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Sample records for high-temperature filtering elements

  1. Assessment of high-temperature filtering elements

    Energy Technology Data Exchange (ETDEWEB)

    Monica Lupion; Francisco J. Gutierrez Ortiz; Benito Navarrete; Vicente J. Cortes [University of Seville, Seville (Spain). E.T.S. Ingenieros

    2008-07-01

    A complete experimental campaign has been carried out in a hot gas filtration test facility so as to test several filtering elements and configurations, particularly, three different types of bag filters and one ceramic candle. The facility was designed to operate under a wide range of conditions, thus providing an excellent tool for the investigation of hot gas filtration applications for the advanced electrical power generation industry such as IGCC, PFBC or fuel cell technologies. Relevant parameters for the characterization and optimization of the performance of the filters have been studied for a variety of operation conditions such as filtration velocity, particle concentration, pressure and temperature among others. Pressure drop across the filter, cleaning pulse interval, baseline pressure drop, filtration efficiency and durability of the filter have been investigated for each type considered and dependences on parameters have been established. On top of that, optimal operating conditions and cleaning strategies were determined. The tests results show that bag filters are a suitable alternative for the hot gas filtration due to the better performance and the high efficiency observed, which makes them suitable for industrial applications operating under high temperature high pressure conditions considered within the study (200-370{degree}C and 4-7.5 barg respectively). 7 refs., 7 figs., 10 tabs.

  2. Assessment performance of high-temperature filtering elements

    Energy Technology Data Exchange (ETDEWEB)

    Monica Lupion; Francisco J. Gutierrez Ortiz; Benito Navarrete; Vicente J. Cortes [University of Seville, Seville (Spain). E.T.S. Ingenieros

    2010-04-15

    An extensive experimental campaign has been carried out in a hot gas filtration test facility so as to test several filtering elements and configurations, particularly, three different types of bag filters and one ceramic candle. The facility was designed to operate under a wide range of conditions, thus providing an excellent tool for the investigation of hot gas filtration applications for the advanced electrical power generation industry such as IGCC, PFBC or fuel cell technologies. Relevant parameters for the characterisation and optimization of the performance of the filters have been studied for a variety of operating conditions such as filtration velocity, particle concentration, pressure and temperature among others. Pressure drop across the filter, cleaning pulse interval, baseline pressure drop, filtration efficiency and durability of the filter have been investigated for each type considered and dependences on parameters have been established. On top of that, optimal operating conditions and cleaning strategies were determined. The tests results show that bag filters are a suitable alternative for the hot gas filtration due to the better performance and the high efficiency observed, which makes them suitable for industrial applications operating under high temperature high pressure conditions considered within the study (200-370{sup o}C and 4-7.5 barg, respectively). 8 refs., 7 figs., 10 tabs.

  3. Filter unit for use at high temperatures

    Science.gov (United States)

    Ciliberti, David F.; Lippert, Thomas E.

    1988-01-01

    A filtering unit for filtering particulates from high temperature gases uses a spiral ceramic spring to bias a ceramic, tubular filter element into sealing contact with a flange about an aperture of a metallic tube sheet. The ceramic spiral spring may contact the upper edge of the filter element and be restrained by a stop member spaced from one end of the tube sheet, or the spring may contact the bottom of the filter element and be restrained by a support member spaced from the opposite end of the tube sheet. The stop member and support member are adjustably secured to the tube sheet. A filtering system uses the ceramic spiral spring to bias a plurality of ceramic, tubular filter elements in a respective plurality of apertures in a tube sheet which divides a vessel into upper and lower enclosed sections.

  4. Planar high temperature superconductor filters with backside coupling

    Science.gov (United States)

    Shen, Zhi-Yuan (Inventor)

    1998-01-01

    An improved high temperature superconducting planar filter wherein the coupling circuit or connecting network is located, in whole or in part, on the side of the substrate opposite the resonators and enables higher power handling capability.

  5. Fiber Bragg Grating Filter High Temperature Sensors

    Science.gov (United States)

    Lyons, Donald R.; Brass, Eric D.; Pencil, Eric (Technical Monitor)

    2001-01-01

    We present a scaled-down method for determining high temperatures using fiber-based Bragg gratings. Bragg gratings are distributed along the length of the optical fiber, and have high reflectivities whenever the optical wavelength is twice the grating spacing. These spatially distinct Bragg regions (located in the core of a fiber) are sensitive to local temperature changes. Since these fibers are silica-based they are easily affected by localized changes in temperature, which results in changes to both the grating spacing and the wavelength reflectivity. We exploit the shift in wavelength reflectivity to measure the change in the local temperature. Note that the Bragg region (sensing area) is some distance away from where the temperature is being measured. This is done so that we can measure temperatures that are much higher than the damage threshold of the fiber. We do this by affixing the fiber with the Bragg sensor to a material with a well-known coefficient of thermal expansion, and model the heat gradient from the region of interest to the actual sensor. The research described in this paper will culminate in a working device as well as be the second portion of a publication pending submission to Optics Letters.

  6. Progress on applications of high temperature superconducting microwave filters

    Science.gov (United States)

    Chunguang, Li; Xu, Wang; Jia, Wang; Liang, Sun; Yusheng, He

    2017-07-01

    In the past two decades, various kinds of high performance high temperature superconducting (HTS) filters have been constructed and the HTS filters and their front-end subsystems have been successfully applied in many fields. The HTS filters with small insertion loss, narrow bandwidth, flat in-band group delay, deep out-of-band rejection, and steep skirt slope are reviewed. Novel HTS filter design technologies, including those in high power handling filters, multiband filters and frequency tunable filters, are reviewed, as well as the all-HTS integrated front-end receivers. The successful applications to various civilian fields, such as mobile communication, radar, deep space detection, and satellite technology, are also reviewed.

  7. Evaluation of fundamental properties of filter materials at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Y.; Hiramatsu, K.; Kawamoto, H. [Japan Fine Ceramics Center, Nagoya (Japan); Araki, T. [Chubu Electric Power Co., Inc., Hekinan (Japan); Yamada, M.; Iida, J. [Center For Coal Utilization Japan, Tokyo (Japan)

    1999-07-01

    In developing a dust collecting technology for high-temperature coal combustion gases for use in a next-generation system of efficient power generation, it is important to raise reliability by ascertaining the relevant physical properties and behaviors of the dust collecting filters. Accordingly, the aim of this research is to clarify the mechanical and thermal properties, and the high-temperature corrosion behaviors (oxidization, reduction), which figure among the fundamental factors restricting reliability in filter materials. In addition, since the ultimate research aim is the selection and development of filters which can be used in the actual dust collecting systems PFBC (950 C in an oxidization atmosphere) and IGCC (700 C in a reduction atmosphere), it is also necessary to conduct tests on the fundamental properties of existing filters, and to classify them for their suitability with given service atmospheres. Finally, for one particular filter selected as suitable for an oxidation atmosphere of 950 C, observations are made of mechanical properties and micro-structural changes before and after an actual dust collecting trial, and cause of damage are investigated. (orig.)

  8. A compact high temperature superconducting bandpass filter for integration with a Josephson mixer

    Science.gov (United States)

    Bai, D. D.; Du, J.; Zhang, T.; He, Y. S.

    2013-10-01

    A compact eight-pole high temperature superconducting (HTS) filter is designed for the RF signal input of an HTS Josephson mixer. The filter has 18.2% fractional bandwidth centered at 11 GHz. A stepped-impedance hairpin resonator is employed to minimize the filter size. The obtained filter size is 10 mm × 2.79 mm, which is very compact. The monolithic HTS Josephson frequency down-converter that incorporated this new filter demonstrated the highest conversion efficiency to date for an HTS Josephson mixer. Both the filter and the on-chip HTS circuit module were fabricated on a 0.5 mm thick MgO wafer with a single-sided YBCO film. The design, simulation, and experimental characterization of the HTS filter are presented in this paper. The early measurement results of the integrated HTS down-converter incorporated this filter are also described.

  9. High-temperature Fabry-Perot-based strain sensor for ceramic barrier filters

    Science.gov (United States)

    Weinstein, Shmuel J.; Vuppala, Veerendra B.; Gunther, Michael F.; Wang, Anbo; Murphy, Kent A.; Claus, Richard O.

    1994-02-01

    We report results from a program to develop fiber-optic sensor-based instrumentation methods to allow the in-situ analysis of ceramic barrier filters. The sensor used was an extrinsic Fabry-Perot cavity created between the ends of two longitudinally aligned fibers. Filters instrumented with these fiber sensors were tested in a combustor simulator at the Westinghouse Science and Technology Center. These tests were performed using silica optical fibers capable of withstanding the high temperature and harsh chemical environment of the combustor. The single-ended approach of the reflective Fabry-Perot sensors is well suited for high thermal strain measurements. The results from several tests are presented.

  10. Characteristics and utilisation of high-temperature (HTHP) filter dusts from pfb gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Ranta, J. [VTT Energy, Espoo (Finland)

    1996-12-31

    The aim of the study was to survey characteristics, utilisation and possible environmental impacts of solid wastes, i.e., in case of biomass, mainly high-temperature filter ash (HTHP) from pressurised fluidised-bed gasification (PFBG). The aim is to utilise solid wastes (slag, filter dust, additives) from biomass gasification instead of dumping. One alternative is recycling to the soil as liming material or fertiliser. It is expected that the ash recycled to forest soils changes the environment less than non-recycled ash. (orig.) 3 refs.

  11. High-temperature high-pressure gas cleanup with ceramic bag filters. Draft final report

    Energy Technology Data Exchange (ETDEWEB)

    Shackleton, M.; Chang, R.; Sawyer, J.; Kuby, W.; Turner-Tamiyasu, E.

    1982-12-06

    Advanced processes designed for the efficient use of coal in the production of energy will benefit from, or even depend upon, highly efficient, economical, high-temperature removal systems for fine particulates. In the case of pressurized fluidized-bed combustion (PFBC), the hot gas cleanup device must operate at approximately 1600/sup 0/F. Existing commercial filter systems are temperature limited due to the filter material, but ceramic fibers intended for refractory insulation offer the promise of a practical high-temperature filter media if they can be incorporated into a design which combines filter performance with acceptable durability. The current work was initiated to further develop and demonstrate on a larger-scale basis, a ceramic fiber filtration system for application to coal-fired PFBC's. The development effort centered around the need to replace the knit metal wire scrim, used in earlier designs as support for the fine fiber ceramic mat filtration medium, with a corrosion-resistant material. This led to the selection of woven ceramic cloth for support of the mat layer. Because of the substantial difference in strength and other material properties between the metal and ceramic cloth, tests were necessary to optimize the filter; pulse parameters such as pulse duration, pulse pressure, and pulse injection orifice size; woven cloth mesh configuration; the technique for clamping the bag to the support; and similar structural, fluid, and control parameters. The demonstration effort included both tests to prove this concept in a real application and a systems analysis to show commercial feasibility of the ceramic filtration approach for hot gas cleanup in PFBC's. 12 references, 57 figures, 23 tables.

  12. Filter-based Aerosol Measurement Experiments using Spherical Aerosol Particles under High Temperature and High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Chan; Jung, Woo Young; Lee, Hyun Chul; Lee, Doo Young [FNC TECH., Yongin (Korea, Republic of)

    2016-05-15

    Optical Particle Counter (OPC) is used to provide real-time measurement of aerosol concentration and size distribution. Glass fiber membrane filter also be used to measure average mass concentration. Three tests (MTA-1, 2 and 3) have been conducted to study thermal-hydraulic effect, a filtering tendency at given SiO{sub 2} particles. Based on the experimental results, the experiment will be carried out further with a main carrier gas of steam and different aerosol size. The test results will provide representative behavior of the aerosols under various conditions. The aim of the tests, MTA 1, 2 and 3, are to be able to 1) establish the test manuals for aerosol generation, mixing, sampling and measurement system, which defines aerosol preparation, calibration, operating and evaluation method under high pressure and high temperature 2) develop commercial aerosol test modules applicable to the thermal power plant, environmental industry, automobile exhaust gas, chemical plant, HVAC system including nuclear power plant. Based on the test results, sampled aerosol particles in the filter indicate that important parameters affecting aerosol behavior aerosols are 1) system temperature to keep above a evaporation temperature of ethanol and 2) aerosol losses due to the settling by ethanol liquid droplet.

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

    Energy Technology Data Exchange (ETDEWEB)

    Crossland, C.E.; Shelleman, D.L.; Spear, K.E. [Pennsylvania State Univ., University Park, PA (United States)] [and others

    1996-08-01

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

  14. Trace elements in migrating high-temperature fluids: Effects of diffusive exchange with the adjoining solid

    Science.gov (United States)

    Kenyon, Patricia M.

    1993-01-01

    Trace element concentrations and isotopic ratios are frequently used to study the behavior of high-temperature fluids in both metamorphic and igneous systems. Many theoretical formulations of the effects of fluid migration on trace elements have assumed instantaneous reequilibration between the migrating fluid and the solid material through which it is passing. This paper investigates the additional effects which arise when equilibration is not instantaneous due to a limited rate of diffusion in the solid, using an analytical steady state solution to a set of partial differential equations describing the exchange of trace elements between the fluid and the solid during the migration of the fluid.

  15. High temperature corrosion of advanced ceramic materials for hot gas filters. Topical report for part 1 of high temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Spear, K.E.; Crossland, C.E.; Shelleman, D.L.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

    1997-12-11

    This program consists of two separate research areas. Part 1, for which this report is written, studied the high temperature corrosion of advanced ceramic hot gas filters, while Part 2 studied the long-term durability of ceramic heat exchangers to coal combustion environments. The objectives of Part 1 were to select two candidate ceramic filter materials for flow-through hot corrosion studies and subsequent corrosion and mechanical properties characterization. In addition, a thermodynamic database was developed so that thermochemical modeling studies could be performed to simulate operating conditions of laboratory reactors and existing coal combustion power plants, and to predict the reactions of new filter materials with coal combustion environments. The latter would make it possible to gain insight into problems that could develop during actual operation of filters in coal combustion power plants so that potential problems could be addressed before they arise.

  16. Characterization of high-current, high-temperature superconductor current lead elements

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, R.C.; Evans, D.J.; Fisher, B.L. [Argonne National Lab., IL (United States); Brockenborough, W.E.; Roberts, P.R.; Rodenbush, A.J. [American Superconductor Corp., Westborough, MA (United States)

    1996-08-01

    The refrigeration loads of current leads for superconducting magnets can be significantly reduced by using high-temperature superconductor (HTS) leads. An HTS conductor type that is well suited for this application is a laminated sintered stack of HTS powder-in-tube (PIT) tapes. The superconducting elements are normally characterized by their manufacturer by measuring critical currents at 77 K in self field. Additional characterization, which correlates electrical performance at 77 K and at lower temperatures with applied magnetic fields, provides the current lead designer and conductor element manufacturer with critical information. For HTS conductor elements comprising a laminated and sintered stack of Bi-2223 PIT tapes having an alloyed Ag sheath, this characterization uses variable applied fields and operating temperatures.

  17. High-temperature superconducting fault-current limiter - optimisation of superconducting elements

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This report summarises the findings of a study initiated to continue the work of a DTI-LINK Collaborative Research Programme 'Enhancing the Properties of Bulk High Temperature Superconductors and their Potential Application as Fault Current Limiters (FCL). Details are given of computer modelling of the quenching process involving the transition from superconducting to normal conducting states undergone by the material when large currents are present. The design of compound elements, and a multi-element model are described along with FCL design covering distribution bus-coupler, embedded generator connection, larger generator connection, hazardous area safety, and interconnection to fault-prone network. The evaluation of thermal loss, test equipment and schedule, the optimised element, installed cost data, and the UK market are considered.

  18. Microwave plasma monitoring system for the elemental composition analysis of high temperature process streams

    Science.gov (United States)

    Woskov, Paul P.; Cohn, Daniel R.; Titus, Charles H.; Surma, Jeffrey E.

    1997-01-01

    Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, high temperature capability refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. The invention may be incorporated into a high temperature process device and implemented in situ for example, such as with a DC graphite electrode plasma arc furnace. The invention further provides a system for the elemental analysis of process streams by removing particulate and/or droplet samples therefrom and entraining such samples in the gas flow which passes through the plasma flame. Introduction of and entraining samples in the gas flow may be facilitated by a suction pump, regulating gas flow, gravity or combinations thereof.

  19. Characterizing high-temperature deformation of internally heated nuclear fuel element simulators

    Energy Technology Data Exchange (ETDEWEB)

    Belov, A.I.; Fong, R.W.L.; Leitch, B.W.; Nitheanandan, T.; Williams, A., E-mail: alexander.belov@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    The sag behaviour of a simulated nuclear fuel element during high-temperature transients has been investigated in an experiment utilizing an internal indirect heating method. The major motivation of the experiment was to improve understanding of the dominant mechanisms underlying the element thermo-mechanical response under loss-of-coolant accident conditions and to obtain accurate experimental data to support development of 3-D computational fuel element models. The experiment was conducted using an electrically heated CANDU fuel element simulator. Three consecutive thermal cycles with peak temperatures up to ≈1000 {sup o}C were applied to the element. The element sag deflections and sheath temperatures were measured. On heating up to 600 {sup o}C, only minor lateral deflections of the element were observed. Further heating to above 700 {sup o}C resulted in an element multi-rate creep and significant permanent bow. Post-test visual and X-ray examinations revealed a pronounced necking of the sheath at the pellet-to-pellet interface locations. A wall thickness reduction was detected in the necked region that is interpreted as a sheath longitudinal strain localization effect. The sheath cross-sectioning showed signs of a 'hard' pellet-cladding interaction due to the applied cycles. A 3-D model of the experiment was generated using the ANSYS finite element code. As a fully coupled thermal mechanical simulation is computationally expensive, it was deemed sufficient to use the measured sheath temperatures as a boundary condition, and thus an uncoupled mechanical simulation only was conducted. The ANSYS simulation results match the experiment sag observations well up to the point at which the fuel element started cooling down. (author)

  20. High-temperature ceramic heat exchanger element for a solar thermal receiver

    Science.gov (United States)

    Strumpf, H. J.; Kotchick, D. M.; Coombs, M. G.

    1982-01-01

    A study has been completed on the development of a high-temperature ceramic heat exchanger element to be integrated into a solar reciver producing heated air. A number of conceptual designs were developed for heat exchanger elements of differing configuration. These were evaluated with respect to thermal performance, pressure drop, structural integrity, and fabricability. The final design selection identified a finned ceramic shell as the most favorable concept. The ceramic shell is surrounded by a larger metallic shell. The flanges of the two shells are sealed to provide a leak-tight pressure vessel. The ceramic shell is fabricated by an innovative combination of slip casting the receiver walls and precision casting the heat transfer finned plates. The fins are bonded to the shell during firing. Fabrication of a one-half scale demonstrator ceramic receiver has been completed.

  1. Gamma spectroscopy for analysis of high temperature reactor fuel element KueFA tests

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, O.; Laurie, M.; Bottomley, P.D.W.; Rondinella, V.V. [European Commission - Joint Research Centre, Eggenstein-Leopoldshafen (Germany). Institute for Transuranium Elements (JRC-ITU); Allelein, H.J. [RWTH Aachen Univ. (Germany). Lehrstuhl fuer Reaktorsicherheit und -technik

    2013-07-01

    The High Temperature Reactor (HTR) is characterized by an advanced design with passive safety features. Fuel elements are constituted by a graphite matrix containing sub-mm-sized fuel particles with TRISO (TRi-ISOtropic) coating designed to provide high fission product retention. During a loss of coolant accident scenario in a HTR the maximum temperature is foreseen to be in the range of 1600-1650 C, remaining well below the melting point of the fuel. An experimental assessment of the fuel behaviour under accident conditions is necessary to investigate the quality of fission product retention of TRISO coated particles in a given fuel element and to validate relevant computer codes. The device used to perform these studies is the cold finger apparatus KueFA (KuehlFinger-Apparatur). (orig.)

  2. Young modulus variation of a brickwork masonry element submitted to high temperatures

    Directory of Open Access Journals (Sweden)

    Maciá, M. E.

    2013-03-01

    Full Text Available In order to understand the thermal behavior of the masonry elements submitted to high temperatures we need to know the variation of their thermal properties with regard to the temperature. Submitted to high temperatures clay brick masonry presents thermomechanical effects (as the variation of Young's modulus, the thermal expansion of the unit and the mortar, spalling, losses of resistance … as well as variation of the properties of the material as result of its degradation. In this article the variation of the module of elasticity of the unit and the mortar is described with regard to high temperatures according to the state of the knowledge. In this article is also exposed the results obtained from the experimental program carried out on elements of clay brick masonry submitted to high temperatures in order to observe the variation of Young's module related to temperature.

    La definición del comportamiento térmico de los elementos de fábrica sometidos a la acción del fuego requiere del conocimiento de la variación de sus propiedades termomecánicas con respecto a la temperatura. Ante las altas temperaturas la fábrica cerámica presenta efectos termomecánicos, como la variación del módulo de Young entre otros, así como la variación de las propiedades del material debidas a la degradación del mismo. En este artículo se describe la variación del módulo de elasticidad de la pieza y el mortero con respecto a altas temperaturas según el estado del conocimiento y se exponen los resultados obtenidos del programa experimental llevado a cabo sobre elementos de fábrica sometidos a altas temperaturas con el fin de observar la variación del módulo de Young con respecto a la temperatura.

  3. Experimental analysis of temperature profiles in ceramic brickwork elements subjected to high temperatures

    Directory of Open Access Journals (Sweden)

    Maciá, M. E.

    2013-12-01

    Full Text Available This article discusses heat transfer through a brick element in order to know the thermal behavior of onedimensional brickwork masonry samples exposed to high temperatures. The object of the tests is to build time-temperature curves according to different thermal steps in transient to experimentally determine the temperature profiles in the interior of a wall. Through this study, it is possible to demonstrate absolute moisture of a factory item from 300 °C (variation of temperatures in the interior of the element, avoid the associated phenomenon of evaporation of water during the thermal process as well as to obtain profiles of temperatures that help calculate the cross section of a factory element subjected to high temperatures.En este artículo se analiza la transferencia de calor a través de un elemento de fábrica de ladrillo con el fin de conocer el comportamiento térmico de secciones de fábrica unidimensionales expuestas a altas temperaturas. El objeto de los ensayos es construir curvas tiempo-temperatura en función de diversos escalones térmicos en régimen transitorio para determinar experimentalmente los perfiles de temperatura en el interior de un muro. A través de este estudio es posible evidenciar el contenido de humedad absoluta de un elemento de fábrica a partir de los 300 ºC (variación de las temperaturas en el interior del elemento, evitar el fenómeno asociado de la evaporación del agua durante el proceso térmico así como obtener perfiles de temperaturas que ayuden a calcular la sección eficaz de un elemento de fábrica sometido a altas temperaturas.

  4. Structure and Properties of Meltblown Polyetherimide as High Temperature Filter Media

    OpenAIRE

    Gajanan Bhat; Vincent Kandagor; Daniel Prather; Ramesh Bhave

    2017-01-01

    Polyetherimide (PEI), an engineering plastic with very high glass transition temperature and excellent chemical and thermal stability, has been processed into a controlled porosity filter media of varying pore size, performance, and surface characteristics. A special grade of the PEI was processed by melt blowing to produce microfiber nonwovens suitable as filter media. The resulting microfiber webs were characterized to evaluate their structure and properties. The fiber webs were further mod...

  5. Porous nuclear fuel element for high-temperature gas-cooled nuclear reactors

    Science.gov (United States)

    Youchison, Dennis L [Albuquerque, NM; Williams, Brian E [Pacoima, CA; Benander, Robert E [Pacoima, CA

    2011-03-01

    Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

  6. Porous nuclear fuel element with internal skeleton for high-temperature gas-cooled nuclear reactors

    Science.gov (United States)

    Youchison, Dennis L.; Williams, Brian E.; Benander, Robert E.

    2013-09-03

    Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

  7. A high temperature ceramic heat exchanger element for a solar thermal receiver

    Science.gov (United States)

    Strumpf, H. J.; Kotchick, D. M.; Coombs, M. G.

    1982-01-01

    The development of a high-temperature ceramic heat exchanger element to be integrated into a solar receiver producing heated air was studied. A number of conceptual designs were developed for heat exchanger elements of differing configuration. These were evaluated with respect to thermal performance, pressure drop, structural integrity, and fabricability. The final design selection identified a finned ceramic shell as the most favorable concept. The shell is surrounded by a larger metallic shell. The flanges of the two shells are sealed to provide a leak-tight pressure vessel. The ceramic shell is to be fabricated by a innovative combination of slip casting the receiver walls and precision casting the heat transfer finned plates. The fins are bonded to the shell during firing. The unit is sized to produce 2150 F air at 2.7 atm pressure, with a pressure drop of about 2 percent of the inlet pressure. This size is compatible with a solar collector providing a receiver input of 85 kw(th). Fabrication of a one-half scale demonstrator ceramic receiver was completed.

  8. The separation efficiency of ceramic barrier filters determined at high temperatures by optical particle size and concentration measurement

    Energy Technology Data Exchange (ETDEWEB)

    Hemmer, G.; Umhauer, H.; Kasper, G. [Univ. Karlsruhe, Inst. fuer Mechanische Verfahrenstechnik und Mechanik, Karlsruhe (Germany); Berbner, S. [Freudenberg Nonwovens, Filtration Div., Hopkinsville, KY (United States)

    1999-07-01

    Based on the experiences of earlier investigations a special optical particle counter was developed capable of recording size and quantity (concentration) of the particles directly within a given gas particle stream under the prevailing conditions (true in-situ measurements at high temperatures). In addition to earlier investigations [1], a second type of ceramic filter media with much smaller porosity and a membrane layer on the filtration side was tested. The candles with a length of 1.5 m which are used in industrial applications were mounted in the same hot gas filtration unit already used before. Measurements on the clean gas side at temperatures of up to 1000 C have been conducted using a fraction of quartz particles as test dust. The particle size ranged between 0.3 {mu}m and 10 {mu}m. Filtration velocity (1.5 cm/s) and final pressure drop of dust cake {delta}p (1000 Pa) were kept constant. As a main result the fractional efficiency as function of temperature is discussed and compared with that obtained before for a filter media of type I: The fractional efficiency values of filter type II are at least 100 times higher than that of filter type I. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Kupp, E.R.; Trubelja, M.F.; Spear, K.E.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States)

    1995-08-01

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

  10. Preparation and properties of hexagonal boron nitride fibers used as high temperature membrane filter

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xinmei, E-mail: houxinmei@ustb.edu.cn; Yu, Ziyou; Li, Yang; Chou, Kuo-Chih

    2014-01-01

    Graphical abstract: - Highlights: • h-BN fibers were successfully fabricated using H{sub 3}BO{sub 3} and C{sub 3}H{sub 6}N{sub 6} as raw materials. • The obtained BN fibers were polycrystalline and uniform in morphology. • It exhibited good oxidation resistance and low thermal expansion coefficient. - Abstract: Hexagonal boron nitride fibers were synthesized via polymeric precursor method using boric acid (H{sub 3}BO{sub 3}) and melamine (C{sub 3}H{sub 6}N{sub 6}) as raw materials. The precursor fibers were synthesized by water bath and BN fibers were prepared from the precursor at 1873 K for 3 h in flowing nitrogen atmosphere. The crystalline phase and microstructures of BN fibers were examined by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and high resolution electron microscopy. The results showed that h-BN fibers with uniform morphology were successfully fabricated. The well-synthesized BN fibers were polycrystalline with 0.4–1.5 μm in diameter and 200–500 μm in length. The as-prepared samples exhibited good oxidation resistance and low thermal expansion coefficient at high temperature.

  11. A six-pole narrow-band high temperature superconducting filter with wide stop-band response at P-band

    Science.gov (United States)

    Gong, Liming; Wei, Bin; Zhang, Ying; Zhang, Xiaoping; Guo, Xubo; Zhang, Guoyong; Cao, Bisong

    2013-10-01

    A quarter-wavelength stepped impedance resonator (QWSIR) is proposed for high temperature superconducting (HTS) filter, offering wide stop-band performance. A six-pole P-band HTS filter with QWSIRs was designed and fabricated. The filter has a fractional bandwidth of 0.8% at 516 MHz and shows the lowest spurious frequency at about 2.15 GHz. The measured results of the HTS filter are in good agreement with simulations.

  12. A Dielectric-Filled Waveguide Antenna Element for 3D Imaging Radar in High Temperature and Excessive Dust Conditions

    Directory of Open Access Journals (Sweden)

    Ding Xu

    2016-08-01

    Full Text Available Three-dimensional information of the burden surface in high temperature and excessive dust industrial conditions has been previously hard to obtain. This paper presents a novel microstrip-fed dielectric-filled waveguide antenna element which is resistant to dust and high temperatures. A novel microstrip-to-dielectric-loaded waveguide transition was developed. A cylinder and cuboid composite structure was employed at the terminal of the antenna element, which improved the return loss performance and reduced the size. The proposed antenna element was easily integrated into a T-shape multiple-input multiple-output (MIMO imaging radar system and tested in both the laboratory environment and real blast furnace environment. The measurement results show that the proposed antenna element works very well in industrial 3D imaging radar.

  13. On-Line Hydrogen-Isotope Measurements of Organic Samples Using Elemental Chromium : An Extension for High Temperature Elemental-Analyzer Techniques

    NARCIS (Netherlands)

    Gehre, Matthias; Renpenning, Julian; Gilevska, Tetyana; Qi, Haiping; Coplen, Tyler B.; Meijer, Harro A. J.; Brand, Willi A.; Schimmelmann, Arndt

    2015-01-01

    The high temperature conversion (HTC) technique using an elemental analyzer with a glassy carbon tube and filling (temperature conversion/elemental analysis, TC/EA) is a widely used method for hydrogen isotopic analysis of water and many solid and liquid organic samples with analysis by

  14. An evaluation of mechanical and high-temperature corrosion properties of Ni-Cr alloy with composition of alloying elements

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sujin; Kim, Dongjin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Helium is used as a coolant in a VHTR owing to its high thermal conductivity, inertness, and low neutron absorption. However, helium inevitably includes impurities that create an imbalance in the surface reactivity at the interface of the coolant and the exposed materials. As the Alloy 617 has been exposed to high temperatures at 950 .deg. C in the impure helium environment of a VHTR, degradation of material is accelerated and mechanical properties decreased. An alloy superior to alloy 617 should be developed. In this study, the mechanical and high-temperature corrosion properties for Ni-Cr alloys fabricated in laboratory were evaluated as a function of the grain boundary strengthening and alloying element composition. The mechanical property and corrosion property for Ni-Cr alloys fabricated in a laboratory were evaluated as a function of the main element composition. The ductility was increased and decreased by increasing the amount of Mo and Cr, respectively. Surface oxide was detached during the corrosion test, because there was not aluminum element in the alloy. Aluminum seems to act as an anti-corrosive role in Ni-based alloy. In conclusion, the addition of Al into the alloy is required to improvement of high temperature corrosion resistance.

  15. Release of inorganic trace elements from high-temperature gasification of coal

    Energy Technology Data Exchange (ETDEWEB)

    Blaesing, Marc

    2012-05-30

    The development of cleaner, more efficient techniques in next-generation coal power plants is becoming increasingly important, especially regarding to the discussion of the influence of CO{sub 2} emissions on global warming. A promising coal utilisation process is the integrated gasification combined cycle process. The direct use of the raw gas requires gas clean-up to prevent downstream parts of the gasifier from several problems. An increased efficiency and a decreased amount of harmful species can be achieved through hot fuel gas cleaning. This clean-up technique requires a comprehensive knowledge of the release characteristics of inorganic coal constituents. The aim of this thesis was to provide enhanced knowledge of the effect of key process parameters and of the chemical constitution of coal on the release of Na, K, S, and Cl species from high-temperature coal gasification. The experimental setup consisted of atmospheric flow tube furnaces and a pressurised furnace. In-situ analysis of the product gas was carried out using molecular beam mass spectrometry. A broad spectrum of different coals with assumed qualitative and quantitative differences in the release characteristics was investigated. Additionally, experiments with model substances were performed. The results of the experimental investigation were compared with thermodynamic calculations. Finally, recommendations, for the operation of a high-temperature gasifier are formulated. (orig.)

  16. Active pixel sensors with substantially planarized color filtering elements

    Science.gov (United States)

    Fossum, Eric R. (Inventor); Kemeny, Sabrina E. (Inventor)

    1999-01-01

    A semiconductor imaging system preferably having an active pixel sensor array compatible with a CMOS fabrication process. Color-filtering elements such as polymer filters and wavelength-converting phosphors can be integrated with the image sensor.

  17. Finite Element Study of Container Structure under Normal and High Temperature

    National Research Council Canada - National Science Library

    Zha, Xiaoxiong; Zuo, Yang

    2016-01-01

    ...) are obtained and compared with the standard temperature curve of ISO-834. Secondly, using the software of Abaqus, a full scale finite element model of multilayer container structure is established...

  18. High temperature electron beam ion source for the production of single charge ions of most elements of the Periodic Table

    CERN Document Server

    Panteleev, V N; Barzakh, A E; Fedorov, D V; Ivanov, V S; Moroz, F V; Orlov, S Y; Seliverstov, D M; Stroe, L; Tecchio, L B; Volkov, Y M

    2003-01-01

    A new type of a high temperature electron beam ion source (HTEBIS) with a working temperature up to 2500 deg. C was developed for production of single charge ions of practically all elements. Off-line tests and on-line experiments making use of the developed ion source coupled with uranium carbide targets of different density, have been carried out. The ionization efficiency measured for stable atoms of many elements varied in the interval of 1-6%. Using the HTEBIS, the yields and on-line production efficiency of neutron rich isotopes of Mn, Fe, Co, Cu, Rh, Pd, Ag, Cd, In, Sn and isotopes of heavy elements Pb, Bi, Po and some others have been determined. The revealed confinement effect of the ions produced in the narrow electron beam inside a hot ion source cavity has been discussed.

  19. Finite element calculation of magnetic bearings with high-temperature superconductors; Finite-Element-Berechnung von Magnetlagern mit Hochtemperatursupraleiter-Volumenkoerpern

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, A.O.

    1996-10-01

    Superconducting magnetic bearings take use of the diamagnetic properties of high-temperature superconductors to obtain a contactless and, therefore, frictionless and wearless bearing. These kinds of bearings are selfstable and can be used in flywheel energy storage systems. The calculation of the main parameters of such bearings - the maximum levitation force, the vertical and the horizontal stiffness - is essentiell for their construction and optimization. Therefore, the first goal of this work is to develop a common available calculation tool which allows both, the calculation of the magnetic forces in superconducting magnetic bearings, as well as the optimization of the bearing parameters. Solving this problem, the electromagnetic field distribution inside of the high-temperature superconductor and in the surrounding air is of main interest. Further, nonlinearities in the superconductor have to be taken into consideration. Therefore, the finite element method is used. To take into consideration the macroscopic electromagnetic behaviour of high-temperature superconductors, it is necessary to develop a new finite element. Using this new element, the calculation and optimization of flywheel energy storage systems which include superconducting magnetic bearings become possible. On the same time, the new element allows to use all the tools of a commercial FE-program. The formulation of the element as well as the integrated models for the macroscopic description of the electromagnetic phenomena in high-temperature superconductors are verified by comparing experimental results with calculated ones. Special procedures for the simulation of motion for the bearing rotor - for both, vertical and horizontal movement - has been developed.

  20. Fourcross shaped metamaterial filters fabricated from high temperature superconducting YBCO and Au thin films for terahertz waves

    Science.gov (United States)

    Demirhan, Y.; Alaboz, H.; Nebioğlu, M. A.; Mulla, B.; Akkaya, M.; Altan, H.; Sabah, C.; Ozyuzer, L.

    2017-07-01

    In this study, we present a new, unique fourcross shaped metamaterial terahertz (THz) filter fabricated from both gold thin films and YBa2Cu3O7-d high T c superconducting thin films. A commercial electromagnetic simulation software, CST Microwave Studio, is used to design and optimize the metamaterial filter structures. The proposed fourcross shaped rectangular filter structure consists of periodic metallic rings where strip lines are located at the sides of the ring. Fourcross metamaterial filters are fabricated by using e-beam lithography and ion beam etching techniques. Terahertz time-domain spectroscopy measurements validated the design predictions for both the center frequencies and bandwidths of the resonances due to the fourcross structures. The resonance switching of the transmission spectra was investigated by lowering the temperature below the critical transition temperature. This resonance switching effect is not observed in filters made up of metals. This novel fourcross rectangular resonator with a temperature-dependent resonance behavior holds great potential for active, tunable and low loss THz devices for imaging, sensing, and detection applications.

  1. Effects of Alloying Elements on Room and High Temperature Tensile Properties of Al-Si Cu-Mg Base Alloys =

    Science.gov (United States)

    Alyaldin, Loay

    In recent years, aluminum and aluminum alloys have been widely used in automotive and aerospace industries. Among the most commonly used cast aluminum alloys are those belonging to the Al-Si system. Due to their mechanical properties, light weight, excellent castability and corrosion resistance, these alloys are primarily used in engineering and in automotive applications. The more aluminum is used in the production of a vehicle, the less the weight of the vehicle, and the less fuel it consumes, thereby reducing the amount of harmful emissions into the atmosphere. The principal alloying elements in Al-Si alloys, in addition to silicon, are magnesium and copper which, through the formation of Al2Cu and Mg2Si precipitates, improve the alloy strength via precipitation hardening following heat treatment. However, most Al-Si alloys are not suitable for high temperature applications because their tensile and fatigue strengths are not as high as desired in the temperature range 230-350°C, which are the temperatures that are often attained in automotive engine components under actual service conditions. The main challenge lies in the fact that the strength of heat-treatable cast aluminum alloys decreases at temperatures above 200°C. The strength of alloys under high temperature conditions is improved by obtaining a microstructure containing thermally stable and coarsening-resistant intermetallics, which may be achieved with the addition of Ni. Zr and Sc. Nickel leads to the formation of nickel aluminide Al3Ni and Al 9FeNi in the presence of iron, while zirconium forms Al3Zr. These intermetallics improve the high temperature strength of Al-Si alloys. Some interesting improvements have been achieved by modifying the composition of the base alloy with additions of Mn, resulting in an increase in strength and ductility at both room and high temperatures. Al-Si-Cu-Mg alloys such as the 354 (Al-9wt%Si-1.8wt%Cu-0.5wt%Mg) alloys show a greater response to heat treatment as a

  2. Volatilization, transport and sublimation of metallic and non-metallic elements in high temperature gases at Merapi Volcano, Indonesia

    Science.gov (United States)

    Symonds, R.B.; Rose, William I.; Reed, M.H.; Lichte, F.E.; Finnegan, David L.

    1987-01-01

    Condensates, silica tube sublimates and incrustations were sampled from 500-800??C fumaroles and lava samples were collected at Merapi Volcano, Indonesia in Jan.-Feb., 1984. With respect to the magma, Merapi gases are enriched by factors greater than 105 in Se, Re, Bi and Cd; 104-105 in Au, Br, In, Pb and W; 103-104 in Mo, Cl, Cs, S, Sn and Ag; 102-103 in As, Zn, F and Rb; and 1-102 in Cu, K, Na, Sb, Ni, Ga, V, Fe, Mn and Li. The fumaroles are transporting more than 106 grams/day ( g d) of S, Cl and F; 104-106 g/d of Al, Br, Zn, Fe, K and Mg; 103-104 g d of Pb, As, Mo, Mn, V, W and Sr; and less than 103 g d of Ni, Cu, Cr, Ga, Sb, Bi, Cd, Li, Co and U. With decreasing temperature (800-500??C) there were five sublimate zones found in silica tubes: 1) cristobalite and magnetite (first deposition of Si, Fe and Al); 2) K-Ca sulfate, acmite, halite, sylvite and pyrite (maximum deposition of Cl, Na, K, Si, S, Fe, Mo, Br, Al, Rb, Cs, Mn, W, P, Ca, Re, Ag, Au and Co); 3) aphthitalite (K-Na sulfate), sphalerite, galena and Cs-K. sulfate (maximum deposition of Zn, Bi, Cd, Se and In; higher deposition of Pb and Sn); 4) Pb-K chloride and Na-K-Fe sulfate (maximum deposition of Pb, Sn and Cu); and 5) Zn, Cu and K-Pb sulfates (maximum deposition of Pb, Sn, Ti, As and Sb). The incrustations surrounding the fumaroles are also chemically zoned. Bi, Cd, Pb, W, Mo, Zn, Cu, K, Na, V, Fe and Mn are concentrated most in or very close to the vent as expected with cooling, atmospheric contamination and dispersion. The highly volatile elements Br, Cl, As and Sb are transported primarily away from high temperature vents. Ba, Si, P, Al, Ca and Cr are derived from wall rock reactions. Incomplete degassing of shallow magma at 915??C is the origin of most of the elements in the Merapi volcanic gas, although it is partly contaminated by particles or wall rock reactions. The metals are transported predominantly as chloride species. As the gas cools in the fumarolic environment, it becomes saturated

  3. Bessel smoothing filter for spectral-element mesh

    Science.gov (United States)

    Trinh, P. T.; Brossier, R.; Métivier, L.; Virieux, J.; Wellington, P.

    2017-06-01

    Smoothing filters are extremely important tools in seismic imaging and inversion, such as for traveltime tomography, migration and waveform inversion. For efficiency, and as they can be used a number of times during inversion, it is important that these filters can easily incorporate prior information on the geological structure of the investigated medium, through variable coherent lengths and orientation. In this study, we promote the use of the Bessel filter to achieve these purposes. Instead of considering the direct application of the filter, we demonstrate that we can rely on the equation associated with its inverse filter, which amounts to the solution of an elliptic partial differential equation. This enhances the efficiency of the filter application, and also its flexibility. We apply this strategy within a spectral-element-based elastic full waveform inversion framework. Taking advantage of this formulation, we apply the Bessel filter by solving the associated partial differential equation directly on the spectral-element mesh through the standard weak formulation. This avoids cumbersome projection operators between the spectral-element mesh and a regular Cartesian grid, or expensive explicit windowed convolution on the finite-element mesh, which is often used for applying smoothing operators. The associated linear system is solved efficiently through a parallel conjugate gradient algorithm, in which the matrix vector product is factorized and highly optimized with vectorized computation. Significant scaling behaviour is obtained when comparing this strategy with the explicit convolution method. The theoretical numerical complexity of this approach increases linearly with the coherent length, whereas a sublinear relationship is observed practically. Numerical illustrations are provided here for schematic examples, and for a more realistic elastic full waveform inversion gradient smoothing on the SEAM II benchmark model. These examples illustrate well the

  4. Finite element based stress analysis of graphite component in high temperature gas cooled reactor core using linear and nonlinear irradiation creep models

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish, E-mail: smohanty@anl.gov; Majumdar, Saurindranath

    2015-10-15

    Highlights: • High temperature gas cooled reactor. • Finite element based stress analysis. • H-451 graphite. • Irradiation creep model. • Graphite reflector stress analysis. - Abstract: Irradiation creep plays a major role in the structural integrity of the graphite components in high temperature gas cooled reactors. Finite element procedures combined with a suitable irradiation creep model can be used to simulate the time-integrated structural integrity of complex shapes, such as the reactor core graphite reflector and fuel bricks. In the present work a comparative study was undertaken to understand the effect of linear and nonlinear irradiation creep on results of finite element based stress analysis. Numerical results were generated through finite element simulations of a typical graphite reflector.

  5. On-line hydrogen-isotope measurements of organic samples using elemental chromium: an extension for high temperature elemental-analyzer techniques.

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Gilevska, Tetyana; Qi, Haiping; Coplen, Tyler B; Meijer, Harro A J; Brand, Willi A; Schimmelmann, Arndt

    2015-01-01

    The high temperature conversion (HTC) technique using an elemental analyzer with a glassy carbon tube and filling (temperature conversion/elemental analysis, TC/EA) is a widely used method for hydrogen isotopic analysis of water and many solid and liquid organic samples with analysis by isotope-ratio mass spectrometry (IRMS). However, the TC/EA IRMS method may produce inaccurate δ(2)H results, with values deviating by more than 20 mUr (milliurey = 0.001 = 1‰) from the true value for some materials. We show that a single-oven, chromium-filled elemental analyzer coupled to an IRMS substantially improves the measurement quality and reliability for hydrogen isotopic compositions of organic substances (Cr-EA method). Hot chromium maximizes the yield of molecular hydrogen in a helium carrier gas by irreversibly and quantitatively scavenging all reactive elements except hydrogen. In contrast, under TC/EA conditions, heteroelements like nitrogen or chlorine (and other halogens) can form hydrogen cyanide (HCN) or hydrogen chloride (HCl) and this can cause isotopic fractionation. The Cr-EA technique thus expands the analytical possibilities for on-line hydrogen-isotope measurements of organic samples significantly. This method yielded reproducibility values (1-sigma) for δ(2)H measurements on water and caffeine samples of better than 1.0 and 0.5 mUr, respectively. To overcome handling problems with water as the principal calibration anchor for hydrogen isotopic measurements, we have employed an effective and simple strategy using reference waters or other liquids sealed in silver-tube segments. These crimped silver tubes can be employed in both the Cr-EA and TC/EA techniques. They simplify considerably the normalization of hydrogen-isotope measurement data to the VSMOW-SLAP (Vienna Standard Mean Ocean Water-Standard Light Antarctic Precipitation) scale, and their use improves accuracy of the data by eliminating evaporative loss and associated isotopic fractionation while

  6. On-line hydrogen-isotope measurements of organic samples using elemental chromium: An extension for high temperature elemental-analyzer techniques

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Gilevska, Tetyana; Qi, Haiping; Coplen, Tyler B.; Meijer, Harro A.J.; Brand, Willi A.; Schimmelmann, Arndt

    2015-01-01

    The high temperature conversion (HTC) technique using an elemental analyzer with a glassy carbon tube and filling (temperature conversion/elemental analysis, TC/EA) is a widely used method for hydrogen isotopic analysis of water and many solid and liquid organic samples with analysis by isotope-ratio mass spectrometry (IRMS). However, the TC/EA IRMS method may produce inaccurate δ2H results, with values deviating by more than 20 mUr (milliurey = 0.001 = 1‰) from the true value for some materials. We show that a single-oven, chromium-filled elemental analyzer coupled to an IRMS substantially improves the measurement quality and reliability for hydrogen isotopic compositions of organic substances (Cr-EA method). Hot chromium maximizes the yield of molecular hydrogen in a helium carrier gas by irreversibly and quantitatively scavenging all reactive elements except hydrogen. In contrast, under TC/EA conditions, heteroelements like nitrogen or chlorine (and other halogens) can form hydrogen cyanide (HCN) or hydrogen chloride (HCl) and this can cause isotopic fractionation. The Cr-EA technique thus expands the analytical possibilities for on-line hydrogen-isotope measurements of organic samples significantly. This method yielded reproducibility values (1-sigma) for δ2H measurements on water and caffeine samples of better than 1.0 and 0.5 mUr, respectively. To overcome handling problems with water as the principal calibration anchor for hydrogen isotopic measurements, we have employed an effective and simple strategy using reference waters or other liquids sealed in silver-tube segments. These crimped silver tubes can be employed in both the Cr-EA and TC/EA techniques. They simplify considerably the normalization of hydrogen-isotope measurement data to the VSMOW-SLAP (Vienna Standard Mean Ocean Water-Standard Light Antarctic Precipitation) scale, and their use improves accuracy of the data by eliminating evaporative loss and associated isotopic fractionation while

  7. Estimation of Temperature Influence on Creep Rate of High-Temperature Elements in Steam Turbines and Steam Pipelines

    Directory of Open Access Journals (Sweden)

    A. G. Gerasimova

    2011-01-01

    Full Text Available The paper considers a high temperature influence on strength characteristics of steam pipelines and steam turbine parts of high and medium pressure. The charts showing a decisive temperature importance in diffuse creep have been presented in the paper. The paper contains a calculation of steel self-diffusion coefficient. Dependence Dsd = f(t for more accurate assessment of  resource characteristics of the applied steel has been proposed in the paper.

  8. International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Testing of Returned Units

    Science.gov (United States)

    Green, Robert D.; Agui, Juan H.; Vijayakumar, R.

    2017-01-01

    The air revitalization system aboard the International Space Station (ISS) provides the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation due to the microgravity environment in Low Earth Orbit (LEO). The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Adsorption (HEPA) media filters deployed at multiple locations in each U.S. Segment module; these filters are referred to as Bacterial Filter Elements, or BFEs. These filters see a replacement interval, as part of maintenance, of 2-5 years dependent on location in the ISS. In this work, we present particulate removal efficiency, pressure drop, and leak test results for a sample set of 8 BFEs returned from the ISS after filter replacement. The results can potentially be utilized by the ISS Program to ascertain whether the present replacement interval can be maintained or extended to balance the on-ground filter inventory with extension of the lifetime of ISS beyond 2024. These results can also provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

  9. Nitinol Embolic Protection Filters: Design Investigation by Finite Element Analysis

    Science.gov (United States)

    Conti, Michele; de Beule, Matthieu; Mortier, Peter; van Loo, Denis; Verdonck, Pascal; Vermassen, Frank; Segers, Patrick; Auricchio, Ferdinando; Verhegghe, Benedict

    2009-08-01

    The widespread acceptance of carotid artery stenting (CAS) to treat carotid artery stenosis and its effectiveness compared with surgical counterpart, carotid endarterectomy (CEA), is still a matter of debate. Transient or permanent neurological deficits may develop in patients undergoing CAS due to distal embolization or hemodynamic changes. Design, development, and usage of embolic protection devices (EPDs), such as embolic protection filters, appear to have a significant impact on the success of CAS. Unfortunately, some drawbacks, such as filtering failure, inability to cross tortuous high-grade stenoses, malpositioning and vessel injury, still remain and require design improvement. Currently, many different designs of such devices are available on the rapidly growing dedicated market. In spite of such a growing commercial interest, there is a significant need for design tools as well as for careful engineering investigations and design analyses of such nitinol devices. The present study aims to investigate the embolic protection filter design by finite element analysis. We first developed a parametrical computer-aided design model of an embolic filter based on micro-CT scans of the Angioguard™ XP (Cordis Endovascular, FL) EPD by means of the open source pyFormex software. Subsequently, we used the finite element method to simulate the deployment of the nitinol filter as it exits the delivery sheath. Comparison of the simulations with micro-CT images of the real device exiting the catheter showed excellent correspondence with our simulations. Finally, we evaluated circumferential basket-vessel wall apposition of a 4 mm size filter in a straight vessel of different sizes and shape. We conclude that the proposed methodology offers a useful tool to evaluate and to compare current or new designs of EPDs. Further simulations will investigate vessel wall apposition in a realistic tortuous anatomy.

  10. Filter Efficiency and Pressure Testing of Returned ISS Bacterial Filter Elements (BFEs)

    Science.gov (United States)

    Green, Robert D.; Agui, Juan H.; Berger, Gordon M.; Vijayakumar, R.; Perry, Jay L.

    2017-01-01

    The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

  11. High temperature superconducting materials

    Energy Technology Data Exchange (ETDEWEB)

    Alario-Franco, M.A. [Universidad Complutense de Madrid (Spain). Facultad de Ciencias Quimicas

    1995-02-01

    The perovskite structure is the basis of all known high-temperature superconducting materials. Many of the most successful (highest T{sub c}) materials are based on mercury and thallium phases but, due to the high toxicity of the component compounds effort has been invested in the substitution of these elements with silver. Progress is reviewed. (orig.)

  12. Investigation of the storage and release of oxygen in a Cu-Pt element of a high-temperature microcombustor

    Science.gov (United States)

    Khaji, Z.; Sturesson, P.; Hjort, K.; Klintberg, L.; Thornell, G.

    2014-11-01

    A miniature combustor for converting organic samples into CO2 with application in carbon isotopic measurements has been manufactured and evaluated. The combustor was made of High-Temperature Co-fired Ceramic (HTCC) alumina green tapes. The device has a built-in screen printed heater and a temperature sensor made of platinum, co-sintered with the ceramic. A copper oxide oxygen supply was added to the combustor after sintering by in-situ electroplating of copper on the heater pattern followed by thermal oxidation. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Thermal Gravimetric Analysis (TGA) were used to study electroplating, oxidation and the oxide reduction processes. The temperature sensor was calibrated by use of a thermocouple. It demonstrates a temperature coefficient resistance of 4.66×10-3/°C between 32 and 660 °C. The heat characterization was done up to 1000 °C by using IR thermography, and the results were compared with the data from the temperature sensor. Combustion of starch confirmed the feasibility of using copper oxide as the source of oxygen of combustion.

