic probabilistic risk analysis of TPS l elements with complex characterizations for damages using a physical model of TPS system and a predictable level of ionizing radiation and space weather. Focusing is given mainly on the TPS model, mathematical models for dynamic probabilistic risk assessment and software for the modeling and prediction of the influence of the free space environment. The probabilistic risk assessment method for TPS is presented considering some deterministic and stochastic factors. The last approach concerns results of experimental research of the temperature distribution on the surface of the honeycomb sandwich panel size 150 x 150 x 20 mm at the diffusion welding in vacuum are considered. An equipment, which provides alignment of temperature fields in a product for the formation of equal strength of welded joints is

  2. Remote sensing of thermal radiation from an aircraft - An analysis and evaluation of crop-freeze protection methods

    Science.gov (United States)

    Sutherland, R. A.; Hannah, H. E.; Cook, A. F.; Martsolf, J. D.

    1981-01-01

    Thermal images from an aircraft-mounted scanner are used to evaluate the effectiveness of crop-freeze protection devices. Data from flights made while using fuel oil heaters, a wind machine and an undercanopy irrigation system are compared. Results show that the overall protection provided by irrigation (at approximately 2 C) is comparable to the less energy-efficient heater-wind machine combination. Protection provided by the wind machine alone (at approximately 1 C) was found to decrease linearly with distance from the machine by approximately 1 C/100 m. The flights were made over a 1.5 hectare citrus grove at an altitude of 450 m with an 8-14 micron detector. General meteorological conditions during the experiments, conducted during the nighttime, were cold (at approximately -6 C) and calm with clear skies.

  3. Evaluation of Characteristics of Non-Metallic Inclusions in P/M Ni-Base Superalloy by Automatic Image Analysis

    Institute of Scientific and Technical Information of China (English)

    Li; Xinggang; Ge; Changchun; Shen; Weiping

    2007-01-01

    Non-metallic inclusions,especially the large ones,within P/M Ni-base superalloy have a major influence on fatigue characteristics,but are not directly measurable by routine inspection.In this paper,a method,automatic image analysis,is proposed for estimation of the content,size and amount of non-metallic inclusions in superalloy.The methodology for the practical application of this method is described and the factors affecting the precision of the estimation are discussed.In the experiment,the characteristics of the non-metallic inclusions in Ni-base P/M superalloy are analyzed.

  4. Prediction of porous walls thermal protection by effusion or transpiration cooling: an analytical approach

    Energy Technology Data Exchange (ETDEWEB)

    Andoh, Y.H. [Institut National Polytechnique Felix Houphouet-Boigny, Yamoussoukro (Ivory Coast); Lips, B. [Centre de Thermique de Lyon, Villeurbanne Cedex (France)

    2003-10-01

    The study is about the thermal control of porous walls submitted to severe heat fluxes. The numerical approach model of heat transfer, developed, is based on energy balance equation. The governing parameters are the volumetric heat transfer coefficient, the equivalent thermal conductivity of the material and fluid flow characteristics. The interactive effects of these parameters on heat transfer are presented to permit to understand the relative importance of varied phenomena occurring. The validity of the results is verified in a thermal behavior study of a porous plate submitted to a heat flux up to 3500 K and cooled by a refrigerant fluid. Good agreement with the previsions is obtained. (author)

  5. Numerical Simulation of a Thermal-Protection Element of a Promising Reusable Capsule-Type Lander

    Science.gov (United States)

    Prosuntsov, P. V.; Shulyakovskii, A. V.; Taraskin, N. Yu.

    2017-01-01

    An indestructible multilayer thermal-barrier coating is proposed for a promising reusable capsule-type lander. This coating is based on a porous carbon-ceramic material. The thermal state of the coating proposed was simulated mathematically for different types of its reinforcement and different values of the porosity and the heat-conductivity coefficient of the carbon-ceramic material. Results of a numerical simulation of the temperature state of an element of the multilayer thermal-barrier coating are presented. On the basis of these data, the thickness and the weight efficiency of the coating were estimated.

  6. Non-metallic, non-Fermi-liquid resistivity of FeCrAs from 0 to 17 GPa.

    Science.gov (United States)

    Tafti, F F; Wu, W; Julian, S R

    2013-09-25

    An unusual, non-metallic resistivity of the 111 iron-pnictide compound FeCrAs is shown to be relatively unchanged under pressures of up to 17 GPa. Combined with our previous finding that this non-metallic behaviour persists from at least 80 mK to 800 K, this shows that the non-metallic phase is exceptionally robust. Antiferromagnetic order, with a Néel temperature TN ∼ 125 K at ambient pressure, is suppressed by pressure at a rate of 7.0 ± 0.4 K GPa(-1), falling to ∼50 K at 10 GPa. We conclude that the formation of a spin-density-wave gap at TN does not play an important role in the non-metallic resistivity of FeCrAs at low temperatures.

  7. Recycling of non-metallic fractions from waste electrical and electronic equipment (WEEE): A review

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruixue; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

    2014-08-15

    Highlights: • NMFs from WEEE were treated by incineration or land filling in the past. • Environmental risks such as heavy metals and BFRs will be the major problems during the NMFs recycling processes. • Methods and technologies of recycling the two types of NMFs from WEEE, plastics, glasses are reviewed. • More environmental impact assessment should be carried out to evaluate the environmental risks of the recycling products. - Abstract: The world’s waste electrical and electronic equipment (WEEE) consumption has increased incredibly in recent decades, which have drawn much attention from the public. However, the major economic driving force for recycling of WEEE is the value of the metallic fractions (MFs). The non-metallic fractions (NMFs), which take up a large proportion of E-wastes, were treated by incineration or landfill in the past. NMFs from WEEE contain heavy metals, brominated flame retardant (BFRs) and other toxic and hazardous substances. Combustion as well as landfill may cause serious environmental problems. Therefore, research on resource reutilization and safe disposal of the NMFs from WEEE has a great significance from the viewpoint of environmental protection. Among the enormous variety of NMFs from WEEE, some of them are quite easy to recycle while others are difficult, such as plastics, glass and NMFs from waste printed circuit boards (WPCBs). In this paper, we mainly focus on the intractable NMFs from WEEE. Methods and technologies of recycling the two types of NMFs from WEEE, plastics, glass are reviewed in this paper. For WEEE plastics, the pyrolysis technology has the lowest energy consumption and the pyrolysis oil could be obtained, but the containing of BFRs makes the pyrolysis recycling process problematic. Supercritical fluids (SCF) and gasification technology have a potentially smaller environmental impact than pyrolysis process, but the energy consumption is higher. With regard to WEEE glass, lead removing is requisite

  8. Phenolic Impregnated Carbon Ablators (PICA) as Thermal Protection Systems for Discovery Missions

    Science.gov (United States)

    Tran, Huy K.; Johnson, Christine E.; Rasky, Daniel J.; Hui, Frank C. L.; Hsu, Ming-Ta; Chen, Timothy; Chen, Y. K.; Paragas, Daniel; Kobayashi, Loreen

    1997-01-01

    This paper presents the development of the light weight Phenolic Impregnated Carbon Ablators (PICA) and its thermal performance in a simulated heating environment for planetary entry vehicles. The PICA material was developed as a member of the Light Weight Ceramic Ablators (LCA's), and the manufacturing process of this material has since been significantly improved. The density of PICA material ranges from 14 to 20 lbm/ft(exp 3), having uniform resin distribution with and without a densified top surface. The thermal performance of PICA was evaluated in the Ames arc-jet facility at cold wall heat fluxes from 375 to 2,960 BtU/ft(exp 2)-s and surface pressures of 0.1 to 0.43 atm. Heat loads used in these tests varied from 5,500 to 29,600 BtU/ft(exp 2) and are representative of the entry conditions of the proposed Discovery Class Missions. Surface and in-depth temperatures were measured using optical pyrometers and thermocouples. Surface recession was also measured by using a template and a height gage. The ablation characteristics and efficiency of PICA are quantified by using the effective heat of ablation, and the thermal penetration response is evaluated from the thermal soak data. In addition, a comparison of thermal performance of standard and surface densified PICA is also discussed.

  9. Computer Simulation of the Formation of Non-Metallic Precipitates During a Continuous Casting of Steel

    Directory of Open Access Journals (Sweden)

    Kalisz D.

    2016-03-01

    Full Text Available The authors own computer software, based on the Ueshima mathematical model with taking into account the back diffusion, determined from the Wołczyński equation, was developed for simulation calculations. The applied calculation procedure allowed to determine the chemical composition of the non-metallic phase in steel deoxidised by means of Mn, Si and Al, at the given cooling rate. The calculation results were confirmed by the analysis of samples taken from the determined areas of the cast ingot. This indicates that the developed computer software can be applied for designing the steel casting process of the strictly determined chemical composition and for obtaining the required non-metallic precipitates.

  10. Injury experience in nonmetallic mineral mining (except stone and coal), 1992

    Energy Technology Data Exchange (ETDEWEB)

    Reich, R.B; Hugler, E.C.

    1994-05-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of nonmetallic mineral mining (except stone and coal) in the United States for 1992. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, occupation, and principal type of mineral. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report.

  11. Injury experience in nonmetallic mineral mining (except stone and coal), 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of nonmetallic mineral mining (except stone and coal) in the United States for 1989. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, occupation, and principal type of mineral. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report. 3 figs., 46 tabs.

  12. Non-metallic catalysts for diamond synthesis under high pressure and high temperature

    Institute of Scientific and Technical Information of China (English)

    孙力玲; 吴奇; 戴道扬; 张君; 秦志成; 王文魁

    1999-01-01

    Recent results on conversion from graphite to diamond by aid of non-metallic catalysts are reviewed. The current status of experimental advances is presented and typical examples from relevant literature are provided for understanding the mechanism of the graphite-diamond conversion by aid of these non-metallic catalysts. Furthermore, a tendency of graphite-diamond transformation assisted by carbonates, sulfates or phosphorus under high pressure and high temperature has been investigated by calculating the activation energy and transformation probability of the carbon atoms over a potential barrier. It was found that the activation energy is highly sensitive to the catalyst chosen. The probability sequence of graphite-diamond transformation with these catalysts was put forward.

  13. Motion behavior of non-metallic particles under high frequency magnetic field

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong-tao; GUO Qing-tao; YU Feng-yun; LI Jie; ZHANG Jian; LI Ting-ju

    2009-01-01

    Non-metallic particles, especially alumina, are the main inclusions in aluminum and its alloys. Numerical simulation and the corresponding experiments were carried out to study the motion behavior of alumina particles in commercial pure aluminum under high frequency magnetic field. At the meantime, multi-pipe experiment was also done to discuss the prospect of continuous elimination of non-metallic particles under high frequency magnetic field. It is shown that: 1) results of numerical simulation are in good agreement with the experimental results, which certificates the rationality of the simulation model; 2) when the intensity of high frequency magnetic field is 0.06 T, the 30 μm alumina particles in melt inner could migrate to the edge and be removed within 2 s; 3) multi-pipe elimination of alumina particles under high frequency magnetic field is also effective and has a good prospect in industrial application.

  14. Thermal Protection System Materials (TPSM): Heat Shield for Extreme Entry Environment Technology (HEEET) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Heatshield for Extreme Entry Environ­ment Technology (HEEET) project seeks to mature a game changing Woven Ther­mal Protection System (TPS) technology to...

  15. MMOD-IMLI: Integrated Thermal Insulation and Micrometeoroid/Orbital Debris Protection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For NASA extended missions in Low Earth Orbit (LEO), Micrometeoroid and Orbital Debris (MMOD) protection for spacecraft, space stations and orbiting fuel depots is...

  16. NON-METALLIC IMPURITIES AND FORMING OF THE STRUCTURE OF THE MODIFIED HIGH-MANGANESE STEEL

    Directory of Open Access Journals (Sweden)

    A. I. Garost

    2006-01-01

    Full Text Available The composition and morphology of chemical associations (non-metallic impurities and other ‘‘secondary” phases at modification of high-manganese steel by nitrogen and nitrideforming elements (vanadium are investigated. The optimal compositions of steel for production of castings are offered. The technology of the steel wear-resistance modification by vanadium of waste of industrial enterprises is worked out.

  17. Behavior of Non-metallic Inclusions in Centrifugal Induction Electroslag Castings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    (para)In order to know the behavior of non-metallic inclusions in centrifugal induction electroslag castings (CIESC), non-metallic inclusions in 5CrMnMo and 4Cr5MoSiV1 were qualitatively and quantitatively analyzed. The largest size of inclusions in the casting and the thermodynamic possibility of TiN precipitation in steel were also calculated. The results show that sulfide inclusions are evenly distributed and the content is low. The amount of oxide inclusions in CIESC 4Cr5MoSiV1 steel is close to the ESR steel and lower than that in the EAF steel, and there are some differences along radial direction. Nitride inclusions are fine and the diameter of the largest one is 3~4um. With the increase of the centrifugal machine's rotational speed, the ratio of round inclusions increases and the ratio of sharp inclusions decreases. According to the experiment and the calculation results, it is pointed out that the largest diameter of non-metallic inclusions in the CIESC 4Cr5MoSiV1 casting is only 6.6mu, and [N%][Ti%] in 4Cr5MoSiV1 steel should be controlled less than 4.4~#U00d7tex010^{-5} in order to further reduce the amount and size of TiN inclusions.

  18. A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

    Science.gov (United States)

    Grady, Joseph E.

    2015-01-01

    The Non-Metallic Gas Turbine Engine project, funded by NASA Aeronautics Research Institute, represents the first comprehensive evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. This will be achieved by assessing the feasibility of using additive manufacturing technologies to fabricate polymer matrix composite and ceramic matrix composite turbine engine components. The benefits include: 50 weight reduction compared to metallic parts, reduced manufacturing costs, reduced part count and rapid design iterations. Two high payoff metallic components have been identified for replacement with PMCs and will be fabricated using fused deposition modeling (FDM) with high temperature polymer filaments. The CMC effort uses a binder jet process to fabricate silicon carbide test coupons and demonstration articles. Microstructural analysis and mechanical testing will be conducted on the PMC and CMC materials. System studies will assess the benefits of fully nonmetallic gas turbine engine in terms of fuel burn, emissions, reduction of part count, and cost. The research project includes a multidisciplinary, multiorganization NASA - industry team that includes experts in ceramic materials and CMCs, polymers and PMCs, structural engineering, additive manufacturing, engine design and analysis, and system analysis.

  19. ASP53, a thermostable protein from Acacia erioloba seeds that protects target proteins against thermal denaturation

    CSIR Research Space (South Africa)

    Mtwisha, L

    2007-02-01

    Full Text Available stages of protein thermal denaturation. ASP53 decreased the rate of loss of alcohol dehydrogenase activity at 55°C, decreased the rate of temperature-dependent loss of secondary structure of haemoglobin and completely inhibited the temperature...

  20. Coolness both underlies and protects against the painfulness of the thermal grill illusion.

    Science.gov (United States)

    Harper, Daniel E; Hollins, Mark

    2014-04-01

    We investigated the contributions of warm and cool signals in generating the thermal grill illusion (TGI), a phenomenon in which interlaced warm and cool bars generate an experience of burning, and under some conditions painful, heat. Each subject underwent 3 runs, 2 of which tested the effects of preadapting subjects to the grill's warm or cool bars (while the interlaced bars were thermally neutral) on the subsequent intensity of the illusion. In a control run, all bars were neutral during the adaptation phase. Thermal visual analogue scale ratings during the warm and cool adaptation periods revealed significant and equivalent adaptation to the 2 temperatures. Adaptation to the grill's cool bars significantly reduced pain and perceived thermal intensity of the TGI, compared to the control condition, while adaptation to the grill's warm bars had little effect. These results suggest that the cool stimulus triggers the pain signals that produce the illusion. The inability of warm adaptation to attenuate the TGI is at odds with theories suggesting that the illusion depends upon a simple addition of warm and cool signals. While the grill's cool bars are necessary for the TGI's painfulness, we also observed that the more often a participant reported feeling coolness or coldness, the less pain he or she experienced from the TGI. These results are consistent with research showing that cool temperatures generate activity in both thermoreceptive-specific, pain-inhibitory neurons and nociceptive dorsal horn neurons.

  1. An evaluation of flight data for the Apollo thermal protection system

    Science.gov (United States)

    Bartlett, E. P.; Curry, D. M.

    1972-01-01

    A study was conducted to correlate Apollo ablation and thermal response flight data using advanced state-of-the-art analytical procedures. The agreement between flight data and predictions is consistently excellent for in-depth temperature distributions, char density profiles, and surface ablation, thus validating the analytical procedures.

  2. 75 FR 5495 - Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events...

    Science.gov (United States)

    2010-02-03

    ... (75 FR 13), that amends the NRC's regulations to provide alternate fracture toughness requirements for....Lesar@nrc.gov . SUPPLEMENTARY INFORMATION: In FR doc. E9-31146, published on January 4, 2010, make the... Pressurized Thermal Shock Events; Correction AGENCY: Nuclear Regulatory Commission. ACTION: Final...

  3. 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

  4. Influence of non-metallic inclusions on the strength properties of screws made of 35B2+Cr steel after softening

    OpenAIRE

    Krawczyk, J.; Pawłowski, B

    2012-01-01

    Purpose: This paper presents the results of the research on the influence of non-metallic inclusions on strength properties of 35B2+Cr steel screws.Design/methodology/approach: The investigations were carried out on screws after softening. The investigated steels with different fraction of non-metallic inclusions were delivered by three different suppliers.Findings: It was proved, that in spite of the level of fraction of non-metallic inclusions compatible with the corresponding standards, th...

  5. Study of irradiation effects in non-metallic conductors

    Energy Technology Data Exchange (ETDEWEB)

    Atobe, Kozo; Fukuoka, Noboru; Honda, Makoto; Kondo, Tadashi; Morishima, Kouichi [Naruto Univ. of Education, Naruto, Tokushima (Japan). Faculty of Science; Okada, Moritami; Nakagawa, Masuo

    1998-01-01

    The production of point defects induced by reactor and the thermal behavior of defects in sintered AlN and c-BN have been investigated using the optical absorption and electron spin resonance (ESR) methods. The absorption band at 370 nm (AlN) and the structureless absorption over the visible region are observed. These specimens also show ESR signals with g-value 2.007 (AlN), 2.006 (BN), which are probably caused by N vacancies with a trapped electron. In addition to these experiments, the difference of the photoluminescence(PL) lines on neutron irradiated CZ-Si and FZ-Si has been also studied. The models of the defect associated with neutron irradiation are discussed. (author)

  6. 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.

  7. 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.

  8. Experimental investigations on active cooling thermal protection structure of hydrocarbon-fueled scramjet combustor in arc heated facility

    Science.gov (United States)

    Jianqiang, Tu; Jinlong, Peng; Xianning, Yang; Lianzhong, Chen

    2016-10-01

    The active cooling thermal protection technology is the efficient method to resolve the long-duration work and reusable problems of hydrocarbon-fueled scramjet combustor, where worst thermo-mechanical loads occur. The fuel is passed through coolant channels adjacent to the heated surfaces to absorb heat from the heating exchanger panels, prior to injection into the combustor. The heating exchanger both cooled down the wall temperature of the combustor wall and heats and cracks the hydrocarbon fuel inside the panel to permit an easier combustion and satisfying combustion efficiency. The subscale active cooling metallic panels, with dimensions of 100×100 mm and different coolant channel sizes, have been tested under typical combustion thermal environment produced by arc heated Turbulent Flow Duct (TFD). The heat exchange ability of different coolant channel sizes has been obtained. The big-scale active cooling metallic panel, with dimensions of 100 × 750 mm and the coolant channel sizes of better heating exchange performance, has been made and tested in the big-scale arc heated TFD facility. The test results show that the local superheated ablation is easy to happen for the cooling fuel assigned asymmetrically in the bigscale active cooling metallic panel, and the cooling fuel rate can reduce 8%˜10% after spraying the Thermal Barrier Coating (TBC) in the heating surface.

  9. Thermal Barrier and Protective Coatings to Improve the Durability of a Combustor Under a Pulse Detonation Engine Environment

    Science.gov (United States)

    Ghosn, Louis J.; Zhu, Dongming

    2008-01-01

    Pulse detonation engine (PDE) concepts are receiving increasing attention for future aeronautic propulsion applications, due to their potential thermodynamic cycle efficiency and higher thrust to density ratio that lead to the decrease in fuel consumption. But the resulting high gas temperature and pressure fluctuation distributions at high frequency generated with every detonation are viewed to be detrimental to the combustor liner material. Experimental studies on a typical metal combustion material exposed to a laser simulated pulse heating showed extensive surface cracking. Coating of the combustor materials with low thermal conductivity ceramics is shown to protect the metal substrate, reduce the thermal stresses, and hence increase the durability of the PDE combustor liner material. Furthermore, the temperature fluctuation and depth of penetration is observed to decrease with increasing the detonation frequency. A crack propagation rate in the coating is deduced by monitoring the variation of the coating apparent thermal conductivity with time that can be utilized as a health monitoring technique for the coating system under a rapid fluctuating heat flux.

  10. Large modular graphite radiant heaters for testing space shuttle thermal protection systems

    Science.gov (United States)

    Cox, B. G.; Christensen, H. E.

    1975-01-01

    A graphite radiant heating array, capable of heating a 5-ft span of shuttle wing leading edge or a 4 x 8 ft flat panel through an entry thermal profile up to 3200 G, has been designed and built by McDonnell Douglas Corporation for NASA-Johnson Space Center. The unique, interchangeable, self-contained heather modules and their versatile support structure/coolant manifold are discussed along with the extensive thermal analysis that accompanied the design effort. A complete description of the geometric capabilities of the array, as well as the design details of the individual modules, is presented. The complete performance envelope of the array is discussed, including maximum temperature and gradients, heating uniformity, and the required utilities and support equipment.

  11. Large modular graphite radiant heaters for testing space shuttle thermal protection systems

    Science.gov (United States)

    Cox, B. G.; Christensen, H. E.

    1975-01-01

    A graphite radiant heating array, capable of heating a 5-ft span of shuttle wing leading edge or a 4 x 8 ft flat panel through an entry thermal profile up to 3200 G, has been designed and built by McDonnell Douglas Corporation for NASA-Johnson Space Center. The unique, interchangeable, self-contained heather modules and their versatile support structure/coolant manifold are discussed along with the extensive thermal analysis that accompanied the design effort. A complete description of the geometric capabilities of the array, as well as the design details of the individual modules, is presented. The complete performance envelope of the array is discussed, including maximum temperature and gradients, heating uniformity, and the required utilities and support equipment.

  12. Thermophysical Properties of Matter - The TPRC Data Series. Volume 3. Thermal Conductivity - Nonmetallic Liquids and Gases

    Science.gov (United States)

    1970-01-01

    1AD634 900) 123. Dimiduk. P.. "A Bibliography of References for the Thermophysical Properties of Helium-4. Hydrogen. Deuterium. Hydrogen Deuteride . Neon...Platinum + Rhodium Platinum + Ruthenium Platinum + Silver Plexiglas Plexiglas AN-P-44A Pliofoam Pluton cloth Plutonium Plutonium , or Plutonium ...Aluminum Plutonium + Iron Plutonium alloy, delta-stabilized Polychloroethylene (polyvinyl chloride) Polychloroethylene (polyvinyl chloride

  13. Thermophysical Properties of Matter - The TPRC Data Series. Volume 8. Thermal Radiative Properties - Nonmetallic Solids

    Science.gov (United States)

    1972-01-01

    Iron oxldes- kaolin -aagneslum oxides- manganese oxldes-marble-nlckel oxldes-obsldlan-opal-opal glass-plexlglas- mylar—polyethylene-pyrocerams—quarts...magnesium oxide, magnesium carbon- ate, high-purity barium sulphate, sodium chloride, flowers of sulphur , and some good white paints [I, 50, 76]. For...S. T.. "Application of Sulphur Coatings to Integrating Spheres." Appl. Opt.. 4(4). 377, 1965. Dunn. S. T.. "Flux Averaging Devices for the

  14. Thermophysical Properties of Matter - The TPRC Data Series. Volume 2. Thermal Conductivity - Nonmetallic Solids

    Science.gov (United States)

    1971-01-01

    researcher, experi- mentalist, and theoretician, the teacher at the graduate level may also use it as a teaching tool to point out to his students the...Thermodynamics and Thermochemistry ," Am. J. Phys., 12(1). 1-7, 1944, The subscripts "th" and "IT" designate "ther- mochemical" and "International

  15. Crack barriers improve the mechanical and thermal properties of non-metallic sinter materials

    Science.gov (United States)

    Gruenthaler, K. H.; Heinrich, W.; Janes, S.; Nixdorf, J.

    1979-01-01

    Means of improving the tensile strength of ceramic composites by introducing ductile intermediate layers capable of absorbing the elastic energy at the rupture front are studied. Tests with an Al203 laminate with niobium inclusions showed that crack propagation could be successfully precluded by dissipation of the energy by deformation and/or delamination at the inclusion/matrix interface.

  16. System Studies on Active Thermal Protection of a Hypersonic Suborbital Passenger Transport Vehicle

    OpenAIRE

    Schwanekamp, Tobias; Meyer, Frank; Reimer, Thomas; Petkov, Ivaylo; Tröltzsch, Anke; Siggel, Martin

    2014-01-01

    Aerodynamic heating is a critical design aspect for the development of reusable hypersonic transport and reentry vehicles. The reliability in terms of thermal resistance is one of the major driving factors with respect to the design margins, the mass balance and finally the total costs of a configuration. Potential designs of active cooling systems for critical regions such as the vehicle nose and leading edges are presented as well as preliminary approaches for their impact on the total mass...

  17. Development of high temperature silicone adhesive formulations for thermal protection system applications

    Science.gov (United States)

    Hockridge, R. R.

    1973-01-01

    Trade-off studies and screening evaluations were made of commercial polymers and silicone foam sheet stock. A low modulus, low density 0.26 gm/cc modification was developed of the GE-RESD PD-200 system based upon GE RTV-560 silicone polymer. The bond system modification was initially characterized for mechanical and thermal properties, evaluated for application methods, and its capability demonstrated as a strain arrestor bond system.

  18. Thermal Stability and Oxidation Resistance of Nanocomposite TiC/a-C Protective Coatings

    NARCIS (Netherlands)

    Martinez-Martinez, Diego; Lopez-Cartes, Carlos; Gago, Raul; Fernandez, Asuncion; Carlos Sanchez-Lopez, Juan

    2009-01-01

    Nanocomposite films composed by small crystallites of hard phases embedded in an amorphous lubricant matrix have been extensively studied as protective coatings. These kinds of coatings have often to work in extreme environments, exposed to high temperatures (above 800-900 degrees C), and/or oxidizi

  19. Flexible fire retardant polyisocyanate modified neoprene foam. [for thermal protective devices

    Science.gov (United States)

    Parker, J. A.; Riccitiello, S. R. (Inventor)

    1973-01-01

    Lightweight, fire resistant foams have been developed through the modification of conventional neoprene-isocyanate foams by the addition of an alkyl halide polymer. Extensive tests have shown that the modified/neoprene-isocyanate foams are much superior in heat protection properties than the foams heretofore employed both for ballistic and ablative purposes.

  20. Dynamic changes in the localization of thermally unfolded nuclear proteins associated with chaperone-dependent protection

    NARCIS (Netherlands)

    Nollen, E A; Salomons, F A; Brunsting, J F; van der Want, J J; Sibon, O C; Kampinga, H H

    2001-01-01

    Molecular chaperones are involved in the protection of cells against protein damage through their ability to hold, disaggregate, and refold damaged proteins or their ability to facilitate degradation of damaged proteins. Little is known about how these processes are spatially coordinated in cells. U

  1. Duplex Al-based thermal spray coatings for corrosion protection in high temperature refinery applications

    Directory of Open Access Journals (Sweden)

    Rocha Adriana da Cunha

    2004-01-01

    Full Text Available The application of thermal spray coatings has been effective in preventing corrosion of steel and iron products. It has been used in a wide range of applications spreading from the petroleum to the food industry. In this work, the performance and effectiveness of a two-layered aluminum-based thermal spray coating applied to an ASTM A387 G11 steel was evaluated. The coating structure was comprised of an inner Al-Fe-Cr layer and an outer layer of aluminum. Coated samples were tested in the reactor zone of a fluid catalytic cracking unit (FCCU of a petrochemical plant for 2.5 years. The reactor zone temperature was about 793 K (520 °C and the environment was a mixed gas containing sulfur, oxygen and carbon. Laboratory-scale tests were also conducted on the coated samples in order to gain a better understanding of the corrosive effect of the gaseous species present in the FCCU atmosphere. Porosity present in the thermal spray coatings allowed the penetration of the atmosphere corrodents, which instigated intergranular corrosion of the steel substrate. The presence of an inner Al-Fe-Cr layer did not prevent coating spallation, which further contributed to the internal corrosion process.

  2. Worldwide distribution of soil dielectric and thermal properties

    NARCIS (Netherlands)

    Hendrickx, J.M.H.; Dam, R.L. van; Borchers, B.; Curtis, J.; Lensen, H.A.; Harmon, R.

    2003-01-01

    Ground penetrating radar and thermal sensors hold much promise for the detection of non-metallic land mines. In previous work we have shown that the performance of ground penetrating radar strongly depends on field soil conditions such as texture, water content, and soil-water salinity since these s

  3. Worldwide distribution of soil dielectric and thermal properties

    NARCIS (Netherlands)

    Hendrickx, J.M.H.; Dam, R.L. van; Borchers, B.; Curtis, J.; Lensen, H.A.; Harmon, R.

    2003-01-01

    Ground penetrating radar and thermal sensors hold much promise for the detection of non-metallic land mines. In previous work we have shown that the performance of ground penetrating radar strongly depends on field soil conditions such as texture, water content, and soil-water salinity since these

  4. High-Temperature Corrosion of Protective Coatings for Boiler Tubes in Thermal Power Plants

    Institute of Scientific and Technical Information of China (English)

    XU Lianyong; JING Hongyang; HUO Lixing

    2005-01-01

    High-temperature corrosion is a serious problem for the water-wall tubes of boilers used in thermal power plants. Oxidation, sulfidation and molten salt corrosion are main corrosion ways.Thereinto, the most severe corrosion occurs in molten salt corrosion environment. Materials rich in oxides formers, such as chromium and aluminum, are needed to resist corrosion in high-temperature and corrosive environment, but processability of such bulk alloys is very limited. High velocity electric arc spraying (HVAS) technology is adopted to produce coatings with high corrosion resistance. By comparison, NiCr (Ni-45Cr-4Ti) is recommended as a promising alloy coating for the water-wall tubes, which can even resist molten salt corrosion attack. In the study of corrosion mechanism, the modern material analysis methods, such as scanning electron microscopy (SEM), X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS), are used. It is found that the corrosion resistances of NiCr and FeCrAI coatings are much better than that of 20g steel, that the NiCr coatings have the best anti-corrosion properties, and that the NiCr coatings have slightly lower pores than FeCrAI coatings.It is testified that corrosion resistance of coatings is mainly determined by chromium content, and the microstructure of a coating is as important as the chemical composition of the material. In addition, the fracture mechanisms of coatings in the cycle of heating and cooling are put forward. The difference of the thermal physical properties between coatings and base metals results in the thermal stress inside the coatings. Consequently, the coatings spall from the base metal.

  5. Inorganic Water Repellent Coatings for Thermal Protection Insulation on an Aerospace Vehicle

    Science.gov (United States)

    Fuerstenau, D. W.; Huang, P.; Ravikumar, R.

    1997-01-01

    The objective of this research was two-fold: first, to identify and test inorganic water-repellent materials that would be hydrophobic even after thermal cycling to temperatures above 600 C and, second, to develop a model that would link hydrophobicity of a material to the chemical properties of its constituent atoms. Four different materials were selected for detailed experimental study, namely, boron nitride, talc, molybdenite, and pyrophyllite, all of which have a layered structure made up of ionic/covalent bonds within the layers but with van der Waals bonds between the layers. The materials tested could be considered hydrophobic for a nonporous surface but none of the observed contact angles exceeded the necessary 90 degrees required for water repellency of porous materials. Boron nitride and talc were observed to retain their water-repellency when heated in air to temperatures that did not exceed 800 C, and molybdenite was found to be retain its hydrophobicity when heated to temperatures up to 600 C. For these three materials, oxidation and decomposition were identified to be the main cause for the breakdown of water repellency after repeated thermal cycling. Pyrophyllite shows the maximum promise as a potential water-repellent inorganic material, which, when treated initially at 900 C, retained its shape and remained hydrophobic for two thermal cycles where the maximum retreatment temperature is 900 C. A model was developed for predicting materials that might exhibit hydrophobicity by linking two chemical properties, namely, that the constituent ions of the compound belong to the soft acid-base category and that the fractional ionic character of the bonds be less than about 20 percent.

  6. Development and validation of purged thermal protection systems for liquid hydrogen fuel tanks of hypersonic vehicles

    Science.gov (United States)

    Helenbrook, R. D.; Colt, J. Z.

    1977-01-01

    An economical, lightweight, safe, efficient, reliable, and reusable insulation system was developed for hypersonic cruise vehicle hydrogen fuel tanks. Results indicate that, a nitrogen purged, layered insulation system with nonpermeable closed-cell insulation next to the cryogenic tank and a high service temperature fibrous insulation surrounding it, is potentially an attractive solution to the insulation problem. For the postulated hypersonic flight the average unit weight of the purged insulation system (including insulation, condensate and fuel boil off) is 6.31 kg/sq m (1.29 psf). Limited cyclic tests of large specimens of closed cell polymethacrylimide foam indicate it will withstand the expected thermal cycle.

  7. Conformal Ablative Thermal Protection Systems (CA-TPS) for Venus and Saturn Backshells

    Science.gov (United States)

    Beck, R.; Gasch, M.; Stackpoole, M.; Wilder, M.; Boghozian, T.; Chavez-Garcia, J.; Prabhu, Dinesh; Kazemba, Cole D.; Venkatapathy, E.

