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Sample records for high temperature removal

  1. Supported ionic liquid membranes for removal of dioxins from high-temperature vapor streams.

    Science.gov (United States)

    Kulkarni, Prashant S; Neves, Luisa A; Coelhoso, Isabel M; Afonso, Carlos A M; Crespo, João G

    2012-01-03

    Dioxins and dioxin-like chemicals are predominantly produced by thermal processes such as incineration and combustion at concentrations in the range of 10-100 ng of I-TEQ/kg (I-TEQ = international toxic equivalents). In this work, a new approach for the removal of dioxins from high-temperature vapor streams using facilitated supported ionic liquid membranes (SILMs) is proposed. The use of ceramic membranes containing specific ionic liquids, with extremely low volatility, for dioxin removal from incineration sources is proposed owing to their stability at very high temperatures. Supported liquid membranes were prepared by successfully immobilizing the ionic liquids tri-C(8)-C(10)-alkylmethylammonium dicyanamide ([Aliquat][DCA]) and 1-n-octyl-3-methylimidazolium dicyanamide ([Omim][DCA]) inside the porous structure of ceramic membranes. The porous inorganic membranes tested were made of titanium oxide (TiO(2)), with a nominal pore size of 30 nm, and aluminum oxide (Al(2)O(3)), with a nominal pore size of 100 nm. The ionic liquids were characterized, and the membrane performance was assessed for the removal of dioxins. Different materials (membrane pore size, type of ionic liquid, and dioxin) and different operating conditions (temperature and flow rate) were tested to evaluate the efficiency of SILMs for dioxin removal. All membranes prepared were stable at temperatures up to 200 °C. Experiments with model incineration gas were also carried out, and the results obtained validate the potential of using ceramic membranes with immobilized ionic liquids for the removal of dioxins from high-temperature vapor sources.

  2. The microbial community in a high-temperature enhanced biological phosphorus removal (EBPR process

    Directory of Open Access Journals (Sweden)

    Ying Hui Ong

    2016-01-01

    Full Text Available An enhanced biological phosphorus removal (EBPR process operated at a relatively high temperature, 28 °C, removed 85% carbon and 99% phosphorus from wastewater over a period of two years. This study investigated its microbial community through fluorescent in situ hybridization (FISH and clone library generation. Through FISH, considerably more Candidatus “Accumulibacter phosphatis” (Accumulibacter-polyphosphate accumulating organisms (PAOs than Candidatus ‘Competibacter phosphatis’ (Competibacter-glycogen accumulating organisms were detected in the reactor, at 36 and 7% of total bacterial population, respectively. A low ratio of Glycogen/Volatile Fatty Acid of 0.69 further indicated the dominance of PAOs in the reactor. From clone library generated, 26 operational taxonomy units were retrieved from the sludge and a diverse population was shown, comprising Proteobacteria (69.6%, Actinobacteria (13.7%, Bacteroidetes (9.8%, Firmicutes (2.94%, Planctomycetes (1.96%, and Acidobacteria (1.47%. Accumulibacter are the only recognized PAOs revealed by the clone library. Both the clone library and FISH results strongly suggest that Accumulibacter are the major PAOs responsible for the phosphorus removal in this long-term EBPR at relatively high temperature.

  3. Highly active mesoporous ferrihydrite supported pt catalyst for formaldehyde removal at room temperature.

    Science.gov (United States)

    Yan, Zhaoxiong; Xu, Zhihua; Yu, Jiaguo; Jaroniec, Mietek

    2015-06-01

    Ferrihydrite (Fh) supported Pt (Pt/Fh) catalyst was first prepared by combining microemulsion and NaBH4 reduction methods and investigated for room-temperature removal of formaldehyde (HCHO). It was found that the order of addition of Pt precursor and ferrihydrite in the preparation process has an important effect on the microstructure and performance of the catalyst. Pt/Fh was shown to be an efficient catalyst for complete oxidation of HCHO at room temperature, featuring higher activity than magnetite supported Pt (Pt/Fe3O4). Pt/Fh and Pt/Fe3O4 exhibited much higher catalytic activity than Pt supported over calcined Fh and TiO2. The abundance of surface hydroxyls, high Pt dispersion and excellent adsorption performance of Fh are responsible for superior catalytic activity and stability of the Pt/Fh catalyst. This work provides some indications into the design and fabrication of the cost-effective and environmentally benign catalysts with excellent adsorption and catalytic oxidation performances for HCHO removal at room temperature.

  4. Removal of H2S using molten carbonate at high temperature.

    Science.gov (United States)

    Kawase, Makoto; Otaka, Maromu

    2013-12-01

    Gasification is considered to be an effective process for energy conversion from various sources such as coal, biomass, and waste. Cleanup of the hot syngas produced by such a process may improve the thermal efficiency of the overall gasification system. Therefore, the cleanup of hot syngas from biomass gasification using molten carbonate is investigated in bench-scale tests. Molten carbonate acts as an absorbent during desulfurization and dechlorination and as a thermal catalyst for tar cracking. In this study, the performance of molten carbonate for removing H2S was evaluated. The temperature of the molten carbonate was set within the range from 800 to 1000 °C. It is found that the removal of H2S is significantly affected by the concentration of CO2 in the syngas. When only a small percentage of CO2 is present, desulfurization using molten carbonate is inadequate. However, when carbon elements, such as char and tar, are continuously supplied, H2S removal can be maintained at a high level. To confirm the performance of the molten carbonate gas-cleaning system, purified biogas was used as a fuel in power generation tests with a molten carbonate fuel cell (MCFC). The fuel cell is a high-performance sensor for detecting gaseous impurities. When purified gas from a gas-cleaning reactor was continuously supplied to the fuel cell, the cell voltage remained stable. Thus, the molten carbonate gas-cleaning reactor was found to afford good gas-cleaning performance.

  5. DEVELOPMENT OF DISPOSABLE SORBENTS FOR CHLORIDE REMOVAL FROM HIGH TEMPERATURE COAL-DERIVED GASES

    Energy Technology Data Exchange (ETDEWEB)

    Gopala Krishnan; Raghubir Gupta

    1999-09-01

    Advanced integrated-gasification combined-cycle (IGCC) and integrated-gasification fuel cell (IGFC) systems require the development of high temperature sorbents for the removal of hydrogen chloride (HCl) vapor to less than 1 parts-per-million (ppm) levels. HCl is a highly reactive, corrosive, and toxic gas which must be removed to meet environmental regulations, to protect power generation equipment, and to minimize deterioration of hot gas desulfurization sorbents. The objective of this program was to develop disposable, alkali-based sorbents capable of reducing HCl vapor levels to less than 1 ppm in the temperature range from 400 to 750 C and pressures in the range from 1 to 20 atm. The primary areas of focus of this program were to investigate different methods of sorbent fabrication, testing their suitability for different reactor configurations, obtaining reaction kinetics data, and conducting a preliminary economic feasibility assessment. This program was a joint effort between SRI International (SRI), Research Triangle Institute (RTI), and General Electric Corporate Research and Development (GE-CRD). SRI, the prime contractor and RTI, a major subcontractor, performed most of the work in this program. Thermochemical calculations indicated that sodium-based sorbents were capable of reducing HCl vapor levels to less than 1 ppm at temperatures up to 650 C, but the regeneration of spent sorbents would require complex process steps. Nahcolite (NaHCO{sub 3}), a naturally-occurring mineral, could be used as an inexpensive sorbent to remove HCl vapor in hot coal gas streams. In the current program, nahcolite powder was used to fabricate pellets suitable for fixed-bed reactors and granules suitable for fluidized-bed reactors. Pilot-scale equipment were used to prepare sorbents in large batches: pellets by disk pelletization and extrusion techniques, and granules by granulation and spray-drying techniques. Bench-scale fixed- and fluidized-bed reactors were assembled at

  6. Novel Sorbent-Based Process for High Temperature Trace Metal Removal

    Energy Technology Data Exchange (ETDEWEB)

    Gokhan Alptekin

    2008-09-30

    The objective of this project was to demonstrate the efficacy of a novel sorbent can effectively remove trace metal contaminants (Hg, As, Se and Cd) from actual coal-derived synthesis gas streams at high temperature (above the dew point of the gas). The performance of TDA's sorbent has been evaluated in several field demonstrations using synthesis gas generated by laboratory and pilot-scale coal gasifiers in a state-of-the-art test skid that houses the absorbent and all auxiliary equipment for monitoring and data logging of critical operating parameters. The test skid was originally designed to treat 10,000 SCFH gas at 250 psig and 350 C, however, because of the limited gas handling capabilities of the test sites, the capacity was downsized to 500 SCFH gas flow. As part of the test program, we carried out four demonstrations at two different sites using the synthesis gas generated by the gasification of various lignites and a bituminous coal. Two of these tests were conducted at the Power Systems Demonstration Facility (PSDF) in Wilsonville, Alabama; a Falkirk (North Dakota) lignite and a high sodium lignite (the PSDF operator Southern Company did not disclose the source of this lignite) were used as the feedstock. We also carried out two other demonstrations in collaboration with the University of North Dakota Energy Environmental Research Center (UNDEERC) using synthesis gas slipstreams generated by the gasification of Sufco (Utah) bituminous coal and Oak Hills (Texas) lignite. In the PSDF tests, we showed successful operation of the test system at the conditions of interest and showed the efficacy of sorbent in removing the mercury from synthesis gas. In Test Campaign No.1, TDA sorbent reduced Hg concentration of the synthesis gas to less than 5 {micro}g/m{sup 3} and achieved over 99% Hg removal efficiency for the entire test duration. Unfortunately, due to the relatively low concentration of the trace metals in the lignite feed and as a result of the

  7. Synchronous Upgrading Iron and Phosphorus Removal from High Phosphorus Oolitic Hematite Ore by High Temperature Flash Reduction

    Directory of Open Access Journals (Sweden)

    Deqing Zhu

    2016-05-01

    Full Text Available In this paper, an effective method was developed to remove phosphorus and upgrade iron from high phosphorus oolitic hematite ore by high temperature flash reduction—a wet magnetic separation process. A thermodynamic analysis of iron and phosphorus mineral reactions and experiments with Fe-P separation process were performed, and the mechanism of phosphorus removal and beneficiation of iron is discussed as well. The results show that under the proper conditions, a final metallic iron powder assaying over 91% Fe and 0.25% P was obtained with iron recovery of 90% and phosphorus removal rate of 91.79% using the new process, indicating that the high temperature flash reduction process is a feasible and efficient way to process this kind of complex and refractory iron ore. Moreover, sodium sulfate is found to be capable of improving the removal of phosphorus and the upgrading of iron, as well as enhancing the growth of metallic iron grains significantly for higher recovery of iron.

  8. Biological phosphorus removal during high-rate, low-temperature, anaerobic digestion of wastewater

    Directory of Open Access Journals (Sweden)

    Ciara eKeating

    2016-03-01

    Full Text Available We report, for the first time, extensive biologically-mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD. A hybrid sludge bed/fixed-film (packed pumice stone reactor was employed for low-temperature (12°C anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis revealed the accumulation of elemental phosphorus (~2% within the sludge bed and fixed-film biofilms. 4’, 6-diamidino-2-phenylindole (DAPI staining indicated phosphorus accumulation was biological in nature and mediated through the formation of intracellular inorganic polyphosphate (polyP granules within these biofilms. DAPI staining further indicated that polyP accumulation was rarely associated with free cells. Efficient and consistent chemical oxygen demand (COD removal was recorded, throughout the 732-day trial, at applied organic loading rates between 0.4-1.5 kg COD m-3 d-1 and hydraulic retention times of 8-24 hours, while phosphate removal efficiency ranged from 28-78% on average per phase. Analysis of protein hydrolysis kinetics and the methanogenic activity profiles of the biomass revealed the development, at 12˚C, of active hydrolytic and methanogenic populations. Temporal microbial changes were monitored using Illumina Miseq analysis of bacterial and archaeal 16S rRNA gene sequences. The dominant bacterial phyla present in the biomass at the conclusion of the trial were the Proteobacteria and Firmicutes and the dominant archaeal genus was Methanosaeta. Trichococcus and Flavobacterium populations, previously associated with low temperature protein degradation, developed in the reactor biomass. The presence of previously characterised polyphosphate accumulating organisms (PAOs such as Rhodocyclus, Chromatiales, Actinobacter and Acinetobacter was

  9. Biological Phosphorus Removal During High-Rate, Low-Temperature, Anaerobic Digestion of Wastewater.

    Science.gov (United States)

    Keating, Ciara; Chin, Jason P; Hughes, Dermot; Manesiotis, Panagiotis; Cysneiros, Denise; Mahony, Therese; Smith, Cindy J; McGrath, John W; O'Flaherty, Vincent

    2016-01-01

    We report, for the first time, extensive biologically mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD). A hybrid sludge bed/fixed-film (packed pumice stone) reactor was employed for low-temperature (12°C) anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate) was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis revealed the accumulation of elemental phosphorus (∼2%) within the sludge bed and fixed-film biofilms. 4', 6-diamidino-2-phenylindole (DAPI) staining indicated phosphorus accumulation was biological in nature and mediated through the formation of intracellular inorganic polyphosphate (polyP) granules within these biofilms. DAPI staining further indicated that polyP accumulation was rarely associated with free cells. Efficient and consistent chemical oxygen demand (COD) removal was recorded, throughout the 732-day trial, at applied organic loading rates between 0.4 and 1.5 kg COD m(-3) d(-1) and hydraulic retention times of 8-24 h, while phosphate removal efficiency ranged from 28 to 78% on average per phase. Analysis of protein hydrolysis kinetics and the methanogenic activity profiles of the biomass revealed the development, at 12°C, of active hydrolytic and methanogenic populations. Temporal microbial changes were monitored using Illumina MiSeq analysis of bacterial and archaeal 16S rRNA gene sequences. The dominant bacterial phyla present in the biomass at the conclusion of the trial were the Proteobacteria and Firmicutes and the dominant archaeal genus was Methanosaeta. Trichococcus and Flavobacterium populations, previously associated with low temperature protein degradation, developed in the reactor biomass. The presence of previously characterized polyphosphate accumulating organisms (PAOs) such as Rhodocyclus, Chromatiales, Actinobacter, and Acinetobacter was recorded

  10. Red soil as a regenerable sorbent for high temperature removal of hydrogen sulfide from coal gas.

    Science.gov (United States)

    Ko, Tzu-Hsing; Chu, Hsin; Lin, Hsiao-Ping; Peng, Ching-Yu

    2006-08-25

    In this study, hydrogen sulfide (H(2)S) was removed from coal gas by red soil under high temperature in a fixed-bed reactor. Red soil powders were collected from the northern, center and southern of Taiwan. They were characterized by XRPD, porosity analysis and DCB chemical analysis. Results show that the greater sulfur content of LP red soils is attributed to the higher free iron oxides and suitable sulfidation temperature is around 773K. High temperature has a negative effect for use red soil as a desulfurization sorbent due to thermodynamic limitation in a reduction atmosphere. During 10 cycles of regeneration, after the first cycle the red soil remained stable with a breakthrough time between 31 and 36 min. Hydrogen adversely affects sulfidation reaction, whereas CO exhibits a positive effect due to a water-shift reaction. COS was formed during the sulfidation stage and this was attributed to the reaction of H(2)S and CO. Results of XRPD indicated that, hematite is the dominant active species in fresh red soil and iron sulfide (FeS) is a product of the reaction between hematite and hydrogen sulfide in red soils. The spinel phase FeAl(2)O(4) was found during regeneration, moreover, the amount of free iron oxides decreased after regeneration indicating the some of the free iron oxide formed a spinel phase, further reducting the overall desulfurization efficiency.

  11. Procedure of Active Residual Heat Removal after Emergency Shutdown of High-Temperature-Gas-Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2014-01-01

    Full Text Available After emergency shutdown of high-temperature-gas-cooled reactor, the residual heat of the reactor core should be removed. As the natural circulation process spends too long period of time to be utilized, an active residual heat removal procedure is needed, which makes use of steam generator and start-up loop. During this procedure, the structure of steam generator may suffer cold/heat shock because of the sudden load of coolant or hot helium at the first few minutes. Transient analysis was carried out based on a one-dimensional mathematical model for steam generator and steam pipe of start-up loop to achieve safety and reliability. The results show that steam generator should be discharged and precooled; otherwise, boiling will arise and introduce a cold shock to the boiling tubes and tube sheet when coolant began to circulate prior to the helium. Additionally, in avoiding heat shock caused by the sudden load of helium, the helium circulation should be restricted to start with an extreme low flow rate; meanwhile, the coolant of steam generator (water should have flow rate as large as possible. Finally, a four-step procedure with precooling process of steam generator was recommended; sensitive study for the main parameters was conducted.

  12. Effects of injection of acetic acid and propionic acid for total phosphorus removal at high temperature in enhanced biological phosphorus removal process.

    Science.gov (United States)

    Ki, C Y; Kwon, K H; Kim, S W; Min, K S; Lee, T U; Park, D J

    2014-01-01

    In summer, wastewater treatment plant total phosphorus (TP) removal efficiency is low in South Korea. The reason is because of high temperatures or significant fluctuation of inflow characteristics caused by frequent rainfall. Hence, this study tried to raise TP removal efficiency by injecting fixed external carbon sources in real sewage. Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) compete to occupy microorganisms at high temperature. Propionate is known to restrain GAOs. Thus, acetate and propionate were chosen as the external carbon source in this study to find out the suitable volume and ratio of carbon source which ensured the dominance of PAOs. An external carbon source was supplied in the anaerobic reactor of the biological phosphorus removal process at high temperature (above 25 °C). TP removal efficiency was improved by injecting an external carbon source compared to that without an external carbon source. Also, it remained relatively stable when injecting an external carbon source, despite the variation in temperature. TP removal efficiency was the highest when injecting acetate and propionate in the proportion of 2:1 (total concentration as chemical oxygen demand (COD) is 12 mg/L in influent).

  13. Modeling of a Large-Scale High Temperature Regenerative Sulfur Removal Process

    DEFF Research Database (Denmark)

    Konttinen, Jukka T.; Johnsson, Jan Erik

    1999-01-01

    -up. Steady-state kinetic reactor models are needed for reactor sizing, and dynamic models can be used for process control design and operator training. The regenerative sulfur removal process to be studied in this paper consists of two side-by-side fluidized bed reactors operating at temperatures of 400......-650°C and at elevated pressure. In this paper, hydrodynamic modeling equations for dense fluidized bed and freeboard are applied for the prediction of the performance of a large-scale regeneration reactor. These equations can partly explain the differences in modeling results observed with a simpler...

  14. Multi-cycle operation of enhanced biological phosphorus removal (EBPR) with different carbon sources under high temperature.

    Science.gov (United States)

    Shen, Nan; Chen, Yun; Zhou, Yan

    2017-05-01

    Many studies reported that it is challenging to apply enhanced biological phosphorus removal (EBPR) process at high temperature. Glycogen accumulating organisms (GAOs) could easily gain their dominance over poly-phosphate accumulating organisms (PAOs) when the operating temperature was in the range of 25 °C-30 °C. However, a few successful EBPR processes operated at high temperature have been reported recently. This study aimed to have an in-depth understanding on the impact of feeding strategy and carbon source types on EBPR performance in tropical climate. P-removal performance of two EBPR systems was monitored through tracking effluent quality and cyclic studies. The results confirmed that EBPR was successfully obtained and maintained at high temperature with a multi-cycle strategy. More stable performance was observed with acetate as the sole carbon source compared to propionate. Stoichiometric ratios of phosphorus and carbon transformation during both anaerobic and aerobic phases were higher at high temperature than low temperature (20±1 °C) except anaerobic PHA/C ratios within most of the sub-cycles. Furthermore, the fractions of PHA and glycogen in biomass were lower compared with one-cycle pulse feed operation. The microbial community structure was more stable in acetate-fed sequencing batch reactor (C2-SBR) than that in propionate-fed reactor (C3-SBR). Accumulibacter Clade IIC was found to be highly abundant in both reactors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Apparatus and method for removing particulate deposits from high temperature filters

    Science.gov (United States)

    Nakaishi, Curtis V.; Holcombe, Norman T.; Micheli, Paul L.

    1992-01-01

    A combustion of a fuel-air mixture is used to provide a high-temperature and high-pressure pulse of gaseous combustion products for the back-flush cleaning of ceramic filter elements contained in a barrier filter system and utilized to separate particulates from particulate-laden process gases at high temperature and high pressure. The volume of gaseous combustion products provided by the combustion of the fuel-air mixture is preferably divided into a plurality of streams each passing through a sonic orifice and conveyed to the open end of each filter element as a high pressure pulse which passes through the filter elements and dislodges dust cake supported on a surface of the filter element.

  16. Kinetic and stoichiometric characterization for efficient enhanced biological phosphorus removal (EBPR) process at high temperatures.

    Science.gov (United States)

    Liau, Kee Fui; Shoji, Tadashi; Ong, Ying Hui; Chua, Adeline Seak May; Yeoh, Hak Koon; Ho, Pei Yee

    2015-04-01

    A recently reported stable and efficient EBPR system at high temperatures around 30 °C has led to characterization of kinetic and stoichiometric parameters of the Activated Sludge Model no. 2d (ASM2d). Firstly, suitable model parameters were selected by identifiability analysis. Next, the model was calibrated and validated. ASM2d was found to represent the processes well at 28 and 32 °C except in polyhyroxyalkanoate (PHA) accumulation of the latter. The values of the kinetic parameters for PHA storage (q PHA), polyphosphate storage (q PP) and growth (μ PAO) of polyphosphate-accumulating organisms (PAOs) at 28 and 32 °C were found to be much higher than those reported by previous studies. Besides, the value of the stoichiometric parameter for the requirement of polyphosphate for PHA storage (Y PO4) was found to decrease as temperature rose from 28 to 32 °C. Values of two other stoichiometric parameters, i.e. the growth yield of heterotrophic organisms (Y H) and PAOs (Y PAO), were high at both temperatures. These calibrated parameters imply that the extremely active PAOs of the study were able to store PHA, store polyphosphate and even utilize PHA for cell growth. Besides, the parameters do not follow the Arrhenius correlation due to the previously reported unique microbial clade at 28 and 32 °C, which actively performs EBPR at high temperatures.

  17. HIGH TEMPERATURE REMOVAL OF H{sub 2}S FROM COAL GASIFICATION PROCESS STREAMS USING AN ELECTROCHEMICAL MEMBRANE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Jack Winnick; Meilin Liu

    2003-06-01

    A bench scale set-up was constructed to test the cell performance at 600-700 C and 1 atm. The typical fuel stream inlet proportions were 34% CO, 22% CO{sub 2}, 35% H{sub 2}, 8% H{sub 2}O, and 450-2000 ppm H{sub 2}S. The fundamental transport restrictions for sulfur species in an electrochemical cell were examined. Temperature and membrane thickness were varied to examine how these parameters affect the maximum flux of H{sub 2}S removal. It was found that higher temperature allows more sulfide species to enter the electrolyte, thus increasing the sulfide flux across the membrane and raising the maximum flux of H{sub 2}S removal. The results identify sulfide diffusion across the membrane as the rate-limiting step in H{sub 2}S removal. The maximum H{sub 2}S removal flux of 1.1 x 10-6 gmol H{sub 2}S min{sup -1} cm{sup -2} (or 3.5 mA cm{sup -2}) was obtained at 650 C, with a membrane that was 0.9 mm thick, 36% porous, and had an estimated tortuosity of 3.6. Another focus of this thesis was to examine the stability of cathode materials in full cell trials. A major hurdle that remains in process scale-up is cathode selection, as the lifetime of the cell will depend heavily on the lifetime of the cathode material, which is exposed to very sour gas. Materials that showed success in the past (i.e. cobalt sulfides and Y{sub 0.9}Ca{sub 0.1}FeO{sub 3}) were examined but were seen to have limitations in operating environment and temperature. Therefore, other novel metal oxide compounds were studied to find possible candidates for full cell trials. Gd{sub 2}TiMoO{sub 7} and La{sub 0.7}Sr{sub 0.3}VO{sub 3} were the compounds that retained their structure best even when exposed to high H{sub 2}S, CO{sub 2}, and H{sub 2}O concentrations.

  18. High-temperature removal of sulphur for biogenic gas products; Hochtemperatur-Entschwefelung fuer biogene Produktgase. Design und Optimierung - Schlussbericht/Jahresbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schildhauer, T.; Biollaz, S.

    2009-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project concerning the development of basics ideas on the design and optimisation of high-temperature methods for the removal of sulphur from biogenic gas products. Tests made as part of the 'Methane from Wood' project at pilot installations in Switzerland and Austria are discussed. Low temperature and high-temperature methods are examined and discussed. A number of sulphur compounds were tested. Also, experiments made using nickel, HDS and CPO catalysers are discussed.

  19. High-efficient nitrogen removal by coupling enriched autotrophic-nitrification and aerobic-denitrification consortiums at cold temperature.

    Science.gov (United States)

    Zou, Shiqiang; Yao, Shuo; Ni, Jinren

    2014-06-01

    This study paid particular attention to total nitrogen removal at low temperature (10°C) by excellent coupling of enriched autotrophic nitrifying and heterotrophic denitrifying consortiums at sole aerobic condition. The maximum specific nitrifying rate of the nitrifying consortium reached 8.85mgN/(gSSh). Further test in four identical lab-scale sequencing batch reactors demonstrated its excellent performance for bioaugmentation in potential applications. On the other hand, the aerobic denitrifying consortium could achieve a specific denitrifying rate of 32.93mgN/(gSSh) under dissolved oxygen of 1.0-1.5mg/L at 10°C. Coupling both kinds of consortiums was proved very successful for a perfect total nitrogen (TN) removal at COD/N of 4 and dissolved oxygen of 1.5-4.5mg/L, which was hardly reached by any single consortium reported previously. The encouraging results from coupling aerobic consortiums implied a huge potential in practical treatment of low-strength domestic wastewater (200-300mg/L COD) during wintertime.

  20. Selective sludge removal in a segregated aerobic granular biomass system as a strategy to control PAO-GAO competition at high temperatures.

    Science.gov (United States)

    Winkler, M-K H; Bassin, J P; Kleerebezem, R; de Bruin, L M M; van den Brand, T P H; van Loosdrecht, M C M

    2011-05-01

    An aerobic granular sludge (AGS) reactor was run for 280 days to study the competition between Phosphate and Glycogen Accumulating Organisms (PAOs and GAOs) at high temperatures. Numerous researches have proven that in suspended sludge systems PAOs are outcompeted by GAOs at higher temperatures. In the following study a reactor was operated at 30 °C in which the P-removal efficiency declined from 79% to 32% after 69 days of operation when biomass removal for sludge retention time (SRT) control was established by effluent withdrawal. In a second attempt at 24 °C, efficiency of P-removal remained on average at 71 ± 5% for 76 days. Samples taken from different depths of the sludge bed analysed using Fluorescent in situ hybridization (FISH) microscopy techniques revealed a distinctive microbial community structure: bottom granules contained considerably more Accumulibacter (PAOs) compared to top granules that were dominated by Competibacter (GAOs). In a third phase the SRT was controlled by discharging biomass exclusively from the top of the sludge bed. The application of this method increased the P-removal efficiency up to 100% for 88 days at 30 °C. Granules selected near the bottom of the sludge bed increased in volume, density and overall ash content; resulting in significantly higher settling velocities. With the removal of exclusively bottom biomass in phase four, P-removal efficiency decreased to 36% within 3 weeks. This study shows that biomass segregation in aerobic granular sludge systems offers an extra possibility to influence microbial competition in order to obtain a desired population. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Experimental tests on a high-temperature H{sub 2}S removal bench-scale system

    Energy Technology Data Exchange (ETDEWEB)

    Caterina Frau; Alessandra Madeddu; M. Giorgia Cutrufello; Carla Cannas; Giampaolo Mura; Paolo Deiana [Sotacarbo S.p.A., Carbonia (Italy)

    2009-07-01

    The behaviour of different commercial sorbents based on zinc oxides has been investigated as high temperature desulphurizing agents from a syngas from high sulphur content coal. A non-reducing gaseous streams containing 1.5 % H{sub 2}S diluted in N{sub 2} has been used as simulated syngas. Comparative tests have been performed isothermally in a bench-scale fixed-bed reactor. In order to check the modifications induced by desulphurization process and to correlate the physicochemical properties of different samples with their performance as H{sub 2}S sorbents, fresh and sulphurized samples were characterized by X-Ray Diffraction (XRD), N{sub 2} physisorption at -196{sup o}C, CHS Elemental Analysis (EA), Scanning Electron Microscopy (SEM), Temperature-Programmed Desorption/Reduction/Oxidation (TPD/R/O). Sorbents showed a good performance as desulphurizing agents and maintained the H{sub 2}S concentration in the outlet gas below 10 ppm. This paper shows the main results of the experimental tests on the bench-scale reactor. Moreover a simulation model has been developed and validated. Under the operating conditions considered, the rate of ZnO pellet sulphidation was limited by mass-transfer resistance, and kinetic parameters of overall reaction were obtained assuming a shrinking core model. A good agreement was obtained between theoretical and experimental results. 14 refs., 10 figs.

  2. Water Recycling removal using temperature-sensitive hydronen

    Energy Technology Data Exchange (ETDEWEB)

    Rana B. Gupta

    2002-10-30

    The overall objective of this project was to study the proposed Water Recycling/Removal Using Temperature-Sensitive Hydrogels. The main element of this technology is the design of a suitable hydrogel that can perform needed water separation for pulp and paper industry. The specific topics studied are to answer following questions: (a) Can water be removed using hydrogel from large molecules such as lignin? (b) Can the rate of separation be made faster? (c) What are the molecular interactions with hydrogel surface? (d) Can a hydrogel be designed for a high ionic strength and high temperature? Summary of the specific results are given.

  3. Regenerable MgO-based sorbents for high-temperature CO{sub 2} removal from syngas: 1. Sorbent development, evaluation, and reaction modeling

    Energy Technology Data Exchange (ETDEWEB)

    Armin Hassanzadeh; Javad Abbasian [Pyrophase Inc., Chicago, IL (United States)

    2010-06-15

    Highly reactive and mechanically strong low-cost regenerable MgO-based sorbents were prepared by modification of dolomite which involved partial calcinations followed by impregnation with a potassium-based salt. The sorbents are capable of removing CO{sub 2} from gasification-based processes such as Integrated Gasification Combined Cycle (IGCC). The sorbents have high reactivity and good capacity toward CO{sub 2} absorption in the temperature range of 300-450{sup o}C at 20 atm. and can be easily regenerated at 500{sup o}C. The reaction appears to be first order with respect to CO{sub 2} concentration with an activation energy of 44 kJ/mol. The reactivity and the absorption capacity of the sorbents increase with increasing temperature, as long as the partial pressure of CO{sub 2} is above the equilibrium value for sorbent carbonation. The reactivity of the sorbents appears to improve in the presence of steam, which is likely due to the increase in the BET surface area and the porosity of the sorbent. A two-zone expanding grain model, consisting of a high-reactivity outer shell and a low-reactivity inner core is shown to provide an excellent fit to the TGA experimental data on sorbent carbonation at various operating conditions. 31 refs., 16 figs.,3 tabs.

  4. High Temperature Materials Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The High Temperature Materials Lab provides the Navy and industry with affordable high temperature materials for advanced propulsion systems. Asset List: Arc Melter...

  5. Step-wise temperature decreasing cultivates a biofilm with high nitrogen removal rates at 9°C in short-term anammox biofilm tests.

    Science.gov (United States)

    Zekker, Ivar; Rikmann, Ergo; Mandel, Anni; Kroon, Kristel; Seiman, Andrus; Mihkelson, Jana; Tenno, Taavo; Tenno, Toomas

    2016-08-01

    The anaerobic ammonium oxidation (anammox) and nitritation-anammox (deammonification) processes are widely used for N-rich wastewater treatment. When deammonification applications move towards low temperature applications (mainstream wastewater has low temperature), temperature effect has to be studied. In current research, in a deammonification moving bed biofilm reactor a maximum total nitrogen removal rate (TNRR) of 1.5 g N m(-2 )d(-1) (0.6 kg N m(-3 )d(-1)) was achieved. Temperature was gradually lowered by 0.5°C per week, and a similar TNRR was sustained at 15°C during biofilm cultivation. Statistical analysis confirmed that a temperature decrease from 20°C down to 15° did not cause instabilities. Instead, TNRR rose and treatment efficiency remained stable at lower temperatures as well. Quantitative polymerase chain reaction analyses showed an increase in Candidatus Brocadia quantities from 5 × 10(3) to 1 × 10(7) anammox gene copies g(-1) total suspended solids (TSS) despite temperature lowered to 15°C. Fluctuations in TNRR were rather related to changes in influent [Formula: see text] concentration. To study the short-term effect of temperature on the TNRR, a series of batch-scale experiments were performed which showed sufficient TNRRs even at 9-15°C (1.24-3.43 mg N g(-1 )TSS h(-1), respectively) with anammox temperature constants (Q10) ranging 1.3-1.6. Experiments showed that a biofilm adapted to 15°C can perform N-removal most sufficiently at temperatures down to 9°C as compared with biofilm adapted to higher temperature. After biomass was adapted to 15°C, the decrease in TNRR in batch tests at 9°C was lower (15-20%) than that for biomass adapted to 17-18°C.

  6. One-dimensional modeling of radial heat removal during depressurized heatup transients in modular pebble-bed and prismatic high temperature gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Savage, M.G.

    1984-07-01

    A one-dimensional computational model was developed to evaluate the heat removal capabilities of both prismatic-core and pebble-bed modular HTGRs during depressurized heatup transients. A correlation was incorporated to calculate the temperature- and neutron-fluence-dependent thermal conductivity of graphite. The modified Zehner-Schluender model was used to determine the effective thermal conductivity of a pebble bed, accounting for both conduction and radiation. Studies were performed for prismatic-core and pebble-bed modular HTGRs, and the results were compared to analyses performed by GA and GR, respectively. For the particular modular reactor design studied, the prismatic HTGR peak temperature was 2152.2/sup 0/C at 38 hours following the transient initiation, and the pebble-bed peak temperature was 1647.8/sup 0/C at 26 hours. These results compared favorably with those of GA and GE, with only slight differences caused by neglecting axial heat transfer in a one-dimensional radial model. This study found that the magnitude of the initial power density had a greater effect on the temperature excursion than did the initial temperature.

  7. [Effect of temperature on stability of nitrogen removal in the ANAMMOX reactor].

    Science.gov (United States)

    Li, Xiang; Huang, Yong; Zheng, Yu-Hui; Yuan, Yi; Li, Da-Peng; Pan, Yang; Zhang, Chun-Lei

    2012-04-01

    The effect of temperature on stability of nitrogen removal efficiency was investigated in an ANANMMOX reactor by measuring the nitrogen removal rate. The results showed that the nitrogen removal rate changed between 1.51 kg x (m3 x d)(-1) and 1.84 kg x (m3 x d)(-1) when the temperature was between 26 degrees C and 37 degrees C. Compared with gradually degrading temperature (nitrogen removal rate variation of amplitude 9.03%), the ladder degrading temperature was more advantageous on the stability of nitrogen removal efficiency. Nitrogen removal rate variation of amplitude was 4.35%. The nitrogen removal rate dropped quickly, when the temperature was below 20 degrees C. Moreover, a large number of NO2(-) -N accumulated in the ANAMMOX process, when temperature is below 15 degrees C in the reactor. A strong relationship between temperature and nitrogen removal rate was found, when the temperature was below 20 degrees C. Based on the effect of temperature on nitrogen removal rate, the strategy about temperature control was proposed to achieve the fast start-up and high efficiency of nitrogen removal under low temperature for the ANANMMOX reactors.

  8. A study of Zn-Mn based sorbent for the high-temperature removal of H2S from coal-derived gas.

    Science.gov (United States)

    Ko, Tzu-Hsing; Chu, Hsin; Liou, Ya-Jing

    2007-08-17

    Zn-Mn based sorbents supported on SiO2, gamma-Al(2)O(3) and ZrO2, prepared by the incipient wetness impregnation method with calcination at 973 K were investigated for the removal of H(2)S from coal derived gas at the temperature ranges of 773-973 K. Results reveal that the SiO2 and ZrO2 supports exhibit the better performance because better removal efficiency. The addition of manganese effectually improves the vaporization of zinc. In addition, some operating parameters were also considered in order to understand as well as screen the suitable conditions for the development of Zn-Mn based sorbents on the removal of H(2)S. Over 98% sorbent utilization was established for the use of SiO2 at 873 K. On the other hand, within the 5-15 wt% of Zn-Mn oxides, no significant change in the sorbent utilization was observed. Up to 30 wt% the sorbent utilization decreased slightly compared to lower contents, which may be attributed to the deficient dispersion. With increasing the H2 concentration, the sorbent utilization decreases and an adverse result is observed in the case of increasing CO concentration. The relationship between CO and H2 could be explained via the water-gas shift reaction. Moreover, the apparent activation energy and frequency factor as well as the predicted results were studied with a deactivation model. The results of regression fitting reveal the accurate prediction breakthrough behaviors for the removal of H(2)S.

  9. HIGH TEMPERATURE DISPLACEMENT SENSOR

    Institute of Scientific and Technical Information of China (English)

    Xu Longxiang; Zhang Jinyu; Schweitzer Gerhard

    2005-01-01

    A high temperature displacement sensor based on the principle of eddy-current is investigated. A new temperature compensation technique by using eddy-current effect is presented to satisfy the special requirement at high temperature up to 550℃. The experiment shows that the temperature compensation technique leads to good temperature stability for the sensors. The variation of the sensitivity as well as the temperature drift of the sensor with temperature compensation technique is only about 7.4% and 90~350 mV at 550℃ compared with that at room temperature, and that of the sensor without temperature compensation technique is about 31.2% and 2~3 V at 550℃ compared with that at room temperature. A new dynamic calibration method for the eddy-current displacement sensor is presented, which is very easy to be realized especially in high frequency and at high temperatures. The high temperature displacement sensors developed are successfully used at temperature up to 550℃ in a magnetic bearing system for more than 100 h.

  10. High-Temperature Superconductivity

    Science.gov (United States)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  11. Temperature dependent fission product removal efficiency due to pool scrubbing

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Shunsuke, E-mail: suchida@iae.or.jp [Institute of Applied Energy, 1-14-2, Nishi-Shimbashi, Minato-ku, Tokyo 105-0003 (Japan); Itoh, Ayumi; Naitoh, Masanori; Okada, Hidetoshi; Suzuki, Hiroyuki [Institute of Applied Energy, 1-14-2, Nishi-Shimbashi, Minato-ku, Tokyo 105-0003 (Japan); Hanamoto, Yukio [KAKEN, Inc., 1044, Hori-machi, Mito 310-0903 (Japan); Osakabe, Masahiro [Tokyo University of Marine Science & Technology, Koutou-ku, Tokyo 135-8533 (Japan); Fujikawa, Masahiro [Japan Broadcasting Corporation, 2-2-1, Jinnan, Shibuya-ku, Tokyo 150-8001 (Japan)

    2016-03-15

    Highlights: • Pool temperature effects on the FP removal were not clearly concluded in the previous publications. • It was confirmed that the removal efficiency decreased with temperature around the boiling point. • A modified empirical formula for FP removal was proposed as a function of sub-cooling temperature. • DF could be predicted with an accuracy within a factor of 2 with the proposed formula. - Abstract: The wet-well of boiling water reactors plays important roles not only to suppress the pressure in the primary containment vessel due to steam scrubbing effects during severe accidents but also to mitigate release of radioactive fission products (FP), aerosols and particulates, into the environment. The effects of steam scrubbing in the wet-well on FP removal have been well studied and reported by changing major parameters determining the removal efficiencies, e.g., aerosol diameters, submergence (depth of scrubbing nozzles) and steam/non-condensable gas volume fraction. Unfortunately, the effects of pool temperature on the FP removal were not clearly concluded in the previous publications, though it would be easily expected that boiling in the pool resulted in reduced aerosol removal efficiency. In order to determine the temperature effects on FP removal efficiency, amounts of cesium in aerosols released from scrubbing pool were measured by changing pool temperature in mini and medium scale scrubbing experiments, and then, it was confirmed that the removal efficiency clearly decreased with temperature around the boiling point. Then, a modified empirical formula to express the FP removal around the boiling point temperature was proposed as a function of sub-cooling temperature by applying the effective steam volume fraction, which was designated as the volume ratio of condensed steam in the pool versus the sum of input steam and non-condensable gas. By comparing the measured removal efficiency with the calculated, it was validated that the

  12. High removal rate laser-based coating removal system

    Science.gov (United States)

    Matthews, Dennis L.; Celliers, Peter M.; Hackel, Lloyd; Da Silva, Luiz B.; Dane, C. Brent; Mrowka, Stanley

    1999-11-16

    A compact laser system that removes surface coatings (such as paint, dirt, etc.) at a removal rate as high as 1000 ft.sup.2 /hr or more without damaging the surface. A high repetition rate laser with multiple amplification passes propagating through at least one optical amplifier is used, along with a delivery system consisting of a telescoping and articulating tube which also contains an evacuation system for simultaneously sweeping up the debris produced in the process. The amplified beam can be converted to an output beam by passively switching the polarization of at least one amplified beam. The system also has a personal safety system which protects against accidental exposures.

  13. 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...... internal resistance of the cell, and long-term stable, it is critical to develop electrode materials that are optimal for steam electrolysis. In this article electrolysis cells for electrolysis of water or steam at temperatures above 200 degrees C for production of H-2 are reviewed. High temperature...... 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...

  14. High Temperature Sorbents for Oxygen

    Science.gov (United States)

    Sharma, Pramod K. (Inventor)

    1996-01-01

    A sorbent capable of removing trace amounts of oxygen (ppt) from a gas stream at a high temperature above 200 C is introduced. The sorbent comprises a porous alumina silicate support such as zeolite containing from 1 to 10 percent by weight of ion exchanged transition metal such as copper or cobalt ions and 0.05 to 1.0 percent by weight of an activator selected from a platinum group metal such as platinum. The activation temperature, oxygen sorption and reducibility are all improved by the presence of the platinum activator.

  15. 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.

  16. High Temperature Capacitor Development

    Energy Technology Data Exchange (ETDEWEB)

    John Kosek

    2009-06-30

    The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions down-hole such as temperature, pressure, heading, etc. Commercial off-the-shelf electronics are not specified to meet these operating conditions. This is due to problems associated with all aspects of the electronics including the resistors and capacitors. With respect to capacitors, increasing temperature often significantly changes capacitance because of the strong temperature dependence of the dielectric constant. Higher temperatures also affect the equivalent series resistance (ESR). High-temperature capacitors usually have low capacitance values because of these dielectric effects and because packages are kept small to prevent mechanical breakage caused by thermal stresses. Electrolytic capacitors do not operate at temperatures above 150oC due to dielectric breakdown. The development of high-temperature capacitors to be used in a high-pressure high-temperature (HPHT) drilling environment was investigated. These capacitors were based on a previously developed high-voltage hybridized capacitor developed at Giner, Inc. in conjunction with a

  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. Au Capping Agent Removal Using Plasma at Mild Temperature

    Directory of Open Access Journals (Sweden)

    Indra Puspitasari

    2016-11-01

    Full Text Available To prevent sintering, ozone treatment at mild temperature is used to remove the capping agent from supported Au nanoparticles. The Au nanoparticles are first synthesized as a colloidal solution and then supported on alumina. Fourier Transform Infra Red (FTIR shows the capping agent is removed completely. Transmission Electron Microscopy (TEM and catalytic test reactions show the Au does not sinter significantly upon low temperature ozone treatment.

  19. High Temperature ESP Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Jack Booker; Brindesh Dhruva

    2011-06-20

    The objective of the High Temperature ESP Monitoring project was to develop a downhole monitoring system to be used in wells with bottom hole well temperatures up to 300°C for measuring motor temperature, formation pressure, and formation temperature. These measurements are used to monitor the health of the ESP motor, to track the downhole operating conditions, and to optimize the pump operation. A 220 ºC based High Temperature ESP Monitoring system was commercially released for sale with Schlumberger ESP motors April of 2011 and a 250 ºC system with will be commercially released at the end of Q2 2011. The measurement system is now fully qualified, except for the sensor, at 300 °C.

  20. 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...

  1. Efficient removal of H2S at high temperature using the ionic liquid solutions of [C4mim]3PMo12O40-An organic polyoxometalate.

    Science.gov (United States)

    Ma, Yunqian; Liu, Xinpeng; Wang, Rui

    2017-06-05

    An innovative approach to H2S capture and sulfur recovery via liquid redox at high temperature has been developed using [C4mim]3PMo12O40 at temperatures ranging from 80 to 180°C, which is superior to the conventional water-based system with an upper limit of working temperature normally below 60°C. The ionic liquids used as solvents include [C4mim]Cl, [C4mim]BF4, [C4mim]PF6 and [C4mim]NTf2. Microscopic observation and turbidity measurement were used to investigate the dissolution of [C4mim]3PMo12O40 in the ionic liquids. Stabilization energy between H2S and the anion of ionic liquid as well as H2O was calculated to illustrate the interaction between H2S and the solvents. The cavity theory can be adopted to illustrate the mechanism for H2S absorption: the Cl(-) ion with small radius can be incorporated into the cavities of [C4mim]3PMo12O40, and interact with H2S strongly. The underlying mechanism for sulfur formation is the redox reaction between H2S and PMo12O40(3-). H2S can be oxidized to elemental sulfur and Mo(6+) is partly reduced during absorption, according to UV-vis and FTIR spectra. The [C4mim]3PMo12O40-[C4mim]Cl after reaction can be readily regenerated by air and thus enabling its efficient and repeatitive use. The absorbent of [C4mim]3PMo12O40-ionic liquid system provides a new approach for wet oxidation desulfurization at high temperature. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. High Temperature Piezoelectric Drill

    Science.gov (United States)

    Bao, Xiaoqi; Scott, James; Boudreau, Kate; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom; Zhang, Shujun

    2009-01-01

    The current NASA Decadal mission planning effort has identified Venus as a significant scientific target for a surface in-situ sampling/analyzing mission. The Venus environment represents several extremes including high temperature (460 deg C), high pressure (9 MPa), and potentially corrosive (condensed sulfuric acid droplets that adhere to surfaces during entry) environments. This technology challenge requires new rock sampling tools for these extreme conditions. Piezoelectric materials can potentially operate over a wide temperature range. Single crystals, like LiNbO3, have a Curie temperature that is higher than 1000 deg C and the piezoelectric ceramics Bismuth Titanate higher than 600 deg C. A study of the feasibility of producing piezoelectric drills that can operate in the temperature range up to 500 deg C was conducted. The study includes the high temperature properties investigations of engineering materials and piezoelectric ceramics with different formulas and doping. The drilling performances of a prototype Ultrasonic/Sonic Drill/Corer (USDC) using high temperate piezoelectric ceramics and single crystal were tested at temperature up to 500 deg C. The detailed results of our study and a discussion of the future work on performance improvements are presented in this paper.

  3. Strangeness at high temperatures

    CERN Document Server

    Schmidt, Christian

    2013-01-01

    We use up to fourth order cumulants of net strangeness fluctuations and their correlations with net baryon number fluctuations to extract information on the strange meson and baryon contribution to the low temperature hadron resonance gas, the dissolution of strange hadronic states in the crossover region of the QCD transition and the quasi-particle nature of strange quark contributions to the high temperature quark-gluon plasma phase.

