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Sample records for coal single stage

  1. Ultrafine coal single stage dewatering and briquetting process

    SciTech Connect

    Wilson, J.W.; Honaker, R.Q.

    1995-12-31

    It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ultrafine coal particles are difficult to dewater and create problems in coal transportation, as well as in storage and handling at utility plants. The objective of this research project is to combine the ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, several types of coal samples with various particle size distributions have been tested for use in the dewatering and briquetting processes. Furthermore, various bitumen emulsions have been tested to determine the optimum dewatering reagent. These dewatering and pelletizing tests were carried out using a lab-scale ram extruder. Discharge from the dewatering and briquetting processes was tested to determine compliance with current federal and state requirements. The influence of bitumen emulsion on the sulfur content of coal pellets made were also examined. In addition, a ram extruder which can be operated continuously to simulate a rotary press operation, has been built and is currently being tested for use in the fine coal dewatering and pelletizing process.

  2. Ultrafine coal single stage dewatering and briquetting process. Technical report, September 1--November 30, 1994

    SciTech Connect

    Wilson, J.W.; Honaker, R.Q.

    1994-12-31

    It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin, are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ultrafine coal particles that are produced are difficult to dewater and they create problems in coal transportation as well as in its storage and handling at utility plants. The objective of this research project is to combine ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, two types of coal samples have been tested for use in the dewatering and briquetting processes. These tests were carried out in conjunction with a selected hydrophobic binder as the dewatering reagent and an uniaxial hydraulic press. The influence of compaction pressure and binder concentration (2 to 5%) on the performance of coal pellets have been evaluated in terms of their water and wear resistance. A laboratory scale ultrafine coal dewatering and briquetting extruder that can be operated continuously for coal pellets fabrication, has been designed and built, and will be available for testing in the next quarter.

  3. Ultrafine coal single stage dewatering and briquetting process. Technical report, December 1, 1994--February 28, 1995

    SciTech Connect

    Wilson, J.W.

    1996-03-01

    It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin, are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ultrafine coal particles that are produced are difficult to dewater and they create problems in coal transportation as well as in its storage and handling at utility plants. The objective of this research project is to combine ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, two types of coal samples have been tested for use in the dewatering and briquetting processes. These tests were carried out using Orimulsion as the dewatering reagent. A ram extruder that can be operated continuously is used to fabricate dewatered pellets. The influence of compaction pressure, curing time, binder concentration (2% to 5%), particle size, and compacting time on the performance of coal pellets have been evaluated in terms of their water resistance and wear vulnerability.

  4. Pilot scale single stage fine coal dewatering and briquetting process. Technical report, September 1--November 30, 1995

    SciTech Connect

    Wilson, J.W.; Ding, Y.; Honaker, R.Q.

    1995-12-31

    The primary goal of the current coal preparation research is to reduce the ash and sulfur content from coal, using fine grinding and various coal cleaning processes to separate finely disseminated mineral matter and pyrite from coal. Small coal particles are produced by the grinding operation, thus the ultrafine coal becomes very difficult to dewater. In addition, the ultrafine coal also creates problems during its transportation, storage and handling at utility plants. The current research is seeking to combine ultrafine coal dewatering and briquetting processes into a single stage operation, using hydrophobic binders as coal dewatering and binding reagents with the help of a compaction device. From previous tests, it has been found that coal pellets with a moisture content of less than 15% and good wear and water resistance can be successfully fabricated at pressures of less than 6,000 psi using a lab scale ram extruder. The primary objective of the research described in this quarter has been to extend the lab scale ultrafine coal dewatering and briquetting process into a pilot scale operation, based on the test data obtained from earlier research. A standard roller briquetting machine was used to dewater fine coal-binder mixtures during the briquetting process. The operating parameters, including moisture content of feed, feed rate, and roller speed, were evaluated on the basis of the performance of the briquettes. Briquettes fabricated at rates of up to 108 pellets per minute exhibited satisfactory water and wear resistance, i.e., less than 7.5% cured moisture and less than 8.3% weight loss after 6 min. of tumbling. Also, coal-binder samples with moisture contents of 40 percent have been successfully dewatered and briquetted. Briquetting of fine coal was possible under current feeding conditions, however, a better feeding system must be designed to further improve the quality of dewatered coal briquettes.

  5. Pilot Scale Single Stage Fine Coal Dewatering and Briquetting Process. Technical report, March 1, 1996 - May 31, 1996

    SciTech Connect

    Wilson, J.W.; Honaker, R.Q.; Ding, Y.; Ho, K.

    1996-12-31

    The primary goal for this ICCI coal research project is to effectively liberate coal from fnely disseminated minerals for Illinois Basin coal by using fine grinding and cleaning processes. However, because of the large surface area generated during the cleaning processes, it is difficult and uneconomic for conventional techniques to dewater the coal fines. In addition, these coal fine pose transportation, storage and handling problems at cleaning and utility facilities. The objective of this research is to combine dewatering and briquetting processes into a single stage operation that will solve the problems mentioned above. To build on the promising results obtained from the previous studies, a pilot scale commercial briquetting machine was used to evaluate this technique. The primary objective of the research in this reporting period is to determine the effectiveness of a single stage dewatering and briquetting technique using a commercial briquetting device. Two types of samples were prepared and the results of the -28 x 100 mesh samples are presented in this report. Modifications were made to the machine in an attempt to solve the back drainage problem. A total of six experiments were conducted and the results indicate that water resistance of coal briquettes increased as curing time increased. However, due to a deficiency of fine particles to bridge the gaps between the coarse particles, the wear resistance of the products declined. Also, at high roll speeds and compaction pressures, the coal briquettes produced tended to have higher moisture content and lower strength. On the other hand, at high feed rates, because of the screw extrusion effect, coal briquettes were produced with lower moisture content and higher strengths.

  6. Pilot scale single stage fine coal dewatering and briquetting process. Final technical report, September 1, 1995--August 31, 1996

    SciTech Connect

    Wilson, J.W.; Honaker, R.Q.; Ding, Y.

    1997-05-01

    The primary goal of the ongoing ICCI coal preparation research project is to reduce ash and sulfur content in coal by using fine grinding and other coal cleaning processes. The ultrafine coal particles that result from the grinding and cleaning operations are difficult to dewater, and create problems in their storage, handling and transportation. The objective of this research is to combine the dewatering and briquetting processes of fine coal preparation into a single stage operation, thereby enhancing the economic viability of utilizing fine coal. A bitumen based emulsion, Orimulsion, has proven to be an effective hydrophobic binder, which helps not only with the briquetting process but also in the expulsion of water from the coal. Encouraging results from the use of a ram extruder briquetting device led to experimentation in the production of briquettes using a lab scale roll briquetting device. In the first quarter of this reporting year, a commercially available lab scale roll briquetting machine was employed (Komarek B-100). Further testing was conducted for the rest of the year with the use of a pilot scale model (Komarek B220-A). Briquettes were produced and evaluated by comparing results developed by adjusting various parameters of the briquetting machines and feed material. Results further substantiate previous findings that curing time dictates both moisture content and strengths of briquettes, and slower roll speeds produce more robust briquettes. A statistical model was set up to determine the optimal range of operating parameters. The statistical model generated from these results provided basic relationships between the roll speed and briquette form pressure.

  7. Two stage liquefaction of coal

    DOEpatents

    Neuworth, Martin B.

    1981-01-01

    A two stage coal liquefaction process and apparatus comprising hydrogen donor solvent extracting, solvent deashing, and catalytic hydrocracking. Preferrably, the catalytic hydrocracking is performed in an ebullating bed hydrocracker.

  8. Two stage coal gasification plant

    SciTech Connect

    Shoebotham, N.M.

    1984-06-26

    This invention relates to a two stage coal gasification plant which comprises a gasifier 1 and a predistillation retort 2. The gasifier has a plurality of gas extraction outlets 4 located in the periphery thereof which feed into a manifold 5 from where a percentage of the gas from the gasifier is extracted. Gas from the predistillation retort is extracted through an outlet near the top of the retort. An agitator 8 is provided for agitation of the coal in the agglomeration zone. The agitator is preferably automatically controlled by means of a temperature sensing device 10 located on an arm thereof.

  9. Two-stage coal liquefaction process

    DOEpatents

    Skinner, Ronald W.; Tao, John C.; Znaimer, Samuel

    1985-01-01

    An improved SRC-I two-stage coal liquefaction process which improves the product slate is provided. Substantially all of the net yield of 650.degree.-850.degree. F. heavy distillate from the LC-Finer is combined with the SRC process solvent, substantially all of the net 400.degree.-650.degree. F. middle distillate from the SRC section is combined with the hydrocracker solvent in the LC-Finer, and the initial boiling point of the SRC process solvent is increased sufficiently high to produce a net yield of 650.degree.-850.degree. F. heavy distillate of zero for the two-stage liquefaction process.

  10. Method of operating a two-stage coal gasifier

    DOEpatents

    Tanca, Michael C.

    1982-01-01

    A method of operating an entrained flow coal gasifier (10) via a two-stage gasification process. A portion of the coal (18) to be gasified is combusted in a combustion zone (30) with near stoichiometric air to generate combustion products. The combustion products are conveyed from the combustion zone into a reduction zone (32) wherein additional coal is injected into the combustion products to react with the combustion products to form a combustible gas. The additional coal is injected into the reduction zone as a mixture (60) consisting of coal and steam, preferably with a coal-to-steam weight ratio of approximately ten to one.

  11. The single electron chemistry of coals

    SciTech Connect

    Larsen, J.W.; Eskay, T.

    1991-01-01

    The objective of this work is to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. Activities carried out in this reporting period are as follows: (1) attempts will be made to demonstrate that the radicals from inertinite maceral group will initiate the polymerization of 4-vinylpyridine; (2) the molecule, N,N-diphenyl-phenylenediamine, will be deposited in coals to characterize their native free radicals; (3) tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) will be used to characterize the numbers and strengths of single electron donors in coals. 7 refs., 4 tabs.

  12. The single electron chemistry of coals

    SciTech Connect

    Larsen, J.W.; Kaushal, P.

    1991-01-18

    Our work on single election transfer in coals led us to the knowledge that the energetics of bond cleavage in radical cations is 20-40 kcal/mole lower than the corresponding homolytic bond cleavage energies. Having made excellent progress in the other areas covered by this proposal, we are extending our studies to the investigation of the formation and cleavage reaction of radical cations in coals. The formation of a radical cation requires the transfer of an electron from a neutral molecule to an appropriate electron acceptor (oxidant). As a first step, we seek oxidants which will form radical cations from functional groups typical of those in coals. We must also study the decomposition behavior of bonds typical of those found in coals. Alkyl and alkoxy aromatic compounds were chosen as the electron donors because of their common occurrence in coals.

  13. Experimental Study of the Ignition of Single Drops of Coal Suspensions and Coal Particles in the Oxidizer Flow

    NASA Astrophysics Data System (ADS)

    Vershinina, K. Yu.; Glushkov, D. O.; Kuznetsov, G. V.; Strizhak, P. A.

    2017-01-01

    An experimental study has been made of the process of ignition of single drops of water-coal and organic water-coal suspensions and coal particles heated by the oxidizer flow. The low-temperature (400-600°C) regime of the initiation of combustion of commensurate (from 1 to 3 mm) drops of water-coal and organic water-coal suspensions and coal particles has been considered. With the use of a high-speed (up to 105 frames/s) video camera and Tema Automative software, the influence of the oxidizer temperature, the gas flow velocity, the size of suspension fuel drops, and the coal particle size on the conditions and integral characteristics of the induction period has been determined. The ignition delay times and the duration of the combustion process of the investigated fuel samples have been established. The features of the stages of stable low-temperature initiation of combustion have been determined.

  14. The single electron chemistry of coals

    SciTech Connect

    Larsen, J.W.; Eskay, T.P.

    1992-01-31

    Depolymerization of coals at low temperatures may offer advantages over thermal bond cleavage. Because bond cleavage energies of radical cations are lower than the corresponding homolytic bond cleavage energies of the same bond, generation of radical cations in coal may make possible depolymerization at lower temperatures. We seek to investigate the above possibility using single molecules containing functional groups common in coals. Since the generation of a radical cation requires the removal of an electron from a neutral molecule, a primary focus of the study will be finding oxidants that will remove an electron from compounds with structural similarity to those typically found in coals. The study must also be concerned with the decomposition of radical cations and the products formed as a result of the decomposition.

  15. Catalytic two-stage coal hydrogenation and hydroconversion process

    DOEpatents

    MacArthur, James B.; McLean, Joseph B.; Comolli, Alfred G.

    1989-01-01

    A process for two-stage catalytic hydrogenation and liquefaction of coal to produce increased yields of low-boiling hydrocarbon liquid and gas products. In the process, the particulate coal is slurried with a process-derived liquid solvent and fed at temperature below about 650.degree. F. into a first stage catalytic reaction zone operated at conditions which promote controlled rate liquefaction of the coal, while simultaneously hydrogenating the hydrocarbon recycle oils at conditions favoring hydrogenation reactions. The first stage reactor is maintained at 650.degree.-800.degree. F. temperature, 1000-4000 psig hydrogen partial pressure, and 10-60 lb coal/hr/ft.sup.3 reactor space velocity. The partially hydrogenated material from the first stage reaction zone is passed directly to the close-coupled second stage catalytic reaction zone maintained at a temperature at least about 25.degree. F. higher than for the first stage reactor and within a range of 750.degree.-875.degree. F. temperature for further hydrogenation and thermal hydroconversion reactions. By this process, the coal feed is successively catalytically hydrogenated and hydroconverted at selected conditions, which results in significantly increased yields of desirable low-boiling hydrocarbon liquid products and minimal production of undesirable residuum and unconverted coal and hydrocarbon gases, with use of less energy to obtain the low molecular weight products, while catalyst life is substantially increased.

  16. Single-stage Mars mission

    NASA Technical Reports Server (NTRS)

    1991-01-01

    President Bush established a three phase Space Exploration Initiative for the future of space exploration. The first phase is the design and construction of Space Station Freedom. The second phase is permanent lunar base. The last phase of the Initiative is the construction of a Mars outpost. The design presented is the concept of a single-stage Mars mission developed by the University of Minnesota Aerospace Design Course. The mission will last approximately 500 days including a 30-60 day stay on Mars.

  17. Process for coal liquefaction in staged dissolvers

    DOEpatents

    Roberts, George W.; Givens, Edwin N.; Skinner, Ronald W.

    1983-01-01

    There is described an improved liquefaction process by which coal is converted to a low ash and low sulfur carbonaceous material that can be used as a fuel in an environmentally acceptable manner without costly gas scrubbing equipment. In the process, coal is slurried with a pasting oil, passed through a preheater and at least two dissolvers in series in the presence of hydrogen-rich gases at elevated temperatures and pressures. Solids, including mineral ash and unconverted coal macerals, are separated from the condensed reactor effluent. In accordance with the improved process, the first dissolver is operated at a higher temperature than the second dissolver. This temperature sequence produces improved product selectivity and permits the incorporation of sufficient hydrogen in the solvent for adequate recycle operations.

  18. A continuous two stage solar coal gasification system

    NASA Astrophysics Data System (ADS)

    Mathur, V. K.; Breault, R. W.; Lakshmanan, S.; Manasse, F. K.; Venkataramanan, V.

    The characteristics of a two-stage fluidized-bed hybrid coal gasification system to produce syngas from coal, lignite, and peat are described. Devolatilization heat of 823 K is supplied by recirculating gas heated by a solar receiver/coal heater. A second-stage gasifier maintained at 1227 K serves to crack remaining tar and light oil to yield a product free from tar and other condensables, and sulfur can be removed by hot clean-up processes. CO is minimized because the coal is not burned with oxygen, and the product gas contains 50% H2. Bench scale reactors consist of a stage I unit 0.1 m in diam which is fed coal 200 microns in size. A stage II reactor has an inner diam of 0.36 m and serves to gasify the char from stage I. A solar power source of 10 kWt is required for the bench model, and will be obtained from a central receiver with quartz or heat pipe configurations for heat transfer.

  19. Combustion of coal gas fuels in a staged combustor

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

    1982-01-01

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  20. Two-stage coal gasification and desulfurization apparatus

    DOEpatents

    Bissett, Larry A.; Strickland, Larry D.

    1991-01-01

    The present invention is directed to a system which effectively integrates a two-stage, fixed-bed coal gasification arrangement with hot fuel gas desulfurization of a first stream of fuel gas from a lower stage of the two-stage gasifier and the removal of sulfur from the sulfur sorbent regeneration gas utilized in the fuel-gas desulfurization process by burning a second stream of fuel gas from the upper stage of the gasifier in a combustion device in the presence of calcium-containing material. The second stream of fuel gas is taken from above the fixed bed in the coal gasifier and is laden with ammonia, tar and sulfur values. This second stream of fuel gas is burned in the presence of excess air to provide heat energy sufficient to effect a calcium-sulfur compound forming reaction between the calcium-containing material and sulfur values carried by the regeneration gas and the second stream of fuel gas. Any ammonia values present in the fuel gas are decomposed during the combustion of the fuel gas in the combustion chamber. The substantially sulfur-free products of combustion may then be combined with the desulfurized fuel gas for providing a combustible fluid utilized for driving a prime mover.

  1. Low-severity catalytic two-stage liquefaction process: Illinois coal conceptual commercial plant design and economics

    SciTech Connect

    Abrams, L.M.; Comolli, A.G.; Popper, G.A.; Wang, C.; Wilson, G.

    1988-09-01

    Hydrocarbon Research, Inc. (HRI) is conducting a program for the United States Department of Energy (DOE) to evaluate a Catalytic Two-Stage Liquefaction (CTSL) Process. This program which runs through 1987, is a continuation of an earlier DOE sponsored program (1983--1985) at HRI to develop a new technology concept for CTSL. The earlier program included bench-scale testing of improved operating conditions for the CTSL Process on Illinois No. 6 bituminous coal and Wyoming sub-bituminous coal, and engineering screening studies to identify the economic incentive for CTSL over the single-stage H-Coal/reg sign/ Process for Illinois No. 6 coal. In the current program these engineering screening studies are extended to deep-cleaned Illinois coal and use of heavy recycle. The results from this comparison will be used as a guide for future experiments with respect to selection of coal feedstocks and areas for further process optimization. A preliminary design for CTSL of Illinois deep-cleaned coal was developed based on demonstrated bench-scale performance in Run No. 227-47(I-27), and from HRI's design experience on the Breckinridge Project and H-Coal/reg sign/ Process pilot plant operations at Catlettsburg. Complete conceptual commercial plant designs were developed for a grassroots facility using HRI's Process Planning Model. Product costs were calculated and economic sensitivities analyzed. 14 refs., 11 figs., 49 tabs.

  2. Method and apparatus for removing coarse unentrained char particles from the second stage of a two-stage coal gasifier

    DOEpatents

    Donath, Ernest E.

    1976-01-01

    A method and apparatus for removing oversized, unentrained char particles from a two-stage coal gasification process so as to prevent clogging or plugging of the communicating passage between the two gasification stages. In the first stage of the process, recycled process char passes upwardly while reacting with steam and oxygen to yield a first stage synthesis gas containing hydrogen and oxides of carbon. In the second stage, the synthesis gas passes upwardly with coal and steam which react to yield partially gasified char entrained in a second stage product gas containing methane, hydrogen, and oxides of carbon. Agglomerated char particles, which result from caking coal particles in the second stage and are too heavy to be entrained in the second stage product gas, are removed through an outlet in the bottom of the second stage, the particles being separated from smaller char particles by a counter-current of steam injected into the outlet.

  3. 30 CFR 72.800 - Single, full-shift measurement of respirable coal mine dust.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... coal mine dust. 72.800 Section 72.800 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH HEALTH STANDARDS FOR COAL MINES Miscellaneous § 72.800 Single, full-shift measurement of respirable coal mine dust. The Secretary will use a single,...

  4. [Pathologic anatomy of experimental pneumoconiosis induced by coal dust in different stages of metamorphism].

    PubMed

    Shkutin, A E; Miakishev, I A

    1978-01-01

    The paper presents the results of investigations of experimental pneumoconiosis caused by inhalational administration of coal dust of the III and IV stages of metamorphism, of the similar petrographic composition without quartz admixtures. Coal dust of the IV stage of metamorphism was found to have more marked fibrogenic properties. Within 6-9 months, fibro-dust foci, destructive bronchites and pulmonary emphysema developed. Coal dust of the III stage of metamorphism within the same period causes only the development of cellular-dust foci, catarrhal bronchitis, and slightly manifest emphysema.

  5. The single electron transfer chemistry of coals. Final report

    SciTech Connect

    Larsen, J.W.; Flowers, R.A. II

    1994-12-31

    This research addressed electron donar properties and radical reactions in coal. Solid residues from pyridine Soxhlet extractions of Pocahontas No. 3, Upper Freeport, Pittsburgh No. 8, Illinois No. 6 and Wyodak coals were exposed to 4-vinylpyridine vapors and swelled. All of the 4-vinylpyridine could not be removed under vacuum at 100{degree}C. Diffuse reflectance FTIR revealed the presence of poly-(4-vinylpyridine) in the Illinois No. 6 and Wyodak coals. EPR spectra displayed the loss of inertinite radicals in Upper Freeport, Illinois No. 6 and Wyodak residues after exposure to 4-vinylpyridine. There was little change in the vitrinite radical density or environment. The molecule N,N{prime}-Diphenyl-p-phenylene diamine (DPPD) was exposed to the solid residues from pyridine Soxhlet extractions of the above coals. Diffuse reflectance FTIR failed to detect the imine product from radical reaction with DPPD. EPR spectra displayed the loss of inertinite radicals in Upper Freeport and Wyodak residues. 7,7,8,8-Tetracyanoquinodimethane (TCNQ) and Tetracyanoethylene (TCNE) were deposited into coals in pyridine. FTIR indicated complete conversion of TCNQ to a material with a singly occupied LUMO. In TCNE the LUMO is about 30% occupied. TCNQ and TCNE were deposited into the pyridine extracts and residues of Illinois No. 6 and Pittsburgh No. 8 coals. Only a small amount of the TCNQ and TCNE displayed nitrile shifts in the IR spectrum of a material with an occupied LUMO. It has been concluded that TCNQ must be part of the aromatic stacks in coal and the TCNQ LUMO is part of an extended band.

  6. Two-stage coal liquefaction without gas-phase hydrogen

    DOEpatents

    Stephens, H.P.

    1986-06-05

    A process is provided for the production of a hydrogen-donor solvent useful in the liquefaction of coal, wherein the water-gas shift reaction is used to produce hydrogen while simultaneously hydrogenating a donor solvent. A process for the liquefaction of coal using said solvent is also provided. The process enables avoiding the use of a separate water-gas shift reactor as well as high pressure equipment for liquefaction. 3 tabs.

  7. Catalytic two-stage coal hydrogenation process using extinction recycle of heavy liquid fraction

    DOEpatents

    MacArthur, J.B.; Comolli, A.G.; McLean, J.B.

    1989-10-17

    A process is described for catalytic two-stage hydrogenation and liquefaction of coal with selective extinction recycle of all heavy liquid fractions boiling above a distillation cut point of about 600--750 F to produce increased yields of low-boiling hydrocarbon liquid and gas products. In the process, the particulate coal feed is slurried with a process-derived liquid solvent normally boiling above about 650 F and fed into a first stage catalytic reaction zone operated at conditions which promote controlled rate liquefaction of the coal, while simultaneously hydrogenating the hydrocarbon recycle oils. The first stage reactor is maintained at 710--800 F temperature, 1,000--4,000 psig hydrogen partial pressure, and 10-90 lb/hr per ft[sup 3] catalyst space velocity. Partially hydrogenated material withdrawn from the first stage reaction zone is passed directly to the second stage catalytic reaction zone maintained at 760--860 F temperature for further hydrogenation and hydroconversion reactions. A 600--750 F[sup +] fraction containing 0--20 W % unreacted coal and ash solids is recycled to the coal slurrying step. If desired, the cut point lower boiling fraction can be further catalytically hydrotreated. By this process, the coal feed is successively catalytically hydrogenated and hydroconverted at selected conditions, to provide significantly increased yields of desirable low-boiling hydrocarbon liquid products and minimal production of hydrocarbon gases, and no net production of undesirable heavy oils and residuum materials. 2 figs.

  8. Catalytic two-stage coal hydrogenation process using extinction recycle of heavy liquid fraction

    DOEpatents

    MacArthur, James B.; Comolli, Alfred G.; McLean, Joseph B.

    1989-01-01

    A process for catalytic two-stage hydrogenation and liquefaction of coal with selective extinction recycle of all heavy liquid fractions boiling above a distillation cut point of about 600.degree.-750.degree. F. to produce increased yields of low-boiling hydrocarbon liquid and gas products. In the process, the particulate coal feed is slurried with a process-derived liquid solvent normally boiling above about 650.degree. F. and fed into a first stage catalytic reaction zone operated at conditions which promote controlled rate liquefaction of the coal, while simultaneously hydrogenating the hydrocarbon recycle oils. The first stage reactor is maintained at 710.degree.-800.degree. F. temperature, 1000-4000 psig hydrogen partial pressure, and 10-90 lb/hr per ft.sup.3 catalyst space velocity. Partially hydrogenated material withdrawn from the first stage reaction zone is passed directly to the second stage catalytic reaction zone maintained at 760.degree.-860.degree. F. temperature for further hydrogenation and hydroconversion reactions. A 600.degree.-750.degree. F..sup.+ fraction containing 0-20 W % unreacted coal and ash solids is recycled to the coal slurrying step. If desired, the cut point lower boiling fraction can be further catalytically hydrotreated. By this process, the coal feed is successively catalytically hydrogenated and hydroconverted at selected conditions, to provide significantly increased yields of desirable low-boiling hydrocarbon liquid products and minimal production of hydrocarbon gases, and no net production of undesirable heavy oils and residuum materials.

  9. Catalytic two-stage coal liquefaction process having improved nitrogen removal

    DOEpatents

    Comolli, Alfred G.

    1991-01-01

    A process for catalytic multi-stage hydrogenation and liquefaction of coal to produce high yields of low-boiling hydrocarbon liquids containing low concentrations of nitogen compounds. First stage catalytic reaction conditions are 700.degree.-800.degree. F. temperature, 1500-3500 psig hydrogen partial pressure, with the space velocity maintained in a critical range of 10-40 lb coal/hr ft.sup.3 catalyst settled volume. The first stage catalyst has 0.3-1.2 cc/gm total pore volume with at least 25% of the pore volume in pores having diameters of 200-2000 Angstroms. Second stage reaction conditions are 760.degree.-870.degree. F. temperature with space velocity exceeding that in the first stage reactor, so as to achieve increased hydrogenation yield of low-boiling hydrocarbon liquid products having at least 75% removal of nitrogen compounds from the coal-derived liquid products.

  10. Single scattering characteristics of volume elements in coal clouds

    SciTech Connect

    Gouesbet, G.; Grehan, G.; Maheu, B.

    1983-07-01

    Single scattering characteristics of volume elements in coal clouds are discussed and computed, with the aim of developing laser diagnosis methods in dense particle-laden flows, where multiple scattering phenomena become predominant. Results are provided for extinction efficiency factors, single scattering albedos asymmetry parameters, forward scattering ratios, and phase functions (rigorous as well as modeled). Interest is focused on coal particles because of their present importance in connection with problems linked to the crisis of energy. Computations are carried out at three wavelengths covering 3 orders of magnitude (0.5145-..mu..m Ar-ion laser; 10.6-..mu..m CO/sub 2/ laser; 337-..mu..m HCN laser) for diameters ranging from approx.1 to approx.100 ..mu..m.

  11. Catalytic multi-stage liquefaction of coal at HTI: Bench-scale studies in coal/waste plastics coprocessing

    SciTech Connect

    Pradhan, V.R.; Lee, L.K.; Stalzer, R.H.

    1995-12-31

    The development of Catalytic Multi-Stage Liquefaction (CMSL) at HTI has focused on both bituminous and sub-bituminous coals using laboratory, bench and PDU scale operations. The crude oil equivalent cost of liquid fuels from coal has been curtailed to about $30 per barrel, thus achieving over 30% reduction in the price that was evaluated for the liquefaction technologies demonstrated in the late seventies and early eighties. Contrary to the common belief, the new generation of catalytic multistage coal liquefaction process is environmentally very benign and can produce clean, premium distillates with a very low (<10ppm) heteroatoms content. The HTI Staff has been involved over the years in process development and has made significant improvements in the CMSL processing of coals. A 24 month program (extended to September 30, 1995) to study novel concepts, using a continuous bench scale Catalytic Multi-Stage unit (30kg coal/day), has been initiated since December, 1992. This program consists of ten bench-scale operations supported by Laboratory Studies, Modelling, Process Simulation and Economic Assessments. The Catalytic Multi-Stage Liquefaction is a continuation of the second generation yields using a low/high temperature approach. This paper covers work performed between October 1994- August 1995, especially results obtained from the microautoclave support activities and the bench-scale operations for runs CMSL-08 and CMSL-09, during which, coal and the plastic components for municipal solid wastes (MSW) such as high density polyethylene (HDPE)m, polypropylene (PP), polystyrene (PS), and polythylene terphthlate (PET) were coprocessed.

  12. Catalytic multi-stage liquefaction of coal. Ninth quarterly report, October 1, 1994--December 31, 1994

    SciTech Connect

    Comolli, A.G.; Johnson, E.S.; Lee, L.K.

    1995-06-01

    This quarterly report covers the activities of Catalytic Multi-Stage Liquefaction of Coal during the Period October 1 - December 31, 1994, at Hydrocarbon Research, Inc. in Lawrenceville and Princeton, New Jersey. This DOE Contract Period was from December 8, 1992 to December 7, 1994 and has been extended to September 30, 1995. The overall objective of this program is to produce liquid fuels from coal by direct liquefaction at a cost that is competitive with conventional fuels. Specifically, this continuous bench-scale program contains provisions to examine new ideas in areas such as: low temperature pretreatments, more effective catalysts, on-line hydrotreating, new coal feedstocks, other hydrogen sources, more concentrated coal feeds and other highly responsive process improvements while assessing the design and economics of the bench-scale results. This quarterly report covers work on Laboratory Scale Studies, Continuous Bench-Scale Operations, Technical Assessment and Project Management.

  13. Combustion behavior of single coal-water slurry droplets, Part 1: Experimental techniques

    SciTech Connect

    Levendis, Y.A.; Metghalchi, M.; Wise, D.

    1991-12-31

    Techniques to produce single droplets of coal-water slurries have been developed in order to study the combustion behavior of the slurries. All stages of slurry combustion are of interest to the present study, however, emphasis will be given to the combustion of the solid agglomerate char which remains upon the termination of the water evaporation and the devolatilization periods. An experimental facility is under construction where combustion of coal-water slurries will be monitored in a variety of furnace temperatures and oxidizing atmospheres. The effect of the initial size of the slurry droplet and the solids loading (coal to water ratio) will be investigated. A drop tube, laminar flow furnace coupled to a near-infrared, ratio pyrometer win be used to monitor temperature-time histories of single particles from ignition to extinction. This paper describes the experimental built-up to this date and presents results obtained by numerical analysis that help understanding the convective and radiating environment in the furnace.

  14. Secondary atomization of single coal-water fuel droplets

    SciTech Connect

    Hassel, G.R.; Scaroni, A.W.

    1989-03-01

    The evaporative behavior of single, well characterized droplets of a lignite coal-water slurry fuel (CWSF) and a carbon black in water slurry was studied as a function of heating rate and droplet composition. Induced droplet heating rates were varied from 0 to 10{sup 5} K/s. Droplets studied were between 97 and 170 {mu}m in diameter, with compositions ranging from 25 to 60% solids by weight. The effect of a commercially available surfactant additive package on droplet evaporation rate, explosive boiling energy requirements, and agglomerate formation was assessed. Surfactant concentrations were varied from none to 2 and 4% by weight solution (1.7 and 3.6% by weight of active species on a dry coal basis). The experimental system incorporated an electrodynamic balance to hold single, free droplets, a counterpropagating pulsed laser heating arrangement, and both video and high speed cinematographic recording systems. Data were obtained for ambient droplet evaporation by monitoring the temporal size, weight, and solids concentration changes. 49 refs., 31 figs.

  15. Design considerations for single-stage and two-stage pneumatic pellet injectors

    SciTech Connect

    Gouge, M.J.; Combs, S.K.; Fisher, P.W.; Milora, S.L.

    1988-09-01

    Performance of single-stage pneumatic pellet injectors is compared with several models for one-dimensional, compressible fluid flow. Agreement is quite good for models that reflect actual breech chamber geometry and incorporate nonideal effects such as gas friction. Several methods of improving the performance of single-stage pneumatic pellet injectors in the near term are outlined. The design and performance of two-stage pneumatic pellet injectors are discussed, and initial data from the two-stage pneumatic pellet injector test facility at Oak Ridge National Laboratory are presented. Finally, a concept for a repeating two-stage pneumatic pellet injector is described. 27 refs., 8 figs., 3 tabs.

  16. Mathematical modeling of the heat treatment and combustion of a coal particle. III. Volatile escape stage

    NASA Astrophysics Data System (ADS)

    Enkhjargal, Kh.; Salomatov, V. V.

    2011-05-01

    The present paper is a continuation of previous publications of the authors in this journal in which two phases of the multistage process of combustion of a coal particle were considered in detail with the help of mathematical modeling: its radiation-convection heating and drying. In the present work, the escape dynamics of volatiles is investigated. The physico-mathematical model of the thermodestruction of an individual coal particle with a dominant influence of endothermal effects has been formulated. Approximate-analytical solutions of this model that are of paramount importance for detailed analysis of the influence of the physical and regime parameters on the escape dynamics of volatiles have been found. The results obtained form the basis for engineering calculations of the volatile escape stage and can be used successfully in the search for effective regimes of burning of various solid fuels, in particular, Shivé-Ovoos coal of Mongolia.

  17. Simulating the multistage environment for single-stage compressor experiments

    SciTech Connect

    Place, J.M.M.; Howard, M.A.; Cumpsty, N.A.

    1996-10-01

    The performance of a single-stage low-speed compressor has been measured both before and after the introduction of certain features of the multistage flow environment. The aim is to make the single-stage rig more appropriate for developing design rules for multistage compressors. End-wall blockage was generated by teeth on the hub and casing upstream of the rotor. A grid fitted upstream produced free-stream turbulence at rotor inlet typical of multistage machines and raised stage efficiency by 1.8 percent at the design point. The potential field that would be generated by blade rows downstream of an embedded stage was replicated by introducing a pressure loss screen at stage exit. This reduced the stator hub corner separation and increased the rotor pressure rise at flow rates below design, changing the shape of the pressure-rise characteristic markedly. These results highlight the importance of features of the flow environment that are often omitted from single-stage experiments and offer improved understanding of stage aerodynamics.

  18. Numerical simulation of ash vaporization during pulverized coal combustion in the laboratory-scale single-burner furnace

    SciTech Connect

    Jiancai Sui; Minghou Xu; Jihua Qiu; Yu Qiao; Yun Yu; Xiaowei Liu; Xiangpeng Gao

    2005-08-01

    CFD tools have been developed to effectively simulate complex, reacting, multiphase flows that exist in utility boilers. In this paper, a model of ash vaporization was established and integrated into a self-developed CFD code to predict ash vaporization in the coal combustion process. Experimental data from a single-particle combustion was used to validate the above model. The calibrated model was then applied to simulate the ash vaporization in a 92.9 kW laboratory-scale single-burner furnace. The effects of different combustion conditions, including air staging, on the ash vaporization were investigated. The results showed that the fraction of ash vaporization is mostly sensitive to coal particle temperature. Ash vaporization primarily occurred after a short interval along the coal particle trajectories when the particle temperatures increased to 1800 K. Air staging influenced the ash vaporization by changing the gas temperature distribution in the furnace. The simulation results showed that the more extreme the staging condition, the lower the overall peak temperature, and hence the lower the amount of ash vaporization. 26 refs., 9 figs.

  19. Giant neglected ameloblastoma: single stage treatment and clinicopathological review.

    PubMed

    Kalavrezos, Nicholas; Baldwin, David James; Walker, D Murray

    2008-10-01

    Giant ameloblastomas may present with massive swelling of the jaws. We report a giant ameloblastoma of the mandible in a Nigerian patient that measured 15.1x12.2x13.6cm and was managed with a single procedure. The tumour was removed by segmental mandibulectomy and reconstructed with a fibular free flap. The excess soft tissue was treated with a bilateral commissuroplasty. Single stage treatment that establishes early functional and aesthetic recovery offers advantages over multi staged procedures, and is therefore the treatment of choice for giant ameloblastomas.

  20. Methane production from coal by a single methanogen

    NASA Astrophysics Data System (ADS)

    Mayumi, Daisuke; Mochimaru, Hanako; Tamaki, Hideyuki; Yamamoto, Kyosuke; Yoshioka, Hideyoshi; Suzuki, Yuichiro; Kamagata, Yoichi; Sakata, Susumu

    2016-10-01

    Coal-bed methane is one of the largest unconventional natural gas resources. Although microbial activity may greatly contribute to coal-bed methane formation, it is unclear whether the complex aromatic organic compounds present in coal can be used for methanogenesis. We show that deep subsurface-derived Methermicoccus methanogens can produce methane from more than 30 types of methoxylated aromatic compounds (MACs) as well as from coals containing MACs. In contrast to known methanogenesis pathways involving one- and two-carbon compounds, this “methoxydotrophic” mode of methanogenesis couples O-demethylation, CO2 reduction, and possibly acetyl-coenzyme A metabolism. Because MACs derived from lignin may occur widely in subsurface sediments, methoxydotrophic methanogenesis would play an important role in the formation of natural gas not limited to coal-bed methane and in the global carbon cycle.

  1. Methane production from coal by a single methanogen.

    PubMed

    Mayumi, Daisuke; Mochimaru, Hanako; Tamaki, Hideyuki; Yamamoto, Kyosuke; Yoshioka, Hideyoshi; Suzuki, Yuichiro; Kamagata, Yoichi; Sakata, Susumu

    2016-10-14

    Coal-bed methane is one of the largest unconventional natural gas resources. Although microbial activity may greatly contribute to coal-bed methane formation, it is unclear whether the complex aromatic organic compounds present in coal can be used for methanogenesis. We show that deep subsurface-derived Methermicoccus methanogens can produce methane from more than 30 types of methoxylated aromatic compounds (MACs) as well as from coals containing MACs. In contrast to known methanogenesis pathways involving one- and two-carbon compounds, this "methoxydotrophic" mode of methanogenesis couples O-demethylation, CO2 reduction, and possibly acetyl-coenzyme A metabolism. Because MACs derived from lignin may occur widely in subsurface sediments, methoxydotrophic methanogenesis would play an important role in the formation of natural gas not limited to coal-bed methane and in the global carbon cycle.

  2. Two-stage/single-stage reversible pump-turbine with supplying pump

    SciTech Connect

    Brcar, A.

    1980-08-12

    In a hydroelectric facility, a vertically mounted rotatable shaft is connected to a motor-generator and carries a pumpturbine with a supplying pump disposed below and immersed in water, the supplying pump disengaging from the shaft when the pump-turbine is driving the motor-generator and engaging the shaft when the motor-generator is driving the pump-turbine and supplying pump, thereby providing a two-stage pumping mode and a single-stage generating mode.

  3. Management of a Single Species Fishery with Stage Structure

    ERIC Educational Resources Information Center

    Kar, T. K.; Pahari, U. K.; Chaudhuri, K. S.

    2004-01-01

    A dynamic model for a single species fishery with stage structure is proposed using taxation as a control instrument to protect the fish population from overexploitation. Criteria for local stability and global stability of the system are derived. The optimal tax policy is established by using Pontryagin's maximal principle. By numerical…

  4. Ectopia cordis, a successful single stage thoracoabdominal repair.

    PubMed

    Samir, Khaled; Ghez, Olivier; Metras, Dominique; Kreitmann, Bernard

    2003-12-01

    This is a report of a case of the rare ectopia cordis malformation of the thoracoabdominal type without intracardiac anomalies. The patient had a successful single stage repair with reduction of the herniating heart and reconstruction of a cartilaginous cover to protect the heart. The result was very good and the follow up for 13 months was very satisfactory.

  5. The single electron chemistry of coals, July 1, 1991--September 30, 1991

    SciTech Connect

    Larsen, J.W.; Eskay, T.P.

    1991-12-31

    The objectives of this work are to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. (1) Attempts will be made to demonstrate that the radicals from inertinite maceral group will initiate the polymerization of 4-vinylpyridine. (2) The molecule, N, N-diphenyl-phenylendiamine, will be deposited in coals to characterize their native free radicals. (3) Tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) will be used to characterize the numbers and strengths of single electron donors in coals.

  6. The single electron chemistry of coals. [Quarterly] report, January 1--March 31, 1992

    SciTech Connect

    Larsen, J.W.; Eskay, T.P.

    1992-07-01

    The objectives of this project is to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. Scope of Work: (1) attempts will be made to demonstrate that the radicals from inertinite maceral group will initiate the polymerization of 4-vinylpyridine; (2) the molecule, N,N-diphenyl-phenylenediamine, will be deposited in coals to characterize their native free radicals; and (3) tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) will be used to characterize the numbers and strengths of single electron donors in coals.

  7. The single electron chemistry of coals, July 1, 1991--September 30, 1991

    SciTech Connect

    Larsen, J.W.; Eskay, T.P.

    1991-01-01

    The objectives of this work are to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. (1) Attempts will be made to demonstrate that the radicals from inertinite maceral group will initiate the polymerization of 4-vinylpyridine. (2) The molecule, N, N-diphenyl-phenylendiamine, will be deposited in coals to characterize their native free radicals. (3) Tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) will be used to characterize the numbers and strengths of single electron donors in coals.

  8. Study of the comminution characteristics of coal by single particle breakage test device

    SciTech Connect

    Sahoo, R.

    2005-09-01

    Single-particle breakage tests of South Blackwater and Ensham coal from the Bowen Basin area in Queensland were conducted by a computer-monitored twin-pendulum device to measure the energy utilization pattern of the breakage particles. Three particle sizes (-16.0+13.2mm, -13.2+11.2mm, -11.2+9.5mm) of each coal were tested by a pendulum device at five input energy levels to measure the specific comminution energy. When particles were tested at constant input energy, the variation of comminution energy between the same size broken particles of Ensham coal was minimal, because Ensham coal is a softer and higher friability coal, which absorbs more input energy than harder coal during breakage tests. For different particle sizes, the specific comminution energy increases linearly with the input energy and the fineness of the breakage products increases with the specific comminution energy. The size distribution graphs are curved but approach linearity in the finer region. At a constant input energy, the twin pendulum breakage product results show that the fineness of the products increases with decrease in particle size and South Blackwater coal produced finer products than the Ensham coal. The t-curves are the family of size distribution curves, which can describe the product size distribution of the breakage particles during single-particle breakage tests.

  9. The single electron chemistry of coals. [Quarterly] report, July 1, 1990--December 30, 1990

    SciTech Connect

    Larsen, J.W.; Kaushal, P.

    1991-01-18

    Our work on single election transfer in coals led us to the knowledge that the energetics of bond cleavage in radical cations is 20-40 kcal/mole lower than the corresponding homolytic bond cleavage energies. Having made excellent progress in the other areas covered by this proposal, we are extending our studies to the investigation of the formation and cleavage reaction of radical cations in coals. The formation of a radical cation requires the transfer of an electron from a neutral molecule to an appropriate electron acceptor (oxidant). As a first step, we seek oxidants which will form radical cations from functional groups typical of those in coals. We must also study the decomposition behavior of bonds typical of those found in coals. Alkyl and alkoxy aromatic compounds were chosen as the electron donors because of their common occurrence in coals.

  10. High density propellant for single stage to orbit vehicles

    NASA Technical Reports Server (NTRS)

    Notardonato, J. J.; Masters, P. A.

    1976-01-01

    Mixed mode propulsion concepts are studied for advanced, single stage earth orbital transportation systems (SSTO) for use in the post-1990 time period. These propulsion concepts are based on the sequential and/or parallel use of high density impulse and high specific impulse propellants in a single stage to increase vehicle performance and reduce dry weight. Specifically, the mixed mode concept utilizes two propulsion systems with two different fuels (mode 1 and mode 2) with liquid oxygen as a common oxidizer. Mode 1 engines would burn a high bulk density fuel for lift-off and early ascent to minimize performance penalties associated with carrying fuel tankage to orbit. Mode 2 engines will complete orbital injection utilizing liquid hydrogen as the fuel.

  11. Single stage earth orbital reusable vehicle. Volume 6: Resources

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The results of a conceptual study of the resource requirements for a single-stage earth-orbital vehicle are presented. All aspects of program costs for the design, manufacture, test, transportation, launch, and facility modifications were considered. The following program costs are discussed: configuration definition, cost groundrules and assumptions, program requirements, work breakdown structure, cost estimation methods, and cost analysis. High cost areas are identified.

  12. Single stage anaerobic digester at Tarleton State University. Final report

    SciTech Connect

    Not Available

    1980-01-01

    The design and operation of the demonstration plant facilities at Tarleton State University to produce methane in a single stage anaerobic digester are described. A combination of manures from hogs and poultry are used as feedstock. Uses for the methane, cost of the digester, and value of the energy produced are discussed. During the 21 months of operation, 310 people have visited the project. (DMC)

  13. Single-stage electronic ballast with high-power factor

    NASA Astrophysics Data System (ADS)

    Park, Chun-Yoon; Kwon, Jung-Min; Kwon, Bong-Hwan

    2014-03-01

    This article proposes a single-stage electronic ballast circuit with high-power factor. The proposed circuit was derived by sharing the switches of the power factor correction (PFC) and the half-bridge LCC resonant inverter. This integration of switches forms the proposed single-stage electronic ballast, which provides an almost unity power factor and a ripple-free input current by using a coupled inductor without increasing the voltage stress. In addition, it realises zero-voltage-switching (ZVS) by employing the self-oscillation technique. The saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. Therefore, the proposed single-stage ballast has the advantage of high-power factor, high efficiency, low cost and high reliability. Steady-state analysis of the PFC and the half-bridge LCC resonant inverter are described. The results of experiments performed using a 30 W fluorescent lamp are also presented to confirm the performance of the proposed ballast.

  14. Environmental performance of air staged combustor with flue gas recirculation to burn coal/biomass

    SciTech Connect

    Anuar, S.H.; Keener, H.M.

    1995-12-31

    The environmental and thermal performance of a 1.07 m diameter, 440 kW atmospheric fluidized bed combustor operated at 700{degrees}C-920{degrees}C and burning coal was studied. Flue gas recirculation was incorporated to enhance the thermal performance and air staging was used to control emissions of SO{sub 2}, CO, NO{sub x} and N{sub 2}O. Studies focused on the effect of excess air, firing rate, and use of sorbent on system performance. The recirculation-staging mode with limestone had the highest thermal efficiency (0.67) using the firing equation. Emission data showed that flue gas recirculation (ratio of 0.7) significantly reduced NO{sub x} emissions; and that use of limestone sorbent at a Ca/S ratio of 3 reduced SO{sub 2} emissions by 64% to approximately 0.310 g/MJ.

  15. Coal.

    ERIC Educational Resources Information Center

    Brant, Russell A.; Glass, Gary B.

    1983-01-01

    Principle work of 23 state geological surveys is summarized. Work includes mapping/estimating coal resources, centralizing data in National Coal Resources Data System through cooperative programs, exploration drilling, and others. Comments on U.S. Geological Survey activities, coal-related conferences/meetings, and industry research activities are…

  16. Developments in laser wakefield accelerators: From single-stage to two-stage

    NASA Astrophysics Data System (ADS)

    Li, Wen-Tao; Wang, Wen-Tao; Liu, Jian-Sheng; Wang, Cheng; Zhang, Zhi-Jun; Qi, Rong; Yu, Chang-Hai; Li, Ru-Xin; Xu, Zhi-Zhan

    2015-01-01

    Laser wakefield accelerators (LWFAs) are compact accelerators which can produce femtosecond high-energy electron beams on a much smaller scale than the conventional radiofrequency accelerators. It is attributed to their high acceleration gradient which is about 3 orders of magnitude larger than the traditional ones. The past decade has witnessed the major breakthroughs and progress in developing the laser wakfield accelerators. To achieve the LWFAs suitable for applications, more and more attention has been paid to optimize the LWFAs for high-quality electron beams. A single-staged LWFA does not favor generating controllable electron beams beyond 1 GeV since electron injection and acceleration are coupled and cannot be independently controlled. Staged LWFAs provide a promising route to overcome this disadvantage by decoupling injection from acceleration and thus the electron-beam quality as well as the stability can be greatly improved. This paper provides an overview of the physical conceptions of the LWFA, as well as the major breakthroughs and progress in developing LWFAs from single-stage to two-stage LWFAs. Project supported by the National Natural Science Foundation of China (Grant Nos. 11127901, 11425418, and 61221064), the National Basic Research Program of China (Grant No. 2011CB808100), and the Science and Technology Talent Project of Shanghai City, China (Grant Nos. 12XD1405200 and 12ZR1451700).

  17. Optimization Strategies for Single-Stage, Multi-Stage and Continuous ADRs

    NASA Technical Reports Server (NTRS)

    Shirron, Peter J.

    2014-01-01

    Adiabatic Demagnetization Refrigerators (ADR) have many advantages that are prompting a resurgence in their use in spaceflight and laboratory applications. They are solid-state coolers capable of very high efficiency and very wide operating range. However, their low energy storage density translates to larger mass for a given cooling capacity than is possible with other refrigeration techniques. The interplay between refrigerant mass and other parameters such as magnetic field and heat transfer points in multi-stage ADRs gives rise to a wide parameter space for optimization. This paper first presents optimization strategies for single ADR stages, focusing primarily on obtaining the largest cooling capacity per stage mass, then discusses the optimization of multi-stage and continuous ADRs in the context of the coordinated heat transfer that must occur between stages. The goal for the latter is usually to obtain the largest cooling power per mass or volume, but there can also be many secondary objectives, such as limiting instantaneous heat rejection rates and producing intermediate temperatures for cooling of other instrument components.

  18. Optimization strategies for single-stage, multi-stage and continuous ADRs

    NASA Astrophysics Data System (ADS)

    Shirron, Peter

    2014-07-01

    Adiabatic Demagnetization Refrigerators (ADR) have many advantages that are prompting a resurgence in their use in spaceflight and laboratory applications. They are solid-state coolers capable of very high efficiency and very wide operating range. However, their low energy storage density translates to larger mass for a given cooling capacity than is possible with other refrigeration techniques. The interplay between refrigerant mass and other parameters such as magnetic field and heat transfer points in multi-stage ADRs gives rise to a wide parameter space for optimization. This paper first presents optimization strategies for single ADR stages, focusing primarily on obtaining the largest cooling capacity per stage mass, then discusses the optimization of multi-stage and continuous ADRs in the context of the coordinated heat transfer that must occur between stages. The goal for the latter is usually to obtain the largest cooling power per mass or volume, but there can also be many secondary objectives, such as limiting instantaneous heat rejection rates and producing intermediate temperatures for cooling of other instrument components.