    2016-01-01

    This poster provides an overview of the work performed to date on the Conformal Ablative TPS (CA-TPS) element of the TPSM project out of GCDP. Under this element, NASA is developing improved ablative TPS materials based on flexible felt for reinforcement rather than rigid reinforcements. By replacing the reinforcements with felt, the resulting materials have much higher strain-to-failure and are much lower in thermal conductivity than their rigid counterparts. These characteristics should allow for larger tile sizes, direct bonding to aeroshells and even lower weight TPS. The conformal phenolic impregnated carbon felt (C-PICA) is a candidate for backshell TPS for both Venus and Saturn entry vehicles.

  8. Gap heating with pressure gradients. [for Shuttle Orbiter thermal protection system tiles

    Science.gov (United States)

    Scott, C. D.; Maraia, R. J.

    1979-01-01

    The heating rate distribution and temperature response on the gap walls of insulating tiles is analyzed to determine significant phenomena and parameters in flows where there is an external surface pressure gradient. Convective heating due to gap flow, modeled as fully developed pipe flow, is coupled with a two-dimensional thermal model of the tiles that includes conduction and radiative heat transfer. To account for geometry and important environmental parameters, scale factors are obtained by curve-fitting measured temperatures to analytical solutions. These scale factors are then used to predict the time-dependent gap heat flux and temperature response of tile gaps on the Space Shuttle Orbiter during entry.

  9. Protection of carbon steel against hot corrosion using thermal spray Si- and Cr-base coatings

    Science.gov (United States)

    Porcayo-Calderon, J.; Gonzalez-Rodriguez, J. G.; Martinez, L.

    1998-02-01

    A Fe75Si thermal spray coating was applied on the surface of a plain carbon steel baffle plate. Beneath this coating, a Ni20Cr coating was applied to give better adherence to the silicon coating. The baffle was installed in the high-temperature, fireside, corrosion zone of a steam generator. At the same time, an uncoated 304 stainless steel baffle was installed nearby for comparison. For 13 months the boiler burned heavy fuel oil with high contents of vanadium. The samples were studied employing scanning electron microscopy, x-ray microanalysis, and x-ray diffraction techniques. After that, it was possible to inspect the structural state of the components, and it was found that the stainless steel baffle plates were destroyed almost completely by corrosion, whereas the carbon steel coated baffle plate did not suffer a significant attack, showing that the performance of the thermal spray coating was outstanding and that the coating was not attacked by vanadium salts of the molten slag.

  10. Novel Hybrid Ablative/Ceramic Layered Composite for Earth Re-entry Thermal Protection: Microstructural and Mechanical Performance

    Science.gov (United States)

    Triantou, K.; Mergia, K.; Marinou, A.; Vekinis, G.; Barcena, J.; Florez, S.; Perez, B.; Pinaud, G.; Bouilly, J.-M.; Fischer, W. P. P.

    2015-04-01

    In view of spacecraft re-entry applications into planetary atmospheres, hybrid thermal protection systems based on layered composites of ablative materials and ceramic matrix composites are investigated. Joints of ASTERM™ lightweight ablative material with Cf/SiC (SICARBON™) were fabricated using commercial high temperature inorganic adhesives. Sound joints without defects are produced and very good bonding of the adhesive with both base materials is observed. Mechanical shear tests under ambient conditions and in liquid nitrogen show that mechanical failure always takes place inside the ablative material with no decohesion of the interface of the adhesive layer with the bonded materials. Surface treatment of the ablative surface prior to bonding enhances both the shear strength and the ultimate shear strain by up to about 60%.

  11. The Effects of Foam Thermal Protection System on the Damage Tolerance Characteristics of Composite Sandwich Structures for Launch Vehicles

    Science.gov (United States)

    Nettles, A. T.; Hodge, A. J.; Jackson, J. R.

    2011-01-01

    For any structure composed of laminated composite materials, impact damage is one of the greatest risks and therefore most widely tested responses. Typically, impact damage testing and analysis assumes that a solid object comes into contact with the bare surface of the laminate (the outer ply). However, most launch vehicle structures will have a thermal protection system (TPS) covering the structure for the majority of its life. Thus, the impact response of the material with the TPS covering is the impact scenario of interest. In this study, laminates representative of the composite interstage structure for the Ares I launch vehicle were impact tested with and without the planned TPS covering, which consists of polyurethane foam. Response variables examined include maximum load of impact, damage size as detected by nondestructive evaluation techniques, and damage morphology and compression after impact strength. Results show that there is little difference between TPS covered and bare specimens, except the residual strength data is higher for TPS covered specimens.

  12. Thermal property of insulation material for HTS power cable

    Science.gov (United States)

    Choi, Yeon Suk; Kim, D. L.; Shin, D. W.; Hwang, S. D.

    2012-06-01

    The thermal property of insulation material is essential in developing a high temperature superconductor (HTS) power cable operating at around liquid nitrogen temperature. The accurate estimate of the heat flux is difficult in the nonmetallic materials because nonmetallic materials have a high thermal resistance and low temperature gradient along the specimen. The objective of the present work is to develop a precise instrument for measuring the thermal conductivity of insulating materials over a temperature range of 30 K to approximately the room temperature by using a cryocooler. The thermal conductivity of Teflon is measured and the accuracy confirmation is carried out by comparing published data. In addition, the experimental results of apparent thermal conductivity of polypropylene laminated paper (PPLP) are presented and the temperature dependency is also discussed

  13. A Fully Non-metallic Gas Turbine Engine Enabled by Additive Manufacturing

    Science.gov (United States)

    Grady, Joseph E.

    2014-01-01

    The Non-Metallic Gas Turbine Engine project, funded by NASA Aeronautics Research Institute (NARI), represents the first comprehensive evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. This will be achieved by assessing the feasibility of using additive manufacturing technologies for fabricating polymer matrix composite (PMC) and ceramic matrix composite (CMC) gas turbine engine components. The benefits of the proposed effort include: 50 weight reduction compared to metallic parts, reduced manufacturing costs due to less machining and no tooling requirements, reduced part count due to net shape single component fabrication, and rapid design change and production iterations. Two high payoff metallic components have been identified for replacement with PMCs and will be fabricated using fused deposition modeling (FDM) with high temperature capable polymer filaments. The first component is an acoustic panel treatment with a honeycomb structure with an integrated back sheet and perforated front sheet. The second component is a compressor inlet guide vane. The CMC effort, which is starting at a lower technology readiness level, will use a binder jet process to fabricate silicon carbide test coupons and demonstration articles. The polymer and ceramic additive manufacturing efforts will advance from monolithic materials toward silicon carbide and carbon fiber reinforced composites for improved properties. Microstructural analysis and mechanical testing will be conducted on the PMC and CMC materials. System studies will assess the benefits of fully nonmetallic gas turbine engine in terms of fuel burn, emissions, reduction of part count, and cost. The proposed effort will be focused on a small 7000 lbf gas turbine engine. However, the concepts are equally applicable to large gas turbine engines. The proposed effort includes a multidisciplinary, multiorganization NASA - industry team that includes experts in

  14. Dual Heat Pulse, Dual Layer Thermal Protection System Sizing Analysis and Trade Studies for Human Mars Entry Descent and Landing

    Science.gov (United States)

    McGuire, Mary Kathleen

    2011-01-01

    NASA has been recently updating design reference missions for the human exploration of Mars and evaluating the technology investments required to do so. The first of these started in January 2007 and developed the Mars Design Reference Architecture 5.0 (DRA5). As part of DRA5, Thermal Protection System (TPS) sizing analysis was performed on a mid L/D rigid aeroshell undergoing a dual heat pulse (aerocapture and atmospheric entry) trajectory. The DRA5 TPS subteam determined that using traditional monolithic ablator systems would be mass expensive. They proposed a new dual-layer TPS concept utilizing an ablator atop a low thermal conductivity insulative substrate to address the issue. Using existing thermal response models for an ablator and insulative tile, preliminary hand analysis of the dual layer concept at a few key heating points indicated that the concept showed potential to reduce TPS masses and warranted further study. In FY09, the followon Entry, Descent and Landing Systems Analysis (EDL-SA) project continued by focusing on Exploration-class cargo or crewed missions requiring 10 to 50 metric tons of landed payload. The TPS subteam advanced the preliminary dual-layer TPS analysis by developing a new process and updated TPS sizing code to rapidly evaluate mass-optimized, full body sizing for a dual layer TPS that is capable of dual heat pulse performance. This paper describes the process and presents the results of the EDL-SA FY09 dual-layer TPS analyses on the rigid mid L/D aeroshell. Additionally, several trade studies were conducted with the sizing code to evaluate the impact of various design factors, assumptions and margins.

  15. Coexistence of metallic and nonmetallic charge transport in PrBa2Cu3O7

    Science.gov (United States)

    Lee, Mark; Suzuki, Y.; Geballe, T. H.

    1995-06-01

    Magnetotransport measurements on highly oriented thin films of PrBa2Cu3O7 demonstrate a unique coexistence of nonmetallic hopping conduction with metallic Boltzmann transport. At high temperature (T>10 K) hopping transport dominates, but when the inelastic conduction freezes out at low temperature, metallic behavior can be distinguished. The hopping conduction is assigned to the CuO2 planes, while the Boltzmann transport arises from the CuO chain structure, in agreement with recent electronic-structure calculations.

  16. Non-metallic inclusions structure dimension in high quality steel with medium carbon contents

    Directory of Open Access Journals (Sweden)

    T. Lipiński

    2009-07-01

    Full Text Available The experimental material consisted of semi-finished products of high-grade, medium-carbon structural steel. The production process involved two melting technologies: steel melting in a 140-ton basic arc furnace with desulfurization and argon refining variants, and in a 100-ton oxygen converter. Billet samples were collected to analyze the content of non-metallic inclusions with the use of an optical microscope and a video inspection microscope. The results were processed and presented in graphic form.

  17. The Effect of Fine Non-Metallic Inclusions on the Fatigue Strength of Structural Steel

    Directory of Open Access Journals (Sweden)

    Lipiński T.

    2015-04-01

    Full Text Available The article discusses the results of a study investigating the effect of the number of fine non-metallic inclusions (up to 2 µm in size on the fatigue strength of structural steel during rotary bending. The study was performed on 21 heats produced in an industrial plant. Fourteen heats were produced in 140 ton electric furnaces, and 7 heats were performed in a 100 ton oxygen converter. All heats were desulfurized. Seven heats from electrical furnaces were refined with argon, and heats from the converter were subjected to vacuum circulation degassing.

  18. Separation of the metallic and non-metallic fraction from printed circuit boards employing green technology.

    Science.gov (United States)

    Estrada-Ruiz, R H; Flores-Campos, R; Gámez-Altamirano, H A; Velarde-Sánchez, E J

    2016-07-05

    The generation of electrical and electronic waste is increasing day by day; recycling is attractive because of the metallic fraction containing these. Nevertheless, conventional techniques are highly polluting. The comminution of the printed circuit boards followed by an inverse flotation process is a clean technique that allows one to separate the metallic fraction from the non-metallic fraction. It was found that particle size and superficial air velocity are the main variables in the separation of the different fractions. In this way an efficient separation is achieved by avoiding the environmental contamination coupled with the possible utilization of the different fractions obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Aerothermal Ground Testing of Flexible Thermal Protection Systems for Hypersonic Inflatable Aerodynamic Decelerators

    Science.gov (United States)

    Bruce, Walter E., III; Mesick, Nathaniel J.; Ferlemann, Paul G.; Siemers, Paul M., III; DelCorso, Joseph A.; Hughes, Stephen J.; Tobin, Steven A.; Kardell, Matthew P.

    2012-01-01

    Flexible TPS development involves ground testing and analysis necessary to characterize performance of the FTPS candidates prior to flight testing. This paper provides an overview of the analysis and ground testing efforts performed over the last year at the NASA Langley Research Center and in the Boeing Large-Core Arc Tunnel (LCAT). In the LCAT test series, material layups were subjected to aerothermal loads commensurate with peak re-entry conditions enveloping a range of HIAD mission trajectories. The FTPS layups were tested over a heat flux range from 20 to 50 W/cm with associated surface pressures of 3 to 8 kPa. To support the testing effort a significant redesign of the existing shear (wedge) model holder from previous testing efforts was undertaken to develop a new test technique for supporting and evaluating the FTPS in the high-temperature, arc jet flow. Since the FTPS test samples typically experience a geometry change during testing, computational fluid dynamic (CFD) models of the arc jet flow field and test model were developed to support the testing effort. The CFD results were used to help determine the test conditions experienced by the test samples as the surface geometry changes. This paper includes an overview of the Boeing LCAT facility, the general approach for testing FTPS, CFD analysis methodology and results, model holder design and test methodology, and selected thermal results of several FTPS layups.

  20. Thermal Protection of Carbon Fiber-Reinforced Composites by Ceramic Particles

    Directory of Open Access Journals (Sweden)

    Baljinder Kandola

    2016-06-01

    Full Text Available The thermal barrier efficiency of two types of ceramic particle, glass flakes and aluminum titanate, dispersed on the surface of carbon-fiber epoxy composites, has been evaluated using a cone calorimeter at 35 and 50 kW/m2, in addition to temperature gradients through the samples’ thicknesses, measured by inserting thermocouples on the exposed and back surfaces during the cone tests. Two techniques of dispersing ceramic particles on the surface have been employed, one where particles were dispersed on semi-cured laminate and the other where their dispersion in a phenolic resin was applied on the laminate surface, using the same method as used previously for glass fiber composites. The morphology and durability of the coatings to water absorption, peeling, impact and flexural tension were also studied and compared with those previously reported for glass-fiber epoxy composites. With both methods, uniform coatings could be achieved, which were durable to peeling or water absorption with a minimal adverse effect on the mechanical properties of composites. While all these properties were comparable to those previously observed for glass fiber composites, the ceramic particles have seen to be more effective on this less flammable, carbon fiber composite substrate.

  1. Protective

    Directory of Open Access Journals (Sweden)

    Wessam M. Abdel-Wahab

    2013-10-01

    Full Text Available Many active ingredients extracted from herbal and medicinal plants are extensively studied for their beneficial effects. Antioxidant activity and free radical scavenging properties of thymoquinone (TQ have been reported. The present study evaluated the possible protective effects of TQ against the toxicity and oxidative stress of sodium fluoride (NaF in the liver of rats. Rats were divided into four groups, the first group served as the control group and was administered distilled water whereas the NaF group received NaF orally at a dose of 10 mg/kg for 4 weeks, TQ group was administered TQ orally at a dose of 10 mg/kg for 5 weeks, and the NaF-TQ group was first given TQ for 1 week and was secondly administered 10 mg/kg/day NaF in association with 10 mg/kg TQ for 4 weeks. Rats intoxicated with NaF showed a significant increase in lipid peroxidation whereas the level of reduced glutathione (GSH and the activity of superoxide dismutase (SOD, catalase (CAT, glutathione S-transferase (GST and glutathione peroxidase (GPx were reduced in hepatic tissues. The proper functioning of the liver was also disrupted as indicated by alterations in the measured liver function indices and biochemical parameters. TQ supplementation counteracted the NaF-induced hepatotoxicity probably due to its strong antioxidant activity. In conclusion, the results obtained clearly indicated the role of oxidative stress in the induction of NaF toxicity and suggested hepatoprotective effects of TQ against the toxicity of fluoride compounds.

  2. Application of the N-Alkane molecular alloys to thermally protected containers for catering

    Directory of Open Access Journals (Sweden)

    Arjona, F.

    2000-08-01

    Full Text Available A thermally controlled transport device was designed and tested. As hot food needs to be transported at temperatures between 60 and 70ºC in order to avoid contamination by microorganisms, the use of Molecular Alloy Phase Change Materials (MAPCM can lead to improvements in this field of application. A heat transfer numerical simulation of the box used for transporting the food was conducted. Despite obvious simplifications, a good agreement between numerical simulation and experimental results was obtained. Furthermore, we compared our experimental results with those from other experiments related to the transport of hot food. Here, pizza is taken as the example, and it is shown that delivering time can be increased three-fold.

    Para evitar la proliferación de microorganismos, los alimentos cocinados deben ser transportados a temperaturas entre 60 y 70ºC. Los Materiales con Cambio de Fase a base de Aleaciones Moleculares (MAPCM representan una solución en este tipo de aplicaciones. Para ello hemos diseñado y probado un contenedor que permite el transporte a temperatura controlada. Se ha realizado la experimentación y simulación numérica de la transferencia de calor en el dispositivo con el objetivo de determinar su rendimiento. A pesar de las necesarias simplificaciones, hemos obtenido un buen acuerdo entre resultados experimentales y de simulación. En este trabajo hemos tomado el transporte de pizzas como ejemplo, mostrando que el tiempo de protección térmica puede ser incrementado utilizando aleaciones moleculares.

  3. Thermal Spray Coatings for High-Temperature Corrosion Protection in Biomass Co-Fired Boilers

    Science.gov (United States)

    Oksa, M.; Metsäjoki, J.; Kärki, J.

    2015-01-01

    There are over 1000 biomass boilers and about 500 plants using waste as fuel in Europe, and the numbers are increasing. Many of them encounter serious problems with high-temperature corrosion due to detrimental elements such as chlorides, alkali metals, and heavy metals. By HVOF spraying, it is possible to produce very dense and well-adhered coatings, which can be applied for corrosion protection of heat exchanger surfaces in biomass and waste-to-energy power plant boilers. Four HVOF coatings and one arc sprayed coating were exposed to actual biomass co-fired boiler conditions in superheater area with a probe measurement installation for 5900 h at 550 and 750 °C. The coating materials were Ni-Cr, IN625, Fe-Cr-W-Nb-Mo, and Ni-Cr-Ti. CJS and DJ Hybrid spray guns were used for HVOF spraying to compare the corrosion resistance of Ni-Cr coating structures. Reference materials were ferritic steel T92 and nickel super alloy A263. The circulating fluidized bed boiler burnt a mixture of wood, peat and coal. The coatings showed excellent corrosion resistance at 550 °C compared to the ferritic steel. At higher temperature, NiCr sprayed with CJS had the best corrosion resistance. IN625 was consumed almost completely during the exposure at 750 °C.

  4. "Super-quenching" state protects Symbiodinium from thermal stress - Implications for coral bleaching.

    Science.gov (United States)

    Slavov, Chavdar; Schrameyer, Verena; Reus, Michael; Ralph, Peter J; Hill, Ross; Büchel, Claudia; Larkum, Anthony W D; Holzwarth, Alfred R

    2016-06-01

    The global rise in sea surface temperatures causes regular exposure of corals to high temperature and high light stress, leading to worldwide disastrous coral bleaching events (loss of symbiotic dinoflagellates (Symbiodinium) from reef-building corals). Our picosecond chlorophyll fluorescence experiments on cultured Symbiodinium clade C cells exposed to coral bleaching conditions uncovered the transformations of the alga's photosynthetic apparatus (PSA) that activate an extremely efficient non-photochemical "super-quenching" mechanism. The mechanism is associated with a transition from an initially heterogeneous photosystem II (PSII) pool to a homogeneous "spillover" pool, where nearly all excitation energy is transferred to photosystem I (PSI). There, the inherently higher stability of PSI and high quenching efficiency of P(700)(+) allow dumping of PSII excess excitation energy into heat, resulting in almost complete cessation of photosynthetic electron transport (PET). This potentially reversible "super-quenching" mechanism protects the PSA against destruction at the cost of a loss of photosynthetic activity. We suggest that the inhibition of PET and the consequent inhibition of organic carbon production (e.g. sugars) in the symbiotic Symbiodinium provide a trigger for the symbiont expulsion, i.e. bleaching.

  5. Compatibility between pipeline anti-corrosion coating and thermal insulator in the presence of cathodic protection

    Energy Technology Data Exchange (ETDEWEB)

    Papavinasam, S.; Doiron, A.

    2008-09-15

    Standard tests were conducted to evaluate and qualify materials used for the development of oil and gas pipeline insulators operating at elevated temperatures. The aim of the study was to demonstrate the efficacy of a modified cathodic disbondment methodology for evaluating the compatibility between anti-corrosion coatings and insulators in the presence of cathodic protection (CP). The surface of the coated panels were maintained at an external surface temperature of a pipeline operating at an internal temperature of 150 degrees C. The panels were also isolated from each other as well as from the heated pipes to ensure that the cathodic disbondment tests could be conducted simultaneously. Chemical and electrochemical changes were monitored using pH, electrochemical quartz crystal microbalance (EQCM) and electrochemical impedance spectroscopy (EIS). Samples with anti-corrosion coatings and insulators of varying thickness were tested with and without an outer polyethylene jacket. Results of the tests will be presented to industry stakeholders in order to obtain further feedback. 9 refs., 1 tab., 4 appendices.

  6. THERMAL NEUTRON BACKSCATTER IMAGING.

    Energy Technology Data Exchange (ETDEWEB)

    VANIER,P.; FORMAN,L.; HUNTER,S.; HARRIS,E.; SMITH,G.

    2004-10-16

    Objects of various shapes, with some appreciable hydrogen content, were exposed to fast neutrons from a pulsed D-T generator, resulting in a partially-moderated spectrum of backscattered neutrons. The thermal component of the backscatter was used to form images of the objects by means of a coded aperture thermal neutron imaging system. Timing signals from the neutron generator were used to gate the detection system so as to record only events consistent with thermal neutrons traveling the distance between the target and the detector. It was shown that this time-of-flight method provided a significant improvement in image contrast compared to counting all events detected by the position-sensitive {sup 3}He proportional chamber used in the imager. The technique may have application in the detection and shape-determination of land mines, particularly non-metallic types.

  7. [An optical-fiber-sensor-based spectrophotometer for soil non-metallic nutrient determination].

    Science.gov (United States)

    He, Dong-xian; Hu, Juan-xiu; Lu, Shao-kun; He, Hou-yong

    2012-01-01

    In order to achieve rapid, convenient and efficient soil nutrient determination in soil testing and fertilizer recommendation, a portable optical-fiber-sensor-based spectrophotometer including immersed fiber sensor, flat field holographic concave grating, and diode array detector was developed for soil non-metallic nutrient determination. According to national standard of ultraviolet and visible spectrophotometer with JJG 178-2007, the wavelength accuracy and repeatability, baseline stability, transmittance accuracy and repeatability measured by the prototype instrument were satisfied with the national standard of III level; minimum spectral bandwidth, noise and excursion, and stray light were satisfied with the national standard of IV level. Significant linear relationships with slope of closing to 1 were found between the soil available nutrient contents including soil nitrate nitrogen, ammonia nitrogen, available phosphorus, available sulfur, available boron, and organic matter measured by the prototype instrument compared with that measured by two commercial single-beam-based and dual-beam-based spectrophotometers. No significant differences were revealed from the above comparison data. Therefore, the optical-fiber-sensor-based spectrophotometer can be used for rapid soil non-metallic nutrient determination with a high accuracy.

  8. Bacterial assimilation reduction of iron in the treatment of non-metallics

    Directory of Open Access Journals (Sweden)

    Peter Malachovský

    2005-11-01

    Full Text Available Natural non-metallics, including granitoide and quartz sands, often contain iron which decreases the whiteness of these raw materials. Insoluble Fe3+ in these samples could be reduced to soluble Fe2+ by bacteria of Bacillus spp. and Saccharomyces spp. The leaching effect, observed by the measurement of Fe2+concentration in a solution, showed higher activities of a bacterial kind isolated from the Bajkal lake and also by using of yeast Saccharomyces sp. during bioleaching of quartz sands. However, allkinds of Bacillus spp. isolated from the Slovak deposit and from Bajkal lake were very active in the iron reduction during bioleaching of the feldspar raw material. This metal was efficiently removed from quartz sands as documented by the Fe2O3 decrease (from 0,317 % to 0,126 % and from feldpars raw materials by the Fe2O3 decrease (from 0,288 % to 0,115 % after bioleaching. The whiteness of these non-metallics was increased during a visual comparison of samples before and after bioleaching but samples contain selected magnetic particles. A removal of iron as well as a release of iron minerals from silicate matrix should increase the effect of the magnetic separation and should give a product which is suitable for industrial applications.

  9. A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

    Science.gov (United States)

    Grady, Joseph E.; Halbig, Michael C.; Singh, Mrityunjay

    2015-01-01

    In a NASA Aeronautics Research Institute (NARI) sponsored program entitled "A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing", evaluation of emerging materials and additive manufacturing technologies was carried out. These technologies may enable fully non-metallic gas turbine engines in the future. This paper highlights the results of engine system trade studies which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. In addition, feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composite were demonstrated. A wide variety of prototype components (inlet guide vanes (IGV), acoustic liners, engine access door) were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included first stage nozzle segments and high pressure turbine nozzle segments for a cooled doublet vane. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

  10. Standard practice for extreme value analysis of nonmetallic inclusions in steel and other microstructural features

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice describes a methodology to statistically characterize the distribution of the largest indigenous nonmetallic inclusions in steel specimens based upon quantitative metallographic measurements. The practice is not suitable for assessing exogenous inclusions. 1.2 Based upon the statistical analysis, the nonmetallic content of different lots of steels can be compared. 1.3 This practice deals only with the recommended test methods and nothing in it should be construed as defining or establishing limits of acceptability. 1.4 The measured values are stated in SI units. For measurements obtained from light microscopy, linear feature parameters shall be reported as micrometers, and feature areas shall be reported as micrometers. 1.5 The methodology can be extended to other materials and to other microstructural features. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish app...

  11. Nonmetallic Inclusion Control of 350 km/h High Speed Rail Steel

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ke-wen; ZENG Jian-hua; WANG Xin-hua

    2009-01-01

    Inclusion has an important effect on quality of high speed rail steel.In consideration of the lower acceptance percentage of the inclusion and its constraint against the requirement for large scale production of 350 km/h high speed rail steel in Panzhihua Iron and Steel (Group) Co,the technology of nonmetallic inclusion control for 350 km/h high speed rail steel was studied.An optimized model of the argon-blowing in ladle furnace (LF),the control of the components of the ladle slag,and the technique of calcium treatment for the molten steel was brought forward.Using the researched technology,the removal ratio of the inclusion was increased and the components,distribution,and shape of the inclusion in the rail steel were changed,which resulted in a reduction in the average total oxygen content to 10.17×10-6 and an increase in the comprehensive acceptance percentage of the nonmetallic inclusion from 48.21% to 98.1%.Test has shown that this metallurgical technology can meet the requirement for large scale production of 350 km/h high speed steel in Panzhihua Iron and Steel (Group) Co.

  12. Novel Honeycomb Sandwich Thermal Protection Materials%一种新型蜂窝夹层结构防热材料

    Institute of Scientific and Technical Information of China (English)

    潘玲英; 林娜; 杨智勇; 李瑞杰

    2012-01-01

    针对实际使用的热环境要求,提出了多种防热结构材料及结构方案.通过石英灯加热试验对其防热性能进行了考核验证.考察了防热涂层、样件结构形式以及材料种类对试验件防热性能的影响.结果表明,防热涂层可显著降低防热试验件的背温,最高降幅达241℃;相对于传统的玻璃纤维/酚醛层压板结构,在满足防热要求的同时,新型蜂窝夹层结构的面密度较低,仅为层压板的50%左右,具有明显的减重优势,其中聚酰亚胺面板的蜂窝夹层结构的面密度仅为酚醛玻璃钢面板夹层结构的80%,其表面加防热涂层样件的背温仅为246℃.%Several thermal protection methods were proposed according to the thermal environment requirements in application. The thermal insulation property of different thermal protection materials and structures was tested by the quartz radiation heating method. The effects of thermal protection coating, structure and material on the thermal insulation property were investigated. Results show that the thermal protection coating can significantly lower the back temperature of the sample. Compared to the general glass fabric reinforced phenolic resin laminate panel, the sandwich test panel prepared by glass fabric honeycomb and polyimide composite panel has lighter weight and good thermal insulation property. The area weight of honeycomb sandwich was only 50% of the laminate panel. And the area weight of sandwich with polyimide composite panel was about 80% of sandwich with phenolic composite panel. The back temperature of sandwich with polyimide panel covered by the thermal protection coating was only 246℃.

  13. Lipocalin 2 regulation by thermal stresses: Protective role of Lcn2/NGAL against cold and heat stresses

    Energy Technology Data Exchange (ETDEWEB)

    Roudkenar, Mehryar Habibi, E-mail: roudkenar@ibto.ir [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Halabian, Raheleh [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Roushandeh, Amaneh Mohammadi [Department of Anatomy, Faculty of Medicine, Medical University of Tabriz, Tabriz (Iran, Islamic Republic of); Nourani, Mohammad Reza [Chemical Injury Research Center, Baqiyatallah Medical Science University, Tehran (Iran, Islamic Republic of); Masroori, Nasser [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Ebrahimi, Majid [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Chemical Injury Research Center, Baqiyatallah Medical Science University, Tehran (Iran, Islamic Republic of); Nikogoftar, Mahin; Rouhbakhsh, Mehdi; Bahmani, Parisa [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Najafabadi, Ali Jahanian [Department of Molecular Biology, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Shokrgozar, Mohammad Ali [National Cell Bank of Iran, Pasteur institute of Iran, Tehran (Iran, Islamic Republic of)

    2009-11-01

    Environmental temperature variations are the most common stresses experienced by a wide range of organisms. Lipocalin 2 (Lcn2/NGAL) is expressed in various normal and pathologic conditions. However, its precise functions have not been fully determined. Here we report the induction of Lcn2 by thermal stresses in vivo, and its role following exposure to cold and heat stresses in vitro. Induction of Lcn2 in liver, heart and kidney was detected by RT-PCR, Western blot and immunohistochemistry following exposure of mice to heat and cold stresses. When CHO and HEK293T cells overexpressing NGAL were exposed to cold stress, cell proliferation was higher compared to controls. Down-regulatrion of NGAL by siRNA in A549 cells resulted in less proliferation when exposed to cold stress compared to control cells. The number of apoptotic cells and expression of pro-apoptotic proteins were lower in the NGAL overexpressing CHO and HEK293T cells, but were higher in the siRNA-transfected A549 cells compared to controls, indicating that NGAL protects cells against cold stress. Following exposure of the cells to heat stress, ectopic expression of NGAL protected cells while addition of exogenous recombinant NGAL to the cell culture medium exacerbated the toxicity of heat stress specially when there was low or no endogenous expression of NGAL. It had a dual effect on apoptosis following heat stress. NGAL also increased the expression of HO-1. Lcn2/NGAL may have the potential to improve cell proliferation and preservation particularly to prevent cold ischemia injury of transplanted organs or for treatment of some cancers by hyperthermia.

  14. A study of many-body phenomena in metal nanoclusters (Au, Cu) close to their transition to the nonmetallic state

    NARCIS (Netherlands)

    Borman, VD; Borisyuk, PV; Lebid'ko, VV; Pushkin, AA; Tronin, VN; Troyan, [No Value; Antonov, DA; Filatov, DO

    2006-01-01

    The results of a study of many-body phenomena in gold and copper nanoclusters are presented. The measured conductivity as a function of nanocluster height h was found to have a minimum at h approximate to 0.6 nm. Conductivity was local in character at nanocluster sizes l infinity) to nonmetallic (ep

  15. RBCC发动机主被动复合热防护方案研究%Investigation on combination of active and passive thermal protection for RBCC engine

    Institute of Scientific and Technical Information of China (English)

    王浩泽; 李江; 秦飞; 魏祥庚

    2015-01-01

    The thermal protection is the key problem for RBCC engine engineering development with the intensive research.The thermal protection scheme was studied in this paper based on the thermal environments which are achieved by numerical simulations of different modes. The results show that active cooling and passive cooling method cannot satisfy the RBCC thermal protection re-quirements either.A new thermal protection with combination of active and passive cooling concept was designed.The C/SiC ceramic matrix composites are used for combustor inner wall.The regenerative cooling modules were installed at the sections heated seriously. The simulation results show that the combination thermal protection resolve the problem of the shortage of coolant and satisfy the thermal protection requirement of RBCC engine operating.%随着对RBCC发动机研究的不断深入,热防护问题已经成为其走向工程应用的关键之一,本文针对RBCC发动机开展了热防护方案的研究。首先,采用数值模拟对RBCC发动机各模态下的热环境进行了分析;然后,进行了RBCC热防护方案的论证,认为目前材料和技术水平下全主动和全被动方案很难满足RBCC热防护的要求;在此基础上,提出了一种主被动相结合的复合热防护方案,并完成了复合热防护方案的设计。该方案内壁整体采用C/SiC陶瓷基复合材料,在受热比较严重的部位加装再生冷却模块,较好地解决了RBCC发动机冷却剂流量不够的问题。通过对方案的校核计算表明,该方案可满足长时间工作RBCC的热防护需要。

  16. Development of FIAT-Based Parametric Thermal Protection System Mass Estimating Relationships for NASA's Multi-Mission Earth Entry Concept

    Science.gov (United States)

    Sepka, Steven A.; Zarchi, Kerry; Maddock, Robert W.; Samareh, Jamshid A.

    2013-01-01

    Part of NASAs In-Space Propulsion Technology (ISPT) program is the development of the tradespace to support the design of a family of multi-mission Earth Entry Vehicles (MMEEV) to meet a wide range of mission requirements. An integrated tool called the Multi Mission System Analysis for Planetary Entry Descent and Landing or M-SAPE tool is being developed as part of Entry Vehicle Technology project under In-Space Technology program. The analysis and design of an Earth Entry Vehicle (EEV) is multidisciplinary in nature, requiring the application many disciplines. Part of M-SAPE's application required the development of parametric mass estimating relationships (MERs) to determine the vehicle's required Thermal Protection System (TPS) for safe Earth entry. For this analysis, the heat shield was assumed to be made of a constant thickness TPS. This resulting MERs will then e used to determine the pre-flight mass of the TPS. Two Mers have been developed for the vehicle forebaody. One MER was developed for PICA and the other consisting of Carbon Phenolic atop an Advanced Carbon-Carbon composition. For the the backshell, MERs have been developed for SIRCA, Acusil II, and LI-900. How these MERs were developed, the resulting equations, model limitations, and model accuracy are discussed in this poster.