  4. 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

  5. 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

  6. Desulfurization at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Panula-Nikkilae, E.; Kurkela, E.; Mojtahedi, W.

    1987-01-01

    Two high-temperature desulfurization methods, furnace injection and gasification-desulfurization are presented. In furnace injection, the efficiency of desulfurization is 50-60%, but this method is applied in energy production plants, where flue gas desulfurization cannot be used. Ca-based sorbents are used as desulfurization material. Factors affecting desulfurization and the effect of injection on the boiler and ash handling are discussed. In energy production based on gasification, very low sulfur emissions can be achieved by conventional low-temperature cleanup. However, high-temperature gas cleaning leads to higher efficiency and can be applied to smaller size classes. Ca-, Fe-, or Zn-based sorbents or mixed metals can be used for desulfurization. Most of the methods under development are based on the use of regenerative sorbents in a cleanup reactor located outside the gasifier. So far, only calcium compounds have been used for desulfurization inside the gasifier.

  7. Ethylene Removal at Low Temperatures under Biofilter and Batch Conditions

    Science.gov (United States)

    Elsgaard, Lars

    2000-01-01

    Removal of the plant hormone ethylene (C2H4) is often required by horticultural storage facilities, which are operated at temperatures below 10°C. The aim of this study was to demonstrate an efficient, biological C2H4 removal under such low-temperature conditions. Peat-soil, acclimated to degradation of C2H4, was packed in a biofilter (687 cm3) and subjected to an airflow (∼73 ml min−1) with 2 ppm (μl liter−1) C2H4. The C2H4 removal efficiencies achieved at 20, 10, and 5°C, respectively, were 99.0, 98.8, and 98.4%. This corresponded to C2H4 levels of 0.022 to 0.032 ppm in the biofilter outlet air. At 2°C, the average C2H4 removal efficiency dropped to 83%. The detailed temperature response of C2H4 removal was tested under batch conditions by incubation of 1-g soil samples in a temperature gradient ranging from 0 to 29°C with increments of 1°C. The C2H4 removal rate was highest at 26°C (0.85 μg of C2H4 g [dry weight]−1 h−1), but remained at levels of 0.14 to 0.28 μg of C2H4 g (dry weight)−1 h−1 at 0 to 10°C. At 35 to 40°C, the C2H4 removal rate was negligible (0.02 to 0.06 μg of C2H4 g [dry weight]−1 h−1). The Q10 (i.e., the ratio of rates 10°C apart) for C2H4 removal was 1.9 for the interval 0 to 10°C. In conclusion, the present results demonstrated microbial C2H4 removal, which proceeded at 0 to 2°C and produced a moderately psychrophilic temperature response. PMID:10966403

  8. Air pollution removal and temperature reduction by Gainesville's urban forest

    Science.gov (United States)

    Francisco Escobedo; Jennifer A. Seitz; Wayne Zipperer

    2009-01-01

    Poor air quality is a common problem in many urban areas. It can lead to human health problems and reduced visibility, and it can impair the health of plants and wildlife. The urban forest can help improve air quality by removing pollutants and by reducing air temperature through shading and transpiration. Trees also emit volatile...

  9. High temperature superconducting compounds

    Science.gov (United States)

    Goldman, Allen M.

    1992-11-01

    The major accomplishment of this grant has been to develop techniques for the in situ preparation of high-Tc superconducting films involving the use of ozone-assisted molecular beam epitaxy. The techniques are generalizable to the growth of trilayer and multilayer structures. Films of both the DyBa2Cu3O(7-x) and YBa2Cu3O(7-x) compounds as well as the La(2-x)Sr(x)CuO4 compound have been grown on the usual substrates, SrTiO3, YSZ, MgO, and LaAlO3, as well as on Si substrates without any buffer layer. A bolometer has been fabricated on a thermally isolated SiN substrate coated with YSZ, an effort carried out in collaboration with Honeywell Inc. The deposition process facilitates the fabrication of very thin and transparent films creating new opportunities for the study of superconductor-insulator transitions and the investigation of photo-doping with carriers of high temperature superconductors. In addition to a thin film technology, a patterning technology has been developed. Trilayer structures have been developed for FET devices and tunneling junctions. Other work includes the measurement of the magnetic properties of bulk single crystal high temperature superconductors, and in collaboration with Argonne National Laboratory, measurement of electric transport properties of T1-based high-Tc films.

  10. High Temperature Piezoelectric Drill

    Science.gov (United States)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom

    2012-01-01

    Venus is one of the planets in the solar systems that are considered for potential future exploration missions. It has extreme environment where the average temperature is 460 deg C and its ambient pressure is about 90 atm. Since the existing actuation technology cannot maintain functionality under the harsh conditions of Venus, it is a challenge to perform sampling and other tasks that require the use of moving parts. Specifically, the currently available electromagnetic actuators are limited in their ability to produce sufficiently high stroke, torque, or force. In contrast, advances in developing electro-mechanical materials (such as piezoelectric and electrostrictive) have enabled potential actuation capabilities that can be used to support such missions. Taking advantage of these materials, we developed a piezoelectric actuated drill that operates at the temperature range up to 500 deg C and the mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) configuration. The detailed results of our study are presented in this paper

  11. 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 ...

  12. Nitrogen Removal by a Nitritation-Anammox Bioreactor at Low Temperature

    NARCIS (Netherlands)

    Hu, Z.; Lotti, T.; De Kreuk, B.M.; Kleerebezem, R.; Van Loosdrecht, M.; Kruit, J.; Jetten, M.S.M.; Kartala, B.

    2013-01-01

    Currently, nitritation-anammox (anaerobic ammonium oxidation) bioreactors are designed to treat wastewaters with high ammonium concentrations at mesophilic temperatures (25 to 40°C). The implementation of this technology at ambient temperatures for nitrogen removal from municipal wastewater followin

  13. 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.

  14. Simultaneous high-temperature removal of alkali and particulates in a pressurized gasification system. Final technical progress report, April 1981-July 1983

    Energy Technology Data Exchange (ETDEWEB)

    Mulik, P.R.; Alvin, M.A.; Bachovchin, D.M.

    1983-09-01

    This program is directed at performing experimental and analytical investigations, deriving system designs, and estimating costs to ascertain the feasibility of using aluminosilicate-based getters for controlling alkali in pressurized gasification systems. Its overall objective is to develop a plan for evaluating a scaled-up version of the gettering process as a unit operation or as an integral part of a particulate removal device. This report describes work completed on the four technical program tasks: Thermodynamic projections; Getter Selection and Qualification; System Performance Projections; and Program Definition for Concept Scale-up during the 27-month contract performance period. Work completed on the thermodynamic projections includes a data base update, development of alkali phase diagrams, and system performance projections. Getter selection and qualification efforts involved over 70 kinetic studies in which a leading candidate getter - emathlite - was selected and characterized. System performance projections identified a packed-bed configuration containing relatively large getter pellets as the preferred contacting device for a full-scale unit. For emathlite, we concluded that full-scale unit bed heights of 2 m or less would be required if we assume annual replacement on the basis of bed saturation capacity. Concept scale-up work involved defining the hardware and test program requirements for further development of the emathlite packed-bed system. 56 references, 80 figures, 74 tables.

  15. 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

  16. High temperature interface superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gozar, A., E-mail: adrian.gozar@yale.edu [Yale University, New Haven, CT 06511 (United States); Bozovic, I. [Yale University, New Haven, CT 06511 (United States); Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2016-02-15

    Highlight: • This review article covers the topic of high temperature interface superconductivity. • New materials and techniques used for achieving interface superconductivity are discussed. • We emphasize the role played by the differences in structure and electronic properties at the interface with respect to the bulk of the constituents. - Abstract: High-T{sub c} superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-T{sub c} Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both ‘passive’ hetero-structures as well as surface-induced effects by external gating are discussed. We conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.

  17. High temperature interfacial superconductivity

    Science.gov (United States)

    Bozovic, Ivan [Mount Sinai, NY; Logvenov, Gennady [Port Jefferson Station, NY; Gozar, Adrian Mihai [Port Jefferson, NY

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  18. 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.

  19. Influence of carbon source and temperature on the denitrifying phosphorus removal process

    Institute of Scientific and Technical Information of China (English)

    WANG Yayi; WANG Shuying; PENG Yongzhen; Zhu Guibing; LING Yunfang

    2007-01-01

    To supply the valuable operating parameters for the popular usage of the new denitrifying phosphors removal process,it is essential to study the dominant biochemical reactions and the characteristics of denitriflying phosphorus removing bacteria(DPB).Thus,parallel batch experiments using DPB sludge were carried out to assess the effect of substrates(sewage,HAc,and endogenous carbon source)on denitriflying dephosphorus removal efficiency in this study.The results showed that the initial specific phosphorus release rate increased with the high concentration of the short-chain volatile fatty acids ratio in the influent,and sufficient phosphorus was released by DPB.This improved the subsequent denitrification and phosphorus uptake efficiency.The specific endogenous denitrification mainly relies on the internal carbon source(PHB)stored by poly-P bacteria.Denitrifying phosphorus removing bacteria were very hungry when the internal PHB was consumed.Consequently,the specific endogenous denitrification rate was low and the phosphorus uptake did not happen.On the other hand,in the experiment,the denitrifying phosphorus removal performance under two temperature conditions(8-10℃ and 25-26℃)was also investigated and analyzed.It was found that the lower temperature decreased the specific phosphorus release and uptake rate,but did not inhibit the denitrifying phosphorus removal completely.Therefore,the negative influence of the low temperature on the overall phosphorus removal was not significant.

  20. 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

  1. Ultra-High Temperature Gratings

    Institute of Scientific and Technical Information of China (English)

    John Canning; Somnath Bandyopadhyay; Michael Stevenson; Kevin Cook

    2008-01-01

    Regenerated gratings seeded by type-Ⅰ gratings are shown to withstand temperatures beyond 1000 ℃. The method of regeneration offers a new approach to increasing temperature resistance of stable fibre Bragg and other gratings. These ultra-high temperature (UHT) gratings extend the applicability of silicate based components to high temperature applications such as monitoring of smelters and vehicle and aircraft engines to high power fibre lasers.

  2. High temperature nanoplasmonics

    Science.gov (United States)

    Alabastri, Alessandro; Toma, Andrea; Malerba, Mario; De Angelis, Francesco; Proietti Zaccaria, Remo

    2016-09-01

    Metallic nanostructures can be utilized as heat nano-sources which can find application in different areas such as photocatalysis, nanochemistry or sensor devices. Here we show how the optical response of plasmonic structures is affected by the increase of temperature. In particular we apply a temperature dependent dielectric function model to different nanoparticles finding that the optical responses are strongly dependent on shape and aspect-ratio. The idea is that when metallic structures interact with an electromagnetic field they heat up due to Joule effect. The corresponding temperature increase modifies the optical response of the particle and thus the heating process. The key finding is that, depending on the structures geometry, absorption efficiency can either increase or decrease with temperature. Since absorption relates to thermal energy dissipation and thus to temperature increase, the mechanism leads to positive or negative loops. Consequently, not only an error would be made by neglecting temperature but it would be not even possible to know, a priori, if the error is towards higher or lower values.

  3. 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.

  4. 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 dev

  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 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...

  7. Preparation and characterization of manganese-based regenerable sorbents for high temperature H2S removal%锰系可再生高温脱硫剂的制备及其性能测试

    Institute of Scientific and Technical Information of China (English)

    郭婧; 王菊; 梁斌

    2013-01-01

    High temperature desulfurization of coal gas is a key step of integrated gasification combined cycle (IGCC) and direct reduced iron (DRI) production,which directly influences the global thermal efficiency.Manganese-based sorbents with different Mn-contents were prepared by coprecipitation method for the high temperature sulfur removal.Precipitation was conducted by neutralizing the mixed solution of manganese nitrate and alumina nitrate with 10% NH3 · H2O at 50℃.And the pH value in precipitation was kept around 9.The sorbents prepared were tested in a fixed-bed reactor by sulfidation-regeneration cycles.XRD,SEM and BET were used to characterise the structural change of the sorbents during the cycles.The sorbents made by coprecipitation method have good Mn/Al dispersibility.The desulfurization reaction at 850℃ was rapid and quantitative.The sulfur capacity increased linearly with increase of manganese content in the sorbents.The S/Mn atomic ratio was within 0.90-0.95 after sulfurization.The sulfur capacity was not influenced by space velocity and H2S content in feed gas.The sulfided sorbent was regenerated using diluted air containing 3% O2 at 850℃.The sulfur capacity was stable after many cycles.So,the sorbents could be used as regenerable sulfur sorbents for high temperature H2S removal.%煤气的高温脱硫净化是IGCC和DRI生产的瓶颈,直接影响整个过程的热效率.在50℃、pH值约为9的条件下采用硝酸锰、硝酸铝混合溶液与氨水进行共沉淀,制备了锰含量不同的脱硫剂,在固定床反应器中考察了脱硫剂的硫化及再生性能,并利用XRD、SEM、BET等手段表征了脱硫剂在硫化/再生过程中的物相和结构变化.共沉淀法制备的脱硫剂Mn/Al分散性好,在850℃高温下进行脱硫反应可以定量快速进行.脱硫硫容与脱硫剂锰含量呈正比,Mn-S/Mn-O交换原子比在0.90~0.95之间,改变空速和进口H2S含量并不改变脱硫硫容.采用O2浓度为3

  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. Alternatives Generation and Analysis for Heat Removal from High Level Waste Tanks

    Energy Technology Data Exchange (ETDEWEB)

    WILLIS, W.L.

    2000-06-15

    This document addresses the preferred combination of design and operational configurations to provide heat removal from high-level waste tanks during Phase 1 waste feed delivery to prevent the waste temperature from exceeding tank safety requirement limits. An interim decision for the preferred method to remove the heat from the high-level waste tanks during waste feed delivery operations is presented herein.

  10. Use of fugacity model to analyze temperature-dependent removal of micro-contaminants in sewage treatment plants.

    Science.gov (United States)

    Thompson, Kelly; Zhang, Jianying; Zhang, Chunlong

    2011-08-01

    Effluents from sewage treatment plants (STPs) are known to contain residual micro-contaminants including endocrine disrupting chemicals (EDCs) despite the utilization of various removal processes. Temperature alters the efficacy of removal processes; however, experimental measurements of EDC removal at various temperatures are limited. Extrapolation of EDC behavior over a wide temperature range is possible using available physicochemical property data followed by the correction of temperature dependency. A level II fugacity-based STP model was employed by inputting parameters obtained from the literature and estimated by the US EPA's Estimations Programs Interface (EPI) including EPI's BIOWIN for temperature-dependent biodegradation half-lives. EDC removals in a three-stage activated sludge system were modeled under various temperatures and hydraulic retention times (HRTs) for representative compounds of various properties. Sensitivity analysis indicates that temperature plays a significant role in the model outcomes. Increasing temperature considerably enhances the removal of β-estradiol, ethinyestradiol, bisphenol, phenol, and tetrachloroethylene, but not testosterone with the highest biodegradation rate. The shortcomings of BIOWIN were mitigated by the correction of highly temperature-dependent biodegradation rates using the Arrhenius equation. The model predicts well the effects of operating temperature and HRTs on the removal via volatilization, adsorption, and biodegradation. The model also reveals that an impractically long HRT is needed to achieve a high EDC removal. The STP model along with temperature corrections is able to provide some useful insight into the different patterns of STP performance, and useful operational considerations relevant to EDC removal at winter low temperatures. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Removal of HCl, NH3, Organic Sulphur and Tar Component from High Temperature Coal Gas%高温煤气中NH3、有机硫、HCl及焦油蒸气的同时脱除

    Institute of Scientific and Technical Information of China (English)

    豆斌林; 鲁军; 申文琴; 沙兴中; 高晋生

    2001-01-01

    The experiments were designed to remove HCl, NH3, organic sulphur and coal tar component from high temperature coal gas, first separately and individually and then in combination and simultaneously by using a fixed-bed reactor. 1-methylnaphthalene was used as a tar model compound, and CS2 as organic sulphur model compound. The tests show that Ni-3 catalyst is an effective catalyst for NH3 and 1-methylnaphthalene decomposition, Ni-3 catalyst sulphurized is also effective for CS2 conversion, and the self-prepared ECl sorbent displays the highest adsorption capacity for HCl vapor. The simultaneous removal of HCl, NH3, organic sulphur and tar component was studied at the reaction temperature range from 300°C to 550°C. The maximum removal efficiencies are 100%, 100%, 79%, 88% for HCl, 1-methylnaphthalene, NH3, and CS2 respectively.%在固定床反应器中对高温煤气中NH3、有机硫化物、HCl及焦油蒸气4种污染物进行了单独和同时脱除的研究,其中选择CS2和1-甲基萘分别作为高温煤气中有机硫化物和焦油蒸气的模型化合物。研究得出,高温煤气中氨催化分解和1-甲基萘催化裂解的最佳催化剂同为Ni-3催化剂,CS2转化的最佳催化剂为硫化态的Ni-3催化剂,最好的脱氯剂为ECl。在NH3、CS2、HCl及1-甲基萘4种污染物同时存在时,将上述脱除剂组合在一起进行同时脱除实验表明:ECl脱氯剂对HCl的转化率和Ni-3催化剂对1-甲基萘的转化率均为100%,氧化态的Ni-3催化剂对NH3的转化率和硫化态的Ni-3催化剂对CS2的转化率则随温度的升高而增加,在300~550°C之间,氨的最大转化率为79%,CS2的最大转化率为88%。

  12. Removal of trichlorobenzene using 'oxygen-enriched' highly active absorbent.

    Science.gov (United States)

    Zhao, Yi; He, Peng; Zhang, Yu-Hai; Ma, Shuangchen

    2011-01-01

    Fly ash, industry lime and an additive, Ca(ClO2)2 (C) were used to prepare the 'oxygen-enriched' highly active absorbent (HAA). The influencing factors for removal of 1,2,4-trichlorobenzene (TCB) using this absorbent such as reaction temperature, simulating gas flow rate, oxygen content, etc. were studied in a self-designed reactor. The optimum experimental conditions of removing 1,2,4-TCB are that the content of an oxidizing additive in the absorbent is 3% (wt), simulating gas flow rate is 100 mL/min, reaction temperature is 250 degrees C, and the content of oxygen in simulating gas is 6%. The maximum removal efficiency is 81.71% in 10 mins. The absorption capacity of the absorbent is 0.000111 g/g. The reaction products were determined by gas chromatograph/mass spectrometer (GC/ MS), 2,6-Bis-[1,1-Dimethylethyl]-4-methyl-Phenol is considered to be the major intermediate product. The reaction route was revealed.

  13. The influence of temperature and salt on metal and sediment removal in stormwater biofilters.

    Science.gov (United States)

    Søberg, Laila C; Viklander, Maria; Blecken, Godecke-Tobias

    2014-01-01

    Stormwater biofilters are used to treat stormwater runoff. In countries with cold winter climates, biofilters are subject to low temperatures which, in some cases, are combined with potentially high salt concentrations from road de-icing, potentially affecting the biofilter's performance. Since stormwater biofilters have been developed without consideration of their critical winter use, a laboratory study was carried out to evaluate the performance of stormwater biofilters subjected to low and high temperatures, with and without salt. Both factors and their interaction had a significant effect on outflow concentrations and removal percentages. Salt had a negative impact on outflow concentrations, causing lower removal percentages for (especially dissolved) metals, this impact being most pronounced for Cu and Pb. The unrealistic combination of salt with high temperature seemed to further amplify the negative impacts of salt despite the fact that temperature alone did not cause significant differences in outflow concentrations and removal percentages. Still, biofilters showed the ability to treat stormwater efficiently under the simulated winter conditions; outflow concentrations for total metals as a minimum met the class 4 threshold value defined in the Swedish freshwater quality guidelines, while inflow concentrations clearly exceeded the threshold value for class 5. The relatively coarse filter material (which is recommended to facilitate infiltration during winter) did not seem to exacerbate biofilter performance.

  14. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...

  15. High Temperature Bell Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The National Research Council (NRC) has identified the need for motors and actuators that can operate in extreme high and low temperature environments as a technical...

  16. 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...

  17. Low temperature removal of surface oxides and hydrocarbons from Ge(100) using atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M., E-mail: m.walker@warwick.ac.uk; Tedder, M.S.; Palmer, J.D.; Mudd, J.J.; McConville, C.F.

    2016-08-30

    Highlights: • Preparation of a clean, well-ordered Ge(100) surface with atomic hydrogen. • Surface oxide layers removed by AHC at room temperature, but not hydrocarbons. • Increasing surface temperature during AHC dramatically improves efficiency. • AHC with the surface heated to 250 °C led to a near complete removal of contaminants. • (2 × 1) LEED pattern from IBA and AHC indicates asymmetric dimer reconstruction. - Abstract: Germanium is a group IV semiconductor with many current and potential applications in the modern semiconductor industry. Key to expanding the use of Ge is a reliable method for the removal of surface contamination, including oxides which are naturally formed during the exposure of Ge thin films to atmospheric conditions. A process for achieving this task at lower temperatures would be highly advantageous, where the underlying device architecture will not diffuse through the Ge film while also avoiding electronic damage induced by ion irradiation. Atomic hydrogen cleaning (AHC) offers a low-temperature, damage-free alternative to the common ion bombardment and annealing (IBA) technique which is widely employed. In this work, we demonstrate with X-ray photoelectron spectroscopy (XPS) that the AHC method is effective in removing surface oxides and hydrocarbons, yielding an almost completely clean surface when the AHC is conducted at a temperature of 250 °C. We compare the post-AHC cleanliness and (2 × 1) low energy electron diffraction (LEED) pattern to that obtained via IBA, where the sample is annealed at 600 °C. We also demonstrate that the combination of a sample temperature of 250 °C and atomic H dosing is required to clean the surface. Lower temperatures prove less effective in removal of the oxide layer and hydrocarbons, whilst annealing in ultra-high vacuum conditions only removes weakly bound hydrocarbons. Finally, we examine the subsequent H-termination of an IBA-cleaned sample using XPS, LEED and ultraviolet

  18. High Energy Laser for Space Debris Removal

    Energy Technology Data Exchange (ETDEWEB)

    Barty, C; Caird, J; Erlandson, A; Beach, R; Rubenchik, A

    2009-10-30

    The National Ignition Facility (NIF) and Photon Science Directorate at Lawrence Livermore National Laboratory (LLNL) has substantial relevant experience in the construction of high energy lasers, and more recently in the development of advanced high average power solid state lasers. We are currently developing new concepts for advanced solid state laser drivers for the Laser Inertial Fusion Energy (LIFE) application, and other high average power laser applications that could become central technologies for use in space debris removal. The debris population most readily addressed by our laser technology is that of 0.1-10 cm sized debris in low earth orbit (LEO). In this application, a ground based laser system would engage an orbiting target and slow it down by ablating material from its surface which leads to reentry into the atmosphere, as proposed by NASA's ORION Project. The ORION concept of operations (CONOPS) is also described in general terms by Phipps. Key aspects of this approach include the need for high irradiance on target, 10{sup 8} to 10{sup 9} W/cm{sup 2}, which favors short (i.e., picoseconds to nanoseconds) laser pulse durations and high energy per pulse ({approx} > 10 kJ). Due to the target's orbital velocity, the potential duration of engagement is only of order 100 seconds, so a high pulse repetition rate is also essential. The laser technology needed for this application did not exist when ORION was first proposed, but today, a unique combination of emerging technologies could create a path to enable deployment in the near future. Our concepts for the laser system architecture are an extension of what was developed for the National Ignition Facility (NIF), combined with high repetition rate laser technology developed for Inertial Fusion Energy (IFE), and heat capacity laser technology developed for military applications. The 'front-end' seed pulse generator would be fiber-optics based, and would generate a temporally, and

  19. Low temperature removal of surface oxides and hydrocarbons from Ge(100) using atomic hydrogen

    Science.gov (United States)

    Walker, M.; Tedder, M. S.; Palmer, J. D.; Mudd, J. J.; McConville, C. F.

    2016-08-01

    Germanium is a group IV semiconductor with many current and potential applications in the modern semiconductor industry. Key to expanding the use of Ge is a reliable method for the removal of surface contamination, including oxides which are naturally formed during the exposure of Ge thin films to atmospheric conditions. A process for achieving this task at lower temperatures would be highly advantageous, where the underlying device architecture will not diffuse through the Ge film while also avoiding electronic damage induced by ion irradiation. Atomic hydrogen cleaning (AHC) offers a low-temperature, damage-free alternative to the common ion bombardment and annealing (IBA) technique which is widely employed. In this work, we demonstrate with X-ray photoelectron spectroscopy (XPS) that the AHC method is effective in removing surface oxides and hydrocarbons, yielding an almost completely clean surface when the AHC is conducted at a temperature of 250 °C. We compare the post-AHC cleanliness and (2 × 1) low energy electron diffraction (LEED) pattern to that obtained via IBA, where the sample is annealed at 600 °C. We also demonstrate that the combination of a sample temperature of 250 °C and atomic H dosing is required to clean the surface. Lower temperatures prove less effective in removal of the oxide layer and hydrocarbons, whilst annealing in ultra-high vacuum conditions only removes weakly bound hydrocarbons. Finally, we examine the subsequent H-termination of an IBA-cleaned sample using XPS, LEED and ultraviolet photoelectron spectroscopy (UPS) in order to examine changes in the work function of Ge(100) upon hydrogenation.

  20. Gallium phosphide high temperature diodes

    Science.gov (United States)

    Chaffin, R. J.; Dawson, L. R.

    1981-01-01

    High temperature (300 C) diodes for geothermal and other energy applications were developed. A comparison of reverse leakage currents of Si, GaAs, and GaP was made. Diodes made from GaP should be usable to 500 C. A Liquid Phase Epitaxy (LPE) process for producing high quality, grown junction GaP diodes is described. This process uses low vapor pressure Mg as a dopant which allows multiple boat growth in the same LPE run. These LPE wafers were cut into die and metallized to make the diodes. These diodes produce leakage currents below ten to the -9th power A/sq cm at 400 C while exhibiting good high temperature rectification characteristics. High temperature life test data is presented which shows exceptional stability of the V-I characteristics.

  1. RPC operation at high temperature

    CERN Document Server

    Aielli, G; Cardarelli, R; Di Ciaccio, A; Di Stante, L; Liberti, B; Paoloni, A; Pastori, E; Santonico, R

    2003-01-01

    The resistive electrodes of RPCs utilised in several current experiments (ATLAS, CMS, ALICE, BABAR and ARGO) are made of phenolic /melaminic polymers, with room temperature resistivities ranging from 10**1**0 Omega cm, for high rate operation in avalanche mode, to 5 multiplied by 10**1**1 Omega cm, for streamer mode operation at low rate. The resistivity has however a strong temperature dependence, decreasing exponentially with increasing temperature. We have tested several RPCs with different electrode resistivities in avalanche as well as in streamer mode operation. The behaviours of the operating current and of the counting rate have been studied at different temperatures. Long-term operation has also been studied at T = 45 degree C and 35 degree C, respectively, for high and low resistivity electrodes RPCs.

  2. Temperature optimization of high con

    Directory of Open Access Journals (Sweden)

    M. Sabry

    2016-06-01

    Full Text Available Active cooling is essential for solar cells operating under high optical concentration ratios. A system comprises four solar cells that are in thermal contact on top of a copper tube is proposed. Water is flowing inside the tube in order to reduce solar cells temperature for increasing their performance. Computational Fluid Dynamics (CFD simulation of such system has been performed in order to investigate the effect of water flow rate, tube internal diameter, and convective heat transfer coefficient on the temperature of the solar cells. It is found that increasing convective heat transfer coefficient has a significant effect on reducing solar cells temperatures operating at low flow rates and high optical concentration ratios. Also, a further increase of water flow rate has no effect on reducing cells temperatures.

  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. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...... temperature allows for utilization of the excess heat for fuel processing. Moreover, it provides an excellent CO tolerance of several percent, and the system needs no purification of hydrogen from a reformer. Continuous service for over 6 months at 150°C has been demonstrated....

  5. Interface high-temperature superconductivity

    Science.gov (United States)

    Wang, Lili; Ma, Xucun; Xue, Qi-Kun

    2016-12-01

    Cuprate high-temperature superconductors consist of two quasi-two-dimensional (2D) substructures: CuO2 superconducting layers and charge reservoir layers. The superconductivity is realized by charge transfer from the charge reservoir layers into the superconducting layers without chemical dopants and defects being introduced into the latter, similar to modulation-doping in the semiconductor superlattices of AlGaAs/GaAs. Inspired by this scheme, we have been searching for high-temperature superconductivity in ultra-thin films of superconductors epitaxially grown on semiconductor/oxide substrates since 2008. We have observed interface-enhanced superconductivity in both conventional and unconventional superconducting films, including single atomic layer films of Pb and In on Si substrates and single unit cell (UC) films of FeSe on SrTiO3 (STO) substrates. The discovery of high-temperature superconductivity with a superconducting gap of ∼20 meV in 1UC-FeSe/STO has stimulated tremendous interest in the superconductivity community, for it opens a new avenue for both raising superconducting transition temperature and understanding the pairing mechanism of unconventional high-temperature superconductivity. Here, we review mainly the experimental progress on interface-enhanced superconductivity in the three systems mentioned above with emphasis on 1UC-FeSe/STO, studied by scanning tunneling microscopy/spectroscopy, angle-resolved photoemission spectroscopy and transport experiments. We discuss the roles of interfaces and a possible pairing mechanism inferred from these studies.

  6. 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.

  7. Study on Relationship between Seasonal Temperatures and Municipal Wastewater Pollutant Concentration and Removal Rate

    Directory of Open Access Journals (Sweden)

    Yuan Shaoxiong

    2016-01-01

    Full Text Available In this study, the temperatures, pollutant concentrations and other indicators of municipal wastewater influent and effluent were tested for 7 months in 6 constructed wetland microcosms; the hydraulic retention time is 2 days. The results indicated that for both influent and effluent, there was a highly significant negative correlation (P<0.01 between the temperature and the pollutant concentrations, there was a significant difference (P<0.05 between seasonal temperatures, and the pollutant concentrations in summer and autumn were significantly different from those in winter (P<0.05. Furthermore, a regression analysis of pollutant concentration (y based on changes in water temperature (x in different seasons was performed. The analysis revealed that the relationship has the form ‘y = a -bx + cx2’, that under certain circumstances, pollutant concentrations can be calculated based on the temperature, and that the concentrations of NH4-N, Total Phosphorus (TP and Soluble Reactive Phosphorus (SRP had a significantly negative correlation with their removal rate (P < 0.01. However, seasonal temperature clearly did not have a direct impact on the pollutant concentration, and some studies have indicated that the different manners in which urban residents use water as the temperature changes may be the real reason that the pollutant concentrations of municipal wastewater vary with seasonal temperature. Furthermore, when designing and operating constructed wetlands, the impact of the changes in pollutant concentrations generated by seasonal temperature should be fully considered, dilution and other means should be taken to ensure purification.

  8. High temperature superconductor current leads

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Poeppel, Roger B. (Glen Ellyn, IL)

    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.

  9. High temperature polymer matrix composites

    Science.gov (United States)

    Serafini, Tito T. (Editor)

    1987-01-01

    These are the proceedings of the High Temperature Polymer Matrix Composites Conference held at the NASA Lewis Research Center on March 16 to 18, 1983. The purpose of the conference is to provide scientists and engineers working in the field of high temperature polymer matrix composites an opportunity to review, exchange, and assess the latest developments in this rapidly expanding area of materials technology. Technical papers are presented in the following areas: (1) matrix development; (2) adhesive development; (3) Characterization; (4) environmental effects; and (5) applications.

  10. High temperature corrosion in gasifiers

    Directory of Open Access Journals (Sweden)

    Bakker Wate

    2004-01-01

    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.

  11. Nonlinear plasmonics at high temperatures

    CERN Document Server

    Sivan, Yonatan

    2016-01-01

    We solve the Maxwell and heat equations self-consistently for metal nanoparticles under intense continuous wave (CW) illumination. Unlike previous studies, we rely on {\\em experimentally}-measured data for the 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 modelling 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 non...

  12. Nonlinear plasmonics at high temperatures

    Directory of Open Access Journals (Sweden)

    Sivan Yonatan

    2017-01-01

    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.

  13. 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.

  14. High-temperature Titanium Alloys

    Directory of Open Access Journals (Sweden)

    A.K. Gogia

    2005-04-01

    Full Text Available The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase equilibria and microstructural stability consideration haverestricted the use of conventional titanium alloys up to about 600 "C, alloys based on TiPl (or,, E,AINb (0, TiAl (y, and titaniumltitanium aluminides-based composites offer a possibility ofquantum jump in the temperature capability of titanium alloys.

  15. 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.

  16. 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.

  17. 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.

  18. High Temperature, High Power Piezoelectric Composite Transducers

    Directory of Open Access Journals (Sweden)

    Hyeong Jae Lee

    2014-08-01

    Full Text Available 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.

  19. High-temperature beryllium embrittlement

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovsky, A.S. [Scientific Research Inst. of Atomic Reactors, Dimitrovgrad (Russian Federation); Fabritsiev, S.A. [D.V. Efremov Scientific Research Institute, 189631 St. Petersburg (Russian Federation); Bagautdinov, R.M. [Scientific Research Inst. of Atomic Reactors, Dimitrovgrad (Russian Federation); Goncharenko, Yu.D. [Scientific Research Inst. of Atomic Reactors, Dimitrovgrad (Russian Federation)

    1996-10-01

    The neutron irradiation effect on the mechanical properties, swelling and fracture surface structure of various beryllium grades was studied in the BOR-60 reactor at 340 to 350 C up to a fluence of 7.2 x 10{sup 21} n/cm{sup 2}. At a mechanical testing temperature of 400 C there was observed a strong anisotropy of plastic beryllium deformation depending on the direction of sample cutting relative to the pressing direction. An increase of the testing temperature up to 700 C resulted in an abrupt embrittlement of all irradiated samples. In the most part of the surface structure the intercrystallite fracture along the grain boundaries was covered entirely with large pores, 1 to 4 {mu}m in size. It was suggested that the increased rate of pore formation along the grain boundaries resulted from a high-temperature embrittlement under irradiation. (orig.).

  20. TPAOH Template Removal from High-Silica ZSM-5 by Low-Temperature Hydrocracking%低温加氢裂解脱除高硅ZSM-5分子筛内TPAOH模板剂

    Institute of Scientific and Technical Information of China (English)

    赵淑蘅; 郎林; 阴秀丽; 杨文申; 吴创之

    2015-01-01

    分子筛膜的合成和应用是近年来的研究热点,特别是具有独特孔道结构的MFI型分子筛膜。但由于膜内有机模板剂在高温脱除时会导致膜产生缺陷,进而影响分子筛膜的应用。所以分子筛膜及分子筛晶体中有机模板剂的低温脱除工艺一直是研究者们致力解决的问题之一。本文系统考察了高硅ZSM-5分子筛晶体内有机模板剂(四丙基氢氧化铵, TPAOH)在H2/N2气氛下的低温裂解脱除规律,采用低温加氢裂解工艺,在350°C以下可有效脱除分子筛晶体孔道内的有机模板剂。通过对裂解后分子筛晶体的比表面积(BET)、热失重(TG)、傅里叶变换红外(FTIR)光谱和拉曼光谱表征证实,相比于空气和氮气气氛,含氢还原性气氛更有利于模板剂的低温脱除,脱除率随温度的升高而增加;280°C时,加氢裂解后晶体的BET比表面积已达到252 m2∙g-1,仍有少量有机残余物;350°C时,加氢裂解后晶体的BET比表面积可达到399 m2∙g-1,仅有微量无机碳残余物。此外,低温加氢裂解后的分子筛表面相对洁净,且氨气程序升温脱附(NH3-TPD)结果表明低温加氢裂解后的ZSM-5分子筛晶体具有相对较多的酸性位。%Zeolite membranes, especial y the MFI-type zeolite membranes, have attracted significant attention for decades because of their special properties. While organic templates such as tetrapropylammonium hydroxide (TPAOH) have typical y been used for the synthesis of ZSM-5 zeolite and zeolite membranes, the templates remain trapped in the as-synthesized zeolite crystals. A common method for removing organic templates and generating porous frameworks is calcination;however, during this process, the channel structure may be affected. In particular, for ZSM-5 membranes, membrane defects may be produced and the separation efficiency therefore may decrease to some extent. In this study, the low-temperature hydrocracking of TPAOH in ZSM-5 zeolite

  1. Rapid removal of bisphenol A on highly ordered mesoporous carbon

    Institute of Scientific and Technical Information of China (English)

    Qian Sui; Jun Huang; Yousong Liu; Xiaofeng Chang; Guangbin Ji; Shubo Deng; Tao Xie; Gang Yu

    2011-01-01

    Bisphenol A (BPA) is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that efforts are made to remove it from the aqueous phase. A novel adsorbent, mesoporous carbon CMK-3,prepared from hexagonal SBA-15 mesoporous silica was studied for BPA removal from aqueous phase, and compared with conventional powdered activated carbon (PAC). Characterization of CMK-3 by transmission electron microscopy (TEM), X-ray diffraction, and nitrogen adsorption indicated that prepared CMK-3 had an ordered mesoporous structure with a high specific surface area of 920 m2/g and a pore-size of about 4.9 nm. The adsorption of BPA on CMK-3 followed a pseudo second-order kinetic model. The kinetic constant was 0.00049 g/(mg·min), much higher than the adsorption of BPA on PAC. The adsorption isotherm fitted slightly better with the Freundlich model than the Langmuir model, and adsorption capacity decreased as temperature increased from 10 to 40℃.No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9to 13.

  2. Advanced wastewater treatment using microalgae: effect of temperature on removal of nutrients and organic carbon

    Science.gov (United States)

    Mohamad, Shurair; Fares, Almomani; Judd, Simon; Bhosale, Rahul; Kumar, Anand; Gosh, Ujjal; Khreisheh, Majeda

    2017-05-01

    This study evaluated the use of mixed indigenous microalgae (MIMA) as a treatment process for wastewaters and CO2 capturing technology at different temperatures. The study follows the growth rate of MIMA, CO2 Capturing from flue gas, removals of organic matter and nutrients from three types of wastewater (primary effluent, secondary effluent and septic effluent). A noticeable difference between the growth patterns of MIMA was observed at different CO2 and different operational temperatures. MIMA showed the highest growth grate when injected with CO2 dosage of 10% compared to the growth for the systems injected with 5% and 15 % of CO2. Ammonia and phosphorus removals for Spirulina were 69%, 75%, and 83%, and 20%, 45% and 75 % for the media injected with 0, 5 and 10% CO2. The results of this study show that simple and cost-effective microalgae-based wastewater treatment systems can be successfully employed at different temperatures as a successful CO2 capturing technology even with the small probability of inhibition at high temperatures.

  3. 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

  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 catalytic membrane reactors

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    Current state-of-the-art inorganic oxide membranes offer the potential of being modified to yield catalytic properties. The resulting modules may be configured to simultaneously induce catalytic reactions with product concentration and separation in a single processing step. Processes utilizing such catalytically active membrane reactors have the potential for dramatically increasing yield reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kinetic selectivity. Examples of commercial interest include hydrogenation, dehydrogenation, partial and selective oxidation, hydrations, hydrocarbon cracking, olefin metathesis, hydroformylation, and olefin polymerization. A large portion of the most significant reactions fall into the category of high temperature, gas phase chemical and petrochemical processes. Microporous oxide membranes are well suited for these applications. A program is proposed to investigate selected model reactions of commercial interest (i.e. dehydrogenation of ethylbenzene to styrene and dehydrogenation of butane to butadiene) using a high temperature catalytic membrane reactor. Membranes will be developed, reaction dynamics characterized, and production processes developed, culminating in laboratory-scale demonstration of technical and economic feasibility. As a result, the anticipated increased yield per reactor pass economic incentives are envisioned. First, a large decrease in the temperature required to obtain high yield should be possible because of the reduced driving force requirement. Significantly higher conversion per pass implies a reduced recycle ratio, as well as reduced reactor size. Both factors result in reduced capital costs, as well as savings in cost of reactants and energy.

  7. 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...

  8. Low temperature biological phosphorus removal and partial nitrification in a pilot sequencing batch reactor system.

    Science.gov (United States)

    Yuan, Qiuyan; Oleszkiewicz, Jan A

    2011-01-01

    Partial nitrification and biological phosphorus removal appear to hold promise of a cost-effective and sustainable biological nutrient removal process. Pilot sequencing batch reactors (SBRs) were operated under anaerobic/aerobic configuration for 8 months. It was found that biological phosphorus removal can be achieved in an SBR system, along with the partial nitrification process. Sufficient volatile fatty acids supply was the key for enhanced biological phosphorus removal. This experiment demonstrated that partial nitrification can be achieved even at low temperature with high dissolved oxygen (>3 mg/L) concentration. Shorter solid retention time (SRT) for nitrite oxidizing bacteria (NOB) than for ammonia oxidizing bacteria due to the nitrite substrate limitation at the beginning of the aeration cycle was the reason that caused NOB wash-out. Controlling SRT should be the strategy for an SBR operated in cold climate to achieve partial nitrification. It was also found that the aerobic phosphorus accumulating organisms' P-uptake was more sensitive to nitrite inhibition than the process of anaerobic P-release.

  9. Simulating daily water temperatures of the Klamath River under dam removal and climate change scenarios

    Science.gov (United States)

    Perry, Russell W.; Risley, John C.; Brewer, Scott J.; Jones, Edward C.; Rondorf, Dennis W.

    2011-01-01

    A one-dimensional daily averaged water temperature model was used to simulate Klamath River temperatures for two management alternatives under historical climate conditions and six future climate scenarios. The analysis was conducted for the Secretarial Determination on removal of four hydroelectric dams on the Klamath River. In 2012, the Secretary of the Interior will determine if dam removal and implementation of the Klamath Basin Restoration Agreement (KBRA) (Klamath Basin Restoration Agreement, 2010) will advance restoration of salmonid fisheries and is in the public interest. If the Secretary decides dam removal is appropriate, then the four dams are scheduled for removal in 2020.

  10. Temperature uniformity mapping in a high pressure high temperature reactor using a temperature sensitive indicator

    NARCIS (Netherlands)

    Grauwet, T.; Plancken, van der I.; Vervoort, L.; Matser, A.M.; Hendrickx, M.; Loey, van A.

    2011-01-01

    Recently, the first prototype ovomucoid-based pressure–temperature–time indicator (pTTI) for high pressure high temperature (HPHT) processing was described. However, for temperature uniformity mapping of high pressure (HP) vessels under HPHT sterilization conditions, this prototype needs to be optim

  11. Influence of Temperature and Dissolved Oxygen on Nitrogen and Phosphorus Removal of Integrated Bioreactor

    Directory of Open Access Journals (Sweden)

    Chunying Wu

    2017-06-01

    Full Text Available An integrated biological membrane sewage treatment device has been designed based on the mechanism of microorganism nitrogen and phosphorus removal and the influence of temperature and dissolved oxygen on nitrogen and phosphorus removal of integrated bioreactor with adoption of this sewage treatment device. The research results shows that the optimal temperature range of microorganism nitrogen and phosphorus removal is 20-30 °C, and the effluent COD removal rate within this range maintains at over 90%; NH4^+-N removal rate is between 95% and 97%. TN removal rate is approximately 81%. In practical production, the internal temperature environment of the sewage reactor should be maintained at above 15 °C, to decrease the inhibition of low-temperature environment on growth and reaction speed of nitrobacteria. In various concentrations of DO in the reactor, there is little change in the effluent COD concentration and effluent COD concentration is influenced by temperature. With the increasing of DO concentration, both effluent TN and TP concentrations present changing features of initially decreasing then increasing. The analysis of the influence of comprehensive dissolved oxygen on microorganism nitrogen and phosphorus removal reveals that when the concentration of DO maintains within the range of 1.0-1.5 mg/L, the sewage purification system can attain a higher nitrogen and phosphorus removal effect.

  12. Passivation of high temperature superconductors

    Science.gov (United States)

    Vasquez, Richard P. (Inventor)

    1991-01-01

    The surface of high temperature superconductors such as YBa2Cu3O(7-x) are passivated by reacting the native Y, Ba and Cu metal ions with an anion such as sulfate or oxalate to form a surface film that is impervious to water and has a solubility in water of no more than 10(exp -3) M. The passivating treatment is preferably conducted by immersing the surface in dilute aqueous acid solution since more soluble species dissolve into the solution. The treatment does not degrade the superconducting properties of the bulk material.

  13. Impact of temperature on ammonium and nitrite removal rates in RAS moving bed biofilters

    DEFF Research Database (Denmark)

    Kinyage, John Peter Hewa; Pedersen, Lars-Flemming

    2016-01-01

    The impact of temperature on bacterial processes is well known; however temperature related data on nitrification rates in aquaculture systems are fragmented and compiled from different studies. We sought to determine ammonium and nitrite removal kinetics over a temperature range from 6 to 36 °C ...

  14. Temperature, plant species and residence time effects on nitrogen removal in model treatment wetlands.

    Science.gov (United States)

    Allen, C R; Stein, O R; Hook, P B; Burr, M D; Parker, A E; Hafla, E C

    2013-01-01

    Total nitrogen (TN) removal in treatment wetlands (TWs) is challenging due to nitrogen cycle complexity and the variation of influent nitrogen species. Plant species, season, temperature and hydraulic loading most likely influence root zone oxygenation and appurtenant nitrogen removal, especially for ammonium-rich wastewater. Nitrogen data were collected from two experiments utilizing batch-loaded (3-, 6-, 9- and 20-day residence times), sub-surface TWs monitored for at least one year during which temperature was varied between 4 and 24 °C. Synthetic wastewater containing 17 mg/l N as NH4 and 27 mg/l amino-N, 450 mg/l chemical oxygen demand (COD), and 13 mg/l SO4-S was applied to four replicates of Carex utriculata, Schoenoplectus acutus and Typha latifolia and unplanted controls. Plant presence and species had a greater effect on TN removal than temperature or residence time. Planted columns achieved approximately twice the nitrogen removal of unplanted controls (40-95% versus 20-50% removal) regardless of season and temperature. TWs planted with Carex outperformed both Typha and Schoenoplectus and demonstrated less temperature dependency. TN removal with Carex was excellent at all temperatures and residence times; Schoenoplectus and Typha TN removal improved at longer residence times. Reductions in TN were not accompanied by increases in NO3, which was consistently below 1 mg/l N.

  15. Jet Cleansing: Pileup Removal at High Luminosity

    CERN Document Server

    Krohn, David; Schwartz, Matthew D; Wang, Lian-Tao

    2013-01-01

    One of the greatest impediments to extracting useful information from high luminosity hadron-collider data is radiation from secondary collisions (i.e. pileup) which can overlap with that of the primary interaction. In this paper we introduce a simple jet-substructure technique termed cleansing which can consistently correct for large amounts of pileup in an observable independent way. Cleansing works at the subjet level, combining tracker and calorimeter-based data to reconstruct the pileup-free primary interaction. The technique can be used on its own, with various degrees of sophistication, or in concert with jet grooming. We apply cleansing to both kinematic and jet shape reconstruction, finding in all cases a marked improvement over previous methods both in the correlation of the cleansed data with uncontaminated results and in measures like S/rt(B). Cleansing should improve the sensitivity of new-physics searches at high luminosity and could also aid in the comparison of precision QCD calculations to co...