  19. Combustion Stages of a Single Heavy Oil Droplet in Microgravity

    NASA Technical Reports Server (NTRS)

    Ikegami, M.; Xu, G.; Ikeda, K.; Honma, S.; Nagaishi, H.; Dietrich, D. L.; Struk, P. M.; Takeshita, Y.

    2001-01-01

    Heavy oil is a common fuel for industrial furnaces, boilers, marines and diesel engines. Previous studies showed that the combustion of heavy oil involves not only the complete burning of volatile matters but also the burn-out of coke residues. Detailed knowledge about heavy oil combustion therefore requires an understanding of the different burning stages of heavy oil droplets in the burner. This in turn, demands knowledge about the single droplet evaporation and combustion characteristics. This study measured the temperature and size histories of heavy oil (C glass) droplets burning in microgravity to elucidate the various stages that occur during combustion. The elimination of the gravity-induced gas convection in microgravity allows the droplet combustion to be studied in greater detail. Noting that the compositions of heavy oil are various, we also tested the fuel blends of a diesel light oil (LO) and a heavy oil residue (HOR).

  20. Downstream processing of antibodies: single-stage versus multi-stage aqueous two-phase extraction.

    PubMed

    Rosa, P A J; Azevedo, A M; Ferreira, I F; Sommerfeld, S; Bäcker, W; Aires-Barros, M R

    2009-12-11

    Single-stage and multi-stage strategies have been evaluated and compared for the purification of human antibodies using liquid-liquid extraction in aqueous two-phase systems (ATPSs) composed of polyethylene glycol 3350 (PEG 3350), dextran, and triethylene glycol diglutaric acid (TEG-COOH). The performance of single-stage extraction systems was firstly investigated by studying the effect of pH, TEG-COOH concentration and volume ratio on the partitioning of the different components of a Chinese hamster ovary (CHO) cells supernatant. It was observed that lower pH values and high TEG-COOH concentrations favoured the selective extraction of human immunoglobulin G (IgG) to the PEG-rich phase. Higher recovery yields, purities and percentage of contaminants removal were always achieved in the presence of the ligand, TEG-COOH. The extraction of IgG could be enhanced using higher volume ratios, however with a significant decrease in both purity and percentage of contaminants removal. The best single-stage extraction conditions were achieved for an ATPS containing 1.3% (w/w) TEG-COOH with a volume ratio of 2.2, which allowed the recovery of 96% of IgG in the PEG-rich phase with a final IgG concentration of 0.21mg/mL, a protein purity of 87% and a total purity of 43%. In order to enhance simultaneously both recovery yield and purity, a four stage cross-current operation was simulated and the corresponding liquid-liquid equilibrium (LLE) data determined. A predicted optimised scheme of a counter-current multi-stage aqueous two-phase extraction was hence described. IgG can be purified in the PEG-rich top phase with a final recovery yield of 95%, a final concentration of 1.04mg/mL and a protein purity of 93%, if a PEG/dextran ATPS containing 1.3% (w/w) TEG-COOH, 5 stages and volume ratio of 0.4 are used. Moreover, according to the LLE data of all CHO cells supernatant components, it was possible to observe that most of the cells supernatant contaminants can be removed during this

  1. The X-33 Program, Proving Single Stage to Orbit

    NASA Technical Reports Server (NTRS)

    Austin, Robert E.; Rising, Jerry J.

    1998-01-01

    The X-33, NASA's flagship for reusable space plane technology demonstration, is on course to permit a crucial decision for the nation by the end of this decade. Lockheed Martin Skunk Works, NASA's partner in this effort, has led a dedicated and talented industry and government team that have met and solved numerous challenges within the first 26 months. This program began by accepting the mandate that included two unprecedented and highly challenging goals: 1) demonstrate single stage to orbit technologies in flight and ground demonstration in less than 42 months and 2) demonstrate a new government and industry management relationship working together with industry in the lead.

  2. Characterization of Subsystems for a WB-003 Single Stage Shuttle

    NASA Technical Reports Server (NTRS)

    MacConochie, Ian O.; Lepsch, Roger A., Jr. (Technical Monitor)

    2002-01-01

    Subsystems for an all oxygen-hydrogen-single-stage shuttle are characterized for a vehicle designated WB-003. Features of the vehicle include all-electric actuation, fiber optics for information circuitry, fuel cells for power generation, and extensive use of composites for structure. The vehicle is sized for the delivery of a 25,000 lb. payload to a space station orbit without crew. When crew are being delivered, they are carried in a module in the payload bay with escape and manual override capabilities. The underlying reason for undertaking this task is to provide a framework for the study of the operations costs of the newer shuttles.

  3. Catalytic Two-Stage Liquefaction (CTSL) process bench studies with bituminous coal. Final report, [October 1, 1988--December 31, 1992

    SciTech Connect

    Comolli, A.G.; Johanson, E.S.; Karolkiewicz, W.F.; Lee, L.K.; Stalzer, R.H.; Smith, T.O.

    1993-03-01

    Reported herein are the details and results of Laboratory and Bench-Scale experiments using bituminous coal concluded at Hydrocarbon Research, Inc., under DOE contract during the period October 1, 1988 to December 31, 1992. The work described is primarily concerned with the application of coal cleaning methods and solids separation methods to the Catalytic Two-Stage Liquefaction (CTSL) Process. Additionally a predispersed catalyst was evaluated in a thermal/catalytic configuration, and an alternative nickel molybdenum catalyst was evaluated for the CTSL process. Three coals were evaluated in this program: Bituminous Illinois No. 6 Burning Star and Sub-bituminous Wyoming Black Thunder and New Mexico McKinley Mine seams. The results from a total of 16 bench-scale runs are reported and analyzed in detail. The tests involving the Illinois coal are reported herein, and the tests involving the Wyoming and New Mexico coals are described in Topical Report No. 1. On the laboratory scale, microautoclave tests evaluating coal, start-up oils, catalysts, thermal treatment, CO{sub 2} addition and sulfur compound effects are reported in Topical Report No. 3. Other microautoclave tests, such as tests on rejuvenated catalyst, coker liquids, and cleaned coals, are described in the Bench Run sections to which they refer. The microautoclave tests conducted for modelling the CTSL process are described in the CTSL Modelling section of Topical Report No. 3 under this contract.

  4. The single electron chemistry of coals. [Quarterly] report, October 1--December 31, 1991

    SciTech Connect

    Larsen, J.W.; Eskay, T.P.

    1992-01-31

    Depolymerization of coals at low temperatures may offer advantages over thermal bond cleavage. Because bond cleavage energies of radical cations are lower than the corresponding homolytic bond cleavage energies of the same bond, generation of radical cations in coal may make possible depolymerization at lower temperatures. We seek to investigate the above possibility using single molecules containing functional groups common in coals. Since the generation of a radical cation requires the removal of an electron from a neutral molecule, a primary focus of the study will be finding oxidants that will remove an electron from compounds with structural similarity to those typically found in coals. The study must also be concerned with the decomposition of radical cations and the products formed as a result of the decomposition.

  5. Single-Stage Reconstruction of Both Cruciate Ligaments

    PubMed Central

    Andreoli, Mauro; Zicaro, Juan Pablo; Yacuzzi, Carlos; Costa-Paz, Matias

    2017-01-01

    Objectives: Isolated Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL), or central pivot lesions are rare. These are frequently associated with collateral ligaments injuries. The purpose of this retrospective study was to evaluate clinical and functional outcomes of 4 patients with acute ACL and PCL injury who underwent a simultaneous single-stage arthroscopic reconstruction. Methods: The inclusion criteria were patients with isolated ACL and PCL injuries, with a minimum follow-up of 2 years. We evaluated the type of graft used, the surgical technique and postoperative complications. The scales used for clinical evaluation were the Knee Society Score (KSS), IKDC, Lysholm and Tegner. Knee stability was assessed using the KT-1000 arthrometer. Results: Three men and one woman, with an average age of 48 years (45 to 56 years) were evaluated. Three presented a sport injury and one a car accident. Mean follow-up was 8 years. In all patients allograft was used for ligament reconstruction. Average postoperative results were: KSS 74-82, Lysholm 76, IKDC 63 and Tegner 6. KT-1000 arthrometer showed an average difference of 4mm compared to the contralateral knee. One patient underwent reintervention due to meniscal injury. Conclusion: ACL and PCL simultaneous single-stage reconstruction is a really demanding surgery. We achieved good results using allograft for both ligaments reconstruction. No clinical or functional postoperative complications were recorded.

  6. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, Darren J.; Bonk, Donald L.; Dowdy, Thomas E.

    1998-01-01

    Polluting NO.sub.x gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO.sub.x gases are removed is directed to introducing NO.sub.x -free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

  7. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, D.J.; Bonk, D.L.; Dowdy, T.E.

    1998-01-13

    Polluting NO{sub x} gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO{sub x} gases are removed is directed to introducing NO{sub x}-free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor. 2 figs.

  8. Single Stage Surgical Outcomes for Large Angle Intermittent Exotropia

    PubMed Central

    Yang, Min; Chen, Jingchang; Shen, Tao; Kang, Ying; Deng, Daming; Lin, Xiaoming; Wu, Heping; Chen, Qiwen; Ye, Xuelian; Li, Jianqun; Yan, Jianhua

    2016-01-01

    Although there were many prior studies about exotropia, few focused on large-angle intermittent exotropia. The goal of this study was to evaluate single-stage surgical outcomes for large-angle intermittent exotropia and analyze risk factors that may affect the success of surgery. Records from intermittent exotropia patients with exodeviations >60 prism diopters(PD) who were surgically treated at the Zhongshan Ophthalmic Center, of Sun Yat-Sen University were reviewed. Included within this review were data on, pre- and post-operative ocular motility, primary alignment, binocular vision and complications. Patients with exodeviations ≤70PD received two-muscle surgery, while those with exodeviations >70PD were subjected to a three-muscle procedure. A total of 40 records were reviewed. The mean exodeviation was 73±9PD at distance and 75±26PD at near. There were 25 patients received two-muscle surgery and 15 the three-muscle procedure. Orthophoria (deviation within 8PD) was obtained in 77.5% of these patients and the ratios of surgical under-correction and over-correction were 15% and 7.5% respectively. However, when combining ocular alignment with binocular vision as the success criteria, success rates decreased to 30%. No statistically significant differences in success rates were obtained between the two- and three-muscle surgery groups. Seven subjects experienced an abduction deficit during the initial postoperative stages, but eventually showed a full recovery. One patient required a second surgery for overcorrection. No statistically significant risk factors for poor outcome were revealed. Our data showed that single-stage two- and three-muscle surgeries for large-angle intermittent exotropia are effective in achieving a favorable outcome. PMID:26919493

  9. Hirschsprung's disease management: from multi staged operation to single staged transanal pull-through.

    PubMed

    Wang, J X; Dahal, G R

    2009-06-01

    Hirschsprung's disease (HD) is a common congenital disease of colorectum. Although it was described more than one century ago, the effective treatment was established only half a century later. The initially treatment consisted of preoperative diverting colostomy, followed by definite pull-through and closure of colostomy on later date. A variety of procedures like Swenson, Duhamel, Rehbein and Soave were evolved with time. With the better understanding of pathogenesis and improvement on surgical technique, now the operation has become less extensive. In recent days, the classical 3 staged procedure is replaced by single staged procedure. All the procedure can be completed transanally. Since De la Torre in 1998, first reported total transanal endorectal pull-through, it became the most popular technique for the treatment of HD.

  10. Single Stage Contactor Testing Of The Next Generation Solvent Blend

    SciTech Connect

    Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

    2014-01-06

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

  11. Coal liquefaction and hydrogenation

    DOEpatents

    Schindler, Harvey D.; Chen, James M.

    1985-01-01

    Disclosed is a coal liquefaction process using two stages. The first stage liquefies the coal and maximizes the product while the second stage hydrocracks the remainder of the coal liquid to produce solvent.

  12. Technology Requirements for Affordable Single-Stage Rocket Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Douglas O.; Piland, William M.

    2004-01-01

    A number of manned Earth-to-orbit (ETO) vehicle options for replacing or complementing the current Space Transportation System are being examined under the Advanced Manned Launch System (AMLS) study. The introduction of a reusable single-stage vehicle (SSV) into the U.S. launch vehicle fleet early in the next century could greatly reduce ETO launch costs. As a part of the AMLS study, the conceptual design of an SSV using a wide variety of enhancing technologies has recently been completed and is described in this paper. This paper also identifies the major enabling and enhancing technologies for a reusable rocket-powered SSV and provides examples of the mission payoff potential of a variety of important technologies. This paper also discusses the impact of technology advancements on vehicle margins, complexity, and risk, all of which influence the total system cost.

  13. Design and development of single-stage-to-orbit vehicles

    NASA Astrophysics Data System (ADS)

    Billig, Frederick S.

    1990-12-01

    A procedure to guide the conceptual design of a single-stage-to-orbit vehicle is presented. Modeling based on historical databases is used to help define plausible flight trajectories and vehicle aerodynamics and to evaluate candidate propulsion cycles. Two conceptual configurations are introduced to examine the sensitivity of vehicle drag, engine cycle selection, and design characteristics on the amount of propelant required to accelerate to orbit. Results show that the choice of the optimum low-speed engine cycle, combined with the ram-scramjet (supersonic combustion ramjet) at high speed, is very sensitive to the engine air capture and vehicle drag coefficient at transonic speeds. For nominal drag and air capture characteristics, the high thrust and relatively low-efficiency ducted rocket/ram-scramjet cycle uses about the same weight of propellant as the highly efficient but lower-thrust turbojet ram-scramjet.

  14. Airbreathing/Rocket Single-Stage-to-Orbit Design Matrix

    NASA Technical Reports Server (NTRS)

    Hunt, James L.

    1995-01-01

    A definitive design/performance study was performed on a single-stage-to-orbit (SSTO) airbreathing propelled orbital vehicle with rocket propulsion augmentation in the Access to Space activities during 1993. A credible reference design was established, but by no means an optimum. The results supported the viability of SSTO airbreathing/rocket vehicles for operational scenarios and indicated compelling reasons to continue to explore the design matrix. This paper will (1) summarize the Access to Space design activity from the SSTO airbreathing/rocket perspective, (2) present an airbreathing/rocket SSTO design matrix established for continued optimization of the design space, and (3) focus on the compelling reasons for airbreathing vehicles in Access to Space scenarios.

  15. Experimental characterization of an industrial pulverized coal-fired furnace under deep staging conditions

    SciTech Connect

    Costa, M.; Azevedo, J.L.T.

    2007-07-01

    Measurements have been performed in a 300 MWe, front-wall-fired, pulverized-coal, utility boiler. This boiler was retrofitted with boosted over fire air injectors that allowed the operation of the furnace under deeper staging conditions. New data are reported for local mean gas species concentration of O{sub 2}, CO, CO{sub 2}, NOx, gas temperatures and char burnout measured at several ports in the boiler including those in the main combustion and staged air regions. Comparisons of the present data with our previous measurements in this boiler, prior to the retrofitting with the new over fire system, show lower O{sub 2} and higher CO concentrations for the new situation as a consequence of the lower stoichiometry in the main combustion zone associated with the present boiler operating condition. Consistently, the measured mean NOx concentrations in the main combustion zone are now lower than those obtained previously, yielding emissions below 500 mg/Nm{sup 3}at 6% O{sub 2}. Finally, the measured values of particle burnout at the furnace exit are acceptable being those measured in the main combustion zone comparable with those obtained with the conventional over fire system.

  16. 85,000-GPM, single-stage, single-suction LMFBR intermediate centrifugal pump

    SciTech Connect

    Fair, C.E.; Cook, M.E. Huber, K.A.; Rohde, R.

    1983-01-01

    The mechanical and hydraulic design features of the 85,000-gpm, single-stage, single-suction pump test article, which is designed to circulate liquid-sodium coolant in the intermediate heat-transport system of a Large-Scale Liquid Metal Fast Breeder Reactor (LS-LMFBR), are described. The design and analytical considerations used to satisfy the pump performance and operability requirements are presented. The validation of pump hydraulic performance using a hydraulic scale-model pump is discussed, as is the featute test for the mechanical-shaft seal system.

  17. Single Particle Source Profiles of Gasoline and Diesel Powered Vehicles, Biomass Burning and Coal Combustion Exhaust Emissions

    NASA Astrophysics Data System (ADS)

    Suess, D. T.; Prather, K. A.; Schauer, J.; Cass, G. R.

    2001-12-01

    Vehicular exhaust, biomass burning, and coal combustion are three significant aerosol sources that have local to global impacts on the earth's atmosphere. They may also contribute to health effects as they can emit carcinogenic species such as polycyclic aromatic hydrocarbons (PAH) and trace metals including beryllium and vanadium. In these source characterization studies, combustion products were diluted to near ambient temperature and pressure using a two stage dilution source sampler. Diluted exhaust emissions were analyzed with an aerosol time-of-flight mass spectrometer (ATOFMS) obtaining real-time measurements of single particle size and chemical composition. In addition, samples were collected using a micro-orifice uniform deposit impactor (MOUDI), which was operated in a manner compatible with advanced chemical analysis techniques, for size segregated mass concentrations. Due to the importance of these particle sources to the atmosphere, differentiating these emissions from each other and other particle sources is essential. Since ATOFMS is a relatively new single particle analysis technique, source characterization experiments are needed to determine qualitative signatures of specific particulate sources for their ambient identification. ATOFMS single particle mass spectra will be discussed introducing chemically distinct single particle types emitted from these combustion sources. Numerous particle types are emitted from each source, as indicated by distinct chemical associations on the single particle level. Examples include, the chemical associations of vanadium with organic carbon (OC) in gasoline powered vehicle emissions, calcium with black carbon (BC) in diesel powered vehicle emissions, beryllium and boron with BC in coal combustion emissions, and potassium with OC from biomass burning emissions. Most importantly, the overall particle type distributions from each source differ significantly. Finally, complementary MOUDI mass distribution data will

  18. System and method for single-phase, single-stage grid-interactive inverter

    DOEpatents

    Liu, Liming; Li, Hui

    2015-09-01

    The present invention provides for the integration of distributed renewable energy sources/storages utilizing a cascaded DC-AC inverter, thereby eliminating the need for a DC-DC converter. The ability to segment the energy sources and energy storages improves the maintenance capability and system reliability of the distributed generation system, as well as achieve wide range reactive power compensation. In the absence of a DC-DC converter, single stage energy conversion can be achieved to enhance energy conversion efficiency.

  19. Method for simultaneous use of a single additive for coal flotation, dewatering, and reconstitution

    DOEpatents

    Wen, Wu-Wey; Gray, McMahan L.; Champagne, Kenneth J.

    1995-01-01

    A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

  20. Method for simultaneous use of a single additive for coal flotation, dewatering and reconstitution

    SciTech Connect

    Wen, Wu-Wey; Gray, M.L.; Champagne, K.J.

    1993-11-09

    A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

  1. NASA Glenn's Single-Stage Axial Compressor Facility Upgraded

    NASA Technical Reports Server (NTRS)

    Brokopp, Richard A.

    2004-01-01

    NASA Glenn Research Center's Single-Stage Axial Compressor Facility was upgraded in fiscal year 2003 to expand and improve its research capabilities for testing high-speed fans and compressors. The old 3000-hp drive motor and gearbox were removed and replaced with a refurbished 7000-hp drive motor and gearbox, with a maximum output speed of 21,240 rpm. The higher horsepower rating permits testing of fans and compressors with higher pressure ratio or higher flow. A new inline torquemeter was installed to provide an alternate measurement of fan and compressor efficiency, along with the standard pressure and temperature measurements. A refurbished compressor bearing housing was also installed with bidirectional rotation capability, so that a variety of existing hardware could be tested. Four new lubrication modules with backup capability were installed for the motor, gearbox, torquemeter, and compressor bearing housing, so that in case the primary pump fails, the backup will prevent damage to the rotating hardware. The combustion air supply line for the facility inlet air system was activated to provide dry air for repeatable inlet conditions. New flow conditioning hardware was installed in the facility inlet plenum tank, which greatly reduced the inlet turbulence. The new inlet can also be easily modified to accommodate 20- or 22-in.-diameter fans and compressors, so a variety of existing hardware from other facilities (such as Glenn's 9- by 15-Foot Low-Speed Wind Tunnel) can be tested in the Single-Stage Axial Compressor Facility. An exhaust line was also installed to provide bleed capability to remove the inlet boundary layer. To improve the operation and control of the facility, a new programmable logic controller (PLC) was installed to upgrade from hardwired relay logic to software logic. The PLC also enabled the usage of human-machine interface software to allow for easier operation of the facility and easier reconfiguration of the facility controls when

  2. High spatial resolution measurements in a single stage ram accelerator

    NASA Technical Reports Server (NTRS)

    Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

    1992-01-01

    High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented in this paper. The ram accelerator is a ramjet-in-tube device which operates in a manner similar to that of a conventional ramjet. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Utilization of special highly instrumented sections of tube has allowed the recording of gas dynamic phenomena with high resolution. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) in a single stage gas mixture are presented and reveal the three-dimensional character of the flow field induced by projectile fins and the canting of the fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, three-dimensional CFD code. The knowledge gained from these experiments and simulations is useful in understanding the underlying nature of ram accelerator propulsive regimes, as well as assisting in the validation of three-dimensional CFD coded which model unsteady, chemically reactive flows.

  3. Development of a large cooling capacity single stage GM cryocooler

    NASA Astrophysics Data System (ADS)

    Yamada, K.

    2014-09-01

    Sumitomo Heavy Industries, Ltd. (SHI) has developed 4 K Gifford-McMahon (GM) cryocoolers for various cryogenic fields including Magnetic resonance imaging (MRI) systems. However, for the purpose of cooling high temperature superconductor (HTS) devices, the needs for cryocoolers with a large cooling capacity in the range of 20-30 K has been rapidly increasing. Recently, SHI developed a large cooling capacity single-stage GM cryocooler, for HTS applications. A typical cooling capacity is 46/52 W at 20 K or 85/96 W at 30 K with 6.9/7.9 kW input power at 50/60 Hz. The cooling capacity degradation caused by inclination is within 24%. And also, a low mechanical vibration and a low acoustic noise have been achieved because the displacer is driven by a motor instead of a pneumatic force. In addition, the cryocooler does not contain lead as a regenerator material, so it complies with restriction of hazardous substances (RoHS) directive.

  4. Single Stage Rocket Technology's real time data system

    NASA Technical Reports Server (NTRS)

    Voglewede, Steven D.

    1994-01-01

    The Single Stage Rocket Technology (SSRT) Delta Clipper Experimental (DC-X) Program is a United States Air Force Ballistic Missile Defense Organization (BMDO) rapid prototyping initiative that is currently demonstrating technology readiness for reusable suborbital rockets. The McDonnell Douglas DC-X rocket performed technology demonstrations at the U.S. Army White Sands Missile Range in New Mexico from April-October in 1993. The DC-X Flight Operations Control Center (FOCC) contains the ground control system that is used to monitor and control the DC-X vehicle and its Ground Support Systems (GSS). The FOCC is operated by a flight crew of three operators. Two operators manage the DC-X Flight Systems and one operator is the Ground Systems Manager. A group from McDonnell Douglas Aerospace at KSC developed the DC-X ground control system for the FOCC. This system is known as the Real Time Data System (RTDS). The RTDS is a distributed real time control and monitoring system that utilizes the latest available commercial off-the-shelf computer technology. The RTDS contains front end interfaces for the DC-X RF uplink/downlink and fiber optic interfaces to the GSS equipment. This paper describes the RTDS architecture and FOCC layout. The DC-X applications and ground operations are covered.

  5. Flow analyses in a single-stage propulsion pump

    SciTech Connect

    Lee, Y.T.; Hah, C.; Loellbach, J. |

    1996-04-01

    Steady-state analyses of the incompressible flow past a single-stage stator/rotor propulsion pump are presented and compared to experimental data. The purpose of the current study is to validate a numerical method for the design application of a typical propulsion pump and for the acoustic analysis based on predicted flowfields. A steady multiple-blade-row approach is used to calculate the flowfields of the stator and the rotor. The numerical method is based on a fully conservative control-volume technique. The Reynolds-averaged Navier-Stokes equations are solved along with the standard two-equation {kappa}-{epsilon} turbulence model. Numerical results for both mean flow and acoustic properties compare well with measurements in the wake of each blade row. The rotor blade has a thick boundary layer in the last quarter of the chord and the flow separates near the trailing edge. These features invalidate many Euler prediction results. Due to the dramatic reduction of the turbulent eddy viscosity in the thick boundary layer, the standard {kappa}-{epsilon} model cannot predict the correct local flow characteristics near the rotor trailing edge and in its near wake. Thus, a modification of the turbulence length scale in the turbulence model is applied in the thick boundary layer in response to the reduction of the turbulent eddy viscosity.

  6. Test of Single-Stage Axial-Flow Fan

    NASA Technical Reports Server (NTRS)

    Bell, E Barton

    1942-01-01

    A single-stage axial fan was built and tested in the shop of the propeller-research tunnel of the NACA. The fan comprised a simple 24-blade rotor having a diameter of 21 inches and a solidity of 0.86 and a set of 37 contravanes having a solidity of 1.33. The rotor was driven by a 25-horsepower motor capable of rotating at a speed of 3600 r.p.m. The fan was tested for volume, pressure, and efficiency over a range of delivery pressures and volumes for a wide range of contravane and blade-angle settings. The test results are presented in chart form in terms of nondimensional units in order that similar fans may be accurately designed with a minimum effort. The maximum efficiency (88 percent) was obtained by the fan at a blade angle of 30 degrees and a contravane angle of 70 degrees. An efficiency of 80 percent was obtained by the fan with the contravanes removed.

  7. Quantitative measurement of atomic sodium in the plume of a single burning coal particle

    SciTech Connect

    van Eyk, P.J.; Ashman, P.J.; Alwahabi, Z.T.; Nathan, G.J.

    2008-11-15

    The release of volatile sodium during coal combustion is a significant factor in the fouling and corrosion of heat transfer surfaces within industrial coal-fired boilers. A method for measuring the temporal release of atomic sodium from a single coal particle is described. Laser absorption was used to calibrate laser-induced fluorescence measurements of atomic sodium utilising the sodium D1 line (589.59 nm) in a purpose-designed flat flame environment. The calibration was then applied to planar laser-induced fluorescence measurements of sodium atoms in the plume from a single Victorian brown coal particle (53 mg) suspended within the flat flame. The peak concentration of atomic sodium was approximately 64.1 ppb after 1080.5 s, which appears to correspond to the end of char combustion. To our knowledge this is the first in situ quantitative measurement of the concentration field of atomic sodium in the plume above a burning particle. A simple kinetic model has been used to estimate the rate of sodium decay in the post-flame gases. Comparison of the estimated and measured decay rates showed reasonable agreement. (author)

  8. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    SciTech Connect

    Mahesh Iyer; Himanshu Gupta; Danny Wong; Liang-Shih Fan

    2005-09-30

    Hydrogen production from coal gasification can be enhanced by driving the equilibrium limited Water Gas Shift reaction forward by incessantly removing the CO{sub 2} by-product via the carbonation of calcium oxide. This project aims at using the OSU patented high-reactivity mesoporous precipitated calcium carbonate sorbent for removing the CO{sub 2} product. Preliminary experiments demonstrate the show the superior performance of the PCC sorbent over other naturally occurring calcium sorbents. Gas composition analyses show the formation of 100% pure hydrogen. Novel calcination techniques could lead to smaller reactor footprint and single-stage reactors that can achieve maximum theoretical H{sub 2} production for multicyclic applications. Sub-atmospheric calcination studies reveal the effect of vacuum level, diluent gas flow rate, thermal properties of the diluent gas and the sorbent loading on the calcination kinetics which play an important role on the sorbent morphology. Steam, which can be easily separated from CO{sub 2}, is envisioned to be a potential diluent gas due to its enhanced thermal properties. Steam calcination studies at 700-850 C reveal improved sorbent morphology over regular nitrogen calcination. A mixture of 80% steam and 20% CO{sub 2} at ambient pressure was used to calcine the spent sorbent at 820 C thus lowering the calcination temperature. Regeneration of calcium sulfide to calcium carbonate was achieved by carbonating the calcium sulfide slurry by bubbling CO{sub 2} gas at room temperature.

  9. 18 W single-stage single-frequency acoustically tailored Raman fiber amplifier.

    PubMed

    Vergien, Christopher; Dajani, Iyad; Robin, Craig

    2012-05-15

    A single-mode polarization-maintaining fiber doped to increase the Raman gain while suppressing stimulated Brillouin scattering (SBS) was utilized in a single-stage counter-pumped Raman fiber amplifier. The SBS suppression was achieved through the acoustic tailoring of the core. A pump probe experiment was conducted to characterize the Brillouin gain and indicated the existence of multiple Brillouin peaks. When the amplifier was seeded with approximately 15 mW of 1178 nm light, 11.5 W of cw output power was obtained with a linewidth ≤2 MHz. The application of a thermal gradient to further mitigate the SBS process increased the output power to 18 W, thus providing a net amplifier gain >30 dB.

  10. Antioxidant response at early stages and low grades of simple coal worker's pneumoconiosis diagnosed by high resolution computed tomography.

    PubMed

    Altin, Remzi; Armutcu, Ferah; Kart, Levent; Gurel, Ahmet; Savranlar, Ahmet; Ozdemir, Hüiseyin

    2004-10-01

    In miners exposed to coal dusts, coal worker's pneumoconiosis (CWP) can occur. The purpose of the present study is to better understand the relations between coal dust exposure and activities of blood plasma antioxidant enzymes, namely, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and lipid peroxidation end product malondialdehyde (MDA) concentration in coal workers with early and low grade simple CWP diagnosed by high resolution computed tomography (HRCT). Forty-three coal workers who had profusions of 0/1-2/2 according to ILO 1980 chest X-ray (CXR) classification, 43 coal workers without CWP (control group 1) and 44 healthy subjects (control group 2) who were randomly selected from the population register or recruited from the hospital staff were enrolled. Coal workers were reevaluated by HRCT (Hosoda-Shida classification) due to its higher sensitivity than standard CXR. Then, blood plasma SOD and GSH-Px activities and MDA plasma levels were measured. CWP was found positive in 46 of 89 coal workers by HRCT evaluation. Profusion 0 (P0, CWP not present), profusion 1 (P1, early CWP) and profusion 2 (P2, low grade CWP) were found in 43, 23 and 19 of patients found to have CWP by HRCT, respectively. We had no worker with profusion 3 (P3). Complicated CWP was shown in four of 46 patients and thesecases were excluded as the study was restricted to early and low-grade pneumoconiosis. In respect to the plasma levels of MDA and plasma activities of SOD and GSH-Px, statistically significant differences were found between CWP cases and control groups (p < 0.01, p < 0.01, p < 0.001 respectively). Statistical differences were also obtained for the plasma activities of SOD and GSH-Px and levels of MDA in relation to HRCT profusions (p < 0.05). In conclusion, these findings suggest an oxidative stress due to increased free radicals and reactive oxygen metabolite production in early stages and low grades of simple CWP diagnosed by HRCT.

  11. Applications of the Magnetocaloric Effect in Single-Stage, Multi-Stage and Continuous Adiabatic Demagnetization Refrigerators

    NASA Technical Reports Server (NTRS)

    Shirron, Peter J.

    2014-01-01

    Adiabatic demagnetization refrigerators (ADR), based on the magnetocaloric effect, are solid-state coolers that were the first to achieve cooling well into the sub-kelvin regime. Although supplanted by more powerful dilution refrigerators in the 1960s, ADRs have experienced a revival due to the needs of the space community for cooling astronomical instruments and detectors to temperatures below 100 mK. The earliest of these were single-stage refrigerators using superfluid helium as a heat sink. Their modest cooling power (<1 µW at 60 mK[1]) was sufficient for the small (6x6) detector arrays[2], but recent advances in arraying and multiplexing technologies[3] are generating a need for higher cooling power (5-10 µW), and lower temperature (<30 mK). Single-stage ADRs have both practical and fundamental limits to their operating range, as mass grows very rapidly as the operating range is expanded. This has led to the development of new architectures that introduce multi-staging as a way to improve operating range, efficiency and cooling power. Multi-staging also enables ADRs to be configured for continuous operation, which greatly improves cooling power per unit mass. This paper reviews the current field of adiabatic demagnetization refrigeration, beginning with a description of the magnetocaloric effect and its application in single-stage systems, and then describing the challenges and capabilities of multi-stage and continuous ADRs.

  12. Comparative assessment of single-stage and two-stage anaerobic digestion for the treatment of thin stillage.

    PubMed

    Nasr, Noha; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George; El Naggar, M Hesham

    2012-05-01

    A comparative evaluation of single-stage and two-stage anaerobic digestion processes for biomethane and biohydrogen production using thin stillage was performed to assess the impact of separating the acidogenic and methanogenic stages on anaerobic digestion. Thin stillage, the main by-product from ethanol production, was characterized by high total chemical oxygen demand (TCOD) of 122 g/L and total volatile fatty acids (TVFAs) of 12 g/L. A maximum methane yield of 0.33 L CH(4)/gCOD(added) (STP) was achieved in the two-stage process while a single-stage process achieved a maximum yield of only 0.26 L CH(4)/gCOD(added) (STP). The separation of acidification stage increased the TVFAs to TCOD ratio from 10% in the raw thin stillage to 54% due to the conversion of carbohydrates into hydrogen and VFAs. Comparison of the two processes based on energy outcome revealed that an increase of 18.5% in the total energy yield was achieved using two-stage anaerobic digestion.

  13. Process for coal liquefaction by separation of entrained gases from slurry exiting staged dissolvers

    DOEpatents

    Givens, Edwin N.; Ying, David H. S.

    1983-01-01

    There is described an improved liquefaction process by which coal is converted to a low ash and low sulfur carbonaceous material that can be used as a fuel in an environmentally acceptable manner without costly gas scrubbing equipment. In the process, coal is slurried with a solvent, passed through a preheater and at least two dissolvers in series in the presence of hydrogen-rich gases at elevated temperatures and pressures. Solids, including mineral ash and unconverted coal macerals are separated from the condensed dissolver effluent. In accordance with the improved process, fresh hydrogen is fed to each dissolver and the entrained gas from each dissolver is separated from the slurry phase and removed from the reactor system before the condensed phase is passed to the next dissolver in the series. In accordance with another process, the feeds to the dissolvers are such that the top of each downstream dissolver is used as a gas-liquid separator.

  14. The effect of model fidelity on prediction of char burnout for single-particle coal combustion

    SciTech Connect

    McConnell, Josh; Sutherland, James C.

    2016-07-09

    In this study, practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully considered. In this work, we consider the importance of model fidelity during char combustion by comparing combinations of simple and complex gas and particle-phase chemistry models. Detailed kinetics based on the GRI 3.0 mechanism and infinitely-fast chemistry are considered in the gas-phase. The Char Conversion Kinetics model and nth-Order Langmuir–Hinshelwood model are considered for char consumption. For devolatilization, the Chemical Percolation and Devolatilization and Kobayashi-Sarofim models are employed. The relative importance of gasification versus oxidation reactions in air and oxyfuel environments is also examined for various coal types. Results are compared to previously published experimental data collected under laminar, single-particle conditions. Calculated particle temperature histories are strongly dependent on the choice of gas phase and char chemistry models, but only weakly dependent on the chosen devolatilization model. Particle mass calculations were found to be very sensitive to the choice of devolatilization model, but only somewhat sensitive to the choice of gas chemistry and char chemistry models. High-fidelity models for devolatilization generally resulted in particle temperature and mass calculations that were closer to experimentally observed values.

  15. Feeding Dysfunction in Children with Single Ventricle Following Staged Palliation

    PubMed Central

    Hill, Garick D.; Silverman, Alan H.; Noel, Richard J.; Simpson, Pippa M.; Slicker, Julie; Scott, Ann E.; Bartz, Peter J.

    2013-01-01

    Objective To determine the prevalence of feeding dysfunction in children with single ventricle defects and identify associated risk factors. Study design Patients aged 2–6 years with single ventricle physiology presenting for routine cardiology follow-up at the Children’s Hospital of Wisconsin were prospectively identified. Parents of the patients completed 2 validated instruments for assessment of feeding dysfunction. Chart review was performed to retrospectively obtain demographic and diagnostic data. Results Instruments were completed for 56 patients; median age was 39 months. Overall, 28 (50%) patients had some form of feeding dysfunction. Compared with a normal reference population, patients with single ventricle had statistically-significant differences in dysfunctional food manipulation (p<0.001), mealtime aggression (p=0.002), choking/gagging/vomiting (p<0.001), resistance to eating (p<0.001) and parental aversion to mealtime (p<0.001). Weight and height for age z-scores were significantly lower in subjects with feeding dysfunction (−0.84 vs. −0.33; p<0.05 and −1.46 vs. −0.56; p=0.001 respectively). Multivariable analysis identified current gastrostomy tube use (p=0.02) and a single parent household (p=0.01) as risk factors for feeding dysfunction. Conclusion Feeding dysfunction is common in children with single ventricle defects, occurring in 50% of our cohort. Feeding dysfunction is associated with worse growth measures. Current gastrostomy tube use and a single parent household were identified as independent risk factors for feeding dysfunction. PMID:24161218

  16. Single-stage experimental evaluation of low aspect ratio, highly loaded blading for compressors. Part 9: Stage F and stage G, volume 1

    NASA Technical Reports Server (NTRS)

    Cheatham, J. G.; Smith, J. D.; Wright, D. L.

    1976-01-01

    Two single-stage, 0.77 hub/tip ratio axial-flow compressors were tested to evaluate the effectiveness of low aspect ratio blading as a means of obtaining higher stage loadings. One compressor, designated Stage F, was comprised of circular arc blading with an aspect ratio of 0.9 for both the rotor and stator. This compressor was tested with uniform inlet flow, hub radial, tip radial, and 180 deg arc circumferential inlet distortion. The second compressor, designated Stage G, was comprised of multiple circular arc blading with an aspect ratio of 1.0 for both the rotor and stator. This compressor was tested with uniform inlet flow only. Design rotor tip speeds for Rotor F and Rotor G were 285 m/sec (934 ft/sec) and 327 m/sec (1,074 ft/sec) respectively. Both stages operated at high loading levels with adequate efficiency and operating range. The peak efficiencies and corresponding average stage diffusion factors for Stages F and G at design rotor speed were 86.4% and 84.1% and 0.59 and 0.55 respectively. The surge margin at peak efficiency for Stage F was 12.6% and the corresponding value for Stage G was 16.5%. Both stages experienced a loss in efficiency with increasing rotor speed; however, the multiple circular arc rotor delayed the characteristic loss in efficiency within increasing Mach number to higher Mach number.

  17. Dynamic modeling of PWM and single-switch single-stage power factor correction converters

    NASA Astrophysics Data System (ADS)

    Zhu, Guangyong

    The concept of averaging has been used extensively in the modeling of power electronic circuits to overcome their inherent time-variant nature. Among various methods, the PWM switch modeling approach is most widely accepted in the study of closed-loop stability and transient response because of its accuracy and simplicity. However, a non-ideal PWM switch model considering conduction losses is not available except for converters operating in continuous conduction mode (CCM) and under small ripple conditions. Modeling of conduction losses under large ripple conditions has not been reported in the open literature, especially when the converter operates in discontinuous conduction mode (DCM). In this dissertation, new models are developed to include conduction losses in the non-ideal PWM switch model under CCM and DCM conditions. The developed model is verified through two converter examples and the effect of conduction losses on the steady state and dynamic responses of the converter is also studied. Another major constraint of the PWM switch modeling approach is that it heavily relies on finding the three-terminal PWM switch. This requirement severely limits its application in modeling single-switch single-stage power factor correction (PFC) converters, where more complex topological structures and switching actions are often encountered. In this work, we developed a new modeling approach which extends the PWM switch concept by identifying the charging and discharging voltages applied to the inductors. The new method can be easily applied to derive large-signal models for a large group of PFC converters and the procedure is elaborated through a specific example. Finally, analytical results regarding harmonic contents and power factors of various PWM converters in PFC applications are also presented here.

  18. The effect of model fidelity on prediction of char burnout for single-particle coal combustion

    DOE PAGES

    McConnell, Josh; Sutherland, James C.

    2016-07-09

    In this study, practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully considered. In this work, we consider the importance of model fidelity during char combustion by comparing combinations of simple and complex gas and particle-phase chemistry models. Detailed kinetics based on the GRI 3.0 mechanism and infinitely-fast chemistry are considered in the gas-phase.more » The Char Conversion Kinetics model and nth-Order Langmuir–Hinshelwood model are considered for char consumption. For devolatilization, the Chemical Percolation and Devolatilization and Kobayashi-Sarofim models are employed. The relative importance of gasification versus oxidation reactions in air and oxyfuel environments is also examined for various coal types. Results are compared to previously published experimental data collected under laminar, single-particle conditions. Calculated particle temperature histories are strongly dependent on the choice of gas phase and char chemistry models, but only weakly dependent on the chosen devolatilization model. Particle mass calculations were found to be very sensitive to the choice of devolatilization model, but only somewhat sensitive to the choice of gas chemistry and char chemistry models. High-fidelity models for devolatilization generally resulted in particle temperature and mass calculations that were closer to experimentally observed values.« less

  19. Investigation of antimatter air-breathing propulsion for single-stage-to-orbit ships

    NASA Astrophysics Data System (ADS)

    Froning, H. D.

    Because the mutual annihilation of matter and antimatter releases all the energy that is stored within the physical structure of material mass, it provides the most powerful reaction that is possible for propulsive thrust. This paper considers the use of such annihilation energy for single-stage-to-orbit vehicles that would be powered by rocket and air-breathing propulsion and would reach and return from orbit with a single propulsive stage.

  20. Synthesis of coal-derived single-walled carbon nanotube from coal by varying the ratio of Zr/Ni as bimetallic catalyst

    NASA Astrophysics Data System (ADS)

    Kumar, Rajesh; Singh, Rajesh Kumar; Ghosh, A. K.; Sen, Raja; Srivastava, S. K.; Tiwari, R. S.; Srivastava, O. N.

    2013-01-01

    In this paper coal, source has been used in place of graphite for synthesis of single-walled carbon nanotubes (SWCNTs) with new Zr/Ni bimetallic catalyst. Using coal as starting material to produce the high-value-added SWCNTs is an economically competent route. SWCNTs have been synthesized by the electric arc discharge method using the so-called heterogeneous annealed coal anode filled with Zr and Ni catalyst. SWCNTs have been synthesized using annealed coal rod. The SWCNTs bundles synthesized generally have diameters of 4-10 nm. Most of those produced with Zr/Ni as the catalyst has a diameter ranging from 2.0 to 1.0 nm. The as-synthesized SWCNTs have been characterized employing XRD, HRTEM, EDX, Raman spectroscopy, and FTIR. It has been found that the change of the ratio of Zr and Ni concentration (wt%) in the catalyst affects the yield of SWCNTs. However, the purity of SWCNTs is very sensitive to the concentration of Zr. An optimal range of Zr/Ni compositions for synthesis of SWCNTs with relatively high purity and yield is obtained at specific concentration of 3:1.

  1. Theory of multiple-stage interband photovoltaic devices and ultimate performance limit comparison of multiple-stage and single-stage interband infrared detectors

    NASA Astrophysics Data System (ADS)

    Hinkey, Robert T.; Yang, Rui Q.

    2013-09-01

    absorbers are designed to absorb and collect an equal number of carriers in each stage. It is shown that for zero-bias operation, this design has a higher ultimate detectivity than a single-absorber device. Such improvements in detectivity are significant for material with αLn ≤ 0.5. Using the results derived for general values of αLn, we offer an outlook for multiple-stage detectors that utilize InAs/GaSb superlattice absorbers.

  2. Combustion of volatile matter during the initial stages of coal combustion

    SciTech Connect

    Marlow, D.; Niksa, S.; Kruger, C.H.

    1990-08-01

    Both the secondary pyrolysis and combustion of the volatiles from a bituminous coal will be studied. Devolatilization and secondary pyrolysis experiments will be conducted in a novel flow reactor in which secondary pyrolysis of the volatiles occurs after devolatilization is complete. This allows unambiguous measurements of the yields from both processes. Measurements will be made for reactor temperatures from 1500 to 1700 K, and a nominal residence time of 200 msec. These conditions are typical of coal combustion. Yields of tar, soot, H{sub 2}, CO, CH{sub 4}, and C{sub 2} and C{sub 3} hydrocarbons will be determined as a function of reactor temperature. The yields will be reported as a function of the temperature of the reactor. The instrumentation for temperature measurements will be developed during future studies. Combustion studies will be conducted in a constant volume bomb, which will be designed and constructed for this study. Tar and soot will be removed before introducing the volatiles to the bomb, so that only the combustion of the light gas volatiles will be considered. The burning velocities of light gas volatiles will be determined both as functions of mixture stoichiometry and the temperature at which the volatiles are pyrolysed. 90 refs., 70 figs., 13 tabs.

  3. Blood anti-oxidant parameters at different stages of pneumoconiosis in coal workers.

    PubMed

    Engelen, J J; Borm, P J; van Sprundel, M; Leenaerts, L

    1990-03-01

    The pneumoconioses are associated with chronic inflammatory processes during which increased amounts of reactive oxygen species are formed in the lower respiratory tract. To characterize the effect(s) of these processes on the defense system against free radicals, we studied 91 individuals with long-term occupational exposure to coal mine dust. Thirty-one subjects were classified with radiological evidence to be pneumoconiotics, while 58 control miners had no pulmonary disorders. We measured antioxidant parameters in red blood cells, considering the latter to reflect the oxidative stress in the lung. Glutathione levels were significantly decreased (p = 0.04) in red blood cells of miners with coal workers' pneumoconiosis with radiograph classification 0/1 to 2/1, while in miners with classification 3/2 to 3/3, the plasma iron concentrations were significantly decreased (p = 0.04). Moreover, some factors of the anti-oxidant system (superoxide dismutase, catalase, glutathione peroxidase) were correlated in the diseased but not in the control miners. Taken together, all data support the role of the erythrocyte as a circulating anti-oxidant carrier and also that changes in red blood cell anti-oxidant factors reflect the oxidative stress imposed by the pneumoconiotic (inflammatory) processes in the lung.

  4. Blood anti-oxidant parameters at different stages of pneumoconiosis in coal workers.

    PubMed Central

    Engelen, J J; Borm, P J; van Sprundel, M; Leenaerts, L

    1990-01-01

    The pneumoconioses are associated with chronic inflammatory processes during which increased amounts of reactive oxygen species are formed in the lower respiratory tract. To characterize the effect(s) of these processes on the defense system against free radicals, we studied 91 individuals with long-term occupational exposure to coal mine dust. Thirty-one subjects were classified with radiological evidence to be pneumoconiotics, while 58 control miners had no pulmonary disorders. We measured antioxidant parameters in red blood cells, considering the latter to reflect the oxidative stress in the lung. Glutathione levels were significantly decreased (p = 0.04) in red blood cells of miners with coal workers' pneumoconiosis with radiograph classification 0/1 to 2/1, while in miners with classification 3/2 to 3/3, the plasma iron concentrations were significantly decreased (p = 0.04). Moreover, some factors of the anti-oxidant system (superoxide dismutase, catalase, glutathione peroxidase) were correlated in the diseased but not in the control miners. Taken together, all data support the role of the erythrocyte as a circulating anti-oxidant carrier and also that changes in red blood cell anti-oxidant factors reflect the oxidative stress imposed by the pneumoconiotic (inflammatory) processes in the lung. PMID:2351120

  5. Downstream processing of virus-like particles: single-stage and multi-stage aqueous two-phase extraction.

    PubMed

    Ladd Effio, Christopher; Wenger, Lukas; Ötes, Ozan; Oelmeier, Stefan A; Kneusel, Richard; Hubbuch, Jürgen

    2015-02-27

    The demand for vaccines against untreated diseases has enforced the research and development of virus-like particle (VLP) based vaccine candidates in recent years. Significant progress has been made in increasing VLP titres during upstream processing in bacteria, yeast and insect cells. Considering downstream processing, the separation of host cell impurities is predominantly achieved by time-intensive ultracentrifugation processes or numerous chromatography and filtration steps. In this work, we evaluate the potential of an alternative separation technology for VLPs: aqueous two-phase extraction (ATPE). The benefits of ATPE have been demonstrated for various biomolecules, but capacity and separation efficiency were observed to be low for large biomolecules such as VLPs or viruses. Both performance parameters were examined in detail in a case study on human B19 parvovirus-like particles derived from Spodoptera frugiperda Sf9 insect cells. A solubility-guided approach enabled the design of polyethylene (PEG) salt aqueous two-phase systems with a high capacity of up to 4.1mg/mL VLPs. Unique separation efficiencies were obtained by varying the molecular weight of PEG, the pH value and by using neutral salt additives. Further improvement of the separation of host cell impurities was achieved by multi-stage ATPE on a centrifugal partition chromatography (CPC) device in 500mL scale. While single-stage ATPE enabled a DNA clearance of 99.6%, multi-stage ATPE improved the separation of host cell proteins (HCPs). The HPLC purity ranged from 16.8% (100% VLP recovery) for the single-stage ATPE to 69.1% (40.1% VLP recovery) for the multi-stage ATPE. An alternative two-step downstream process is presented removing the ATPS forming polymer, cell debris and 99.77% DNA with a HPLC purity of 90.6% and a VLP recovery of 63.9%.

  6. Assessing the Validity of a Single-Item HIV Risk Stage-of-Change Measure

    ERIC Educational Resources Information Center

    Napper, Lucy E.; Branson, Catherine M.; Fisher, Dennis G.; Reynolds, Grace L.; Wood, Michelle M.

    2008-01-01

    This study examined the validity of a single-item measure of HIV risk stage of change that HIV prevention contractors were required to collect by the California State Office of AIDS. The single-item measure was compared to the more conventional University of Rhode Island Change Assessment (URICA). Participants were members of Los Angeles…

  7. Catalytic Two-Stage Liquefaction (CTSL{trademark}) process bench studies and PDU scale-up with sub-bituminous coal. Final report

    SciTech Connect

    Comolli, A.G.; Johanson, E.S.; Karolkiewicz, W.F.; Lee, L.K.T.; Stalzer, R.H.; Smith, T.O.