  17. Characterization of a 50kW Inductively Coupled Plasma Torch for Testing of Ablative Thermal Protection Materials

    Science.gov (United States)

    Greene, Benton R.; Clemens, Noel T.; Varghese, Philip L.; Bouslog, Stanley A.; Del Papa, Steven V.

    2017-01-01

    With the development of new manned spaceflight capabilities including NASA's Orion capsule and the Space-X Dragon capsule, there is a renewed importance of understanding the dynamics of ablative thermal protection systems. To this end, a new inductively coupled plasma torch facility is being developed at UT-Austin. The torch operates on argon and/or air at plasma powers up to 50 kW. In the present configuration the flow issues from a low-speed subsonic nozzle and the hot plume is characterized using slug calorimetry and emission spectroscopy. Preliminary measurements using emission spectroscopy have indicated that the torch is capable of producing an air plasma with a temperature between 6,000 K and 8,000 K depending on the power and flow settings and an argon plasma with a temperature of approximately 12,000 K. The operation envelope was measured, and heat flux measured for every point within the envelope using both a slug calorimeter and a Gardon gauge heat flux sensor. The torch was found to induce a stagnation point heat flux of between 90 and 225 W/sq cm.

  18. Thermal and overcharge abuse analysis of a redox shuttle for overcharge protection of LiFePO4

    Science.gov (United States)

    Lamb, Joshua; Orendorff, Christopher J.; Amine, Khalil; Krumdick, Gregory; Zhang, Zhengcheng; Zhang, Lu; Gozdz, Antoni S.

    2014-02-01

    This work investigated the performance and abuse tolerance of cells protected using the redox shuttle 1,4-bis(2-methoxyethoxy)-2,5-di-tert-butylbenzene. The thermal efficiencies were evaluated using isothermal battery calorimetry. Cells containing the overcharge shuttle were observed to reach a steady state value of approximately 3.8 V, with a small variance in direct proportion to the applied current. In all cases the heat output from the cells was measured to reach ∼90% of the total input power. The heat output was also measured using isothermal calorimetry. At higher rates of overcharge, the data shows that the cell containing the shuttle rapidly reaches a steady state voltage, while the temperature increases until a moderately high steady state temperature is reached. The control cell meanwhile rapidly increases in both applied voltage and cell temperature until cell failure. Two cells in series were taken deliberately out of balance individually, then charged as a single pack to observe the time needed to bring the cells into balance with one another.

  19. Exertional thermal strain, protective clothing and auxiliary cooling in dry heat: evidence for physiological but not cognitive impairment.

    Science.gov (United States)

    Caldwell, Joanne N; Patterson, Mark J; Taylor, Nigel A S

    2012-10-01

    Individuals exposed to extreme heat may experience reduced physiological and cognitive performance, even during very light work. This can have disastrous effects on the operational capability of aircrew, but such impairment could be prevented by auxiliary cooling devices. This hypothesis was tested under very hot-dry conditions, in which eight males performed 2 h of low-intensity exercise (~30 W) in three trials, whilst wearing biological and chemical protective clothing: temperate (control: 20°C, 30% relative humidity) and two hot-dry trials (48°C, 20% relative humidity), one without (experimental) and one with liquid cooling (water at 15°C). Physiological strain and six cognitive functions were evaluated (MiniCog Rapid Assessment Battery), and participants drank to sustain hydration state. Maximal core temperatures averaged 37.0°C (±0.1) in the control trial, and were significantly elevated in the experimental trial (38.9°C ± 0.3; P 0.05). However, despite inducing profound hyperthermia and volitional fatigue, no cognitive degradation was evident in the heat (P > 0.05). Since extensive dehydration was prevented, it appears that thermal strain in the absence of dehydration may have minimal impact upon cognitive function, at least as evaluated within this experiment.

  20. In-Flight Aeroelastic Stability of the Thermal Protection System on the NASA HIAD, Part I: Linear Theory

    Science.gov (United States)

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

    2014-01-01

    Conical shell theory and piston theory aerodynamics are used to study the aeroelastic stability of the thermal protection system (TPS) on the NASA Hypersonic Inflatable Aerodynamic Decelerator (HIAD). Structural models of the TPS consist of single or multiple orthotropic conical shell systems resting on several circumferential linear elastic supports. The shells in each model may have pinned (simply-supported) or elastically-supported edges. The Lagrangian is formulated in terms of the generalized coordinates for all displacements and the Rayleigh-Ritz method is used to derive the equations of motion. The natural modes of vibration and aeroelastic stability boundaries are found by calculating the eigenvalues and eigenvectors of a large coefficient matrix. When the in-flight configuration of the TPS is approximated as a single shell without elastic supports, asymmetric flutter in many circumferential waves is observed. When the elastic supports are included, the shell flutters symmetrically in zero circumferential waves. Structural damping is found to be important in this case. Aeroelastic models that consider the individual TPS layers as separate shells tend to flutter asymmetrically at high dynamic pressures relative to the single shell models. Several parameter studies also examine the effects of tension, orthotropicity, and elastic support stiffness.

  1. 箭上电缆防热设计及试验研究%An investigate of thermal protection design and experiment for rocket cable

    Institute of Scientific and Technical Information of China (English)

    何振威; 王伟; 王智勇; 胡由宏; 罗俊青

    2016-01-01

    对箭上电缆热环境进行总结,从对电缆热防护机理的分析着手,依据传热模式建立复合传热网络。调查并评价目前常用的防热材料和防护结构,提出了一体化系统结构设计理念。设计针对电缆防热考核系统的地面热结构试验,通过试验数据分析典型防护结构的温度响应。通过上述分析和总结,形成一套完善的设计、分析和验证流程。%In this paper, we focus on the thermal protection for rocket cable. The thermal environment was summarized firstly. A complex network of heat transfer was shown based on heat transfer theory. The materials and method for thermal protection was introduced, and then, a new idea about an integrated thermal protection system was bring out. The thermo-structure test aim at the cable was also described, therefore, the results which make a great impact on analyze were obtained. There by, a consummate flow chart including design, analysis and validate was built.

  2. Calculating the Carrying Capacity of Flexural Prestressed Concrete Beams with Non-Metallic Reinforcement

    Directory of Open Access Journals (Sweden)

    Mantas Atutis

    2011-04-01

    Full Text Available The article reviews moment resistance design methods of prestressed concrete beams with fibre-reinforced polymer (FRP reinforcement. FRP tendons exhibit linear elastic response to rupture without yielding and thus failure is expected to be brittle. The structural behaviour of beams prestressed with FRP tendons is different from beams with traditional steel reinforcement. Depending on the reinforcement ratio, the flexural behaviour of the beam can be divided into several groups. The numerical results show that depending on the nature of the element failure, moment resistance calculation results are different by using reviewed methods. It was found, that the use of non-metallic reinforcement in prestressed concrete structures is effective: moment capacity is about 5% higher than that of the beams with conventional steel reinforcement.Article in Lithuanian

  3. Complex Nonmetallic Inclusions Formed in Billets Heated for Rolling and Characteristics of Structural Steels

    Science.gov (United States)

    Zaitsev, A. I.; Koldaev, A. V.; Arutyunyan, N. A.; Shaposhnikov, N. G.; Dunaev, S. F.

    2017-03-01

    Complex bimetallic inclusions formed in billets from steels 09G2S and K52 during heating for rolling are studied by methods of electron microscopy and local x-ray spectrum analysis. To check the established evolution of oxide inclusions based on aluminomagnesium spinel and other oxide compositions, individual inclusions of manganese sulfide and complex oxide-sulfide inclusions, a method developed by the Severstal'Company and the Karpov NIFKhI for determining the content of corrosion-active nonmetallic inclusions (CANI) as a function of the heating mode is applied to the steels studied. It is recommended to increase the temperature and duration of heating of billets for hot rolling in order to lower the content of CANI and to raise the resistance of the steels to local corrosion.

  4. Capacitance probe for detection of anomalies in non-metallic plastic pipe

    Science.gov (United States)

    Mathur, Mahendra P.; Spenik, James L.; Condon, Christopher M.; Anderson, Rodney; Driscoll, Daniel J.; Fincham, Jr., William L.; Monazam, Esmail R.

    2010-11-23

    The disclosure relates to analysis of materials using a capacitive sensor to detect anomalies through comparison of measured capacitances. The capacitive sensor is used in conjunction with a capacitance measurement device, a location device, and a processor in order to generate a capacitance versus location output which may be inspected for the detection and localization of anomalies within the material under test. The components may be carried as payload on an inspection vehicle which may traverse through a pipe interior, allowing evaluation of nonmetallic or plastic pipes when the piping exterior is not accessible. In an embodiment, supporting components are solid-state devices powered by a low voltage on-board power supply, providing for use in environments where voltage levels may be restricted.

  5. Ambipolar surface state transport in nonmetallic stoichiometric Bi2Se3 crystals

    Science.gov (United States)

    Syers, Paul; Paglione, Johnpierre

    2017-01-01

    Achieving true bulk insulating behavior in Bi2Se3 , the archetypal topological insulator with a simplistic one-band electronic structure and sizable band gap, has been prohibited by a well-known self-doping effect caused by selenium vacancies, whose extra electrons shift the chemical potential into the bulk conduction band. We report a synthesis method for achieving stoichiometric Bi2Se3 crystals that exhibit nonmetallic behavior in electrical transport down to low temperatures. Hall-effect measurements indicate the presence of both electron- and holelike carriers, with the latter identified with surface state conduction and the achievement of ambipolar transport in bulk Bi2Se3 crystals without gating techniques. With carrier mobilities surpassing the highest values yet reported for topological surface states in this material, the achievement of ambipolar transport via upward band bending is found to provide a key method to advancing the potential of this material for future study and applications.

  6. Combined nonmetallic electronegativity equalisation and point-dipole interaction model for the frequency-dependent polarisability

    Science.gov (United States)

    Smalø, Hans S.; Åstrand, Per-Olof; Mayer, Alexandre

    2013-07-01

    A molecular mechanics model for the frequency-dependent polarisability is presented. It is a combination of a recent model for the frequency dependence in a charge-dipole model [Nanotechnology 19, 025203, 2008] and a nonmetallic modification of the electronegativity equalisation model rephrased as atom-atom charge-transfer terms [J. Chem. Phys. 131, 044101, 2009]. An accurate model for the frequency-dependent polarisability requires a more accurate partitioning into charge and dipole contributions than the static polarisability, which has resulted in several modifications of the charge-transfer model. Results are presented for hydrocarbons, including among others, alkanes, polyenes and aromatic systems. Although their responses to an electric field are quite different in terms of the importance of charge-transfer contributions, it is demonstrated that their frequency-dependent polarisabilities can be described with the same model and the same set of atom-type parameters.

  7. Quantitative Study on Nonmetallic Inclusion Particles in Steels by Automatic Image Analysis With Extreme Values Method

    Institute of Scientific and Technical Information of China (English)

    Cássio Barbosa; José Brant de Campos; J(ǒ)neo Lopes do Nascimento; Iêda Maria Vieira Caminha

    2009-01-01

    The presence of nonmetallic inclusion particles which appear during steelmaking process is harmful to the properties of steels, which is mainly as a function of some aspects such as size, volume fraction, shape, and distribution of these particles. The automatic image analysis technique is one of the most important tools for the quantitative determination of these parameters. The classical Student approach and the Extreme Values Method (EVM) were used for the inclusion size and shape determination and the evaluation of distance between the inclusion particles. The results thus obtained indicated that there were significant differences in the characteristics of the inclusion particles in the analyzed products. Both methods achieved results with some differences, indicating that EVM could be used as a faster and more reliable statistical methodology.

  8. The share of non-metallic inclusions in high-grade steel for machine parts

    Directory of Open Access Journals (Sweden)

    T. Lipiński

    2010-10-01

    Full Text Available The aim of this work was to compare the differences in the purity steel in the dimensions of inclusion particles as dependent on various steel production processes. The experimental material consisted of semi-finished products of high-grade, medium-carbon constructional steel with: manganese, chromium, nickel, molybdenum and boron. The impurity content of steel was low as phosphorus and sulphur levels did not exceed 0.025%. The experimental material consisted of steel products obtained in three metallurgical processes: electric, electric with argon refining and oxygen converter with vacuum degassing of steel. Billet samples were collected to determine: chemical composition, relative volume of non-metallic inclusions, dimensions of impurities. The results were processed and presented in graphic form.

  9. Morphology and Orientation Selection of Non-metallic Inclusions in Electrified Molten Metal

    Science.gov (United States)

    Zhao, Z. C.; Qin, R. S.

    2017-10-01

    The effect of electric current on morphology and orientation selection of non-metallic inclusions in molten metal has been investigated using theoretical modeling and numerical calculation. Two geometric factors, namely the circularity ( fc ) and alignment ratio ( fe ) were introduced to describe the inclusions shape and configuration. Electric current free energy was calculated and the values were used to determine the thermodynamic preference between different microstructures. Electric current promotes the development of inclusion along the current direction by either expatiating directional growth or enhancing directional agglomeration. Reconfiguration of the inclusions to reduce the system electric resistance drives the phenomena. The morphology and orientation selection follow the routine to reduce electric free energy. The numerical results are in agreement with our experimental observations.

  10. Industrial application of liquid steel filtration out of dispersed nonmetallic phase in the continuous casting machine

    Directory of Open Access Journals (Sweden)

    K. Janiszewski

    2013-01-01

    Full Text Available Hitherto existing investigations concerning the ceramic filter use in the steel making processes (both of laboratory and industrial scale have given good results. The obtained results of filtration (in the laboratory have proved that this method may be used as an effective and cheap way of steel filtration from non-metallic inclusions. Placing filters in the tundish is the best location in consideration of limiting the possibility of secondary pollution of steel. Yet, the results presented in this paper, of an experiment prepared and carried out in the industrial environment, are the only positive results obtained, which are connected with so much quantities of liquid steel processed with use of the multi-hole ceramic filters.

  11. Efficient and durable hydrogen evolution electrocatalyst based on nonmetallic nitrogen doped hexagonal carbon

    Science.gov (United States)

    Liu, Yanming; Yu, Hongtao; Quan, Xie; Chen, Shuo; Zhao, Huimin; Zhang, Yaobin

    2014-10-01

    The feasibility of renewable energy technology, hydrogen production by water electrolysis, depends on the design of efficient and durable electrocatalyst composed of earth-abundant elements. Herein, a highly active and stable nonmetallic electrocatalyst, nitrogen doped hexagonal carbon (NHC), was developed for hydrogen production. It exhibited high activity for hydrogen evolution with a low overpotential of only 65 mV, an apparent exchange current density of 5.7 × 10-2 mA cm-2 and a high hydrogen production rate of 20.8 mL cm-2 h-1 at -0.35 V. The superior hydrogen evolution activity of NHC stemmed from the intrinsic electrocatalytic property of hexagonal nanodiamond, the rapid charge transfer and abundance of electrocatalytic sites after nitrogen doping. Moreover, NHC was stable in a corrosive acidic solution during electrolysis under high current density.

  12. Magnetohydrodynamic study of electromagnetic separation of nonmetallic inclusions from aluminum melt

    Institute of Scientific and Technical Information of China (English)

    SHU; Da(疏达); SUN; Baode(孙宝德); WANG; Jun(王俊); ZHANG; Xueping(张雪萍); ZHOU; Yaohe(周尧和)

    2002-01-01

    Magnetohydrodynamic flow around the nonmetallic inclusions in aluminum melt and the force exerted on the inclusions were explored by dimensional analysis and numerical calculations. Dimensional analysis shows that the invariant characterizes the force exerted on the inclusions and the flow intensity of the melt. The physical significance of A is represented as a modified particle Reynolds number that reflects the effects of electromagnetic force. The fluid flow around the particle becomes unstable when A>2×103. It is shown that the neglect of the inertial terms has little effect on the force exerted on the inclusions in the range of A≤1×106. However, the analytical solution of the maximum velocity inside the melt does not apply due to the appearance of turbulent flow in the case of A>2×103.

  13. 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.

  14. Analysis and simulation of non-metallic inclusions in spheroidal graphite iron

    Science.gov (United States)

    Pustal, B.; Schelnberger, B.; Bührig-Polaczek, A.

    2016-03-01

    Non-metallic inclusions in spheroidal cast iron (SGI) reduce fatigue strength and yield strength. This type of inclusion usually accumulates at grain boundaries. Papers addressing this topic show the overall impact of both the fraction of so-called white (carbides) and black (non-metallic) inclusions on mechanical properties. In the present work we focus on the origin and the formation conditions of black Mg-bearing inclusions, further distinguishing between Si-bearing and non-Si-bearing Mg inclusions. The formation was simulated applying thermodynamic approaches. Moreover, appropriate experiments have been carried out and a large number of particles have been studied applying innovative feature analysis with regard to shape, size, and composition. Magnesium silicates are predicted at elevated oxygen concentrations, whereas at low levels of oxygen sulphides and carbides appear at a late stage of solidification. Experiments with three consecutive flow obstacles show that the amount of magnesium silicates decrease after each of the three obstacles, whereas the fraction of non-Si-bearing inclusions remains approximately constant. The size of inclusions divides in halves over the flow path and the number of particles increases accordingly. We point out that based on feature analysis Mg-O-C bearing inclusion show disadvantageous form factors for which reason this kind of inclusions may be extremely harmful in terms of crack initiation. All results obtained indicate that magnesium silicates are entrapped on mould filling, whereas Mg-(O, C, S, P, N) bearing particles are precipitates at late stages of solidification. Consequently, the only avoidance strategy is setting up optimum retained magnesium content.

  15. Organic Ablative Coating Thermal Protection Mechanism and Composition%有机消融涂层防热隔热机理及组成分析

    Institute of Scientific and Technical Information of China (English)

    马天信

    2013-01-01

      讨论了有机消融材料防热隔热的机理,对消融涂层的组成和各种影响因素作了分析,为消融涂料的研究与应用提供了依据。%The mechanism of thermal protection and thermal insulation of organic ablative materials are discussed. The composition and effective factors of organic ablative coating are analysed in this article.

  16. Thermal Protective Coatings

    Science.gov (United States)

    1976-03-31

    within 2 minutes for the No. 4. Sodiurn silicate was tested with alumnnunm hydroxide, nerlite, vermiculite and borax filler systems. None of the systems...1.27 cm) thick, 3/16 inch (0.48 cm) cell size, 5.5 lbs/ft 3 (88.1 kg/m 3 ) glass/phenolic honey - p comib set into the fire retardant maLerial. The sheets...COATING SPECIMEN PERCENT BY WEIGHT THICKNESS WEIGHT ANO. MATRIX FILLrR 1’fLS (CM) LBS/FT. (kg,’-), 26 50% Shell 828 Epoxy Resin Borax - 54 (.14) .39

  17. 常用高、低温防护服着装舒适性研究%Comfortableness evaluation of thermal protective clothing and cold protective clothing at workplaces

    Institute of Scientific and Technical Information of China (English)

    周书林

    2013-01-01

    A comprehensive evaluation of protective clothing usually relates to multi-aspects the safety and ergonomics characteristics.Based on research of the insulation performance for commonly used thermal protective clothing and cold protective clothing,a preliminary study was carried out on clothing comfort,so as to provide base for selection and design improvement of thermal protective clothing and cold protective clothing.In the study,the materials of the tested clothes were determined with thermal plane-table,physiological index changes for six healthy males wearing tested clothes in artificial climate cabin were also determined.The results showed that there is significant difference in permeabihty,moisture permeability,clothing pressure with different type thermal protective clothing and cold protective clothing.The factors affecting the comfortableness of clothing include the material,design and concrete technology of the tested protective clothing.%防护服装的全面评价通常涉及安全性、工效学特性等多个方面.在常用高、低温防护服隔热性能研究基础上,对服装的舒适性进行了初步研究,以期为高低温防护服的选用和设计改进等提供依据.本研究应用热平板仪、人工气候室等研究设备以及真人着装实验,对高低温作业典型工种常用的耐高温防护服和低温防护服的舒适性能进行了研究.研究结果显示,不同类型高、低温防护服的透气性、透湿性、着装压力、肢体活动角度等均表现出一定差异,防护服的面料、结构和工艺等均影响到其整体舒适性,并提出了相应的改善建议.

  18. In situ performance and potential applications of a thermal bed-load measurement method

    CSIR Research Space (South Africa)

    Ilgner, HJ

    2010-09-01

    Full Text Available Methods to detect the flow condition at the pipeline invert are reviewed. New results of a small heated plate inserted into a non-metallic pipe are presented. This thermal method is based on mini-heaters and can detect erratic flow behaviour near...

  19. Survey of European and Major ISC Facilities for Supporting Mars and Sample Return Mission Aerothermodynamics and Tests Required for Thermal Protection System and Dynamic Stability

    Directory of Open Access Journals (Sweden)

    Mathilde Bugel

    2011-01-01

    Full Text Available In the frame of future sample return missions to Mars, asteroids, and comets, investigated by the European Space Agency, a review of the actual aerodynamics and aerothermodynamics capabilities in Europe for Mars entry of large vehicles and high-speed Earth reentry of sample return capsule has been undertaken. Additionally, capabilities in Canada and Australia for the assessment of dynamic stability, as well as major facilities for hypersonic flows available in ISC, have been included. This paper provides an overview of European current capabilities for aerothermodynamics and testing of thermal protection systems. This assessment has allowed the identification of the needs in new facilities or upgrade of existing ground tests for covering experimentally Mars entries and Earth high-speed reentries as far as aerodynamics, aerothermodynamics, and thermal protection system testing are concerned.

  20. Design and Analysis of Ceramic Matrix Composite Shingle Thermal Protection System%陶瓷基复合材料盖板式热防护系统的设计与分析

    Institute of Scientific and Technical Information of China (English)

    任青梅; 张婕

    2013-01-01

    陶瓷基复合材料盖板式热防护系统是一种具有防热/承载一体化功能的新型热防护结构。本文在国内外研究基础上,对盖板热防护系统进行了初步设计与分析,提出了盖板式热防护系统设计方案,进行了相关热响应分析,并在热载荷与气动压力载荷联合作用下,进行了结构应力与变形分析,对盖板热防护系统静强度性能进行了初步评估。%Ceramic matrix composite shingle thermal protection system is a new thermal protection structure with the function incorporating insulate and carrying capacity. The preliminary design and analysis about shingle thermal protection system is done based on the oversea investigation. The shingle thermal protection system scheme is presented. Thermal response analysis of shingle thermal protection system is done. Structure stress and distortion is obtained under thermal heat lfux and aerodynamical pressure simutaneously. The static performance of shingle thermal protection system is evaluated.

  1. Numerical 2D and 3D Investigation of Non-Metallic (Glass, Carbon) Fiber Pull-Out Micromechanics 9in Concrete Matrix)

    OpenAIRE

    Khabaz, A; Krasņikovs, A; Kononova, O; Mačanovskis, A

    2010-01-01

    Short non-metallic (glass, carbon) fibre use for concrete disperse reinforcment is of particular interest, because of much higher fibre/matrix interface area value comparing to industrially produced steel fibres.

  2. An Analysis on the Moisture and Thermal Protective Performance of Firefighter Clothing Based on Different Layer Combinations and Effect of Washing on Heat Protection and Vapour Transfer Performance

    Directory of Open Access Journals (Sweden)

    Ozgur Atalay

    2015-01-01

    Full Text Available Fabric assemblies for firefighting clothing have been tested for heat protection and comfort. The constituent materials and fabric structures have been specifically selected and tailored for firefighters’ clothing. In order to do this, four types of outer shell fabrics, four types of moisture barrier fabrics, and four types of heat barriers with different weights and material compositions were used to make a multilayered fabric assembly. Heat transfer (flame, heat transfer (radiant, and water vapour resistance tests were conducted according to the latest EN469 test standard which also recommends washing tests. These tests reveal that material content and material brand have considerable effect on the required performance levels of heat protection. In addition, while washing tests have improved water vapor transfer properties, they have a deteriorating effect on heat protection performance. Considering heat protection and moisture comfort properties, the optimal assemblies are thereby identified.

  3. Cystic fibrosis transmembrane conductance regulator (CFTR) potentiators protect G551D but not ΔF508 CFTR from thermal instability.

    Science.gov (United States)

    Liu, Xuehong; Dawson, David C

    2014-09-01

    The G551D cystic fibrosis transmembrane conductance regulator (CFTR) mutation is associated with severe disease in ∼5% of cystic fibrosis patients worldwide. This amino acid substitution in NBD1 results in a CFTR chloride channel characterized by a severe gating defect that can be at least partially overcome in vitro by exposure to a CFTR potentiator. In contrast, the more common ΔF508 mutation is associated with a severe protein trafficking defect, as well as impaired channel function. Recent clinical trials demonstrated a beneficial effect of the CFTR potentiator, Ivacaftor (VX-770), on lung function of patients bearing at least one copy of G551D CFTR, but no comparable effect on ΔF508 homozygotes. This difference in efficacy was not surprising in view of the established difference in the molecular phenotypes of the two mutant channels. Recently, however, it was shown that the structural defect introduced by the deletion of F508 is associated with the thermal instability of ΔF508 CFTR channel function in vitro. This additional mutant phenotype raised the possibility that the differences in the behavior of ΔF508 and G551D CFTR, as well as the disparate efficacy of Ivacaftor, might be a reflection of the differing thermal stabilities of the two channels at 37 °C. We compared the thermal stability of G551D and ΔF508 CFTR in Xenopus oocytes in the presence and absence of CTFR potentiators. G551D CFTR exhibited a thermal instability that was comparable to that of ΔF508 CFTR. G551D CFTR, however, was protected from thermal instability by CFTR potentiators, whereas ΔF508 CFTR was not. These results suggest that the efficacy of VX-770 in patients bearing the G551D mutation is due, at least in part, to the ability of the small molecule to protect the mutant channel from thermal instability at human body temperature.

  4. Heat-Insulation Property Evaluation of thermal protective clothing and cold protective clothing usually used at workplaces%常用高、低温防护服隔热性能研究

    Institute of Scientific and Technical Information of China (English)

    张忠彬; 刘宝龙; 李俊; 王云仪; 周书林

    2011-01-01

    为评价常用类型高、低温防护服的防护性能,本研究应用热平板仪、人工气候室和暖体假人等研究设备,对高低温作业典型工种常用的耐高温防护服和低温防护服的隔热性能进行了研究.研究结果显示,不同类型高、低温防护服的服装面料、服装整体的隔热性表现出一定差异,模拟环境下的着装生理学测试结果也存在不同,防护服的面料、结构和工艺等均影响到其整体隔热性能.防护服装的全面评价通常涉及安全性、工效学特性等多个方面,有必要从服装的舒适性、工效学特性等方面进一步研究,并开展大规模的现场人体穿着实验,从而为高低温防护服的选用和设计改进等提供依据.%In order to elucidate heat-insulation property of thermal protective clothing and cold protective clothing usually used at typical workplaces existing heat stress or cold stress, heat resistance for tested clothes and their materials were determined with thermal plane-table and thermal manikin, physiological index changes for six healthy males wearing tested clothes in artificial climate cabin were also determined. The results suggest that there is significant difference in heat insulate property for different type thermal protective clothing and cold protective clothing, as well as physiological index of the six healthy males such as temperature under clothes and average skin temperature. Factors affecting heat insulation property include the material, design and concrete technology of tested protective clothing. Thus, to provide scientific data for selection and improving of tested protective clothing, further studies are needed to make comprehensive evaluation for these tested clothes, such as assessment on ergonomics and comfort of tested clothes, and so on.

  5. 非金属矿物在医药行业的应用与前景%Medicinal Application and Prospect of Non-metallic Mineral

    Institute of Scientific and Technical Information of China (English)

    鲍康德; 周春晖

    2012-01-01

    Deep procession of non-metallic mineral and application on bio-/medicinal area is a new high-technical industry. This paper summarizes the appl ication history and status in quo of non-metallic minerals in pharmaceutical industry; identification, classification and development tendency of non-metallic minerals for pharmaceutical use. The focus is to introduce the development history of non-metallic minerals for pharmaceutical use, and explore the application prospect of non-metallic minerals in pharmaceutical industry, so as to provide theory basis for sufficiently exploring the potential of non-metallic minerals.%非金属矿物深加工并被用于生物医药领域系高新技术产业.本文综述了非金属矿物的医药应用历史、现状;药用非金属矿物的鉴别、分类和发展趋势.重点介绍了非金属矿物的药用开发历程,并展望了非金属矿物在医药行业的应用前景,以期为充分发掘非金属矿物的潜能提供理论指导.

  6. Numerical analysis of the non-metallic inclusions distribution and separation in a two-strand tundish

    Directory of Open Access Journals (Sweden)

    T. Merder

    2013-04-01

    Full Text Available The tundish plays an important role in the challenging task of a “clean steel” production process. The flow of the liquid steel in tundish has a crucial influence on non-metallic inclusions distribution and separation. The article presents computational studies of non-metallic inclusions separation in a two-strand industrial tundish during steady-state casting. Tundish capacity is 7,5 t. First, flow structure in the tundish was investigated using water model of the industrial tundish in a 1:2 scale. The experimental results, regarding RTD characteristics were used to validate numerical model. With validated model, particle distribution and separation in the two-strand tundish were investigated numerically. For modelling the separation of particles at the fluid surface, a modified boundary condition has been implemented.

  7. An aviation security (AVSEC) screening demonstrator for the detection of non-metallic threats at 28-33 GHz

    Science.gov (United States)

    Salmon, Neil A.; Bowring, Nick; Hutchinson, Simon; Southgate, Matthew; O'Reilly, Dean

    2013-10-01

    The unique selling proposition of millimetre wave technology for security screening is that it provides a stand-off or portal scenario sensing capability for non-metallic threats. The capabilities to detect some non-metallic threats are investigated in this paper, whilst recommissioning the AVSEC portal screening system at the Manchester Metropolitan University. The AVSEC system is a large aperture (1.6 m) portal screening imager which uses spatially incoherent illumination at 28-33 GHz from mode scrambling cavities to illuminate the subject. The imaging capability is critically analysed in terms of this illumination. A novel technique for the measurement of reflectance, refractive index and extinction coefficient is investigated and this then use to characterise the signatures of nitromethane, hexane, methanol, bees wax and baking flour. Millimetre wave images are shown how these liquids in polycarbonate bottles and the other materials appear against the human body.

  8. Determination of eye safety filter protection factors associated with retinal thermal hazard and blue light photochemical hazard for intense pulsed light sources

    Energy Technology Data Exchange (ETDEWEB)

    Clarkson, D McG [Department of Clinical Physics and Bioengineering, Arden Cancer Centre, Walsgrave Hospital, UHCW NHS Trust, Coventry, CV2 2DX (United Kingdom)

    2006-02-21

    An assessment is provided of protection factors afforded for retinal thermal hazard and blue light photochemical hazard for a range of filters used with intense pulsed light sources (IPLs). A characteristic IPL spectrum based on black body radiation at 5000 K with a low cut filter at 515 nm was identified as suitable for such estimations. Specific filters assessed included types with idealized transmission properties and also a range of types whose transmission characteristics were measured by means of a Bentham DMc150 spectroradiometer. Predicted behaviour based on these spectra is outlined which describes both the effectiveness of protection and the level of luminous transmittance afforded. The analysis showed it was possible to describe a figure of merit for a particular filter material relating the degree of protection provided and corresponding value of luminous transmittance. This consideration is important for providing users of IPL equipment with safety eyewear with adequate level of visual transmittance. (note)

  9. Thermal drilling in planetary ices: an analytic solution with application to planetary protection problems of radioisotope power sources.

    Science.gov (United States)

    Lorenz, Ralph D

    2012-08-01

    Thermal drilling has been applied to studies of glaciers on Earth and proposed for study of the martian ice caps and the crust of Europa. Additionally, inadvertent thermal drilling by radioisotope sources released from the breakup of a space vehicle is of astrobiological concern in that this process may form a downward-propagating "warm little pond" that could convey terrestrial biota to a habitable environment. A simple analytic solution to the asymptotic slow-speed case of thermal drilling is noted and used to show that the high thermal conductivity of the low-temperature ice on Europa and Titan makes thermal drilling qualitatively more difficult than at Mars. It is shown that an isolated General Purpose Heat Source (GPHS) "brick" can drill effectively on Earth or Mars, whereas on Titan or Europa with ice at 100 K, the source would stall and become stuck in the ice with a surface temperature of <200 K.

  10. Toward environmentally-benign utilization of nonmetallic fraction of waste printed circuit boards as modifier and precursor

    Energy Technology Data Exchange (ETDEWEB)

    Hadi, Pejman; Ning, Chao; Ouyang, Weiyi; Xu, Meng [Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region (Hong Kong); Lin, Carol S.K. [School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong Special Administrative Region (Hong Kong); McKay, Gordon, E-mail: kemckayg@ust.hk [Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region (Hong Kong); Division of Sustainable Development, College of Science, Engineering and Technology, Hamad bin Khalifa University, Doha (Qatar)

    2015-01-15

    Highlights: • Environmental impacts of electronic waste and specifically waste printed circuit boards. • Review of the recycling techniques of waste printed circuit boards. • Advantages of physico-mechanical recycling techniques over chemical methods. • Utilization of nonmetallic fraction of waste printed circuit boards as modifier/filler. • Recent advances in the use of nonmetallic fraction of waste printed circuit boards as precursor. - Abstract: Electronic waste, including printed circuit boards, is growing at an alarming rate due to the accelerated technological progress and the shorter lifespan of the electronic equipment. In the past decades, due to the lack of proper economic and environmentally-benign recycling technologies, a major fraction of e-waste generated was either destined to landfills or incinerated with the sole intention of its disposal disregarding the toxic nature of this waste. Recently, with the increasing public awareness over their environment and health issues and with the enaction of more stringent regulations, environmentally-benign recycling has been driven to be an alternative option partially replacing the traditional eco-unfriendly disposal methods. One of the most favorable green technologies has been the mechanical separation of the metallic and nonmetallic fraction of the waste printed circuit boards. Although metallic fraction, as the most profitable component, is used to generate the revenue of the separation process, the nonmetallic fraction (NMF) has been left isolated. Herein, the recent developments in the application of NMF have been comprehensively reviewed and an eco-friendly emerging usage of NMF as a value-added material for sustainable remediation has been introduced.