  16. High Temperature Radio Frequency Loads

    CERN Document Server

    Federmann, S; Grudiev, A; Montesinos, E; Syratchev, I

    2011-01-01

    In the context of energy saving and recovery requirements the design of reliable and robust RF power loads which permit a high outlet temperature and high pressure of the cooling water is desirable. Cooling water arriving at the outlet withmore than 150 ◦C and high pressure has a higher value than water with 50 ◦C under low pressure. Conventional RF power loads containing dielectric and magnetic materials as well as sensitive ceramic windows usually do not permit going much higher than 90 ◦C. Here we present and discuss several design concepts for "metal only" RF high power loads. One concept is the application of magnetic steel corrugated waveguides near cutoff – this concept could find practical use above several GHz. Another solution are resonant structures made of steel to be installed in large waveguides for frequencies of 500 MHz or lower. Similar resonant structures above 100 MHz taking advantage of the rather high losses of normal steel may also be used in coaxial line geometries with large di...

  17. NEW TRENDS IN AMMONIA NITROGEN REMOVAL FROM WASTEWATER: NITRITATION – ANAMMOX AT LOW TEMPERATURE

    Directory of Open Access Journals (Sweden)

    Mariusz Tomaszewski

    2017-04-01

    Full Text Available Partial nitrification (nitritation – anammox (anaerobic ammonia oxidation process is increasingly used to treat wastewater, characterized by a high nitrogen content and high temperature (25 - 40°C. It is connected with the optimal temperature of anammox bacteria, which is at the range between 30 and 40°C. Mainstream application of anammox for the municipal wastewater, characterized by lower temperature seems to be one of the most challenging, but profitable process. Thenceforth, the research performed in the field of the nitritation – anammox at low temperature (10 - 20°C become more and more intense. Compared with the conventional nitrification – denitrification system, nitritation – anammox reduces oxygen demand, eliminates the need for organic carbon source and produces less excess sludge. As a result, it allows to a significant cost reduction. This paper reviews the most important and recent information in the field of nitritation – anammox process at low temperature. Effective nitrogen removal from the municipal wastewater was demonstrated at 15°C in a pilot scale and at 12°C in a laboratory scale reactor. The best performance is achieved in sequencing batch reactors and moving bed reactors with biofilm or granular biomass, as well as combinations of these technologies. Molecular biology studies shows that anammox bacteria of the genus Candidatus Brocadia may have the biggest predispositions to adapt to low temperature. However, temperature about 10°C, time and method of biomass adaptation are still the main challenges for stable and common nitritation – anammox process.

  18. Nitrogen Removal Characteristics of Pseudomonas putida Y-9 Capable of Heterotrophic Nitrification and Aerobic Denitrification at Low Temperature

    Directory of Open Access Journals (Sweden)

    Yi Xu

    2017-01-01

    Full Text Available The cold-adapted bacterium Pseudomonas putida Y-9 was investigated and exhibited excellent capability for nitrogen removal at 15°C. The strain capable of heterotrophic nitrification and aerobic denitrification could efficiently remove ammonium, nitrate, and nitrite at an average removal rate of 2.85 mg, 1.60 mg, and 1.83 mg NL−1 h−1, respectively. Strain Y-9 performed nitrification in preference to denitrification when ammonium and nitrate or ammonium and nitrite coexisted in the solution. Meantime, the presence of nitrate had no effect on the ammonium removal rate of strain Y-9, and yet the presence of high concentration of nitrite would inhibit the cell growth and decrease the nitrification rate. The experimental results indicate that P. putida Y-9 has potential application for the treatment of wastewater containing high concentrations of ammonium along with its oxidation products at low temperature.

  19. 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

    with 3 cm diameter graphite-based fuel pebbles slowly circulating up through the core. Molten salt coolant (FLiBe) at 700°C flows concurrently (at significantly higher velocity) with the pebbles and is used to remove heat generated in the reactor core (approximately 1280 W/pebble), and supply it to a power conversion system. Refueling equipment continuously sorts spent fuel pebbles and replaces spent or damaged pebbles with fresh fuel. By combining greater or fewer numbers of pebble channel assemblies, multiple reactor designs with varying power levels can be offered. The PB-AHTR design is discussed in detail in Reference [1] and is shown schematically in Fig. 1. Fig. 1. PB-AHTR concept (drawing taken from Peterson et al., Design and Development of the Modular PB-AHTR Proceedings of ICApp 08). Pebble behavior within the core is a key issue in proving the viability of this concept. This includes understanding the behavior of the pebbles thermally, hydraulically, and mechanically (quantifying pebble wear characteristics, flow channel wear, etc). The experiment being developed is an initial step in characterizing the pebble behavior under realistic PB-AHTR operating conditions. It focuses on thermal and hydraulic behavior of a static pebble bed using a convective salt loop to provide prototypic fluid conditions to the bed, and a unique inductive heating technique to provide prototypic heating in the pebbles. The facility design is sufficiently versatile to allow a variety of other experimentation to be performed in the future. The facility can accommodate testing of scaled reactor components or sub-components such as flow diodes, salt-to-salt heat exchangers, and improved pump designs as well as testing of refueling equipment, high temperature instrumentation, and other reactor core designs.

  20. 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...

  1. Cohort removal induces changes in body temperature, pain sensitivity, and anxiety-like behavior

    Directory of Open Access Journals (Sweden)

    Keizo eTakao

    2016-06-01

    Full Text Available Mouse behavior is analyzed to elucidate the effects of various experimental manipulations, including gene mutation and drug administration. When the effect of a factor of interest is assessed, other factors, such as age, sex, temperature, apparatus, and housing, are controlled in experiments by matching, counterbalancing, and/or randomizing. One such factor that has not attracted much attention is the effect of sequential removal of animals from a common cage (cohort removal. Here we evaluated the effects of cohort removal on rectal temperature, pain sensitivity, and anxiety-like behavior by analyzing the combined data of a large number of C57BL/6J mice that we collected using a comprehensive behavioral test battery. Rectal temperature increased in a stepwise manner according to the position of sequential removal from the cage, consistent with previous reports. In the hot plate test, the mice that were removed first from the cage had a significantly longer latency to show the first paw response than the mice removed later. In the elevated plus maze, the mice removed first spent significantly less time on the open arms compared to the mice removed later. The results of the present study demonstrated that cohort removal induces changes in body temperature, pain sensitivity, and anxiety-like behavior in mice. Cohort removal also increased the plasma corticosterone concentration in mice. Thus, the ordinal position in the sequence of removal from the cage should be carefully counterbalanced between groups when the effect of experimental manipulations, including gene manipulation and drug administration, are examined using behavioral tests.

  2. Cohort Removal Induces Changes in Body Temperature, Pain Sensitivity, and Anxiety-Like Behavior.

    Science.gov (United States)

    Takao, Keizo; Shoji, Hirotaka; Hattori, Satoko; Miyakawa, Tsuyoshi

    2016-01-01

    Mouse behavior is analyzed to elucidate the effects of various experimental manipulations, including gene mutation and drug administration. When the effect of a factor of interest is assessed, other factors, such as age, sex, temperature, apparatus, and housing, are controlled in experiments by matching, counterbalancing, and/or randomizing. One such factor that has not attracted much attention is the effect of sequential removal of animals from a common cage (cohort removal). Here we evaluated the effects of cohort removal on rectal temperature, pain sensitivity, and anxiety-like behavior by analyzing the combined data of a large number of C57BL/6J mice that we collected using a comprehensive behavioral test battery. Rectal temperature increased in a stepwise manner according to the position of sequential removal from the cage, consistent with previous reports. In the hot plate test, the mice that were removed first from the cage had a significantly longer latency to show the first paw response than the mice removed later. In the elevated plus maze, the mice removed first spent significantly less time on the open arms compared to the mice removed later. The results of the present study demonstrated that cohort removal induces changes in body temperature, pain sensitivity, and anxiety-like behavior in mice. Cohort removal also increased the plasma corticosterone concentration in mice. Thus, the ordinal position in the sequence of removal from the cage should be carefully counterbalanced between groups when the effect of experimental manipulations, including gene manipulation and drug administration, are examined using behavioral tests.

  3. Temperature influence on biological phosphorus removal induced by aerobic/extended-idle regime.

    Science.gov (United States)

    Chen, Hong-Bo; Wang, Dong-Bo; Li, Xiao-Ming; Yang, Qi; Luo, Kun; Zeng, Guang-Ming

    2014-05-01

    Previous researches have demonstrated that biological phosphorus removal (BPR) from wastewater could be driven by the aerobic/extended-idle (A/EI) regime. This study further investigated temperature effects on phosphorus removal performance in six A/EI sequencing batch reactors (SBRs) operated at temperatures ranging from 5 to 30 °C. The results showed that phosphorus removal efficiency increased with temperature increasing from 5 to 20 °C but slightly decreased when temperature continually increased to 30 °C. The highest phosphorus removal rate of 97.1 % was obtained at 20 °C. The biomass cultured at 20 °C contained more polyphosphate accumulating organisms (PAO) and less glycogen accumulating organisms (GAO) than that cultured at any other temperatures investigated. The mechanism studies revealed that temperature affected the transformations of glycogen and polyhydroxyalkanoates, and the activities of exopolyphosphatase and polyphosphate kinase activities. In addition, phosphorus removal performances of the A/EI and traditional anaerobic/oxic (A/O) SBRs were compared at 5 and 20 °C, respectively. The results showed the A/EI regime drove better phosphorus removal than the A/O regime at both 5 and 20 °C, and more PAO and less GAO abundances in the biomass might be the principal reason for the higher BPR in the A/EI SBRs as compared with the A/O SBRs.

  4. Ammonium removal of drinking water at low temperature by activated carbon filter biologically enhanced with heterotrophic nitrifying bacteria.

    Science.gov (United States)

    Qin, Wen; Li, Wei-Guang; Zhang, Duo-Ying; Huang, Xiao-Fei; Song, Yang

    2016-03-01

    We sought to confirm whether use of Acinetobacter strains Y7 and Y16, both strains of heterotrophic nitrifying bacteria, was practical for removing ammonium (NH4 (+)-N) from drinking water at low temperatures. To test this, ammonium-containing drinking water was treated with strains Y7 and Y16 at 8 and 2 °C. Continuous ammonium treatment was conducted in order to evaluate the performance of three biologically enhanced activated carbon (BEAC) filters in removing ammonium. The three BEAC filters were inoculated with strain Y7, strain Y16, and a mixture of strains Y7 and Y16, respectively. A granular activated carbon (GAC) filter, without inoculation by any strains, was tested in parallel with the BEAC filters as control. The results indicated that NH4 (+)-N removal was significant when a BEAC filter was inoculated with the mixture of strains Y7 and Y16 (BEAC-III filter). Amounts of 0.44 ± 0.05 and 0.25 ± 0.05 mg L(-1) NH4 (+)-N were removed using the BEAC-III filter at 8 and 2 °C, respectively. These values were 2.8-4.0-fold higher than the values of ammonium removal acquired using the GAC filter. The synergistic effect of using strains Y7 and Y16 in concert was the cause of the high-ammonium removal efficiency achieved by using the BEAC-III filter at low temperatures. In addition, a high C/N ratio may promote NH4 (+)-N removal efficiency by improving biomass and microbial activity. This study provides new insight into the use of biofilters to achieve biological removal of ammonium at low temperature.

  5. 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.

  6. High temperature control rod assembly

    Energy Technology Data Exchange (ETDEWEB)

    Vollman, Russell E. (Solana Beach, CA)

    1991-01-01

    A high temperature nuclear control rod assembly comprises a plurality of substantially cylindrical segments flexibly joined together in succession by ball joints. The segments are made of a high temperature graphite or carbon-carbon composite. The segment includes a hollow cylindrical sleeve which has an opening for receiving neutron-absorbing material in the form of pellets or compacted rings. The sleeve has a threaded sleeve bore and outer threaded surface. A cylindrical support post has a threaded shaft at one end which is threadably engaged with the sleeve bore to rigidly couple the support post to the sleeve. The other end of the post is formed with a ball portion. A hollow cylindrical collar has an inner threaded surface engageable with the outer threaded surface of the sleeve to rigidly couple the collar to the sleeve. the collar also has a socket portion which cooperates with the ball portion to flexibly connect segments together to form a ball and socket-type joint. In another embodiment, the segment comprises a support member which has a threaded shaft portion and a ball surface portion. The threaded shaft portion is engageable with an inner threaded surface of a ring for rigidly coupling the support member to the ring. The ring in turn has an outer surface at one end which is threadably engageably with a hollow cylindrical sleeve. The other end of the sleeve is formed with a socket portion for engagement with a ball portion of the support member. In yet another embodiment, a secondary rod is slidably inserted in a hollow channel through the center of the segment to provide additional strength. A method for controlling a nuclear reactor utilizing the control rod assembly is also included.

  7. High temperature autoclave vacuum seals

    Science.gov (United States)

    Hoffman, J. R.; Simpson, W. G.; Walker, H. M.

    1971-01-01

    Aluminum sheet forms effective sealing film at temperatures up to 728 K. Soft aluminum wire rings provide positive seal between foil and platen. For applications at temperatures above aluminum's service temperature, stainless steel is used as film material and copper wire as sealant.

  8. Temperature Dependent Residual Stress Models for Ultra-High-Temperature Ceramics on High Temperature Oxidation

    Science.gov (United States)

    Wang, Ruzhuan; Li, Weiguo

    2016-11-01

    The strength of SiC-depleted layer of ultra-high-temperature ceramics on high temperature oxidation degrades seriously. The research for residual stresses developed within the SiC-depleted layer is important and necessary. In this work, the residual stress evolutions in the SiC-depleted layer and the unoxidized substrate in various stages of oxidation are studied by using the characterization models. The temperature and oxidation time dependent mechanical/thermal properties of each phase in SiC-depleted layer are considered in the models. The study shows that the SiC-depleted layer would suffer from large tensile stresses due to the great temperature changes and the formation of pores on high temperature oxidation. The stresses may lead to the cracking and even the delamination of the oxidation layer.

  9. Temperature Dependent Residual Stress Models for Ultra-High-Temperature Ceramics on High Temperature Oxidation

    Science.gov (United States)

    Wang, Ruzhuan; Li, Weiguo

    2017-08-01

    The strength of SiC-depleted layer of ultra-high-temperature ceramics on high temperature oxidation degrades seriously. The research for residual stresses developed within the SiC-depleted layer is important and necessary. In this work, the residual stress evolutions in the SiC-depleted layer and the unoxidized substrate in various stages of oxidation are studied by using the characterization models. The temperature and oxidation time dependent mechanical/thermal properties of each phase in SiC-depleted layer are considered in the models. The study shows that the SiC-depleted layer would suffer from large tensile stresses due to the great temperature changes and the formation of pores on high temperature oxidation. The stresses may lead to the cracking and even the delamination of the oxidation layer.

  10. Removal of high-molecular weight polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    Ulrich Vasconcelos

    2011-01-01

    Full Text Available Alternatives for the removal of high-molecular weight polycyclic aromatic hydrocarbons (HWM-PAH from soil were tested by adding fertilizer or glycerol, as well as the combination of both. Experiments were carried out for 60 days in reactors containing a HWM-PAH-contaminated soil (8030 μg kg-1, accompanied by pH monitoring, humidity control and quantification of total heterotrophic bacteria and total fungus. Fertilizer addition removed 41.6% of HWM-PAH. Fertilizer and glycerol in combination removed 46.2%. When glycerol was added individually, degradation reached 50.4%. Glycerol also promoted the increase of degradation rate during the first 30 days suggesting the HMW-PAH removal occurred through cometabolic pathways.

  11. Experiments on aerosol removal by high-pressure water spray

    Energy Technology Data Exchange (ETDEWEB)

    Corno, Ada del, E-mail: delcorno@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Morandi, Sonia, E-mail: morandi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Parozzi, Flavio, E-mail: parozzi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Araneo, Lucio, E-mail: lucio.araneo@polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy); CNR-IENI, via Cozzi 53, I-20125 Milano (Italy); Casella, Francesco, E-mail: francesco2.casella@mail.polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy)

    2017-01-15

    Highlights: • Experimental research to measure the efficiency of high-pressure sprays in capturing aerosols if applied to a filtered containment venting system in case of severe accident. • Cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration in the range 2–90 mg/m{sup 3}. • Carried out in a chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls equipped with a high pressure water spray with single nozzle. • Respect to low-pressure sprays, removal efficiency turned out significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure sprays system. - Abstract: An experimental research was managed in the framework of the PASSAM European Project to measure the efficiency of high-pressure sprays in capturing aerosols when applied to a filtered containment venting system in case of severe accident. The campaign was carried out in a purposely built facility composed by a scrubbing chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls to permit the complete view of the aerosol removal process, where the aerosol was injected to form a cloud of specific particle concentration. The chamber was equipped with a high pressure water spray system with a single nozzle placed on its top. The test matrix consisted in the combination of water pressure injections, in the range 50–130 bar, on a cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration ranging between 2 and 99 mg/m{sup 3}. The spray was kept running for 2 min and the efficiency of the removal was evaluated, along the test time, using an optical particle sizer. With respect to low-pressure sprays, the removal efficiency turned out much more significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure spray system. The highest removal rate was

  12. High-temperature thermocouples and related methods

    Science.gov (United States)

    Rempe, Joy L.; Knudson, Darrell L.; Condie, Keith G.; Wilkins, S. Curt

    2011-01-18

    A high-temperature thermocouple and methods for fabricating a thermocouple capable of long-term operation in high-temperature, hostile environments without significant signal degradation or shortened thermocouple lifetime due to heat induced brittleness.

  13. 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.

  14. High temperature suppression of dioxins.

    Science.gov (United States)

    Zhan, Ming-Xiu; Chen, Tong; Fu, Jian-Ying; Lin, Xiao-Qing; Lu, Sheng-Yong; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-03-01

    Combined Sulphur-Nitrogen inhibitors, such as sewage sludge decomposition gases (SDG), thiourea and amidosulphonic acid have been observed to suppress the de novo synthesis of dioxins effectively. In this study, the inhibition of PCDD/Fs formation from model fly ash was investigated at unusually high temperatures (650 °C and 850 °C), well above the usual range of de novo tests (250-400 °C). At 650 °C it was found that SDG evolving from dried sewage sludge could suppress the formation of 2,3,7,8-substituted PCDD/Fs with high efficiency (90%), both in weight units and in I-TEQ units. Additionally, at 850 °C, three kinds of sulphur-amine or sulphur-ammonium compounds were tested to inhibit dioxins formation during laboratory-scale tests, simulating municipal solid waste incineration. The suppression efficiencies of PCDD/Fs formed through homogeneous gas phase reactions were all above 85% when 3 wt. % of thiourea (98.7%), aminosulphonic acid (96.0%) or ammonium thiosulphate (87.3%) was added. Differences in the ratio of PCDFs/PCDDs, in weight average chlorination level and in the congener distribution of the 17 toxic PCDD/Fs indicated that the three inhibitors tested followed distinct suppression pathways, possibly in relation to their different functional groups of nitrogen. Furthermore, thiourea reduced the (weight) average chlorinated level. In addition, the thermal decomposition of TUA was studied by means of thermogravimetry-fourier transform infrared spectroscopy (TG-FTIR) and the presence of SO2, SO3, NH3 and nitriles (N≡C bonds) was shown in the decomposition gases; these gaseous inhibitors might be the primary dioxins suppressants.

  15. High temperature power electronics for space

    Science.gov (United States)

    Hammoud, Ahmad N.; Baumann, Eric D.; Myers, Ira T.; Overton, Eric

    1991-01-01

    A high temperature electronics program at NASA Lewis Research Center focuses on dielectric and insulating materials research, development and testing of high temperature power components, and integration of the developed components and devices into a demonstrable 200 C power system, such as inverter. An overview of the program and a description of the in-house high temperature facilities along with experimental data obtained on high temperature materials are presented.

  16. 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.

  17. 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

  18. Electrochemical removal of segregated silicon dioxide impurities from yttria stabilized zirconia surfaces at elevated temperatures

    DEFF Research Database (Denmark)

    Andersen, Thomas; Hansen, Karin Vels; Mogensen, Mogens Bjerg;

    2011-01-01

    Here we report on the electrochemical removal of segregated silicon dioxide impurities from Yttria Stabilized Zirconia (YSZ) surfaces at elevated temperatures studied under Ultra High Vacuum (UHV) conditions. YSZ single crystals were heated in vacuum by an applied 18kHz a.c. voltage using the ionic...... and XPS analysis. Silicon enrichment of the surface was only observed at oxygen and water vapor partial pressures above 25mbar and 10mbar, respectively. No silicon was observed on crystals annealed in vacuum and at oxygen and water vapor partial pressures below 10mbar. The YSZ seems to get partially...... electrochemically reduced by the a.c. voltage when no oxidation substances are present. The absence of silicon on the surfaces annealed in vacuum or at low oxygen or water vapor partial pressures was attributed to electrochemical reduction of silicon dioxide to volatile silicon monoxide on the YSZ surface...

  19. Foreground removal from Planck Sky Model temperature maps using a MLP neural network

    DEFF Research Database (Denmark)

    Nørgaard-Nielsen, Hans Ulrik; Hebert, K.

    2009-01-01

    Unfortunately, the Cosmic Microwave Background (CMB) radiation is contaminated by emission originating in the Milky Way (synchrotron, free-free and dust emission). Since the cosmological information is statistically in nature, it is essential to remove this foreground emission and leave the CMB...... with no systematic errors. To demonstrate the feasibility of a simple multilayer perceptron (MLP) neural network for extracting the CMB temperature signal, we have analyzed a specific data set, namely the Planck Sky Model maps, developed for evaluation of different component separation methods before including them...... in the Planck data analysis pipeline. It is found that a MLP neural network can provide a CMB map of about 80% of the sky to a very high degree uncorrelated with the foreground components. Also the derived power spectrum shows little evidence for systematic errors....

  20. Influence of temperature in phosphate removal by microalgae in heterotrophic bioreactors

    Directory of Open Access Journals (Sweden)

    Maria Isabel Queiroz

    2012-08-01

    Full Text Available The removal of total dissolved phosphate by the cyanobacteria Aphanothece microscopica Nägeli cultivated heterotrophically in dairy processing wastewater was investigated in this work. The experiments were carried out in bioreactors operating in a batch mode, fed with 4.5 L of wastewater. The experimental conditions were as follows: initial cell concentration of 0.2 g/L, pH adjusted to 7.6, isothermal reactor operating at temperatures of 10, 20 and 30ºC with absence of light and continuous aeration of 1 VVM. The results showed that phosphate removal is strongly dependent on process temperature. A. microscopica Nägeli was effective in the removal phosphate achieving removal rates of 3.77 mg/L.h, which reflected in the conversion of 98.4% in hydraulic detention times of 24 h.

  1. Photochemical removal of organic contaminants from silicon surface at room temperature

    Science.gov (United States)

    Fominski, V. Yu.; Naoumenko, O. I.; Nevolin, V. N.; Alekhin, A. P.; Markeev, A. M.; Vyukov, L. A.

    1996-04-01

    Using in situ x-ray photoelectron spectroscopy we have investigated the possibility of photochemical organic contaminant removal from a silicon surface at room temperature in oxygen and fluorine containing atmospheres (O2, NF3/H2, O2/NF3/H2). In contrast to UV irradiation in O2 and NF3/H2 reagents, the possibility of complete organic contaminant removal has been observed in O2/NF3/H2 gas mixture.

  2. Effects of Temperature and [S] on the Kinetics of Nitrogen Removal from Liquid Steel

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The kinetics of denitrogenation from liquid steel was studied byusing an oxygen-nitrogen analysis system(LECO TC-436) under 1600℃~2813℃ conditions. The results show that when [S]=0.005%, nitrogen removal was controlled by nitrogen transfer in liquid diffusion layer, when [S]=0.012% and 0.140%, it was controlled by both nitrogen transfer in liquid diffusion layer and the chemical reaction at the liquid-gas interface below 2250℃, and by nitrogen transfer in liquid diffusion layer under 2250℃~2813℃ conditions. The activation energy Ea was 57 k J/mol for 0.0050%[S], 95 k J/mol for 0.012%[S], 165 k J/mol for 0.140%[S]. The resistance of sulphur on nitrogen removal decreased with the temperature rose, and disappeared at 2630℃. Based on the results obtained, it has been answered why the nitrogen in liquid steel can be decreased rapidly by carbon-oxygen reaction under very high oxygen and sulphur content conditions during the BOF, EAF, VOD and AOD steelmaking processes.

  3. Thermodynamics of High Temperature Plasmas

    Directory of Open Access Journals (Sweden)

    Ettore Minardi

    2009-03-01

    Full Text Available In this work we discuss how and to what extent the thermodynamic concepts and the thermodynamic formalism can be extended to the description of high temperature states of the plasma not necessarily associated with a Boltzmann distribution and with thermal equilibrium.The discussion is based on the “magnetic or electrostatic entropy concept”, an interpretative and predictive tool based on probability and information, defined in a suitably coarse-grained possibility space of all current density or of all electric charge density distributions under testable constraints, and whose variation properties are proven to be related under certain conditions to the equilibrium and the stability of the system. In the case of magnetic equilibrium the potentiality of the magnetic entropy concept is illustrated by comparing the predictions of the current density and pressure profiles with the observations in different tokamak machines and different tokamak regimes, as well as by showing how the equilibrium and the stability in devices as different as the reversed field pinch or the magnetic well are described by the variation properties of the same entropy functional applied to the different situations. In fact it emerges that the maximum of the entropy can be seen in these different cases as an optimization constraint for the minimum of the magnetic energy. The application of the entropy concept to the electrostatic processes shows in particular that the so-called reactive instabilities (non-dissipative, non-resonant instabilities with a marginal point admit a neighboring state with higher entropy and are therefore of special relevance from the point of view of the physical evolution of the system. In this case the thermodynamic formalism allows the introduction of the concept of “thermodynamic fluctuations” of the macroscopic charge density and provides a method for the calculation of the “thermodynamic” fluctuation levels both on the stable as

  4. High temperature superconducting fault current limiter

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    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).

  5. (Krauss) at constant high temperatures

    African Journals Online (AJOL)

    the various physical and chemical factors that may affect freshwater snails. However ... order to assess the effect of temperature on the organism, it is essential to ..... of snails by parasites is of cardinal importance to shed light on the population ...

  6. 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.

  7. Simultaneous Removal of NOx and Mercury in Low Temperature Selective Catalytic and Adsorptive Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Neville G. Pinto; Panagiotis G. Smirniotis

    2006-03-31

    The results of a 18-month investigation to advance the development of a novel Low Temperature Selective Catalytic and Adsorptive Reactor (LTSCAR), for the simultaneous removal of NO{sub x} and mercury (elemental and oxidized) from flue gases in a single unit operation located downstream of the particulate collectors, are reported. In the proposed LTSCAR, NO{sub x} removal is in a traditional SCR mode but at low temperature, and, uniquely, using carbon monoxide as a reductant. The concomitant capture of mercury in the unit is achieved through the incorporation of a novel chelating adsorbent. As conceptualized, the LTSCAR will be located downstream of the particulate collectors (flue gas temperature 140-160 C) and will be similar in structure to a conventional SCR. That is, it will have 3-4 beds that are loaded with catalyst and adsorbent allowing staged replacement of catalyst and adsorbent as required. Various Mn/TiO{sub 2} SCR catalysts were synthesized and evaluated for their ability to reduce NO at low temperature using CO as the reductant. It has been shown that with a suitably tailored catalyst more than 65% NO conversion with 100% N{sub 2} selectivity can be achieved, even at a high space velocity (SV) of 50,000 h-1 and in the presence of 2 v% H{sub 2}O. Three adsorbents for oxidized mercury were developed in this project with thermal stability in the required range. Based on detailed evaluations of their characteristics, the mercaptopropyltrimethoxysilane (MPTS) adsorbent was found to be most promising for the capture of oxidized mercury. This adsorbent has been shown to be thermally stable to 200 C. Fixed-bed evaluations in the targeted temperature range demonstrated effective removal of oxidized mercury from simulated flue gas at very high capacity ({approx}>58 mg Hg/g adsorbent). Extension of the capability of the adsorbent to elemental mercury capture was pursued with two independent approaches: incorporation of a novel nano-layer on the surface of the

  8. High Temperature and Pressure Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank

    and oxygen with a new type of alkaline electrolysis cell at high temperatures and pressures. To perform measurements under high pressure and at elevated temperatures it was necessary to build a measurement system around an autoclave which could stand high temperatures up to 250 °C and pressures up to 200 bar...... as well as extremely caustic environments. Based on a literature study to identify resistant materials for these conditions, Inconel 600 was selected among the metals which are available for autoclave construction. An initial single atmosphere high temperature and pressure measurement setup was build...... comprising this autoclave. A second high temperature and pressure measurement setup was build based on experiences from the first setup in order to perform automatized measurements. The conductivity of aqueous KOH at elevated temperatures and high concentrations was investigated using the van der Pauw method...

  9. High-temperature protective coatings on superalloys

    Institute of Scientific and Technical Information of China (English)

    刘培生; 梁开明; 周宏余

    2002-01-01

    Protective coatings are essential for superalloys to serve as blades of gas turb ines at high temperatures, and they primarily include aluminide coating, MCrAlY overlay coating, thermal barrier coating and microcrystalline coating. In this paper, all these high-temperature coatings are reviewed as well as their preparing techniques. Based on the most application and the main failure way, the importance is then presented for further deepgoing study on the high-temperature oxidation law of aluminide coatings.

  10. High Temperature Heterojunction Bipolar Transistors

    Science.gov (United States)

    1994-04-15

    2700 cmW/V-s at room temperature, a far higher value than ever found for GaN or AlGaN. Thus a GaN/ InGaN HEMT would be analogous to InP/InGaAs HEMTs...Spire’s ECR plasma source modif led as a crystal growth reactor. 8 The substrate for the film deposition is mounted on a sample holder which is...The three samples from the second growth run were also characterized. One sample was found to have a very even frosty white haze on it. The other

  11. A high temperature fuel element

    Energy Technology Data Exchange (ETDEWEB)

    Sekido, A.; Nakai, M.; Ninomiya, Y.

    1982-12-21

    A solid electrolyte which conducts electricity with heating by oxygen ions and operates at a temperature of 1,000C is used in the element. The cathode, besides the ionic conductivity in oxygen, has an electron conductivity. The anode has electron conductivity. Substances such as Bi203, into which oxides of alkaline earth metals are added, are used for making the cathode. The electrolyte consists of ZrO2 and Y2O3, to which CaO is added. WC, to which an H2 type fuel is fed, serves as the anode. The element has a long service life.

  12. Removal of parabens and their chlorinated by-products by periphyton: influence of light and temperature.

    Science.gov (United States)

    Song, Chaofeng; Hu, Hongjuan; Ao, Hongyi; Wu, Yonghong; Wu, Chenxi

    2017-02-01

    The extensive use of parabens as preservatives in food and pharmaceuticals and personal care products results in frequent detection of their residuals in aquatic environment. In this work, the adsorption and removal of four parabens (methyl-, ethyl-, propyl-, and butyl-paraben) and two chlorinated methyl-parabens (CMPs) by periphyton were studied. Characteristics of the periphyton were identified to explore the possible relationship between paraben removal and periphyton properties. Results showed that linear adsorption coefficients (K d) vary from 554.4 to 808.6 L kg(-1) for the adsorption parabens and CMPs to autoclaved periphyton. The adsorption strength is positively related to the hydrophobicity of these compounds. Removal of parabens from water by periphyton was efficient with half-life (t 1/2) values estimated using first-order kinetic model ranging from 0.49 to 3.29 days, but CMPs were more persistent with t 1/2 ranging from 1.15 to 25.57 days, and t 1/2 increased with the chlorination degree. Higher incubation temperature accelerated the removal of all tested compounds, while a better removal of CMPs was observed in dark condition. Analysis of periphyton properties suggests that bacteria played a more important role in the removal of CMPs, but no specific relationship between periphyton properties and paraben removal ability can be established.

  13. Ultrasonic Sensors for High Temperature Applications

    Science.gov (United States)

    Tittmann, Bernhard; Aslan, Mustafa

    1999-05-01

    Many processes take place under conditions other than ambient, and chief among these is high temperature. Examples of high temperature industrial processes are resin transfer molding, molten metal infiltration and rheocasting of composite metals alloys. The interaction of waves with viscous fluids is an additional complication adding to an already complicated problem of operating a sensor at high temperature for extended periods of time. This report attempts to provide an insight into the current state of the art of sensor techniques for in-situ high temperature monitoring.

  14. 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

  15. 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...

  16. 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

  17. Alloys developed for high temperature applications

    Science.gov (United States)

    Basuki, Eddy Agus; Prajitno, Djoko Hadi; Muhammad, Fadhli

    2017-01-01

    Alloys used for high temperatures applications require combinations of mechanical strength, microstructural stability and corrosion/oxidation resistance. Nickel base superalloys have been traditionally the prime materials utilized for hot section components of aircraft turbine engines. Nevertheless, due to their limited melting temperatures, alloys based on intermetallic compounds, such as TiAl base alloys, have emerged as high temperature materials and intensively developed with the main aim to replace nickel based superalloys. For applications in steam power plants operated at lower temperatures, ferritic high temperature alloys still attract high attention, and therefore, development of these alloys is in progress. This paper highlights the important metallurgical parameters of high temperature alloys and describes few efforts in the development of Fe-Ni-Al based alloys containing B2-(Fe,Ni)Al precipitates, oxide dispersion strengthening (ODS) ferritic steels and titanium aluminide based alloys include important protection system of aluminide coatings.

  18. Study on a transient optical fiber high temperature measurement system

    Science.gov (United States)

    Cai, Lulu; Liu, Yusha; Wang, Yutian

    2009-07-01

    High temperature is one of the most important parameters in the fields of scientific research and industrial production. At present, thermocouple, thermo resistive and radiance thermometer are already technologically mature which can be adopted to measure the general temperature, but when it comes to the transient high temperature that changes pretty quickly in wretched conditions, those traditional pyrometers can not meet the requirements any more. In this paper, we designed a transient optical high temperature measurement system. First, design of the temperature measurement probe. The system took blackbody cavity sensor together with optical fiber to receive the measured signal, here, the integrated emissivity model of the blackbody cavity was established and the optimum structure parameters were confirmed. Secondly, design of the entire temperature measurement system. A contact-noncontact measurement method was applied, which is to make the blackbody cavity and the measured high-temperature source contact, the fiber probe and the blackbody cavity noncontact, as a result, the error caused by contact measurement is overcame and the precision is guaranteed at the same time. In addition, a fiber grating was introduced as the wavelength filter device which can realize the dynamic filter of narrow-band signals and reduce the impact of background light. Thirdly, signal processing. In this part, we applied labVIEW software and wavelet analysis method. All of the signal acquisition and processing were realized in the labVIEW environment. Through calling matlab in labVIEW, the signals from optical fiber detector were wavelet denoised and decomposed, thus the temperature information was extracted, and the temperature value was obtained. On basis of wavelet transformation, the paper adopted the 4dB wavelet with horizontal scale of 5 to realize the feature extraction and noise removal, parts of the signals before and after the wavelet noise removal were given and analyzed

  19. 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

  20. 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.

  1. Corrosion Resistant Coatings for High Temperature Applications

    Energy Technology Data Exchange (ETDEWEB)

    Besman, T.M.; Cooley, K.M.; Haynes, J.A.; Lee, W.Y.; Vaubert, V.M.

    1998-12-01

    Efforts to increase efficiency of energy conversion devices have required their operation at ever higher temperatures. This will force the substitution of higher-temperature structural ceramics for lower temperature materials, largely metals. Yet, many of these ceramics will require protection from high temperature corrosion caused by combustion gases, atmospheric contaminants, or the operating medium. This paper discusses examples of the initial development of such coatings and materials for potential application in combustion, aluminum smelting, and other harsh environments.

  2. Preliminary Strength Measurements of High Temperature Ash Filter Deposits

    Energy Technology Data Exchange (ETDEWEB)

    Kang, B.S.; Johnson, E.K.; Mallela, R.; Barberio, J.F. [West Virginia Univ., Morgantown, WV (United States). Dept. of Mechanical and Aerospace Engineering

    1996-12-31

    The objective of this study is to develop and evaluate preliminary strength measurement techniques for high temperature candle filter ash deposits. The efficient performance of a high temperature gas filtering system is essential for many of the new thermal cycles being proposed for power plants of the future. These new cycles hold the promise of higher thermal efficiency and lower emissions of pollutants. Many of these cycles involve the combustion or gasification of coal to produce high temperature gases to eventually be used in gas turbines. These high temperature gases must be relatively free of particulates. Today, the candle filter appears to be the leading candidate for high temperature particulate removal. The performance of a candle filter depends on the ash deposits shattering into relatively large particles during the pulse cleaning (back flushing) of the filters. These relatively large particles fall into the ash hopper and are removed from the system. Therefore, these 1247 particles must be sufficiently large so that they will not be re-entrained by the gas flow. The shattering process is dictated by the strength characteristics of the ash deposits. Consequently, the objective of this research is to develop measurements for the desired strength characteristics of the ash deposits. Experimental procedures were developed to measure Young`s modulus of the ash deposit at room temperature and the failure tensile strain of ash deposits from room temperature to elevated temperatures. Preliminary data has been obtained for both soft and hard ash deposits. The qualifier ``preliminary`` is used to indicate that these measurements are a first for this material, and consequently, the measurement techniques are not perfected. In addition, the ash deposits tested are not necessarily uniform and further tests are needed in order to obtain meaningful average data.

  3. High-Temperature Passive Power Electronics

    Science.gov (United States)

    1997-01-01

    In many future NASA missions - such as deep-space exploration, the National AeroSpace Plane, minisatellites, integrated engine electronics, and ion or arcjet thrusters - high-power electrical components and systems must operate reliably and efficiently in high-temperature environments. The high-temperature power electronics program at the NASA Lewis Research Center focuses on dielectric and insulating material research, the development and characterization of high-temperature components, and the integration of the developed components into a demonstrable 200 C power system - such as an inverter. NASA Lewis has developed high-temperature power components through collaborative efforts with the Air Force Wright Laboratory, Northrop Grumman, and the University of Wisconsin. Ceramic and film capacitors, molypermalloy powder inductors, and a coaxially wound transformer were designed, developed, and evaluated for high-temperature operation.

  4. A Road Towards High Temperature Superconductors

    Science.gov (United States)

    2013-08-01

    AFRL-AFOSR-UK-TR-2013-0040 A Road Towards High Temperature Superconductors Guy Deutscher Tel Aviv University Research... Superconductors 5a. CONTRACT NUMBER FA8655-10-1-3011 5b. GRANT NUMBER Grant 10-3011 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S...issue in trying to make useful high temperature superconductors is obviously to discover superconductivity at higher temperatures. But there is also

  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. 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...

  7. 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....

  8. 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...

  9. Ceramic fibres for high temperature insulation

    Energy Technology Data Exchange (ETDEWEB)

    Padgett, G.C.

    1986-03-01

    Traditionally, refractory linings for high temperature plant and furnaces have comprised either brick or some form of concrete. In recent years, energy conservation has encouraged the greater use of high temperature insulation which is also available in either brick or a lightweight concrete. As an alternative, insulation can also be achieved using fibrous products or fibres combining low heat transfer with low heat capacity.

  10. Effect of temperature on removal of trace organic chemicals in managed aquifer recharge systems

    KAUST Repository

    Alidina, Mazahirali

    2015-03-01

    This study was undertaken to investigate whether changes in temperature experienced in MAR systems affect attenuation of trace organic chemicals (TOrCs). A set of laboratory-scale soil columns were placed in a temperature-controlled environmental chamber and operated at five different temperature set-points (30, 20, 10, 8 and 4. °C) covering the range of typical groundwater temperatures in cold, moderate and arid climate regions. Removal of bulk organic carbon both in the infiltration zone as well as during deeper infiltration was independent of temperature. Of the 22 TOrCs investigated, only six chemicals exhibited changes in attenuation as a function of temperature. Attenuation of four of the compounds (diclofenac, gemfibrozil, ketoprofen and naproxen) decreased as the temperature was reduced from 30. °C to 4. °C, likely due to decreased microbial activity at lower temperatures. As the temperature was decreased, however, attenuation of oxybenzone and trimethoprim were noted to increase. This increased attenuation was likely due to more efficient sorption at lower temperatures, though possible changes in the microbial composition as the temperature decreased may also have contributed to this change. Changes in rate constants of attenuation (. ka) for the biotransformed TOrCs with temperature suggested the existence of a critical temperature at 10. °C for three of the four TOrCs, where significant changes to rates of attenuation occurred. Results from this study indicated that for most TOrCs, changes in temperature do not impact their attenuation. Thus, seasonal changes in temperature are not considered to be a major concern for attenuation of most TOrCs in MAR systems.

  11. Laboratory Study on the Removal of Fluorine from High Fluorine Bearing Zinc Oxide Ore

    Institute of Scientific and Technical Information of China (English)

    Yaozhong LAN; Liaoyuan YE; Rose W. Smith

    2005-01-01

    An ever increasing demand for zinc has resulted in worldwide efforts to exploit complex and lean grade reserves of zinc oxide ore. In this study experiments were done on zinc recovery from high-fluorine bearing zinc oxide ore. First the effect of different variables on fluorine removal was investigated. Optimum experimental conditions occurred when the temperature was 1173 K, roasting time was 90 min and air flow was at a velocity of 5 m/min, the fluorine removal from the samples reached over 93%. The results obtained indicate that fluorine removal is not enhanced by adding diluted sulfuric acid or water as a binder. Second the roasted materials were leached with a diluted sulfuric acid,neutralized, flocculated and filtrated. The residual fluorine content in the leached solutions was less than 38 mg/L,which satisfies the requirement of fluorine content in the leached solutions for the production of electrolytic zinc.

  12. Highly efficient removal of arsenic metal ions with high superficial area hollow magnetite nanoparticles synthetized by AACVD method

    Energy Technology Data Exchange (ETDEWEB)

    Monárrez-Cordero, B.; Amézaga-Madrid, P.; Antúnez-Flores, W.; Leyva-Porras, C.; Pizá-Ruiz, P. [Centro de Investigación en Materiales Avanzados S.C., and Laboratorio Nacional de Nanotecnología, Miguel de Cervantes 120, Chihuahua, Chih. C.P. 31109 (Mexico); Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx [Centro de Investigación en Materiales Avanzados S.C., and Laboratorio Nacional de Nanotecnología, Miguel de Cervantes 120, Chihuahua, Chih. C.P. 31109 (Mexico)

    2014-02-15

    Highlights: ► Fast and high arsenic removal efficiency, almost 100% in one minute. ► Successful synthesis of high purity magnetite hollow nanoparticles is reported. ► They were synthesized by one step aerosol assisted CVD technique. ► Detailed microstructural characterization by electron microscopy was performed. -- Abstract: New nanotechnology alternatives and methodologies have been developed in order to overcome the limitations of conventional techniques for metal ions removal from water. Currently, the removal of heavy metals requires multiple steps which include the separation and post-treatment of the generated sludge. Usually, this sludge is composed of dangerous environmental pollutants mixed with the material used for removing the metal ion. Thus, the removal of these metals becomes a challenging task. Herein we report the synthesis of magnetite nanoparticles with high specific area by the aerosol assisted chemical vapour deposition method. Deposition temperature were fixed at 450 °C and a mixture of Ar–air were used as a carrier gas, a flow of 1.0 and 0.015 L min{sup −1} were used for Ar and air, respectively. The precursor solution was a dilution of Fe (II) chloride in methanol, with different concentration 0.01, 0.05 and 0.1 mol dm{sup −3}. The crystalline structure of the nanoparticles was characterized by grazing incidence X-ray diffraction. Morphology and microstructure were analyzed by field emission scanning electron microscopy, scanning probe microscopy and transmission electron microscopy. Magnetic properties were evaluated with a vibrating sample magnetometer and specific area was measured by the Brunauer–Emmett–Teller method. To determine the removal efficiency of arsenic ion from water, several tests were carried out at six exposition times 1, 3, 5, 10, 20 and 30 min. Results showed high removal efficiency, more than 99%, in less than 1 min.

  13. Effective removal of methotrexate by high-flux hemodialysis.

    Science.gov (United States)

    Saland, Jeffrey M; Leavey, Patrick J; Bash, Robert O; Hansch, Eleonora; Arbus, Gerald S; Quigley, Raymond

    2002-10-01

    The purpose of the present study was to examine the clearance of methotrexate (MTX) by high-flux hemodialysis (HD) in pediatric oncology patients. We present three patients who experienced nephrotoxicity and prolonged exposure to toxic MTX concentrations following high-dose infusions during treatment for osteogenic sarcomas. Each patient was successfully treated with high-flux HD, followed by carboxypeptidase G2 (CPDG2) in two cases. Minimal systemic toxicity occurred. We review the literature and discuss guidelines for early and aggressive treatment for this complication of high-dose MTX therapy. Clinically important removal of MTX depends upon prompt initiation of HD after detection of nephrotoxicity and delayed clearance of MTX. Therapy is indicated in cases where compassionate use of CPDG(2) may not be available, or while awaiting its delivery.

  14. Development of a High Temperature Microbial Fermentation Processfor Butanol Production

    Energy Technology Data Exchange (ETDEWEB)

    St. Jeor, Jeffery D.; Reed, David W.; Daubaras, Dayna L.; Thompson, Vicki S.

    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.

  15. 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...

  16. The removal of reactive dyes using high-ash char

    Directory of Open Access Journals (Sweden)

    Moreira R.F.P.M.

    2001-01-01

    Full Text Available The thermodynamics and kinetics of adsorption of reactive dyes on high-ash char was studied. Equilibrium data were obtained using the static method with controlled agitation at temperatures in the range of 30 to 60ºC. The Langmuir isotherm model was used to describe the equilibrium of adsorption, and the equilibrium parameters, R L, in the range of 0 to 1 indicate favorable adsorption. The amount of dye adsorbed increased as temperature increased from 30 to 40ºC, but above 40ºC the increase in temperature resulted in a decrease in the amount of dye adsorbed. The kinetic data presented are for controlled agitation at 50 rpm and constant temperature with dye concentrations in the range of 10 ppm to50 ppm. The film mass transfer coefficient, Kf, and the effective diffusivity inside the particle, De, were fitted to the experimental data. The results indicate that internal diffusion governs the adsorption rate.

  17. Thermoelastic properties of minerals at high temperature

    Indian Academy of Sciences (India)

    Sanjay Upadhyay; Hem Chandra; Meenakashi Joshi; Deepika P Joshi

    2011-01-01

    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 the Kumar’s formulation by taking into the account the concept of anharmonicity in minerals above the Debye temperature (D). In our present study, we have investigated the thermophysical properties of two minerals (pyrope-rich garnet and MgAl2O4) under high temperatures and calculated the second-order elastic constant () and bulk modulus (T) of the above minerals, in two cases first by taking Anderson–Gruneisen parameter (T) as temperature-independent and then by treating T as temperature-dependent parameter. The results obtained when T is temperature-dependent are in close agreement with experimental data.