    1993-03-01

    Reported are the details and results of Laboratory and Bench-Scale experiments using sub-bituminous coal conducted at Hydrocarbon Research, Inc., under DOE Contract No. DE-AC22-88PC88818 during the period October 1, 1988 to December 31, 1992. The work described is primarily concerned with testing of the baseline Catalytic Two-Stage Liquefaction (CTSL{trademark}) process with comparisons with other two stage process configurations, catalyst evaluations and unit operations such as solid separation, pretreatments, on-line hydrotreating, and an examination of new concepts. In the overall program, three coals were evaluated, bituminous Illinois No. 6, Burning Star and sub-bituminous Wyoming Black Thunder and New Mexico McKinley Mine seams. The results from a total of 16 bench-scale runs are reported and analyzed in detail. The runs (experiments) concern process variables, variable reactor volumes, catalysts (both supported, dispersed and rejuvenated), coal cleaned by agglomeration, hot slurry treatments, reactor sequence, on-line hydrotreating, dispersed catalyst with pretreatment reactors and CO{sub 2}/coal effects. The tests involving the Wyoming and New Mexico Coals are reported herein, and the tests involving the Illinois coal are described in Topical Report No. 2. On a laboratory scale, microautoclave tests evaluating coal, start-up oils, catalysts, thermal treatment, CO{sub 2} addition and sulfur compound effects were conducted and reported in Topical Report No. 3. Other microautoclave tests are described in the Bench Run sections to which they refer such as: rejuvenated catalyst, coker liquids and cleaned coals. The microautoclave tests conducted for modelling the CTSL{trademark} process are described in the CTSL{trademark} Modelling section of Topical Report No. 3 under this contract.

  8. Cyclohexane triggers staged growth of pure and vertically aligned single wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ayala, P.; Grüneis, A.; Grimm, D.; Kramberger, C.; Engelhard, R.; Rümmeli, M.; Schumann, J.; Kaltofen, R.; Büchner, B.; Schaman, C.; Kuzmany, H.; Gemming, T.; Barreiro, A.; Pichler, T.

    2008-03-01

    An innovative staged chemical vapor deposition (SCVD) approach providing flexible control over the feedstock type during single wall carbon nanotube (SWNTs) growth is proposed. The efficiency of staged growth by means of a cyclohexane/methane system using thin film catalysts is here illustrated. The mechanism involves the nucleation stage efficiently triggered by cyclohexane, followed by methane assisting a growth stage yielding high purity SWNTs vertically aligned with lengths of several hundred μm. In addition, SCVD also facilitates catalyst free SWNT detachment enabling repeated growth.

  9. Geologic parameters controlling natural gas production from single, deeply buried coal reservoir

    SciTech Connect

    Decker, D.

    1986-05-01

    Methane occluded in coal reservoirs is being commercially produced in the Appalachian, Warrior, San Juan, and Piceance basins. Of these, the Piceance basin, with an estimated 100 tcf of coal-bed methane, represents the largest coal-bed methane resource in the US. Exploration efforts applied to this vast resource have been hampered by lack of appropriate exploration, drilling, completion, stimulation, and production methods. The Deep Coal Seam project sponsored by the Gas Research Institute and operated by Resource Enterprises, Inc., at the Red Mountain site, Mesa County, Colorado, was established to develop, improve, evaluate, and communicate the technology required to produce gas from deeply buried coal reservoirs. Regional geologic studies have established the Red Mountain site as representing most of the coal-bed methane resource within the Piceance basin. The project is focused on the D coal seam, belonging to the Cameo coal group of the Williams Fork formation, Upper Cretaceous Mesaverde Group. The D coal seam thickness ranges from 16 to 20 ft (5 to 6 m) throughout the site, with an average drilling depth of 5500 ft (1700 m). This coal seam is medium-volatile bituminous in rank, with an average gas content of 250 standard ft/sup 3//ton (8 standard cm/sup 3//g).

  10. Features of the Kaiser effect in coal specimens at different stages of the triaxial axisymmetric deformation

    SciTech Connect

    Shkuratnik, V.L.; Filimonov, Y.L.; Kuchurin, S.V.

    2007-01-15

    The experimental data are presented for the features of formation and manifestation of the acoustic-emission and deformation memory effects in specimens of anthracite at different stages of the triaxial cyclic deformation by the Karman scheme in the pre-limiting and post-limiting zones.

  11. The single electron chemistry of coals, January 1, 1990--March 30, 1990

    SciTech Connect

    Larsen, J.W.; Flowers, R.A. II.

    1990-04-16

    The Wyodak, Upper Freeport and Pocahontas No. 3 samples containing DPPD display a decrease in spin density as compared to the starting coals. Coincident with this decrease is a loss or decrease of the narrow inertinite signal in the esr spectrum of these coals. The Pittsburgh No. 8 coal sample containing DPPD also displays a loss of spin density as compared to the starting coal but there is no change in the esr spectrum. These results compare well with earlier work involving 4-vinylpyridine and the same coal samples. We discovered the presence of poly(4-vinylpyridine) in our coal samples and a concurrent loss of inertinite radical density. It is possible that the inertinite radicals may initiate the polymerization or in the present work may abstract hydrogen from DPPD. No C=N stretch was displayed in the IR spectrum to substantiate this claim.

  12. Venturestar{trademark} single stage to orbit reusable launch vehicle program overview

    SciTech Connect

    Baumgartner, R.I.

    1997-01-01

    Lockheed Martin is developing the VentureStar{trademark} Single Stage To Orbit Reusable Launch Vehicle system. The VentureStar{trademark} launch system will drastically reduce the cost to place payloads in orbit. This paper describes the VentureStar{trademark} Single Stage To Orbit Reusable Launch Vehicle Program, system and technology. The technology to achieve VentureStar{trademark} will be demonstrated in the National Aeronautics and Space Administration X-33 Phase II Advanced Technology Demonstration Program. The X-33 program, vehicle, and technology are described herein. {copyright} {ital 1997 American Institute of Physics.}

  13. Evaluation of single vs. staged mesophilic anaerobic digestion of kitchen waste with and without microwave pretreatment.

    PubMed

    Shahriari, Haleh; Warith, Mostafa; Hamoda, Mohamed; Kennedy, Kevin

    2013-08-15

    Effects of single and dual stage (acidogenic-methanogenic) mesophilic anaerobic digestion (AD) of kitchen waste (KW) was evaluated at hydraulic retention times (HRTs) of 20, 15, 12 and 9 d with and without thermal microwave (MW) pretreatment (145 °C). Anaerobic acidification in terms of acid accumulation was superior compared to microaerophilic acidification. Maximum anaerobic acidification of KW was determined to occur with an HRT of 2 d which was then selected for the acidification stage. The dual stage AD system fed with untreated KW produced the maximum biogas and volatile solids (VS) stabilization efficiencies at the shortest HRT of 9 d. Conversely, for free liquid resulting from MW pretreatment of KW the two stage reactor at 20 d HRT produced three fold more methane compared with the untreated free liquid control. However, MW pretreatment and AD of the free liquid fraction only, was not a sustainable treatment option. For KW, staging of the AD process had a greater positive impact on waste stabilization and methane yield compared to single stage reactors or MW pretreatment. KW can be characterized as being a readily biodegradable solid waste; concomitantly it is recommended that digester staging without MW pretreatment be employed to maximize methane yield and production.

  14. Arrhythmias Following Comprehensive Stage II Surgical Palliation in Single Ventricle Patients.

    PubMed

    Wilhelm, Carolyn M; Paulus, Diane; Cua, Clifford L; Kertesz, Naomi J; Cheatham, John P; Galantowicz, Mark; Fernandez, Richard P

    2016-03-01

    Post-operative arrhythmias are common in pediatric patients following cardiac surgery. Following hybrid palliation in single ventricle patients, a comprehensive stage II palliation is performed. The incidence of arrhythmias in patients following comprehensive stage II palliation is unknown. The purpose of this study is to determine the incidence of arrhythmias following comprehensive stage II palliation. A single-center retrospective chart review was performed on all single ventricle patients undergoing a comprehensive stage II palliation from January 2010 to May 2014. Pre-operative, operative, and post-operative data were collected. A clinically significant arrhythmia was defined as an arrhythmia which led to cardiopulmonary resuscitation or required treatment with either pacing or antiarrhythmic medication. Statistical analysis was performed with Wilcoxon rank-sum test and Fisher's exact test with p < 0.05 significant. Forty-eight single ventricle patients were reviewed (32 hypoplastic left heart syndrome, 16 other single ventricle variants). Age at surgery was 185 ± 56 days. Cardiopulmonary bypass time was 259 ± 45 min. Average vasoactive-inotropic score was 5.97 ± 7.58. Six patients (12.5 %) had clinically significant arrhythmias: four sinus bradycardia, one 2:1 atrioventricular block, and one slow junctional rhythm. No tachyarrhythmias were documented for this patient population. Presence of arrhythmia was associated with elevated lactate (p = 0.04) and cardiac arrest (p = 0.002). Following comprehensive stage II palliation, single ventricle patients are at low risk for development of tachyarrhythmias. The most frequent arrhythmia seen in these patients was sinus bradycardia associated with respiratory compromise.

  15. Combustion and NOx emission characteristics with respect to staged-air damper opening in a 600 MWe down-fired pulverized-coal furnace under deep-air-staging conditions.

    PubMed

    Kuang, Min; Li, Zhengqi; Wang, Zhihua; Jing, Xinjing; Liu, Chunlong; Zhu, Qunyi; Ling, Zhongqian

    2014-01-01

    Deep-air-staging combustion conditions, widely used in tangential-fired and wall-arranged furnaces to significantly reduce NOx emissions, are premature up to now in down-fired furnaces that are designed especially for industry firing low-volatile coals such as anthracite and lean coal. To uncover combustion and NOx emission characteristics under deep-air-staging conditions within a newly operated 600 MWe down-fired furnace and simultaneously understand the staged-air effect on the furnace performance, full-load industrial-size measurements taken of gas temperatures and species concentrations in the furnace, CO and NOx emissions in flue gas, and carbon in fly ash were performed at various staged-air damper openings of 10%, 20%, 30%, and 50%. Increasing the staged-air damper opening, gas temperatures along the flame travel (before the flame penetrating the staged-air zone) increased initially but then decreased, while those in the staged-air zone and the upper part of the hopper continuously decreased and increased, respectively. On opening the staged-air damper to further deepen the air-staging conditions, O2 content initially decreased but then increased in both two near-wall regions affected by secondary air and staged air, respectively, whereas CO content in both two regions initially increased but then decreased. In contrast to the conventional understanding about the effects of deep-air-staging conditions, here increasing the staged-air damper opening to deepen the air-staging conditions essentially decreased the exhaust gas temperature and carbon in fly ash and simultaneously increased both NOx emissions and boiler efficiency. In light of apparently low NOx emissions and high carbon in fly ash (i.e., 696-878 mg/m(3) at 6% O2 and 9.81-13.05%, respectively) developing in the down-fired furnace under the present deep-air-staging conditions, further adjustments such as enlarging the staged-air declination angle to prolong pulverized-coal residence times in the

  16. Lateral parascapular extrapleural approach for single-stage excision of dumb-bell neurofibroma.

    PubMed

    O'Reilly, G; Jackowski, A; Weiner, G; Thomas, D

    1994-01-01

    An excision of a T1 dumb-bell neurofibroma via a single-stage lateral parascapular extrapleural approach is described. The different surgical approaches that can be used to approach dumb-bell tumours are reviewed, together with the relevant literature.

  17. The role of the dental technician in fabricating the single-stage implant prosthesis.

    PubMed

    Fedoretz, M; Fedoretz, T

    1999-01-01

    With the initiation of the concept of osseointegration, the use of dental implants has become a predictable and frequently used addition to comprehensive planning and treatment of edentulous patients. Implantology poses challenges for the dental laboratory not present in any other existing specialty. Single-stage implant surgery represents such an innovation.

  18. Genomic Prediction of Single Crosses in the Early Stages of a Maize Hybrid Breeding Pipeline

    PubMed Central

    Kadam, Dnyaneshwar C.; Potts, Sarah M.; Bohn, Martin O.; Lipka, Alexander E.; Lorenz, Aaron J.

    2016-01-01

    Prediction of single-cross performance has been a major goal of plant breeders since the beginning of hybrid breeding. Recently, genomic prediction has shown to be a promising approach, but only limited studies have examined the accuracy of predicting single-cross performance. Moreover, no studies have examined the potential of predicting single crosses among random inbreds derived from a series of biparental families, which resembles the structure of germplasm comprising the initial stages of a hybrid maize breeding pipeline. The main objectives of this study were to evaluate the potential of genomic prediction for identifying superior single crosses early in the hybrid breeding pipeline and optimize its application. To accomplish these objectives, we designed and analyzed a novel population of single crosses representing the Iowa Stiff Stalk synthetic/non-Stiff Stalk heterotic pattern commonly used in the development of North American commercial maize hybrids. The performance of single crosses was predicted using parental combining ability and covariance among single crosses. Prediction accuracies were estimated using cross-validation and ranged from 0.28 to 0.77 for grain yield, 0.53 to 0.91 for plant height, and 0.49 to 0.94 for staygreen, depending on the number of tested parents of the single cross and genomic prediction method used. The genomic estimated general and specific combining abilities showed an advantage over genomic covariances among single crosses when one or both parents of the single cross were untested. Overall, our results suggest that genomic prediction of single crosses in the early stages of a hybrid breeding pipeline holds great potential to redesign hybrid breeding and increase its efficiency. PMID:27646704

  19. Heat and mass transfer in a coal-water fuel particle at the stage of "thermal" treatment

    NASA Astrophysics Data System (ADS)

    Salomatov, V. V.; Syrodoy, S. V.; Kuznetsov, G. V.

    2016-07-01

    The problem of heat and mass transfer has been solved numerically under the conditions of coal-water fuel particle ignition. The concurrent processes of evaporation, filtration of steam, thermal decomposition of the organic part of coal, thermal and chemical interaction of steam and coke carbon, and oxidation of products of their reaction and volatiles by the external oxidizer have been taken into account. The scales of influence of individual thermophysical and thermochemical properties of coals on the characteristics and conditions of ignition of coal-water slurry have been determined.

  20. Two-stage coal liquefaction process materials from the Wilsonville Facility operated in the nonintegrated and integrated modes: chemical analyses and biological testing

    SciTech Connect

    Later, D.W.

    1985-01-01

    This document reports the results from chemical analyses and biological testing of process materials sampled during operation of the Wilsonville Advanced Coal Liquefaction Research and Development Facility (Wilsonville, Alabama) in both the noncoupled or nonintegrated (NTSL Run 241) and coupled or integrated (ITSL Run 242) two-stage liquefaction operating modes. Mutagenicity and carcinogenicity assays were conducted in conjunction with chromatographic and mass spectrometric analyses to provide detailed, comparative chemical and biological assessments of several NTSL and ITSL process materials. In general, the NTSL process materials were biologically more active and chemically more refractory than analogous ITSL process materials. To provide perspective, the NTSL and ITSL results are compared with those from similar testing and analyses of other direct coal liquefaction materials from the solvent refined coal (SRC) I, SRC II and EDS processes. Comparisons are also made between two-stage coal liquefaction materials from the Wilsonville pilot plant and the C.E. Lummus PDU-ITSL Facility in an effort to assess scale-up effects in these two similar processes. 36 references, 26 figures, 37 tables.

  1. Single-stage reconstruction of flexor tendons with vascularized tendon transfers.

    PubMed

    Cavadas, P C; Pérez-García, A; Thione, A; Lorca-García, C

    2015-03-01

    The reconstruction of finger flexor tendons with vascularized flexor digitorum superficialis (FDS) tendon grafts (flaps) based on the ulnar vessels as a single stage is not a popular technique. We reviewed 40 flexor tendon reconstructions (four flexor pollicis longus and 36 finger flexors) with vascularized FDS tendon grafts in 38 consecutive patients. The donor tendons were transferred based on the ulnar vessels as a single-stage procedure (37 pedicled flaps, three free flaps). Four patients required composite tendon and skin island transfer. Minimum follow-up was 12 months, and functional results were evaluated using a total active range of motion score. Multiple linear regression analysis was performed to evaluate the factors that could be associated with the postoperative total active range of motion. The average postoperative total active range of motion (excluding the thumbs) was 178.05° (SD 50°). The total active range of motion was significantly lower for patients who were reconstructed with free flaps and for those who required composite tendon and skin island flap. Age, right or left hand, donor/motor tendon and pulley reconstruction had no linear effect on total active range of motion. Overall results were comparable with a published series on staged tendon grafting but with a lower complication rate. Vascularized pedicled tendon grafts/flaps are useful in the reconstruction of defects of finger flexor tendons in a single stage, although its role in the reconstructive armamentarium remains to be clearly established.

  2. Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

    PubMed Central

    Güntürkün, Onur

    2014-01-01

    While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed single-neuron activity while animals are acquiring an operantly conditioned response, or when that response is extinguished. But even in these cases, observation periods usually encompass only a single stage of learning, i.e. acquisition or extinction, but not both (exceptions include protocols employing reversal learning; see Bingman et al.1 for an example). However, acquisition and extinction entail different learning mechanisms and are therefore expected to be accompanied by different types and/or loci of neural plasticity. Accordingly, we developed a behavioral paradigm which institutes three stages of learning in a single behavioral session and which is well suited for the simultaneous recording of single neurons' action potentials. Animals are trained on a single-interval forced choice task which requires mapping each of two possible choice responses to the presentation of different novel visual stimuli (acquisition). After having reached a predefined performance criterion, one of the two choice responses is no longer reinforced (extinction). Following a certain decrement in performance level, correct responses are reinforced again (reacquisition). By using a new set of stimuli in every session, animals can undergo the acquisition-extinction-reacquisition process repeatedly. Because all three stages of learning occur in a single behavioral session, the paradigm is ideal for the simultaneous observation of the spiking output of multiple single neurons. We use pigeons as model systems, but the task can easily be adapted to any other species capable of conditioned discrimination learning. PMID:24961391

  3. Single-stage electrohydraulic servosystem for actuating on airflow valve with frequencies to 500 hertz

    NASA Technical Reports Server (NTRS)

    Webb, J. A., Jr.; Mehmed, O.; Lorenzo, C. F.

    1980-01-01

    An airflow valve and its electrohydraulic actuation servosystem are described. The servosystem uses a high-power, single-stage servovalve to obtain a dynamic response beyond that of systems designed with conventional two-stage servovalves. The electrohydraulic servosystem is analyzed and the limitations imposed on system performance by such nonlinearities as signal saturations and power limitations are discussed. Descriptions of the mechanical design concepts and developmental considerations are included. Dynamic data, in the form of sweep-frequency test results, are presented and comparison with analytical results obtained with an analog computer model is made.

  4. Microbial community structure and dynamics in two-stage vs single-stage thermophilic anaerobic digestion of mixed swine slurry and market bio-waste.

    PubMed

    Merlino, Giuseppe; Rizzi, Aurora; Schievano, Andrea; Tenca, Alberto; Scaglia, Barbara; Oberti, Roberto; Adani, Fabrizio; Daffonchio, Daniele

    2013-04-15

    The microbial community of a thermophilic two-stage process was monitored during two-months operation and compared to a conventional single-stage process. Qualitative and quantitative microbial dynamics were analysed by Denaturing Gradient Gel Electrophoresis (DGGE) and real-time PCR techniques, respectively. The bacterial community was dominated by heat-shock resistant, spore-forming clostridia in the two-stage process, whereas a more diverse and dynamic community (Firmicutes, Bacteroidetes, Synergistes) was observed in the single-stage process. A significant evolution of bacterial community occurred over time in the acidogenic phase of the two-phase process with the selection of few dominant species associated to stable hydrogen production. The archaeal community, dominated by the acetoclastic Methanosarcinales in both methanogen reactors, showed a significant diversity change in the single-stage process after a period of adaptation to the feeding conditions, compared to a constant stability in the methanogenic reactor of the two-stage process. The more diverse and dynamic bacterial and archaeal community of single-stage process compared to the two-stage process accounted for the best degradation activity, and consequently the best performance, in this reactor. The microbiological perspective proved a useful tool for a better understanding and comparison of anaerobic digestion processes.

  5. Grid Integration of Single Stage Solar PV System using Three-level Voltage Source Converter

    NASA Astrophysics Data System (ADS)

    Hussain, Ikhlaq; Kandpal, Maulik; Singh, Bhim

    2016-08-01

    This paper presents a single stage solar PV (photovoltaic) grid integrated power generating system using a three level voltage source converter (VSC) operating at low switching frequency of 900 Hz with robust synchronizing phase locked loop (RS-PLL) based control algorithm. To track the maximum power from solar PV array, an incremental conductance algorithm is used and this maximum power is fed to the grid via three-level VSC. The use of single stage system with three level VSC offers the advantage of low switching losses and the operation at high voltages and high power which results in enhancement of power quality in the proposed system. Simulated results validate the design and control algorithm under steady state and dynamic conditions.

  6. Prediction of single stage limit language and adult language via Yusof-Goode approach

    NASA Astrophysics Data System (ADS)

    Lim, Wen Li; Yusof, Yuhani; Rosli, Norhayati

    2014-06-01

    Yusof-Goode (Y-G) rule, a new symbolization of representing rule in splicing system under framework of formal language theory to model the recombinant behaviors of DNA molecules, was introduced by Yusof in 2012. A language that contains the strings resulting from a splicing system is called splicing language. Limit language is a subset of splicing language where it is restricted to the molecules that will be present in the system after the reaction has run to completion. Adult language is a subset of limit language where it does not participate in further splicing. In this paper, the new concept of single stage splicing languages is introduced and some theorems have been formulated to stipulate the final state product of single stage limit languages of Yusof-Goode splicing system based on the characteristic of one initial string andone rule.

  7. High peak-power kilohertz laser system employing single-stage multi-pass amplification

    DOEpatents

    Shan, Bing; Wang, Chun; Chang, Zenghu

    2006-05-23

    The present invention describes a technique for achieving high peak power output in a laser employing single-stage, multi-pass amplification. High gain is achieved by employing a very small "seed" beam diameter in gain medium, and maintaining the small beam diameter for multiple high-gain pre-amplification passes through a pumped gain medium, then leading the beam out of the amplifier cavity, changing the beam diameter and sending it back to the amplifier cavity for additional, high-power amplification passes through the gain medium. In these power amplification passes, the beam diameter in gain medium is increased and carefully matched to the pump laser's beam diameter for high efficiency extraction of energy from the pumped gain medium. A method of "grooming" the beam by means of a far-field spatial filter in the process of changing the beam size within the single-stage amplifier is also described.

  8. Validation of a PC based program for single stage absorption heat pump

    SciTech Connect

    Zaltash, A.; Ally, M.R.

    1991-09-01

    An interactive computer code was developed to evaluate single stage absorption heat pump performance for temperature amplifier and heat amplifier modes using water as the refrigerant. This program performs the cycle calculations for single stage cycles based on the polynomial expressions developed to correlate experimental vapor-liquid-equilibrium (VLE) and specific enthalpy-concentration data for LiBr/water and (Li, K, Na)NO{sub 3}/water systems as well as the properties of pure water. The operating parameters obtained by this program were tested against mass and energy balances in documented cases and the results show that the maximum deviation between coefficient of performance (COP) values obtained by this software and the ones previously calculated is less than 3%. In addition, this program was used to study the effect of solution temperature leaving the absorber on the other operating parameters. This type of analysis could be used to improve and optimize cycle design. 4 refs.

  9. Validation of a PC based program for single stage absorption heat pump. Final report

    SciTech Connect

    Zaltash, A.; Ally, M.R.

    1991-09-01

    An interactive computer code was developed to evaluate single stage absorption heat pump performance for temperature amplifier and heat amplifier modes using water as the refrigerant. This program performs the cycle calculations for single stage cycles based on the polynomial expressions developed to correlate experimental vapor-liquid-equilibrium (VLE) and specific enthalpy-concentration data for LiBr/water and (Li, K, Na)NO{sub 3}/water systems as well as the properties of pure water. The operating parameters obtained by this program were tested against mass and energy balances in documented cases and the results show that the maximum deviation between coefficient of performance (COP) values obtained by this software and the ones previously calculated is less than 3%. In addition, this program was used to study the effect of solution temperature leaving the absorber on the other operating parameters. This type of analysis could be used to improve and optimize cycle design. 4 refs.

  10. Single-stage osseointegrated implants for nasal prosthodontic rehabilitation: A clinical report.

    PubMed

    de Carvalho, Bruna M D F; Freitas-Pontes, Karina M; de Negreiros, Wagner A; Verde, Marcus A R L

    2015-08-01

    Malignant tumors in the nasal region may be treated by means of invasive surgical procedures, with large facial losses. Nasal prostheses, retained by osseointegrated facial implants, instead of plastic surgery, will, in most patients, offer good biomechanical and cosmetic results. This clinical report describes the prosthetic rehabilitation of a patient with nasal cancer who had the entire nasal vestibule removed in a single-stage surgical procedure in order to shorten the rehabilitation time. The nasal prosthesis was built on a 3-magnet bar and was made of platinum silicone with intrinsic pigmentation, thereby restoring the patient's appearance and self-esteem. The authors concluded that single-stage implants may reduce the rehabilitation time to as little as 1 month, and the correct use of materials and techniques may significantly improve the nasal prosthesis.

  11. Investigation of Single-Stage Modified Turbine of Mark 25 Torpedo Power Plant

    NASA Technical Reports Server (NTRS)

    Hoyt, Jack W.

    1947-01-01

    Efficiency investigations have been made on a single-stage modification of the turbine of a Mark 25 aerial torpedo to determine the performance of the unit with five different turbine nozzles. The output of the turbine blades was computed by analyzing the windage and mechanical-friction losses of the unit. The turbine was faund to be most efficient with a cast nozzle having sharp-edged inlets to the nine nozzle ports. An analysis af the effectiveness af the first and second stages of the standard Mark 25 torpedo turbine indicates that the first- stage turbine contributes nearly all the brake power produced at blade-jet speed ratios above 0.26.

  12. Dimension Determination of Precursive Stall Events in a Single Stage High Speed Compressor

    NASA Technical Reports Server (NTRS)

    Bright, Michelle M.; Qammar, Helen K.; Hartley, Tom T.

    1996-01-01

    This paper presents a study of the dynamics for a single-stage, axial-flow, high speed compressor core, specifically, the NASA Lewis rotor stage 37. Due to the overall blading design for this advanced core compressor, each stage has considerable tip loading and higher speed than most compressor designs, thus, the compressor operates closer to the stall margin. The onset of rotating stall is explained as bifurcations in the dynamics of axial compressors. Data taken from the compressor during a rotating stall event is analyzed. Through the use of a box-assisted correlation dimension methodology, the attractor dimension is determined during the bifurcations leading to rotating stall. The intent of this study is to examine the behavior of precursive stall events so as to predict the entrance into rotating stall. This information may provide a better means to identify, avoid or control the undesirable event of rotating stall formation in high speed compressor cores.

  13. Project management lessons learned on SDIO's Delta Star and Single Stage Rocket Technology programs

    NASA Technical Reports Server (NTRS)

    Klevatt, Paul L.

    1992-01-01

    The topics are presented in viewgraph form and include the following: a Delta Star (Delta 183) Program Overview, lessons learned, and rapid prototyping and the Single Stage Rocket Technology (SSRT) Program. The basic objective of the Strategic Defense Initiative Programs are to quickly reduce key uncertainties to a manageable range of parameters and solutions, and to yield results applicable to focusing subsequent research dollars on high payoff areas.

  14. Single-stage repair of aortic coarctation and multiple concomitant cardiac lesions through a median sternotomy.

    PubMed

    Kervan, Umit; Yurdakok, Okan; Genc, Bahadir; Ozen, Anil; Saritas, Ahmet; Kucuker, Seref Alp; Pac, Mustafa

    2013-01-01

    Through a median sternotomy, we performed a single-stage repair of severe aortic coarctation, ventricular septal defect, patent foramen ovale, and mitral valve insufficiency. The severe aortic coarctation was repaired by interposing a synthetic graft between the distal ascending aorta and the descending aorta. We first repaired the coarctation with the 38-year-old man on cardiopulmonary bypass, before aortic cross-clamping, in order to shorten the cross-clamp time.

  15. Adaptive kanban control mechanism for a single-stage hybrid system

    NASA Astrophysics Data System (ADS)

    Korugan, Aybek; Gupta, Surendra M.

    2002-02-01

    In this paper, we consider a hybrid manufacturing system with two discrete production lines. Here the output of either production line can satisfy the demand for the same type of product without any penalties. The interarrival times for demand occurrences and service completions are exponentially distributed i.i.d. variables. In order to control this type of manufacturing system we suggest a single stage pull type control mechanism with adaptive kanbans and state independent routing of the production information.

  16. Single Stage to Orbit: Politics, Space Technology, and the Quest for Reusable Rocketry

    NASA Technical Reports Server (NTRS)

    Butrica, Andrew J.

    2003-01-01

    While the glories and tragedies of the space shuttle make headlines and move the nation, the story of the shuttle forms an inseparable part of a lesser-known but no less important drama-the search for a re-useable single-stage-to-orbit rocket. Here an award-winning student of space science, Andrew J. Butrica, examines the long and tangled history of this ambitious concept, from it first glimmerings in the 1920s, when technicians dismissed it as unfeasible, to its highly expensive heyday in the midst of the Cold War, when conservative-backed government programs struggled to produce an operational flight vehicle. Butrica finds a blending of far-sighted engineering and heavy-handed politics. To the first and oldest idea-that of the reusable rocket-powered single-stage- to-orbit vehicle-planners who belonged to what President Eisenhower referred to as the military-industrial complex added experimental (" X "), "aircraft-like" capabilities and, eventually, a "faster, cheaper, smaller" managerial approach. Single Stage to Orbit traces the interplay of technology, corporate interest, and politics, a combination that well served the conservative space agenda and ultimately triumphed-not in the realization of inexpensive, reliable space transport-but in a vision of space militarization and commercialization that would appear settled United States policy in the early twenty-first century. "The 'holy grail' of the spaceship movement has been the development of a vehicle that could accomplish single stage to orbit (SSTO) flight. This study describes the evolution of this concept from the 192'0s to the present, revealing a conservative space agenda that has not yet been the subject of historical analysis. As such, it makes an important contribution to space history literature."-Roger D. Launius, The Smithsonian Institution.

  17. Single-stage, batch, leach-bed, thermophilic anaerobic digestion of spent sugar beet pulp.

    PubMed

    Koppar, Abhay; Pullammanappallil, Pratap

    2008-05-01

    Spent sugar beet pulp as received was digested in a single-stage, batch, unmixed, leach-bed, laboratory scale thermophilic anaerobic digester. Biogasification of each 0.450 kg (wet weight) batch of spent pulp was initiated by inoculating with anaerobically digested liquor from previous run. The average methane yield was 0.336 m3 CH4 at STP (kgVS)(-1), the maximum methane production rate was 0.087 m3 CH4 at STP (kgVS)(-1)d(-1), average lag time to initiate methanogenesis was only 0.44 days and time required to achieve 95% methane yield was 8 days. The pH in the digesters ranged between 8.0 and 9.5. High rates of methane generation were sustained even at high pH values. The equivalent organic loading rate in the batch digesters was 4 kgCODm(-3)d(-1). The digestion process used here offers significant improvements over one-stage and two-stage systems reported in the literature with comparable performance as it is a single-stage system where the feedstock does not require size reduction, and mixing is not required in the digester.

  18. Single-stage bilateral pulmonary resections by video-assisted thoracic surgery for multiple small nodules

    PubMed Central

    Yao, Feng; Yang, Haitang

    2016-01-01

    Background Surgical treatment is thought to be the most effective strategy for multiple small nodules. However, in general, one-stage bilateral resection is not recommended due to its highly invasive nature. Methods Clinical records of patients undergoing one-stage bilateral resections of multiple pulmonary nodules between January 2009 and September 2014 in a single institution were retrospectively reviewed. Results Simultaneous bilateral pulmonary resection by conventional video-assisted thoracic surgery (VATS) was undertaken in 29 patients. Ground glass opacity (GGO) accounted for 71.9% (46/64) of total lesions, including 26 pure GGO and 20 mixed GGO lesions. One case underwent bilateral lobectomy that was complicated by postoperative dyspnea. Lobar-sublobar (L/SL) resection and bilateral sublobar resection (SL-SL) were conducted in 16 and 12 cases, respectively, and most of these cases had uneventful postoperative courses. There was no significant difference with regard to postoperative complications (P=0.703), duration of use of chest drains (P=0.485), between one- and two-stage groups. Mean postoperative follow-up in cases of primary lung cancer was 31.4 (range, 10–51) months. There was neither recurrence nor deaths at final follow-up. Conclusions Single-stage bilateral surgery in selected cases with synchronous bilateral multiple nodules (SBMNs) is feasible and associated with satisfactory outcomes. PMID:27076942

  19. Single-stage laryngotracheal reconstruction for the treatment of subglottic stenosis in children

    PubMed Central

    Smith, Mariana Magnus; Schweiger, Cláudia; Manica, Denise; Meotti, Camila Degen; Eneas, Larissa Valency; Kuhl, Gabriel; Marostica, Paulo Jose Cauduro

    2012-01-01

    Summary Introduction: In recent decades, airway reconstruction has become the treatment of choice for subglottic stenosis (SGS) in children, which is performed in either single or multiple stages. However, there is evidence in the literature that single-stage surgery is more effective. Objective: To evaluate the success rate of single-stage laryngotracheoplasty (LTP) and cricotracheal resection (CTR) in patients that were treated in our hospital. Materials and Method: We performed a retrospective study of children undergoing laryngotracheal reconstruction. Results: Twenty-four children were included. The etiology of SGS was postintubation in 91.6% and congenital in 8.3%. One patient (4.2%) had grade 4 SGS, 17 (70.8%) presented with grade 3 SGS, 4 (16.6%) had grade 2 SGS, 1 (4.2%) had grade 3 SGS associated with glottic stenosis, and 1 (4.2%) had grade 3 SGS with tracheal stenosis. We performed 26 LTPs and 3 CTRs. Decannulation rates were 66% in the CTR procedures and 85.7% in the LTP procedures; the overall decannulation rate was 83.3%. All children presented with fever in the postoperative period, but were afebrile after the tube was removed. Conclusion: Our series showed a decannulation rate of 83.3%. PMID:25991938

  20. Red Mud Catalytic Pyrolysis of Pinyon Juniper and Single-Stage Hydrotreatment of Oils

    SciTech Connect

    Agblevor, Foster A.; Elliott, Douglas C.; Santosa, Daniel M.; Olarte, Mariefel V.; Burton, Sarah D.; Swita, Marie; Beis, Sedat H.; Christian, Kyle; Sargent, Brandon

    2016-10-20

    Pinyon juniper biomass feedstocks, which cover a large acreage of rangeland in the western United States, are being eradicated and, therefore, considered as a convenient biomass feedstock for biofuel production. Pinyon juniper whole biomass (wood, bark, and leaves) were pyrolyzed in a pilot-scale bubbling fluidized-bed reactor at 450 °C, and the noncondensable gases were recycled to fluidize the reactor. Red mud was used as the in situ catalyst for the pyrolysis of the pinyon juniper biomass. The pyrolysis products were condensed in three stages, and products were analyzed for physicochemical properties. The condenser oil formed two phases with the aqueous fraction, whereas the electrostatic precipitator oils formed a single phase. The oil pH was 3.3; the higher heating value (HHV) was 28 MJ/kg; and the viscosity was less than 100 cP. There was a direct correlation between the viscosity of the oils and the alcohol/ether content of the oils, and this was also related to the aging rate of the oils. The catalytic pyrolysis oils were hydrotreated in a continuous single-stage benchtop hydrotreater to produce hydrocarbon fuels with a density of 0.80$-$0.82 cm3/g. The hydrotreater ran continuously for over 300 h with no significant catalyst deactivation or coke formation. This is the first time that such a long single-stage hydrotreatment has been demonstrated on biomass catalytic pyrolysis oils.

  1. Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression

    NASA Astrophysics Data System (ADS)

    Varshnay, N. K.; Singh, A.; Benerji, N. S.

    2017-02-01

    Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression suitable for material processing applications are presented here. The laser incorporates in-built compact gas circulation and gas cooling to ensure fresh gas mixture between the electrodes for repetitive operation. A magnetically coupled tangential blower is used for gas circulation inside the laser chamber for repetitive operation. The exciter consists of C-C energy transfer circuit and thyratron is used as a high-voltage main switch with single-stage magnetic pulse compression (MPC) between thyratron and the laser electrodes. Low inductance of the laser head and uniform and intense pre-ionization are the main features of the electric circuit used in the laser. A 250 ns rise time voltage pulse was compressed to 100 ns duration with a single-stage magnetic pulse compressor using Ni-Zn ferrite cores. The laser can generate about 150 mJ at ˜100 Hz rep-rate reliably from a discharge volume of 100 cm 3. 2D spatial laser beam profile generated is presented here. The profile shows that the laser beam is completely filled with flat-top which is suitable for material processing applications. The SEM image of the microhole generated on copper target is presented here.

  2. Single Stage Single Switch Power Supply (S4PS)Design for Low Power HB-LED Lighting

    NASA Astrophysics Data System (ADS)

    Shrivastava, Ashish; Singh, Bhim

    2013-05-01

    This paper presents an improved power quality converter (IPQC)-based power supply design for high brightness light emitting diode (HB-LED) low power lighting. The IPQC circuit uses a Cuk buck-boost converter to operate it in a discontinuous conduction mode (DCM) using the voltage follower technique for the mitigation of harmonic contents present in the AC mains current. Subsequently, reduction in harmonic contents results in improving the power quality indices at the AC mains. Single-stage single switch converter topology is used, which has less component count, size and cost as compared to the two-stage converter topology. DCM operation has an advantage that only output voltage control loop is required as compared to three control loops required in the continuous conduction mode operation. An 18-W LED driver is designed, modeled and simulated using MATLAB/Simulink software for 220 V, 50 Hz AC mains. The performance of the proposed LED driver is observed in terms of total harmonic distortion of the input current (THDi), input power factor (PF) and crest factor (CF) taking into account the strict international standard of IEC 61000-3-2 for class C equipments.

  3. Extracorporeal Membrane Oxygenation Outcomes After the Comprehensive Stage II Procedure in Patients With Single Ventricles.

    PubMed

    Gomez, Daniel; Duffy, Vicky; Hersey, Diane; Backes, Carl; Rycus, Peter; McConnell, Patrick; Voss, Jordan; Galantowicz, Mark; Cua, Clifford L

    2017-01-01

    Outcomes for extracorporeal membrane oxygenation (ECMO) have been described for patients with single ventricle physiology (SVP) undergoing cavopulmonary connection (Glenn procedure). An alternative surgical pathway for patients with SVP consists of an initial hybrid procedure followed by a comprehensive Stage II procedure. No data exist describing the outcomes of patients requiring ECMO after the comprehensive Stage II procedure. The goal of this study is to describe the outcomes for patients who required ECMO after the comprehensive Stage II procedure. Data from the Extracorporeal Life Support Organization (ELSO) registry from 2001 to 2015 for children undergoing the comprehensive Stage II procedure older than 3 months of age were retrospectively analyzed. Demographics and ECMO characteristics were recorded. A total of six children required ECMO support after the comprehensive Stage II procedure (2 males, 4 females). Four patients had the diagnosis of hypoplastic left heart syndrome and two patients had the diagnosis of an unbalanced atrioventricular septal defect. Bypass time was 242.8 ± 110.9 min and cross-clamp time was 91.2 ± 46.2 min for the surgical procedure. Weight was 5.8 ± 1.3 kg and age was 150.2 + 37.9 days at time of ECMO. ECMO duration was 276.0 ± 218.1 h. Complications during the ECMO run included hemorrhage in four patients (67%), renal dysfunction in two patients (33%), and neurologic injury in two patients (33%). Four patients (67%) were discharged alive after ECMO decannulation. Despite being a much more extensive surgical procedure, the morbidity and mortality after ECMO in patients undergoing the comprehensive Stage II procedure are similar to those in patients undergoing the Glenn procedure. If needed, ECMO support is reasonable for patients after the comprehensive Stage II procedure.

  4. Single-item vs multiple-item measures of stage of change in compliance with prescribed medications.

    PubMed

    Cook, Christopher L; Perri, Matthew

    2004-02-01

    The Stage of Change construct from the Transtheoretical Model of behavioral change has been widely utilized in the assessment of various health behaviors. The majority of these tests measure the Stage of Change construct using the single-item. multiple-choice format. This study validated the use of a single-item measure in measuring readiness to comply with taking a prescribed medication. A sample of 161 subjects tested the multiple-item Stage of Change measure, then a refined multiple-item survey was tested with 59 subjects. With the latter survey, discriminating subjects at the differing stages of change dimensions was difficult. A correlation of .91 was found for stage classifications between ratings on the single-item and multiple-item scales. The use of the single-item measure seems reasonable when assessing stage of change in compliance with prescribed medication.

  5. Sleep stage and obstructive apneaic epoch classification using single-lead ECG

    PubMed Central

    2010-01-01

    Background Polysomnography (PSG) is used to define physiological sleep and different physiological sleep stages, to assess sleep quality and diagnose many types of sleep disorders such as obstructive sleep apnea. However, PSG requires not only the connection of various sensors and electrodes to the subject but also spending the night in a bed that is different from the subject's own bed. This study is designed to investigate the feasibility of automatic classification of sleep stages and obstructive apneaic epochs using only the features derived from a single-lead electrocardiography (ECG) signal. Methods For this purpose, PSG recordings (ECG included) were obtained during the night's sleep (mean duration 7 hours) of 17 subjects (5 men) with ages between 26 and 67. Based on these recordings, sleep experts performed sleep scoring for each subject. This study consisted of the following steps: (1) Visual inspection of ECG data corresponding to each 30-second epoch, and selection of epochs with relatively clean signals, (2) beat-to-beat interval (RR interval) computation using an R-peak detection algorithm, (3) feature extraction from RR interval values, and (4) classification of sleep stages (or obstructive apneaic periods) using one-versus-rest approach. The features used in the study were the median value, the difference between the 75 and 25 percentile values, and mean absolute deviations of the RR intervals computed for each epoch. The k-nearest-neighbor (kNN), quadratic discriminant analysis (QDA), and support vector machines (SVM) methods were used as the classification tools. In the testing procedure 10-fold cross-validation was employed. Results QDA and SVM performed similarly well and significantly better than kNN for both sleep stage and apneaic epoch classification studies. The classification accuracy rates were between 80 and 90% for the stages other than non-rapid-eye-movement stage 2. The accuracies were 60 or 70% for that specific stage. In five

  6. Multi-functional stage-scanning fluorescence micro/nanoscope for single-lipid dynamics

    NASA Astrophysics Data System (ADS)

    Yang, Li-Ling; Hsieh, Chia-Fen; Chang, Yi-Ren; Shen, Jie-Pan; Chang, Yu-Chung; Chou, Chia-Fu

    2012-02-01

    We combine pulsed laser, supercontinuum radiation source and fast single-photon counting peripherals to obtain a multifunctional micro/nano-scope. This provides us with better spatial and temporal resolution to observe fast dynamics. Performing fluorescence correlation spectroscopy for fast dynamics (<μs) with sub-diffraction limit resolution to observe the initial state of single-lipid dynamics in supported lipid bilayers and living cells is our goal. Lipid raft serves as a platform for recruiting signaling components of effective signal transduction. However, the dynamics of sub-200nm rapidly aggregated lipid rafts are still not elucidated in living cells. We here report our recent progress on the construction of this multi-functional stage-scanning fluorescence micro/nanoscope for single-lipid dynamics study.

  7. Nuclear magnetic resonance studies of ancient buried wood-I. Observations on the origin of coal to the brown coal stage

    USGS Publications Warehouse

    Hatcher, P.G.; Breger, I.A.; Earl, W.L.

    1981-01-01

    Various wood fragments buried in sediments under anaerobic conditions for from 450 yr to approximately 8 Myr have been examined by solid-state 13C nuclear magnetic resonance. Cellulose and other carbohydrates, the major components of Holocene wood, have been shown to be gradually hydrolyzed or otherwise lost under the conditions of burial. Lignin structures, however, are preserved relatively unchanged and become concentrated by difference as the carbohydrates disappear. Thus, a fragment of coalified wood isolated from a Miocene brown coal was found to be still composed of approximately 75% lignin and 25% cellulose. On the basis of our observations, we suggest that coalification of woody tissue progresses directly from lignin to coal and that such coalification may be retarded until most of the cellulose disappears. ?? 1981.

  8. Plasma gasification of refuse derived fuel in a single-stage system using different gasifying agents.

    PubMed

    Agon, N; Hrabovský, M; Chumak, O; Hlína, M; Kopecký, V; Masláni, A; Bosmans, A; Helsen, L; Skoblja, S; Van Oost, G; Vierendeels, J

    2016-01-01

    The renewable evolution in the energy industry and the depletion of natural resources are putting pressure on the waste industry to shift towards flexible treatment technologies with efficient materials and/or energy recovery. In this context, a thermochemical conversion method of recent interest is plasma gasification, which is capable of producing syngas from a wide variety of waste streams. The produced syngas can be valorized for both energetic (heat and/or electricity) and chemical (ammonia, hydrogen or liquid hydrocarbons) end-purposes. This paper evaluates the performance of experiments on a single-stage plasma gasification system for the treatment of refuse-derived fuel (RDF) from excavated waste. A comparative analysis of the syngas characteristics and process yields was done for seven cases with different types of gasifying agents (CO2+O2, H2O, CO2+H2O and O2+H2O). The syngas compositions were compared to the thermodynamic equilibrium compositions and the performance of the single-stage plasma gasification of RDF was compared to that of similar experiments with biomass and to the performance of a two-stage plasma gasification process with RDF. The temperature range of the experiment was from 1400 to 1600 K and for all cases, a medium calorific value syngas was produced with lower heating values up to 10.9 MJ/Nm(3), low levels of tar, high levels of CO and H2 and which composition was in good agreement to the equilibrium composition. The carbon conversion efficiency ranged from 80% to 100% and maximum cold gas efficiency and mechanical gasification efficiency of respectively 56% and 95%, were registered. Overall, the treatment of RDF proved to be less performant than that of biomass in the same system. Compared to a two-stage plasma gasification system, the produced syngas from the single-stage reactor showed more favourable characteristics, while the recovery of the solid residue as a vitrified slag is an advantage of the two-stage set-up.

  9. New technique for single-staged repair of aortic coarctation and coexisting cardiac disorder.

    PubMed

    Korkmaz, Askin Ali; Guden, Mustafa; Onan, Burak; Tarakci, Sevim Indelen; Demir, Ali Soner; Sagbas, Ertan; Sarikaya, Tugay

    2011-01-01

    The management of adults with aortic coarctation and a coexisting cardiac disorder is still a surgical challenge. Single-staged procedures have lower postoperative morbidity and mortality rates than do 2-staged procedures. We present our experience with arch-to-descending aorta bypass grafting in combination with intracardiac or ascending aortic aneurysm repair.From October 2004 through April 2010, 5 patients (4 men, 1 woman; mean age, 45.8 ± 9.4 yr) underwent anatomic bypass grafting of the arch to the descending aorta through a median sternotomy and concomitant repair of an intracardiac disorder or an ascending aortic aneurysm. Operative indications included coarctation of the aorta in all cases, together with severe mitral insufficiency arising from damaged chordae tendineae in 2 patients, ascending aortic aneurysm with aortic regurgitation in 2 patients, and coronary artery disease in 1 patient. Data from early and midterm follow-up were reviewed.There was no early or late death. Follow-up was complete for all patients, and the mean follow-up period was 34.8 ± 18 months (range, 18 mo-5 yr). All grafts were patent. No late graft-related sequelae or reoperations were observed.For single-staged repair of aortic coarctation with a coexistent cardiac disorder, we propose arch-to-descending aorta bypass through a median sternotomy as an alternative for selected patients.

  10. 386 mW/20 K single-stage Stirling-type pulse tube cryocooler

    NASA Astrophysics Data System (ADS)

    Chen, Liubiao; Zhou, Qiang; Jin, Hai; Zhu, Wenxiu; Wang, Junjie; Zhou, Yuan

    2013-10-01

    Recently, we reported a single-stage Stirling-type pulse tube cryocooler (SPTC) that achieved a no-load temperature of 18.6 K and 0.2 W/20.6 K with 268 W input power at the frequency of 38 Hz. By further optimizing the regenerator, using the stainless steel screens only, a new SPTC driven by a dual-opposed linear compressor has been built and tested. At present, a lowest temperature of 15.5 K, which is a new record for single-stage SPTC, and 386 mW/20 K cooling power can be achieved with 246 W input power, which is comparable to the two-stage SPTC with a similar input power. The optimization process of regenerator will be presented in this paper. Experimental results indicate that it is important for SPTC to reduce the flow resistance of regenerator at the warm end and enhance the regenerative capacity of the cold end to improve the cooling performance. Lead spheres were also employed as part of the regenerator to achieve the possible lower temperature, but the test results show that there is no evident improvement in achieving lower temperature.

  11. Injection blow moulding single stage process: Validation of the numerical simulation through tomography analysis

    NASA Astrophysics Data System (ADS)

    Biglione, Jordan; Béreaux, Yves; Charmeau, Jean-Yves

    2016-10-01

    The injection blow moulding single stage process has been made available on standard injection moulding machine. Both the injection moulding stage and the blow moulding stage are being taken care of in an injection mould. Thus the dimensions of this mould are those of a conventional injection moulding mould. The fact that the two stages are located in the same mould leads to a process more constrained than the conventional one. This process introduces temperature gradients, molecular orientation, high stretch rates and high cooling rates. These constraints lead to a small processing window. In practice, the preform has to remain sufficiently melted to be blown so that the process takes place between the melting temperature and the crystallization temperature. In our numerical approach, the polymer is supposed to be blown in its molten state. Hence we have identified the mechanical behaviour of the polymer in its molten state through dynamical rheology experiments. A viscous Cross model has been proved to be relevant to the problem. Thermal dependence is assumed by an Arrhenius law. The process is simulated through a finite element code (POLYFLOW software) in the Ansys Workbench framework. Thickness measurements using image analysis of tomography data are performed and comparisons with the simulation results show good agreements.

  12. The μ-RWELL: A compact, spark protected, single amplification-stage MPGD

    NASA Astrophysics Data System (ADS)

    Poli Lener, M.; Bencivenni, G.; de Olivera, R.; Felici, G.; Franchino, S.; Gatta, M.; Maggi, M.; Morello, G.; Sharma, A.

    2016-07-01

    In this work we present two innovative architectures of resistive MPGDs based on the WELL-amplification concept: - the micro-Resistive WELL (μ-RWELL) is a compact spark-protected single amplification-stage Micro-Pattern Gas Detector (MPGD). The amplification stage, realized with a structure very similar to a GEM foil (called WELL), is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new architecture, showing an excellent space resolution, 50 μm, is a very compact device, robust against discharges and exhibiting a large gain (>104), simple to construct and easy for engineering and then suitable for large area tracking devices as well as digital calorimeters. - the Fast Timing Micro-pattern (FTM): a new device with an architecture based on a stack of several coupled full-resistive layers where drift and multiplication stages (WELL type) alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings, providing a signal with a gain of 104-105. The main advantage of this new device is the improvement of the timing provided by the competition of the ionization processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as for applications like medical imaging.