  13. Enhanced photocatalytic oxidation of gaseous elemental mercury by TiO2 in a high temperature environment.

    Science.gov (United States)

    Shen, Huazhen; Ie, Iau-Ren; Yuan, Chung-Shin; Hung, Chung-Hsuang; Chen, Wei-Hsiang; Luo, Jinjing; Jen, Yi-Hsiu

    2015-05-30

    The photo-oxidation of Hg(0) in a lab-scale reactor by titanium dioxide (TiO2) coated on the surface of glass beads was investigated at high temperatures. TiO2 was calcinated at four different temperatures of 300 °C, 400 °C, 500 °C and 600 °C (noted as Ti300, Ti400, Ti500 and Ti600) and characterized for its physicochemical properties. The calcinated TiO2 coating on the glass beads was then tested to compare the photo-oxidation efficiencies of Hg(0) with an incident light of 365 nm. The results showed that the oxidation efficiencies of Hg(0) for Ti400 and Ti500 were higher than those of Ti300 and Ti600. To enhance the photo-oxidation efficiency of Hg(0), Ti400 was selected to examine the wave lengths (λ) of 254 nm, 365 nm and visible light with various influent Hg(0) concentrations. The effects of irradiation strength and the presence of oxygen on the photo-oxidation efficiency of Hg(0) were further investigated, respectively. This study revealed that the wave length (λ) of 254 nm could promote the photo-oxidation efficiency of Hg(0) at 140 and 160 °C, while increasing the influent Hg(0) concentration and could enhance the photo-oxidation rate of Hg(0). However, the influence of 5% O2 present in the flue gas for the enhancement of Hg(0) oxidation was limited. Moreover, the intensity of the incident wave length of 365 nm and visible light were demonstrated to boost the photo-oxidation efficiency of Hg(0) effectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. High Temperature Capacitors for Venus Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR program, TRS Technologies has developed several new dielectrics for high temperature applications including signal conditioning, filtering and energy...

  15. Modelling of the material flow of Nd-Fe-B magnets under high temperature deformation via finite element simulation method.

    Science.gov (United States)

    Chen, Yen-Ju; Lee, Yen-I; Chang, Wen-Cheng; Hsiao, Po-Jen; You, Jr-Shian; Wang, Chun-Chieh; Wei, Chia-Min

    2017-01-01

    Hot deformation of Nd-Fe-B magnets has been studied for more than three decades. With a good combination of forming processing parameters, the remanence and (BH)max values of Nd-Fe-B magnets could be greatly increased due to the formation of anisotropic microstructures during hot deformation. In this work, a methodology is proposed for visualizing the material flow in hot-deformed Nd-Fe-B magnets via finite element simulation. Material flow in hot-deformed Nd-Fe-B magnets could be predicted by simulation, which fitted with experimental results. By utilizing this methodology, the correlation between strain distribution and magnetic properties enhancement could be better understood.

  16. Faraday imaging at high temperatures

    Science.gov (United States)

    Hackel, Lloyd A.; Reichert, Patrick

    1997-01-01

    A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid.

  17. High Temperature Oxidation Behavior of gamma-Ni+gamma'-Ni3Al Alloys and Coatings Modified with Pt and Reactive Elements

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Nan [Iowa State Univ., Ames, IA (United States)

    2007-12-01

    Materials for high-pressure turbine blades must be able to operate in the high-temperature gases (above 1000 C) emerging from the combustion chamber. Accordingly, the development of nickel-based superalloys has been constantly motivated by the need to have improved engine efficiency, reliability and service lifetime under the harsh conditions imposed by the turbine environment. However, the melting point of nickel (1455 C) provides a natural ceiling for the temperature capability of nickel-based superalloys. Thus, surface-engineered turbine components with modified diffusion coatings and overlay coatings are used. Theses coatings are capable of forming a compact and adherent oxide scale, which greatly impedes the further transport of reactants between the high-temperature gases and the underlying metal and thus reducing attack by the atmosphere. Typically, these coatings contain β-NiAl as a principal constituent phase in order to have sufficient aluminum content to form an Al2O3 scale at elevated temperatures. The drawbacks to the currently-used {beta}-based coatings, such as phase instabilities, associated stresses induced by such phase instabilities, and extensive coating/substrate interdiffusion, are major motivations in this study to seek next-generation coatings. The high-temperature oxidation resistance of novel Pt + Hf-modified γ-Ni + γ-Ni3Al-based alloys and coatings were investigated in this study. Both early-stage and 4-days isothermal oxidation behavior of single-phase γ-Ni and γ'-Ni3Al alloys were assessed by examining the weight changes, oxide-scale structures, and elemental concentration profiles through the scales and subsurface alloy regions. It was found that Pt promotes Al2O3 formation by suppressing the NiO growth on both γ-Ni and γ'Ni3Al single-phase alloys. This effect increases with increasing Pt content. Moreover, Pt exhibits this effect even at

  18. Single Active Element Based Voltage-Mode Multifunction Filter

    Directory of Open Access Journals (Sweden)

    Jitendra Mohan

    2014-01-01

    Full Text Available The paper presents a new voltage-mode multifunction filter. The proposed filter employs single modified fully differential second generation current conveyor (FDCCII, two grounded capacitors, and three resistors. The proposed circuit enjoys the employment of two grounded capacitors (attractive for absorbing shunt parasitic capacitance and ideal for IC implementation. The proposed circuit provides all five generic filter responses (low pass (LP, high pass (HP, band pass (BP, notch (NH, and all pass (AP filter responses simultaneously with single input. The novel proposed filter has low active and passive sensitivities. A number of time domain and frequency domain simulation results depicted through PSPICE using 0.18 µm TSMC process parameters are included to validate the theory. The proposed circuit is expected to enhance the existing knowledge on the subject.

  19. Coupling in-situ X-ray micro- and nano-tomography and discrete element method for investigating high temperature sintering of metal and ceramic powders

    Science.gov (United States)

    Yan, Zilin; Martin, Christophe L.; Bouvard, Didier; Jauffrès, David; Lhuissier, Pierre; Salvo, Luc; Olmos, Luis; Villanova, Julie; Guillon, Olivier

    2017-06-01

    The behaviour of various powder systems during high temperature sintering has been investigated by coupling X-ray microtomography and discrete element method (DEM). Both methods are particularly relevant to analyse particle interactions and porosity changes occurring during sintering. Two examples are presented. The first one deals with a copper powder including artificially created pores which sintering has been observed in situ at the European synchrotron and simulated by DEM. 3D images with a resolution of 1.5 μm have been taken at various times of the sintering cycle. The comparison of the real displacement of particle centers with the displacement derived from the mean field assumption demonstrates significant particle rearrangement in some regions of the sample. Although DEM simulation showed less rearrangement, it has been able to accurately predict the densification kinetics. The second example concerns multilayer ceramic capacitors (MLCCs) composed of hundreds of alternated metal electrode and ceramic dielectric layers. The observation of Ni-based MLCCs by synchrotron nanotomography at Argon National Laboratory with a spatial resolution between 10 and 50 nm allowed understanding the origin of heterogeneities formed in Ni layers during sintering. DEM simulations confirmed this analysis and provided clues for reducing these defects.

  20. Coupling in-situ X-ray micro- and nano-tomography and discrete element method for investigating high temperature sintering of metal and ceramic powders

    Directory of Open Access Journals (Sweden)

    Yan Zilin

    2017-01-01

    Full Text Available The behaviour of various powder systems during high temperature sintering has been investigated by coupling X-ray microtomography and discrete element method (DEM. Both methods are particularly relevant to analyse particle interactions and porosity changes occurring during sintering. Two examples are presented. The first one deals with a copper powder including artificially created pores which sintering has been observed in situ at the European synchrotron and simulated by DEM. 3D images with a resolution of 1.5 μm have been taken at various times of the sintering cycle. The comparison of the real displacement of particle centers with the displacement derived from the mean field assumption demonstrates significant particle rearrangement in some regions of the sample. Although DEM simulation showed less rearrangement, it has been able to accurately predict the densification kinetics. The second example concerns multilayer ceramic capacitors (MLCCs composed of hundreds of alternated metal electrode and ceramic dielectric layers. The observation of Ni-based MLCCs by synchrotron nanotomography at Argon National Laboratory with a spatial resolution between 10 and 50 nm allowed understanding the origin of heterogeneities formed in Ni layers during sintering. DEM simulations confirmed this analysis and provided clues for reducing these defects.

  1. High-throughput simultaneous determination of plasma water deuterium and 18-oxygen enrichment using a high-temperature conversion elemental analyzer with isotope ratio mass spectrometry.

    Science.gov (United States)

    Richelle, M; Darimont, C; Piguet-Welsch, C; Fay, L B

    2004-01-01

    This paper presents a high-throughput method for the simultaneous determination of deuterium and oxygen-18 (18O) enrichment of water samples isolated from blood. This analytical method enables rapid and simple determination of these enrichments of microgram quantities of water. Water is converted into hydrogen and carbon monoxide gases by the use of a high-temperature conversion elemental analyzer (TC-EA), that are then transferred on-line into the isotope ratio mass spectrometer. Accuracy determined with the standard light Antartic precipitation (SLAP) and Greenland ice sheet precipitation (GISP) is reliable for deuterium and 18O enrichments. The range of linearity is from 0 up to 0.09 atom percent excess (APE, i.e. -78 up to 5725 delta per mil (dpm)) for deuterium enrichment and from 0 up to 0.17 APE (-11 up to 890 dpm) for 18O enrichment. Memory effects do exist but can be avoided by analyzing the biological samples in quintuplet. This method allows the determination of 1440 samples per week, i.e. 288 biological samples per week. Copyright 2004 John Wiley & Sons, Ltd.

  2. Potential of energy harvesting in barium titanate based laminates from room temperature to cryogenic/high temperatures: measurements and linking phase field and finite element simulations

    Science.gov (United States)

    Narita, Fumio; Fox, Marina; Mori, Kotaro; Takeuchi, Hiroki; Kobayashi, Takuya; Omote, Kenji

    2017-11-01

    This paper studies the energy harvesting characteristics of piezoelectric laminates consisting of barium titanate (BaTiO3) and copper (Cu) from room temperature to cryogenic/high temperatures both experimentally and numerically. First, the output voltages of the piezoelectric BaTiO3/Cu laminates were measured from room temperature to a cryogenic temperature (77 K). The output power was evaluated for various values of load resistance. The results showed that the maximum output power density is approximately 2240 nW cm‑3. The output voltages of the BaTiO3/Cu laminates were also measured from room temperature to a higher temperature (333 K). To discuss the output voltages of the BaTiO3/Cu laminates due to temperature changes, phase field and finite element simulations were combined. A phase field model for grain growth was used to generate grain structures. The phase field model was then employed for BaTiO3 polycrystals, coupled with the time-dependent Ginzburg–Landau theory and the oxygen vacancies diffusion, to calculate the temperature-dependent piezoelectric coefficient and permittivity. Using these properties, the output voltages of the BaTiO3/Cu laminates from room temperature to both 77 K and 333 K were analyzed by three dimensional finite element methods, and the results are presented for several grain sizes and oxygen vacancy densities. It was found that electricity in the BaTiO3 ceramic layer is generated not only through the piezoelectric effect caused by a thermally induced bending stress but also by the temperature dependence of the BaTiO3 piezoelectric coefficient and permittivity.

  3. High temperature structural silicides

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, J.J.

    1997-03-01

    Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi{sub 2}-based materials, which are borderline ceramic-intermetallic compounds. MoSi{sub 2} single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi{sub 2} possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi{sub 2}-Si{sub 3}N{sub 4} composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi{sub 2}-based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing.

  4. Moire interferometry at high temperatures

    Science.gov (United States)

    Wu, Jau-Je

    1992-01-01

    The objective of this study was to provide an optical technique allowing full-field in-plane deformation measurements at high temperature by using high-sensitivity moire interferometry. This was achieved by a new approach of performing deformation measurements at high temperatures in a vacuum oven using an achromatic interferometer. The moire system setup was designed with particular consideration for the stability, compactness, flexibility, and ease of control. A vacuum testing environment was provided to minimize the instability of the patterns by protecting the optical instruments from the thermal convection currents. Also, a preparation procedure for the high-temperature specimen grating was developed with the use of the plasma-etched technique. Gold was used as a metallic layer in this procedure. This method was demonstrated on a ceramic block, metal/matrix composite, and quartz. Thermal deformation of a quartz specimen was successfully measured in vacuum at 980 degrees Celsius, with the sensitivity of 417 nm per fringe. The stable and well-defined interference patterns confirmed the feasibility of the developments, including the high-temperature moire system and high-temperature specimen grating. The moire system was demonstrated to be vibration-insensitive. Also, the contrast of interference fringes at high temperature was enhanced by means of a spatial filter and a narrow band interference filter to minimize the background noise from the flow of the specimen and heater. The system was verified by a free thermal expansion test of an aluminum block. Good agreement demonstrated the validity of the optical design. The measurements of thermal deformation mismatch were performed on a graphite/epoxy composite, a metal/matrix composite equipped with an optical fiber, and a cutting tool bit. A high-resolution data-reduction technique was used to measure the strain distribution of the cutting tool bit.

  5. Miniature wideband filter based on coupled-line sections and quasi-lumped element resonator

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter

    2007-01-01

    A new design of a wideband bandpass filter is proposed, based on coupled-line sections and quasi-lumped element resonator, taking advantage of the last one to introduce two transmission zeros and suppress a spurious response. The proposed filter demonstrates significantly improved characteristics...

  6. International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Drop Testing of Returned Units

    Science.gov (United States)

    Green, Robert D.; Agui, Juan H.; Vijayakumar, R.; Berger, Gordon M.; Perry, Jay L.

    2017-01-01

    The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

  7. Improvement of Stopband Performance in Parallel-Coupled Bandpass Filters Using Quasi-Lumped Elements

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter

    2008-01-01

    , with adjustable locations of transmission zeros for desired performance. The device is fabricated in standard thick-film manufacturing technology. Based on parallel-coupled line theory, the impedance inverter model for this device is developed. The passband filter centered at 5.5 GHz with a 3 dB relative......This paper is aimed at improving the rejection level as well as overcoming the bandwidth limitations for classical coupled-line filters. A planar microwave coupled-line filter employing a quasi-lumped element resonator considerably improving the stopband characteristics is presented. The proposed...... bandpass filter has a compact footprint, and exhibits good stopband rejection with no repeated passband at twice the center frequency in comparison with the traditional coupled-line filter. By introducing the quasi-lumped element resonator, two transmission zeros at upper and lower stopbands are created...

  8. Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer–chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS)

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B.; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A.; Schimmelmann, Arndt

    2017-01-01

    Rationale: Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems.

  9. High temperature battery. Hochtemperaturbatterie

    Energy Technology Data Exchange (ETDEWEB)

    Bulling, M.

    1992-06-04

    To prevent heat losses of a high temperature battery, it is proposed to make the incoming current leads in the area of their penetration through the double-walled insulating housing as thermal throttle, particularly spiral ones.

  10. Supplementary First-Order All-Pass Filters with Two Grounded Passive Elements Using FDCCII

    Directory of Open Access Journals (Sweden)

    K. Pal

    2011-06-01

    Full Text Available In this study, two novel first-order all-pass filters are proposed using only one grounded resistor and one grounded capacitor along with a fully differential current conveyor (FDCCII. There is no element-matching restriction. The presented all-pass filter circuits can be made electronically tunable due to the electronic resistors. Furthermore, the presented circuits enjoy high-input impedance for easy cascadability. The theoretical results are verified with SPICE simulations.

  11. Switched-capacitor elements for VIS-SC-filters with reduced influences of parasitic capacitances

    Science.gov (United States)

    Pandel, J.

    1981-03-01

    A number of switched-capacitor elements for SC-filters based on voltage inverter switches will be described. All of them are insensitive to the main parasitics occurring in MOS integrated circuits, i.e. the parasitic capacitances between the bottom plates of the implemented capacitors and substrate. The reduction of parasitic effects does not lead to an increasing of the very low attenuation sensitivity with respect to element variations when simulating lossless ladder circuits between resistive terminations. Experimental results of a seventh order low-pass filter built with discrete components are in good agreement with theory.

  12. Image search engine with selective filtering and feature-element-based classification

    Science.gov (United States)

    Li, Qing; Zhang, Yujin; Dai, Shengyang

    2001-12-01

    With the growth of Internet and storage capability in recent years, image has become a widespread information format in World Wide Web. However, it has become increasingly harder to search for images of interest, and effective image search engine for the WWW needs to be developed. We propose in this paper a selective filtering process and a novel approach for image classification based on feature element in the image search engine we developed for the WWW. First a selective filtering process is embedded in a general web crawler to filter out the meaningless images with GIF format. Two parameters that can be obtained easily are used in the filtering process. Our classification approach first extract feature elements from images instead of feature vectors. Compared with feature vectors, feature elements can better capture visual meanings of the image according to subjective perception of human beings. Different from traditional image classification method, our classification approach based on feature element doesn't calculate the distance between two vectors in the feature space, while trying to find associations between feature element and class attribute of the image. Experiments are presented to show the efficiency of the proposed approach.

  13. High Temperature QCD

    CERN Document Server

    Lombardo, M P

    2012-01-01

    I review recent results on QCD at high temperature on a lattice. Steady progress with staggered fermions and Wilson type fermions allow a quantitative description of hot QCD whose accuracy in many cases parallels that of zero temperature studies. Simulations with chiral quarks are coming of age, and togheter with theoretical developments trigger interesting developments in the analysis of the critical region. Issues related with the universality class of the chiral transition and the fate of the axial symmetry are discussed in the light of new numerical and analytical results. Transport coefficients and analysis of bottomonium spectra compare well with results of heavy ion collisions at RHIC and LHC. Model field theories, lattice simulations and high temperature systematic expansions help building a coherent picture of the high temperature phase of QCD. The (strongly coupled) Quark Gluon Plasma is heavily investigated, and asserts its role as an inspiring theoretical laboratory.

  14. Highly efficient high temperature electrolysis

    DEFF Research Database (Denmark)

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard

    2008-01-01

    High temperature electrolysis of water and steam may provide an efficient, cost effective and environmentally friendly production of H-2 Using electricity produced from sustainable, non-fossil energy sources. To achieve cost competitive electrolysis cells that are both high performing i.e. minimum...... electrolysis is favourable from a thermodynamic point of view, because a part of the required energy can be supplied as thermal heat, and the activation barrier is lowered increasing the H-2 production rate. Only two types of cells operating at high temperature (above 200 degrees C) have been described...... electrolysis using SOECs is competitive to H-2 production from fossil fuels at electricity prices below 0.02-0.03 is an element of per kWh. Though promising SOEC results on H-2 production have been reported a substantial R&D is still required to obtain inexpensive, high performing and long-term stable...

  15. High Temperature Electrolysis

    DEFF Research Database (Denmark)

    Elder, Rachael; Cumming, Denis; Mogensen, Mogens Bjerg

    2015-01-01

    High temperature electrolysis of carbon dioxide, or co-electrolysis of carbon dioxide and steam, has a great potential for carbon dioxide utilisation. A solid oxide electrolysis cell (SOEC), operating between 500 and 900. °C, is used to reduce carbon dioxide to carbon monoxide. If steam is also...... input to the cell then hydrogen is produced giving syngas. This syngas can then be further reacted to form hydrocarbon fuels and chemicals. Operating at high temperature gives much higher efficiencies than can be achieved with low temperature electrolysis. Current state of the art SOECs utilise a dense...

  16. Methodology of water quality index (WQI) development for filtrated water using irradiated basic filter elements

    Science.gov (United States)

    Anuar, Nuraslinda; Muhamad Pauzi, Anas; Abu Bakar, Asyraf Arif

    2017-01-01

    Clean water production can be achieved by using common simple water filtration system that consists of an empty bottle and the filter elements such as cotton/coffee filter, sands, and gravels, which can be easily assembled and used. To reduce the time to get an acceptably clean water using the common water filtration, this paper will discuss on a solution to increase the filtration effectiveness of the filter elements by irradiating gossypium (or commonly known as cotton), and silica oxide which is the main composition material for sand and gravel from various scale based on the Wentworth scale. There were few studies regarding gamma and neutron irradiation of silica based materials that proves that gamma and neutron irradiation introduce defects, hence, we expect that it may lead to the formation of micropores and alter the water filtration effectiveness. It was established that higher amount of irradiation results in higher concentration of defects. This paper will firstly review literatures on the effect of gamma and neutron irradiation effect on filter elements such as sands and papers, and then develops a water quality index (WQI) that reflects the water appearance quality of the filtrated water. The WQI focuses on the physical appearance such as smells and color of the filtered water.

  17. High-temperature superconductors

    CERN Document Server

    Saxena, Ajay Kumar

    2010-01-01

    The present book aims at describing the phenomenon of superconductivity and high-temperature superconductors discovered by Bednorz and Muller in 1986. The book covers the superconductivity phenomenon, structure of high-Tc superconductors, critical currents, synthesis routes for high Tc materials, superconductivity in cuprates, the proximity effect and SQUIDs, theories of superconductivity and applications of superconductors.

  18. High temperature superconductivity: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bedell, K.S.; Coffey, D. (Los Alamos National Lab., NM (USA)); Meltzer, D.E. (Florida Univ., Gainesville, FL (USA)); Pines, D. (Illinois Univ., Urbana, IL (USA)); Schrieffer, J.R. (California Univ., Santa Barbara, CA (USA)) (eds.)

    1990-01-01

    This book is the result of a symposium at Los Alamos in 1989 on High Temperature Superconductivity. The topics covered include: phenomenology, quantum spin liquids, spin space fluctuations in the insulating and metallic phases, normal state properties, and numerical studies and simulations. (JF)

  19. Life at High Temperatures

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 9. Life at High Temperatures. Ramesh Maheshwari. General Article Volume 10 Issue 9 September 2005 pp 23-36. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/010/09/0023-0036. Keywords.

  20. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  1. High temperature future

    Energy Technology Data Exchange (ETDEWEB)

    Sheinkopf, K. [Solar Energy Research and Education Foundation, Washington, DC (United States)

    1994-09-01

    During the past few years, there have been dramatic accomplishments and success of high temperature solar thermal systems and significant development of these systems. High temperature technologies, about 500 F and higher, such as dish engines, troughs, central receiver power towers and solar process heat systems, have been tested, demonstrated and used in an array of applications, including many cost-effective utility bulk power production and demand side supply projects in the United States. Large systems provide power and hot water to prisons, schools, nursing homes and other institutions. Joint ventures with industry, utility projects, laboratory design assistance and other activities are building a solid industry of US solar thermal systems ready for use today.

  2. Gaseous byproducts from high-temperature thermal conversion elemental analysis of nitrogen- and sulfur-bearing compounds with considerations for δ2H and δ18O analyses.

    Science.gov (United States)

    Hunsinger, Glendon B; Tipple, Christopher A; Stern, Libby A

    2013-07-30

    High-temperature, conversion-reduction (HTC) systems convert hydrogen and oxygen in materials into H2 and CO for δ(2)H and δ(18)O measurements by isotope ratio mass spectrometry. HTC of nitrogen- and sulfur-bearing materials produces unintended byproduct gases that could affect isotope analyses by: (1) allowing isotope exchange reactions downstream of the HTC reactor, (2) creating isobaric or co-elution interferences, and (3) causing deterioration of the chromatography. This study characterizes these HTC byproducts. A HTC system (ThermoFinnigan TC/EA) was directly connected to a gas chromatograph/quadrupole mass spectrometer in scan mode (m/z 8 to 88) to identify the volatile products generated by HTC at conversion temperatures of 1350 °C and 1450 °C for a range of nitrogen- and sulfur-bearing solids [keratin powder, horse hair, caffeine, ammonium nitrate, potassium nitrate, ammonium sulfate, urea, and three nitrated organic explosives (PETN, RDX, and TNT)]. The prominent HTC byproduct gases include carbon dioxide, hydrogen cyanide, methane, acetylene, and water for all nitrogen-bearing compounds, as well as carbon disulfide, carbonyl sulfide, and hydrogen sulfide for sulfur-bearing compounds. The 1450 °C reactor temperature reduced the abundance of most byproduct gases, but increased the significant byproduct, hydrogen cyanide. Inclusion of a post-reactor chemical trap containing Ascarite II and Sicapent, in series, eliminated the majority of byproducts. This study identified numerous gaseous HTC byproducts. The potential adverse effects of these gases on isotope ratio analyses are unknown but may be mitigated by higher HTC reactor temperatures and purifying the products with a purge-and-trap system or with chemical traps. Published in 2013. This article is a U.S. Government work and is in the public domain in the USA.

  3. A high-order spatial filter for a cubed-sphere spectral element model

    Science.gov (United States)

    Kang, Hyun-Gyu; Cheong, Hyeong-Bin

    2017-04-01

    A high-order spatial filter is developed for the spectral-element-method dynamical core on the cubed-sphere grid which employs the Gauss-Lobatto Lagrange interpolating polynomials (GLLIP) as orthogonal basis functions. The filter equation is the high-order Helmholtz equation which corresponds to the implicit time-differencing of a diffusion equation employing the high-order Laplacian. The Laplacian operator is discretized within a cell which is a building block of the cubed sphere grid and consists of the Gauss-Lobatto grid. When discretizing a high-order Laplacian, due to the requirement of C0 continuity along the cell boundaries the grid-points in neighboring cells should be used for the target cell: The number of neighboring cells is nearly quadratically proportional to the filter order. Discrete Helmholtz equation yields a huge-sized and highly sparse matrix equation whose size is N*N with N the number of total grid points on the globe. The number of nonzero entries is also almost in quadratic proportion to the filter order. Filtering is accomplished by solving the huge-matrix equation. While requiring a significant computing time, the solution of global matrix provides the filtered field free of discontinuity along the cell boundaries. To achieve the computational efficiency and the accuracy at the same time, the solution of the matrix equation was obtained by only accounting for the finite number of adjacent cells. This is called as a local-domain filter. It was shown that to remove the numerical noise near the grid-scale, inclusion of 5*5 cells for the local-domain filter was found sufficient, giving the same accuracy as that obtained by global domain solution while reducing the computing time to a considerably lower level. The high-order filter was evaluated using the standard test cases including the baroclinic instability of the zonal flow. Results indicated that the filter performs better on the removal of grid-scale numerical noises than the explicit

  4. High temperature superconductors

    CERN Document Server

    Paranthaman, Parans

    2010-01-01

    This essential reference provides the most comprehensive presentation of the state of the art in the field of high temperature superconductors. This growing field of research and applications is currently being supported by numerous governmental and industrial initiatives in the United States, Asia and Europe to overcome grid energy distribution issues. The technology is particularly intended for densely populated areas. It is now being commercialized for power-delivery devices, such as power transmission lines and cables, motors and generators. Applications in electric utilities include current limiters, long transmission lines and energy-storage devices that will help industries avoid dips in electric power.

  5. Second Order Low-Pass and High-Pass Filter Designs Using Method of Synthetic Immitance Elements

    Directory of Open Access Journals (Sweden)

    Pavel Brandstetter

    2013-01-01

    Full Text Available The paper briefly describes the basics of frequency filter design method using synthetic immittance elements with current conveyors. An introduction of the paper explains the advantages and also disadvantages of using this method. Other chapters briefly introduce a design process of simple second order low-pass and high-pass filter. A theory of current conveyors is discussed too, because they are the basic building blocs of proposed synthetic element and also active frequency filters. Finally, the particular solutions of low-pass and high-pass filters are given and verified by OrCAD PSpice simulations.

  6. A technique for monitoring SO2 in combustion exhausts: Use of a non-Nernstian sensing element in combination with an upstream catalytic filter

    Energy Technology Data Exchange (ETDEWEB)

    West, David L [ORNL; Montgomery, Fred C [ORNL; Armstrong, Timothy R. [ORNL

    2009-01-01

    Detection of sulfur dioxide (SO2) at high temperature (600 750 oC) in the presence of some interferents found in typical combustion exhausts (oxides of nitrogen (NO2 and NO, "NOx"), CO2, CO, and hydrocarbon (C3H6)) is described. The detection scheme involves use of a catalytic filter in front of a non-Nernstian sensing element. The catalytic filter was a Ni:Cr powder bed operating at 850 oC and the sensing elements were pairs of platinum (Pt) and oxide (Ba-promoted copper chromite ((Ba,Cu)xCryOz) and Sr-modified lanthanum ferrite (LSF)) electrodes on yttria-stabilized zirconia. The Ni:Cr powder bed was capable of reducing the sensing element response to NOx, CO, and C3H6, but the presence of NOx (100 ppm by volume) still interfered with the SO2 response of the Pt-(Ba,Cu)xCryOz sensing element at 600 oC, causing approximately a 7 mV (20%) reduction in the response to 120 ppm SO2 and a response equivalent to about 20 ppm SO2 in the in the absence of SO2. The Pt-LSF sensing element, operated at 750 oC, did not suffer from this NOx interference but at the cost of a reduced SO2 response magnitude (120 ppm SO2 yielded ~10 mV, in contrast to ~30 mV for the Pt-(Ba,Cu)xCryOz sensing element). The powder bed and Pt-LSF sensing element were operated continuously over approximately 350 hours, and the response to SO2 drifted downward by about 7%, with most of this change occurring during the initial 100 hours of operation.

  7. High temperature measuring device

    Science.gov (United States)

    Tokarz, Richard D.

    1983-01-01

    A temperature measuring device for very high design temperatures (to 2,000.degree. C.). The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensionally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

  8. Energy-filtering transmission electron microscopy (EFTEM) in the elemental analysis of pseudoexfoliative material.

    Science.gov (United States)

    Schlötzer-Schrehardt, U; Körtje, K H; Erb, C

    2001-02-01

    To obtain more information on the basic nature of the pathological matrix product accumulating in pseudoexfoliation (PEX) syndrome by analyzing its elemental composition at the subcellular level. Energy-filtering transmission electron microscopy (EFTEM), combining the two microanalytical techniques of electron spectroscopic imaging (ESI) and energy-loss spectroscopy (EELS), were performed on ultrathin sections of lens specimens with PEX syndrome using a transmission electron microscope equipped with an integrated electron energy filter. EFTEM is based on inner shell ionization of elements present in the sample giving rise to characteristic signals in well-defined energy-loss regions. The EEL-spectra, demonstrating the presence of a particular element by its specific electron energy-loss edge, were recorded with an integrated scintillator-photomultiplier-system. ESI generated graphic images of elemental localization in the sections after a process of background correction with an IBAS image analysis program. Energy-dispersive X-ray (EDX) analysis of PEX deposits on hydrated lenses was conducted by variable pressure scanning electron microscopy. The ESI element distribution images of both intracapsular and supracapsular PEX material displayed high signals for nitrogen, sulfur, calcium, chlorine, and zinc in clear association with the PEX fibrils. The corresponding EEL-spectra confirmed the data obtained by ESI and showed the presence of the element-specific energy-loss edges. The presence of these elements in PEX fibrils was further confirmed by EDX analysis. No specific signals were obtained for phosphorus, oxygen, or aluminum. This study demonstrates the presence of nitrogen, sulfur, chlorine, zinc, and calcium both in mature and in aggregating PEX fibrils of the lens capsule. EFTEM proved to be a highly sensitive method for the microanalytical study of biological material with unknown composition, such as PEX material, at the subcellular level.

  9. High temperature materials and mechanisms

    CERN Document Server

    2014-01-01

    The use of high-temperature materials in current and future applications, including silicone materials for handling hot foods and metal alloys for developing high-speed aircraft and spacecraft systems, has generated a growing interest in high-temperature technologies. High Temperature Materials and Mechanisms explores a broad range of issues related to high-temperature materials and mechanisms that operate in harsh conditions. While some applications involve the use of materials at high temperatures, others require materials processed at high temperatures for use at room temperature. High-temperature materials must also be resistant to related causes of damage, such as oxidation and corrosion, which are accelerated with increased temperatures. This book examines high-temperature materials and mechanisms from many angles. It covers the topics of processes, materials characterization methods, and the nondestructive evaluation and health monitoring of high-temperature materials and structures. It describes the ...

  10. Spectral element filtering techniques for large eddy simulation with dynamic estimation

    CERN Document Server

    Blackburn, H M

    2003-01-01

    Spectral element methods have previously been successfully applied to direct numerical simulation of turbulent flows with moderate geometrical complexity and low to moderate Reynolds numbers. A natural extension of application is to large eddy simulation of turbulent flows, although there has been little published work in this area. One of the obstacles to such application is the ability to deal successfully with turbulence modelling in the presence of solid walls in arbitrary locations. An appropriate tool with which to tackle the problem is dynamic estimation of turbulence model parameters, but while this has been successfully applied to simulation of turbulent wall-bounded flows, typically in the context of spectral and finite volume methods, there have been no published applications with spectral element methods. Here, we describe approaches based on element-level spectral filtering, couple these with the dynamic procedure, and apply the techniques to large eddy simulation of a prototype wall-bounded turb...

  11. High Temperature Hybrid Elastomers

    Science.gov (United States)

    Drake, Kerry Anthony

    Conventional high temperature elastomers are produced by chain polymerization of olefinic or fluorinated olefinic monomers. Ultimate thermal stabilities are limited by backbone bond strengths, lower thermal stability of cross-link sites relative to backbone bonds, and depolymerization or "unzipping" at high temperatures. In order to develop elastomers with enhanced thermal stability, hybrid thermally cross-linkable polymers that consisted only of organic-inorganic and aromatic bonds were synthesized and evaluated. The addition of phenylethynyl or phenylacetylinic functional groups to these polymers resulted in conversion of the polymers into high temperature elastomers when cross-linked by thermal curing. Polyphenyoxydiphenylsilanes were synthesized via several different condensation reactions. Results of these synthetic reactions, which utilized both hydroquinone and biphenol as monomers, were systematically evaluated to determine the optimal synthetic conditions for subsequent endcapping reactions. It was determined that dichlorodiphenylsilane condensations with biphenol in toluene or THF were best suited for this work. Use of excess dichlorodiphenylsilane yielded polymers of appropriate molecular weights with terminal reactive chlorosilane groups that could be utilized for coupling with phenylethynyl reagents in a subsequent reaction. Two new synthetic routes were developed to endcap biphenoxysilanes with ethynyl containing substituents, to yield polymers with cross-linkable end groups. Endcapping by lithiumphenylacetylide and 4[(4-fluorophenylethynyl))phenol yielded two new polymers that could be thermally cross-linked on heating above 300 °C. Successful endcapping was verified chemically by 13C NMR, FTIR and Raman analysis. Exothermic peaks consistent with ethynyl curing reactions were observed in endcapped polymers by DSC. A new diacetylinic polymer was prepared through reaction of 4,4'-buta-1,3-diyne-1,4-diyldiphenol and dichlorodiphenylsilane. This

  12. HIGH TEMPERATURE VACUUM MIXER

    Directory of Open Access Journals (Sweden)

    E. D. Chertov

    2015-01-01

    Full Text Available The work is devoted to the creation of a new type of mixer to produce homogeneous mixtures of dissimilar materials applied to recycling of housing and communal services waste. The article describes the design of a dual-chamber device of the original high-temperature vacuum mixer, there investigated the processes occurring in the chambers of such devices. The results of theoretical and experimental research of the process of mixing recycled polyethylene with a mixture of "grinded food waste – Eco wool” are presented. The problem of the optimum choice of bending the curvilinear blades in the working volume of the seal, which is achieved by setting their profile in the form of involute arc of several circles of different radii, is examined . The dependences, allowing to define the limits of the changes of the main mode parameters the angular velocity of rotation of the working body of the mixer using two ways of setting the profile of the curvilinear blade mixer are obtained. Represented design of the mixer is proposed to use for a wide range of tasks associated with the mixing of the components with a strongly pronounced difference of physic al chemical properties and, in particular, in the production of composites out of housing and communal services waste.

  13. Advances in high temperature chemistry

    CERN Document Server

    Eyring, Leroy

    1969-01-01

    Advances in High Temperature Chemistry, Volume 2 covers the advances in the knowledge of the high temperature behavior of materials and the complex and unfamiliar characteristics of matter at high temperature. The book discusses the dissociation energies and free energy functions of gaseous monoxides; the matrix-isolation technique applied to high temperature molecules; and the main features, the techniques for the production, detection, and diagnosis, and the applications of molecular beams in high temperatures. The text also describes the chemical research in streaming thermal plasmas, as w

  14. Lightweight High-Temperature Thermal Insulation

    Science.gov (United States)

    Wagner, W. R.; Fasheh, J. I.

    1985-01-01

    Fine Ni/Cr fibers sintered into corrosion-resistant, fireproof batt. Possible applications include stoves, furnaces, safes, fire clothing, draperies in public buildings, wall firebreaks, airplane walls, and jetengine components. New insulation takes advantage of some of same properties of nickel/chromium alloy useful in heating elements in toasters, namely, corrosion and oxidation resistance even at high temperatures.

  15. Elemental mapping in achromatic atomic-resolution energy-filtered transmission electron microscopy.

    Science.gov (United States)

    Forbes, B D; Houben, L; Mayer, J; Dunin-Borkowski, R E; Allen, L J

    2014-12-01

    We present atomic-resolution energy-filtered transmission electron microscopy (EFTEM) images obtained with the chromatic-aberration-corrected FEI Titan PICO at the Ernst-Ruska Centre, Jülich, Germany. We find qualitative agreement between experiment and simulation for the background-subtracted EFTEM images of the Ti-L2,3 and O-K edges for a specimen of SrTiO3 oriented down the [110] zone axis. The simulations utilize the transition potential formulation for inelastic scattering, which permits a detailed investigation of contributions to the EFTEM image. We find that energy-filtered images of the Ti-L2,3 and O-K edges are lattice images and that the background-subtracted core-loss maps may not be directly interpretable as elemental maps. Simulations show that this is a result of preservation of elastic contrast, whereby the qualitative details of the image are determined primarily by elastic, coherent scattering. We show that this effect places a constraint on the range of specimen thicknesses which could theoretically yield directly useful elemental maps. In general, interpretation of EFTEM images is ideally accompanied by detailed simulations. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Effects of floral metal accumulation on floral visitor communities: introducing the elemental filter hypothesis.

    Science.gov (United States)

    Meindl, George A; Ashman, Tia-Lynn

    2015-03-01

    • For plant species that occur in heavy-metal-rich soil, floral metal accumulation may produce an "elemental filter" that reduces pollinator visitation rate and species richness and changes pollinator species composition relative to closely related species growing on normal soils. Consequently, metal hyperaccumulation may contribute to pollinator-mediated reproductive isolation between closely related plant species that differ in metal accumulation.• To test these ideas, we characterized plant-pollinator interactions in a sympatric pair of species that differ in metal accumulation (Streptanthus polygaloides, a nickel (Ni) hyperaccumulator, and S. tortuosus, a nonaccumulator). To test the elemental filter hypothesis, we presented arrays of S. polygaloides that were grown in either Ni-treated or control soils to insects at both S. polygaloides and S. tortuosus sites and recorded visitation.• Naturally occurring S. polygaloides hyperaccumulated Ni in anthers and accumulated Ni in nectar, while S. tortuosus did not. Floral visitation rates in natural populations were higher to S. tortuosus than S. polygaloides. In addition, while floral visitor richness was similar, few pollinator taxa were shared between the two plant species. Nickel-treatment of S. polygaloides reduced visits by bees, but only for arrays presented at S. tortuosus sites.• We show that the Ni hyperaccumulator S. polygaloides hosts a distinct floral visitor community, indicating that metal accumulation creates a filter for pollinators, similar to that documented for herbivores. Our study highlights a novel mechanism by which the abiotic environment can alter plant-pollinator interactions, and consequently plant reproduction and speciation. © 2015 Botanical Society of America, Inc.

  17. High Temperature Aquifer Storage

    Science.gov (United States)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2016-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing

  18. High-Temperature Piezoelectric Sensing

    Directory of Open Access Journals (Sweden)

    Xiaoning Jiang

    2013-12-01

    Full Text Available Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented.

  19. Elemental mapping in achromatic atomic-resolution energy-filtered transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, B.D. [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Houben, L. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Mayer, J. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Central Facility for Electron Microscopy, RWTH Aachen University, D-52074 Aachen (Germany); Dunin-Borkowski, R.E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Allen, L.J., E-mail: lja@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2014-12-15

    We present atomic-resolution energy-filtered transmission electron microscopy (EFTEM) images obtained with the chromatic-aberration-corrected FEI Titan PICO at the Ernst-Ruska Centre, Jülich, Germany. We find qualitative agreement between experiment and simulation for the background-subtracted EFTEM images of the Ti–L{sub 2,3} and O–K edges for a specimen of SrTiO{sub 3} oriented down the [110] zone axis. The simulations utilize the transition potential formulation for inelastic scattering, which permits a detailed investigation of contributions to the EFTEM image. We find that energy-filtered images of the Ti–L{sub 2,3} and O–K edges are lattice images and that the background-subtracted core-loss maps may not be directly interpretable as elemental maps. Simulations show that this is a result of preservation of elastic contrast, whereby the qualitative details of the image are determined primarily by elastic, coherent scattering. We show that this effect places a constraint on the range of specimen thicknesses which could theoretically yield directly useful elemental maps. In general, interpretation of EFTEM images is ideally accompanied by detailed simulations. - Highlights: • Achromatic atomic-resolution EFTEM images were obtained for STO 〈110〉. • Simulations were in qualitative agreement with Ti–L{sub 2,3} and O–K edge maps. • The experimental EFTEM maps are not directly interpretable as elemental maps. • Image intensities are strongly determined by preservation of elastic contrast. • Interpretation of EFTEM images is ideally accompanied by detailed simulations.

  20. Evaluation of mechanical properties and structural changes of ceramic filter materials for hot gas cleaning under simulated process conditions

    OpenAIRE

    Westerheide, R.; Wehd, C. von der; Rehak, P.; Adler, J.

    2002-01-01

    In the combined cycle technology for advanced coal fired power plants at high temperatures up to 950 °C the removal of particles from the stream to the gas turbine is carried out with ceramic filter elements. These elements consist often of siliceous bonded coarse grained silicon carbide. A stable long term operation of the filter elements leads to the demands on good resistance towards thermal, mechanical and chemical loading. The structure of ceramic filter elements consists usually of a hi...

  1. An efficient implementation of a high-order filter for a cubed-sphere spectral element model

    Science.gov (United States)

    Kang, Hyun-Gyu; Cheong, Hyeong-Bin

    2017-03-01

    A parallel-scalable, isotropic, scale-selective spatial filter was developed for the cubed-sphere spectral element model on the sphere. The filter equation is a high-order elliptic (Helmholtz) equation based on the spherical Laplacian operator, which is transformed into cubed-sphere local coordinates. The Laplacian operator is discretized on the computational domain, i.e., on each cell, by the spectral element method with Gauss-Lobatto Lagrange interpolating polynomials (GLLIPs) as the orthogonal basis functions. On the global domain, the discrete filter equation yielded a linear system represented by a highly sparse matrix. The density of this matrix increases quadratically (linearly) with the order of GLLIP (order of the filter), and the linear system is solved in only O (Ng) operations, where Ng is the total number of grid points. The solution, obtained by a row reduction method, demonstrated the typical accuracy and convergence rate of the cubed-sphere spectral element method. To achieve computational efficiency on parallel computers, the linear system was treated by an inverse matrix method (a sparse matrix-vector multiplication). The density of the inverse matrix was lowered to only a few times of the original sparse matrix without degrading the accuracy of the solution. For better computational efficiency, a local-domain high-order filter was introduced: The filter equation is applied to multiple cells, and then the central cell was only used to reconstruct the filtered field. The parallel efficiency of applying the inverse matrix method to the global- and local-domain filter was evaluated by the scalability on a distributed-memory parallel computer. The scale-selective performance of the filter was demonstrated on Earth topography. The usefulness of the filter as a hyper-viscosity for the vorticity equation was also demonstrated.

  2. High-temperature sapphire optical sensor fiber coatings

    Science.gov (United States)

    Desu, Seshu B.; Claus, Richard O.; Raheem, Ruby; Murphy, Kent A.

    1990-10-01

    Advanced coal-fired power generation systems, such as pressurized fluidized-bed combustors and integrated gasifier-combined cycles, may provide cost effective future alternatives for power generation, improve our utilization of coal resources, and decrease our dependence upon oil and gas. When coal is burned or converted to combustible gas to produce energy, mineral matter and chemical compounds are released as solid and gaseous contaminants. The control of contaminants is mandatory to prevent pollution as well as degradation of equipment in advanced power generation. To eliminate the need for expensive heat recovery equipment and to avoid efficiency losses it is desirable to develop a technology capable of cleaning the hot gas. For this technology the removal of particle contaminants is of major concern. Several prototype high temperature particle filters have been developed, including ceramic candle filters, ceramic bag filters, and ceramic cross-flow (CXF) filters. Ceramic candle filters are rigid, tubular filters typically made by bonding silicon carbide or alumina-silica grains with clay bonding materials and perhaps including alumina-silica fibers. Ceramic bag filters are flexible and are made from long ceramic fibers such as alumina-silica. CXF filters are rigid filters made of stacks of individual lamina through which the dirty and clean gases flow in cross-wise directions. CXF filters are advantageous for hot gas cleanup applications since they offer a large effective filter surface per unit volume. The relatively small size of the filters allows the pressurized vessel containing them to be small, thus reducing potential equipment costs. CXF filters have shown promise but have experienced degradation at normal operational high temperatures (close to 1173K) and high pressures (up to 24 bars). Observed degradation modes include delamination of the individual tile layers, cracking at either the tile-torid interface or at the mounting flange, or plugging of

  3. MODELING REFLECTANCE AND TRANSMITTANCE OF QUARTZ-FIBER FILTER SAMPLES CONTAINING ELEMENTAL CARBON PARTICLES: IMPLICATIONS FOR THERMAL/OPTICAL ANALYSIS. (R831086)

    Science.gov (United States)

    A radiative transfer scheme that considers absorption, scattering, and distribution of light-absorbing elemental carbon (EC) particles collected on a quartz-fiber filter was developed to explain simultaneous filter reflectance and transmittance observations prior to and during...

  4. High-temperature brushless DC motor controller

    Energy Technology Data Exchange (ETDEWEB)

    Cieslewski, Crzegorz; Lindblom, Scott C.; Maldonado, Frank J.; Eckert, Michael Nathan

    2017-05-16

    A motor control system for deployment in high temperature environments includes a controller; a first half-bridge circuit that includes a first high-side switching element and a first low-side switching element; a second half-bridge circuit that includes a second high-side switching element and a second low-side switching element; and a third half-bridge circuit that includes a third high-side switching element and a third; low-side switching element. The motor controller is arranged to apply a pulse width modulation (PWM) scheme to switch the first half-bridge circuit, second half-bridge circuit, and third half-bridge circuit to power a motor.

  5. Fundamental aspects of high-temperature corrosion

    OpenAIRE

    Rapp, Robert

    1993-01-01

    Some recent considerations in three widely different aspects of high-temperature corrosion are summarized: 1) reactions at the metal/scale interface in support of scale growth; 2) mass transfer effects in the control of evaporation of volatile reaction products; and 3) the codeposition of multiple elements for diffusion coatings using halide-activated cementation packs. The climb of misfit edge dislocations from the metal/scale interface can achieve the annihilation of vacancies associated wi...

  6. High-Temperature Thermoelectric Energy Conversion

    Science.gov (United States)

    Wood, C.

    1987-01-01

    Theory of thermoelectric energy conversion at high temperatures and status of research on conversion materials reviewed in report. Shows highest values of thermoelectric figure of merit, Z, found in semiconductor materials. Semiconductors keep wide choice of elements and compounds. Electrical properties tailored to particular application by impurity doping and control of stoichiometry. Report develops definition of Z useful for comparing materials and uses it to evaluate potentials of different classes of materialsmetals, semiconductors, and insulators.

  7. High temperature superconductor accelerator magnets

    NARCIS (Netherlands)

    van Nugteren, J.

    2016-01-01

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding 20T. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and

  8. High Temperature Electrostrictive Ceramics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TRS Technologies proposes to develop high temperature electrostrictors from bismuth-based ferroelectrics. These materials will exhibit high strain and low loss in...

  9. High Temperature Materials Laboratory (HTML)

    Data.gov (United States)

    Federal Laboratory Consortium — The six user centers in the High Temperature Materials Laboratory (HTML), a DOE User Facility, are dedicated to solving materials problems that limit the efficiency...

  10. High temperature heat exchange: nuclear process heat applications

    Energy Technology Data Exchange (ETDEWEB)

    Vrable, D.L.

    1980-09-01

    The unique element of the HTGR system is the high-temperature operation and the need for heat exchanger equipment to transfer nuclear heat from the reactor to the process application. This paper discusses the potential applications of the HTGR in both synthetic fuel production and nuclear steel making and presents the design considerations for the high-temperature heat exchanger equipment.

  11. Conversion of elemental mercury to the oxidized form in a fabric filter baghouse

    Energy Technology Data Exchange (ETDEWEB)

    McManus, T.J.; Agbede, R.O.; Khosah, R.P. [Advanced Technology Systems, Inc., Monroeville, PA (United States)

    1998-12-31

    The US Department of Energy`s Federal Energy Technology Center (DOE-FETC) has in the last several years funded efforts on identifying a sampling and analytical method to differentiate and quantify the chemical forms of mercury emitted from coal-fired electric utility boilers. DOE-FETC requested Advanced Technology Systems, Inc. (ATS) to develop new methodologies for determining the chemical species of mercury in coal flue gas, either by the modification of existing ones or by the introduction of novel methods. Through the efforts of ATS and others, this goal was attained and demonstrated by the final validation of the Ontario-Hydro Method. Also, in these mercury method comparison studies performed by ATS, conversion of elemental mercury to oxidized mercury in a fabric filter baghouse was observed. Investigation of this type of phenomenon was a step beyond mercury species measurement in that this had an impact on the design of mercury control devices for coal-fired power plants which must be mercury species-specific. Moreover, long and short term transport and deposition into the ecosystem with the resulting human and animal toxicity are the ultimate concerns and are all dependent upon the mercury species involved. Results will be reported from a five day study in which mercury species were measured and identified utilizing the Ontario-Hydro Method at the outlet of a baghouse accepting natural gas flue gas spiked with various mercury species.

  12. Production of porous filter elements from PEUAPM nanocomposites and silver nanoparticles; Producao de elementos filtrantes porosos a partir de nanocompositos de PEUAPM e nanoparticulas de prata

    Energy Technology Data Exchange (ETDEWEB)

    Bizzo, M.A.; Hui, W.S., E-mail: mbizzo@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Departamento de Engenharia Metalurgica e de Materiais

    2014-07-01

    The production of filter elements for water based in polymers is widespread in the market, but has an undesirable characteristic: they are not efficient and able to retain or eliminate microorganisms at all times. This paper proposes to produce nanocomposite filters with biocidal properties composed of ultra-high molecular weight polyethylene(UHMWPE) and silver nanoparticles, the UHMWPE is responsible for the uniform porous structure of the filters and the silver nanoparticles incorporated on the polymer are responsible for the biocide action. Particulate polymer that presents a different particle size curve was used for sintering the filters. Samples of filter elements obtained in this work were characterized by the techniques of X-ray diffraction, scanning electron microscopy and EDS microanalysis. The results indicated a porosity of approximately 49% in the filter, and the formation of the nanocomposite. key-words: nanocomposites, silver, UHMWPE, filter elements. (author)

  13. High temperature superconductor current leads

    Science.gov (United States)

    Hull, John R.; Poeppel, Roger B.

    1995-01-01

    An electrical lead having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths.

  14. High temperature corrosion in gasifiers

    Directory of Open Access Journals (Sweden)

    Wate Bakker

    2004-03-01

    Full Text Available Several commercial scale coal gasification combined cycle power plants have been built and successfully operated during the last 5-10 years. Supporting research on materials of construction has been carried out for the last 20 years by EPRI and others. Emphasis was on metallic alloys for heat exchangers and other components in contact with hot corrosive gases at high temperatures. In this paper major high temperature corrosion mechanisms, materials performance in presently operating gasifiers and future research needs will be discussed.