  18. Low to high temperature energy conversion system

    Science.gov (United States)

    Miller, C. G. (Inventor)

    1977-01-01

    A method for converting heat energy from low temperature heat sources to higher temperature was developed. It consists of a decomposition chamber in which ammonia is decomposed into hydrogen and nitrogen by absorbing heat of decomposition from a low temperature energy source. A recombination reaction then takes place which increases the temperature of a fluid significantly. The system is of use for the efficient operation of compact or low capital investment turbine driven electrical generators, or in other applications, to enable chemical reactions that have a critical lower temperature to be used. The system also recovers heat energy from low temperature heat sources, such as solar collectors or geothermal sources, and converts it to high temperatures.

  19. 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.

  20. PETIs as High-Temperature Resin-Transfer-Molding Materials

    Science.gov (United States)

    Connell, John N.; Smith, Joseph G., Jr.; Hergenrother, Paul M.

    2005-01-01

    Compositions of, and processes for fabricating, high-temperature composite materials from phenylethynyl-terminated imide (PETI) oligomers by resin-transfer molding (RTM) and resin infusion have been developed. Composites having a combination of excellent mechanical properties and long-term high-temperature stability have been readily fabricated. These materials are particularly useful for the fabrication of high-temperature structures for jet-engine components, structural components on highspeed aircraft, spacecraft, and missiles. Phenylethynyl-terminated amide acid oligomers that are precursors of PETI oligomers are easily made through the reaction of a mixture of aromatic diamines with aromatic dianhydrides at high stoichiometric offsets and 4-phenylethynylphthalic anhydride (PEPA) as an end-capper in a polar solvent such as N-methylpyrrolidinone (NMP). These oligomers are subsequently cyclodehydrated -- for example, by heating the solution in the presence of toluene to remove the water by azeotropic distillation to form low-molecular-weight imide oligomers. More precisely, what is obtained is a mixture of PETI oligomeric species, spanning a range of molecular weights, that exhibits a stable melt viscosity of less than approximately 60 poise (and generally less than 10 poise) at a temperature below 300 deg C. After curing of the oligomers at a temperature of 371 deg C, the resulting polymer can have a glass-transition temperature (Tg) as high as 375 C, the exact value depending on the compositions.

  1. High temperature structural, polymeric foams from high internal emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Hoisington, M.A.; Duke, J.R.; Apen, P.G.

    1996-02-01

    In 1982, a high internal phase emulsion (HIPE) polymerization process to manufacture microcellular, polymeric foam systems was patented by Unilever. This patent discloses a polymerization process that occurs in a water-in-oil emulsion in which the water represents at least 76% of the emulsion by volume. The oil phase consists of vinyl monomers such as styrene and acrylates that are crosslinked by divinyl monomers during polymerization. After polymerization and drying to remove the water phase, the result is a crosslinked polymer foam with an open cell microstructure that is homogeneous throughout in terms of morphology, density, and mechanical properties. Since 1982, numerous patents have examined various HIPE polymerized foam processing techniques and applications that include absorbents for body fluids, cleaning materials, and ion exchange systems. All the published HIPE polymerized foams have concentrated on materials for low temperature applications. Copolymerization of styrene with maleic anhydride and N-substituted maleimides to produce heat resistant thermoplastics has been studied extensively. These investigations have shown that styrene will free radically copolymerize with N-substituted maleimides to create an alternating thermoplastic copolymer with a Tg of approximately 200{degrees}C. However, there are many difficulties in attempting the maleimide styrene copolymerization in a HIPE such as lower polymerization temperatures, maleimide solubility difficulties in both styrene and water, and difficulty obtaining a stable HIPE with a styrene/maleimide oil phase. This work describes the preparation of copolymer foams from N-ethylmaleimide and Bis(3-ethyl-5-methyl-4-maleimide-phenyl)methane with styrene based monomers and crosslinking agents.

  2. Dimensionality of high temperature superconductivity in oxides

    Science.gov (United States)

    Chu, C. W.

    1989-01-01

    Many models have been proposed to account for the high temperature superconductivity observed in oxide systems. Almost all of these models proposed are based on the uncoupled low dimensional carrier Cu-O layers of the oxides. Results of several experiments are presented and discussed. They suggest that the high temperature superconductivity observed cannot be strictly two- or one-dimensional, and that the environment between the Cu-O layers and the interlayer coupling play an important role in the occurrence of such high temperature superconductivity. A comment on the very short coherence length reported is also made.

  3. 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.

  4. 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.

  5. High temperature and pressure alkaline electrolysis

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...... 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...

  6. 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.

  7. 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.

  8. Development of high temperature capable piezoelectric sensors

    Science.gov (United States)

    Suprock, Andrew D.; Tittmann, Bernhard R.

    2017-02-01

    The objective of the project was to investigate the influence of the temperature effect on ultrasonic transducers based on a comparison of the effects of high temperature conditions versus those of high temperature and irradiation on the transducer system. There was also a preliminary move towards the establishment of the means for optimizing the bulk single crystal transducer fabrication process in order to achieve peak efficiency and maximum effectiveness in both irradiated and non-irradiated high temperature applications. Optimization of the material components within the transducer will greatly increase non-destructive testing abilities for industry, structural health monitoring. Here is presented a progress report on the testing of several different piezoelectric materials under high temperature conditions. The viability of aluminum nitride (AlN) as a transducer material in high temperature conditions has been previously explored [1] and has been further tested to ensure reliability. Bistmuth Titanate (BiT) has also been tested and has displayed excellent effectiveness for high temperature application.

  9. Effects of vegetation, season and temperature on removal pollutants in experimental floating treatment wetlands

    OpenAIRE

    Van de Moortel, Annelies; Meers, Erik; Niels DE PAUW; Tack, Filip

    2010-01-01

    The research and interest towards the use of constructed floating wetlands for (waste)water treatment is emerging as more treatment opportunities are marked out, and the technique is applied more often. To evaluate the effect of a floating macrophyte mat and the influence of temperature and season on physico-chemical changes and removal, two constructed floating wetlands (CFWs), including a floating macrophyte mat, and a control, without emergent vegetation, were built. Raw domestic wastewate...

  10. Broadband, High-Temperature Ultrasonic Transducer

    Science.gov (United States)

    Parker, F. Raymond; Winfree, William P.; Barrows, Danny A.

    1995-01-01

    Materials chosen for endurance at high temperatures and acoustic coupling and damping. Acoustic transducer designed to exhibit broad frequency response and to survive temperatures close to melting points of brazing alloys. Attached directly and continuously to hot object monitored ultrasonically: for example, it can be attached to relatively cool spot on workpiece during brazing for taking ultrasonic quality-control measurements.

  11. Temperature effects on nitrogen cycling and nitrate removal-production efficiency in bed form-induced hyporheic zones

    Science.gov (United States)

    Zheng, Lizhi; Cardenas, M. Bayani; Wang, Lichun

    2016-04-01

    Hyporheic flow in aquatic sediment controls solute and heat transport thereby mediating the fate of nutrients and contaminants, dissolved oxygen, and temperature in the hyporheic zone (HZ). We conducted a series of numerical simulations of hyporheic processes within a dune with different uniform temperatures, coupling turbulent open channel fluid flow, porous fluid flow, and reactive solute transport to study the temperature dependence of nitrogen source/sink functionality and its efficiency. Two cases were considered: a polluted stream and a pristine stream. Sensitivity analysis was performed to investigate the influence of stream water [NO3-]/[NH4+]. The simulations showed that in both cases warmer temperatures resulted in shallower denitrification zones and oxic-anoxic zone boundaries, but the trend of net denitrification rate and nitrate removal or production efficiency of the HZ for these two cases differed. For both cases, at high [NO3-]/[NH4+], the HZ functioned as a NO3- sink with the nitrate removal efficiency increasing with temperature. But at low [NO3-]/[NH4+] for the polluted stream, the HZ is a NO3- sink at low temperature but then switches to a NO3- source at warmer temperatures. For the pristine stream case, the HZ was always a NO3- source, with the NO3- production efficiency increasing monotonically with temperature. In addition, although the interfacial fluid flux expectedly increased with increasing temperature due to decreasing fluid viscosity, the total nitrate flux into the HZ did not follow this trend. This is because when HZ nitrification is high, uniformly elevated [NO3-] lowers dispersive fluxes into the HZ. We found that there are numerous confounding and interacting factors that combined to lead to the final temperature dependence of N transformation reaction rates. Although the temperature effect on the rate constant can be considered as the dominant factor, simply using the Arrhenius equation to predict the reaction rate would lead to

  12. 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...

  13. High Temperature Self-Healing Metallic Composite

    Science.gov (United States)

    Kutelia, E. R.; Bakhtiyarov, S. I.; Tsurtsumia, O. O.; Bakhtiyarov, A. S.; Eristavi, B.

    2012-01-01

    This work presents the possibility to realize the self healing mechanisms for heterogeneous architectural metal/ceramic high temperature sandwich thermal barrier coating systems on the surfaces refractory metals by analogy of wound healing in the skin.

  14. 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...

  15. 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)

  16. Application Fields of High-Temperature Superconductors

    OpenAIRE

    Hott, Roland

    2003-01-01

    Potential application fields for cuprate high-temperature superconductors (HTS) and the status of respective projects are reviewed. The availability of a reliable and inexpensive cooling technique will be essential for a future broad acceptance of HTS applications.

  17. Measuring Moduli Of Elasticity At High Temperatures

    Science.gov (United States)

    Wolfenden, Alan

    1993-01-01

    Shorter, squatter specimens and higher frequencies used in ultrasonic measurement technique. Improved version of piezo-electric ultrasonic composite oscillator technique used to measure moduli of elasticity of solid materials at high temperatures.

  18. Silicon carbide, an emerging high temperature semiconductor

    Science.gov (United States)

    Matus, Lawrence G.; Powell, J. Anthony

    1991-01-01

    In recent years, the aerospace propulsion and space power communities have expressed a growing need for electronic devices that are capable of sustained high temperature operation. Applications for high temperature electronic devices include development instrumentation within engines, engine control, and condition monitoring systems, and power conditioning and control systems for space platforms and satellites. Other earth-based applications include deep-well drilling instrumentation, nuclear reactor instrumentation and control, and automotive sensors. To meet the needs of these applications, the High Temperature Electronics Program at the Lewis Research Center is developing silicon carbide (SiC) as a high temperature semiconductor material. Research is focussed on developing the crystal growth, characterization, and device fabrication technologies necessary to produce a family of silicon carbide electronic devices and integrated sensors. The progress made in developing silicon carbide is presented, and the challenges that lie ahead are discussed.

  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. Removal of NO(x) at low temperature over mesoporous alpha-Mn2O3 catalyst.

    Science.gov (United States)

    Jeon, Mi-Jin; Park, Sung Hoon; Kim, Ji Man; Jeon, Jong-Ki; Kim, Sang Chai; Kim, Do Heui; Park, Young-Kwon

    2014-03-01

    Low-temperature selective catalytic reduction was carried out over various kinds of manganese oxide (MnOx) catalysts. Mesoporous alpha-Mn2O3, commercial bulk Mn2O3, and Mn/SBA-15 were used as the catalyst. The NOx removal performances of the catalysts were compared. Three different amounts of Mn (5, 10, and 15 wt%) were impregnated on SBA-15 to synthesize Mn/SBA-15. The physical and chemical properties of the catalysts were examined by Brunauer-Emmett-Teller, X-ray diffraction, X-ray photoelectron spectroscopy, and H2-temperature programmed reduction analyses. Of all catalysts examined, mesoporous alpha-Mn2O3 exhibited the highest low-temperature SCR de-NOx efficiency, reaching about 90% at 175 degrees C. This is attributed to strong reducing ability and high oxygen mobility of mesoporous alpha-Mn2O3 and well dispersed Mn2O3 in its mesoporous framework.

  1. 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.

  2. PLA recycling by hydrolysis at high temperature

    Science.gov (United States)

    Cristina, Annesini Maria; Rosaria, Augelletti; Sara, Frattari; Fausto, Gironi

    2016-05-01

    In this work the process of PLA hydrolysis at high temperature was studied, in order to evaluate the possibility of chemical recycling of this polymer bio-based. In particular, the possibility to obtain the monomer of lactic acid from PLA degradation was investigated. The results of some preliminary tests, performed in a laboratory batch reactor at high temperature, are presented: the experimental results show that the complete degradation of PLA can be obtained in relatively low reaction times.

  3. Recent developments in high temperature organic polymers

    Science.gov (United States)

    Hergenrother, P. M.

    1991-01-01

    Developments in high temperature organic polymers during the last 5 years with major emphasis on polyimides and poly(arylene ether)s are discussed. Specific polymers or series of polymers have been selected to demonstrate unique properties or the effect chemical structure has upon certain properties. This article is not intended to be a comprehensive review of high temperature polymer advancements during the last 5 years.

  4. ANALYSIS OF A HIGH TEMPERATURE GAS-COOLED REACTOR POWERED HIGH TEMPERATURE ELECTROLYSIS HYDROGEN PLANT

    Energy Technology Data Exchange (ETDEWEB)

    M. G. McKellar; E. A. Harvego; A. M. Gandrik

    2010-11-01

    An updated reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The reactor heat is used to produce heat and electric power to the HTE plant. A Rankine steam cycle with a power conversion efficiency of 44.4% was used to provide the electric power. The electrolysis unit used to produce hydrogen includes 1.1 million cells with a per-cell active area of 225 cm2. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 42.8% at a hydrogen production rate of 1.85 kg/s (66 million SCFD) and an oxygen production rate of 14.6 kg/s (33 million SCFD). An economic analysis of this plant was performed with realistic financial and cost estimating The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.03/kg of hydrogen was calculated assuming an internal rate of return of 10% and a debt to equity ratio of 80%/20% for a reactor cost of $2000/kWt and $2.41/kg of hydrogen for a reactor cost of $1400/kWt.

  5. High-temperature discontinuously reinforced aluminum

    Science.gov (United States)

    Zedalis, M. S.; Bryant, J. D.; Gilman, P. S.; Das, S. K.

    1991-08-01

    High-temperature discontinuously reinforced aluminum (HTDRA) composites have been developed for elevated-temperature applications by incorporating SiC particulate reinforcement into a rapidly solidified, high-temperature Al-Fe-V-Si (alloy 8009) matrix. HTDRA combines the superior elevated-temperature strength, stability and corrosion resistance of the 8009 matrix with the excellent specific stiffness and abrasion resistance of the discontinuous SiC particulate reinforcement. On a specific stiffness basis, HTDRA is competitive with Ti-6-Al-4V and 17-4 PH stainless steel to temperatures approaching 480°C. Potential aerospace applications being considered for HTDRA include aircraft wing skins, missile bodies, and miscellaneous engine, spacecraft and hypersonic vehicle components.

  6. Removal of formaldehyde by a pulsed dielectric barrier discharge in dry air in the 20 °C to 300 °C temperature range

    Science.gov (United States)

    Blin-Simiand, N.; Pasquiers, S.; Magne, L.

    2016-05-01

    The influence of the gas mixture temperature, from 20 °C up to 300 °C, on the removal of formaldehyde, diluted at low concentration (less than 800 ppm) in dry air at atmospheric pressure, by a pulsed dielectric barrier discharge (DBD) is studied by means of Fourier transform infrared spectroscopy and micro gas chromatography. Efficient removal of CH2O is obtained and it is found that the characteristic energy, less than 200 J l-1, is a decreasing function of the temperature over the whole range of concentration values under consideration. Byproducts issued from the removal are identified and quantified (CO, CO2, HCOOH, HNO3). Experimental results are analysed using a zero-dimensional simplified DBD-reactor model in order to gain insights on the chemical processes involved. It is shown that the dissociation of the molecule competes with oxidation reactions at low temperature, whereas at high temperature oxidation processes dominate.

  7. 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.

  8. Relativistic QED Plasma at Extremely High Temperature

    CERN Document Server

    Masood, Samina S

    2016-01-01

    Renormalization scheme of QED (Quantum Electrodynamics) at high temperatures is used to calculate the effective parameters of relativistic plasma in the early universe. Renormalization constants of QED play role of effective parameters of the theory and can be used to determine the collective behavior of the medium. We explicitly show that the dielectric constant, magnetic reluctivity, Debye length and the plasma frequency depend on temperature in the early universe. Propagation speed, refractive index, plasma frequency and Debye shielding length of a QED plasma are computed at extremely high temperatures in the early universe. We also found the favorable conditions for the relativistic plasma from this calculations.

  9. 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

  10. 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.

  11. Synthesis and development of processes for the recovery of sulfur from acid gases. Part 1, Development of a high-temperature process for removal of H2S from coal gas using limestone -- thermodynamic and kinetic considerations; Part 2, Development of a zero-emissions process for recovery of sulfur from acid gas streams

    Energy Technology Data Exchange (ETDEWEB)

    Towler, Gavin P. [Univ. of California, Berkeley, CA (United States)

    1993-05-01

    Limestone can be used more effectively as a sorbent for H2S in high-temperature gas-cleaning applications if it is prevented from undergoing calcination. Sorption of H2S by limestone is impeded by sintering of the product CaS layer. Sintering of CaS is catalyzed by CO2, but is not affected by N2 or H2. The kinetics of CaS sintering was determined for the temperature range 750--900°C. When hydrogen sulfide is heated above 600°C in the presence of carbon dioxide elemental sulfur is formed. The rate-limiting step of elemental sulfur formation is thermal decomposition of H2S. Part of the hydrogen thereby produced reacts with CO2, forming CO via the water-gas-shift reaction. The equilibrium of H2S decomposition is therefore shifted to favor the formation of elemental sulfur. The main byproduct is COS, formed by a reaction between CO2 and H2S that is analogous to the water-gas-shift reaction. Smaller amounts of SO2 and CS2 also form. Molybdenum disulfide is a strong catalyst for H2S decomposition in the presence of CO2. A process for recovery of sulfur from H2S using this chemistry is as follows: Hydrogen sulfide is heated in a high-temperature reactor in the presence of CO2 and a suitable catalyst. The primary products of the overall reaction are S2, CO, H2 and H2O. Rapid quenching of the reaction mixture to roughly 600°C prevents loss Of S2 during cooling. Carbonyl sulfide is removed from the product gas by hydrolysis back to CO2 and H2S. Unreacted CO2 and H2S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H2 and CO, which recovers the hydrogen value from the H2S. This process is economically favorable compared to the existing sulfur

  12. High-temperature granulites and supercontinents

    Institute of Scientific and Technical Information of China (English)

    J.L.R. Touret; M. Santosh; J.M. Huizenga

    2016-01-01

    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 post-dating 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.

  13. 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.

  14. Models of optimal technology for removing oil by secondary methods of developing highly viscous oil fields

    Energy Technology Data Exchange (ETDEWEB)

    Jewulski, J.

    1982-01-01

    This paper presents research on developing several methods of optimal technology for removing oil in highly viscous oil fields from the following wells: Lubno-3, Kharklova-Gvaretstvo 154 and Vetzhno (heavy oil). The problem connected with preparing the displacement fluids, with special emphasis on the authors patented technology for producing micellar solutions are discussed. The studies of dislocation fluids (including modified ones) were conducted at 3 temperatures: 293, 308, and 323/sup 0/K and with and without micellar solutions. The tests were used to idetify static regressive models of oil removal from oil fields. The model is satisfactorily accurate in predicting the amount of oil yield by using various secondary methods. Practical conclusions are reached based on an analysis of the studies. These conclusions provide the basis for industrial tests to increase the effectiveness of waterflooding highly viscous oil fields. They can also be used to develop old (gased) oil fields, an advantage considering the current fuel-energy situation.

  15. High-entropy alloys as high-temperature thermoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Shafeie, Samrand [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Guo, Sheng, E-mail: sheng.guo@chalmers.se [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Hu, Qiang [Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang 330029 (China); Fahlquist, Henrik [Bruker AXS Nordic AB, 17067 Solna (Sweden); Erhart, Paul [Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Palmqvist, Anders, E-mail: anders.palmqvist@chalmers.se [Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden)

    2015-11-14

    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.

  16. High-entropy alloys as high-temperature thermoelectric materials

    Science.gov (United States)

    Shafeie, Samrand; Guo, Sheng; Hu, Qiang; Fahlquist, Henrik; Erhart, Paul; Palmqvist, Anders

    2015-11-01

    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.

  17. Er:YAG removal of subgingival calculi: efficiency, temperature, and surface quality

    Science.gov (United States)

    Stock, Karl; Hibst, Raimund; Keller, Ulrich

    1996-12-01

    Aim of this study was to evaluate a handpiece with a special fiber tip for Er:YAG laser removal of subgingival calculus. The morphological changes of the treated areas were observed by light microscopy and SEM. To evaluate the efficiency, the time for complete removal of the calculi was measured. The temperature development in the pulp during laser treatment was investigated by a thermocouple inserted into a root canal. After calculi ablation, only smooth ablation traces are visible. The depth of the ablation traces is about 100 micrometers . Roughness of the treated area is similar to the untreated area. The ablation efficiency depends strongly on the shape and location of the calculi and varies between 4.6 and 20 mm2/min. During non stop preparation the maximum occurred temperature in pulp was 7.8 K. The results show that the Er:YAG laser with the used fiber delivery systems and handpiece is suitable for effective and sparing removal of subgingival calculus in periodontal treatment.

  18. High-temperature superconducting conductors and cables

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.E.; Maley, M.P.; Boulaevskii, L.; Willis, J.O.; Coulter, J.Y.; Ullmann, J.L.; Cho, Jin; Fleshler, S.

    1996-09-01

    This is the final report of a 3-year LDRD project at LANL. High-temperature superconductivity (HTS) promises more efficient and powerful electrical devices such as motors, generators, and power transmission cables; however this depends on developing HTS conductors that sustain high current densities J{sub c} in high magnetic fields at temperatures near liq. N2`s bp. Our early work concentrated on Cu oxides but at present, long wire and tape conductors can be best made from BSCCO compounds with high J{sub c} at low temperatures, but which are degraded severely at temperatures of interest. This problem is associated with thermally activated motion of magnetic flux lines in BSCCO. Reducing these dc losses at higher temperatures will require a high density of microscopic defects that will pin flux lines and inhibit their motion. Recently it was shown that optimum defects can be produced by small tracks formed by passage of energetic heavy ions. Such defects result when Bi is bombarded with high energy protons. The longer range of protons in matter suggests the possibility of application to tape conductors. AC losses are a major limitation in many applications of superconductivity such as power transmission. The improved pinning of flux lines reduces ac losses, but optimization also involves other factors. Measuring and characterizing these losses with respect to material parameters and conductor design is essential to successful development of ac devices.

  19. High Temperature VARTM of Phenylethynyl Terminated Imides

    Science.gov (United States)

    Ghose, Sayata; Watson, Kent A.; Cano, Roberto J.; Britton, Sean M.; Jensen, Brian J.; Connell, John W.; Herring, Helen M.; Linberry, Quentin J.

    2009-01-01

    LaRC phenylethynyl terminated imide (PETI) resins were processed into composites using high temperature vacuum assisted resin transfer molding (VARTM). Although initial runs yielded composites with high void content, process modifications reduced voids to <3%. Photomicrographs were taken and void contents and T(sub g)s of the panels were determined.

  20. Reactive Plasticizers for High Temperature Quinoxaline Thermoplastics

    Science.gov (United States)

    1976-06-01

    involves essentially two steps, consolidation of boardy prepreg into sheet stock and thermoforming the sheet stock into structural components. A...problem associated with the fabrication process is the high temperatures required in both the consolidation and thermoforming operations. High processing

  1. Fluctuations and correlations in high temperature QCD

    CERN Document Server

    Bellwied, R; Fodor, Z; Katz, S D; Pasztor, A; Ratti, C; Szabo, K K

    2015-01-01

    We calculate second- and fourth-order cumulants of conserved charges in a temperature range stretching from the QCD transition region towards the realm of (resummed) perturbation theory. We perform lattice simulations with staggered quarks; the continuum extrapolation is based on $N_t=10\\dots24$ in the crossover-region and $N_t=8\\dots16$ at higher temperatures. We find that the Hadron Resonance Gas model predictions describe the lattice data rather well in the confined phase. At high temperatures (above $\\sim$250 MeV) we find agreement with the three-loop Hard Thermal Loop results.

  2. Ultra High Temperature Ceramics for aerospace applications

    OpenAIRE

    Jankowiak, A.; Justin, J.F.

    2014-01-01

    Après relecture une erreur est apparue dans le document et doit être retiré; International audience; The Ultra High Temperature Ceramics (UHTCs) are of great interest for different engineering sectors and notably the aerospace industry. Indeed, hypersonic flights, re-entry vehicles, propulsion applications and so on, require new materials that can perform in oxidizing or corrosive atmospheres at temperatures higher than 2000°C and sometimes, for long life-time. To fulfil these requirements, U...

  3. Effects of High Temperature on Collector Coatings

    Science.gov (United States)

    Lowery, J. R.

    1982-01-01

    Report reveals electroplated black chrome is good coating for concentrating collectors in which temperatures are in the 650 degrees-800 degrees F (340 degrees - 430 degrees C) range. Black chrome thermal emittance is low and solar-absorption properties are not seriously degraded at high temperatures. Black coatings are used to increase absorption of solar energy by base metal while decreasing emission of infrared energy. Coatings are intended to improve efficiency of solar collectors.

  4. Low Temperature Heating and High Temperature Cooling in Buildings

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk

    , a single-family house designed for plus-energy targets and equipped with a radiant water-based floor heating and cooling system was studied by means of full-scale measurements, dynamic building simulations and thermodynamic evaluation tools. Thermal indoor environment and energy performance of the house...... performance of heating and cooling systems for achieving the same thermal indoor environment. The results show that it is crucial to minimize the heating and cooling demands in the design phase since these demands determine the terminal units and heat sources and sinks that could be used. Low temperature...... heating and high temperature cooling systems (a radiant water-based floor heating and cooling system in this study) proved to be superior to compared systems, evaluated with different system analysis tools; energy, exergy, and entransy. Radiant systems should be coupled to appropriate heating and cooling...

  5. Removal of nitrate by modified pine sawdust: effects of temperature and co-existing anions.

    Science.gov (United States)

    Keränen, Anni; Leiviskä, Tiina; Hormi, Osmo; Tanskanen, Juha

    2015-01-01

    The effect of temperature, sulphate and phosphate, and the initial nitrate concentration on nitrate removal was studied with synthetic solutions. Chemically modified pine sawdust (Pinus sylvestris) anion exchange resin (MPSD) was used in the sorption studies. The resin was synthesized by reacting pine sawdust with epichlorohydrin, ethylenediamine and triethylamine in the presence of N,N-dimethylformamide. Nitrate removal was successful at 5-70 °C. Higher temperatures caused nitrate removal to decrease moderately, but sorption capacities of 22.2-32.8 mg/g for NO3-N were achieved. The removal of nitrate in the presence of sulphate or phosphate was studied at concentrations of 30 mg N/l, 10-500 mg S/l and 1-50 mg P/l. A significant decrease in nitrate reduction was observed at sulphate and phosphate concentrations of 100 mg S/l and 50 mg P/l, respectively. The effect of initial nitrate concentration was studied in column. Nitrate sorption was clearly dependent on the initial concentration. Desorption of nitrate in column was completed using about 80 bed volumes of 0.1 M NaCl solution. The sorption data were fitted to the Langmuir, Freundlich and Redlich-Peterson adsorption models. The Redlich-Peterson and Langmuir models gave the best fit, which suggests monolayer sorption. Thermodynamic studies revealed that the sorption of nitrate was spontaneous and exothermic in nature. The results imply that modified pine sawdust could be a feasible alternative in the treatment of real industrial wastewaters.

  6. Removal of high concentration CO2 from natural gas at elevated pressure via absorption process in packed column

    Institute of Scientific and Technical Information of China (English)

    L.S.Tan; K.K.Lau; M.A.Bustam; A.M.Shariff

    2012-01-01

    Carbon dioxide (CO2) removal is an essential step in natural gas (NG) processing to provide high quality gas stream products and minimize operational difficulties.This preliminary study aims to investigate the removal of CO2 at high concentration level from the mixture of CO2-NG gas stream at elevated pressure via absorption process.This is to explore the possibility of exploring high CO2 content natural gas reserves by treatment at offshore platform.A mixed amine solvent,Stonvent-Ⅱ,was used for the absorption of approximately 75 vol% CO2 in CO2-NG stream at a pressure of 10 barg.The initial solvent temperature was varied in order to study the impact of initial temperature on the absorption performance.Preliminary study at temperatures of 35 ℃ and 45 ℃ indicates that Stonvent-Ⅱ was able to perform almost 100% removal of CO2 under both conditions.However,the CO2 absorption effect took place faster when the initial liquid temperature was lower.This is because when the initial liquid temperature is high,the temperature increase in the packing bed caused by the reaction heat is high which impacts the efficiency of absorption negatively.

  7. Aerobic granules formation and nutrients removal characteristics in sequencing batch airlift reactor (SBAR) at low temperature.

    Science.gov (United States)

    Bao, Ruiling; Yu, Shuili; Shi, Wenxin; Zhang, Xuedong; Wang, Yulan

    2009-09-15

    To understand the effect of low temperature on the formation of aerobic granules and their nutrient removal characteristics, an aerobic granular sequencing batch airlift reactor (SBAR) has been operated at 10 degrees C using a mixed carbon source of glucose and sodium acetate. The results showed that aerobic granules were obtained and that the reactor performed in stable manner under the applied conditions. The granules had a compact structure and a clear out-surface. The average parameters of the granules were: diameter 3.4mm, wet density 1.036 g mL(-1), sludge volume index 37 mL g(-1), and settling velocity 18.6-65.1 cm min(-1). Nitrite accumulation was observed, with a nitrite accumulation rate (NO(2)(-)-N/NO(x)(-)-N) between 35% and 43% at the beginning of the start-up stage. During the stable stage, NO(x) was present at a level below the detection limit. However, when the influent COD concentration was halved (resulting in COD/N a reduction of the COD/N from 20:1 to 10:1) nitrite accumulation was observed once more with an effluent nitrite accumulation rate of 94.8%. Phosphorus release was observed in the static feeding phase and also during the initial 20-30 min of the aerobic phase. Neither the low temperature nor adjustment of the COD/P ratio from 100:1 to 25:1 had any influence on the phosphorus removal efficiency under the operating conditions. In the granular reactor with the influent load rates for COD, NH(4)(+)-N, and PO(4)(3-)-P of 1.2-2.4, 0.112 and 0.012-0.024 kg m(-3)d(-1), the respective removal efficiencies at low temperature were 90.6-95.4%, 72.8-82.1% and 95.8-97.9%.

  8. Joining of ultra-high temperature ceramics

    OpenAIRE

    Silvestroni, Laura; Sciti, Diletta; Esposito, Laura; Glaeser, Andreas

    2012-01-01

    In the last decade, ultra-high temperature ceramics raised renewed interest after the first studies in the 60's. Thanks to their high melting point, superior to any group of materials, and to their set of interesting physical and engineering properties, they find application in aerospace industry, propulsion field, as cladding materials in generation IV nuclear reactors and solar absorbers in novel HT CSP systems. Recent efforts were devoted to the achievement of high strength and toughness m...

  9. High temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    This book is a comprehensive review of high-temperature polymer electrolyte membrane fuel cells (PEMFCs). PEMFCs are the preferred fuel cells for a variety of applications such as automobiles, cogeneration of heat and power units, emergency power and portable electronics. The first 5 chapters...... of the book describe rationalization and illustration of approaches to high temperature PEM systems. Chapters 6 - 13 are devoted to fabrication, optimization and characterization of phosphoric acid-doped polybenzimidazole membranes, the very first electrolyte system that has demonstrated the concept...... of and motivated extensive research activity in the field. The last 11 chapters summarize the state-of-the-art of technological development of high temperature-PEMFCs based on acid doped PBI membranes including catalysts, electrodes, MEAs, bipolar plates, modelling, stacking, diagnostics and applications....

  10. Low toxicity high temperature PMR polyimide

    Science.gov (United States)

    Pater, Ruth H. (Inventor)

    1992-01-01

    In-situ polymerization of monomer reactants (PMR) type polyimides constitute an important class of ultra high performance composite matrix resins. PMR-15 is the best known and most widely used PMR polyimide. An object of the present invention is to provide a substantially improved high temperature PMR-15 system that exhibits better processability, toughness, and thermo-oxidative stability than PMR-15, as well as having a low toxicity. Another object is to provide new PMR polyimides that are useful as adhesives, moldings, and composite matrices. By the present invention, a new PMR polyimide comprises a mixture of the following compounds: 3,4'-oxydianiline (3,4'-ODA), NE, and BTDE which are then treated with heat. This PMR was designated LaRC-RP46 and has a broader processing window, better reproducibility of high quality composite parts, better elevated temperature mechanical properties, and higher retention of mechanical properties at an elevated temperature, particularly, at 371 C.

  11. High temperature superconductivity the road to higher critical temperature

    CERN Document Server

    Uchida, Shin-ichi

    2015-01-01

    This book presents an overview of material-specific factors that influence Tc and give rise to diverse Tc values for copper oxides and iron-based high- Tc superconductors on the basis of more than 25 years of experimental data, to most of which the author has made important contributions. The book then explains why both compounds are distinct from others with similar crystal structure and whether or not one can enhance Tc, which in turn gives a hint on the unresolved pairing mechanism. This is an unprecedented new approach to the problem of high-temperature superconductivity and thus will be inspiring to both specialists and non-specialists interested in this field.   Readers will receive in-depth information on the past, present, and future of high-temperature superconductors, along with special, updated information on what the real highest Tc values are and particularly on the possibility of enhancing Tc for each member material, which is important for application. At this time, the highest Tc has not been...

  12. High temperature and pressure alkaline electrolysis

    DEFF Research Database (Denmark)

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

    2013-01-01

    and pressures. Two measurement systems were built to perform measurements under high pressures and at elevated temperatures of up to 95 bar and 250 °C, respectively. The conductivity of aqueous KOH and aqueous KOH immobilized in a porous SrTiO3 structure were investigated at elevated temperatures and high...... 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...... concentrations of the electrolyte using the van der Pauw method in combination with electrochemical impedance spectroscopy (EIS). Conductivity values as high as 2.9 S cm-1 for 45 wt% KOH aqueous KOH and 0.84 S cm-1 for the immobilized KOH of the same concentration were measured at 200 °C. Porous SrTiO3 was used...

  13. 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

  14. High Temperature Protonic Conductors by Melt Growth

    Science.gov (United States)

    2007-11-02

    ceramic materials of BaCe1 -xNdxO3-a and Ba3(CaNb2)O9 that exhibit high temperature protonic conductance and superior mechanical properties at elevated...TEM). The mechanical behavior BaCe1 -xNdxO3-a (x=0 to 0.2) and Ba3(CaNb2)O9 ceramics in the elastic, brittle and plastic regime will be studied...spatial variations of compositions in BaCe1 -xNdxO3-a and Ba3(CaNb2)O9 following high temperature wet atmosphere treatment will be measured using a

  15. Laboratory Study of O2(b1Σ g+, υ = 1) Collisional Removal at Thermospheric Temperatures

    Science.gov (United States)

    Wouters, E. R.; Pejaković, D. A.; Phillips, K. E.; Kalogerakis, K. S.

    2003-12-01

    In the Earth's thermosphere, energy transfer from O(1D) to O2 generates oxygen molecules in the υ = 0 and 1 levels of the O2(b1Σg+) state. The emissions in the O2(b1Σ g+ - X3Σ g-) system (Atmospheric Band) present a major component of the Earth's airglow. Interpretation of the measured intensities of O2 Atmospheric Band emissions can yield altitude profiles of oxygen atom density and local temperature in the lower thermosphere. To achieve this goal accurate laboratory measurements of the collisional removal rate coefficients of O2(b, υ = 1) and their temperature dependence are essential. Atmospheric observations suggest that the relevant colliders for the removal of O2(b, υ = 1) in the lower thermosphere are O2 and O(3P). We report measurements of the rate coefficients for the collisional removal of O2(b, υ = 1) by O2, N2, and CO2, at temperatures in the range 300--1000 K. A state-specific two-laser technique is used, in which the visible output of the first laser directly excites O2 to O2(b, υ = 1), and the ultraviolet output of the second laser probes the O2(b, υ = 1) population by resonantly enhanced multiphoton ionization via the υ= 4 level of the d1Π g Rydberg state. The temporal evolution of the O2(b, υ = 1) population is monitored by varying the time delay between the two laser pulses. The rate coefficient of the collisional removal of O2(b, υ = 1) by O2 increases monotonically with temperature from about 1.5 x 10-11 cm3 s-1 to about 6*E-11 cm3 s-1 in the range 300--1000 K. Experiments with colliders N2 and CO2 determine the upper limits for the removal rate coefficients of O2(b, υ = 1) by N2 and CO2 to be 2 orders of magnitude smaller. This work extends previous studies of O2(b, υ = 1) at room and low temperatures.1,2 We are currently planning experiments to investigate the collisional removal of O2(b, υ = 1) by O atoms. This study was supported by the NSF's Grant ATM-0209229. The participation of K. Phillips in this project was funded by

  16. Characteristics of high power diode laser removal of multilayer chlorinated rubber coatings from concrete surfaces

    Science.gov (United States)

    Schmidt, Marc J. J.; Li, Lin; Spencer, Julian T.

    1999-08-01

    This paper reports the technical feasibility and process characteristics of removing chlorinated rubber (CR) coatings from concrete surfaces utilising a 60 W continuous wave (cw) diode laser operating at 810 nm wavelength. Coating layers of various thickness have been removed under an oxygen shroud-gas, as well as Ar and N 2. Optical microscopy and energy dispersive analysis of X-rays (EDX) have been utilised to verify this. The reflectivity properties of the CR material from the visible to the near infrared wavelengths, as well as their behaviour under high temperatures have been examined with a normal incidence spectrometer and a differential thermal analysis/thermal gravimetric analysis (DTA/TGA) system. The resulting drop in reflectivity explains the possibility of sustaining the combustion, even though the reflection coefficient of white CR at 810 nm is almost 100%.

  17. High-temperature MAS-NMR at high spinning speeds.

    Science.gov (United States)

    Kirchhain, Holger; Holzinger, Julian; Mainka, Adrian; Spörhase, Andreas; Venkatachalam, Sabarinathan; Wixforth, Achim; van Wüllen, Leo

    2016-09-01

    A low cost version to enable high temperature MAS NMR experiments at temperatures of up to 700°C and spinning speeds of up to 10kHz is presented. The method relies on inductive heating using a metal coated rotor insert. The metal coating is accomplished via a two step process involving physical vapor deposition and galvanization.

  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. High temperature reactors for cogeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Verfondern, Karl [Forschungszentrum Juelich (Germany). IEK-6; Allelein, Hans-Josef [Forschungszentrum Juelich (Germany). IEK-6; RWTH Aachen (Germany). Lehrstuhl fuer Reaktorsicherheit und -technik (LRST)

    2016-05-15

    There is a large potential for nuclear energy also in the non-electric heat market. Many industrial sectors have a high demand for process heat and steam at various levels of temperature and pressure to be provided for desalination of seawater, district heating, or chemical processes. The future generation of nuclear plants will be capable to enter the wide field of cogeneration of heat and power (CHP), to reduce waste heat and to increase efficiency. This requires an adjustment to multiple needs of the customers in terms of size and application. All Generation-IV concepts proposed are designed for coolant outlet temperatures above 500 C, which allow applications in the low and medium temperature range. A VHTR would even be able to cover the whole temperature range up to approx. 1 000 C.

  20. 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.

  1. 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

  2. High-Temperature Capacitor Polymer Films

    Science.gov (United States)

    Tan, Daniel; Zhang, Lili; Chen, Qin; Irwin, Patricia

    2014-12-01

    Film capacitor technology has been under development for over half a century to meet various applications such as direct-current link capacitors for transportation, converters/inverters for power electronics, controls for deep well drilling of oil and gas, direct energy weapons for military use, and high-frequency coupling circuitry. The biaxially oriented polypropylene film capacitor remains the state-of-the-art technology; however, it is not able to meet increasing demand for high-temperature (>125°C) applications. A number of dielectric materials capable of operating at high temperatures (>140°C) have attracted investigation, and their modifications are being pursued to achieve higher volumetric efficiency as well. This paper highlights the status of polymer dielectric film development and its feasibility for capacitor applications. High-temperature polymers such as polyetherimide (PEI), polyimide, and polyetheretherketone were the focus of our studies. PEI film was found to be the preferred choice for high-temperature film capacitor development due to its thermal stability, dielectric properties, and scalability.

  3. High temperature fatigue behaviour of intermetallics

    Indian Academy of Sciences (India)

    K Bhanu Sankara Rao

    2003-06-01

    There would be considerable benefits in developing new structural materials where high use temperatures and strength coupled with low density are minimum capabilities. Nickel and titanium aluminides exhibit considerable potential for near-term application in various branches of modern industry due to the number of property advantages they possess including low density, high melting temperature, high thermal conductivity, and excellent environmental resistance, and their amenability for significant improvment in creep and fatigue resistance through alloying. Reliability of intermetallics when used as engineering materials has not yet been fully established. Ductility and fracture toughness at room and intermediate temperatures continue to be lower than the desired values for production implementation. In this paper, progress made towards improving strain-controlled fatigue resistance of nickel and titanium aluminides is outlined. The effects of manufacturing processes and micro alloying on low cycle fatigue behaviour of NiAl are addressed. The effects of microstructure, temperature of testing, section thickness, brittle to ductile transition temperature, mean stress and environment on fatigue behaviour of same -TiAl alloys are discussed.

  4. Growth and heavy metal removal by Klebsiella aerogenes at different pH and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Al-Shahwani, M.F.; Jazrawi, S.F.; Al-Rawi, E.H.; Ayar, N.S.

    1984-01-01

    A strain of Klebsiella aerogenes isolated from Rustamiyah Station for treatment of wastewater was examined for its ability to grow in a media supplemented with maximum tolerance concentrations of Pb/sup + +/, Zn/sup + +/, Ni/sup + +/, and Cd/sup + +/, separately, at different temperatures and initial pH. The results indicated that at 28/sup 0/C during the first 24 hr, Pb/sup + +/ and Ni/sup + +/ had no effect on the growth of the bacteria, while the presence of Zn/sup + +/ and Cd/sup + +/ decreased the cell count. The growth reached a maximum level after the second day and started to decrease gradually. The bacterial count at 37/sup 0/C was less than that at 28/sup 0/C. No bacterial multiplication occurred at 44/sup 0/C. There was little difference between heavy metal removal at 28 and 37/sup 0/C. At 44/sup 0/C, little removal took place. In general, slightly acidic or neutral medium was better for both bacterial growth and metal removal.

  5. Upgrading biogas by a low-temperature CO2 removal techni

    Directory of Open Access Journals (Sweden)

    Ahmed M.I. Yousef

    2016-06-01

    Full Text Available Biogas, a renewable energy source, is primarily composed of methane and carbon dioxide and other gaseous species. Biogas upgrading for removing CO2 from raw biogas is a necessary step before the biogas to be used as vehicle fuel or injected into the natural gas grid. Therefore, the present work aimed to propose a low-temperature CO2 removal process as an alternative to the conventional biogas upgrading technologies (water scrubbing, chemical and physical scrubbing, membranes and Pressure swing adsorption. A typical model biogas mixture of 60 mol.% CH4 and 40 mol.% CO2 is considered. The present process showed that a product purity of 94.5 mol.% CH4 is obtained from compressed biogas by combining distillation, flash separation, auxiliary refrigeration and internal heat recovery with a potential specific energy consumption of 0.26 kW h/Nm3 raw biogas. The process has been simulated in Aspen HYSYS with avoiding the occurrence of CO2 freeze-out. The process delivers the captured CO2 in liquid form with a purity of 99.7 mol.% as a by-product for transport at 110 bar. It is concluded that the proposed upgrading process can serve as a new environmentally friendly approach to CO2 removal with an interesting energy-efficient alternative to the conventional upgrading techniques.

  6. 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...

  7. 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...... of dissolved oxygen. A potential step method (hydrodynamic chronocoulometry) is evaluated for simultaneous measurement of diffusivity and solubility of oxygen by means of RDE. Finally, the ORR tests are extended to conc. H3PO4 at more relevant working temperatures and under increased oxygen pressure. Direct...... of platinumphosphoric acid. At room temperature, a relative slow ORR hindering process is active, which requires using a fast method (cyclic voltammetry with high scan rate / hydrodynamic chronocoulometry) to accurately measure the diffusion limited currents, and thus, oxygen diffusivity and solubility. In conc. H3PO4...

  8. 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.

  9. Thermosyphon Method for Cooling the Rotor Blades of High-Temperature Steam Turbines

    Directory of Open Access Journals (Sweden)

    Bogomolov Alexander R.

    2016-01-01

    Full Text Available The design scheme of closed two-phase thermosyphon were suggested that can provide standard thermal operation of blades of high-temperature steam turbine. The method for thermosyphon calculation is developed. The example of thermal calculation was implemented, it showed that to cool the steam turbine blades at their heating by high-temperature steam, the heat can be removed in the rear part of the blades by air with the temperature of about 440°C.

  10. Thermosyphon Method for Cooling the Rotor Blades of High-Temperature Steam Turbines

    Science.gov (United States)

    Bogomolov, Alexander R.; Temnikova, Elena Yu.

    2016-02-01

    The design scheme of closed two-phase thermosyphon were suggested that can provide standard thermal operation of blades of high-temperature steam turbine. The method for thermosyphon calculation is developed. The example of thermal calculation was implemented, it showed that to cool the steam turbine blades at their heating by high-temperature steam, the heat can be removed in the rear part of the blades by air with the temperature of about 440°C.

  11. Thermosyphon Method for Cooling the Rotor Blades of High-Temperature Steam Turbines

    OpenAIRE

    Bogomolov Alexander R.; Temnikova Elena Yu.

    2016-01-01

    The design scheme of closed two-phase thermosyphon were suggested that can provide standard thermal operation of blades of high-temperature steam turbine. The method for thermosyphon calculation is developed. The example of thermal calculation was implemented, it showed that to cool the steam turbine blades at their heating by high-temperature steam, the heat can be removed in the rear part of the blades by air with the temperature of about 440°C.

  12. Nuclear and Quark Matter at High Temperature

    CERN Document Server

    Biro, T S; Schram, Z

    2016-01-01

    We review important ideas on nuclear and quark matter description on the basis of high- temperature field theory concepts, like resummation, dimensional reduction, interaction scale separation and spectral function modification in media. Statistical and thermodynamical concepts are spotted in the light of these methods concentrating on the - partially still open - problems of the hadronization process.

  13. Technology of high temperature organic coolant

    Energy Technology Data Exchange (ETDEWEB)

    Makin, R.S.; Vorobei, M.P.; Kuprienko, V.A.; Starkov, V.A.; Tsykanov, V.A.; Checketkin, Y.V. [Research Institute of Atomic Reactors, Ulyanovsk (Russian Federation)

    1993-12-31

    Research has been performed on the problems related to the use of high temperature organic coolants in small and medium nuclear power plants. The work performed and also the experience of operating the ARBUS reactor confirmed the inherent safety features, reliability, and enhanced safety margins of the plants with this type of coolants. The advantages of this system and research highlights are presented.

  14. Enamel for high-temperature superalloys

    Science.gov (United States)

    Levin, H.; Lent, W. E.

    1977-01-01

    Desired optical and high temperature enamel properties are obtained with glasses prepared from the system Li2O-ZrO2-nSiO2. Molar compositions range from n=4 to n=1.3, to which are added minor amounts in varying combinations of alumina, alkali fluorides, boric oxide, alkali oxides, and akaline earth oxides.