  13. Single-trial ERP analysis reveals facial expression category in a three-stage scheme.

    PubMed

    Zhang, Dandan; Luo, Wenbo; Luo, Yuejia

    2013-05-28

    Emotional faces are salient stimuli that play a critical role in social interactions. Following up on previous research suggesting that the event-related potentials (ERPs) show differential amplitudes in response to various facial expressions, the current study used trial-to-trial variability assembled from six discriminating ERP components to predict the facial expression categories in individual trials. In an experiment involved 17 participants, fearful trials were differentiated from non-fearful trials as early as the intervals of N1 and P1, with a mean predictive accuracy of 87%. Single-trial features in the occurrence of N170 and vertex positive potential could distinguish between emotional and neutral expressions (accuracy=90%). Finally, the trials associated with fearful, happy, and neutral faces were completely separated during the window of N3 and P3 (accuracy=83%). These categorization findings elucidated the temporal evolution of facial expression extraction, and demonstrated that the spatio-temporal characteristics of single-trial ERPs can distinguish facial expressions according to a three-stage scheme, with "fear popup," "emotional/unemotional discrimination," and "complete separation" as processing stages. This work constitutes the first examination of neural processing dynamics beyond multitrial ERP averaging, and directly relates the prediction performance of single-trial classifiers to the progressive brain functions of emotional face discrimination.

  14. Relationship of serum elastin peptide level to single breath transfer factor for carbon monoxide in French coal miners

    PubMed Central

    Frette, C.; Jacob, M. P.; Wei, S. M.; Bertrand, J. P.; Laurent, P.; Kauffmann, F.; Pham, Q. T.

    1997-01-01

    BACKGROUND: Clinical and epidemiological studies have given discordant results on the usefulness of the level of circulating elastin peptide (EP), a potential marker of both elastin destruction (a key phenomenon in pulmonary emphysema) and neosynthesis, for assessing structural changes in the lung extracellular matrix. The aim of the present study was to explore the relationship between levels of EP and forced expiratory volume in one second (FEV1) and single breath transfer factor for carbon monoxide (TLCO and KCO) in coal miners. METHODS: The study population comprised 227 working coal miners aged 34-50 years consisting of 75 miners heavily exposed to underground coal dust with pulmonary radiographs classified as 0/1 or 1/0 by the International Labour Office classification, 75 exposed miners with radiographs classified as normal (0/0), and 77 miners slightly exposed to coal dust with normal radiographs. The subjects answered a standardised questionnaire and performed spirometric tests and a carbon monoxide (CO) transfer test. RESULTS: No association was observed between EP levels and % predicted FEV1 (or FEV1/FVC). The level of EP increased significantly with decreased % predicted TLCO (r = -0.20). Miners in the lowest % predicted KCO quintile had higher EP levels than the rest (3.28 (1.37) vs 2.47 (1.16)). A significantly lower EP level was observed in miners with radiographs classified as 1/0 or 0/1, especially in those with round opacities, compared with miners with a normal radiograph, and in current smokers compared with the rest. CONCLUSIONS: The results of this study suggest that the level of EP may reflect some remodelling activity in emphysema and lung fibrosis. 


 PMID:9516897

  15. A single-stage optical load-balanced switch for data centers.

    PubMed

    Huang, Qirui; Yeo, Yong-Kee; Zhou, Luying

    2012-10-22

    Load balancing is an attractive technique to achieve maximum throughput and optimal resource utilization in large-scale switching systems. However current electronic load-balanced switches suffer from severe problems in implementation cost, power consumption and scaling. To overcome these problems, in this paper we propose a single-stage optical load-balanced switch architecture based on an arrayed waveguide grating router (AWGR) in conjunction with fast tunable lasers. By reuse of the fast tunable lasers, the switch achieves both functions of load balancing and switching through the AWGR. With this architecture, proof-of-concept experiments have been conducted to investigate the feasibility of the optical load-balanced switch and to examine its physical performance. Compared to three-stage load-balanced switches, the reported switch needs only half of optical devices such as tunable lasers and AWGRs, which can provide a cost-effective solution for future data centers.

  16. Cystolithotomy during robotic radical prostatectomy: Single-stage procedure for concomitant bladder stones

    PubMed Central

    Tan, Gerald Y.; Sooriakumaran, Prasanna; Peters, David L.; Srivastava, Abhishek; Tewari, Ashutosh

    2012-01-01

    Asymptomatic concomitant vesical calculi are an occasional finding on routine radiologic staging and evaluation of patients with early prostate cancer. We report the first case of single-stage robotic cystolithotomy for multiple bladder stones in a 64-year-old man undergoing robotic-assisted radical prostatectomy, and discuss the approaches available for ensuring complete stone clearance in this unique setting. We show that concomitant bladder stone extraction during robotic-assisted radical prostatectomy is feasible and does not add significantly to operative time. This technique avoids the need to undergo additional general anesthetic procedures with potential complications such as bleeding, urethral stricture formation, and bladder perforation, prior to the prostatectomy. PMID:22557729

  17. Two-stage vs single-stage thermophilic anaerobic digestion: comparison of energy production and biodegradation efficiencies.

    PubMed

    Schievano, Andrea; Tenca, Alberto; Scaglia, Barbara; Merlino, Giuseppe; Rizzi, Aurora; Daffonchio, Daniele; Oberti, Roberto; Adani, Fabrizio

    2012-08-07

    Two-stage anaerobic digestion (AD) for integrated biohydrogen and biomethane production from organic materials has been reported to promise higher process efficiency and energy recoveries as compared to traditional one-stage AD. This work presents a comparison between two-stage (reactors R1 and R2) and one-stage (reactor R3) AD systems, fed with identical organic substrates and loading rates, focusing the attention on chemical and microbiological aspects. Contrary to previous experiences, no significant differences in overall energy recovery were found for the two-stage and one-stage AD systems. However, an accumulation in R2 of undegraded intermediate metabolites (volatile fatty acids, ketones, amines, amino acids, and phenols) was observed by GC-MS. These compounds were thought to be both cause and effect of this partial inefficiency of the two-stage system, as confirmed also by the less diverse, and thereby less efficient, population of fermentative bacteria observed (by PCR-DGGE) in R2. The extreme environment of R1 (low pH and high metabolites concentrations) probably acted as selector of metabolic pathways, favoring H(2)-producing bacteria able to degrade such a wide variability of intermediate metabolites while limiting other strains. Therefore, if two-stage AD may potentially lead to higher energy recoveries, further efforts should be directed to ensure process efficiency and stability.

  18. Numerical simulation of air and oxy-fuel combustion of single coal particles using the reactive implicit continuous-fluid Eulerian (RICE) method

    NASA Astrophysics Data System (ADS)

    Lewtak, Robert

    2013-10-01

    The paper presents the mathematical model of air and oxy-fuel combustion of single coal particles. The combustion process has been treated as a spherically-symmetric one. The 1-dimensional time-dependent conservation equations governing the process have been numerically solved using the RICE method. The presence of a coal particle, which was treated as a discrete Lagrange particle, has modified the boundary conditions at the gas-solid interface. Numerical results show good agreement with the experimental results.

  19. Immediate Single-Stage Reconstruction of Complex Frontofaciobasal Injuries: Part I

    PubMed Central

    Awadalla, Akram Mohamed; Ezzeddine, Hichem; Fawzy, Naglaaa; Saeed, Mohammad Al; Ahmad, Mohammad R.

    2014-01-01

    Objective To determine if immediate (within 6 hours of adequate resuscitation) single-stage repair of complex craniofacial injuries could be accomplished with acceptable morbidity and mortality taking into consideration the cosmetic appearance of the patient. Patients and Methods A total of 26 patients (19 men, 7 women) ranging in age from 8 to 58 years with Glasgow Coma Scale scores of 5 to 15 all had a combined single-stage repair of their complex craniofacial injuries within 6 hours of their admission. After initial assessment and adequate resuscitation, they were evaluated with three-dimensional computed tomography of the face and head. Coronal skin flap was used for maximum exposure for frontal sinus exenteration as well as dural repair, cortical debridement, calvarial reconstruction, and titanium mesh placement. Results Neurosurgical outcome at both the early and late evaluations was judged as good in 22 of 26 patients (85%), moderate in 3 of 26 (11%), and poor in 1 of the 26 (3.8%). Cosmetic surgical outcome at the early evaluation showed 17 of 26 (65%) to be excellent, 4 of 26 (15.5%) to be good, 4 patients (15.5%) to be fair, and 1 patient (3.8%) to be poor. At the late reevaluation, the fair had improved to good with an additional reconstructive procedure, and the poor had improved to fair with another surgery. There was no calvarial osteomyelitis, graft resorption, or intracranial abscess. Complications included three patients (11%): one (3.8%) had tension pneumocephaly and meningitis, one (3.8%) had delayed cerebrospinal fluid leak with recurrent attacks of meningitis, and one had a maxillary sinus infection (3.8%) secondary to front maxillary fistula. Conclusion The immediate single-stage repair of complex craniofacial injuries can be performed with acceptable results, a decreased need for reoperation, and improved cosmetic and functional outcomes. PMID:25844296

  20. Staged bilateral single-port thoracoscopic lung volume reduction surgery: A report of 11 cases

    PubMed Central

    Zhang, Miao; Wang, Heng; Pan, Xue-Feng; Wu, Wen-Bin; Zhang, Hui

    2016-01-01

    The aim of the present study was to investigate the feasibility and efficacy of staged bilateral single-port thoracoscopic lung volume reduction surgery (LVRS) for patients with chronic obstructive pulmonary emphysema (COPE). Eleven male patients with a mean age of 60.27±12.11 years with bilateral COPE and bullae were admitted to the Department of Thoracic Surgery, Xuzhou Central Hospital from January 2013 to June 2014. The patients underwent staged bilateral single-port thoracoscopic LVRS. The hyperinflated bullae were resected using endoscopic staplers (Endo-GIA), followed by continuous suture and biological glue for reinforcement of the margin. In addition, pulmonary function, blood gas assay, 6-min walk distance (6MWD) and life quality evaluated by a short form 36-item health survey questionnaire (SF-36) were recorded before and after LVRS, respectively. All the patients survived after surgery. The chest tube drainage time was 9.09±1.31 days and postoperative hospital stay was 15.73±2.75 days, with 5 cases of persistent air leakage and 7 cases of pulmonary infection which were finally cured. The patients were followed up for 3 to 12 months, and the pulmonary function, partial pressure of oxygen (pO2), 6MWD and life quality after unilateral or bilateral LVRS were improved compared to these parameters before surgery. However, there was no significant difference between unilateral and bilateral LVRS in terms of life quality. In conclusion, staged bilateral single-port thoracoscopic LVRS may improve the short-term life quality of patients with COPE. PMID:27882084

  1. Simulation model of a single-stage lithium bromide-water absorption cooling unit

    NASA Technical Reports Server (NTRS)

    Miao, D.

    1978-01-01

    A computer model of a LiBr-H2O single-stage absorption machine was developed. The model, utilizing a given set of design data such as water-flow rates and inlet or outlet temperatures of these flow rates but without knowing the interior characteristics of the machine (heat transfer rates and surface areas), can be used to predict or simulate off-design performance. Results from 130 off-design cases for a given commercial machine agree with the published data within 2 percent.

  2. The Lifetime Estimate for ACSR Single-Stage Splice Connector Operating at Higher Temperatures

    SciTech Connect

    Wang, Jy-An John; Graziano, Joe; Chan, John

    2011-01-01

    This paper is the continuation of Part I effort to develop a protocol of integrating analytical and experimental approaches to evaluate the integrity of a full tension single-stage splice connector (SSC) assembly during service at high operating temperature.1The Part II efforts are mainly focused on the thermal mechanical testing, thermal-cycling simulation and its impact on the effective lifetime of the SSC system. The investigation indicates that thermal cycling temperature and frequency, conductor cable tension loading, and the compressive residual stress field within a SSC system have significant impact on the SSC integrity and the associated effective lifetime.

  3. Effects of relaxed static longitudinal stability on a single-stage-to-orbit vehicle design

    NASA Technical Reports Server (NTRS)

    Freeman, D. C., Jr.; Wilhite, A. W.

    1979-01-01

    The effects of relaxing longitudinal stability requirements on single stage to orbit space vehicles is studied. A comparison of the mass and performance characteristics of two vehicles, one designed for positive levels of longitudinal stability and the other designed with relaxed stability requirements in a computer aided design process is presented. Both vehicles, required to meet the same mission characteristics are described. Wind tunnel tests, conducted over a Mach number range from 0.3 to 4.63 to verify estimated aerodynamic characteristics, are discussed.

  4. Tracking Single C. elegans Using a USB Microscope on a Motorized Stage.

    PubMed

    Yemini, Eviatar I; Brown, André E X

    2015-01-01

    Locomotion and gross morphology have been important phenotypes for C. elegans genetics since the inception of the field and remain relevant. In parallel with developments in genome sequencing and editing, phenotyping methods have become more automated and quantitative, making it possible to detect subtle differences between mutants and wild-type animals. In this chapter, we describe how to calibrate a single-worm tracker consisting of a USB microscope mounted on a motorized stage and how to record and analyze movies of worms crawling on food. The resulting quantitative phenotypic fingerprint can sensitively identify differences between mutant and wild-type worms.

  5. Laparoendoscopic single-site radical hysterectomy for early stage cervical cancer

    PubMed Central

    Park, Ju Young; Kim, Yoo Min; Lee, Yoo-Young; Kim, Tae-Joong; Lee, Jeong-Won; Kim, Byoung-Gie; Bae, Duk-Soo

    2017-01-01

    Technical developments have made laparoendoscopic single-site (LESS) surgery increasingly more feasible for treating gynecological conditions, including cancer. However, complex surgeries such as radical hysterectomy have rarely been performed with single-port access because of technical difficulties. The majority of the difficulties are due to the inefficient retraction of tissue during dissection. Here, we report a detailed description of LESS radical hysterectomy plus pelvic lymph node dissection that was successfully performed in two patients with stage IB1 cervical cancer. We used our expertise with LESS to perform space development as much as possible before the ligaments were resected. The oncologic clearance was comparable to that of conventional laparoscopic radical hysterectomy. PMID:28217681

  6. Resuscitation and perioperative management of the high-risk single ventricle patient: first-stage palliation.

    PubMed

    Lowry, Adam W

    2012-01-01

    Infants born with hypoplastic left heart syndrome or other lesions resulting in a single right ventricle face the highest risk of mortality among all forms of congenital heart disease. Before the modern era of surgical palliation, these conditions were universally lethal; recent refinements in surgical technique and perioperative management have translated into dramatic improvements in survival. Nonetheless, these infants remain at a high risk of morbidity and mortality, and an appreciation of single ventricle physiology is fundamental to the care of these high-risk patients. Herein, resuscitation and perioperative management of infants with hypoplastic left heart syndrome are reviewed. Basic neonatal and pediatric life support recommendations are summarized, and perioperative first-stage clinical management strategies are reviewed.

  7. Sleeve gastrectomy as a single-stage bariatric operation: indications and limitations.

    PubMed

    Daskalakis, Markos; Weiner, Rudolf A

    2009-01-01

    Sleeve gastrectomy (SG) was initially described as a first-step procedure followed by either biliopancreatic diversion with duodenal switch or Roux-en-Y gastric bypass in super-super obese patients. Multiple recent reports have documented SG as single therapy in the treatment of morbid obesity. However,the indications for this procedure are still under evaluation.Accumulating data demonstrate that SG can be an effective and safe procedure for super-super-obese or high-risk patients either as a single operation or as a bridge to more definitive surgery. SG can also be performed in patients who require anti-inflammatory medication or in patients with conditions such as Crohn's disease, cirrhosis, anemia, or severe osteoporosis which preclude intestinal bypass. Furthermore,SG represents not only a safe alternative for morbidly obese patients on anticoagulant medication or immunosuppressive agents but also for those with multiple intra-abdominal adhesions or after failed gastric banding. In addition, SG can be performed safely in morbid obese adolescents. The main limitation of this novel bariatric procedure is the lack of longterm data on sustained weight loss and resolution of obesity related comorbidities. Moreover, the fact that SG is an irreversible operation adds to its weakness as a bariatric procedure, at least until definitive results concerning its efficacy are obtained. SG is effective and safe as a single-stage procedure for certain cohorts of patients. However, the broad application of SG as a single-stage procedure in the bariatric field can be established only if the procedure is standardized and longterm results are available.

  8. A high-order positivity-preserving single-stage single-step method for the ideal magnetohydrodynamic equations

    NASA Astrophysics Data System (ADS)

    Christlieb, Andrew J.; Feng, Xiao; Seal, David C.; Tang, Qi

    2016-07-01

    We propose a high-order finite difference weighted ENO (WENO) method for the ideal magnetohydrodynamics (MHD) equations. The proposed method is single-stage (i.e., it has no internal stages to store), single-step (i.e., it has no time history that needs to be stored), maintains a discrete divergence-free condition on the magnetic field, and has the capacity to preserve the positivity of the density and pressure. To accomplish this, we use a Taylor discretization of the Picard integral formulation (PIF) of the finite difference WENO method proposed in Christlieb et al. (2015) [23], where the focus is on a high-order discretization of the fluxes (as opposed to the conserved variables). We use the version where fluxes are expanded to third-order accuracy in time, and for the fluid variables space is discretized using the classical fifth-order finite difference WENO discretization. We use constrained transport in order to obtain divergence-free magnetic fields, which means that we simultaneously evolve the magnetohydrodynamic (that has an evolution equation for the magnetic field) and magnetic potential equations alongside each other, and set the magnetic field to be the (discrete) curl of the magnetic potential after each time step. In this work, we compute these derivatives to fourth-order accuracy. In order to retain a single-stage, single-step method, we develop a novel Lax-Wendroff discretization for the evolution of the magnetic potential, where we start with technology used for Hamilton-Jacobi equations in order to construct a non-oscillatory magnetic field. The end result is an algorithm that is similar to our previous work Christlieb et al. (2014) [8], but this time the time stepping is replaced through a Taylor method with the addition of a positivity-preserving limiter. Finally, positivity preservation is realized by introducing a parameterized flux limiter that considers a linear combination of high and low-order numerical fluxes. The choice of the free

  9. Ventricular morphology is a determinant of diastolic performance in patients with single ventricle physiology undergoing stage 3 palliative surgery.

    PubMed

    Seckeler, Michael D; O'Leary, Edward; Anitha Jayakumar, K

    2015-04-01

    Patients with single ventricle anatomy undergo staged surgical palliation which results in pulmonary and systemic circulations in series with a single systemic pump. Single right ventricular morphology has been found to be an independent risk factor for worse survival. We sought to compare patients with single left (SLV) and single right (SRV) ventricular morphology to identify hemodynamic differences that may contribute to worse survival in patients with a single right ventricular. Single center, retrospective review of invasive hemodynamic data. All patients with single ventricle anatomy who underwent superior cavo-pulmonary anastomosis (Stage 2 palliation) and/or total cavo-pulmonary anastomosis (Stage 3 palliation) from August 1995 through May 2011 were identified. Patients were compared over time, and SLV and SRV patients were compared. Seventy-nine single ventricle patients (56 % SRV) underwent staged palliation and were analyzed. There was no difference in overall mortality (12 % SLV, 11 % SRV). There was no difference in hemodynamics at pre-Stage 2 catheterization between ventricular morphology, but SRV patients had higher ventricular end-diastolic pressure at pre-Stage 3 catheterization (7.6 vs. 6.4 mmHg, p = 0.026). End-diastolic pressure decreased after Stage 2 surgery for SLV patients, but not SRV patients. Intrinsic differences in morphology, function, and response to performing as the systemic ventricle between single right and left ventricles may lead to an elevated ventricular end-diastolic pressure. This could limit passive flow through the pulmonary circuit and coronary perfusion after Stage 3 palliation and potentially lead to poorer long-term performance for SRV patients.

  10. Coal liquefaction process streams characterization and evaluation: Application of liquid chromatographic separation methods to THF-soluble portions of integrated two-stage coal liquefaction resids

    SciTech Connect

    Green, J.B.; Pearson, C.D.; Young, L.L.; Green, J.A. )

    1992-05-01

    This study demonstrated the feasibility of using non-aqueous ion exchange liquid chromatography (NIELC) for the examination of the tetrahydrofuran (THF)-soluble distillation resids and THF-soluble whole oils derived from direct coal liquefaction. The technique can be used to separate the material into a number of acid, base, and neutral fractions. Each of the fractions obtained by NIELC was analyzed and then further fractionated by high-performance liquid chromatography (HPLC). The separation and analysis schemes are given in the accompanying report. With this approach, differences can be distinguished among samples obtained from different process streams in the liquefaction plant and among samples obtained at the same sampling location, but produced from different feed coals. HPLC was directly applied to one THF-soluble whole process oil without the NIELC preparation, with limited success. The direct HPLC technique used was directed toward the elution of the acid species into defined classes. The non-retained neutral and basic components of the oil were not analyzable by the direct HPLC method because of solubility limitations. Sample solubility is a major concern in the application of these techniques.

  11. Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 5: Analysis and design of stages D and E

    NASA Technical Reports Server (NTRS)

    Brent, J. A.; Cheatham, J. G.; Clemmons, D. R.

    1972-01-01

    A conventional and a tandem bladed stage were designed for a comparative experimental evaluation in a 0.8 hub/tip ratio single-stage compressor. Based on a preliminary design study, a radially constant work input distribution was selected for the rotor designs. Velocity diagrams and blade leading and trailing edge angles selected for the conventional rotor and stator were used in the design of the tandem blading. The effects of axial velocity ratio and secondary flow on turning were included in the selection of blade leading and trailing edge angles. Design values of rotor tip velocity and stage pressure ratio were 757 ft/sec and 1.26, respectively.

  12. Early experience with laparoscopic sleeve gastrectomy as a single-stage bariatric procedure.

    PubMed

    Lewis, Catherine E; Dhanasopon, Andrew; Dutson, Erik P; Mehran, Amir

    2009-10-01

    Laparoscopic sleeve gastrectomy (LSG) as a single-stage restrictive bariatric procedure is becoming increasingly popular, especially in patients who are high risk and/or superobese. Between November 21, 2006, and September 30, 2008, 42 patients underwent LSG at our institution. Average age was 47 +/- 11 years, average body mass index was 54 +/- 10 kg/m2, and 62 per cent were female. Preoperative indications for LSG included contraindication to laparoscopic Roux-en-Y gastric bypass (n = 11), severe coronary artery disease and/or congestive heart failure (n = 3), significant liver disease (n = 3), and patient preference (n = 4). Intraoperative indications for LSG included a foreshortened mesentery with inability to create a gastrojejunostomy (n = 13), extensive adhesions (n = 5), and intraoperative findings concerning for cirrhosis (n = 3). Twelve complications occurred in six patients: laparoscopic to open conversion (n = 1), reoperation (n = 3), nosocomial pneumonia (n = 1), wound infection (n = 1), bleeding (n = 1), pulmonary embolus (n = 1), readmission (n = 3), and superior splenic pole infarction. There was one death resulting from pulmonary embolism that occurred 2 weeks postoperatively. Preliminary excess body weight loss at 3, 6, 9, and 12 months was 29, 32 t, 38, and 30 per cent, respectively, and many patients had improvement or resolution of obesity-related comorbidities. Early review of our experience demonstrates that LSG may be an effective single-stage bariatric procedure. Additional follow up will be necessary to better define its long-term safety and efficacy.

  13. Heavy metal bioleaching and sludge stabilization in a single-stage reactor using indigenous acidophilic heterotrophs.

    PubMed

    Mehrotra, Akanksha; Sreekrishnan, T R

    2017-01-10

    Simultaneous sludge digestion and metal leaching (SSDML) have been reported at mesophilic temperature. It is generally perceived that while sludge stabilization is effected by heterotrophs at neutral pH, metal bioleaching is done by acidophilic autotrophs. However, little information is available on the microbial communities involved in the process. This study carried out SSDML in a single-stage reactor using sludge indigenous microorganisms and looked at the bacterial communities responsible for the process. Volatile suspended solids were reduced by more than 40%. The concentration of zinc, copper, chromium, cadmium and nickel decreased by more than 45% in the dry sludge. Acidophilic species of Alicyclobacillus genus were the dominant heterotrophs. A few heterotrophic bacteria were detected which can oxidize iron (Alicyclobacillus ferrooxydans, Alicyclobacillus ferripilum and Ferrimicrobium acidiphilum). Acidithiobacillus ferrooxidans (autotroph) was responsible for the oxidation of both iron and sulfur which lead to a change in the pH from neutral to acidic. The presence of acidophilic heterotrophs, which can oxidize either iron or sulfur, enhanced the efficiency of SSDML process with respect to sludge stabilization and metal leaching. This study shows that it is possible to carry out the SSDML in a single-stage reactor with indigenous microorganisms.

  14. A tetrad of bicuspid aortic valve association: A single-stage repair

    PubMed Central

    Barik, Ramachandra; Patnaik, A. N.; Mishra, Ramesh C.; Kumari, N. Rama; Gulati, A. S.

    2012-01-01

    We report a 27 years old male who presented with a combination of both congenital and acquired cardiac defects. This syndrome complex includes congenital bicuspid aortic valve, Seller's grade II aortic regurgitation, juxta- subclavian coarctation, stenosis of ostium of left subclavian artery and ruptured sinus of Valsalva aneurysm without any evidence of infective endocarditis. This type of constellation is extremely rare. Neither coarctation of aorta with left subclavian artery stenosis nor the rupture of sinus Valsalva had a favorable pathology for percutaneus intervention. Taking account into morbidity associated with repeated surgery and anesthesia patient underwent a single stage surgical repair of both the defects by two surgical incisions. The approaches include median sternotomy for rupture of sinus of Valsalva and lateral thoracotomy for coarctation with left subclavian artery stenosis. The surgery was uneventful. After three months follow up echocardiography showed mild residual gradient across the repaired coarctation segment, mild aortic regurgitation and no residual left to right shunt. This patient is under follow up. This is an extremely rare case of single stage successful repair of coarctation and rupture of sinus of Valsalva associated with congenital bicuspid aortic valve. PMID:22629035

  15. Dual-Fuel Propulsion in Single-Stage Advanced Manned Launch System Vehicle

    NASA Technical Reports Server (NTRS)

    Lepsch, Roger A., Jr.; Stanley, Douglas O.; Unal, Resit

    1995-01-01

    As part of the United States Advanced Manned Launch System study to determine a follow-on, or complement, to the Space Shuttle, a reusable single-stage-to-orbit concept utilizing dual-fuel rocket propulsion has been examined. Several dual-fuel propulsion concepts were investigated. These include: a separate-engine concept combining Russian RD-170 kerosene-fueled engines with space shuttle main engine-derivative engines: the kerosene- and hydrogen-fueled Russian RD-701 engine; and a dual-fuel, dual-expander engine. Analysis to determine vehicle weight and size characteristics was performed using conceptual-level design techniques. A response-surface methodology for multidisciplinary design was utilized to optimize the dual-fuel vehicles with respect to several important propulsion-system and vehicle design parameters, in order to achieve minimum empty weight. The tools and methods employed in the analysis process are also summarized. In comparison with a reference hydrogen- fueled single-stage vehicle, results showed that the dual-fuel vehicles were from 10 to 30% lower in empty weight for the same payload capability, with the dual-expander engine types showing the greatest potential.

  16. Biological phosphorus removal in sequencing batch reactor with single-stage oxic process.

    PubMed

    Wang, Dong-Bo; Li, Xiao-Ming; Yang, Qi; Zeng, Guang-Ming; Liao, De-Xiang; Zhang, Jie

    2008-09-01

    The performance of biological phosphorus removal (BPR) in a sequencing batch reactor (SBR) with single-stage oxic process was investigated using simulated municipal wastewater. The experimental results showed that BPR could be achieved in a SBR without anaerobic phase, which was conventionally considered as a key phase for BPR. Phosphorus (P) concentration 0.22-1.79 mg L(-1) in effluent can be obtained after 4h aeration when P concentration in influent was about 15-20 mg L(-1), the dissolved oxygen (DO) was controlled at 3+/-0.2 mg L(-1) during aerobic phase and pH was maintained 7+/-0.1, which indicated the efficiencies of P removal were achieved 90% above. Experimental results also showed that P was mainly stored in the form of intracellular storage of polyphosphate (poly-P), and about 207.235 mg phosphates have been removed by the discharge of rich-phosphorus sludge for each SBR cycle. However, the energy storage poly-beta-hydroxyalkanoates (PHA) was almost kept constant at a low level (5-6 mg L(-1)) during the process. Those results showed that phosphate could be transformed to poly-P with single-stage oxic process without PHA accumulation, and BPR could be realized in net phosphate removal.

  17. Nontangent, Developed Contour Bulkheads for a Single-Stage Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Wu, K. Chauncey; Lepsch, Roger A., Jr.

    2000-01-01

    Dry weights for single-stage launch vehicles that incorporate nontangent, developed contour bulkheads are estimated and compared to a baseline vehicle with 1.414 aspect ratio ellipsoidal bulkheads. Weights, volumes, and heights of optimized bulkhead designs are computed using a preliminary design bulkhead analysis code. The dry weights of vehicles that incorporate the optimized bulkheads are predicted using a vehicle weights and sizing code. Two optimization approaches are employed. A structural-level method, where the vehicle's three major bulkhead regions are optimized separately and then incorporated into a model for computation of the vehicle dry weight, predicts a reduction of4365 lb (2.2 %) from the 200,679-lb baseline vehicle dry weight. In the second, vehicle-level, approach, the vehicle dry weight is the objective function for the optimization. For the vehicle-level analysis, modified bulkhead designs are analyzed and incorporated into the weights model for computation of a dry weight. The optimizer simultaneously manipulates design variables for all three bulkheads to reduce the dry weight. The vehicle-level analysis predicts a dry weight reduction of 5129 lb, a 2.6% reduction from the baseline weight. Based on these results, nontangent, developed contour bulkheads may provide substantial weight savings for single stage vehicles.

  18. Lumbar extracavitary corpectomy with a single stage circumferential arthrodesis: surgical technique and clinical series.

    PubMed

    Singh, Kern; Park, Daniel K

    2012-07-01

    Circumferential arthrodesis and reconstruction is necessary after a lumbar corpectomy in the setting of malignancy and infection. The advent of expandable cage technology now allows for safe anterior column reconstruction via a posterior approach with no transection and minimal retraction of the lumbar spinal nerve roots. Fifteen patients underwent a single-stage, circumferential corpectomy and anterior spinal reconstruction with an expandable cage via a midline, posterior, lateral lumbar extracavitary approach. Posterior segmental pedicle screw fixation and iliac crest bone graft was used in all cases. Fifteen lumbar extracavitary corpectomy nerve root-sparing procedures have been performed to date, with at least 1-year follow-up (12 tumors/3 infections). No patient suffered any neurological complications. One patient suffered from a postoperative myocardial infarction 10 days after the procedure. Two patients had medical complications that were treated without sequelae. We present a technical description and case series of patients undergoing a single-stage, circumferential corpectomy and anterior spinal reconstruction with an expandable cage via a midline, posterior, lateral lumbar extracavitary approach with at least 1-year follow-up. The technique is safe, technically feasible, and obviates an anterior approach in this oftentimes critically ill patient population.

  19. FINAL DESIGN OF ILC RTML EXTRACTION LINE FOR SINGLE STAGE BUNCH COMPRESSOR

    SciTech Connect

    Seletskiy, S.; Solyak, N.

    2011-03-28

    The use of single stage bunch compressor (BC) in the International Linear Collider (ILC) Damping Ring to the Main Linac beamline (RTML) requires new design for the extraction line (EL). The EL located downstream of the BC will be used for both an emergency abort dumping of the beam and the tune-up continuous train-by-train extraction. It must accept both compressed and uncompressed beam with energy spread of 3.54% and 0.15% respectively. In this paper we report the final design that allowed minimizing the length of such extraction line while offsetting the beam dumps from the main line by 5m distance required for acceptable radiation level in the service tunnel. Proposed extraction line can accommodate beams with different energy spreads at the same time providing the beam size suitable for the aluminum ball dump window. We described the final design of the ILC RTML extraction line located downstream of the new single-stage bunch compressor. The extraction line is only 24m long and is capable of accepting and transmitting 220kW of beam power. The EL can be used for both fast intra-train and continual extraction, and is capable of accepting both 0.15% and 3.54% energy spread beams at 5MeV and 4.37MeV respectively.

  20. Hearing rehabilitation with single-stage bilateral vibroplasty in a child with Franceschetti syndrome.

    PubMed

    Sargsyan, Sona; Rahne, Torsten; Kösling, Sabrina; Eichler, Gerburg; Plontke, Stefan K

    2014-05-01

    Hearing is of utmost importance for normal speech and social development. Even children who have mild or unilateral permanent hearing loss may experience difficulties with understanding speech, as well as problems with educational and psycho-social development. The increasing advantages of middle-ear implant technologies are opening new perspectives for restoring hearing. Active middle-ear implants can be used in children and adolescents with hearing loss. In addition to the well-documented results for improving speech intelligibility and quality of hearing in sensorineural hearing loss active middle-ear implants are now successfully used in patients with conductive and mixed hearing loss. In this article we present a case of successful, single-stage vibroplasty, on the right side with the fixation of the FMT on the stapes and PORP CLiP vibroplasty on the left side in a 6-year-old girl with bilateral mixed hearing loss and multiple dyslalia associated with Franceschetti syndrome (mandibulofacial dysostosis). CT revealed bilateral middle-ear malformations as well as an atretic right and stenotic left external auditory canal. Due to craniofacial dysmorphia airway and (post)operative, management is significantly more difficult in patients with a Franceschetti syndrome which in this case favoured a single-stage bilateral procedure. No intra- or postoperative surgical complications were reported. The middle-ear implants were activated 4 weeks after surgery. In the audiological examination 6 months after surgery, the child showed 100% speech intelligibility with activated implants on each side.

  1. Safety and Efficacy of Single-Stage Surgical Treatment for Congenital Scoliosis Associated with Intraspinal Mass

    PubMed Central

    Zhang, Bo-bo; Tao, Hui-ren; Wu, Tai-lin; Wang, Lin; Duan, Chun-guang; Zhang, Tao; Li, Tao; Yang, Wei-zhou; Liu, Ming; Ma, Jun

    2017-01-01

    For congenital scoliosis associated with intraspinal anomaly, surgical treatment is often advocated. However, the safety and efficacy of single-stage intraspinal mass resection and scoliosis correction remain unclear. The purpose of this study was to retrospectively evaluate the feasibility and risk factors of single-stage surgical treatment for congenital scoliosis associated with intraspinal mass. Patients’ clinical records were reviewed for demographic and radiographic data, operating time, intraoperative blood loss, perioperative complications, and postoperative pathologic results. Two female and 5 male patients with an average age of 19.14 ± 7.52 years (range, 11–31 years) were evaluated. Patients were followed for a minimum of 24 months after initial surgical treatment, with an average of 49.71 ± 32.90 months (range, 27–99 months). Spinal curvature was corrected from an average of 69.57 ± 20.44° to 29.14 ± 9.87°, demonstrating a mean correction rate of 55.05% ± 18.75%. No obvious loss of correction was observed at the final follow-up. Complications included transient neurologic deficit, cerebrospinal fluid leakage, and intraspinal mass recurrence in 1 patient each. There was no paralysis or permanent nerve damage. In conclusion, simultaneous intraspinal mass resection and scoliosis correction appears to be safe and effective. PMID:28117436

  2. Mathematical modeling of wire-duct single-stage electrostatic precipitators.

    PubMed

    Talaie, M R

    2005-09-30

    A two-dimensional mathematical model was developed to simulate the performance of wire-duct single-stage electrostatic precipitators (ESP). The model presented by Talaie et al. [M.R. Talaie, M. Taheri, J. Fathikaljahi, A new method to evaluate the voltage-current characteristics applicable for a single-stage electrostatic precipitator, J. Electrostat., 53 (3) (2001) 221-233] was used for prediction of electric field strength distribution and V-I characteristic for high-voltage wire-plate configuration. Simple Lagrangian approach was used to predict particle movement. Normal k-epsilon turbulent flow model with considering electrical body force due to ion and charged particle flow was used to evaluate gas velocity distribution. Ignoring the effect of particle movement and fluid flow, the results of electrical part of mathematical model are in good agreement with experimental data of Penny and Matick [G.W. Penny, R.E. Matrick, Potential in DC corona field, Trans. AIEE Part 1, 79 (1960) 91-99]. The prediction of corona sheath radius and its variation with particle loading and applied voltage is the main distinguishing feature of the present model. This fact was not included in the earlier models.

  3. Novel Regenerator Material Improving the Performance of a Single Stage Pulse Tube Cooler

    NASA Astrophysics Data System (ADS)

    Koettig, T.; Nawrodt, R.; Moldenhauer, S.; Thürk, M.; Seidel, P.

    2006-04-01

    The authors have undertaken basic research and prototype developments on various four valve pulse tube refrigerators (FVPTR) since several years. Systematic studies have been carried out to characterize the basics of the arising loss mechanisms of this type of pulse tube refrigerator with its active type of phase shifting. Recently, a single-stage FVPTR in coaxial arrangement has been designed for maximum refrigeration power at cooling temperatures below 30 K limited by an available electrical input power of 6.2 kW. At present the single stage cooler provides a cooling capacity of 10 W or 20 W at working temperatures of 22 K or 27 K, respectively. Instead of lead spheres, lead coated screens have been applied in the coldest part of the regenerator in order to decrease the pressure drop. The improvement of the refrigerator overcomes the well known shortcoming of a refrigerator with a regenerator partially filled with lead spheres at working-temperatures above 50 K. Numerical simulations of the thermodynamical process yield to continuative lead screen parameter studies. The results raise hope for achievable minimum temperatures down to 15 K. We report on the improved performance of the FVPTR due to the use of lead-coated screens.

  4. Two-Stage Single-Compartment Models to Evaluate Dissolution in the Lower Intestine.

    PubMed

    Markopoulos, Constantinos; Vertzoni, Maria; Symillides, Mira; Kesisoglou, Filippos; Reppas, Christos

    2015-09-01

    The purpose was to propose two-stage single-compartment models for evaluating dissolution characteristics in distal ileum and ascending colon, under conditions simulating the bioavailability and bioequivalence studies in fasted and fed state by using the mini-paddle and the compendial flow-through apparatus (closed-loop mode). Immediate release products of two highly dosed active pharmaceutical ingredients (APIs), sulfasalazine and L-870,810, and one mesalamine colon targeting product were used for evaluating their usefulness. Change of medium composition simulating the conditions in distal ileum (SIFileum ) to a medium simulating the conditions in ascending colon in fasted state and in fed state was achieved by adding an appropriate solution in SIFileum . Data with immediate release products suggest that dissolution in lower intestine is substantially different than in upper intestine and is affected by regional pH differences > type/intensity of fluid convection > differences in concentration of other luminal components. Asacol® (400 mg/tab) was more sensitive to type/intensity of fluid convection. In all the cases, data were in line with available human data. Two-stage single-compartment models may be useful for the evaluation of dissolution in lower intestine. The impact of type/intensity of fluid convection and viscosity of media on luminal performance of other APIs and drug products requires further exploration.

  5. Shape Optimization of the Assisted Bi-directional Glenn surgery for stage-1 single ventricle palliation

    NASA Astrophysics Data System (ADS)

    Verma, Aekaansh; Shang, Jessica; Esmaily-Moghadam, Mahdi; Wong, Kwai; Marsden, Alison

    2016-11-01

    Babies born with a single functional ventricle typically undergo three open-heart surgeries starting as neonates. The first of these stages (BT shunt or Norwood) has the highest mortality rates of the three, approaching 30%. Proceeding directly to a stage-2 Glenn surgery has historically demonstrated inadequate pulmonary flow (PF) & high mortality. Recently, the Assisted Bi-directional Glenn (ABG) was proposed as a promising means to achieve a stable physiology by assisting the PF via an 'ejector pump' from the systemic circulation. We present preliminary parametrization and optimization results for the ABG geometry, with the goal of increasing PF. To limit excessive pressure increases in the Superior Vena Cava (SVC), the SVC pressure is included as a constraint. We use 3-D finite element flow simulations coupled with a single ventricle lumped parameter network to evaluate PF & the pressure constraint. We employ a derivative free optimization method- the Surrogate Management Framework, in conjunction with the OpenDIEL framework to simulate multiple simultaneous evaluations. Results show that nozzle diameter is the most important design parameter affecting ABG performance. The application of these results to patient specific situations will be discussed. This work was supported by an NSF CAREER award (OCI1150184) and by the XSEDE National Computing Resource.

  6. Hemodynamic consequences of LPA stenosis in single ventricle stage 2 LPN circulation with automatic registration

    NASA Astrophysics Data System (ADS)

    Schiavazzi, Daniele E.; Kung, Ethan O.; Dorfman, Adam L.; Hsia, Tain-Yen; Baretta, Alessia; Arbia, Gregory; Marsden, Alison L.

    2013-11-01

    Congenital heart diseases such as hypoplastic left heart syndrome annually affect about 3% of births in the US alone. Surgical palliation of single ventricle patients is performed in stages. Consequently to the stage 2 surgical procedure or other previous conditions, a stenosis of the left pulmonary artery (LPA) is often observed, raising the clinical question of whether or not it should be treated. The severity of stenoses are commonly assessed through geometric inspection or catheter in-vivo pressure measurements with limited quantitative information about patient-specific physiology. The present study uses a multiscale CFD approach to provide an assessment of the severity of LPA stenoses. A lumped parameter 0D model is used to simulate stage 2 circulation, and parameters are automatically identified accounting for uncertainty in the clinical data available for a cohort of patients. The importance of the latter parameters, whether alone or in groups, is also ranked using forward uncertainty propagation methods. Various stenosis levels are applied to the three-dimensional SVC-PA junction model using a dual mesh-morphing approach. Traditional assessments methodologies are compared to the results of our findings and critically discussed.

  7. Single-stage laparoscopic cholecystectomy and intraoperative endoscopic retrograde cholangiopancreatography: is this strategy feasible in Australia?

    PubMed

    March, Brayden; Burnett, David; Gani, Jon

    2016-11-01

    Currently in Australasia, concomitant cholecystolithiasis and choledocholithiasis are usually managed with two procedures: laparoscopic cholecystectomy (LC) and pre or postoperative endoscopic retrograde cholangiopancreatography (ERCP). This approach exposes the patient to the risk of complications from the common bile duct stone(s) while awaiting ERCP, the risks of the ERCP itself (particularly pancreatitis) and the need for a second anaesthetic. This article explores the evidence for a newer hybrid approach, single stage LC and intraoperative ERCP (SSLCE) and compares this approach with the commonly used alternatives. SSLCE offers reduced rates of pancreatitis, reduced length of hospital stay and reduced cost compared with the two-stage approach and requires only one anaesthetic. There is a reduced risk of bile leak compared with procedures that involve a choledochotomy, and ductal clearance rates are superior to trans-cystic exploration and equivalent to the standard two-stage approach. Barriers to widespread implementation relate largely to operating theatre logistics and availability of appropriate endoscopic expertise, although when bile duct stones are anticipated these issues are manageable. There is compelling justification in the literature to gather prospective evidence surrounding SSLCE in the Australian Healthcare system.

  8. Single-Crystal Sapphire High-Temperature Measurement Instrument for Coal Gasification

    NASA Astrophysics Data System (ADS)

    Zhang, Yibing; Pickrell, Gary; Qi, Bing; May, Russell G.; Wang, Anbo

    2003-09-01

    Based on the broadband polarimetric differential interferometry (BPDI) technology, a complete prototype optical sensor instrumentation system was designed and implemented for on-line reliable and accurate high temperature measurement in a slagging coal gasifier, which operates under high temperatures and extremely corrosive conditions. A wide dynamic measurement range from room temperature up to 1600 °C with a resolution better than 0.1 °C and high accuracy is achieved; long-term operating stability has also been tested.

  9. Performances of single and two-stage pulse tube cryocoolers under different vacuum levels with and without thermal radiation shields

    NASA Astrophysics Data System (ADS)

    Kasthurirengan, Srinivasan; Behera, Upendra; Nadig, D. S.; Krishnamoorthy, V.

    2012-06-01

    Single and two-stage Pulse Tube Cryocoolers (PTC) have been designed, fabricated and experimentally studied. The single stage PTC reaches a no-load temperature of ~ 29 K at its cold end, the two-stage PTC reaches ~ 2.9 K in its second stage cold end and ~ 60 K in its first stage cold end. The two-stage Pulse Tube Cryocooler provides a cooling power of ~ 250 mW at 4.2 K. The single stage system uses stainless steel meshes along with Pb granules as its regenerator materials, while the two-stage PTC uses combinations of Pb along with Er3Ni / HoCu2 as the second stage regenerator materials. Normally, the above systems are insulated by thermal radiation shields and mounted inside a vacuum chamber which is maintained at high vacuum. To evaluate the performance of these systems in the possible conditions of loss of vacuum with and without radiation shields, experimental studies have been performed. The heat-in-leak under such severe conditions has been estimated from the heat load characteristics of the respective stages. The experimental results are analyzed to obtain surface emissivities and effective thermal conductivities as a function of interspace pressure.

  10. Heavy recycle solvent studies in two-stage coal liquefaction. Final technical report, September 1, 1982-December 30, 1983

    SciTech Connect

    Longanbach, J. R.

    1984-01-10

    The objective of this program has been to study the chemistry of the components with high boiling points in a direct coal liquefaction recycle solvent and to identify those components which lead to higher overall yields and improved product stability in the initial coal dissolution step of direct coal liquefaction processes. The major conclusions are: -454 C recycle solvent is primarily aromatic hydrocarbons (73%) and contains almost no asphaltenes; +454 C recycle solvent is primarily asphaltenes and aromatic hydrocarbons; recycle solvent also contains aliphatic hydrocarbons, N-containing aromatics and O-containing aromatics; heteroatoms in coal derived materials seem to be grouped by type, i.e. acidic O and basic N and sulfur occur together; under helium a small net amount of hydrogen and more CO and CO/sub 2/ are produced than under hydrogen; under hydrogen the amounts of H/sub 2/S and hydrocarbon gases are increased and a small amount of hydrogen gas is usually consumed; overall coal conversions to THF solubles are improved by adding more -454 C solvent but decreased by adding +454 C solvent; for added fractions of -454 C solvent the pecent conversion to THF solubles increases in the order aromatic hydrocarbons (+7.2) > aliphatic hydrocarbons (+0.8) > no added solvent (0.0) > N-containing aromatics (-0.9) > O-containing aromatics (-22.1); percent conversion to THF solubles using -454 C solvent with +454 C solvent fractions added decrease in the order aliphatics (+3.7) > aromatic hydrocarbons (+3.0) > no added solvent (0.0) > O-containing aromatics (-9.3) > N-containing aromatics (-13.3); of the +454 C solvent components, aromatic hydrocarbons and aliphatic hydrocarbons are beneficial but total only approx. 25% of the +454 C recycle solvent; and steric effects may be important in determining the effectiveness of the heavier solvent components as liquefaction solvents. 28 references, 25 figures, 31 tables.

  11. Two-Stage Separation of V(IV) and Al(III) by Crystallization and Solvent Extraction from Aluminum-Rich Sulfuric Acid Leaching Solution of Stone Coal

    NASA Astrophysics Data System (ADS)

    Shi, Qihua; Zhang, Yimin; Liu, Tao; Huang, Jing; Liu, Hong

    2016-12-01

    To improve separation of V(IV) and Al(III) from aluminum-rich sulfuric acid leaching solution of stone coal, the two-stage separation by crystallization and solvent extraction methods have been developed. A co-extraction coefficient (k) was put forward to evaluate comprehensively co-extraction extent in different solutions. In the crystallization stage, 68.2% of aluminum can be removed from the solution. In the solvent extraction stage, vanadium was selectively extracted using di-2-ethylhexyl phosphoric acid/tri-n-butyl phosphate from the crystalline mother solution, followed by H2SO4 stripped efficiently. A V2O5 product with purity of 98.39% and only 0.10% Al was obtained after oxidation, precipitation, and calcination. Compared with vanadium extraction from solution without crystallization, the counter-current extraction stage of vanadium can be decreased from 6 to 3 and co-extraction coefficient (k) decreased from 2.51 to 0.58 with two-stage separation. It is suggested that the aluminum removal by crystallization can evidently weaken the influence of aluminum co-extraction on vanadium extraction and improve the selectivity of solvent extraction for vanadium.

  12. Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 7: Data and performance for stage E

    NASA Technical Reports Server (NTRS)

    Cheatham, J. G.

    1974-01-01

    An axial flow compressor stage, having tandem airfoil blading, was designed for zero rotor prewhirl, constant rotor work across the span, and axial discharge flow. The stage was designed to produce a pressure ratio of 1.265 at a rotor tip velocity of 757 ft/sec. The rotor has an inlet hub/tip ratio of 0.8. The design procedure accounted for the rotor inlet boundary layer and included the effects of axial velocity ratio and secondary flow on blade row performance. The objectives of this experimental program were (1) to obtain performance with uniform and distorted inlet flow for comparison with the performance of a stage consisting of single-airfoil blading designed for the same vector diagrams and (2) to evaluate the effectiveness of accounting for the inlet boundary layer, axial velocity ratio, and secondary flows in the stage design.

  13. Single-stage nonintubated uniportal thoracoscopic resection of synchronous bilateral pulmonary nodules after coil labeling

    PubMed Central

    Zhang, Miao; Wang, Tao; Zhang, You-Wei; Wu, Wen-Bin; Wang, Heng; Xu, Rong-Hua

    2017-01-01

    Abstract Rationale: Preoperative localization of small pulmonary nodules is essential for precise resection, besides, the optimal treatment for pulmonary nodules is controversial and the prognosis without surgery is uncertain. Patient concerns: Herein we present a patient with compromised pulmonary function harboring synchronous triple ground-glass nodules located separately in different pulmonary lobes. Diagnoses: The pathological diagnosis of the nodules were chronic inflammation, inflammatory pseudotumor and atypical adenomatous hyperplasia, respectively. Interventions: The patient underwent single-stage, non-intubated thoracoscopic pulmonary wedge resection after computed tomography-guided coil labeling of the nodules. Outcomes: The postoperative recovery was encouragingly fast without obvious complications. Lessons: Non-intubated thoracoscopic pulmonary wedge resection is feasible for patients with compromised lung function, meanwhile, preoperative coil labeling of small nodules is reliable. PMID:28328859

  14. Feasibility Study of Laboratory Simulation of Single-Stage-to-Orbit Vehicle Base Heating

    NASA Technical Reports Server (NTRS)

    Park, Chung Sik; Sharma, Surendra; Edwards, Thomas A. (Technical Monitor)

    1995-01-01

    The feasibility of simulating in a laboratory the heating environment of the base region of the proposed reusable single-stage-to-orbit vehicle during its ascent is examined. The propellant is assumed to consist of hydrocarbon (RP1), liquid hydrogen (LH2), and liquid oxygen (LO2), which produces CO and H2 as the main combustible components of the exhaust effluent. Since afterburning in the recirculating region can dictate the temperature of the base flowfield and ensuing heating phenomena, laboratory simulation focuses on the thermochemistry of the afterburning. By extrapolating the Saturn V flight data, the Damkohler number, in the base region with afterburning for SSTO vehicle, is estimated to be between 30 and 140. It is shown that a flow with a Damkohler number of 1.8 to 25 can be produced in an impulse ground test facility. Even with such a reduced Damkohler number, the experiment can adequately reproduce the main features of the flight environment.