  15. Accumulation of Elements in Salix and Other Species Used in Vegetation Filters with Focus on Wood Fuel Quality

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Anneli

    2007-07-01

    Woody or herbaceous perennials used as vegetation filters for treatment of different types of wastes can be suitable for production of solid biofuels when their above ground harvestable biomass yield is sufficiently high and when biomass contains appropriate concentrations of minerals with regard to fuel combustion processes. The concentrations of nitrogen (N), potassium (K) and heavy metals (especially Zn and Cd) in fuel should be low and calcium (Ca) concentrations high to avoid technical problems and environmentally harmful emissions during combustion. Since soil supplementation with essential elements improves biomass yield, a conflict might arise between yield and quality aims. There are various possibilities to influence fuel quality during the growing phase of the life cycle of perennial biomass crops. This study assessed the suitability of two deciduous woody perennials (Salix and Populus) and two summer green herbaceous perennials (Phragmites and Urtica) for phytoremediation in terms of growth and nutrient allocation patterns. Salix and Populus proved suitable as vegetation filters when nutrients were available to plants in near-optimal proportions, but when unbalanced nutrient solutions (wastewater) were applied, stem biomass fraction was strongly reduced. Phragmites was more tolerant to wastewater treatment in terms of plant biomass production and nutrient allocation patterns, so if the N:P ratio of the wastewater is suboptimal, a vegetation filter using Phragmites could be considered. In further studies, a method was developed to determine the proportions of nutrient-rich bark in coppiced Salix, while heavy metal phytoextraction capacity was assessed in two Salix vegetation filters. The relevance of proportion of bark on wood fuel quality and element removal from vegetation filters was also investigated. The concentrations of the elements studied in harvestable Salix shoot biomass were higher, meaning lower wood fuel quality, in plantations where

  16. (Krauss) at constant high temperatures

    African Journals Online (AJOL)

    Snail Research Unit of the SAMRC and Department of Zoology, Potchefstroom University for CHE,. Potchefstroom. The survival of the freshwater snail species Bulinus africanus, Bulinus g/obosus and Biompha/aria pfeifferi at extreme high temperatures was experimentally investigated. Snails were exposed to temperatures ...

  17. High Temperature Superconductor Machine Prototype

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Træholt, Chresten

    2011-01-01

    A versatile testing platform for a High Temperature Superconductor (HTS) machine has been constructed. The stationary HTS field winding can carry up to 10 coils and it is operated at a temperature of 77K. The rotating armature is at room temperature. Test results and performance for the HTS field...

  18. High-Temperature Optical Sensor

    Science.gov (United States)

    Adamovsky, Grigory; Juergens, Jeffrey R.; Varga, Donald J.; Floyd, Bertram M.

    2010-01-01

    A high-temperature optical sensor (see Figure 1) has been developed that can operate at temperatures up to 1,000 C. The sensor development process consists of two parts: packaging of a fiber Bragg grating into a housing that allows a more sturdy thermally stable device, and a technological process to which the device is subjected to in order to meet environmental requirements of several hundred C. This technology uses a newly discovered phenomenon of the formation of thermally stable secondary Bragg gratings in communication-grade fibers at high temperatures to construct robust, optical, high-temperature sensors. Testing and performance evaluation (see Figure 2) of packaged sensors demonstrated operability of the devices at 1,000 C for several hundred hours, and during numerous thermal cycling from 400 to 800 C with different heating rates. The technology significantly extends applicability of optical sensors to high-temperature environments including ground testing of engines, flight propulsion control, thermal protection monitoring of launch vehicles, etc. It may also find applications in such non-aerospace arenas as monitoring of nuclear reactors, furnaces, chemical processes, and other hightemperature environments where other measurement techniques are either unreliable, dangerous, undesirable, or unavailable.

  19. Chemistry of high temperature superconductors

    CERN Document Server

    1991-01-01

    This review volume contains the most up-to-date articles on the chemical aspects of high temperature oxide superconductors. These articles are written by some of the leading scientists in the field and includes a comprehensive list of references. This is an essential volume for researchers working in the fields of ceramics, materials science and chemistry.

  20. High temperature component life assessment

    CERN Document Server

    Webster, G A

    1994-01-01

    The aim of this book is to investigate and explain the rapid advances in the characterization of high temperature crack growth behaviour which have been made in recent years, with reference to industrial applications. Complicated mathematics has been minimized with the emphasis placed instead on finding solutions using simplified procedures without the need for complex numerical analysis.

  1. Properties of high temperature SQUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Falco, C. M.; Wu, C. T.

    1978-01-01

    A review is given of the present status of weak links and dc and rf biased SQUIDs made with high temperature superconductors. A method for producing reliable, reproducible devices using Nb/sub 3/Sn is outlined, and comments are made on directions future work should take.

  2. High-temperature flooding injury

    Science.gov (United States)

    This problem, also called scald, is most serious in the hot desert valleys of the southwestern United States, subtropical regions in eastern Australia, and western Asia and northern Africa (Middle East) where fields are established and irrigated under high temperatures. The disorder also occurs to...

  3. High-Temperature-Superconductor Films In Microwave Circuits

    Science.gov (United States)

    Bhasin, K. B.; Warner, J. D.; Romanofsky, R. R.; Heinen, V. O.; Chorey, C. M.

    1993-01-01

    Report discusses recent developments in continuing research on fabrication and characterization of thin films of high-temperature superconducting material and incorporation of such films into microwave circuits. Research motivated by prospect of exploiting superconductivity to reduce electrical losses and thereby enhancing performance of such critical microwave components as ring resonators, filters, transmission lines, phase shifters, and feed lines in phased-array antennas.

  4. High Temperature Heat Exchanger Project

    Energy Technology Data Exchange (ETDEWEB)

    Anthony E. Hechanova, Ph.D.

    2008-09-30

    The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective

  5. Motor for High Temperature Applications

    Science.gov (United States)

    Roopnarine (Inventor)

    2013-01-01

    A high temperature motor has a stator with poles formed by wire windings, and a rotor with magnetic poles on a rotor shaft positioned coaxially within the stator. The stator and rotor are built up from stacks of magnetic-alloy laminations. The stator windings are made of high temperature magnet wire insulated with a vitreous enamel film, and the wire windings are bonded together with ceramic binder. A thin-walled cylinder is positioned coaxially between the rotor and the stator to prevent debris from the stator windings from reaching the rotor. The stator windings are wound on wire spools made of ceramic, thereby avoiding need for mica insulation and epoxy/adhesive. The stator and rotor are encased in a stator housing with rear and front end caps, and rear and front bearings for the rotor shaft are mounted on external sides of the end caps to keep debris from the motor migrating into the bearings' races.

  6. High temperature superconductor accelerator magnets

    OpenAIRE

    van Nugteren, J.

    2016-01-01

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding 20T. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and development before they can be applied in a practical accelerator magnet. In order to study HTS in detail, a five tesla demonstrator magnet named Feather-M2 is designed and constructed. The magnet is ...

  7. High Temperature Superconductor Accelerator Magnets

    OpenAIRE

    Van Nugteren, Jeroen; ten Kate, Herman; de Rijk, Gijs; Dhalle, Marc

    2016-01-01

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding $20T$. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and development before they can be applied in a practical accelerator magnet. In order to study HTS in detail, a five tesla demonstrator magnet named Feather-M2 is designed and constructed. The magnet ...

  8. Nanoscale high-temperature superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, P.; Wei, J.Y.T.; Ananth, V.; Morales, P.; Skocpol, W

    2004-08-01

    We discuss the exciting prospects of studying high-temperature superconductivity in the nanometer scale from the perspective of experiments, theory and simulation. In addition to enabling studies of novel quantum phases in an unexplored regime of system dimensions and parameters, nanoscale high-temperature superconducting structures will allow exploration of fundamental mechanisms with unprecedented insight. The prospects include, spin-charge separation, detection of electron fractionalization via novel excitations such as vison, stripe states and their dynamics, preformed cooper pairs or bose-condensation in the underdoped regime, and other quantum-ordered states. Towards this initiative, we present the successful development of a novel nanofabrication technique for the epitaxial growth of nanoscale cuprates. Combining the techniques of e-beam lithography and nanomachining, we have been able to fabricate the first generation of high-temperature superconducting nanoscale devices, including Y-junctions, four-probe wires and rings. Their initial transport characterization and scanning tunneling microscopy reveal the integrity of the crystal structure, grown on nanometer scale lateral dimensions. Here, we present atomic force micrographs and electrical characterization of a few nanoscale YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) samples.

  9. High temperature thermoelectric energy conversion

    Science.gov (United States)

    Wood, Charles

    1987-01-01

    The theory and current status of materials research for high-temperature thermoelectric energy conversion are reviewed. Semiconductors are shown to be the preferred class of materials for this application. Optimization of the figure of merit of both broadband and narrow-band semiconductors is discussed as a function of temperature. Phonon scattering mechanisms are discussed, and basic material guidelines are given for reduction of thermal conductivity. Two general classes of materials show promise for high temperature figure of merit (Z) values, namely the rare earth chalcogenides and the boron-rich borides. The electronic transport properties of the rare earth chalcogenides are explicable on the basis of degenerate or partially degenerate n-type semiconductors. Boron and boron-rich borides exhibit p-type hopping conductivity, with detailed explanations proposed for the transport differing from compound to compound. Some discussion is presented on the reasons for the low thermal conductivities in these materials. Also, ZTs greater than one appear to have been realized at high temperature in many of these compounds.

  10. Summary: High Temperature Downhole Motor

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, David W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    Directional drilling can be used to enable multi-lateral completions from a single well pad to improve well productivity and decrease environmental impact. Downhole rotation is typically developed with a motor in the Bottom Hole Assembly (BHA) that develops drilling power (speed and torque) necessary to drive rock reduction mechanisms (i.e., the bit) apart from the rotation developed by the surface rig. Historically, wellbore deviation has been introduced by a “bent-sub,” located in the BHA, that introduces a small angular deviation, typically less than 3 degrees, to allow the bit to drill off-axis with orientation of the BHA controlled at the surface. The development of a high temperature downhole motor would allow reliable use of bent subs for geothermal directional drilling. Sandia National Laboratories is pursuing the development of a high temperature motor that will operate on either drilling fluid (water-based mud) or compressed air to enable drilling high temperature, high strength, fractured rock. The project consists of designing a power section based upon geothermal drilling requirements; modeling and analysis of potential solutions; and design, development and testing of prototype hardware to validate the concept. Drilling costs contribute substantially to geothermal electricity production costs. The present development will result in more reliable access to deep, hot geothermal resources and allow preferential wellbore trajectories to be achieved. This will enable development of geothermal wells with multi-lateral completions resulting in improved geothermal resource recovery, decreased environmental impact and enhanced well construction economics.

  11. Very High Temperature Sound Absorption Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase I demonstrated experimentally a very high temperature acoustically absorbing coating for ducted acoustics applications. High temperature survivability at 3500...

  12. Microwave Filters

    OpenAIRE

    Zhou, Jiafeng

    2010-01-01

    The general theory of microwave filter design based on lumped-element circuit is described in this chapter. The lowpass prototype filters with Butterworth, Chebyshev and quasielliptic characteristics are synthesized, and the prototype filters are then transformed to bandpass filters by lowpass to bandpass frequency mapping. By using immitance inverters ( J - or K -inverters), the bandpass filters can be realized by the same type of resonators. One design example is given to verify the theory ...

  13. High Temperature Battery for Drilling Applications

    Energy Technology Data Exchange (ETDEWEB)

    Josip Caja

    2009-12-31

    In this project rechargeable cells based on the high temperature electrochemical system Na/beta''-alumina/S(IV) in AlCl3/NaCl were developed for application as an autonomous power source in oil/gas deep drilling wells. The cells operate in the temperature range from 150 C to 250 C. A prototype DD size cell was designed and built based on the results of finite element analysis and vibration testing. The cell consisted of stainless steel case serving as anode compartment with cathode compartment installed in it and a seal closing the cell. Critical element in cell design and fabrication was hermetically sealing the cell. The seal had to be leak tight, thermally and vibration stable and compatible with electrode materials. Cathode compartment was built of beta''-alumina tube which served as an electrolyte, separator and cathode compartment.

  14. Atomic resolution elemental mapping using energy-filtered imaging scanning transmission electron microscopy with chromatic aberration correction.

    Science.gov (United States)

    Krause, F F; Rosenauer, A; Barthel, J; Mayer, J; Urban, K; Dunin-Borkowski, R E; Brown, H G; Forbes, B D; Allen, L J

    2017-10-01

    This paper addresses a novel approach to atomic resolution elemental mapping, demonstrating a method that produces elemental maps with a similar resolution to the established method of electron energy-loss spectroscopy in scanning transmission electron microscopy. Dubbed energy-filtered imaging scanning transmission electron microscopy (EFISTEM) this mode of imaging is, by the quantum mechanical principle of reciprocity, equivalent to tilting the probe in energy-filtered transmission electron microscopy (EFTEM) through a cone and incoherently averaging the results. In this paper we present a proof-of-principle EFISTEM experimental study on strontium titanate. The present approach, made possible by chromatic aberration correction, has the advantage that it provides elemental maps which are immune to spatial incoherence in the electron source, coherent aberrations in the probe-forming lens and probe jitter. The veracity of the experiment is supported by quantum mechanical image simulations, which provide an insight into the image-forming process. Elemental maps obtained in EFTEM suffer from the effect known as preservation of elastic contrast, which, for example, can lead to a given atomic species appearing to be in atomic columns where it is not to be found. EFISTEM very substantially reduces the preservation of elastic contrast and yields images which show stability of contrast with changing thickness. The experimental application is demonstrated in a proof-of-principle study on strontium titanate. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. High temperature structural sandwich panels

    Science.gov (United States)

    Papakonstantinou, Christos G.

    High strength composites are being used for making lightweight structural panels that are being employed in aerospace, naval and automotive structures. Recently, there is renewed interest in use of these panels. The major problem of most commercial available sandwich panels is the fire resistance. A recently developed inorganic matrix is investigated for use in cases where fire and high temperature resistance are necessary. The focus of this dissertation is the development of a fireproof composite structural system. Sandwich panels made with polysialate matrices have an excellent potential for use in applications where exposure to high temperatures or fire is a concern. Commercial available sandwich panels will soften and lose nearly all of their compressive strength temperatures lower than 400°C. This dissertation consists of the state of the art, the experimental investigation and the analytical modeling. The state of the art covers the performance of existing high temperature composites, sandwich panels and reinforced concrete beams strengthened with Fiber Reinforced Polymers (FRP). The experimental part consists of four major components: (i) Development of a fireproof syntactic foam with maximum specific strength, (ii) Development of a lightweight syntactic foam based on polystyrene spheres, (iii) Development of the composite system for the skins. The variables are the skin thickness, modulus of elasticity of skin and high temperature resistance, and (iv) Experimental evaluation of the flexural behavior of sandwich panels. Analytical modeling consists of a model for the flexural behavior of lightweight sandwich panels, and a model for deflection calculations of reinforced concrete beams strengthened with FRP subjected to fatigue loading. The experimental and analytical results show that sandwich panels made with polysialate matrices and ceramic spheres do not lose their load bearing capability during severe fire exposure, where temperatures reach several

  16. External calibration strategy for trace element quantification in botanical samples by LA-ICP-MS using filter paper

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Matheus A.G.; Voss, Mônica; Corazza, Gabriela; Flores, Erico M.M.; Dressler, Valderi L., E-mail: vdressler@gmail.com

    2016-01-28

    The use of reference solutions dispersed on filter paper discs is proposed for the first time as an external calibration strategy for matrix matching and determination of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, V and Zn in plants by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). The procedure is based on the use of filter paper discs as support for aqueous reference solutions, which are further evaporated, resulting in solid standards with concentrations up to 250 μg g{sup −1} of each element. The use of filter paper for calibration is proposed as matrix matched standards due to the similarities of this material with botanical samples, regarding to carbon concentration and its distribution through both matrices. These characteristics allowed the use of {sup 13}C as internal standard (IS) during the analysis by LA-ICP-MS. In this way, parameters as analyte signal normalization with {sup 13}C, carrier gas flow rate, laser energy, spot size, and calibration range were monitored. The calibration procedure using solution deposition on filter paper discs resulted in precision improvement when {sup 13}C was used as IS. The method precision was calculated by the analysis of a certified reference material (CRM) of botanical matrix, considering the RSD obtained for 5 line scans and was lower than 20%. Accuracy of LA-ICP-MS determinations were evaluated by analysis of four CRM pellets of botanical composition, as well as by comparison with results obtained by ICP-MS using solution nebulization after microwave assisted digestion. Plant samples of unknown elemental composition were analyzed by the proposed LA method and good agreement were obtained with results of solution analysis. Limits of detection (LOD) established for LA-ICP-MS were obtained by the ablation of 10 lines on the filter paper disc containing 40 μL of 5% HNO{sub 3} (v v{sup −1}) as calibration blank. Values ranged from 0.05 to 0.81  μg g{sup −1}. Overall, the use of filter

  17. Compact planar microwave blocking filters

    Science.gov (United States)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

    2012-01-01

    A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

  18. Solute strengthening at high temperatures

    Science.gov (United States)

    Leyson, G. P. M.; Curtin, W. A.

    2016-08-01

    The high temperature behavior of solute strengthening has previously been treated approximately using various scaling arguments, resulting in logarithmic and power-law scalings for the stress-dependent energy barrier Δ E(τ ) versus stress τ. Here, a parameter-free solute strengthening model is extended to high temperatures/low stresses without any a priori assumptions on the functional form of Δ E(τ ) . The new model predicts that the well-established low-temperature, with energy barrier Δ {{E}\\text{b}} and zero temperature flow stress {τy0} , transitions to a near-logarithmic form for stresses in the regime 0.2intermediate-temperature and the associated transition for the activation volume. Overall, the present analysis unifies the different qualitative models in the literature and, when coupled with the previous parameter-free solute strengthening model, provides a single predictive model for solute strengthening as a function of composition, temperature, and strain rate over the full range of practical utility.

  19. High temperature PEM fuel cells

    Science.gov (United States)

    Zhang, Jianlu; Xie, Zhong; Zhang, Jiujun; Tang, Yanghua; Song, Chaojie; Navessin, Titichai; Shi, Zhiqing; Song, Datong; Wang, Haijiang; Wilkinson, David P.; Liu, Zhong-Sheng; Holdcroft, Steven

    There are several compelling technological and commercial reasons for operating H 2/air PEM fuel cells at temperatures above 100 °C. Rates of electrochemical kinetics are enhanced, water management and cooling is simplified, useful waste heat can be recovered, and lower quality reformed hydrogen may be used as the fuel. This review paper provides a concise review of high temperature PEM fuel cells (HT-PEMFCs) from the perspective of HT-specific materials, designs, and testing/diagnostics. The review describes the motivation for HT-PEMFC development, the technology gaps, and recent advances. HT-membrane development accounts for ∼90% of the published research in the field of HT-PEMFCs. Despite this, the status of membrane development for high temperature/low humidity operation is less than satisfactory. A weakness in the development of HT-PEMFC technology is the deficiency in HT-specific fuel cell architectures, test station designs, and testing protocols, and an understanding of the underlying fundamental principles behind these areas. The development of HT-specific PEMFC designs is of key importance that may help mitigate issues of membrane dehydration and MEA degradation.

  20. Direct separation of arsenic and antimony oxides by high-temperature filtration with porous FeAl intermetallic.

    Science.gov (United States)

    Zhang, Huibin; Liu, Xinli; Jiang, Yao; Gao, Lin; Yu, Linping; Lin, Nan; He, Yuehui; Liu, C T

    2017-09-15

    A temperature-controlled selective filtration technology for synchronous removal of arsenic and recovery of antimony from the fume produced from reduction smelting process of lead anode slimes was proposed. The chromium (Cr) alloyed FeAl intermetallic with an asymmetric pore structure was developed as the high-temperature filter material after evaluating its corrosive resistance, structural stability and mechanical properties. The results showed that porous FeAl alloyed with 20wt.% Cr had a long term stability in a high-temperature sulfide-bearing environment. The separation of arsenic and antimony trioxides was realized principally based on their disparate saturated vapor pressures at specific temperature ranges and the asymmetric membrane of FeAl filter elements with a mean pore size of 1.8μm. Pilot-scale filtration tests showed that the direct separation of arsenic and antimony can be achieved by a one-step or two-step filtration process. A higher removal percentage of arsenic can reach 92.24% at the expense of 6∼7% loss of antimony in the two-step filtration process at 500∼550°C and 300∼400°C. The FeAl filters had still good permeable and mechanical properties with 1041h of uninterrupted service, which indicates the feasibility of this high-temperature filtration technology. Copyright © 2017. Published by Elsevier B.V.

  1. Measurement of thermodynamic temperature of high temperature fixed points

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I. [All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), 46 Ozernaya St., Moscow 119361 (Russian Federation)

    2013-09-11

    The paper is devoted to VNIIOFI's measurements of thermodynamic temperature of the high temperature fixed points Co-C, Pt-C and Re-C within the scope of the international project coordinated by the Consultative Committee for Thermometry working group 5 'Radiation Thermometry'. The melting temperatures of the fixed points were measured by a radiance mode radiation thermometer calibrated against a filter radiometer with known irradiance spectral responsivity via a high temperature black body. This paper describes the facility used for the measurements, the results and estimated uncertainties.

  2. Measurement of thermodynamic temperature of high temperature fixed points

    Science.gov (United States)

    Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I.

    2013-09-01

    The paper is devoted to VNIIOFI's measurements of thermodynamic temperature of the high temperature fixed points Co-C, Pt-C and Re-C within the scope of the international project coordinated by the Consultative Committee for Thermometry working group 5 "Radiation Thermometry". The melting temperatures of the fixed points were measured by a radiance mode radiation thermometer calibrated against a filter radiometer with known irradiance spectral responsivity via a high temperature black body. This paper describes the facility used for the measurements, the results and estimated uncertainties.

  3. HIgh Temperature Photocatalysis over Semiconductors

    Science.gov (United States)

    Westrich, Thomas A.

    Due in large part to in prevalence of solar energy, increasing demand of energy production (from all sources), and the uncertain future of petroleum energy feedstocks, solar energy harvesting and other photochemical systems will play a major role in the developing energy market. This dissertation focuses on a novel photochemical reaction process: high temperature photocatalysis (i.e., photocatalysis conducted above ambient temperatures, T ≥ 100°C). The overarching hypothesis of this process is that photo-generated charge carriers are able to constructively participate in thermo-catalytic chemical reactions, thereby increasing catalytic rates at one temperature, or maintaining catalytic rates at lower temperatures. The photocatalytic oxidation of carbon deposits in an operational hydrocarbon reformer is one envisioned application of high temperature photocatalysis. Carbon build-up during hydrocarbon reforming results in catalyst deactivation, in the worst cases, this was shown to happen in a period of minutes with a liquid hydrocarbon. In the presence of steam, oxygen, and above-ambient temperatures, carbonaceous deposits were photocatalytically oxidized over very long periods (t ≥ 24 hours). This initial experiment exemplified the necessity of a fundamental assessment of high temperature photocatalytic activity. Fundamental understanding of the mechanisms that affect photocatalytic activity as a function of temperatures was achieved using an ethylene photocatalytic oxidation probe reaction. Maximum ethylene photocatalytic oxidation rates were observed between 100 °C and 200 °C; the maximum photocatalytic rates were approximately a factor of 2 larger than photocatalytic rates at ambient temperatures. The loss of photocatalytic activity at temperatures above 200 °C is due to a non-radiative multi-phonon recombination mechanism. Further, it was shown that the fundamental rate of recombination (as a function of temperature) can be effectively modeled as a

  4. Nonlinear plasmonics at high temperatures

    Science.gov (United States)

    Sivan, Yonatan; Chu, Shi-Wei

    2017-01-01

    We solve the Maxwell and heat equations self-consistently for metal nanoparticles under intense continuous wave (CW) illumination. Unlike previous studies, we rely on experimentally-measured data for metal permittivity for increasing temperature and for the visible spectral range. We show that the thermal nonlinearity of the metal can lead to substantial deviations from the predictions of the linear model for the temperature and field distribution and, thus, can explain qualitatively the strong nonlinear scattering from such configurations observed experimentally. We also show that the incompleteness of existing data of the temperature dependence of the thermal properties of the system prevents reaching a quantitative agreement between the measured and calculated scattering data. This modeling approach is essential for the identification of the underlying physical mechanism responsible for the thermo-optical nonlinearity of the metal and should be adopted in all applications of high-temperature nonlinear plasmonics, especially for refractory metals, for both CW and pulsed illumination.

  5. Nonlinear plasmonics at high temperatures

    Directory of Open Access Journals (Sweden)

    Sivan Yonatan

    2016-10-01

    Full Text Available We solve the Maxwell and heat equations self-consistently for metal nanoparticles under intense continuous wave (CW illumination. Unlike previous studies, we rely on experimentally-measured data for metal permittivity for increasing temperature and for the visible spectral range. We show that the thermal nonlinearity of the metal can lead to substantial deviations from the predictions of the linear model for the temperature and field distribution and, thus, can explain qualitatively the strong nonlinear scattering from such configurations observed experimentally. We also show that the incompleteness of existing data of the temperature dependence of the thermal properties of the system prevents reaching a quantitative agreement between the measured and calculated scattering data. This modeling approach is essential for the identification of the underlying physical mechanism responsible for the thermo-optical nonlinearity of the metal and should be adopted in all applications of high-temperature nonlinear plasmonics, especially for refractory metals, for both CW and pulsed illumination.

  6. High Temperature Composite Heat Exchangers

    Science.gov (United States)

    Eckel, Andrew J.; Jaskowiak, Martha H.

    2002-01-01

    High temperature composite heat exchangers are an enabling technology for a number of aeropropulsion applications. They offer the potential for mass reductions of greater than fifty percent over traditional metallics designs and enable vehicle and engine designs. Since they offer the ability to operate at significantly higher operating temperatures, they facilitate operation at reduced coolant flows and make possible temporary uncooled operation in temperature regimes, such as experienced during vehicle reentry, where traditional heat exchangers require coolant flow. This reduction in coolant requirements can translate into enhanced range or system payload. A brief review of the approaches and challengers to exploiting this important technology are presented, along with a status of recent government-funded projects.

  7. Processing of extraterrestrial materials by high temperature vacuum vaporization

    Science.gov (United States)

    Grimley, R. T.; Lipschutz, M. E.

    1983-01-01

    It is noted that problems associated with the extraction and concentration of elements and commpounds important for the construction and operation of space habitats have received little attention. High temperature vacuum vaporization is considered a promising approach; this is a technique for which the space environment offers advantages in the form of low ambient pressures and temperatures and the possibility of sustained high temperatures via solar thermal energy. To establish and refine this new technology, experimental determinations must be made of the material release profiles as a function of temperature, of the release kinetics and chemical forms of material being transported, and of the various means of altering release kinetics. Trace element data determined by neutron activation analysis of meteorites heated to 1400 C in vacuum is summarized. The principal tool, high temperature spectrometry, is used to examine the vaporization thermodynamics and kinetics of major and minor elements from complex multicomponent extraterrestrial materials.

  8. Creep resistant high temperature martensitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.; Jablonski, Paul D.; Cowen, Christopher J.

    2015-11-13

    The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M.sub.23C.sub.6 carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650.degree. C.

  9. Creep resistant high temperature martensitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.; Jablonski, Paul D.; Cowen, Christopher J.

    2017-01-31

    The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, copper, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M.sub.23C.sub.6carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650.degree. C.

  10. On-wafer high temperature characterization system

    Science.gov (United States)

    Teodorescu, L.; ǎghici, F., Dr; Rusu, I.; Brezeanu, G.

    2016-12-01

    In this work a on-wafer high temperature characterization system for wide bandgap semiconductor devices and circuits has been designed, implemented and tested. The proposed system can perform the wafer temperature adjustment in a large domain, from the room temperature up to 3000C with a resolution better than +/-0.50C. In order to obtain both low-noise measurements and low EMI, the heating element of the wafer chuck is supplied in two ways: one is from a DC linear power supply connected to the mains electricity, another one is from a second DC unit powered by batteries. An original temperature control algorithm, different from classical PID, is used to modify the power applied to the chuck.

  11. Transmission Level High Temperature Superconducting Fault Current Limiter

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Gary [SuperPower, Inc., Schenectady, NY (United States)

    2016-10-05

    The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high-temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high-temperature superconducting material used evolved from 1st generation (1G) BSCCO-2212 melt cast bulk high-temperature superconductors to 2nd generation (2G) YBCO-based high-temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology, that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. A number of these modules are arranged in an m x n array to form the current-limiting matrix.

  12. High temperature alkali corrosion of ceramics in coal gas: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pickrell, G.R.; Sun, T.; Brown, J.J. Jr.

    1994-12-31

    There are several ceramic materials which are currently being considered for use as structural elements in coal combustion and coal conversion systems because of their thermal and mechanical properties. These include alumina (refractories, membranes, heat engines); silicon carbide and silicon nitride (turbine engines, internal combustion engines, heat exchangers, particulate filters); zirconia (internal combustion engines, turbine engines, refractories); and mullite and cordierite (particulate filters, refractories, heat exchangers). High temperature alkali corrosion has been known to cause premature failure of ceramic components used in advanced high temperature coal combustion systems such as coal gasification and clean-up, coal fired gas turbines, and high efficiency heat engines. The objective of this research is to systematically evaluate the alkali corrosion resistance of the most commonly used structural ceramics including silicon carbide, silicon nitride, cordierite, mullite, alumina, aluminum titanate, and zirconia. The study consists of identification of the alkali reaction products and determination of the kinetics of the alkali reactions as a function of temperature and time. 145 refs., 29 figs., 12 tabs.

  13. Transient Heating and Thermomechanical Stress Modeling of Ceramic HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Bogle, Brandon [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kelly, James [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haslam, Jeffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-29

    The purpose of this report is to showcase an initial finite-element analysis model of a ceramic High-Efficiency Particulate (HEPA) Air filter design. Next generation HEPA filter assemblies are being developed at LLNL to withstand high-temperature fire scenarios by use of ceramics and advanced materials. The filters are meant for use in radiological and nuclear facilities, and are required to survive 500°C fires over an hour duration. During such conditions, however, collecting data under varying parameters can be challenging; therefore, a Finite Element Analysis model of the filter was conducted using COMSOL ® Multiphysics to analyze the effects of fire. Finite Element Analysis (FEA) modelling offers several opportunities: researchers can quickly and easily consider impacts of potential design changes, material selection, and flow characterization on filter performance. Specifically, this model provides stress references for the sealant at high temperatures. Modeling of full filter assemblies was deemed inefficient given the computational requirements, so a section of three tubes from the assembly was modeled. The model looked at the transient heating and thermomechanical stress development during a 500°C air flow at 6 CFM. Significant stresses were found at the ceramic-metal interfaces of the filter, and conservative temperature profiles at locations of interest were plotted. The model can be used for the development of sealants that minimize stresses at the ceramic-metal interface. Further work on the model would include the full filter assembly and consider heat losses to make more accurate predictions.

  14. High Temperature Superconducting Underground Cable

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Roger, A.

    2010-02-28

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the world’s first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  15. High temperature two component explosive

    Science.gov (United States)

    Mars, James E.; Poole, Donald R.; Schmidt, Eckart W.; Wang, Charles

    1981-01-01

    A two component, high temperature, thermally stable explosive composition comprises a liquid or low melting oxidizer and a liquid or low melting organic fuel. The oxidizer and fuel in admixture are incapable of substantial spontaneous exothermic reaction at temperatures on the order of 475.degree. K. At temperatures on the order of 475.degree. K., the oxidizer and fuel in admixture have an activation energy of at least about 40 kcal/mol. As a result of the high activation energy, the preferred explosive compositions are nondetonable as solids at ambient temperature, and become detonable only when heated beyond the melting point. Preferable oxidizers are selected from alkali or alkaline earth metal nitrates, nitrites, perchlorates, and/or mixtures thereof. Preferred fuels are organic compounds having polar hydrophilic groups. The most preferred fuels are guanidinium nitrate, acetamide and mixtures of the two. Most preferred oxidizers are eutectic mixtures of lithium nitrate, potassium nitrate and sodium nitrate, of sodium nitrite, sodium nitrate and potassium nitrate, and of potassium nitrate, calcium nitrate and sodium nitrate.

  16. High Temperature Superconductor Accelerator Magnets

    CERN Document Server

    AUTHOR|(CDS)2079328; de Rijk, Gijs; Dhalle, Marc

    2016-11-10

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding $20T$. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and development before they can be applied in a practical accelerator magnet. In order to study HTS in detail, a five tesla demonstrator magnet named Feather-M2 is designed and constructed. The magnet is based on ReBCO coated conductor, which is assembled into a $10kA$ class Roebel cable. A new and optimized Aligned Block layout is used, which takes advantage of the anisotropy of the conductor. This is achieved by providing local alignment of the Roebel cable in the coil windings with the magnetic field lines. A new Network Model capable of analyzing transient electro-magnetic and thermal phenomena in coated conductor cables and coils is developed. This model is necessary to solve critical issues in coated conductor ac...

  17. High Temperature Chemistry at NASA: Hot Topics

    Science.gov (United States)

    Jacobson, Nathan S.

    2014-01-01

    High Temperature issues in aircraft engines Hot section: Ni and Co based Superalloys Oxidation and Corrosion (Durability) at high temperatures. Thermal protection system (TPS) and RCC (Reinforced Carbon-Carbon) on the Space Shuttle Orbiter. High temperatures in other worlds: Planets close to their stars.

  18. High-temperature enzymatic breakdown of cellulose.

    Science.gov (United States)

    Wang, Hongliang; Squina, Fabio; Segato, Fernando; Mort, Andrew; Lee, David; Pappan, Kirk; Prade, Rolf

    2011-08-01

    Cellulose is an abundant and renewable biopolymer that can be used for biofuel generation; however, structural entrapment with other cell wall components hinders enzyme-substrate interactions, a key bottleneck for ethanol production. Biomass is routinely subjected to treatments that facilitate cellulase-cellulose contacts. Cellulases and glucosidases act by hydrolyzing glycosidic bonds of linear glucose β-1,4-linked polymers, producing glucose. Here we describe eight high-temperature-operating cellulases (TCel enzymes) identified from a survey of thermobacterial and archaeal genomes. Three TCel enzymes preferentially hydrolyzed soluble cellulose, while two preferred insoluble cellulose such as cotton linters and filter paper. TCel enzymes had temperature optima ranging from 85°C to 102°C. TCel enzymes were stable, retaining 80% of initial activity after 120 h at 85°C. Two modes of cellulose breakdown, i.e., with endo- and exo-acting glucanases, were detected, and with two-enzyme combinations at 85°C, synergistic cellulase activity was observed for some enzyme combinations.

  19. High temperature vapors science and technology

    CERN Document Server

    Hastie, John

    2012-01-01

    High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

  20. Modeling and analytical simulation of high-temperature gas filtration ...

    African Journals Online (AJOL)

    High temperature filtration in combustion and gasification processes is a highly interdisciplinary field. Thus, particle technology in general has to be supported by elements of physics, chemistry, thermodynamics and heat and mass transfer processes. Presented in this paper is the analytical method for describing ...

  1. Nonlinear tracking in a diffusion process with a Bayesian filter and the finite element method

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Thygesen, Uffe Høgsbro; Madsen, Henrik

    2011-01-01

    become complicated using SMC because Monte Carlo randomness is introduced. The finite element (FE) method solves the Kolmogorov equations of the SDE numerically on a triangular unstructured mesh for which boundary conditions to the state-space are simple to incorporate. The FE approach to nonlinear state...... estimation is suited for off-line data analysis because the computed smoothed state densities, maximum a posteriori parameter estimates and state sequence are deterministic conditional on the finite element mesh and the observations. The proposed method is conceptually similar to existing point...... on the state-space do not in general provide analytical solutions. A widely used numerical approach is the sequential Monte Carlo (SMC) method which relies on stochastic simulations to approximate state densities. For offline analysis, however, accurate smoothed state density and parameter estimation can...

  2. Studying the effect of Ruthenium on High Temperature Mechanical Properties of Nickel Based Superalloys and Determining the Universal Behavior of Ruthenium at Atomic Scale with respect to alloying elements, Stress and Temperature

    Directory of Open Access Journals (Sweden)

    Sriswaroop Dasari

    2016-10-01

    Full Text Available Any property of a material is a function of its microstructure and microstructure is a function of material composition. So, to maximize the desired properties of a material, one has to understand the evolution of microstructure which in turn is nothing but the reflection of the role of alloying elements. Research has not been done to understand the universal behavior of a certain base/alloying element. Let’s take the example of Cl- ion in HCl, we all know that in general, chloride ion can only be replaced by Fluoride or oxygen ion and that no other ion can replace it. But when you consider a metal like Ni, Co, Cr, Fe etc. there is no establishment that it behaves only in a certain way. Though I concord to the fact that discovery of universal behavior of Ni is lot complex than chloride ion, I think that future research should be focused in this direction also. Superalloys are the candidate materials required to improve thermal efficiency of a gas turbine by allowing higher turbine inlet gas temperatures. Gas turbines are the heart of local power systems, next generation jet engines and high performance space rockets. Recent research in superalloys showed that addition of some alloying elements in minor quantities can result in drastic change in properties. Such an alloying element is Ruthenium (Ru. Addition of Ruthenium to superalloys has shown improvement in mechanical properties by an order of magnitude. However reasons for such improvement are not known yet. Hence, there is a need to identify its role and discover the universal behavior of ruthenium to utilize it efficiently. In this proposal, we study materials with different compositions that are derived based on one ruthenium containing superalloy, and different thermomechanical history. Based on the evolution of microstructures and results of mechanical testing, we plan to determine the exact role of Ruthenium and prediction of its behavior with respect to other elements in the material

  3. High temperature skin friction measurement

    Science.gov (United States)

    Tcheng, Ping; Holmes, Harlan K.; Supplee, Frank H., Jr.

    1989-01-01

    Skin friction measurement in the NASA Langley hypersonic propulsion facility is described. The sensor configuration utilized an existing balance, modified to provide thermal isolation and an increased standoff distance. For test run times of about 20 sec and ambient-air cooling of the test section and balance, the modified balance performed satisfactorily, even when it was subjected to acoustic and structural vibration. The balance is an inertially balanced closed-loop servo system where the current to a moving-coil motor needed to restore or null the output from the position sensor is a measure of the force or skin friction tending to displace the moving element. The accuracy of the sensor is directly affected by the position sensor in the feedback loop, in this case a linear-variable differential transformer which has proven to be influenced by temperature gradients.

  4. Properties of thin films for high temperature flow sensors

    Science.gov (United States)

    Albin, Sacharia

    1991-01-01

    Requirements of material parameters of high temperature flow sensors are identified. Refractory metal silicides offer high temperature sensitivity and high frequency response and are stable up to 1000 C. Intrinsic semiconductors of high band gap are also considered as sensor elements. SiC and diamond are identified. Combined with substrates of low thermal and electrical conductivity, such as quartz or Al2O3, these materials meet several requirements of high sensitivity and frequency response. Film deposition and patterning techniques suitable for these materials are identified.

  5. Deep Trek High Temperature Electronics Project

    Energy Technology Data Exchange (ETDEWEB)

    Bruce Ohme

    2007-07-31

    This report summarizes technical progress achieved during the cooperative research agreement between Honeywell and U.S. Department of Energy to develop high-temperature electronics. Objects of this development included Silicon-on-Insulator (SOI) wafer process development for high temperature, supporting design tools and libraries, and high temperature integrated circuit component development including FPGA, EEPROM, high-resolution A-to-D converter, and a precision amplifier.

  6. Advances in high temperature chemistry 1

    CERN Document Server

    Eyring, Leroy

    2013-01-01

    Advances in High Temperature Chemistry, Volume 1 describes the complexities and special and changing characteristics of high temperature chemistry. After providing a brief definition of high temperature chemistry, this nine-chapter book goes on describing the experiments and calculations of diatomic transition metal molecules, as well as the advances in applied wave mechanics that may contribute to an understanding of the bonding, structure, and spectra of the molecules of high temperature interest. The next chapter provides a summary of gaseous ternary compounds of the alkali metals used in

  7. High temperature phase equilibria and phase diagrams

    CERN Document Server

    Kuo, Chu-Kun; Yan, Dong-Sheng

    2013-01-01

    High temperature phase equilibria studies play an increasingly important role in materials science and engineering. It is especially significant in the research into the properties of the material and the ways in which they can be improved. This is achieved by observing equilibrium and by examining the phase relationships at high temperature. The study of high temperature phase diagrams of nonmetallic systems began in the early 1900s when silica and mineral systems containing silica were focussed upon. Since then technical ceramics emerged and more emphasis has been placed on high temperature

  8. Estimation of high temperature metal-silicate partition coefficients

    Science.gov (United States)

    Jones, John H.; Capobianco, Christopher J.; Drake, Michael J.

    1992-12-01

    It has been known for some time that abundances of siderophile elements in the upper mantle of the Earth are far in excess of those expected from equilibrium between metal and silicate at low pressures and temperatures. Murthy (1991) has re-examined this excess of siderophile element problem by estimating liquid metal/liquid silicate partition coefficients reduces from their measured values at a lower temperature, implying that siderophile elements become much less siderophilic at high temperatures. Murthy then draws the important conclusion that metal/silicate equilibrium at high temperatures can account for the abundances of siderophile elements in the Earth's mantle. Of course, his conclusion is critically dependent on the small values of the partition coefficients he calculates. Because the numerical values of most experimentally-determined partition coefficients increase with increasing temperature at both constant oxygen fugacity and at constant redox buffer, we think it is important to try an alternative extrapolation for comparison. We have computed high temperature metal/silicate partition coefficients under a different set of assumptions and show that such long temperature extrapolations yield values which are critically dependent upon the presumed chemical behavior of the siderophile elements in the system.

  9. Spectroscopic diagnostics of high temperature plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Moos, W.

    1990-01-01

    A three-year research program for the development of novel XUV spectroscopic diagnostics for magnetically confined fusion plasmas is proposed. The new diagnostic system will use layered synthetic microstructures (LSM) coated, flat and curved surfaces as dispersive elements in spectrometers and narrow band XUV filter arrays. In the framework of the proposed program we will develop impurity monitors for poloidal and toroidal resolved measurements on PBX-M and Alcator C-Mod, imaging XUV spectrometers for electron density and temperature fluctuation measurements in the hot plasma core in TEXT or other similar tokamaks and plasma imaging devices in soft x-ray light for impurity behavior studies during RF heating on Phaedrus T and carbon pellet ablation in Alcator C-Mod. Recent results related to use of multilayer in XUV plasma spectroscopy are presented. We also discuss the latest results reviewed to q{sub o} and local poloidal field measurements using Zeeman polarimetry.

  10. High temperature superconductors in electromagnetic applications

    CERN Document Server

    Richens, P E

    2000-01-01

    powder-in-tube and dip-coated, have been made using a novel single loop tensometer that enables the insertion of a reasonably long length of conductor into the bore of a high-field magnet. The design, construction, and characterization of a High Temperature Superconducting (HTS) magnet is described. The design stage has involved the development of computer software for the calculation of the critical current of a solenoid wound from anisotropic HTS conductor. This calculation can be performed for a variety of problems including those involving magnetic materials such as iron by the incorporation of finite element electromagnetic analysis software. This has enabled the optimization of the magnet's performance. The HTS magnet is wound from 190 m of silver-matrix Bi sub 2 Sr sub 2 Ca sub 2 Cu sub 3 O sub 1 sub 0 powder-in-tube tape conductor supplied by Intermagnetics General Corporation. The dimensions are 70 mm bore and 70 mm length, and it consists of 728 turns. Iron end-plates were utilized in order to reduc...

  11. High temperature superconducting fault current limiter

    Science.gov (United States)

    Hull, John R.

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  12. Technological Evolution of High Temperature Superconductors

    Science.gov (United States)

    2015-12-01

    TEMPERATURE SUPERCONDUCTORS by Jordan R. White December 2015 Thesis Advisor: Clifford Whitcomb Co-Advisor: Fotis Papoulias THIS PAGE INTENTIONALLY...AND SUBTITLE TECHNOLOGICAL EVOLUTION OF HIGH TEMPERATURE SUPERCONDUCTORS 5. FUNDING NUMBERS 6. AUTHOR(S) Jordan R. White 7. PERFORMING ORGANIZATION...trends. 14. SUBJECT TERMS electric ships, high temperature superconductor , HTS 15. NUMBER OF PAGES 111 16. PRICE CODE 17. SECURITY CLASSIFICATION

  13. Trace-Metal Scavenging from Biomass Syngas with Novel High-Temperature Sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Gale, Thomas K. [Southern Research Inst., Birmingham, AL (United States); Walsh, Pete M. [Southern Research Inst., Birmingham, AL (United States)

    2007-03-21

    downstream equipment from damage. Finally, the high-temperature sorbent technology would be expanded to look at the role that these sorbents play in relation to tars and acid gases, which are the other significant pollutants within syngas. In addition to the technology development work described above, all of the information obtained in this work was to be incorporated into a syngas speciation model, which would allow direct prediction of transformations that occur in syngas as it passes from the gasifier and the sorbent-injection section and through the barrier filters. Unfortunately, Congressional budget cuts prevented most of this work from being accomplished. Hopefully, additional funds will be provided to this work in the future, which will allow its completion. However, at the halting point of this project, the following has been accomplished. A major initial objective of the project was accomplished, which was to determine whether or not high-temperature sorbents found to work within vitiated air might also work in an inert environment. Kaolinite, one of the sorbents previously investigated as a high-temperature sorbent for incinerators, was found to effectively capture potassium. In addition, while previous work on short-time (i.e., 1 to 2 seconds) dispersed-phase reactions found that sorbent utilization was limited to two metal oxide species captured for every one aluminosilicate crystal structure, the present investigation found that many times higher insoluble metal/sorbent capture ratios were obtained. This result not only suggests that small additions of sorbent might be highly effective, but the fact that the products were insoluble (in part due to the temperature of sorbent injection, i.e., < 1500 °F) may be an indication that the products are unlikely to react with, corrode, or otherwise damage the candle-filter elements. There has been little work on the capture of potassium metal vapor by high-temperature sorbents, prior to this work. The fact that

  14. SCANNING ELECTRON MICROSCOPY OF “ROSA” FILTER ELEMENTS FROM HEMOFENIX APPARATUS, AND OF BLOOD IN MEMBRANE PLASMAPHERESIS AND LASER IRRADIATION

    Directory of Open Access Journals (Sweden)

    I. M. Baybekov

    2013-01-01

    Full Text Available Aim. To study with scanning electron microscopy an interaction between structural elements of “Rosa” filters (a component of HEMOFENIХ with erythrocytes during membrane plasmapheresis and under the effect of la- ser irradiation performed during plasmapheresis. Materials and methods. Using scanning electron microscopy and morphometry, blood cells and plasma-filter components were studied in patients with myasthenia gravis. Results. It has been revealed that the percentage of pathologic forms of erythrocytes increased in peripheral blood of patients with myasthenia gravis. Plasmapheresis leads to an increase in the number of pathologic forms of erythrocytes in peripheral blood as well as on plasma-filter components. Conclusion. Laser irradiation, in turn, promotes the significant reduction of pathological forms of erythrocytes number in peripheral blood and on plasma-filter components. 

  15. Aeronautical applications of high-temperature superconductors

    Science.gov (United States)

    Turney, George E.; Luidens, Roger W.; Uherka, Kenneth; Hull, John

    1989-01-01

    The successful development of high-temperature superconductors (HTS) could have a major impact on future aeronautical propulsion and aeronautical flight vehicle systems. A preliminary examination of the potential application of HTS for aeronautics indicates that significant benefits may be realized through the development and implementation of these newly discovered materials. Applications of high-temperature superconductors (currently substantiated at 95 k) were envisioned for several classes of aeronautical systems, including subsonic and supersonic transports, hypersonic aircraft, V/STOL aircraft, rotorcraft, and solar, microwave and laser powered aircraft. Introduced and described are the particular applications and potential benefits of high-temperature superconductors as related to aeronautics and/or aeronautical systems.

  16. Symposium on high temperature and materials chemistry

    Energy Technology Data Exchange (ETDEWEB)

    1989-10-01

    This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions.

  17. Spatial filters for high average power lasers

    Science.gov (United States)

    Erlandson, Alvin C

    2012-11-27

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second slit filter positioned between the second pair of cylindrical lenses.

  18. High Temperature Solid State Lithium Battery Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reliable energy systems with high energy density capable of operating at high temperatures, pressures and radiation levels are needed for certain NASA missions....

  19. Novel High Temperature Strain Gauge Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced high-temperature sensor technology and bonding methods are of great interests in designing and developing advanced future aircraft. Current state-of-the-art...

  20. High Temperature Fiberoptic Thermal Imaging System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase 1 program will fabricate and demonstrate a small diameter single fiber endoscope that can perform high temperature thermal imaging in a jet engine...

  1. High Temperature Capacitors for Venus Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High temperature power electronics have become a vital aspect of future designs for power converters in spacecraft, battle zone electric power, satellite power...

  2. Ion Based High-Temperature Pressure Sensor

    National Research Council Canada - National Science Library

    Zdenek, Jeffrey S; Anthenien, Ralph A

    2004-01-01

    .... The environment encountered in such engines necessitates high temperature and durable (vibration resistant) devices. Traditional pressure sensors can be used, however thermal insulating materials must be used to protect the diaphragm...

  3. Lightweight, High-Temperature Radiator Panels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight, high-temperature radiators are needed for future, high-efficiency power conversion systems for Nuclear Electric Propulsion (NEP). Creare has developed...

  4. Panel report on high temperature ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Nolet, T C [ed.

    1979-01-01

    Fundamental research is reported concerning high temperature ceramics for application in turbines, engines, batteries, gasifiers, MHD, fuel cells, heat exchangers, and hot wall combustors. Ceramics microstructure and behavior are included. (FS)

  5. High Temperature Rechargeable Battery Development Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This small business innovation research is intended to develop and proof the concept of a highly efficient, high temperature rechargeable battery for supporting...

  6. Mechanical Proprieties of Steel at High Temperatures

    Directory of Open Access Journals (Sweden)

    Ana-Diana Ancaş

    2005-01-01

    Full Text Available The experimental test results obtained in the study of steel mechanical proprieties variation in case of high temperatures (fire are presented. The proprieties are referring to: Young’s modulus, E, the elastic limit, σe, and the characteristic diagram of the material (the rotation stress-strain. Theoretical laws that the model the steel behaviour at high temperature have been elaborated based on the most significant studies presented in the literature.

  7. High temperature superconductors and other superfluids

    CERN Document Server

    Alexandrov, A S

    2017-01-01

    Written by eminent researchers in the field, this text describes the theory of superconductivity and superfluidity starting from liquid helium and a charged Bose-gas. It also discusses the modern bipolaron theory of strongly coupled superconductors, which explains the basic physical properties of high-temperature superconductors. This book will be of interest to fourth year graduate and postgraduate students, specialist libraries, information centres and chemists working in high-temperature superconductivity.

  8. Investigations into High Temperature Components and Packaging

    Energy Technology Data Exchange (ETDEWEB)

    Marlino, L.D.; Seiber, L.E.; Scudiere, M.B.; M.S. Chinthavali, M.S.; McCluskey, F.P.

    2007-12-31

    The purpose of this report is to document the work that was performed at the Oak Ridge National Laboratory (ORNL) in support of the development of high temperature power electronics and components with monies remaining from the Semikron High Temperature Inverter Project managed by the National Energy Technology Laboratory (NETL). High temperature electronic components are needed to allow inverters to operate in more extreme operating conditions as required in advanced traction drive applications. The trend to try to eliminate secondary cooling loops and utilize the internal combustion (IC) cooling system, which operates with approximately 105 C water/ethylene glycol coolant at the output of the radiator, is necessary to further reduce vehicle costs and weight. The activity documented in this report includes development and testing of high temperature components, activities in support of high temperature testing, an assessment of several component packaging methods, and how elevated operating temperatures would impact their reliability. This report is organized with testing of new high temperature capacitors in Section 2 and testing of new 150 C junction temperature trench insulated gate bipolar transistor (IGBTs) in Section 3. Section 4 addresses some operational OPAL-GT information, which was necessary for developing module level tests. Section 5 summarizes calibration of equipment needed for the high temperature testing. Section 6 details some additional work that was funded on silicon carbide (SiC) device testing for high temperature use, and Section 7 is the complete text of a report funded from this effort summarizing packaging methods and their reliability issues for use in high temperature power electronics. Components were tested to evaluate the performance characteristics of the component at different operating temperatures. The temperature of the component is determined by the ambient temperature (i.e., temperature surrounding the device) plus the

  9. Implicit filtered P{sub N} for high-energy density thermal radiation transport using discontinuous Galerkin finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Laboure, Vincent M., E-mail: vincent.laboure@tamu.edu [Nuclear Engineering Department, Texas A& M University, College Station, TX 77843 (United States); McClarren, Ryan G., E-mail: rgm@tamu.edu [Nuclear Engineering Department, Texas A& M University, College Station, TX 77843 (United States); Hauck, Cory D., E-mail: hauckc@ornl.gov [Computational and Applied Mathematics Group, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Mathematics, University of Tennessee Knoxville, TN 37996-1320 (United States)

    2016-09-15

    In this work, we provide a fully-implicit implementation of the time-dependent, filtered spherical harmonics (FP{sub N}) equations for non-linear, thermal radiative transfer. We investigate local filtering strategies and analyze the effect of the filter on the conditioning of the system, showing in particular that the filter improves the convergence properties of the iterative solver. We also investigate numerically the rigorous error estimates derived in the linear setting, to determine whether they hold also for the non-linear case. Finally, we simulate a standard test problem on an unstructured mesh and make comparisons with implicit Monte Carlo (IMC) calculations.