  15. Nuclear and quark matter at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Biro, Tamas S. [H.A.S. Wigner Research Centre for Physics, Budapest (Hungary); Jakovac, Antal [Roland Eotvos University, Budapest (Hungary); Schram, Zsolt [University of Debrecen, Institute for Theoretical Physics, Debrecen (Hungary)

    2017-03-15

    We review important ideas on nuclear and quark matter description on the basis of high-temperature field theory concepts, like resummation, dimensional reduction, interaction scale separation and spectral function modification in media. Statistical and thermodynamical concepts are spotted in the light of these methods concentrating on the -partially still open- problems of the hadronization process. (orig.)

  16. Analysis of iron oxidation at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, J.C.; Peng, K.Y.; Gadalla, A.M.; Gadalla, N. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemical Engineering

    1995-10-01

    A new theory for the high-temperature oxidation of iron is proposed, in which the rate-limiting step is ternary diffusion of ferric, ferrous, and oxygen ions in the iron oxides that are formed. The predictions of this theory are compared with previously published experimental data. The only thermodynamic information required is a phase diagram.

  17. Dynamics of Gauge Fields at High Temperature

    NARCIS (Netherlands)

    Nauta, B.J.

    2000-01-01

    An effective description of dynamical Bose fields is provided by the classical (high-temperature) limit of thermal field theory. The main subject of this thesis is to improve the ensuing classical field theory, that is, to include the dominant quantum corrections and to add counter terms for the Ray

  18. Photoemission studies of high-temperature superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Margaritondo, G. (Inst. de Physique Appliquee, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (CH))

    1990-11-01

    Photoemission spectroscopy has recently emerged as one of the leading techniques in the study of high-temperature superconductors. Relevant successes include the direct detection of the superconductivity gap, tests for departure from Fermi-liquid behavior, and many interface chemical studies with technological interest. The authors present a review of the fundamental and applied aspects of this technique.

  19. High-temperature carbidization of carboniferous rocks

    Science.gov (United States)

    Goldin, B. A.; Grass, V. E.; Nadutkin, A. V.; Nazarova, L. Yu.

    2009-08-01

    Processes of thermal metamorphism of carboniferous rocks have been studied experimentally. The conditions of high-temperature interaction of shungite carbon with components of the contained rocks, leading to formation of carbide compounds, have been determined. The results of this investigation contribute to the works on searching for new raw material for prospective material production.

  20. 10.3 High-temperature Instrumentation

    Science.gov (United States)

    Piazza, Anthony

    2008-01-01

    This viewgraph presentation describes high temperature instrumentation development from 1960-1970, 1980-1990 and 2000-present. The contents include: 1) Background; 2) Objective; 3) Application and Sensor; 4) Attachment Techniques; 5) Evaluation/Characterization Testing; and 6) Future testing.

  1. Anharmonic phonons and high-temperature superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, V.H.; Cohen, M.L. (Department of Physics, University of California at Berkeley, and Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

    1993-07-01

    We examine a simple model of anharmonic phonons with application to the superconducting isotope effect. Linear and quadratic electron-phonon coupling are considered for various model potentials. The results of the model calculations are compared with the high-temperature superconductors La[sub 2[minus][ital x

  2. High-temperature langasite SAW oxygen sensor.

    Science.gov (United States)

    Zheng, Peng; Chin, Tao-Lun; Greve, David; Oppenheim, Irving; Malone, Vanessa; Cao, Limin

    2011-08-01

    High-temperature langasite SAW oxygen sensors using sputtered ZnO as a resistive gas-sensing layer were fabricated and tested. Sensitivity to oxygen gas was observed between 500°C to 700°C, with a sensitivity peak at about 625°C, consistent with the theoretical predictions of the acoustoelectric effect.

  3. Dynamics of Gauge Fields at High Temperature

    NARCIS (Netherlands)

    Nauta, B.J.

    2000-01-01

    An effective description of dynamical Bose fields is provided by the classical (high-temperature) limit of thermal field theory. The main subject of this thesis is to improve the ensuing classical field theory, that is, to include the dominant quantum corrections and to add counter terms for the Ray

  4. Solar-driven high temperature radiant cooling

    Institute of Scientific and Technical Information of China (English)

    SONG ZhaoPei; WANG RuZhu; ZHAI XiaoQiang

    2009-01-01

    Solar energy is widely used as one of the most important renewable energy. In addition to the growing applications of solar PV and solar water heater, solar cooling is also considered very valuable and the related researches are developing fast because of the synchronism between solar irradiance and building cooling load. Current studies mainly focus on the high temperature solar collector technique and heat-driven cooling technique, while little concern has been paid to the transport process of cooling power. In this paper, the high temperature radiant cooling is studied as an alternative way for transporting cooling power, and the performance of the combination of radiant ceiling and solar cooling is also studied. From simulation and theoretical analysis results, high temperature radiant cooling terminal shows better cooling power transportation ability against conventional air-conditioning terminal, and its thermal comfort is improved. Experiment results indicate that radiant cooling can enhance the chiller's COP (Coefficient of Performance) by 17% and cooling power regeneration by 50%.According to analysis in this paper, high temperature radiant cooling is proved to be suitable for solar cooling system, and out work can serve as a reference for later system design and promotion.

  5. 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...

  6. The Evolution of High Temperature Gas Sensors.

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, F. H. (Fernando H.); Brosha, E. L. (Eric L.); Mukundan, R. (Rangachary)

    2001-01-01

    Gas sensor technology based on high temperature solid electrolytes is maturing rapidly. Recent advances in metal oxide catalysis and thin film materials science has enabled the design of new electrochemical sensors. We have demonstrated prototype amperometric oxygen sensors, nernstian potentiometric oxygen sensors that operate in high sulfur environments, and hydrocarbon and carbon monoxide sensing mixed potentials sensors. Many of these devices exhibit part per million sensitivities, response times on the order of seconds and excellent long-term stability.

  7. High temperature internal friction measurements of 3YTZP zirconia polycrystals. High temperature background and creep

    OpenAIRE

    Simas, P.; Castillo-Rodríguez, Miguel; Nó, M. L.; De-Bernardi, S.; Gómez-García, D.; Domínguez-Rodríguez, Alejandro; San Juan, J.

    2014-01-01

    This work focuses on the high-temperature mechanic properties of a 3 mol % yttria zirconia polycrystals (3YTZP), fabricated by hot-pressureless sintering. Systematic measurements of mechanical loss as a function of temperature and frequency were performed. An analytical method, based on the generalised Maxwell rheological model, has been used to analyse the high temperature internal friction background (HTB). This method has been previously applied to intermetallic compounds...

  8. High-pressure-high-temperature treatment of natural diamonds

    CERN Document Server

    Royen, J V

    2002-01-01

    The results are reported of high-pressure-high-temperature (HPHT) treatment experiments on natural diamonds of different origins and with different impurity contents. The diamonds are annealed in a temperature range up to 2000 sup o C at stabilizing pressures up to 7 GPa. The evolution is studied of different defects in the diamond crystal lattice. The influence of substitutional nitrogen atoms, plastic deformation and the combination of these is discussed. Diamonds are characterized at room and liquid nitrogen temperature using UV-visible spectrophotometry, Fourier transform infrared spectrophotometry and photoluminescence spectrometry. The economic implications of diamond HPHT treatments are discussed.

  9. High removal rate of cross-linked SU-8 resist using hydrogen radicals generated by tungsten hot-wire catalyzer

    Energy Technology Data Exchange (ETDEWEB)

    Kono, Akihiko, E-mail: a.kono@neptune.kanazawa-it.ac.jp [Kanazawa Institute of Technology, 7-1 Ougigaoka, Nonoichi, Ishikawa 921-8501 (Japan); Arai, Yu; Maruoka, Takeshi; Yamamoto, Masashi; Goto, Yousuke; Takahashi, Seiji; Nishiyama, Takashi [Kanazawa Institute of Technology, 7-1 Ougigaoka, Nonoichi, Ishikawa 921-8501 (Japan); Horibe, Hideo [Osaka City University, Sugimoto, Sumiyoshiku, Osaka 558-8585 (Japan)

    2014-07-01

    This paper discusses the removal of chemically amplified negative-tone i-line resist SU-8 using hydrogen radicals generated by the catalytic decomposition of H{sub 2} molecules in H{sub 2}/N{sub 2} mixed gas (H{sub 2}:N{sub 2} = 10:90 vol.%) using a tungsten hot-wire catalyzer. SU-8 resists with exposure doses from 7 to 280 mJ/cm{sup 2} were removed by hydrogen radicals, although the SU-8 removal rate was independent of the exposure dose. The SU-8 removal rate increased with both substrate and catalyzer temperature, in addition to a decrease in the distance between the catalyzer and substrate. A high removal rate for cross-linked SU-8 with an exposure dose of 14 mJ/cm{sup 2} of approximately 4 μm/min was achieved with a catalyzer to substrate distance of 20 mm, and catalyzer and initial substrate temperatures of 2400 and 165 °C, respectively. - Highlights: • Chemically amplified negative-tone i-line resist SU-8 removed by hydrogen radicals • Hydrogen radicals generated by catalytic H{sub 2} decomposition using hot-wire catalyzer • The cross-linked SU-8 resist was removed at a rate of approximately 4 μm/min.

  10. High temperature furnace modeling and performance verifications

    Science.gov (United States)

    Smith, James E., Jr.

    1992-01-01

    Analytical, numerical, and experimental studies were performed on two classes of high temperature materials processing sources for their potential use as directional solidification furnaces. The research concentrated on a commercially available high temperature furnace using a zirconia ceramic tube as the heating element and an Arc Furnace based on a tube welder. The first objective was to assemble the zirconia furnace and construct parts needed to successfully perform experiments. The 2nd objective was to evaluate the zirconia furnace performance as a directional solidification furnace element. The 3rd objective was to establish a data base on materials used in the furnace construction, with particular emphasis on emissivities, transmissivities, and absorptivities as functions of wavelength and temperature. A 1-D and 2-D spectral radiation heat transfer model was developed for comparison with standard modeling techniques, and were used to predict wall and crucible temperatures. The 4th objective addressed the development of a SINDA model for the Arc Furnace and was used to design sample holders and to estimate cooling media temperatures for the steady state operation of the furnace. And, the 5th objective addressed the initial performance evaluation of the Arc Furnace and associated equipment for directional solidification. Results of these objectives are presented.

  11. Avaliação da temperatura desenvolvida durante a remoção de pino intra-radicular, com instrumentos cortantes rotatórios em alta rotação Evaluation of the temperature generated during the removal of posts with burs in high speed handpiece

    Directory of Open Access Journals (Sweden)

    Tomie Nakakuki de CAMPOS

    1998-07-01

    Full Text Available Com a preocupação de avaliar os efeitos danosos da transmissão de calor aos tecidos periodontais, este trabalho teve como objetivo avaliar a temperatura gerada durante a remoção de pinos intra-radiculares com o uso de instrumentos cortantes rotatórios (ICR em alta rotação. Para se obter os registros da temperatura durante os desgastes, foram fixados fios termopares ao redor do terço médio e terço apical da raiz de incisivos centrais superiores extraídos, conectados a termômetros digitais. Através da análise de variância, verificou-se que houve diferença estatisticamente significante, de 5%, entre as regiões medidas e as ligas utilizadas. Analisando as regiões, observou-se, na região mediana, amplitude de 9,1oC, e, na região apical, amplitude de 6,2oC. A liga de CuAlZn (GOLDENT alcançou média de amplitude maior, 10,3oC, as ligas de CuAl (DURACAST, 6,3oC, e a de PdAg (PORS-ON 4, 6,3oC. Provavelmente, os fatores que interferiram foram o grau de refrigeração, a pressão e o corte intermitente. Baseando-se na metodologia utilizada, concluiu-se que a remoção de pinos intra-radiculares, através do uso de ICR em alta rotação, pode gerar amplitudes de temperatura críticas de acordo com a região do desgaste e liga utilizada.Due to the concern with the damaging effects of heat distribution on periodontal tissues, this study had the objective of evaluating the temperature generated during the removal of posts with burs in high speed handpieces. Fixed thermopars around the medium and apical regions of the roots of extracted superior central incisors, connected to digital thermometers, were used to obtain temperature measurements during wearing down. Analysis of variance demonstrated a statistically significant difference, to the level of 5%, between the regions where the temperature was taken and the alloys used. When comparing the differences between the regions of roots, the medium portion presented a variation of 9.1oC, and

  12. High temperature superconductors applications in telecommunications

    Science.gov (United States)

    Kumar, A. Anil; Li, Jiang; Zhang, Ming Fang

    1995-01-01

    The purpose of this paper is twofold: (1) to discuss high temperature superconductors with specific reference to their employment in telecommunications applications; and (2) 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

  13. 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.

  14. High exposures to organic solvents among graffiti removers.

    Science.gov (United States)

    Anundi, H; Lind, M L; Friis, L; Itkes, N; Langworth, S; Edling, C

    1993-01-01

    The exposure to organic solvents among 12 graffiti removers was studied. Health effects were also assessed by structured interview and a symptom questionnaire. Blood and urine samples were collected at the end of the day of air sampling. The concentrations of dichloromethane, glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone in the breathing zone of each worker were measured during one working day. The 8-h time-weighted average exposure to dichloromethane ranged from 18 to 1200 mg/m3. The Swedish Permissible Exposure Limit value for dichloromethane is 120 mg/m3. The air concentrations of glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone were low or not detectable. No exposure-related deviations in the serum concentrations of creatinine, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase or hyaluronan or the urine concentrations of alpha 1-microglobulin, beta 2-microglobulin or N-acetyl-beta-glucosaminidase were found. Irritative symptoms of the eyes and upper respiratory tract were more prevalent than in the general population. This study demonstrates that old knowledge about work hazards is not automatically transferred to new professions. Another aspect is that the public is also exposed as the job is performed during daytime in underground stations. At least for short periods, bystanders may be exposed to high concentrations of organic solvent vapours. People with predisposing conditions, e.g. asthmatics, may risk adverse reactions.

  15. Comments on theories of high temperature superconductivity

    Directory of Open Access Journals (Sweden)

    T. M. Rice

    2006-09-01

    Full Text Available   The recently discovered MgB2 superconductors have a record transition temperature for a BCS superconductor due to the high vibration frequencies associated with its light elements. The transition temperatures in the cuprate family of superconductors are much higher but these do not fit the BCS paradigm. The most promising microscopic origin for their many anomalous properties lies in magnetic pairing described by the RVB (Resonant Valence Bond ansatz. However a comprehensive theoretical description of the key anomalous properties of the cuprates remains to be an open challenge.

  16. The metallurgy of high temperature alloys

    Science.gov (United States)

    Tien, J. K.; Purushothaman, S.

    1976-01-01

    Nickel-base, cobalt-base, and high nickel and chromium iron-base alloys are dissected, and their microstructural and chemical components are assessed with respect to the various functions expected of high temperature structural materials. These functions include the maintenance of mechanical integrity over the strain-rate spectrum from creep resistance through fatigue crack growth resistance, and such alloy stability expectations as microstructural coarsening resistance, phase instability resistance and oxidation and corrosion resistance. Special attention will be given to the perennial conflict and trade-off between strength, ductility and corrosion and oxidation resistance. The newest developments in the constitution of high temperature alloys will also be discussed, including aspects relating to materials conservation.

  17. Optically transparent high temperature shape memory polymers.

    Science.gov (United States)

    Xiao, Xinli; Qiu, Xueying; Kong, Deyan; Zhang, Wenbo; Liu, Yanju; Leng, Jinsong

    2016-03-21

    Optically transparent shape memory polymers (SMPs) have potential in advanced optoelectronic and other common shape memory applications, and here optically transparent shape memory polyimide is reported for the first time. The polyimide possesses a glass transition temperature (Tg) of 171 °C, higher than the Tg of other transparent SMPs reported, and the influence of molecular structure on Tg is discussed. The 120 μm thick polyimide film exhibits transmittance higher than 81% in 450-800 nm, and the possible mechanism of its high transparency is analyzed, which will benefit further research on other transparent high temperature SMPs. The transparent polyimide showed excellent thermomechanical properties and shape memory performances, and retained high optical transparency after many shape memory cycles.

  18. 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.

  19. Thermoelectric properties by high temperature annealing

    Science.gov (United States)

    Ren, Zhifeng (Inventor); Chen, Gang (Inventor); Kumar, Shankar (Inventor); Lee, Hohyun (Inventor)

    2009-01-01

    The present invention generally provides methods of improving thermoelectric properties of alloys by subjecting them to one or more high temperature annealing steps, performed at temperatures at which the alloys exhibit a mixed solid/liquid phase, followed by cooling steps. For example, in one aspect, such a method of the invention can include subjecting an alloy sample to a temperature that is sufficiently elevated to cause partial melting of at least some of the grains. The sample can then be cooled so as to solidify the melted grain portions such that each solidified grain portion exhibits an average chemical composition, characterized by a relative concentration of elements forming the alloy, that is different than that of the remainder of the grain.

  20. 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...... (RDE) and (ii) a gas diffusion electrode (GDE) setup designed for experiments in conc. H3PO4. The pressurized cell is demonstrated by tests on polycrystalline platinum electrodes up to 150 ºC. Functionality of the RDE system is proved studying the oxygen reduction reaction (ORR) at temperatures up...... 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...

  1. 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.

  2. Gasification of high ash, high ash fusion temperature bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  3. Gasification of high ash, high ash fusion temperature bituminous coals

    Science.gov (United States)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  4. 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

  5. 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.

  6. 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.

  7. Modeling Study of High Pressure and High Temperature Reservoir Fluids

    DEFF Research Database (Denmark)

    Varzandeh, Farhad

    to 250 °C and 2400 bar, in the deep petroleum reservoirs. Furthermore, many of these deep reservoirs are found offshore, including the North Sea and the Gulf of Mexico, making the development even more risky. On the other hand, development of these high pressure high temperature (HPHT) fields can...

  8. Pulse Radiolysis at High Temperatures and High Pressures

    DEFF Research Database (Denmark)

    Christensen, H.; Sehested, Knud

    1981-01-01

    A set-up enabling pulse radiolysis measurements at high temperatures (up to 320°C) and high pressures (up to 140 bar) has been constructed in collaboration between Risö National Laboratory and Studsvik Energiteknik. The cell has been used for experiments with aqueous solutions with the purpose...

  9. Preparation of magnetic hierarchically porous microspheres with temperature-controlled wettability for removal of oils.

    Science.gov (United States)

    Tao, Shengyang; Ding, Yunzhe; Jiang, Lei; Li, Guangtao

    2017-04-15

    A series of monodispersed microspheres with hierarchically porous structures were prepared by microfluidic devices. Phase separation of the silica sol in microdroplets was adopted to construct these structures. The effects of velocity ratios (for both the continuous and the dispersed phases), collection solvents and calcination temperatures were investigated. The diameters of the microspheres were tuned from 148μm to 940μm by adjusting the velocity ratio. Tests revealed that the surface areas and pore volumes of the microspheres can reach 495m(2)g(-1) and 0.6068mlg(-1), respectively. The macroporous structure can be controlled by the collection solvents, and the wettability of the microspheres is determined by the calcination temperature. A calcination temperature of 450°C leads to a hydrophilic surface property. Fe3O4 nanoparticles were added to the silica sol to form magnetic microspheres, and the porous structure was not affected. This kind of hybrid microsphere adsorbs 3.29 times its own weight in toluene. These spheres can adsorb oil on water surfaces, and then be removed from the water with an external magnetic field. The microspheres can be recovered and reused more than 10 times. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. High temperature alloys: their exploitable potential

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, J.B.; Merz, M.; Nihoul, J.; Ward, J. (eds.) (Commission of the European Communities, Petten (Netherlands). Joint Nuclear Research Center; NET-TEAM, Garching (DE))

    1987-01-01

    This book is the proceedings of a conference dealing with fundamental and technical aspects of the applications of high temperature alloys. It is split into five sections which cover the opening session of the conference and four further sessions covering: the theoretical and practical limits for HT alloys; the potential for development in alloys and processing; engineering considerations; the future outlook. The different sessions each included a number of invited papers followed by a series of posters and were concluded by a presentation of a 'synthesis' by a session rapporteur and general discussion. This structure is retained in the proceedings, including the discussion points in those cases where the authors have provided written answers to the questions raised. This book will be of interest to metallurgists, materials scientists, physicists and research workers in high temperature materials.

  11. 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...... media, as well as localized sampling of gas evolved at the electrodes for gas analysis. A number of safety and engineering design challenges have been addressed. Furthermore, we present a series of electrochemical cell holders that have been constructed in order to accommodate different types of cells......, 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...

  12. 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.

  13. High temperature superconductor materials and applications

    Science.gov (United States)

    Doane, George B., III. (Editor); Banks, Curtis; Golben, John

    1991-01-01

    One of the areas concerned itself with the investigation of the phenomena involved in formulating and making in the laboratory new and better superconductor material with enhanced values of critical current and temperature. Of special interest were the chemistry, physical processes, and environment required to attain these enhanced desirable characteristics. The other area concerned itself with producing high temperature superconducting thin films by pulsed laser deposition techniques. Such films are potentially very useful in the detection of very low power signals. To perform this research high vacuum is required. In the course of this effort, older vacuum chambers were maintained and used. In addition, a new facility is being brought on line. This latter activity has been replete with the usual problems of bringing a new facility into service. Some of the problems are covered in the main body of this report.

  14. Fast pyrolysis of biomass at high temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna

    This Ph.D. thesis describes experimental and modeling investigations of fast high temperature pyrolysis of biomass. Suspension firing of biomass is widely used for power generation and has been considered as an important step in reduction of greenhouse gas emissions by using less fossil fuels. Fast...... 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...... and shape, composition, reactivity and burnout depend significantly on the operating conditions of the fast pyrolysis. Biomass fast pyrolysis experiments were performed in a laboratory-scale wire mesh reactor and bench scale atmospheric pressure drop tube / entrained flow reactors with the aim...

  15. 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...

  16. 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...

  17. 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.

  18. 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.

  19. On quark number susceptibilities at high temperatures

    CERN Document Server

    Bazavov, A; Hegde, P; Karsch, F; Miao, C; Mukherjee, Swagato; Petreczky, P; Schmidt, C; Velytsky, A

    2013-01-01

    We calculated second and fourth order quark number susceptibilities for 2+1 flavor QCD in the high temperature region using two improved staggered fermion formulations. The calculations are performed at several lattice spacing and we show that in the continuum limit the two formulations give consistent results. We compare our continuum extrapolated results on quark number susceptibilities with recent weak coupling calculations, and find that these cannot simultaneously explain the lattice results for second and fourth order quark number susceptibilities.

  20. Intermetallic-based high-temperature materials

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.

    1999-07-01

    The intermetallic-based alloys for high-temperature applications are introduced. General characteristics of intermetallics are followed by identification of nickel and iron aluminides as the most practical alloys for commercial applications. An overview of the alloy compositions, melting processes, and mechanical properties for nickel and iron aluminizes are presented. The current applications and commercial producers of nickel and iron aluminides are given. A brief description of the future prospects of intermetallic-based alloys is also given.

  1. Intermetallic-Based High-Temperature Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.

    1999-04-25

    The intermetallic-based alloys for high-temperature applications are introduced. General characteristics of intermetallics are followed by identification of nickel and iron aluminides as the most practical alloys for commercial applications. An overview of the alloy compositions, melting processes, and mechanical properties for nickel and iron aluminizes are presented. The current applications and commercial producers of nickel and iron aluminizes are given. A brief description of the future prospects of intermetallic-based alloys is also given.

  2. Hydrogen dominant metallic alloys: high temperature superconductors?

    Science.gov (United States)

    Ashcroft, N W

    2004-05-07

    The arguments suggesting that metallic hydrogen, either as a monatomic or paired metal, should be a candidate for high temperature superconductivity are shown to apply with comparable weight to alloys of metallic hydrogen where hydrogen is a dominant constituent, for example, in the dense group IVa hydrides. The attainment of metallic states should be well within current capabilities of diamond anvil cells, but at pressures considerably lower than may be necessary for hydrogen.

  3. High Temperature Superconducting Maglev Measurement System

    OpenAIRE

    Wang, Jia-Su; Wang, Su-Yu

    2010-01-01

    Three high temperature superconducting (HTS) Maglev measurement systems were successfully developed in the Applied Superconductivity Laboratory (ASCLab) of Southwest Jiaotong University, P. R. China. These systems include liquid nitrogen vessel, Permanent Magnet Guideway (PMG), data collection and processing, mechanical drive and Autocontrol features. This chapter described the three different measuring systems along with their theory of operations and workflow. The SCML-01 HTS Maglev measure...

  4. GRAPHENE PEEK COMPOSITES AS HIGH TEMPERATURE ADHESIVES

    Science.gov (United States)

    2017-09-05

    Price DW, Roberts JA, Scott JB, Wadhawan A, Ye Z, Tour JM. Nanotubes in microwave fields : light emission , intense heat, outgassing, and reconstruction...Arepalli S, Yowell LL, Tour JM. Carbon nanotube composite curing through absorption of microwave radiation. Composites Science and Technology. 2008 Dec...polymer that is suitable for high-temperature applications. Graphene is a two-dimensional form of carbon nanomaterial that has been studied

  5. Technological evolution of high temperature superconductors

    OpenAIRE

    White, Jordan R.

    2015-01-01

    Approved for public release; distribution is unlimited High temperature superconducting (HTS) cables are currently being used in the commercial energy industry primarily for demonstration purposes and to evaluate the feasibility of large-scale implementation into the electric grid. While still in the evaluation stage, the U.S. Navy is finding the test results promising and is investigating its potential use for future electric ships to supply power to electric propulsion motors and possibl...

  6. Development of High-Temperature Strain Gages.

    Science.gov (United States)

    1961-03-17

    lengths the article is either dipped in a slip (finely divided tend to require a support for the grid, while shorter coating material suspended in a...liquid) or the lengths require too many loops to achieve the slip is sprayed onto the article , followed in both cases by high-temperature fusion. An...Electrochemistry. Electrical Instruments. Magnetic Measurements. Dielectrics. Metrology. Photometry and Colorimetry. Refractometry . Photographic Research

  7. Simultaneous removal of NO x and SO2 by low-temperature selective catalytic reduction over modified activated carbon catalysts

    Science.gov (United States)

    Liu, Ye; Ning, Ping; Li, Kai; Tang, Lihong; Hao, Jiming; Song, Xin; Zhang, Guijian; Wang, Chi

    2017-03-01

    A series of modified porous activated carbon (AC) catalysts prepared by impregnation were investigated for the low-temperature (≤250°C) selective catalytic reduction (SCR) of NO x with NH3 with simultaneous removal of SO2. The effects of various preparation conditions and reaction conditions on NO and SO2 conversions were observed, such as support type, active components, copper loading, calcination temperature and presence of H2O and O2. The modified AC catalysts were characterized by BET, XRD, TG and TPX methods. The activity test results showed that the optimal catalyst is 15% Cu/WCSAC which can provide 52% NO conversion and 68% SO2 conversion simultaneously at 175°C with a space velocity of 30000 h‒1, and the optimal calcination temperature was 500°C. The presence of H2O could inhibit NO conversion and promote the SO2 conversion. The effect of O2 (0-5%) was evaluated, and the NO and SO2 conversions were best when the concentration of O2 was 3%. Research demonstrated that Cu/WCSAC catalyst was a kind of potential catalysts due to the amorphous phase, high specific areas and high active ability.

  8. Spurious weather radar echo identification and removal using multisource temperature information

    Science.gov (United States)

    Michelson, Daniel B.; Sunhede, Daniel

    2004-03-01

    A simple and pragmatic method utilising the difference between analysed near-surface and Meteosat IR temperatures ([Delta] T) is presented and applied with the aim of identifying and removing non-precipitation echoes in weather radar composite imagery. Despite inherent deficiencies in these multisource data, such as lower spatial and temporal resolutions relative to the radar data, [Delta] T is demonstrated to efficiently identify efficiently those areas void of potentially precipitating clouds, and to remove radar echoes in them. A set of 243 manually analysed composites from the summer of 2000 was used to evaluate the method. False alarm rates (FAR), percent correct (PC) and Hanssen-Kuipers skill (HKS) scores were calculated from standard contingency tables for five echo classes: weak, strong, land, sea, and all. FAR was lowered in all classes, PC was generally raised by a few percent to be over 95%, while HKS either remained unchanged or was slightly lowered through the application of [Delta] T. These results indicate that [Delta] T successfully removes a significant amount of non-precipitation, sometimes at the expense of a small amount of true precipitation. This penalty is larger over sea, which indicates that the method may need to be tuned differently for land and sea environments. This method may act as a foundation on which improvements to radar data quality control can be made with the introduction of new and improved satellite instrumentation such as that found on board the Meteosat Second Generation platform. However, this type of method should remain complementary to improved signal processing and radar data analysis techniques.

  9. Current trends in high temperature design

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, D.L. (Illinois Univ., Urbana, IL (United States). Dept. of Mechanical Engineering)

    1992-01-01

    A review of high temperature design guidelines has been carried out in preparation for designing a solar storage module for the Freedom Spacelab. Three major guidelines, N47, R5 and RCC-MR form the basis of the survey. The main issues with current, mature design in the power industry appear to be adequately covered by these guidelines. A significant finding is that long established models of material damage have survived the test of time very well. A new design regime referred to as Very High Temperature Design (VHTD) is identified. The characteristics of this regime are changing material properties which require some changes in philosophy in drafting of future codes, particularly in regard to definitions of yield strengths and other design allowables. Finally, there is some discussion of the more general use of the stress/strain plane, e.g. isochronous curves, for representation of very complex material constitutive behaviour. A concept called the 'Relaxation Locus', which summarizes essential local constrained component behavior, is introduced and its application to high temperature design problems is discussed briefly. (author).

  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. Ultra high temperature particle bed reactor design

    Science.gov (United States)

    Lazareth, Otto; Ludewig, Hans; Perkins, K.; Powell, J.

    1990-01-01

    A direct nuclear propulsion engine which could be used for a mission to Mars is designed. The main features of this reactor design are high values for I(sub sp) and very efficient cooling. This particle bed reactor consists of 37 cylindrical fuel elements embedded in a cylinder of beryllium which acts as a moderator and reflector. The fuel consists of a packed bed of spherical fissionable fuel particles. Gaseous H2 passes over the fuel bed, removes the heat, and is exhausted out of the rocket. The design was found to be neutronically critical and to have tolerable heating rates. Therefore, this particle bed reactor design is suitable as a propulsion unit for this mission.

  12. 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...

  13. 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...

  14. The NDT methods under high temperature service environment

    Directory of Open Access Journals (Sweden)

    Zhang Zhen-guo

    2016-01-01

    Full Text Available Concerning the detective requirement of the equipment under high temperature running status, this paper summarizes the technical characteristics and related applications of several non-destructive testing methods(NDT, such as thermal infrared imaging technology in high temperature, ultrasonic testing technique in high temperature, pulsed eddy current technology in high temperature and magnetic powder flaw detection technology in high temperature, penetration testing technique in high temperature and indirect visual detection in high temperature and on-line monitoring system in high temperature.

  15. A comparison of temperature profile depending on skin types for laser hair removal therapy.

    Science.gov (United States)

    Kim, Tae-Hoon; Lee, Gwi-Won; Youn, Jong-In

    2014-11-01

    Although numerous lasers with different wavelengths are available for laser hair removal, their use in individuals with dark-pigmented skin remains a challenge. The present study aims to develop a numerical heat diffusion model considering skin types over various wavelengths. This numerical mode uses Pennes approximation to represent heat from metabolism, blood perfusion and an external heating source. The heat diffusion model is experimentally validated by using agar-based skin tissue phantoms. Diode lasers with four different wavelengths were used with two antithetical skin models. The pulse width and beam spot size were set to 200 ms and 1 cm(2), respectively. Temperature distribution along the hair structure and skin tissue was examined to determine both thermal confinement and heat transfer to the hair follicle. Experimental results are well matched with the numerical results. The results show that for the light skin model, thermal confinement is well achieved over various wavelengths, and treatment efficacy is expected to be better at a shorter wavelength. Otherwise, for the dark skin model, thermal confinement is poorly achieved as the wavelength decreases (hair tip and the hair root is significantly large compared with the light skin model, which may lead to adverse effects. We believe that the developed numerical model will help to establish optimal laser parameters for different individuals during laser hair removal.

  16. An integrated approach to remove and mitigate carbonate scale in a low temperature sandstone reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Al-Saiari, H.A.; Nasr-El-Din, H.A.

    2006-03-15

    Calcium carbonate and iron sulfide scales were detected in several wells in a low temperature sandstone reservoir. These scales were detected downhole; covering perforations and in-take of submersible pumps. The presence of scale has adversely affected well performance. The paper will present the results of detailed studies conducted to design and field test acid treatment to remove the scale and a new scale squeeze treatment to mitigate scale formation. The treatment has been successfully applied to more than 35 wells. Some of these wells were de scaled before the squeeze, while other wells were squeeze before scale detection. Field data indicated that the acid treatment resorted well productivity. The scale squeeze treatment which utilized a newly developed inhibitor was successfully applied in the field and has a life time that exceeded two years in most of the treated wells. (Author)

  17. Room temperature synthesis of a Zn(II) metal-organic coordination polymer for dye removal

    Science.gov (United States)

    Abbasi, Alireza; Gharib, Maniya; Najafi, Mahnaz; Janczak, Jan

    2016-03-01

    A new one-dimensional (1D) coordination polymer, [Zn(4,4‧-bpy)(H2O)4](ADC)·4H2O (1) (4,4‧-bpy=4,4‧-bipyridine and H2ADC=acetylenedicarboxylic acid), was synthesized at room temperature. The crystal structure of the coordination polymer was determined by single-crystal X-ray diffraction analysis. Compound 1 was also characterized by FT-IR, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). The catalytic activity of 1 was evaluated in the color removal of Bismarck brown as a representative of dye pollutant in water under mild conditions. Coordination polymer 1 exhibited good catalytic activity and stability in the decolorization of Bismarck brown and could be easily recovered and reused for at least three cycles.

  18. Technology of high-temperature organic coolant

    Energy Technology Data Exchange (ETDEWEB)

    Vorobei, M.P.; Makin, R.S.; Kuprienko, V.A. [and others

    1993-12-31

    A wide range of studies were carried out in RIAR on the problems connected with the use of high-temperature organic coolant at nuclear power plants. The work performed and successful experience gained in persistent operation of the ARBUS reactor confirmed the inherent safety characteristics, high operational reliability, as well as improved safety of stations with similar reactors. A large scope of studies were carried out at the ARBUS pilot reactor and loop with the organic coolant of the MIR reactor and a wide range of problems were solved. The studies are described.

  19. Precipitation Hardenable High Temperature Shape Memory Alloy

    Science.gov (United States)

    Noebe, Ronald Dean (Inventor); Draper, Susan L. (Inventor); Nathal, Michael V. (Inventor); Crombie, Edwin A. (Inventor)

    2010-01-01

    A composition of the invention is a high temperature shape memory alloy having high work output, and is made from (Ni+Pt+Y),Ti(100-x) wherein x is present in a total amount of 49-55 atomic % Pt is present in a total amount of 10-30 atomic %, Y is one or more of Au, Pd. and Cu and is present in a total amount of 0 to 10 atomic %. The alloy has a matrix phase wherein the total concentration of Ni, Pt, and the one or more of Pd. Au, and Cu is greater than 50 atomic %.

  20. High Temperature Sensing Systems--Characteristics of Rechargeable Batteries at High Temperature--

    OpenAIRE

    2001-01-01

     High temperature discharge characteristics were measured at 100℃ for commercial available Nickel Cadmium and Nickel Metal Hydride rechargeable batteries. A Nickel Cadmium battery has superior dis­charge characteristics than a Nickel Metal Hydride battery. A life cycle of rechargeable battery can be esti­mated by measuring an internal resistance of the battery during charge at room temperature.

  1. Microporous metal-organic framework with dual functionalities for highly efficient removal of acetylene from ethylene/acetylene mixtures

    Science.gov (United States)

    Hu, Tong-Liang; Wang, Hailong; Li, Bin; Krishna, Rajamani; Wu, Hui; Zhou, Wei; Zhao, Yunfeng; Han, Yu; Wang, Xue; Zhu, Weidong; Yao, Zizhu; Xiang, Shengchang; Chen, Banglin

    2015-06-01

    The removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene is a technologically very important, but highly challenging task. Current removal approaches include the partial hydrogenation over a noble metal catalyst and the solvent extraction of cracked olefins, both of which are cost and energy consumptive. Here we report a microporous metal-organic framework in which the suitable pore/cage spaces preferentially take up much more acetylene than ethylene while the functional amine groups on the pore/cage surfaces further enforce their interactions with acetylene molecules, leading to its superior performance for this separation. The single X-ray diffraction studies, temperature dependent gas sorption isotherms, simulated and experimental column breakthrough curves and molecular simulation studies collaboratively support the claim, underlying the potential of this material for the industrial usage of the removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene at room temperature through the cost- and energy-efficient adsorption separation process.

  2. Microporous metal–organic framework with dual functionalities for highly efficient removal of acetylene from ethylene/acetylene mixtures

    KAUST Repository

    Hu, Tong-Liang

    2015-06-04

    The removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene is a technologically very important, but highly challenging task. Current removal approaches include the partial hydrogenation over a noble metal catalyst and the solvent extraction of cracked olefins, both of which are cost and energy consumptive. Here we report a microporous metal–organic framework in which the suitable pore/cage spaces preferentially take up much more acetylene than ethylene while the functional amine groups on the pore/cage surfaces further enforce their interactions with acetylene molecules, leading to its superior performance for this separation. The single X-ray diffraction studies, temperature dependent gas sorption isotherms, simulated and experimental column breakthrough curves and molecular simulation studies collaboratively support the claim, underlying the potential of this material for the industrial usage of the removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene at room temperature through the cost- and energy-efficient adsorption separation process.

  3. High Temperature Materials for Chemical Propulsion Applications

    Science.gov (United States)

    Elam, Sandra; Hickman, Robert; O'Dell, Scott

    2007-01-01

    Radiation or passively cooled thrust chambers are used for a variety of chemical propulsion functions including apogee insertion, reaction control for launch vehicles, and primary propulsion for planetary spacecraft. The performance of these thrust chambers is limited by the operating temperature of available materials. Improved oxidation resistance and increased operating temperatures can be achieved with the use of thermal barrier coatings such as zirconium oxide (ZrO2) and hafnium oxide (HfO2). However, previous attempts to include these materials showed cracking and spalling of the oxide layer due to poor bonding. Current research at NASA's Marshall Space Flight Center (MSFC) has generated unique, high temperature material options for in-space thruster designs that are capable of up to 2500 C operating temperatures. The research is focused on fabrication technologies to form low cost Iridium,qF_.henium (Ir/Re) components with a ceramic hot wall created as an integral, functionally graded material (FGM). The goal of this effort is to further de?celop proven technologies for embedding a protective ceramic coating within the Ir/Re liner to form a robust functional gradient material. Current work includes the fabrication and testing of subscale samples to evaluate tensile, creep, thermal cyclic/oxidation, and thermophysical material properties. Larger test articles have also being fabricated and hot-fire tested to demonstrate the materials in prototype thrusters at 1O0 lbf thrust levels.

  4. High temperature measurement of water vapor absorption

    Science.gov (United States)

    Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

    1985-01-01

    An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

  5. Efficient removal and highly selective adsorption of Hg2+ by polydopamine nanospheres with total recycle capacity

    Science.gov (United States)

    Zhang, Xiulan; Jia, Xin; Zhang, Guoxiang; Hu, Jiamei; Sheng, Wenbo; Ma, Zhiyuan; Lu, Jianjiang; Liu, Zhiyong

    2014-09-01

    This study reported a new method for efficient removal of Hg2+ from contaminated water using highly selective adsorptive polydopamine (PDA) nanospheres, which were uniform and had a small diameter (150-200 nm). The adsorption isotherms, kinetics, thermodynamics were investigated. Also, the effects of ionic strength, co-existing ions on removing ability of PDA nanospheres for Hg2+ were studied. Adsorption of Hg2+ was very fast and efficient as adsorption equilibrium was completed within 4 h and the maximum adsorption capacities were 1861.72 mg/g, 2037.22 mg/g, and 2076.81 mg/g at 298 K, 313 K, and 328 K respectively, increasing with increasing of temperature. The PDA nanospheres exhibited highly selective adsorption of Hg2+ and had a total desorption capacity of 100% in hydrochloric acid solution, pH 1. The results showed that the structure of PDA nanospheres remained almost unchanged after recycling five times. Furthermore, X-ray photoelectron spectroscopy (XPS) was employed to determine the elements of PDA nanospheres before and after Hg2+ adsorption. Considering their efficient and highly Hg2+ selective adsorption, total recycle capacity, and high stability, PDA nanospheres will be feasible in a number of practical applications.

  6. High-temperature alloys for high-power thermionic systems

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kwang S.; Jacobson, D.L.; D' cruz, L.; Luo, Anhua; Chen, Bor-Ling.

    1990-08-01

    The need for structural materials with useful strength above 1600 k has stimulated interest in refractory-metal alloys. Tungsten possesses an extreme high modulus of elasticity as well as the highest melting temperature among metals, and hence is being considered as one of the most promising candidate materials for high temperature structural applications such as space nuclear power systems. This report is divided into three chapters covering the following: (1) the processing of tungsten base alloys; (2) the tensile properties of tungsten base alloys; and (3) creep behavior of tungsten base alloys. Separate abstracts were prepared for each chapter. (SC)

  7. LHDAC setup for high temperature and high pressure studies

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Nishant N., E-mail: nnpatel@barc.gov.in; Meenakshi, S., E-mail: nnpatel@barc.gov.in; Sharma, Surinder M., E-mail: nnpatel@barc.gov.in [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-04-24

    A ytterbium fibre laser (λ = 1.07 μm) based laser heated diamond anvil cell (LHDAC) facility has been recently set up at HP and SRPD, BARC for simultaneous high temperature and high pressure investigation of material properties. Synthesis of GaN was carried out at pressure of ∼9 GPa and temperature of ∼1925 K in a Mao-Bell type diamond anvil cell (DAC) using the LHDAC facility. The retrieved sample has been characterized using our laboratory based micro Raman setup.

  8. 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.

  9. 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...

  10. Integrated High Temperature Coal-to-Hydrogen System with CO2 Separation

    Energy Technology Data Exchange (ETDEWEB)

    James A. Ruud; Anthony Ku; Vidya Ramaswamy; Wei Wei; Patrick Willson

    2007-05-31

    A significant barrier to the commercialization of coal-to-hydrogen technologies is high capital cost. The purity requirements for H{sub 2} fuels are generally met by using a series of unit clean-up operations for residual CO removal, sulfur removal, CO{sub 2} removal and final gas polishing to achieve pure H{sub 2}. A substantial reduction in cost can be attained by reducing the number of process operations for H{sub 2} cleanup, and process efficiency can be increased by conducting syngas cleanup at higher temperatures. The objective of this program was to develop the scientific basis for a single high-temperature syngas-cleanup module to produce a pure stream of H{sub 2} from a coal-based system. The approach was to evaluate the feasibility of a 'one box' process that combines a shift reactor with a high-temperature CO{sub 2}-selective membrane to convert CO to CO{sub 2}, remove sulfur compounds, and remove CO{sub 2} in a simple, compact, fully integrated system. A system-level design was produced for a shift reactor that incorporates a high-temperature membrane. The membrane performance targets were determined. System level benefits were evaluated for a coal-to-hydrogen system that would incorporate membranes with properties that would meet the performance targets. The scientific basis for high temperature CO{sub 2}-selective membranes was evaluated by developing and validating a model for high temperature surface flow membranes. Synthesis approaches were pursued for producing membranes that integrated control of pore size with materials adsorption properties. Room temperature reverse-selectivity for CO{sub 2} was observed and performance at higher temperatures was evaluated. Implications for future membrane development are discussed.

  11. The NASA high temperature superconductivity program

    Science.gov (United States)

    Sokoloski, Martin M.; Romanofsky, Robert R.

    1990-01-01

    It has been recognized from the onset that high temperature superconductivity held great promise for major advances across a broad range of NASA interests. The current effort is organized around four key areas: communications and data, sensors and cryogenics, propulsion and power, and space materials technology. Recently, laser ablated YBa2Cu3O(7-x) films on LaAIO produced far superior RF characteristics when compared to metallic films on the same substrate. This achievement has enabled a number of unique microwave device applications, such as low insertion loss phase shifters and high Q filters. Melt texturing and melt quenched techniques are being used to produce bulk materials with optimized magnetic properties. These yttrium enriched materials possess enhanced flux pinning characteristics and will lead to prototype cryocooler bearings. Significant progress has also occurred in bolometer and current lead technology. Studies are being conducted to evaluate the effect of high temperature superconducting materials on the performance and life of high power magneto-plasma-dynamic thrusters. Extended studies were also performed to evaluate the benefit of superconducting magnetic energy storage for LEO space station, lunar and Mars mission applications. The project direction and level of effort of the program are also described.

  12. 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.

  13. Permanent magnets composed of high temperature superconductors

    Science.gov (United States)

    Weinstein, Roy; Chen, In-Gann; Liu, Jay; Lau, Kwong

    1991-01-01

    A study of persistent, trapped magnetic field has been pursued with high-temperature superconducting (HTS) materials. The main effort is to study the feasibility of utilization of HTS to fabricate magnets for various devices. The trapped field, when not in saturation, is proportional to the applied field. Thus, it should be possible to replicate complicated field configurations with melt-textured YBa2Cu3O7 (MT-Y123) material, bypassing the need for HTS wires. Presently, materials have been developed from which magnets of 1.5 T, at 77 K, can be fabricated. Much higher field is available at lower operating temperature. Stability of a few percent per year is readily attainable. Results of studies on prototype motors and minimagnets are reported.

  14. High-temperature insulation; Hochtemperatur-Waermeisolierung

    Energy Technology Data Exchange (ETDEWEB)

    Fuehres, M.

    1995-12-31

    For high-temperature insulations of industrial plants in the temperature range above 800 C preferably fibrous insulating materials are used. For this purpose ceramic fibres are more and more used. Apart from energy conservation possibilities up to 50% ceramic fibre products are characterized by a large field of the most different applications compared to conventional fire-resistant materials such as stone and compounds. The properties, production and the field of application are gone into in detail. (BWI) [Deutsch] In der Hochtemperaturisolierung industrieller Anlagen werden im Temperaturbereich oberhalb von 800 C bevorzugt faserfoermige Daemmstoffe eingesetzt. In zunehmendem Masse werden hierzu Keramikfasern eingesetzt. Neben den Einsparmoeglichkeiten im Energieverbrauch von bis zu 50% gegenueber konventionellen feuerfesten Werkstoffen wie Steinen und Massen zeichnen sich Keramikfaser-Produkte durch eine breite Palette vielfaeltigster Einsatzmoeglichkeiten aus. Es wird ausfuehrlich auf Eigenschaften, Herstellung und Einsatzmoeglichkeiten eingegangen. (BWI)

  15. Graphite thermal expansion reference for high temperature

    Science.gov (United States)

    Gaal, P. S.