  11. Characterization of impact damage in metallic/nonmetallic composites using x-ray computed tomography imaging

    Science.gov (United States)

    Green, William H.; Wells, Joseph M.

    1999-12-01

    Characterizing internal impact damage in composites can be difficult, especially in structurally complex composites or those consisting of many materials. Many methods for nondestructive inspection/nondestructive testing (NDI/NDT) of materials have been known and in use for many years, including x-ray film, real-time, and digital radiographic techniques, and ultrasonic techniques. However, these techniques are generally not capable of three-dimensional (3D) mapping of complex damage patterns, which is necessary to visualize and understand damage cracking modes. Conventional x-ray radiography suffers from the loss of 3D information. Structural complexity and signal dispersion in materials with many interfaces significantly effect ultrasonic inspection techniques. This makes inspection scan interpretation difficult, especially in composites containing a number of different materials (i.e., polymer, ceramic, and metallic). X-ray computed tomography (CT) is broadly applicable to any material or test object through which a beam of penetrating radiation may be passed and detected, including metals, plastics, ceramics, metallic/nonmetallic composites, and assemblies. The principal advantage of CT is that it provides densitometric (that is, radiological density and geometry) images of thin cross sections through an object. Because of the absence of structural superposition, images are much easier to interpret than conventional radiological images. The user can quickly learn to read CT data because images correspond more closely to the way the human mind visualizes 3D structures than projection radiology (that is, film radiography, real-time radiography (RTR), and digital radiography (DR)). Any number of CT images, or slices, from scanning an object can be volumetrically reconstructed to produce a 3D attenuation map of the object. The 3D attenuation data can be rendered using multiplanar or 3D solid visualization. In multiplanar visualization there are four planes of view

  12. Formation of a deposit on workpiece surface in polishing nonmetallic materials

    Science.gov (United States)

    Filatov, Yu. D.; Monteil, G.; Sidorko, V. I.; Filatov, O. Y.

    2013-05-01

    During the last decades in the theory of machining nonmetallic materials some serious advances have been achieved in the field of applying fundamental scientific approaches to the grinding and polishing technologies for high-quality precision surfaces of electronic components, optical systems, and decorative articles made of natural and synthetic stone [1-9]. These achievements include a cluster model of material removal in polishing dielectric workpieces [1-3, 6-7] and a physical-statistical model of formation of debris (wear) particles and removal thereof from a workpiece surface [8-10]. The aforesaid models made it possible to calculate, without recourse to Preston's linear law, the removal rate in polishing nonmetallic materials and the wear intensity for bound-abrasive tools. Equally important for the investigation of the workpiece surface generation mechanism and formation of debris particles are the kinetic functions of surface roughness and reflectance of glass and quartz workpiece surfaces, which have been established directly in the course of polishing. During the in situ inspection of a workpiece surface by laser ellipsometry [11] and reflectometry [12] it was found out that the periodic change of the light reflection coefficient of a workpiece surface being polished is attributed to the formation of fragments of a deposit consisting of work material particles (debris particles) and tool wear particles [13, 14]. The subsequent studies of the mechanism of interaction between the debris particles and wear particles in the tool-workpiece contact zone, which were carried out based on classical concepts [15, 16], yielded some unexpected results. It was demonstrated that electrically charged debris and wear particles, which are located in the coolant-filled gap between a tool and a workpiece, move by closed circular trajectories enclosed in spheres measuring less than one fifth of the gap thickness. This implies that the probability of the debris and wear

  13. Determinants of Electricity Demand in Nonmetallic Mineral Products Industry: Evidence from a Comparative Study of Japan and China

    Directory of Open Access Journals (Sweden)

    Gang Du

    2015-06-01

    Full Text Available Electricity intensity is an important indicator for measuring production efficiency. A comparative study could offer a new perspective on investigating determinants of electricity demand. The Japanese non-metallic mineral products industry is chosen as the object for comparison considering its representative position in production efficiency. By adopting the cointegration model, this paper examines influencing factors of electricity demand in Japanese and Chinese non-metallic mineral products industries under the same framework. Results indicate that although economic growth and industrial development stages are different between the two countries, major factors that affect the sectoral energy consumption are the same. Specifically, economic growth and industrial activity contribute to the growth of sectoral electricity consumption, while R&D intensity, per capita productivity and electricity price are contributors to the decline of sectoral electricity consumption. Finally, in order to further investigate the development trend of sectoral electricity demand, future electricity consumption and conservation potential are predicted under different scenarios. Electricity demand of the Chinese non-metallic mineral products industry is predicted to be 680.53 TWh (terawatt-hours in 2020 and the sectoral electricity conservation potentials are estimated to be 118.26 TWh and 216.25 TWh under the moderate and advanced electricity-saving scenarios, respectively.

  14. VALIDATION OF AN ALGORITHM FOR NONMETALLIC INTRAOCULAR FOREIGN BODIES' COMPOSITION IDENTIFICATION BASED ON COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING.

    Science.gov (United States)

    Moisseiev, Elad; Barequet, Dana; Zunz, Eran; Barak, Adiel; Mardor, Yael; Last, David; Goez, David; Segal, Zvi; Loewenstein, Anat

    2015-09-01

    To validate and evaluate the accuracy of an algorithm for the identification of nonmetallic intraocular foreign body composition based on computed tomography and magnetic resonance imaging. An algorithm for the identification of 10 nonmetallic materials based on computed tomography and magnetic resonance imaging has been previously determined in an ex vivo porcine model. Materials were classified into 4 groups (plastic, glass, stone, and wood). The algorithm was tested by 40 ophthalmologists, which completed a questionnaire including 10 sets of computed tomography and magnetic resonance images of eyes with intraocular foreign bodies and were asked to use the algorithm to identify their compositions. Rates of exact material identification and group identification were measured. Exact material identification was achieved in 42.75% of the cases, and correct group identification in 65%. Using the algorithm, 6 of the materials were exactly identified by over 50% of the participants, and 7 were correctly classified according to their groups by over 75% of the materials. The algorithm was validated and was found to enable correct identification of nonmetallic intraocular foreign body composition in the majority of cases. This is the first study to report and validate a clinical tool allowing intraocular foreign body composition based on their appearance in computed tomography and magnetic resonance imaging, which was previously impossible.

  15. Activity concentration of natural radioactive nuclides in nonmetallic industrial raw materials in Japan.

    Science.gov (United States)

    Iwaoka, Kazuki; Tabe, Hiroyuki; Yonehara, Hidenori

    2014-11-01

    Natural materials such as rock, ore, and clay, containing natural radioactive nuclides are widely used as industrial raw materials in Japan. If these are high concentrations, the workers who handle the material can be unknowingly exposed to radiation at a high level. In this study, about 80 nonmetallic natural materials frequently used as industrial raw materials in Japan were comprehensively collected from several industrial companies, and the activity concentrations of (238)U series, (232)Th series and (40)K in the materials was determined by ICP-MS (inductively-coupled plasma mass spectrometer) and gamma ray spectrum analyses. Effective doses to workers handling them were estimated by using methods for dose estimation given in the RP 122. We found the activity concentrations to be lower than the critical values defined by regulatory requirements as described in the IAEA Safety Guide. The maximum estimated effective dose to workers handling these materials was 0.16 mSv y(-1), which was lower than the reference level (1-20 mSv y(-1)) for existing situation given in the ICRP Publ.103.

  16. Absorption of non-metallic inclusions by steelmaking slags—a review

    Directory of Open Access Journals (Sweden)

    Bruno Henrique Reis

    2014-04-01

    Full Text Available The formation of non-metallic inclusions during steelmaking is inevitable and, when not properly controlled, can cause performance and production problems. Slag is one of the resources available to carry out this control. In steelmaking, it is generally understood that inclusions are naturally absorbed by slag when flotation is sufficient. However, separation and dissolution may define the inclusion absorption capacity of slag. The discussion in this review explains the relationship between separation and the contact angle at the steel/inclusion interface, which differentiates the mechanism from liquid and solid inclusions. Whereas liquid particles show more predictable behavior in experimental observations, thermodynamic analysis is necessary in order to describe the removal of solid particles. Among other findings, it is evident that slag viscosity and the formation of compounds at the inclusion/slag interface strongly influence inclusion dissolution capacity. Following a detailed description of findings in the literature, this review considers the most influential factors to aid in optimizing slags for inclusion absorption.

  17. Strength and deformability of concrete beams reinforced by non-metallic fiber and composite rebar

    Science.gov (United States)

    Kudyakov, K. L.; Plevkov, V. S.; Nevskii, A. V.

    2015-01-01

    Production of durable and high-strength concrete structures with unique properties has always been crucial. Therefore special attention has been paid to non-metallic composite and fiber reinforcement. This article describes the experimental research of strength and deformability of concrete beams with dispersed and core fiber-based reinforcement. As composite reinforcement fiberglass reinforced plastic rods with diameters 6 mm and 10 mm are used. Carbon and basalt fibers are used as dispersed reinforcement. The developed experimental program includes designing and production of flexural structures with different parameters of dispersed fiber and composite rebar reinforcement. The preliminary testing of mechanical properties of these materials has shown their effectiveness. Structures underwent bending testing on a special bench by applying flexural static load up to complete destruction. During the tests vertical displacements were recorded, as well as value of actual load, slippage of rebars in concrete, crack formation. As a result of research were obtained structural failure and crack formation graphs, value of fracture load and maximum displacements of the beams at midspan. Analysis of experimental data showed the effectiveness of using dispersed reinforcement of concrete and the need for prestressing of fiberglass composite rebar.

  18. Stepped-Frequency Ground-Penetrating Radar for Detection of Small Non-metallic Buried Objects

    DEFF Research Database (Denmark)

    Jakobsen, Kaj Bjarne; Sørensen, Helge Bjarup Dissing; Nymann, Ole

    1997-01-01

    to an HP8753C Network Analyzer through a 5 m long Sucoflex coaxial cable. The data are collected automatically using an HPIB interface. The collected data contains both the amplitude and phase information of the reflection coefficient. Data are measured at up to a maximum of 401 different frequencies...... at each measurement point using a mesh-grid with a resolution down to 1 mm by 1 mm. The size of the scan area is 1410 mm by 210 mm. Measurements have been performed on loamy soil containing a buried M-56, a non-metallic AP-mine, and various other mine-like objects made of solid plastic, brass, aluminum......, steel, and wood. The presented results are based on probe-data measured at 100 different frequencies at each measurement point and a coarser mesh-grid of 10 mm by 10 mm, since it is found that less probe-data is needed. Our experiments show that even less amount of probe-data may be necessary....

  19. A Five-year Performance Study of Low VOC Coatings over Zinc Thermal Spray for the Protection of Carbon Steel at the Kennedy Space Center

    Science.gov (United States)

    Kolody, Mark R.; Curran, Jerome P.; Calle, Luz Marina

    2014-01-01

    The launch facilities at the Kennedy Space Center (KSC) are located approximately 1000 feet from the Atlantic Ocean where they are exposed to salt deposits, high humidity, high UV degradation, and acidic exhaust from solid rocket boosters. These assets are constructed from carbon steel, which requires a suitable coating to provide long-term protection to reduce corrosion and its associated costs. While currently used coating systems provide excellent corrosion control performance, they are subject to occupational, safety, and environmental regulations at the Federal and State levels that limit their use. Many contain high volatile organic compounds (VOCs), hazardous air pollutants, and other hazardous materials. Hazardous waste from coating operations include vacuum filters, zinc dust, hazardous paint related material, and solid paint. There are also worker safety issues such as exposure to solvents and isocyanates. To address these issues, top-coated thermal spray zinc coating systems were investigated as a promising environmentally friendly corrosion protection for carbon steel in an acidic launch environment. Additional benefits of the combined coating system include a long service life, cathodic protection to the substrate, no volatile contaminants, and high service temperatures. This paper reports the results of a performance based study to evaluate low VOC topcoats (for thermal spray zinc coatings) on carbon steel for use in a space launch environment.

  20. Research Progress of Novel Lightweight Thermal Protection Composites%新型轻质热防护复合材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    韩杰才; 洪长青; 张幸红; 程海明; 薛华飞

    2015-01-01

    针对未来深空探测飞行器对轻质复合材料的需求,总结了国内外航天防热复合材料的最新研究进展,提出了飞行器轻质热防护复合材料和充气式再入减速器热防护复合材料的设计、制备、考核和评价方法。重点介绍了两类新型轻质热防护复合材料设计、纳/微米结构调控和极端环境考核的阶段性研究成果,揭示了服役环境-结构设计-材料制备-性能评价-系统集成的相关性,为我国载人航天复合材料与结构的快速发展提供技术支撑。%According to the requirements on novel lightweight aerospace composites in the field ofdeep space exploration, this paper summarized the latest research progress of thermal protection aerospacecomposites at home and abroad.The design, preparation, test and evaluation method oflightweight thermal protection materials and inflatable flexible thermal protection materials were proposed.The progressive achievements including materials preparation, microstructure controlling atnano/micro-scale length, and environmental testing for two kinds of lightweight composites at extremeenvironment were mainly discussed.The relationship between service condition, materialspreparation, property evaluation and system integration for novel aerospace composites were revealedand analyzed.The paper may serve as a technological support for the development of advanced aerospacecomposites and structure in China.

  1. Evaluation of three thermal protection systems in a hypersonic high-heating-rate environment induced by an elevon deflected 30 deg

    Science.gov (United States)

    Taylor, A. H.; Jackson, L. R.; Weinstein, I.

    1977-01-01

    Three thermal protection systems proposed for a hypersonic research airplane were subjected to high heating rates in the Langley 8 foot, high temperature structures tunnel. Metallic heat sink (Lockalloy), reusable surface insulation, and insulator-ablator materials were each tested under similar conditions. The specimens were tested for a 10 second exposure on the windward side of an elevon deflected 30 deg. The metallic heat sink panel exhibited no damage; whereas the reusable surface insulation tiles were debonded from the panel and the insulator-ablator panel eroded through its thickness, thus exposing the aluminum structure to the Mach 7 environment.

  2. A New Way of Doing Business: Reusable Launch Vehicle Advanced Thermal Protection Systems Technology Development: NASA Ames and Rockwell International Partnership

    Science.gov (United States)

    Carroll, Carol W.; Fleming, Mary; Hogenson, Pete; Green, Michael J.; Rasky, Daniel J. (Technical Monitor)

    1995-01-01

    NASA Ames Research Center and Rockwell International are partners in a Cooperative Agreement (CA) for the development of Thermal Protection Systems (TPS) for the Reusable Launch Vehicle (RLV) Technology Program. This Cooperative Agreement is a 30 month effort focused on transferring NASA innovations to Rockwell and working as partners to advance the state-of-the-art in several TPS areas. The use of a Cooperative Agreement is a new way of doing business for NASA and Industry which eliminates the traditional customer/contractor relationship and replaces it with a NASA/Industry partnership.

  3. High-Temperature Properties of Ceramic Fibers and Insulations for Thermal Protection of Atmospheric Entry and Hypersonic Cruise Vehicles

    Science.gov (United States)

    Kourtides, Demetrius A.; Pitts, William C.; Araujo, Myrian; Zimmerman, R. S.

    1988-01-01

    Multilayer insulations which will operate in the 500C to 1000C temperature range are being considered for possible applications on aerospace vehicles subject to convective and radiative heating during atmospheric entry. The insulations described in this paper consist of ceramic fabrics, insulations, and metal foils quilted together using ceramic thread. As these types of insulations have highly anisotropic properties, the total heat transfer characteristics of these insulations must be determined. Data are presented on the thermal diffusivity and thermal conductivity of four types of multilayer insulations and are compared to the baseline Advanced Flexible Reusable Surface Insulation

  4. Dietary lecithin potentiates thermal tolerance and cellular stress protection of milk fish (Chanos Chanos) reared under low dose endosulfan-induced stress.

    Science.gov (United States)

    Kumar, Neeraj; Minhas, P S; Ambasankar, K; Krishnani, K K; Rana, R S

    2014-12-01

    Endosulfan is an organochlorine pesticide commonly found in aquatic environments that has been found to reduce thermal tolerance of fish. Lipotropes such as the food additive, Lecithin has been shown to improve thermal tolerance in fish species. This study was conducted to evaluate the role of lipotropes (lecithin) for enhancing the thermal tolerance of Chanos chanos reared under sublethal low dose endosulfan-induced stress. Two hundred and twenty-five fish were distributed randomly into five treatments, each with three replicates. Four isocaloric and isonitrogenous diets were prepared with graded levels of lecithin: normal water and fed with control diet (En0/L0), endosulfan-treated water and fed with control diet (En/L0), endosulfan-treated water and fed with 1% (En/L1%), 1.5% (En/L 1.5%) and 2% (En/L 2%) lecithin supplemented feed. The endosulfan in treated water was maintained at the level of 1/40th of LC50 (0.52ppb). At the end of the five weeks, critical temperature maxima (CTmax), lethal temperature maxima (LTmax), critical temperature minima (CTmin) and lethal temperature minima (LTmin) were Determined. There was a significant (Plecithin on temperature tolerance (CTmax, LTmax, CTmin and LTmin) of the groups fed with 1, 1.5 and 2% lecithin-supplemented diet compared to control and endosulfan-exposed groups. Positive correlations were observed between CT max and LTmax (R(2)=0.934) as well as between CTmin and LTmin (R(2)=0.9313). At the end of the thermal tolerance study, endosulfan-induced changes in cellular stress enzymes (Catalase, SOD and GST in liver and gill and neurotansmitter enzyme, brain AChE) were significantly (plecithin. We herein report the role of lecithin in enhancing the thermal tolerance and protection against cellular stress in fish exposed to an organochlorine pesticide. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Detection of Non-metallic Inclusions in Centrifugal Continuous Casting Steel Billets

    Science.gov (United States)

    Wang, Qiangqiang; Zhang, Lifeng; Seetharaman, Sridhar; Yang, Shufeng; Yang, Wen; Wang, Yi

    2016-06-01

    In the current study, automated particle analysis was employed to detect non-metallic inclusions in steel during a centrifugal continuous casting process of a high-strength low alloy steel. The morphology, composition, size, area fraction, amount, and spatial distribution of inclusions in steel were obtained. Etching experiment was performed to reveal the dendrite structure of the billet and to discuss the effect of centrifugal force on the distribution of oxide inclusions in the final solidified steel by comparing the solidification velocity with the critical velocity reported in literature. It was found that the amount of inclusions was highest in samples from the tundish (~250 per mm2), followed by samples from the mold (~200 per mm2), and lowest in billet samples (~86 per mm2). In all samples, over 90 pct of the inclusions were smaller than 2μm. In steel billets, the content of oxides, dual-phase oxide-sulfides, and sulfides in inclusions were found to be 10, 30, and 60 pct, respectively. The dual-phase inclusions were oxides with sulfides precipitated on the outer surface. Oxide inclusions consisted of high Al2O3 and high MnO which were solid at the molten steel temperature, implying that the calcium treatment was insufficient. Small oxide inclusions very uniformly distributed on the cross section of the billet, while there were more sulfide inclusions showing a banded structure at the outside 25 mm layer of the billet. The calculated solidification velocity was higher than the upper limit at which inclusions were entrapped by the solidifying front, revealing that for oxide inclusions smaller than 8μm in this study, the centrifugal force had little influence on its final distribution in billets. Instead, oxide inclusions were rapidly entrapped by solidifying front.

  6. Thermal protection of β-carotene in re-assembled casein micelles during different processing technologies applied in food industry.

    Science.gov (United States)

    Sáiz-Abajo, María-José; González-Ferrero, Carolina; Moreno-Ruiz, Ana; Romo-Hualde, Ana; González-Navarro, Carlos J

    2013-06-01

    β-Carotene is a carotenoid usually applied in the food industry as a precursor of vitamin A or as a colourant. β-Carotene is a labile compound easily degraded by light, heat and oxygen. Casein micelles were used as nanostructures to encapsulate, stabilise and protect β-carotene from degradation during processing in the food industry. Self-assembly method was applied to re-assemble nanomicelles containing β-carotene. The protective effect of the nanostructures against degradation during the most common industrial treatments (sterilisation, pasteurisation, high hydrostatic pressure and baking) was proven. Casein micelles protected β-carotene from degradation during heat stabilisation, high pressure processing and the processes most commonly used in the food industry including baking. This opens new possibilities for introducing thermolabile ingredients in bakery products.

  7. CoFe 2O 4 spinel protection coating thermally converted from the electroplated Co-Fe alloy for solid oxide fuel cell interconnect application

    Science.gov (United States)

    Bi, Z. H.; Zhu, J. H.; Batey, J. L.

    CoFe 2O 4 has been demonstrated as a potential spinel coating for protecting the Cr-containing ferritic interconnects. This spinel had an electrical conductivity of 0.85 S cm -1 at 800 °C in air and an average coefficient of thermal expansion (CTE) of 11.80 × 10 -6 K -1 from room temperature to 800 °C. A series of Co-Fe alloys were co-deposited onto the Crofer 22 APU ferritic steel via electroplating with an acidic chloride solution. After thermal oxidation in air at 800 °C, a CoFe 2O 4 spinel layer was attained from the plated Co 0.40Fe 0.60 film. Furthermore, a channeled Crofer 22 APU interconnect electrodeposited with a 40-μm Co 0.40Fe 0.60 alloy film as a protective coating was evaluated in a single-cell configuration. The presence of the dense, Cr-free CoFe 2O 4 spinel layer was effective in blocking the Cr migration/transport and thus contributed to the improvement in cell performance stability.

  8. High temperature properties of ceramic fibers and insulations for thermal protection of atmospheric entry and hypersonic cruise vehicles

    Science.gov (United States)

    Kourtides, Demetrius A.; Pitts, William C.; Araujo, Myrian; Zimmerman, R. S.

    1988-01-01

    Multilayer insulations (MIs) which will operate in the 500 to 1000 C temperature range are being considered for possible applications on aerospace vehicles subject to convective and radiative heating during atmospheric entry. The insulations described consist of ceramic fibers, insulations, and metal foils quilted together with ceramic thread. As these types of insulations have highly anisotropic properties, the total heat transfer characteristics must be determined. Data are presented on the thermal diffusivity and thermal conductivity of four types of MIs and are compared to the baseline Advanced Flexible Reusable Surface Insulation currently used on the Space Shuttle Orbiter. In addition, the high temperature properties of the fibers used in these MIs are discussed. The fibers investigated included silica and three types of aluminoborosilicate (ABS). Static tension tests were performed at temperatures up to 1200 C and the ultimate strain, tensile strength, and tensile modulus of single fibers were determined.

  9. Influence of Low-Alloy Cast Steel Modification on Primary Structure Refinement, Type and Shape of Non-Metallic Inclusions

    Directory of Open Access Journals (Sweden)

    Bartocha D.

    2015-04-01

    Full Text Available In the article there are presented methods and results of investigation which main aim were determination of influence of melting technology (gas extraction, vacuum refining, slag refining and extraction, deoxidation and degassing and type of used modifiers on the type and shape of non-metallic inclusions and the primary structure refining. Low alloy cast steel melted in laboratory conditions, in an inductive furnace was investigated. Additions of FeNb, FeV, FeTi and FeZr modifiers were applied. The contents of oxygen and nitrogen in obtained cast steel were determined.

  10. 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.

  11. Protection of Reinforced Concrete Structures of Waste Water Treatment Reservoirs with Stainless Steel Coating Using Arc Thermal Spraying Technique in Acidified Water

    Science.gov (United States)

    Lee, Han-Seung; Park, Jin-Ho; Singh, Jitendra Kumar; Ismail, Mohamed A.

    2016-01-01

    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. PMID:28773875

  12. Thermal Sprayed Aluminium for Subsea Heat Exchanger Surfaces : Effect of Temperature on Protection Current Requirement and Calcareous Development

    OpenAIRE

    Wilson, Håvard

    2014-01-01

    More and more equipment in the Oil and Gas Industry are being placed Subsea. Thisincludes subsea coolers with high internal temperatures. With high temperatures comewith challenges within material selection and corrosion. Traditional material choices like carbon steel and organic coatings with cathodic protection (CP) is not an option for subsea coolers. This is due to insulating properties to the organic coatings and the dense calcareous deposits which form on the surface of the steel.Therma...

  13. Frost-protected shallow foundation: work in seasonally-freezing through grounds, practice of thermal calculation (rus

    Directory of Open Access Journals (Sweden)

    Belyakov V.A.

    2011-12-01

    Full Text Available The object of research is frost-protected shallow foundations.The article focuses on a technique of solving the nonstationary and nonlinear problem of freezing/thawing of soil in a 2D target setting, using software based on the finite-element method. The COSMOS/M package from Structural Research & Analysis Corp. is used as an example. The article also mentions some peculiarities of data input, caused by the non-linearity and nonstationarity of the problem.

  14. Unintended Thermal Injuries from Radiofrequency Ablation: Organ Protection with an Angioplasty Balloon Catheter in an Animal Model

    Directory of Open Access Journals (Sweden)

    Martha-Grace Knuttinen

    2014-01-01

    Full Text Available Objectives: The aim of this study was to investigate a novel approach of using a balloon catheter as a protective device to separate liver from the diaphragm or nearby bowel during radiofrequency ablation (RFA of hepatic dome tumors in an animal model. Materials and Methods: All experimental procedures were approved by animal Institutional Review Board. Using a 3 cm RF needle electrode, 70 hepatic ablation zones were created using ultrasound in 7 pigs. 50 lesions were created using balloon interposition between liver and diaphragm; 20 lesions were created using the balloon device interposed posteriorly between liver and bowel. Additional 21 control lesions were performed. Animals were sacrificed immediately; diaphragm and bowel were then visually inspected and sectioned. Diaphragmatic and bowel injury was then classified according to the depth of thickness. Results: Control lesions caused full thickness injury, either to diaphragm or bowel. During ablation of lesions with balloon interposition, there was significantly less diaphragmatic injury, P < 0.001 and less bowel injury, P < 0.01. Conclusion: Using balloon interposition as a protective device has advantages over previous saline infusion or CO 2 insufflation, providing a safe way to expand percutaneous RFA of liver tumors located on the undersurface of the diaphragm. In addition, this method may be used in protection of other organs adjacent to areas being ablated.

  15. INFLUENCE ОF MODIFIER THERMAL TREATMENT ОN CHARACTERISTICS ОF COMPOSITE MATERIALS FOR PROTECTIVE COATINGS

    Directory of Open Access Journals (Sweden)

    V. Ivashko

    2012-01-01

    Full Text Available This paper presents results that reveal influence of modifiers characterized by different nature and composition and subjected to heat treatment on operational characteristics of single and binary compositions. Interaction between dispersed clay particles and dependence of  coating properties on  their mass content in oligomeric and polymeric matrices have been justified in the paper. The paper contains data that prove an increase of coating hardness by 15–20 %. The coating composition includes thermally-treated dispersed clay particles.

  16. 大型抽水蓄能机组热工保护设置与应用%Setting and Application of Thermal Protections for Large Pumped-storage Power Units

    Institute of Scientific and Technical Information of China (English)

    彭煜民

    2012-01-01

    The unit of pumped -storage power station will be run in many different conditions and switched between them frequently. The thermal protections have important roles on the normal operation of units and the mitigation of accidents. The thermal protections, including temperature protection, pressure and pressure difference protection, flow protection, liquid level protection, displacement/position protection, vibration protection, over-speed protection and powerhouse flooded protection, are analyzed in detail herein. The experiences can be as references to the design of other pumped-storage power stations.%抽水蓄能电站机组运行工况多且工况转换频繁,热工保护对机组正常运行、避免扩大事故有着举足轻重的作用.对热工保护中的温度保护、压力压差保护、流量保护、液位保护、位移(位置)保护、振动保护、过速保护及水淹厂房等保护做了详细的分析与说明,可供其他抽水蓄能电站进行热工保护设计时借鉴.

  17. X-ray detection of ingested non-metallic foreign bodies.

    Science.gov (United States)

    Saps, Miguel; Rosen, John M; Ecanow, Jacob

    2014-05-08

    To determine the utility of X-ray in identifying non-metallic foreign body (FB) and assess inter-radiologist agreement in identifying non-metal FB. Focus groups of nurses, fellows, and attending physicians were conducted to determine commonly ingested objects suitable for inclusion. Twelve potentially ingested objects (clay, plastic bead, crayon, plastic ring, plastic army figure, glass bead, paperclip, drywall anchor, eraser, Lego™, plastic triangle toy, and barrette) were embedded in a gelatin slab placed on top of a water-equivalent phantom to simulate density of a child's abdomen. The items were selected due to wide availability and appropriate size for accidental pediatric ingestion. Plain radiography of the embedded FBs was obtained. Five experienced radiologists blinded to number and types of objects were asked to identify the FBs. The radiologist was first asked to count the number of items that were visible then to identify the shape of each item and describe it to a study investigator who recorded all responses. Overall inter-rater reliability was analyzed using percent agreement and κ coefficient. We calculated P value to assess the probability of error involved in accepting the κ value. Fourteen objects were radiographed including 12 original objects and 2 duplicates. The model's validity was supported by clear identification of a radiolucent paperclip as a positive control, and lack of identification of plastic beads (negative control) despite repeated inclusion. Each radiologist identified 7-9 of the 14 objects (mean 8, 67%). Six unique objects (50%) were identified by all radiologists and four unique objects (33%) were not identified by any radiologist (plastic bead, Lego™, plastic triangle toy, and barrette). Identification of objects that were not present, false-positives, occurred 1-2 times per radiologist (mean 1.4). An additional 17% of unique objects were identified by less than half of the radiologists. Agreement between radiologists was

  18. CAVE: A computer code for two-dimensional transient heating analysis of conceptual thermal protection systems for hypersonic vehicles

    Science.gov (United States)

    Rathjen, K. A.

    1977-01-01

    A digital computer code CAVE (Conduction Analysis Via Eigenvalues), which finds application in the analysis of two dimensional transient heating of hypersonic vehicles is described. The CAVE is written in FORTRAN 4 and is operational on both IBM 360-67 and CDC 6600 computers. The method of solution is a hybrid analytical numerical technique that is inherently stable permitting large time steps even with the best of conductors having the finest of mesh size. The aerodynamic heating boundary conditions are calculated by the code based on the input flight trajectory or can optionally be calculated external to the code and then entered as input data. The code computes the network conduction and convection links, as well as capacitance values, given basic geometrical and mesh sizes, for four generations (leading edges, cooled panels, X-24C structure and slabs). Input and output formats are presented and explained. Sample problems are included. A brief summary of the hybrid analytical-numerical technique, which utilizes eigenvalues (thermal frequencies) and eigenvectors (thermal mode vectors) is given along with aerodynamic heating equations that have been incorporated in the code and flow charts.

  19. Study on Non-Metallic Inclusions in Laser-Welded TRIP-Aided Nb-Microalloyed Steel

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2014-10-01

    Full Text Available The work concerns the studies on non-metallic inclusions occuring in laser-welded Si-Al TRIP steel containing Nb and Ti microadditions. Laser welding tests of 2 mm thick thermomechanically rolled sheets were carried out using keyhole welding and a solid-state laser. The results of laser welding in the air atmosphere for the heat input value of 0.048 kJ/mm are included. The distribution, type and chemical composition of non-metallic inclusions formed in the base metal, heat-affected zone, and fusion zone are analysed in detail. It was found that the base metal contains rare, fine oxysulphides. Their chemical composition was modified by rare earth elements. Numerous oxide inclusions of a various size and a chemical composition occur in the fusion zone. The dependence between a size of particles and their chemical composition was observed. A microstructure of steel was assessed using light microscopy and scanning electron microscopy techniques.

  20. Non-Metallic Inclusions and Hot-Working Behaviour of Advanced High-Strength Medium-Mn Steels

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2016-06-01

    Full Text Available The work addresses the production of medium-Mn steels with an increased Al content. The special attention is focused on the identification of non-metallic inclusions and their modification using rare earth elements. The conditions of the thermomechanical treatment using the metallurgical Gleeble simulator and the semi-industrial hot rolling line were designed for steels containing 3 and 5% Mn. Hot-working conditions and controlled cooling strategies with the isothermal holding of steel at 400°C were selected. The effect of Mn content on the hot-working behaviour and microstructure of steel was addressed. The force-energetic parameters of hot rolling were determined. The identification of structural constituents was performed using light microscopy and scanning electron microscopy methods. The addition of rare earth elements led to the total modification of non-metallic inclusions, i.e., they replaced Mn and Al forming complex oxysulphides. The Mn content in a range between 3 and 5% does not affect the inclusion type and the hot-working behaviour. In contrast, it was found that Mn has a significant effect on a microstructure.

  1. Effects of Zr, Ti, and Al Additions on Nonmetallic Inclusions and Impact Toughness of Cast Low-Alloy Steel

    Science.gov (United States)

    Bizyukov, Pavel V.; Giese, Scott R.

    2017-03-01

    A microalloying of the low-carbon and low-alloy cast steel was conducted with Zr, Ti, and Al that were added to the steel in four combinations. After heat treatment, the samples were tested for impact toughness at room temperature using the Charpy method. The highest values of impact toughness were obtained in the group treated with Zr, while Zr-Ti and Zr-Ti-Al groups showed moderate toughness values; the lowest values were observed in the Zr-Al group. Difference among the treatment groups was observed in the fracture mechanisms, morphology, and area distribution of the inclusions. High toughness values achieved in the trials treated with zirconium corresponded with smooth ductile fracture. The metal treated with a combination of zirconium and titanium had a relatively small area occupied by inclusions, but its toughness was also moderate. Lowest impact toughness values corresponded with the larger area occupied by the inclusions in the trials treated with aluminum. Also, a connection between the solubility product [Al][N] and impact toughness was established. The study also provides a qualitative description and quantitative analysis of the nonmetallic inclusions formation as a result of microalloying treatment. The precipitation sequence of the inclusions was described based on the thermochemical calculations for the nonmetallic compounds discovered in the experimental steel. A description of the size distribution, morphology, and composition was conducted for the oxides, nitrides, sulfides, and multiphase particles.

  2. Toward environmentally-benign utilization of nonmetallic fraction of waste printed circuit boards as modifier and precursor.