  10. DEVELOPMENT OF AN ADHESIVE CANDLE FILTER SAFEGUARD DEVICE

    Energy Technology Data Exchange (ETDEWEB)

    John P. Hurley; Ann K. Henderson; Jan W. Nowok; Michael L. Swanson

    2002-01-01

    In order to reach the highest possible efficiencies in a coal-fired turbine-based power system, the turbine should be directly fired with the products of coal conversion. Two main types of systems employ these turbines: those based on pressurized fluidized-bed combustors and those based on integrated gasification combined cycles. In both systems, suspended particulates must be cleaned from the gas stream before it enters the turbine so as to prevent fouling and erosion of the turbine blades. To produce the cleanest gas, barrier filters are being developed and are in use in several facilities. Barrier filters are composed of porous, high-temperature materials that allow the hot gas to pass but collect the particulates on the surface. The three main configurations of the barrier filters are candle, cross-flow, and tube filters. Both candle and tube filters have been tested extensively. They are composed of coarsely porous ceramic that serves as a structural support, overlain with a thin, microporous ceramic layer on the dirty gas side that serves as the primary filter surface. They are highly efficient at removing particulate matter from the gas stream and, because of their ceramic construction, are resistant to gas and ash corrosion. However, ceramics are brittle and individual elements can fail, allowing particulates to pass through the hole left by the filter element and erode the turbine. Preventing all failure of individual ceramic filter elements is not possible at the present state of development of the technology. Therefore, safeguard devices (SGDs) must be employed to prevent the particulates streaming through occasional broken filters from reaching the turbine. However, the SGD must allow for the free passage of gas when it is not activated. Upon breaking of a filter, the SGD must either mechanically close or quickly plug with filter dust to prevent additional dust from reaching the turbine. Production of a dependable rapidly closing autonomous mechanical

  11. High-temperature sorbent method for removal of sulfur containing gases from gaseous mixtures

    Science.gov (United States)

    Young, John E.; Jalan, Vinod M.

    1984-01-01

    A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorption capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

  12. High-temperature sorbent method for removal of sulfur-containing gases from gaseous mixtures

    Science.gov (United States)

    Young, J.E.; Jalan, V.M.

    1982-07-07

    A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorbtion capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

  13. Sandia_HighTemperatureComponentEvaluation_2015

    Energy Technology Data Exchange (ETDEWEB)

    Cashion, Avery T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    The objective of this project is to perform independent evaluation of high temperature components to determine their suitability for use in high temperature geothermal tools. Development of high temperature components has been increasing rapidly due to demand from the high temperature oil and gas exploration and aerospace industries. Many of these new components are at the late prototype or first production stage of development and could benefit from third party evaluation of functionality and lifetime at elevated temperatures. In addition to independent testing of new components, this project recognizes that there is a paucity of commercial-off-the-shelf COTS components rated for geothermal temperatures. As such, high-temperature circuit designers often must dedicate considerable time and resources to determine if a component exists that they may be able to knead performance out of to meet their requirements. This project aids tool developers by characterization of select COTS component performances beyond published temperature specifications. The process for selecting components includes public announcements of project intent (e.g., FedBizOps), direct discussions with candidate manufacturers,and coordination with other DOE funded programs.

  14. Copper Alloy For High-Temperature Uses

    Science.gov (United States)

    Dreshfield, Robert L.; Ellis, David L.; Michal, Gary

    1994-01-01

    Alloy of Cu/8Cr/4Nb (numbers indicate parts by atom percent) improved over older high-temperature copper-based alloys in that it offers enhanced high temperature strength, resistance to creep, and ductility while retaining most of thermal conductivity of pure copper; in addition, alloy does not become embrittled upon exposure to hydrogen at temperatures as high as 705 degrees C. Designed for use in presence of high heat fluxes and active cooling; for example, in heat exchangers in advanced aircraft and spacecraft engines, and other high-temperature applications in which there is need for such material. High conductivity and hardness of alloy exploited in welding electrodes and in high-voltage and high-current switches and other applications in which wear poses design problem.

  15. High temperature thrust chamber for spacecraft

    Science.gov (United States)

    Chazen, Melvin L. (Inventor); Mueller, Thomas J. (Inventor); Kruse, William D. (Inventor)

    1998-01-01

    A high temperature thrust chamber for spacecraft (20) is provided herein. The high temperature thrust chamber comprises a hollow body member (12) having an outer surface and an internal surface (16) defining the high temperature chamber (10). The body member (12) is made substantially of rhenium. An alloy (18) consisting of iridium and at least alloying metal selected of the group consisting of rhodium, platinum and palladium is deposited on at least a portion of the internal surface (16) of the body member (12). The iridium and the alloying metal are electrodeposited onto the body member (12). A HIP cycle is performed upon the body member (12) to cause the coating of iridium and the alloying metal to form the alloy (18) which protects the body member (12) from oxidation.

  16. The flavoured BFSS model at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Yuhma; Filev, Veselin G. [School of Theoretical Physics, Dublin Institute for Advanced Studies,10 Burlington Road, Dublin 4 (Ireland); Kováčik, Samuel [School of Theoretical Physics, Dublin Institute for Advanced Studies,10 Burlington Road, Dublin 4 (Ireland); Faculty of Mathematics, Physics and Informatics,Comenius University Bratislava, Mlynská dolina, Bratislava, 842 48 (Slovakia); O’Connor, Denjoe [School of Theoretical Physics, Dublin Institute for Advanced Studies,10 Burlington Road, Dublin 4 (Ireland)

    2017-01-25

    We study the high-temperature series expansion of the Berkooz-Douglas matrix model, which describes the D0/D4-brane system. At high temperature the model is weakly coupled and we develop the series to second order. We check our results against the high-temperature regime of the bosonic model (without fermions) and find excellent agreement. We track the temperature dependence of the bosonic model and find backreaction of the fundamental fields lifts the zero-temperature adjoint mass degeneracy. In the low-temperature phase the system is well described by a gaussian model with three masses m{sub A}{sup t}=1.964±0.003, m{sub A}{sup l}=2.001±0.003 and m{sub f}=1.463±0.001, the adjoint longitudinal and transverse masses and the mass of the fundamental fields respectively.

  17. Application of High Temperature Superconductors to Accelerators

    CERN Document Server

    Ballarino, A

    2000-01-01

    Since the discovery of high temperature superconductivity, a large effort has been made by the scientific community to investigate this field towards a possible application of the new oxide superconductors to different devices like SMES, magnetic bearings, flywheels energy storage, magnetic shielding, transmission cables, fault current limiters, etc. However, all present day large scale applications using superconductivity in accelerator technology are based on conventional materials operating at liquid helium temperatures. Poor mechanical properties, low critical current density and sensitivity to the magnetic field at high temperature are the key parameters whose improvement is essential for a large scale application of high temperature superconductors to such devices. Current leads, used for transferring currents from the power converters, working at room temperature, into the liquid helium environment, where the magnets are operating, represent an immediate application of the emerging technology of high t...

  18. High-temperature heat-pump fluids

    Science.gov (United States)

    Bertinat, M. P.

    1988-05-01

    Heat pumps could be immensely useful in many industrial processes, but standard working fluids are unsuitable for the high temperatures involved. The ideal high-temperature heat-pump fluid should have a high (but not too high) critical temperature, a moderate critical pressure ( approximately=5.0 MPa) and a low (but not too low) boiling point. There are many organic fluids that do meet the above thermodynamic criteria The author's list of 250 contained dozens of them including many of the common laboratory solvents such as ethanol, ether and especially acetone. Unfortunately most of them are highly flammable. The ideal work fluid for high-temperature heat pumps will probably always remain elusive and water, despite its drawbacks will continue to be the best choice in most applications

  19. High Temperature, Wireless Seismometer Sensor for Venus

    Science.gov (United States)

    Ponchak, George E.; Scardelletti, Maximilian C.; Taylor, Brandt; Beard, Steve; Meredith, Roger D.; Beheim, Glenn M.; Hunter Gary W.; Kiefer, Walter S.

    2012-01-01

    Space agency mission plans state the need to measure the seismic activity on Venus. Because of the high temperature on Venus (462? C average surface temperature) and the difficulty in placing and wiring multiple sensors using robots, a high temperature, wireless sensor using a wide bandgap semiconductor is an attractive option. This paper presents the description and proof of concept measurements of a high temperature, wireless seismometer sensor for Venus. A variation in inductance of a coil caused by the movement of an aluminum probe held in the coil and attached to a balanced leaf-spring seismometer causes a variation of 700 Hz in the transmitted signal from the oscillator/sensor system at 426? C. This result indicates that the concept may be used on Venus.

  20. Materials for high-temperature fuel cells

    CERN Document Server

    Jiang, San Ping; Lu, Max

    2013-01-01

    There are a large number of books available on fuel cells; however, the majority are on specific types of fuel cells such as solid oxide fuel cells, proton exchange membrane fuel cells, or on specific technical aspects of fuel cells, e.g., the system or stack engineering. Thus, there is a need for a book focused on materials requirements in fuel cells. Key Materials in High-Temperature Fuel Cells is a concise source of the most important and key materials and catalysts in high-temperature fuel cells with emphasis on the most important solid oxide fuel cells. A related book will cover key mater

  1. Melt processed high-temperature superconductors

    CERN Document Server

    1993-01-01

    The achievement of large critical currents is critical to the applications of high-temperature superconductors. Recent developments have shown that melt processing is suitable for producing high J c oxide superconductors. Using magnetic forces between such high J c oxide superconductors and magnets, a person could be levitated.This book has grown largely out of research works on melt processing of high-temperature superconductors conducted at ISTEC Superconductivity Research Laboratory. The chapters build on melt processing, microstructural characterization, fundamentals of flux pinning, criti

  2. Electrons and Phonons in High Temperature Superconductors

    Directory of Open Access Journals (Sweden)

    Anu Singh

    2013-01-01

    Full Text Available The defect-induced anharmonic phonon-electron problem in high-temperature superconductors has been investigated with the help of double time thermodynamic electron and phonon Green’s function theory using a comprehensive Hamiltonian which includes the contribution due to unperturbed electrons and phonons, anharmonic phonons, impurities, and interactions of electrons and phonons. This formulation enables one to resolve the problem of electronic heat transport and equilibrium phenomenon in high-temperature superconductors in an amicable way. The problem of electronic heat capacity and electron-phonon problem has been taken up with special reference to the anharmonicity, defect concentration electron-phonon coupling, and temperature dependence.

  3. Neutron experiments on high-temperature superconductors

    Science.gov (United States)

    Mook, H. A., Jr.

    1989-12-01

    This report details the trip to the ILL to perform neutron scattering research on high-temperature superconductivity. The trip was very successful because of the excellent users' facilities available at the ILL. The data we accumulated were of high quality and will make an impact on our understanding of high-temperature superconductivity. However, we cannot continue to run a research program in this field with the limited beam time available at the ILL. To make substantial progress in this field, we must restart the High Flux Isotope Reactor.

  4. Development of filter element from nanocomposites of ultra high molar mass polyethylene having silver nanoparticles; Desenvolvimento de elemento filtrante a partir de nanocompositos de polietileno de ultra-alta massa molar contendo nanoparticulas de prata

    Energy Technology Data Exchange (ETDEWEB)

    Bizzo, Maurizio A.; Wang, S. Hui, E-mail: mbizzo@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica de Engenharia Metalurgica e de Materiais

    2015-07-01

    The production of polymer based filter elements for water is widespread in the market but has an undesirable characteristic, they are not always efficient and capable of retaining or eliminating microorganisms. This paper proposes the production of filters with biocidal activity, comprised by nanocomposites of ultra-high molar mass polyethylene (UHMMPE) containing silver nanoparticles. The polymer is responsible for the uniform porous structure of the filter element and the Ag nanoparticles for its biocidal action. The filter elements were produced from two kinds of UHMMPE particles with different particle size distributions, one in the range of 150 to 200μm and the other of 300 to 400μm. Samples were collected from the obtained filter elements and characterized by X-ray diffractometry, scanning electron microscopy and microanalysis. The results indicated the formation of nanocomposite containing silver nanoparticles. (author)

  5. High temperatures influence sexual development differentially in ...

    Indian Academy of Sciences (India)

    Although sex determination in amphibians is believed to be a genetic process, environmental factors such as temperatureare known to influence the sex differentiation and development. Extremely low and high temperatures influence gonadaldevelopment and sex ratio in amphibians but the mechanism of action is not ...

  6. High-temperature granulites and supercontinents

    Directory of Open Access Journals (Sweden)

    J.L.R. Touret

    2016-01-01

    Full Text Available The formation of continents involves a combination of magmatic and metamorphic processes. These processes become indistinguishable at the crust-mantle interface, where the pressure-temperature (P-T conditions of (ultra high-temperature granulites and magmatic rocks are similar. Continents grow laterally, by magmatic activity above oceanic subduction zones (high-pressure metamorphic setting, and vertically by accumulation of mantle-derived magmas at the base of the crust (high-temperature metamorphic setting. Both events are separated from each other in time; the vertical accretion postdating lateral growth by several tens of millions of years. Fluid inclusion data indicate that during the high-temperature metamorphic episode the granulite lower crust is invaded by large amounts of low H2O-activity fluids including high-density CO2 and concentrated saline solutions (brines. These fluids are expelled from the lower crust to higher crustal levels at the end of the high-grade metamorphic event. The final amalgamation of supercontinents corresponds to episodes of ultra-high temperature metamorphism involving large-scale accumulation of these low-water activity fluids in the lower crust. This accumulation causes tectonic instability, which together with the heat input from the sub-continental lithospheric mantle, leads to the disruption of supercontinents. Thus, the fragmentation of a supercontinent is already programmed at the time of its amalgamation.

  7. High Temperature Corrosion in Biomass Incineration Plants

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Maahn, Ernst emanuel; Gotthjælp, K.

    1997-01-01

    The aim of the project is to study the role of ash deposits in high temperature corrosion of superheater materials in biomass and refuse fire combined heat and power plants. The project has included the two main activities: a) A chemical characterisation of ash deposits collected from a major...

  8. High Temperature Resistant Exhaust Valve Spindle

    DEFF Research Database (Denmark)

    Bihlet, Uffe Ditlev

    of the engine, new high temperature alloys are required for a specific engine component, the exhaust valve spindle. Two alloys are used for an exhaust valve spindle; one for the bottom of the spindle, and one for the spindle seat. Being placed in the exhaust gas stream, combustion products such as V2O5 and Na2...

  9. Helium-cooled high temperature reactors

    Energy Technology Data Exchange (ETDEWEB)

    Trauger, D.B.

    1985-01-01

    Experience with several helium cooled reactors has been favorable, and two commercial plants are now operating. Both of these units are of the High Temperature Graphite Gas Cooled concept, one in the United States and the other in the Federal Republic of Germany. The initial helium charge for a reactor of the 1000 MW(e) size is modest, approx.15,000 kg.

  10. Thermoelastic properties of minerals at high temperature

    Indian Academy of Sciences (India)

    under high temperatures and calculated the second-order elastic constant (Cij ) and bulk modulus. (KT) of the above minerals, in two cases first by taking Anderson–Gruneisen parameter (δT) as temperature-independent and then by treating δT as temperature-dependent parameter. The results obtained when δT is ...

  11. High temperature spectral gamma well logging

    Energy Technology Data Exchange (ETDEWEB)

    Normann, R.A.; Henfling, J.A.

    1997-01-01

    A high temperature spectral gamma tool has been designed and built for use in small-diameter geothermal exploration wells. Several engineering judgments are discussed regarding operating parameters, well model selection, and signal processing. An actual well log at elevated temperatures is given with spectral gamma reading showing repeatability.

  12. Complex performance during exposure to high temperatures.

    Science.gov (United States)

    1969-06-01

    The effects of high temperature on psychomotor performance and physiological function were studied on male pilots (age 30-51) holding a current medical certificate. A total of 41 runs were made at neutral (23.8C (75F), or hot (60.0C (140F), 71.1C (16...

  13. Thermoelastic properties of minerals at high temperature

    Indian Academy of Sciences (India)

    The knowledge of elasticity of the minerals is useful for interpreting the structure and composition of the lower mantle and also in seismic studies. The purpose of the present study is to discuss a simple and straightforward method for evaluating thermoelastic properties of minerals at high temperatures. We have extended ...

  14. High Temperature Ultrasonic Transducer for Real-time Inspection

    Science.gov (United States)

    Amini, Mohammad Hossein; Sinclair, Anthony N.; Coyle, Thomas W.

    A broadband ultrasonic transducer with a novel porous ceramic backing layer is introduced to operate at 700 °C. 36° Y-cut lithium niobate (LiNbO3) single crystal was selected for the piezoelectric element. By appropriate choice of constituent materials, porosity and pore size, the acoustic impedance and attenuation of a zirconia-based backing layer were optimized. An active brazing alloy with high temperature and chemical stability was selected to bond the transducer layers together. Prototype transducers have been tested at temperatures up to 700 °C. The experiments confirmed that transducer integrity was maintained.

  15. High temperature charge amplifier for geothermal applications

    Science.gov (United States)

    Lindblom, Scott C.; Maldonado, Frank J.; Henfling, Joseph A.

    2015-12-08

    An amplifier circuit in a multi-chip module includes a charge to voltage converter circuit, a voltage amplifier a low pass filter and a voltage to current converter. The charge to voltage converter receives a signal representing an electrical charge and generates a voltage signal proportional to the input signal. The voltage amplifier receives the voltage signal from the charge to voltage converter, then amplifies the voltage signal by the gain factor to output an amplified voltage signal. The lowpass filter passes low frequency components of the amplified voltage signal and attenuates frequency components greater than a cutoff frequency. The voltage to current converter receives the output signal of the lowpass filter and converts the output signal to a current output signal; wherein an amplifier circuit output is selectable between the output signal of the lowpass filter and the current output signal.

  16. High Temperature Wireless Communication And Electronics For Harsh Environment Applications

    Science.gov (United States)

    Hunter, G. W.; Neudeck, P. G.; Beheim, G. M.; Ponchak, G. E.; Chen, L.-Y

    2007-01-01

    In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary. These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and electronics, with associated packaging, that will be able to operate under the harsh environments present in an engine. However, given the harsh environments inherent in propulsion systems, the development of engine-compatible electronics and sensors is not straightforward. The ability of a sensor system to operate in a given environment often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature environments where supporting technologies are often not capable of operation in engine conditions. Further, for every sensor going into an engine environment, i.e., for every new piece of hardware that improves the in-situ intelligence of the components, communication wires almost always must follow. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems. NASA Glenn Research Center (GRC) is presently leading the development of electronics, communication systems, and sensors capable of prolonged stable

  17. Nonlinear performance characterization in an eight-pole quasi-elliptic bandpass filter

    Energy Technology Data Exchange (ETDEWEB)

    Mateu, J [Centre Tecnologic de Telecomunicacions de Catalunya, Edifici Nexus, Gran Capita, 2nd Floor, Room 202-203, 08034 Barcelona (Spain); Collado, C [Universitat Politecnica de Catalunya, Department of Signal Theory and Communications, Campus Nord UPC, D3-Jordi Girona, 1-3, 08034 Barcelona (Spain); Menendez, O [Universitat Politecnica de Catalunya, Department of Signal Theory and Communications, Campus Nord UPC, D3-Jordi Girona, 1-3, 08034 Barcelona (Spain); O' Callaghan, J M [Universitat Politecnica de Catalunya, Department of Signal Theory and Communications, Campus Nord UPC, D3-Jordi Girona, 1-3, 08034 Barcelona (Spain)

    2004-05-01

    In this work we predict the nonlinear behaviour of an eight-pole quasi-elliptic bandpass high temperature superconducting (HTS) filter with an equivalent circuit extracted from intermodulation measurements performed at the centre of the filter passband. We present measurements that show that the equivalent circuit is able to predict the intermodulation products produced by the filter when driven by two in-band or out-of-band sinusoidal signals. Numerical techniques based on harmonic balance are used to extract the elements of the equivalent circuit and to simulate its nonlinear performance.

  18. High Temperature Mechanisms for Venus Exploration

    Science.gov (United States)

    Ji, Jerri; Narine, Roop; Kumar, Nishant; Singh, Sase; Gorevan, Steven

    Future Venus missions, including New Frontiers Venus In-Situ Explorer and three Flagship Missions - Venus Geophysical Network, Venus Mobile Explorer and Venus Surface Sample Return all focus on searching for evidence of past climate change both on the surface and in the atmospheric composition as well as in the interior dynamics of the planet. In order to achieve these goals and objectives, many key technologies need to be developed for the Venus extreme environment. These key technologies include sample acquisition systems and other high-temperature mechanisms and mobility systems capable of extended operation when directly exposed to the Venus surface or lower atmosphere environment. Honeybee Robotics has developed two types of high temperature motors, the materials and components in both motors were selected based on the requirement to survive temperatures above a minimum of 460° C, at earth atmosphere. The prototype Switched Reluctance Motor (SRM) has been operated non-continuously for over 20 hours at Venus-like conditions (460° C temperature, mostly CO2 gas environment) and it remains functional. A drilling system, actuated by two SRMs was tested in Venus-like conditions, 460° C temperature and mostly CO2 gas environment, for more than 15 hours. The drill successfully completed three tests by drilling into chalk up to 6 inches deep in each test. A first generation Brushless DC (BLDC) Motor and high temperature resolver were also tested and the feasibility of the designs was demonstrated by the extended operation of both devices under Venus-like condition. Further development of the BLDC motor and resolver continues and these devices will, ultimately, be integrated into the development of a high temperature sample acquisition scoop and high temperature joint (awarded SBIR Phase II in October, 2007). Both the SR and BLDC motors will undergo extensive testing at Venus temperature and pressure (TRL6) and are expected to be mission ready before the next New

  19. Stability projections for high temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Laquer, H.L.; Edeskuty, F.J.; Hassenzahl, W.V.; Wipf, S.L.

    1989-03-01

    The stability of the new high temperature superconducting oxides has been analyzed, using the methodology developed over the last 25 years for conventional Type II superconductors. The results are presented in graphical form for the temperature range from 4 to 100 K. For a 90 K superconductor the first flux jump field peaks above 7 T at 60 K, ( and for a 120 k superconductor it peaks above 12 T at 75 K). The maximum adiabatically stable thickness increases dramatically. The linear dimension of the minimum propagating zone increases by a factor of 3 to 5, and the quench propagation velocity drops by 4 orders of magnitude. The high temperature superconducting materials will, therefore, have much higher stability than conventional Type II superconductors; their high flux jump fields will make ultra-fine multifilamentary conductors unnecessary and improve the outlook for tape conductors; the energy to create a propagating zone is increased; however, methods of coil protection will have to be modified.

  20. Metallic Membranes for High Temperature Hydrogen Separation

    DEFF Research Database (Denmark)

    Ma, Y.H.; Catalano, Jacopo; Guazzone, Federico

    2013-01-01

    Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water-gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd...... membrane fabrication methods have matured over the last decades, and the deposition of very thin films (1–5 µm) of Pd over porous ceramics or modified porous metal supports is quite common. The H2 permeances and the selectivities achieved at 400–500 °C were in the order of 50–100 Nm3/m/h/bar0.5 and greater...... than 1000, respectively. This chapter describes in detail composite Pd-based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400...

  1. High temperature aircraft research furnace facilities

    Science.gov (United States)

    Smith, James E., Jr.; Cashon, John L.

    1992-01-01

    Focus is on the design, fabrication, and development of the High Temperature Aircraft Research Furnace Facilities (HTARFF). The HTARFF was developed to process electrically conductive materials with high melting points in a low gravity environment. The basic principle of operation is to accurately translate a high temperature arc-plasma gas front as it orbits around a cylindrical sample, thereby making it possible to precisely traverse the entire surface of a sample. The furnace utilizes the gas-tungsten-arc-welding (GTAW) process, also commonly referred to as Tungsten-Inert-Gas (TIG). The HTARFF was developed to further research efforts in the areas of directional solidification, float-zone processing, welding in a low-gravity environment, and segregation effects in metals. The furnace is intended for use aboard the NASA-JSC Reduced Gravity Program KC-135A Aircraft.

  2. High Temperature Phenomena in Shock Waves

    CERN Document Server

    2012-01-01

    The high temperatures generated in gases by shock waves give rise to physical and chemical phenomena such as molecular vibrational excitation, dissociation, ionization, chemical reactions and inherently related radiation. In continuum regime, these processes start from the wave front, so that generally the gaseous media behind shock waves may be in a thermodynamic and chemical non-equilibrium state. This book presents the state of knowledge of these phenomena. Thus, the thermodynamic properties of high temperature gases, including the plasma state are described, as well as the kinetics of the various chemical phenomena cited above. Numerous results of measurement and computation of vibrational relaxation times, dissociation and reaction rate constants are given, and various ionization and radiative mechanisms and processes are presented. The coupling between these different phenomena is taken into account as well as their interaction with the flow-field. Particular points such as the case of rarefied flows an...

  3. Silicon Carbide Nanotube Oxidation at High Temperatures

    Science.gov (United States)

    Ahlborg, Nadia; Zhu, Dongming

    2012-01-01

    Silicon Carbide Nanotubes (SiCNTs) have high mechanical strength and also have many potential functional applications. In this study, SiCNTs were investigated for use in strengthening high temperature silicate and oxide materials for high performance ceramic nanocomposites and environmental barrier coating bond coats. The high · temperature oxidation behavior of the nanotubes was of particular interest. The SiCNTs were synthesized by a direct reactive conversion process of multiwall carbon nanotubes and silicon at high temperature. Thermogravimetric analysis (TGA) was used to study the oxidation kinetics of SiCNTs at temperatures ranging from 800degC to1300degC. The specific oxidation mechanisms were also investigated.

  4. High temperature impedance spectroscopy of barium stannate ...

    Indian Academy of Sciences (India)

    Abstract. Polycrystalline powder of BaSnO3 was prepared at 1300 ◦C using a high-temperature solid-state reac- tion technique. X-ray diffraction analysis indicated the formation of a single-phase cubic structure with lattice parameter: a = (4·1158 ± 0·0003) Å. The synthesized powder was characterized using X-ray diffraction ...

  5. High temperature materials; Materiaux a hautes temperatures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The aim of this workshop is to share the needs of high temperature and nuclear fuel materials for future nuclear systems, to take stock of the status of researches in this domain and to propose some cooperation works between the different research organisations. The future nuclear systems are the very high temperature (850 to 1200 deg. C) gas cooled reactors (GCR) and the molten salt reactors (MSR). These systems include not only the reactor but also the fabrication and reprocessing of the spent fuel. This document brings together the transparencies of 13 communications among the 25 given at the workshop: 1) characteristics and needs of future systems: specifications, materials and fuel needs for fast spectrum GCR and very high temperature GCR; 2) high temperature materials out of neutron flux: thermal barriers: materials, resistance, lifetimes; nickel-base metal alloys: status of knowledge, mechanical behaviour, possible applications; corrosion linked with the gas coolant: knowledge and problems to be solved; super-alloys for turbines: alloys for blades and discs; corrosion linked with MSR: knowledge and problems to be solved; 3) materials for reactor core structure: nuclear graphite and carbon; fuel assembly structure materials of the GCR with fast neutron spectrum: status of knowledge and ceramics and cermets needs; silicon carbide as fuel confinement material, study of irradiation induced defects; migration of fission products, I and Cs in SiC; 4) materials for hydrogen production: status of the knowledge and needs for the thermochemical cycle; 5) technologies: GCR components and the associated material needs: compact exchangers, pumps, turbines; MSR components: valves, exchangers, pumps. (J.S.)

  6. High temperature mechanical properties of iron aluminides

    Directory of Open Access Journals (Sweden)

    Morris, D. G.

    2001-04-01

    Full Text Available Considerable attention has been given to the iron aluminide family of intermetallics over the past years since they offer considerable potential as engineering materials for intermediate to high temperature applications, particularly in cases where extreme oxidation or corrosion resistance is required. Despite efforts at alloy development, however, high temperature strength remains low and creep resistance poor. Reasons for the poor high-temperature strength of iron aluminides will be discussed, based on the ordered crystal structure, the dislocation structure found in the material, and the mechanisms of dislocation pinning operating. Alternative ways of improving high temperature strength by microstructural modification and the inclusion of second phase particles will also be considered.

    Durante los últimos años se ha prestado mucha atención a la familia de intermetálicos Fe-Al, puesto que estos constituyen un considerable potencial como materiales de ingeniería en aplicaciones a temperaturas intermedias o altas, sobre todo en casos donde se necesita alta resistencia a la oxidación o corrosión. A pesar del considerable esfuerzo desarrollado para obtener aleaciones con mejores propiedades, su resistencia mecánica a alta temperatura no es muy elevada. Se discutirán los aspectos que contribuyen a la baja resistencia mecánica a temperatura elevada en función de la estructura de dislocaciones y los mecanismos de anclaje que operan en este intermetálico. Se considerarán, también, maneras alternativas para mejorar la resistencia a temperatura elevada mediante la modificación de la microestructura y la incorporación de partículas de segunda fase.

  7. Thermal fuse for high-temperature batteries

    Science.gov (United States)

    Jungst, Rudolph G.; Armijo, James R.; Frear, Darrel R.

    2000-01-01

    A thermal fuse, preferably for a high-temperature battery, comprising leads and a body therebetween having a melting point between approximately 400.degree. C. and 500.degree. C. The body is preferably an alloy of Ag--Mg, Ag--Sb, Al--Ge, Au--In, Bi--Te, Cd--Sb, Cu--Mg, In--Sb, Mg--Pb, Pb--Pd, Sb--Zn, Sn--Te, or Mg--Al.

  8. High Temperature Perforating System for Geothermal Applications

    Energy Technology Data Exchange (ETDEWEB)

    Smart, Moises E. [Schlumberger Technology Corporation, Sugar Land, TX (United States)

    2017-02-28

    The objective of this project is to develop a perforating system consisting of all the explosive components and hardware, capable of reliable performance in high temperatures geothermal wells (>200 ºC). In this light we will focused on engineering development of these components, characterization of the explosive raw powder and developing the internal infrastructure to increase the production of the explosive from laboratory scale to industrial scale.

  9. High-temperature technological processes: Thermophysical principles

    Science.gov (United States)

    Rykalin, N. N.; Uglov, A. A.; Anishchenko, L. M.

    The book is concerned with the principles of thermodynamics and heat transfer theory underlying high-temperature technological processes. Some characteristics of electromagnetic radiation and heat transfer in solids, liquids, and gases are reviewed, and boundary layer theory, surface phenomena, and phase transitions are examined. The discussion includes an analysis of a number of specific processes, such as treatment by concentrated energy fluxes (electron-beam and laser processing) and plasma machining.

  10. High temperature, high power piezoelectric composite transducers.

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-08-08

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  11. High temperature dynamic engine seal technology development

    Science.gov (United States)

    Steinetz, Bruce M.; Dellacorte, Christopher; Machinchick, Michael; Mutharasan, Rajakkannu; Du, Guang-Wu; Ko, Frank; Sirocky, Paul J.; Miller, Jeffrey H.

    1992-01-01

    Combined cycle ramjet/scramjet engines being designed for advanced hypersonic vehicles, including the National Aerospace Plane (NASP), require innovative high temperature dynamic seals to seal the sliding interfaces of the articulated engine panels. New seals are required that will operate hot (1200 to 2000 F), seal pressures ranging from 0 to 100 psi, remain flexible to accommodate significant sidewall distortions, and resist abrasion over the engine's operational life. This report reviews the recent high temperature durability screening assessments of a new braided rope seal concept, braided of emerging high temperature materials, that shows promise of meeting many of the seal demands of hypersonic engines. The paper presents durability data for: (1) the fundamental seal building blocks, a range of candidate ceramic fiber tows; and for (2) braided rope seal subelements scrubbed under engine simulated sliding, temperature, and preload conditions. Seal material/architecture attributes and limitations are identified through the investigations performed. The paper summarizes the current seal technology development status and presents areas in which future work will be performed.

  12. New fluid for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Riva, M.; Flohr, F. [Solvay Fluor GmbH, Hannover (Germany); Froeba, A.P. [Lehrstuhl fuer Technische Thermodynamik (LTT), Univ. Erlangen (Germany)

    2006-12-15

    As a result of the worldwide increased consumption of energy, energy saving measures come more and more in the focus of commercial acting. Besides the efficiency enhancement of energy consuming systems the utilization of waste heat is an additional possibility of saving energy. Areas where this might be feasible are geothermal power plants, local combined heat and power plants, solar-thermal-systems and high temperature heat pumps (HTHP). All these applications need a transfer fluid which secures the transport of the energy from it's source to the place where it is needed at high temperatures. The paper will start with a description or overview of promising energy sources and their utilization. The thermophysical properties of an azeotropic binary mixture of HFC-365mfc and a per-fluoro-poly-ether (PFPE) which fulfils the requirements on a high temperature working fluid are introduced in the second part of the paper. First results and practical experiences in an ORC process are shown in this context followed by an estimation regarding the saved energy or the improved efficiency respectively for other applications The paper will end with a brief outlook on possible new applications e.g. autarkic systems or immersion cooling of electrical parts. (orig.)

  13. Laser Plasma Coupling for High Temperature Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Kruer, W.

    1999-11-04

    Simple scaling models indicate that quite high radiation temperatures can be achieved in hohlraums driven with the National Ignition Facility. A scaling estimate for the radiation temperature versus pulse duration for different size NIF hohlraums is shown in Figure 1. Note that a radiation temperature of about 650 ev is projected for a so-called scale 1 hohlraum (length 2.6mm, diameter 1.6mm). With such high temperature hohlraums, for example, opacity experiments could be carried out using more relevant high Z materials rather than low Z surrogates. These projections of high temperature hohlraums are uncertain, since the scaling model does not allow for the very strongly-driven laser plasma coupling physics. Lasnex calculations have been carried out to estimate the plasma and irradiation conditions in a scale 1 hohlraum driven by NIF. Linear instability gains as high as exp(100) have been found for stimulated Brillouin scattering, and other laser-driven instabilities are also far above their thresholds. More understanding of the very strongly-driven coupling physics is clearly needed in order to more realistically assess and improve the prospects for high temperature hohlraums. Not surprisingly, this regime has been avoided for inertial fusion applications and so is relatively unexplored.

  14. Vapor phase lubrication of high temperature alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hanyaloglu, B.F.; Graham, E.E.; Oreskovic, T.; Hajj, C.G. [Cleveland State Univ., OH (United States)

    1995-06-01

    In a previous study, it was found that when a nickel-based superalloy IN750 was heated to high temperatures, a passive layer of aluminum oxide formed on the surface, preventing vapor phase lubrication. In this study, two nickel-chrome-iron alloys and a nickel-copper alloy were studied for high temperature lubrication to see if these alloys, which contained small amounts of aluminum, would exhibit similar behavior. It was found that under static conditions, all three alloys formed a lubricious nodular coating when exposed to a vapor of aryl phosphate. Under dynamic sliding conditions at 500{degrees}C, these alloys were successfully lubricated with a coefficient of friction of 0.1 and no detectable wear. In order to explain these results, a direct correlation between successful vapor phase lubrication and the composition of the alloys containing aluminum has been proposed. If the ratio of copper/aluminum or iron/aluminum is greater that 100 vapor phase, lubrication will be successful. If the ratio is less than 10, a passive aluminum oxide layer will prevent vapor phase lubrication. By selecting alloys with a high iron or copper content, vapor phase lubrication can provide excellent lubrication at high temperatures. 14 refs., 11 figs., 1 tab.

  15. High-temperature biotrickling filtration of hydrogen sulphide.

    Science.gov (United States)

    Datta, Indrani; Fulthorpe, Roberta R; Sharma, Shobha; Allen, D Grant

    2007-03-01

    Biofiltration of malodorous reduced sulphur compounds such as hydrogen sulphide has been confined to emissions that are at temperatures below 40 degrees C despite the fact that there are many industrial emissions (e.g. in the pulp and paper industry) at temperatures well above 40 degrees C. This paper describes our study on the successful treatment of hydrogen sulphide gas at temperatures of 40, 50, 60 and 70 degrees C using a microbial community obtained from a hot spring. Three biotrickling filter (BTF) systems were set up in parallel for a continuous run of 9 months to operate at three different temperatures, one of which was always at 40 degrees C as a mesophilic control and the other two were for exploring high-temperature operation up to 70 degrees C. The continuous experiment and a series of batch experiments in glass bottles (250 ml) showed that addition of glucose and monosodium glutamate enhanced thermophilic biofiltration of hydrogen sulphide gas and a removal rate of 40 g m(-3) h(-1) was achieved at 70 degrees C. We suggest that the glucose is acting as a carbon source for the existing microbial community in the BTFs, whereas glutamate is acting as a compatible solute. The use of such organic compounds to enhance biodegradation of hydrogen sulphide, particularly at high temperatures, has not been demonstrated to our knowledge and, hence, has opened up a range of possibilities for applying biofiltration to hot gas effluent.

  16. Novel High Temperature Magnetic Bearings for Space Vehicle Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Previous high temperature magnetic bearings employed only electromagnets. The work proposed in this SBIR program seeks to utilize High Temperature Permanent Magnets...

  17. Novel High Temperature Magnetic Bearings for Space Vehicle Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Previous high temperature magnetic bearings employed electromagnets only. The work proposed in this SBIR program seeks to utilize High Temperature Permanent Magnets...

  18. High Temperature Fluoride Salt Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cunningham, Richard Burns [Univ. of Tennessee, Knoxville, TN (United States); Fugate, David L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peretz, Fred J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robb, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yoder, Jr, Graydon L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    Effective high-temperature thermal energy exchange and delivery at temperatures over 600°C has the potential of significant impact by reducing both the capital and operating cost of energy conversion and transport systems. It is one of the key technologies necessary for efficient hydrogen production and could potentially enhance efficiencies of high-temperature solar systems. Today, there are no standard commercially available high-performance heat transfer fluids above 600°C. High pressures associated with water and gaseous coolants (such as helium) at elevated temperatures impose limiting design conditions for the materials in most energy systems. Liquid salts offer high-temperature capabilities at low vapor pressures, good heat transport properties, and reasonable costs and are therefore leading candidate fluids for next-generation energy production. Liquid-fluoride-salt-cooled, graphite-moderated reactors, referred to as Fluoride Salt Reactors (FHRs), are specifically designed to exploit the excellent heat transfer properties of liquid fluoride salts while maximizing their thermal efficiency and minimizing cost. The FHR s outstanding heat transfer properties, combined with its fully passive safety, make this reactor the most technologically desirable nuclear power reactor class for next-generation energy production. Multiple FHR designs are presently being considered. These range from the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) [1] design originally developed by UC-Berkeley to the Small Advanced High-Temperature Reactor (SmAHTR) and the large scale FHR both being developed at ORNL [2]. The value of high-temperature, molten-salt-cooled reactors is also recognized internationally, and Czechoslovakia, France, India, and China all have salt-cooled reactor development under way. The liquid salt experiment presently being developed uses the PB-AHTR as its focus. One core design of the PB-AHTR features multiple 20 cm diameter, 3.2 m long fuel channels

  19. Microstructural Evolution and Mechanical Behavior of High Temperature Solders: Effects of High Temperature Aging

    Science.gov (United States)

    Hasnine, M.; Tolla, B.; Vahora, N.

    2017-12-01

    This paper explores the effects of aging on the mechanical behavior, microstructure evolution and IMC formation on different surface finishes of two high temperature solders, Sn-5 wt.% Ag and Sn-5 wt.% Sb. High temperature aging showed significant degradation of Sn-5 wt.% Ag solder hardness (34%) while aging has little effect on Sn-5 wt.% Sb solder. Sn-5 wt.% Ag experienced rapid grain growth as well as the coarsening of particles during aging. Sn-5 wt.% Sb showed a stable microstructure due to solid solution strengthening and the stable nature of SnSb precipitates. The increase of intermetallic compound (IMC) thickness during aging follows a parabolic relationship with time. Regression analysis (time exponent, n) indicated that IMC growth kinetics is controlled by a diffusion mechanism. The results have important implications in the selection of high temperature solders used in high temperature applications.

  20. Phase transformation strengthening of high-temperature superalloys

    Science.gov (United States)

    Smith, T. M.; Esser, B. D.; Antolin, N.; Carlsson, A.; Williams, R. E. A.; Wessman, A.; Hanlon, T.; Fraser, H. L.; Windl, W.; McComb, D. W.; Mills, M. J.

    2016-11-01

    Decades of research has been focused on improving the high-temperature properties of nickel-based superalloys, an essential class of materials used in the hot section of jet turbine engines, allowing increased engine efficiency and reduced CO2 emissions. Here we introduce a new `phase-transformation strengthening' mechanism that resists high-temperature creep deformation in nickel-based superalloys, where specific alloying elements inhibit the deleterious deformation mode of nanotwinning at temperatures above 700 °C. Ultra-high-resolution structure and composition analysis via scanning transmission electron microscopy, combined with density functional theory calculations, reveals that a superalloy with higher concentrations of the elements titanium, tantalum and niobium encourage a shear-induced solid-state transformation from the γ' to η phase along stacking faults in γ' precipitates, which would normally be the precursors of deformation twins. This nanoscale η phase creates a low-energy structure that inhibits thickening of stacking faults into twins, leading to significant improvement in creep properties.

  1. Design of High Field Solenoids made of High Temperature Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bartalesi, Antonio; /Pisa U.

    2010-12-01

    This thesis starts from the analytical mechanical analysis of a superconducting solenoid, loaded by self generated Lorentz forces. Also, a finite element model is proposed and verified with the analytical results. To study the anisotropic behavior of a coil made by layers of superconductor and insulation, a finite element meso-mechanic model is proposed and designed. The resulting material properties are then used in the main solenoid analysis. In parallel, design work is performed as well: an existing Insert Test Facility (ITF) is adapted and structurally verified to support a coil made of YBa{sub 2}Cu{sub 3}O{sub 7}, a High Temperature Superconductor (HTS). Finally, a technological winding process was proposed and the required tooling is designed.

  2. Damping in high-temperature superconducting levitation systems

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R.

    2009-12-15

    Methods and apparatuses for improved damping in high-temperature superconducting levitation systems are disclosed. A superconducting element (e.g., a stator) generating a magnetic field and a magnet (e.g. a rotor) supported by the magnetic field are provided such that the superconducting element is supported relative to a ground state with damped motion substantially perpendicular to the support of the magnetic field on the magnet. Applying this, a cryostat housing the superconducting bearing may be coupled to the ground state with high damping but low radial stiffness, such that its resonant frequency is less than that of the superconducting bearing. The damping of the cryostat may be substantially transferred to the levitated magnetic rotor, thus, providing damping without affecting the rotational loss, as can be derived applying coupled harmonic oscillator theory in rotor dynamics. Thus, damping can be provided to a levitated object, without substantially affecting the rotational loss.

  3. Development of ultrasonic high temperature system for severe accidents research

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Kil Mo; Kang, Kyung Ho; Kim, Young Ro and others

    2000-07-01

    The aims of this study are to find a gap formation between corium melt and the reactor lower head vessel, to verify the principle of the gap formation and to analyze the effect of the gap formation on the thermal behavior of corium melt and the lower plenum. This report aims at suggesting development of a new high temperature measuring system using an ultrasonic method which overcomes the limitations of the present thermocouple method used for severe accident experiments. Also, this report describes the design and manufacturing method of the ultrasonic system. At that time, the sensor element is fabricated to a reflective element using 1mm diameter and 50 mm and 80 mm long tungsten alloy wires. This temperature measuring system is intended to measure up to 2800 deg C.

  4. Ultra-High Temperature Distributed Wireless Sensors

    Energy Technology Data Exchange (ETDEWEB)

    May, Russell; Rumpf, Raymond; Coggin, John; Davis, Williams; Yang, Taeyoung; O' Donnell, Alan; Bresnahan, Peter

    2013-03-31

    Research was conducted towards the development of a passive wireless sensor for measurement of temperature in coal gasifiers and coal-fired boiler plants. Approaches investigated included metamaterial sensors based on guided mode resonance filters, and temperature-sensitive antennas that modulate the frequency of incident radio waves as they are re-radiated by the antenna. In the guided mode resonant filter metamaterial approach, temperature is encoded as changes in the sharpness of the filter response, which changes with temperature because the dielectric loss of the guided mode resonance filter is temperature-dependent. In the mechanically modulated antenna approach, the resonant frequency of a vibrating cantilever beam attached to the antenna changes with temperature. The vibration of the beam perturbs the electrical impedance of the antenna, so that incident radio waves are phase modulated at a frequency equal to the resonant frequency of the vibrating beam. Since the beam resonant frequency depends on temperature, a Doppler radar can be used to remotely measure the temperature of the antenna. Laboratory testing of the guided mode resonance filter failed to produce the spectral response predicted by simulations. It was concluded that the spectral response was dominated by spectral reflections of radio waves incident on the filter. Laboratory testing of the mechanically modulated antenna demonstrated that the device frequency shifted incident radio waves, and that the frequency of the re-radiated waves varied linearly with temperature. Radio wave propagation tests in the convection pass of a small research boiler plant identified a spectral window between 10 and 13 GHz for low loss propagation of radio waves in the interior of the boiler.

  5. High temperature superconductors applications in telecommunications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A.A.; Li, J.; Zhang, M.F. [Prairie View A& M Univ., Texas (United States)

    1994-12-31

    The purpose of this paper is twofold: to discuss high temperature superconductors with specific reference to their employment in telecommunications applications; and to discuss a few of the limitations of the normally employed two-fluid model. While the debate on the actual usage of high temperature superconductors in the design of electronic and telecommunications devices-obvious advantages versus practical difficulties-needs to be settled in the near future, it is of great interest to investigate the parameters and the assumptions that will be employed in such designs. This paper deals with the issue of providing the microwave design engineer with performance data for such superconducting waveguides. The values of conductivity and surface resistance, which are the primary determining factors of a waveguide performance, are computed based on the two-fluid model. A comparison between two models-a theoretical one in terms of microscopic parameters (termed Model A) and an experimental fit in terms of macroscopic parameters (termed Model B)-shows the limitations and the resulting ambiguities of the two-fluid model at high frequencies and at temperatures close to the transition temperature. The validity of the two-fluid model is then discussed. Our preliminary results show that the electrical transport description in the normal and superconducting phases as they are formulated in the two-fluid model needs to be modified to incorporate the new and special features of high temperature superconductors. Parameters describing the waveguide performance-conductivity, surface resistance and attenuation constant-will be computed. Potential applications in communications networks and large scale integrated circuits will be discussed. Some of the ongoing work will be reported. In particular, a brief proposal is made to investigate of the effects of electromagnetic interference and the concomitant notion of electromagnetic compatibility (EMI/EMC) of high T{sub c} superconductors.

  6. High temperature sensors for exhaust diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Svenningstorp, Henrik

    2000-07-01

    One of the largest problems that we will have to deal with on this planet this millennium is to stop the pollution of our environment. In many of the ongoing works to reduce toxic emissions, gas sensors capable of enduring rough environments and high temperatures, would be a great tool. The different applications where sensors like this would be useful vary between everything from online measurement in the paper industry and food industry to measurement in the exhaust pipe of a car. In my project we have tested Schottky diodes and MlSiCFET sensor as gas sensors operating at high temperatures. The measurement condition in the exhaust pipe of a car is extremely tough, not only is the temperature high and the different gases quite harmful, there are also a lot of particles that can affect the sensors in an undesirable way. In my project we have been testing Schottky diodes and MlSiCFET sensors based on SiC as high temperature sensors, both in the laboratory with simulated exhaust and after a real engine. In this thesis we conclude that these sensors can work in the hostile environment of an engines exhaust. It is shown that when measuring in a gas mixture with a fixed I below one, where the I-value is controlled by the O{sub 2} concentration, a sensor with a catalytic gate metal as sensitive material respond more to the increased O{sub 2} concentration than the increased HC concentration when varying the two correspondingly. A number of different sensors have been tested in simulated exhaust towards NO{sub x}. It was shown that resistivity changes in the thin gate metal influenced the gas response. Tests have been performed where sensors were a part of a SCR system with promising results concerning NH{sub 3} sensitivity. With a working temperature of 300 deg C there is no contamination of the metal surface.

  7. High temperature behaviour of a zircon ceramic

    Energy Technology Data Exchange (ETDEWEB)

    Carbonneau, X.; Olagnon, C.; Fantozzi, G. [INSA, Villeurbanne (France). GEMMPM; Hamidouche, M. [Lab. Science des Materiaux, Univ. de Setif (Algeria); Torrecillas, R. [Inst. Nacional del Carbon, Oviedo (Spain)

    1997-12-31

    The high temperature properties of a sintered zircon material has been tested up to 1200 C. A significant creep rate is observed, mainly attributed to the presence of glassy phase. The sub-critical crack growth measured in double torsion showed that above 1000 C, the crack velocity is reduced either by stress relaxation or by crack healing. The thermal shock analysis under a heat exchange coefficient of 600 W/m{sup 2}/K showed a regular decrease rather that a sudden fall off of properties. (orig.) 3 refs.

  8. High temperature and pressure electrochemical test station

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Allebrod, Frank; Mogensen, Mogens Bjerg

    2013-01-01

    An electrochemical test station capable of operating at pressures up to 100 bars and temperatures up to 400 ◦C has been established. It enables control of the partial pressures and mass flow of O2, N2, H2, CO2, and H2O in a single or dual environment arrangement, measurements with highly corrosive......, to the electrochemical characterization of high temperature and pressure alkaline electrolysis cells and the use of pseudo-reference electrodes for the separation of each electrode contribution. A future perspective of various electrochemical processes and devices that can be developed with the use of the established...

  9. High temperature superconducting digital circuits and subsystems

    Energy Technology Data Exchange (ETDEWEB)

    Martens, J.S.; Pance, A.; Whiteley, S.R.; Char, K.; Johansson, M.F.; Lee, L. [Conductus, Sunnyvale, CA (United States); Hietala, V.M.; Wendt, J.R. [Sandia National Labs., Albuquerque, NM (United States); Hou, S.Y.; Phillips, J. [AT and T Bell Labs., Murray Hill, NJ (United States)

    1993-10-01

    The advances in the fabrication of high temperature superconducting devices have enabled the demonstration of high performance and useful digital circuits and subsystems. The yield and uniformity of the devices is sufficient for circuit fabrication at the medium scale integration (MSI) level with performance not seen before at 77 K. The circuits demonstrated to date include simple gates, counters, analog to digital converters, and shift registers. All of these are mid-sized building blocks for potential applications in commercial and military systems. The processes used for these circuits and blocks will be discussed along with observed performance data.

  10. Encapsulation of high temperature molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Oxley, James D.; Mathur, Anoop Kumar

    2017-05-16

    The present disclosure relates to a method of encapsulating microcapsules containing relatively high temperature phase change materials and the microcapsules so produced. The microcapsules are coated with an inorganic binder, film former and an inorganic filler. The microcapsules may include a sacrificial layer that is disposed between the particle and the coating. The microcapsules may also include an inner coating layer, sacrificial layer and outer coating layer. The microcapsules are particularly useful for thermal energy storage in connection with, e.g., heat collected from concentrating solar collectors.

  11. Quench in high temperature superconductor magnets

    CERN Document Server

    Schwartz, J.

    2013-01-01

    High field superconducting magnets using high temperature superconductors are being developed for high energy physics, nuclear magnetic resonance and energy storage applications. Although the conductor technology has progressed to the point where such large magnets can be readily envisioned, quench protection remains a key challenge. It is well-established that quench propagation in HTS magnets is very slow and this brings new challenges that must be addressed. In this paper, these challenges are discussed and potential solutions, driven by new technologies such as optical fiber based sensors and thermally conducting electrical insulators, are reviewed.

  12. Sorbents Remove Oxygen At High Temperatures

    Science.gov (United States)

    Sharma, Pramod K.