    1974-01-01

    The design requirements of the aerospace and high-temperature nuclear reactor industries necessitate reliable thermal expansion data for graphite and other carbonaceous materials. The feasibility of an acceptable reference for calibration of expansion measuring systems that operate in carbon-rich atmospheres at temperatures ranging to 2500 C is the prime subject of this work. Present-day graphite technology provides acceptable materials for stable, reproducible references, as reflected by some of the candidate materials. The repeatability for a single specimen in a given expansion measuring system was found to be plus or minus 1%, while the combined results of several tests made on a number of samples fell within a plus or minus 2.5% band.

  16. 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.

  17. 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.

  18. High temperature polymer electrolyte membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    K.Scott; M. Mamlouk

    2006-01-01

    One of the major issues limiting the introduction of polymer electrolyte membrane fuel cells (PEMFCs) is the low temperature of operation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO, inevitably present in reformed fuel. In order to alleviate the problem of CO poisoning and improve the power density of the cell, operating at temperature above 100 ℃ is preferred. Nafion(R) -type perfluorosulfonated polymers have been typically used for PEMFC. However, the conductivity of Nafion(R) -type polymers is not high enough to be used for fuel cell operations at higher temperature ( > 90 ℃) and atmospheric pressure because they dehydrate under these condition.An additional problem which faces the introduction of PEMFC technology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications. Consequently the use of alternative fuels such as methanol and ethanol is of interest, especially if this can be used directly in the fuel cell, without reformation to hydrogen. A limitation of the direct use of alcohol is the lower activity of oxidation in comparison to hydrogen, which means that power densities are considerably lower. Hence to improve activity and power output higher temperatures of operation are preferable. To achieve this goal, requires a new polymer electrolyte membrane which exhibits stability and high conductivity in the absence of liquid water.Experimental data on a polybenzimidazole based PEMFC were presented. A simple steady-state isothermal model of the fuel cell is also used to aid in fuel cell performance optimisation. The governing equations involve the coupling of kinetic, ohmic and mass transport. This paper also considers the advances made in the performance of direct methanol and solid polymer electrolyte fuel cells and considers their limitations in relation to the source and type of fuels to be used.

  19. Optimization of growth temperature of multi-walled carbon nanotubes synthesized by spray pyrolysis method and application for arsenic removal

    Directory of Open Access Journals (Sweden)

    S. Mageswari

    2014-12-01

    Full Text Available Multi-walled carbon nanotubes have been synthesized at different temperatures ranging from 550 °C to 750 °C on silica supported Fe-Co catalyst by spray pyrolysis method using Citrus limonum oil under nitrogen atmosphere. The as-grown MWNTs were characterized by scanning electron microscope (SEM, high resolution transmission electron microscope (HRTEM, X-ray diffraction analysis (XRD and Raman spectral studies. The HRTEM and Raman spectroscopic studies confirmed the evolution of MWNTs with the outer diameter between 25 and 38 nm. The possibility of use of as-grown MWNTs as an adsorbent for removal of As (V ions from drinking water was studied. Adsorption isotherm data were interpreted by the Langmuir and Freundlich equations. Kinetic data were studied using Elovich, pseudo-first order and pseudo-second order equations in order to elucidate the reaction mechanism.

  20. High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Turnquist, Norman [GE Global Research, Munchen (Germany); Qi, Xuele [GE Global Research, Munchen (Germany); Raminosoa, Tsarafidy [GE Global Research, Munchen (Germany); Salas, Ken [GE Global Research, Munchen (Germany); Samudrala, Omprakash [GE Global Research, Munchen (Germany); Shah, Manoj [GE Global Research, Munchen (Germany); Van Dam, Jeremy [GE Global Research, Munchen (Germany); Yin, Weijun [GE Global Research, Munchen (Germany); Zia, Jalal [GE Global Research, Munchen (Germany)

    2013-12-20

    This report summarizes the progress made during the April 01, 2010 – December 30, 2013 period under Cooperative Agreement DE-EE0002752 for the U.S. Department of Energy entitled “High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems.” The overall objective of this program is to advance the technology for well fluids lifting systems to meet the foreseeable pressure, temperature, and longevity needs of the Enhanced Geothermal Systems (EGS) industry for the coming ten years. In this program, lifting system requirements for EGS wells were established via consultation with industry experts and site visits. A number of artificial lift technologies were evaluated with regard to their applicability to EGS applications; it was determined that a system based on electric submersible pump (ESP) technology was best suited to EGS. Technical barriers were identified and a component-level technology development program was undertaken to address each barrier, with the most challenging being the development of a power-dense, small diameter motor that can operate reliably in a 300°C environment for up to three years. Some of the targeted individual component technologies include permanent magnet motor construction, high-temperature insulation, dielectrics, bearings, seals, thrust washers, and pump impellers/diffusers. Advances were also made in thermal management of electric motors. In addition to the overall system design for a full-scale EGS application, a subscale prototype was designed and fabricated. Like the full-scale design, the subscale prototype features a novel “flow-through-the-bore” permanent magnet electric motor that combines the use of high temperature materials with an internal cooling scheme that limits peak internal temperatures to <330°C. While the full-scale high-volume multi-stage pump is designed to lift up to 80 kg/s of process water, the subscale prototype is based on a production design that can pump 20 kg/s and has been modified

  1. 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

  2. Fail Safe, High Temperature Magnetic Bearings

    Science.gov (United States)

    Minihan, Thomas; Palazzolo, Alan; Kim, Yeonkyu; Lei, Shu-Liang; Kenny, Andrew; Na, Uhn Joo; Tucker, Randy; Preuss, Jason; Hunt, Andrew; Carter, Bart; hide

    2002-01-01

    This paper contributes to the magnetic bearing literature in two distinct areas: high temperature and redundant actuation. Design considerations and test results are given for the first published combined 538 C (1000 F) high speed rotating test performance of a magnetic bearing. Secondly, a significant extension of the flux isolation based, redundant actuator control algorithm is proposed to eliminate the prior deficiency of changing position stiffness after failure. The benefit of the novel extension was not experimentally demonstrated due to a high active stiffness requirement. In addition, test results are given for actuator failure tests at 399 C (750 F), 12,500 rpm. Finally, simulation results are presented confirming the experimental data and validating the redundant control algorithm.

  3. 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...

  4. High temperature flat plate solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Hozumi, S.; Aso, S.; Ebisu, K.; Uchino, H.

    1981-04-01

    Improvements in the efficiency of collectors are of great importance for extending the utilization of solar energy for heating and cooling in homes. A highly efficient collector makes the system size small and decreases the system cost effectively. From the view of the amount of energy collected, the efficient collector has a multiple effect, not only because of the high increase in instantaneous efficiency, but also because of the large usable intensity range of the insolation. On the basis of a functional analysis for a flat collector, the materials and parameters were selected and optimized, and a new high temperature flat collector was designed. The collector has 2 panes. The first pane is low iron glass and the second pane is a thin film of fluorinated ethylene-propylene copolymer. The overall solar transmittance for the two panes is 0.89. The collecting panel and its water paths were formed by means of welding and hydraulic expansion. The selective absorbing surface consists of colored stainless steel whose absorption characteristic is 0.89 and emission characteristic is 0.16. The thermal insulator preventing backward heatloss consists of double layers of urethane foam and glass wool. Furthermore, the sustained method for the second pane is contrived so as to prevent water condensation on the panes and excessive elevation of the absorber temperature during no load heating.

  5. Removal of Dye from Textile Wastewater Using Plant Oils Under Different pH and Temperature Conditions

    OpenAIRE

    A. S. Mahmoud; Abdel E. Ghaly; M. S. Brooks

    2007-01-01

    The effectiveness of five plant oils (cottonseed, olive, canola sunflower and used cooking oil) for the removal of dye from textile wastewater was evaluated. The study revealed that the dye removal efficiency increased as the temperature was increased. Under low pH, both the oil and dye split into two components each. Neither one of the oil components joined with either one of the dye components. However, the observed reduction in the absorbance under acidic conditions can be attributed to th...

  6. Robust high temperature oxygen sensor electrodes

    DEFF Research Database (Denmark)

    Lund, Anders

    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 ......-based electrodes and one porous electrode based on the perovskite-structured strontium and vanadiumdoped lanthanum chromium oxide (LSCV) were investigated. The porous electrodes were applied on yttrium-stabilised zirconium oxide (YSZ) substrates in a collaboration with the company PBI...

  7. High Temperature Sodium Thermal Convection Test Loop

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A project for the evaluation of compatibility characteristic of structural materials used in China experimental fast reactor(CEFR) has been in operation. The conditions which these structural materials contact with liquid sodium in reactor can be simulated by the tests in high temperature sodium thermal convection test loop. The main aims of designing and constructing the thermal convection test loop is for the corrosion test of CEFR materials, and the objective is to obtain the corrosion data of domestic materials.The main features of the test loop are shown in Fig.1. The primary components of the loop

  8. Applications of bulk high-temperature superconductors

    Science.gov (United States)

    Hull, J. R.

    The development of high-temperature superconductors (HTS's) can be broadly generalized into thin-film electronics, wire applications, and bulk applications. We consider bulk HTS's to include sintered or crystallized forms that do not take the geometry of filaments or tapes, and we discuss major applications for these materials. For the most part applications may be realized with the HTS's cooled to 77 K, and the properties of the bulk HTS's are often already sufficient for commercial use. A non-exhaustive list of applications for bulk HTS's includes trapped field magnets, hysteresis motors, magnetic shielding, current leads, and magnetic bearings. These applications are briefly discussed in this paper.

  9. 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...... number of biomass and refuse fired combined heat and power plant boilers, b) Laboratory exposures and metallurgical examinations of material specimens with ash deposits in well-defined gas environments with HCl and SO2 in a furnace....

  10. 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.

  11. High temperature quark localization by Polyakov loops

    CERN Document Server

    Kovacs, Tamas G; Bruckmann, Falk; Schierenberg, Sebastian

    2011-01-01

    We study the low eigenmodes of the overlap and staggered Dirac operator at high temperature. We show that the recently found localized quark modes obeying Poisson statistics are connected to physical gauge field objects with their size and density scaling in the continuum limit. The localized modes are also strongly correlated with large fluctuations of the Polyakov loop. Based on that we construct a random matrix model of the low Dirac modes inspired by dimensional reduction. Our model reproduces the Poisson to random matrix transition seen in the lattice Dirac spectrum.

  12. Symmetry Non-restoration at High Temperature

    CERN Document Server

    Rius, N

    1998-01-01

    We discuss the (non)-restoration of global and local symmetries at high temperature. First, we analyze a two-scalar model with $Z_2 \\times Z_2$ symmetry using the exact renormalization group. We conclude that inverse symmetry breaking is possible in this kind of models within the perturbative regime. Regarding local symmetries, we consider the $SU(2) \\otimes U(1)$ gauge symmetry and focus on the case of a strongly interacting scalar sector. Employing a model-independent chiral Lagrangian we find indications of symmetry restoration.

  13. High temperature decomposition of hydrogen peroxide

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2011-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  14. Aerospace applications of high temperature superconductivity

    Science.gov (United States)

    Heinen, V. O.; Connolly, D. J.

    1991-01-01

    Space application of high temperature superconducting (HTS) materials may occur before most terrestrial applications because of the passive cooling possibilities in space and because of the economic feasibility of introducing an expensive new technology which has a significant system benefit in space. NASA Lewis Research Center has an ongoing program to develop space technology capitalizing on the potential benefit of HTS materials. The applications being pursued include space communications, power and propulsion systems, and magnetic bearings. In addition, NASA Lewis is pursuing materials research to improve the performance of HTS materials for space applications.

  15. High-temperature superconducting current leads

    Science.gov (United States)

    Hull, J. R.

    1992-07-01

    The use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature is near commercial realization. The use of HTSs in this application has the potential to reduce refrigeration requirements and helium boiloff to values significantly lower than the theoretical best achievable with conventional leads. Considerable advantage is achieved by operating these leads with an intermediate temperature heat sink. The HTS part of the lead can be made from pressed and sintered powder. Powder-in-tube fabrication is also possible, however, the normal metal part of the lead acts as a thermal short and cannot provide much stabilization without increasing the refrigeration required. Lead stability favors designs with low current density. Such leads can be manufactured with today's technology, and lower refrigeration results from the same allowable burnout time. Higher current densities result in lower boiloff for the same lead length, but bumout times can be very short. In comparing experiment to theory, the density of helium vapor needs to be accounted for in calculating the expected boiloff. For very low-loss leads, two-dimensional heat transfer and the state of the dewar near the leads may play a dominant role in lead performance.

  16. NITRATE REMOVAL BY ANTARCTIC PSYCHROPHILIC YEAST CELLS UNDER HIGH SALT CONDITIONS (19th Symposium on Polar Biology)

    OpenAIRE

    カタヤマ-ヒラヤマ, ケイコ; イシカワ, サトシ; ニシカワ, ジロウ; ツジ, マサオ; コミヤマ, ヨシヒロ; ヒラヤマ, キミアキ; Keiko, KATAYAMA-HIRAYAMA; Satoshi, ISHIKAWA; Jiro, NISHIKAWA; Masao, TSUJI; Yoshihiro, KOMIYAMA; Kimiaki, HIRAYAMA

    1998-01-01

    We researched nitrate removal in water with high salt concentrations at low temperature using Candida sp. which was isolated from the upper layer of Lake Vanda in the McMurdo Dry Valleys, Antarctica. The strain was cultured in a synthetic medium that contained nitrate as the sole nitrogen source The time course for the growth, and the nitrate and the total organic carbon (TOC) removals were examined aerobically in the presence of 0-20% NaCl at 5℃. The effects of pH and the C/N ratio on the re...

  17. High power densities from high-temperature material interactions

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.F.

    1981-01-01

    Thermionic energy conversion (TEC) and metallic-fluid heat pipes (MFHPs) offer important and unique advantages in terrestrial and space energy processing. And they are well suited to serve together synergistically. TEC and MFHPs operate through working-fluid vaporization, condensation cycles that accept great thermal power densities at high temperatures. TEC and MFHPs have apparently simple, isolated performance mechanisms that are somewhat similar. And they also have obviously difficult, complected material problems that again are somewhat similar. Intensive investigation reveals that aspects of their operating cycles and material problems tend to merge: high-temperature material effects determine the level and lifetime of performance. Simplified equations verify the preceding statement for TEC and MFHPs. Material properties and interactions exert primary influences on operational effectiveness. And thermophysicochemical stabilities dictate operating temperatures which regulate the thermoemissive currents of TEC and the vaporization flow rates of MFHPs. Major high-temperature material problems of TEC and MFHPs have been solved. These solutions lead to productive, cost-effective applications of current TEC and MFHPs - and point to significant improvements with anticipated technological gains.

  18. Comparison of spatial interpolation methods for gridded bias removal in surface temperature forecasts

    Science.gov (United States)

    Mohammadi, Seyedeh Atefeh; Azadi, Majid; Rahmani, Morteza

    2017-08-01

    All numerical weather prediction (NWP) models inherently have substantial biases, especially in the forecast of near-surface weather variables. Statistical methods can be used to remove the systematic error based on historical bias data at observation stations. However, many end users of weather forecasts need bias corrected forecasts at locations that scarcely have any historical bias data. To circumvent this limitation, the bias of surface temperature forecasts on a regular grid covering Iran is removed, by using the information available at observation stations in the vicinity of any given grid point. To this end, the running mean error method is first used to correct the forecasts at observation stations, then four interpolation methods including inverse distance squared weighting with constant lapse rate (IDSW-CLR), Kriging with constant lapse rate (Kriging-CLR), gradient inverse distance squared with linear lapse rate (GIDS-LR), and gradient inverse distance squared with lapse rate determined by classification and regression tree (GIDS-CART), are employed to interpolate the bias corrected forecasts at neighboring observation stations to any given location. The results show that all four interpolation methods used do reduce the model error significantly, but Kriging-CLR has better performance than the other methods. For Kriging-CLR, root mean square error (RMSE) and mean absolute error (MAE) were decreased by 26% and 29%, respectively, as compared to the raw forecasts. It is found also, that after applying any of the proposed methods, unlike the raw forecasts, the bias corrected forecasts do not show spatial or temporal dependency.

  19. Cyclic Oxidation of High-Temperature Alloy Wires in Air

    Science.gov (United States)

    Reigel, Marissa M.

    2004-01-01

    High-temperature alloy wires are proposed for use in seal applications for future re-useable space vehicles. These alloys offer the potential for improved wear resistance of the seals. The wires must withstand the high temperature environments the seals are subjected to as well as maintain their oxidation resistance during the heating and cooling cycles of vehicle re-entry. To model this, the wires were subjected to cyclic oxidation in stagnant air. of this layer formation is dependent on temperature. Slow growing oxides such as chromia and alumina are desirable. Once the oxide is formed it can prevent the metal from further reacting with its environment. Cyclic oxidation models the changes in temperature these wires will undergo in application. Cycling the temperature introduces thermal stresses which can cause the oxide layer to break off. Re-growth of the oxide layer consumes more metal and therefore reduces the properties and durability of the material. were used for cyclic oxidation testing. The baseline material, Haynes 188, has a Co base and is a chromia former while the other two alloys, Kanthal A1 and PM2000, both have a Fe base and are alumina formers. Haynes 188 and Kanthal A1 wires are 250 pm in diameter and PM2000 wires are 150 pm in diameter. The coiled wire has a total surface area of 3 to 5 sq cm. The wires were oxidized for 11 cycles at 1204 C, each cycle containing a 1 hour heating time and a minimum 20 minute cooling time. Weights were taken between cycles. After 11 cycles, one wire of each composition was removed for analysis. The other wire continued testing for 70 cycles. Post-test analysis includes X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) for phase identification and morphology.

  20. 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...

  1. High-Temperature, High-Load-Capacity Radial Magnetic Bearing

    Science.gov (United States)

    Provenza, Andrew; Montague, Gerald; Kascak, Albert; Palazzolo, Alan; Jansen, Ralph; Jansen, Mark; Ebihara, Ben

    2005-01-01

    A radial heteropolar magnetic bearing capable of operating at a temperature as high as 1,000 F (=540 C) has been developed. This is a prototype of bearings for use in gas turbine engines operating at temperatures and speeds much higher than can be withstood by lubricated rolling-element bearings. It is possible to increase the maximum allowable operating temperatures and speeds of rolling-element bearings by use of cooling-air systems, sophisticated lubrication systems, and rotor-vibration- damping systems that are subsystems of the lubrication systems, but such systems and subsystems are troublesome. In contrast, a properly designed radial magnetic bearing can suspend a rotor without contact, and, hence, without need for lubrication or for cooling. Moreover, a magnetic bearing eliminates the need for a separate damping system, inasmuch as a damping function is typically an integral part of the design of the control system of a magnetic bearing. The present high-temperature radial heteropolar magnetic bearing has a unique combination of four features that contribute to its suitability for the intended application: 1. The wires in its electromagnet coils are covered with an insulating material that does not undergo dielectric breakdown at high temperature and is pliable enough to enable the winding of the wires to small radii. 2. The processes used in winding and potting of the coils yields a packing factor close to 0.7 . a relatively high value that helps in maximizing the magnetic fields generated by the coils for a given supplied current. These processes also make the coils structurally robust. 3. The electromagnets are of a modular C-core design that enables replacement of components and semiautomated winding of coils. 4. The stator is mounted in such a manner as to provide stable support under radial and axial thermal expansion and under a load as large as 1,000 lb (.4.4 kN).

  2. Removal of the Pesticide Pymetrozine from Aqueous Solution by Biochar Produced from Brewer's Spent Grain at Different Pyrolytic Temperatures

    Directory of Open Access Journals (Sweden)

    Xinguo Xi

    2014-10-01

    Full Text Available Biochar (BC produced from brewer's spent grain (BSG via slow pyrolysis at 300, 400, 500, 600, and 700 °C was characterized and investigated as an adsorbent for the removal of the pesticide pymetrozine from aqueous solution. Batch BSG BCs adsorption experiments were carried out under various conditions (such as pH, pymetrozine concentration, and BC dosage to adsorb the pymetrozine. The BSG BCs adsorption pymetrozine capacities were increased by 21.4% to 55.5% under pyrolysis temperatures of 300, 400, 500, and 600 °C compared to 700 °C with a pyrolysis time of 2 h and by 19.0% to 52.1% at 4 h. At solution pH values of 2, 4, 6, and 8, the adsorption capacities were increased by 9.6% to 39.5% compared with that at pH 10. A similar adsorption tendency was found for the different BCs dosage. In the first 60 min, BC absorbed 70% to 80% pymetrozine. The Langmuir and Freundlich model were highly correlated with BC adsorption. The magnitude of free energy decreased by 32.2% to 47.3% with increasing temperature. The value of the enthalpy change showed the adsorption to be endothermic. The BSG BC had high efficiency in adsorbing pymetrozine and had great potential to prevent the water pollution and reuse the waste of the beer factory.

  3. Apparatus for accurately measuring high temperatures

    Science.gov (United States)

    Smith, D.D.

    The present invention is a thermometer used for measuring furnace temperatures in the range of about 1800/sup 0/ to 2700/sup 0/C. The thermometer comprises a broadband multicolor thermal radiation sensor positioned to be in optical alignment with the end of a blackbody sight tube extending into the furnace. A valve-shutter arrangement is positioned between the radiation sensor and the sight tube and a chamber for containing a charge of high pressure gas is positioned between the valve-shutter arrangement and the radiation sensor. A momentary opening of the valve shutter arrangement allows a pulse of the high gas to purge the sight tube of air-borne thermal radiation contaminants which permits the radiation sensor to accurately measure the thermal radiation emanating from the end of the sight tube.

  4. Cast Aluminum Alloy for High Temperature Applications

    Science.gov (United States)

    Lee, Jonathan A.

    2003-01-01

    Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450 F (232 C) to about 750 F (400 C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. It can be very economically produced from conventional permanent mold, sand casting or investment casting, with silicon content ranging from 6% to 18%. At high silicon levels, the alloy exhibits excellent dimensional stability, surface hardness and wear resistant properties.

  5. 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...

  6. High-Temperature Ionization in Protoplanetary Disks

    CERN Document Server

    Desch, Steven J

    2015-01-01

    We calculate the abundances of electrons and ions in the hot (> 500 K), dusty parts of protoplanetary disks, treating for the first time the effects of thermionic and ion emission from the dust grains. High-temperature ionization modeling has involved simply assuming that alkali elements such as potassium occur as gas-phase atoms and are collisionally ionized following the Saha equation. We show that the Saha equation often does not hold, because free charges are produced by thermionic and ion emission and destroyed when they stick to grain surfaces. This means the ionization state depends not on the first ionization potential of the alkali atoms, but rather on the grains' work functions. The charged species' abundances typically rise abruptly above about 800 K, with little qualitative dependence on the work function, gas density, or dust-to-gas mass ratio. Applying our results, we find that protoplanetary disks' dead zone, where high diffusivities stifle magnetorotational turbulence, has its inner edge locat...

  7. Filter unit for use at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ciliberti, D.F.; Lippert, T.E.

    1988-04-05

    A filtering unit for the filtering of particulates from a particulate-containing high temperature gas stream is described comprising a ceramic, tubular filter element, having a closed bottom and side walls and an open top at the upper region thereof, disposed in an aperture in a tube sheet. The walls of the tube sheet about the aperature have an inwardly extending flange thereon, with the open top of the ceramic, tubular filter element adjacent one surface of the tube sheet where filtered gases are discharged, and the closed bottom and side walls exposed to the area of the opposite surface of the tube sheet where a particulate-containing high temperature gas stream to be filtered is present. A ceramic spiral spring is provided at an end of the ceramic, tubular filter element to bias the upper region of the ceramic, tubular filter element into contact with the flange so as to seal the ceramic, tubular filter element to the flange on the tube sheet.

  8. Development of high temperature coal gas desulfurization systems -- An overview

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B.; Lau, F.S.; Wangergow, J.R.; Zarnegar, M.K. [Inst. of Gas Technology, Des Plaines, IL (United States)

    1997-12-31

    Integrated Gasification Combined-Cycle (IGCC) processes are among the leading contenders for generation of electricity from coal in the 21st century. Coal gas desulfurization to sufficiently low levels at temperatures above 350 C is now recognized as crucial to efficient and economical utilization of coal in advanced IGCC processes. The implementation of hot coal gas desulfurization heavily relies on the development of regenerable sorbent materials that can efficiently remove H{sub 2}S (from several thousand ppmv levels down to a few ppmv) over a very large number of sulfidation/regeneration cycles. Over the last two decades, development of high temperature desulfurization sorbents has been focused on using various combinations of transition metal oxides as regenerable sorbents. The selection of suitable metal oxides is generally based on a number of requirements imposed by the IGCC process, which include favorable thermodynamic equilibria during sulfidation and regeneration, relatively high sulfidation and regeneration reactivities, good mechanical strength and structural stability, and environmental friendliness, all at a reasonably low cost. The desulfurization reactor can have a fixed-bed, a moving-bed, a transport reactor, or a bubbling fluidized-bed reactor design. Depending on process conditions and the application intended, each of these reactor configurations offers advantages, but also has limitations. The parameters guiding the choice of a reactor system include reactivity of the sorbent, crush strength and/or attrition resistance of the sorbent, absorption capacity of the sorbent, temperature distribution inside the reactors, and SO{sub 2} concentration in the regeneration product gas. This paper provides an overview of high temperature fuel gas desulfurization within the context of IGCC processes. The paper focuses on the studies related to the development of regenerable sorbents and addresses thermodynamic considerations, sulfidation kinetics

  9. High Heat Flux Surface Coke Deposition and Removal Assessment

    Science.gov (United States)

    2015-01-01

    etc. have on coke deposition from RP-1 and RP-2 as well as showing that we can oxidize and remove these deposits using ozone , would be very...Meeting; 29 Apr. - 3 May, Colorado Springs, CO. 10Billingsley, M.C. H.Y. Lyu and R.W. Bates (2007). "Experimental and Numerical Investigations of RP...5th Modeling and Simulation Subcommittee Joint Meeting, Denver, CO, 14-17 May. 11Linne, D.L., M. L. Meyer, T. Edwards, and D. A. Eitman (1997

  10. Thermal Hydraulics of the Very High Temperature Gas Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh; Eung Kim; Richard Schultz; Mike Patterson; Davie Petti

    2009-10-01

    The U.S Department of Energy (DOE) is conducting research on the Very High Temperature Reactor (VHTR) design concept for the Next Generation Nuclear Plant (NGNP) Project. The reactor design will be a graphite moderated, thermal neutron spectrum reactor that will produce electricity and hydrogen in a highly efficient manner. The NGNP reactor core will be either a prismatic graphite block type core or a pebble bed core. The NGNP will use very high-burnup, low-enriched uranium, TRISO-coated fuel, and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during reactor core-accidents. The objectives of the NGNP Project are to: Demonstrate a full-scale prototype VHTR that is commercially licensed by the U.S. Nuclear Regulatory Commission, and Demonstrate safe and economical nuclear-assisted production of hydrogen and electricity. The DOE laboratories, led by the INL, perform research and development (R&D) that will be critical to the success of the NGNP, primarily in the areas of: • High temperature gas reactor fuels behavior • High temperature materials qualification • Design methods development and validation • Hydrogen production technologies • Energy conversion. This paper presents current R&D work that addresses fundamental thermal hydraulics issues that are relevant to a variety of possible NGNP designs.

  11. High density and high temperature plasmas in Large Helical Device

    Science.gov (United States)

    Komori, Akio

    2010-11-01

    Recently a new confinement regime called Super Dense Core (SDC) mode was discovered in Large Helical Device (LHD). An extremely high density core region with more than ~ 1 × 1021 m-3 is obtained with the formation of an Internal Diffusion Barrier (IDB). The density gradient at the IDB is very high and the particle confinement in the core region is ~ 0.2 s. It is expected, for the future reactor, that the IDB-SDC mode has a possibility to achieve the self-ignition condition with lower temperature than expected before. Conventional approaches to increase the temperature have also been tried in LHD. For the ion heating, the perpendicular neutral beam injection effectively increased the ion temperature up to 5.6 keV with the formation of the internal transport barrier (ITB). In the electron heating experiments with 77 GHz gyrotrons, the highest electron temperature more than 15 keV was achieved, where plasmas are in the neoclassical regime.

  12. High density and high temperature plasmas in Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Komori, Akio, E-mail: komori@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)

    2010-11-01

    Recently a new confinement regime called Super Dense Core (SDC) mode was discovered in Large Helical Device (LHD). An extremely high density core region with more than {approx} 1 x 10{sup 21} m{sup -3} is obtained with the formation of an Internal Diffusion Barrier (IDB). The density gradient at the IDB is very high and the particle confinement in the core region is {approx} 0.2 s. It is expected, for the future reactor, that the IDB-SDC mode has a possibility to achieve the self-ignition condition with lower temperature than expected before. Conventional approaches to increase the temperature have also been tried in LHD. For the ion heating, the perpendicular neutral beam injection effectively increased the ion temperature up to 5.6 keV with the formation of the internal transport barrier (ITB). In the electron heating experiments with 77 GHz gyrotrons, the highest electron temperature more than 15 keV was achieved, where plasmas are in the neoclassical regime.

  13. Effects of Large Dam Removal and Groundwater Pumping on Stream Temperature under Humid, Semiarid, and Arid Conditions

    Science.gov (United States)

    Risley, J. C.; Constantz, J. E.; Essaid, H.; Rounds, S. A.

    2010-12-01

    The effects of large upstream dam removal and in-reach groundwater pumping on streamflows and stream temperature was analyzed for humid, semiarid, and arid conditions with long dry seasons representing typical climate conditions where large dams are present, such as the western US or eastern Australia. A MODFLOW-2000 model, with options for stream-aquifer interaction and grid-block rewetting, was constructed to simulate monthly streamflows for 12 watershed scenarios described below. For each scenario, streamflow output became input into a stream temperature simulation model. Stream temperatures were simulated using the CE-QUAL-W2 water quality model over a 110 km model grid, with the presence and removal of a dam at the top of the reach and pumping in the lower 60 km of the reach. Measured meteorological data from three locations in Oregon and California representing the three meterologic conditions were used as model input to simulate the impact of varying climate conditions on streamflows and stream temperature. For each climate condition, four hypothetical watershed scenarios were modeled: (1) natural (no dam or pumping), (2) large upstream dam present, (3) dam with in-reach pumping, and (4) no dam with pumping continued, resulting in 12 cases. Dam removal, in the presence or absence of pumping, created significant changes in streamflow characteristics, resulting in significant changes in stream temperature throughout the year for all three climate conditions. From March to August, the presence of a dam caused monthly mean stream temperatures to decrease on average by approximately 3.0°C, 2.5°C, and 2.0°C for the humid, semiarid, and arid conditions, respectively; however, stream temperatures generally increased from September to February. Pumping caused stream temperatures to warm in summer and cool in winter by generally less than 0.5°C. Though dam removal led to greater changes in stream temperature than pumping, ephemeral conditions were increased both

  14. High-Temperature Water-Gas Shift Membrane Reactor Study

    Energy Technology Data Exchange (ETDEWEB)

    Ciocco, M.V.; Iyoha, O.; Enick, R.M.; Killmeyer, R.P.

    2007-06-01

    NETL’s Office of Research and Development is exploring the integration of membrane reactors into coal gasification plants as a way of increasing efficiency and reducing costs. Water-Gas Shift Reaction experiments were conducted in membrane reactors at conditions similar to those encountered at the outlet of a coal gasifier. The changes in reactant conversion and product selectivity due to the removal of hydrogen via the membrane reactor were quantified. Research was conducted to determine the influence of residence time and H2S on CO conversion in both Pd and Pd80wt%Cu membrane reactors. Effects of the hydrogen sulfide-to-hydrogen ratio on palladium and a palladium-copper alloy at high-temperature were also investigated. These results were compared to thermodynamic calculations for the stability of palladium sulfides.

  15. Temperature of electro dynamic tether for space debris removal and its effect on Lorentz force

    OpenAIRE

    2014-01-01

    Electrodynamics tether (EDT) systems is expected as an effective system for deorbiting space debris. EDT systems is a high efficiency propulsion system using the Lorentz force generated by the interference with the earth's magnetic field and the current through the tether. The conductivity of the tether varies with temperacture of tether in orbit, and it affects the Lorentz force that EDT systems can generate. Tether temperature in orbit depends on the thermal optical property. However, the s...

  16. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

    Ceramic gas separation membranes can provide very high separation factors if the pore size is sufficiently small to separate gas molecules by molecular sieving and if oversized pores are adequately limited. Ceramic membranes typically have some pores that are substantially larger than the mean pore size and that should be regarded as defects. To assess the effects of such defects on the performance of ceramic membranes, a simple mathematical model has been developed to describe flow through a gas separation membrane that has a primary mode of flow through very small pores but that has a secondary mode of flow through undesirably large pores. This model permits separation factors to be calculated for a specified gas pair as a function of the molecular weights and molecular diameters of the gases, the membrane pore diameter, and the diameter and number of defects. This model will be described, and key results from the model will be presented. The separation factors of the authors membranes continue to be determined using a permeance test system that measures flows of pure gases through a membrane at temperatures up to 275{degrees}C. A primary goal of this project for FY 1996 is to develop a mixed gas separation system for measuring the separation efficiency of membranes at higher temperatures. Performance criteria have been established for the planned mixed gas separation system and design of the system has been completed. The test system is designed to measure the separation efficiency of membranes at temperatures up to 600{degrees}C and pressures up to 100 psi by separating the constituents of a gas mixture containing hydrogen. The system will accommodate the authors typical experimental membrane that is tubular and has a diameter of about 9 mm and a length of about 23 cm. The design of the new test system and its expected performance will be discussed.

  17. 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

  18. Potential aerospace applications of high temperature superconductors

    Science.gov (United States)

    Selim, Raouf

    1994-01-01

    The recent discovery of High Temperature Superconductors (HTS) with superconducting transition temperature, T(sub c), above the boiling point of liquid nitrogen has opened the door for using these materials in new and practical applications. These materials have zero resistance to electric current, have the capability of carrying large currents and as such have the potential to be used in high magnetic field applications. One of the space applications that can use superconductors is electromagnetic launch of payloads to low-earth-orbit. An electromagnetic gun-type launcher can be used in small payload systems that are launched at very high velocity, while sled-type magnetically levitated launcher can be used to launch larger payloads at smaller velocities. Both types of launchers are being studied by NASA and the aerospace industry. The use of superconductors will be essential in any of these types of launchers in order to produce the large magnetic fields required to obtain large thrust forces. Low Temperature Superconductor (LTS) technology is mature enough and can be easily integrated in such systems. As for the HTS, many leading companies are currently producing HTS coils and magnets that potentially can be mass-produced for these launchers. It seems that designing and building a small-scale electromagnetic launcher is the next logical step toward seriously considering this method for launching payloads into low-earth-orbit. A second potential application is the use of HTS to build sensitive portable devices for the use in Non Destructive Evaluation (NDE). Superconducting Quantum Interference Devices (SQUID's) are the most sensitive instruments for measuring changes in magnetic flux. By using HTS in SQUID's, one will be able to design a portable unit that uses liquid nitrogen or a cryocooler pump to explore the use of gradiometers or magnetometers to detect deep cracks or corrosion in structures. A third use is the replacement of Infra-Red (IR) sensor leads on

  19. High pressure/high temperature thermogravimetric apparatus. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Calo, J.M.; Suuberg, E.M.

    1999-12-01

    The purpose of this instrumentation grant was to acquire a state-of-the-art, high pressure, high temperature thermogravimetric apparatus (HP/HT TGA) system for the study of the interactions between gases and carbonaceous solids for the purpose of solving problems related to coal utilization and applications of carbon materials. The instrument that we identified for this purpose was manufactured by DMT (Deutsche Montan Technologies)--Institute of Cokemaking and Coal Chemistry of Essen, Germany. Particular features of note include: Two reactors: a standard TGA reactor, capable of 1100 C at 100 bar; and a high temperature (HT) reactor, capable of operation at 1600 C and 100 bar; A steam generator capable of generating steam to 100 bar; Flow controllers and gas mixing system for up to three reaction gases, plus a separate circuit for steam, and another for purge gas; and An automated software system for data acquisition and control. The HP/TP DMT-TGA apparatus was purchased in 1996 and installed and commissioned during the summer of 1996. The apparatus was located in Room 128 of the Prince Engineering Building at Brown University. A hydrogen alarm and vent system were added for safety considerations. The system has been interfaced to an Ametek quadruple mass spectrometer (MA 100), pumped by a Varian V250 turbomolecular pump, as provided for in the original proposed. With this capability, a number of gas phase species of interest can be monitored in a near-simultaneous fashion. The MS can be used in a few different modes. During high pressure, steady-state gasification experiments, it is used to sample, measure, and monitor the reactant/product gases. It can also be used to monitor gas phase species during nonisothermal temperature programmed reaction (TPR) or temperature programmed desorption (TPD) experiments.

  20. High-temperature superconducting undulator magnets

    Science.gov (United States)

    Kesgin, Ibrahim; Kasa, Matthew; Ivanyushenkov, Yury; Welp, Ulrich

    2017-04-01

    This paper presents test results on a prototype superconducting undulator magnet fabricated using 15% Zr-doped rare-earth barium copper oxide high temperature superconducting (HTS) tapes. On an 11-pole magnet we demonstrate an engineering current density, J e, of more than 2.1 kA mm‑2 at 4.2 K, a value that is 40% higher than reached in comparable devices wound with NbTi-wire, which is used in all currently operating superconducting undulators. A novel winding scheme enabling the continuous winding of tape-shaped conductors into the intricate undulator magnets as well as a partial interlayer insulation procedure were essential in reaching this advance in performance. Currently, there are rapid advances in the performance of HTS; therefore, achieving even higher current densities in an undulator structure or/and operating it at temperatures higher than 4.2 K will be possible, which would substantially simplify the cryogenic design and reduce overall costs.

  1. High-rate nitrogen removal and microbial community of an up-flow anammox reactor with ceramics as biomass carrier.

    Science.gov (United States)

    Ren, Yuhui; Li, Dong; Li, Xiangkun; Yang, Liu; Ding, An; Zhang, Jie

    2014-10-01

    Nitrogen removal performance and responsible microbial community of anammox process at low temperatures, and long term effect of dissolved oxygen (DO) on the performance of anammox process were investigated in a biofilm reactor, which was operated at 33±1°C (159d) and 20±2°C (162d) with an influent DO concentration of 0.7-1.5mgL(-1). Nitrogen removal recovered to 70% after 2wk with the temperature drastically decreasing from 33±1°C to 20±2°C. At 20±2°C, the average effluent (NH4(+)-N+NO2(-)-N) concentration was 0.08±0.08mgL(-1) at a hydraulic retention time of 1.5h. A total nitrogen removal efficiency of the reactor of 1.0gNL(-1)d(-1) was obtained for up to one month while the nitrogen loading rate was 1.16gNL(-1)d(-1). Results of T-RFLP and 16S rRNA phylogenic analysis revealed that Candidatus Jettenia asiatica, as confirmed to adapt to low temperature, was considered to be responsible for the stable and high nitrogen removal performance.

  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. On Silicides in High Temperature Titanium Alloys

    Directory of Open Access Journals (Sweden)

    C. Ramachandra

    1986-04-01

    Full Text Available High temperature titanium alloys like IMI 685 contain small amounts of silicon (~ 0.25 wt. per cent to improve creep resistance. Different types of silicides, namely Ti5Si3 (TiZr5Si3(S1 and (TiZr6 Si3 (S2, have been observed to precipitate in various silicon-bearing titanium alloys depending upon their composition and heat treatment. The precipitation of silicides, their orientation relationship with the matrix in different alloys, and the beneficial influence of thermo-mechanical treatment on the distribution of silicides have been pointed out. The effect of silicides on mechanical properties and fracture of the commercial alloy IMI 685 is also indicated.

  4. 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.

  5. Turbine vane with high temperature capable skins

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Jay A [Oviedo, FL

    2012-07-10

    A turbine vane assembly includes an airfoil extending between an inner shroud and an outer shroud. The airfoil can include a substructure having an outer peripheral surface. At least a portion of the outer peripheral surface is covered by an external skin. The external skin can be made of a high temperature capable material, such as oxide dispersion strengthened alloys, intermetallic alloys, ceramic matrix composites or refractory alloys. The external skin can be formed, and the airfoil can be subsequently bi-cast around or onto the skin. The skin and the substructure can be attached by a plurality of attachment members extending between the skin and the substructure. The skin can be spaced from the outer peripheral surface of the substructure such that a cavity is formed therebetween. Coolant can be supplied to the cavity. Skins can also be applied to the gas path faces of the inner and outer shrouds.

  6. Electrode Kinetics in High Temperature Fuel Cells

    DEFF Research Database (Denmark)

    Bay, Lasse

    1998-01-01

    The O_2 reduction on Pt electrode with an yttria stabilized zirconia (YSZ) electrolyte is examined with potential step, voltammetry and impedance measurements. Inductive hysteresis are observed in all cases, indicating an activation-deactivation process for the electrode reaction. The same is found...... when the electrolyte is Gd doped ceria. The activation is generated by current passage. The time constant for the hysteresis is large considering the high operating temperatures, 800- 1000^oC. For the activation process potential steps give two time constants 10^2s and 10^3s for an anodic current, 10...... treated by modelling. The phenomenological model proposed can explain the principal behaviour of the inductive hysteresis. The activation process has first order dependence of the current density and the deactivation first order with respect to the activation.AFM pictures of the electrode...

  7. High temperature superconductivity space experiment (HTSSE)

    Science.gov (United States)

    Ritter, J. C.; Nisenoff, M.; Price, G.; Wolf, S. A.

    1991-01-01

    An experiment dealing with high-temperature superconducting devices and components in space is discussed. A variety of devices (primarily passive microwave and millimeter-wave components) has been procured and will be integrated with a cryogenic refrigerating and data acquisition system to form the space package, which will be launched in late 1992. This space experiment is expected to demonstrate that this technology is sufficiently robust to survive the space environment and that the technology has the potential to improve the operation of space systems significantly. The devices for the initial launch have been evaluated electrically, thermally, and mechanically, and will be integrated into the final space package early in 1991. The performance of the devices is summarized, and some potential applications of this technology in space systems are outlined.

  8. High Temperature Calcination - MACT Upgrade Equipment Pilot Plant Test

    Energy Technology Data Exchange (ETDEWEB)

    Richard D. Boardman; B. H. O& #39; Brien; N. R. Soelberg; S. O. Bates; R. A. Wood; C. St. Michel

    2004-02-01

    About one million gallons of acidic, hazardous, and radioactive sodium-bearing waste are stored in stainless steel tanks at the Idaho Nuclear Technology and Engineering Center (INTEC), which is a major operating facility of the Idaho National Engineering and Environmental Laboratory. Calcination at high-temperature conditions (600 C, with alumina nitrate and calcium nitrate chemical addition to the feed) is one of four options currently being considered by the Department of Energy for treatment of the remaining tank wastes. If calcination is selected for future processing of the sodium-bearing waste, it will be necessary to install new off-gas control equipment in the New Waste Calcining Facility (NWCF) to comply with the Maximum Achievable Control Technology (MACT) standards for hazardous waste combustors and incinerators. This will require, as a minimum, installing a carbon bed to reduce mercury emissions from their current level of up to 7,500 to <45 {micro}g/dscm, and a staged combustor to reduce unburned kerosene fuel in the off-gas discharge to <100 ppm CO and <10 ppm hydrocarbons. The staged combustor will also reduce NOx concentrations of about 35,000 ppm by 90-95%. A pilot-plant calcination test was completed in a newly constructed 15-cm diameter calciner vessel. The pilot-plant facility was equipped with a prototype MACT off-gas control system, including a highly efficient cyclone separator and off-gas quench/venturi scrubber for particulate removal, a staged combustor for unburned hydrocarbon and NOx destruction, and a packed activated carbon bed for mercury removal and residual chloride capture. Pilot-plant testing was performed during a 50-hour system operability test January 14-16, followed by a 100-hour high-temperature calcination pilot-plant calcination run January 19-23. Two flowsheet blends were tested: a 50-hour test with an aluminum-to-alkali metal molar ratio (AAR) of 2.25, and a 50-hour test with an AAR of 1.75. Results of the testing

  9. Chemical stability of high-temperature superconductors

    Science.gov (United States)

    Bansal, Narottam P.

    1992-01-01

    A review of the available studies on the chemical stability of the high temperature superconductors (HTS) in various environments was made. The La(1.8)Ba(0.2)CuO4 HTS is unstable in the presence of H2O, CO2, and CO. The YBa2Cu3O(7-x) superconductor is highly susceptible to degradation in different environments, especially water. The La(2-x)Ba(x)CuO4 and Bi-Sr-Ca-Cu-O HTS are relatively less reactive than the YBa2Cu3O(7-x). Processing of YBa2Cu3O(7-x) HTS in purified oxygen, rather than in air, using high purity noncarbon containing starting materials is recommended. Exposure of this HTS to the ambient atmosphere should also be avoided at all stages during processing and storage. Devices and components made out of these oxide superconductors would have to be protected with an impermeable coating of a polymer, glass, or metal to avoid deterioration during use.

  10. HIGH TEMPERATURE OXIDATION PERFORMANCE OF ALUMINIDE COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    Pint, B.A.; Zhang, Y.; Haynes, J.A.; Wright, I.G.

    2003-04-22

    In order to determine the potential benefits and limitations of aluminide coatings, coatings made by chemical vapor deposition (CVD) on Fe- and Ni-base alloy substrates are being evaluated in various high-temperature environments. Testing of coatings on representative ferritic (Fe-9Cr-1Mo) and austenitic (type 304L stainless steel) alloys has found that high frequency thermal cycling (1h cycle time) can significantly degrade the coating. Based on comparison with similar specimens with no thermal cycling or a longer cycle time (100h), this degradation was not due to Al loss from the coating but most likely because of the thermal expansion mismatch between the coating and the substrate. Several coated Ni-base alloys were tested in a high pressure (20atm) steam-CO2 environment for the ZEST (zero-emission steam turbine) program. Coated specimens showed less mass loss than the uncoated specimens after 1000h at 900 C and preliminary characterization examined the post-test coating structure and extent of attack.

  11. Assessment of high-temperature battery systems

    Energy Technology Data Exchange (ETDEWEB)

    Sen, R K

    1989-02-01

    Three classes of high-temperature batteries are being developed internationally with transportation and stationary energy storage applications in mind: sodium/sulfur, lithium/metal sulfide, and sodium/metal chloride. Most attention is being given to the sodium/sulfur system. The Office of Energy Storage and Distribution (OESD) and the Office of Transportation Systems (OTS) of the US Department of Energy (DOE) are actively supporting the development of this battery system. It is anticipated that pilot-scale production facilities for sodium/sulfur batteries will be in operation in the next couple of years. The lithium/metal sulfide and the sodium/metal chloride systems are not receiving the same level of attention as the sodium/sulfur battery. Both of these systems are in an earlier stage of development than sodium/sulfur. OTS and OESD are supporting work on the lithium/iron sulfide battery in collaboration with the Electric Power Research Institute (EPRI); the work is being carried out at Argonne National Laboratory (ANL). The sodium/metal chloride battery, the newest member of the group, is being developed by a Consortium of South African and British companies. Very little DOE funds are presently allocated for research on this battery. The purpose of this assessment is to evaluate the present status of the three technologies and to identify for each technology a prioritized list of R and D issues. Finally, the assessment includes recommendations to DOE for a proposed high-temperature battery research and development program. 18 figs., 21 tabs.