  15. The Integrity of ACSR Full Tension Single-Stage Splice Connector at Higher Operation Temperature

    SciTech Connect

    Wang, Jy-An John; Lara-Curzio, Edgar; King Jr, Thomas J

    2008-10-01

    Due to increases in power demand and limited investment in new infrastructure, existing overhead power transmission lines often need to operate at temperatures higher than those used for the original design criteria. This has led to the accelerated aging and degradation of splice connectors. It is manifested by the formation of hot-spots that have been revealed by infrared imaging during inspection. The implications of connector aging is two-fold: (1) significant increases in resistivity of the splice connector (i.e., less efficient transmission of electricity) and (2) significant reductions in the connector clamping strength, which could ultimately result in separation of the power transmission line at the joint. Therefore, the splice connector appears to be the weakest link in electric power transmission lines. This report presents a protocol for integrating analytical and experimental approaches to evaluate the integrity of full tension single-stage splice connector assemblies and the associated effective lifetime at high operating temperature.

  16. An implementable digital adaptive flight controller designed using stabilized single-stage algorithms

    NASA Technical Reports Server (NTRS)

    Alag, G.; Kaufman, H.

    1977-01-01

    An explicit adaptive controller, which makes direct use of on-line parameter identification, has been developed and applied to both the linearized and nonlinear equations of motion for the F-8 aircraft. This controller is composed of an on-line weighted least squares parameter identifier, a Kalman state filter, and a real model following control law designed using single-stage performance indices. The corresponding control gains are readily adjustable in accordance with parameter changes to ensure asymptotic stability if the conditions of perfect model following are satisfied, and stability in the sense of boundedness otherwise. Simulation experiments with realistic measurement noise indicate that the controller was effective in compensating for parameter variations and capable of rapid recovery from a set of erroneous initial parameter estimates which defined a set of destabilizing gains.

  17. An implementable digital adaptive flight controller designed using stabilized single stage algorithms

    NASA Technical Reports Server (NTRS)

    Kaufman, H.; Alag, G.

    1975-01-01

    Simple mechanical linkages have not solved the many control problems associated with high performance aircraft maneuvering throughout a wide flight envelope. One procedure for retaining uniform handling qualities over such an envelope is to implement a digital adaptive controller. Towards such an implementation an explicit adaptive controller which makes direct use of on-line parameter identification, has been developed and applied to both linearized and nonlinear equations of motion for a typical fighter aircraft. This controller is composed of an on-line weighted least squares parameter identifier, a Kalman state filter, and a model following control law designed using single stage performance indices. Simulation experiments with realistic measurement noise indicate that the proposed adaptive system has the potential for on-board implementation.

  18. Approach to key technologies identification for rocket powered single stage to orbit vehicles

    NASA Astrophysics Data System (ADS)

    Deneu, F.; Terrenoire, P.

    1996-03-01

    A reusable vertical take off, vertical landing rocket powered single stage to orbit vehicle has been studied as a part of the Aérospatiale future launchers systematic study policy. The main goal of this study is to investigate the key points of this kind of configurations, especially identify, classify and quantify the specific problems, key technologies, tools and test facilities needed and the development costs and schedule. Concurrent engineering techniques were used to take into account all the viewpoints (such as RAMS, abort, operations viewpoints) from the very beginning of this study in order to perform a multidisciplinary conceptual design. The configuration presented here is a conical shape, 60 m long, 1200 ton gross lift-off weight vehicle which delivers to and is able to bring back from a space station a 10 ton payload. This paper presents the study methodology, the systems requirements taken into account and the reference vehicle.

  19. Single stage to orbit mass budgets derived from propellant density and specific impulse

    SciTech Connect

    Whitehead, J.C.

    1996-06-06

    The trade between specific impulse (Isp) and density is examined in view of Single Stage To Orbit (SSTO) requirements. Mass allocations for vehicle hardware are derived from these two properties, for several propellant combinations and a dual-fuel case. This comparative analysis, based on flight-proven hardware, indicates that the higher density of several alternative propellants compensates for reduced Isp, when compared with cryogenic oxygen and hydrogen. Approximately half the orbiting mass of a rocket- propelled SSTO vehicle must be allocated to propulsion hardware and residuals. Using hydrogen as the only fuel requires a slightly greater fraction of orbiting mass for propulsion, because hydrogen engines and tanks are heavier than those for denser fuels. The advantage of burning both a dense fuel and hydrogen in succession depends strongly on tripropellant engine weight. The implications of the calculations for SSTO vehicle design are discussed, especially with regard to the necessity to minimize non-tankage structure.

  20. An adaptive guidance law for single stage to low earth orbit

    NASA Technical Reports Server (NTRS)

    Pamadi, Bandu N.

    1989-01-01

    An adaptive guidance algorithm based on a cubic spline representation of the ascent profile and imposition of a dynamic pressure constraint is studied for a single stage to low earth orbit. The flight path is divided into initial and terminal phases. In the initial phase, fully adaptive, and in the terminal phase, semi-adaptive, guidance schemes are used. The cubic spline paqrameters are determined by gradient optimization for maximum payload to orbit. In the terminal phase, a linear quadratic regulator is used to derive the optimal feedback gains to keep the vehicle close to the nominal path. The computational aspects of the guidance algorithm are examined and criteria are developed to ensure stability and convergence.

  1. Robust H∞ stabilization of a hard disk drive system with a single-stage actuator

    NASA Astrophysics Data System (ADS)

    Harno, Hendra G.; Kiin Woon, Raymond Song

    2015-04-01

    This paper considers a robust H∞ control problem for a hard disk drive system with a single stage actuator. The hard disk drive system is modeled as a linear time-invariant uncertain system where its uncertain parameters and high-order dynamics are considered as uncertainties satisfying integral quadratic constraints. The robust H∞ control problem is transformed into a nonlinear optimization problem with a pair of parameterized algebraic Riccati equations as nonconvex constraints. The nonlinear optimization problem is then solved using a differential evolution algorithm to find stabilizing solutions to the Riccati equations. These solutions are used for synthesizing an output feedback robust H∞ controller to stabilize the hard disk drive system with a specified disturbance attenuation level.

  2. An Air-Breathing Launch Vehicle Concept for Single-Stage-to-Orbit

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.

    1999-01-01

    The "Trailblazer" is a 300-lb payload, single-stage-to-orbit launch vehicle concept that uses air-breathing propulsion to reduce the required propellant fraction. The integration of air-breathing propulsion is done considering performance, structural and volumetric efficiency, complexity, and design risk. The resulting configuration is intended to be viable using near-term materials and structures. The aeropropulsion performance goal for the Trailblazer launch vehicle is an equivalent effective specific impulse (I*) of 500 sec. Preliminary analysis shows that this requires flight in the atmosphere to about Mach 10, and that the gross lift-off weight is 130,000 lb. The Trailblazer configuration and proposed propulsion system operating modes are described. Preliminary performance results are presented, and key technical issues are highlighted. An overview of the proposed program plan is given.

  3. Projectile acceleration in a single-stage gun at breech pressures below 50 MPa

    NASA Astrophysics Data System (ADS)

    Sasoh, A.; Ohba, S.; Takayama, K.

    Experimental studies were carried out to investigate projectile acceleration in a single-stage gun at breech pressures below 50 MPa. The gun was driven by firing either liquid or solid propellant. In-bore projectile velocity was continuously recorded using the well-known, precise VISAR interferometer technique so that accurate projectile acceleration data could be deduced. Both the attained projectile acceleration and muzzle exit velocity depend upon the charge-to-mass ratio and the pressure at which the blow-out disk ruptures. The results obtained from these experiments render information on the interplay between propellant combustion and projectile acceleration for low in-bore pressure regimes, and they provide the input data required for adequate numerical simulation.

  4. Rocket-powered single-stage vehicle configuration selection and design

    NASA Technical Reports Server (NTRS)

    Stanley, Douglas O.; Engelund, Walter C.; Lepsch, Roger A.; Mcmillin, Mark; Wurster, Kathryn E.; Powell, Richard W.; Guinta, Anthony A.; Unal, Resit

    1993-01-01

    A reusable rocket-powered, single-stage launch vehicle has been designed as a part of NASA's Advanced Manned Launch System (AMLS) study to examine options for a next-generation manned space transportation system. The configuration selection process utilized a response surface methodology for multidisciplinary optimization. The methodology was utilized to determine the minimum dry weight entry vehicle to meet constraints on landing velocity and on subsonic, supersonic, and hypersonic trim and stability. Once the optimum configuration was determined, a multidisciplinary conceptual vehicle design was performed. This paper presents the results of the configuration selection methodology and summarizes the overall conceptual design process with special attention given to the individual disciplines of weights/ sizing, structures/materials, configuration, flight mechanics, aerodynamics, aeroheating, propulsion, and operations.

  5. Single stage, low noise, advanced technology fan. Volume 5: Fan acoustics. Section 1: Results and analysis

    NASA Technical Reports Server (NTRS)

    Jutras, R. R.

    1976-01-01

    The acoustic tests and data analysis for a 0.508-scale fan vehicle of a 111,300 newton (25,000 pound) thrust, full-size engine, which would have application on an advanced transport aircraft, is described. The single-stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec (1,650 ft/sec) to achieve the desired pressure ratio in a single-stage fan with low radius ratio (0.38), and to maintain adequate stall margin. The fan has 44 tip-shrouded rotor blades and 90 outlet guide vanes. The two basic approaches taken in the acoustic design were: (1) minimization of noise at the source, and (2) suppression of the generated noise in the inlet and bypass exhaust duct. Suppression of the generated noise was accomplished in the inlet through use of the hybrid concept (wall acoustic treatment plus airflow acceleration suppression) and in the exhaust duct with extensive acoustic treatment including a splitter. The goal of the design was attainment of twenty effective perceived noise decibels (20 EPNdB) below current Federal Air Regulation noise standards for a full-scale fan at the takeoff, cutback, and approach conditions. The suppression goal of FAR 36-20 was not reached, but improvements in the technology of both front and aft fan-noise suppression were realized. The suppressed fan noise was shown to be consistent with the proposed federal regulation on aircraft noise.

  6. Single stage evaluation of highly loaded high Mach number compressor stages. 6: Data and performance of cantilevered stator

    NASA Technical Reports Server (NTRS)

    Merrow, A. S.

    1972-01-01

    A compressor stage with a rotor tip speed of 1600 ft/sec was tested to evaluate its performance with a cantilevered stator and a rotating inner shroud beneath the stator. Both the rotor blades and the stator vanes were composed of multiple circular arc airfoil sections. Comparison of data taken during this test of the cantilevered stator and previous tests with the same compressor and airfoil geometry in a shroud stator configuration showed only slight differences in stage performance with no significant effect on overall efficiency. However, the severity of the stator wake near the rotating hub was decreased at all flows including the near surge condition. Stall and wise open discharge corrected weight flows were the same as for the shrouded stator configuration.

  7. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2003-04-01

    This report summarizes technical progress over the first six months of the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Research efforts were focused on analyzing and testing factors that impact performance degradation of the initially designed sensor prototype, including sensing element movement within the sensing probe and optical signal quality degradation. Based these results, a new version of the sensing system was designed by combining the sapphire disk sensing element and the single crystal zirconia right angle light reflector into one novel single crystal sapphire right angle prism. The new sensor prototype was tested up to 1650 C.

  8. Improvement of vibration energy harvesters through a two-stage design: power production at single frequency excitation.

    PubMed

    Fernando, Joseph S; Sun, Qiao

    2013-11-01

    A vibration harvester is usually designed to work in resonance responding to source vibration. Many existing types of harvesters use a single mechanical resonator to amplify the excitation vibrations. However, these harvesters are inherently limited in the amount of power that they can produce, due to their design, particularly in the limited number of design parameters. In our study, we propose a two-stage design to improve a harvester's performance both in power production and in bandwidth widening. In this paper, we demonstrate that a two-stage design can increase the power production when the device is intended to operate under a single frequency excitation. Harvester parameters are optimized to provide maximum power production. Power production comparisons between single-stage and two-stage harvesters are made through numerical simulation and experiments.

  9. Influence of air-staging on the concentration profiles of NH{sub 3} and HCN in the combustion chamber of a CFB boiler burning coal

    SciTech Connect

    Kassman, H.; Karlsson, M.; Aamand, L.E.

    1999-07-01

    The characterization of the concentration profiles of NH{sub 3} and HCN are of great importance for increasing the knowledge of the formation and destruction pathways of NO and N{sub 2}O in a fluidized bed boiler. Further improvements of the sampling methods for the determination of both NH{sub 3} and HCN in the combustion chamber in full-scale CFB boilers are also needed. A gas-sampling probe connected to a Fourier Transform Infrared (FTIR) instrument and a gas-quenching (GQ) probe in which the sample is quenched directly in the probe tip by a circulating trapper solution were used. The FTIR technique is based on analysis of hot combustion gases, whereas the trapper solutions from the GQ probe were analyzed by means of wet chemistry. The tests were performed during coal combustion in a 12 MW CFB boiler, which was operated at three air-staging cases with the addition of limestone for sulfur capture. The concentration profiles of NH{sub 3} and HCN in the combustion chamber showed a different pattern concerning the influence of air-staging. The highest levels of NH{sub 3} were observed during reducing condition (severe air-staging), and the lowest were found under oxidizing conditions (no air-staging). The levels of HCN were much lower than those measured for NH{sub 3}. The highest levels of HCN were observed for reversed air-staging and severe air-staging showed almost no HCN. The potential reactors involving NH{sub 3} and HCN in the combustion chamber as well as the potential measurement errors in each sampling technique are discussed for the three air-staging cases.

  10. Intermediate stages of electrochemical oxidation of single-crystalline platinum revealed by in situ Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Yi-Fan; Kooyman, Patricia J.; Koper, Marc T. M.

    2016-08-01

    Understanding the atomistic details of how platinum surfaces are oxidized under electrochemical conditions is of importance for many electrochemical devices such as fuel cells and electrolysers. Here we use in situ shell-isolated nanoparticle-enhanced Raman spectroscopy to identify the intermediate stages of the electrochemical oxidation of Pt(111) and Pt(100) single crystals in perchloric acid. Density functional theory calculations were carried out to assist in assigning the experimental Raman bands by simulating the vibrational frequencies of possible intermediates and products. The perchlorate anion is suggested to interact with hydroxyl phase formed on the surface. Peroxo-like and superoxo-like two-dimensional (2D) surface oxides and amorphous 3D α-PtO2 are sequentially formed during the anodic polarization. Our measurements elucidate the process of the electrochemical oxidation of platinum single crystals by providing evidence for the structure-sensitive formation of a 2D platinum-(su)peroxide phase. These results may contribute towards a fundamental understanding of the mechanism of degradation of platinum electrocatalysts.

  11. Intermediate stages of electrochemical oxidation of single-crystalline platinum revealed by in situ Raman spectroscopy

    PubMed Central

    Huang, Yi-Fan; Kooyman, Patricia J.; Koper, Marc T. M.

    2016-01-01

    Understanding the atomistic details of how platinum surfaces are oxidized under electrochemical conditions is of importance for many electrochemical devices such as fuel cells and electrolysers. Here we use in situ shell-isolated nanoparticle-enhanced Raman spectroscopy to identify the intermediate stages of the electrochemical oxidation of Pt(111) and Pt(100) single crystals in perchloric acid. Density functional theory calculations were carried out to assist in assigning the experimental Raman bands by simulating the vibrational frequencies of possible intermediates and products. The perchlorate anion is suggested to interact with hydroxyl phase formed on the surface. Peroxo-like and superoxo-like two-dimensional (2D) surface oxides and amorphous 3D α-PtO2 are sequentially formed during the anodic polarization. Our measurements elucidate the process of the electrochemical oxidation of platinum single crystals by providing evidence for the structure-sensitive formation of a 2D platinum-(su)peroxide phase. These results may contribute towards a fundamental understanding of the mechanism of degradation of platinum electrocatalysts. PMID:27514695

  12. Single stage: dorsolateral onlay buccal mucosal urethroplasty for long anterior urethral strictures using perineal route

    PubMed Central

    Prabha, Vikram; Devaraju, Shishir; Vernekar, Ritesh; Hiremath, Murigendra

    2016-01-01

    ABSTRACT Objective To assess the outcome of single stage dorsolateral onlay buccal mucosal urethroplasty for long anterior urethral strictures (>4cm long) using a perineal incision. Materials and Methods From August 2010 to August 2013, 20 patients underwent BMG urethroplasty. The cause of stricture was Lichen sclerosis in 12 cases (60%), Instrumentation in 5 cases (25%), and unknown in 3 cases (15%). Strictures were approached through a perineal skin incision and penis was invaginated into it to access the entire urethra. All the grafts were placed dorsolaterally, preserving the bulbospongiosus muscle, central tendon of perineum and one-sided attachement of corpus spongiosum. Procedure was considered to be failure if the patient required instrumentation postoperatively. Results Mean stricture length was 8.5cm (range 4 to 12cm). Mean follow-up was 22.7 months (range 12 to 36 months). Overall success rate was 85%. There were 3 failures (meatal stenosis in 1, proximal stricture in 1 and whole length recurrent stricture in 1). Other complications included wound infection, urethrocutaneous fistula, brownish discharge per urethra and scrotal oedema. Conclusion Dorsolateral buccal mucosal urethroplasty for long anterior urethral strictures using a single perineal incision is simple, safe and easily reproducible by urologists with a good outcome. PMID:27286122

  13. Progression in sulfur isotopic compositions from coal to fly ash: Examples from single-source combustion in Indiana

    USGS Publications Warehouse

    Yaofa, Jiang; Elswick, E.R.; Mastalerz, Maria

    2008-01-01

    Sulfur occurs in multiple mineral forms in coals, and its fate in coal combustion is still not well understood. The sulfur isotopic composition of coal from two coal mines in Indiana and fly ash from two power plants that use these coals were studied using geological and geochemical methods. The two coal beds are Middle Pennsylvanian in age; one seam is the low-sulfur ( 5%) Springfield Coal Member of the Petersburg Formation. Both seams have ash contents of approximately 11%. Fly-ash samples were collected at various points in the ash-collection system in the two plants. The results show notable difference in ??34S for sulfur species within and between the low-sulfur and high-sulfur coal. The ??34S values for all sulfur species are exclusively positive in the low-sulfur Danville coal, whereas the ??34S values for sulfate, pyritic, and organic sulfur are both positive and negative in the high-sulfur Springfield coal. Each coal exhibits a distinct pattern of stratigraphic variation in sulfur isotopic composition. Overall, the ??34S for sulfur species values increase up the section in the low-sulfur Danville coal, whereas they show a decrease up the vertical section in the high-sulfur Springfield coal. Based on the evolution of ??34S for sulfur species, it is suggested that there was influence of seawater on peat swamp, with two marine incursions occurring during peat accumulation of the high-sulfur Springfield coal. Therefore, bacterial sulfate reduction played a key role in converting sulfate into hydrogen sulfide, sulfide minerals, and elemental sulfur. The differences in ??34S between sulfate sulfur and pyritic sulfur is very small between individual benches of both coals, implying that some oxidation occurred during deposition or postdeposition. The ??34S values for fly ash from the high-sulfur Springfield coal (averaging 9.7???) are greatly enriched in 34S relative to those in the parent coal (averaging 2.2???). This indicates a fractionation of sulfur isotopes

  14. Single and multi-stage phase demodulation based order-tracking

    NASA Astrophysics Data System (ADS)

    Coats, Michael D.; Randall, Robert B.

    2014-02-01

    Order-tracking is a method to remove speed fluctuations from a varying frequency signal allowing constant frequency based Machine Condition Monitoring (MCM) analysis techniques to be employed. This paper describes the generalised Phase Demodulation based Order-Tracking (PDOT) methodology whereby the "mapping" between rotation angle and time is obtained by phase demodulation of a reference signal. A variety of reference signal types can be used, including a tachometer, a shaft encoder, or an extracted reference signal from the response data signal itself, but each has different properties, which have to be taken into account. The primary advantage of the PDOT method, as opposed to methods based in the time domain, is that in principle it gives samples of the true relationship between rotation angle and time. For this to be true, however, there has to be no aliasing, in the sense of overlap of sidebands of the order to be demodulated with those of higher orders in the frequency domain. The paper defines the conditions for which this is valid. The PDOT method can be employed using a single stage, or the result improved by using progressive iterations in a multi-stage approach, even in the case of large speed variations, but for the iterations to give an improvement there must be no aliasing at the first stage. Such improvement is useful for some analyses, such as gear diagnostics, but not of much benefit for some others such as bearing diagnostics, where the characteristic frequencies are only stable to about 1-2%. A summary of the basic PDOT method is presented, highlighting the maximum speed variations of approximately ±30% which can be compensated for, and then the generalised PDOT method is presented using a variety of reference signal types and numbers of stages. Multiple experimental examples are presented for different applications of PDOT, including bearing diagnostics and gear diagnostics, in the presence of small to large speed variations, highlighting the

  15. Coal liquefaction

    DOEpatents

    Schindler, Harvey D.

    1985-01-01

    In a two-stage liquefaction wherein coal, hydrogen and liquefaction solvent are contacted in a first thermal liquefaction zone, followed by recovery of an essentially ash free liquid and a pumpable stream of insoluble material, which includes 850.degree. F.+ liquid, with the essentially ash free liquid then being further upgraded in a second liquefaction zone, the liquefaction solvent for the first stage includes the pumpable stream of insoluble material from the first liquefaction stage, and 850.degree. F.+ liquid from the second liquefaction stage.

  16. Elastic and optical anisotropy of the single-coal monolithic high-temperature (HT) carbonization products obtained on a laboratory scale

    SciTech Connect

    Marta Krzesinska; Slawomira Pusz; Andrzej Koszorek

    2005-10-01

    The aim of the present study was to investigate the directional dependences of the elastic and optical properties of monolithic single-coal high-temperature (HT) carbonization products obtained on a laboratory scale (with very slow heating rate) from coals of different caking propensity. Sixteen monolithic HT carbonization products, mainly cokes, were produced in the Jenkner retort furnace using 16 various types of coals of varying rank (from 83.1 wt % carbon to 98.3 wt % carbon) with a Roga index (RI) in the range of 0-76. Coals were carbonized in the form of monolithic blocks. The physical parameters such as true density, porosity, ultrasonic velocity, and dynamic elastic moduli, as well as optical reflectance parameters (R{sub max}, R{sub min}, R{sub am}), were determined for the resultant products. The elastic and optical properties of the HT carbonization products were related to their porosity and the rank of the parent coals. It was determined that the HT carbonization products exhibit the different directional properties of the studied parameters, and they can be divided into three groups, with respect to the observed differences. The properties of these groups were related to the parent coal rank and the caking propensity (i.e., to the RI value). Anisotropy of the coke matrix structure was determined to be important for discussion about the anisotropic properties of cokes. 50 refs., 9 figs., 4 tabs.

  17. Health and safety evaluation of a modified tunnel borer design for application to single entry coal mine development

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.

    1982-01-01

    A health and safety analysis of a single entry coal tunnel borer system is given. The results of the health analysis indicated that while the tunnel borer design offered improvements in dust control through the use of water sprays, a higher face ventilation rule, and the application of spalling rather than the conventional grinding process, it interjected an additional mutagen and toxic compound into the environment through the use of shotcrete. The tunnel borer system easily conformed with the prescribed fatality limit, but exceeded the required limits for disabling and overall injuries. It also exhibited projected disabling and overall injury rates considerably higher than existing continuous mining injury rates. Consequently, the tunnel borer system was not considered an advanced system.

  18. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2003-11-01

    This report summarizes technical progress over the second six month period of the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Research efforts were focused on evaluating corrosion effects in single crystal sapphire at temperatures up to 1400 C, and designing the sensor mechanical packaging with input from Wabash River Power Plant. Upcoming meetings will establish details for the gasifier field test.

  19. Single-stage experimental evaluation of tandem-airfoil rotor stator blading for compressors. Part 6: Data and performance for stage D

    NASA Technical Reports Server (NTRS)

    Clemmons, D. R.

    1973-01-01

    An axial flow compressor stage, having single-airfoil blading, was designed for zero rotor prewhirl, constant rotor work across the span, and axial discharge flow. The stage was designed to produce a pressure ratio of 1.265 at a rotor tip velocity of 757 ft/sec. The rotor had an inlet hub/tip ratio of 0.8. The design procedure accounted for the rotor inlet boundary layer and included the effects of axial velocity ratio and secondary flow on blade row performance. The objectives of this experimental program were: (1) to obtain performance with uniform and distorted inlet flow for comparison with the performance of a stage consisting of tandem-airfoil blading designed for the same vector diagrams; and (2) to evaluate the effectiveness of accounting for the inlet boundary layer, axial velocity ratio, and secondary flows in the stage design. With uniform inlet flow, the rotor achieved a maximum adiabatic efficiency of 90.1% at design equivalent rotor speed and a pressure ratio of 1.281. The stage maximum adiabatic efficiency at design equivalent rotor speed with uniform inlet flow was 86.1% at a pressure ratio of 1.266. Hub radial, tip radial, and circumferential distortion of the inlet flow caused reductions in surge pressure ratio of approximately 2, 10 and 5%, respectively, at design rotor speed.

  20. A Multidisciplinary Performance Analysis of a Lifting-Body Single-Stage-to-Orbit Vehicle

    NASA Technical Reports Server (NTRS)

    Tartabini, Paul V.; Lepsch, Roger A.; Korte, J. J.; Wurster, Kathryn E.

    2000-01-01

    Lockheed Martin Skunk Works (LMSW) is currently developing a single-stage-to-orbit reusable launch vehicle called VentureStar(TM) A team at NASA Langley Research Center participated with LMSW in the screening and evaluation of a number of early VentureStar(TM) configurations. The performance analyses that supported these initial studies were conducted to assess the effect of a lifting body shape, linear aerospike engine and metallic thermal protection system (TPS) on the weight and performance of the vehicle. These performance studies were performed in a multidisciplinary fashion that indirectly linked the trajectory optimization with weight estimation and aerothermal analysis tools. This approach was necessary to develop optimized ascent and entry trajectories that met all vehicle design constraints. Significant improvements in ascent performance were achieved when the vehicle flew a lifting trajectory and varied the engine mixture ratio during flight. Also, a considerable reduction in empty weight was possible by adjusting the total oxidizer-to-fuel and liftoff thrust-to-weight ratios. However, the optimal ascent flight profile had to be altered to ensure that the vehicle could be trimmed in pitch using only the flow diverting capability of the aerospike engine. Likewise, the optimal entry trajectory had to be tailored to meet TPS heating rate and transition constraints while satisfying a crossrange requirement.

  1. Aortic root aneurysm in an adult patient with aortic coarctation: a single-stage approach.

    PubMed

    Ananiadou, Olga G; Koutsogiannidis, Charilaos; Ampatzidou, Fotini; Drossos, George E

    2012-09-01

    Coarctation of the aorta is a common congenital defect that may be undiagnosed until adulthood. Moreover, coarctation is associated with congenital and acquired cardiac pathology that may require surgical intervention. The management of an adult patient with aortic coarctation and an associated cardiac defect poses a great technical challenge since there are no standard guidelines for the therapy of such a complex pathology. Several extra-anatomic bypass grafting techniques have been described, including methods in which distal anastomosis is performed on the descending thoracic aorta, allowing simultaneous intracardiac repair. We report here a 37-year old man who was diagnosed with an aortic root aneurysm and aortic coarctation. The patient was treated electively with a single-stage approach through a median sternotomy that consisted of valve-sparing replacement of the aortic root and ascending-to-descending extra-anatomic aortic bypass, using a 18-mm Dacron graft. Firstly, the aortic root was replaced with the Yacoub remodelling procedure, and then the distal anastomosis was performed to the descending aorta, behind the heart, with the posterior pericardial approach. The extra-anatomic bypass graft was brought laterally from the right atrium and implanted in the ascending graft. Postoperative recovery was uneventful and a control computed tomographic angiogram 1 month after complete repair showed good results.

  2. Orbital Single Particle Tracking on a commercial confocal microscope using piezoelectric stage feedback

    PubMed Central

    Lanzanò, Luca; Gratton, Enrico

    2014-01-01

    Single Particle Tracking (SPT) is a technique used to locate fluorescent particles with nanometer precision. In the orbital tracking method the position of a particle is obtained analyzing the distribution of intensity along a circular orbit scanned around the particle. In combination with an active feedback this method allows tracking of particles in 2D and 3D with millisecond temporal resolution. Here we describe a SPT setup based on a feedback approach implemented with minimal modification of a commercially available confocal laser scanning microscope, the Zeiss LSM 510, in combination with an external piezoelectric stage scanner. The commercial microscope offers the advantage of a user-friendly software interface and pre-calibrated hardware components. The use of an external piezo-scanner allows the addition of feedback into the system but also represents a limitation in terms of its mechanical response. We describe in detail this implementation of the orbital tracking method and discuss advantages and limitations. As an example of application to live cell experiments we perform the 3D tracking of acidic vesicles in live polarized epithelial cells. PMID:25419461

  3. Low energy single-staged anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for wastewater treatment.

    PubMed

    Aslam, Muhammad; McCarty, Perry L; Shin, Chungheon; Bae, Jaeho; Kim, Jeonghwan

    2017-03-06

    An aluminum dioxide (Al2O3) ceramic membrane was used in a single-stage anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for low-strength wastewater treatment. The AFCMBR was operated continuously for 395days at 25°C using a synthetic wastewater having a chemical oxygen demand (COD) averaging 260mg/L. A membrane net flux as high as 14.5-17L/m(2)h was achieved with only periodic maintenance cleaning, obtained by adding 25mg/L of sodium hypochlorite solution. No adverse effect of the maintenance cleaning on organic removal was observed. An average SCOD in the membrane permeate of 23mg/L was achieved with a 1h hydraulic retention time (HRT). Biosolids production averaged 0.014±0.007gVSS/gCOD removed. The estimated electrical energy required to operate the AFCMBR system was 0.039kWh/m(3), which is only about 17% of the electrical energy that could be generated with the methane produced.

  4. Trim drag reduction concepts for horizontal takeoff single-stage-to-Orbit vehicles

    NASA Technical Reports Server (NTRS)

    Shaughnessy, John D.; Gregory, Irene M.

    1991-01-01

    The results of a study to investigate concepts for minimizing trim drag of horizontal takeoff single-stage-to-orbit (SSTO) vehicles are presented. A generic hypersonic airbreathing conical configuration was used as the subject aircraft. The investigation indicates that extreme forward migration of the aerodynamic center as the vehicle accelerates to orbital velocities causes severe aerodynamic instability and trim moments that must be counteracted. Adequate stability can be provided by active control of elevons and rudder, but use of elevons to produce trim moments results in excessive trim drag and fuel consumption. To alleviate this problem, two solution concepts are examined. Active control of the center of gravity (COG) location to track the aerodynamic center decreases trim moment requirements, reduces elevon deflections, and leads to significant fuel savings. Active control of the direction of the thrust vector produces required trim moments, reduces elevon deflections, and also results in significant fuel savings. It is concluded that the combination of active flight control to provide stabilization, (COG) position control to minimize trim moment requirements, and thrust vectoring to generate required trim moments has the potential to significantly reduce fuel consumption during ascent to orbit of horizontal takeoff SSTO vehicles.

  5. Rocket-Induced Magnetohydrodynamic Ejector: A Single-Stage-to-Orbit Advanced Propulsion Concept

    NASA Technical Reports Server (NTRS)

    Cole, John; Campbell, Jonathan; Robertson, Anthony

    1995-01-01

    During the atmospheric boost phase of a rocket trajectory, magnetohydrodynamic (MHD) principles can be utilized to augment the thrust by several hundred percent without the input of additional energy. The concept is an MHD implementation of a thermodynamic ejector. Some ejector history is described and some test data showing the impressive thrust augmentation capabilities of thermodynamic ejectors are provided. A momentum and energy balance is used to derive the equations to predict the MHD ejector performance. Results of these equations are compared with the test data and then applied to a specific performance example. The rocket-induced MHD ejector (RIME) engine is described and a status of the technology and availability of the engine components is provided. A top level vehicle sizing analysis is performed by scaling existing MHD designs to the required flight vehicle levels. The vehicle can achieve orbit using conservative technology. Modest improvements are suggested using recently developed technologies, such as superconducting magnets, which can improve predicted performance well beyond those expected for current single-stage-to-orbit (SSTO) designs.

  6. Optoelectronic gain control of a microwave single stage GaAs MESFET amplifier

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.

    1988-01-01

    Gain control of a single stage GaAs MESFET amplifier is demonstrated by the use of optical illumination of photon energy greater than the GaAs bandgap. The optical illumination is supplied by a semiconductor laser diode and is coupled to the Schottky gate of the MESFET by an optical fiber. The increase in gain is observed to be as much as 5.15 dB when the MESFET is biased close to pinchoff, that is, V(sub gs) equals -1.5 V and with optical illumination of 1.5 mW. The computed maximum available gain (MAG) and current gain (bar h sub 21 bar) from the de-embedded s-parameters show that MAG is unaffected by optical illumination, however, bar h(sub 21)bar increases by more than 2 dB under optical illumination of 1.5 mW. The maximum frequency of oscillation (F sub max) and the unity current gain cut-off frequency (F sub t) obtained by extrapolating the MAG and bar h(sub 21)bar curves, respectively, show that the F(sub max) is insensitive to optical illumination but F(sub t) increases by 5 GHz.

  7. Single stage batch adsorber design for efficient Eosin yellow removal by polyaniline coated ligno-cellulose.

    PubMed

    Debnath, Sushanta; Ballav, Niladri; Maity, Arjun; Pillay, Kriveshini

    2015-01-01

    Polyaniline-coated lignin-based adsorbent (PLC) was synthesized and used for uptake of reactive dye eosin yellow (EY) from aqueous solution. The adsorption capability of the adsorbent was found to be more effective than the unmodified adsorbent (LC). In particular, the adsorption capability of the PLC was effective over a wider pH range. This could be owing to its higher point of zero charge, which is more favorable for the uptake of the anionic dye. Adsorption isotherm models suggested a monolayer adsorption was predominant. The mean free energy of adsorption (E(DR)) was found to have values between 8 and 16 kJ mol(-1) which suggests that an electrostatic mechanism of adsorption predominated over other underlying mechanisms. The adsorption process was also found to be spontaneous, with increasing negative free energy values observed at higher temperatures. Chemisorption process was supported by the changes in enthalpy above 40 kJ mol(-1) and by the results of desorption studies. This new adsorbent was also reusable and regenerable over four successive adsorption-desorption cycles. The single stage adsorber design revealed that PLC can be applicable as an effective biosorbent for the treatment of industrial effluents containing EY dye.

  8. A single-stage synthesis of dimethyl ether in liquid phase

    SciTech Connect

    Tartamella, T.L.; Lee, S.; Kulik, C.J.

    1994-12-31

    A novel, single-stage process for the synthesis of dimethyl ether (DME) has been developed using CO rich syngas in the liquid phase (LPDME). This process utilizes a three-phase, mechanically agitated slurry reactor and makes use of a dual catalyst system consisting of Cu/ZnO/Al{sub 2}O{sub 3} as the methanol synthesis catalyst and {gamma}-Al{sub 2}O{sub 3} for the subsequent conversion to DME. The catalyst is slurried in an inert mineral oil which facilitates effective heat removal. The process involves the synthesis of methanol as an inter-mediate in the production of DME. In doing so, there is a reduction of the chemical equilibrium limitations previously encountered in methanol synthesis alone. As a result, enhanced catalyst activity, per-pass conversion and reactor productivity over methanol synthesis is observed. The process excels over its liquid phase methanol counterpart (LPMeOH{trademark}) in many areas. Specifically, a increase in reactor productivity as high as 95% is attained in the production of DME over LPMeOH{trademark}. Also, a 60% increase in syngas conversion is attained over the production of methanol alone. Experimental studies compare reactor productivities for methanol vs. DME synthesis for several slurry ratios. Also, the effect of temperature and pressure on synthesis rates for methanol and DME are also examined.

  9. Single stage, low noise, advanced technology fan. Volume 1: Aerodynamic design

    NASA Technical Reports Server (NTRS)

    Sullivan, T. J.; Younghans, J. L.; Little, D. R.

    1976-01-01

    The aerodynamic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec 11,650 ft/sec). The fan and booster components are designed in a scale model flow size convenient for testing with existing facility and vehicle hardware. The design corrected flow per unit annulus area at the fan face is 215 kg/sec sq m (44.0 lb m/sec sq ft) with a hub-tip ratio of 0.38 at the leading edge of the fan rotor. This results in an inlet corrected airflow of 117.9 kg/sec (259.9 lb m/sec) for the selected rotor tip diameter if 90.37 cm (35.58 in.). The variable geometry inlet is designed utilizing a combination of high throat Mach number and acoustic treatment in the inlet diffuser for noise suppression (hybrid inlet). A variable fan exhaust nozzle was assumed in conjunction with the variable inlet throat area to limit the required area change of the inlet throat at approach and hence limit the overall diffusion and inlet length. The fan exit duct design was primarily influenced by acoustic requirements, including length of suppressor wall treatment; length, thickness and position on a duct splitter for additional suppressor treatment; and duct surface Mach numbers.

  10. Single stage, low noise advanced technology fan. Volume 3: Acoustic design

    NASA Technical Reports Server (NTRS)

    Kazin, S. B.; Mishler, R. B.

    1976-01-01

    The acoustic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec (1,650 ft/sec). The two basic approaches taken in the acoustic design were: (1) minimization of noise at the source, and (2) suppression of the generated noise in the inlet and bypass exhaust duct. Suppression of the generated noise is accomplished in the inlet through use of the hybrid concept (wall acoustic treatment plus airflow acceleration suppression) and in the exhaust duct with extensive acoustic treatment including a splitter. The goal of the design was attainment of twenty effective perceived noise decibels (20 EPNdB) below current Federal Air Regulation noise standards for a full-scale fan at the takeoff, cutback, and approach conditions. Predicted unsuppressed and suppressed fore and aft maximum perceived noise levels indicate that the cutback condition is the most critical with respect to the goal, which is probably unattainable for that condition. This is also true for aft radiated noise in the approach condition.

  11. Citrullination as early-stage indicator of cell response to Single-Walled Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Mohamed, Bashir Mustafa; Movia, Dania; Knyazev, Anton; Langevin, Dominique; Davies, Anthony Mitchell; Prina-Mello, Adriele; Volkov, Yuri

    2013-01-01

    Single-walled carbon nanotubes (SWCNTs) have been widely explored as potential technologies for information systems and medical applications. The impact of SWCNTs on human health is of prime concern, if SWCNTs have a future in the manufacturing industry. This study proposes a novel, inflammation-independent paradigm of toxicity for SWCNTs, identifying the protein citrullination process as early-stage indicator of inflammatory responses of macrophages (THP-1) and of subtle phenotypic damages of lung epithelial (A549) cells following exposure to chemically-treated SWCNTs. Our results showed that, while most of the cellular responses of A549 cells exposed to SWCNTs are different to those of similarly treated THP-1 cells, the protein citrullination process is triggered in a dose- and time-dependent manner in both cell lines, with thresholds comparable between inflammatory (THP-1) and non-inflammatory (A549) cell types. The cellular mechanism proposed herein could have a high impact in predicting the current risk associated with environmental exposure to SWCNTs.

  12. Stage-specific predator species help each other to persist while competing for a single prey

    PubMed Central

    De Roos, A. M.; Schellekens, T.; Van Kooten, T.; Persson, L.

    2008-01-01

    Prey in natural communities are usually shared by many predator species. How predators coexist while competing for the same prey is one of the fundamental questions in ecology. Here, we show that competing predator species may not only coexist on a single prey but even help each other to persist if they specialize on different life history stages of the prey. By changing the prey size distribution, a predator species may in fact increase the amount of prey available for its competitor. Surprisingly, a predator may not be able to persist at all unless its competitor is also present. The competitor thus significantly increases the range of conditions for which a particular predator can persist. This “emergent facilitation” is a long-term, population-level effect that results from asymmetric increases in the rate of prey maturation and reproduction when predation relaxes competition among prey. Emergent facilitation explains observations of correlated increases of predators on small and large conspecific prey as well as concordance in their distribution patterns. Our results suggest that emergent facilitation may promote the occurrence of complex, stable, community food webs and that persistence of these communities could critically depend on diversity within predator guilds. PMID:18779580

  13. Real time guidance and propulsion control for single-stage-to-orbit airbreathing vehicles

    NASA Astrophysics Data System (ADS)

    Corban, John Eric

    1989-03-01

    Problems associated with on-board trajectory optimization and with the synthesis of guidance laws are addressed for ascent to low-Earth-orbit of an air-breathing, single-stage-to-orbit vehicle. A multi-mode propulsion system is assumed which incorporates turbojet, ramjet, SCRAMJET, and rocket engines. An energy state approximation is applied to a four-state dynamic model for flight of a point mass over a spherical non-rotating Earth. An algorithm for generating fuel-optimal climb profiles is derived via singular perturbation theory. This algorithm results from application of the minimum principle to a low order dynamic model that includes general functional dependence on angle of attack and a component of thrust normal to the flight path. Maximum dynamic pressure and maximum aerodynamic heating rate constraints are considered in addition to acceleration limits. Switching conditions are derived which, under appropriate assumptions, govern optimal transition from one propulsion mode to another. The use of bank angle to modulate the magnitude of the vertical component of lift is shown to improve the index of performance slightly. A nonlinear transformation technique is employed to derive a feedback controller for tracking the computed trajectory. Numerical results illustrate the nature of the resulting fuel-optimal climb paths and the performance of the feedback control law.

  14. Maximum organic loading rate for the single-stage wet anaerobic digestion of food waste.

    PubMed

    Nagao, Norio; Tajima, Nobuyuki; Kawai, Minako; Niwa, Chiaki; Kurosawa, Norio; Matsuyama, Tatsushi; Yusoff, Fatimah Md; Toda, Tatsuki

    2012-08-01

    Anaerobic digestion of food waste was conducted at high OLR from 3.7 to 12.9 kg-VS m(-3) day(-1) for 225 days. Periods without organic loading were arranged between the each loading period. Stable operation at an OLR of 9.2 kg-VS (15.0 kg-COD) m(-3) day(-1) was achieved with a high VS reduction (91.8%) and high methane yield (455 mL g-VS-1). The cell density increased in the periods without organic loading, and reached to 10.9×10(10) cells mL(-1) on day 187, which was around 15 times higher than that of the seed sludge. There was a significant correlation between OLR and saturated TSS in the sludge (y=17.3e(0.1679×), r(2)=0.996, P<0.05). A theoretical maximum OLR of 10.5 kg-VS (17.0 kg-COD) m(-3) day(-1) was obtained for mesophilic single-stage wet anaerobic digestion that is able to maintain a stable operation with high methane yield and VS reduction.

  15. Aortic root aneurysm in an adult patient with aortic coarctation: a single-stage approach

    PubMed Central

    Ananiadou, Olga G.; Koutsogiannidis, Charilaos; Ampatzidou, Fotini; Drossos, George E.

    2012-01-01

    Coarctation of the aorta is a common congenital defect that may be undiagnosed until adulthood. Moreover, coarctation is associated with congenital and acquired cardiac pathology that may require surgical intervention. The management of an adult patient with aortic coarctation and an associated cardiac defect poses a great technical challenge since there are no standard guidelines for the therapy of such a complex pathology. Several extra-anatomic bypass grafting techniques have been described, including methods in which distal anastomosis is performed on the descending thoracic aorta, allowing simultaneous intracardiac repair. We report here a 37-year old man who was diagnosed with an aortic root aneurysm and aortic coarctation. The patient was treated electively with a single-stage approach through a median sternotomy that consisted of valve-sparing replacement of the aortic root and ascending-to-descending extra-anatomic aortic bypass, using a 18-mm Dacron graft. Firstly, the aortic root was replaced with the Yacoub remodelling procedure, and then the distal anastomosis was performed to the descending aorta, behind the heart, with the posterior pericardial approach. The extra-anatomic bypass graft was brought laterally from the right atrium and implanted in the ascending graft. Postoperative recovery was uneventful and a control computed tomographic angiogram 1 month after complete repair showed good results. PMID:22647969

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

    NASA Technical Reports Server (NTRS)

    Alexander, Reginald; Stanley, Thomas Troy

    2001-01-01

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

  17. Biological testing and chemical analysis of process materials from an integrated two stage coal liquefaction: a status report

    SciTech Connect

    Wilson, B.W.; Buhl, P.; Moroni, E.C.

    1983-07-01

    Samples for chemical characterization and biological testing were obtained from ITSL runs 3LCF7, 3LCF8 and 3LCF9. Chemical analysis of these materials showed that SCT products were composed of fewer compounds than analogous materials from Solvent Refined Coal (SRC) processes. Major components in the SCT materials were three-, four-, five- and six-ring neutral polycyclic aromatic hydrocarbons (PAH). Methyl(C/sub 1/) and C/sub 2/ homologs of these compounds were present in relatively low concentrations, compared to their non-alkylated homologs. Organic nitrogen was primarily in the form of tertiary polycyclic aromatic nitrogen heterocycles and carbazoles. Little or no amino PAH (APAH) or cyano PAH were detected in samples taken during normal PDU operations, however, mutagenic APAH were produced during off-normal operation. Microbial mutagenicity appeared to be due mainly to the presence of APAH which were probably formed in the LC finer due to failure of the catalyst to promote deamination following carbon-nitrogen bond scission of nitrogen-containing hydroaromatics. This failure was observed for the off-normal runs where it was likely that the catalyst had been deactivated. Carcinogenic activity of ITSL materials as assessed by (tumors per animal) in the initiation/promotion mouse skin painting assay was slightly reduced for materials produced with good catalyst under normal operation compared to those collected during recycle of the LC Finer feed. Initiation activity of the latter samples did not appear to be significantly different from that of other coal derived materials with comparable boiling ranges. The observed initiation activity was not unexpected, considering analytical data which showed the presence of four-, five- and six-ring PAH in ITSL materials.

  18. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang; Zhengyu Huang

    2004-04-01

    This report summarizes technical progress over the third six month period of the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Research efforts were focused on sensor probe design and machining, sensor electronics design, software algorithm design, sensor field installation procedures, and sensor remote data access and control. Field testing will begin in the next several weeks.

  19. On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2005-11-01

    This report summarizes technical progress April-September 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report. The sensing system will be installed and tested at TECO's Polk Power Station. Following a site visit in June 2005, our efforts have been focused on preparing for that field test, including he design of the sensor mechanical packaging, sensor electronics, the data transfer module, and the necessary software codes to accommodate this application.. We are currently ready to start sensor fabrication.

  20. On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

    SciTech Connect

    Kristie Cooper; Anbo Wang

    2007-03-31

    This report summarizes technical progress October 2006 - March 2007 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. During the second phase, an alternative high temperature sensing system based on Fabry-Perot interferometry was developed that offers a number of advantages over the BPDI solution. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. The sapphire wafer-based interferometric sensing system that was installed at TECO's Polk Power Station remained in operation for seven months. Our efforts have been focused on monitoring and analyzing the real-time data collected, and preparing for a second field test.

  1. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang; Zhengyu Huang; Yizheng Zhu

    2005-04-01

    This report summarizes technical progress October 2004-March 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report.

  2. Implementation of a Single-Stage-To-Orbit (SSTO) model for stability and control analysis

    NASA Technical Reports Server (NTRS)

    Ingalls, Stephen A.

    1995-01-01

    Three NASA centers: Marshall Space Flight Center (MSFC), Langley Research Center (LaRC), and Johnson Space Center (JSC) are currently involved in studying a family of single-stage- and two-stage-to-orbit (SSTO/TSTO) vehicles to serve as the next generation space transportation system (STS). A rocketed winged-body is the current focus. The configuration (WB001) is a vertically-launched, horizontally-landing system with circular cross-section. Preliminary aerodynamic data was generated by LaRC and is a combination of wind-tunnel data, empirical methods, and Aerodynamic Preliminary Analysis System-(APAS) generated values. JSC's efforts involve descent trajectory design, stability analysis, and flight control system synthesis. Analysis of WB001's static stability indicates instability in 'tuck' (C(sub mu) less than 0: Mach = 0.30, alpha greater than 3.25 deg; Mach = 0.60, alpha greater than 8.04), an unstable dihedral effects (C(sub l(beta)) greater than 0: Mach = 30,alpha less than 12 deg.; Mach = 0.60, alpha less than 10.00 deg.), and, most significantly, an unstable weathercock stability derivative, C(sub n(beta)), at all angles of attack and subsonic Mach numbers. Longitudinal trim solutions for Mach = 0.30 and 0.60 indicate flight path angle possibilities ranging from around 12 (M = 0.30) to slightly over 20 degrees at Mach = 0.60. Trim angles of attack increase from 6.24 at Mach 0.60 and 10,000 feet to 17.7 deg. at Mach 0.30, sea-level. Lateral trim was attempted for a design cross-wind of 25.0 knots. The current vehicle aerodynamic and geometric characteristics will only yield a lateral trim solution at impractical tip-fin deflections (approximately equal to 43 deg.) and bank angles (21 deg.). A study of the lateral control surfaces, tip-fin controllers for WB001, indicate increased surface area would help address these instabilities, particularly the deficiency in C(sub n(beta)), but obviously at the expense of increased vehicle weight. Growth factors of

  3. EVALUATION OF INTERNALLY STAGED COAL BURNERS AND SORBENT JET AERODYNAMICS FOR COMBINED SO2/NOX CONTROL IN UTILITY BOILERS, VOLUME 1, TESTING IN A 10 MILLION BTU/HR EXPERIMENTAL FURNACE

    EPA Science Inventory

    The document gives results of tests conducted in a 2 MWt experimental furnace to: (1) investigate ways to reduce NOx emissions from utility coal burners without external air ports (i.e., with internal fuel/air staging); and (2) improve the performance of calcium-based sorbents fo...