    1995-01-01

    Cobalt-exchanged, platinized zeolites 13X and L found conveniently reducible in hot gaseous mixture of hydrogen and nitrogen and thereafter useful as sorbents of trace amounts of oxygen at high temperatures. Aided by catalytic action of platinum, sorbents exhibit rapid oxygen-sorption kinetics and, according to thermodynamic properties of O2/CoO system, capable of lowering level of oxygen in otherwise inert gaseous atmosphere to less than 1 part per trillion in temperature range of 400 to 800 degrees C. Inert atmospheres with these oxygen levels required for processing of certain materials in semiconductor industry.

  13. A review of high-temperature adhesives

    Science.gov (United States)

    St.clair, A. K.; St.clair, T. L.

    1981-01-01

    The development of high temperature adhesives and polyphenylquinoxalines (PPQ) is reported. Thermoplastic polyimides and linear PPQ adhesive are shown to have potential for bonding both metals and composite structures. A nadic terminated addition polyimide adhesive, LARC-13, and an acetylene terminated phenylquinoxaline (ATPQ) were developed. Both of the addition type adhesives are shown to be more readily processable than linear materials but less thermooxidatively stable and more brittle. It is found that the addition type adhesives are able to perform, at elevated temperatures up to 595 C where linear systems fail thermoplastically.

  14. High Temperature Materials Laboratory third annual report

    Energy Technology Data Exchange (ETDEWEB)

    Tennery, V.J.; Foust, F.M.

    1990-12-01

    The High Temperature Materials Laboratory has completed its third year of operation as a designated DOE User Facility at the Oak Ridge National Laboratory. Growth of the user program is evidenced by the number of outside institutions who have executed user agreements since the facility began operation in 1987. A total of 88 nonproprietary agreements (40 university and 48 industry) and 20 proprietary agreements (1 university, 19 industry) are now in effect. Sixty-eight nonproprietary research proposals (39 from university, 28 from industry, and 1 other government facility) and 8 proprietary proposals were considered during this reporting period. Research projects active in FY 1990 are summarized.

  15. High Temperature Ultrasonic Transducers for In-Service Inspection of Liquid Metal Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Posakony, Gerald J.; Harris, Robert V.; Baldwin, David L.; Jones, Anthony M.; Bond, Leonard J.

    2011-12-31

    In-service inspection of liquid metal (sodium) fast reactors requires the use of ultrasonic transducers capable of operating at high temperatures (>200°C), high gamma radiation fields, and the chemically reactive liquid sodium environment. In the early- to mid-1970s, the U.S. Atomic Energy Commission supported development of high-temperature, submersible single-element transducers, used for scanning and under-sodium imaging in the Fast Flux Test Facility and the Clinch River Breeder Reactor. Current work is building on this technology to develop the next generation of high-temperature linear ultrasonic transducer arrays for under-sodium viewing and in-service inspections.

  16. Two-phase chromium-niobium alloys exhibiting improved mechanical properties at high temperatures

    Science.gov (United States)

    Liu, Chain T.; Takeyama, Masao

    1994-01-01

    The specification discloses chromium-niobium alloys which exhibit improved mechanical properties at high temperatures in the range of 1250.degree. C. and improved room temperature ductility. The alloys contain a Cr.sub.2 Nb-rich intermetallic phase and a Cr-rich phase with an overall niobium concentration in the range of from about 5 to about 18 at. %. The high temperature strength is substantially greater than that of state of the art nickel-based superalloys for enhanced high temperature service. Further improvements in the properties of the compositions are obtained by alloying with rhenium and aluminum; and additional rare-earth and other elements.

  17. Technology trends in high temperature pressure transducers: The impact of micromachining

    Science.gov (United States)

    Mallon, Joseph R., Jr.

    1992-01-01

    This paper discusses the implications of micromachining technology on the development of high temperature pressure transducers. The introduction puts forth the thesis that micromachining will be the technology of choice for the next generation of extended temperature range pressure transducers. The term micromachining is defined, the technology is discussed and examples are presented. Several technologies for high temperature pressure transducers are discussed, including silicon on insulator, capacitive, optical, and vibrating element. Specific conclusions are presented along with recommendations for development of the technology.

  18. Medium Deep High Temperature Heat Storage

    Science.gov (United States)

    Bär, Kristian; Rühaak, Wolfram; Schulte, Daniel; Welsch, Bastian; Chauhan, Swarup; Homuth, Sebastian; Sass, Ingo

    2015-04-01

    Heating of buildings requires more than 25 % of the total end energy consumption in Germany. Shallow geothermal systems for indirect use as well as shallow geothermal heat storage systems like aquifer thermal energy storage (ATES) or borehole thermal energy storage (BTES) typically provide low exergy heat. The temperature levels and ranges typically require a coupling with heat pumps. By storing hot water from solar panels or thermal power stations with temperatures of up to 110 °C a medium deep high temperature heat storage (MDHTS) can be operated on relatively high temperature levels of more than 45 °C. Storage depths of 500 m to 1,500 m below surface avoid conflicts with groundwater use for drinking water or other purposes. Permeability is typically also decreasing with greater depth; especially in the crystalline basement therefore conduction becomes the dominant heat transport process. Solar-thermal charging of a MDHTS is a very beneficial option for supplying heat in urban and rural systems. Feasibility and design criteria of different system configurations (depth, distance and number of BHE) are discussed. One system is designed to store and supply heat (300 kW) for an office building. The required boreholes are located in granodioritic bedrock. Resulting from this setup several challenges have to be addressed. The drilling and completion has to be planned carefully under consideration of the geological and tectonical situation at the specific site.

  19. Development of High Temperature Gas Sensor Technology

    Science.gov (United States)

    Hunter, Gary W.; Chen, Liang-Yu; Neudeck, Philip G.; Knight, Dak; Liu, Chung-Chiun; Wu, Quing-Hai; Zhou, Huan-Jun

    1997-01-01

    The measurement of engine emissions is important for their monitoring and control. However, the ability to measure these emissions in-situ is limited. We are developing a family of high temperature gas sensors which are intended to operate in harsh environments such as those in an engine. The development of these sensors is based on progress in two types of technology: (1) The development of SiC-based semiconductor technology; and (2) Improvements in micromachining and microfabrication technology. These technologies are being used to develop point-contact sensors to measure gases which are important in emission control especially hydrogen, hydrocarbons, nitrogen oxides, and oxygen. The purpose of this paper is to discuss the development of this point-contact sensor technology. The detection of each type of gas involves its own challenges in the fields of materials science and fabrication technology. Of particular importance is sensor sensitivity, selectivity, and stability in long-term, high temperature operation. An overview is presented of each sensor type with an evaluation of its stage of development. It is concluded that this technology has significant potential for use in engine applications but further development is necessary.

  20. High-temperature superconductors make major progress

    CERN Multimedia

    CERN Bulletin

    2014-01-01

    This month's Nature Materials featured an important breakthrough for high-temperature superconductors. A new method has been found for processing Bi-2212 high-temperature superconducting round wire in order to drastically increase its critical current density. The result confirms that this conductor is a serious candidate for future very-high-field magnets.   This image shows the cross-section of two Bi-2212 wires. The bottom wire has less leakage and void porosity due to a heat treatment done at an overpressure of 100 bar - about 100 times the pressure used to produce the top wire (image from [Nature Materials, Vol. 13 (2014), 10.1038/nmat3887]). The workhorse for building superconducting accelerator magnets has been, so far, the Niobium-Titanium (Nb-Ti) alloy superconductor. But with Nb-Ti having reached its full potential, other conductors must be used to operate in higher magnetic fields beyond those reached with the LHC magnets. Today, the intermetallic Niobium-Tin (Nb3Sn) is th...

  1. Conformal Properties in High Temperature QCD

    CERN Document Server

    Ishikawa, K -I; Nakayama, Yu; Yoshie, T

    2015-01-01

    We investigate the properties of quarks and gluons above the chiral phase transition temperature $T_c,$ using the RG improved gauge action and the Wilson quark action with two degenerate quarks mainly on a $32^3\\times 16$ lattice. In the one-loop perturbation theory, the thermal ensemble is dominated by the gauge configurations with effectively $Z(3)$ center twisted boundary conditions, making the thermal expectation value of the spatial Polyakov loop take a non-trivial $Z(3)$ center. This is in agreement with our lattice simulation of high temperature QCD. We further observe that the temporal propagator of massless quarks at extremely high temperature $\\beta=100.0 \\, (T \\simeq10^{58} T_c)$ remarkably agrees with the temporal propagator of free quarks with the $Z(3)$ twisted boundary condition for $t/L_t \\geq 0.2$, but differs from that with the $Z(3)$ trivial boundary condition. As we increase the mass of quarks $m_q$, we find that the thermal ensemble continues to be dominated by the $Z(3)$ twisted gauge fi...

  2. Hole-doped cuprate high temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chu, C.W.; Deng, L.Z.; Lv, B.

    2015-07-15

    Highlights: • Historical discoveries of hole-doped cuprates and representative milestone work. • Several simple and universal scaling laws of the hole-doped cuprates. • A comprehensive classification list with references for hole-doped cuprates. • Representative physical parameters for selected hole-doped cuprates. - Abstract: Hole-doped cuprate high temperature superconductors have ushered in the modern era of high temperature superconductivity (HTS) and have continued to be at center stage in the field. Extensive studies have been made, many compounds discovered, voluminous data compiled, numerous models proposed, many review articles written, and various prototype devices made and tested with better performance than their nonsuperconducting counterparts. The field is indeed vast. We have therefore decided to focus on the major cuprate materials systems that have laid the foundation of HTS science and technology and present several simple scaling laws that show the systematic and universal simplicity amid the complexity of these material systems, while referring readers interested in the HTS physics and devices to the review articles. Developments in the field are mostly presented in chronological order, sometimes with anecdotes, in an attempt to share some of the moments of excitement and despair in the history of HTS with readers, especially the younger ones.

  3. A Simple Candle Filter Safeguard Device

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, J.P.; Henderson, A.K.; Swanson, M.L.

    2002-09-18

    In order to reach the highest possible efficiencies in a coal-fired turbine-based power system, the turbine should be directly fired with the products of coal utilization. Two main designs employ these turbines: those based on pressurized fluidized-bed combustors (PFBCs) and those based on integrated gasification combined cycles (IGCCs). In both designs, the suspended particulates, or dust, must be cleaned from the gas before it enters the turbine to prevent fouling and erosion of the blades. To produce the cleanest gas, barrier filters are being developed and are in commercial use. Barrier filters are composed of porous, high-temperature materials that allow the hot gas to pass but collect the dust on the surface. The three main configurations are candle, cross-flow, and tube. Both candle and tube filters have been tested extensively. They are primarily composed of coarsely porous ceramic that serves as a structural support, overlain with a thin, microporous ceramic layer o n the dirty gas side that serves as the primary filter surface. They are highly efficient at removing particulate matter from the gas stream and, because of their ceramic construction, are resistant to gas and ash corrosion. However, ceramics are brittle, and individual elements can fail, allowing the particulates to pass through the hole left by the filter element and erode the turbine. Because of the possibility of occasional filter breakage, safeguard devices (SGDs) must be employed to prevent the dust streaming through broken filters from reaching the turbine. The Energy & Environmental Research Center (EERC) safeguard device is composed of three main parts: the ceramic substrate, the adhesive coating, and the safeguard device housing. This report describes the development and laboratory testing of each of those parts as well as the bench-scale performance of both types of complete SGDs.

  4. Filter service system

    Science.gov (United States)

    Sellers, Cheryl L [Peoria, IL; Nordyke, Daniel S [Arlington Heights, IL; Crandell, Richard A [Morton, IL; Tomlins, Gregory [Peoria, IL; Fei, Dong [Peoria, IL; Panov, Alexander [Dunlap, IL; Lane, William H [Chillicothe, IL; Habeger, Craig F [Chillicothe, IL

    2008-12-09

    According to an exemplary embodiment of the present disclosure, a system for removing matter from a filtering device includes a gas pressurization assembly. An element of the assembly is removably attachable to a first orifice of the filtering device. The system also includes a vacuum source fluidly connected to a second orifice of the filtering device.

  5. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter.

    Science.gov (United States)

    Chowdhury, Amor; Sarjaš, Andrej

    2016-09-15

    The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation.

  6. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter

    Science.gov (United States)

    Chowdhury, Amor; Sarjaš, Andrej

    2016-01-01

    The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation. PMID:27649197

  7. Regenerative particulate filter development

    Science.gov (United States)

    Descamp, V. A.; Boex, M. W.; Hussey, M. W.; Larson, T. P.

    1972-01-01

    Development, design, and fabrication of a prototype filter regeneration unit for regenerating clean fluid particle filter elements by using a backflush/jet impingement technique are reported. Development tests were also conducted on a vortex particle separator designed for use in zero gravity environment. A maintainable filter was designed, fabricated and tested that allows filter element replacement without any leakage or spillage of system fluid. Also described are spacecraft fluid system design and filter maintenance techniques with respect to inflight maintenance for the space shuttle and space station.

  8. Fast pyrolysis of biomass at high temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna

    . Different particle shapes of beechwood and leached wheat straw chars produced in the drop tube reactor which have similar potassium content suggested a stronger influence of the major biomass cell wall compounds (cellulose, hemicellulose, lignin and extractives) and silicates on the char morphology than...... multi core structures compared to pinewood soot generated at 1400°C, combining both single and multi core particles.Beechwood and wheat straw soot samples had multi and single core particles at both temperatures.In thermogravimetric analysis, the maximal reaction rate of pinewood soot was shifted...... pyrolysis at high temperatures plays a significant role in the overall combustion process since the biomass type, the reaction kinetics and heat transfer rates during pyrolysis influence the volatile gas release. The solid residue yield and its properties in suspension firing, including particle size...

  9. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

    This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... to 140 ºC and oxygen pressures up to ~100 bar at room temperature. The GDE cell is successfully tested at 130 ºC by means of direct oxidation of methanol and ethanol, respectively. In the second part of the thesis, the emphasis is put on the ORR in H3PO4 with particular focus on the mass transport...... oxidation of ethanol is in principle a promising concept to supply HTPEM-FCs with a sustainable and on large scale available fuel (ethanol from biomass). However, the intermediate temperature tests in the GDE setup show that even on Pt-based catalysts the reaction rates become first significant...

  10. High temperature superconductors for magnetic suspension applications

    Science.gov (United States)

    Mcmichael, C. K.; Cooley, R. S.; Chen, Q. Y.; Ma, K. B.; Lamb, M. A.; Meng, R. L.; Chu, C. W.; Chu, W. K.

    1994-01-01

    High temperature superconductors (HTS) hold the promise for applications in magnetic levitation bearings, vibration damping, and torque coupling. Traditional magnetic suspension systems require active feedback and vibration controls in which power consumption and low frequency vibration are among the major engineering concerns. HTS materials have been demonstrated to be an enabling approach towards such problems due to their flux trapping properties. In our laboratory at TCSUH, we have been conducting a series of experiments to explore various mechanical applications using HTS. We have constructed a 30 lb. model flywheel levitated by a hybrid superconducting magnetic bearing (HSMB). We are also developing a levitated and vibration-dampled platform for high precision instrumentation. These applications would be ideal for space usages where ambient temperature is adequate for HTS to operate properly under greatly reduced cryogenic requirements. We will give a general overview of these potential applications and discuss the operating principles of the HTS devices we have developed.

  11. High-temperature ordered intermetallic alloys V

    Energy Technology Data Exchange (ETDEWEB)

    Baker, I. (ed.) (Dartmouth Coll., Hanover, NH (United States). Thayer School of Engineering); Darolia, R. (ed.) (GE Aircraft Engines, Cincinnati, OH (United States)); Whittenberger, J.D. (ed.) (NASA, Cleveland, OH (United States). Lewis Research Center); Yoo, M.H. (ed.) (Oak Ridge National Lab., TN (United States))

    1993-01-01

    These proceedings represent the written record of the High-Temperature Ordered Intermetallic Alloys 5 Symposium which was held in conjunction with the 1992 Fall Materials Research Society meeting in Boston, Massachusetts. This symposium, which was the fifth in the series originated by C.C Koch, C.T. Liu and N.S. Stoloff in 1984, was very successful with 86 oral presentations over four days, and approximately 140 posters given during two lively evening sessions. Such a response, in view of the increasing number of conferences being held on intermetallics each year, reveals the continued high regard for this series of symposia. Individual papers have been processed separately for inclusion in the appropriate data bases.

  12. High temperature chemically resistant polymer concrete

    Science.gov (United States)

    Sugama, T.; Kukacka, L.E.

    High temperature chemically resistant, non-aqueous polymer concrete composites consist of about 12 to 20% by weight of a water-insoluble polymer binder. The binder is polymerized in situ from a liquid vinyl-type monomer or mixture of vinyl containing monomers such as triallylcyanurate, styrene, acrylonitrile, acrylamide, methacrylamide, methyl-methacrylate, trimethylolpropane trimethacrylate and divinyl benzene. About 5 to 40% by weight of a reactive inorganic filler selected from the group consisting of tricalcium silicate and dicalcium silicate and mixtures containing less than 2% free lime, and about 48 to 83% by weight of silica sand/ and a free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, other orgaic peroxides and combinations to initiate polymerization of the monomer in the presence of the inorganic filers are used.

  13. FY16 ASME High Temperature Code Activities

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, M. J. [Chromtech Inc., Oak Ridge, TN (United States); Jetter, R. I. [R. I Jetter Consulting, Pebble Beach, CA (United States); Sham, T. -L. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-01

    One of the objectives of the ASME high temperature Code activities is to develop and validate both improvements and the basic features of Section III, Division 5, Subsection HB, Subpart B (HBB). The overall scope of this task is to develop a computer program to be used to assess whether or not a specific component under specified loading conditions will satisfy the elevated temperature design requirements for Class A components in Section III, Division 5, Subsection HB, Subpart B (HBB). There are many features and alternative paths of varying complexity in HBB. The initial focus of this task is a basic path through the various options for a single reference material, 316H stainless steel. However, the program will be structured for eventual incorporation all the features and permitted materials of HBB. Since this task has recently been initiated, this report focuses on the description of the initial path forward and an overall description of the approach to computer program development.

  14. Gravimeter using high-temperature superconductor bearing.

    Energy Technology Data Exchange (ETDEWEB)

    Hull, J. R.

    1998-09-11

    We have developed a sensitive gravimeter concept that uses an extremely low-friction bearing based on a permanent magnet (PM) levitated over a high-temperature superconductor (HTS). A mass is attached to the PM by means of a cantilevered beam, and the combination of PM and HTS forms a bearing platform that has low resistance to rotational motion but high resistance to horizontal, vertical, or tilting motion. The combination acts as a low-loss torsional pendulum that can be operated in any orientation. Gravity acts on the cantilevered beam and attached mass, accelerating them. Variations in gravity can be detected by time-of-flight acceleration, or by a control coil or electrode that would keep the mass stationary. Calculations suggest that the HTS gravimeter would be as sensitive as present-day superconducting gravimeters that need cooling to liquid helium temperatures, but the HTS gravimeter needs cooling only to liquid nitrogen temperatures.

  15. Thermomechanics of composite structures under high temperatures

    CERN Document Server

    Dimitrienko, Yu I

    2016-01-01

    This pioneering book presents new models for the thermomechanical behavior of composite materials and structures taking into account internal physico-chemical transformations such as thermodecomposition, sublimation and melting at high temperatures (up to 3000 K). It is of great importance for the design of new thermostable materials and for the investigation of reliability and fire safety of composite structures. It also supports the investigation of interaction of composites with laser irradiation and the design of heat-shield systems. Structural methods are presented for calculating the effective mechanical and thermal properties of matrices, fibres and unidirectional, reinforced by dispersed particles and textile composites, in terms of properties of their constituent phases. Useful calculation methods are developed for characteristics such as the rate of thermomechanical erosion of composites under high-speed flow and the heat deformation of composites with account of chemical shrinkage. The author expan...

  16. Diamond switches for high temperature electronics

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, R.R.; Rondeau, G.; Qi, Niansheng [Alameda Applied Sciences Corp., San Leandro, CA (United States)] [and others

    1996-04-25

    Diamond switches are well suited for use in high temperature electronics. Laboratory feasibility of diamond switching at 1 kV and 18 A was demonstrated. DC blocking voltages up to 1 kV were demonstrated. A 50 {Omega} load line was switched using a diamond switch, with switch on-state resistivity {approx}7 {Omega}-cm. An electron beam, {approx}150 keV energy, {approx}2 {mu}s full width at half maximum was used to control the 5 mm x 5 mm x 100 {mu}m thick diamond switch. The conduction current temporal history mimics that of the electron beam. These data were taken at room temperature.

  17. Robust high temperature oxygen sensor electrodes

    DEFF Research Database (Denmark)

    Lund, Anders

    reaction kinetics. At oxygen partial pressures below 10-6 bar at 700 C, the mass transport processes dominated the response time. The response time increased with decreasing oxygen partial pressure and inlet gas flow rate. A series of porous platinum electrodes were impregnated with the ionically...... conducting gadolinium-doped cerium oxide (CGO). The addition of CGO was found to decrease the polarisation resistance of the oxygen reaction by up to an order of magnitude compared with a single phase platinum electrode by increasing the effective triple phase boundary (TPB) length. It did not have any......Platinum is the most widely used material in high temperature oxygen sensor electrodes. However, platinum is expensive and the platinum electrode may, under certain conditions, suffer from poisoning, which is detrimental for an oxygen sensor. The objective of this thesis is to evaluate electrode...

  18. Toroidal high temperature superconducting coils for ISTTOK

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, H., E-mail: hf@ipfn.ist.utl.pt [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Goemoery, F. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104 Bratislava (Slovakia); Corte, A. della; Celentano, G. [ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Souc, J. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104 Bratislava (Slovakia); Silva, C.; Carvalho, I.; Gomes, R. [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Di Zenobio, A.; Messina, G. [ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy)

    2011-10-15

    High temperature superconductors (HTS) are very attractive to be used in fusion devices mainly due to lower operations costs. The HTS technology has reached a point where the construction of toroidal field coils for a tokamak is possible. The feasibility of a tokamak operating with HTS is extremely relevant and ISTTOK is the ideal candidate for a meaningful test due to its small size (and consequently lower cost) and the possibility to operate in a steady-state inductive regime. In this paper, a conceptual study of the ISTTOK upgrade to a superconducting device is presented, along with the relevant boundary conditions to achieve a permanent toroidal field with HTS. It is shown that the actual state of the art in HTS allows the design of a toroidal field coil capable of generating the appropriate field on plasma axis while respecting the structural specification of the machine.

  19. Measuring nanowire thermal conductivity at high temperatures

    Science.gov (United States)

    Wang, Xiaomeng; Yang, Juekuan; Xiong, Yucheng; Huang, Baoling; Xu, Terry T.; Li, Deyu; Xu, Dongyan

    2018-02-01

    This work extends the micro-thermal-bridge method for thermal conductivity measurements of nanowires to high temperatures. The thermal-bridge method, based on a microfabricated device with two side-by-side suspended membranes with integrated platinum resistance heaters/thermometers, has been used to determine thermal conductivity of various nanowires/nanotubes/nanoribbons at relatively low temperatures. However, to date, thermal conductivity characterization of nanowires at temperatures above 600 K has seldom been reported presumably due to several technical difficulties including the instability of the microfabricated thermometers, radiation heat loss, and the effect of the background conductance on the measurement. Here we report on our attempt to address the aforementioned challenges and demonstrate thermal conductivity measurement of boron nanoribbons up to 740 K. To eliminate high temperature resistance instability, the device is first annealed at 1023 K for 5 min in an argon atmosphere. Two radiation shields are installed in the measurement chamber to minimize radiation heat loss from the measurement device to the surroundings; and the temperature of the device at each set point is calibrated by an additional thermocouple directly mounted on the chip carrier. The effect of the background conductance is eliminated by adopting a differential measurement scheme. With all these modifications, we successfully measured the thermal conductivity of boron nanoribbons over a wide temperature range from 27 K to 740 K. The measured thermal conductivity increases monotonically with temperature and reaches a plateau of ~2.5 W m‑1 K‑1 at approximately 400 K, with no clear signature of Umklapp scattering observed in the whole measurement temperature range.

  20. HIGH TEMPERATURE, HIGH POWER HETEROGENEOUS NUCLEAR REACTOR

    Science.gov (United States)

    Hammond, R.P.; Wykoff, W.R.; Busey, H.M.

    1960-06-14

    A heterogeneous nuclear reactor is designed comprising a stationary housing and a rotatable annular core being supported for rotation about a vertical axis in the housing, the core containing a plurality of radial fuel- element supporting channels, the cylindrical empty space along the axis of the core providing a central plenum for the disposal of spent fuel elements, the core cross section outer periphery being vertically gradated in radius one end from the other to provide a coolant duct between the core and the housing, and means for inserting fresh fuel elements in the supporting channels under pressure and while the reactor is in operation.

  1. Devices comprised of discrete high-temperature superconductor chips disposed on a surface

    Energy Technology Data Exchange (ETDEWEB)

    Van Duzer, T.

    1993-06-01

    A structure exposed to electromagnetic radiation is described, comprising: a metal surface and a plurality of discrete elements, each element including an insulating substrate and a high-temperature superconducting material substantially covering a face of said substrate, a portion of said metal surface being substantially covered with said elements with said superconducting material thereof adjacent to and in electrical contact with said metal surface, thereby reducing ohmic losses on exposure of said structure to said electromagnetic radiation.

  2. NONDESTRUCTIVE EVALUATION OF CERAMIC CANDLE FILTERS

    Energy Technology Data Exchange (ETDEWEB)

    Roger H.L. Chen, Ph.D.; Alejandro Kiriakidis

    1999-09-01

    excessive back pulsing conditions and high temperature transient) could be reflected from the shift of vibration frequencies. These shifts are due to changes in structural properties such as stiffness, which are directly related to the Young's modulus of the candle filters. Further studies are necessary in implementing and verifying the applicability of dynamic NDE characterization methods for actual in-situ conditions, and in establishing a systematic testing procedure for field applications. Also investigations on the filter's natural frequency due to the effect of dust cake or due to the change of boundary conditions may provide insight as to how the filter will perform in the field.

  3. Fiber optic, Fabry-Perot high temperature sensor

    Science.gov (United States)

    James, K.; Quick, B.

    1984-01-01

    A digital, fiber optic temperature sensor using a variable Fabry-Perot cavity as the sensor element was analyzed, designed, fabricated, and tested. The fiber transmitted cavity reflection spectra is dispersed then converted from an optical signal to electrical information by a charged coupled device (CCD). A microprocessor-based color demodulation system converts the wavelength information to temperature. This general sensor concept not only utilizes an all-optical means of parameter sensing and transmitting, but also exploits microprocessor technology for automated control, calibration, and enhanced performance. The complete temperature sensor system was evaluated in the laboratory. Results show that the Fabry-Perot temperature sensor has good resolution (0.5% of full seale), high accuracy, and potential high temperature ( 1000 C) applications.

  4. Thermomechanical fatigue life prediction of high temperature components

    Energy Technology Data Exchange (ETDEWEB)

    Seifert, Thomas; Hartrott, Philipp von; Riedel, Hermann; Siegele, Dieter [Fraunhofer-Inst. fuer Werkstoffmechanik (IWM), Freiburg (Germany)

    2009-07-01

    The aim of the work described in this paper is to provide a computational method for fatigue life prediction of high temperature components, in which the time and temperature dependent fatigue crack growth is a relevant damage mechanism. The fatigue life prediction is based on a law for microcrack growth and a fracture mechanics estimate of the cyclic crack tip opening displacement. In addition, a powerful model for nonisothermal cyclic plasticity is employed, and an efficient laboratory test procedure is proposed for the determination of the model parameters. The models are efficiently implemented into finite element programs and are used to predict the fatigue life of a cast iron exhaust manifold and a notch in the perimeter of a turbine rotor made of a ferritic/martensitic 10%-chromium steel. (orig.)

  5. The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF)

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, Warren R.L.; Cozzi, Giulio [Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); De Boni, Antonella; Gabrieli, Jacopo [University of Venice, Department of Environmental Science, Venice (Italy); Asti, Massimo; Merlone Borla, Edoardo; Parussa, Flavio [Centro Ricerche Fiat, Orbassano (Italy); Moretto, Ezio [FIAT Powertrain Technologies S.p.A, Turin (Italy); Cescon, Paolo; Barbante, Carlo [University of Venice, Department of Environmental Science, Venice (Italy); Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); Boutron, Claude [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, B.P. 96, Saint Martin d' Heres Cedex (France)

    2011-03-15

    Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g{sup -1} for Pd, 0.4 ng g{sup -1} for Rh and 4.3 ng g{sup -1} for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and ''soluble'' phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km{sup -1} for Rh to 70.5 ng km{sup -1} for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter. (orig.)

  6. The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF).

    Science.gov (United States)

    Cairns, Warren R L; De Boni, Antonella; Cozzi, Giulio; Asti, Massimo; Borla, Edoardo Merlone; Parussa, Flavio; Moretto, Ezio; Cescon, Paolo; Boutron, Claude; Gabrieli, Jacopo; Barbante, Carlo

    2011-03-01

    Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g(-1) for Pd, 0.4 ng g(-1) for Rh and 4.3 ng g(-1) for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and "soluble" phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km(-1) for Rh to 70.5 ng km(-1) for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter.

  7. High Temperature Integrated Thermoelectric Ststem and Materials

    Energy Technology Data Exchange (ETDEWEB)

    Mike S. H. Chu

    2011-06-06

    The final goal of this project is to produce, by the end of Phase II, an all ceramic high temperature thermoelectric module. Such a module design integrates oxide ceramic n-type, oxide ceramic p-type materials as thermoelectric legs and oxide ceramic conductive material as metalizing connection between n-type and p-type legs. The benefits of this all ceramic module are that it can function at higher temperatures (> 700 C), it is mechanically and functionally more reliable and it can be scaled up to production at lower cost. With this all ceramic module, millions of dollars in savings or in new opportunities recovering waste heat from high temperature processes could be made available. A very attractive application will be to convert exhaust heat from a vehicle to reusable electric energy by a thermoelectric generator (TEG). Phase I activities were focused on evaluating potential n-type and p-type oxide compositions as the thermoelectric legs. More than 40 oxide ceramic powder compositions were made and studied in the laboratory. The compositions were divided into 6 groups representing different material systems. Basic ceramic properties and thermoelectric properties of discs sintered from these powders were measured. Powders with different particles sizes were made to evaluate the effects of particle size reduction on thermoelectric properties. Several powders were submitted to a leading thermoelectric company for complete thermoelectric evaluation. Initial evaluation showed that when samples were sintered by conventional method, they had reasonable values of Seebeck coefficient but very low values of electrical conductivity. Therefore, their power factors (PF) and figure of merits (ZT) were too low to be useful for high temperature thermoelectric applications. An unconventional sintering method, Spark Plasma Sintering (SPS) was determined to produce better thermoelectric properties. Particle size reduction of powders also was found to have some positive benefits

  8. High-Temperature Shape Memory Polymers

    Science.gov (United States)

    Yoonessi, Mitra; Weiss, Robert A.

    2012-01-01

    physical conformation changes when exposed to an external stimulus, such as a change in temperature. Such materials have a permanent shape, but can be reshaped above a critical temperature and fixed into a temporary shape when cooled under stress to below the critical temperature. When reheated above the critical temperature (Tc, also sometimes called the triggering or switching temperature), the materials revert to the permanent shape. The current innovation involves a chemically treated (sulfonated, carboxylated, phosphonated, or other polar function group), high-temperature, semicrystalline thermoplastic poly(ether ether ketone) (Tg .140 C, Tm = 340 C) mix containing organometallic complexes (Zn++, Li+, or other metal, ammonium, or phosphonium salts), or high-temperature ionic liquids (e.g. hexafluorosilicate salt with 1-propyl-3- methyl imidazolium, Tm = 210 C) to form a network where dipolar or ionic interactions between the polymer and the low-molecular-weight or inorganic compound forms a complex that provides a physical crosslink. Hereafter, these compounds will be referred to as "additives". The polymer is semicrystalline, and the high-melt-point crystals provide a temporary crosslink that acts as a permanent crosslink just so long as the melting temperature is not exceeded. In this example case, the melting point is .340 C, and the shape memory critical temperature is between 150 and 250 C. PEEK is an engineering thermoplastic with a high Young fs modulus, nominally 3.6 GPa. An important aspect of the invention is the control of the PEEK functionalization (in this example, the sulfonation degree), and the thermal properties (i.e. melting point) of the additive, which determines the switching temperature. Because the compound is thermoplastic, it can be formed into the "permanent" shape by conventional plastics processing operations. In addition, the compound may be covalently cross - linked after forming the permanent shape by S-PEEK by applying ionizing

  9. Electrochemical high-temperature gas sensors

    Science.gov (United States)

    Saruhan, B.; Stranzenbach, M.; Yüce, A.; Gönüllü, Y.

    2012-06-01

    Combustion produced common air pollutant, NOx associates with greenhouse effects. Its high temperature detection is essential for protection of nature. Component-integration capable high-temperature sensors enable the control of combustion products. The requirements are quantitative detection of total NOx and high selectivity at temperatures above 500°C. This study reports various approaches to detect NO and NO2 selectively under lean and humid conditions at temperatures from 300°C to 800°C. All tested electrochemical sensors were fabricated in planar design to enable componentintegration. We suggest first an impedance-metric gas sensor for total NOx-detection consisting of NiO- or NiCr2O4-SE and PYSZ-electrolyte. The electrolyte-layer is about 200μm thickness and constructed of quasi-single crystalline columns. The sensing-electrode (SE) is magnetron sputtered thin-layers of NiO or NiCr2O4. Sensor sensitivity for detection of total NOx has been measured by applying impedance analysis. The cross-sensitivity to other emission gases such as CO, CO2, CH4 and oxygen (5 vol.%) has been determined under 0-1000ppm NO. Sensor maintains its high sensitivity at temperatures up to 550°C and 600°C, depending on the sensing-electrode. NiO-SE yields better selectivity to NO in the presence of oxygen and have shorter response times comparing to NiCr2O4-SE. For higher temperature NO2-sensing capability, a resistive DC-sensor having Al-doped TiO2-sensing layers has been employed. Sensor-sensitivity towards NO2 and cross-sensitivity to CO has been determined in the presence of H2O at temperatures 600°C and 800°C. NO2 concentrations varying from 25 to 100ppm and CO concentrations from 25 to 75ppm can be detected. By nano-tubular structuring of TiO2, NO2 sensitivity of the sensor was increased.

  10. High Temperature Properties and Recent Research Trend of Mg-RE Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Soo Woo [Korea Institute of Science and Technology Information, Seoul (Korea, Republic of)

    2017-04-15

    For the applications in automotive, aircraft, aerospace, and electronic industries, the lightest structural Mg alloys have received much attention since 2000. There has been some progress for the improvement of the mechanical properties such as room temperature strength, formability and mechanical anisotropy. However, the high temperature strength of Mg alloys is very low to be used for the parts and structures of high temperature conditions. For the last decade, considerable efforts are concentrated for the development of Mg alloys to be used at high temperature. Newly developing Mg-RE alloys are the good examples for the high temperature use. In this regard, this review paper introduces the recent research trends for the development of Mg-RE alloys strengthened with some precipitates and the long period stacking ordered (LPSO) structures related RE elements.

  11. High Temperature Dry Sliding Friction and Wear Performance of Laser Cladding WC/Ni Composite Coating

    Directory of Open Access Journals (Sweden)

    YANG Jiao-xi

    2016-06-01

    Full Text Available Two different types of agglomerate and angular WC/Ni matrix composite coatings were deposited by laser cladding. The high temperature wear resistance of these composite coatings was tested with a ring-on-disc MMG-10 apparatus. The morphologies of the worn surfaces were observed using a scanning electron microscopy (SEM equipped with an energy dispersive spectroscopy (EDS for elemental composition. The results show that the high temperature wear resistance of the laser clad WC/Ni-based composite coatings is improved significantly with WC mass fraction increasing. The 60% agglomerate WC/Ni composite coating has optimal high temperature wear resistance. High temperature wear mechanism of 60% WC/Ni composite coating is from abrasive wear of low temperature into composite function of the oxidation wear and abrasive wear.

  12. In situ observation and measurement of composites subjected to extremely high temperature

    Science.gov (United States)

    Fang, Xufei; Yu, Helong; Zhang, Guobing; Su, Hengqiang; Tang, Hongxiang; Feng, Xue

    2014-03-01

    In this work, we develop an instrument to study the ablation and oxidation process of materials such as C/SiC (carbon fiber reinforced silicon carbide composites) and ultra-high temperature ceramic in extremely high temperature environment. The instrument is integrated with high speed cameras with filtering lens, infrared thermometers and water vapor generator for image capture, temperature measurement, and humid atmosphere, respectively. The ablation process and thermal shock as well as the temperature on both sides of the specimen can be in situ monitored. The results show clearly the dynamic ablation and liquid oxide flowing. In addition, we develop an algorithm for the post-processing of the captured images to obtain the deformation of the specimens, in order to better understand the behavior of the specimen subjected to high temperature.

  13. High-temperature archeointensity measurements from Mesopotamia

    Science.gov (United States)

    Gallet, Yves; Le Goff, Maxime

    2006-01-01

    We present new archeointensity results obtained from 127 potsherds and baked brick fragments dated from the last four millennia BC which were collected from different Syrian archeological excavations. High temperature magnetization measurements were carried out using a laboratory-built triaxial vibrating sample magnetometer (Triaxe), and ancient field intensity determinations were derived from the experimental procedure described by Le Goff and Gallet [Le Goff and Gallet. Earth Planet. Sci. Lett. 229 (2004) 31-43]. As some of the studied samples were previously analyzed using the classical Thellier and Thellier [Thellier and Thellier . Ann. Geophys. 15 (1959) 285-376] method revised by Coe [Coe. J. Geophys. Res. 72 (1967) 3247-3262], a comparison of the results is made from the two methods. The differences both at the fragment and site levels are mostly within ± 5%, which strengthens the validity of the experimental procedure developed for the Triaxe. The new data help to better constrain the geomagnetic field intensity variations in Mesopotamia during archeological times, with the probable occurrence of an archeomagnetic jerk around 2800-2600 BC.

  14. Energy storage via high temperature superconductivity (SMES)

    Energy Technology Data Exchange (ETDEWEB)

    Mikkonen, R. [Tampere Univ. of Technology (Finland)

    1998-10-01

    The technology concerning high temperature superconductors (HTS) is matured to enabling different kind of prototype applications including SMES. Nowadays when speaking about HTS systems, attention is focused on the operating temperature of 20-30 K, where the critical current and flux density are fairly close to 4.2 K values. In addition by defining the ratio of the energy content of a novel HTS magnetic system and the required power to keep the system at the desired temperature, the optimum settles to the above mentioned temperature range. In the frame of these viewpoints a 5 kJ HTS SMES system has been designed and tested at Tampere University of Technology with a coil manufactured by American Superconductor (AMSC). The HTS magnet has inside and outside diameters of 252 mm and 317 mm, respectively and axial length of 66 mm. It operates at 160 A and carries a total of 160 kA-turns to store the required amount of energy. The effective magnetic inductance is 0.4 H and the peak axial field is 1.7 T. The magnet is cooled to the operating temperature of 20 K with a two stage Gifford-McMahon type cryocooler with a cooling power of 60 W at 77 K and 8 W at 20 K. The magnetic system has been demonstrated to compensate a short term loss of power of a sensitive consumer

  15. High temperature deformation of silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Calvillo, Pablo, E-mail: pablo.rodriguez@ctm.com.es [CTM - Technologic Centre, Materials Technology Area, Manresa, Cataluna (Spain); Department of Materials Science and Metallurgical Engineering, Universidad Politecnica de Cataluna, Barcelona (Spain); Houbaert, Yvan, E-mail: Yvan.Houbaert@UGent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Petrov, Roumen, E-mail: Roumen.Petrov@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Kestens, Leo, E-mail: Leo.kestens@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Colas, Rafael, E-mail: rafael.colas@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico)

    2012-10-15

    The microstructure and texture development during high temperature plane strain compression of 2% in weight silicon steel was studied. The tests were carried out at a constant strain rate of 5 s{sup -1} with reductions of 25, 35 and 75% at temperatures varying from 800 to 1100 Degree-Sign C. The changes in microstructure and texture were studied by means of scanning electron microscopy and electron backscattered diffraction. The microstructure close to the surface of the samples was equiaxed, which is attributed to the shear caused by friction, whereas that at the centre of the specimens was made of a mixture of elongated and fine equiaxed grains, the last ones attributed to the action of dynamic recovery followed by recrystallization. It was found that the volume fraction of these equiaxed grains augmented as reduction and temperature increased; a 0.7 volume fraction was accomplished with a 75% reduction at 1100 Degree-Sign C. The texture of the equiaxed and elongated grains was found to vary with the increase of deformation and temperature, as the {gamma}-fibre tends to disappear and the {alpha}-fibre to increase towards the higher temperature range. -- Highlights: Black-Right-Pointing-Pointer The plastic deformation of a silicon containing steel is studied by plane strain compression. Black-Right-Pointing-Pointer Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. Black-Right-Pointing-Pointer Texture, by EBSD, is revealed to be similar in either type of grains.

  16. Rapid sulfur capture studies at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Richards, G.A.; Lawson, W.F.; Maloney, D.J.; Shaw, D.W.

    1990-12-01

    Determine conditions that would reproduce optimum sulfur capture ( super-equilibrium'') behavior. No attempt was made to extract kinetic data for calcination or sulfur capture, as might be done in a comprehensive study of sorbent behavior. While some interesting anomalies are present in the calcination data and in the limited surface area data, no attempt was made to pursue those issues. Since little sulfur capture was observed at operating conditions where super-equilibrium'' might be expected to occur, tests were stopped when the wide range of parameters that were studied failed to produce significant sulfur capture via the super-equilibrium mechanism. Considerable space in this report is devoted to a description of the experiment, including details of the GTRC construction. This description is included because we have received requests for a detailed description of the GTRC itself, as well as the pressurized dry powder feed system. In addition, many questions about accurately sampling the sulfur species from a high-temperature, high-pressure reactor were raised during the course of this investigation. A full account of the development of the gas and particulate sampling train in thus provided. 8 refs., 17 figs., 2 tabs.

  17. Electronic phase separation and high temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kivelson, S.A. [Univ. of California, Los Angeles, CA (United States). Dept. of Physics; Emery, V.J. [Brookhaven National Lab., Upton, NY (United States)

    1994-01-11

    The authors review the extensive evidence from model calculations that neutral holes in an antiferromagnet separate into hole-rich and hole-poor phases. All known solvable limits of models of holes in a Heisenberg antiferromagnet exhibit this behavior. The authors show that when the phase separation is frustrated by the introduction of long-range Coulomb interactions, the typical consequence is either a modulated (charge density wave) state or a superconducting phase. The authors then review some of the strong experimental evidence supporting an electronically-driven phase separation of the holes in the cuprate superconductors and the related Ni oxides. Finally, the authors argue that frustrated phase separation in these materials can account for many of the anomalous normal state properties of the high temperature superconductors and provide the mechanism of superconductivity. In particular, it is shown that the T-linear resistivity of the normal state is a paraconductivity associated with a novel composite pairing, although the ordered superconducting state is more conventional.

  18. High temperature superconductors at optimal doping

    Directory of Open Access Journals (Sweden)

    W. E. Pickett

    2006-09-01

    Full Text Available   Intensive study of the high temperature superconductors has been ongoing for two decades. A great deal of this effort has been devoted to the underdoped regime, where the new and difficult physics of the doped Mott insulator has met extra complications including bilayer coupling/splitting, shadow bands, and hot spots. While these complications continue to unfold, in this short overview the focus is moved to the region of actual high-Tc, that of optimal doping. The focus here also is not on the superconducting state itself, but primarily on the characteristics of the normal state from which the superconducting instability arises, and even these can be given only a broad-brush description. A reminder is given of two issues,(i why the “optimal Tc” varies,for n-layered systems it increases for n up to 3, then decreases for a given n, Tc increases according to the ‘basis’ atom in the order Bi, Tl, Hg (ii how does pressure, or a particular uniaxial strain, increase Tc when the zero-strain system is already optimally doped?

  19. High temperature and pressure alkaline electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2013-01-01

    for immobilization of aqueous KOH solutions. Electrolysis cells with this electrolyte and metal foam based gas diffusion electrodes were successfully demonstrated at temperatures up to 250 °C at 40 bar. Different electro-catalysts were tested in order to reduce the oxygen and hydrogen overpotentials. Current...... the operational temperature and pressure to produce pressurized hydrogen at high rate (m3 H2·h-1·m-2 cell area) and high electrical efficiency. This work describes an exploratory technical study of the possibility to produce hydrogen and oxygen with a new type of alkaline electrolysis cell at high temperatures...... densities of 1.1 A cm-2 and 2.3 A cm-2 have been measured at a cell voltage of 1.5 V and 1.75 V, respectively, without noble metal catalysts. Electrical efficiencies of almost 99 % at 1.1 A cm-2 and 85 % at 2.3 A cm-2 were obtained....

  20. High Temperature Fatigue Life Evaluation Using Small Specimen

    National Research Council Canada - National Science Library

    NOGAMI, Shuhei; HISAKA, Chiaki; FUJIWARA, Masaharu; WAKAI, Eichi; HASEGAWA, Akira

    2017-01-01

    For developing the high temperature fatigue life evaluation method using small specimen, the effect of specimen size and test environment on the high temperature fatigue life of the reduced activation...

  1. High temperature sensing using higher-order-mode rejected sapphire-crystal fiber gratings

    Science.gov (United States)

    Zhan, Chun; Kim, Jae Hun; Lee, Jon; Yin, Stuart; Ruffin, Paul; Luo, Claire

    2007-09-01

    In this paper, we report the fabrication of higher-order-mode rejected fiber Bragg gratings (FBGs) in sapphire crystal fiber using infrared (IR) femtosecond laser illumination. The grating is tested in high temperature furnace up to 1600 degree Celsius. As sapphire fiber is only available as highly multimode fiber, a scheme to filter out higher order modes in favor for the fundamental mode is theoretically evaluated and experimentally demonstrated. The approach is to use an ultra thin sapphire crystal fiber (60 micron in diameter) to decrease the number of modes. The small diameter fiber also enables bending the fiber to certain radius which is carefully chosen to provide low loss for the fundamental mode LP01 and high loss for the other high-order modes. After bending, less-than-2-nm resonant peak bandwidth is achieved. The grating spectrum is improved, and higher resolution sensing measurement can be achieved. This mode filtering method is very easy to implement. Furthermore, the sapphire fiber is sealed with hi-purity alumina ceramic cement inside a flexible high temperature titanium tube, and the highly flexible titanium tube offers a robust packaging to sapphire fiber. Our high temperature sapphire grating sensor is very promising in extremely high temperature sensing application.

  2. Investigation of pseudo bi-polar nickel-cadmium batteries as filter elements for pulsed power loads. Master's thesis

    Energy Technology Data Exchange (ETDEWEB)

    Cimino, M.B.; Gearing, G.M.

    1984-12-01

    This investigation consisted of several tests of specially fabricated nickel-cadmium batteries having circular disk-type electrodes. These batteries were evaluated as filter elements between a constant-current power supply and a 5-Hz pulsed load demanding approximately twice the power-supply current during the load on portion of the cycle. Short tests lasting 10,000 cycles were conducted at up to 21 C rate and an equivalent energy density of over 40 Joules per pound. In addition, two batteries were subjected to 10,000,000 charge/discharge cycles, one at a 6.5 C rate and the other at a 13 C rate. Assuming an electrode-to-battery weight ratio of 0.5, these tests represent an energy density of about 7 and 14 Joules per pound, respectively. Energy density, efficiency, capacitance, average voltage, and available capacity were tracked during these tests.

  3. Experimental formulation of a kinetic model describing the nitrification process in biological aerated filters filled with plastic elements.

    Science.gov (United States)

    Siciliano, Alessio; De Rosa, Salvatore

    2015-01-01

    The present work reports the results of a series of experimental tests performed on cylindrically shaped biological aerated filters (BAFs) to define a new model for reactors design. The nitrification performance was analysed by monitoring a laboratory pilot plant over a six-month period; the dependence of the nitrification rate from the biomass surface density, from ammonia nitrogen concentration and dissolved oxygen concentration was determined using kinetic batch tests. The controls performed on the pilot plant exhibited a nitrification efficiency of approximately 98% at loadings up to [Formula: see text]. Over this value, the pilot plant performance decreased without a correlation with the applied loads. In response to the inlet ammonia loading increase, the bacterial surface density showed a logistic growing trend. The results of kinetic tests proved that the nitrification rate was not affected by the ammonia nitrogen concentration; instead, a first-order kinetic with respect to the dissolved oxygen concentration was detected. Moreover, it was observed that a minimum oxygen concentration, which was proportional to the bacterial surface density, was necessary to initiate the nitrification process. The reaction rate related to bacterial surface density exhibited an increasing trend that was followed by a subsequent decreasing behaviour. The results of kinetic tests and the identification of the relationship between bacterial surface density and ammonia loading permitted the formulation of a mathematical model to predict BAFs' nitrification efficiency.

  4. Spectral emissivity of candidate alloys for very high temperature reactors in high temperature air environment

    Energy Technology Data Exchange (ETDEWEB)

    Cao, G., E-mail: gcao@wisc.edu; Weber, S.J.; Martin, S.O.; Sridharan, K.; Anderson, M.H.; Allen, T.R.

    2013-10-15

    Emissivity measurements for candidate alloys for very high temperature reactors were carried out in a custom-built experimental facility, capable of both efficient and reliable measurements of spectral emissivities of multiple samples at high temperatures. The alloys studied include 304 and 316 austenitic stainless steels, Alloy 617, and SA508 ferritic steel. The oxidation of alloys plays an important role in dictating emissivity values. The higher chromium content of 304 and 316 austenitic stainless steels, and Alloy 617 results in an oxide layer only of sub-micron thickness even at 700 °C and consequently the emissivity of these alloys remains low. In contrast, the low alloy SA508 ferritic steel which contains no chromium develops a thicker oxide layer, and consequently exhibits higher emissivity values.

  5. Spectral emissivity of candidate alloys for very high temperature reactors in high temperature air environment

    Science.gov (United States)

    Cao, G.; Weber, S. J.; Martin, S. O.; Sridharan, K.; Anderson, M. H.; Allen, T. R.

    2013-10-01

    Emissivity measurements for candidate alloys for very high temperature reactors were carried out in a custom-built experimental facility, capable of both efficient and reliable measurements of spectral emissivities of multiple samples at high temperatures. The alloys studied include 304 and 316 austenitic stainless steels, Alloy 617, and SA508 ferritic steel. The oxidation of alloys plays an important role in dictating emissivity values. The higher chromium content of 304 and 316 austenitic stainless steels, and Alloy 617 results in an oxide layer only of sub-micron thickness even at 700 °C and consequently the emissivity of these alloys remains low. In contrast, the low alloy SA508 ferritic steel which contains no chromium develops a thicker oxide layer, and consequently exhibits higher emissivity values.

  6. Implementation Challenges for Ceramic Matrix Composites in High Temperature Applications

    Science.gov (United States)

    Singh, Mrityunjay

    2004-01-01

    Ceramic matrix composites are leading candidate materials for a number of applications in aeronautics, space, energy, electronics, nuclear, and transportation industries. In the aeronautics and space exploration systems, these materials are being considered for applications in hot sections of jet engines such as the combustor liner, nozzle components, nose cones, leading edges of reentry vehicles and space propulsion components. Applications in the energy and environmental industries include radiant heater tubes, heat exchangers, heat recuperators, gas and diesel particulate filters (DPFs), and components for land based turbines for power generation. These materials are also being considered for use in the first wall and blanket components of fusion reactors. There are a number of critical issues and challenges related to successful implementation of composite materials. Fabrication of net and complex shape components with high density and tailorable matrix properties is quite expensive, and even then various desirable properties are not achievable. In this presentation, microstructure and thermomechanical properties of composites fabricated by two techniques (chemical vapor infiltration and melt infiltration), will be presented. In addition, critical need for robust joining and assembly technologies in successful implementation of these systems will be discussed. Other implementation issues will be discussed along with advantages and benefits of using these materials for various components in high temperature applications.