    Science.gov (United States)

    Hadi, Pejman; Ning, Chao; Ouyang, Weiyi; Xu, Meng; Lin, Carol S K; McKay, Gordon

    2015-01-01

    Electronic waste, including printed circuit boards, is growing at an alarming rate due to the accelerated technological progress and the shorter lifespan of the electronic equipment. In the past decades, due to the lack of proper economic and environmentally-benign recycling technologies, a major fraction of e-waste generated was either destined to landfills or incinerated with the sole intention of its disposal disregarding the toxic nature of this waste. Recently, with the increasing public awareness over their environment and health issues and with the enaction of more stringent regulations, environmentally-benign recycling has been driven to be an alternative option partially replacing the traditional eco-unfriendly disposal methods. One of the most favorable green technologies has been the mechanical separation of the metallic and nonmetallic fraction of the waste printed circuit boards. Although metallic fraction, as the most profitable component, is used to generate the revenue of the separation process, the nonmetallic fraction (NMF) has been left isolated. Herein, the recent developments in the application of NMF have been comprehensively reviewed and an eco-friendly emerging usage of NMF as a value-added material for sustainable remediation has been introduced. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Effectiveness of Shot Peening In Suppressing Fatigue Cracking At Non-Metallic Inclusions In Udimet(Registered Trademark)720

    Science.gov (United States)

    Barrie, Robert L.; Gabb, Timothy P.; Telesman, Jack; Kantzos, Peter T.; Prescenzi, Anthony; Biles, T.; Bonacuse, P. J.

    2006-01-01

    The fatigue lives of modern powder metallurgy disk alloys can be reduced over an order of magnitude by cracking at inherent non-metallic inclusions. The objective of this work was to study the effectiveness of shot peening in suppressing LCF crack initiation and growth at surface nonmetallic inclusions. Inclusions were carefully introduced at elevated levels during powder metallurgy processing of the nickel-base disk superalloy Udimet 720. Multiple strain-controlled fatigue tests were then performed on machined specimens with and without shot peened test sections at 427 C and 650 C. The low cycle fatigue lives and failure initiation sites varied as functions of inclusion content, shot peening, and fatigue conditions. A large majority of the failures in as-machined specimens with the introduced inclusions occurred at cracks initiating from inclusions intersecting the specimen surface. These inclusions reduced fatigue life by up to 100X, when compared to lives of material without inclusions residing at specimen surface. Large inclusions produced the greatest reductions in life for tests at low strain ranges and high strain ratios. Shot peening improved life in many cases by reducing the most severe effects of inclusions.

  4. Effectiveness of Shot Peening in Suppressing Fatigue Cracking at Non-Metallic Inclusions in Udimet(trademark) 720

    Science.gov (United States)

    Barrie, Robert L.; Gabb, Timothy P.; Telesman, Jack; Kantzos, Peter T.; Prescenzi, Anthony; Biles, Tiffany; Bonacuse, Peter J.

    2005-01-01

    The fatigue lives of modern powder metallurgy disk alloys can be reduced by over an order of magnitude by surface cracking at inherent non-metallic inclusions. The objective of this work was to study the effectiveness of shot peening in suppressing LCF crack initiation and growth at surface nonmetallic inclusions. Inclusions were carefully introduced at elevated levels during powder metallurgy processing of the nickel-base disk superalloy Udimet 720. Multiple strain-controlled fatigue tests were then performed on machined specimens at 427 and 650 C in peened and unpeened conditions. Analyses were performed to compare the low cycle fatigue lives and failure initiation sites as a function of inclusion content, shot peening, and fatigue conditions. A large majority of the failures in as-machined specimens with introduced inclusions occurred at cracks initiating from inclusions intersecting the specimen surface. The inclusions could reduce fatigue life by up to 100X. Large inclusions had the greatest effect on life in tests at low strain ranges and high strain ratios. Shot peening can be used to improve life in these conditions by reducing the most severe effects of inclusions.

  5. AES and SIMS analysis of non-metallic inclusions in a low-carbon chromium-steel.

    Science.gov (United States)

    Gammer, Katharina; Rosner, M; Poeckl, G; Hutter, H

    2003-05-01

    In the final step of secondary metallurgical steel processing, calcium is added. Besides Mg, Ca is the most powerful deoxidiser and desulfurisation agent. It reacts with dissolved oxygen and sulfur and reduces oxides and sulfides thereby forming non-metallic inclusions. Within this paper we present the analysis of such inclusions in a low-carbon chromium-steel. Depending on the time of quenching of the steel sample, different structures were revealed by REM, Auger and SIMS: If the steel was quenched immediately after Ca-addition, non-metallic inclusions that appeared to have "cavities" could be detected with SEM. SIMS investigations of these particles showed ring-shaped structures and revealed that the ring is made up of Al, Ca, Mg, O and S. No secondary ions however could be retrieved from the core inside the ring, thus leaving the nature of the "cavities" unclear. If the steel sample was quenched 3 min after Ca addition, inclusions did not have a ring-shaped structure but a compact one.

  6. Space shuttle orbiter trimmed center-of-gravity extension study. Volume 3: Impact of retrofits for center-of-gravity extension on orbiter thermal-protection system

    Science.gov (United States)

    Dunavant, J. C.

    1979-01-01

    Heat transfer studies were conducted at Mach 10.3 on space shuttle orbiter models with the S-2 fillet and C-4 canard retrofit moldlines which were generated in aerodynamic and system design studies to increase the allowable c.g. range of the orbiter. Areas of orbiter most strongly affected were the sides where a shear layer which separated along the wing leading edge impinged. Analytical studies of the heating effect on the thermal-protection system were made which indicated that scar weight on the orbiter sides due to allowances for retrofits of the S-2 fillet and C-4 canard is small (less than about 90 kg (200 lbs) in comparison to the total weight of the retrofit).

  7. Modeling the heat and mass transfer in the pores of the thermal protection carbon-carbon frame during the gas-phase deposition of silicon carbide

    Directory of Open Access Journals (Sweden)

    Reznik Sergey V.

    2017-01-01

    Full Text Available This paper is dedicated to the numerical simulation of the gas-phase deposition into the porous carbon-carbon frame for the gradient thermal protection of reentry vehicles. The paper presents the specifics of creating the representative volume elements of the porous carbon-carbon frames based on the microstructure data from the computed tomography scanner, electronic scanning microscope and porosimetry results. The finite-element models of the representative volume elements are created in order to obtain the net independent solution, including the special finite elements at the phase interfaces. The finite-element and finite-volume method was used for calculation, implemented in MSC.Digimat and ANSYS software packages. The effect of the reagent parameters on the gas-phase deposition process, uniformity and rate of silicon carbide deposition was simulated parametrically, and the results are presented.

  8. Evaluation of the potential of optical switching materials for overheating protection of thermal solar collectors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Huot, G.; Roecker, Ch.; Schueler, A.

    2008-01-15

    Providing renewable energy for domestic hot water production and space heating, thermal solar collectors are more and more widespread, and users' expectations with respect to performance and service lifetime are rising continuously. The durability of solar collector materials is a critical point as the collector lifetime should be at least 25 years. Overheating and the resulting stagnation of the collector is a common problem with solar thermal systems. During stagnation high temperatures lead to water evaporation, glycol degradation, and stresses in the collector with increasing pressure. Special precautions are necessary to release this pressure; only mechanical solutions exist nowadays. Additionally, the occurring elevated temperatures lead to degradation of the materials that compose collectors: seals, insulation materials, and also the selective coating which is the most important part of the collector. A promising way to achieve active cooling of collectors without any mechanical device for pressure release or collector emptying is to produce a selective coating which is able to switch its optical properties at a critical temperature Tc. An optical switch allows changing the selective coating efficiency; the goal is to obtain a coating with a poor selectivity above Tc (decreasing of absorptance, increasing of emittance). Obtaining self-cooling collectors will allow increasing collector surfaces on facades and roofs in order to get high efficiency and hot water production during winter without inconvenient overheating during summer. Optical switching of materials can be obtained by many ways. Inorganic and organic thermochromic compounds, and organic thermotropic coatings are the main types of switching coatings that have been studied at EPFL-LESO-PB. Aging studies of organic thermochromic paints fabricated at EPFL suggest that the durability of organic compounds might not be sufficient for glazed metallic collectors. First samples of inorganic coatings

  9. Possible Applications of Hardening Slurries with Fly Ash from Thermal Treatment of Municipal Sewage Sludge in Environmental Protection Structures

    Science.gov (United States)

    Falacinski, Paweł; Szarek, Łukasz

    2016-06-01

    In Poland, in recent years, there has been a rapid accumulation of sewage sludge - a by-product in the treatment of urban wastewater. This has come about as a result of infrastructure renewal, specifically, the construction of modern sewage treatment plants. The more stringent regulations and strategic goals adopted for modern sewage management have necessitated the application of modern engineering methodology for the disposal of sewage sludge. One approach is incineration. As a consequence, the amount of fly ash resulting from the thermal treatment of municipal sewage sludge has grown significantly. Hence, intensive work is in progress for environmentally safe management of this type of waste. The aim of the experiment was to evaluate the possibility of using the fly ash that results from municipal sewage sludge thermal treatment (SSTT) as an additive to hardening slurries. This type of hardening slurry with various types of additives, e.g. coal combustion products, is used in the construction of cut-off walls in hydraulic structures. The article presents the technological and functional parameters of hardening slurries with an addition of fly ash obtained by SSTT. Moreover, the usefulness of these slurries is analysed on the basis of their basic properties, i.e. density, contractual viscosity, water separation, structural strength, volumetric density, hydraulic conductivity, compressive and tensile strength. The mandated requirements for slurries employed in the construction of cut-off walls in flood embankments are listed as a usefulness criteria. The article presents the potential uses of fly ash from SSTT in hardening slurry technology. It also suggests directions for further research to fully identify other potential uses of this by-product in this field.

  10. Self-response multi-functional composite material base on carbon nanotube paper using deicing, flame retardancy, thermal insulation, and lightning-strike protection

    Science.gov (United States)

    Chu, Hetao; Zhang, Zhichun; Liu, Yanju; Leng, Jinsong

    2015-04-01

    Carbon nanotube paper (CNP) based multi-functional composite material is an attractive candidate for deicing, flame retardancy, thermal insulation and lighting strike protection due to the excellent conductivity, light weight and thin dimensions. In this article, multi-functional carbon nanotube paper was fabricated successfully by using commercial carbon nanotube. As a deicing composite material, carbon nanotube was used directly without pretreatment in fabricating carbon nanotube paper. The conductivities of the carbon nanotube paper and deicing composite were 77.8S/cm and 64.9S/ respectively. Electrical heating and deicing performance were test by infrared camera with deicing time less than 220s and 450s to melt a certain amount of ice under different ambient condition. CNT was grafted by zirconium (IV) butoxide solution and dimethyl dichlorosilicane to form co-oligomers on the tube surface while oligomers decompose under a certain temperature to develop an inorganic layer of silicon zirconium oxide. The oxidizing temperature of carbon nanotube increases more than 20°C and the weight loss rate decreases 20% than the untreated carbon nanotube. Lightning protection material required high electro conductivity, due to the utmost high current in a short time. Therefore, silver nanoparticles were deposited on the surface of carbon nanotube with the diameter around 100nm. The conductivity increased sharply from 84s/cm to1756s/cm with the mount of 5.9wt% Ag of the modified carbon nanotube paper because the silver nanoparticles deposited on the surface. In addition, the silver modified also can be used as thermal insulation material decreasing the infrared radiation.

  11. Instrument for Measuring Thermal Conductivity of Materials at Low Temperatures

    Science.gov (United States)

    Fesmire, James; Sass, Jared; Johnson, Wesley

    2010-01-01

    With the advance of polymer and other non-metallic material sciences, whole new series of polymeric materials and composites are being created. These materials are being optimized for many different applications including cryogenic and low-temperature industrial processes. Engineers need these data to perform detailed system designs and enable new design possibilities for improved control, reliability, and efficiency in specific applications. One main area of interest is cryogenic structural elements and fluid handling components and other parts, films, and coatings for low-temperature application. An important thermal property of these new materials is the apparent thermal conductivity (k-value).

  12. Energy Consumption and Carbon Dioxide Emissions of China’s Non-Metallic Mineral Products Industry: Present State, Prospects and Policy Analysis

    Directory of Open Access Journals (Sweden)

    Hui Hu

    2014-11-01

    Full Text Available China is the largest non-metallic mineral producer in the world and one of the key consumers of four major non-metallic mineral products, including cement, refractories, plate glass and ceramics. The non-metallic mineral products industry’s rapid growth has brought about a large demand for energy. The present study provides an overview of China’s non-metallic mineral products industry in terms of production, energy consumption and carbon dioxide emissions. In this industry, the energy efficiency is relatively low and the level of carbon dioxide emission is much higher than developed countries’ average. This study interprets the effects of some newly issued policies and analyses the influential factors in achieving energy conservation and emission reduction goals. It also discusses the prospects for saving energy and emission reduction in the industry. Retrofitting facilities and using new production technologies is imperative. Additionally, implementing market-based policies, promoting industrial transformation and effective international cooperation would help decrease carbon dioxide emissions and energy consumption.

  13. Effect of Calcium Treatment on Non-Metallic Inclusions in Ultra-Low Oxygen Steel Refined by High Basicity High Al2O3 Sla

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; WANG Xin-hua; JIANG Min; WANG Wan-jun

    2011-01-01

    The influence of calcium treatment on non-metallic inclusions had been studied when control technology of refining top slag in ladle furnace was used in ultra-low oxygen steelmaking. A sufficient amount aluminium was added to experimental heats for final

  14. Effect of the structural parameters changes in the multi-strand tundish on the non-metallic inclusions distribution and separation

    Directory of Open Access Journals (Sweden)

    M. Warzecha

    2014-10-01

    Full Text Available The aim of presented studies was to investigate the fluid flow change and non-metallic inclusions removal changes due to tundish construction modifications. In presented study, numerical simulations were used. Numerical simulations are carried out with the finite-volume commercial code ANSYS Fluent. Steady-state casting conditions for the flow structure and the inclusions removal process are analysed.

  15. Development of dispersion-strengthened Ni-Cr-ThOz alloys for the space shuttle thermal protection system

    Science.gov (United States)

    Blankenship, C. P.; Saunders, N. T.

    1972-01-01

    Manufacturing processes were developed for TD-NiCr providing small sheet (45 x 90 cm), and larger sheet (60 x 150 cm) and foil. The alternate alloy, DS-NiCr, was produced by pack-chromizing Ni-ThO2 sheet. Formability criteria are being established for basic sheet forming processes, which are brake forming, corrugation forming, joggling, dimpling, and beading. Resistance spot welding (fusion and solid state), resistance seam welding, solid state diffusion welding, and brazing are included in the joining programs. Major emphasis is centered on an Al-modified Ni-Cr-ThO2 alloy development. These alloys, containing 3 to 5% Al, form the protective Al2O3 scale. This enhances oxidation resistance under reentry conditions. Both TD-NiCrAl and DS-NiCrAl alloys are included. A tentative composition of Ni-16Cr-3.5Al-2ThO2 was selected based on oxidation resistance and fabricability.

  16. Estimation of the ionic charge of non-metallic species into an electrical discharge through a web application

    Science.gov (United States)

    Pérez Gutiérrez, B. R.; Vera-Rivera, F. H.; Niño, E. D. V.

    2016-08-01

    Estimate the ionic charge generated in electrical discharges will allow us to know more accurately the concentration of ions implanted on the surfaces of nonmetallic solids. For this reason, in this research a web application was developed to allow us to calculate the ionic charge generated in an electrical discharge from the experimental parameters established in an ion implantation process performed in the JUPITER (Joint Universal Plasma and Ion Technologies Experimental Reactor) reactor. The estimated value of the ionic charge will be determined from data acquired on an oscilloscope, during startup and shutdown of electrical discharge, which will then be analyzed and processed. The study will provide best developments with regard to the application of ion implantation in various industrial sectors.

  17. A comparative study of sliding wear of nonmetallic dental restorative materials with emphasis on micromechanical wear mechanisms.

    Science.gov (United States)

    Dupriez, Nataliya Deyneka; von Koeckritz, Ann-Kristin; Kunzelmann, Karl-Heinz

    2015-05-01

    The purpose of this study is to investigate the in vitro tribological behavior of modern nonmetallic restorative materials. Specimen prepared of IPS e.max Press lithium disilicate glass ceramic, IPS Empress Esthetic leucite-reinforced glass ceramic, Everest ZS Blanks yttria-stabilized zirconia and Lava Ultimate composite were subjected to wear using a wear machine designed to simulate occlusal loads. The wear of the investigated materials and antagonists were evaluated by a three-dimensional surface scanner. The quantitative wear test results were used to compare and rank the materials. Specimens were divided into two groups with steatite and alumina antagonists. For each antagonist material an analysis of variance was applied. As a post hoc test of the significant differences, Tukey's honest significant difference test was used. With steatite antagonist: wear of zirconia materials mechanical properties (hardness and fracture toughness) and with materials microstructure. Wear mechanisms are discussed. © 2014 Wiley Periodicals, Inc.

  18. Effect of Non-metallic Inclusions in Fe-Al-Ti-O-N-S Alloy on Grain Size

    Science.gov (United States)

    Choi, Wonjin; Matsuura, Hiroyuki; Tsukihashi, Fumitaka

    2016-06-01

    The effect of characteristics of non-metallic inclusions in Fe-Al-Ti-O-N-S alloys with various compositions at 1473 K (1200 °C) on the microstructure was studied. The ASTM grain size number was determined in as-cast and heated samples by the optical microscopy, and the inclusion types in each sample were determined from composition analysis by field-emission scanning electron microscope with energy-dispersive spectroscopy. The TiN-based inclusions certainly had a positive effect on the grain refinement. On the other hand, TiS-based inclusions exhibited no influence on the decrease of grain size. In addition, the formation and evolution behavior of inclusions by heating solid-state Fe-Al-Ti-O-N-S alloys with those locations were clarified. A different change of inclusions in alloys was observed depending on the distribution and composition of inclusions.

  19. Characteristics and Modification of Non-metallic Inclusions in Titanium-Stabilized AISI 409 Ferritic Stainless Steel

    Science.gov (United States)

    Kruger, Dirk; Garbers-Craig, Andrie

    2017-06-01

    This study describes an investigation into the improvement of castability, final surface quality and formability of titanium-stabilized AISI 409 ferritic stainless steel on an industrial scale. Non-metallic inclusions found in this industrially produced stainless steel were first characterized using SEM-EDS analyses through the INCA-Steel software platform. Inclusions were found to consist of a MgO·Al2O3 spinel core, which acted as heterogeneous nucleation site for titanium solubility products. Plant-scale experiments were conducted to either prevent the formation of spinel, or to modify it by calcium treatment. Modification to spherical dual-phase spinel-liquid matrix inclusions was achieved with calcium addition, which eliminated submerged entry nozzle clogging for this grade. Complete modification to homogeneous liquid calcium aluminates was achieved at high levels of dissolved aluminum. A mechanism was suggested to explain the extent of modification achieved.

  20. Detection of Surface and Subsurface Cracks in Metallic and Non-Metallic Materials Using a Complementary Split-Ring Resonator

    Directory of Open Access Journals (Sweden)

    Ali Albishi

    2014-10-01

    Full Text Available Available microwave techniques for crack detection have some challenges, such as design complexity and working at a high frequency. These challenges make the sensing apparatus design complex and relatively very expensive. This paper presents a simple method for surface and subsurface crack detection in metallic and non-metallic materials based on complementary split-ring resonators (CSRRs. A CSRR sensor can be patterned on the ground plane of a microstrip line and fabricated using printed circuit board technology. Compared to available microwave techniques for sub-millimeter crack detection, the methods presented here show distinct advantages, such as high spatial resolution, high sensitivity and design simplicity. The response of the CSRR as a sensor for crack detection is studied and analysed numerically. Experimental validations are also presented.

  1. Characteristics and Modification of Non-metallic Inclusions in Titanium-Stabilized AISI 409 Ferritic Stainless Steel

    Science.gov (United States)

    Kruger, Dirk; Garbers-Craig, Andrie

    2017-02-01

    This study describes an investigation into the improvement of castability, final surface quality and formability of titanium-stabilized AISI 409 ferritic stainless steel on an industrial scale. Non-metallic inclusions found in this industrially produced stainless steel were first characterized using SEM-EDS analyses through the INCA-Steel software platform. Inclusions were found to consist of a MgO·Al2O3 spinel core, which acted as heterogeneous nucleation site for titanium solubility products. Plant-scale experiments were conducted to either prevent the formation of spinel, or to modify it by calcium treatment. Modification to spherical dual-phase spinel-liquid matrix inclusions was achieved with calcium addition, which eliminated submerged entry nozzle clogging for this grade. Complete modification to homogeneous liquid calcium aluminates was achieved at high levels of dissolved aluminum. A mechanism was suggested to explain the extent of modification achieved.

  2. Standard practice for process compensated resonance testing via swept sine input for metallic and Non-Metallic parts

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice describes a general procedure for using the process compensated resonance testing (PCRT) via swept sine input method to identify metallic and non-metallic parts’ resonant pattern differences that can be used to indentify parts with anomalies causing deficiencies in the expected performance of the part in service. This practice is intended for use with instruments capable of exciting, measuring, recording, and analyzing multiple whole body mechanical vibration resonant frequencies within parts exhibiting acoustical ringing in the audio, or ultrasonic, resonant frequency ranges, or both. PCRT is used in the presence of manufacturing process variance to distinguish acceptable parts from those containing significant anomalies in physical characteristics expected to significantly alter the performance. Such physical characteristics include, but are not limited to, cracks, voids, porosity, shrink, inclusions, discontinuities, grain and crystalline structure differences, density related anomalies...

  3. The uncertainties calculation of acoustic method for measurement of dissipative properties of heterogeneous non-metallic materials

    Directory of Open Access Journals (Sweden)

    Мaryna O. Golofeyeva

    2015-12-01

    Full Text Available The effective use of heterogeneous non-metallic materials and structures needs measurement of reliable values of dissipation characteristics, as well as common factors of their change during the loading process. Aim: The aim of this study is to prepare the budget for measurement uncertainty of dissipative properties of composite materials. Materials and Methods: The method used to study the vibrational energy dissipation characteristics based on coupling of vibrations damping decrement and acoustic velocity in a non-metallic heterogeneous material is reviewed. The proposed method allows finding the dependence of damping on vibrations amplitude and frequency of strain-stress state of material. Results: Research of the accuracy of measurement method during the definition of decrement attenuation of fluctuations in synthegran was performed. The international approach for evaluation of measurements quality is used. It includes the common practice international rules for uncertainty expression and their summation. These rules are used as internationally acknowledged confidence measure to the measurement results, which includes testing. The uncertainties budgeting of acoustic method for measurement of dissipative properties of materials were compiled. Conclusions: It was defined that there are two groups of reasons resulting in errors during measurement of materials dissipative properties. The first group of errors contains of parameters changing of calibrated bump in tolerance limits, displacement of sensor in repeated placement to measurement point, layer thickness variation of contact agent because of irregular hold-down of resolvers to control surface, inaccuracy in reading and etc. The second group of errors is linked with density and Poisson’s ratio measurement errors, distance between sensors, time difference between signals of vibroacoustic sensors.

  4. Effect of Acid-Soluble Aluminum on the Evolution of Non-metallic Inclusions in Spring Steel

    Science.gov (United States)

    Wang, Yong; Tang, Haiyan; Wu, Tuo; Wu, Guanghui; Li, Jingshe

    2017-04-01

    The content of acidic soluble aluminum in molten steel ([Al]s) is of significance to the control of total oxygen (TO), the formation of non-metallic inclusions, and the improvement of the surface quality of billets. Industrial trials and thermodynamic calculations were performed to study the effects of [Al]s content on the TO and the evolution of non-metallic inclusions in 60Si2Mn-Cr spring steel that was deoxidized by Si-Mn ((low aluminum process (LAP)) and Si-Mn-Al (high aluminum process (HAP)). The results show that the [Al]s contents in billets are within 0.0060 to 0.0069 mass pct in the LAP and 0.016 to 0.055 mass pct in the HAP. The TO content at each station of the LAP is higher than that in the HAP; the inclusions of billets were mainly of the CaO-Al2O3-SiO2 type in the former, and of the CaO-Al2O3-MgO and CaS-Al2O3-MgO types in the latter. A tendency is found that the higher the [Al]s, the easier it is to deviate from the low melting point region of the inclusion distribution and the larger the size of the inclusions. The relationships between [Al]s and the melting point of the oxide inclusions and the Al2O3 content in the oxide inclusions are also discussed in terms of experiment and calculation.

  5. Characterization of Space Shuttle External Tank Thermal Protection System (TPS) Materials in Support of the Columbia Accident Investigation

    Science.gov (United States)

    Wingard, Charles D.

    2004-01-01

    NASA suffered the loss of the seven-member crew of the Space Shuttle Columbia on February 1, 2003 when the vehicle broke apart upon re-entry to the Earth's atmosphere. The final report of the Columbia Accident Investigation Board (CAIB) determined that the accident was caused by a launch ascent incident-a suitcase-sized chunk of insulating foam on the Shuttle's External Tank (ET) broke off, and moving at almost 500 mph, struck an area of the leading edge of the Shuttle s left wing. As a result, one or more of the protective Reinforced Carbon-Carbon (RCC) panels on the wing leading edge were damaged. Upon re-entry, superheated air approaching 3,000 F breached the wing damage and caused the vehicle breakup and loss of crew. The large chunk of insulating foam that broke off during the Columbia launch was determined to come from the so-called bipod ramp area where the Shuttle s orbiter (containing crew) is attached to the ET. Underneath the foam in the bipod ramp area is a layer of TPS that is a cork-filled silicone rubber composite. In March 2003, the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama received cured samples of the foam and composite for testing from the Michoud Assembly Facility (MAF) in New Orleans, Louisiana. The MAF is where the Shuttle's ET is manufactured. The foam and composite TPS materials for the ET have been well characterized for mechanical property data at the super-cold temperatures of the liquid oxygen and hydrogen fuels used in the ET. However, modulus data on these materials is not as well characterized. The TA Instruments 2980 Dynamic Mechanical Analyzer (DMA) was used to determine the modulus of the two TPS materials over a range of -145 to 95 C in the dual cantilever bending mode. Multi-strain, fixed frequency DMA tests were followed by multi-frequency, fixed strain tests to determine the approximate bounds of linear viscoelastic behavior for the two materials. Additional information is included in the original extended

  6. 电厂热工DCS保护误动和拒动原因、对策分析%Analysis on the causes and Countermeasures of malfunction and rejection of thermal power DCS protection in power plant

    Institute of Scientific and Technical Information of China (English)

    张全

    2016-01-01

    保护误动主要是由于保护系统自身故障引起的,使得主辅设备停运;保护拒动的产生,主要是在主辅设备发生故障时,需要保护系统的运行和工作时,但是保护系统由于自身的故障而停止工作,进而造成了事故的扩大,产生了保护拒动.分析电厂热工DCS保护误动、拒动的原因,找出相关的防范对策,对于提高火力发电厂的经济效益具有重要意义.%Protection misoperation is mainly due to the protection system due to its failure,the winner of the auxiliary equipment outage;tripping protection,mainly in main and auxiliary equipment failure, the need for protection system running and working,but protection system due to their own fault and stop working,which resulted in the expansion of the accident,the protection maloperation.It is significant to analyze the reason of malfunction and refusal of thermal power DCS protection and find out the relevant countermeasures, which is of great significance to improve the economic benefit of thermal power plant.

  7. Problematic issues of air protection during thermal processes related to the energetic uses of sewage sludge and other waste. Case study: Co-combustion in peaking power plant.

    Science.gov (United States)

    Hroncová, Emília; Ladomerský, Juraj; Musil, Juraj

    2017-08-19

    Currently, it is necessary to deal with issues related to the emissions as there is a constantly increasing interest in combusting sludge from sewage treatment plants in the boilers for wood. An analysis of the energetic importance of the combustion of sewage sludge has already been carried out, but the effects of various treatments of the sludge are not always clear, e.g. composting and subsequent combustion to the air pollution. Investments in other thermal processes of energetic utilisation of sewage sludge and organic waste are not always successfully implemented. The objective of this paper is to point out some problematic cases for acceptance of thermal processes related to energetic use of waste in terms of the air protection. The other aim is to mention the experience with solutions of such issues in Slovakia. There are mentioned first results of the operational validation experiments during the energy generation in circulating fluidized bed boiler in peaking power plant (Power 110MW) with the addition of the so-called alternative fuel based on wood and sewage sludge to the main fuel - black coal (anthracite). And there has already been achieved the highest share of 12.4%w. (dry matter) of sewage sludge in form of compost in blend with black coal, which is technologically viable. Moreover analyzed the problems of the authorization and operation of the co-combustion of sewage sludge and of combustion of products of various kinds of pyrolysis waste - pyrolysis gas and pyrolysis oil are analyzed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. In-Flight Aeroelastic Stability of the Thermal Protection System on the NASA HIAD, Part II: Nonlinear Theory and Extended Aerodynamics

    Science.gov (United States)

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

    2015-01-01

    Conical shell theory and a supersonic potential flow aerodynamic theory are used to study the nonlinear pressure buckling and aeroelastic limit cycle behavior of the thermal protection system for NASA's Hypersonic Inflatable Aerodynamic Decelerator. The structural model of the thermal protection system consists of an orthotropic conical shell of the Donnell type, resting on several circumferential elastic supports. Classical Piston Theory is used initially for the aerodynamic pressure, but was found to be insufficient at low supersonic Mach numbers. Transform methods are applied to the convected wave equation for potential flow, and a time-dependent aerodynamic pressure correction factor is obtained. The Lagrangian of the shell system is formulated in terms of the generalized coordinates for all displacements and the Rayleigh-Ritz method is used to derive the governing differential-algebraic equations of motion. Aeroelastic limit cycle oscillations and buckling deformations are calculated in the time domain using a Runge-Kutta method in MATLAB. Three conical shell geometries were considered in the present analysis: a 3-meter diameter 70 deg. cone, a 3.7-meter 70 deg. cone, and a 6-meter diameter 70 deg. cone. The 6-meter configuration was loaded statically and the results were compared with an experimental load test of a 6-meter HIAD. Though agreement between theoretical and experimental strains was poor, the circumferential wrinkling phenomena observed during the experiments was captured by the theory and axial deformations were qualitatively similar in shape. With Piston Theory aerodynamics, the nonlinear flutter dynamic pressures of the 3-meter configuration were in agreement with the values calculated using linear theory, and the limit cycle amplitudes were generally on the order of the shell thickness. The effect of axial tension was studied for this configuration, and increasing tension was found to decrease the limit cycle amplitudes when the circumferential

  9. Conformal Ablative Thermal Protection System for Small and Large Scale Missions: Approaching TRL 6 for Planetary and Human Exploration Missions and TRL 9 for Small Probe Missions

    Science.gov (United States)

    Beck, R. A. S.; Gasch, M. J.; Milos, F. S.; Stackpoole, M. M.; Smith, B. P.; Switzer, M. R.; Venkatapathy, E.; Wilder, M. C.; Boghhozian, T.; Chavez-Garcia, J. F.

    2015-01-01

    In 2011, NASAs Aeronautics Research Mission Directorate (ARMD) funded an effort to develop an ablative thermal protection system (TPS) material that would have improved properties when compared to Phenolic Impregnated Carbon Ablator (PICA) and AVCOAT. Their goal was a conformal material, processed with a flexible reinforcement that would result in similar or better thermal characteristics and higher strain-to-failure characteristics that would allow for easier integration on flight aeroshells than then-current rigid ablative TPS materials. In 2012, NASAs Space Technology Mission Directorate (STMD) began funding the maturation of the best formulation of the game changing conformal ablator, C-PICA. Progress has been reported at IPPW over the past three years, describing C-PICA with a density and recession rates similar to PICA, but with a higher strain-to-failure which allows for direct bonding and no gap fillers, and even more important, with thermal characteristics resulting in half the temperature rise of PICA. Overall, C-PICA should be able to replace PICA with a thinner, lighter weight, less complicated design. These characteristics should be particularly attractive for use as backshell TPS on high energy planetary entry vehicles. At the end of this year, the material should be ready for missions to consider including in their design, in fact, NASAs Science Mission Directorate (SMD) is considering incentivizing the use of C-PICA in the next Discovery Proposal call. This year both scale up of the material to large (1-m) sized pieces and the design and build of small probe heatshields for flight tests will be completed. NASA, with an industry partner, will build a 1-m long manufacturing demonstration unit (MDU) with a shape based on a mid LD lifting body. In addition, in an effort to fly as you test and test as you fly, NASA, with a second industry partner, will build a small probe to test in the Interactive Heating Facility (IHF) arc jet and, using nearly the

  10. 盖板式热防护系统研究现状及发展趋势%Research Status and Development of Generic Shingle Thermal Protection System

    Institute of Scientific and Technical Information of China (English)

    周长灵; 徐鸿照; 朱杉; 陈斌; 杜斌

    2016-01-01

    The status of research and application of generic shingle thermal protection system (TPS) for hypersonic aircrafts was briefly reviewed in this paper. The generic shingle TPS is mainly divided into two categories, being metallic based and ceramic-matrix composite based, respectively. The advantages and the disadvantages of both categories are discussed. Finally, the development trend of the TPS for hypersonic aircrafts is prospected.%本文综述了国内外关于盖板式热防护系统的研究及应用现状。盖板式热防护系统主要分为金属式热防护系统及非金属无机复合材料热防系统,本文对其各自的优缺点进行了简要的阐述,并对未来飞行器热防护系统的发展趋势进行了展望。

  11. A title-gap flow model for use in aerodynamic loads assessment of space shuttle thermal protection system: Parallel gap faces

    Science.gov (United States)

    Dwoyer, D. L.; Newman, P. A.; Thames, F. C.; Melson, N. D.