  4. Design analysis and risk assessment for a single stage to orbit nuclear thermal rocket

    NASA Astrophysics Data System (ADS)

    Labib, Satira I.

    Recent advances in high power density fuel materials have renewed interest in nuclear thermal rockets (NTRs) as a viable propulsion technology for future space exploration. This thesis describes the design of three NTR reactor engines designed for the single stage to orbit launch of payloads from 1-15 metric tons. Thermal hydraulic and rocket engine analyses indicate that the proposed rocket engines are able to reach specific impulses in excess of 700 seconds. Neutronics analyses performed using MCNP5 demonstrate that the hot excess reactivity, shutdown margin, and submersion criticality requirements are satisfied for each NTR reactor. The reactors each consist of a 40 cm diameter core packed with hexagonal tungsten cermet fuel elements. The core is surrounded by radial and axial beryllium reflectors and eight boron carbide control drums. At the same power level, the 40 cm reactor results in the lowest radiation dose rate of the three reactors. Radiation dose rates decrease to background levels ~3.5 km from the launch site. After a one-year decay time, all of the activated materials produced by an NTR launch would be classified as Class A low-level waste. The activation of air produces significant amounts of argon-41 and nitrogen-16 within 100 m of the launch. The derived air concentration, DAC, from the activation products decays to less than unity within two days, with only argon-41 remaining. After 10 minutes of full power operation the 120 cm core corresponding to a 15 MT payload contains 2.5 x 1013, 1.4 x 1012, 1.5 x 1012, and 7.8 x 10 7 Bq of 131I, 137Cs, 90Sr, and 239Pu respectively. The decay heat after shutdown increases with increasing reactor power with a maximum decay heat of 108 kW immediately after shutdown for the 15 MT payload.

  5. A parametric sensitivity study for single-stage-to-orbit hypersonic vehicles using trajectory optimization

    NASA Technical Reports Server (NTRS)

    Lovell, T. Alan; Schmidt, D. K.

    1994-01-01

    The class of hypersonic vehicle configurations with single stage-to-orbit (SSTO) capability reflect highly integrated airframe and propulsion systems. These designs are also known to exhibit a large degree of interaction between the airframe and engine dynamics. Consequently, even simplified hypersonic models are characterized by tightly coupled nonlinear equations of motion. In addition, hypersonic SSTO vehicles present a major system design challenge; the vehicle's overall mission performance is a function of its subsystem efficiencies including structural, aerodynamic, propulsive, and operational. Further, all subsystem efficiencies are interrelated, hence, independent optimization of the subsystems is not likely to lead to an optimum design. Thus, it is desired to know the effect of various subsystem efficiencies on overall mission performance. For the purposes of this analysis, mission performance will be measured in terms of the payload weight inserted into orbit. In this report, a trajectory optimization problem is formulated for a generic hypersonic lifting body for a specified orbit-injection mission. A solution method is outlined, and results are detailed for the generic vehicle, referred to as the baseline model. After evaluating the performance of the baseline model, a sensitivity study is presented to determine the effect of various subsystem efficiencies on mission performance. This consists of performing a parametric analysis of the basic design parameters, generating a matrix of configurations, and determining the mission performance of each configuration. Also, the performance loss due to constraining the total head load experienced by the vehicle is evaluated. The key results from this analysis include the formulation of the sizing problem for this vehicle class using trajectory optimization, characteristics of the optimal trajectories, and the subsystem design sensitivities.

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

    NASA Technical Reports Server (NTRS)

    Alexander, Reginald Andrew; Stanley, Thomas Troy

    1999-01-01

    Presented is a design tool and process that connects several disciplines which are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system and in the case of SSTO vehicles with air breathing propulsion, which is currently being studied by the National Aeronautics and Space Administration (NASA); the thermal protection system (TPS) is linked directly to almost every major system. The propulsion system pushes the vehicle to velocities on the order of 15 times the speed of sound in the atmosphere before pulling up to go to orbit which results high temperatures on the external surfaces of the vehicle. Thermal protection systems to maintain the structural integrity of the vehicle must be able to mitigate the heat transfer to the structure and be lightweight. Herein lies the interdependency, in that as the vehicle's speed increases, the TPS requirements are increased. And as TPS masses increase the effect on the propulsion system and all other systems is compounded. To adequately determine insulation masses for a vehicle such as the one described above, the aeroheating loads must be calculated and the TPS thicknesses must be calculated for the entire vehicle. To accomplish this an ascent or reentry trajectory is obtained using the computer code Program to Optimize Simulated Trajectories (POST). The trajectory is then used to calculate the convective heat rates on several locations on the vehicles using the Miniature Version of the JA70 Aerodynamic Heating Computer Program (MINIVER). Once the heat rates are defined for each body point on the vehicle, then insulation thickness that are required to maintain the vehicle within structural limits are calculated using Systems Improved Numerical Differencing Analyzer (SINDA) models. If the TPS masses are too heavy for the performance of the vehicle the process may be repeated altering the trajectory or some other input to reduce

  7. Single stage circumferential lingual mucosal graft urethroplasty in near obliterative bulbar urethra stricture: A novel technique

    PubMed Central

    Sharma, Umesh; Yadav, Sher Singh; Tomar, Vinay; Garg, Amit

    2016-01-01

    Aims: This is a prospective study of the use and efficacy of a novel technique of circumferential tubularised lingual mucosal graft (LMG) in obliterative and near obliterative bulbar urethral stricture of >2 cm where excisional and augmented anastomotic urethroplasty are not feasible. Materials and Methods: The stenotic urethral segment was opened dorsally in midline and fibrosed urethra was excised taking care to preserve the healthy spongiosum tissue. LMG (av. Length 3 cm) was placed from one end of corporal body towards spongy tissue in a circumferential manner. Another LMG was placed in similar manner to deal with longer stricture. The urethra was tubularised over 14 Fr silicone catheter. Results: A total of 12 men, of mean age 47 years underwent this procedure. The mean follow up period was 11 months starting from July 2014 till manuscript submission. Follow up included voiding cystourethrogram at 3 weeks, cystoscopy at 3 months (one patient didn’t turned up) and subsequent follow up. Mean stricture length was 4.66 cm (range, 3–8.5 cm) and mean operative time was 195 min. (range, 160 to 200 min.). The technique was successful (normal voiding with no need for any post-operative procedure) in 11(91.6%) patients. One patient developed early recurrence at 4 month of surgery and had anastomotic stricture which was successfully managed by direct visual internal urethrotomy. Conclusion: Single stage circumferential tubularised graft urethroplasty is an excellent technique for strictures that include segments of obliterative and near obliterative diseased urethra. It provide a wider neourethra than patch graft urethroplasty. PMID:27141182

  8. MAGNESIUM ISOTOPE EVIDENCE FOR SINGLE STAGE FORMATION OF CB CHONDRULES BY COLLIDING PLANETESIMALS

    SciTech Connect

    Olsen, Mia B.; Schiller, Martin; Krot, Alexander N.; Bizzarro, Martin

    2013-10-10

    Chondrules are igneous spherical objects preserved in chondritic meteorites and believed to have formed during transient heating events in the solar protoplanetary disk. Chondrules present in the metal-rich CB chondrites show unusual chemical and petrologic features not observed in other chondrite groups, implying a markedly distinct formation mechanism. Here, we report high-precision Mg-isotope data for 10 skeletal olivine chondrules from the Hammadah al Hamra 237 (HH237) chondrite to probe the formation history of CB chondrules. The {sup 27}Al/{sup 24}Mg ratios of individual chondrules are positively correlated to their stable Mg-isotope composition (μ{sup 25}Mg), indicating that the correlated variability was imparted by a volatility-controlled process (evaporation/condensation). The mass-independent {sup 26}Mg composition (μ{sup 26}Mg*) of chondrules is consistent with single stage formation from an initially homogeneous magnesium reservoir if the observed μ{sup 25}Mg variability was generated by non-ideal Rayleigh-type evaporative fractionation characterized by a β value of 0.5142, in agreement with experimental work. The magnitude of the mass-dependent fractionation (∼300 ppm) is significantly lower than that suggested by the increase in {sup 27}Al/{sup 24}Mg values, indicating substantial suppression of isotopic fractionation during evaporative loss of Mg, possibly due to evaporation at high Mg partial pressure. Thus, the Mg-isotope data of skeletal chondrules from HH237 are consistent with their origin as melts produced in the impact-generated plume of colliding planetesimals. The inferred μ{sup 26}Mg* value of –3.87 ± 0.93 ppm for the CB parent body is significantly lower than the bulk solar system value of 4.5 ± 1.1 ppm inferred from CI chondrites, suggesting that CB chondrites accreted material comprising an early formed {sup 26}Al-free component.

  9. Minced Tissue in Compressed Collagen: A Cell-containing Biotransplant for Single-staged Reconstructive Repair.

    PubMed

    Chamorro, Clara I; Zeiai, Said; Reinfeldt Engberg, Gisela; Fossum, Magdalena

    2016-02-24

    Conventional techniques for cell expansion and transplantation of autologous cells for tissue engineering purposes can take place in specially equipped human cell culture facilities. These methods include isolation of cells in single cell suspension and several laborious and time-consuming events before transplantation back to the patient. Previous studies suggest that the body itself could be used as a bioreactor for cell expansion and regeneration of tissue in order to minimize ex vivo manipulations of tissues and cells before transplanting to the patient. The aim of this study was to demonstrate a method for tissue harvesting, isolation of continuous epithelium, mincing of the epithelium into small pieces and incorporating them into a three-layered biomaterial. The three-layered biomaterial then served as a delivery vehicle, to allow surgical handling, exchange of nutrition across the transplant, and a controlled degradation. The biomaterial consisted of two outer layers of collagen and a core of a mechanically stable and slowly degradable polymer. The minced epithelium was incorporated into one of the collagen layers before transplantation. By mincing the epithelial tissue into small pieces, the pieces could be spread and thereby the propagation of cells was stimulated. After the initial take of the transplants, cell expansion and reorganization would take place and extracellular matrix mature to allow ingrowth of capillaries and nerves and further maturation of the extracellular matrix. The technique minimizes ex vivo manipulations and allow cell harvesting, preparation of autograft, and transplantation to the patient as a simple one-stage intervention. In the future, tissue expansion could be initiated around a 3D mold inside the body itself, according to the specific needs of the patient. Additionally, the technique could be performed in an ordinary surgical setting without the need for sophisticated cell culturing facilities.

  10. Single stage biological nitrogen removal by nitritation and anaerobic ammonium oxidation in biofilm systems.

    PubMed

    Helmer, C; Tromm, C; Hippen, A; Rosenwinkel, K H; Seyfried, C F; Kunst, S

    2001-01-01

    In full scale wastewater treatment plants with at times considerable deficits in the nitrogen balances, it could hitherto not be sufficiently explained which reactions are the cause of the nitrogen losses and which micro-organisms participate in the process. The single stage conversion of ammonium into gaseous end-products--which is henceforth referred to as deammonification--occurs particularly frequently in biofilm systems. In the meantime, one has succeeded to establish the deammonification processes in a continuous flow moving-bed pilot plant. In batch tests with the biofilm covered carriers, it was possible for the first time to examine the nitrogen conversion at the intact biofilm. Depending on the dissolved oxygen (DO) concentration, two autotrophic nitrogen converting reactions in the biofilm could be proven: one nitritation process under aerobic conditions and one anaerobic ammonium oxidation. With the anaerobic ammonium oxidation, ammonium as electron donor was converted with nitrite as electron acceptor. The end-product of this reaction was N2. Ammonium and nitrite did react in a stoichiometrical ratio of 1:1.37, a ratio which has in the very same dimension been described for the ANAMMOX-process (1:1.31 +/- 0.06). Via the oxygen concentration in the surrounding medium, it was possible to control the ratio of nitritation and anaerobic ammonium oxidation in the nitrogen conversion of the biofilm. Both processes were evenly balanced at a DO concentration of 0.7 mg/l, so that it was possible to achieve a direct, almost complete elimination of ammonium without addition of nitrite. One part of the provided ammonium did participate in the nitritation, the other in the anaerobic ammonium oxidation. Through the aerobic ammonium oxidation into nitrite within the outer oxygen supplied layers of the biofilm, the reaction partner was produced for the anaerobic ammonium oxidation within the inner layers of the biofilm.

  11. Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 3: Data and performance for stage C

    NASA Technical Reports Server (NTRS)

    Brent, J. A.; Clemmons, D.

    1972-01-01

    Stage C, comprised of tandem-airfoil rotor C and tandem-airfoil stator B, was designed and tested to establish performance data for comparison with the performance of conventional single-airfoil blading. Velocity diagrams and blade leading and trailing edge metal angles selected for the conventional rotor and stator blading were used in the design of the tandem blading. The rotor had an inlet hub/tip ratio of 0.8 and a design tip velocity of 757 ft/sec. At design equivalent rotor speed, rotor C achieved a maximum adiabatic efficiency of 91.8% at a pressure ratio of 1.31. The stage maximum adiabatic efficiency was 86.5% at a pressure ratio of 1.31.

  12. Fine Anthracite Coal Washing Using Spirals

    SciTech Connect

    R.P. Killmeyer; P.H. Zandhuis; M.V. Ciocco; W. Weldon; T. West; D. Petrunak

    2001-05-31

    The spiral performed well in cleaning the coarse 8 x 16 mesh size fraction, as demonstrated by the Ep ranging from 0.091 to 0.177. This is in line with typical spiral performance. In addition, the presence of the coarser size fraction did not significantly affect spiral performance on the typical 16 x 100 mesh fraction, in which the Ep ranged from 0.144 to 0.250. Changes in solids concentration and flow rate did not show a clear correlation with spiral performance. However, for difficult-to-clean coals with high near-gravity material, such as this anthracite, a single-stage spiral cleaning such a wide size fraction may not be able to achieve the clean coal ash and yield specifications required. In the first place, while the performance of the spiral on the coarse 8 x 16 mesh fraction is good with regard to Ep, the cutpoints (SG50s) are high (1.87 to 1.92), which may result in a clean coal with a higher-than-desired ash content. And second, the combination of the spiral's higher overall cutpoint (1.80) with the high near-gravity anthracite results in significant misplaced material that increases the clean coal ash error. In a case such as this, one solution may be to reclean the clean coal and middlings from the first-stage spiral in a second stage spiral.

  13. Single Nucleotide Polymorphisms as Prognostic and Predictive Factors of Adjuvant Chemotherapy in Colorectal Cancer of Stages I and II

    PubMed Central

    Horvat, Matej; Potočnik, Uroš; Repnik, Katja; Kavalar, Rajko; Štabuc, Borut

    2016-01-01

    Colorectal cancer (CRC) is a highly heterogeneous disease regarding the stage at time of diagnosis and there is special attention regarding adjuvant chemotherapy in unselected patients with stage I and stage II. The clinicohistologically based TNM staging system with emphasis on histological evaluation of primary tumor and resected regional lymph nodes remains the standard of staging, but it has restricted sensitivity resulting in false downward stage migration. Molecular characteristics might predispose tumors to a worse prognosis and identification of those enables identifying patients with high risk of disease recurrence. Suitable predictive markers also enable choosing the most appropriate therapy. The current challenge facing adjuvant chemotherapy in stages I and II CRC is choosing patients with the highest risk of disease recurrence who are going to derive most benefit without facing unnecessary adverse effects. Single nucleotide polymorphisms (SNPs) are one of the potential molecular markers that might help us identify patients with unfavorable prognostic factors regarding disease initiation and recurrence and could determine selection of an appropriate chemotherapy regimen in the adjuvant and metastatic setting. In this paper, we discuss SNPs of genes involved in the multistep processes of cancerogenesis, metastasis, and the metabolism of chemotherapy that might prove clinically significant. PMID:26884752

  14. Coal liquefaction and hydrogenation

    DOEpatents

    Schindler, Harvey D.

    1985-01-01

    The coal liquefaction process disclosed uses three stages. The first stage is a liquefaction. The second and third stages are hydrogenation stages at different temperatures and in parallel or in series. One stage is within 650.degree.-795.degree. F. and optimizes solvent production. The other stage is within 800.degree.-840.degree. F. and optimizes the C.sub.5 -850.degree. F. product.

  15. Collection of ultrafine diesel particulate matter (DPM) in cylindrical single-stage wet electrostatic precipitators.

    PubMed

    Saiyasitpanich, Phirun; Keener, Tim C; Lu, Mingming; Khang, Soon-Jai; Evans, Douglas E

    2006-12-15

    Long-term exposures to diesel particulate matter (DPM) emissions are linked to increasing adverse human health effects due to the potential association of DPM with carcinogenicity. Current diesel vehicular particulate emission regulations are based solely upon total mass concentration, albeit it is the submicrometer particles that are highly respirable and the most detrimental to human health. In this study, experiments were performed with a tubular single-stage wet electrostatic precipitator (wESP) to evaluate its performance for the removal of number-based DPM emissions. A nonroad diesel generator utilizing a low sulfur diesel fuel (500 ppmw) operating under varying load conditions was used as a stationary DPM emission source. An electrical low-pressure impactor (ELPI) was used to quantify the number concentration distributions of diesel particles in the diluted exhaust gas at each tested condition. The wESP was evaluated with respect to different operational control parameters such as applied voltage, gas residence time, etc., to determine their effect on overall collection efficiency, as well as particle size dependent collection efficiency. The results show that the total DPM number concentrations in the untreated diesel exhaust are in the magnitude of approximately108/cm(3) at all engine loads with the particle diameter modes between 20 and 40 nm. The measured collection efficiency of the wESP operating at 70 kV based on total particle numbers was 86% at 0 kW engine load and the efficiency decreased to 67% at 75 kW due to a decrease in gas residence time and an increase in particle concentrations. At a constant wESP voltage of 70 kV and at 75 kW engine load, the variation of gas residence time within the wESP from approximately 0.1 to approximately 0.4 s led to a substantial increase in the collection efficiency from 67% to 96%. In addition, collection efficiency was found to be directly related to the applied voltage, with increasing collection efficiency

  16. Single-stage experimental evaluation of compressor blading with slots and vortex generators, part 5

    NASA Technical Reports Server (NTRS)

    Brent, J. A.

    1972-01-01

    An experimental investigation was conducted to determine the extent that slots and vortex generators can increase the efficiency and stable operating range of highly loaded compressor stages. With slots in the rotor and stator, the stage performance both with and without vortex generators was inferior to that achieved with the unslotted blading. However, with vortex generators, stator slots, and an unslotted rotor, the stable operating range increased 25% and the stage peak efficiency increased 2.1% over the values achieved with the unslotted rotor and stator without vortex generators, at design equivalent rotor speed.

  17. Influence of phase transformations and heat and mass exchange on the course of the processes of pyrolysis of single high-ash-coal particles at elevated pressures

    SciTech Connect

    V.P. Patskov

    2007-03-15

    A comparative analysis of equilibrium and nonequilibrium models for calculation of the rates of phase transitions (evaporation and condensation) of pyrolysis products and the influence of convective heat and mass exchange with inert ash particles and the gas flow in pyrolysis of single particles of high-ash bituminous coals in the operation of technological units with a circulating fluidized bed under pressure is made.

  18. High energy, single-polarized, single-transverse-mode, nanosecond pulses generated by a multi-stage Yb-doped photonic crystal fiber amplifier

    NASA Astrophysics Data System (ADS)

    Shen, Xinglai; Zhang, Haitao; Hao, He; Li, Dan; Li, Qinghua; Yan, Ping; Gong, Mali

    2015-06-01

    We report the construction of a cascaded fiber amplifier where a 40-μm-core-diameter photonic crystal fiber is utilized in the main amplifier stage. Single-transverse-mode, linearly-polarized, 7.5 ns pulses with 1.5 mJ energy, 123 kW peak power and 10 nm spectral bandwidth centered at 1062 nm are generated. To our knowledge, the pulse energy we obtain is the highest from 40-μm-core-diameter photonic crystal fibers, and also the highest for long pulses (>1 ns) with linear polarization and single transverse mode.

  19. Thermal behaviour and kinetics of coal/biomass blends during co-combustion.

    PubMed

    Gil, M V; Casal, D; Pevida, C; Pis, J J; Rubiera, F

    2010-07-01

    The thermal characteristics and kinetics of coal, biomass (pine sawdust) and their blends were evaluated under combustion conditions using a non-isothermal thermogravimetric method (TGA). Biomass was blended with coal in the range of 5-80 wt.% to evaluate their co-combustion behaviour. No significant interactions were detected between the coal and biomass, since no deviations from their expected behaviour were observed in these experiments. Biomass combustion takes place in two steps: between 200 and 360 degrees C the volatiles are released and burned, and at 360-490 degrees C char combustion takes place. In contrast, coal is characterized by only one combustion stage at 315-615 degrees C. The coal/biomass blends presented three combustion steps, corresponding to the sum of the biomass and coal individual stages. Several solid-state mechanisms were tested by the Coats-Redfern method in order to find out the mechanisms responsible for the oxidation of the samples. The kinetic parameters were determined assuming single separate reactions for each stage of thermal conversion. The combustion process of coal consists of one reaction, whereas, in the case of the biomass and coal/biomass blends, this process consists of two or three independent reactions, respectively. The results showed that the chemical first order reaction is the most effective mechanism for the first step of biomass oxidation and for coal combustion. However, diffusion mechanisms were found to be responsible for the second step of biomass combustion.

  20. Staged surgical management of hypoplastic left heart syndrome: a single institution 12 year experience

    PubMed Central

    McGuirk, S P; Griselli, M; Stumper, O F; Rumball, E M; Miller, P; Dhillon, R; de Giovanni, J V; Wright, J G; Barron, D J; Brawn, W J

    2006-01-01

    Objective To describe a 12 year experience with staged surgical management of the hypoplastic left heart syndrome (HLHS) and to identify the factors that influenced outcome. Methods Between December 1992 and June 2004, 333 patients with HLHS underwent a Norwood procedure (median age 4 days, range 0–217 days). Subsequently 203 patients underwent a bidirectional Glenn procedure (stage II) and 81 patients underwent a modified Fontan procedure (stage III). Follow up was complete (median interval 3.7 years, range 32 days to 11.3 years). Results Early mortality after the Norwood procedure was 29% (n  =  95); this decreased from 46% (first year) to 16% (last year; p < 0.05). Between stages, 49 patients died, 27 before stage II and 22 between stages II and III. There were one early and three late deaths after stage III. Actuarial survival (SEM) was 58% (3%) at one year and 50% (3%) at five and 10 years. On multivariable analysis, five factors influenced early mortality after the Norwood procedure (p < 0.05). Pulmonary blood flow supplied by a right ventricle to pulmonary artery (RV‐PA) conduit, arch reconstruction with pulmonary homograft patch, and increased operative weight improved early mortality. Increased periods of cardiopulmonary bypass and deep hypothermic circulatory arrest increased early mortality. Similar factors also influenced actuarial survival after the Norwood procedure. Conclusion This study identified an improvement in outcome after staged surgical management of HLHS, which was primarily attributable to changes in surgical technique. The RV‐PA conduit, in particular, was associated with a notable and independent improvement in early and actuarial survival. PMID:15939721

  1. Autologous collagen induced chondrogenesis (ACIC: Shetty-Kim technique) - A matrix based acellular single stage arthroscopic cartilage repair technique.

    PubMed

    Shetty, Asode Ananthram; Kim, Seok Jung; Shetty, Vishvas; Jang, Jae Deog; Huh, Sung Woo; Lee, Dong Hwan

    2016-01-01

    The defects of articular cartilage in the knee joint are a common degenerative disease and currently there are several established techniques to treat this problem, each with their own advantages and shortcomings. Autologous chondrocyte implantation is the current gold standard but the technique is expensive, time-consuming and most versions require two stage procedures and an arthrotomy. Autologous collagen induced chondrogenesis (ACIC) is a single-stage arthroscopic procedure and we developed. This method uses microfracture technique with atelocollagen mixed with fibrin gel to treat articular cartilage defects. We introduce this ACIC techniques and its scientific background.

  2. Anterior cruciate ligament reconstruction tunnel size: causes of tunnel enlargement and implications for single versus two-stage revision reconstruction.

    PubMed

    Rizer, Magda; Foremny, Gregory Brian; Rush, Augustus; Singer, Adam D; Baraga, Michael; Kaplan, Lee D; Jose, Jean

    2017-02-01

    Anterior cruciate ligament (ACL) reconstructions have increased over the past 25 years. The increased incidence of ACL reconstructions has translated into a larger number of graft failures and revision ACL procedures. It is important to understand the causes of graft failure when evaluating for a revision ACL reconstruction and to appreciate changes in tunnel anatomy over time prior to planning revision surgery. In this manuscript, tunnel size for ACL reconstruction and implications for single-stage versus two-stage revision ACL reconstruction will be discussed, as well as causes of tunnel enlargement, including mechanical and biological factors.

  3. Pure, single phase, high crystalline, chamfered-edge zeolite 4A synthesized from coal fly ash for use as a builder in detergents.

    PubMed

    Hui, K S; Chao, C Y H

    2006-09-01

    Single phase chamfered-edge zeolite 4A samples in pure form with a high crystallinity were synthesized by applying step-change of synthesis temperature during hydrothermal treatment of coal fly ash. The calcium binding capacity of these zeolite 4A samples (prepared from coal fly ash) and the commercial detergent grade zeolite 4A were tested for usage as a detergent builder. The results show that these zeolite 4A samples behaved similarly as the commercial one in removing calcium ions during the washing cycle. Moreover, from the leaching tests (evaluation of toxicological safety), the results show that these zeolite 4A samples leached the same elements (Sb, As, Se and Tl) as the commercial one with the concentrations in the same order of magnitude. This shows that the toxicological effect of the coal fly ash converted zeolite 4A was not worse than that of the commercial sample. Finally, economic and environmental aspects of converting coal fly ash to useful products were discussed.

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

    NASA Technical Reports Server (NTRS)

    Alexander, Reginald A.; Stanley, Thomas Troy

    1999-01-01

    Presented is a design tool and process that connects several disciplines which are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system and in the case of SSTO vehicles with air breathing propulsion, which is currently being studied by the National Aeronautics and Space Administration (NASA); the thermal protection system (TPS) is linked directly to almost every major system. The propulsion system pushes the vehicle to velocities on the order of 15 times the speed of sound in the atmosphere before pulling up to go to orbit which results high temperatures on the external surfaces of the vehicle. Thermal protection systems to maintain the structural integrity of the vehicle must be able to mitigate the heat transfer to the structure and be lightweight. Herein lies the interdependency, in that as the vehicle's speed increases, the TPS requirements are increased. And as TPS masses increase the effect on the propulsion system and all other systems is compounded. To adequately determine insulation masses for a vehicle such as the one described above, the aeroheating loads must be calculated and the TPS thicknesses must be calculated for the entire vehicle. To accomplish this an ascent or reentry trajectory is obtained using the computer code Program to Optimize Simulated Trajectories (POST). The trajectory is then used to calculate the convective heat rates on several locations on the vehicles using the Miniature Version of the JA70 Aerodynamic Heating Computer Program (MINIVER). Once the heat rates are defined for each body point on the vehicle, then insulation thicknesses that are required to maintain the vehicle within structural limits are calculated using Systems Improved Numerical Differencing Analyzer (SINDA) models. If the TPS masses are too heavy for the performance of the vehicle the process may be repeated altering the trajectory or some other input to

  5. A burner for plasma-coal starting of a boiler

    NASA Astrophysics Data System (ADS)

    Peregudov, V. S.

    2008-04-01

    Advanced schemes of a plasma-coal burner with single-and two-stage chambers for thermochemical preparation of fuel are described. The factors causing it becoming contaminated with slag during oil-free starting of a boiler are considered, and methods for preventing this phenomenon are pointed out.

  6. Rapid Single-Stage Separation of Micrometer-Long and High-Purity Semiconducting Carbon Nanotubes by Gel Filtration

    NASA Astrophysics Data System (ADS)

    Thendie, Boanerges; Miyata, Yasumitsu; Kitaura, Ryo; Miyauchi, Yuhei; Matsuda, Kazunari; Shinohara, Hisanori

    2013-06-01

    We demonstrate the separation of high-purity, long semiconducting single-wall carbon nanotubes (s-SWCNTs) by single-stage gel filtration. Semiconducting SWCNTs are preferentially adsorbed on an allyl dextran-based gel column and then eluted with surfactant solution at a rate that depends on nanotube length as well as electronic type of nanotubes. These differences allow the separation of length-sorted and purity-enhanced s-SWCNTs by fractionated collection of the eluate, which provides the desired nanotubes for electronic device applications.

  7. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 95. Progress report

    SciTech Connect

    Childs, M.; Conrad, R.

    1997-09-01

    ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generated for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area.

  8. Feasibility study of generating ultra-high harmonic radiation with a single stage echo-enabled harmonic generation scheme

    NASA Astrophysics Data System (ADS)

    Zhou, Kaishang; Feng, Chao; Wang, Dong

    2016-10-01

    The echo enabled harmonic generation (EEHG) scheme holds the ability for the generation of fully coherent soft x-ray free-electron laser (FEL) pulses directly from external UV seeding sources. In this paper, we study the feasibility of using a single stage EEHG to generate coherent radiation in the "water window" and beyond. Using the high-order operating modes of the EEHG scheme, intensive numerical simulations have been performed considering various three-dimensional effects. The simulation results demonstrated that coherent soft x-ray radiation at 150th harmonic (1.77 nm) of the seed can be produced by a single stage EEHG. The decreasing of the final bunching factor at the desired harmonic caused by intra beam scattering (IBS) effect has also been analyzed.

  9. Modeling of DNA single stage splicing language via Yusof-Goode approach: One string with two rules

    NASA Astrophysics Data System (ADS)

    Lim, Wen Li; Yusof, Yuhani; Mudaber, Mohammad Hassan

    2015-02-01

    Splicing system plays a pivotal role in attempts to recombine sets of double-stranded DNA molecules when acted by restriction enzymes and ligase. Traditional method of finding the result of DNA recombination through experiment is both time and money consuming. Hence, finding the number of patterns of DNA single stage splicing language through formalism of splicing system is a way to optimize the searching process. From the biological perspective, it predicts the number of types of molecules that will exist in the system under existence of restriction enzymes and ligase. In this paper, some theorems, corollaries and examples that lead to the predictions of single stage splicing languages involving one pattern string and two rules are presented via Yusof-Goode approach.

  10. Single and joint action toxicity of heavy metals on early developmental stages of Chinese rare minnow (Gobiocypris rarus).

    PubMed

    Zhu, Bin; Wu, Zong-Fan; Li, Jun; Wang, Gao-Xue

    2011-11-01

    In this work, acute toxicities of heavy metals (Cu, Zn and Cd) were evaluated singly or in mixtures on Chinese rare minnow (Gobiocypris rarus) in its early stages of development (embryos, larvae). Normal embryos not later than 3 h post-fertilization and newly hatched larvae were selected for the tests. The embryos were exposed to the metal solutions studied until developing to the stages of somite formation (15 h), tail detachment (25 h 10 min), heart-beat visible (34 h 10 min), pectoral fin bud appearance (47 h 40 min) and hatching (75 h), respectively. Exposures of the larvae were continued for 24 h. Results from the single toxicity tests revealed that the mortality of embryos increases obviously with increasing exposure duration. G. rarus appears to be more sensitive to heavy metal exposures at larval stage than at embryonic stage. The toxicity order of the tested metals was Cu>Cd>Zn for the embryos and Cu>Zn>Cd for the larvae with LC₅₀ as the toxicity criterion. These data suggest that the sensitivity of G. rarus to heavy metals (Cu, Zn and Cd) is different and it depends on the exposition duration and the stages of fish development. Among the metals tested, Cu is the one most toxic to G. rarus at its early development stages. In addition, results of the mixture experiments showed that binary combinations of Cu-Zn and Cu-Cd had strictly synergistic lethal effects on the larvae. The enhanced toxicity suggested inclusion of mixture considerations in the risk assessment of heavy metals might be recommended.

  11. Testing of polyimide second-stage rod seals for single-state applications in advanced aircraft hydraulic systems

    NASA Technical Reports Server (NTRS)

    Waterman, A. W.

    1977-01-01

    Machined polyimide second-stage rod seals were evaluated to determine their suitability for single-stage applications where full system pressure acts on the upstream side of the seal. The 6.35-cm (2.5-in.) K-section seal was tested in impulse screening tests where peak pressure was increased in 3.448-MPa (500-psi) increments each 20,000 cycles. Seal failure occurred at 37.92 MPa (5,500 psi), indicating a potential for acceptability in a 27.58-MPa (4,000-psi) system. Static pressurization for 600 sec at pressures in excess of 10.34 MPa (1,500 psi) revealed structural inadequacy of the seal cross section to resist fracture and extrusion. Endurance testing showed the seals capable of at least 65,000 1.27-cm (0.5-in.) cycles at 450 K (350 F) without leakage. It was concluded that the second-stage seals were proven to be exceptional in the 1.379-MPa (200-psi) applications for which they were designed, but polyimide material properties are not adequate for use in this design at pressure loading equivalent to that present in single-stage applications.

  12. Late-stage sulfides and sulfarsenides in Lower Cambrian black shale (stone coal) from the Huangjiawan mine, Guizhou Province, People's Republic of China

    NASA Astrophysics Data System (ADS)

    Belkin, H. E.; Luo, K.

    2008-03-01

    The Ni-Mo Huangjiawan mine, Guizhou Province, People’s Republic of China, occurs in Lower Cambrian black shale (stone coal) in an area where other mines have recently extracted ore from the same horizon. Detailed electron microprobe (EMPA) and scanning electron microscope (SEM) analyses of representative thin sections have revealed a complex assemblage of sulfides and sulfarsenides. Early sulfidic and phosphatic nodules and host matrix have been lithified, somewhat fractured, and then mineralized with later-stage sulfides and sulfarsenides. Gersdorffite, millerite, polydymite, pyrite, sphalerite, chalcopyrite, galena, and clausthalite have been recognized. EMPA data are given for the major phases. Pyrite trace-element distributions and coeval Ni-, As-sulfides indicate that in the main ore layer, the last sulfide deposition was Ni-As-Co-rich. Mo and V deposition were early in the petrogenesis of these rocks. The assemblages gersdorffite-millerite-polydymite (pyrite) and millerite-gersdorffite (pyrite) and the composition of gersdorffite indicate a formation temperature of between 200° and 300 °C suggesting that the last solutions to infiltrate and mineralize the samples were related to hydrothermal processes. Environmentally sensitive elements such as As, Cd, and Se are hosted by sulfides and sulfarsenides and are the main source of these elements to residual soil. Crops grown on them are enriched in these elements, and they may be hazardous for animal and human consumption.

  13. The effect of staging of reburning fuel to reduce NO{sub x} and N{sub 2}O levels during fluidized bed coal combustion

    SciTech Connect

    Gulyurtlu, I.K.; Bordalo, C.; Cabrita, I.A.

    1995-12-31

    Studies have been undertaken with the objective of using biomass waste as a reburning fuel which could be introduced to the combustor at different heights. The staging of the secondary air was also implemented as a further measure for controlling the emissions of NO{sub x} and N{sub 2}O. The biomass waste contains very high volatile content and very small amounts of fuel-N. Upon release, these volatiles are generally released as NH{sub y} compounds rather than HCN or other CN groups. Consequently, the reactions leading to the formation of both N{sub 2}O and NO{sub x} appear to be suppressed and the presence of high levels of hydrocarbon radicals originating from volatiles consequently gives rise to a reduction in NO{sub x} amounts. Experimental results obtained suggest that the N{sub 2}O amounts could be lowered by about 20 to 40% and NO{sub x} values were found to be brought down below 250 ppm. With only coal combustion the levels of NO{sub x} and N{sub 2}O were measured to be about 400 and 100 ppm respectively. No adverse effects on SO{sub 2} capture were observed.

  14. Late-stage sulfides and sulfarsenides in Lower Cambrian black shale (stone coal) from the Huangjiawan mine, Guizhou Province, People's Republic of China

    USGS Publications Warehouse

    Belkin, H.E.; Luo, K.

    2008-01-01

    The Ni-Mo Huangjiawan mine, Guizhou Province, People's Republic of China, occurs in Lower Cambrian black shale (stone coal) in an area where other mines have recently extracted ore from the same horizon. Detailed electron microprobe (EMPA) and scanning electron microscope (SEM) analyses of representative thin sections have revealed a complex assemblage of sulfides and sulfarsenides. Early sulfidic and phosphatic nodules and host matrix have been lithified, somewhat fractured, and then mineralized with later-stage sulfides and sulfarsenides. Gersdorffite, millerite, polydymite, pyrite, sphalerite, chalcopyrite, galena, and clausthalite have been recognized. EMPA data are given for the major phases. Pyrite trace-element distributions and coeval Ni-, As-sulfides indicate that in the main ore layer, the last sulfide deposition was Ni-As-Co-rich. Mo and V deposition were early in the petrogenesis of these rocks. The assemblages gersdorffite-millerite-polydymite (pyrite) and millerite-gersdorffite (pyrite) and the composition of gersdorffite indicate a formation temperature of between 200?? and 300??C suggesting that the last solutions to infiltrate and mineralize the samples were related to hydrothermal processes. Environmentally sensitive elements such as As, Cd, and Se are hosted by sulfides and sulfarsenides and are the main source of these elements to residual soil. Crops grown on them are enriched in these elements, and they may be hazardous for animal and human consumption. ?? Springer-Verlag 2007.

  15. Study of SSIN (Single Stage Interconnection Networks) Parallel Processing Interconnection Networks

    DTIC Science & Technology

    1988-10-31

    Processing Networks,----_ 𔄃 ABSTRACT (Continue on reverse if necessary and identify by bloc;umr.ber) The increase in dynamic average path length ( DAPL ...increase in dynamic average path length ( DAPL ) with network size is moderate while it is significantly less than log 2N , the number of stages needed in

  16. Analysis and classification of sleep stages based on difference visibility graphs from a single-channel EEG signal.

    PubMed

    Zhu, Guohun; Li, Yan; Wen, Peng Paul

    2014-11-01

    The existing sleep stages classification methods are mainly based on time or frequency features. This paper classifies the sleep stages based on graph domain features from a single-channel electroencephalogram (EEG) signal. First, each epoch (30 s) EEG signal is mapped into a visibility graph (VG) and a horizontal VG (HVG). Second, a difference VG (DVG) is obtained by subtracting the edges set of the HVG from the edges set of the VG to extract essential degree sequences and to detect the gait-related movement artifact recordings. The mean degrees (MDs) and degree distributions (DDs) P (k) on HVGs and DVGs are analyzed epoch-by-epoch from 14,963 segments of EEG signals. Then, the MDs of each DVG and HVG and seven distinguishable DD values of P (k) from each DVG are extracted. Finally, nine extracted features are forwarded to a support vector machine to classify the sleep stages into two, three, four, five, and six states. The accuracy and kappa coefficients of six-state classification are 87.5% and 0.81, respectively. It was found that the MDs of the VGs on the deep sleep stage are higher than those on the awake and light sleep stages, and the MDs of the HVGs are just the reverse.

  17. Primary coal crushers grow to meet demand

    SciTech Connect

    Fiscor, S.

    2009-09-15

    Mine operators look for more throughput with less fines generation in primary crushers (defined here as single role crushers and two stage crushers). The article gives advice on crusher selection and application. Some factors dictating selection include the desired product size, capacity, Hard Grove grindability index, percentage of rock to be freed and hardness of that rock. The hardness of coal probably has greatest impact on product fineness. 2 refs., 1 fig., 1 tab.

  18. Hydrogen production from sugar industry wastes using single-stage photofermentation.

    PubMed

    Keskin, Tugba; Hallenbeck, Patrick C

    2012-05-01

    Beet molasses and black strap are two major waste streams of the sugar industry. They both contain high amounts of sucrose, making them suitable substrates for biological hydrogen production. Photofermentation, usually used to convert organic acids to hydrogen, has the potential capacity to effectively use a variety of feed stocks, including sugars. A comparative study on photofermentative biohydrogen production from beet molasses, black strap, and sucrose was conducted. With yields of 10.5 mol H(2)/mol sucrose for beet molasses (1g/l sugar); 8 mol H(2)/mol sucrose for black strap (1g/l sugar) and 14 mol H(2)/mol sucrose for pure sucrose, a one stage photofermentation system appears promising as an alternative to two-stage systems given the potential savings in energy input and operational costs.

  19. Gas pollutants removal in a single- and two-stage ejector-venturi scrubber.

    PubMed

    Gamisans, Xavier; Sarrà, Montserrrat; Lafuente, F Javier

    2002-03-29

    The absorption of SO(2) and NH(3) from the flue gas into NaOH and H(2)SO(4) solutions, respectively has been studied using an industrial scale ejector-venturi scrubber. A statistical methodology is presented to characterise the performance of the scrubber by varying several factors such as gas pollutant concentration, air flowrate and absorbing solution flowrate. Some types of venturi tube constructions were assessed, including the use of a two-stage venturi tube. The results showed a strong influence of the liquid scrubbing flowrate on pollutant removal efficiency. The initial pollutant concentration and the gas flowrate had a slight influence. The use of a two-stage venturi tube considerably improved the absorption efficiency, although it increased energy consumption. The results of this study will be applicable to the optimal design of venturi-based absorbers for gaseous pollution control or chemical reactors.

  20. Frenectomy with semilunar coronally repositioned flap: A single stage approach - simple solution for complex problem.

    PubMed

    Deshmukh, Jeevanand; Khatri, Richa; Fernandes, Bennete; Kulkarni, Vinaya Kumar; Singh, Shubhra

    2015-01-01

    Gingival recession is defined as the displacement of gingival margin apical to cementoenamel junction. Aberrant frenum attachment can contribute to the progression of recession by generating tension on the marginal tissues. Treating such defects is a two stage procedure-frenectomy and recession coverage procedure. New techniques are developed to increase the predictability, reduce patient discomfort and number of surgical sites. Also, these techniques try to satisfy patients esthetic demands, which include the final colour and tissue blend of the covered area. In this case report, we present a method for coronally repositioning gingiva for root coverage over the maxillary central incisors while simultaneously performing a frenectomy, thus being clinically advantageous compared to two-stage technique.

  1. Frenectomy with semilunar coronally repositioned flap: A single stage approach - simple solution for complex problem

    PubMed Central

    Deshmukh, Jeevanand; Khatri, Richa; Fernandes, Bennete; Kulkarni, Vinaya Kumar; Singh, Shubhra

    2015-01-01

    Gingival recession is defined as the displacement of gingival margin apical to cementoenamel junction. Aberrant frenum attachment can contribute to the progression of recession by generating tension on the marginal tissues. Treating such defects is a two stage procedure-frenectomy and recession coverage procedure. New techniques are developed to increase the predictability, reduce patient discomfort and number of surgical sites. Also, these techniques try to satisfy patients esthetic demands, which include the final colour and tissue blend of the covered area. In this case report, we present a method for coronally repositioning gingiva for root coverage over the maxillary central incisors while simultaneously performing a frenectomy, thus being clinically advantageous compared to two-stage technique. PMID:26392698

  2. Comparison of Favorable Early-Stage Hodgkin's Lymphoma Treatments: A Single-Institution Review

    SciTech Connect

    Samant, Rajiv; Alomary, Ibraheem; Alsaeed, Eyad; Al-jasir, Badr; Bence-Bruckler, Isabelle; Cross, Peter; Genest, Paul; Huebsch, Lothar

    2010-03-15

    Purpose: To compare outcomes of patients receiving combined-modality chemotherapy and radiation (CMT) vs. other approaches for early-stage Hodgkin's lymphoma (HL). Methods and Materials: A review of patients with nonbulky, early-stage (IA/IIA) HL treated between 1984 and 2002 was performed to determine the treatment approaches used and the outcomes obtained. Results: There were 173 adult patients with newly diagnosed early-stage HL (49% men, 51% women, median age 33 [range 17-82] years). Treatment was as follows: extended-field radiotherapy alone (EFRT) 49%; chemotherapy alone (CTA) 13%; and CMT 38%. Among CMT patients, 36% received abbreviated doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy (three to four cycles) followed by involved-field radiotherapy. With a median follow-up of 8.3 years, the estimated 10-year relapse-free survival (RFS) and overall survival (OS) rates for the entire cohort were 78% and 85%, respectively. The 10-year RFS and OS rates for the various groups were as follows: 69% and 81% for EFRT; 78% and 84% for CTA; and 87% and 89% for CMT. The 10-year RFS rate was significantly higher (p < 0.01) among CMT patients. The use of EFRT has diminished from approximately 90% in the 1980s to virtually no use at present, whereas the use of CTA and CMT has increased significantly (p < 0.01). Conclusion: Early-stage HL treatment has changed dramatically over the past 2 decades, and our results support the superiority and continued use of CMT, specifically abbreviated-course chemotherapy and involved-field radiotherapy, as an appropriate treatment approach.

  3. Single-session motivational interviewing for drug detoxification inpatients: effects on self-efficacy, stages of change and substance use.

    PubMed

    Berman, Anne H; Forsberg, Lars; Durbeej, Natalie; Källmén, Håkan; Hermansson, Ulric

    2010-02-01

    Thirty-five inpatients at a Stockholm hospital drug user detoxification unit received single-session Motivational Interviewing (MI) between 2006 and 2008. At baseline and after 3 months, they were compared to a semi-randomized control group of 52 patients with treatment as usual. In the MI group, self-efficacy increased regarding abstention in connection with positive feelings, appreciation of positive drug effects increased, and participants tended to transition toward preparation/action stages of change. Despite implementation challenges, the study demonstrates the feasibility and effectiveness of single-session MI delivery in the inpatient drug detoxification setting and suggests paths for future research on delivery of single-session MI.

  4. Integration of single-fiber reflectance spectroscopy into ultrasound-guided endoscopic lung cancer staging of mediastinal lymph nodes.

    PubMed

    Kanick, Stephen Chad; van der Leest, Cor; Aerts, Joachim G J V; Hoogsteden, Henk C; Kascáková, Slávka; Sterenborg, Henricus J C M; Amelink, Arjen

    2010-01-01

    We describe the incorporation of a single-fiber reflectance spectroscopy probe into the endoscopic ultrasound fine-needle aspiration (EUS-FNA) procedure utilized for lung cancer staging. A mathematical model is developed to extract information about the physiological and morphological properties of lymph tissue from single-fiber reflectance spectra, e.g., microvascular saturation, blood volume fraction, bilirubin concentration, average vessel diameter, and Mie slope. Model analysis of data from a clinical pilot study shows that the single-fiber reflectance measurement is capable of detecting differences in the physiology between normal and metastatic lymph nodes. Moreover, the clinical data show that probe manipulation within the lymph node can perturb the in vivo environment, a concern that must be carefully considered when developing a sampling strategy. The data show the feasibility of this novel technique; however, the potential clinical utility has yet to be determined.

  5. Integration of single-fiber reflectance spectroscopy into ultrasound-guided endoscopic lung cancer staging of mediastinal lymph nodes

    NASA Astrophysics Data System (ADS)

    Kanick, Stephen Chad; van der Leest, Cor; Aerts, Joachim G. J. V.; Hoogsteden, Henk C.; Kaščáková, Slávka; Sterenborg, Henricus J. C. M.; Amelink, Arjen

    2010-01-01

    We describe the incorporation of a single-fiber reflectance spectroscopy probe into the endoscopic ultrasound fine-needle aspiration (EUS-FNA) procedure utilized for lung cancer staging. A mathematical model is developed to extract information about the physiological and morphological properties of lymph tissue from single-fiber reflectance spectra, e.g., microvascular saturation, blood volume fraction, bilirubin concentration, average vessel diameter, and Mie slope. Model analysis of data from a clinical pilot study shows that the single-fiber reflectance measurement is capable of detecting differences in the physiology between normal and metastatic lymph nodes. Moreover, the clinical data show that probe manipulation within the lymph node can perturb the in vivo environment, a concern that must be carefully considered when developing a sampling strategy. The data show the feasibility of this novel technique; however, the potential clinical utility has yet to be determined.

  6. Single-stage Dynamic Reanimation of the Smile in Irreversible Facial Paralysis by Free Functional Muscle Transfer

    PubMed Central

    Thiele, Jan; Bannasch, Holger; Stark, G. Bjoern; Eisenhardt, Steffen U.

    2015-01-01

    Unilateral facial paralysis is a common disease that is associated with significant functional, aesthetic and psychological issues. Though idiopathic facial paralysis (Bell’s palsy) is the most common diagnosis, patients can also present with a history of physical trauma, infectious disease, tumor, or iatrogenic facial paralysis. Early repair within one year of injury can be achieved by direct nerve repair, cross-face nerve grafting or regional nerve transfer. It is due to muscle atrophy that in long lasting facial paralysis complex reconstructive methods have to be applied. Instead of one single procedure, different surgical approaches have to be considered to alleviate the various components of the paralysis. The reconstruction of a spontaneous dynamic smile with a symmetric resting tone is a crucial factor to overcome the functional deficits and the social handicap that are associated with facial paralysis. Although numerous surgical techniques have been described, a two-stage approach with an initial cross-facial nerve grafting followed by a free functional muscle transfer is most frequently applied. In selected patients however, a single-stage reconstruction using the motor nerve to the masseter as donor nerve is superior to a two-stage repair. The gracilis muscle is most commonly used for reconstruction, as it presents with a constant anatomy, a simple dissection and minimal donor site morbidity. Here we demonstrate the pre-operative work-up, the post-operative management, and precisely describe the surgical procedure of single-stage microsurgical reconstruction of the smile by free functional gracilis muscle transfer in a step by step protocol. We further illustrate common pitfalls and provide useful tips which should enable the reader to truly comprehend the procedure. We further discuss indications and limitations of the technique and demonstrate representative results. PMID:25868011

  7. Single-stage dynamic reanimation of the smile in irreversible facial paralysis by free functional muscle transfer.

    PubMed

    Thiele, Jan; Bannasch, Holger; Stark, G Bjoern; Eisenhardt, Steffen U

    2015-03-01

    Unilateral facial paralysis is a common disease that is associated with significant functional, aesthetic and psychological issues. Though idiopathic facial paralysis (Bell's palsy) is the most common diagnosis, patients can also present with a history of physical trauma, infectious disease, tumor, or iatrogenic facial paralysis. Early repair within one year of injury can be achieved by direct nerve repair, cross-face nerve grafting or regional nerve transfer. It is due to muscle atrophy that in long lasting facial paralysis complex reconstructive methods have to be applied. Instead of one single procedure, different surgical approaches have to be considered to alleviate the various components of the paralysis. The reconstruction of a spontaneous dynamic smile with a symmetric resting tone is a crucial factor to overcome the functional deficits and the social handicap that are associated with facial paralysis. Although numerous surgical techniques have been described, a two-stage approach with an initial cross-facial nerve grafting followed by a free functional muscle transfer is most frequently applied. In selected patients however, a single-stage reconstruction using the motor nerve to the masseter as donor nerve is superior to a two-stage repair. The gracilis muscle is most commonly used for reconstruction, as it presents with a constant anatomy, a simple dissection and minimal donor site morbidity. Here we demonstrate the pre-operative work-up, the post-operative management, and precisely describe the surgical procedure of single-stage microsurgical reconstruction of the smile by free functional gracilis muscle transfer in a step by step protocol. We further illustrate common pitfalls and provide useful tips which should enable the reader to truly comprehend the procedure. We further discuss indications and limitations of the technique and demonstrate representative results.