  7. High-Temperature Enzymatic Breakdown of Cellulose▿†

    Science.gov (United States)

    Wang, Hongliang; Squina, Fabio; Segato, Fernando; Mort, Andrew; Lee, David; Pappan, Kirk; Prade, Rolf

    2011-01-01

    Cellulose is an abundant and renewable biopolymer that can be used for biofuel generation; however, structural entrapment with other cell wall components hinders enzyme-substrate interactions, a key bottleneck for ethanol production. Biomass is routinely subjected to treatments that facilitate cellulase-cellulose contacts. Cellulases and glucosidases act by hydrolyzing glycosidic bonds of linear glucose β-1,4-linked polymers, producing glucose. Here we describe eight high-temperature-operating cellulases (TCel enzymes) identified from a survey of thermobacterial and archaeal genomes. Three TCel enzymes preferentially hydrolyzed soluble cellulose, while two preferred insoluble cellulose such as cotton linters and filter paper. TCel enzymes had temperature optima ranging from 85°C to 102°C. TCel enzymes were stable, retaining 80% of initial activity after 120 h at 85°C. Two modes of cellulose breakdown, i.e., with endo- and exo-acting glucanases, were detected, and with two-enzyme combinations at 85°C, synergistic cellulase activity was observed for some enzyme combinations. PMID:21685160

  8. Laser Brazing of High Temperature Braze Alloy

    Science.gov (United States)

    Gao, Y. P.; Seaman, R. F.; McQuillan, T. J.; Martiens, R. F.

    2000-01-01

    The Space Shuttle Main Engine (SSME) consists of 1080 conical tubes, which are furnace brazed themselves, manifolds, and surrounding structural jacket making almost four miles of braze joints. Subsequent furnace braze cycles are performed due to localized braze voids between the coolant tubes. SSME nozzle experiences extremely high heat flux (180 mW/sq m) during hot fire. Braze voids between coolant tubes may result in hot combustion gas escape causing jacket bulges. The nozzle can be disqualified for flight or result in mission failure if the braze voids exceed the limits. Localized braze processes were considered to eliminate braze voids, however, damage to the parent materials often prohibited use of such process. Being the only manned flight reusable rocket engine, it has stringent requirement on the braze process. Poor braze quality or damage to the parent materials limits the nozzle service life. The objective of this study was to develop a laser brazing process to provide quality, localized braze joints without adverse affect on the parent materials. Gold (Au-Cu-Ni-Pd-Mn) based high temperature braze alloys were used in both powder and wire form. Thin section iron base superalloy A286 tube was used as substrate materials. Different Laser Systems including CO2 (10.6 micrometers, 1kW), ND:YAG (1.06 micrometers, 4kW). and direct diode laser (808nm. 150W) were investigated for brazing process. The laser process variables including wavelength. laser power, travel speed and angle of inclination were optimized according to bead geometry and braze alloy wetting at minimum heat input level, The properties of laser brazing were compared to that of furnace brazing. Microhardness profiles were used for braze joint property comparison between laser and furnace brazing. The cooling rate of laser brazing was compared to furnace brazing based on secondary dendritic arm spacing, Both optical and Scanning Electron Microscope (SEM) were used to evaluate the microstructures of

  9. High-temperature spreading kinetics of metals

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, N.

    2005-05-15

    In this PhD work a drop transfer setup combined with high speed photography has been used to analyze the spreading of Ag on polished polycrystalline Mo and single crystalline Mo (110) and (100) substrates. The objective of this work was to unveil the basic phenomena controlling spreading in metal-metal systems. The observed spreading kinetics were compared with current theories of low and high temperature spreading such as a molecular kinetic model and a fluid flow model. Analyses of the data reveal that the molecular model does describe the fastest velocity data well for all the investigated systems. Therefore, the energy which is dissipated during the spreading process is a dissipation at the triple line rather than dissipation due to the viscosity in the liquid. A comparison of the determined free activation energy for wetting of {delta}G95{approx}145kJ/mol with literature values allows the statement that the rate determining step seems to be a surface diffusion of the Ag atoms along the triple line. In order to investigate possible ridge formation, due to local atomic diffusion of atoms of the substrate at the triple during the spreading process, grooving experiments of the polycrystalline Mo were performed to calculate the surface diffusities that will control ridge evolution. The analyses of this work showed that a ridge formation at the fastest reported wetting velocities was not possible if there is no initial perturbation for a ridge. If there was an initial perturbation for a ridge the ridge had to be much smaller than 1 nm in order to be able to move with the liquid font. Therefore ridge formation does not influence the spreading kinetics for the studied system and the chosen conditions. SEM, AFM and TEM investigations of the triple line showed that ridge formation does also not occur at the end of the wetting experiment when the drop is close to equilibrium and the wetting velocity is slow. (orig.)

  10. High temperature inorganic membranes for separating hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Fain, D.E.; Roettger, G.E. [Oak Ridge K-25 Site, TN (United States)

    1995-08-01

    Effort has continued to accumulate data on the transport of gases over the temperature range from room temperature to 275{degrees}C with inorganic membranes having a range of pore radii from approximately 0.25 nm to 3 mn. An experimental alumina membrane having an estimated mean pore radius of 0.25 nm has been fabricated and tested. Extensive testing of this membrane indicated that the separation factor for helium and carbon tetrafluoride at 250{degrees}C was 59 and the extrapolated high temperature separation factor was 1,193. For safety reasons, earlier flow measurements concentrated on helium, carbon dioxide, and carbon tetrafluoride. New data have been acquired with hydrogen to verify the agreement with the other gases. During the measurements with hydrogen, it was noted that a considerable amount of moisture was present in the test gas. The source of this moisture and its effect on permeance was examined. Improvements were implemented to the flow test system to minimize the water content of the hydrogen test gas, and subsequent flow measurements have shown excellent results with hydrogen. The extrapolation of separation factors as a function of temperature continues to show promise as a means of using the hard sphere model to determine the pore size of membranes. The temperature dependence of helium transport through membranes appears to be considerably greater than other gases for the smallest pore sizes. The effort to extend temperature dependence to the hard sphere model continues to be delayed, primarily because of a lack of adequate adsorption data.

  11. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  12. Packaging Technology for SiC High Temperature Electronics

    Science.gov (United States)

    Chen, Liang-Yu; Neudeck, Philip G.; Spry, David J.; Meredith, Roger D.; Nakley, Leah M.; Beheim, Glenn M.; Hunter, Gary W.

    2017-01-01

    High-temperature environment operable sensors and electronics are required for long-term exploration of Venus and distributed control of next generation aeronautical engines. Various silicon carbide (SiC) high temperature sensors, actuators, and electronics have been demonstrated at and above 500 C. A compatible packaging system is essential for long-term testing and application of high temperature electronics and sensors in relevant environments. This talk will discuss a ceramic packaging system developed for high temperature electronics, and related testing results of SiC integrated circuits at 500 C facilitated by this high temperature packaging system, including the most recent progress.

  13. Spatial filters for high power lasers

    Science.gov (United States)

    Erlandson, Alvin Charles; Bayramian, Andrew James

    2014-12-02

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first longitudinal slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second longitudinal slit filter positioned between the second pair of cylindrical lenses.

  14. Transport Processes in High Temperature QCD Plasmas

    Science.gov (United States)

    Hong, Juhee

    The transport properties of high temperature QCD plasmas can be described by kinetic theory based on the Boltzmann equation. At a leading-log approximation, the Boltzmann equation is reformulated as a Fokker-Planck equation. First, we compute the spectral densities of Tµν and Jµ by perturbing the system with weak gravitational and electromagnetic fields. The spectral densities exhibit a smooth transition from free-streaming quasi-particles to hydrodynamics. This transition is analyzed with hydrodynamics and diffusion equation up to second order. We determine all of the first and second order transport coefficients which characterize the linear response in the hydrodynamic regime. Second, we simulate the wake of a heavy quark moving through the plasmas. At long distances, the energy density and flux distributions show sound waves and a diffusion wake. The kinetic theory calculations based on the Boltzmann equation at weak coupling are compared to the strong coupling results given by the AdS/CFT correspondence. By using the hard-thermal-loop effective theory, we determine the photon emission rate at next-to-leading order (NLO), i.e., at order g2mD /T. There are three mechanisms which contribute to the leading-order photon emission: (2 ↔ 2) elastic scatterings, (1 ↔ 2) collinear bremsstrahlung, and (1 ↔ 1) quark-photon conversion due to soft fermion exchange. At NLO, these three mechanisms are not completely independent. When the transverse momentum between quark and photon becomes soft, the Compton scattering with a soft gluon reduces to wide-angle bremsstrahlung. Similarly, bremsstrahlung reduces to the quark-photon conversion process when the photon carries most of the incoming momentum. Therefore, the rates should be matched to determine the wide-angle NLO correction. Collinear bremsstrahlung can be accounted for by solving an integral equation which corresponds to summing ladder diagrams. With O(g) corrections in the collision kernel and the asymptotic

  15. Filtração de aerossóis em altas temperaturas utilizando filtros cerâmicos de dupla camada: influência do diâmetro de partícula na eficiência de coleta Filtration of aerosols at high temperatures using a double layer ceramic filter: influence of the particle diameter in the collection efficiency

    Directory of Open Access Journals (Sweden)

    N. L de Freitas

    2004-12-01

    Full Text Available Neste trabalho foram utilizados filtros cerâmicos para filtração de aerossóis, constituídos por dupla camada, onde a primeira camada é formada por um suporte celular de elevada porosidade com diâmetro de poro controlado e a segunda formada por uma película filtrante. A camada suporte foi obtida pela técnica de replicação cerâmica de espuma poliuretânica, por meio da impregnação de uma suspensão aquosa de Al2O3. Foram utilizados suportes de 45 e 75 poros/polegada. A membrana filtrante (Al2O3 e argila foi a mesma para ambos os suportes, sendo composta por uma massa granular cerâmica de baixa porosidade. Os experimentos de filtração foram realizados em temperaturas de 25 a 700 ºC onde mediu-se a capacidade dos filtros de limpar um aerossol de partículas finas polidispersas (diâmetro mediano de 4,6 µm e calculou-se a eficiência de coleta para diâmetros de partícula entre 0,4 e 8,5 µm. Os resultados mostraram que a eficiência diminuiu com o aumento da temperatura e aumentou com o diâmetro da partícula.In this work, ceramic filters were used for aerosol filtration. The filters were constituted by two layers, where the first layer was formed by of a highly porous ceramic support with controlled pore size and the second layer constituted by a fine membrane. The ceramic support was obtained from polymeric foams utilizing a technique of alumina impregnation. The supports had 45 and 75 pores per inch (ppi. The membrane (a mixture of alumina and clay was the same for the two supports, with much smaller pore sizes. The filtration experiments were accomplished at temperatures varying from 25 to 700 ºC, where the ability of the filters for cleaning an aerosol constituted by fine particles (median diameter of 4.6 µm was measured. The collection efficiency was calculated for particle diameters between 0.4 and 8.5 µm. The results showed that the collection efficiency decreased with the increase of the temperature and increased

  16. High temperature hardness of steels and iron-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Torres, H., E-mail: torres@ac2t.at; Varga, M.; Ripoll, M. Rodríguez

    2016-08-01

    Hot hardness, related to the mechanical strength and wear resistance of materials at high temperatures, has been measured from room temperature up to 800 °C for a comprehensive set of iron-based alloys having different microstructures and chemical compositions. The results obtained suggest the existence of several softening regimes with increasing temperatures, also with a massive hardness drop observed to begin at temperatures close to 0.5 times the melting temperature for most of the chosen alloys. Austenitic steel grades were also observed to show a significant softening behaviour at moderate temperatures compared to ferritic and martensitic alloys, attributed to the dislocation dynamics of face cubic centred alloys. The exact nature of the temperature dependence shown by hardness has been proposed to adopt the form of an exponential Arrhenius equation. Another model suggested in the available literature is also discussed within this context. Additionally, the role of alloying elements has been correlated to the softening behaviour. Molybdenum or boron were found to slow down the softening behaviour, while carbide-forming elements such as vanadium and tungsten were found to be beneficial for room temperature hardness.

  17. Ultra high temperature diffusion apparatus and operating procedures

    Energy Technology Data Exchange (ETDEWEB)

    Wyrick, S.B.

    1985-11-15

    It is the purpose of this paper to present an experimental apparatus which is capable of measuring diffusion coefficients of interdiffusing gases in the temperature range 300K to 2500K. Because of the high temperatures which will be encountered, a special alloy of tantalum (T-111) is used to house the diffusion process. This T-111 diffusion cell is heated via radiation heat from a tungsten heating element powered by a Saban saturable reactor power supply. The diffusion cell heating element are encased in a nickel-plated copper cooling can. This entire assembly is enclosed in an Ultek vacuum chamber to prevent oxidation of the diffusion cell. This report covers the construction and calibration of the diffusion cell, details of the gas loading and sampling system, and complete information on the components required to operate the vacuum furnace. Thus far, several experiments have been run in the temperature range 600K to 800K and the resulting diffusion coefficients agree fairly well with previously published values. 21 refs., 9 figs., 4 tabs.

  18. High temperature gas cleaning for pressurized gasification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Alden, H.; Hagstroem, P.; Hallgren, A.; Waldheim, L. [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    The purpose of the project was to build an apparatus to study pressurized, high temperature gas cleaning of raw gasification gas generated from biomass. A flexible and easy to operate pressurized apparatus was designed and installed for the investigations in high temperature gas cleaning by means of thermal, catalytic or chemical procedures. A semi continuos fuel feeding concept, at a maximum rate of 700 g/h, allowed a very constant formation of a gas product at 700 deg C. The gas product was subsequently introduced into a fixed bed secondary reactor where the actual gas cleanup or reformation was fulfilled. The installation work was divided into four work periods and apart from a few delays the work was carried out according to the time plan. During the first work period (January - June 1994) the technical design, drawings etc. of the reactor and additional parts were completed. All material for the construction was ordered and the installation work was started. The second work period (July - December 1994) was dedicated to the construction and the installation of the different components. Initial tests with the electrical heating elements, control system and gas supply were assigned to the third work period (January - June 1995). After the commissioning and the resulting modifications, initial pyrolysis and tar decomposition experiments were performed. During the fourth and final work period, (June - December 1995) encouraging results from first tests allowed the experimental part of the project work to commence, however in a slightly reduced program. The experimental part of the project work comparatively studied tar decomposition as a function of the process conditions as well as of the choice of catalyst. Two different catalysts, dolomite and a commercial Ni-based catalyst, were evaluated in the unit. Their tar cracking ability in the pressure interval 1 - 20 bar and at cracker bed temperatures between 800 - 900 deg C was compared. Long term tests to study

  19. Evaluation of Steel Element’s Strength at High Temperature (fire

    Directory of Open Access Journals (Sweden)

    Ana-Diana Ancaş

    2006-01-01

    Full Text Available In the first part of the paper there shall be considerations on the hypothesis and possibilities of assessing the fire resistance of the steel structural elements. After the critical presentation and analysis of the breaking criteria used regarding structures’ calculations at high temperatures, the way of determining the fire resistance of a metal beam stressed at pure bending is presented.

  20. High-temperature pressure sensors with strain gauges based on silicon whiskers

    OpenAIRE

    Druzhinin A. A.; Kutrakov A. P.; Maryamova I. I.

    2012-01-01

    Studies aimed at the creating of piezoresistive pressure sensors based on silicon whiskers, operating at high temperatures were carried out. Using the glass adhesive for strain gauges mounting on spring elements of covar alloy gave the possibility to elevate the sensor’s operating temperature range. Several modifications of pressure sensors based on the proposed strain-unit design were developed.

  1. High-temperature pressure sensors with strain gauges based on silicon whiskers

    Directory of Open Access Journals (Sweden)

    Druzhinin A. A.

    2012-12-01

    Full Text Available Studies aimed at the creating of piezoresistive pressure sensors based on silicon whiskers, operating at high temperatures were carried out. Using the glass adhesive for strain gauges mounting on spring elements of covar alloy gave the possibility to elevate the sensor’s operating temperature range. Several modifications of pressure sensors based on the proposed strain-unit design were developed.

  2. High-temperature corrosion resistance of ceramics and ceramic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, P.F.

    1996-06-01

    Ceramics and ceramic composites offer the potential to operate fossil energy systems at the higher temperatures necessary for improved energy efficiency and better environmental control. However, because many fossil fuel-derived processes contain sulfur, chlorine, and carbon, as well as oxygen, degradation from high-temperature corrosion and environmental effects arising from reactions of solids with gases and condensable products is a common life-determining factor in operating systems. Ceramic-based products are not immune to such degradation; adequate corrosion resistance must be assured to exploit the technical and economic potential of such materials. This is normally accomplished by using stable, sound oxides that exist in their bulk form, that naturally grow as surface layers upon exposure to an oxidizing environment, or that are deposited as a coating on a susceptible material. It is therefore important to examine the critical issues with respect to more environmental stability of ceramics that have the potential to be corrosion resistant in particular fossil environments. Key aspects include not only chemical compatibility, but the influence of the environment on the mechanical behavior of the ceramic materials. In addition, for coatings, the mechanical reliability of the ceramic is a key issue in that an otherwise corrosion-resistant surface layer must remain sound and adherent in order to provide protection to the underlying substrate. The purpose of this work is to support the development of advanced ceramics and ceramic composites for applications in fossil environments by examining critical issues related to high-temperature corrosion resistance. More specifically, the overall objective of this task is to examine the chemical compatibility and reliability of potentially corrosion-resistant ceramics being developed as protective overcoats and/or structural materials as parts of other work elements funded by the AR&TD Program.

  3. ADVANCED SECOND GENERATION CERAMIC CANDLE FILTERS

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Alvin

    2002-01-31

    Through sponsorship from the Department of Energy's National Energy Technology Laboratory (DOE/NETL), development and manufacture of advanced second generation candle filters was undertaken in the early 1990's. Efforts were primarily focused on the manufacture of fracture toughened, 1.5 m, continuous fiber ceramic composite (CFCC) and filament wound candle filters by 3M, McDermott, DuPont Lanxide Composites, and Techniweave. In order to demonstrate long-term thermal, chemical, and mechanical stability of the advanced second generation candle filter materials, Siemens Westinghouse initiated high temperature, bench-scale, corrosion testing of 3M's CVI-SiC and DuPont's PRD-66 mini-candles, and DuPont's CFCC SiC-SiC and IF&P Fibrosic{sup TM} coupons under simulated, pressurized fluidized-bed combustion (PFBC) conditions. This effort was followed by an evaluation of the mechanical and filtration performance of the advanced second generation filter elements in Siemens Westinghouse's bench-scale PFBC test facility in Pittsburgh, Pennsylvania. Arrays of 1.4-1.5 m 3M CVI-SiC, DuPont PRD-66, DuPont SiC-SiC, and IF&P Fibrosic{sup TM} candles were subjected to steady state process operating conditions, increased severity thermal transients, and accelerated pulse cycling test campaigns which represented {approx}1760 hours of equivalent filter operating life. Siemens Westinghouse subsequently participated in early material surveillance programs which marked entry of the 3M CVI-SiC and DuPont PRD-66 candle filters in Siemens Westinghouse Advanced Particulate Filtration (APF) system at the American Electric Power (AEP) Tidd Demonstration Plant in Brilliant, Ohio. Siemens Westinghouse then conducted an extended, accelerated life, qualification program, evaluating the performance of the 3M, McDermott, and Techniweave oxide-based CFCC filter elements, modified DuPont PRD-66 elements, and the Blasch, Scapa Cerafil{sup TM}, and Specific Surface monolithic

  4. Water Filter

    Science.gov (United States)

    1982-01-01

    A compact, lightweight electrolytic water sterilizer available through Ambassador Marketing, generates silver ions in concentrations of 50 to 100 parts per billion in water flow system. The silver ions serve as an effective bactericide/deodorizer. Tap water passes through filtering element of silver that has been chemically plated onto activated carbon. The silver inhibits bacterial growth and the activated carbon removes objectionable tastes and odors caused by addition of chlorine and other chemicals in municipal water supply. The three models available are a kitchen unit, a "Tourister" unit for portable use while traveling and a refrigerator unit that attaches to the ice cube water line. A filter will treat 5,000 to 10,000 gallons of water.

  5. High temperature triaxial tests on Rochester shale

    Science.gov (United States)

    Bruijn, Rolf; Burlini, Luigi; Misra, Santanu

    2010-05-01

    Phyllosilicates are one of the major components of the crust, responsible for strength weakening during deformation. High pressure and temperature experiments of natural samples rich in phyllosilicates are needed to test the relevance of proposed weakening mechanisms induced by phyllosilicates, derived from lab experiments on single phase and synthetic polyphase rocks and single crystals. Here, we present the preliminary results of a series of high temperature triaxial tests performed on the illite-rich Rochester Shale (USA - New York) using a Paterson type gas-medium HPT testing machine. Cylindrical samples with homogeneous microstructure and 12-14% porosity were fabricated by cold and hot-isostatically pressing, hot-pressed samples were deformed up to a total shortening of 7.5 to 13%. To study the significance of mica dehydration, iron or copper jackets were used in combination with non-porous or porous spacers. Water content was measured before and after experiments using Karl Fischer Titration (KFT). All experiments show, after yielding at 0.6% strain, rapid hardening in nearly linear fashion until about 4-5% strain, from where stress increases at reducing rates to values at 10% strain, between 400 and 675 MPa, depending on experimental conditions. Neither failure nor steady state however, is achieved within the maximum strain of 13%. Experiments performed under 500 °C and 300 MPa confining pressure show weak strain rate dependence. In addition, iron-jacketed samples appear harder than copper-jacketed ones. At 700 °C samples are 17 to 37% weaker and more sensitive to strain rate than during 500 °C experiments. Although, iron-jacketed samples behave stronger than copper-jacketed ones. By visual inspection, samples appear homogeneously shortened. Preliminary analysis suggests that deformation is mostly accommodated by pore collapse. Although, with finite strain, pore collapse becomes less significant. A temperature, strain rate and jacket material dependent

  6. Analytic Models of High-Temperature Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Stygar, W.A.; Olson, R.E.; Spielman, R.B.; Leeper, R.J.

    2000-11-29

    A unified set of high-temperature-hohlraum models has been developed. For a simple hohlraum, P{sub s} = [A{sub s}+(1{minus}{alpha}{sub W})A{sub W}+A{sub H}]{sigma}T{sub R}{sup 4} + (4V{sigma}/c)(dT{sub R}{sup r}/dt) where P{sub S} is the total power radiated by the source, A{sub s} is the source area, A{sub W} is the area of the cavity wall excluding the source and holes in the wall, A{sub H} is the area of the holes, {sigma} is the Stefan-Boltzmann constant, T{sub R} is the radiation brightness temperature, V is the hohlraum volume, and c is the speed of light. The wall albedo {alpha}{sub W} {triple_bond} (T{sub W}/T{sub R}){sup 4} where T{sub W} is the brightness temperature of area A{sub W}. The net power radiated by the source P{sub N} = P{sub S}-A{sub S}{sigma}T{sub R}{sup 4}, which suggests that for laser-driven hohlraums the conversion efficiency {eta}{sub CE} be defined as P{sub N}/P{sub LASER}. The characteristic time required to change T{sub R}{sup 4} in response to a change in P{sub N} is 4V/C[(l{minus}{alpha}{sub W})A{sub W}+A{sub H}]. Using this model, T{sub R}, {alpha}{sub W}, and {eta}{sub CE} can be expressed in terms of quantities directly measurable in a hohlraum experiment. For a steady-state hohlraum that encloses a convex capsule, P{sub N} = {l_brace}(1{minus}{alpha}{sub W})A{sub W}+A{sub H}+[(1{minus}{alpha}{sub C})(A{sub S}+A{sub W}{alpha}{sub W})A{sub C}/A{sub T}]{r_brace}{sigma}T{sub RC}{sup 4} where {alpha}{sub C} is the capsule albedo, A{sub C} is the capsule area, A{sub T} {triple_bond} (A{sub S}+A{sub W}+A{sub H}), and T{sub RC} is the brightness temperature of the radiation that drives the capsule. According to this relation, the capsule-coupling efficiency of the baseline National-Ignition-Facility (NIF) hohlraum is 15% higher than predicted by previous analytic expressions. A model of a hohlraum that encloses a z pinch is also presented.

  7. Modelling of fuel bundle deformation at high temperatures: requirements, models and steps for consideration

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.; Xu, Z.; Fan, H.; Nitheanandan, T. [Atomic Energy of Canada Limited, MIssissauga, Ontario (Canada)

    2010-07-01

    To model thermal mechanical bundle deformation behaviour under high temperature conditions, several factors need to be considered. These are the sources of loads, deformation mechanisms, interactions within bundle components, bundle and pressure tube (PT) interaction, and boundary constraints on the fuel bundles under in-reactor conditions. This paper describes the modelling of the following three processes: Bundle slumping due to high temperature creep-sag of individual elements and endplates; Differential element expansion and fuel element bowing; and, Bundle distortion under axial loads. To model these processes, a number of key mechanisms for bundle deformation must be considered, which include: 1) Interaction of fuel elements in a bundle with their neighbours, 2) Endplate deformation, 3) Fuel elements lateral deformation under various loads and mechanisms, 4) Interaction within a fuel element, 5) Material property change at high temperatures, 6) Transient response of a bundle, and 7) Bundle configuration change. This paper summarises the new models needed for the mechanistic modelling of the key mechanisms mentioned above and provides an example to show how an endplate plasticity model is developed with results. (author)

  8. Magnesium Diecasting Alloys for High Temperature Applications

    Science.gov (United States)

    Pekguleryuz, Mihriban O.; Kaya, A. Arslan

    New growth area for automotive use of magnesium is powertrain applications such as the transmission case and engine block. These applications see service conditions in the temperature range of 150-200C under 50-70 MPa of tensile and compressive loads. In addition, metallurgical stability, fatigue resistance, corrosion resistance and castability requirements need to be met. A decade of research and development has resulted in a number of creep- resistant magnesium alloys that are potential candidates for elevated-temperature automotive applications. These alloys are mostly based on rare-earth and alkaline earth element additions to magnesium. This paper gives an overview of the various magnesium alloy systems for use in elevated-temperature applications.

  9. High temperature experimental characterization of microscale thermoelectric effects

    Science.gov (United States)

    Favaloro, Tela

    temperature vacuum thermostats are designed and fabricated with optical imaging capability and interchangeable measurement stages for various electrical and thermoelectric characterizations. We demonstrate the simultaneous measurement of in-plane electrical conductivity and Seebeck coefficient of thin-film or bulk thermoelectric materials. Furthermore, we utilize high-speed circuitry to implement the transient Harman technique and directly determine the cross-plane figure of merit of thin film thermoelectric materials at high temperatures. Transient measurements on thin film devices are subject to complications from the growth substrate, non-ideal contacts and other detrimental thermal and electrical effects. A strategy is presented for optimizing device geometry to mitigate the impact of these parasitics. This design enabled us to determine the cross-plane thermoelectric material properties in a single high temperature measurement of a 25mum InGaAs thin film with embedded ErAs (0.2%) nanoparticles using the bipolar transient Harman technique in conjunction with thermoreflectance thermal imaging. This approach eliminates discrepancies and potential device degradation from the multiple measurements necessary to obtain individual material parameters. Finite element method simulations are used to analyze non-uniform current and temperature distributions over the device area and determine the three dimensional current path for accurate extraction of material properties from the thermal images. Results match with independent measurements of thermoelectric material properties for the same material composition, validating this approach. We apply high magnification thermoreflectance imaging to create temperature maps of vanadium dioxide nanobeams and examine electro-thermal energy conversion along the nanobeam length. The metal to insulator transition of strongly correlated materials is subject to strong lattice coupling which brings about the unique one-dimensional alignment of

  10. Scaling Studies for High Temperature Test Facility and Modular High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Richard R. Schult; Paul D. Bayless; Richard W. Johnson; James R. Wolf; Brian Woods

    2012-02-01

    The Oregon State University (OSU) High Temperature Test Facility (HTTF) is an integral experimental facility that will be constructed on the OSU campus in Corvallis, Oregon. The HTTF project was initiated, by the U.S. Nuclear Regulatory Commission (NRC), on September 5, 2008 as Task 4 of the 5-year High Temperature Gas Reactor Cooperative Agreement via NRC Contract 04-08-138. Until August, 2010, when a DOE contract was initiated to fund additional capabilities for the HTTF project, all of the funding support for the HTTF was provided by the NRC via their cooperative agreement. The U.S. Department of Energy (DOE) began their involvement with the HTTF project in late 2009 via the Next Generation Nuclear Plant (NGNP) project. Because the NRC's interests in HTTF experiments were only centered on the depressurized conduction cooldown (DCC) scenario, NGNP involvement focused on expanding the experimental envelope of the HTTF to include steady-state operations and also the pressurized conduction cooldown (PCC).

  11. Study Progress of Physiological Responses in High Temperature Environment

    Science.gov (United States)

    Li, K.; Zheng, G. Z.; Bu, W. T.; Wang, Y. J.; Lu, Y. Z.

    2017-10-01

    Certain workers are exposed to high temperatures for a long time. Heat stress will result in a series of physiological responses, and cause adverse effects on the health and safety of workers. This paper summarizes the physiological changes of cardiovascular system, core temperature, skin temperature, water-electrolyte metabolism, alimentary system, neuroendocrine system, reaction time and thermal fatigue in high temperature environments. It can provide a theoretical guidance for labor safety in high temperature environment.

  12. First high-temperature electronics products survey 2005.

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy Allen

    2006-04-01

    On April 4-5, 2005, a High-Temperature Electronics Products Workshop was held. This workshop engaged a number of governmental and private industry organizations sharing a common interest in the development of commercially available, high-temperature electronics. One of the outcomes of this meeting was an agreement to conduct an industry survey of high-temperature applications. This report covers the basic results of this survey.

  13. Predicting High Temperature Dislocation Physics in HCP Crystal Structures

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, Abigail [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carpenter, John S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez Saez, Enrique [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-09

    This report applies models and experiments to answer key questions about the way materials deform; specifics regarding phase field dislocations dynamics; as well as high temperature rolling experiments.

  14. High temperature sensor/microphone development for active noise control

    Science.gov (United States)

    Shrout, Thomas R.

    1993-01-01

    1000 C. Concurrent with the materials study was an effort to define issues involved in the development of a microphone capable of operation at temperatures up to 1000 C; important since microphones capable of operation above 260 C are not generally available. The distinguishing feature of a microphone is its diaphragm which receives sound from the atmosphere: whereas, most other acoustic sensors receive sound through the solid structure on which they are installed. In order to gain an understanding of the potential problems involved in designing and testing a high temperature microphone, a prototype was constructed using a commercially available lithium niobate piezoelectric element in a stainless steel structure. The prototype showed excellent frequency response at room temperature, and responded to acoustic stimulation at 670 C, above which temperature the voltage output rapidly diminished because of decreased resistivity in the element. Samples of the PLS material were also evaluated in a simulated microphone configuration, but their voltage output was found to be a few mV compared to the 10 output of the prototype.

  15. Research of a Novel Ultra-High Pressure Sensor with High-Temperature Resistance

    Directory of Open Access Journals (Sweden)

    Guo-Dong Zhang

    2017-12-01

    Full Text Available Ultra-high pressure measurement has significant applications in various fields such as high pressure synthesis of new materials and ultra-high pressure vessel monitoring. This paper proposes a novel ultra-high pressure sensor combining a truncated-cone structure and a silicon-on-insulator (SOI piezoresistive element for measuring the pressure up to 1.6 GPa. The truncated-cone structure attenuates the measured pressure to a level that can be detected by the SOI piezoresistive element. Four piezoresistors of the SOI piezoresistive element are placed along specific crystal orientation and configured as a Wheatstone bridge to obtain voltage signals. The sensor has an advantage of high-temperature resistance, in that the structure of the piezoresistive element can avoid the leakage current at high temperature and the truncated-cone structure separates the piezoresistive element from the heat environment. Furthermore, the upper surface diameter of the truncated-cone structure is designed to be 2 mm for the application of small scale. The results of static calibration show that the sensor exhibits a good performance in hysteresis and repeatability. The temperature experiment indicates that the sensor can work steadily at high temperature. This study would provide a better insight to the research of ultra-high pressure sensors with larger range and smaller size.

  16. Development of Instrument Transmitter Protecting Device against High-Temperature Condition during Severe Accidents

    Directory of Open Access Journals (Sweden)

    Min Yoo

    2014-01-01

    Full Text Available Reliable information through instrumentation systems is essential in mitigating severe accidents such as the one that occurred at the Fukushima Daiichi nuclear power plant. There are five elements which might pose a potential threat to the reliability of parameter detection at nuclear power plants during a severe accident: high temperature, high pressure, high humidity, high radiation, and missiles generated during the evolution of a severe accident. Of these, high temperature apparently poses the most serious threat, since thin shielding can get rid of pressure, humidity, radiation (specifically, alpha and beta radiations, and missile effects. In view of this fact, our study focused on designing an instrument transmitter protecting device that can eliminate the high-temperature effect on transmitters to maintain their functional integrity. We present herein a novel concept for designing such a device in terms of heat transfer model that takes into account various heat transfer mechanisms associated with the device.

  17. Development of BS-PT based high temperature ultrasonic transducer

    Science.gov (United States)

    Bilgunde, Prathamesh; Bond, Leonard J.

    2017-04-01

    High temperature (HT) environment in liquid metal cooled reactors poses major challenges towards development of ultrasonic transducer which is a key enabling technology for safety of reactors. In the current work, BS-PT (BiScO3- PbTiO3) piezoelectric material based ultrasonic transducer is proposed for the structural health monitoring at HT. Physics based model using finite element method simulates effect of temperature increase on the transduction ability of the BSPT piezoelectric material. Pulse-echo contact measurements are performed up to 260C which is the hot stand by temperature for liquid metal cooled reactors, to study the performance of the acoustic coupling agent and the BS-PT piezoelectric material bonded to a low-carbon steel sample. Experimental contact measurements indicate 6dB reduction in amplitude of the first backwall echo from 20C to 260C. Also, 0.1 MHz reduction in the fundamental and third harmonic resonance is observed in the spectral analysis of the first backwall echo.

  18. High temperature superconducting axial field magnetic coupler: realization and test

    Science.gov (United States)

    Belguerras, L.; Mezani, S.; Lubin, T.; Lévêque, J.; Rezzoug, A.

    2015-09-01

    Contactless torque transmission through a large airgap is required in some industrial applications in which hermetic isolation is necessary. This torque transmission usually uses magnetic couplers, whose dimension strongly depends on the airgap flux density. The use of high temperature superconducting (HTS) coils to create a strong magnetic field may constitute a solution to reduce the size of the coupler. It is also possible to use this coupler to replace a torque tube in transmitting the torque produced by a HTS motor to its load. This paper presents the detailed construction and tests of an axial field HTS magnetic coupler. Pancake coils have been manufactured from BSCCO tape and used in one rotor of the coupler. The second rotor is mainly composed of NdFeB permanent magnets. Several tests have been carried out showing that the constructed coupler is working properly. A 3D finite element (FE) model of the studied coupler has been developed. Airgap magnetic field and torque measurements have been carried out and compared to the FE results. It has been shown that the measured and the computed quantities are in satisfactory agreement.

  19. Improved Creep Measurements for Ultra-High Temperature Materials

    Science.gov (United States)

    Hyers, Robert W.; Ye, X.; Rogers, Jan R.

    2010-01-01

    Our team has developed a novel approach to measuring creep at extremely high temperatures using electrostatic levitation (ESL). This method has been demonstrated on niobium up to 2300 C, while ESL has melted tungsten (3400 C). This method has been extended to lower temperatures and higher stresses and applied to new materials, including a niobium-based superalloy, MASC. High-precision machined spheres of the sample are levitated in the NASA MSFC ESL, a national user facility and heated with a laser. The samples are rotated with an induction motor at up to 30,000 revolutions per second. The rapid rotation loads the sample through centripetal acceleration, producing a shear stress of about 60 MPa at the center, causing the sample to deform. The deformation of the sample is captured on high-speed video, which is analyzed by machine-vision software from the University of Massachusetts. The deformations are compared to finite element models to determine the constitutive constants in the creep relation. Furthermore, the non-contact method exploits stress gradients within the sample to determine the stress exponent in a single test.

  20. Ceramic fiber reinforced filter

    Science.gov (United States)

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  1. Effect of microstructure on the high temperature strength of nitride ...

    Indian Academy of Sciences (India)

    The effect of these parameters on room temperature and high temperature strength of the composite up to 1300°C in ambient condition were studied. The high temperature flexural strength of the composite of all compositions increased at 1200 and 1300°C because of oxidation of Si3N4 phase and blunting crack front.

  2. 46 CFR 56.60-5 - Steel (High temperature applications).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steel (High temperature applications). 56.60-5 Section... SYSTEMS AND APPURTENANCES Materials § 56.60-5 Steel (High temperature applications). (a) (Reproduces 124.2.A.) Upon prolonged exposure to temperatures above 775 °F (412 °C), the carbide phase of plain carbon...

  3. The impact of high temperatures on foraging behaviour and body ...

    African Journals Online (AJOL)

    High temperatures can pose significant thermoregulation challenges for endotherms, and determining how individual species respond to high temperatures will be important for predicting the impact of global warming on wild populations. Animals can adjust their behaviour or physiology to cope with higher temperatures, ...

  4. Contactor/filter improvements

    Science.gov (United States)

    Stelman, David

    1989-01-01

    A contactor/filter arrangement for removing particulate contaminants from a gaseous stream includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. The housing further includes a gas inlet means, a gas outlet means, and means for moving a body of granular material through the zone. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. Disposed on the upstream face of the filter element is a cover screen which isolates the filter element from contact with the moving granular bed and collects a portion of the particulates so as to form a dust cake having openings small enough to exclude the granular material, yet large enough to receive the dust particles. In one embodiment, the granular material is comprised of prous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses.

  5. Periodical rocking long period gratings in PANDA fibers for high temperature and refractive index sensing

    Science.gov (United States)

    Jin, Wa; Bi, Wei-hong; Fu, Xing-hu; Fu, Guang-wei

    2017-09-01

    We report periodical rocking long period gratings (PR-LPGs) in PANDA fibers fabricated with CO2 laser. The PR-LPGs achieve very high coupling efficiency of 19 dB with 12 periods and a 3.5° twist angle in just one scanning cycle, which is much more effective than the conventional CO2 laser fabrication technique. This type of LPGs exhibits polarization-selective resonance dips which demonstrate different sensitivities to environmental parameters. The high temperature and external refractive index sensitivities are measured simultaneously, so it can be used as a wavelength-selective polarization filter and sensor.

  6. Proteomics of Rice Grain under High Temperature Stress

    Directory of Open Access Journals (Sweden)

    Toshiaki eMitsui

    2013-03-01

    Full Text Available Recent proteomic analyses revealed dynamic changes of metabolisms during rice grain development. Interestingly, proteins involved in glycolysis, citric acid cycle, lipid metabolism, and proteolysis were accumulated at higher levels in mature grain than those of developing stages. High temperature stress in rice ripening period causes damaged (chalky grains which have loosely packed round shape starch granules. The high temperature stress response on protein expression is complicated, and the molecular mechanism of the chalking of grain is obscure yet. Here, the current state on the proteomics research of rice grain grown under high temperature stress is briefly overviewed.

  7. Analysis of the high-temperature particulate collection problem

    Energy Technology Data Exchange (ETDEWEB)

    Razgaitis, R.

    1977-10-01

    Particulate agglomeration and separation at high temperatures and pressures are examined, with particular emphasis on the unique features of the direct-cycle application of fluidized-bed combustion. The basic long-range mechanisms of aerosol separation are examined, and the effects of high temperature and high pressure on usable collection techniques are assessed. Primary emphasis is placed on those avenues that are not currently attracting widespread research. The high-temperature, particulate-collection problem is surveyed, together with the peculiar requirements associated with operation of turbines with particulate-bearing gas streams. 238 references.

  8. Forming limit diagram of aluminum AA6063 tubes at high temperatures by bulge tests

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Seyed Jalal; Naeini, Hassan Moslemi; Liaghat, Gholamhossein [Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Tafti, Rooholla Azizi [Yazd University, Yazd (Iran, Islamic Republic of); Rahmani, Farzad [Kar Higher Education Institute, Qazvin (Iran, Islamic Republic of)

    2014-11-15

    A free bulge test and ductile fracture criteria were used to obtain the forming limit diagrams (FLD) of aluminum alloy AA6063 tubes at high temperatures. Ductile fracture criteria were calibrated using the results of uniaxial tension tests at various elevated temperatures and different strain rates through adjusting the Zener-Holloman parameter. High temperature free bulge test of tubes was simulated in finite element software Abaqus, and tube bursting was predicted using ductile fracture criteria under different loading paths. FLDs which were obtained from finite element simulation were compared to experimental results to select the most accurate criterion for prediction of forming limit diagram. According to the results, all studied ductile fracture criteria predict similarly when forming condition is close to the uniaxial tension, while Ayada criterion predicts the FLD at 473 K and 573 K very well.

  9. Fuel particles for high temperature reactors; Combustibles a particules pour reacteurs a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pheip, M. [CEA Cadarache (DEN/CAD/DEC/SESC/LIPA), 13 - Saint Paul lez Durance (France). Dept. d' Etudes des Combustibles; Masson, M. [CEA Valrho, Dept. Radiochimie et Procedes, 30 (France); Perrais, Ch. [CEA Cadarache (DEN/DEC/SPUA), 13 - Saint Paul lez Durance (France). Dept. d' Etudes des Combustibles; Pelletier, M. [CEA Cadarache (DEN/DEC/SESC), 13 - Saint Paul lez Durance (France). Dept. d' Etudes des Combustibles

    2007-07-15

    The concept of fuel particles with a millimeter size was born at the end of the 1950's and is the reference concept of high or very high temperature gas-cooled reactors (HTR/VHTR). The specificity of this fuel concerns its fine divided structure, its all-ceramic composition and its micro-confining properties with respect to fission products. These 3 properties when combined together allow the access to high temperatures and to a high level of safety. This article presents: 1 - the general properties of particle fuels; 2 - the fabrication and control of fuel elements: nuclei elaboration processes, vapor deposition coating of nuclei, shaping of fuel elements, quality control of fabrication; 3 - the fuel particles behaviour under irradiation: mechanical and thermal behaviour, behaviour and diffusion of fission products, ruining mode; 4 - the reprocessing of particle fuels: stakes and options, direct storage, separation of constituents, processing of carbonous wastes; 5 - conclusion. (J.S.)

  10. High temperature engineering research facilities and experiments in China

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuanhui; Liu, Meisheng; Yao, Huizhong; Ju, Huaiming [Institute of Nuclear Technology, Tsinghua University, Beijing (China)

    1998-09-01

    June 14, 1995, the construction of a pebble bed type high temperature gas-cooled reactor (HTGR) started in China. It is a test reactor with 10 MW thermal power output (termed HTR- 10). The test reactor is located on the site of Institute of Nuclear Energy Technology (INET) of Tsinghua University in the northwest suburb of Beijing, about 40 km away from the city. Design of the HTR-10 test reactor represents the features of HTR-Modular design: `side-by-side` arrangement, spherical fuel elements with `multi-pass` loading scheme, completely passive decay heat removal, reactor shutdown systems in the side reflector, etc. However, in the HTR-10 design some modifications from the HTR-Module were made to satisfy Chinese conditions. For example, the steam generator is composed of a number of modular helical tubes with small diameter, pulse pneumatic discharging apparatus are used in the fuel handling system and step motor driving control rods are designed. These modifications would cause some uncertainty in our design. It is necessary to do engineering experiments to prove these new or modified ideas. Therefore, a program of engineering experiments for HTR-10 key technologies is being conducted at INET. The main aims of these engineering experiments are to verify the designed characteristics and performance of the components and systems, to feedback on design and to obtain operational experiences. Those engineering experiments are depressurization test of the hot gas duct at room temperature and operating pressure, performance test of the hot gas duct at operating helium temperature and pressure, performance test of the pulse pneumatic fuel handling system, test of the control rods driving apparatus, two phase flow stability test for the once through steam generator and cross mixture test at the bottom of the reactor core

  11. Inorganic Nanostructured High-Temperature Magnet Wires Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop a high-temperature tolerant electrically-insulating coating for magnet wires. The Phase I program will result in a flexible, inorganic...

  12. Double Bag VARTM for High Temperature Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Cost and size are limiting factors in efforts to produce high strength, high stiffness, and high temperature composite parts. To address these issues, new processes...

  13. High Temperature Electrical Insulation Materials for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's future space science missions cannot be realized without the state of the art high temperature insulation materials of which higher working temperature, high...

  14. Radiation Shielding Utilizing A High Temperature Superconducting Magnet Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project aims to leverage near-term high-temperature superconducting technologies to assess applicability of magnetic shielding for protecting against exposure...

  15. Micromachined High-Temperature Sensors for Planet Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In phase I of the SBIR program, LEEOAT Company will develop, simulate, fabricate and test high-temperature piezoelectric miniature sensors (up to 800oC), for...

  16. InGaN High Temperature Photovoltaic Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objectives of this Phase II project are to develop InGaN photovoltaic cells for high temperature and/or high radiation environments to TRL 4 and to define the...

  17. Heat exchangers and recuperators for high temperature waste gases

    Science.gov (United States)

    Meunier, H.

    General considerations on high temperature waste heat recovery are presented. Internal heat recovery through combustion air preheating and external heat recovery are addressed. Heat transfer and pressure drop in heat exchanger design are discussed.

  18. Probing High Temperature Superconductors with Magnetometry in Ultrahigh Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lu [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-07-26

    The objective of this research is to investigate the high-field magnetic properties of high temperature superconductors, materials that conduct electricity without loss. A technique known as high-resolution torque magnetometry that was developed to directly measure the magnetization of high temperature superconductors. This technique was implemented using the 65 Tesla pulsed magnetic field facility that is part of the National High Magnetic Field Laboratory at Los Alamos National Laboratory. This research addressed unanswered questions about the interplay between magnetism and superconductivity, determine the electronic structure of high temperature superconductors, and shed light on the mechanism of high temperature superconductivity and on potential applications of these materials in areas such as energy generation and power transmission. Further applications of the technology resolve the novel physical phenomena such as correlated topological insulators, and spin liquid state in quantum magnets.

  19. Leaders in high temperature superconductivity commercialization win superconductor industry award

    CERN Multimedia

    2007-01-01

    CERN's Large Hadron Collider curretn leads project head Amalia Ballarino named superconductor industry person of the year 2006. Former high temperature superconductivity program manager at the US Department of energy James Daley wins lifetime achievement award. (1,5 page)

  20. High Temperature Radiators for Electric Propulsion Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The VASIMR propulsion system uses a high temperature Loop Heat Pipe (LHP) radiator to reject heat from the helicon section. The current baseline radiator uses...

  1. High Temperature Sound Absorption Coating - Soundown HT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MPAC and UMR are proposing development of an Acoustic Control System for high temperature gas flow in ducts. This control system is based on a passive inorganic...

  2. High Temperature Venus Drill and Sample Delivery System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We proposed to design, build and test a high temperature Pneumatic Drill and Trencher system for Venus subsurface exploration. The Venus Drill and Trencher will be...

  3. High Accuracy, Miniature Pressure Sensor for Very High Temperatures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SiWave proposes to develop a compact, low-cost MEMS-based pressure sensor for very high temperatures and low pressures in hypersonic wind tunnels. Most currently...

  4. Novel High Temperature Membrane for PEM Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed in this STTR program is a high temperature membrane to increase the efficiency and power density of PEM fuel cells. The NASA application is...

  5. Research at Very High Pressures and High Temperatures

    Science.gov (United States)

    Bundy, Francis P.

    1977-01-01

    Reviews research and apparatus utilized in the study of the states and characteristics of materials at very high temperatures and pressures. Includes three examples of the research being conducted. (SL)

  6. Radiometric characterization of a high temperature blackbody in the visible and near infrared

    Energy Technology Data Exchange (ETDEWEB)

    Taubert, R. D.; Hollandt, J. [Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, D-10587 Berlin (Germany)

    2013-09-11

    At the Physikalisch-Technische Bundesanstalt the radiance temperature in the range from 962 °C to 3000 °C is disseminated by applying a high temperature blackbody (HTBB) with a directly heated pyrolytic graphite cavity. The thermodynamic radiance temperature of the HTBB was measured in the temperature range from 1000 °C to 3000 °C by applying almost simultaneously absolutely calibrated silicon photodiode based filter radiometers with centre wavelengths at 476 nm, 676 nm, 800 nm, 900 nm and 1000 nm and InGaAs photodiode based filter radiometers with centre wavelengths at 1300 nm, 1550 nm and 1595 nm. The results demonstrate that, expressed in terms of irradiance, within an uncertainty of 0.1 % (k=1) in a broad wavelength range the thermodynamic radiance temperature of the HTBB is wavelength independent in the investigated temperature interval.

  7. Characterization of Thick and Thin Film SiCN for Pressure Sensing at High Temperatures

    Directory of Open Access Journals (Sweden)

    Rama B. Bhat

    2010-02-01

    Full Text Available Pressure measurement in high temperature environments is important in many applications to provide valuable information for performance studies. Information on pressure patterns is highly desirable for improving performance, condition monitoring and accurate prediction of the remaining life of systems that operate in extremely high temperature environments, such as gas turbine engines. A number of technologies have been recently investigated, however these technologies target specific applications and they are limited by the maximum operating temperature. Thick and thin films of SiCN can withstand high temperatures. SiCN is a polymer-derived ceramic with liquid phase polymer as its starting material. This provides the advantage that it can be molded to any shape. CERASET™ also yields itself for photolithography, with the addition of photo initiator 2, 2-Dimethoxy-2-phenyl-acetophenone (DMPA, thereby enabling photolithographical patterning of the pre-ceramic polymer using UV lithography. SiCN fabrication includes thermosetting, crosslinking and pyrolysis. The technology is still under investigation for stability and improved performance. This work presents the preparation of SiCN films to be used as the body of a sensor for pressure measurements in high temperature environments. The sensor employs the phenomenon of drag effect. The pressure sensor consists of a slender sensitive element and a thick blocking element. The dimensions and thickness of the films depend on the intended application of the sensors. Fabrication methods of SiCN ceramics both as thin (about 40–60 µm and thick (about 2–3 mm films for high temperature applications are discussed. In addition, the influence of thermosetting and annealing processes on mechanical properties is investigated.

  8. Plasticity In High Temperature Materials: Tantalum and Monazite

    Science.gov (United States)

    2014-03-12

    AFRL-OSR-VA-TR-2014-0065 PLASTICITY IN HIGH TEMPERATURE MATERIALS: TANTALUM AND MONAZITE Jeffrey Kysar THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE...Agency Air Force Office of Scientific Research Title of Project Plasticity in High Temperature Materials: Tantalum and Monazite February 28, 2014...centered cu- bic tantalum , the methodology also demonstrated a relationship between dislocation mean free path length and GND density. A framework to

  9. High temperature resistant nanofiber by bubbfil-spinning

    Directory of Open Access Journals (Sweden)

    Li Ya

    2015-01-01

    Full Text Available Heat-resisting nanofibers have many potential applications in various industries, and the bubbfil spinning is the best candidate for mass-production of such materials. Polyether sulfone/zirconia solution with a bi-solvent system is used in the experiment. Experimental result reveals that polyether sulfone/zirconia nanofibers have higher resistance to high temperature than pure polyether sulfone fibers, and can be used as high-temperature-resistant filtration materials.

  10. SiC device development for high temperature sensor applications

    Science.gov (United States)

    Shor, J. S.; Goldstein, David; Kurtz, A. D.; Osgood, R. M.

    1992-01-01

    Progress made in the processing and characterization of 3C-SiC for high temperature sensor applications is reviewed. Piezoresistance properties of silicon carbide and the temperature coefficient of resistivity of n-type beta-SiC are presented. In addition, photoelectrical etching and dopant selective etch-stops in SiC and high temperature Ohmic contacts for n-type beta-SiC sensors are discussed.

  11. High temperature superconductor cable concepts for fusion magnets

    CERN Document Server

    AUTHOR|(CDS)2078397

    2013-01-01

    Three concepts of high temperature superconductor cables carrying kA currents (RACC, CORC and TSTC) are investigated, optimized and evaluated in the scope of their applicability as conductor in fusion magnets. The magnetic field and temperature dependence of the cables is measured; the thermal expansion and conductivity of structure, insulation and filling materials are investigated. High temperature superconductor winding packs for fusion magnets are calculated and compared with corresponding low temperature superconductor cases.

  12. Dynamic high-temperature Kolsky tension bar techniques

    OpenAIRE

    Song Bo; Nelson Kevin; Lipinski Ronald; Bignell John; Ulrich G.B.; George E.P.