    1981-01-01

    The problem of predicting aerodynamic loads on the insulating tiles of the space shuttle thermal protection system (TPS) is discussed and seen to require a method for predicting pressure and mass flux in the gaps between tiles. A mathematical model of the tile-gap flow is developed, based upon a slow viscous (Stokes) flow analysis, and is verified against experimental data. The tile-gap pressure field is derived from a solution of the two-dimensional Laplace equation; the mass-flux vector is then calculated from the pressure gradient. The means for incorporating this model into a lumped-parameter network analogy for porous-media flow is given. The means for incorporating this model into a lumped-parameter network analogy for porous-media flow is given. The flow model shows tile-gap mass flux to be very sensitive to the gap width indicating a need for coupling the TPS flow and tile displacement calculation. Analytical and experimental work to improve TPS flow predictions and a possible shuttle TPS hardware modification are recommended.

  12. Crack nucleation using combined crystal plasticity modelling, high-resolution digital image correlation and high-resolution electron backscatter diffraction in a superalloy containing non-metallic inclusions under fatigue.

    Science.gov (United States)

    Zhang, Tiantian; Jiang, Jun; Britton, Ben; Shollock, Barbara; Dunne, Fionn

    2016-05-01

    A crystal plasticity finite-element model, which explicitly and directly represents the complex microstructures of a non-metallic agglomerate inclusion within polycrystal nickel alloy, has been developed to study the mechanistic basis of fatigue crack nucleation. The methodology is to use the crystal plasticity model in conjunction with direct measurement at the microscale using high (angular) resolution-electron backscatter diffraction (HR-EBSD) and high (spatial) resolution-digital image correlation (HR-DIC) strain measurement techniques. Experimentally, this sample has been subjected to heat treatment leading to the establishment of residual (elastic) strains local to the agglomerate and subsequently loaded under conditions of low cyclic fatigue. The full thermal and mechanical loading history was reproduced within the model. HR-EBSD and HR-DIC elastic and total strain measurements demonstrate qualitative and quantitative agreement with crystal plasticity results. Crack nucleation by interfacial decohesion at the nickel matrix/agglomerate inclusion boundaries is observed experimentally, and systematic modelling studies enable the mechanistic basis of the nucleation to be established. A number of fatigue crack nucleation indicators are also assessed against the experimental results. Decohesion was found to be driven by interface tensile normal stress alone, and the interfacial strength was determined to be in the range of 1270-1480 MPa.

  13. Metallic and Non-Metallic Materials for the Primary Support Structure

    Energy Technology Data Exchange (ETDEWEB)

    RA Wolf; RP Corson

    2006-02-21

    The primary support structure (PSS) is required for mechanical support of reactor module (RM) components and mounting of the RM to the spacecraft. The PSS would provide support and accept all loads associated with dynamic (e. g., launch and maneuvering) or thermally induced loading. Prior to termination of NRPCT involvement in Project Prometheus, the NRPCT Mechanical Systems team developed preliminary finite element models to gain a basic understanding of the behavior of the structure, but optimization of the models, specification of the final design, and materials selection were not completed. The Space Plant Materials team had evaluated several materials for potential use in the primary support structure, namely titanium alloys, beryllium, aluminum alloys and carbon-carbon composites. The feasibility of application of each material system was compared based on mass, stiffness, thermal expansion, and ease of fabrication. Due to insufficient data on environmental factors, such as temperatures and radiation, and limited modeling support, a final materials selection was not made.

  14. 废弃电路板中非金属组分的回收利用%Recycling of non-metallic fractions from waste printed circuit boards

    Institute of Scientific and Technical Information of China (English)

    刘旸; 刘静欣; 江晓健; 郭学益

    2016-01-01

    废弃电路板是电子废弃物的重要组成部分。目前工业生产及工艺开发多针对极具经济回收价值的电路板金属组分。然而,占电路板质量分数70%的非金属组分却关注较少。文章分析了废弃电路板非金属组分的组成及其有害组分,其含有树脂及玻璃纤维等有价成分和溴、夹杂重金属等污染环境的物质,其回收利用对于资源循环利用及环境保护均有重要意义。非金属组分回收利用主要有物理处理和化学处理2种技术:物理处理技术主要将非金属组分用作结构材料填料、塑料改性剂和建筑材料改性剂;化学处理技术通过焚烧将非金属组分用作燃料和熔剂或通过热解回收或溶剂分解回收可将非金属组分转化为化工产品。这2种技术在非金属组分资源化利用上各有优势,都已有部分工业化应用。%Waste printed circuit boards (WPCBs) are important parts in the electronic waste. Nowadays, recov-ering metals from WPCBs are developed but non-metallic fractions which accounts for 70% of waste printed circuit boards have not been effectively utilized. The non-metallic fractions and hazards in waste printed cir-cuit boards were analyzed in this paper. The results show that resins and glass fiber in non-metallic fractions can be recycled and bromine and heavy metals could pollute environment. Recovering non-metallic fractions are important to recycling and environment, which can be divided into physical recycling technology and chemical recycling technology, with the formal using non-metallic fractions as the filler materials, plastic modifier or building material modifiers, and the latter using non-metallic fractions as the fuel and smelting flux through incineration or convert non-metallic fractions into chemical products through pyrolysis or solvent decomposition. Both technologies have their own advantages in resource utilization of non-metallic fractions, and partly

  15. 非金属制品石棉检测预处理方法的研究%Samples Preparation of Nonmetallic Material for Testing Asbestos

    Institute of Scientific and Technical Information of China (English)

    虞接华; 袁坤珍; 甘浩; 刘斌

    2015-01-01

    通过对非金属材料中石棉检测的预处理方法进行实验探索,发现“灰化法”+“研磨法”操作简便、效果明显,成本低廉,对于一般样品是一种比较理想的石棉检测试样的处理方法,灰化处理的温度为480℃、时间为3 h。%Samples preparations of nonmetallic material for testing asbestos were studied. The ashing+milling method was a simple, effective, low cost, and a ideal means of pretreatment nonmetallic material samples for testing asbestos. Testing showed that ashing temperature should be 480 ℃ for 3 h.

  16. Effect of inhomogeneous distribution of non-metallic inclusions on crack path deflection in G42CrMo4 steel at different loading rates

    Directory of Open Access Journals (Sweden)

    S. Henschel

    2015-10-01

    Full Text Available An inhomogeneous distribution of non-metallic inclusions can result from the steel casting process. The aim of the present study was to investigate the damaging effect of an inhomogeneous distribution of nonmetallic inclusions on the crack extension behavior. To this end, the fracture toughness behavior in terms of quasi-static J-a curves was determined at room temperature. Additionally, dynamic fracture mechanics tests in an instrumented Charpy impact-testing machine were performed. The fracture surface of fracture mechanics specimens was analyzed by means of scanning electron microscopy. It was shown that an inhomogeneous distribution significantly affected the path and, therefore, the plane of crack growth. Especially clusters of non-metallic inclusions with a size of up to 200 μm exhibited a very low crack growth resistance. Due to the damaging effect of the clusters, the growing crack was strongly deflected towards the cluster. Furthermore, crack tip blunting was completely inhibited when inclusions were located at the fatigue precrack tip. Due to the large size of the non-metallic inclusion clusters, the height difference introduced by crack path deflection was significantly larger than the stretch zone height due to the crack tip blunting. However, the crack path deflection introduced by a cluster was not associated with a toughness increasing mechanism. The e dynamic loading ( 1 0.5 5 s MPam 10   K did not result in a transition from ductile fracture to brittle fracture. However, the crack growth resistance decreased with increased loading rate. This was attributed to the higher portion of relatively flat regions where the dimples were less distinct.

  17. The Influence of Technological Parameters of X70 Stainless Steel Ladle Refining on the Residual Content of Non-Metallic Inclusions

    Directory of Open Access Journals (Sweden)

    Babanin A.

    2015-09-01

    Full Text Available It is demonstrated that during secondary refining at the ladle furnace the carbon content of steel and the residence time of the metal in the ladle exert a significant impact on the residual content of non-metallic inclusions (NMI in steel. Mathematical calculations showed that the dynamic forces have minor effect on the motion of small sized NMI, making it difficult to penetrate deep into the slag.

  18. HVOF Thermal Spray TiC/TiB2 Coatings for AUSC Boiler/Turbine Components for Enhanced Corrosion Protection

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Kanchan [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mechanical Engineering and Energy Processes; Koc, Rasit [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mechanical Engineering and Energy Processes; Fan, Chinbay [Gas Technology Inst., Des Plaines, IL (United States)

    2016-12-07

    The high temperatures of operations still pose significant risk of degradation and fatigue from oxidizing, corroding and eroding environment. In addition to unused O2, water from combustion and SOx from the coal sulfur oxidation that result in highly corrosive environment, acid gases such as HCl and other sulfur compounds may also be present. These adverse effects are further accelerated due to the elevated temperatures. In addition, ash particulates and unburnt carbon and pyritic sulfur can cause erosion of the surface and thus loss of material. Unburnt carbon and pyritic sulfur may also cause localized reduction sites. Thus, fireside corrosion protection and steam oxidation protection alternatives to currently used Ni-Cr overlays need to be identified and evaluated. Titanium carbide (TiC) is a suitable alternative on account of the material features such as the high hardness, the high melting point, the high strength and the low density for the substitution or to be used in conjunction with NiCr for enhancing the fireside corrosion and erosion of the materials. Another alternative is the use of titanium boride as a coating for chemical stability required for long-term service and high erosion resistance over the state-of-the-art, high fracture toughness (K1C ~12 MPam1/2) and excellent corrosion resistance (kp~1.9X10-11 g2/cm4/s at 800°C in air). The overarching aim of the research endeavor was to synthesize oxidation, corrosion and wear resistant TiC and TiB2 coating powders, apply thermal spray coating on existing boiler materials and characterize the coated substrates for corrosion resistance for applications at high temperatures (500 -750 °C) and high pressures (~350 bars) using the HVOF process and to demonstrate the feasibility of these coating to be used in AUSC boilers and turbines.

  19. Study of the physicochemical effects on the separation of the non-metallic fraction from printed circuit boards by inverse flotation.

    Science.gov (United States)

    Flores-Campos, R; Estrada-Ruiz, R H; Velarde-Sánchez, E J

    2017-09-06

    Recycling printed circuit boards using green technology is increasingly important due to the metals these contain and the environmental care that must be taken when separating the different materials. Inverse flotation is a process that can be considered a Green Technology, which separates metallic from non-metallic fractions. The degree of separation depends on how much material is adhered to air bubbles. The contact angle measurement allows to determine, in an easy way, whether the flotation process will occur or not and thus establish a material as hydrophobic or not. With the material directly obtained from the milling process, it was found that the contact angle of the non-metallic fraction-liquid-air system increases as temperature increases. In the same way, the increments in concentration of frother in the liquid increase the contact angle of the non-metallic fraction-liquid-air system. 10ppm of Methyl Isobutyl Carbinol provides the highest contact angle as well as the highest material charging in the bubble. Copyright © 2017. Published by Elsevier Ltd.

  20. A Collaborative Analysis Tool for Integrating Hypersonic Aerodynamics, Thermal Protection Systems, and RBCC Engine Performance for Single Stage to Orbit Vehicles

    Science.gov (United States)

    Stanley, Thomas Troy; Alexander, Reginald

    1999-01-01

    Presented is a computer-based tool that connects several disciplines that are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system, as is the case of SSTO vehicles with air breathing propulsion, which is currently being studied by NASA. The deficiencies in the scramjet powered concept led to a revival of interest in Rocket-Based Combined-Cycle (RBCC) propulsion systems. An RBCC propulsion system integrates airbreathing and rocket propulsion into a single engine assembly enclosed within a cowl or duct. A typical RBCC propulsion system operates as a ducted rocket up to approximately Mach 3. At this point the transitions to a ramjet mode for supersonic-to-hypersonic acceleration. Around Mach 8 the engine transitions to a scram4jet mode. During the ramjet and scramjet modes, the integral rockets operate as fuel injectors. Around Mach 10-12 (the actual value depends on vehicle and mission requirements), the inlet is physically closed and the engine transitions to an integral rocket mode for orbit insertion. A common feature of RBCC propelled vehicles is the high degree of integration between the propulsion system and airframe. At high speeds the vehicle forebody is fundamentally part of the engine inlet, providing a compression surface for air flowing into the engine. The compressed air is mixed with fuel and burned. The combusted mixture must be expanded to an area larger than the incoming stream to provide thrust. Since a conventional nozzle would be too large, the entire lower after body of the vehicle is used as an expansion surface. Because of the high external temperatures seen during atmospheric flight, the design of an airbreathing SSTO vehicle requires delicate tradeoffs between engine design, vehicle shape, and thermal protection system (TPS) sizing in order to produce an optimum system in terms of weight (and cost) and maximum performance.

  1. A Collaborative Analysis Tool for Integrated Hypersonic Aerodynamics, Thermal Protection Systems, and RBCC Engine Performance for Single Stage to Orbit Vehicles

    Science.gov (United States)

    Stanley, Thomas Troy; Alexander, Reginald; Landrum, Brian

    2000-01-01

    Presented is a computer-based tool that connects several disciplines that are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system, as is the case of SSTO vehicles with air breathing propulsion, which is currently being studied by NASA. An RBCC propulsion system integrates airbreathing and rocket propulsion into a single engine assembly enclosed within a cowl or duct. A typical RBCC propulsion system operates as a ducted rocket up to approximately Mach 3. Then there is a transition to a ramjet mode for supersonic-to-hypersonic acceleration. Around Mach 8 the engine transitions to a scramjet mode. During the ramjet and scramjet modes, the integral rockets operate as fuel injectors. Around Mach 10-12 (the actual value depends on vehicle and mission requirements), the inlet is physically closed and the engine transitions to an integral rocket mode for orbit insertion. A common feature of RBCC propelled vehicles is the high degree of integration between the propulsion system and airframe. At high speeds the vehicle forebody is fundamentally part of the engine inlet, providing a compression surface for air flowing into the engine. The compressed air is mixed with fuel and burned. The combusted mixture must be expanded to an area larger than the incoming stream to provide thrust. Since a conventional nozzle would be too large, the entire lower after body of the vehicle is used as an expansion surface. Because of the high external temperatures seen during atmospheric flight, the design of an airbreathing SSTO vehicle requires delicate tradeoffs between engine design, vehicle shape, and thermal protection system (TPS) sizing in order to produce an optimum system in terms of weight (and cost) and maximum performance. To adequately determine the performance of the engine/vehicle, the Hypersonic Flight Inlet Model (HYFIM) module was designed to interface with the RBCC

  2. Evolution of Ti-Based Nonmetallic Inclusions During Solution Treatment of Maraging 250 Steel: Thermodynamic Calculations and Experimental Verification

    Science.gov (United States)

    Shmulevitsh, Mati; Pinkas, Malki; Weizman, Amir; Frage, Nachum

    2011-06-01

    The evolution of Ti-based nonmetallic inclusions in Maraging 250 steel, namely Ti(CxN1-x) and Ti4C2S2, was investigated experimentally. Their stability in austenite also was analyzed by a thermodynamic analysis of the Fe-Ni-Ti-C-N-S system. It was established that the total concentration of the inclusions decreases from 0.024 pct to 0.008 pct after treatment at 1453 K (1180 °C) for 3 hours. The Ti4C2S2 inclusions completely dissolve in austenite at 1523 K (1250 °C) during 1 hour of treatment. The composition of the carbonitride inclusions is shifted toward higher TiN contents when they dissolve in austenite. Nitrogen-enriched titanium carbonitride inclusions are stable in austenite and their fraction may be reduced only by controlling nitrogen content in the steel. The experimental observations are in good agreement with the results of the thermodynamic analysis.

  3. Deformation and fracture properties of metals with non-metallic inclusions; Verformung und Bruch von Metallen mit nichtmetallischen Einschluessen

    Energy Technology Data Exchange (ETDEWEB)

    Schmauder, S.; Soppa, E. [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt

    1998-12-31

    Microstructural effects due to formation of non-uniform lines of non-metallic inclusions in the matrix are examined with respect to their macro-, meso-, and micromechanical effects in the alloy Al(6061) reinforced by SiC inclusions. A comparative analysis of results obtained with various microstructures reveals essential differences in the formation of shear bands, stress peaks, and strain concentrations in the material structure. The maxima and the distribution of those field variables are determined not only by the arrangement of inclusions clusters in the stringers but also depend on the presence and number of single-particle inclusions in pure matrix material. The banding of the microstructure causes a strongly anisotropic behaviour in terms of stress and strain distributions. (orig./CB) [Deutsch] In diesem Beitrag werden Gefuegeeinfluesse aufgrund unterschiedlich starker zeiliger Anordnungen der Teilchen in der Matrix im Hinblick auf ihre makro-, meso- und mikromechanischen Auswirkungen am Beispiel einer SiC-teilchenverstaerkten Aluminiumlegierung Al(6061) untersucht. Ein Vergleich der Ergebnisse verschiedener Gefuege zeigt wesentliche Unterschiede hinsichtlich der Ausbildung von Scherbaendern, Spannungsspitzen und von Dehnungskonzentrationen im Werkstoffgefuege. Die Maxima und die Verteilung dieser Feldgroessen sind nicht nur abhaengig davon, wie die Teilchen in den Zeilen angeordnet sind, sondern auch davon, ob einzelne Teilchen in reinen Matrixbereichen vorhanden sind. Die Zeiligkeit des Gefueges fuehrt zu einem stark anisotropen Verhalten hinsichtlich Spannungs- und Dehnungsverteilungen. (orig.)

  4. Assessment of Different Turbulence Models for the Motion of Non-metallic Inclusion in Induction Crucible Furnace

    Science.gov (United States)

    Barati, H.; Wu, M.; Kharicha, A.; Ludwig, A.

    2016-07-01

    Turbulent fluid flow due to the electromagnetic forces in induction crucible furnace (ICF) is modeled using k-ɛ, k-ω SST and Large Eddy Simulation (LES) turbulence models. Fluid flow patterns calculated by different turbulence models and their effects on the motion of non-metallic inclusions (NMI) in the bulk melt have been investigated. Results show that the conventional k-ɛ model cannot solve the transient flow in ICF properly. With k-ω model transient flow and oscillation behavior of the flow pattern can be solved, and the motion of NMI can be tracked fairly well. LES model delivers the best modeling result on both details of the transient flow pattern and motion trajectories of NMI without the limitation of NMI size. The drawback of LES model is the long calculation time. Therefore, for general purpose to estimate the dynamic behavior of NMI in ICF both k-ω SST and LES are recommended. For the precise calculation of the motion of NMI smaller than 10 μm only LES model is appropriate.

  5. Yttrium modifying influence on the shape and amount of nonmetallic inclusions in the austenitic high alloy steel

    Directory of Open Access Journals (Sweden)

    Андрій Володимирович Патюпкін

    2016-07-01

    Full Text Available Yttrium influence on the form and amount of non-metallic inclusions in steel 06H23N18M5 was studied. It has been found that yttrium binds oxygen and other elements into heterogeneous compounds, it resulting in the transition of impurities into passive state. Oxide inclusions, sulfide inclusions and globules formed as a result of steel components reactions with oxygen, sulfur and nitrogen dissolved in metal are mostly found in the structure. It was found that by modifying and refining austenitic steels with yttrium service properties of the deposited layer can be adjusted. X-ray diffraction and X-ray spectrum analysis revealed that the modified steel 06H23N18M5 + 0.02% Y has a heterogeneous structure with uniformly distributed inclusions of σ-phase and composite carbides (Fe, Cr, Mo 23C6. It is possible that Y modification resulted in the appearance of chemically resistant intermetallic σ-phase in these steels, for nucleation was facilitated by increasing the number of crystallization centers as dispersed primary yttrium oxy-sulfide compounds

  6. A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing, Part II: Additive Manufacturing and Characterization of Polymer Composites

    Science.gov (United States)

    Chuang, Kathy C.; Grady, Joseph E.; Arnold, Steven M.; Draper, Robert D.; Shin, Eugene; Patterson, Clark; Santelle, Tom; Lao, Chao; Rhein, Morgan; Mehl, Jeremy

    2015-01-01

    This publication is the second part of the three part report of the project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing" funded by NASA Aeronautics Research Institute (NARI). The objective of this project was to conduct additive manufacturing to produce aircraft engine components by Fused Deposition Modeling (FDM), using commercially available polyetherimides-Ultem 9085 and experimental Ultem 1000 mixed with 10% chopped carbon fiber. A property comparison between FDM-printed and injection molded coupons for Ultem 9085, Ultem 1000 resin and the fiber-filled composite Ultem 1000 was carried out. Furthermore, an acoustic liner was printed from Ultem 9085 simulating conventional honeycomb structured liners and tested in a wind tunnel. Composite compressor inlet guide vanes were also printed using fiber-filled Ultem 1000 filaments and tested in a cascade rig. The fiber-filled Ultem 1000 filaments and composite vanes were characterized by scanning electron microscope (SEM) and acid digestion to determine the porosity of FDM-printed articles which ranged from 25 to 31%. Coupons of Ultem 9085, experimental Ultem 1000 composites and XH6050 resin were tested at room temperature and 400F to evaluate their corresponding mechanical properties. A preliminary modeling was also initiated to predict the mechanical properties of FDM-printed Ultem 9085 coupons in relation to varied raster angles and void contents, using the GRC-developed MAC/GMC program.

  7. 多场耦合计算平台与高超声速热防护结构传热问题研究%Multi-field Coupled Computing Platform and Thermal Transfer of Hypersonic Thermal Protection Structures

    Institute of Scientific and Technical Information of China (English)

    张兵; 韩景龙

    2011-01-01

    A multi-field coupled computing platform using multi-zone iteration is developed to solve conjugate heat transfer problems. Based on the element features of the finite element method (FEM) and finite volume method (FVM), a local conservative remapping method is presented for thermal flux and aerodynamic load interpolation. Shared memory is employed for faster data exchange for the general FEMs/computational fluid dynamics (CFD) software. The problems of conjugate heat transfer for a cooled converging-diverging nozzle and a cylindrical leading edge in hypersonic flow are studied. Effects of mesh density, nonlinear material properties and radiation are considered during the computation,and the results show good agreement with the existing experimental data. The relationships are investigated between the stagnation temperature, cooling power and the thickness of the nose thermal protection structure (TPS) of a quasi-X-34 hypersonic vehicle under hypersonic cruise conditions. The results indicate that the thickness variations exhibit no significant influence on stagnation temperature, while the cooling power drops sharply as the thickness increases. Furthermore, the nonlinear material emission properties have significant influence on the analysis results.%从有限元法(FEM)和有限体积法(FVM)的单元特性出发,提出一种具有局部守恒特性的界面载荷插值方法.采用共享内存技术开发适用于通用有限元和计算流体力学(CFD)软件的多场耦合计算平台,并基于分区耦合方式实现流固耦合传热计算.作为验证,分别将ANSYS与Fluent和CFD-FASTRAN软件进行耦合,计算外壁冷却的喷管和高超声速圆柱绕流的耦合传热问题,结果与实验值吻合良好.针对类X-34飞行器的头部热防护结构(TSP),考虑材料非线性和辐射效应,对高超声速巡航状态下驻点温度和结构冷却系统功率随热防护层厚度的变化规律进行了研究.计算结果表明:驻点温度随热

  8. Conformal Ablative Thermal Protection System for Planetary and Human Exploration Missions: Overview of the Technology Maturation Efforts Funded by NASA's Game Changing Development Program

    Science.gov (United States)

    Beck, Robin A.; Arnold, James O.; Gasch, Matthew J.; Stackpoole, Margaret M.; Fan, Wendy; Szalai, Christine E.; Wercinski, Paul F.; Venkatapathy, Ethiraj

    2012-01-01

    The Office of Chief Technologist (OCT), NASA has identified the need for research and technology development in part from NASA's Strategic Goal 3.3 of the NASA Strategic Plan to develop and demonstrate the critical technologies that will make NASA's exploration, science, and discovery missions more affordable and more capable. Furthermore, the Game Changing Development Program (GCDP) is a primary avenue to achieve the Agency's 2011 strategic goal to "Create the innovative new space technologies for our exploration, science, and economic future." In addition, recently released "NASA space Technology Roadmaps and Priorities," by the National Research Council (NRC) of the National Academy of Sciences stresses the need for NASA to invest in the very near term in specific EDL technologies. The report points out the following challenges (Page 2-38 of the pre-publication copy released on February 1, 2012): Mass to Surface: Develop the ability to deliver more payload to the destination. NASA's future missions will require ever-greater mass delivery capability in order to place scientifically significant instrument packages on distant bodies of interest, to facilitate sample returns from bodies of interest, and to enable human exploration of planets such as Mars. As the maximum mass that can be delivered to an entry interface is fixed for a given launch system and trajectory design, the mass delivered to the surface will require reduction in spacecraft structural mass; more efficient, lighter thermal protection systems; more efficient lighter propulsion systems; and lighter, more efficient deceleration systems. Surface Access: Increase the ability to land at a variety of planetary locales and at a variety of times. Access to specific sites can be achieved via landing at a specific location (s) or transit from a single designated landing location, but it is currently infeasible to transit long distances and through extremely rugged terrain, requiring landing close to the

  9. Electronic structure and Schottky-barrier formation on GaAs (100) surfaces prepared by thermal desorption of a protective arsenic coating

    Energy Technology Data Exchange (ETDEWEB)

    Spindt, C.J.; Yamada, M.; Meissner, P.L.; Miyano, K.E.; Kendelewicz, T.; Herrera-Gomez, A.; Spicer, W.E. (Stanford Electronics Laboratories, Stanford University, Stanford, California 94305-4055 (United States)); Arko, A.J. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))

    1992-05-15

    Soft-x-ray photoemission spectroscopy has been used to characterize GaAs(100) surfaces and interfaces grown by molecular-beam epitaxy and prepared by the thermal desorption of a protective As coating. The samples studied were grown and arsenic capped identically to those used in a previous study (Brillson {ital et} {ital al}., J. Vac. Sci. Technol. B 6, 1263 (1988)). In this previous work, unpinned'' Schottky-barrier formation was reported, with barrier heights over a wide (0.75-eV) range. This is a striking result, as it was previously believed that all metals will pin GaAs surfaces in a narrow energy range near the middle of the band gap. This large range of barrier heights later led to the suggestion that the (100) surface could become an insulating layer that could screen out the effects of metal-induced gap states. Motivated by this work, we have studied Al and Au Schottky barriers since the deposition of these two metals gave the extreme low and high barriers in the 0.75-eV range. We have also characterized the clean surfaces prepared by desorbing the As caps at different temperatures. The As 3{ital d} and Ga 3{ital d} core levels showed that the surface stoichiometry could be varied significantly with the desorption temperature. The As 3{ital d} line shape was found to be the best indication of the surface stoichiometry after the anneal. The valence-band spectra did not show any strong features which could be used to determine when the sample was completely decapped. The electronic structure of the surface layer was investigated experimentally, and no evidence of an insulating reconstruction was found. In our study of band bending, we found that the low-doped samples used here and in the earlier study showed significant photovoltages resulting in incorrect band-bending measurements. We also found that the Au measurements are made difficult by the presence of core-level shifts due to Au-Ga alloying.

  10. Au and Al Schottky barrier formation on GaAs (100) surfaces prepared by thermal desorption of a protective arsenic coating

    Energy Technology Data Exchange (ETDEWEB)

    Spindt, C.J.; Yamada, M.; Meissner, P.L.; Miyano, K.E.; Herrera, A.; Spicer, W.E. (Stanford Univ., CA (United States). Stanford Electronics Labs.); Arko, A.J. (Los Alamos National Lab., NM (United States)); Woodall, J.M.; Pettit, G.D. (International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center)

    1991-01-01

    Photoelectron spectroscopy has been used as a tool to investigate the initial stages of Schottky barrier formation on GaAs (100) surfaces. This is a popular technique that has been used by many researchers in the past to measure the band bending (or shift) of the valence band and conduction band (a measure of the Schottky barrier shift), while the Fermi level remains fixed at the system ground (i.e., the ground of the spectrometer). Metal deposition on a semiconductor surface can alter the Schottky barrier at the surface and pin the Fermi level near the middle of the energy gap. Extremely clean and crystallographically perfect surfaces are required in this study. Toward this end, a method of protecting the GaAs surface was employed which consists of capping the GaAs surface with a layer of As. Upon introduction into the high vacuum system the As is thermally desorbed, revealing a pure GaAs surface. Our work was motivated by a previous study (Brillson et al) on similarly capped specimens, which suggested that metal overlayers do not pin the Schottky barrier in GaAs. Barrier heights varied by as much as 0.75 eV between Al and Au overlayers. This large energy range is a striking result in view of the fact that a considerable number of prior studies on both (110) and (100) surfaces have found that all metals will pin within a narrow (0.25 eV) range at midgap. We repeated the measurements of Brillson on the identically doped samples used in their study using two extreme range metals of Au and Al as overlayers. We found that the barrier height measurements on low doped n-type samples used in this work and in the previous work are affected by photovoltaic effects, even at room temperature. This was determined from taking spectra at a number of temperatures between 20 K and room temperature and looking for shifts. 16 refs., 7 figs.

  11. ZrB2-SiC as a protective coating for C/SiC composites: Effect of high temperature oxidation on thermal shock property and protection mechanism

    Directory of Open Access Journals (Sweden)

    Xiang Yang

    2016-06-01

    Full Text Available ZrB2-SiC coating was prepared on C/SiC composites surface by slurry method, and then the thermal fatigue behavior of ZrB2-SiC coated C/SiC composites was studied. The composition of the coating layers was characterized by XRD, SEM and EDS. With the thickness was 200 μm, the coating was ZrB2 and SiC. During thermal cycle between 1773 K in air and 373 K in boiling water, the weight of the ZrB2-SiC coated composites decreased lightly. The decrease of the flexural strength during the thermal cycle was primarily due to the debonding of the fiber–matrix interfaces and the oxidation of the coated samples. Compared with the uncoated C/SiC composites, the coating played an important role in enhancing the resistance to the thermal shock.

  12. The effect of non-metallic inclusions on the fracture toughness master curve in high copper reactor pressure vessel welds

    Science.gov (United States)

    Oh, Yong-Jun; Lee, Bong-Sang; Hong, Jun-Hwa

    2002-03-01

    The fracture toughness of two high copper reactor pressure vessel welds having low upper shelf energy was evaluated in accordance with the master curve method of ASTM E1921. The resultant data were correlated to the metallurgical factors involved in the brittle fracture initiation to provide a metallurgical-based understanding of the master curve. The tests were performed using pre-cracked Charpy V-notched specimens and the master curve was made with an average of T0 values determined at different temperatures. In all specimens, the cleavage fracture initiated at non-metallic inclusion ranging from 0.7 to 3.5 μm in diameter showing a scatter with the specimens and testing temperatures. Temperature dependency of the triggering particle size was not found. The fracture toughness ( KJC) was inversely proportional to the square root of the triggering inclusion diameter ( di) at respective temperatures. From this relationship, we determined median KJC values which correspond to the average value of triggering inclusion diameter of all tested specimens and defined them as a modified median KJC ( K'JC(med) ). The obtained K'JC(med) values showed quite smaller deviation from the master curve at different temperatures than the experimental median KJC values. This suggests that the master curve is on the premise of a constant dimension of key microstructural factor in a material regardless of the testing temperature. But the inclusion size at trigger point played an important role in the absolute position of the master curve with temperature and the consequent T0 value.

  13. The effect of non-metallic inclusions on the fracture toughness master curve in high copper reactor pressure vessel welds

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Yong-Jun E-mail: yjoh@kaeri.re.kr; Lee, Bong-Sang; Hong, Jun-Hwa

    2002-03-01

    The fracture toughness of two high copper reactor pressure vessel welds having low upper shelf energy was evaluated in accordance with the master curve method of ASTM E1921. The resultant data were correlated to the metallurgical factors involved in the brittle fracture initiation to provide a metallurgical-based understanding of the master curve. The tests were performed using pre-cracked Charpy V-notched specimens and the master curve was made with an average of T{sub 0} values determined at different temperatures. In all specimens, the cleavage fracture initiated at non-metallic inclusion ranging from 0.7 to 3.5 {mu}m in diameter showing a scatter with the specimens and testing temperatures. Temperature dependency of the triggering particle size was not found. The fracture toughness (K{sub J{sub C}}) was inversely proportional to the square root of the triggering inclusion diameter (d{sub i}) at respective temperatures. From this relationship, we determined median K{sub J{sub C}} values which correspond to the average value of triggering inclusion diameter of all tested specimens and defined them as a modified median K{sub J{sub C}} (K{sup '}{sub J{sub C}}{sub (med)}). The obtained K{sup '}{sub J{sub C}}{sub (med)} values showed quite smaller deviation from the master curve at different temperatures than the experimental median K{sub J{sub C}} values. This suggests that the master curve is on the premise of a constant dimension of key microstructural factor in a material regardless of the testing temperature. But the inclusion size at trigger point played an important role in the absolute position of the master curve with temperature and the consequent T{sub 0} value.

  14. Agglomeration of Non-metallic Inclusions at Steel/Ar Interface: In- Situ Observation Experiments and Model Validation

    Science.gov (United States)

    Mu, Wangzhong; Dogan, Neslihan; Coley, Kenneth S.

    2017-10-01

    Better understanding of agglomeration behavior of nonmetallic inclusions in the steelmaking process is important to control the cleanliness of the steel. In this work, a revision on the Paunov simplified model has been made according to the original Kralchevsky-Paunov model. Thus, this model has been applied to quantitatively calculate the attractive capillary force on inclusions agglomerating at the liquid steel/gas interface. Moreover, the agglomeration behavior of Al2O3 inclusions at a low carbon steel/Ar interface has been observed in situ by high-temperature confocal laser scanning microscopy (CLSM). The velocity and acceleration of inclusions and attractive forces between Al2O3 inclusions of various sizes were calculated based on the CLSM video. The results calculated using the revised model offered a reasonable fit with the present experimental data for different inclusion sizes. Moreover, a quantitative comparison was made between calculations using the equivalent radius of a circle and those using the effective radius. It was found that the calculated capillary force using equivalent radius offered a better fit with the present experimental data because of the inclusion characteristics. Comparing these results with other studies in the literature allowed the authors to conclude that when applied in capillary force calculations, the equivalent radius is more suitable for inclusions with large size and irregular shape, and the effective radius is more appropriate for inclusions with small size or a large shape factor. Using this model, the effect of inclusion size on attractive capillary force has been investigated, demonstrating that larger inclusions are more strongly attracted.