  12. TOWARD A REMOVAL OF TEMPERATURE DEPENDENCIES FROM ABUNDANCE DETERMINATIONS: NGC 628

    Energy Technology Data Exchange (ETDEWEB)

    Croxall, Kevin V. [Department of Astronomy, The Ohio State University, 4051 McPherson Laboratory, 140 West 18th Avenue, Columbus, OH 43210 (United States); Smith, J. D.; Pellegrini, E. [Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Brandl, B. R. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Groves, B. A.; Kreckel, K.; Sandstrom, K. M.; Walter, F.; Schinnerer, E. [Max-Planck-Institut fur Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Kennicutt, R. C.; Galametz, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Johnson, B. D. [Institut d' Astrophysique de Paris, UMR7095 CNRS, Université Pierre and Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France); Armus, L. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Beirão, P. [Observatoire de Paris, 61 avenue de l' Observatoire, F-75014 Paris (France); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Dale, D. A. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Hinz, J. L. [MMT Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Hunt, L. K. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Koda, J., E-mail: croxall@astronomy.ohio-state.edu [Department of Physics and Astronomy, SUNY Stony Brook, Stony Brook, NY 11794-3800 (United States)

    2013-11-10

    The metal content of a galaxy, a key property for distinguishing between viable galaxy evolutionary scenarios, strongly influences many of the physical processes in the interstellar medium. An absolute and robust determination of extragalactic metallicities is essential in constraining models of chemical enrichment and chemical evolution. Current gas-phase abundance determinations, however, from optical fine-structure lines are uncertain to 0.8 dex as conversion of these optical line fluxes to abundances is strongly dependent on the electron temperature of the ionized gas. In contrast, the far-infrared (far-IR) emission lines can be used to derive an O{sup ++} abundance that is relatively insensitive to temperature, while the ratio of the optical to far-IR lines provides a consistent temperature to be used in the derivation of an O{sup +} abundance. We present observations of the [O III] 88 μm fine-structure line in NGC 628 that were obtained as part of the Key Insights on Nearby Galaxies: a Far Infared Survey with Herschel program. These data are combined with optical integrated field unit data to derive oxygen abundances for seven H II regions. We find the abundance of these regions to all lie between the high and low values of strong-line calibrations and to be in agreement with estimates that assume temperature fluctuations are present in the H II regions.

  13. Dynamic Model of High Temperature PEM Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2007-01-01

    cathode air cooled 30 cell HTPEM fuel cell stack developed at the Institute of Energy Technology at Aalborg University. This fuel cell stack uses PEMEAS Celtec P-1000 membranes, runs on pure hydrogen in a dead end anode configuration with a purge valve. The cooling of the stack is managed by running...... conduction through stack insulation, cathode air convection and heating of the inlet gasses in manifold. Various measurements are presented to validate the model predictions of the stack temperatures....

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

    Energy Technology Data Exchange (ETDEWEB)

    Vinayak N. Kabadi

    2000-05-01

    The flow VLE apparatus designed and built for a previous project was upgraded and recalibrated for data measurements for this project. The modifications include better and more accurate sampling technique, addition of a digital recorder to monitor temperature and pressure inside the VLE cell, and a new technique for remote sensing of the liquid level in the cell. VLE data measurements for three binary systems, tetralin-quinoline, benzene--ethylbenzene and ethylbenzene--quinoline, have been completed. The temperature ranges of data measurements were 325 C to 370 C for the first system, 180 C to 300 C for the second system, and 225 C to 380 C for the third system. The smoothed data were found to be fairly well behaved when subjected to thermodynamic consistency tests. SETARAM C-80 calorimeter was used for incremental enthalpy and heat capacity measurements for benzene--ethylbenzene binary liquid mixtures. Data were measured from 30 C to 285 C for liquid mixtures covering the entire composition range. An apparatus has been designed for simultaneous measurement of excess volume and incremental enthalpy of liquid mixtures at temperatures from 30 C to 300 C. The apparatus has been tested and is ready for data measurements. A flow apparatus for measurement of heat of mixing of liquid mixtures at high temperatures has also been designed, and is currently being tested and calibrated.

  15. Mechanical behavior of high strength ceramic fibers at high temperatures

    Science.gov (United States)

    Tressler, R. E.; Pysher, D. J.

    1991-01-01

    The mechanical behavior of commercially available and developmental ceramic fibers, both oxide and nonoxide, has been experimentally studied at expected use temperatures. In addition, these properties have been compared to results from the literature. Tensile strengths were measured for three SiC-based and three oxide ceramic fibers for temperatures from 25 C to 1400 C. The SiC-based fibers were stronger but less stiff than the oxide fibers at room temperature and retained more of both strength and stiffness to high temperatures. Extensive creep and creep-rupture experiments have been performed on those fibers from this group which had the best strengths above 1200 C in both single filament tests and tests of fiber bundles. The creep rates for the oxides are on the order of two orders of magnitude faster than the polymer derived nonoxide fibers. The most creep resistant filaments available are single crystal c-axis sapphire filaments. Large diameter CVD fabricated SiC fibers are the most creep and rupture resistant nonoxide polycrystalline fibers tested to date.

  16. High rates of denitrification and nitrate removal in cold seep sediments

    OpenAIRE

    Bowles, Marshall; Joye, Samantha

    2010-01-01

    We measured denitrification and nitrate removal rates in cold seep sediments from the Gulf of Mexico. Heterotrophic potential denitrification rates were assayed in time-series incubations. Surficial sediments inhabited by Beggiatoa exhibited higher heterotrophic potential denitrification rates (32 μ N reduced day−1) than did deeper sediments (11 μ N reduced day−1). Nitrate removal rates were high in both sediment horizons. These nitrate removal rates translate into rapid turnover times (...

  17. Characterization of cadmium removal from aqueous solution by biochar produced from a giant Miscanthus at different pyrolytic temperatures.

    Science.gov (United States)

    Kim, Woong-Ki; Shim, Taeyong; Kim, Yong-Seong; Hyun, Seunghun; Ryu, Changkook; Park, Young-Kwon; Jung, Jinho

    2013-06-01

    The objective of this study was to investigate the feasibility of biochar for removing Cd from aqueous solution. Biochars were produced from a Miscanthus sacchariflorus via slow pyrolysis at 300, 400, 500 and 600°C. Higher pyrolytic temperature resulted in biochar with a higher aromatic structure and fewer polar functional groups. In particular, pH and surface area of biochar increased greatly at pyrolytic temperatures ≥ 500°C, which increased Cd sorption capacity up to 13.24 mgg(-1). The diffuse-controlled Cd removal was likely due to a surface sorption or a precipitation reaction depending on pH. A simulation with the visual MINTEQ program indicated that the precipitate was Cd(OH)2. In addition, biochar treatment significantly removed the acute toxicity of Cd toward Daphnia magna, resulting in increase of EC50 (50% effective concentration) value from 0.16 to 0.76 mgL(-1).

  18. 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

  19. Stream Temperature Spatial and Temporal Response to Large Dam Removal and Groundwater Pumping under Varying Climate Conditions

    Science.gov (United States)

    Risley, J. C.; Constantz, J. E.; Essaid, H.; Rounds, S. A.

    2016-12-01

    We simulated the effects of large upstream dam removal and in-reach groundwater pumping on stream temperature spatial and temporal patterns in a hypothetical river basin under varying climate conditions. A MODFLOW-2000 model, with options for stream-aquifer interaction and grid-block rewetting, was constructed to simulate monthly streamflows for 12 watershed scenarios described below. For each scenario, streamflow output became input into a stream temperature simulation model. Stream temperatures were simulated using the CE-QUAL-W2 water quality model over a 110 km model grid, with the presence and removal of a dam at the top of the reach and pumping in the lower 60 km of the reach. Measured meteorological data from three locations in Oregon and California representing the three meteorological conditions were used as model input to simulate the impact of varying climate conditions on streamflows and stream temperature. For each climate condition, four hypothetical watershed scenarios were modeled: (1) natural (no dam or pumping), (2) large upstream dam present, (3) dam with in-reach pumping, and (4) no dam with pumping continued, resulting in 12 cases. If a transition from a humid to more arid environment occurs under future climate change, the simulations showed that decreased streamflow, increased solar radiation, and increased air temperatures would result in overall increased stream temperatures as expected. From March to August, the presence of a dam caused monthly mean stream temperatures to decrease on average by approximately 3.0°C, 2.5°C, and 2.0°C for the humid, semiarid, and arid conditions, respectively; however, stream temperatures generally increased from September to February. Pumping caused stream temperatures to warm in summer and cool in winter by generally less than 0.5°C. Though dam removal led to greater changes in stream temperature than pumping, ephemeral conditions were increased both temporally and spatially by pumping.

  20. A novel heterotrophic nitrifying and aerobic denitrifying bacterium, Zobellella taiwanensis DN-7, can remove high-strength ammonium.

    Science.gov (United States)

    Lei, Yu; Wang, Yangqing; Liu, Hongjie; Xi, Chuanwu; Song, Liyan

    2016-05-01

    A novel heterotrophic bacterium capable of heterotrophic nitrification and aerobic denitrification was isolated from ammonium contaminated landfill leachate and physiochemical and phylogenetically identified as Zobellella taiwanensis DN-7. DN-7 converted nitrate, nitrate, and ammonium to N2 as the primary end product. Single factor experiments suggested that the optimal conditions for ammonium removal were trisodium citrate as carbon source, C/N ratio 8, pH 8.0-10.0, salinity less than 3 %, temperature 30 °C, and rotation speed more than 150 rpm. Specifically, DN-7 could remove 1000.0 and 2000.0 mg/L NH4 (+)-N completely within 96 and 216 h, with maximum removal rates of 19.6 and 17.3 mg L(-1) h(-1), respectively. These results demonstrated that DN-7 is a promising candidate for application of high-strength ammonium wastewater treatments.

  1. High Molecular Weight Polybenzimidazole Membranes for High Temperature PEMFC

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Cleemann, Lars Nilausen; Steenberg, T.;

    2014-01-01

    High temperature operation of proton exchange membrane fuel cells under ambient pressure has been achieved by using phosphoric acid doped polybenzimidazole (PBI) membranes. To optimize the membrane and fuel cells, high performance polymers were synthesized of molecular weights from 30 to 94 k...... showed enhanced chemical stability towards radical attacks under the Fenton test, reduced volume swelling upon the acid doping and improved mechanical strength at acid doping levels of as high as about 11 mol H3PO4 per molar repeat polymer unit. The PBI‐78kDa/10.8PA membrane, for example, exhibited...... tensile strength of 30.3 MPa at room temperature or 7.3 MPa at 130 °C and a proton conductivity of 0.14 S cm–1 at 160 °C. Fuel cell tests with H2 and air at 160 °C showed high open circuit voltage, power density and a low degradation rate of 1.5 μV h–1 at a constant load of 300 mA cm–2....

  2. Crystal structures at high pressures and temperatures

    Science.gov (United States)

    Caldwell, Wendel Alexander

    2000-10-01

    The diamond anvil cell (DAC) is a unique instrument that can generate pressures equivalent to those inside planetary interiors (pressures on the order of 1 million atmospheres) under sustained conditions. When combined with a bright source of collimated x-rays, the DAC can be used to probe the structure of materials in-situ at ultra-high pressures. An understanding of the high-pressure structure of materials is important in determining what types of processes may take place in the Earth at great depths. Motivated by previous studies showing that xenon becomes metallic at pressures above ˜1 megabar (100 GPa), we examined the stable structures and reactivity of xenon at pressures approaching that of the core-mantle boundary in the Earth. Our findings indicate the transformation of xenon from face-centered cubic (fcc) to hexagonal close-packed (hcp) structures is kinetically hindered at room temperature, with the equilibrium fcc--hcp phase boundary at 21 (+/-3) gigapascals, a pressure lower than was previously thought. Additionally, we find no tendency on the part of xenon to form a metal alloy with iron or platinum to at least 100 to 150 gigapascals, making it unlikely that the Earth's core serves as a reservoir for primordial xenon. Measurements of the compressibility of natural (Mg.75,Fe .25)2SiO4 gamma-spinel at pressures of the Earth's transition zone yield a pressure derivative of the bulk modulus K0 ' = 6.3 (+/-0.3). As gamma-spinel is considered to be a dominant mineral phase of the transition-zone of the Earth's mantle (400--670 km depth), the relatively high value of K0' for gamma-spinel may help explain the rapid increase with depth of seismic velocities through the transition zone. The thermodynamics, mechanisms and kinetics of pressure-induced amorphization are not well understood. We report here new studies indicating little or no entropy difference between the crystalline and glassy states of Ca(OH) 2 (portlandite). Additional work on the pressure

  3. 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?

  4. High-Temperature Shape Memory Alloys

    Science.gov (United States)

    Biffi, C. A.; Tuissi, A.

    2014-10-01

    In this paper, an experimental study of laser micro-processing on a Cu-Zr-based shape memory alloy (SMA), which is suitable for high-temperature (HT) applications, is discussed. A first evaluation of the interaction between a laser beam and Zr50Cu28Ni7Co15 HT SMA is highlighted. Single laser pulses at various levels of power and pulse duration were applied to evaluate their effect on the sample surfaces. Blind and through microholes were produced with sizes on the order of a few hundreds of microns; the results were characterized from the morphological viewpoint using a scanning electron microscope. The high beam quality allows the holes to be created with good circularity and little melted material around the hole periphery. An analysis of the chemical composition was performed using energy dispersive spectroscopy, revealing that compositional changes were limited, while important oxidation occurred on the hole surfaces. Additionally, laser micro-cutting tests were also proposed to evaluate the cut edge morphology and dimensions. The main result of this paper concerned the good behavior of the material upon interaction with the laser beam, which suggests that microfeatures can be successfully produced in this alloy.

  5. 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...

  6. Assessment of microelectronics packaging for high temperature, high reliability applications

    Energy Technology Data Exchange (ETDEWEB)

    Uribe, F.

    1997-04-01

    This report details characterization and development activities in electronic packaging for high temperature applications. This project was conducted through a Department of Energy sponsored Cooperative Research and Development Agreement between Sandia National Laboratories and General Motors. Even though the target application of this collaborative effort is an automotive electronic throttle control system which would be located in the engine compartment, results of this work are directly applicable to Sandia`s national security mission. The component count associated with the throttle control dictates the use of high density packaging not offered by conventional surface mount. An enabling packaging technology was selected and thermal models defined which characterized the thermal and mechanical response of the throttle control module. These models were used to optimize thick film multichip module design, characterize the thermal signatures of the electronic components inside the module, and to determine the temperature field and resulting thermal stresses under conditions that may be encountered during the operational life of the throttle control module. Because the need to use unpackaged devices limits the level of testing that can be performed either at the wafer level or as individual dice, an approach to assure a high level of reliability of the unpackaged components was formulated. Component assembly and interconnect technologies were also evaluated and characterized for high temperature applications. Electrical, mechanical and chemical characterizations of enabling die and component attach technologies were performed. Additionally, studies were conducted to assess the performance and reliability of gold and aluminum wire bonding to thick film conductor inks. Kinetic models were developed and validated to estimate wire bond reliability.

  7. Geochemistry of Aluminum in High Temperature Brines

    Energy Technology Data Exchange (ETDEWEB)

    Benezeth, P.; Palmer, D.A.; Wesolowski, D.J.

    1999-05-18

    The objective ofthis research is to provide quantitative data on the equilibrium and thermodynamic properties of aluminum minerals required to model changes in permeability and brine chemistry associated with fluid/rock interactions in the recharge, reservoir, and discharge zones of active geothermal systems. This requires a precise knowledge of the thermodynamics and speciation of aluminum in aqueous brines, spanning the temperature and fluid composition rangesencountered in active systems. The empirical and semi-empirical treatments of the solubility/hydrolysis experimental results on single aluminum mineral phases form the basis for the ultimate investigation of the behavior of complex aluminosilicate minerals. The principal objective in FY 1998 was to complete the solubility measurements on boehmite (AIOOH) inNaC1 media( 1 .O and 5.0 molal ionic strength, IOO-250°C). However, additional measurements were also made on boehmite solubility in pure NaOH solutions in order to bolster the database for fitting in-house isopiestic data on this system. Preliminary kinetic Measurements of the dissolution/precipitation of boehmite was also carried out, although these were also not planned in the earlier objective. The 1999 objectives are to incorporate these treatments into existing codes used by the geothermal industry to predict the chemistry ofthe reservoirs; these calculations will be tested for reliability against our laboratory results and field observations. Moreover, based on the success of the experimental methods developed in this program, we intend to use our unique high temperature pH easurement capabilities to make kinetic and equilibrium studies of pH-dependent aluminosilicate transformation reactions and other pH-dependent heterogeneous reactions.

  8. High Metal Removal Rate Process for Machining Difficult Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bates, Robert; McConnell, Elizabeth

    2016-06-29

    Machining methods across many industries generally require multiple operations to machine and process advanced materials, features with micron precision, and complex shapes. The resulting multiple machining platforms can significantly affect manufacturing cycle time and the precision of the final parts, with a resultant increase in cost and energy consumption. Ultrafast lasers represent a transformative and disruptive technology that removes material with micron precision and in a single step manufacturing process. Such precision results from athermal ablation without modification or damage to the remaining material which is the key differentiator between ultrafast laser technologies and traditional laser technologies or mechanical processes. Athermal ablation without modification or damage to the material eliminates post-processing or multiple manufacturing steps. Combined with the appropriate technology to control the motion of the work piece, ultrafast lasers are excellent candidates to provide breakthrough machining capability for difficult-to-machine materials. At the project onset in early 2012, the project team recognized that substantial effort was necessary to improve the application of ultrafast laser and precise motion control technologies (for micromachining difficult-to-machine materials) to further the aggregate throughput and yield improvements over conventional machining methods. The project described in this report advanced these leading-edge technologies thru the development and verification of two platforms: a hybrid enhanced laser chassis and a multi-application testbed.

  9. High Temperature Oxidation and Corrosion Properties of High Entropy Superalloys

    Directory of Open Access Journals (Sweden)

    Te-Kang Tsao

    2016-02-01

    Full Text Available The present work investigates the high temperature oxidation and corrosion behaviour of high entropy superalloys (HESA. A high content of various solutes in HESA leads to formation of complex oxides, however the Cr and Al activities of HESA are sufficient to promote protective chromia or alumina formation on the surface. By comparing the oxidation and corrosion resistances of a Ni-based superalloy—CM247LC, Al2O3-forming HESA can possess comparable oxidation resistance at 1100 °C, and Cr2O3-forming HESA can exhibit superior resistance against hot corrosion at 900 °C. This work has demonstrated the potential of HESA to maintain surface stability in oxidizing and corrosive environments.

  10. High pressure study of high-temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Souliou, Sofia-Michaela

    2014-09-29

    The current thesis studies experimentally the effect of high external pressure on high-T{sub c} superconductors. The structure and lattice dynamics of several members of the high-T{sub c} cuprate and Fe-based superconductors families were investigated by means of Raman spectroscopy and X-ray diffraction under well-controlled, hydrostatic high pressure and low temperature conditions. The lattice dynamics of the high-T{sub c} superconductor YBa{sub 2}Cu{sub 3}O{sub 6+x} have been investigated systematically by Raman spectroscopy as a function of doping (x = 0.95, 0.75, 0.60, 0.55, and 0.45) and external pressure. Under ambient pressure conditions, in addition to the Raman modes expected from group theory, we observe new Raman active phonons upon cooling the underdoped samples, at temperatures well above the superconducting transition temperature. The doping dependence and the onset temperatures of the new Raman features suggest that they are associated with the incommensurate charge density wave (CDW) state recently discovered in underdoped cuprates using synchrotron X-ray scattering techniques. Under high pressure conditions (from 2 to 12 GPa), our Raman measurements on highly ordered underdoped YBa{sub 2}Cu{sub 3}O{sub 6.55} samples do not show any of the new Raman phonons seen at ambient pressure. High pressure and low temperature Raman measurements have been performed on the underdoped superconductor YBa{sub 2}Cu{sub 4}O{sub 8}. A clear renormalization of some of the Raman phonons is seen below T{sub c} as a result of the changes in the phonon self-energy upon the opening of the superconducting gap, with the most prominent one being that of the B{sub 1g}-like buckling phonon mode. The amplitude of this renormalization strongly increases with pressure, resembling the effect of hole doping in YBa{sub 2}Cu{sub 3}O{sub 6+x}. At ∝ 10 GPa, the system undergoes a reversible pressure-induced structural phase transition to a non-centrosymmmetric structure (space group

  11. PRELIMINARY ASSESSMENT OF THE LOW-TEMPERATURE WASTE FORM TECHNOLOGY COUPLED WITH TECHNETIUM REMOVAL

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.

    2014-05-13

    The U.S. Department of Energy Office of Environmental Management (EM) is engaging the national laboratories to provide the scientific and technological rigor to support EM program and project planning, technology development and deployment, project execution, and assessment of program outcomes. As an early demonstration of this new responsibility, Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) have been chartered to implement a science and technology program addressing low-temperature waste forms for immobilization of DOE aqueous waste streams, including technetium removal as an implementing technology. As a first step, the laboratories examined the technical risks and uncertainties associated with the Cast Stone waste immobilization projects at Hanford. Science and technology needs were identified for work associated with 1) conducting performance assessments and risk assessments of waste form and disposal system performance, and 2) technetium chemistry in tank wastes and separations of technetium from waste processing streams. Technical approaches to address the science and technology needs were identified and an initial sequencing priority was suggested. The following table summarizes the most significant science and technology needs and associated approaches to address those needs. These approaches and priorities will be further refined and developed as strong integrated teams of researchers from national laboratories, contractors, industry, and academia are brought together to provide the best science and technology solutions. Implementation of a science and technology program that addresses these needs by pursuing the identified approaches will have immediate benefits to DOE in reducing risks and uncertainties associated with near-term decisions regarding supplemental immobilization at Hanford. Longer term, the work has the potential for cost savings and for providing a strong technical foundation for future

  12. Rheological assessment of nanofluids at high pressure high temperature

    Science.gov (United States)

    Kanjirakat, Anoop; Sadr, Reza

    2013-11-01

    High pressure high temperature (HPHT) fluids are commonly encountered in industry, for example in cooling and/or lubrications applications. Nanofluids, engineered suspensions of nano-sized particles dispersed in a base fluid, have shown prospective as industrial cooling fluids due to their enhanced rheological and heat transfer properties. Nanofluids can be potentially utilized in oil industry for drilling fluids and for high pressure water jet cooling/lubrication in machining. In present work rheological characteristics of oil based nanofluids are investigated at HPHT condition. Nanofluids used in this study are prepared by dispersing commercially available SiO2 nanoparticles (~20 nm) in a mineral oil. The basefluid and nanofluids with two concentrations, namely 1%, and 2%, by volume, are considered in this investigation. The rheological characteristics of base fluid and the nanofluids are measured using an industrial HPHT viscometer. Viscosity values of the nanofluids are measured at pressures of 100 kPa to 42 MPa and temperatures ranging from 25°C to 140°C. The viscosity values of both nanofluids as well as basefluid are observed to have increased with the increase in pressure. Funded by Qatar National Research Fund (NPRP 08-574-2-239).

  13. Survey of processes for high temperature-high pressure gas purification. [52 references

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.P.; Edwards, M.S.

    1978-11-01

    In order to ensure the optimum operating efficiency of a combined-cycle electric power generating system, it is necessary to provide gas treatment processes capable of operating at high temperatures (> 1000/sup 0/F) and high pressures (> 10 atm (absolute)). These systems will be required to condition the inlet stream to the gas turbine to suitable levels of gas purity (removal of particulate matter, sulfur, nitrogen, and alkali metal compounds) to be compatible with both environmental and machine constraints. A survey of the available and developmental processes for the removal of these various contaminant materials has been conducted. Based on the data obtained from a variety of sources, an analysis has been performed to evaluate the performance of a number of potential cleanup processes in view of the overall system needs. The results indicate that commercially available, reliable, and economically competitive hot-gas cleanup systems (for the removal of H/sub 2/S, particulate matter, alkali, and nitrogen compounds) capable of conditioning raw product gas to the levels required for turbine use will not be available for some time.

  14. 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

  15. 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.

  16. Siloxanes removal from biogas by high surface area adsorbents.

    Science.gov (United States)

    Gislon, P; Galli, S; Monteleone, G

    2013-12-01

    Biogas utilized for energy production needs to be free from organic silicon compounds, as their burning has damaging effects on turbines and engines; organic silicon compounds in the form of siloxanes can be found in biogas produced from urban wastes, due to their massive industrial use in synthetic product, such as cosmetics, detergents and paints. Siloxanes removal from biogas can be carried out by various methods (Mona, 2009; Ajhar et al., 2010 May; Schweigkofler and Niessner, 2001); aim of the present work is to find a single practical and economic way to drastically and simultaneously reduce both the hydrogen sulphide and the siloxanes concentration to less than 1 ppm. Some commercial activated carbons previously selected (Monteleone et al., 2011) as being effective in hydrogen sulfide up taking have been tested in an adsorption measurement apparatus, by flowing the most volatile siloxane (hexamethyldisiloxane or L2) in a nitrogen stream, typically 100-200 ppm L2 over N2, through an activated carbon powder bed; the adsorption process was analyzed by varying some experimental parameters (concentration, grain size, bed height). The best activated carbon shows an adsorption capacity of 0.1g L2 per gram of carbon. The next thermogravimetric analysis (TGA) confirms the capacity data obtained experimentally by the breakthrough curve tests. The capacity results depend on L2 concentration. A regenerative carbon process is then carried out by heating the carbon bed up to 200 °C and flushing out the adsorbed L2 samples in a nitrogen stream in a three step heating procedure up to 200 °C. The adsorption capacity is observed to degrade after cycling the samples through several adsorption-desorption cycles. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. NOVEL REFRACTORY MATERIALS FOR HIGH ALKALI, HIGH TEMPERATURE ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James Gordon [ORNL; Smith, Jeffrey D [ORNL; O' Hara, Kelley [University of Missouri, Rolla; Rodrigues-Schroer, Angela [Minteq International, Inc.; Colavito, [Minteq International, Inc.

    2012-08-01

    A project was led by Oak Ridge National Laboratory (ORNL) in collaboration with a research team comprised of the academic institution Missouri University of Science and Technology (MS&T), and the industrial company MINTEQ International, Inc. (MINTEQ), along with representatives from the aluminum, chemical, glass, and forest products industries. The project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al 2O3, MgAl2O4, or other similar spinel structured or alumina-based unshaped refractory compositions (castables, gunnables, shotcretes, etc.) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, high-alkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries. Both practical refractory development experience and computer modeling techniques were used to aid in the design of this new family of materials. The newly developed materials were expected to offer alternative material choices for high-temperature, high-alkali environments that were capable of operating at higher temperatures (goal of increasing operating temperature by 100-200oC depending on process) or for longer periods of time (goal of twice the life span of current materials or next process determined service increment). This would lead to less process down time, greater energy efficiency for associated manufacturing processes (more heat kept in process), and materials that could be installed/repaired in a more efficient manner. The overall project goal was a 5% improvement in energy efficiency (brought about through a 20% improvement in thermal efficiency) resulting in a savings of 3.7 TBtu/yr (7.2 billion ft3 natural gas) by the year 2030. Additionally, new

  18. Measuring Specific Heats at High Temperatures

    Science.gov (United States)

    Vandersande, Jan W.; Zoltan, Andrew; Wood, Charles

    1987-01-01

    Flash apparatus for measuring thermal diffusivities at temperatures from 300 to 1,000 degrees C modified; measures specific heats of samples to accuracy of 4 to 5 percent. Specific heat and thermal diffusivity of sample measured. Xenon flash emits pulse of radiation, absorbed by sputtered graphite coating on sample. Sample temperature measured with thermocouple, and temperature rise due to pulse measured by InSb detector.

  19. 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...

  20. Thermoelectric Powered High Temperature Wireless Sensing

    Science.gov (United States)

    Kucukkomurler, Ahmet

    This study describes use of a thermoelectric power converter to transform waste heat into electrical energy to power an RF receiver and transmitter, for use in harsh environment wireless temperature sensing and telemetry. The sensing and transmitting module employs a DS-1820 low power digital temperature sensor to perform temperature to voltage conversion, an ATX-34 RF transmitter, an ARX-34 RF receiver module, and a PIC16f84A microcontroller to synchronize data communication between them. The unit has been tested in a laboratory environment, and promising results have been obtained for an actual automotive wireless under hood temperature sensing and telemetry implementation.

  1. Critical Temperature Characteristics of Layered High-Temperature Superconductor Under Pressure

    Institute of Scientific and Technical Information of China (English)

    LIANG Fang-Ying

    2009-01-01

    We consider a Ginzburg-Landau modified model of layered high-temperature superconductor under pres-sure. We have theoretically studied the relation between the pressure and the temperature of layered high-temperature superconductor. If the pressure is not a constant, we have a relation of quadratic equation between the pressure and the temperature of layered high-temperature superconductor. In a special case, we find the critical temperature decreases with further increasing pressure. In another special case, the critical temperature increases with further increasing pressure.

  2. High temperature superconductivity induced by incipient magnetism

    Science.gov (United States)

    Weger, M.; Pereg, Y.

    1990-10-01

    We consider the BCS gap equation, with an attractive interaction λ with an upper cutoff ω 0 and lower cutoff ω 1, and a repulsive interaction μ with cutoffΓ. We consider parameters such that a superconducting solution does not exist. We add a repulsive interaction ν eith cutoff ω1 ( ω1 < ω0), and show that this repulsive interaction (that we attribute to incipient magnetism) induces a superconducting state possessing a high transition temperature. In this state, the gap function Δ(ɛ) oscillates as function of ɛ, with a period of order ω 0. We also find solutions antisymmetric in energy [ Δ( ɛ) = - Δ(- ɛ) ], which turn out to be almost degenerate with the normal, symmetric ones. We discuss the physical implications of this model. Our model thus combines a low frequency repulsion due to antiferromagnetic interactions, with excitonic attraction at intermediate frequencies, and ordinary Coulomb repulsion above that. All frequency ranges, and coupling strengths, are comparable with the bandwidth.

  3. High temperature bacterial leaching: HIOX project

    Energy Technology Data Exchange (ETDEWEB)

    Morin, D.; D' Hugues, P.; Bonney, C. F.; Norris, P.; Shwab, W.; Sundkvist, J-E.; Bridges, P. [Bureau de Recherhes Geologiques et Minieres, Orleans (France)

    2001-07-01

    The HIOX project was designed to investigate the use of thermophilic bacterial cultures for the leaching of chalcopyrite (CuFeS{sub 2}, the natural source of copper). Beyond bacterial leaching, the study also encompassed the downstream processing steps in an effort to develop a new method for the recovery of copper in an economical and environmentally-friendly process. Using the HIOX process copper recovery was increased to better than 90 per cent within 5 days with a 12 per cent solids culture, although some potentially limiting factors such as foam generation, nutrient concentrations and mixing/aeration efficiency were also identified. The study resulted in the establishment of a mass balance based on a simplified flowsheet of the process. Techno-economic evaluation carried out at three sites indicated technical feasibility using relatively conventional equipment and capital and operating costs in ranges that suggest that bioleaching with high temperature bacteria is an attractive alternative for the treatment of chalcopyrite concentrate. 5 tabs.

  4. Turbulent Flow past High Temperature Surfaces

    Science.gov (United States)

    Mehmedagic, Igbal; Thangam, Siva; Carlucci, Pasquale; Buckley, Liam; Carlucci, Donald

    2014-11-01

    Flow over high-temperature surfaces subject to wall heating is analyzed with applications to projectile design. In this study, computations are performed using an anisotropic Reynolds-stress model to study flow past surfaces that are subject to radiative flux. The model utilizes a phenomenological treatment of the energy spectrum and diffusivities of momentum and heat to include the effects of wall heat transfer and radiative exchange. The radiative transport is modeled using Eddington approximation including the weighted effect of nongrayness of the fluid. The time-averaged equations of motion and energy are solved using the modeled form of transport equations for the turbulence kinetic energy and the scalar form of turbulence dissipation with an efficient finite-volume algorithm. The model is applied for available test cases to validate its predictive capabilities for capturing the effects of wall heat transfer. Computational results are compared with experimental data available in the literature. Applications involving the design of projectiles are summarized. Funded in part by U.S. Army, ARDEC.

  5. 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.

  6. 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.

  7. Spin injection into high temperature superconductor

    CERN Document Server

    Severac, C H L

    2000-01-01

    DELTA M versus pulse length was measured. It showed two regions: above 100 mu s DELTA M is the same for both magnetic and non-magnetic material and can be attributed to heating. Below 100 mu s, DELTA M is only significant for the CMR samples. This is attributed to the injection of highly spin polarised carriers that are believed to reduce the order parameter over the whole sample, and hence l sub C and the magnetic moment of the sample. As part of a search for colossal magneto-resistance (CMR) materials with Curie temperature below the superconducting transition of YBCO, we made an investigation of the magnetic and electrical characteristics of Chromium doped LCMO. We found that the conduction mechanism which depends on the orbital order via the double-exchange mechanism, is decoupled from the ferromagnetic behaviour, which is related to spin order. Work on the injection of dc-current from half metallic CMR material into YBa sub 2 Cu sub 3 O sub 7 sub - subdelta (YBCO) showed a shift and a compression in the ...

  8. Development of Strengthened Bundle High Temperature Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States); Demko, J.A. [Oak Ridge Inst. for Science and Education, TN (United States); Tomsic, M. [Plastronic, Inc., Troy, OH (United States); Sinha, U. [Southwire Company, Carollton, GA (United States)

    1997-12-31

    In the process of developing high temperature superconducting (HTS) transmission cables, it was found that mechanical strength of the superconducting tape is the most crucial property that needs to be improved. It is also desirable to increase the current carrying capacity of the conductor so that fewer layers are needed to make the kilo-amp class cables required for electric utility usage. A process has been developed by encapsulating a stack of Bi-2223/Ag tapes with a silver or non-silver sheath to form a strengthened bundle superconductor. This process was applied to HTS tapes made by the Continuous Tube Forming and Filling (CTFF) technique pursued by Plastronic Inc. and HTS tapes obtained from other manufacturers. Conductors with a bundle of 2 to 6 HTS tapes have been made. The bundled conductor is greatly strengthened by the non-silver sheath. No superconductor degradation as compared to the sum of the original critical currents of the individual tapes was seen on the finished conductors.

  9. High-temperature Gas Reactor (HTGR)

    Science.gov (United States)

    Abedi, Sajad

    2011-05-01

    General Atomics (GA) has over 35 years experience in prismatic block High-temperature Gas Reactor (HTGR) technology design. During this period, the design has recently involved into a modular have been performed to demonstrate its versatility. This versatility is directly related to refractory TRISO coated - particle fuel that can contain any type of fuel. This paper summarized GA's fuel cycle studies individually and compares each based upon its cycle sustainability, proliferation-resistance capabilities, and other performance data against pressurized water reactor (PWR) fuel cycle data. Fuel cycle studies LEU-NV;commercial HEU-Th;commercial LEU-Th;weapons-grade plutonium consumption; and burning of LWR waste including plutonium and minor actinides in the MHR. results show that all commercial MHR options, with the exception of HEU-TH, are more sustainable than a PWR fuel cycle. With LEU-NV being the most sustainable commercial options. In addition, all commercial MHR options out perform the PWR with regards to its proliferation-resistance, with thorium fuel cycle having the best proliferation-resistance characteristics.

  10. 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.)

  11. Brazing Refractory Metals Used In High-Temperature Nuclear Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    A. J. Palmer; C. J. Woolstenhulme

    2009-06-01

    As part of the U. S. Department of Energy (DOE) sponsored Next Generation Nuclear Project (NGNP) currently ongoing at Idaho National Laboratory (INL), the irradiation performance of candidate high-temperature gas reactor fuels and materials is being evaluated at INL’s Advanced Test Reactor (ATR). The design of the first Advanced Gas Reactor (AGR 1) experiment, currently being irradiated in the ATR, required development of special techniques for brazing niobium and molybdenum. Brazing is one technique used to join refractory metals to each other and to stainless steel alloys. Although brazing processes are well established, it is difficult to braze niobium, molybdenum, and most other refractory metals because they quickly develop adherent oxides when exposed to room-temperature air. Specialized techniques and methods were developed by INL to overcome these obstacles. This paper describes the techniques developed for removing these oxides, as well as the ASME Section IX-qualified braze procedures that were developed as part of the AGR-1 project. All brazes were made using an induction coil with an inert or reducing atmosphere at low pressure. Other parameters, such as filler metals, fluxes used, and general setup procedures, are also discussed.

  12. The influence of temperature and SRT on high-solid digestion of municipal sewage sludge.

    Science.gov (United States)

    Jahn, L; Baumgartner, T; Svardal, K; Krampe, J

    2016-01-01

    The influence of temperature and solids retention time (SRT) on high-solid digestion of municipal sewage sludge was investigated in laboratory-scale reactors. Digestion with high-solid concentration reduces the required digestion volume and is advantageous for urban areas. The experimental conditions comprised total suspended solids (TSS) in digested sludge between 4.0 and 4.6%, temperatures in a range of 33 to 41 °C and the SRT between 10 and 25 d. High-solid digestion operates with increased NH4-N concentrations released from organic compounds. The anaerobic process can be limited by high NH4-N concentration and toxic NH3. In this study a stable digestion was observed up to 2,000 mg L(-1) NH4-N and 75 mg L(-1) NH3. Volatile suspended solids (VSS) and chemical oxygen demand removal was 53% and 57% respectively. However, digestion with 10 d SRT led to a declined VSS removal of 49%. The removal at 41 and 37 °C showed minor differences, while reduced NH4-N release and reduced methane production were observed at 33 °C. For economic reasons, high-solid digestion at 41 °C is not recommended, but will not impair VSS removal. The outcomes of this study confirm that digestion with up to 7.8% TSS in the feed is feasible for the tested temperatures and SRT down to 15 d.

  13. Vortices in high-performance high-temperature superconductors

    Science.gov (United States)

    Kwok, Wai-Kwong; Welp, Ulrich; Glatz, Andreas; Koshelev, Alexei E.; Kihlstrom, Karen J.; Crabtree, George W.

    2016-11-01

    The behavior of vortex matter in high-temperature superconductors (HTS) controls the entire electromagnetic response of the material, including its current carrying capacity. Here, we review the basic concepts of vortex pinning and its application to a complex mixed pinning landscape to enhance the critical current and to reduce its anisotropy. We focus on recent scientific advances that have resulted in large enhancements of the in-field critical current in state-of-the-art second generation (2G) YBCO coated conductors and on the prospect of an isotropic, high-critical current superconductor in the iron-based superconductors. Lastly, we discuss an emerging new paradigm of critical current by design—a drive to achieve a quantitative correlation between the observed critical current density and mesoscale mixed pinning landscapes by using realistic input parameters in an innovative and powerful large-scale time dependent Ginzburg-Landau approach to simulating vortex dynamics.

  14. Vortices in high-performance high-temperature superconductors.

    Science.gov (United States)

    Kwok, Wai-Kwong; Welp, Ulrich; Glatz, Andreas; Koshelev, Alexei E; Kihlstrom, Karen J; Crabtree, George W

    2016-11-01

    The behavior of vortex matter in high-temperature superconductors (HTS) controls the entire electromagnetic response of the material, including its current carrying capacity. Here, we review the basic concepts of vortex pinning and its application to a complex mixed pinning landscape to enhance the critical current and to reduce its anisotropy. We focus on recent scientific advances that have resulted in large enhancements of the in-field critical current in state-of-the-art second generation (2G) YBCO coated conductors and on the prospect of an isotropic, high-critical current superconductor in the iron-based superconductors. Lastly, we discuss an emerging new paradigm of critical current by design-a drive to achieve a quantitative correlation between the observed critical current density and mesoscale mixed pinning landscapes by using realistic input parameters in an innovative and powerful large-scale time dependent Ginzburg-Landau approach to simulating vortex dynamics.

  15. High performance internal reforming unit for high temperature fuel cells

    Science.gov (United States)

    Ma, Zhiwen; Venkataraman, Ramakrishnan; Novacco, Lawrence J.

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  16. Multi-Scale Porous Ultra High Temperature Ceramics

    Science.gov (United States)

    2015-01-08

    Final 3. DATES COVERED (From - To) 28-Mar-2013 - 27-Sep-2015 4. TITLE AND SUBTITLE Multi-Scale Porous Ultra High Temperature Ceramics ...report summarizes the main outcomes of research to develop multi-scale porosity Ultra High Temperature Ceramic materials. Processing conditions were...flights. 15. SUBJECT TERMS Ultra High Temperature Ceramics , Colloidal Powder Processing, Multi-scale Porous Materials, Lattice Monte

  17. Low Temperature Photoluminescence (PL) from High Electron Mobility Transistors (HEMTs)

    Science.gov (United States)

    2015-03-01

    TECHNICAL REPORT RDMR-WD-14-55 LOW TEMPERATURE PHOTOLUMINESCENCE (PL) FROM HIGH ELECTRON MOBILITY TRANSISTORS (HEMTS...DATE March 2015 3. REPORT TYPE AND DATES COVERED Final 4. TITLE AND SUBTITLE Low Temperature Photoluminescence (PL) From High Electron...temperature Photoluminescence (PL) from High Electron Mobility Transistor (HEMT) structures that have been modified by proton irradiation. The samples are

  18. Structural integrity and life extension of high-temperature components

    Institute of Scientific and Technical Information of China (English)

    WANG Chun; SHEN Shi-ming

    2005-01-01

    Four different topics for high-temperature components, namely the development of the assessment codes for the structural integrity of high-temperature components, the application of continuous damage mechanics and probabilistic damage mode on the life assessment of high-temperature components, the life extension for high-tem perature components and a proposed strategy for remanufacturing of high-temperature components were discussed in this paper. These topics should provide some important insights for the design and re-design of high- temperature components.

  19. High efficiency pollutant removal with the Moving-Bed Copper Oxide Process

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H.W.; Hoffman, J.S.; Yeh, J.T. [Dept. of Energy, Pittsburgh, PA (United States). Pittsburgh Energy Technology Center; Resnik, K.P.; Vore, P.A. [Gilbert Commonwealth, Inc., Pittsburgh, PA (United States)

    1995-12-31

    Dry, regenerable flue gas cleanup techniques that use a sorbent can have various advantages, such as simultaneous removal of pollutants, production of a salable by-product, and low costs when compared to commercially available scrubbing technology. Due to the temperature of reaction, the placement of the process into an advanced power system could actually increase the thermal efficiency of the plant. One such technique, the Moving-Bed Copper Oxide Process, is capable of simultaneously removing sulfur oxides and nitric oxides within the reactor system. A parametric study of the process was conducted on a life-cycle test system. All process steps, including absorption and regeneration, were integrated into this life-cycle test system so that continuous, long-term operation of the total process cold be experimentally evaluated. The effects of absorption temperature, sorbent and gas residence times, and inlet SO{sub 2} and NO{sub x} concentration on removal efficiencies and overall operational performance are discussed.

  20. 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.

  1. Field Evaluation of Ultra-High Pressure Water Systems for Runway Rubber Removal

    Science.gov (United States)

    2014-04-01

    ER D C/ G SL T R- 14 -1 1 Field Evaluation of Ultra-High Pressure Water Systems for Runway Rubber Removal G eo te ch ni ca l a nd S tr...Field Evaluation of Ultra-High Pressure Water Systems for Runway Rubber Removal Aaron B. Pullen Applied Research Associates, Inc. 421 Oak Avenue...Engineer Center Tyndall Air Force Base, FL 32403-5319 ERDC/GSL TR-14-11 ii Abstract Runway rubber removal is a maintenance function employed to

  2. Effective management of heat transfer fluid flash point temperatures using a light-ends removal kit (LERK

    Directory of Open Access Journals (Sweden)

    Christopher Ian Wright

    2014-11-01

    Full Text Available Heat transfer fluids (HTF need to be regularly sampled to assess the extent of thermal degradation, oxidative state, the accumulation of short-chained light-ends and contamination by intrinsic or extrinsic particles. The build-up of light-ends in a HTF system presents a potential fire hazard. A light-ends removal kit (LERK enables light-ends to be removed continuously, helping to push-up flash point temperatures. In the current case, the concentration of light-ends started to build-up in the client’s system and a LERK was subsequently installed. Data is presented that shows how effective the LERK was in restoring mean closed flash point temperature to stable levels, similar to those seen for a virgin HTF. Closed flash point temperature was, in this case, more variable than open flash point temperature. This highlights the need to make direct measurements of closed flash point temperature as opposed to indirect measurements of open flash point temperature. This case emphasises the need for regular HTF sampling and analysis, and that the installation of a LERK can help maintain the condition and life of a HTF.

  3. Synthesis colloidal Kyllinga brevifolia-mediated silver nanoparticles at different temperature for methylene blue removal

    Science.gov (United States)

    Isa, Norain; Sarijo, Siti Halimah; Aziz, Azizan; Lockman, Zainovia

    2017-09-01

    Metallic nanoparticles are well known of having wide applications in various fields such as, catalysis, electronics, energy, chemistry and medicine due to its unique physico-chemical properties. In this study, nanocatalyst Kyllinga brevifolia-mediated silver nanoparticles (AgNPs) were prepared by reduction of silver nitrate using aqueous extract of Kyllinga brevifolia at different temperature. The formations of AgNPs were monitored using UV-visible spectroscopy. Transmission electron microscope (TEM) results reveal that the AgNPs well dispersed with average particle size are 22.34 and 6.73 nm for synthesized at room temperature and cold temperature respectively. The biomolecules present in the Kyllinga brevifolia aqueous extract responsible for the formation of AgNPs were identified using Fourier transform infrared (FTIR). Our AgNPs performed excellent catalytic activity in degradation of methylene blue (MB) dyes via electron relay effect. MB is toxic to ecological system and also has carcinogenic properties. The AgNPs nanocatalysts synthesized in this study are highly dispersed, quasi-spherical and due to their size in nanoscale, they have shown effectiveness for degradation of MB dyes. More importantly, our AgNPs were prepared using biomolecules as capping and reducing agent, which make our product "greener" than available AgNPs that are commonly prepared using hydrazine and borohydride; which are harmful substances to human and environment. Not only the AgNPs can act as nanocatalyst for degradation of MB, they can also be expected to degrade other types of toxic dyes used in textiles industry.

  4. Fusion reactors-high temperature electrolysis (HTE)

    Energy Technology Data Exchange (ETDEWEB)

    Fillo, J.A. (ed.)

    1978-01-01

    Results of a study to identify and develop a reference design for synfuel production based on fusion reactors are given. The most promising option for hydrogen production was high-temperature electrolysis (HTE). The main findings of this study are: 1. HTE has the highest potential efficiency for production of synfuels from fusion; a fusion to hydrogen energy efficiency of about 70% appears possible with 1800/sup 0/C HTE units and 60% power cycle efficiency; an efficiency of about 50% possible with 1400/sup 0/C HTE units and 40% power cycle efficiency. 2. Relative to thermochemical or direct decomposition methods HTE technology is in a more advanced state of development, 3. Thermochemical or direct decomposition methods must have lower unit process or capital costs if they are to be more attractive than HTE. 4. While design efforts are required, HTE units offer the potential to be quickly run in reverse as fuel cells to produce electricity for restart of Tokamaks and/or provide spinning reserve for a grid system. 5. Because of the short timescale of the study, no detailed economic evaluation could be carried out.A comparison of costs could be made by employing certain assumptions. For example, if the fusion reactor-electrolyzer capital installation is $400/(KW(T) ($1000/KW(E) equivalent), the H/sub 2/ energy production cost for a high efficiency (about 70 %) fusion-HTE system is on the same order of magnitude as a coal based SNG plant based on 1976 dollars. 6. The present reference design indicates that a 2000 MW(th) fusion reactor could produce as much at 364 x 10/sup 6/ scf/day of hydrogen which is equivalent in heating value to 20,000 barrels/day of gasoline. This would fuel about 500,000 autos based on average driving patterns. 7. A factor of three reduction in coal feed (tons/day) could be achieved for syngas production if hydrogen from a fusion-HTE system were used to gasify coal, as compared to a conventional syngas plant using coal-derived hydrogen.