  8. Dynamic variability of the heading-flowering stages of single rice in China based on field observations and NDVI estimations.

    PubMed

    Zhang, Zhao; Song, Xiao; Chen, Yi; Wang, Pin; Wei, Xing; Tao, Fulu

    2015-05-01

    Although many studies have indicated the consistent impact of warming on the natural ecosystem (e.g., an early flowering and prolonged growing period), our knowledge of the impacts on agricultural systems is still poorly understood. In this study, spatiotemporal variability of the heading-flowering stages of single rice was detected and compared at three different scales using field-based methods (FBMs) and satellite-based methods (SBMs). The heading-flowering stages from 2000 to 2009 with a spatial resolution of 1 km were extracted from the SPOT/VGT NDVI time series data using the Savizky-Golay filtering method in the areas in China dominated by single rice of Northeast China (NE), the middle-lower Yangtze River Valley (YZ), the Sichuan Basin (SC), and the Yunnan-Guizhou Plateau (YG). We found that approximately 52.6 and 76.3 % of the estimated heading-flowering stages by a SBM were within ±5 and ±10 days estimation error (a root mean square error (RMSE) of 8.76 days) when compared with those determined by a FBM. Both the FBM data and the SBM data had indicated a similar spatial pattern, with the earliest annual average heading-flowering stages in SC, followed by YG, NE, and YZ, which were inconsistent with the patterns reported in natural ecosystems. Moreover, diverse temporal trends were also detected in the four regions due to different climate conditions and agronomic factors such as cultivar shifts. Nevertheless, there were no significant differences (p > 0.05) between the FBM and the SBM in both the regional average value of the phenological stages and the trends, implying the consistency and rationality of the SBM at three scales.

  9. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    SciTech Connect

    Mahesh Iyer; Shwetha Ramkumar; Liang-Shih Fan

    2006-03-31

    Hydrogen production from coal gasification can be enhanced by driving the equilibrium limited Water Gas Shift reaction forward by incessantly removing the CO{sub 2} by-product via the carbonation of calcium oxide. This project uses the high-reactivity mesoporous precipitated calcium carbonate sorbent for removing the CO{sub 2} product to enhance H{sub 2} production. Preliminary experiments demonstrate the show the superior performance of the PCC sorbent over other naturally occurring calcium sorbents. It was observed that the CO{sub 2} released during the in-situ calcination causes the deactivation of the iron oxide WGS catalyst by changing the active phase of the catalyst from magnetite (F{sub 3}O{sub 4}). Detailed understanding of the iron oxide phase diagram helped in developing a catalyst pretreatment procedure using a H{sub 2}/H{sub 2}O system. Intermediate catalyst pretreatment helps prevent its deactivation by reducing the catalyst back to its active magnetite (Fe{sub 3}O{sub 4}) form. Multicyclic runs which consist of combined WGS/carbonation reaction followed by in-situ calcination with a subsequent catalyst pretreatment procedure sustains the catalytic activity and prevents deactivation. The water gas shift reaction was studied at different temperatures, different steam to carbon monoxide ratios (S/C) 3:1, 2:1, 1:1 and different total pressures ranging from 0-300 psig. The CO conversion was found to have an optimal value with increasing pressure, S/C ratio and temperatures. The combined water gas shift and carbonation reaction was investigated at 650 C, S/C ratio of 3:1and at different pressures of 0-300 psig.

  10. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage

    SciTech Connect

    Mahesh Iyer; Shwetha Ramkumar; Liang-Shih Fan

    2006-09-30

    Enhancement in the production of high purity hydrogen from fuel gas, obtained from coal gasification, is limited by thermodynamics of the Water Gas Shift Reaction. However, this constraint can be overcome by concurrent water-gas shift (WGS) and carbonation reactions to enhance H{sub 2} production by incessantly driving the equilibrium-limited WGS reaction forward and in-situ removing the CO2 product from the gas mixture. The spent sorbent is then regenerated by calcining it to produce a pure stream of CO{sub 2} and CaO which can be reused. However while performing the cyclic carbonation and calcination it was observed that the CO{sub 2} released during the in-situ calcination causes the deactivation of the iron oxide WGS catalyst. Detailed understanding of the iron oxide phase diagram helped in developing a catalyst pretreatment procedure using a H{sub 2}/H{sub 2}O system to convert the deactivated catalyst back to its active magnetite (Fe{sub 3}O{sub 4}) form. The water gas shift reaction was studied at different temperatures, different steam to carbon monoxide ratios (S/C) 3:1, 2:1, 1:1 and different total pressures ranging from 0-300 psig. The combined water gas shift and carbonation reaction was investigated at temperatures ranging from 600-700C, S/C ratio of 3:1 to 1:1 and at different pressures of 0-300 psig and the calcium looping process was found to produce high purity hydrogen with in-situ CO{sub 2} capture.

  11. Assessment of advanced coal gasification processes

    NASA Technical Reports Server (NTRS)

    Mccarthy, J.; Ferrall, J.; Charng, T.; Houseman, J.

    1981-01-01

    A technical assessment of the following advanced coal gasification processes is presented: high throughput gasification (HTG) process; single stage high mass flux (HMF) processes; (CS/R) hydrogasification process; and the catalytic coal gasification (CCG) process. Each process is evaluated for its potential to produce synthetic natural gas from a bituminous coal. Key similarities, differences, strengths, weaknesses, and potential improvements to each process are identified. The HTG and the HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging, and syngas as the initial raw product gas. The CS/R hydrogasifier is also SRT, but is nonslagging and produces a raw gas high in methane content. The CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier.

  12. Single-step microwave digestion with HNO(3) alone for determination of trace elements in coal by ICP spectrometry.

    PubMed

    Wang, Jie; Nakazato, Tetsuya; Sakanishi, Kinya; Yamada, Osamu; Tao, Hiroaki; Saito, Ikuo

    2006-02-28

    A microwave digestion method with HNO(3) alone was conducted at a temperature as high as 250 degrees C for determination of 19 trace elements (Li, Be, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Cd, Cs, Ba, Hg, and Pb) in coal jointly by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and flow injection ICP-MS (FI-ICP-MS). The validity of determination was assessed by using three standard coals, SRM 1632c, BCR 180, and SARM 19. It was found that the high-temperature digestion led to an extensive decomposition of the organic matrix and clay in coal, and no dissolved and solid carbon remained in the final solution after evaporation. Good recoveries were observed for all trace elements in three coals, with the exception of V, Rb, and Cs in high-ash SARM 19. Additionally, FI-ICP-MS combined with the present digestion without evaporation pretreatment was proved to be a rapid and efficient approach for determination of ultra-trace elements such as Se, Cd, and Hg in coal.

  13. Selective solvent absorption in coal conversion

    SciTech Connect

    Larsen, J.W.; Lapucha, A.; Lazarov, L.; Amui, J.

    1992-04-01

    The objectives of this project are: (1) to determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; and (2) to determine the composition of the solvent absorbed by and present within the coal in the first stage of direct coal liquefaction.

  14. On Simon's two-stage design for single-arm phase IIA cancer clinical trials under beta-binomial distribution.

    PubMed

    Liu, Junfeng; Lin, Yong; Shih, Weichung Joe

    2010-05-10

    Simon (Control. Clin. Trials 1989; 10:1-10)'s two-stage design has been broadly applied to single-arm phase IIA cancer clinical trials in order to minimize either the expected or the maximum sample size under the null hypothesis of drug inefficacy, i.e. when the pre-specified amount of improvement in response rate (RR) is not expected to be observed. This paper studies a realistic scenario where the standard and experimental treatment RRs follow two continuous distributions (e.g. beta distribution) rather than two single values. The binomial probabilities in Simon's (Control. Clin. Trials 1989; 10:1-10) design are replaced by prior predictive Beta-binomial probabilities that are the ratios of two beta functions and domain-restricted RRs involve incomplete beta functions to induce the null hypothesis acceptance probability. We illustrate that Beta-binomial mixture model based two-stage design retains certain desirable properties for hypothesis testing purpose. However, numerical results show that such designs may not exist under certain hypothesis and error rate (type I and II) setups within maximal sample size approximately 130. Furthermore, we give theoretical conditions for asymptotic two-stage design non-existence (sample size goes to infinity) in order to improve the efficiency of design search and to avoid needless searching.

  15. Development and Design of a Single-Stage Cryogenic Modulator for Comprehensive Two-Dimensional Gas Chromatography.

    PubMed

    Mostafa, Ahmed; Górecki, Tadeusz

    2016-05-17

    A new liquid nitrogen-based single-stage cryogenic modulator was developed and characterized. In addition, a dedicated liquid nitrogen delivery system was developed. A well-defined restriction placed inside a deactivated fused silica capillary was used to increase the cooling surface area and provide very efficient trapping. At the same time, it enabled modulation of the carrier gas flow owing to changes in gas viscosity with temperature. Gas flow is almost unimpeded at the trapping temperature but reduced to nearly zero at the desorption temperature, which prevents analyte breakthrough. Peak widths for n-alkanes of 30-40 ms at half height were obtained. Most importantly, even the solvent peak could be modulated, which is not feasible with any commercially available thermal modulator. Evaluation of the newly developed system in two-dimensional gas chromatography (GC × GC) separations of some real samples such as regular gasoline and diesel fuel showed that the analytical performance of this single-stage modulator is fully competitive to those of the more complicated dual-stage modulators.

  16. Plant growth and elemental uptake by floating vegetation on a single stage swine wastewater lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods are needed for utilizing nutrients contained within animal wastewater lagoons. One potential method for removing nutrients is to have vegetation growing on the lagoon. A study was conducted from 2005-2008 to determine the feasibility of growing vegetation on floating platforms on a single ...

  17. Single-stage management of a neglected radial club hand deformity in an adult

    PubMed Central

    Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul; Mancha, David Ghorau

    2015-01-01

    Radial club hand is an intercalary congenital deformity involving the forearm, wrist and hand. A congenital absence of radius (partial or complete) and ulnar bowing are classical radiographic abnormalities seen in this condition. This deformity is usually treated surgically in infants and young children but the management of this problem in an adult is complex and challenging. We present a neglected case of an adult with severe and rigid deformity that was successfully treated by one-stage correction involving ulnar osteotomy and wrist arthrodesis, simultaneously. PMID:25670786

  18. DEVELOPMENT, TESTING, AND DEMONSTRATION OF AN OPTIMAL FINE COAL CLEANING CIRCUIT

    SciTech Connect

    Steven R. Hadley; R. Mike Mishra; Michael Placha

    1999-01-27

    The objective of this project was to improve the efficiency of the fine coal froth flotation circuit in commercial coal preparation plants. The plant selected for this project, Cyprus Emerald Coal Preparation Plant, cleans 1200-1400 tph of Pittsburgh seam raw coal and uses conventional flotation cells to clean the minus 100-mesh size fraction. The amount of coal in this size fraction is approximately 80 tph with an average ash content of 35%. The project was carried out in two phases. In Phase I, four advanced flotation cells, i.e., a Jameson cell, an Outokumpu HG tank cell, an open column, and a packed column cell, were subjected to bench-scale testing and demonstration. In Phase II, two of these flotation cells, the Jameson cell and the packed column, were subjected to in-plant, proof-of-concept (POC) pilot plant testing both individually and in two-stage combination in order to ascertain whether a two-stage circuit results in lower levelized production costs. The bench-scale results indicated that the Jameson cell and packed column cell would be amenable to the single- and two-stage flotation approach. POC tests using these cells determined that single-stage coal matter recovery (CMR) of 85% was possible with a product ash content of 5.5-7%. Two-stage operation resulted in a coal recovery of 90% with a clean coal ash content of 6-7.5%. This compares favorably with the plant flotation circuit recovery of 80% at a clean coal ash of 11%.

  19. A perspective on syngas from coal

    SciTech Connect

    Rath, L.K.; Longanbach, J.R. )

    1991-01-01

    Syngas, a mixture of hydrogen and carbon monoxide, has been produced from coal for more than 100 years. But today most syngas is produced from noncoal feedstocks, by catalytic steam reforming of natural gas and naphtha or partial oxidation of heavy hydrocarbons such as petroleum resid. Three types of syngas, characterized by their H{sub 2}/CO ratio, are needed. Low ratio, H{sub 2}/CO = 0.4-0.8, syngas can be used in recently developed processes such as the Liquid Phase Methanol synthesis and the Shell Fischer-Tropsch wax synthesis; moderate ratio, H{sub 2}/CO = 0.8-1.5, syngas is used in the Tennessee Eastman coal based synthesis of methanol and acetic anhydride; high ratio, H{sub 2}/CO = 1.8-2.5, syngas is used in traditional methanol synthesis and the Fischer-Tropsch synthesis at Sasol. Different types of gasifiers are available for the production of syngas. These include Lurgi fixed-bed dry bottom and slagging gasifiers, agglomerating fluidized-bed gasifiers, single and two-stage entrained slurry feed gasifiers, and single-stage entrained dry feed gasifiers. The cost of syngas from subbituminous coal is shown to be relatively insensitive to the H{sub 2}/CO ratio produced and may soon be competitive with natural gas-based syngas in some parts of the country due to the increasing demand for and cost of natural gas. Recent in this paper, DOE sponsored research on three topics on the production of syngas from coal, coal gasifiers for the direct production of high hydrogen content syngas, advanced methods to separate hydrogen from syngas at elevated temperatures and biological conversion of coal to syngas, are also discussed.

  20. Cooperative research program in coal liquefaction

    SciTech Connect

    Huffman, G.P.; Sendlein, L.V.A.

    1991-01-01

    This report is a coordinated effort of the Consortium for Fossil Fuel Liquefaction Science. The topics concerning coal liquefaction discussed are: sulfate promoted metal oxides as direct coal liquefaction catalysts; low temperature depolymerization and liquefaction of premium R.S. coal samples; construction of continuous flow-through gas reactor for liquefaction investigations; generic structural characterization and liquefaction research; macerals, model compounds and iron catalyst dispersion; coal structure/liquefaction yield correlation by means of advanced NMR techniques; GC/MS of model compound mixtures; catalytic cracking, hydrogenation and liquefaction of coals under milder conditions; ENDOR investigations of coal liquefaction under mild conditions; catalytic dehydrogenation of model compounds in relation to direct coal liquefaction; surface characterization of catalyst added coal samples; computational chemistry of model compounds and molecular fragments of relevance to coal liquefaction; chemical characterization and hydrogenation reactions of single coal particles; thermolytic cleavage of selected coal-related linkages at mild temperatures; solvent sorption and FTIR studies on the effect of catalytic depolymerization reactions in coal; bioprocessing of coal; chemical routes to breaking bonds; novel liquefaction concepts cyclic olefins: novel new donors for coal liquefaction; better hydrogen transfer in coal liquefaction; catalytic hydropyrolysis and energized extraction of coals; gallium catalyst in mild coal liquefaction; potential of temperature microscope in coal liquefaction; evaluation of nitride catalysts for hydrotreatment and coal liquefaction; coprocessing and coal liquefaction with novel catalysts.

  1. Single-Stage Versus Multi-Stage Pull-Through for Hirschsprung’s Disease: Practice Trends and Outcomes in Infants

    PubMed Central

    Sulkowski, Jason P.; Cooper, Jennifer N.; Congeni, Anthony; Pearson, Erik G.; Nwomeh, Benedict C.; Doolin, Edward J.; Blakely, Martin L.; Minneci, Peter C.; Deans, Katherine J.

    2014-01-01

    Purpose To evaluate surgical treatments and outcomes in a multi-institutional cohort of neonates with Hirschsprung’s Disease (HD). Methods Using the Pediatric Health Information System (PHIS) from 1999–2009, neonates diagnosed with HD were identified and classified as having a single stage pull-through (SSPT) or multi-stage pull-through (MSPT). Diagnosis and classification algorithms and clinical variables and outcomes were validated by multi-institutional chart review. Groups were compared using logistic regression modeling and propensity-score matched analysis to account for baseline differences between groups. Results 1,555 neonates with HD were identified; 77.2% underwent SSPT and 22.8% underwent MSPT. Misclassification of disease or surgical treatment was <2%. Rates of SSPT increased over time (p=0.03). Compared to SSPT, patients undergoing MSPT had significantly lower birth weights and higher rates of prematurity, non-HD gastrointestinal anomalies, enterocolitis, and preoperative mechanical ventilation. Patients undergoing MSPT had significantly higher rates of readmissions (58.5% vs. 37.9%) and additional operations (38.7% vs. 26%). Results were consistent in the propensity-score matched analysis. Conclusion Most neonates with HD undergo SSPT. In patients with similar observed baseline characteristics, MSPT was associated with worse outcomes suggesting that some infants currently selected to undergo MSPT may have better outcomes with SSPT. However, there remains a subgroup of MSPT patients who were too ill to be adequately compared to SSPT patients; for this subgroup of severely ill infants with HD, MSPT may be the best option. PMID:25475806

  2. High yield single stage conversion of glucose to hydrogen by photofermentation with continuous cultures of Rhodobacter capsulatus JP91.

    PubMed

    Abo-Hashesh, Mona; Desaunay, Nicolas; Hallenbeck, Patrick C

    2013-01-01

    Photofermentative hydrogen (H(2)) production from glucose with the photosynthetic bacterium Rhodobacter capsulatus JP91 (hup(-)) was examined using a photobioreactor operated in continuous mode. Stable and high hydrogen yields on glucose were obtained at three different retention times (HRTs; 24, 48 and 72 h). The H(2) production rates, varying between 0.57 and 0.81 mmol/h, and optical densities (OD(600 nm)) were similar for the different HRTs examined. However, the rate of glucose consumption was influenced by HRT being greater at HRT 24h than HRTs 48 and 72 h. The highest hydrogen yield, 9.0 ± 1.2 mol H(2)/mol glucose, was obtained at 48 h HRT. These results show that single stage photofermentative hydrogen production from glucose using photobioreactors operated in continuous culture mode gives high, nearly stoichiometric yields of hydrogen from glucose, and thus is considerably more promising than either two stage photofermentation or co-culture approaches.

  3. Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

    PubMed

    Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

    2010-02-01

    Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers.

  4. Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil

    SciTech Connect

    Totsche, K.U.; Jann, S.; Kogel-Knabner, I.

    2007-05-15

    Mobile colloidal and suspended matter is likely to affect the mobility of polycyclic aromatic hydrocarbons (PAHs) in the unsaturated soil zone at contaminated sites. We studied the release of mobile particles and dissolved organic matter as a function of variable climatic boundary conditions, and their effect on the export of PAHs at a coal tar-contaminated site using zero-tension lysimeters. Seepage water samples were analyzed for dissolved organic carbon (DOC), pH, electrical conductivity, turbidity, and particles larger than 0.7 {mu}m. The 16 Environmental Protection Agency PAHs were analyzed in the filtrate < 0.7 m and in the particle fraction. Our results show that extended no-flow periods that are followed by high-intensity rain events, such as thunderstorms, promote the mobilization of particles in the size 0.7 to 200 m. Mobilization is enforced by extended drying during summer. High particle concentrations are also associated with freezing and thawing cycles followed by either rain or snowmelt events. The export of PAHs is strongly connected to the release of particles in the 0.7- to 200-{mu}m size fraction. During the 2-yr monitoring period, up to 0.418 {mu}g kg{sup -1} PAHs were mobilized in the. ltrate (< 0.7 m) while the eightfold mass, 3.36 {mu}g kg{sup -1}, was exported with the retentate (0.7-200 {mu}m). Equilibrium dissolution of PAHs and transport in the dissolved phase seem to be of minor importance for the materials studied. Extreme singular-release events occurred in January 2003 and January 2004, when up to 55 {mu}g L{sup -1} PAHs per one single seepage event were observed within the retentate. Freezing and thawing cycles affect the PAH source materials, that is, the remnants of the nonaqueous phase liquid (NAPL). High mechanical strain during freezing results in the formation of particles. At the onset of the thawing and following rain or snowmelt events, PAHs associated with these particles are then exported from the lysimeter.

  5. Effects of CeO2 on the XPS valence band spectra of coal under the combustion initialization stage at 400°C

    NASA Astrophysics Data System (ADS)

    Qi, Cheng-lin; Zhang, Jian-liang; Ma, Chao; Feng, Gen-sheng; Song, Zhong-ping

    2013-04-01

    In order to get the catalytic mechanism of CeO2 on graphite and coal at 400°C, the morphologies of coal, graphite, and CeO2 before and after combustion were analyzed through X-ray photoelectron spectroscopy (XPS). It is found that the particle size of coal is mostly between 11.727 and 64.79 μm, while the particle size of CeO2 is between 1.937 and 11.79 μm. The agglomeration of coal and CeO2 can be seen by scanning electron microscopy (SEM) after reaction. XPS results show that with the addition of CeO2, the intensity of binding energy gets stronger, but there is no energy peak transition. Comparing the character of coal with and without the addition of CeO2, it can be seen that the C-C bond fractures first at 400°C, while the C-H energy-band takes electrons at the same time to be far away from the Fermi level, and the O 2s, O 2p, and C sp hybrid orbitals are all excited. Adding CeO2 can enhance the activity of the whole coal. In addition, through XPS analysis, combined with the oxygen transfer theory and the electron transfer theory, the catalytic mechanism of CeO2 for pulverized coal combustion could be obtained.

  6. Functional Genomics of 5- to 8-Cell Stage Human Embryos by Blastomere Single-Cell cDNA Analysis

    PubMed Central

    Galán, Amparo; Montaner, David; Póo, M. Eugenia; Valbuena, Diana; Ruiz, Verónica; Aguilar, Cristóbal; Dopazo, Joaquín; Simón, Carlos

    2010-01-01

    Blastomere fate and embryonic genome activation (EGA) during human embryonic development are unsolved areas of high scientific and clinical interest. Forty-nine blastomeres from 5- to 8-cell human embryos have been investigated following an efficient single-cell cDNA amplification protocol to provide a template for high-density microarray analysis. The previously described markers, characteristic of Inner Cell Mass (ICM) (n = 120), stemness (n = 190) and Trophectoderm (TE) (n = 45), were analyzed, and a housekeeping pattern of 46 genes was established. All the human blastomeres from the 5- to 8-cell stage embryo displayed a common gene expression pattern corresponding to ICM markers (e.g., DDX3, FOXD3, LEFTY1, MYC, NANOG, POU5F1), stemness (e.g., POU5F1, DNMT3B, GABRB3, SOX2, ZFP42, TERT), and TE markers (e.g., GATA6, EOMES, CDX2, LHCGR). The EGA profile was also investigated between the 5-6- and 8-cell stage embryos, and compared to the blastocyst stage. Known genes (n = 92) such as depleted maternal transcripts (e.g., CCNA1, CCNB1, DPPA2) and embryo-specific activation (e.g., POU5F1, CDH1, DPPA4), as well as novel genes, were confirmed. In summary, the global single-cell cDNA amplification microarray analysis of the 5- to 8-cell stage human embryos reveals that blastomere fate is not committed to ICM or TE. Finally, new EGA features in human embryogenesis are presented. PMID:21049019

  7. Reproductive success, early life stage development, and survival of westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to elevated selenium in an area of active coal mining.

    PubMed

    Rudolph, Barri-Lynn; Andreller, Iisak; Kennedy, Christopher J

    2008-04-15

    The effects of accumulated Se on the reproductive success and larval development of cutthroat trout (Oncorhynchus clarki lewis,) collected from a site of active coal mining in British Columbia were assessed. Eggs from 12 fish from an exposed site (Clode Pond) and 16 from a reference site (O'Rourke Lake) were field-collected and reared in the laboratory. Egg Se concentrations ranged from 12.3 to 16.7 and 11.8 to 140.0 microg/g dry weight (dw) from fish collected at the reference and exposed sites, respectively. Other studies, including those with this species, have not shown Se to affect egg viability; however, in the present study, eggs with Se concentrations > 86.3 microg/g dw were not successfully fertilized or were nonviable at fertilization, while eggs with concentrations > 46.8 and < 75.4 microg/g dw were fertilized (96% reached the eyed stage) but did not produce viable fry. A significant positive relationship between egg Se concentration and alevin mortality was observed. Deformities were analyzed in surviving fry which developed from eggs with Se concentrations between 11.8 and 20.6 microg/g dw. No relationship between Se concentration in eggs and deformities or edema was found in this range, suggesting that the no-effect threshold for deformity is > 20.6 microg/g dw. The present data, in conjunction with the data from several other studies in temperate fish, suggest that current Se thresholds are conservative for cold-water fish.

  8. Reproductive success, early life stage development, and survival of westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to elevated selenium in an area of active coal mining

    SciTech Connect

    Barri-Lynn Rudolph; Iisak Andreller; Christopher J. Kennedy

    2008-04-15

    The effects of accumulated Se on the reproductive success and larval development of cutthroat trout (Oncorhynchus clarki lewisi) collected from a site of active coal mining in British Columbia were assessed. Eggs from 12 fish from an exposed site (Clode Pond) and 16 from a reference site (O'Rourke Lake) were field-collected and reared in the laboratory. Egg Se concentrations ranged from 12.3 to 16.7 and 11.8 to 140.0 {mu}g/g dry weight (dw) from fish collected at the reference and exposed sites, respectively. Other studies, including those with this species, have not shown Se to affect egg viability. However, in the present study, eggs with Se concentrations >86.3 {mu}g/g dw were not successfully fertilized or were nonviable at fertilization, while eggs with concentrations >46.8 and <75.4 {mu}g/g dw were fertilized (96% reached the eyed stage) but did not produce viable fry. A significant positive relationship between egg Se concentration and alevin mortality was observed. Deformities were analyzed in surviving fry which developed from eggs with Se concentrations between 11.8 and 20.6 {mu}g/g dw. No relationship between Se concentration in eggs and deformities or edema was found in this range, suggesting that the no-effect threshold for deformity is >20.6 {mu}g/g dw. The present data, in conjunction with the data from several other studies in temperate fish, suggest that current Se thresholds are conservative for cold-water fish. 25 refs., 3 figs.

  9. Single stage treatment of ankylosis of the temporomandibular joint using patient-specific total joint replacement and virtual surgical planning.

    PubMed

    Haq, Jahrad; Patel, Nishma; Weimer, Katherine; Matthews, N Shaun

    2014-04-01

    Ankylosis of the temporomandibular joint (TMJ) is a debilitating condition that can result in pain, trismus, and a poor quality of life. It can be caused by injury, infection, and rheumatoid disease. Current management includes gap arthroplasty, interpositional arthroplasty, and reconstruction. Traditionally, joints are reconstructed using stock implants, or the procedure is done in two stages with an additional computed tomography (CT) scan between the resective and reconstructive procedures and use of stereolithographic models to aid the design of the definitive prostheses. We describe a technique for the resection of ankylosis and reconstruction of the joint in a single operation using virtually designed custom-made implants. Five patients with ankylosis of the TMJ had a single stage operation with reconstruction between 2010 and 2012. All had preoperative high-resolution CT with contrast angiography. During an international web-based teleconference between the surgeon and the engineer a virtual resection of the ankylosis was done using the reconstructed CT images. The bespoke cutting guides and implants were designed virtually at the same time and were then manufactured precisely using computer-aided design and manufacture (CAD-CAM) over 6 weeks. After release of the ankylosis and reconstruction, the patients underwent an exercise regimen to improve mouth opening. Follow-up was for a minimum of 6 months. Four patients had one operation, and one patient had two. Median/Mean maximum incisal opening increased from 0.6mm before operation to 25 mm afterwards (range 23-27), and there was minimal surgical morbidity. This new method effectively treats ankylosis of the TMJ in a single stage procedure. Fewer operations and hospital stays, and the maintenance of overall clinical outcome are obvious advantages.

  10. Single-stage endovascular treatment in patients with severe extracranial large vessel stenosis and concomitant ipsilateral unruptured intracranial aneurysm

    PubMed Central

    Kaçar, Emre; Nas, Ömer Fatih; Erdoğan, Cüneyt; Hakyemez, Bahattin

    2015-01-01

    PURPOSE We aimed to evaluate the safety and effectiveness of single-stage endovascular treatment in patients with severe extracranial large vessel stenosis and concomitant ipsilateral unruptured intracranial aneurysm. METHODS Hospital database was screened for patients who underwent single-stage endovascular treatment between February 2008 and June 2013 and seven patients were identified. The procedures included unilateral carotid artery stenting (CAS) (n=4), bilateral CAS (n=2), and proximal left subclavian artery stenting (n=1) along with ipsilateral intracranial aneurysm treatment (n=7). The mean internal carotid artery stenosis was 81.6% (range, 70%–95%), and the subclavian artery stenosis was 90%. All aneurysms were unruptured. The mean aneurysm diameter was 7.7 mm (range, 5–13 mm). The aneurysms were ipsilateral to the internal carotid artery stenosis (internal carotid artery aneurysm) in five patients, and in the anterior communicating artery in one patient. The patient with subclavian artery stenosis had a fenestration aneurysm in the proximal basilar artery. Stenting of the extracranial large vessel stenosis was performed before aneurysm treatment in all patients. In two patients who underwent bilateral CAS, the contralateral carotid artery stenosis, which had no aneurysm distally, was treated initially. RESULTS There were no procedure-related complications or technical failure. The mean clinical follow-up period was 18 months (range, 9–34 months). One patient who underwent unilateral CAS experienced contralateral transient ischemic attack during the clinical follow-up. There was no restenosis on six-month follow-up angiograms, and all aneurysms were adequately occluded. CONCLUSION A single-stage procedure appears to be feasible for treatment of patients with severe extracranial large vessel stenosis and concomitant ipsilateral intracranial aneurysm. PMID:26359875

  11. Two-stage single-phase grid-connected photovoltaic system with reduced complexity

    NASA Astrophysics Data System (ADS)

    da Silva, Cintia S.; Motta, Filipe R.; Tofoli, Fernando L.

    2011-06-01

    This article presents a grid-connected photovoltaic (PV) system using the classical DC-DC buck converter, which is responsible for stepping down the resulting voltage from several series-connected panels. Besides, the structure provides high power factor operation by injecting a quasi-sinusoidal current into the grid, with near no displacement in relation to the line voltage at the point of common coupling among the PV system and the loads. A CSI employing thyristors is cascaded with the DC-DC stage so that AC voltage results. The inverter output voltage level is adjusted by using a low-frequency transformer, which also provides galvanic isolation. The proposed system is described as mathematical approach and design guidelines are presented, providing an overview of the topology. An experimental prototype is also implemented, and relevant results to validate the proposal are discussed.

  12. Improving pancreatic cancer diagnosis using circulating tumor cells: prospects for staging and single-cell analysis

    PubMed Central

    Court, Colin M; Ankeny, Jacob S; Hou, Shuang; Tseng, Hsian-Rong; Tomlinson, James S

    2016-01-01

    Pancreatic cancer (PC) is the fourth most common cause of cancer-related death in the USA, primarily due to late presentation coupled with an aggressive biology. The lack of adequate biomarkers for diagnosis and staging confound clinical decision-making and delay potentially effective therapies. Circulating tumor cells (CTCs) are a promising new biomarker in PC. Preliminary studies have demonstrated their potential clinical utility, and newer CTC isolation platforms have the potential to provide clinicians access to tumor tissue in a reliable, real-time manner. Such a ‘liquid biopsy’ has been demonstrated in several cancers, and small studies have demonstrated its potential applications in PC. This article reviews the available literature on CTCs as a biomarker in PC and presents the latest innovations in CTC research as well as their potential applications in PC. PMID:26390158

  13. Single-Stage, 3.4:1-Pressure-Ratio Aspirated Fan Developed and Demonstrated

    NASA Technical Reports Server (NTRS)

    Braunscheidel, Edward P.

    2004-01-01

    Researchers are constantly pursuing technologies that will increase the performance of gas turbine engines. The aspirated compressor concept discussed here would allow the compression system to perform its task with about one-half of the compressor blades. To accomplish this, the researchers applied boundary layer control to the blades, casing, and hub. This method of boundary layer control consisted of removing small amounts of air from the main flow path at critical areas of the compressor. This bleed air could be used by other systems such as engine cooling or could be re-injected into lower pressure areas that require air for enhanced performance. This effort was initiated by the Massachusetts Institute of Technology (MIT) in response to a solicitation from the Defense Advanced Research Projects Agency (DARPA) who sought to advance research in flow control technology. The NASA Glenn Research Center partnered with MIT (principal investigator), Honeywell Aircraft Engines (cycle analysis, structural analysis, and mechanical design), and Pratt & Whitney (cycle analysis and aero-analysis) to conceptualize, design, analyze, build, and test the aspirated fan stage. The aero-design and aero-analysis of this fan stage were jointly executed by MIT and Glenn to minimize the amount of bleed flow needed and to maintain the highest efficiency possible (ref. 1). Mechanical design issues were complicated by the need to have a shrouded rotor with hollow blades, with rotor stress levels beyond the capabilities of titanium. The high stress issues were addressed by designing a shroud that was filament wound with a carbon fiber/epoxy matrix, resulting in an assembly that was strong enough to handle the high stresses. Both the rotor (preceding photographs) and stator (following photograph) were fabricated in two halves and then bolted together at the hub and tip, permitting the bleed passages to be machined into each half before assembly.

  14. Effect of Blade-surface Finish on Performance of a Single-stage Axial-flow Compressor

    NASA Technical Reports Server (NTRS)

    Moses, Jason J; Serovy, George, K

    1951-01-01

    A set of modified NACA 5509-34 rotor and stator blades was investigated with rough-machine, hand-filed, and highly polished surface finishes over a range of weight flows at six equivalent tip speeds from 672 to 1092 feet per second to determine the effect of blade-surface finish on the performance of a single-stage axial-flow compressor. Surface-finish effects decreased with increasing compressor speed and with decreasing flow at a given speed. In general, finishing blade surfaces below the roughness that may be considered aerodynamically smooth on the basis of an admissible-roughness formula will have no effect on compressor performance.

  15. Subsonic-to-Hypersonic Aerodynamic Characteristics for a Winged, Circular-Body, Single-Stage-to-Orbit Spacecraft Configuration

    NASA Technical Reports Server (NTRS)

    Phillips, W. P.; Engelund, W. C.

    1995-01-01

    Experimental aerodynamic characteristics were obtained for a generic, winged, circular-body, single-stage-to-orbit spacecraft configuration. The baseline configuration was longitudinally stable and trimmable at almost all Mach numbers from 0.15 to 10.0--with the exception occurring at low supersonic speeds. Landing speed and subsonic-to-hypersonic longitudinal stability and control appear to be within design guidelines. Lateral-directional instabilities found over the entire speed range, however, create a problem area for this configuration. Longitudinal aerodynamic predictions made utilizing the Aerodynamic Preliminary Analysis System (APAS) were in qualitative, often quantitative agreement with experimental values.

  16. A novel single-stage procedure for increasing the width of attached gingiva and eliminating the aberrant frenal attachment.

    PubMed

    Kumar, Santhosh; Suresh P, Gautham; Anand, K Meena

    2015-03-01

    Common treatment for buccal gingival recession caused by an aberrant frenal attachment includes elimination of the frenum and treatment of the gingival recession by soft tissue graft to increase the width of the attached gingiva that in turn results in root coverage. Keratinised gingival, if present in adequate amount, maintains the gingival health by protecting the marginal gingiva. This not only considers the desires of the patient but also explores the potential regenerative capacity of the tissues. This report describes a novel single-stage procedure for increasing the width of the attached gingiva and eliminating the aberrant frenal attachment.

  17. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 1993

    SciTech Connect

    Conrad, R.; Childs, M.; Rivera-Dirks, C.; Coriz, F.

    1995-07-01

    Area G, in Technical Area 54, has been the principle facility at Los Alamos National Laboratory for the storage and disposal of low-level and transuranic (TRU) radioactive wastes since 1957. The current environmental investigation consisted of ESH-19 personnel who collected soil and single-stage water samples around the perimeter of Area G to characterize possible contaminant movement through surface-water runoff. These samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241 (soil only), and cesium 137. The metals, mercury, lead, and barium, were analyzed using x-ray fluorescence.

  18. Coal liquefaction and hydrogenation: Processes and equipment. (Latest citations from the US Patent database). Published Search

    SciTech Connect

    Not Available

    1993-07-01

    The bibliography contains citations of selected patents concerning methods, processes, and apparatus for coal liquefaction and hydrogenation. Included are patents for catalytic two-stage, catalytic single-step, fixed-bed, hydrogen-donor, internal heat transfer, and multi-phase processes. Topics also include catalyst production, catalyst recovery, desulfurization, pretreatment of coals, energy recovery processes, solvent product separation, hydrogenating gases, and pollution control. (Contains 250 citations and includes a subject term index and title list.)

  19. Single Stage Silicone Border Molded Closed Mouth Impression Technique-Part II.

    PubMed

    Solomon, E G R

    2011-09-01

    Functioning of a complete denture depends to a great extent on the impression technique. Several impression techniques have been described in the literature since the turn of this century when Greene [Clinical courses in dental prothesis, 1916] brothers introduced the first scientific system of recording dental impression. Advocates of each technique have their own claim of superiority over the other. The introduction of elastomeric impression materials [Skinner and Cooper, J Am Dent Assoc 51:523-536, 1955] has made possible new techniques of recording impression for complete denture construction. These rubber like materials are of two types; one has a polysulfide base and is popularily known as polysulfide rubber (Thiokol and Mercaptan). The other variety has a silicone base known as silicone rubber or silicone elastomer. Silicone elastomers are available in four different consistencies; a thin easy flowing light bodied material,a creamy medium bodied material, a highly viscous heavy bodied material and a kneadable putty material. This paper describes an active closed mouth impression technique with one stage border molding using putty silicone material as a substitute for low fusing compound.

  20. Design, construction, and measurement of a dielectric single-mirror two-stage (DSMTS) photovoltaic concentrator

    NASA Astrophysics Data System (ADS)

    Mohedano Arroyo, Ruben; Benitez, Pablo; Minano, Juan C.; Bercero, Francisco; Lobato, Pablo

    2001-11-01

    The 30 X DSMTS is a trough-like photovoltaic concentrator, meant to track the sun in one axis, which has a mirror allocating two concentration stages and a secondary lens that increases its acceptance up to +/- 2.3 degrees. Provided that the sun subtends an angle of +/- 0.256 degrees, such acceptance seems excessive. However, thanks to it, we can relax requirements that often demand accuracy in systems of the kind. For instance, the shape of the mirror can be achieved by simply bending an aluminum sheet. To foresee the results we may expect of this strategy, we carried out some mechanical calculations, whose results are the boundary conditions that lead to a minimum standard deviation on the local slope of the elastic mirror with regards to the theoretical value. We checked by ray tracing that such an error actually provoked a small decrease on the acceptance. This fact persuaded us to carry out the manufacture of two elastic prototypes. In the test that have been performed so far with them we achieved an acceptance angle of +/- 1.63 degrees and a collection efficiency of 98 percent at a geometrical concentration of 30 times, results that can be considered as outstanding in the photovoltaics framework.

  1. Single high dose intraoperative electrons for advanced stage pancreatic cancer: Phase I pilot study

    SciTech Connect

    Goldson, A.L.; Ashaveri, E.; Espinoza, M.C.

    1981-07-01

    Phase I toxicity studies with intraoperative radiotherapy proved to be a feasible adjunct to surgery for unresectable malignancies of the pancreas at Howard University Hospital. There have been minimal side effects or complications related to the combination of limited surgical decompression and intraoperative radiotherapy alone. The toxic effects of intraoperative radiotherapy on normal tissues is being assessed on a dose volume basis. Doses of 2000 to 2500 rad in a single exposure to include the pancreas, regional nodes and duodenum are acceptable if the total treatment volume is less than or equal to 100 cm. The tumoricidal effects on the cancer are demonstratable when one reviews the pathological specimens that illustrate massive tumor necrosis and fibros replacement, but in all cases reviewed, viable cancer was noted. Intraoperative radiotherapy, therefore, represents a significant boost dose for resectable, partially resectable or non-resectable tumors when added to conventional external beam irradiation and/or chemotherapy. Preliminary clinical data and minimal toxicity justifies further investigation.

  2. Coalification of cuticle and compressed leaf tissue of the Carboniferous seed fern, Macroneuropteris (Neuropteris) scheuchzeri--Implications for coalification to the bituminous coal stage

    SciTech Connect

    Lyons, P.C.; Orem, W.H. . National Center); Zodrow, E.L. )

    1992-01-01

    C-13 NMR analyses of leaf cuticle and the compressed and coalified leaf tissues of the late Carboniferous seed fern Macroneuropteris (Neuropteris) scheuchzeri from shale from the Sydney Mines Formation, Sydney Coalfield, Nova Scotia, Canada, indicate a variable degree of coalification. In preliminary NMR spectra the cuticle shows a dominantly aliphatic region and a subdued aromatic region, whereas the compressed leaf tissues show two subequal aromatic and aliphatic regions, which are typical of high volatile bituminous coals. The spectrum of the cuticle shows some indication of resonance in the 60- to 80-ppm region, possibly indicating the presence of residual cellulose that is found in lignite and subbituminous coal, but not in bituminous coal. The compressed tissues show an indication of a shoulder in the 150- to 160-ppm region, possibly phenolic moieties from lignin, which is found in high volatile bituminous coals. Leaf tissue is thought to be rich in cellulose and poor in lignin, so it is surprising that the C-13 NMR spectrum of the compressed leaf tissue appears identical to spectra from vitrinite-rich, high volatile bituminous coal. These results indicate that the nature of plant precursors plays a significant role in coalification and also that the selective loss of cellulosic components and the attendant enrichment in lignin are not necessarily a precondition for the generation of the macromolecular structure of bituminous coal. The authors suggest that dominantly cellulose-based molecules from leaf tissue coalify in much the same way as lignin-based molecules from woody tissue.

  3. Single-virus tracking approach to reveal the interaction of Dengue virus with autophagy during the early stage of infection

    NASA Astrophysics Data System (ADS)

    Chu, Li-Wei; Huang, Yi-Lung; Lee, Jin-Hui; Huang, Long-Ying; Chen, Wei-Jun; Lin, Ya-Hsuan; Chen, Jyun-Yu; Xiang, Rui; Lee, Chau-Hwang; Ping, Yueh-Hsin

    2014-01-01

    Dengue virus (DENV) is one of the major infectious pathogens worldwide. DENV infection is a highly dynamic process. Currently, no antiviral drug is available for treating DENV-induced diseases since little is known regarding how the virus interacts with host cells during infection. Advanced molecular imaging technologies are powerful tools to understand the dynamics of intracellular interactions and molecular trafficking. This study exploited a single-virus particle tracking technology to address whether DENV interacts with autophagy machinery during the early stage of infection. Using confocal microscopy and three-dimensional image analysis, we showed that DENV triggered the formation of green fluorescence protein-fused microtubule-associated protein 1A/1B-light chain 3 (GFP-LC3) puncta, and DENV-induced autophagosomes engulfed DENV particles within 15-min postinfection. Moreover, single-virus particle tracking revealed that both DENV particles and autophagosomes traveled together during the viral infection. Finally, in the presence of autophagy suppressor 3-methyladenine, the replication of DENV was inhibited and the location of DENV particles spread in cytoplasma. In contrast, the numbers of newly synthesized DENV were elevated and the co-localization of DENV particles and autophagosomes was detected while the cells were treated with autophagy inducer rapamycin. Taken together, we propose that DENV particles interact with autophagosomes at the early stage of viral infection, which promotes the replication of DENV.

  4. SPECHT – Single-stage phosphopeptide enrichment and stable-isotope chemical tagging: Quantitative phosphoproteomics of insulin action in muscle

    PubMed Central

    Kettenbach, Arminja N.; Sano, Hiroyuki; Keller, Susanna R.; Lienhard, Gustav E.; Gerber, Scott A.

    2014-01-01

    The study of cellular signaling remains a significant challenge for translational and clinical research. In particular, robust and accurate methods for quantitative phosphoproteomics in tissues and tumors represent significant hurdles for such efforts. In the present work, we design, implement and validate a method for single-stage phosphopeptide enrichment and stable isotope chemical tagging, or SPECHT, that enables the use of iTRAQ, TMT and/or reductive dimethyl-labeling strategies to be applied to phosphoproteomics experiments performed on primary tissue. We develop and validate our approach using reductive dimethyl-labeling and HeLa cells in culture, and find these results indistinguishable from data generated from more traditional SILAC-labeled HeLa cells mixed at the cell level. We apply the SPECHT approach to the quantitative analysis of insulin signaling in a murine myotube cell line and muscle tissue, identify known as well as new phosphorylation events, and validate these phosphorylation sites using phospho-specific antibodies. Taken together, our work validates chemical tagging post-single-stage phosphoenrichment as a general strategy for studying cellular signaling in primary tissues. PMID:25463755

  5. Single-stage fermentation process for high-value biohythane production with the treatment of distillery spent-wash.

    PubMed

    Pasupuleti, Suresh Babu; Venkata Mohan, S

    2015-01-01

    The current communication reports the development of a single-stage biosystem for biohythane production from wastewater treatment. A semi-pilot scale bioreactor with 34 L capacity was used for this study. Maximum biohythane production of 147.5 ± 2.4 L was observed after five cycles of operation with production rate of 4.7 ± 0.1L/h. The biohythane composition (H2/(H2+CH4)) varied from 0.60 to 0.23 during stabilized fifth cycle of operation. During each cycle of operation, higher H2 fraction was noticed within 12h of cycle period followed by CH4 production for rest of operation (36 h). During biohythane production, COD removal efficiency of 60 ± 5% (SDR, 29.0 ± 1.9 kg CODr/m(3)-day) was also achieved. The synergistic function of volatile fatty acids (VFA) production and consumption during process in hybrid biosystem played vital role on the composition of biohythane. The single-stage biosystem facilitates production of high valued and cost efficient biofuel (biohythane) with fewer controls than individual acidogenic and methanogenic processes.

  6. Some triple-filament lead isotope ratio measurements and an absolute growth curve for single-stage leads

    USGS Publications Warehouse

    Stacey, J.S.; Delevaux, M.E.; Ulrych, T.J.

    1969-01-01

    Triple-filament analyses of three standard lead samples are used to calibrate a mass spectrometer in an absolute sense. The bias we measure is 0.0155 percent per mass unit, and the precision (for 95% confidence limits) is ??0.13% or less for all ratios relative to 204Pb. Although its precision is not quite so good as that of the lead-tetramethyl method in the analysis of large samples, the triple-filament method is less complex and is an attractive alternative for smaller sample sizes down to 500 ??g. Triple-filament data are presented for six possibly single-stage lead ores and one feldspar. These new data for ores are combined with corrected tetramethyl data for stratiform lead deposits to compute absolute parameters for a universal single-stage lead isotope growth curve. Absolute isotopic ratios for primeval lead have been determined by Oversby and because all the previous data for both meteorites and lead ores were similarly fractionated, the absolute value of 238U 204Pb = 9.09 ?? 0.06 for stratiform leads is little different from the value 8.99 ?? 0.05 originally computed by Ostic, Russell and Stanton. Absolute values for lead isotope ratios for all interlaboratory standard samples presently available from the literature are tabulated. ?? 1969.

  7. Single stage reconstruction of ruptured tendoachilles tendon with skin cover using distally based superficial sural artery flap.

    PubMed

    Abhyankar, Suhas V; Kulkarni, Ananta; Agarwal, Naveen Kumar

    2009-10-01

    Ruptured tendoachilles along with skin defect is a complex problem to reconstruct. Both things require a priority. Single stage reconstruction of ruptured tendoachilles tendon with skin cover using distally based superficial sural arterial flap allows us to perform both. This procedure gives excellent result, shortens the stay, thereby reducing the cost. This method is a simple solution to the complex problem like ruptured tendoachilles with skin defect. In this study, 6 patients with rupture of tendoachilles tendon due to penetrating injury, with skin defect are presented. The repair was done using aponeurotic part of tendoachilles tendon, taken from proximal part of tendoachilles in the midline measuring around 2 to 2.5 cm in width and 8 to 10 cm in length, with intact distal attachment. The tendon was turned upside down by 180 degrees and sutured to the distal stump of the tendoachilles tendon without tension. The skin defect was covered using distally based superficial sural artery flap in the same sitting. The follow-up period was 9 to 30 months. All patients showed good results. In one patient there was distal necrosis of 1.5 cm of the distally based superficial sural artery flap, which healed satisfactorily with conservative treatment. Single stage tendoachilles reconstruction can be used with good functional result and patient satisfaction.

  8. Evaluation of a miniaturised single-stage thermal modulator for comprehensive two-dimensional gas chromatography of petroleum contaminated soils.

    PubMed

    Jacobs, Matthew R; Edwards, Matthew; Górecki, Tadeusz; Nesterenko, Pavel N; Shellie, Robert A

    2016-09-09

    A novel miniaturised single-stage resistively heated thermal modulator was investigated as an alternative to cryogenic modulation for use in comprehensive two-dimensional gas chromatography (GC×GC). The single-stage thermal modulator described herein yielded average retention time relative standard deviations (RSD) of ≤0.2% RSD (first-dimension) and ≤3.4% RSD (second-dimension). The average peak widths generated by the modulator were 72±3ms, and the peak area precision was better than 5.3% RSD for a range of polar and non-polar test analytes. GC×GC analysis can be performed using this modulator without the requirement for cryogenic cooling or additional pressure control modules for flow modulation. The modulator and associated electronics are compact and amenable towards field analysis. The modulator was used for qualitative and quantitative characterisation of petroleum-contaminated soils derived from a sub-Antarctic research station at Macquarie Island. The limit of detection compared to standard 1D GC analysis was improved from 64 to 11mgkg(-1). An automated method of analysing and categorising samples using principal component analysis is presented.