  15. Tunable electronic structures of germanium monochalcogenide nanosheets via light non-metallic atom functionalization: a first-principles study.

    Science.gov (United States)

    Ding, Yi; Wang, Yanli

    2016-08-17

    Germanium monochalcogenides, i.e. GeS and GeSe sheets, are isoelectronic analogues of phosphorene, which have been synthesized in recent experiments (P. Ramasamy et al., J. Mater. Chem. C, 2016, 4, 479). Utilizing first-principles calculations, we have investigated their tunable electronic and magnetic properties via light non-metallic atom (B, C, N, O, Si, P, S) functionalization. We find that on these GeS and GeSe sheets O and S adatoms prefer to locate at the top site above the Ge atom, while the other ones like to occupy the anion site, which push the original S/Se atom to the hollow site instead. O and S adatoms slightly affect the semiconducting behaviour of the doped systems, while B, C, N, Si, P ones will drastically modify their band structures and induce versatile spintronic properties. Through the supercell calculations, B and C adatoms are found to induce a bipolar semiconducting behaviour in the decorated systems, while the N/P adatom will cause a spin-gapless-semiconducting/nearly-half-metallic feature in them. The B/C/N/Si/P-substituted GeS/GeSe sheet can be formed by removing the hollow-site S/Se atom from the adatom-decorated structures, which exhibit an opposite semiconducting/metallic behaviour to their phosphorene counterparts. A general odd-even rule is proposed for this phenomenon, which shows that an odd (even) number of valence electron difference between the substitution and host atoms would cause a metallic (semiconducting) feature in the substituted systems. Our study demonstrates that atom functionalization is an efficient way to tailor the properties of GeS and GeSe nanosheets, which have adaptable electronic properties for potential applications in nanoelectronics and spintronics.

  16. 轻质热防护系统波纹夹芯结构热力耦合分析%Structural Analysis of Corrugated-Core Sandwich Panels for Lightweight Thermal Protection System

    Institute of Scientific and Technical Information of China (English)

    王琪; 吉庭武; 谢公南; 张卫红

    2013-01-01

    高超声速飞行器在出人大气层或持续在空间飞行时,将遭受严苛的气动加热载荷.对热防护系统进行传热分析是进行热力耦合分析的基础,而温度分布的特点直接影响到波纹夹芯结构的热应力等问题.首先对一体化热防护系统(integrated thermal protection system,ITPS)进行隔热性能分析,得到整个结构的温度场;然后采用顺序耦合的数值方法,模拟分析ITPS波纹夹芯结构单胞的热力耦合性能,给出波纹夹芯结构在静力载荷以及热力耦合载荷条件下的应力场、位移场,并对计算结果进行了讨论.结果表明波纹夹芯结构在初始尺寸及约束条件下,只满足在高温热流作用下飞行器低压区使用,而当气动压力大于等于15 000 Pa时,结构将发生破坏.%Hypersonic aircrafts enter across the atmosphere with high flight speed and over a long period of time, resulting in an intense aerodynamic heating load. Thermal analysis of ther-mal protection system (TPS) is the base of thermal-mechanical coupling analysis; and the char-acteristics of temperature distribution affect thermal stress of corrugated sandwich structure di-rectly. The analysis process was divided into three steps. The insulation performance of the in-tegrated thermal protection system (FTPS) was analyzed to get the temperature distribution firstly. Then a sequence coupled numerical method was used to simulate the thermo-mechanical coupling performance of ITPS. Finally the stress field and displacement field of the corrugated sandwich structure unit cell were obtained and results were discussed. The calculation results show that the structure with initial size and constraints only satisfy the use of low-pressure zone, and structure will fail when the pressure is greater than 15 000 Pa.

  17. Forming images with thermal neutrons

    Science.gov (United States)

    Vanier, Peter E.; Forman, Leon

    2003-01-01

    Thermal neutrons passing through air have scattering lengths of about 20 meters. At further distances, the majority of neutrons emanating from a moderated source will scatter multiple times in the air before being detected, and will not retain information about the location of the source, except that their density will fall off somewhat faster than 1/r2. However, there remains a significant fraction of the neutrons that will travel 20 meters or more without scattering and can be used to create an image of the source. A few years ago, a proof-of-principle "camera" was demonstrated that could produce images of a scene containing sources of thermalized neutrons and could locate a source comparable in strength with an improvised nuclear device at ranges over 60 meters. The instrument makes use of a coded aperture with a uniformly redundant array of openings, analogous to those used in x-ray and gamma cameras. The detector is a position-sensitive He-3 proportional chamber, originally used for neutron diffraction. A neutron camera has many features in common with those designed for non-focusable photons, as well as some important differences. Potential applications include detecting nuclear smuggling, locating non-metallic land mines, assaying nuclear waste, and surveying for health physics purposes.

  18. Prediction of Leakage Rates Through Sealing Connections with Nonmetallic Gaskets%非金属平垫片密封连接的泄漏率预测

    Institute of Scientific and Technical Information of China (English)

    顾伯勤; 陈晔; 朱大胜

    2007-01-01

    In this work,a model of gas leakage through nonmetallic gaskets was developed in order to predict leakage rate of gasket sealing connections. The model was verified by the leakage experiments on two types of gaskets: compressed non-asbestos fiber gasket and flexible graphite gasket reinforced with tanged metal sheet. The coefficients in the leakage rate formula were obtained by regression of experimental data for each type of gasket.The model was also validated against the experimental leakage data by other researchers and shown to produce accurate predications. Furthermore,the model was applied to a bolted flanged connection in service in order to assess the tightness of the connection.

  19. Thermal insulation of buildings classified as historical monuments with particular emphasis on moisture protection; Hygrisch motivierter Waermeschutz von Altbauten mit denkmalgeschuetzter Fassade

    Energy Technology Data Exchange (ETDEWEB)

    Haeupl, P.; Martin, R.; Fechner, H.; Neue, J. [Technische Univ. Dresden (Germany). Inst. fuer Bauklimatik

    1997-12-31

    Buildings classified as historical must not be fitted with external thermal insulation elements. This project investigates a `gentle` type of an internal thermal insulation system with capillary activity permitting diffusion. A 120-year-old building with a historical house-front was thermally insulated at the inside using a 30-millimetre-thick calcium silicate plate with embedded fibres having capillary activity. The paper discusses the heat flow densities between the internal thermal insulation and the original part of the structure. Moisture fields in the wall in the case of mineral wool insulation and internal thermal insulation with capillary activity are compared. Moisture distribution in the area of the juncture between masonry and window and in the area of the beam head is shown by means of diagrams. (MSK) [Deutsch] Weil bei denkmalgeschuetzten Fassanden ein aussen angebrachtes Thermoverbundsystem nicht moeglich ist, wird in diesem Projekt eine sanfte kapillaraktive, diffusionsoffene Innendaemmung untersucht. Als Referenzobjekt wurde ein etwa 120 Jahre altes Gruenderzeithaus mit denkmalgeschuetzter Fassade mit einer 30mm dicken faserdotierten kapillaraktiven Calciumsilikatplatte innenseitig gedaemmt. Im Folgenden werden die Waermestromdichten zwischen Innendaemmung und Altkonstruktion erlaeutert. Die Feuchtefelder in der Wand bei Mineralwolleindaemmung und bei kapillaraktiver Innendaemmung werden verglichen. Die Feuchteverteilung im Bereich des Fenteranschlusses und des Balkenkopfes wird in Diagrammen dargestellt.

  20. Thermal Clothing

    Science.gov (United States)

    1997-01-01

    Gateway Technologies, Inc. is marketing and developing textile insulation technology originally developed by Triangle Research and Development Corporation. The enhanced thermal insulation stems from Small Business Innovation Research contracts from NASA's Johnson Space Center and the U.S. Air Force. The effectiveness of the insulation comes from the microencapsulated phase-change materials originally made to keep astronauts gloved hands warm. The applications for the product range from outer wear, housing insulation, and blankets to protective firefighting gear and scuba diving suits. Gateway has developed and begun marketing thermal regulating products under the trademark, OUTLAST. Products made from OUTLAST are already on the market, including boot and shoe liners, winter headgear, hats and caps for hunting and other outdoor sports, and a variety of men's and women's ski gloves.

  1. Study of the nature of non-metallic inclusions in samples of aluminum and silicon killed low carbon steels, collected in the refining treatment and continuous casting stages

    Directory of Open Access Journals (Sweden)

    José Carlos Santos Pires

    2004-12-01

    Full Text Available The amount, distribution, size and chemical composition of non-metallic inclusions have a direct influence on steel properties. By controlling size and chemical composition of these inclusions, it is possible to get a product with good quality. The identification of the nature and the control of inclusion formation are very important for steel cleanness. The behavior of these inclusions is predictable, in some extent, by the determination of the chemical composition of non-metallic phases that form such inclusions. With the objective of studying the chemical composition, the size and the distribution of such inclusions, samples of aluminum and silicon killed low carbon steels were collected in a national steel industry in the secondary refining and continuous casting stages. These samples were analyzed in the scanning electron microscope (SEM coupled to an energy dispersive analysis system (EDS. From the results, it was possible to evaluate the nature of inclusions and to analyze the effectiveness of the refining process in the reduction of the number and area fraction of the inclusions. It was also possible to verify that the inclusions that remained after treatment, are less damage both to the steel properties as to the continuous casting process (clogging of the submerged valve.

  2. Strength and deformability of compressed concrete elements with various types of non-metallic fiber and rods reinforcement under static loading

    Science.gov (United States)

    Nevskii, A. V.; Baldin, I. V.; Kudyakov, K. L.

    2015-01-01

    Adoption of modern building materials based on non-metallic fibers and their application in concrete structures represent one of the important issues in construction industry. This paper presents results of investigation of several types of raw materials selected: basalt fiber, carbon fiber and composite fiber rods based on glass and carbon. Preliminary testing has shown the possibility of raw materials to be effectively used in compressed concrete elements. Experimental program to define strength and deformability of compressed concrete elements with non-metallic fiber reinforcement and rod composite reinforcement included design, manufacture and testing of several types of concrete samples with different types of fiber and longitudinal rod reinforcement. The samples were tested under compressive static load. The results demonstrated that fiber reinforcement of concrete allows increasing carrying capacity of compressed concrete elements and reducing their deformability. Using composite longitudinal reinforcement instead of steel longitudinal reinforcement in compressed concrete elements insignificantly influences bearing capacity. Combined use of composite rod reinforcement and fiber reinforcement in compressed concrete elements enables to achieve maximum strength and minimum deformability.

  3. A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing Part I: System Analysis, Component Identification, Additive Manufacturing, and Testing of Polymer Composites

    Science.gov (United States)

    Grady, Joseph E.; Haller, William J.; Poinsatte, Philip E.; Halbig, Michael C.; Schnulo, Sydney L.; Singh, Mrityunjay; Weir, Don; Wali, Natalie; Vinup, Michael; Jones, Michael G.; Patterson, Clark; Santelle, Tom; Mehl, Jeremy

    2015-01-01

    The research and development activities reported in this publication were carried out under NASA Aeronautics Research Institute (NARI) funded project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing." The objective of the project was to conduct evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. The results of the activities are described in three part report. The first part of the report contains the data and analysis of engine system trade studies, which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. The technical scope of activities included an assessment of the feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composites, which were accomplished by fabricating prototype engine components and testing them in simulated engine operating conditions. The manufacturing process parameters were developed and optimized for polymer and ceramic composites (described in detail in the second and third part of the report). A number of prototype components (inlet guide vane (IGV), acoustic liners, engine access door) were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included turbine nozzle components. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

  4. 基于热网络的异步电机过载保护模型及数字算法%Overload Protection Model of Asynchronous Motor Basing on Thermal Network and Digital Algorithm

    Institute of Scientific and Technical Information of China (English)

    李洪涛; 李奎; 倪素娟

    2011-01-01

    According to the different heat sources within the motor, the motor can be divided to five parts,namely, the stator core,the stator slot winding,rotor bar and rotor core, then the lumped parameter method was respectively used to them to establish an five-order thermal network model of asynchronous motor. With ensuring the accuracy of the thermal models,the full-order thermal models could be systematically reduced via pole-zero cancellation. As a result, a low-order thermal network models, which had nearly the major response characteristics in the frequency band of interest and was more simple for estimating the motor temperature, was obtained. In order to make the low-order themal network models could be applied to intelligent motor thermal overload protection relay, an discretization algorithm was proposed.%以试验样机为例,依据电机内部不同的发热源将电机分作五部分,即定子铁心和机壳、定子槽绕组、定子绕组端部、转子导条和转子铁心,分别应用集总参数法建立了五阶的热网络分布模型.在保证模型精度的前提下,利用零极点对消法对五阶热模型进行了降阶简化,从而得到了反应电机温升主要特性、精度高、计算简单的低阶热网络模型.对低阶热模型进行离散化,得到了适用于智能电机过载保护继电器的数字算法.

  5. Effect of Interface Structure on Thermal Boundary Conductance by using First-principles Density Functional Perturbation Theory

    Institute of Scientific and Technical Information of China (English)

    GAO Xue; ZHANG Yue; SHANG Jia-Xiang

    2011-01-01

    We choose a Si/Ge interface as a research object to investigate the infiuence of interface disorder on thermal boundary conductance. In the calculations, the diffuse mismatch model is used to study thermal boundary conductance between two non-metallic materials, while the phonon dispersion relationship is calculated by the first-principles density functional perturbation theory. The results show that interface disorder limits thermal transport. The increase of atomic spacing at the interface results in weakly coupled interfaces and a decrease in the thermal boundary conductance. This approach shows a simplistic method to investigate the relationship between microstructure and thermal conductivity.%We choose a Si/Ge interface as a research object to investigate the influence of interface disorder on thermal boundary conductance.In the calculations,the diffuse mismatch model is used to study thermal boundary conductance between two non-metallic materials,while the phonon dispersion relationship is calculated by the first-principles density functional perturbation theory.The results show that interface disorder limits thermal transport.The increase of atomic spacing at the interface results in weakly coupled interfaces and a decrease in the thermal boundary conductance.This approach shows a simplistic method to investigate the relationship between microstructure and thermal conductivity.It is well known that interfaces can play a dominant role in the overall thermal transport characteristics of structures whose length scale is less than the phonon mean free path.When heat flows across an interface between two different materials,there exists a temperature jump at the interface.Thermal boundary conductance (TBC),which describes the efficiency of heat flow at material interfaces,plays an importance role in the transport of thermal energy in nanometerscale devices,semiconductor superlattices,thin film multilayers and nanocrystalline materials.[1

  6. 低压船用电动机绝缘与绕组热保护%Insulation of the Low Voltage Marine Motor and Thermal Protection of Its Winding

    Institute of Scientific and Technical Information of China (English)

    王强; 陈金刚

    2013-01-01

      讲述低压船用三相异步电动机绝缘与绕组热保护。介绍了电机用防潮加热带、PTC热敏电阻、热电阻PT100和热电偶在低压船用三相异步电动机上的安装、测量及使用方法。明确电动机在潮湿环境下,绝缘电阻低时防潮加热带的作用,并阐述电机绕组热保护的控制原理以及电机线圈及轴承温度测量的方法和意义。%Insulation of the low voltage marine motor and thermal protection of its winding was described. Instal-lation, measurement and operation of the moisture-proof heating tape, PTC thermistor, thermal resistance PT100 and thermocouple in the low voltage marine three-phase asyn-chronous motor were introduced. The effect of the moisture-proof heating tape in condition that the motor operating under the moist environment was determined. The motor winding overheat protection control principle as well as the motor coil and bearing temperature measurement methods and significance were also discussed.

  7. Recycling of nonmetallics

    Science.gov (United States)

    Amey, E.B.; Kelly, T.D.

    1996-01-01

    The first factor determining recyclability is the composition of the material itself. Metals, for example, can be reused with little or no loss in quality. Paper and rubber, by this criterion, are less recyclable. Each time paper is recycled, some cellulose fibers are broken. Shorter fibers can mean weaker paper of perceived lower quality and value. Vulcanizing is an irreversible chemical process that precludes recycling rubber in its original form. Both materials may be reused in other applications often of lower value than the original one. To be recyclable, the discarded material must have a collection infrastructure at the source of waste generation, at a central collection site, or at curbside. The recovered material must also have a market. If it is priced noncompetitively or no market exists, if it does not meet specifications, or if it requires special technology investments which cannot be recovered through future sales, the recovered material may be stockpiled or discarded rather than recycled. ?? 1996 International Association for Mathematical Geology.

  8. PRIMARY STAGE OF PAKIS-STEM-BLOCK SYSTEM AS THERMAL PROTECTIVE TO FLAT BARE CONCRETE ROOFTOP IN TROPICAL CLIMATE OF SURABAYA

    Directory of Open Access Journals (Sweden)

    Danny Santoso Mintorogo

    2011-07-01

    Full Text Available In the era of global warming and increasing urban heat island condition, flat concrete deck on shop-houses may be less sustainable to handle the excessive solar heat radiation impacts on the roof surfaces. Innovative alternative roofing system is needed to manage heat radiation that will lead to sustainable factors likes energy savings, less energy body used on the roofing materials, and provide comprehensive environmental friendly roof system. This paper discusses about particular environmental friendly materials such as “Pakis-Stem Blocks” system is a good thermal resistant to absorb the solar sun heat and provide natural cooling through convective-wind without adding substantial loads to the roof structures. “Pakis-stem blocks” are easier, cheaper and more valuable than other sub-structure roofing materials as thermal resistant layer on flat bare concrete deck besides green roofing systems.

  9. The materials and elements production practice of counter-erosional and thermal protection system of the SPR-solid-propellant sustainer nozzle

    Science.gov (United States)

    Shkurenko, V. M.

    1993-06-01

    This paper presents the production scheme for heat- and erosion-protective carbon plastic materials for heat shield elements of solid-propellant nozzles. Attention is also given the method of manufacturing adhesive joint assemblies, and the production scheme is included.

  10. INFLUENCE OF MAGNETIC AND ELECTRIC GRINDING PARAMETERS ON HARDNESS, WEAR-RESISTANCE AND CHEMICAL COMPOSITION OF PROTECTIVE GAS AND THERMAL COATINGS

    OpenAIRE

    N. V. Spiridonov; M. V. Neroda; I. O. Sokorov

    2010-01-01

    The paper investigates influence of magnetic and electric grinding parameters on formation of physical and mechanical properties of protective coatings. It has been established that it is possible to control chemical composition, properties and qualitative characteristics of hardening coatings while changing technological process parameters. 

  11. INFLUENCE OF MAGNETIC AND ELECTRIC GRINDING PARAMETERS ON HARDNESS, WEAR-RESISTANCE AND CHEMICAL COMPOSITION OF PROTECTIVE GAS AND THERMAL COATINGS

    Directory of Open Access Journals (Sweden)

    N. V. Spiridonov

    2010-01-01

    Full Text Available The paper investigates influence of magnetic and electric grinding parameters on formation of physical and mechanical properties of protective coatings. It has been established that it is possible to control chemical composition, properties and qualitative characteristics of hardening coatings while changing technological process parameters. 

  12. Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semiannual technical report, January 14, 1997--August 14, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Schorr, B.S.; Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1997-08-31

    Research is presently being conducted to determine the optimum ceramic/metal combination in thermally sprayed metal matrix composite coatings for erosion and corrosion resistance in new coal-fired boilers. The research will be accomplished by producing model cermet composites using powder metallurgy and electrodeposition methods in which the effect of ceramic/metal combination for the erosion and corrosion resistance will be determined. These results will provide the basis for determining the optimum hard phase constituent size and volume percent in thermal spray coatings. Thermal spray coatings will be applied by our industrial sponsor and tested in our erosion and corrosion laboratories. Bulk powder processed Ni-Al{sub 2}O{sub 3} composites were produced at Idaho National Engineering Laboratory. The composite samples contained 0, 21, 27, 37, and 45 volume percent Al{sub 2}O{sub 3} with an average particle size of 12 um. Also, to deposit model Ni-Al{sub 2}O{sub 3} coatings, an electrodeposition technique was developed and coatings with various volume fractions (0-35%) of Al{sub 2}O{sub 3} were produced. The powder and electrodeposition processing of Ni-Al{sub 2}O{sub 3} Composites provide the ability to produce two phase microstructure without changing the microstructure of the matrix material. Therefore, the effect of hard second phase particles size and volume fraction on erosion resistance could be analyzed.

  13. Analysis of industry development of building materials and ore mining and dressing of non-metallic minerals%2011年建材及非金属矿采选业行业发展分析

    Institute of Scientific and Technical Information of China (English)

    何军生

    2012-01-01

    In 2011, the growth of building materials production remained stable, industrial structure contiuned to optimise, economic porfits improved. In this paper, the author firstly discusses economic operation of building materials and ore mining and dressing of non-metallic minerals in 2011, to adjust the industrial structure of building materials and ore mining and dressing of non-metallic minerals to impove the quality of the economic operation, predicts the development trend of industry of building materials and ore mining and dressing of non-metallic minerals in 2012. At last, the author puts forward to policy suggestions which accelerate industry deleopment of the building materials and ore mining and dressing of non-metallic minerals%2011年建材工业生产增长速度保持平稳,产业结构继续优化,经济效益提高.本文首先讨论了2011年建材工业经济及非金属矿采选行业经济运行情况,做到调整建材及非金属矿选行业产业结构,提高经济运行质量,预测了2012年建材及非金属矿选行业未来发展趋势,最后提出促进建材及非金属矿选行业发展的政策建议.

  14. Comprehensive Evaluation of Thermal and Moisture Comfortableness of Fabric for Firefighter Protective Clothing%消防服用织物材料热湿舒适性综合评价

    Institute of Scientific and Technical Information of China (English)

    漆政昆; 张和平; 黄冬梅; 程旭东; 杨晖

    2012-01-01

    为提高消防服的热湿舒适性能,减少消防员在灭火救援过程中的热应激反应,基于现有消防服用织物材料的物性参数和单项热湿舒适性指标,采用多元回归分析的方法综合评价消防服各层材料的热湿舒适性能,研究各外层材料的单项热湿舒适性指标与物性参数之间的关系.结果表明:以黑色芳砜伦为外层材料、Goretex为防水透气层材料、Nomex针刺毡为隔热层材料、Nomex/FR-VISCOSE(50% Nomex,50%阻燃黏胶)为舒适层材料的消防服热湿舒适性最好,并得出织物的吸湿速率常数、透湿率和干燥率与物性参数之间的显著多元回归模型.%For the sake of improving the thermal-moisture comfortableness of firefighter protective clothing (FPC) and reducing the heat stress response by firefighters in fire fighting and rescue processes,the thermal-moisture comfortableness of each fabric was evaluated comprehensively and the relationship between the physical parameters and individual thermal-moisture comfortableness was studied using the multiple regression analysis method. The results indicate that the thermal-moisture comfortableness of the items of FPC with the PSA (Polysulfonamide) fabric as the outer shell,Goretex as the moisture barrier layer, Nomex needle punched fiber as thermal barrier layer and Nomex /FR-VISCOSE (50% Nomex, 50% flame retardant viscose) as comfort layer is the best of all. Multiple regression mathematical models were built for moisture absorption rate, surface density, and the water vapour transmission rate. The thermal-moisture comfortableness of items of FPC can be effectively evaluated and analized using the comprehensive evaluation system.

  15. Small heat shock protein Hsp27 protects myosin S1 from heat-induced aggregation, but not from thermal denaturation and ATPase inactivation.

    Science.gov (United States)

    Markov, Denis I; Pivovarova, Anastasia V; Chernik, Ivan S; Gusev, Nikolai B; Levitsky, Dmitrii I

    2008-04-30

    We applied different methods, such as turbidity measurements, dynamic light scattering, differential scanning calorimetry and co-sedimentation assay, to analyze the interaction of small heat shock protein Hsp27 with isolated myosin head (myosin subfragment 1, S1) under heat-stress conditions. Upon heating at 43 degrees C, Hsp27 effectively suppresses S1 aggregation, and this effect is enhanced by mutations mimicking Hsp27 phosphorylation. However, Hsp27 was unable to prevent thermal unfolding of myosin heads and to maintain their ATPase activity under heat-shock conditions.

  16. AOT/isooctane reverse micelles with a microaqueous core act as protective shells for enhancing the thermal stability of Chromobacterium viscosum lipase.

    Science.gov (United States)

    Hong, Sung-Chul; Park, Kyung-Min; Son, Young-Hwan; Jung, Ho-Sup; Kim, Keesung; Choi, Seung Jun; Chang, Pahn-Shick

    2015-07-15

    According to the different environmental systems for lipase reactions, changes in thermal stability were investigated by employing the Chromobacterium viscosum lipase and a two-step series-type deactivation model. The half-life (6.81 h) of the lipase entrapped in reverse micelles at 70 °C was 9.87- and 14.80-fold longer than that in glycerol pool or in aqueous buffer. The deactivation constants for the first and second step (k1 and k2) at all temperatures drastically decreased when the lipase was entrapped in reverse micelles. In particular, k1 (3.84 h(-1)) at 70 °C in reverse micelles was 1.57-fold lower than that in aqueous buffer (6.03 h(-1)). Based on the fluorescence spectrometry, the amount of excited forms of tryptophan and tyrosine increased markedly during the thermal-treatment in aqueous buffer, whereas no significant fluctuation was noted in the reversed micellar system. These results indicated that the encapsulation in reverse micelles could be favorable for preventing the enzyme from heat-induced denaturation.

  17. Modeling of effusion in the presence of a turbulent parietal flow. Application to the thermal protection of walls; Modelisation de l`effusion en presence d`un ecoulement parietal turbulent. Application a la protection thermique des parois

    Energy Technology Data Exchange (ETDEWEB)

    Belletre, J.; Bataille, F.; Lallemaned, A. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)

    1997-12-31

    The effusion of a cold gas through a porous wall submitted to a hot turbulent parietal flow is studied in order to reduce the convective heat fluxes between the wall and the hot fluid. A modeling of the turbulent dynamical and thermal boundary layer is obtained using a RNG k-{epsilon} model. The cold gas injection through the porous plate and the fluid-wall friction are taken into account using a discrete succession of pores and solid elements. For a 1% injection rate, the modeling results agree with experiments performed in a test-duct. On the other hand, convective heat fluxes on the porous plate are calculated using semi-empirical correlations and different injection rates and temperatures of the hot flow. (J.S.) 23 refs.

  18. Arc-heated Direct-connected Testing Technology Investigation on Scramjet Combustor Thermal Protection System%发动机燃烧室热防护系统电弧加热直连式试验技术

    Institute of Scientific and Technical Information of China (English)

    涂建强; 陈连忠; 马雪松; 陈海群; 王琴

    2013-01-01

    基于原有的电弧加热直连式试验燃烧室性能测试平台,阐述了结合燃油燃烧试验方法,发展了对主动和被动热防护冲压发动机燃烧室热防护性能进行长时间考核的新方法。根据主动冷却燃烧室的试验要求,改进燃油供给控制系统,使其在出口管路压力升高时能长时间稳定供给燃油;采用B型热电偶、隔热毡和高温合金钢卡环安装方法对燃烧室外壁面温度进行接触式测量,获取燃烧室的温度分布;采用轴向不限位的支撑和位移传感器测量燃烧室的轴向变形情况。通过以上3方面的测量技术创新,燃烧室热防护性能考核的电弧加热直连式试验技术能够对发动机燃烧室热防护性能进行千秒量级的考核,并且能够长时间获取燃烧室的燃油供给量、壁面温度分布和轴向变形等数据。%Based on the original arc-heater direct-connected scramjet combustor working performance test facility, a new method, which is used to test the long-time thermal protection performance of the active and passive scramjet combustor thermal protection system (TPS), has been developed. According to the active scramjet combustor test demand, the fuel supply and control system has been improved, which can steadily supply fuel when the exit pressure is increasing. The temperature distributing of the scramjet exterior wall has been measured by the B-type thermocouples, heat-insulation felt and high-temperature alloy steel ring. The axial deformation of the scramjet has been gained by the axial-free supports and displacement sensors. With the three parts improvement, the arc-heater direct-connected testing technology of the scramjet combustor TPS thermal protection performance can last for thousand seconds. And a mass of the scramjet combustor thermal protection performance data in the normal work situation, such as the fuel flux, the exterior wall temperature distributing and the axial

  19. Radiation Protection

    Science.gov (United States)

    ... EPA United States Environmental Protection Agency Search Search Radiation Protection Share Facebook Twitter Google+ Pinterest Contact Us Radiation Protection Document Library View and download EPA radiation ...

  20. 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.

  1. Thermal conductivity and stability of a three-phase blend of carbon nanotubes, conductive polymer, and silver nanoparticles incorporated into polycarbonate nanocomposites

    KAUST Repository

    Patole, Archana

    2015-04-16

    Metallic and non-metallic nanofillers can be used together in the design of polycarbonate (PC) nanocomposites with improved electrical properties. Here, the preparation of three-phase blend (carbon nanotubes (CNT), silver nanoparticles, and conductive polymer) in a two-step process before incorporation in the PC is reported. First, ethylene diamine functionalized multiwall carbon nanotubes (MWCNT-EDA) were decorated with Ag nanoparticles. Next, the Ag-decorated CNTs were coated with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). Due to the high thermal conductivity instrinsic to both metallic and non-metallic phases, it is expected that the thermal properties of the resulting nanocomposite would largely differ from those of pristine PC. We thus investigated in detail how this hybrid conductive blend affected properties such as the glass transition temperature, the thermal stability, and the thermal conductivity of the nanocomposite. It was found that this strategy results in improved thermal conductivity and thermal stability of the material. © 2015 Wiley Periodicals, Inc.

  2. Thermal-Insulation Properties of Multilayer Textile Packages

    OpenAIRE

    Matusiak Małgorzata; Kowalczyk Sylwia

    2014-01-01

    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 ...

  3. 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.

  4. The Protective Effects of Epigallocatechin Gallate Against Distant Organ Damage After Severe Skin Burns--Experimental Study Using a Rat Model of Thermal Trauma.

    Science.gov (United States)

    Hosnuter, Mubin; Melikoglu, Cenk; Aslan, Cem; Saglam, Gulcan; Sutcu, Recep

    2015-01-01

    Epigallocatechin gallate (EGCG), a green tea polyphenol, has potent antioxidant properties. The purpose of the present study was to examine the possible preventative effects of EGCG against internal organ injury due to large-surface skin burns in a rat model. The study design involved three groups of rats: a sham group and two groups with 25-30% full-thickness burns: (a) the sham group without burns or treatment (n=18); (b) the control burn group (burns+sterile saline, n=18); and (c) the burn treatment group (burns+treatment with EGCG, n=18). EGCG was administered intraperitoneally immediately after the thermal injury, and daily in 100 μmol/kg doses. Kidney and lung tissue samples were taken to determine the levels of malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), and glutathione peroxidase (GPX) after the first, third and seventh post-burn days. In the EGCG-treated burn group, SOD and GPX activity were significantly higher than in the burn control group. Additionally, MDA and TNF-α levels were significantly lower in the EGCG-treated burn group. Based on this study, it might be anticipated that EGCG treatment may be beneficial in burn injury cases.

  5. Au and Al Schottky barrier formation on GaAs (100) surfaces prepared by thermal desorption of a protective arsenic coating

    Energy Technology Data Exchange (ETDEWEB)

    Spindt, C.J.; Yamada, M.; Meissner, P.L.; Miyano, K.E.; Herrera, A.; Spicer, W.E. (Stanford Electronics Laboratories, Stanford University, Stanford, California 94305-4055 (US)); Arko, A.J. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (US))

    1991-07-01

    Soft x-ray photoemission spectroscopy has been used to investigate the initial stages of Schottky barrier formation on GaAs (100) surfaces prepared by the thermal desorption of an As cap. This work was motivated by a previous study (Brillson {ital et} {ital al}., J. Vac. Sci. Technol. B {bold 6}, 1263 (1988)) of identically grown and capped samples which reported unpinned'' Schottky barrier formation, with barrier heights falling over a wide range (0.75 eV) of energies. This large energy range is a striking result, as a considerable number of prior studies on both (110) and (100) surfaces have found that all metals will pin in a narrow (0.25 eV) range near midgap. Since Au and Al are the extremes of the larger 0.75 eV span of Schottky barriers, we have studied the deposition of these two metals. We found that the barrier height measurements on the low doped {ital n}-type samples used in this work and in the paper referenced above are affected by photovoltaic effects, even at room temperature. These photovoltaic effects cause shifts in the band bending, which are an artifact of the measurement. We also performed measurements on more heavily doped samples, and the photovoltaic effects were removed. In addition, we point out that Au--Ga alloying makes the case of Au potentially misleading. With the photovoltaic effects removed, and the Au--Ga alloying carefully accounted for, we found that the barriers heights for Au and Al differ by only 0.25 eV.

  6. Can we predict temperature-dependent chemical toxicity to marine organisms and set appropriate water quality guidelines for protecting marine ecosystems under different thermal scenarios?

    Science.gov (United States)

    Zhou, Guang-Jie; Wang, Zhen; Lau, Edward Tak Chuen; Xu, Xiang-Rong; Leung, Kenneth Mei Yee

    2014-10-15

    Temperature changes due to climate change and seasonal fluctuation can have profound implications on chemical toxicity to marine organisms. Through a comprehensive meta-analysis by comparing median lethal or effect concentration data of six chemicals for various saltwater species obtained at different temperatures, we reveal that the chemical toxicity generally follows two different models: (1) it increases with increasing temperature and (2) it is the lowest at an optimal temperature and increases with increasing or decreasing temperature from the optimal temperature. Such observations are further supported by temperature-dependent hazardous concentration 10% (HC10) values derived from species sensitivity distributions which are constructed using the acute toxicity data generated at different temperatures. Considering these two models and natural variations of seawater temperature, we can scientifically assess whether applying an assessment factor (e.g. 10) to modify water quality guidelines of the chemicals can adequately protect marine ecosystems in tropics, subtropics and temperate regions, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Thermally conducting electron transfer polymers

    Science.gov (United States)

    Byrd, N. R.; Jenkins, R. K.; Lister, J. L.