  5. NOvel Refractory Materials for High Alkali, High Temperature Environments

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, J.G.; Griffin, R. (MINTEQ International, Inc.)

    2011-08-30

    Refractory materials can be limited in their application by many factors including chemical reactions between the service environment and the refractory material, mechanical degradation of the refractory material by the service environment, temperature limitations on the use of a particular refractory material, and the inability to install or repair the refractory material in a cost effective manner or while the vessel was in service. The objective of this project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al2O3 spinel or other similar magnesia/alumina containing unshaped refractory composition (castables, gunnables, shotcretes, etc) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, highalkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries. A research team was formed to carry out the proposed work led by Oak Ridge National Laboratory (ORNL) and was comprised of the academic institution Missouri University of Science and Technology (MS&T), and the industrial company MINTEQ International, Inc. (MINTEQ), along with representatives from the aluminum, chemical, glass, and forest products industries. The two goals of this project were to produce novel refractory compositions which will allow for improved energy efficiency and to develop new refractory application techniques which would improve the speed of installation. Also methods of hot installation were sought which would allow for hot repairs and on-line maintenance leading to reduced process downtimes and eliminating the need to cool and reheat process vessels.

  6. Extreme Environment High Temperature Communication Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

  7. High temperature cement raw meal flowability

    DEFF Research Database (Denmark)

    Maarup, Claus; Hjuler, Klaus; Dam-Johansen, Kim

    2014-01-01

    The flowability of cement raw meal is investigated at temperatures up to 850°C in a specially designed monoaxial shear tester. Consolidation stresses of 0.94, 1.87 and 2.79kPa are applied. The results show that the flowability is reduced as temperature is increased above 550°C, indicated by incre......The flowability of cement raw meal is investigated at temperatures up to 850°C in a specially designed monoaxial shear tester. Consolidation stresses of 0.94, 1.87 and 2.79kPa are applied. The results show that the flowability is reduced as temperature is increased above 550°C, indicated...

  8. High Temperature Acoustic Noise Reduction Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is to use combustion synthesis techniques to manufacture ceramic-based acoustic liners capable of withstanding temperatures up to 2500?C....

  9. CAST-IRONS AT HIGH TEMPERATURES

    Directory of Open Access Journals (Sweden)

    A. N. Krutilin

    2008-01-01

    Full Text Available The results of investigations of physical-mechanical characteristics of cast iron slugs, received by semicontinuos way of casting, at temperatures from 850 up to 1100^ С are given. 

  10. 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.

  11. High Temperature Reactive Thermoplastic Aromatic Polyimides

    Science.gov (United States)

    1980-04-01

    temperatures and isothermal aging studies of the polymer, as well as, Dr. E. G. Jones for mass spectra TGA analysis . iii AFWAL-TR-80-4013 TABLE OF CONTENTS...after 200 hours (Figure 6). Mass spectra TGA analysis was carried out on polymer VIIIb from room temperature to 900’C using a 4.2°C/minute heating rate

  12. HIGH TEMPERATURE MATERIALS AND STRENGTH STUDY IN CHINA

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the past half century China has developed and formed her own system of high temperature materials for power, automobile and aero-engine industries in the temperature range from 550 ℃ to 1 100 ℃. These high temperature materials include heat-resisting steels, iron-base, nickel-iron-base and nickel-base superalloys. Some achievements in high temperature strength study, new technologies and new alloy development are also discussed.

  13. Inelastic deformation and damage at high temperature

    Science.gov (United States)

    Krempl, E.

    1992-06-01

    Combined experimental and theoretical investigations into the inelastic deformation and damage behavior of engineering alloys at elevated temperatures are being pursued. The analysis of previously performed strain rate change and relaxation tests on modified 9Cr-1Mo steel showed the need for inclusion of a recovery of state term in the growth laws for the state variables of the viscoplasticity theory based on overstress (VBO). Recovery of state terms were introduced and the experimental results were satisfactorily simulated. The finite deformation theory of VBO has been developed further to include a convected derivative rationale for the choice of the objective stress rate. The reversing direct current voltage drop measurements during low cycle fatigue at elevated temperature were improved. A passive filter bank and new positioning devices for the coils were installed. Tests at 650 C and lasting several days showed excessive, uncontrollable temperature changes. It was decided to drop the test temperature to 538 C which is close to the operating temperature of type 304 stainless steel. The temperature fluctuations in torsion tests were within +/- 3 C which was considered satisfactory.

  14. Inelastic deformation and damage at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Krempl, E.

    1992-01-01

    Combined experimental and theoretical investigations into the inelastic deformation and damage behavior of engineering alloys at elevated temperatures are being pursued. The analysis of previously performed strain rate change and relaxation tests on modified 9Cr-1Mo steel showed the need for inclusion of a recovery of state term in the growth laws for the state variables of the viscoplasticity theory based on overstress (VBO). Recovery of state terms were introduced and the experimental results were satisfactorily simulated. The finite deformation theory of VBO has been developed further to include a convected derivative rationale for the choice of the objective stress rate. The reversing direct current voltage drop measurements during low cycle fatigue at elevated temperature were improved. A passive filter bank and new positioning devices for the coils were installed. Tests at 650{degrees}C and lasting several days showed excessive, uncontrollable temperature changes. It was decided to drop the test temperature to 538{degrees}C which is close to the operating temperature of Type 304 Stainless Steel. The temperature fluctuations in torsion tests were within {plus minus}3{degrees}C which was considered satisfactory. Testing will continue at 538{degrees}C.

  15. High-Temperature, High-Concentration Solar Thermoelectric Generators

    Science.gov (United States)

    Warren, Emily; Baranowski, Lauryn; Olsen, Michele; Ndione, Paul; Netter, Judy; Goodrich, Alan; Gray, Matthew; Parilla, Philip; Ginley, David; Toberer, Eric

    2014-03-01

    Solar thermoelectric generators (STEGs) powered with concentrated solar energy have potential for use as primary energy converters or as topping-cycles for more conventional concentrated solar power (CSP) technologies. Modeling based on current record modules from JPL suggests thermoelectric efficiencies of 18 % could be experimentally expected with a temperature gradient of 1000 - 100°C. Integrating these state-of-the-art TEGs with a concentrating solar receiver requires simultaneous optimization of optical, thermal, and thermoelectric systems. This talk will discuss the modeling, design, and experimental testing of STEG devices under concentrated sunlight. We have developed a model that combines thermal circuit modeling with optical ray tracing to design selective absorber coatings and cavities to minimize radiation losses from the system. We have fabricated selective absorber coatings and demonstrated that these selective absorber films can minimize blackbody radiation losses at high temperature and are stable after thermal cycling to 1000°C. On-sun testing of STEG devices and thermal simulators is ongoing and preliminary results will be discussed.

  16. Fast Impulse Noise Removal from Highly Corrupted Images

    CERN Document Server

    Hosseini, Hossein

    2011-01-01

    In this paper, we suggest a general model for the fixed-valued impulse noise and propose a two-stage method for high density noise suppression while preserving the image details. In the first stage, we apply an iterative impulse detector, exploiting the image entropy, to identify the corrupted pixels and then employ an Adaptive Iterative Mean filter (AIM) to restore them. The filter is adaptive in terms of the number of iterations, which is different for each noisy pixel, according to their Euclidean distance from the nearest uncorrupted pixel. Experimental results show that the AIM filter is fast and outperforms the best existing techniques in both objective and subjective performance measures.

  17. Solid sorbents for removal of carbon dioxide from gas streams at low temperatures

    Science.gov (United States)

    Sirwardane, Ranjani V.

    2005-06-21

    New low-cost CO.sub.2 sorbents are provided that can be used in large-scale gas-solid processes. A new method is provided for making these sorbents that involves treating substrates with an amine and/or an ether so that the amine and/or ether comprise at least 50 wt. percent of the sorbent. The sorbent acts by capturing compounds contained in gaseous fluids via chemisorption and/or physisorption between the unit layers of the substrate's lattice where the polar amine liquids and solids and/or polar ether liquids and solids are located. The method eliminates the need for high surface area supports and polymeric materials for the preparation of CO.sub.2 capture systems, and provides sorbents with absorption capabilities that are independent of the sorbents' surface areas. The sorbents can be regenerated by heating at temperatures in excess of 35.degree. C.

  18. Solid Sorbents for Removal of Carbon Dioxide from Gas Streams at Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sirwardane, Ranjani V.

    2005-06-21

    New low-cost CO2 sorbents are provided that can be used in large-scale gas-solid processes. A new method is provided for making these sorbents that involves treating substrates with an amine and/or an ether so that the amine and/or ether comprise at least 50 wt. percent of the sorbent. The sorbent acts by capturing compounds contained in gaseous fluids via chemisorption and/or physisorption between the unit layers of the substrate's lattice where the polar amine liquids and solids and/or polar ether liquids and solids are located. The method eliminates the need for high surface area supports and polymeric materials for the preparation of CO2 capture systems, and provides sorbents with absorption capabilities that are independent of the sorbents' surface areas. The sorbents can be regenerated by heating at temperatures in excess of 35 degrees C.

  19. Removing Known SPS Intensity Limitations for High Luminosity LHC Goals

    CERN Document Server

    Shaposhnikova, Elena; Bohl, Thomas; Cruikshank, Paul; Goddard, Brennan; Kaltenbacher, Thomas; Lasheen, Alexandre; Perez Espinos, Jaime; Repond, Joël; Salvant, Benoit; Vollinger, Christine

    2016-01-01

    In preparation of the SPS as an LHC injector its impedance was significantly reduced in 1999 - 2000. A new SPS impedance reduction campaign is planned now for the High Luminosity (HL)-LHC project, which requires bunch intensities twice as high as the nominal one. One of the known intensity limitations is a longitudinal multi-bunch instability with a threshold 3 times below this operational intensity. The instability is presently cured using the 4th harmonic RF system and controlled emittance blow-up, but reaching the HL-LHC parameters cannot be assured without improving the machine impedance. Recently the impedance sources responsible for this instability were identified and implementation of their shielding and damping is foreseen during the next long shutdown (2019 - 2020) in synergy with two other important upgrades: amorphous carbon coating of (part of) the vacuum chamber against the e-cloud effect and rearrangement of the 200 MHz RF system. In this paper the strategy of impedance reduction is presented t...

  20. High-dimensional camera shake removal with given depth map.

    Science.gov (United States)

    Yue, Tao; Suo, Jinli; Dai, Qionghai

    2014-06-01

    Camera motion blur is drastically nonuniform for large depth-range scenes, and the nonuniformity caused by camera translation is depth dependent but not the case for camera rotations. To restore the blurry images of large-depth-range scenes deteriorated by arbitrary camera motion, we build an image blur model considering 6-degrees of freedom (DoF) of camera motion with a given scene depth map. To make this 6D depth-aware model tractable, we propose a novel parametrization strategy to reduce the number of variables and an effective method to estimate high-dimensional camera motion as well. The number of variables is reduced by temporal sampling motion function, which describes the 6-DoF camera motion by sampling the camera trajectory uniformly in time domain. To effectively estimate the high-dimensional camera motion parameters, we construct the probabilistic motion density function (PMDF) to describe the probability distribution of camera poses during exposure, and apply it as a unified constraint to guide the convergence of the iterative deblurring algorithm. Specifically, PMDF is computed through a back projection from 2D local blur kernels to 6D camera motion parameter space and robust voting. We conduct a series of experiments on both synthetic and real captured data, and validate that our method achieves better performance than existing uniform methods and nonuniform methods on large-depth-range scenes.

  1. Rapid startup and high rate nitrogen removal from anaerobic sludge digester liquor using a SNAP process.

    Science.gov (United States)

    Qiao, Sen; Nishiyama, Takashi; Fujii, Tatsuo; Bhatti, Zafar; Furukawa, Kenji

    2012-02-01

    In this study, a single-stage autotrophic nitrogen removal reactor, packed with a novel acrylic fiber biomass carrier material (Biofix), was applied for nitrogen removal from sludge digester liquor. For rapid start-up, conventional activated sludge was added to the reactor soon after the attachment of anammox biomass on the Biofix carriers, which allowed conventional activated sludge to form a protective layer of biofilm around the anammox biomass. The Nitrogen removal efficiency reached 75% within 1 week at a nitrogen loading rate of 0.46 kg-N/m(3)/day for synthetic wastewater treatment. By the end of the synthetic wastewater treatment period, the maximum nitrogen removal rate had increased to 0.92 kg-N/m(3)/day at a nitrogen loading rate of 1.0 kg-N/m(3)/day. High nitrogen removal rate was also achieved during the actual raw digester liquor treatment with the highest nitrogen removal rate being 0.83 kg-N/m(3)/day at a nitrogen loading rate of 0.93 kg-N/m(3)/day. The thick biofilm on Biofix carriers allowed anammox bacteria to survive under high DO concentration of 5-6 mg/l resulting in stable and high nitrogen removal performance. FISH and CLSM analysis demonstrated that anammox bacteria coexisted and surrounded by ammonium oxidizing bacteria.

  2. Radionuclide removal from reactor wastes by HGMF. [High gradient magnetic filter

    Energy Technology Data Exchange (ETDEWEB)

    Emory, B.B.

    1981-04-01

    This paper describes experiments conducted to support the use of a high gradient magnetic filter (HGMF) to remove radioactive particulate matter generated by internal decontamination of water-cooled nuclear reactors. Decontamination schemes for reduction of radiation exposure at power reactors call for the introduction of chemical reagents into the primary circuit to loosen and flush the radioactive corrosion products from the internal surfaces. This produces large volumes of liquid radioactive wastes which must be treated to remove the soluble and particulate material so that the water can be disposed of. Mechanical filters produce a large volume of filter material versus the volume of particulates removed and are limited as to the smallest particulate size removed, with resultant recontamination of the cleaned surfaces. The majority of the material removed is in the particulate form and is magnetically susceptible, therefore the HGMF has provided to be ideally suited to this application. 3 figures, 1 table.

  3. Intensified nitrogen removal of constructed wetland by novel integration of high rate algal pond biotechnology.

    Science.gov (United States)

    Ding, Yi; Wang, Wei; Liu, Xingpo; Song, Xinshan; Wang, Yuhui; Ullman, Jeffrey L

    2016-11-01

    High rate algal pond (HRAP) was combined with constructed wetland (CW) to intensify nitrogen removal through optimizing nitrification and denitrification. Nitrification and denitrification process mainly depends on the oxygen content and carbon source level in CWs. Algal biomass was enriched in HRAP, and dissolved oxygen (DO) concentration was increased via photosynthesis. Algal debris increased COD as degradable bioresource. The results showed that HRAP-CW hybrid systems effectively promoted the nitrogen removal performance due to rich DO and COD. The extension of hydraulic retention time in HRAP significantly improved NH4-N and TN removals by 10.9% and 11.1% in hybrid systems, respectively. The highest NH4-N and TN removals in hybrid systems respectively reached 67.2% and 63.5%, which were significantly higher than those in single CW. The study suggested that the hybrid system had the application potentials in nitrogen removal from wastewater.

  4. [Genesis study of omphacite at high pressure and high temperature].

    Science.gov (United States)

    Xiao, Ben-Fu; Yi, Li; Wang, Duo-Jun; Xie, Chao; Tang, Xue-Wu; Liu, Lei; Cui, Yue-Ju

    2013-11-01

    The melting and recrystallizing experiments of alkali basalt powder and mixture of pure oxides mixed as stoichiometry were performed at 3 GPa and 1 200 degrees C. Electronic microprobe analysis and Raman spectra showed that the recrystallized products were omphacites, the FWHM (full width at half maximum) of the Raman peak was narrow and its shape was sharp, which is attributed to the stable Si-O tetrahedral structure and the high degree of order in omphacite. Based on the results of previous studies, the influencing factors of omphacite genesis and its primary magma were discussed. The results showed that the formation of omphacite could be affected by many factors, such as the composition of parent rocks, the concentration of fluid in the system and the conditions of pressure and temperature. This result could support some experimental evidences on the genesis studies of omphacite and eclogite.

  5. 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.

  6. Presence of helminth eggs in domestic wastewater and its removal at low temperature UASB reactors in Peruvian highlands.

    Science.gov (United States)

    Yaya-Beas, Rosa-Elena; Cadillo-La-Torre, Erika-Alejandra; Kujawa-Roeleveld, Katarzyna; van Lier, Jules B; Zeeman, Grietje

    2016-03-01

    This work studied the anaerobic sludge filtration capacity for pathogens reduction in a 29 L and 1.65 m height lab-scale UASB reactor treating domestic wastewater at low temperatures in the city of Puno (Peru). The anaerobic sludge filtration capacity was performed applying upflow velocities of 0.12, 0.14, 0.16, 0.20, 0.27 and 0.41 m/h. Results show that the HE removal varied between 89 and 95% and the most common specie was Ascaris lumbricoides. Faecal coliform and Escherichia coli removal varied in the range of 0.9-2.1 and 0.8-1.6 log10 respectively. Likely related to the low operational temperatures, the total COD removal varied between 37 and 62%. The best performance in terms of removal of HE, total COD and turbidity was obtained at the lowest upflow velocity of 0.12 m/h. In order to meet WHO standards for water reuse a post-treatment unit will be required to polish the effluent.

  7. Acetylene-chromene terminated resins as high temperature thermosets

    Science.gov (United States)

    Godschalx, J. P.; Inbasekaran, M. N.; Bartos, B. R.; Scheck, D. M.; Laman, S. A.

    1990-01-01

    A novel phase transfer catalyzed process for the preparation of propargyl ethers has been developed. The propargyl ethers serve as precursors to a new class of thermosetting resins called acetylene-chromene terminated (ACT) resins. Heat treatment of a solution of propargyl ethers with various catalysts, followed by removal of solvent leads to the ACT resins via partial conversion of the propargyl ether groups to chromenes. This process reduces the energy content of the resin systems and reduces the amount of shrinkage found during cure. Due to the presence of the solvent the process is safe and gives rise to low viscosity products suitable for resin transfer molding and filament winding type applications. Due to the high glass transition temperature, high modulus, and low moisture uptake the cured resins display better than 232 C/wet performance. The thermal stability of the ACT resins in air at 204 C is superior to that of conventional bismaleimide resins. The resins also display excellent electrical properties.

  8. Acetylene-chromene terminated resins as high temperature thermosets

    Science.gov (United States)

    Godschalx, J. P.; Inbasekaran, M. N.; Bartos, B. R.; Scheck, D. M.; Laman, S. A.

    1990-01-01

    A novel phase transfer catalyzed process for the preparation of propargyl ethers has been developed. The propargyl ethers serve as precursors to a new class of thermosetting resins called acetylene-chromene terminated (ACT) resins. Heat treatment of a solution of propargyl ethers with various catalysts, followed by removal of solvent leads to the ACT resins via partial conversion of the propargyl ether groups to chromenes. This process reduces the energy content of the resin systems and reduces the amount of shrinkage found during cure. Due to the presence of the solvent the process is safe and gives rise to low viscosity products suitable for resin transfer molding and filament winding type applications. Due to the high glass transition temperature, high modulus, and low moisture uptake the cured resins display better than 232 C/wet performance. The thermal stability of the ACT resins in air at 204 C is superior to that of conventional bismaleimide resins. The resins also display excellent electrical properties.

  9. Performance of a completely autotrophic nitrogen removal over nitrite process for treating wastewater with different substrates at ambient temperature

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Chang; Dong Li; Yuhai Liang; Zhuo Yang; Shaoming Cui; Tao Liu; Huiping Zeng

    2013-01-01

    The stability and parameters of a bio-ceramic filter for completely autotrophic nitrogen removal were investigated.The completely autotrophic nitrogen removal over nitrite (CANON) reactor was fed with different concentrations of ammonia (400,300,and 200 mg N/L) but constant influent ammonia load.The results showed that the CANON system can achieve good treatment performance at ambient temperature (15-23℃).The average removal rate and removal loading of NH4 +-N and TN was 83.90%,1.26 kg N/(m3.day),and 70.14%,1.09 kg N/(m3.day),respectively.Among the influencing factors like pH,dissolved oxygen and alkalinity,it was indicated that the pH was the key parameter of the performance of the CANON system.Observing the variation of pH would contribute to better control of the CANON system in an intuitive and fast way.Denaturing gradient gel electrophoresis analysis of microorganisms further revealed that there were some significant changes in the community structure of ammonium oxidizing bacteria,which had low diversity in different stages,while the species of anaerobic ammonium oxidizing (anammox) bacteria were fewer and the community composition was relatively stable.These observations showed that anaerobic ammonia oxidation was more stable than the aerobic ammonia oxidation,which could explain that why the CANON system maintained a good removal efficiency under the changing substrate conditions.

  10. Advanced High Temperature Reactor Systems and Economic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David Eugene [ORNL; Peretz, Fred J [ORNL; Qualls, A L [ORNL

    2011-09-01

    The Advanced High Temperature Reactor (AHTR) is a design concept for a large-output [3400 MW(t)] fluoride-salt-cooled high-temperature reactor (FHR). FHRs, by definition, feature low-pressure liquid fluoride salt cooling, coated-particle fuel, a high-temperature power cycle, and fully passive decay heat rejection. The AHTR's large thermal output enables direct comparison of its performance and requirements with other high output reactor concepts. As high-temperature plants, FHRs can support either high-efficiency electricity generation or industrial process heat production. The AHTR analysis presented in this report is limited to the electricity generation mission. FHRs, in principle, have the potential to be low-cost electricity producers while maintaining full passive safety. However, no FHR has been built, and no FHR design has reached the stage of maturity where realistic economic analysis can be performed. The system design effort described in this report represents early steps along the design path toward being able to predict the cost and performance characteristics of the AHTR as well as toward being able to identify the technology developments necessary to build an FHR power plant. While FHRs represent a distinct reactor class, they inherit desirable attributes from other thermal power plants whose characteristics can be studied to provide general guidance on plant configuration, anticipated performance, and costs. Molten salt reactors provide experience on the materials, procedures, and components necessary to use liquid fluoride salts. Liquid metal reactors provide design experience on using low-pressure liquid coolants, passive decay heat removal, and hot refueling. High temperature gas-cooled reactors provide experience with coated particle fuel and graphite components. Light water reactors (LWRs) show the potentials of transparent, high-heat capacity coolants with low chemical reactivity. Modern coal-fired power plants provide design experience

  11. Influence of material removal programming on ion beam figuring of high-precision optical surfaces

    Science.gov (United States)

    Liao, Wenlin; Dai, Yifan; Xie, Xuhui

    2014-09-01

    Ion beam figuring (IBF) provides a nanometer/subnanometer precision fabrication technology for optical components, where the surface materials on highlands are gradually removed by the physical sputtering effect. In this deterministic method, the figuring process is usually divided into several iterations and the sum of the removed material in each iteration is expected to approach the ideally removed material as nearly as possible. However, we find that the material removal programming in each iteration would influence the surface error convergence of the figuring process. The influence of material removal programming on the surface error evolution is investigated through the comparative study of the contour removal method (CRM) and the geometric proportion removal method (PRM). The research results indicate that the PRM can maintenance the smoothness of the surface topography during the whole figuring process, which would benefit the stable operation of the machine tool and avoid the production of mid-to-high spatial frequency surface errors. Additionally, the CRM only has the corrective effect on the area above the contour line in each iteration, which would result in the nonuniform convergence of the surface errors in various areas. All these advantages distinguish PRM as an appropriate material removal method for ultraprecision optical surfaces.

  12. High-temperature responses of North American cacti

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.D.; Didden-Zopfy, B.; Nobel, P.S.

    1984-04-01

    High-temperature tolerances of 14 species of North American cacti were investigated. A reduction in the proportion of chlorenchyma cells taking up a vital stain (neutral red) and reduced nocturnal acid accumulation were used as indicators of high-temperature damage. All species tolerated relatively high tissue temperatures, the mean maximum tolerance being 64/sup 0/C, with an absolute maximum of 69/sup 0/ for two species of ferocactus. Such tissue tolerances to high temperature may be unsurpassed in vascular plants. Morphological features can affect tissue temperatures. Specifically, thin-stemmed species such as the cylindropuntias attain lower maximum temperatures under identical microclimatic conditions than do more massive species; they also tend to be less tolerant of high-temperature stress. Stem diameter changes of three species of columnar ceriod cacti along a Sonoran Desert latitudinal transect were previously attributed to adaptation to progressively colder temperatures northward. Such changes can also be interpreted as a morphological adaptation to high temperatures, particularly in the southern Sonoran Desert. Interspecific differences in high-temperature tolerance may account for distributional differences among other species. Acclimation of high-temperature tolerances in response to increasing day/night air temperatures was observed in all 14 species, especially at higher growh temperatures. From 40/sup 0/ day/30/sup 0/ night to 50/sup 0//40/sup 0/, the tolerable tissue temperatures increased an average of 6/sup 0/. Half-times for the acclimation shifts were 1-3d. Although cacti attain extremely high tissue temperatures in desert habitats, tolerance of high temperatures and pronounced acclimation potential allow them to occur in some of the hottest habitats in North America.

  13. NOVEL REFRACTORY MATERIALS FOR HIGH ALKALI, HIGH TEMPERATURE ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James Gordon [ORNL; Smith, Jeffrey D [ORNL; O' Hara, Kelley [University of Missouri, Rolla; Rodrigues-Schroer, Angela [Minteq International, Inc.; Colavito, [Minteq International, Inc.

    2012-08-01

    A project was led by Oak Ridge National Laboratory (ORNL) in collaboration with a research team comprised of the academic institution Missouri University of Science and Technology (MS&T), and the industrial company MINTEQ International, Inc. (MINTEQ), along with representatives from the aluminum, chemical, glass, and forest products industries. The project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al 2O3, MgAl2O4, or other similar spinel structured or alumina-based unshaped refractory compositions (castables, gunnables, shotcretes, etc.) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, high-alkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries. Both practical refractory development experience and computer modeling techniques were used to aid in the design of this new family of materials. The newly developed materials were expected to offer alternative material choices for high-temperature, high-alkali environments that were capable of operating at higher temperatures (goal of increasing operating temperature by 100-200oC depending on process) or for longer periods of time (goal of twice the life span of current materials or next process determined service increment). This would lead to less process down time, greater energy efficiency for associated manufacturing processes (more heat kept in process), and materials that could be installed/repaired in a more efficient manner. The overall project goal was a 5% improvement in energy efficiency (brought about through a 20% improvement in thermal efficiency) resulting in a savings of 3.7 TBtu/yr (7.2 billion ft3 natural gas) by the year 2030. Additionally, new

  14. High temperature ceramic membrane reactors for coal liquid upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T. (University of Southern California, Los Angeles, CA (United States). Dept. of Chemical Engineering); Liu, P.K.T. (Aluminum Co. of America, Pittsburgh, PA (United States)); Webster, I.A. (Unocal Corp., Los Angeles, CA (United States))

    1992-01-01

    Membrane reactors are today finding extensive applications for gas and vapor phase catalytic reactions (see discussion in the introduction and recent reviews by Armor [92], Hsieh [93] and Tsotsis et al. [941]). There have not been any published reports, however, of their use in high pressure and temperature liquid-phase applications. The idea to apply membrane reactor technology to coal liquid upgrading has resulted from a series of experimental investigations by our group of petroleum and coal asphaltene transport through model membranes. Coal liquids contain polycyclic aromatic compounds, which not only present potential difficulties in upgrading, storage and coprocessing, but are also bioactive. Direct coal liquefaction is perceived today as a two-stage process, which involves a first stage of thermal (or catalytic) dissolution of coal, followed by a second stage, in which the resulting products of the first stage are catalytically upgraded. Even in the presence of hydrogen, the oil products of the second stage are thought to equilibrate with the heavier (asphaltenic and preasphaltenic) components found in the feedstream. The possibility exists for this smaller molecular fraction to recondense with the unreacted heavy components and form even heavier undesirable components like char and coke. One way to diminish these regressive reactions is to selectively remove these smaller molecular weight fractions once they are formed and prior to recondensation. This can, at least in principle, be accomplished through the use of high temperature membrane reactors, using ceramic membranes which are permselective for the desired products of the coal liquid upgrading process. An additional incentive to do so is in order to eliminate the further hydrogenation and hydrocracking of liquid products to undesirable light gases.

  15. 454-Pyrosequencing Analysis of Bacterial Communities from Autotrophic Nitrogen Removal Bioreactors Utilizing Universal Primers: Effect of Annealing Temperature

    Directory of Open Access Journals (Sweden)

    Alejandro Gonzalez-Martinez

    2015-01-01

    Full Text Available Identification of anaerobic ammonium oxidizing (anammox bacteria by molecular tools aimed at the evaluation of bacterial diversity in autotrophic nitrogen removal systems is limited by the difficulty to design universal primers for the Bacteria domain able to amplify the anammox 16S rRNA genes. A metagenomic analysis (pyrosequencing of total bacterial diversity including anammox population in five autotrophic nitrogen removal technologies, two bench-scale models (MBR and Low Temperature CANON and three full-scale bioreactors (anammox, CANON, and DEMON, was successfully carried out by optimization of primer selection and PCR conditions (annealing temperature. The universal primer 530F was identified as the best candidate for total bacteria and anammox bacteria diversity coverage. Salt-adjusted optimum annealing temperature of primer 530F was calculated (47°C and hence a range of annealing temperatures of 44–49°C was tested. Pyrosequencing data showed that annealing temperature of 45°C yielded the best results in terms of species richness and diversity for all bioreactors analyzed.

  16. Trichloroethylene removal and bacterial variations in the up-flow anaerobic sludge blanket reactor in response to temperature shifts.

    Science.gov (United States)

    Zhang, Ying; Hu, Miao; Li, Pengfei; Wang, Xin; Meng, Qingjuan

    2015-07-01

    Trichloroethylene (TCE) degradation and the variations of bacteria composition and structure in the up-flow anaerobic sludge blanket (UASB) reactor were investigated by increasing the operating temperature from 20 to 40 °C. The influent was supplemented with 36.5 mg/L of TCE. There was a rise in the chemical oxygen demand (COD) removal efficiency from 20 to 35 °C and a decline when temperature enhanced to 40 °C. It reached maximum at 35 °C. In addition, TCE removal efficiency increased with temperature varying from 20 to 35 °C, and it dropped dramatically to 78.38 % at 40 °C, which presumably because the genus of Dehalobacter, a kind of bacteria with the ability to dechlorinate TCE to the corresponding chlorinated products, was not detected at 40 °C according to sequencing results. The Illumina MiSeq platform was adopted to explore the bacteria composition and structure in response to temperature shifts. The results indicated that temperature impacted greatly on the dominance and presence of specific populations at different taxonomic levels. Importantly, the class Dehalococcoidia was detected from 25 to 40 °C, in which there were many well-known Dehalococcoides sp. strains that were capable of complete dechlorination of TCE to ethene. It also suggested the potential function of the dominant genera (non-dechlorinating bacteria and dechlorinating bacteria) in the reactor.

  17. Metallic substrates for high temperature superconductors

    Science.gov (United States)

    Truchan, Thomas G.; Miller, Dean J.; Goretta, Kenneth C.; Balachandran, Uthamalingam; Foley, Robert

    2002-01-01

    A biaxially textured face-centered cubic metal article having grain boundaries with misorientation angles greater than about 8.degree. limited to less than about 1%. A laminate article is also disclosed having a metal substrate first rolled to at least about 95% thickness reduction followed by a first annealing at a temperature less than about 375.degree. C. Then a second rolling operation of not greater than about 6% thickness reduction is provided, followed by a second annealing at a temperature greater than about 400.degree. C. A method of forming the metal and laminate articles is also disclosed.

  18. Survey of industrial coal conversion equipment capabilities: high-temperature, high-pressure gas purification

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J. P.; Edwards, M. S.

    1978-06-01

    In order to ensure optimum operating efficiencies for combined-cycle electric generating systems, it is necessary to provide gas treatment equipment capable of operating at high temperatures (>1000/sup 0/F) and high pressure (>10 atmospheres absolute). This equipment, when assembled in a process train, will be required to condition the inlet stream to a gas turbine to suitable levels of gas purity (removal of particulate matter, sulfur, nitrogen, and alkali metal compounds) so that it will be compatible with both environmental and machine constraints. In this work, a survey of the available and developmental equipment for the removal of particulate matter and sulfur compounds has been conducted. In addition, an analysis has been performed to evaluate the performance of a number of alternative process configurations in light of overall system needs. Results from this study indicate that commercially available, reliable, and economically competitive hot-gas cleanup equipment capable of conditioning raw product gas to the levels required for high-temperatue turbine operation will not be available for some time.

  19. Cryogenic deformation of high temperature superconductive composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Peter R. (Groton, MA); Michels, William (Brookline, MA); Bingert, John F. (Jemez Springs, NM)

    2001-01-01

    An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

  20. High Temperature Resistant Exhaust Valve Spindle

    DEFF Research Database (Denmark)

    Bihlet, Uffe Ditlev

    Transport by ship remains the most economical and environmentally friendly mode of transport with a very low weight specific CO2 footprint. Further increase of the fuel efficiency of large ships will results in a higher internal engine temperature. To allow this without compromising the reliabili...

  1. High rates of denitrification and nitrate removal in cold seep sediments.

    Science.gov (United States)

    Bowles, Marshall; Joye, Samantha

    2011-03-01

    We measured denitrification and nitrate removal rates in cold seep sediments from the Gulf of Mexico. Heterotrophic potential denitrification rates were assayed in time-series incubations. Surficial sediments inhabited by Beggiatoa exhibited higher heterotrophic potential denitrification rates (32 μM N reduced day(-1)) than did deeper sediments (11 μM N reduced day(-1)). Nitrate removal rates were high in both sediment horizons. These nitrate removal rates translate into rapid turnover times (cold seeps and the requirement for novel mechanisms to provide nitrate to the sediment microbial community.

  2. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Adcock, K.D.; Fain, D.E.; James, D.L.; Powell, L.E.; Raj, T.; Roettger, G.E.; Sutton, T.G. [East Tennessee Technology Park, Oak Ridge, TN (United States)

    1997-12-01

    The separative performance of the authors` ceramic membranes has been determined in the past using a permeance test system that measured flows of pure gases through a membrane at temperatures up to 275 C. From these data, the separation factor was determined for a particular gas pair from the ratio of the pure gas specific flows. An important project goal this year has been to build a Mixed Gas Separation System (MGSS) for measuring the separation efficiencies of membranes at higher temperatures and using mixed gases. The MGSS test system has been built, and initial operation has been achieved. The MGSS is capable of measuring the separation efficiency of membranes at temperatures up to 600 C and pressures up to 100 psi using a binary gas mixture such as hydrogen/methane. The mixed gas is fed into a tubular membrane at pressures up to 100 psi, and the membrane separates the feed gas mixture into a permeate stream and a raffinate stream. The test membrane is sealed in a stainless steel holder that is mounted in a split tube furnace to permit membrane separations to be evaluated at temperatures up to 600 C. The compositions of the three gas streams are measured by a gas chromatograph equipped with thermal conductivity detectors. The test system also measures the temperatures and pressures of all three gas streams as well as the flow rate of the feed stream. These data taken over a range of flows and pressures permit the separation efficiency to be determined as a function of the operating conditions. A mathematical model of the separation has been developed that permits the data to be reduced and the separation factor for the membrane to be determined.

  3. High rate nitrogen removal in an alum sludge-based intermittent aeration constructed wetland.

    Science.gov (United States)

    Hu, Yuansheng; Zhao, Yaqian; Zhao, Xiaohong; Kumar, Jeyakumar L G

    2012-04-17

    A new development on treatment wetland technology for the purpose of achieving high rate nitrogen removal from high strength wastewater has been made in this study. The laboratory scale alum sludge-based intermittent aeration constructed wetland (AlS-IACW) was integrated with predenitrification, intermittent aeration, and step-feeding strategies. Results obtained from 280 days of operation have demonstrated extraordinary nitrogen removal performance with mean total nitrogen (TN) removal efficiency of 90% under high N loading rate (NLR) of 46.7 g N m(-2) d(-1). This performance was a substantial improvement compared to the reported TN removal performance in literature. Most significantly, partial nitrification and simultaneous nitrification denitrification (SND) via nitrite was found to be the main nitrogen conversion pathways in the AlS-IACW system under high dissolved oxygen concentrations (3-6 mg L(-1)) without specific control. SND under high dissolved oxygen (DO) brings high nitrogen conversion rates. Partial nitrification and SND via nitrite can significantly reduce the demand for organic carbon compared with full nitrification and denitrification via nitrate (up to 40%). Overall, these mechanisms allow the system to maintaining efficient and high rate TN removal even under carbon limiting conditions.

  4. 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.

  5. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent

    Science.gov (United States)

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

  6. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent - paper

    Science.gov (United States)

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

  7. Autotrophic nitrogen removal from low strength waste water at low temperature

    NARCIS (Netherlands)

    Hendrickx, T.L.G.; Wang, Y.; Kampman, C.; Zeeman, G.; Temmink, B.G.; Buisman, C.J.N.

    2012-01-01

    Direct anaerobic treatment of municipal waste waters allows for energy recovery in the form of biogas. A further decrease in the energy requirement for waste water treatment can be achieved by removing the ammonium in the anaerobic effluent with an autotrophic process, such as anammox. Until now,

  8. Woodchip denitrification bioreactors: Impact of temperature and hydraulic retention time on nitrate removal

    Science.gov (United States)

    Woodchip denitrification bioreactors, a relatively new technology for edge-of-field treatment of subsurface agricultural drainage water, have shown potential for nitrate removal. However, very few studies have evaluated the performance of these reactors under controlled conditions similar to the fie...

  9. Autotrophic nitrogen removal from low strength waste water at low temperature

    NARCIS (Netherlands)

    Hendrickx, T.L.G.; Wang, Y.; Kampman, C.; Zeeman, G.; Temmink, B.G.; Buisman, C.J.N.

    2012-01-01

    Direct anaerobic treatment of municipal waste waters allows for energy recovery in the form of biogas. A further decrease in the energy requirement for waste water treatment can be achieved by removing the ammonium in the anaerobic effluent with an autotrophic process, such as anammox. Until now, an

  10. Vibrational relaxation in very high temperature nitrogen

    Science.gov (United States)

    Hansen, C. Frederick

    1991-01-01

    Vibrational relaxation of N2 molecules is considered at temperatures up to 40,000 K in gas mixtures that contain electrons as well as heavy collision partners. The theory of vibrational relaxation due to N2-N2 collisions is fit to experimental data to 10,000 K by choice of the shape of the intermolecular potential and size of the collision cross section. These values are then used to extrapolate the theory to 40,000 K.

  11. High Temperature LFMR in Yttrium Doped Perovskite Manganites

    Institute of Scientific and Technical Information of China (English)

    盛晓波; 童林夙; 林萍华; 杨石强; 储成林; 翟亚

    2003-01-01

    Porous ceramic samples of Y doped perovskite manganites were prepared. In these samples, the transition from high temperature paramagnetic insulator to low temperature ferromagnetic metal as well as the low field magnetoresistance (LFMR) effect at the low temperature is similar to that in dense samples. Opposite to that in dense samples, LFMR effect in porous sample is observed at the high temperature close to the peak of MR-T curves. The results suggest that the high temperature LFMR effect and the applicable colossal magnetoresistance (CMR) materials could be obtained by controlling the microstructures of this class of perovskite manganites.

  12. Chemical interferences when using high gradient magnetic separation for phosphate removal: consequences for lake restoration.

    Science.gov (United States)

    de Vicente, I; Merino-Martos, A; Guerrero, F; Amores, V; de Vicente, J

    2011-09-15

    A promising method for lake restoration is the treatment of lake inlets through the specific adsorption of phosphate (P) on strongly magnetizable particles (Fe) and their subsequent removal using in-flow high gradient magnetic separation (HGMS) techniques. In this work, we report an extensive investigation on the chemical interferences affecting P removal efficiencies in natural waters from 20 Mediterranean ponds and reservoirs. A set of three treatments were considered based on different Fe particles/P concentration ratios. High P removal efficiencies (>80%) were found in freshwater lakes (conductivities<600 μ S cm(-1)). However, a significant reduction in P removal was observed for extremely high mineralized waters. Correlation analysis showed that major cations (Mg(2+), Na(+) and K(+)) and anions (SO(4)(2-) and Cl(-)) played an essential role in P removal efficiency. Comparison between different treatments have shown that when increasing P and Fe concentrations at the same rate or when increasing Fe concentrations for a fixed P concentration, there exist systematic reductions in the slope of the regression lines relating P removal efficiency and the concentration of different chemical variables. These results evidence a general reduction in the chemical competition between P and other ions for adsorption sites on Fe particles. Additional analyses also revealed a reduction in water color, dissolved organic carbon (DOC) and reactive silicate (Si) concentrations with the addition of Fe microparticles.

  13. 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...

  14. Effects of rapid temperature rising on nitrogen removal and microbial community variation of anoxic/aerobic process for ABS resin wastewater treatment.

    Science.gov (United States)

    Luo, Huilong; Song, Yudong; Zhou, Yuexi; Yang, Liwei; Zhao, Yaqian

    2017-02-01

    ABS resin wastewater is a high-temperature nitrogenous organic wastewater. It can be successfully treated with anoxic/aerobic (A/O) process. In this study, the effect of temperature on nitrogen removal and microbial community after quick temperature rise (QTR) was investigated. It was indicated that QTR from 25 to 30 °C facilitated the microbial growth and achieved a similar effluent quality as that at 25 °C. QTR from 25 to 35 °C or 40 °C resulted in higher effluent concentration of chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total nitrogen (TN), and total phosphorus (TP). Illumina MiSeq pyrosequencing analysis illustrated that the richness and diversity of the bacterial community was decreased as the temperature was increased. The percentage of many functional groups was changed significantly. QTR from 25 to 40 °C also resulted in the inhibition of ammonia oxidation rate and high concentration of free ammonia, which then inhibited the growth of NOB (Nitrospira), and thus resulted in nitrite accumulation. The high temperature above 35 °C promoted the growth of a denitrifying bacterial genus, Denitratisoma, which might increase N2O production during the denitrification process.

  15. 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).

  16. H{sub 2}S removal from coal gas at elevated temperature and pressure in fluidized bed with zinc titanate sorbents. 2. Sorbent durability

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W.; Abbasian, J. [Enviropower Inc., Espoo (Finland)

    1995-09-01

    High-temperature high-pressure sulfur removal is considered as one of the key steps of the hot gas cleanup train of an IGCC process. Coal-derived gasifier gas contains sulfur gases (mainly H{sub 2}S) which are converted to SO{sub 2} when the gas is combusted in the gas turbine. Cyclic sulfidation/regeneration tests were carried out in a pressurized fluidized bed reactor to remove H{sub 2}S from a simulated coal gas to below 100 ppmv, using regenerable zinc titanate sorbents. The results, which were reported in part 1 of this paper, showed that the sorbent reactivity deteriorates in the cyclic process. In part 2, physical, chemical, and structural changes which the sorbents undergo in the cyclic tests are reported and discussed. The results of analyses conducted with fresh and used sorbents indicate that the loss of reactivity and sorbent deterioration is probably due to zinc migration to the surface of the sorbent particle during the high-temperature high-pressure cyclic process. 13 refs., 11 figs., 2 tabs.

  17. Rapid Preparation of Biosorbents with High Ion Exchange Capacity from Rice Straw and Bagasse for Removal of Heavy Metals

    Directory of Open Access Journals (Sweden)

    Supitcha Rungrodnimitchai

    2014-01-01

    Full Text Available This work describes the preparation of the cellulose phosphate with high ion exchange capacity from rice straw and bagasse for removal of heavy metals. In this study, rice straw and bagasse were modified by the reaction with phosphoric acid in the presence of urea. The introduced phosphoric group is an ion exchangeable site for heavy metal ions. The reaction by microwave heating yielded modified rice straw and modified bagasse with greater ion exchange capacities (∼3.62 meq/g and shorter reaction time (1.5–5.0 min than the phosphorylation by oil bath heating. Adsorption experiments towards Pb2+, Cd2+, and Cr3+ ions of the modified rice straw and the modified bagasse were performed at room temperature (heavy metal concentration 40 ppm, adsorbent 2.0 g/L. The kinetics of adsorption agreed with the pseudo-second-order model. It was shown that the modified rice straw and the modified bagasse could adsorb heavy metal ions faster than the commercial ion exchange resin (Dowax. As a result of Pb2+ sorption test, the modified rice straw (RH-NaOH 450W removed Pb2+ much faster in the initial step and reached 92% removal after 20 min, while Dowax (commercial ion exchange resin took 90 min for the same removal efficiency.

  18. High Temperature Power Converters for Military Hybrid Electric Vehicles

    Science.gov (United States)

    2011-08-09

    M) MINI-SYMPOSIUM AUGUST 9-11 DEARBORN, MICHIGAN HIGH TEMPERATURE POWER CONVERTERS FOR MILITARY HYBRID ELECTRIC VEHICLES ABSTRACT...SUBTITLE High Temperature Power Converters for Military Hybrid Electric Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...public release High Temperature Power Converters for Military Hybrid Electric Vehicles Page 2 of 8 I. INTRODUCTION Today, wide bandgap devices

  19. 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.

  20. Gallium Oxide Nanostructures for High Temperature Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Chintalapalle, Ramana V. [Univ. of Texas, El Paso, TX (United States)

    2015-04-30

    Gallium oxide (Ga2O3) thin films were produced by sputter deposition by varying the substrate temperature (Ts) in a wide range (Ts=25-800 °C). The structural characteristics and electronic properties of Ga2O3 films were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Rutherford backscattering spectrometry (RBS) and spectrophotometric measurements. The effect of growth temperature is significant on the chemistry, crystal structure and morphology of Ga2O3 films. XRD and SEM analyses indicate that the Ga2O3 films grown at lower temperatures were amorphous while those grown at Ts≥500 oC were nanocrystalline. RBS measurements indicate the well-maintained stoichiometry of Ga2O3 films at Ts=300-800 °C. The electronic structure determination indicated that the nanocrystalline Ga2O3films exhibit a band gap of ~5 eV. Tungsten (W) incorporated Ga2O3 films were produced by co-sputter deposition. W-concentration was varied by the applied sputtering-power. No secondary phase formation was observed in W-incorporated Ga2O3 films. W-induced effects were significant on the structure and electronic properties of Ga2O3 films. The band gap of Ga2O3 films without W-incorporation was ~5 eV. Oxygen sensor characteristics evaluated using optical and electrical methods indicate a faster response in W-doped Ga2O3 films compared to intrinsic Ga2O3 films. The results demonstrate the applicability of both intrinsic and W-doped Ga-oxide films for oxygen sensor application at temperatures ≥700 °C.