    2015-01-01

    Kolsky tension bar techniques were modified for dynamic high-temperature tensile characterization of thin-sheet alloys. An induction coil heater was used to heat the specimen while a cooling system was applied to keep the bars at room temperature during heating. A preload system was developed to generate a small pretension load in the bar system during heating in order to compensate for the effect of thermal expansion generated in the high-temperature tensile specimen. A laser system was appl...

  13. High temperature deformation mechanisms of cemented carbides and cermets

    OpenAIRE

    Buss, Katharina

    2004-01-01

    The motivation of this work derives from the need of the cutting tool industry to improve its products in order to support harder and harder working conditions, namely increasing cutting speeds and working on stronger modern materials. The lifetime of the tools is limited by plastic deformation that occurs at the cutting edge under working conditions, which involve high temperatures and stresses. The high temperature deformation of the materials that are used for the production of cutting too...

  14. Process for Forming a High Temperature Single Crystal Canted Spring

    Science.gov (United States)

    DeMange, Jeffrey J (Inventor); Ritzert, Frank J (Inventor); Nathal, Michael V (Inventor); Dunlap, Patrick H (Inventor); Steinetz, Bruce M (Inventor)

    2017-01-01

    A process for forming a high temperature single crystal canted spring is provided. In one embodiment, the process includes fabricating configurations of a rapid prototype spring to fabricate a sacrificial mold pattern to create a ceramic mold and casting a canted coiled spring to form at least one canted coil spring configuration based on the ceramic mold. The high temperature single crystal canted spring is formed from a nickel-based alloy containing rhenium using the at least one coil spring configuration.

  15. Thermodynamic Temperature of High-Temperature Fixed Points Traceable to Blackbody Radiation and Synchrotron Radiation

    Science.gov (United States)

    Wähmer, M.; Anhalt, K.; Hollandt, J.; Klein, R.; Taubert, R. D.; Thornagel, R.; Ulm, G.; Gavrilov, V.; Grigoryeva, I.; Khlevnoy, B.; Sapritsky, V.

    2017-10-01

    Absolute spectral radiometry is currently the only established primary thermometric method for the temperature range above 1300 K. Up to now, the ongoing improvements of high-temperature fixed points and their formal implementation into an improved temperature scale with the mise en pratique for the definition of the kelvin, rely solely on single-wavelength absolute radiometry traceable to the cryogenic radiometer. Two alternative primary thermometric methods, yielding comparable or possibly even smaller uncertainties, have been proposed in the literature. They use ratios of irradiances to determine the thermodynamic temperature traceable to blackbody radiation and synchrotron radiation. At PTB, a project has been established in cooperation with VNIIOFI to use, for the first time, all three methods simultaneously for the determination of the phase transition temperatures of high-temperature fixed points. For this, a dedicated four-wavelengths ratio filter radiometer was developed. With all three thermometric methods performed independently and in parallel, we aim to compare the potential and practical limitations of all three methods, disclose possibly undetected systematic effects of each method and thereby confirm or improve the previous measurements traceable to the cryogenic radiometer. This will give further and independent confidence in the thermodynamic temperature determination of the high-temperature fixed point's phase transitions.

  16. Microstructure Based Material-Sand Particulate Interactions and Assessment of Coatings for High Temperature Turbine Blades

    Science.gov (United States)

    Murugan, Muthuvel; Ghoshal, Anindya; Walock, Michael; Nieto, Andy; Bravo, Luis; Barnett, Blake; Pepi, Marc; Swab, Jeffrey; Pegg, Robert Tyler; Rowe, Chris; hide

    2017-01-01

    Gas turbine engines for military/commercial fixed-wing and rotary wing aircraft use thermal barrier coatings in the high-temperature sections of the engine for improved efficiency and power. The desire to further make improvements in gas turbine engine efficiency and high power-density is driving the research and development of thermal barrier coatings and the effort of improving their tolerance to fine foreign particulates that may be contained in the intake air. Both commercial and military aircraft engines often are required to operate over sandy regions such as in the Middle-East nations, as well as over volcanic zones. For rotorcraft gas turbine engines, the sand ingestion is adverse during take-off, hovering near ground, and landing conditions. Although, most of the rotorcraft gas turbine engines are fitted with inlet particle separators, they are not 100 percent efficient in filtering fine sand particles of size 75 microns or below. The presence of these fine solid particles in the working fluid medium has an adverse effect on the durability of turbine blade thermal barrier coatings and overall performance of the engine. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The objective of this research is to understand the fine particle interactions with typical ceramic coatings of turbine blades at the microstructure level. A finite-element based microstructure modeling and analysis has been performed to investigate particle-surface interactions, and restitution characteristics. Experimentally, a set of tailored thermal barrier coatings and surface treatments were down-selected through hot burner rig tests and then applied to first stage nozzle vanes of the Gas Generator Turbine of a typical rotorcraft gas turbine engine. Laser Doppler velocity measurements were performed

  17. Evaluation of the ICET Test Stand to Assess the Performance of a Range of Ceramic Media Filter Elements in Support of ASME AG-1 Subsection FO

    Energy Technology Data Exchange (ETDEWEB)

    Schemmel, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-26

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

  18. Packaging Technologies for High Temperature Electronics and Sensors

    Science.gov (United States)

    Chen, Liangyu; Hunter, Gary W.; Neudeck, Philip G.; Beheim, Glenn M.; Spry, David J.; Meredith, Roger D.

    2013-01-01

    This paper reviews ceramic substrates and thick-film metallization based packaging technologies in development for 500degC silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-based chiplevel packages with gold (Au) thick-film metallization have been electrically characterized at temperatures up to 550degC. A 96% alumina based edge connector for a PCB level subsystem interconnection has also been demonstrated recently. The 96% alumina packaging system composed of chip-level packages and PCBs has been tested with high temperature SiC devices at 500degC for over 10,000 hours. In addition to tests in a laboratory environment, a SiC JFET with a packaging system composed of a 96% alumina chip-level package and an alumina printed circuit board mounted on a data acquisition circuit board was launched as a part of the MISSE-7 suite to the International Space Station via a Shuttle mission. This packaged SiC transistor was successfully tested in orbit for eighteen months. A spark-plug type sensor package designed for high temperature SiC capacitive pressure sensors was developed. This sensor package combines the high temperature interconnection system with a commercial high temperature high pressure stainless steel seal gland (electrical feed-through). Test results of a packaged high temperature capacitive pressure sensor at 500degC are also discussed. In addition to the pressure sensor package, efforts for packaging high temperature SiC diode-based gas chemical sensors are in process.

  19. High-temperature transport in the Hubbard Model

    Science.gov (United States)

    Shastry, B. Sriram; Perepelitsky, Edward; Galatas, Andrew; Khatami, Ehsan; Mravlje, Jernej; Georges, Antoine

    We examine the general behavior of the frequency and momentum dependent single-particle scattering rate and the transport coefficients, of many-body systems in the high-temperature limit. We find that the single-particle scattering rate always saturates in temperature, while the transport coefficients always decay like 1/T, where T is the temperature. A consequence of this is a resistivity which is ubiquitously linear in T at high temperatures. For the Hubbard model, by using the high-temperature series, we are able to calculate the first few moments of the single particle scattering rate Σ (k --> , ω) and the conductivity σ (k --> , ω) in the high-temperature regime in d spatial dimensions. Further in the case of d --> ∞ , we are able to calculate a large number of moments using symbolic computation. We make a direct comparison between these moments and those obtained through Dynamical Mean Field Theory (DMFT). Finally, we use the moments to reconstruct the ω-dependent optical conductivity σ (ω) =limk-->0 σ (k --> , ω) in the high-temperature regime. The work at UCSC was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES) under Award # FG02-06ER46319.

  20. Test plans of the high temperature test operation at HTTR

    Energy Technology Data Exchange (ETDEWEB)

    Sakaba, Nariaki; Nakagawa, Shigeaki; Takada, Eiji [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

    2003-03-01

    HTTR plans a high temperature test operation as the fifth step of the rise-to-power tests to achieve a reactor outlet coolant temperature of 950 degrees centigrade in the 2003 fiscal year. Since HTTR is the first HTGR in Japan which uses coated particle fuel as its fuel and helium gas as its coolant, it is necessary that the plan of the high temperature test operation is based on the previous rise-to-power tests with a thermal power of 30 MW and a reactor outlet coolant temperature at 850 degrees centigrade. During the high temperature test operation, reactor characteristics, reactor performances and reactor operations are confirmed for the safety and stability of operations. This report describes the evaluation result of the safety confirmations of the fuel, the control rods and the intermediate heat exchanger for the high temperature test operation. Also, problems which were identified during the previous operations are shown with their solution methods. Additionally, there is a discussion on the contents of the high temperature test operation. As a result of this study, it is shown that the HTTR can safely achieve a thermal power of 30 MW with the reactor outlet coolant temperature at 950 degrees centigrade. (author)

  1. Experimental assessment of accident scenarios for the high temperature reactor fuel system

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, O.; Avincola, V.; Bottomley, P.D.W.; Rondinella, V.V. [European Commission Joint Research Centre - Institute for Transuranium Elements (JRC-ITU) (Germany)

    2012-11-01

    The High Temperature Reactor (HTR) is an advanced reactor concept with particular safety features. Fuel elements are constituted by a graphite matrix containing sub-mm-sized fuel particles with TRISO (tri-isotropic) coating designed to provide high fission product retention. Passive safety features of the HTR include a low power density in the core compared to other reactor designs; this ensures sufficient heat transport in a loss of coolant accident scenario. The temperature during such events would not exceed 1600 C, remaining well below the melting point of the fuel. An experimental assessment of the fuel behaviour under severe accident conditions is necessary to confirm the fission product retention of TRISO coated particles and to validate relevant computer codes. Though helium is used as coolant for the HTR system, additional corrosion effects come into play in case of an in-leakage affecting the primary circuit. The experimental scope of the present work focuses on two key aspects associated with the HTR fuel safety. Fission product retention at high temperatures (up to {proportional_to}1800 C) is analyzed with the so-called cold finger apparatus (KueFA: Kuehlfinger-Apparatur), while the performance of HTR fuel elements in case of air/steam ingress accidents is assessed with a high temperature corrosion apparatus (KORA: Korrosions-Apparatur). (orig.)

  2. TECHNICAL TRAINING SEMINAR: High Temperature Superconductors: Progress and Issues

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Monday 24 June from 14:30 to 15:30 - Training Centre Auditorium - bldg. 593-11 High Temperature Superconductors: Progress and Issues Prof. Jan Evetts / UNIVERSITY OF CAMBRIDGE, Department of Materials Science and Metallurgy, UK Grappling with grain boundaries: Current transport processes in granular High Temperature Superconductors (HTS) The development of High Temperature Superconductors, seen from a materials scientist's point of view, is relevant to the superconductivity community at CERN: their possible high current applications can include high performance magnets for future accelerators. There is an urgent need to develop a quantitative description of HTS conductors in terms of their complex anisotropy, inhomogeneity and dimensionality. This is essential both for the practical specification of a conductor and for charting routes to conductor optimisation. The critical current, the n-value, dissipation and quenching characteristics are amongst most important parameters that make up an engineering specifi...

  3. Structure of liquid oxides at very high temperatures

    CERN Document Server

    Landron, C; Thiaudiere, D; Price, D L; Greaves, G N

    2003-01-01

    The structural characterization of condensed matter by synchrotron radiation combined with neutron data constitutes a powerful structural tool in material science. In order to investigate refractory liquids at very high temperatures, we have developed a new analysis chamber for performing combined X-ray absorption and diffraction measurements by using laser heating and aerodynamic levitation. A similar system has been designed for neutron experiments. This high temperature equipment presents several advantages: the container does not physically or chemically perturb the sample, heterogeneous nucleation during cooling is suppressed and pollution by the container is removed. This cell can operate under various gas conditions from room temperature up to 3000 deg. C obtained by means of a sealed 125 W CO sub 2 laser. Experiments have been performed at LURE, ESRF and at ISIS. We have studied the local structure around the cations in several liquid and solid oxides. We have shown that high temperature synchrotron d...

  4. High-Temperature Cuprate Superconductors Experiment, Theory, and Applications

    CERN Document Server

    Plakida, Nikolay Maksimilianovich

    2010-01-01

    High-Temperature Cuprate Superconductors provides an up-to-date and comprehensive review of the properties of these fascinating materials. The essential properties of high-temperature cuprate superconductors are reviewed on the background of their theoretical interpretation. The experimental results for structural, magnetic, thermal, electric, optical and lattice properties of various cuprate superconductors are presented with respect to relevant theoretical models. A critical comparison of various theoretical models involving strong electron correlations, antiferromagnetic spin fluctuations, phonons and excitons provides a background for understanding of the mechanism of high-temperature superconductivity. Recent achievements in their applications are also reviewed. A large number of illustrations and tables gives valuable information for specialists. A text-book level presentation with formulation of a general theory of strong-coupling superconductivity will help students and researches to consolidate their...

  5. High Temperature Membrane with Humidification-Independent Cluster Structure

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, Ludwig [FuelCell Energy, Inc., Danbury, CT (United States)

    2015-07-10

    The objective of this project was to develop high temperature membranes to facilitate the wide-spread deployment of hydrogen fuel cells. High temperature membranes offer significant advantages in PEM system operation, overall capital and operating costs. State-of-the-art Nafion-based membranes are inadequate for the high temperature operation. These conventional membranes become unstable at higher temperatures (90-120°C) and lose their conductivity, particularly at low relative humidity. In this program, alternate materials were developed to enable fabrication of novel high performance composite membranes. FCE’s concept for the multi-component composite membrane, named mC2, has been used in the design of more conductive membranes.

  6. Improved controlled atmosphere high temperature scanning probe microscope

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Wu, Yuehua; Jacobsen, Torben

    2013-01-01

    ) is monitored by an oxygen sensor. We present here some examples of its capabilities demonstrated by high temperature topography with simultaneously ac electrical conductance measurements during atmosphere changes, electrochemical impedance spectroscopy at various temperatures, and measurements of the surface......To locally access electrochemical active surfaces and interfaces in operando at the sub-micron scale at high temperatures in a reactive gas atmosphere is of great importance to understand the basic mechanisms in new functional materials, for instance, for energy technologies, such as solid oxide...... fuel cells and electrolyzer cells. Here, we report on advanced improvements of our original controlled atmosphere high temperature scanning probe microscope, CAHT-SPM. The new microscope can employ a broad range of the scanning probe techniques including tapping mode, scanning tunneling microscopy...

  7. Probability based high temperature engineering creep and structural fire resistance

    CERN Document Server

    Razdolsky, Leo

    2017-01-01

    This volume on structural fire resistance is for aerospace, structural, and fire prevention engineers; architects, and educators. It bridges the gap between prescriptive- and performance-based methods and simplifies very complex and comprehensive computer analyses to the point that the structural fire resistance and high temperature creep deformations will have a simple, approximate analytical expression that can be used in structural analysis and design. The book emphasizes methods of the theory of engineering creep (stress-strain diagrams) and mathematical operations quite distinct from those of solid mechanics absent high-temperature creep deformations, in particular the classical theory of elasticity and structural engineering. Dr. Razdolsky’s previous books focused on methods of computing the ultimate structural design load to the different fire scenarios. The current work is devoted to the computing of the estimated ultimate resistance of the structure taking into account the effect of high temperatur...

  8. HIGH TEMPERATURE HIGH PRESSURE THERMODYNAMIC MEASUREMENTS FOR COAL MODEL COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

    Vinayak N. Kabadi

    1999-02-20

    It is well known that the fluid phase equilibria can be represented by a number of {gamma}-models , but unfortunately most of them do not function well under high temperature. In this calculation, we mainly investigate the performance of UNIQUAC and NRTL models under high temperature, using temperature dependent parameters rather than using the original formulas. the other feature of this calculation is that we try to relate the excess Gibbs energy G{sup E}and enthalpy of mixing H{sup E}simultaneously. In other words, we will use the high temperature and pressure G{sup E} and H{sup E}data to regress the temperature dependant parameters to find out which model and what kind of temperature dependant parameters should be used.

  9. High-temperature injury and auxin biosynthesis in microsporogenesis.

    Directory of Open Access Journals (Sweden)

    Atsushi eHigashitani

    2013-03-01

    Full Text Available Plant reproductive development is more sensitive than vegetative growth to many environmental stresses. With global warming, in particular, plant high temperature injury is becoming an increasingly serious problem. In wheat, barley, and various other commercially important crops, the early phase of anther development is especially susceptible to high temperatures. We recently demonstrated that high temperature causes cell-proliferation arrest and represses auxin signaling in a tissue-specific manner of the anther cells of barley and Arabidopsis. These phenomena were accompanied by comprehensive alterations in transcription including repression of cell-proliferation related genes and YUCCA auxin biosynthesis genes. Moreover, application of auxin completely improved the transcriptional alterations, the production of normal pollen grains, and seed setting rate under increasing temperatures. These denote that auxin, which has been used widely as potent and selective herbicides, is useful for the promotion of plant fertility and maintenance of crop yields under the global warming conditions.

  10. Handbook of high-temperature superconductivity theory and experiment

    CERN Document Server

    Brooks, James S

    2007-01-01

    Since the 1980s, a general theme in the study of high-temperature superconductors has been to test the BCS theory and its predictions against new data. At the same time, this process has engendered new physics, new materials, and new theoretical frameworks. Remarkable advances have occurred in sample quality and in single crystals, in hole and electron doping in the development of sister compounds with lower transition temperatures, and in instruments to probe structure and dynamics. Handbook of High-Temperature Superconductvity is a comprehensive and in-depth treatment of both experimental and theoretical methodologies by the the world's top leaders in the field. The Editor, Nobel Laureate J. Robert Schrieffer, and Associate Editor James S. Brooks, have produced a unified, coherent work providing a global view of high-temperature superconductivity covering the materials, the relationships with heavy-fermion and organic systems, and the many formidable challenges that remain.

  11. Water Filters

    Science.gov (United States)

    1993-01-01

    The Aquaspace H2OME Guardian Water Filter, available through Western Water International, Inc., reduces lead in water supplies. The filter is mounted on the faucet and the filter cartridge is placed in the "dead space" between sink and wall. This filter is one of several new filtration devices using the Aquaspace compound filter media, which combines company developed and NASA technology. Aquaspace filters are used in industrial, commercial, residential, and recreational environments as well as by developing nations where water is highly contaminated.

  12. ULTRA-HIGH TEMPERATURE SENSORS BASED ON OPTICAL PROPERTY MODULATION AND VIBRATION-TOLERANT INTERFEROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Nabeel A. Riza

    2004-11-10

    The goals of the first six months of this project were to lay the foundations for both the SiC front-end optical chip fabrication as well as the free-space laser beam interferometer designs and preliminary tests. In addition, a Phase I goal was to design and experimentally build the high temperature and pressure infrastructure and test systems that will be used in the next 6 months for proposed sensor experimentation and data processing. All these goals have been achieved and are described in detail in the report. Both design process and diagrams for the mechanical elements as well as the optical systems are provided. In addition, photographs of the fabricated SiC optical chips, the high temperature & pressure test chamber instrument, the optical interferometer, the SiC sample chip holder, and signal processing data are provided. The design and experimentation results are summarized to give positive conclusions on the proposed novel high temperature optical sensor technology. The goals of the second six months of this project were to conduct high temperature sensing tests using the test chamber and optical sensing instrument designs developed in the first part of the project. In addition, a Phase I goal was to develop the basic processing theory and physics for the proposed first sensor experimentation and data processing. All these goals have been achieved and are described in detail. Both optical experimental design process and sensed temperature are provided. In addition, photographs of the fabricated SiC optical chips after deployment in the high temperature test chamber are shown from a material study point-of-view.

  13. Direct Utilization of Coal Syngas in High Temperature Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Ismail B. [West Virginia University, Morgantown, WV (United States)

    2014-10-30

    This EPSCoR project had two primary goals: (i) to build infrastructure and work force at WVU to support long-term research in the area of fuel cells and related sciences; (ii) study effects of various impurities found in coal-syngas on performance of Solid Oxide Fuel Cells (SOFC). As detailed in this report the WVU research team has made significant accomplishments in both of these areas. What follows is a brief summary of these accomplishments: State-of-the-art test facilities and diagnostic tools have been built and put into use. These include cell manufacturing, half-cell and full-cell test benches, XPS, XRD, TEM, Raman, EDAX, SEM, EIS, and ESEM equipment, unique in-situ measurement techniques and test benches (Environmental EM, Transient Mass-Spectrometer-MS, and IR Optical Temperature measurements). In addition, computational capabilities have been developed culminating in a multi-scale multi-physics fuel cell simulation code, DREAM-SOFC, as well as a Beowulf cluster with 64 CPU units. We have trained 16 graduate students, 10 postdoctoral fellows, and recruited 4 new young faculty members who have actively participated in the EPSCoR project. All four of these faculty members have already been promoted to the tenured associate professor level. With the help of these faculty and students, we were able to secure 14 research awards/contracts amounting to a total of circa $5.0 Million external funding in closely related areas of research. Using the facilities mentioned above, the effects of PH3, HCl, Cl2, and H2S on cell performance have been studied in detail, mechanisms have been identified, and also remedies have been proposed and demonstrated in the laboratory. For example, it has been determined that PH3 reacts rapidly with Ni to from secondary compounds which may become softer or even melt at high temperature and then induce Ni migration to the surface of the cell changing the material and micro-structural properties of the cell drastically. It is found that

  14. Nanostructured oxide materials and modules for high temperature power generation from waste heat

    DEFF Research Database (Denmark)

    Van Nong, Ngo; Pryds, Nini

    2013-01-01

    are not easily satisfied by conventional thermoelectric materials. Not only they must possess a sufficient thermoelectric performance, they should also be stable at high temperatures, nontoxic and low-cost comprising elements, and must be also able to be processed and shaped cheaply. Oxides are among......A large amount of thermal energy that emitted from many industrial processes is available as waste heat. Thermoelectric power generators that convert heat directly into electricity can offer a very promising way for waste heat recovery. However, the requirements for this task place in the materials...... the strongest candidate materials for this purpose. In this review, the progress in the development of two representative p- and n-type novel oxide materials based on Ca3Co4O9 and doped-ZnO is presented. Thermoelectric modules built up from these oxides were fabricated, tested at high temperatures, and compared...

  15. Preparation and Pore Structure Stability at High Temperature of Porous Fe-Al Intermetallics

    Science.gov (United States)

    Shen, P. Z.; Gao, H. Y.; Song, M.; He, Y. H.

    2013-12-01

    Porous Fe-Al intermetallics with different nominal compositions (from Fe-8 wt.% Al to Fe-50 wt.% Al) were fabricated by Fe and Al elemental powders through reaction synthesis. The effects of the Al content on the pore structure properties, and the comparison of pore structure stabilities at high-temperatures among the porous Fe-Al intermetallics and porous Ti, Ni, 316L stainless steel samples, were systematically studied. Results showed that the open porosity, maximum pore size, and permeability vary with the Al content. Porous Fe-(25-30 wt.%) Al intermetallics show good shape controllability and excellent pore structure stability at 1073 K in air, which suggests that these porous Fe-Al intermetallics could be used for filtration at high temperatures.

  16. Compressive behaviour at High Temperatures of Fibre Reinforced Concretes

    Directory of Open Access Journals (Sweden)

    S. O. Santos

    2009-01-01

    Full Text Available This paper summarizes the research that is being carried out at the Universities of Coimbra and Rio de Janeiro, on fibre reinforced concretes at high temperatures. Several high strength concrete compositions reinforced with fibres (polypropylene, steel and glass fibres were developed. The results of compressive tests at high temperatures (300 °C, 500 °C and 600 °C and after heating and cooling down of the concrete are presented in the paper. In both research studies, the results indicated that polypropylene fibers prevent concrete spalling. 

  17. High Temperature PEM Fuel Cell Systems, Control and Diagnostics

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Justesen, Kristian Kjær

    2015-01-01

    Various system topologies are available when it comes to designing high temperature PEM fuel cell systems. Very simple system designs are possible using pure hydrogen, and more complex system designs present themselves when alternative fuels are desired, using reformer systems. The use of reformed...... fuels utilizes one of the main advantages of the high temperature PEM fuel cell: robustness to fuel quality and impurities. In order for such systems to provide efficient, robust, and reliable energy, proper control strategies are needed. The complexity and nonlinearity of many of the components...

  18. A gallium phosphide high-temperature bipolar junction transistor

    Science.gov (United States)

    Zipperian, T. E.; Dawson, L. R.; Chaffin, R. J.

    1981-01-01

    Preliminary results are reported on the development of a high temperature (350 C) gallium phosphide bipolar junction transistor (BJT) for geothermal and other energy applications. This four-layer p(+)n(-)pp(+) structure was formed by liquid phase epitaxy using a supercooling technique to insure uniform nucleation of the thin layers. Magnesium was used as the p-type dopant to avoid excessive out-diffusion into the lightly doped base. By appropriate choice of electrodes, the device may also be driven as an n-channel junction field-effect transistor. The initial design suffers from a series resistance problem which limits the transistor's usefulness at high temperatures.

  19. Modeling high temperature materials behavior for structural analysis

    CERN Document Server

    Naumenko, Konstantin

    2016-01-01

    This monograph presents approaches to characterize inelastic behavior of materials and structures at high temperature. Starting from experimental observations, it discusses basic features of inelastic phenomena including creep, plasticity, relaxation, low cycle and thermal fatigue. The authors formulate constitutive equations to describe the inelastic response for the given states of stress and microstructure. They introduce evolution equations to capture hardening, recovery, softening, ageing and damage processes. Principles of continuum mechanics and thermodynamics are presented to provide a framework for the modeling materials behavior with the aim of structural analysis of high-temperature engineering components.

  20. High temperature metal matrix composites for future aerospace systems

    Science.gov (United States)

    Stephens, Joseph R.

    1988-01-01

    Research was conducted on metal matrix composites and intermetallic matrix composites to understand their behavior under anticipated future operating conditions envisioned for aerospace power and propulsion systems of the 21st century. Extremes in environmental conditions, high temperature, long operating lives, and cyclic conditions dictate that the test evaluations not only include laboratory testing, but simulated flight conditions. The various processing techniques employed to fabricate composites are discussed along with the basic research underway to understand the behavior of high temperature composites, and the relationship of this research to future aerospace systems.

  1. Optimum high temperature strength of two-dimensional nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Monclús, M. A.; Molina-Aldareguía, J. M., E-mail: jon.molina@imdea.org [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Zheng, S. J.; Mayeur, J. R.; Beyerlein, I. J.; Mara, N. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Polcar, T. [Czech Technical University in Prague, Technická 2, Prague 6 (Czech Republic); Llorca, J. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science, Polytechnic University of Madrid, E. T. S. de Ingenieros de Caminos, 28040 Madrid (Spain)

    2013-11-01

    High-temperature nanoindentation was used to reveal nano-layer size effects on the hardness of two-dimensional metallic nanocomposites. We report the existence of a critical layer thickness at which strength achieves optimal thermal stability. Transmission electron microscopy and theoretical bicrystal calculations show that this optimum arises due to a transition from thermally activated glide within the layers to dislocation transmission across the layers. We demonstrate experimentally that the atomic-scale properties of the interfaces profoundly affect this critical transition. The strong implications are that interfaces can be tuned to achieve an optimum in high temperature strength in layered nanocomposite structures.

  2. Optimum high temperature strength of two-dimensional nanocomposites

    Directory of Open Access Journals (Sweden)

    M. A. Monclús

    2013-11-01

    Full Text Available High-temperature nanoindentation was used to reveal nano-layer size effects on the hardness of two-dimensional metallic nanocomposites. We report the existence of a critical layer thickness at which strength achieves optimal thermal stability. Transmission electron microscopy and theoretical bicrystal calculations show that this optimum arises due to a transition from thermally activated glide within the layers to dislocation transmission across the layers. We demonstrate experimentally that the atomic-scale properties of the interfaces profoundly affect this critical transition. The strong implications are that interfaces can be tuned to achieve an optimum in high temperature strength in layered nanocomposite structures.

  3. High-temperature plasmonic thermal emitter for thermophotovotaics

    DEFF Research Database (Denmark)

    Liu, Jingjing; Guler, Urcan; Li, Wei

    2014-01-01

    We use titanium nitride (TiN) to demonstrate an ultra-thin plasmonic thermal emitter operating at high temperatures (830 K). The spectrally selective emitter exhibits a large emittance at around 2.5 μm and below, and suppresses emission at longer wavelengths.......We use titanium nitride (TiN) to demonstrate an ultra-thin plasmonic thermal emitter operating at high temperatures (830 K). The spectrally selective emitter exhibits a large emittance at around 2.5 μm and below, and suppresses emission at longer wavelengths....

  4. Margins in high temperature leak-before-break assessments

    Energy Technology Data Exchange (ETDEWEB)

    Budden, P.J.; Hooton, D.G.

    1997-04-01

    Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep.

  5. High Temperature Materials Characterization and Advanced Materials Development

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Seog; Kim, D. H.; Kim, S. H. (and others)

    2007-06-15

    The project has been carried out for 2 years in stage III in order to achieve the final goals of performance verification of the developed materials, after successful development of the advanced high temperature material technologies for 3 years in Stage II. The mechanical and thermal properties of the advanced materials, which were developed during Stage II, were evaluated at high temperatures, and the modification of the advanced materials were performed. Moreover, a database management system was established using user-friendly knowledge-base scheme to complete the integrated-information material database in KAERI material division.

  6. Fiber-optic flow sensors for high-temperature environment operation up to 800°C.

    Science.gov (United States)

    Chen, Rongzhang; Yan, Aidong; Wang, Qingqing; Chen, Kevin P

    2014-07-01

    This Letter presents an all-optical high-temperature flow sensor based on hot-wire anemometry. High-attenuation fibers (HAFs) were used as the heating elements. High-temperature-stable regenerated fiber Bragg gratings were inscribed in HAFs and in standard telecom fibers as temperature sensors. Using in-fiber light as both the heating power source and the interrogation light source, regenerative fiber Bragg grating sensors were used to gauge the heat transfer from an optically powered heating element induced by the gas flow. Reliable gas flow measurements were demonstrated between 0.066  m/s and 0.66  m/s from the room temperature to 800°C. This Letter presents a compact, low-cost, and multiflexible approach to measure gas flow for high-temperature harsh environments.

  7. Water Filters

    Science.gov (United States)

    1987-01-01

    A compact, lightweight electrolytic water filter generates silver ions in concentrations of 50 to 100 parts per billion in the water flow system. Silver ions serve as effective bactericide/deodorizers. Ray Ward requested and received from NASA a technical information package on the Shuttle filter, and used it as basis for his own initial development, a home use filter.

  8. High-Temperature Luminescence Quenching of Colloidal Quantum Dots

    NARCIS (Netherlands)

    Zhao, Y.|info:eu-repo/dai/nl/355358352; Riemersma, C.; Pietra, F|info:eu-repo/dai/nl/355358395; de Mello Donega, C.|info:eu-repo/dai/nl/125593899; Meijerink, A.|info:eu-repo/dai/nl/075044986

    2012-01-01

    Thermal quenching of quantum dot (QD) luminescence is important for application in luminescent devices. Systematic studies of the quenching behavior above 300 K are, however, lacking. Here, high-temperature (300–500 K) luminescence studies are reported for highly efficient CdSe core–shell quantum

  9. High temperature surface imaging using atomic force microscopy

    NARCIS (Netherlands)

    Broekmaat, Joska Johannes; Brinkman, Alexander; Blank, David H.A.; Rijnders, Augustinus J.H.M.

    2008-01-01

    Atomic force microscopy (AFM) is one of the most important tools in nanotechnology and surface science. Because of recent developments, nowadays, it is also used to study dynamic processes, such as thin film growth and surface reaction mechanisms. These processes often take place at high temperature

  10. genetic analysis for high temperature tolerance in bread wheat ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    selection (Reynolds et al., 1994). A number of high temperature stress-related traits have received considerable attention, in particular membrane thermostability (Saadalla et al., 1990), canopy temperature depression (Blum et al., 1982), proline content and chlorophyll content. Information on the genetic control of ...

  11. The costae presenting in high-temperature-induced vestigial wings ...

    Indian Academy of Sciences (India)

    It has long been noted that high temperature produces great variation in wing forms of the vestigial mutant of Drosophila. Most of the wings have defects in the wing blade and partially formed wing margin, which are the result of autonomous cell death in the presumptive wing blade or costal region of the wing disc.

  12. Results from the Danish high temperature superconducting power cable project

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Østergaard, Jacob

    2002-01-01

    For the first time, a high temperature superconducting (HTS) demonstration cable system has been installed in a utility network supplying electricity to consumers. The cable is a 30-m long, 30kVrms, 2, 000Arms cable, installed in the network of Copenhagen Energy at a substation supplying...

  13. Advanced energy analysis of high temperature fuel cell systems

    NARCIS (Netherlands)

    Kouffeld, R.W.J.; Veringa, H.J.; De Groot, A.

    In this thesis the performance of high temperature fuel cell systems is studied using a new method of exergy analysis. The thesis consists of three parts: ⢠In the first part a new analysis method is developed, which not only considers the total exergy losses in a unit operation, but which

  14. Cryostat for a high-temperature superconducting power cable

    NARCIS (Netherlands)

    Chevtchenko, O.A.; Smit, J.J.; Geschiere, A.

    2010-01-01

    Cryostat for a high-temperature superconducting power cable, comprising concentric tubes, an annular region between said tubes, wherein a multilayer thermal insulation and getter material for supporting high vacuum conditions are provided in said annular region, and wherein the multilayer insulation

  15. Current hurdles to the success of high temperature membrane reactors

    NARCIS (Netherlands)

    Saracco, G.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1994-01-01

    High-temperature catalytic processs performed using inorganic membranes have been in recent years a fast growing area of research, which seems to have not yet reached its peak. Chemical engineers, catalysts and materials scientists have addressed this topic from different viewpoint in a common

  16. Physics and Materials Science of High Temperature Superconductors

    Science.gov (United States)

    1989-08-26

    SUPERCONDUCTIVITY OF BULK HIGH TEMPERATURE SUPERCONDUCTORS. F. M. Costa and J. M. Vieira, Departamento de Eng. Ceramica e de Vidro, Universidade de Aveiro...Lisboa, Portugal; F. Costa, Dep Eng Ceramica e do Vidro, Universidade de Aveiro, P-3800 Avaerio, Portugal; and J. M. Alves and M. M. Godinho, Dep Fisica

  17. Search for New and Better High Temperature Superconductors

    Science.gov (United States)

    2014-03-30

    Nanometer-Scale Scanning Tunneling Potentiometry Appendix A – List of publications from the MURI (Also endnotes for text) 1) Introduction This...scanning tunneling potentiometry ) for nanometer-scale transport characterization of thin films. In addition, we actively addressed the questions: (1...assessing materials for their potential to exhibit high temperature superconductivity. 2.6 Nanometer-Scale Scanning Tunneling Potentiometry

  18. Part-load performance of a high temperature Kalina cycle

    DEFF Research Database (Denmark)

    Modi, Anish; Andreasen, Jesper Graa; Kærn, Martin Ryhl

    2015-01-01

    The Kalina cycle has recently seen increased interest as an alternative to the conventional steam Rankine cycle. The cycle has been studied for use with both low and high temperature applications such as geothermal power plants, ocean thermal energy conversion, waste heat recovery, gas turbine...

  19. A Snapshot View of High Temperature Superconductivity 2002

    Energy Technology Data Exchange (ETDEWEB)

    Schuller, Ivan K. [Univ. of California, San Diego, CA (United States); Bansil, Arun [Northeastern Univ., Boston, MA (United States); Basov, Dimitri N. [Univ. of California, San Diego, CA (United States)

    2002-04-05

    This report outlines the conclusions of a workshop on High Temperature Superconductivity held April 5-8, 2002 in San Diego. The purpose of this report is to outline and highlight some outstanding and interesting issues in the field of High Temperature Superconductivity. The range of activities and new ideas that arose within the context of High Temperature Superconductors is so vast and extensive that it is impossible to summarize it in a brief document. Thus, this report does not pretend to be all-inclusive and cover all areas of activity. It is a restricted snapshot and it only presents a few viewpoints. The complexity and difficulties with high temperature superconductivity are well illustrated by the Buddhist parable of the blind men trying to describe “experimentally” an elephant. These very same facts clearly illustrate that this is an extremely active field, with many unanswered questions, and with a great future potential for discoveries and progress in many (sometimes unpredictable) directions. It is very important to stress that, independently of any current or future applications, this is a very important area of basic research.

  20. Core Physics of Pebble Bed High Temperature Nuclear Reactors

    NARCIS (Netherlands)

    Auwerda, G.J.

    2014-01-01

    To more accurately predict the temperature distribution inside the reactor core of pebble bed type high temperature reactors, in this thesis we investigated the stochastic properties of randomly stacked beds and the effects of the non-homogeneity of these beds on the neutronics and

  1. The high temperature Ising model is a critical percolation model

    NARCIS (Netherlands)

    Meester, R.W.J.; Camia, F.; Balint, A.

    2010-01-01

    We define a new percolation model by generalising the FK representation of the Ising model, and show that on the triangular lattice and at high temperatures, the critical point in the new model corresponds to the Ising model. Since the new model can be viewed as Bernoulli percolation on a random

  2. Extruded Self-Lubricating Solid For High-Temperature Use

    Science.gov (United States)

    Sliney, H. E.; Waters, W. J.; Soltis, R. F.; Bemis, K.

    1996-01-01

    "EX-212" denotes high-density extruded form of composite solid material self-lubricating over wide range of temperatures. Properties equal or exceed those of powder-metallurgy version of this material. Developed for use in advanced engines at high temperatures at which ordinary lubricants destroyed.

  3. Fracture toughness and reliability in high-temperature structural ...

    Indian Academy of Sciences (India)

    The potential of these ceramics and ceramic matrix composites for high temperature applications in defence and aerospace applications such as gas turbine engines, radomes, and other energy conversion hardware have been well recognized. Numerous investigations were pursued to improve fracture toughness and ...

  4. Advanced energy analysis of high temperature fuel cell systems

    NARCIS (Netherlands)

    De Groot, A.

    2004-01-01

    In this thesis the performance of high temperature fuel cell systems is studied using a new method of exergy analysis. The thesis consists of three parts: ⢠In the first part a new analysis method is developed, which not only considers the total exergy losses in a unit operation, but which

  5. Engineering Materials for Very High Temperatures: An ONRL Workshop

    Science.gov (United States)

    1988-08-29

    high temperature, time-dependent strength of hot isostatically pressed (HIP’ed) Y-TZP (Swab, Katz, & Starita , 1987). In this instance a commercially...12, p-137-14 6. Swab, J, Katz, R. N. & Starita , C., (1987), unpublished research. Tracy, C. & Slavin, M. J., (1927), Presented at 89th annual meeting

  6. High temperature flow behaviour of SiC reinforced lithium ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. The compressive flow behaviour of lithium aluminosilicate (LAS) glass, with and without SiC particulate reinforcements, was studied. The LAS glass crystallized to β spodumene during high-temperature testing. The flow behaviour of LAS glass changed from Newtonian to non-Newtonian due to the presence of.

  7. Self-propagating high temperature synthesis and magnetic ...

    Indian Academy of Sciences (India)

    Ni–Zn ferrite powders were synthesized by self-propagating high temperature synthesis (SHS) method. X-ray diffraction, TEM and vibrating sample magnetometry (VSM) were used to characterize the phase composition, microstructure and magnetic properties of the combustion products. The effect of the combustion ...

  8. Effect of microstructure on the high temperature strength of nitride ...

    Indian Academy of Sciences (India)

    Unknown

    Effect of microstructure on the high temperature strength of nitride bonded silicon carbide composite. J RAKSHIT and P K DAS*. Central Glass and Ceramic Research Institute, Kolkata 700 032, India. MS received 15 March 2002; revised 3 August 2002. Abstract. Four compositions of nitride bonded SiC were fabricated with ...

  9. Tetrazole substituted polymers for high temperature polymer electrolyte fuel cells

    DEFF Research Database (Denmark)

    Henkensmeier, Dirk; My Hanh Duong, Ngoc; Brela, Mateusz

    2015-01-01

    interesting for use in a high temperature fuel cell (HT PEMFC). Based on these findings, two polymers incorporating the proposed TZ groups were synthesised, formed into membranes, doped with PA and tested for fuel cell relevant properties. At room temperature, TZ-PEEN and commercial meta-PBI showed...

  10. The rhizobium-pea symbiosis as affected by high temperatures

    NARCIS (Netherlands)

    Frings, J.F.J.

    1976-01-01

    A study has been made concerning the effect of high temperatures on the symbiosis of Rhizobium leguminosarum and pea plants (Pisum sativum). At 30°C, no nodules were found on the roots of plants growing in nutrient solution after inoculation with

  11. Auxins reverse plant male sterility caused by high temperatures

    National Research Council Canada - National Science Library

    Tadashi Sakata; Takeshi Oshino; Shinya Miura; Mari Tomabechi; Yuta Tsunaga; Nahoko Higashitani; Yutaka Miyazawa; Hideyuki Takahashi; Masao Watanabe; Atsushi Higashitani; Mark Estelle

    2010-01-01

    .... Application of auxin completely reversed male sterility in both plant species. These findings suggest that tissue-specific auxin reduction is the primary cause of high temperature injury, which leads to the abortion of pollen development. Thus, the application of auxin may help sustain steady yields of crops despite future climate change.

  12. High temperature fracture characteristics of a nanostructured ferritic alloy (NFA)

    Science.gov (United States)

    Byun, Thak Sang; Kim, Jeoung Han; Yoon, Ji Hyun; Hoelzer, David T.

    2010-12-01

    The nanostructured ferritic alloys (NFAs) have been developed to improve high temperature strength and radiation resistance by refining grains and including nanoclusters. Among the key properties of NFAs needed to be assessed for advanced reactor applications the cracking resistance at high temperatures has not been well known. In this work, therefore, the high temperature fracture behavior has been investigated for the latest nanostructured ferritic alloy 14YWT (SM10). The fracture toughness of the alloy was above 140 MPa √m at low temperatures, room temperature (RT) and 200 °C, but decreased to a low fracture toughness range of 52-82 MPa √m at higher temperatures up to 700 °C. This behavior was explained by the fractography results indicating that the unique nanostructure of 14YWT alloy produced shallow plasticity layers at high temperatures and a low-ductility grain boundary debonding occurred at 700 °C. The discussion also proposes methods to improve resistance to cracking.

  13. Dehydration kinetics of Portland cement paste at high temperature

    NARCIS (Netherlands)

    Zhang, Q.; Ye, G.

    2012-01-01

    Portland cement paste is a multiphase compound mainly consisting of calcium-silicate-hydrate (CSH) gel, calcium hydroxide (CH) crystal, and unhydrated cement core. When cement paste is exposed to high temperature, the dehydration of cement paste leads to not only the decline in strength, but also

  14. Adaptation of microorganisms and their transport systems to high temperatures

    NARCIS (Netherlands)

    Tolner, B; Poolman, B.; Konings, W.N

    1997-01-01

    Growth of Bacteria and Archaea has been observed at temperatures up to 95 and 110 degrees C, respectively. These thermophiles are adapted to environments of high temperature by changes in the membrane lipid composition, higher thermostabilities of the (membrane) proteins, higher turnover rates of

  15. High Temperature coatings based on β-NiAI

    Energy Technology Data Exchange (ETDEWEB)

    Severs, Kevin [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    High temperature alloys are reviewed, focusing on current superalloys and their coatings. The synthesis, characerization, and oxidation performance of a NiAl–TiB2 composite are explained. A novel coating process for Mo–Ni–Al alloys for improved oxidation performance is examined. The cyclic oxidation performance of coated and uncoated Mo–Ni–Al alloys is discussed.

  16. Different patterns of transcriptomic response to high temperature ...

    African Journals Online (AJOL)

    Polyploidy is an important evolutionary force in plants and may have significant impact on plant breeding. In this study, expression changes between diploid and tetraploid Dioscorea zingiberensis C. H. under control and high temperature conditions were investigated by sequence-related amplified polymorphism ...

  17. High temperature performance of soy-based adhesives

    Science.gov (United States)

    Jane L. O’Dell; Christopher G. Hunt; Charles R. Frihart

    2013-01-01

    We studied the high temperature performance of soy meal processed to different protein concentrations (flour, concentrate, and isolate), as well as formulated soy-based adhesives, and commercial nonsoy adhesives for comparison. No thermal transitions were seen in phenol-resorcinol-formaldehyde (PRF) or soy-phenol-formaldehyde (SoyPF) or in as-received soy flour...

  18. Alternative control of nanoparticles dispersity in high-temperature ...

    African Journals Online (AJOL)

    The 1-dimentional model of aerosol process which includes a hot aerosol stream flowing through a tube with thermal gradients between the aerosol stream and the reactor cooled walls was developed to predict the aerosol formation, growth and thermophoretic deposition in high-temperature reactors. The mass and energy ...

  19. DEVELOPMENT OF HIGH-TEMPERATURE TITANIUM ALLOY VT9,

    Science.gov (United States)

    The paper describes work, done in 1957-58, in the course of the development of the high-temperature (HT) Ti alloy currently termed BT9(VT9). The...target requirements for the new alloy specified the development of a Ti alloy for forging billets and stamping blanks which at 500 degrees centigrade

  20. Development of High Temperature SiC Based Hydrogen/Hydrocarbon Sensors with Bond Pads for Packaging

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Chen, Liangyu; Biagi-Labiosa, Azlin M.; Ward, Benjamin J.; Lukco, Dorothy; Gonzalez, Jose M., III; Lampard, Peter S.; Artale, Michael A.; Hampton, Christopher L.

    2011-01-01

    This paper describes efforts towards the transition of existing high temperature hydrogen and hydrocarbon Schottky diode sensor elements to packaged sensor structures that can be integrated into a testing system. Sensor modifications and the technical challenges involved are discussed. Testing of the sensors at 500 C or above is also presented along with plans for future development.

  1. HALLIBURTON SPERRY-SUN DOE HIGH TEMPERATURE LWD PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Spross

    2005-03-15

    The objective of this project was to build a high temperature, cost-effective, logging while drilling (HT-LWD) system with the ability to operate at 175 C with more than 100 hours mean time between failures (MTBF). Such a commercial real-time formation evaluation (FE) system would help operators to drill and produce hydrocarbon resources from moderately deep, hot reservoirs which otherwise might be uneconomic to drill. The project plan was to combine the existing Sperry-Sun high temperature directional and gamma logging system with lower temperature FE sensors which were upgraded to higher temperature operation as part of the project. The project was to be completed in two phases. Phase I included the development of the HT system, building two complete systems, demonstrating operational capability at 175 C and survivability at 200 C in the laboratory, and successfully testing the system in two low temperature field tests. Phase II was to test the system in a well with a bottom hole temperature of 175 C. The high temperature FE sensors developed as part of this project include gamma ray (DGR), resistivity (EWR-Phase 4), neutron (CTN), and density (SLD). The existing high temperature pulser and telemetry system was upgraded to accommodate the data and bandwidth requirements of the additional sensors. Environmental and lifetime testing of system components and modules indicates that system life and reliability goals will be substantially exceeded. The system has performed well in domestic and international high temperature wells (to 175 C). In addition to the sensor modules specified in the project contract, Sperry has now upgraded other system components to higher temperature as well. These include a LWD sonic sensor (BAT), pressure while drilling sensor (PWD), and a more powerful central system controller (CIM).

  2. Ceramic HEPA Filter Program

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

    2012-04-30

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  3. Optimal filtering

    CERN Document Server

    Anderson, Brian D O

    1979-01-01

    This graduate-level text augments and extends beyond undergraduate studies of signal processing, particularly in regard to communication systems and digital filtering theory. Vital for students in the fields of control and communications, its contents are also relevant to students in such diverse areas as statistics, economics, bioengineering, and operations research.Topics include filtering, linear systems, and estimation; the discrete-time Kalman filter; time-invariant filters; properties of Kalman filters; computational aspects; and smoothing of discrete-time signals. Additional subjects e

  4. Fiber-reinforced composite hot-gas filters

    Science.gov (United States)

    Stinton, D. P.; Lowden, R. A.; Chang, R.

    1987-05-01

    A chemical vapor deposition process was developed for the fabrication of high-temperature particulate filters. Fibrous materials such as Nicalon (SiC) felt and aluminosilicate papers were used as the filter material. Preliminary evaluation of filter specimens fabricated from Nicalon revealed extremely encouraging results. Cleanable filters with collection efficiencies of greater than 99.9% were recorded for both PFBC flyash and gasifier char.

  5. Alloying effects on the high-temperature oxidation resistance of Cr-Cr{sub 2}Nb

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, P.F.; DeVan, J.H.

    1994-09-01

    Alloying effects on the high-temperature oxidation resistance of Cr-Cr{sub 2}Nb were examined on the basis of isothermal exposures to air at 950 C. Additions of either Re and Al or Fe, Ni, and Al had relatively little effect on weight gains relative to the Cr-6% Nb binary alloy. One alloying element that improved the mechanical behavior of Cr-Cr{sub 2}Nb alloys substantially increased the oxidation rates and spallation susceptibilities of Cr-6 and -12% Nb alloys. However, the addition of another element completely offset these deleterious effects. The presence of this latter element resulted in the best overall oxidation behavior (in terms of both weight gains and spallation tendencies) of all Cr-Cr{sub 2}Nb compositions. Its beneficial effect can be attributed to improvement in the oxidation resistance of the Cr-rich phase.

  6. Material Solutions to Mitigate the Alkali Chloride-Induced High Temperature Corrosion

    DEFF Research Database (Denmark)

    Kiamehr, Saeed

    in the course of corrosion as well as the role of potassium chloride vapor. Results showed that while the majority of the alloys formed protective slow-growing oxides in the absence of KCl, they all suffered from significant attack when KCl was present. Thereby the inability of Cr to form a protective oxide......High temperature corrosion induced by potassium chloride (KCl) is a major challenge for biomass-based power plants. The current study aims at identification or development of alloys or coatings that can yield a better performance at a target metal temperature of 600oC compared to austenitic...... of metals. This was aimed at identifying the constituent elements of a corrosion resistant alloy. Calculations suggested Al, Si, Cr, Ti, Y, Ce, Ta, Hf and Zr as suitable oxide-forming elements as well as Mo, Ni and Co as suitable matrix-forming elements. However, the presence of potassium in the environment...

  7. Image Filtering with Field Programmable Gate Array

    Directory of Open Access Journals (Sweden)

    Arūnas Šlenderis

    2013-05-01

    Full Text Available The research examined the use of field programmable gate arrays (FPGA in image filtering. Experimental and theoretical researches were reviewed. Experiments with Cyclone III family FPGA chip with implemented NIOS II soft processor were considered. Image filtering was achieved with symmetrical and asymmetrical finite impulse response filters with convolution kernel. The system, which was implemented with 3×3 symmetrical filter, which was implemented using the hardware description language, uses 59% of logic elements of the chip and 10 multiplication elements. The system with asymmetrical filter uses the same amount of logic elements and 13 multiplication elements. Both filter systems consume approx. 545 mW of power. The system, which is designed for filter implementation in C language, uses 65% of all logical elements and consumes 729 mW of power.Article in Lithuanian

  8. Thermohydraulic modeling of very high temperature reactors in regimes with loss of coolant using CFD

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Uebert G.; Dominguez, Dany S. [Universidade Estadual de Santa Cruz (UESC), Ilh´eus, BA (Brazil). Programa de P´os-Graduacao em Modelagem Computacional em Ciencia e Tecnologia; Mazaira, Leorlen Y.R.; Lira, Carlos A.B.O. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Hernandez, Carlos R.G., E-mail: uebert.gmoreira@gmail.com, E-mail: dsdominguez@gmail.com, E-mail: leored1984@gmail.com, E-mail: cabol@ufpe.br, E-mail: cgh@instec.cu [Instituto Superior de Tecnologas y Ciencias Aplicadas (InSTEC), La Habana (Cuba)

    2017-07-01

    The nuclear energy is a good alternative to meet the continuous increase in world energy demand. In this perspective, VHTRs (Very High Temperature Reactors) are serious candidates for energy generation due to its inherently safe performance, low power density and high conversion efficiency. However, the viability of these reactors depends on an efficient safety system in the operation of nuclear plants. The HTR (High Temperature Reactor)-10 model, an experimental reactor of the pebble bed type, is used as a case study in this work to perform the thermohydraulic simulation. Due to the complex patterns flow that appear in the pebble bed reactor core, and advances in computational capacity, CFD (Computational Fluid Dynamics) techniques are used to simulate these reactors. A realistic approach is adopted to simulate the central annular column of the reactor core, which each pebble bed element is modeled in detail. As geometrical model of the fuel elements was selected the BCC (Body Centered Cubic) arrangement. Previous works indicate this arrangement as the configuration that obtain higher fuel temperatures inside the core. Parameters considered for reactor design are available in the technical report of benchmark issues by IAEA (TECDOC-1694). Among the results obtained, we obtained the temperature profiles with different mass flow rates for the coolant. In general, the temperature distributions calculated are consistent with phenomenological behaviour. Even without consider the reactivity changes to reduce the reactor power or other safety procedures, the maximum temperatures do not exceed the recommended limits for fuel elements. (author)

  9. Flight prototype regenerative particulate filter system development

    Science.gov (United States)

    Green, D. C.; Garber, P. J.