    1969-01-01

    New polymeric material exhibits excellent physical shock protection, high electrical resistance, and thermal conductivity. It is especially useful for electronic circuitry, such as subminiaturization of components and modular construction of circuits.

  8. Non-Metallic Biomaterials for Tooth Repair and Replacement. By Pekka Vallittu, Woodhead Publishing, 2013; 406 pages. Price £145.00/US$245.00/€175.00 ISBN 978-0-85709-244-1

    Directory of Open Access Journals (Sweden)

    Shu-Kun Lin

    2013-01-01

    Full Text Available 1. Discusses the properties of enamel and dentin and their role in adhesive dental restoration;2. Chapters also examine the wear properties of dental ceramics, glasses and bioactive glass ceramics for tooth repair and replacement;3. Dental composites and antibacterial restorative materials are also considered;4. Provides a concise overview of non-metallic biomaterials for dental clinicians, materials scientists and academic researchers alike.As the demand for healthy, attractive teeth increases, the methods and materials employed in restorative dentistry have become progressively more advanced. Non-metallic biomaterials for tooth repair and replacement focuses on the use of biomaterials for a range of applications in tooth repair and, in particular, dental restoration.

  9. 废弃电路板非金属粉末作为水泥增强材料的试验研究%Experiment on taking waste circuit board nonmetallic powder as cement augmentation material

    Institute of Scientific and Technical Information of China (English)

    谢俊; 刘卫东; 杨琴华; 霍晓凡

    2014-01-01

    In view of the problem that waste circuit board nonmetallic powder is difficult to deal with, based on the analysis of composition of waste circuit board nonmetal powder, the paper proposed to take it as a kind of reinforced material which is mixed into concrete and mortar.The experiment results show that the circuit board nonmetallic powder can increase obviously the early compressive strength of concrete and mortar,when non-metallic powder of one kind of fine powdery waste printed circuit boards is mixed at 16. 5%, the early compressive strength after three days increased by 22%.The compressive strength of mor-tar after also inhence after 28 days, so the nonmetallic powder can be used as a kind of cement reinforced material.%针对废弃电路板非金属粉末难以处理的问题,在分析了废弃电路板非金属粉末组成成分的基础上,提出了将其作为一种增强材料掺入到混凝土和砂浆中以增强混凝土和砂浆的强度。结果表明:废弃电路板非金属粉末对混凝土以及砂浆的早期抗压强度提高明显,A种细粉末状废弃电路板非金属粉末在掺量为16.5%时,3 d早期强度提高22%。对砂浆28 d抗压强度也有所提高,故非金属粉末可以作为水泥增强材料。

  10. Thermal Reactor Safety

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

  11. 某超声速飞行器保护罩用弹射器的高温防护特性%Thermal Protection Performances of Ejector for a Supersonic Aircraft Retainer

    Institute of Scientific and Technical Information of China (English)

    刘世毅; 韩言勋; 刘媛媛

    2015-01-01

    The ejector is used to hold down and shoot off the retainer of a supersonic aircraft. The retainer is located at the head of the vehicle, therefore the temperature increases quickly with the impact of aerodynamic drag. For the sake of safety and reliability, the ejector needs thermal protection to meet the safety requirement of the powder in the pyrotechnic device. The theoretical analysis, numerical calculations and experiments of high temperature resistant characteristics of the ejector are introduced in this paper. The environment temperature around the device is reduced obviously by means of slowing heat transfer, optimizing structure, and using heat insulation and phase change material. The experiments validate that the ejector could reduce the efficiency of heat exchange effectively, and the temperature of the cartridge could satisfy the safety demand in the extra high thermal conditions. This research could contribute to the design and experiment of high temperature protection of pyrotechnic devices in spacecraft.%某型弹射器应用于超声速飞行器保护罩的连接固定与弹射分离。由于保护罩位于飞行器头部,受到气动阻力的影响,升温迅速。为了保证弹射器能够在飞行过程中正常安全工作,使装药部位的温度满足火药安全使用要求,需要对其采取热防护措施。文章围绕弹射器的耐高温性能设计开展了相关理论分析、数值仿真及试验验证工作。通过减小热传导途径,优化产品结构设计,采取隔热、相变吸热等措施降低弹射器内部的环境温度。经过热传导试验验证,在模拟飞行器极端的高温环境条件下,弹射器结构能够有效降低热传导效率,保证主装药部位的温度满足火药安全使用要求。该方法为航天火工装置的高温防护设计与验证提供了有效的技术途径。

  12. Thermal-Diode Sandwich Panel

    Science.gov (United States)

    Basiulis, A.

    1986-01-01

    Thermal diode sandwich panel transfers heat in one direction, but when heat load reversed, switches off and acts as thermal insulator. Proposed to control temperature in spacecraft and in supersonic missiles to protect internal electronics. In combination with conventional heat pipes, used in solar panels and other heat-sensitive systems.

  13. Triboelectric separation technology for removing inorganics from non-metallic fraction of waste printed circuit boards: Influence of size fraction and process optimization.

    Science.gov (United States)

    Zhang, Guangwen; Wang, Haifeng; He, Yaqun; Yang, Xing; Peng, Zhen; Zhang, Tao; Wang, Shuai

    2017-02-01

    Removing inorganics from non-metallic fraction (NMF) of waste printed circuit boards (WPCBs) is an effective mean to improve its usability. The effect of size fraction on the triboelectric separation of NMF of WPCBs was investigated in a lab triboelectric separation system and the separation process was optimized in this paper. The elements distribution in raw NMF collected from typical WPCBs recycling plant and each size fraction obtained by sieving were analyzed by X-ray fluorescence (XRF). The results show that the main inorganic elements in NMF are P, Ba, Mn, Sb, Ti, Pb, Zn, Sn, Mg, Fe, Ca, Cu, Al and Si. The inorganic content of each size fraction increased with the size decreasing. The metal elements are mainly distributed in -0.2mm size fraction, and concentrated in middle product of triboelectric separation. The loss on ignition (LOI) of positive product and negative product is higher than that of the middle product for the -0.355mm size fraction, while the LOI presents gradually increasing trend from negative to positive plate for the +0.355mm size fraction. Based on the separation results and mineralogical characterizations of each size fraction of NMF, the pretreatment process including several mineral processing operations was added before triboelectric separation and better separation result was obtained. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Evaluation on the Feasibility of Using Ultrasonic Testing of Reactor Pressure Vessel Welds for Assessing Flaw Density/Distribution per 10 CFR 50.61a, Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Edmund J.; Anderson, Michael T.

    2014-06-10

    This technical letter report provides the status of an assessment undertaken by PNNL at the request of the NRC to verify the capability of periodic ASME-required volumetric examinations of reactor vessels to characterize the density and distribution of flaws of interest for applying §50.61a on a plant-by-plant basis. The PTS rule, described in the Code of Federal Regulations, Title 10, Section 50.61 (§50.61), "Fracture Toughness Requirements for Protection against Pressurized Thermal Shock Events," establishes screening criteria to ensure that the potential for a reactor vessel to fail due to a PTS event is deemed to be acceptably low. Recently, the NRC completed a research program that concluded that the risk of through-wall cracking due to a PTS event is much lower than previously estimated. The NRC subsequently developed and promulgated an alternate PTS rule, §50.61a, that can be implemented by PWR licensees. The §50.61a rule differs from §50.61 in that it requires licensees who choose to follow this alternate method to analyze the results from periodic volumetric examinations required by the ASME Code, Section XI, Rules for Inservice Inspection (ISI) of Nuclear Power Plants.

  15. 氢氧火箭发动机射流仿真与试验台热防护%Thermal Protection and Plume Simulation for Hydrogen/Oxygen Rocket Engine Test Stage

    Institute of Scientific and Technical Information of China (English)

    李茂; 王占林

    2014-01-01

    The plume characteristics of the hydrogen/oxygen rocket engine were studied with the method of CFD ( computational fluid dynamics ) .The influences of the geometry model , the combus-tion model and the turbulence model on the characteristics of the combustion flowfield were ana-lyzed .The results from the numerical simulation were compared with those from the experiments qualitatively and quantitatively .Based on the distributions of the temperature from the numerical simulation results in the different tests , the armor plate was designed for the thermal protection and applied for the test stage .It is confirmed that the approach is effective and reliable .%采用计算流体方法获得氢氧火箭发动机地面试验射流特征,开展了几何模型、燃烧模型和湍流模型对射流场的影响分析以及与试验结果的定性和定量对比。依据不同试验模式下的射流场温度的数值分布,提出试验台钢板防护方案并进行防护,试验证明方案可靠有效。

  16. Design of heating and thermal protection of lubricator of water injection well linkage test%注水井联动测试防喷管加热保温技术设计

    Institute of Scientific and Technical Information of China (English)

    韩文超

    2012-01-01

    The linkage test technology combines with bridge the eccentric water distribution to short testing time and advance testing effect for water injection well. But in winter linkage test could not be applied smoothly because low temperature made water in lubricator to ice. Three heating and thermal protection technologies which were carbon fibre inner heating, ribbon heater whole casting heating and silica gel hot plate heating split to solute the problems and make sure linkage test applied smoothly in winter.%注水井联动测试技术与桥式偏心分层配水工艺相结合,可缩短测试时间,提高测调效率,但在进行联动测试时,防喷管内部的水几乎不流动,随着冬季气温降低,管内极易结冰,使得冬季联动测试工作无法正常开展.为此,本文提出3种防喷管加热保温技术设计,碳纤维内衬加热技术、电热带整体外包加热技术和硅胶电热板分体加热技术,解决防喷管内部水结冻的问题,保证冬季水井联动测试工作顺利开展.

  17. FORMULATION OF EXPANSIVE MORTAR TO TILL THE STONES USING NON-METALLIC MINERALS OF NORTHEAST OF COUNTRY

    Directory of Open Access Journals (Sweden)

    Danielly Vieira de Lucena

    2015-03-01

    Full Text Available One of the most significant methods of advanced technology for mining, the rock massif is employing expansive mortar for cutting of Rock. Furthermore, the entire expansive mortar commercialized in the Brazilian domestic market are imported, as well as those in industrialized country. Both have components from the external market. The aim of this work is to develop expansive mortar with raw materials that have regional and pressure sufficient to remove the rocks of granite and marble type expansion. For this, expansive grout formulations using calcium oxide, calcium carbonate, carboxymethylcellulose are used - CMC (Portland cement, and from the chemical analysis by means of thermal analysis, X-ray diffraction and laser granulometry compared the results with a commercial mortar. The results indicated that the formulations showed characteristics similar to the commercial mortar.

  18. Compósitos SiCf /SiC utilizados em sistemas de proteção térmica SiCf /SiC composites for thermal protection systems

    Directory of Open Access Journals (Sweden)

    M. Florian

    2005-09-01

    Full Text Available Compósitos de carbeto de silício (SiC reforçado com fibras de carbeto de silício (SiCf são materiais candidatos em potencial para utilização em sistemas de proteção térmica em altas temperaturas devido principalmente à boa condutividade térmica na direção da fibra e muito baixa condutividade térmica na direção transversal à fibra, alta dureza, estabilidade térmica e à corrosão por oxidação. O compósito SiCf/SiC possui uma matriz de SiC reforçada com fibras contínuas policristalinas de SiC e é obtido por reações de conversão em altas temperaturas e atmosfera controlada, utilizando o compósito carbono/carbono como precursor. O processo de Reação Química em Vapor (CVR foi utilizado para a fabricação de compósitos SiCf/SiC com alta pureza na fase de SiC-beta. O compósito precursor de carbono/carbono foi fabricado com fibra de carbono não estabilizada e matriz carbonosa derivada da resina fenólica na forma de carbono isotrópico. O compósito convertido exibiu uma densidade de 1,75 g/cm³, com 40% de porosidade aberta e resistência à flexão de 80 MPa medida por ensaio flexão em 4 pontos. A área especifica medida pela técnica de BET é dependente da temperatura de conversão e das condições inicias do precursor de carbono, podendo chegar a 18 m²/g.Composites based on silicon carbide are potential candidate materials for thermal protection systems mainly due to its good thermal conductivity in fiber direction and very low transversal thermal conductivity, high hardness, corrosion and thermal resistance. SiCf/SiC composite presents a SiC matrix reinforced with SiC polycrystalline continuous fibers. The composite was obtained by conversion reactions at high temperature and controlled atmosphere from a carbon/carbon composite precursor. The CVR process was used to fabricate SiC /SiC composite with crystalline high-purity beta-SiC from a carbon-carbon precursor fabricated with non-stabilized carbon fiber and

  19. Thermal comfort

    CSIR Research Space (South Africa)

    Osburn, L

    2010-01-01

    Full Text Available Thermal comfort is influenced by environmental parameters as well as other influences including asymmetric heating and cooling conditions. Additionally, some aspects of thermal comfort may be exploited so as to enable a building to operate within a...

  20. Inkjet printing of Chitlac-nanosilver--a method to create functional coatings for non-metallic bone implants.

    Science.gov (United States)

    Nganga, Sara; Moritz, Niko; Kolakovic, Ruzica; Jakobsson, Kristina; Nyman, Johan O; Borgogna, Massimiliano; Travan, Andrea; Crosera, Matteo; Donati, Ivan; Vallittu, Pekka K; Sandler, Niklas

    2014-12-01

    Biostable fiber-reinforced composites, based on bisphenol-A-dimethacrylate and triethyleneglycoldimethacrylate thermoset polymer matrix reinforced with E-glass fibers have been successfully used in cranial reconstructions and the material has been approved for clinical use. As a further refinement of these implants, antimicrobial, non-cytotoxic coatings on the composites were created by an immersion procedure driven by strong electrostatic interactions. Silver nanoparticles (nAg) were immobilized in lactose-modified chitosan (Chitlac) to prepare the bacteriostatic coatings. Herein, we report the use of inkjet technology (a drop-on-demand inkjet printer) to deposit functional Chitlac-nAg coatings on the thermoset substrates. Characterization methods included scanning electron microscopy, scanning white light interferometry and electro-thermal atomic absorption spectroscopy. Inkjet printing enabled the fast and flexible functionalization of the thermoset surfaces with controlled coating patterns. The coatings were not impaired by the printing process: the kinetics of silver release from the coatings created by inkjet printing and conventional immersion technique was similar. Further research is foreseen to optimize printing parameters and to tailor the characteristics of the coatings for specific clinical applications.

  1. Non-metallic coating thickness prediction using artificial neural network and support vector machine with time resolved thermography

    Science.gov (United States)

    Wang, Hongjin; Hsieh, Sheng-Jen; Peng, Bo; Zhou, Xunfei

    2016-07-01

    A method without requirements on knowledge about thermal properties of coatings or those of substrates will be interested in the industrial application. Supervised machine learning regressions may provide possible solution to the problem. This paper compares the performances of two regression models (artificial neural networks (ANN) and support vector machines for regression (SVM)) with respect to coating thickness estimations made based on surface temperature increments collected via time resolved thermography. We describe SVM roles in coating thickness prediction. Non-dimensional analyses are conducted to illustrate the effects of coating thicknesses and various factors on surface temperature increments. It's theoretically possible to correlate coating thickness with surface increment. Based on the analyses, the laser power is selected in such a way: during the heating, the temperature increment is high enough to determine the coating thickness variance but low enough to avoid surface melting. Sixty-one pain-coated samples with coating thicknesses varying from 63.5 μm to 571 μm are used to train models. Hyper-parameters of the models are optimized by 10-folder cross validation. Another 28 sets of data are then collected to test the performance of the three methods. The study shows that SVM can provide reliable predictions of unknown data, due to its deterministic characteristics, and it works well when used for a small input data group. The SVM model generates more accurate coating thickness estimates than the ANN model.

  2. Thermal Protection Systems Nondestructive Evaluation Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA's need for evaluation of bondline and in-depth integrity for lightweight rigid and/or flexible ablative materials, Physical Optics Corporation (POC)...

  3. Thermal Conductivity Designed Hard Protective Thin Films

    Science.gov (United States)

    2014-05-01

    University of Leoben. After his PhD in 2001 on Materials Science Aspects of Nanocrystalline PVD Hard Coatings in collaboration with the West Bohemian...Vienna University of Technology) Materials Science and Technology Karlsplatz 13 Wien (Vienna) 1040, AUSTRIA EOARD Grant 13-2147 Report Date: May...University of Technology) Materials Science and Technology Karlsplatz 13 Wien (Vienna) 1040, AUSTRIA 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 9

  4. Woven Thermal Protection System (WTPS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Planetary entry and near-Earth object return missions with an anticipated heat flux between 1,500 and 10,000 W/cm2 are currently limited to one viable TPS material...

  5. Optimization study of heat transfer properties for generic shingle ceramic thermal protection system%盖板式陶瓷热防护系统的传热性能优化

    Institute of Scientific and Technical Information of China (English)

    李广德; 张长瑞; 胡海峰; 张玉娣

    2014-01-01

    For the demand of hypersonic aircraft for generic shingle ceramic thermal protection system (TPS),the transient heat transfer model of TPS structure was established and the influences of some factors,such as material properties,thickness,phase change materials and its location, on heat transfer properties were investigated.Results show that:material properties and thickness of heat insulation layer play a key role in heat transfer properties,while these of the heat protection layer almost exist no effect;the introduction of phase change materials obviously improves the heat transfer properties of TPS structure;the location optimization of phase change layer is an effective method to improve the heat transfer properties and reduce the thickness;the thickness optimization of heat insulation layer can provide reference for the TPS design.%针对高超声速飞行器对盖板式陶瓷热防护系统的迫切需求,建立了热防护系统结构瞬态传热模型;并研究了防隔热层的物性参数,厚度尺寸,相变层的种类、位置等因素对热防护系统结构传热性能的影响。结果表明,隔热层物性参数及厚度尺寸对热防护系统结构传热性能具有决定性影响,而防热层的物性参数及厚度尺寸几乎不产生影响。相变材料的引入能够明显改善热防护系统结构的传热性能。调整和优化相变层位置是改善热防护系统结构传热性能、降低结构厚度的一个有效途径。隔热层厚度的优化结果可为热防护系统结构设计提供一定的参考和依据。

  6. 用于燃气锅炉低碳钢耐冲蚀-腐蚀磨损的双层热喷涂层%Thermal Sprayed Dual-layer Coatings for Steel Protection against Corrosion-Erosion at Power Boilers

    Institute of Scientific and Technical Information of China (English)

    王卜谦; 税正荣; 王海斗

    2001-01-01

    为防护发电厂锅炉的热交换器管道的腐蚀冲蚀磨损,研究开发了一种热喷涂双层涂层(高速火焰喷涂Cr3C2/TiC–25NiCr涂层+燃烧电弧喷涂Ni21Cr9Mo35Nb涂层).在锅炉管道上实际应用两年后,对这种双涂层进行冲蚀试验和金相分析,并对其性能进行讨论.结果发现,燃烧电弧喷涂Ni21Cr9Mo3.5Nb涂层在高硫及氯环境中是一种良好的防护涂层.%The heat exchanger tubes of power plant boilers suffer from corrosion-erosion by ash particles and corrosive gases attack at elevated temperatures. The tube wastage rate depends on the boiler design and operation, the characteristics of ash particles, environment conditions, and tube materials. Thermal sprayed dual-layer coatings (HVOF Cr3C2/TiC-25NiCr coating and combustion arc-sprayed Ni21Cr9Mo3.5Nb coating) were developed for the tube corrosion-erosion protection. The erosion test comparison and metallographic examination of the coated tube after two years service in boiler were presented and its performance was discussed. The combustion arc-sprayed Ni21Cr9Mo3.5Nb coating was found a good solution for relatively high sulfur and chlorine environment.

  7. Sun protection

    Science.gov (United States)

    ... surfaces that reflect light, such as water, sand, concrete, snow, and areas that are painted white. DO ... protect the ears or sides of the face. Special clothing that protects the skin by absorbing UV ...

  8. Negotiating Protection

    DEFF Research Database (Denmark)

    Bille, Mikkel

    strategies are entangled in cultural, religious, and national identities. Using ethnographic methods, I investigate protection against selected risks: harm from evil eyes, violation of domestic sanctity, and cultural heritage dilapidation. Protection against these risks is examined through studies...

  9. Sun Protection

    Science.gov (United States)

    ... 100% UV ray protection (look for models that advertise both UVB and UVA protection). Use a broad- ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  10. Low Conductivity Thermal Barrier Coatings

    Science.gov (United States)

    Zhu, Dong-Ming

    2005-01-01

    Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and requirements will be discussed. An experimental approach is established to monitor in real time the thermal conductivity of the coating systems subjected to high-heat-flux, steady-state and cyclic temperature gradients. Advanced low conductivity thermal barrier coatings have also been developed using a multi-component defect clustering approach, and shown to have improved thermal stability. The durability and erosion resistance of low conductivity thermal barrier coatings have been improved utilizing advanced coating architecture design, composition optimization, in conjunction with more sophisticated modeling and design tools.

  11. An innovate method to recycle non-metallic materials from waste printed circuit board.%废线路板非金属物料再生利用新型工艺研究

    Institute of Scientific and Technical Information of China (English)

    段华波; 李金惠; 王斯婷

    2012-01-01

    The reuse of non-metallic material separated from PWBs residues before and after thermo-shocked pretreatment was investigated. With the blending of various additives from silane coupling agents, lubricant agents, anti-oxidizing agents to processing modifier, the non-metallic material could be filled to produce polymeric composite materials subjected to the injection and molding processes. Said method was also appropriate to thermo-shocked non-metallic material. The mechanical property was qualified by compared with the standard limit of related composite materials. The maximum amount of recyclate that could be added to a composite board was 30% of weight, with the additive agents of: silane coupling agents (1%), lubricant agents (1%), anti-oxidizing agents (1%) and processing modifier (5%).%以加热改性处理前后的废线路板非金属物料为对象,对其再生利用工艺进行了研究.通过添加硅烷偶联剂、润滑剂、抗氧化剂和改性剂等助剂改性共混,基于挤出注塑成型工艺过程,可制备废线路板非金属物料填充增强聚丙烯复合板材,该工艺同时可适合一定温度条件下加热改性处理后的非金属物料,其主要力学性能符合相关制品产品质量标准.确定的优化参数为:非金属物料添加质量分数30%,添加助剂包括硅烷偶联剂(1%)、润滑剂(1%)、抗氧化剂(1%)和改性剂(5%).

  12. The Effect of Core Configuration on Thermal Barrier Thermal Performance

    Science.gov (United States)

    DeMange, Jeffrey J.; Bott, Robert H.; Druesedow, Anne S.

    2015-01-01

    Thermal barriers and seals are integral components in the thermal protection systems (TPS) of nearly all aerospace vehicles. They are used to minimize heat transfer through interfaces and gaps and protect underlying temperature-sensitive components. The core insulation has a significant impact on both the thermal and mechanical properties of compliant thermal barriers. Proper selection of an appropriate core configuration to mitigate conductive, convective and radiative heat transfer through the thermal barrier is challenging. Additionally, optimization of the thermal barrier for thermal performance may have counteracting effects on mechanical performance. Experimental evaluations have been conducted to better understand the effect of insulation density on permeability and leakage performance, which can significantly impact the resistance to convective heat transfer. The effect of core density on mechanical performance was also previously investigated and will be reviewed. Simple thermal models were also developed to determine the impact of various core parameters on downstream temperatures. An extended understanding of these factors can improve the ability to design and implement these critical TPS components.

  13. Combined Pressure and Thermal Window System for Space Vehicles

    Science.gov (United States)

    Svartstrom, Kirk Nils (Inventor)

    2017-01-01

    A window system for a vehicle comprising a pressure and thermal window pane, a seal system, and a retainer system. The pressure and thermal window pane may be configured to provide desired pressure protection and desired thermal protection when exposed to an environment around the vehicle during operation of the vehicle. The pressure and thermal window pane may have a desired ductility. The seal system may be configured to contact the pressure and thermal window pane to seal the pressure and thermal window pane. The retainer system may be configured to hold the seal system and the pressure and thermal window pane.

  14. Highly Thermal Conductive Nanocomposites

    Science.gov (United States)

    Sun, Ya-Ping (Inventor); Connell, John W. (Inventor); Veca, Lucia Monica (Inventor)

    2015-01-01

    Disclosed are methods for forming carbon-based fillers as may be utilized in forming highly thermal conductive nanocomposite materials. Formation methods include treatment of an expanded graphite with an alcohol/water mixture followed by further exfoliation of the graphite to form extremely thin carbon nanosheets that are on the order of between about 2 and about 10 nanometers in thickness. Disclosed carbon nanosheets can be functionalized and/or can be incorporated in nanocomposites with extremely high thermal conductivities. Disclosed methods and materials can prove highly valuable in many technological applications including, for instance, in formation of heat management materials for protective clothing and as may be useful in space exploration or in others that require efficient yet light-weight and flexible thermal management solutions.

  15. Computation of ablation of thermal-protection layer in long-time working solid rocket motors%长时间工作固体火箭发动机燃烧室热防护层烧蚀计算

    Institute of Scientific and Technical Information of China (English)

    张斌; 刘宇; 王长辉; 任军学

    2011-01-01

    为了研究长时间工作固体火箭发动机燃烧室的热防护性能,运用三方程烧蚀模型和运动边界显示差分格式,对长时间固体火箭发动机内绝热层烧蚀及温度场进行了耦合计算.计算得到了化学烧蚀率、扩散烧蚀率、燃烧室内壁温度等参数.计算结果表明,所研究的长时间工作发动机燃烧室烧蚀由扩散过程控制.此外,在求解烧蚀子程序时,提出了一种简便有效的赋初值方法.采用文中方法在得到合理计算结果的同时,使得烧蚀计算时间大大缩短.该项研究为长时间工作固体火箭发动机燃烧室热防护层设计提供了有效的分析手段.%In order to study thermal-protection function of long-time working solid rocket motors, insulation ablation and temperature field of long-time working solid rocket motors were coupling calculated by moving boundary explicit-difference method and three equations ablation model. Ablation velocity caused by chemical reaction or diffnsion process and temperature of inner wall were calculated. Numerical results show that the ablation is restricted by the diffusion process. In addition, when solving the ablation subroutine,a convenient and effective method for setting initial value was proposed. Using this new method, the reasonable results were obtained and the calculation time was greatly decreased. This research can offer an effective analytical method for long-time working solid rocket motors.

  16. Gear's method with a BICG variant - solutions, algorithms, applications in temperature calculation in fire protection and thermal insulation; Das Verfahren von Gear mit BICG-Loeser - Grundlagen, Algorithmen und Anwendungen auf Temperaturberechnungen aus dem Brand- und Waermeschutz

    Energy Technology Data Exchange (ETDEWEB)

    Liebau, F. [Technische Univ. Berlin (Germany). Fachbereich 3 - Mathematik; Rudolphi, R. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2001-07-01

    If we apply the multistep method of W. Gear for the integration of a system of ordinary differential equations to the nonlinear heat conduction equation in the implementation EPISODE, this results in memory problems due to the band structure of the Jacobian, because EPISODE uses a LU-decomposition with pivoting. The report describes measures which suit this method to the actual conditions. If we use the storage scheme for sparse matrices from Liebau, Rudolphi, only the nonzero elements of the Jacobian are stored. In case of a linear problem, this matrix only has to be computed once. The BI-CGSTAB-method, an iterative method, replaces the LU-decomposition resp. the solution of the linear (and possibly non-symmetric) system of equations resulting from the corrector step. If {tau} is the time step length and h the space step length, this BICG-variant has good convergence properties for a moderate ratio of {tau}/h{sup 2}. The report also includes a short description of the program INSTATCP developed in Borland Delphi 4/Object Pascal. Two applications from the field of fire protection and thermal insulation in buildings (fire insulated steel column and vertically perforated brick) show that the modifications of the Gear method work effectively. (orig.) [German] Wird das Mehrschnittverfahren von W. Gear zur Integration eines Systems gewoehnlicher Differentialgleichungen in der Implementation EPISODE auf die nichtlineare Waermeleitungsgleichung angewandt, so ergeben sich aufgrund der Bandstruktur der Jacobi-Matrix Speicherplatzprobleme, da EPISODE eine LU-Zerlegung mit Pivot-Wahl benutzt. Der Bericht beschreibt Massnahmen, mit denen das Verfahren an die hier vorliegende Situation angepasst wird. Durch die Verwendung des Speicherschemas fuer Sparse-Matrizen aus Liebau, Rudolphi werden nur die Nichtnullelemente der Jacobi-Matrix gespeichert. Liegt insbesondere ein lineares Problem vor, so braucht diese Matrix nur einmal berechnet zu werden. Das BI-CGSTAB-Verfahren, also

  17. Protecting the skin during thyroidectomy

    Directory of Open Access Journals (Sweden)

    Renan Bezerra Lira

    2014-01-01

    Full Text Available In this note we describe the standard technical maneuver used in our department to protect the skin during thyroidectomy in order to get the best aesthetic result. We use surgical gloves to protect the skin during these operations to reduce the negative impact of thermal trauma and mechanical retractors and energy delivery devices at the edges of the skin incised. This practice is effective, inexpensive, rapid, reproducible and showed no complication in our experience of over 2,500 thyroidectomies.

  18. A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing of Ceramic Composites. Part III; Additive Manufacturing and Characterization of Ceramic Composites

    Science.gov (United States)

    Halbig, Michael C.; Grady, Joseph E.; Singh, Mrityunjay; Ramsey, Jack; Patterson, Clark; Santelle, Tom

    2015-01-01

    This publication is the third part of a three part report of the project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing" funded by NASA Aeronautics Research Institute (NARI). The objective of this project was to conduct additive manufacturing to produce ceramic matrix composite materials and aircraft engine components by the binder jet process. Different SiC powders with median sizes ranging from 9.3 to 53.0 microns were investigated solely and in powder blends in order to maximize powder packing. Various infiltration approaches were investigated to include polycarbosilane (SMP-10), phenolic, and liquid silicon. Single infiltrations of SMP-10 and phenolic only slightly filled in the interior. When the SMP-10 was loaded with sub-micron sized SiC powders, the infiltrant gave a much better result of filling in the interior. Silicon carbide fibers were added to the powder bed to make ceramic matrix composite materials. Microscopy showed that the fibers were well distributed with no preferred orientation on the horizontal plane and fibers in the vertical plane were at angles as much as 45deg. Secondary infiltration steps were necessary to further densify the material. Two to three extra infiltration steps of SMP-10 increased the density by 0.20 to 0.55 g/cc. However, the highest densities achieved were 2.10 to 2.15 g/cc. Mechanical tests consisting of 4 point bend tests were conducted. Samples from the two CMC panels had higher strengths and strains to failure than the samples from the two nonfiber reinforced panels. The highest strengths were from Set N with 65 vol% fiber loading which had an average strength of 66 MPa. Analysis of the fracture surfaces did not reveal pullout of the reinforcing fibers. Blunt fiber failure suggested that there was not composite behavior. The binder jet additive manufacturing method was used to also demonstrate the fabrication of turbine engine vane components of two different designs and sizes. The

  19. Design of Harmonics-Caused Thermal Overload Protection for AC Filter Reactor and Its Application in HVDC Power Transmission Projects%交流滤波器电抗器谐波热过负荷保护设计及其在直流工程中的应用

    Institute of Scientific and Technical Information of China (English)

    张民; 贺仁睦; 李泰; 孙哲

    2013-01-01

    In HVDC power transmission projects the thermal overload of AC filter reactor may occur due to harmonic currents. The harmonics-caused thermal overload protection is the main protection for the reactor to avoid the damage due to thermal overload, so it is necessary for the correct configuraion of related protection parameters to understand the principle of this protection and master its design and implementation. The design and implementation of harmonics-caused thermal overload protection for AC filter reactor are researched in depth, and the skin-effect of harmonic currents, the determination of filter paramters, protection algorithm and setting calculation are analyzed in detail, and according to the designed withstanding ability of AC filter reactor to harmonic currents the correctness of the desing and related paramters are checked by PSCAD/EMTDC simulation. Based on the presented method and according to the skin-effect coefficient provided by reactor manufacturer the parameters of skin-effect filter can be calculated, and according to thermal equivalent current of harmonic currents the setting of the protection can be calculated. The proposed method is available for reference to the configuration of thermal overload protection for AC filter reactor used in HVDC projects.%在直流输电工程中,交流滤波器电抗器在谐波电流的作用下会出现发热或过载现象,电抗器谐波热过负荷保护是避免电抗器因过热导致损坏的主保护,理解并掌握该保护的设计原理及实现过程才能在实际工程中正确配置保护相关参数,详细研究了交流滤波器电抗器热过负荷保护的设计及实现方法,对保护中的集肤效应滤波器参数确定方法、保护算法、定值计算均进行了详细分析,并根据交流滤波器电抗器耐受谐波电流设计能力通过PSCAD/EMTDC仿真计算校核了保护设计及相关参数的正确性,在实际工程中可以按照所述方法根据电抗器生产厂

  20. Rare earth metals influence on morphology of non-metallic inclusions and mechanism of GP240GH and G17CrMo5-5cast steel cracking

    Directory of Open Access Journals (Sweden)

    M. Gajewski

    2009-10-01

    Full Text Available This paper presents results of research carried out in order to specify the influence of the rare earth metals on the morphology of the occuring non-metallic inclusions as well as on the cracking mechanism of GP240GH cast carbon steel and G17CrMo5-5 (0.18%C, 1.2%Cr, 0.53%Mo high temperature cast steel. The tests have been performed on successive industrial melts adding rare earth metals to the ladle during tapping of heat melt from the furnace. It was found that ball-shaped non-metalic inclusions occuring as a result of the rare earth metals influence are heterogenic and they significantly influence the cracking mechanism of Charpy specimens and the impact strength. The morphology of the specimens fracture surface has been substantially changed as a result of the rare earth metals modification. The impact strength of the tested cast carbon steel increased from 100 J/cm2 to ca 155 J/cm2, and the high-temperature cast steel from 30 J/cm2 to ca 100 J/cm2.