    1974-01-01

    The effort to design, fabricate, and test a flight prototype Filter Regeneration Unit used to regenerate (clean) fluid particulate filter elements is reported. The design of the filter regeneration unit and the results of tests performed in both one-gravity and zero-gravity are discussed. The filter regeneration unit uses a backflush/jet impingement method of regenerating fluid filter elements that is highly efficient. A vortex particle separator and particle trap were designed for zero-gravity use, and the zero-gravity test results are discussed. The filter regeneration unit was designed for both inflight maintenance and ground refurbishment use on space shuttle and future space missions.

  10. Application of High-Temperature Extrinsic Fabry-Perot Interferometer Strain Sensor

    Science.gov (United States)

    Piazza, Anthony

    2008-01-01

    In this presentation to the NASA Aeronautics Sensor Working Group the application of a strain sensor is outlined. The high-temperature extrinsic Fabry-Perot interferometer (EFPI) strain sensor was developed due to a need for robust strain sensors that operate accurately and reliably beyond 1800 F. Specifically, the new strain sensor would provide data for validating finite element models and thermal-structural analyses. Sensor attachment techniques were also developed to improve methods of handling and protecting the fragile sensors during the harsh installation process. It was determined that thermal sprayed attachments are preferable even though cements are simpler to apply as cements are more prone to bond failure and are often corrosive. Previous thermal/mechanical cantilever beam testing of EFPI yielded very little change to 1200 F, with excellent correlation with SG to 550 F. Current combined thermal/mechanical loading for sensitivity testing is accomplished by a furnace/cantilever beam loading system. Dilatometer testing has can also be used in sensor characterization to evaluate bond integrity, evaluate sensitivity and accuracy and to evaluate sensor-to-sensor scatter, repeatability, hysteresis and drift. Future fiber optic testing will examine single-mode silica EFPIs in a combined thermal/mechanical load fixture on C-C and C-SiC substrates, develop a multi-mode Sapphire strain-sensor, test and evaluate high-temperature fiber Bragg Gratings for use as strain and temperature sensors and attach and evaluate a high-temperature heat flux gauge.

  11. High-temperature vesuvianite: crystal chemistry and surface considerations

    Science.gov (United States)

    Elmi, Chiara; Brigatti, Maria Franca; Pasquali, Luca; Montecchi, Monica; Laurora, Angela; Malferrari, Daniele; Nannarone, Stefano

    2011-06-01

    A multi-methodical approach has been applied for characterizing the bulk and surface crystal chemical features of a high-temperature vesuvianite crystal from skarns of Mount Somma-Vesuvius Volcano (Naples, Italy). Vesuvianite belongs to the space group P4/ nnc with unit cell parameters a = 15.633(1) Å, c = 11.834(1) Å and chemical formula (Ca18.858 Na0.028 Ba0.004 K0.006 Sr0.005 □0.098)19.000 (Al8.813 Ti0.037 Mg2.954 Mn0.008 Fe{0.114/2+} Fe{1.375/3+} Cr0.008 B0.202)13.511 Si18.000(O0.261 F0.940 OH7.799)9.000. Structure refinement, which converges at R = 0.0328, demonstrates a strong positional disorder down the fourfold axes, indicating that the Y1 site is split into two positions (Y1A and Y1B) alternatively occupied. However, because of X4 proximity to Y1B and Y1A, X4 cannot be occupied if Y1B or Y1A are. Overall Y1 occupancy (Y1A + Y1B) reaches approximately 0.5, as common in vesuvianite and occupancy of Y1B site is extremely limited. Moreover, T1 position, limitedly occupied, accommodates the excess of cations generally related to Y position. A small quantity (0.202 apfu) of boron is sited at the T2 site that, like T1, is poorly occupied. The determination of the amount of each element on the (100) vesuvianite surface, obtained through X-ray photoelectron spectroscopy high-resolution spectra in the region of the Si2p, Al2p, Mg1s, and Ca2p core levels, evidences that a greater amount of aluminum and a smaller amount of calcium characterize the surface with respect to the bulk. Although both of these features require further investigation, we may consider the Al increase can be related to preferential orientation of Al-rich sites on the (100) plane. Furthermore, the surface structure of vesuvianite suggests that Al, Ca, and Mg cations maintain coordination features at the surface similar to the bulk. Silica, however, while presenting fourfold coordination, shows also a [1]-fold small coordinated component at binding energy 99.85 eV, due to broken Si-O bonds at

  12. Cyclic high temperature heat storage using borehole heat exchangers

    Science.gov (United States)

    Boockmeyer, Anke; Delfs, Jens-Olaf; Bauer, Sebastian

    2016-04-01

    The transition of the German energy supply towards mainly renewable energy sources like wind or solar power, termed "Energiewende", makes energy storage a requirement in order to compensate their fluctuating production and to ensure a reliable energy and power supply. One option is to store heat in the subsurface using borehole heat exchangers (BHEs). Efficiency of thermal storage is increasing with increasing temperatures, as heat at high temperatures is more easily injected and extracted than at temperatures at ambient levels. This work aims at quantifying achievable storage capacities, storage cycle times, injection and extraction rates as well as thermal and hydraulic effects induced in the subsurface for a BHE storage site in the shallow subsurface. To achieve these aims, simulation of these highly dynamic storage sites is performed. A detailed, high-resolution numerical simulation model was developed, that accounts for all BHE components in geometrical detail and incorporates the governing processes. This model was verified using high quality experimental data and is shown to achieve accurate simulation results with excellent fit to the available experimental data, but also leads to large computational times due to the large numerical meshes required for discretizing the highly transient effects. An approximate numerical model for each type of BHE (single U, double U and coaxial) that reduces the number of elements and the simulation time significantly was therefore developed for use in larger scale simulations. The approximate numerical model still includes all BHE components and represents the temporal and spatial temperature distribution with a deviation of less than 2% from the fully discretized model. Simulation times are reduced by a factor of ~10 for single U-tube BHEs, ~20 for double U-tube BHEs and ~150 for coaxial BHEs. This model is then used to investigate achievable storage capacity, injection and extraction rates as well as induced effects for

  13. High temperature oxidation of iron-chromium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mikkelsen, Lars

    2003-06-15

    The high temperature oxidation of the ferritic alloy Fe78Cr22 has been investigated in the present work. The effect of small alloying additions of cerium and/or silicon was also investigated. The alloys were oxidized at 973, 1173 and 1373 K in either air or a hydrogen/argon mixture. The various reaction atmospheres contained between 0.02 and 50% water vapour. The oxide scales formed on the various alloys at 973 K consisted of thin chromia layers. The oxide scales grown on the alloys at 1173 K also consisted of a chromia layer. The microstructure of the chromia scales was found to depend on the reaction atmosphere. The chromia scales grown in hydrogen/argon atmospheres formed oxide whiskers and oxide ridges at the surface of the scales, while the chromia scales grown in air formed larger oxide grains near the surface. This difference in oxide microstructure was due to the vaporization of chromium species from the chromia scales grown in air. Two different growth mechanisms are proposed for the growth of oxide whiskers. The growth rate of the chromia scales was independent of the oxygen activity. This is explained by a growth mechanism of the chromia scales, where the growth is governed by the diffusion of interstitial chromium. The addition of silicon to the iron-chromium alloy resulted in the formation of silica particles beneath the chromia scale. The presence of silicon in the alloy was found to decrease the growth rate of the chromia scale. This is explained by a blocking mechanism, where the silica particles beneath the chromia scale partly block the outwards diffusion of chromium from the alloy to the chromia scale. The addition of cerium to the iron-chromium alloy improved the adhesion of the chromia scale to the alloy and decreased the growth rate of chromia. It was observed that the minimum concentration of cerium in the alloy should be 0.3 at.% in order to observe an effect of the cerium addition. The effect of cerium is explained by the &apos

  14. Effect of Thermal Degradation on High Temperature Ultrasonic Transducer Performance in Small Modular Reactors

    Science.gov (United States)

    Bilgunde, Prathamesh N.; Bond, Leonard J.

    Prototype ultrasonic NDT transducers for use in immersion in coolants for small modular reactors have shown low signal to noise ratio. The reasons for the limitations in performance at high temperature are under investigation, and include changes in component properties. This current work seeks to quantify the issue of thermal expansion and degradation of the piezoelectric material in a transducer using a finite element method. The computational model represents an experimental set up for an ultrasonic transducer in a pulse-echo mode immersed in a liquid sodium coolant. Effect on transmitted and received ultrasonic signal due to elevated temperature (∼200oC) has been analysed.

  15. The thermodynamic database COST MP0602 for materials for high-temperature lead-free soldering

    Directory of Open Access Journals (Sweden)

    Kroupa A.

    2012-01-01

    Full Text Available The current state of thermodynamic modelling in the field of high-temperature lead-free soldering is presented. A consistent thermodynamic database, containing 18 elements (Ag, Al, Au, Bi, Co, Cu, Ga, Ge, Mg, Ni, P, Pb, Pd, Sb, Sn, Ti and Zn has been created. The thermodynamic data for the most of the important binary and selected ternary systems were checked and included into the database. The database was tested using major commercial software packages. Such reliable and sophisticated software coupled to reliable thermodynamic databases are necessary prerequisites for application of thermodynamics in advanced alloys design.

  16. Performance and Reliability of Bonded Interfaces for High-temperature Packaging: Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    DeVoto, Douglas J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-19

    As maximum device temperatures approach 200 °Celsius, continuous operation, sintered silver materials promise to maintain bonds at these high temperatures without excessive degradation rates. A detailed characterization of the thermal performance and reliability of sintered silver materials and processes has been initiated for the next year. Future steps in crack modeling include efforts to simulate crack propagation directly using the extended finite element method (X-FEM), a numerical technique that uses the partition of unity method for modeling discontinuities such as cracks in a system.

  17. Analysis of the Thermal Load of Structural Elements High-Power DC Supply with the Transformer of Ripple Filter with Current Overload

    Directory of Open Access Journals (Sweden)

    Jaroslav Lokvenc

    2017-01-01

    Full Text Available Design of the high-power DC supply quite logically based on the required electrical parameters and expected or defined operating conditions. A prerequisite trouble-free operation is also the correct choice of construction materials. Both in terms of mechanical strength and stability, and in terms of thermal load. The article deals with thermal conditions in the high-power DC supply with the transformer of ripple filter for long-term current overload.

  18. High point for CERN and high-temperature superconductors

    CERN Multimedia

    2007-01-01

    Amalia Ballarino is named the Superconductor Industry Person of the year 2006. Amalia Ballarino showing a tape of high-superconducting material used for the LHC current leads.The CERN project leader for the high-temperature superconducting current leads for the LHC, Amalia Ballarino, has received the award for "Superconductor Industry Person of the Year". This award, the most prestigious international award in the development and commercialization of superconductors, is presented by the leading industry newsletter "Superconductor Week". Amalia Ballarino was selected from dozens of nominations from around the world by a panel of recognized leading experts in superconductivity. "It is a great honour for me," says Amalia Ballarino. "It has been many years of hard work, and it’s a great satisfaction to see that the work has been completed successfully." Amalia Ballarino has been working on high-temperature superconducting materials sin...

  19. High-temperature metal corrosion tests for HI decomposer

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Young; Kim, Young Soo; Sah, In Jin; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2012-05-15

    The Sulfur-Iodine thermochemical Nuclear hydrogen production process is composed of three parts, Bunsen reaction, sulfuric acid decomposition reaction and hydriodic acid decomposition reaction. Among them, hydriodic acid decomposition reaction has low kinetics and equilibrium yield is poor, being an efficiency-determining step.1) Thus, many efforts are tried to raise the reaction rate and yield, such as extractive/reactive distillation or EED method. High temperature decomposition process,2) another candidate of HI decomposition method nowadays, has a simple process but due to highly corrosive environment, a material problem is one of crucial obstacles. In this paper, a number of structure material candidates are tested at high temperature for HI decomposition process

  20. High temperature solar thermal technology: The North Africa Market

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

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

  1. Cavitation at migrating boundaries during high temperature fatigue

    Energy Technology Data Exchange (ETDEWEB)

    Raman, V.

    1987-06-01

    There is growing interest in the role of migrating boundaries during high temperature deformation. One area of current interest is the manner in which grain boundary migration can influence deformation and fracture at elevated temperatures. Much of the detailed treatments of intergranular cracking and cavitation during creep deformation have centered on effects occurring at stationary grain boundaries. The conventional idea represented in numerous publications is that grain boundary sliding plays an important role in intergranular fracture at elevated temperatures. The large stress concentrations developed at irregularities on grain boundaries are frequently cited as the principal reason for the easy generation of cracks and cavities. This article concludes that high temperature fatigue can cause significant migration and sliding in Al-3% Mg and Pb-2% Sn solid solution alloys, and that microcavitation and cracking takes place at the migrating boundaries in specimens tested at large strain amplitudes and low test frequencies. Cavities may be isolated within grains due to boundary migration.

  2. Optical Fiber Strain Instrumentation for High Temperature Aerospace Structural Monitoring

    Science.gov (United States)

    Wang, A.

    2002-01-01

    The objective of the program is the development and laboratory demonstration of sensors based on silica optical fibers for measurement of high temperature strain for aerospace materials evaluations. A complete fiber strain sensor system based on white-light interferometry was designed and implemented. An experiment set-up was constructed to permit testing of strain measurement up to 850 C. The strain is created by bending an alumina cantilever beam to which is the fiber sensor is attached. The strain calibration is provided by the application of known beam deflections. To ensure the high temperature operation capability of the sensor, gold-coated single-mode fiber is used. Moreover, a new method of sensor surface attachment which permits accurate sensor gage length determination is also developed. Excellent results were obtained at temperatures up to 800-850 C.

  3. High-temperature lead-free solder alternatives

    DEFF Research Database (Denmark)

    Nachiappan, Vivek Chidambaram; Hattel, Jesper Henri; Hald, John

    2011-01-01

    For lead-free solders in the high-temperature regime, unfortunately, a limited number of alloying systems are available. These are Bi based alloys, gold involving alloys and Zn–Al based alloys. Based on these systems, possible candidate alloys were designed to have a melting range between 270°C......-temperature soldering. Therefore, further research and development of high-temperature lead-free soldering is obviously needed....... and 350°C. Each has its own superior characteristics as well as some drawbacks however none of them can fulfill all the requirements to replace the current high-lead content solders. Even the alternative technologies that are currently being developed cannot address several critical issues of high...

  4. Solar Power for Near Sun, High-Temperature Missions

    Science.gov (United States)

    Landis, Geoffrey A.

    2008-01-01

    Existing solar cells lose performance at the high temperatures encountered in Mercury orbit and inward toward the sun. For future missions designed to probe environments close to the sun, it is desirable to develop array technologies for high temperature and high light intensity. Approaches to solar array design for near-sun missions include modifying the terms governing temperature of the cell and the efficiency at elevated temperature, or use of techniques to reduce the incident solar energy to limit operating temperature. An additional problem is found in missions that involve a range of intensities, such as the Solar Probe + mission, which ranges from a starting distance of 1 AU from the sun to a minimum distance of 9.5 solar radii, or 0.044 AU. During the mission, the solar intensity ranges from one to about 500 times AM0. This requires a power system to operate over nearly three orders of magnitude of incident intensity.

  5. Development of a High Temperature Microbial Fermentation Processfor Butanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Jeor, Jeffery D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reed, David W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Daubaras, Dayna L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thompson, Vicki S. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-06-01

    Transforming renewable biomass into cost competitive high-performance biofuels and bioproducts is key to US energy security. Butanol production by microbial fermentation and chemical conversion to polyolefins, elastomers, drop-in jet or diesel fuel, and other chemicals is a promising solution. A high temperature fermentation process can facilitate butanol recovery up to 40%, by using gas stripping. Other benefits of fermentation at high temperatures are optimal hydrolysis rates in the saccharification of biomass which leads to maximized butanol production, decrease in energy costs associated with reactor cooling and capital cost associated with reactor design, and a decrease in contamination and cost for maintaining a sterile environment. Butanol stripping at elevated temperatures gives higher butanol production through constant removal and continuous fermentation. We describe methods used in an attempt to genetically prepare Geobacillus caldoxylosiliticus for insertion of a butanol pathway. Methods used were electroporation of electrocompetent cells, ternary conjugation with E. coli, and protoplast fusion.

  6. Liquid Fuel Production from Biomass via High Temperature Steam Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Grant L. Hawkes; Michael G. McKellar

    2009-11-01

    A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-fed biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K. Parametric studies of system pressure, biomass moisture content and low temperature alkaline electrolysis are also presented.

  7. [Fluoride emission from different soil minerals at high temperatures].

    Science.gov (United States)

    Wu, W; Xie, Z; Xu, J; Liu, C

    2001-03-01

    The emission characteristics of fluoride pollutants from montmorillonite, kaolinite, vermiculite, geothite and allophane were studied to elucidate the mechanism of fluoride-releasing from soils during brick and tile making at high temperatures from 300 degrees C to 1000 degrees C. The rate of fluoride emission varied with temperature, mineral type, heating time, specific surface area and cations added to minerals. The escape of crystalline water resulting from crystal lattice collapse at a certain high temperature was found to affect the rate of fluoride emission. Calcium compounds could decrease fluoride emission rate from montmorillonite. At 800 degrees C, the rate of fluoride emission from Ca-treated montmorillonite decreased by 59.6% compared to untreated montmorillonite. The order for fluoride-fixing capacity of the 5 calcium compounds at 800 degrees C was as follows: CaCO3 > CaO > Ca3(PO4)2 > Ca(OH)2 > CaSO4.

  8. Designing high-temperature steels via surface science and thermodynamics

    Science.gov (United States)

    Gross, Cameron T.; Jiang, Zilin; Mathai, Allan; Chung, Yip-Wah

    2016-06-01

    Electricity in many countries such as the US and China is produced by burning fossil fuels in steam-turbine-driven power plants. The efficiency of these power plants can be improved by increasing the operating temperature of the steam generator. In this work, we adopted a combined surface science and computational thermodynamics approach to the design of high-temperature, corrosion-resistant steels for this application. The result is a low-carbon ferritic steel with nanosized transition metal monocarbide precipitates that are thermally stable, as verified by atom probe tomography. High-temperature Vickers hardness measurements demonstrated that these steels maintain their strength for extended periods at 700 °C. We hypothesize that the improved strength of these steels is derived from the semi-coherent interfaces of these thermally stable, nanosized precipitates exerting drag forces on impinging dislocations, thus maintaining strength at elevated temperatures.

  9. Nanocarbon synthesis by high-temperature oxidation of nanoparticles

    Science.gov (United States)

    Nomura, Ken-Ichi; Kalia, Rajiv K.; Li, Ying; Nakano, Aiichiro; Rajak, Pankaj; Sheng, Chunyang; Shimamura, Kohei; Shimojo, Fuyuki; Vashishta, Priya

    2016-04-01

    High-temperature oxidation of silicon-carbide nanoparticles (nSiC) underlies a wide range of technologies from high-power electronic switches for efficient electrical grid and thermal protection of space vehicles to self-healing ceramic nanocomposites. Here, multimillion-atom reactive molecular dynamics simulations validated by ab initio quantum molecular dynamics simulations predict unexpected condensation of large graphene flakes during high-temperature oxidation of nSiC. Initial oxidation produces a molten silica shell that acts as an autocatalytic ‘nanoreactor’ by actively transporting oxygen reactants while protecting the nanocarbon product from harsh oxidizing environment. Percolation transition produces porous nanocarbon with fractal geometry, which consists of mostly sp2 carbons with pentagonal and heptagonal defects. This work suggests a simple synthetic pathway to high surface-area, low-density nanocarbon with numerous energy, biomedical and mechanical-metamaterial applications, including the reinforcement of self-healing composites.

  10. Systems and Methods for Implementing High-Temperature Tolerant Supercapacitors

    Science.gov (United States)

    Brandon, Erik J. (Inventor); West, William C. (Inventor); Bugga, Ratnakumar V. (Inventor)

    2016-01-01

    Systems and methods in accordance with embodiments of the invention implement high-temperature tolerant supercapacitors. In one embodiment, a high-temperature tolerant super capacitor includes a first electrode that is thermally stable between at least approximately 80C and approximately 300C; a second electrode that is thermally stable between at least approximately 80C and approximately 300C; an ionically conductive separator that is thermally stable between at least approximately 80C and 300C; an electrolyte that is thermally stable between approximately at least 80C and approximately 300C; where the first electrode and second electrode are separated by the separator such that the first electrode and second electrode are not in physical contact; and where each of the first electrode and second electrode is at least partially immersed in the electrolyte solution.

  11. High Temperature Boost (HTB) Power Processing Unit (PPU) Formulation Study

    Science.gov (United States)

    Chen, Yuan; Bradley, Arthur T.; Iannello, Christopher J.; Carr, Gregory A.; Mohammad, Mojarradi M.; Hunter, Don J.; DelCastillo, Linda; Stell, Christopher B.

    2013-01-01

    This technical memorandum is to summarize the Formulation Study conducted during fiscal year 2012 on the High Temperature Boost (HTB) Power Processing Unit (PPU). The effort is authorized and supported by the Game Changing Technology Division, NASA Office of the Chief Technologist. NASA center participation during the formulation includes LaRC, KSC and JPL. The Formulation Study continues into fiscal year 2013. The formulation study has focused on the power processing unit. The team has proposed a modular, power scalable, and new technology enabled High Temperature Boost (HTB) PPU, which has 5-10X improvement in PPU specific power/mass and over 30% in-space solar electric system mass saving.

  12. A dc transmission cable prototype using high-temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Beales, T.P.; Friend, C.M. [BICC Cables Ltd, Hedgeley Road, Hebburn, Tyne and Wear NE31 1XR (United Kingdom); Segir, W.; Ferrero, E. [Ceat Cavi Industrie srl, Via Brescia 16, 10036 Settimo Torinese (Italy); Vivaldi, F.; Ottonello, L. [Ansaldo Ricerche srl, Corso Perrone 25, 16161 Genoa (Italy)

    1996-01-01

    This paper gives the results from a recent collaboration between BICC Cables Ltd, its Italian subsidiary Ceat Cavi srl, and Ansaldo Ricerche srl on the design and testing of a high-temperature superconducting dc transmission cable prototype. The cable was designed to carry 10 000 A at 40 kV, operating at 40 K. Qualification testing was carried out from 4.2 K up to 40 K. At an operating temperature of 31 K the prototype cable had a current capacity of 11 067 A (the largest dc current reported in a high-temperature prototype to date), which represents a tenfold increase in current over a conventional 1000 mm{sup 2} copper cable. (author)

  13. Additives for high temperature liquid lubricants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yavrouian, A.H.; Repar, J.; Moran, C.M.; Lawton, E.A.; Anderson, M.S.

    1994-01-15

    The purpose of this task was to perform research for the Department of Energy (DOE) on the synthesis and characterization of additives for liquid lubricants which could lead to significant improvements in the major tribological task area of friction and wear reduction at high temperature. To this end JPL surveyed candidate precursor compounds which are soluble in liquid lubricants, synthesized the most promising of these materials, characterized them and submitted these additives to National Institute of Standards and Technology (NIST) for evaluation.

  14. A simple figure of merit for high temperature superconducting switches

    Energy Technology Data Exchange (ETDEWEB)

    Honig, E.M.

    1989-01-01

    The discovery of the new high temperature superconductors has revived interest in many special applications, including superconducting switches. For comparison of switch types, a simple figure of merit based in switch performance is proposed, derived for superconducting switches, and then calculated for thyristors and vacuum switches. The figure of merit is then used to show what critical current density would be needed for superconducting switches to compete with more conventional switches. 46 refs., 1 fig.

  15. Scientific Pluralism: the battle of High Temperature Superconductivity

    CERN Document Server

    Lederer, Pascal

    2015-01-01

    The early development of conflicting theories (i.e. one aspect of scientific pluralism) about the microscopic mechanism of High Temperature Superconductivity is described. The biographical roots of this diversity are stressed, as well as its subjective/objective roots. Scientific pluralism is discussed in relation with this study, as well as various philosophical teachnings about relativism, the Duhem-Quine thesis on the underdetermination of theory by facts, and the dialectics of knowledge and nature.

  16. Optical Fiber High Temperature Sensor Instrumentation for Energy Intensive Industries

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Kristie L.; Wang, Anbo; Pickrell, Gary R.

    2006-11-14

    This report summarizes technical progress during the program “Optical Fiber High Temperature Sensor Instrumentation for Energy Intensive Industries”, performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The objective of this program was to use technology recently invented at Virginia Tech to develop and demonstrate the application of self-calibrating optical fiber temperature and pressure sensors to several key energy-intensive industries where conventional, commercially available sensors exhibit greatly abbreviated lifetimes due primarily to environmental degradation. A number of significant technologies were developed under this program, including • a laser bonded silica high temperature fiber sensor with a high temperature capability up to 700°C and a frequency response up to 150 kHz, • the world’s smallest fiber Fabry-Perot high temperature pressure sensor (125 x 20 μm) with 700°C capability, • UV-induced intrinsic Fabry-Perot interferometric sensors for distributed measurement, • a single crystal sapphire fiber-based sensor with a temperature capability up to 1600°C. These technologies have been well demonstrated and laboratory tested. Our work plan included conducting major field tests of these technologies at EPRI, Corning, Pratt & Whitney, and Global Energy; field validation of the technology is critical to ensuring its usefulness to U.S. industries. Unfortunately, due to budget cuts, DOE was unable to follow through with its funding commitment to support Energy Efficiency Science Initiative projects and this final phase was eliminated.

  17. Nonequilibrium Phase Chemistry in High Temperature Structure Alloys

    Science.gov (United States)

    Wang, R.

    1991-01-01

    Titanium and nickel aluminides of nonequilibrium microstructures and in thin gauge thickness were identified, characterized and produced for potential high temperature applications. A high rate sputter deposition technique for rapid surveillance of the microstructures and nonequilibrium phase is demonstrated. Alloys with specific compositions were synthesized with extended solid solutions, stable dispersoids, and specific phase boundaries associated with different heat treatments. Phase stability and mechanical behavior of these nonequilibrium alloys were investigated and compared.

  18. High-Temperature Gas-Cooled Test Reactor Point Design

    Energy Technology Data Exchange (ETDEWEB)

    Sterbentz, James William [Idaho National Laboratory; Bayless, Paul David [Idaho National Laboratory; Nelson, Lee Orville [Idaho National Laboratory; Gougar, Hans David [Idaho National Laboratory; Kinsey, James Carl [Idaho National Laboratory; Strydom, Gerhard [Idaho National Laboratory; Kumar, Akansha [Idaho National Laboratory

    2016-04-01

    A point design has been developed for a 200 MW high-temperature gas-cooled test reactor. The point design concept uses standard prismatic blocks and 15.5% enriched UCO fuel. Reactor physics and thermal-hydraulics simulations have been performed to characterize the capabilities of the design. In addition to the technical data, overviews are provided on the technological readiness level, licensing approach and costs.

  19. Automatic 3D inspection metrology for high-temperature objects

    Science.gov (United States)

    Han, Liya; Li, Zhongwei; Zhong, Kai; Yi, Jie; Shi, Yusheng; Cheng, Xu; Zhan, Guomin; Chen, Ran

    2017-06-01

    3D Visual Inspection for high-temperature objects has attracted more and more attention in the industrial and manufacture field. Until now it is still difficult to measure the shape of high-temperature objects due to the following problems: 1) the radiation and heat transfer through the air seriously affect both human and measurement equipment, so the manual measurement is not capable in this situation. 2) Because of the difficulties to handle the surfaces of the hot objects, it is hard to use artificial markers to align different pieces of data. In order to solve these problems, an automatic 3D shape measurement system for high-temperature objects is proposed by combing an industrial robot with a structured blue light 3D scanner. In this system, the route for inspection is planned with the cooled object and then executed automatically with the same object in hot state to avoid artificial operations. The route is carefully planned to reduce the exposure time of the measurement equipment under the high-temperature situation. Then different pieces of data are premapped during the planning procedure. In the executing procedure, they can be aligned accurately thanks to the good repeatability of the industrial robot. Finally, different pieces of data are merged without artificial markers and the results are better than methods with traditional hand-eye calibration. Experiments verify that the proposed system can conduct the inspection of forging parts under the temperature of 900°C and the alignment precision is 0.0013rad and 0.28mm.

  20. High Temperature PEM Fuel Cell Stacks with Advent TPS Meas

    Directory of Open Access Journals (Sweden)

    Neophytides Stylianos

    2017-01-01

    Full Text Available High power/high energy applications are expected to greatly benefit from high temperature Polymer Electrolyte Membrane Fuel Cells (PEMFCs. In this work, a combinatorial approach is presented, in which separately developed and evaluated MEAs, design and engineering are employed to result in reliable and effective stacks operating above 180°C and having the characteristics well matched to applications including auxiliary power, micro combined heat and power, and telecommunication satellites.

  1. Heat conductivity of high-temperature thermal insulators

    Science.gov (United States)

    Kharlamov, A. G.

    The book deals essentially with the mechanisms of heat transfer by conduction, convection, and thermal radiation in absorbing and transmitting media. Particular attention is given to materials for gas-cooled reactor systems, the temperature dependent conductivities of high-temperature insulations in vacuum, and the thermal conductivities of MgO, Al2O3, ZrO2, and other powders at temperatures up to 2000 C. The thermal conductivity of pyrolitic graphite and graphite foam are studied.

  2. Advances in High Temperature Materials for Additive Manufacturing

    Science.gov (United States)

    Nordin, Nurul Amira Binti; Johar, Muhammad Akmal Bin; Ibrahim, Mohd Halim Irwan Bin; Marwah, Omar Mohd Faizan bin

    2017-08-01

    In today’s technology, additive manufacturing has evolved over the year that commonly known as 3D printing. Currently, additive manufacturing have been applied for many industries such as for automotive, aerospace, medical and other commercial product. The technologies are supported by materials for the manufacturing process to produce high quality product. Plus, additive manufacturing technologies has been growth from the lowest to moderate and high technology to fulfil manufacturing industries obligation. Initially from simple 3D printing such as fused deposition modelling (FDM), poly-jet, inkjet printing, to selective laser sintering (SLS), and electron beam melting (EBM). However, the high technology of additive manufacturing nowadays really needs high investment to carry out the process for fine products. There are three foremost type of material which is polymer, metal and ceramic used for additive manufacturing application, and mostly they were in the form of wire feedstock or powder. In circumstance, it is crucial to recognize the characteristics of each type of materials used in order to understand the behaviours of the materials on high temperature application via additive manufacturing. Therefore, this review aims to provide excessive inquiry and gather the necessary information for further research on additive material materials for high temperature application. This paper also proposed a new material based on powder glass, which comes from recycled tempered glass from automotive industry, having a huge potential to be applied for high temperature application. The technique proposed for additive manufacturing will minimize some cost of modelling with same quality of products compare to the others advanced technology used for high temperature application.

  3. Ionic liquid electrolyte for supercapacitor with high temperature compatibility

    Science.gov (United States)

    Haque, Mazharul; Li, Qi; Kuzmenko, Volodymyr; Smith, Anderson D.; Enoksson, Peter

    2017-11-01

    This work describes the electrochemical investigation of two ionic liquids (ILs), 1-ethyl-3-methylimidazolium acetate (EMIM Ac) and 1-butyl-3-methylimidazolium chloride (BMIM Cl), as electrolytes in supercapacitors (SC). A comprehensive study on high temperature (HT) endurance that is required for system integration in microelectronics has also been carried out. It has been found that EMIM Ac containing SC performs better than a BMIM Cl containing SC, and HT treatment improves the capacitive performance.

  4. High-Temperature Luminescence Quenching of Colloidal Quantum Dots

    OpenAIRE

    Zhao, Y.; Riemersma, C.; Pietra, F; de Mello Donega, C.; Meijerink, A.

    2012-01-01

    Thermal quenching of quantum dot (QD) luminescence is important for application in luminescent devices. Systematic studies of the quenching behavior above 300 K are, however, lacking. Here, high-temperature (300–500 K) luminescence studies are reported for highly efficient CdSe core–shell quantum dots (QDs), aimed at obtaining insight into temperature quenching of QD emission. Through thermal cycling (yoyo) experiments for QDs in polymer matrices, reversible and irreversible luminescence quen...

  5. Glycerin Reformation in High Temperature and Pressure Water

    Science.gov (United States)

    2012-01-01

    hygroscopic, while ethanol is renewable and non-toxic (94). Water has a detrimental effect on the reaction because soaps can be formed, which cause...Lavric, V. (2005) Delocalized organic pollutant destruction through a self-sustaining supercritical water oxidation process, Energy Conversion and...2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Glycerin Reformation in High Temperature and Pressure Water

  6. Diamond based detectors for high temperature, high radiation environments

    Science.gov (United States)

    Metcalfe, A.; Fern, G. R.; Hobson, P. R.; Smith, D. R.; Lefeuvre, G.; Saenger, R.

    2017-01-01

    Single crystal CVD diamond has many desirable properties as a radiation detector; exceptional radiation hardness and physical hardness, chemical inertness, low Z (close to human tissue, good for dosimetry and transmission mode applications), wide bandgap (high temperature operation with low noise and solar blind), an intrinsic pathway to fast neutron detection through the 12C(n,α)9Be reaction. This combination of radiation hardness, temperature tolerance and ability to detect mixed radiation types with a single sensor makes diamond particularly attractive as a detector material for harsh environments such as nuclear power station monitoring (fission and fusion) and oil well logging. Effective exploitation of these properties requires the development of a metallisation scheme to give contacts that remain stable over extended periods at elevated temperatures (up to 250°C in this instance). Due to the cost of the primary detector material, computational modelling is essential to best utilise the available processing methods for optimising sensor response through geometry and conversion media configurations and to fully interpret experimental data. Monte Carlo simulations of our diamond based sensor have been developed, using MCNP6 and FLUKA2011, assessing the sensor performance in terms of spectral response and overall efficiency as a function of the detector and converter geometry. Sensors with varying metallisation schemes for high temperature operation have been fabricated at Brunel University London and by Micron Semiconductor Limited. These sensors have been tested under a varied set of conditions including irradiation with fast neutrons and alpha particles at high temperatures. The presented study indicates that viable metallisation schemes for high temperature contacts have been successfully developed and the modelling results, supported by preliminary experimental data from partners, indicate that the simulations provide a reasonable representation of

  7. Zirconium diboride thin films for use in high temperature sensors and MEMS devices

    Science.gov (United States)

    Stewart, David M.; Bernhardt, George P.; Lad, Robert J.

    2017-05-01

    Sensors and MEMS devices operating in high temperature environments require stable thin films with high electrical conductivity for use as electrodes, bond pads, and other components. Metal films are unreliable because of thermodynamically driven morphological instability and agglomeration over long times. Zirconium diboride (ZrB2) is an ultra-high temperature conducting ceramic with a melting point of 3245°C, with low atomic diffusion rates compared to other materials. To evaluate ZrB2 as a high temperature film, 200 nm thick ZrB2 films were synthesized on r-sapphire substrates using e-beam co-evaporation of elemental Zr and B sources. Film stability was characterized after post-deposition thermal treatments from 600-1000°C in both reducing (vacuum) and oxidizing (air) environments. ZrB2 films deposited at room temperature are amorphous, but have short-range order characteristic of ZrB2 bonding. ZrB2 films grown at 600°C are polycrystalline with preferred changes occur after annealing at 850°C for 55 hours in vacuum, and film electrical conductivity remains leads to ZrB2 film decomposition into ZrO2 and B2O3 phases, the latter of which is volatile. X-ray diffraction indicates that a 50 nm thick hexagonal boron nitride (h-BN) capping layer grown on top of ZrB2 via magnetron sputtering hinders oxidation, but the ZrB2 eventually transforms to ZrO2. These results indicate that ZrB2 films are attractive for potential use in sensors and MEMS devices in high temperature reducing environments, and for short times in oxidizing environments when covered with a h-BN capping layer.

  8. High Temperature Fuel Cladding Chemical Interactions Between TRIGA Fuels and 304 Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Emmanuel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Keiser, Jr., Dennis D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Forsmann, Bryan [Boise State Univ., ID (United States); Janney, Dawn E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Henley, Jody [Idaho National Lab. (INL), Idaho Falls, ID (United States); Woolstenhulme, Eric C. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    High-temperature fuel-cladding chemical interactions (FCCI) between TRIGA (Training, Research, Isotopes, General Atomics) fuel elements and the 304 stainless steel (304SS) are of interest to develop an understanding of the fuel behavior during transient reactor scenarios. TRIGA fuels are composed of uranium (U) particles dispersed in a zirconium-hydride (Zr-H) matrix. In reactor, the fuel is encased in 304-stainless-steel (304SS) or Incoloy 800 clad tubes. At high temperatures, the fuel can readily interact with the cladding, resulting in FCCI. A number of FCCI can take place in this system. Interactions can be expected between the cladding and the Zr-H matrix, and/or between the cladding and the U-particles. Other interactions may be expected between the Zr-H matrix and the U-particles. Furthermore, the fuel contains erbium-oxide (Er-O) additions. Interactions can also be expected between the Er-O, the cladding, the Zr-H and the U-particles. The overall result is that very complex interactions may take place as a result of fuel and cladding exposures to high temperatures. This report discusses the characterization of the baseline fuel microstructure in the as-received state (prior to exposure to high temperature), characterization of the fuel after annealing at 950C for 24 hours and the results from diffusion couple experiments carries out at 1000C for 5 and 24 hours. Characterization was carried out via scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with sample preparation via focused ion beam in situ-liftout-technique.

  9. Directional transport of droplets on wettability patterns at high temperature

    Science.gov (United States)

    Huang, Shuai; Yin, Shaohui; Chen, Fengjun; Luo, Hu; Tang, Qingchun; Song, Jinlong

    2018-01-01

    Directional transport of liquid has attracted increasing interest owing to its potential of application in lab-on-a-chip, microfluidic devices and thermal management technologies. Although numerous strategies have been developed to achieve directional transport of liquid at low temperature, controlling the directional transport of liquid at high temperature remains to be a challenging issue. In this work, we reported a novel strategy in which different parts of droplet contacted with surface with different wettability patterns, resulting in a discrepant evaporative vapor film to achieve the directional transport of liquid. The experimental results showed that the state of the liquid on wettability patterned surface gradually changed from contact boiling to Leidenfrost state with the increase of substrate temperature Ts, and liquid on superhydrophilic surface was in composite state of contact boiling and Leidenfrost when Ts was higher than 200 °C. Inspired by the different evaporation states of droplet on the wettability boundary, controlling preferential motion of droplets was observed at high temperature. By designing a surface with wettability pattern on which superhydrophobic region and superhydrophilic region are alternately arranged, a controlled directional transport of droplet can be achieved at high temperature.

  10. Moisture diffusivity of HPFRC exposed to high temperatures

    Science.gov (United States)

    Fořt, Jan; Pavlík, Zbyšek; Černý, Robert

    2017-07-01

    Concrete structures suffer from a high-temperature exposure, among others from the damage induced by spalling. The cracks propagation is connected with the degree of material water saturation and rate of damage during the release of free and bound water from cement hydrates as a result of material high-temperature heating. In case of High Performance Concrete (HPC), its dense structure increases concrete damage due to the formation of higher water vapor pressures compared to normal strength concrete. On this account, detail information on the influence of a high-temperature load on the permeability of a High Performance Fiber Reinforced Concrete (HPFRC) represents worth information for proper building and structural design. In this study, 1-D liquid water transport in HPFRC samples exposed to the laboratory temperature and temperatures of 800 °C and 1000 °C is studied. Experimentally measured moisture profiles are used for the calculation of moisture dependent moisture diffusivity using inverse analysis method based on Boltzmann-Matano treatment. The K-spline software tool, developed at the Department of Materials Engineering and Chemistry, FCE, CTU in Prague is used to get high accuracy of the computational inverse procedure.

  11. High temperature strain of metals and alloys. Physical fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Levitin, V. [National Technical Univ., Zaporozhye (Ukraine)

    2006-07-01

    The author shows how new in-situ X-ray investigations and transmission electron microscope studies lead to novel explanations of high-temperature deformation and creep in pure metals, solid solutions and super alloys. This approach is the first to find unequivocal and quantitative expressions for the macroscopic deformation rate by means of three groups of parameters: substructural characteristics, physical material constants and external conditions. Creep strength of the studied uptodate single crystal super alloys is greatly increased over conventional polycrystalline super alloys. The contents of this book include: macroscopic characteristics of strain at high temperatures; experimental equipment and technique of in situ X-ray investigations; experimental data and structural parameters in deformed metals; sub-boundaries as dislocation sources and obstacles; the physical mechanism of creep and the quantitative structural model; simulation of the parameters evolution; system of differential equations; high-temperature deformation of industrial super alloys; single crystals of super alloys; effect of composition, orientation and temperature on properties; and creep of some refractory metals.

  12. Polyimide/Glass Composite High-Temperature Insulation

    Science.gov (United States)

    Pater, Ruth H.; Vasquez, Peter; Chatlin, Richard L.; Smith, Donald L.; Skalski, Thomas J.; Johnson, Gary S.; Chu, Sang-Hyon

    2009-01-01

    Lightweight composites of RP46 polyimide and glass fibers have been found to be useful as extraordinarily fire-resistant electrical-insulation materials. RP46 is a polyimide of the polymerization of monomeric reactants (PMR) type, developed by NASA Langley Research Center. RP46 has properties that make it attractive for use in electrical insulation at high temperatures. These properties include high-temperature resistance, low relative permittivity, low dissipation factor, outstanding mechanical properties, and excellent resistance to moisture and chemicals. Moreover, RP46 contains no halogen or other toxic materials and when burned it does not produce toxic fume or gaseous materials. The U. S. Navy has been seeking lightweight, high-temperature-resistant electrical-insulation materials in a program directed toward reducing fire hazards and weights in ship electrical systems. To satisfy the requirements of this program, an electrical-insulation material must withstand a 3-hour gas-flame test at 1,600 F (about 871 C). Prior to the development reported here, RP46 was rated for use at temperatures from -150 to +700 F (about -101 to 371 C), and no polymeric product - not even RP46 - was expected to withstand the Navy 3-hour gas-flame test.

  13. Phase Change Material Systems for High Temperature Heat Storage.

    Science.gov (United States)

    Perraudin, David Y S; Binder, Selmar R; Rezaei, Ehsan; Ortonaa, Alberto; Haussener, Sophia

    2015-01-01

    Efficient, cost effective, and stable high-temperature heat storage material systems are important in applications such as high-temperature industrial processes (metal processing, cement and glass manufacturing, etc.), or electricity storage using advanced adiabatic compressed air energy storage. Incorporating phase change media into heat storage systems provides an advantage of storing and releasing heat at nearly constant temperature, allowing steady and optimized operation of the downstream processes. The choice of, and compatibility of materials and encapsulation for the phase change section is crucial, as these must guarantee good and stable performance and long lifetime at low cost. Detailed knowledge of the material properties and stability, and the coupled heat transfer, phase change, and fluid flow are required to allow for performance and lifetime predictions. We present coupled experimental-numerical techniques allowing prediction of the long-term performance of a phase change material-based high-temperature heat storage system. The experimental investigations focus on determination of material properties (melting temperature, heat of fusion, etc.) and phase change material and encapsulation interaction (stability, interface reactions, etc.). The computational investigations focus on an understanding of the multi-mode heat transfer, fluid flow, and phase change processes in order to design the material system for enhanced performance. The importance of both the experimental and numerical approaches is highlighted and we give an example of how both approaches can be complementarily used for the investigation of long-term performance.

  14. Update on High-Temperature Coils for Electromagnets

    Science.gov (United States)

    Kascak, Albert F.; Montague, Gerald T.; Palazzolo, Alan; Preuss, Jason; Carter, Bart; Tucker, Randall; Hunt, Andrew

    2005-01-01

    A report revisits the subject matter of "High-Temperature Coils for Electromagnets" (LEW-17164), NASA Tech Briefs, Vol. 26, No. 8, (August 2002) page 38. To recapitulate: Wires have been developed for use in electromagnets that operate at high temperatures. The starting material for a wire of this type can be either a nickel-clad, ceramic-insulated copper wire or a bare silver wire. The wire is covered by electrical-insulation material that is intended to withstand operating temperatures in the range from 800 to 1,300 F (.430 to .700 C): The starting wire is either primarily wrapped with S-glass as an insulating material or else covered with another insulating material wrapped in S-glass prior to the winding process. A ceramic binding agent is applied as a slurry during the winding process to provide further insulating capability. The turns are pre-bent during winding to prevent damage to the insulation. The coil is then heated to convert the binder into ceramic. The instant report mostly reiterates the prior information and presents some additional information on the application of the ceramic binding agent and the incorporation of high-temperature wire into the windings.

  15. The Status of the US High-Temperature Gas Reactors

    Directory of Open Access Journals (Sweden)

    Andrew C. Kadak

    2016-03-01

    Full Text Available In 2005, the US passed the Energy Policy Act of 2005 mandating the construction and operation of a high-temperature gas reactor (HTGR by 2021. This law was passed after a multiyear study by national experts on what future nuclear technologies should be developed. As a result of the Act, the US Congress chose to develop the so-called Next-Generation Nuclear Plant, which was to be an HTGR designed to produce process heat for hydrogen production. Despite high hopes and expectations, the current status is that high temperature reactors have been relegated to completing research programs on advanced fuels, graphite and materials with no plans to build a demonstration plant as required by the US Congress in 2005. There are many reasons behind this diminution of HTGR development, including but not limited to insufficient government funding requirements for research, unrealistically high temperature requirements for the reactor, the delay in the need for a “hydrogen” economy, competition from light water small modular light water reactors, little utility interest in new technologies, very low natural gas prices in the US, and a challenging licensing process in the US for non-water reactors.

  16. High temperature material characterization and advanced materials development

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Seog; Kim, D. H.; Kim, S. H. and others

    2005-03-15

    The study is to characterize the structural materials under the high temperature, one of the most significant environmental factors in nuclear systems. And advanced materials are developed for high temperature and/or low activation in neutron irradiation. Tensile, fatigue and creep properties have been carried out at high temperature to evaluate the mechanical degradation. Irradiation tests were performed using the HANARO. The optimum chemical composition and heat treatment condition were determined for nuclear grade 316NG stainless steel. Nitrogen, aluminum, and tungsten were added for increasing the creep rupture strength of FMS steel. The new heat treatment method was developed to form more stable precipitates. By applying the novel whiskering process, high density SiC/SiC composites with relative density above 90% could be obtained even in a shorter processing time than the conventional CVI process. Material integrated databases are established using data sheets. The databases of 6 kinds of material properties are accessible through the home page of KAERI material division.

  17. Development of high temperature, radiation hard detectors based on diamond

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, Alex, E-mail: Alex.Metcalfe@brunel.ac.uk [Wolfson Centre for Materials Processing, Brunel University London, Uxbridge UB8 3PH (United Kingdom); Fern, George R. [Wolfson Centre for Materials Processing, Brunel University London, Uxbridge UB8 3PH (United Kingdom); Hobson, Peter R. [Centre for Sensors & Instrumentation, College of Engineering, Design and Physical Sciences, Brunel University London, Uxbridge UB8 3PH (United Kingdom); Ireland, Terry; Salimian, Ali; Silver, Jack [Wolfson Centre for Materials Processing, Brunel University London, Uxbridge UB8 3PH (United Kingdom); Smith, David R. [Centre for Sensors & Instrumentation, College of Engineering, Design and Physical Sciences, Brunel University London, Uxbridge UB8 3PH (United Kingdom); Lefeuvre, Gwenaelle [Micron Semiconductor Ltd., Lancing BN15 8 SJ (United Kingdom); Saenger, Richard [Schlumberger Limited, 91240 Clamart (France)

    2017-02-11

    Single crystal CVD diamond has many desirable properties compared to current, well developed, detector materials; exceptional radiation, chemical and physical hardness, chemical inertness, low Z (close to human tissue, good for dosimetry), wide bandgap and an intrinsic pathway to fast neutron detection through the {sup 12}C(n,α){sup 9}Be reaction. However effective exploitation of these properties requires development of a suitable metallisation scheme to give stable contacts for high temperature applications. To best utilise available processing techniques to optimise sensor response through geometry and conversion media configurations, a reliable model is required. This must assess the performance in terms of spectral response and overall efficiency as a function of detector and converter geometry. The same is also required for proper interpretation of experimental data. Sensors have been fabricated with varying metallisation schemes indented to permit high temperature operation; Present test results indicate that viable fabrication schemes for high temperature contacts have been developed and present modelling results, supported by preliminary data from partners indicate simulations provide a useful representation of response. - Highlights: • Radiation sensors using diamond as the sensitive volume have been constructed. • Functionality of these sensors with minimal degradation has been confirmed at 100 °C. • Sensitisation to thermal neutrons by addition of conversion layers has been modelled. • Modelling suggests 4× efficiency improvements from 3d converter-substrate interfaces.

  18. Note: Zeeman splitting measurements in a high-temperature plasma

    Energy Technology Data Exchange (ETDEWEB)

    Golingo, R. P.; Shumlak, U.; Den Hartog, D. J. [Aerospace and Energetics Research Program, University of Washington, Seattle, Washington 98195-2250 (United States)

    2010-12-15

    The Zeeman effect has been used for measurement of magnetic fields in low-temperature plasma, but the diagnostic technique is difficult to implement in a high-temperature plasma. This paper describes new instrumentation and methodology for simultaneous measurement of the entire Doppler-broadened left and right circularly polarized Zeeman spectra in high-temperature plasmas. Measurements are made using spectra emitted parallel to the magnetic field by carbon impurities in high-temperature plasma. The Doppler-broadened width is much larger than the magnitude of the Zeeman splitting, thus simultaneous recording of the two circularly polarized Zeeman line profiles is key to accurate measurement of the magnetic field in the ZaP Z-pinch plasma device. Spectral data are collected along multiple chords on both sides of the symmetry axis of the plasma. This enables determination of the location of the current axis of the Z-pinch and of lower-bound estimates of the local magnetic field at specific radial locations in the plasma.

  19. Effect of High Temperature on Properties of Glass Concrete

    Directory of Open Access Journals (Sweden)

    Wang Wei Chien

    2017-01-01

    Full Text Available In this study, the concrete is mixed with glass fibers which are 0.5%, 1.0% and 1.5% of cement weight and 0.6 cm long. The effect of fiber addition level on the compressive strength, bending strength and residual compressive strength and thermal conductivity after heating of concrete is discussed. The test results show that an appropriate addition of glass fiber to the concrete at room temperature is favorable for the compressive strength. A low addition of relatively short glass fiber has insignificant effect on the bending strength. However, the adverse effect on the bending strength will increase if the addition level is too high. The addition of glass fiber can improve the loss of concrete strength under the effect of high temperature not exceeding 500°C, and a relatively high compressive strength remains under the effect of high temperature not exceeding 800°C. The high temperature can reduce the thermal conductivity of glass concrete, and the higher the addition level of glass fiber is, the lower is the thermal conductivity. Keywords: Glass fiber, concrete, heating, thermal conductivity

  20. Sourcebook on high-temperature electronics and instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Veneruso, A.F. (ed.)

    1981-10-01

    This sourcebook summarizes the high-temperature characteristics of a number of commercially available electronic components and materials required in geothermal well-logging instruments that must operate to 275/sup 0/C. The sourcebook is written to provide a starting place for instrument designers, who need to know the high-temperature electronic products that are available and the design and performance limitations of these products. The electronic component information given includes the standard repertoire of passive devices such as resistors, capacitors, and magnetics; the active devices and integrated circuits sections emphasize silicon semiconductor JFETs and CMOS circuits; and, to complete the electronics, interconnections and packaging of hybrid microelectronics are described. Thermal insulation and refrigeration alternatives are also presented in the sourcebook. Finally, instrument housing materials and high-temperature cables and cablehead connectors are listed. This information was compiled as part of the Geothermal Logging Instrumentation Development Program that Sandia National Laboratories conducted for the US Department of Energy's Divison of Geothermal Energy from 1976 to 1981.