  9. Treatment of Early Stage Endometrial Cancer by Transumbilical Laparoendoscopic Single-Site Surgery Versus Traditional Laparoscopic Surgery

    PubMed Central

    Cai, Hui-hua; Liu, Mu-biao; He, Yuan-li

    2016-01-01

    Abstract To compare the outcomes of transumbilical laparoendoscopic single-site surgery (TU-LESS) versus traditional laparoscopic surgery (TLS) for early stage endometrial cancer (EC). We retrospectively reviewed the medical records of patients with early stage EC who were surgically treated by TU-LESS or TLS between 2011 and 2014 in a tertiary care teaching hospital. We identified 18 EC patients who underwent TU-LESS. Propensity score matching was used to match this group with 18 EC patients who underwent TLS. All patients underwent laparoscopic-assisted vaginal hysterectomy, bilateral salpingo-oophorectomy, and systematic pelvic lymphadenectomy by TU-LESS or TLS without conversion to laparoscopy or laparotomy. Number of pelvic lymph nodes retrieved, operative time and estimated blood loss were comparable between 2 groups. Satisfaction values of the cosmetic outcome evaluated by the patient at day 30 after surgery were significantly higher in TU-LESS group than that in TLS group (9.6 ± 0.8 vs 7.5 ± 0.7, P < 0.001), while there was no statistical difference in postoperative complications within 30 days after surgery, postoperative hospital stay, and hospital cost. For the surgical management of early stage EC, TU-LESS may be a feasible alternative approach to TLS, with comparable short-term surgical outcomes and superior cosmetic outcome. Future large-scale prospective studies are needed to identify these benefits. PMID:27057851

  10. Effects of Hot Streak Shape on Rotor Heating in a High-Subsonic Single-Stage Turbine

    NASA Technical Reports Server (NTRS)

    Dorney, Daniel J.; Gundy-Burlet, Karen L.; Norvig, Peter (Technical Monitor)

    1999-01-01

    Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location (clocking) of the hot streak relative to the first-stage vane airfoils can be used to minimize the adverse effects of the hot streak. The effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have also been evaluated. In the present investigation, three-dimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine operating in high subsonic flow. In addition to a simulation of the baseline turbine, simulations have been performed for circular and elliptical hot streaks of varying sizes in an effort to represent different combustor designs. The predicted results for the baseline simulation show good agreement with the available experimental data. The results of the hot streak simulations indicate: that a) elliptical hot streaks mix more rapidly than circular hot streaks, b) for small hot streak surface area the average rotor temperature is not a strong function of hot streak temperature ratio or shape, and c) hot streaks with larger surface area interact with the secondary flows at the rotor hub endwall, generating an additional high temperature region.

  11. A novel clinicopathological analysis of early stage ovarian Sertoli-Leydig cell tumors at a single institution

    PubMed Central

    Nam, Seon Mi; Kim, Jee Whan; Eoh, Kyung Jin; Kim, Hye Min; Lee, Jung Yun; Nam, Eun Ji; Kim, Sunghoon; Kim, Sang Wun

    2017-01-01

    Objective To evaluate the clinical and pathologic characteristics of patients who were diagnosed with ovarian Sertoli-Leydig cell tumors (SLCTs) in a single institution. Methods The medical records of 11 patients who were pathologically diagnosed with SLCTs beginning in 1995 in a single institute was reviewed. Results The median patient age was 31 years (range, 16 to 70 years). Patient International Federation of Gynecology and Obstetrics stages were IA, IC, and IIB in 3 (27.3%), 6 (54.5%), and 2 (18.2%) patients, respectively. Six patients (54.5%) had grade 3 tumors, 3 patients (27.3%) had grade 2 tumors, and 1 patient (9.1%) had a grade 1 tumor. Four patients without children underwent fertility-sparing surgery, and 7 patients had full staging surgery, including a hysterectomy and bilateral salpingo-oophorectomy, with a laparoscopic approach used in 3. Eight patients underwent pelvic lymph node dissection, and 8 patients were administered adjuvant chemotherapy consisting of bleomycin, etoposide, and cisplatin in 6 cases, a modified bleomycin, etoposide, and cisplatin regimen in 1 case, and a combined paclitaxel and cisplatin regimen in 1 case. Two patients died of disease and were re-diagnosed with Sertoli form endometrioid carcinoma. The other patients remain alive without recurrence at the time of reporting. Conclusion Our findings suggest that regardless of tumor stage or grade, ovarian SLCT patients have a good prognosis. Close observation and unilateral salpingo-oophorectomy would be beneficial for women who still wish to have children, while hysterectomy and bilateral salpingo-oophorectomy with adjuvant chemotherapy would be the optimal treatment in other cases. Furthermore, meticulous pathologic diagnosis is needed to develop a precise treatment strategy. PMID:28217670

  12. Rice identification at the early stage of the rice growth season with single fine quad Radarsat-2 data

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoqian; Zhang, Pengbin; Shen, Kejian; Pei, Zhiyuan

    2016-10-01

    The objective of the study was to determine whether rice identification and acreage estimation accuracy at the early stage of the rice growth season using single fine quad Radarsat-2 images could meet the demand of rice monitoring. The Leizhou site (20°52'N, 110°05'E) is located in Guangdong Province in southern China and is dominated by rice paddies. There was a lack of optical data acquisitions during certain years. There are two rice growth seasons per year. Multitemporal Radarsat-2 products were acquired in the early rice growth season of 2014. First, multi-temporal backscattering coefficients and polarimetric parameters based on H/A/Alpha and Yamaguchi polarimetric decomposition theories were extracted and analyzed to distinguish between rice paddies and other typical land cover types, which could help select the optimal rice growth stage and image characteristics for early season classification. Second, an object-oriented technique was applied to time series backscattering coefficient images (HH, HV, VH, VV), H/A/Alpha images (Entropy, Anistropy and Alpha) and Yamaguchi images (volume, double-bounce, surface and helix). Based on the segmentation images, the supervised Bayes, KNN, SVM and Decision tree classifier were used to identify rice. The results indicated that in flat area, 1) Backscatter images and Yamaguchi images were better than H/A/Alpha images in the rice identification application, and 2) At the early rice growth season, the 0430-Yamaguchi image combined with the objectoriented decision tree algorithm were capable of delivering highly accurate maps of rice (0.9236), while the 0524- backscatter image combined with the object-oriented decision tree algorithm could acquire the highest classification accuracy (0.9278) at the end of the rice growth season. Jointing stage is considered to be appropriate for rice identification at the early season. The study demonstrated that it was possible to identify rice at the early season with single quad C

  13. Fixed-bed gasification research using US coals. Volume 9. Gasification of Elkhorn bituminous coal

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) group. This report is the ninth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Elkhorn bituminous coal. The period of gasificastion test was September 13 to October 12, 1983. 9 refs., 24 figs., 35 tabs.

  14. Fixed-bed gasification research using US coals. Volume 4. Gasification of Leucite Hills subbituminous coal

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-03-31

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the fourth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Leucite Hills subbituminous coal from Sweetwater County, Wyoming. The period of the gasification test was April 11-30, 1983. 4 refs., 23 figs., 27 tabs.

  15. Conditions of Core Formation in the Early Earth: Single Stage or Heterogeneous Accretion?

    NASA Technical Reports Server (NTRS)

    Righter, Kevin

    2010-01-01

    Since approx.1990 high pressure and temperature (PT) experiments on metal-silicate systems have showed that partition coefficients [D(met/sil)] for siderophile (iron-loving) elements are much different than those measured at low PT conditions [1,2]. The high PT data have been used to argue for a magma ocean during growth of the early Earth [3,4]. In the ensuing decades there have been hundreds of new experiments carried out and published on a wide range of siderophile elements (> 80 experiments published for Ni, Co, Mo, W, P, Mn, V, Cr, Ga, Cu and Pd). At the same time several different models have been advanced to explain the siderophile elements in Earth's mantle: a) shallow depth magma ocean 25-30 GPa [3,5]; b) deep magma ocean; up to 50 GPa [6,7], and c) early reduced and later oxidized magma ocean [8,9]. Some studies have drawn conclusions based on a small subset of siderophile elements, or a set of elements that provides little leverage on the big picture (like slightly siderophile elements), and no single study has attempted to quantitatively explain more than 5 elements at a time. The purpose of this abstract is to identify issues that have lead to a difference in interpretation, and to present updated predictive expressions based on new experimental data. The resulting expressions will be applied to the siderophile element depletions in Earth's upper mantle.

  16. Cell death stages in single apoptotic and necrotic cells monitored by Raman microspectroscopy

    NASA Astrophysics Data System (ADS)

    Brauchle, Eva; Thude, Sibylle; Brucker, Sara Y.; Schenke-Layland, Katja

    2014-04-01

    Although apoptosis and necrosis have distinct features, the identification and discrimination of apoptotic and necrotic cell death in vitro is challenging. Immunocytological and biochemical assays represent the current gold standard for monitoring cell death pathways; however, these standard assays are invasive, render large numbers of cells and impede continuous monitoring experiments. In this study, both room temperature (RT)-induced apoptosis and heat-triggered necrosis were analyzed in individual Saos-2 and SW-1353 cells by utilizing Raman microspectroscopy. A targeted analysis of defined cell death modalities, including early and late apoptosis as well as necrosis, was facilitated based on the combination of Raman spectroscopy with fluorescence microscopy. Spectral shifts were identified in the two cell lines that reflect biochemical changes specific for either RT-induced apoptosis or heat-mediated necrosis. A supervised classification model specified apoptotic and necrotic cell death based on single cell Raman spectra. To conclude, Raman spectroscopy allows a non-invasive, continuous monitoring of cell death, which may help shedding new light on complex pathophysiological or drug-induced cell death processes.

  17. Mapping the energy landscape for second-stage folding of a single membrane protein

    PubMed Central

    Min, Duyoung; Jefferson, Robert E; Bowie, James U; Yoon, Tae-Young

    2016-01-01

    Membrane proteins are designed to fold and function in a lipid membrane, yet folding experiments within a native membrane environment are challenging to design. Here we show that single-molecule forced unfolding experiments can be adapted to study helical membrane protein folding under native-like bicelle conditions. Applying force using magnetic tweezers, we find that a transmembrane helix protein, Escherichia coli rhomboid protease GlpG, unfolds in a highly cooperative manner, largely unraveling as one physical unit in response to mechanical tension above 25 pN. Considerable hysteresis is observed, with refolding occurring only at forces below 5 pN. Characterizing the energy landscape reveals only modest thermodynamic stability (ΔG = 6.5 kBT) but a large unfolding barrier (21.3 kBT) that can maintain the protein in a folded state for long periods of time (t1/2 ~3.5 h). The observed energy landscape may have evolved to limit the existence of troublesome partially unfolded states and impart rigidity to the structure. PMID:26479439

  18. Low Energy Multi-Stage Atrial Defibrillation Therapy Terminates Atrial Fibrillation with Less Energy than a Single Shock

    PubMed Central

    Li, Wenwen; Janardhan, Ajit H.; Fedorov, Vadim V.; Sha, Qun; Schuessler, Richard B.; Efimov, Igor R.

    2011-01-01

    Background Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multi-stage defibrillation therapy and tested it in a canine model of AF. Methods and Results AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of three stages: ST1 (1-4 low energy biphasic shocks), ST2 (6-10 ultra-low energy monophasic shocks), and ST3 (anti-tachycardia pacing). Firstly, ST1 testing compared single or multiple monophasic (MP) and biphasic (BP) shocks. Secondly, several multi-stage therapies were tested: ST1 versus ST1+ST3 versus ST1+ST2+ST3. Thirdly, three shock vectors were compared: superior vena cava to distal coronary sinus (SVC>CSd), proximal coronary sinus to left atrial appendage (CSp>LAA) and right atrial appendage to left atrial appendage (RAA>LAA). The atrial defibrillation threshold (DFT) of 1BP shock was less than 1MP shock (0.55 ± 0.1 versus 1.38 ± 0.31 J; p =0.003). 2-3 BP shocks terminated AF with lower peak voltage than 1BP or 1MP shock and with lower atrial DFT than 4 BP shocks. Compared to ST1 therapy alone, ST1+ST3 lowered the atrial DFT moderately (0.51 ± 0.46 versus 0.95 ± 0.32 J; p = 0.036) while a three-stage therapy, ST1+ST2+ST3, dramatically lowered the atrial DFT (0.19 ± 0.12 J versus 0.95 ± 0.32 J for ST1 alone, p=0.0012). Finally, the three-stage therapy ST1+ST2+ST3 was equally effective for all studied vectors. Conclusions Three-stage electrotherapy significantly reduces the AF defibrillation threshold and opens the door to low energy atrial defibrillation at or below the pain threshold. PMID:21980076

  19. Single stage bilateral uniportal videothoracoscopic sympathicotomy for hyperhidrosis: can it be managed as an outpatient procedure?

    PubMed Central

    Erşen, Ezel; Kılıç, Burcu; Kara, Hasan Volkan; İşcan, Mehlika; Kaynak, Kamil; Turna, Akif

    2016-01-01

    Introduction The videothoracoscopic approach is minimally invasive with benefits that include less postoperative pain and shorter hospital stay. It is also a safe procedure which can be performed on an outpatient basis. Aim To determine whether videothoracoscopic sympathicotomy can be performed safely in most patients as an outpatient procedure. Material and methods Between July 2005 and October 2015, a total of 92 patients underwent bilateral and single port thoracoscopic sympathicotomy in our department on an outpatient basis. The level of sympathicotomy was T2 in 2 (2.2%) patients, T2 to T3 in 31 (33%) patients, T2 to T4 in 46 (50%) patients and T3 to T4 in 12 (13%) patients. Demographic data, length of postoperative stay, substitution index (SI), admission rate (AR) and readmission rate (RR), complications and patient satisfaction were reviewed retrospectively. Results Two (2.2%) patients suffered from chest pain, while 4 (4.3%) patients complained about pain at the port site. Mean discharge time after surgery was 5.1 h (range: 4–6 h), mean duration of hospital stay was 0.15 days (0–3 days) postoperatively and the mean operation time was 43.6 min (15–130 min). In 8 (8.6%) patients, pneumothorax was detected on postoperative chest X-ray, while 5 (5.4%) patients required chest tube drainage. Mild or moderate compensatory sweating developed in 32 (34.7%) patients. No recurrence was observed, and the satisfaction rate was 96.7%. Substitution index and admission rate were 91.3% and 11% respectively, while RR was 0%. Conclusions Bilateral video-assisted thoracoscopic sympathicotomy can be performed safely in most patients as an outpatient procedure. PMID:27458488

  20. Analysis of the twice-line-frequency light flicker of an LED lamp driven by a single-stage PFC circuit

    NASA Astrophysics Data System (ADS)

    Li, Yi; Han, Gyung-Seok; Kim, Hee-Jun

    2014-07-01

    A large twice-line-frequency light flicker is a problem for a light-emitting-diode (LED) lamp driven by a single-stage power-factor-correction (PFC) circuit. This paper proposes a driving circuit for solving this problem. Furthermore, possible factors that influence the light flicker of a single-stage PFC driven LED lamp are analyzed. The theoretical analysis results are verified by using both simulations and experiments.

  1. PERFACT procedure to treat supralevator fistula-in-ano: A novel single stage sphincter sparing procedure

    PubMed Central

    Garg, Pankaj

    2016-01-01

    AIM: To prospectively perform the PERFACT procedure in supralevator anal fistula/abscess. METHODS: Magnetic resonance imaging was done preoperatively in all the patients. Proximal cauterization around the internal opening, emptying regularly of fistula tracts and curettage of tracts (PERFACT) was done in all patients with supralevator fistula or abscess. All types of anal fistula and/or abscess with supralevator extension, whether intersphincteric or transsphincteric, were included in the study. The internal opening along with the adjacent mucosa was electrocauterized. The resulting wound was left open to heal by secondary intention so as to heal (close) the internal opening by granulation tissue. The supralevator tract/abscess was drained and thoroughly curetted. It was regularly cleaned and kept empty in the postoperative period. The primary outcome parameter was complete fistula healing. The secondary outcome parameters were return to work and change in incontinence scores (Vaizey objective scoring system) assessed preoperatively and at 3 mo after surgery. RESULTS: Seventeen patients were prospectively enrolled and followed for a median of 13 mo (range 5-21 mo). Mean age was 41.1 ± 13.4 years, M:F - 15:2. Fourteen (82.4%) had a recurrent fistula, 8 (47.1%) had an associated abscess, 14 (82.4%) had multiple tracts and 5 (29.4%) had horseshoe fistulae. Infralevator part of fistula was intersphincteric in 4 and transsphincteric in 13 patients. Two patients were excluded. Eleven out of fifteen (73.3%) were cured and 26.7% (4/15) had a recurrence. Two patients with recurrence were reoperated on with the same procedure and one was cured. Thus, the overall healing rate was 80% (12/15). All the patients could resume normal work within 48 h of surgery. There was no deterioration in incontinence scores (Vaizey objective scoring system). This is the largest series of supralevator fistula-in-ano (SLF) published to date. CONCLUSION: PERFACT procedure is an effective single

  2. Abort performance for a winged-body single-stage to orbit vehicle. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Lyon, Jeffery A.

    1995-01-01

    Optimal control theory is employed to determine the performance of abort to orbit (ATO) and return to launch site (RTLS) maneuvers for a single-stage to orbit vehicle. The vehicle configuration examined is a seven engine, winged-body vehicle, that lifts-off vertically and lands horizontally. The abort maneuvers occur as the vehicle ascends to orbit and are initiated when the vehicle suffers an engine failure. The optimal control problems are numerically solved in discretized form via a nonlinear programming (NLP) algorithm. A description highlighting the attributes of this NLP method is provided. ATO maneuver results show that the vehicle is capable of ascending to orbit with a single engine failure at lift-off. Two engine out ATO maneuvers are not possible from the launch pad, but are possible after launch when the thrust to weight ratio becomes sufficiently large. Results show that single engine out RTLS maneuvers can be made for up to 180 seconds after lift-off and that there are scenarios for which RTLS maneuvers should be performed instead of ATP maneuvers.

  3. Predictive modeling of the virtual Hemi-Fontan operation for second stage single ventricle palliation: two patient-specific cases.

    PubMed

    Kung, Ethan; Baretta, Alessia; Baker, Catriona; Arbia, Gregory; Biglino, Giovanni; Corsini, Chiara; Schievano, Silvia; Vignon-Clementel, Irene E; Dubini, Gabriele; Pennati, Giancarlo; Taylor, Andrew; Dorfman, Adam; Hlavacek, Anthony M; Marsden, Alison L; Hsia, Tain-Yen; Migliavacca, Francesco

    2013-01-18

    Single ventricle hearts are congenital cardiovascular defects in which the heart has only one functional pumping chamber. The treatment for these conditions typically requires a three-staged operative process where Stage 1 is typically achieved by a shunt between the systemic and pulmonary arteries, and Stage 2 by connecting the superior venous return to the pulmonary circulation. Surgically, the Stage 2 circulation can be achieved through a procedure called the Hemi-Fontan, which reconstructs the right atrium and pulmonary artery to allow for an enlarged confluence with the superior vena cava. Based on pre-operative data obtained from two patients prior to Stage 2 surgery, we developed two patient-specific multi-scale computational models, each including the 3D geometrical model of the surgical junction constructed from magnetic resonance imaging, and a closed-loop systemic lumped-parameter network derived from clinical measurements. "Virtual" Hemi-Fontan surgery was performed on the 3D model with guidance from clinical surgeons, and a corresponding multi-scale simulation predicts the patient's post-operative hemodynamic and physiologic conditions. For each patient, a post-operative active scenario with an increase in the heart rate (HR) and a decrease in the pulmonary and systemic vascular resistance (PVR and SVR) was also performed. Results between the baseline and this "active" state were compared to evaluate the hemodynamic and physiologic implications of changing conditions. Simulation results revealed a characteristic swirling vortex in the Hemi-Fontan in both patients, with flow hugging the wall along the SVC to Hemi-Fontan confluence. One patient model had higher levels of swirling, recirculation, and flow stagnation. However, in both models, the power loss within the surgical junction was less than 13% of the total power loss in the pulmonary circulation, and less than 2% of the total ventricular power. This implies little impact of the surgical junction

  4. Coal liquefaction process

    DOEpatents

    Maa, Peter S.

    1978-01-01

    A process for liquefying a particulate coal feed to produce useful petroleum-like liquid products which comprises contacting; in a series of two or more coal liquefaction zones, or stages, graded with respect to temperature, an admixture of a polar compound; or compounds, a hydrogen donor solvent and particulate coal, the total effluent being passed in each instance from a low temperature zone, or stage to the next succeeding higher temperature zone, or stage, of the series. The temperature within the initial zone, or stage, of the series is maintained about 70.degree. F and 750.degree. F and the temperature within the final zone, or stage, is maintained between about 750.degree. F and 950.degree. F. The residence time within the first zone, or stage, ranges, generally, from about 20 to about 150 minutes and residence time within each of the remaining zones, or stages, of the series ranges, generally, from about 10 minutes to about 70 minutes. Further steps of the process include: separating the product from the liquefaction zone into fractions inclusive of a liquid solvent fraction; hydrotreating said liquid solvent fraction in a hydrogenation zone; and recycling the hydrogenated liquid solvent mixture to said coal liquefaction zones.

  5. Bacterial and methanogenic archaeal communities during the single-stage anaerobic digestion of high-strength food wastewater.

    PubMed

    Jang, Hyun Min; Kim, Ji Hyun; Ha, Jeong Hyub; Park, Jong Moon

    2014-08-01

    Single-stage anaerobic digestion (AD) was operated to treat high-strength food wastewater (FWW) derived from food waste recycling facilities at two different organic loading rates (OLRs) of 3.5 (Phase I) and 7 (Phase II) kgCOD/m(3)d. Changes in composition of microbial communities were investigated using quantitative real-time PCR (qPCR) and barcoded-pyrosequencing. At the high FWW loading rate, AD showed efficient performance (i.e., organic matter removal and methane production). Bacterial communities were represented by the phyla Bacteroidetes, Firmicutes, Synergistetes and Actinobacteria. During the entire digestion process, the relative abundance phylum Chloroflexi decreased significantly. The qPCR analysis demonstrated that the methanogenic communities shifted from aceticlastic (Methanosarcinales) to hydrogenotrophic methanogens (Methanobacteriales and Methanomicrobiales) with high increase in the proportion of syntrophic bacterial communities. Canonical correspondence analysis revealed a strong relationship between reactor performance and microbial community shifts.

  6. Effects of increased leading-edge thickness on performance of a transonic rotor blade. [in single stage transonic compressor

    NASA Technical Reports Server (NTRS)

    Reid, L.; Urasek, D. C.

    1972-01-01

    A single-stage transonic compressor was tested with two rotor blade leading-edge configurations to investigate the effect of increased leading-edge thickness on the performance of a transonic blade row. The original rotor blade configuration was modified by cutting back the leading edge sufficiently to double the blade leading-edge thickness and thus the blade gap blockage in the tip region. At design speed this modification resulted in a decrease in rotor overall peak efficiency of four points. The major portion of this decrement in rotor overall peak efficienty was attributed to the flow conditions in the outer 30 percent of the blade span. At 70 and 90 percent of design speed, the modification had very little effect on rotor overall performance.

  7. Monolithic in-based III-V compound semiconductor focal plane array cell with single stage CCD output

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R. (Inventor); Cunningham, Thomas J. (Inventor); Krabach, Timothy N. (Inventor); Staller, Craig O. (Inventor)

    1995-01-01

    A monolithic semiconductor imager includes an indium-based III-V compound semiconductor monolithic active layer of a first conductivity type, an array of plural focal plane cells on the active layer, each of the focal plane cells including a photogate over a top surface of the active layer, a readout circuit dedicated to the focal plane cell including plural transistors formed monolithically with the monolithic active layer and a single-stage charge coupled device formed monolithically with the active layer between the photogate and the readout circuit for transferring photo-generated charge accumulated beneath the photogate during an integration period to the readout circuit. The photogate includes thin epitaxial semiconductor layer of a second conductivity type overlying the active layer and an aperture electrode overlying a peripheral portion of the thin epitaxial semiconductor layer, the aperture electrode being connectable to a photogate bias voltage.

  8. Monolithic in-based III-V compound semiconductor focal plane array cell with single stage CCD output

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R. (Inventor); Cunningham, Thomas J. (Inventor); Krabach, Timothy N. (Inventor); Staller, Craig O. (Inventor)

    1994-01-01

    A monolithic semiconductor imager includes an indium-based III-V compound semiconductor monolithic active layer of a first conductivity type, an array of plural focal plane cells on the active layer, each of the focal plane cells including a photogate over a top surface of the active layer, a readout circuit dedicated to the focal plane cell including plural transistors formed monolithically with the monolithic active layer and a single-stage charge coupled device formed monolithically with the active layer between the photogate and the readout circuit for transferring photo-generated charge accumulated beneath the photogate during an integration period to the readout circuit. The photogate includes thin epitaxial semiconductor layer of a second conductivity type overlying the active layer and an aperture electrode overlying a peripheral portion of the thin epitaxial semiconductor layer, the aperture electrode being connectable to a photogate bias voltage.

  9. An Equation of State study of a Boron Nitride rubber composite using a Single Stage Gas Gun

    NASA Astrophysics Data System (ADS)

    Taylor, Peter; Keightley, Peter

    2007-06-01

    The equation of state of a Boron Nitride powder / Neoprene / Polythene composite has been determined experimentally up to 5GPa using a single stage Helium gas gun. The newly commissioned gun operates using a fast acting gas valve breech, and is capable of launching a 65mm diameter flyer at up to 1km/s. A series of 1D plate impact experiments has been employed using a shock reverberation or ring-up technique in which the sample is sandwiched between layers of a higher shock impedence material. Manganin stress gauges are used to measure the stress levels and shock arrival times as the shocks reverberate within the sample layer. The Hugoniot has been determined from the measured stress and shock velocity at several impact velocities for the first shock. Subsequent reflected shocks within the sample have been measured and used to determine off Hugoniot states and hence Gruniesen Gamma in order to derive the equation of state.

  10. Single-Stage Operation for Giant Schwannoma at the Craniocervical Junction with Minimal Laminectomy: A Case Report and Literature Review

    PubMed Central

    Yoon, Sun; Park, Hunho; Lee, Kyu-Sung; Park, Seoung Woo

    2016-01-01

    Here we report a single-stage operation we performed on a patient with a large schwannoma that extended from the lower clivus to the cervico-thoracic junction caudally. A number of authors have previously performed multilevel laminectomy to remove giant schwannomas that extend for considerable length. This technique has caused cervical instability such as kyphosis or gooseneck deformity on several occasions. We removed the tumor with a left lateral suboccipital craniectomy with laminectomy only at C1 and without any subsequent surgery-related neurologic deficits. However, this technique requires meticulous preoperative evaluation on existence of Cerebrospinal fluid (CSF) cleft between the tumor and spinal cord on magnetic resonance imaging, of tumor origin located at the upper cervical root, and of detachment of tumor from the origin site. PMID:27800002

  11. The MARVEL domain protein, Singles Bar, is required for progression past the pre-fusion complex stage of myoblast fusion

    PubMed Central

    Estrada, Beatriz; Maeland, Anne D.; Gisselbrecht, Stephen S.; Bloor, James W.; Brown, Nicholas H.; Michelson, Alan M.

    2007-01-01

    Summary Multinucleated myotubes develop by the sequential fusion of individual myoblasts. Using a convergence of genomic and classical genetic approaches, we have discovered a novel gene, singles bar (sing), that is essential for myoblast fusion. sing encodes a small multipass transmembrane protein containing a MARVEL domain, which is found in vertebrate proteins involved in processes such as tight junction formation and vesicle trafficking where—as in myoblast fusion—membrane apposition occurs. sing is expressed in both founder cells and fusion competent myoblasts preceding and during myoblast fusion. Examination of embryos injected with double-stranded sing RNA or embryos homozygous for ethane methyl sulfonate-induced sing alleles revealed an identical phenotype: replacement of multinucleated myofibers by groups of single, myosin-expressing myoblasts at a stage when formation of the mature muscle pattern is complete in wild-type embryos. Unfused sing mutant myoblasts form clusters, suggesting that early recognition and adhesion of these cells is unimpaired. To further investigate this phenotype, we undertook electron microscopic ultrastructural studies of fusing myoblasts in both sing and wild-type embryos. These experiments revealed that more sing mutant myoblasts than wild-type contain pre-fusion complexes, which are characterized by electron-dense vesicles paired on either side of the fusing plasma membranes. In contrast, embryos mutant for another muscle fusion gene, blown fuse (blow), have a normal number of such complexes. Together, these results lead to the hypothesis that sing acts at a step distinct from that of blow, and that sing is required on both founder cell and fusion-competent myoblast membranes to allow progression past the pre-fusion complex stage of myoblast fusion, possibly by mediating fusion of the electron-dense vesicles to the plasma membrane. PMID:17537424

  12. Pretreatment of coal during transport

    DOEpatents

    Johnson, Glenn E.; Neilson, Harry B.; Forney, Albert J.; Haynes, William P.

    1977-04-19

    Many available coals are "caking coals" which possess the undesirable characteristic of fusing into a solid mass when heated through their plastic temperature range (about 400.degree. C.) which temperature range is involved in many common treatment processes such as gasification, hydrogenation, carbonization and the like. Unless the caking properties are first destroyed, the coal cannot be satisfactorily used in such processes. A process is disclosed herein for decaking finely divided coal during its transport to the treating zone by propelling the coal entrained in an oyxgen-containing gas through a heated transport pipe whereby the separate transport and decaking steps of the prior art are combined into a single step.

  13. Advanced froth flotation techniques for fine coal cleaning

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1994-12-31

    Advanced column flotation cells offer many potential advantages for the treatment of fine coal. The most important of these is the ability to achieve high separation efficiencies using only a single stage of processing. Unfortunately, industrial flotation columns often suffer from poor recovery, low throughput and high maintenance requirements as compared to mechanically-agitated conventional cells. These problems can usually be attributed to poorly-designed air sparging systems. This article examines the problems of air sparging in greater detail and offers useful guidelines for designing bubble generators for industrial flotation columns. The application of these principles in the design of a successful advanced fine coal flotation circuit is also presented.

  14. Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 2: Data and performance for stage A

    NASA Technical Reports Server (NTRS)

    Brent, J. A.

    1972-01-01

    Stage A, comprised of a conventional rotor and stator, was designed and tested to establish a performance baseline for comparison with the results of subsequent tests planned for two tandem-blade stages. The rotor had an inlet hub/tip ratio of 0.8 and a design tip velocity of 757 ft/sec. At design equivalent rotor speed, rotor A achieved a maximum adiabatic efficiency of 85.1 percent at a pressure ratio of 1.29. The stage maximum adiabatic efficiency was 78.6 percent at a pressure ratio of 1.27.

  15. Coal Research

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Coal slurries are "clean" pulverized coal mixed with oil or water. Significant fuel savings can be realized when using coal slurries. Advanced Fuels Technology (AFT) utilized a COSMIC program, (Calculation of Complex Chemical Equilibrium Compositions), which provides specific capabilities for determining combustion products. The company has developed a cleaning process that removes much of the mineral sulphur and ash from the coals.

  16. Geochemistry of vanadium (V) in Chinese coals.

    PubMed

    Liu, Yuan; Liu, Guijian; Qu, Qinyuan; Qi, Cuicui; Sun, Ruoyu; Liu, Houqi

    2016-10-11

    Vanadium in coals may have potential environmental and economic impacts. However, comprehensive knowledge of the geochemistry of V in coals is lacking. In this study, abundances, distribution and modes of occurrence of V are reviewed by compiling >2900 reported Chinese coal samples. With coal reserves in individual provinces as the weighting factors, V in Chinese coals is estimated to have an average abundance of 35.81 μg/g. Large variation of V concentration is observed in Chinese coals of different regions, coal-forming periods, and maturation ranks. According to the concentration coefficient of V in coals from individual provinces, three regions are divided across Chinese coal deposits. Vanadium in Chinese coals is probably influenced by sediment source and sedimentary environment, supplemented by late-stage hydrothermal fluids. Specifically, hydrothermal fluids have relatively more significant effect on the enrichment of V in local coal seams. Vanadium in coals is commonly associated with aluminosilicate minerals and organic matter, and the modes of V occurrence in coal depend on coal-forming environment and coal rank. The Chinese V emission inventory during coal combustion is estimated to be 4906 mt in 2014, accounting for 50.55 % of global emission. Vanadium emissions by electric power plants are the largest contributor.

  17. Characterization and single-stage denitrification anaerobic digestion of spent stream from the hydrolysis-fermentation-combustion process

    NASA Astrophysics Data System (ADS)

    Singh, Ramnik

    The demand for ethanol as an oxygenate and octane booster in automobile fuel is growing. A number of processes are being investigated for conversion of biomass to ethanol. The Hydrolysis-Fermentation-Combustion (HFC) process for fuel ethanol production developed at the University of California Forest Products Laboratory, Richmond, California is at the stage of technology transfer following over two decades of research and development. This study addresses the technology to be used in treatment of spent streams to be discharged from this process. The treatment design combines a single stage denitrification and anaerobic digestion (SSDAD) for the biological treatment of a representative stream from this process. A typical spent stream contained a wide range of soluble organic materials including: unfermented sugars, components of the feedstocks solubilized in the hydrolysis, acid degradation products of carbohydrates, cleavage products of lignin, water-soluble extractives and phenolics, terpenes and other unfermented organic material, and nitrate ion from the nitric acid used as a catalyst in the hydrolysis reaction. Three sets of experiments were conducted in laboratory scale anaerobic digesters. Commonly available anaerobic sludge from local sewage treatment plants was used as a starter seed and was successfully acclimated to the high nitrate substrate leading to enrichment of denitrifiers. Necessary nutrients and trace elements were identified and supplied to satisfy the obligatory requirements of different groups of bacterial groups present. A major finding was the unique role of ammonium hydroxide in controlling pH leading to steady-state operation of the digester. At steady state operation the reduction in COD was 65%, the nitrate reduction was 88% and the nitrite reduction was 100%. Nitrate was reduced to safe nitrogen gas without buildup of any intermediate products. Organic material was converted to useful methane gas and carbon dioxide. The SSDAD system was

  18. Impact of stage and comorbidities on five-year survival after radical cystectomy in Poland: single centre experience

    PubMed Central

    Dybowski, Bartosz; Ossoliński, Krzysztof; Ossolińska, Anna; Peller, Michał; Radziszewski, Piotr

    2015-01-01

    Introduction Long-term outcomes of patients treated for invasive bladder cancer in Poland are poorly documented in the literature. Impact of various clinical parameters on their survival is even less well studied. Radical cystectomy is a major surgery, so the patients’ condition can be equally important as cancer stage. The aim of the study was to assess 5-year overall survival (OS) after cystectomy and impact of comorbidity on OS in a single Polish academic centre. Material and methods Clinical data of all patients who underwent cystectomy in years 2004-2006 for urothelial cancer were retrospectively reviewed. Survival status was determined at least 5 years after surgery. Pathological variables, comorbidities, surgery delay and complications were evaluated as potential predictors of OS. Kaplan-Meier estimates of the survival function as well as Cox proportional hazards models were utilized. Results Thirty-day, 1-year and 5-year OS for 63 patients was 98.4%, 58.7% and 31.7%, respectively. None of the investigated parameters were significantly related to five-year OS. However, a composite parameter consisting of stage, diabetes status and postoperative course was found as a significant predictor. Five-year OS in 16 patients with pT1-2 and without diabetes and without post-operative complications was higher than in the remaining 47 patients (56% vs. 23%; P = 0.02). Conclusions Five-year OS in our group was lower than in most published international series but concordant with a previous Polish report. Improvement in survival after radical cystectomy may be expected when early diagnosis will be accompanied by optimal care of patients with diabetes mellitus and avoidance of postoperative complications. PMID:26568866

  19. Application of noncatalytic gas-solid reactions for a single pellet of changing size to the modeling of fluidized-bed combustion of coal char containing sulfur

    SciTech Connect

    Rehmat, A.; Saxena, S.C.; Land, R.H.

    1980-09-01

    A mechanistic model is developed for coal char combustion, with sulfur retention by limestone or dolomite sorbent, in a gas fluidized bed employing noncatalytic single pellet gas-solid reactions. The shrinking core model is employed to describe the kinetics of chemical reactions taking place on a single pellet; changes in pellet size as the reaction proceeds are considered. The solids are assumed to be in back-mix condition whereas the gas flow is regarded to be in plug flow. Most char combustion occurs near the gas distributor plate (at the bottom of the bed), where the bubbles are small and consequently the mass transfer rate is high. For such a case, the analysis is considerably simplified by ignoring the bubble phase since it plays an insignificant role in the overall rate of carbon conversion. Bubble-free operation is also encounterd in the turbulent regime, where the gas flow is quite high and classical bubbles do not exist. Formulation of the model includes setting up heat and mass balance equations pertaining to a single particle (1) exposed to a varying reactant concentration along the height of the bed and (2) whose size changes during reaction. These equations are then solved numerically to account for particles of all sizes in the bed in obtaining the overall carbon conversion efficiency and resultant sulfur retention. In particular, the influence on sorbent requirement of several fluid-bed variables such as oxygen concentration profile, particle size, reaction rate for sulfation reaction, and suflur adsorption efficiency are examined.

  20. Comparison of complication rates of unilateral, staged bilateral, and single-session bilateral surgery for the treatment of bilateral medial patellar luxation in dogs.

    PubMed

    Fullagar, Bronwyn A; Rajala-Schultz, Päivi; Hettlich, Bianca F

    2017-01-01

    This retrospective study compared complication rates in 93 client-owned dogs (119 stifles) undergoing single-session bilateral, staged bilateral, or unilateral surgery for bilateral medial patellar luxation. Clinical characteristics and complication rates were compared and risk factors for major complications were explored. Sixty-five dogs had unilateral, 16 staged bilateral and 11 single-session bilateral surgery. Complications occurred in 28/119 stifles (24%), 11 (9%) of which required revision surgery. Patellar reluxation occurred in 7/119 (6%) stifles, with no revision required. There was no significant association between timing of surgery and incidence of complications. In dogs < 10 kg with bilateral medial patellar luxation, single-session bilateral surgery is a feasible treatment option with a complication rate comparable to staged bilateral or unilateral medial patellar luxation surgery.

  1. Parametric study of ascent performance of a vertically launched hydrogen-fueled single-stage reusable transport

    NASA Technical Reports Server (NTRS)

    Rehder, J. J.

    1977-01-01

    Ascent performance characteristics were studied for a vertical-take-off, horizontal-landing, single-stage-to-orbit transport vehicle powered by hydrogen fuel rocket with a mixture of fixed- and dual-position nozzles. The analysis was made by systematically varying two sets of trajectory similarity parameters based on the propulsive and aerodynamic characteristics of the vehicle and by calculating a trajectory for each combination of the parameters. The propulsion parameters were the initial thrust-weight ratio, engine combination, and the two expansion ratios of the dual-position rocket nozzles. The aerodynamic parameters were the ratio of reference area to initial weight and the ratio of maximum allowable normal force to initial weight. A first-order analysis was carried out to determine the effect on the performance of including the engine mass penalty. This analysis indicates that the configuration with the lowest initial mass for a given payload requires all dual-position nozzles with initial expansion ratio of 50 and a final expansion ratio of 150.

  2. The Inguinal Adipodermal Graft: a Single-Stage Technique for Cranial Linear Grove-like Defects Correction

    PubMed Central

    Vlajcic, Zlatko; Zic, Rado

    2016-01-01

    Introduction: In reconstruction of post-traumatic craniofacial defects Palacos R-40 is mostly used by neurosurgeons and by maxillofacial surgeons after tumor removal with consequently noticeable irregularities on the shape of the cranial region and face. We harvested customized adipodermal (AD) graft in low inguinal region and use it as an inlay autologous graft for surface irregularities correction with a 100% survival and without noticeable reduction of the graft volume. Material and Methods: Between 2009 and 2015, an adipodermal gaft was used in 5 cases of craniofacial post-traumatic defects, 3 of which were due to Palacos R-40 cranial reconstruction and 2 connected to maxillofacial tumor removal and post-traumatic reconstruction. Results: There were no complications and a satisfactory aesthetic result was achieved in all cases. Conclusion: The inguinal inlay autologous AD graft is, due to our best knowledge, an original single-stage procedure for those typical cranial grove-like defects correction. It gives a wide option of different shapes with relatively easy to proceed and predictable result. PMID:27594750

  3. Structural Sizing of a 25,000-lb Payload, Air-Breathing Launch Vehicle For Single-Stage-To-Orbit

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.; Kosareo, Daniel N.; Palac, Don (Technical Monitor)

    2000-01-01

    In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (5 to 10 years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

  4. The role of pH control on biohydrogen production by single stage hybrid dark- and photo-fermentation.

    PubMed

    Zagrodnik, R; Laniecki, M

    2015-10-01

    The role of pH control on biohydrogen production by co-culture of dark-fermentative Clostridium acetobutylicum and photofermentative Rhodobacter sphaeroides was studied. Single stage dark fermentation, photofermentation and hybrid co-culture systems were studied at different values of controlled and uncontrolled pH. Increasing pH during dark fermentation resulted in lower hydrogen production rate (HPR) and longer lag time for both controlled and uncontrolled conditions. However, it only slightly affected cumulative H2 volume. Results have shown that pH control at pH 7.5 increased photofermentative hydrogen production from 0.966 to 2.502 L H2/L(medium) when compared to uncontrolled process. Fixed pH value has proven to be an important control strategy also for the hybrid process and resulted in obtaining balanced co-culture of dark and photofermentative bacteria. Control of pH at 7.0 was found optimum for bacteria cooperation in the co-culture what resulted in obtaining 2.533 L H2/L(medium) and H2 yield of 6.22 mol H2/mol glucose.

  5. Old Crow tephra across eastern Beringia: a single cataclysmic eruption at the close of Marine Isotope Stage 6

    NASA Astrophysics Data System (ADS)

    Preece, S. J.; Pearce, N. J. G.; Westgate, J. A.; Froese, D. G.; Jensen, B. J. L.; Perkins, W. T.

    2011-08-01

    Old Crow tephra is the largest and most widespread Quaternary eruption presently known in eastern Beringia. Its major- and trace-element geochemistry, Fe-Ti oxides, and stratigraphic and paleoecological context indicate that it is the result of a single cataclysmic eruption. The proximal region may well have experienced tephra fallout from small eruptions just prior to or after the Old Crow event, but there is no evidence to indicate that the distal area was affected. We recalculate the glass fission-track age at 124 ± 10 ka, which, coupled with stratigraphic and paleoenvironmental reconstructions, indicates that deposition occurred prior to development of the last interglacial boreal forest, which suggests a latest Marine Isotope Stage (MIS) 6 age. The bulk tephra volume erupted is estimated by three different approaches, that are in broad agreement at ˜200 km 3, but this result must be considered as tentative given the poor controls on definition of isopachs over such a large area. The source caldera, although presently unrecognized, is located in the eastern Aleutian arc, possibly at or near the Emmons Lake volcanic center.

  6. Feasibility of a responsive, hybrid propulsion augmented, Vertical-Takeoff-and-Landing, Single-Stage-to-Orbit launch system

    NASA Astrophysics Data System (ADS)

    Pelaccio, Dennis G.

    1996-03-01

    A novel, reusable, Vertical-Takeoff-and-Landing, Single-Stage-to-Orbit (VTOL/SSTO) launch system concept, named HYP-SSTO, is presented in this paper. This launch vehicle system concept uses a highly coupled, main high performance liquid oxygen/liquid hydrogen (LOX/LH2) propulsion system, that is used only for launch, with a hybrid auxiliary propulsion system which is used during final orbit insertion, major orbit maneuvering, and landing propulsive burn phases of flight. By using a hybrid propulsion system for major orbit maneuver burns and landing, this launch system concept has many advantages over conventional VTOL/SSTO concepts that use LOX/LH2 propulsion system(s) burns for all phases of flight. Because hybrid propulsion systems are relatively simple and inert by their nature, this concept has the potential to support short turnaround times between launches, be economical to develop, and be competitive in terms of overall system life-cycle cost. This paper provides a technical description of the novel, reusable HYP-SSTO launch system concept. Launch capability performance, as well as major design and operational system attributes, are identified and discussed.

  7. Engineering characterisation of a shaken, single-use photobioreactor for early stage microalgae cultivation using Chlorella sorokiniana.

    PubMed

    Ojo, E O; Auta, H; Baganz, F; Lye, G J

    2014-12-01

    This work describes the characterisation and culture performance of a novel, orbitally shaken, single-use photobioreactor (SUPBr) system for microalgae cultivation. The SUPBr mounted on an orbitally shaken platform was illuminated from below. Investigation of fluid hydrodynamics indicated a range of different flow regimes and the existence of 'in-phase' and 'out-of-phase' conditions. Quantification of the fluid mixing time (tm) indicated a decrease in tm values with increasing shaking frequency up to 90 rpm and then approximately constant tm values in the range 15-40 s. For batch cultivation of Chlorella sorokiniana, the highest biomass concentration achieved was 6.6 g L(-1) at light intensity of 180 μmol m2 s(-1). Doubling the total working volume resulted in 35-40% reduction in biomass yield while shaking frequency had little influence on culture kinetics and fatty methyl esters composition. Overall this work demonstrates the utility of the SUPBr for early stage development of algal cultivation processes.

  8. Computational Study of a McDonnell Douglas Single-Stage-to-Orbit Vehicle Concept for Aerodynamic Analysis

    NASA Technical Reports Server (NTRS)

    Prabhu, Ramadas K.

    1996-01-01

    This paper presents the results of a computational flow analysis of the McDonnell Douglas single-stage-to-orbit vehicle concept designated as the 24U. This study was made to determine the aerodynamic characteristics of the vehicle with and without body flaps over an angle of attack range of 20-40 deg. Computations were made at a flight Mach number of 20 at 200,000 ft. altitude with equilibrium air, and a Mach number of 6 with CF4 gas. The software package FELISA (Finite Element Langley imperial College Sawansea Ames) was used for all the computations. The FELISA software consists of unstructured surface and volume grid generators, and inviscid flow solvers with (1) perfect gas option for subsonic, transonic, and low supersonic speeds, and (2) perfect gas, equilibrium air, and CF4 options for hypersonic speeds. The hypersonic flow solvers with equilibrium air and CF4 options were used in the present studies. Results are compared with other computational results and hypersonic CF4 tunnel test data.

  9. Structural refinement of 00Cr13Ni5Mo2 supermartensitic stainless steel during single-stage intercritical tempering

    NASA Astrophysics Data System (ADS)

    Xu, Da-kun; Liu, Yong-chang; Ma, Zong-qing; Li, Hui-jun; Yan, Ze-sheng

    2014-03-01

    The 00Cr13Ni5Mo2 supermartensitic stainless steel was first tempered at 570-730°C for 2 h to observe the microstructure and hardness changes. The tempering temperature was set to 600, 650, and 700°C, which is below, equal to, and above the austenite transformation start temperature, respectively, for each holding period to investigate the effects of tempering time on the structure and properties of the steel. The microstructure of the specimens was examined by optical microscopy and transmission electronic microscopy, and the phase composition was detected by X-ray diffraction. As expected, lath refinement was observed in the steel tempered at 700°C, and the refinement degree significantly depended on the tempering time. Contrary to normal steel softening by tempering, the hardness performance of the steel was significantly enhanced primarily because of the refinement of martensite laths after single-stage intercritical tempering. It is believed that the reverse transformation of martensite (α') to austenite (γ) is responsible for the refinement.

  10. Heat transfer and oil flow studies on a single-stage-to-orbit control-configured winged entry vehicle

    NASA Technical Reports Server (NTRS)

    Helms, V. T., III; Bradley, P. F.

    1984-01-01

    Results are presented for oil flow and phase change paint heat transfer tests conducted on a 0.006 scale model of a proposed single stage to orbit control configured vehicle. The data were taken at angles of attack up to 40 deg at a free stream Mach number of 10 for Reynolds numbers based on model length of 0.5 x 10 to the 6th power, 1.0 x 10 to the 6th power and 2.0 x 10 to the 6th power. The magnitude and distribution of heating are characterized in terms of angle of attack and Reynolds number aided by an analysis of the flow data which are used to suggest the presence of various three dimensional flow structures that produce the observed heating patterns. Of particular interest are streak heating patterns that result in high localized heat transfer rates on the wing windward surface at low to moderate angles of attack. These streaks are caused by the bow-shock/wing-shock interaction and formation of the wing-shock. Embedded vorticity was found to be associated with these interactions.

  11. Dynamic Behavior of Single-Stage Bellows of Titanium-Nickel Shape Memory Alloy Under Cyclic Loading

    NASA Astrophysics Data System (ADS)

    Semba, Hiromasa; Okabe, Nagatoshi; Yamaji, Toru; Okita, Keisuke; Yamauchi, Kiyoshi

    The dynamic behavior of TiNi shape memory alloy (SMA) bellows is examined in light of its potential use as elements in seismic protection devices. Dynamic property results obtained from cyclic tests under tension-compression loading of TiNi SMA single-stage bellows, with different shapes and with different heat treatments, are reported as a function of displacement amplitude and frequency. It was found that the displacement-force loops were almost symmetric with respect to the central point for almost all specimens. The normalized secant stiffness diminishes significantly with increasing bulge height as well as displacement amplitude. From hysteretic cycles, an equivalent damping of about 15% was recognized for longtime-aged bellows with relatively high bulge height. Frequencies, in the range of interest for seismic applications, had a small influence on damping values. Under the conditions studied in this research, the bellows had better damping performance in a martensite phase than in a rhombohedral phase. SMA bellows in martensite phase subjected to the longtime-ageing have great potential as an element in seismic devices.

  12. Structural Sizing of a 25,000-lb Payload, Air-breathing Launch Vehicle for Single-stage-to-orbit

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.; Kosareo, Daniel N.

    2001-01-01

    In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (five to ten years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

  13. Flow Field in a Single-Stage Model Air Turbine With Seal Rings and Pre-Swirled Purge Flow

    NASA Astrophysics Data System (ADS)

    Dunn, Dennis M.

    Modern gas turbines operate at high mainstream gas temperatures and pressures, which requires high durability materials. A method of preventing these hot gases from leaking into the turbine cavities is essential for improved reliability and cost reduction. Utilizing bleed-off air from the compressor to cool internal components has been a common solution, but at the cost of decreasing turbine performance. The present work thoroughly describes the complex flow field between the mainstream gas and a single rotor-stator disk cavity, and mechanisms of mainstream gas ingestion. A combined approach of experimental measurement and numerical simulation are performed on the flow in a single-stage model gas turbine. Mainstream gas ingestion into the cavity is further reduced by utilizing two axially overlapping seal rings, one on the rotor disk and the other on the stator wall. Secondary purge air is injected into the rotor-stator cavity pre-swirled through the stator radially inboard of the two seal rings. Flow field predictions from the simulations are compared against experimental measurements of static pressure, velocity, and tracer gas concentration acquired in a nearly identical model configuration. Operational conditions were performed with a main airflow Reynolds number of 7.86e4 and a rotor disk speed of 3000rpm. Additionally the rotational Reynolds number was 8.74 e5 with a purge air nondimensional flow rate cw=4806. The simulation models a 1/14 rotationally periodic sector of the turbine rig, consisting of four rotor blades and four stator vanes. Gambit was used to generate the three-dimensional unstructured grids ranging from 10 to 20 million cells. Effects of turbulence were modeled using the single-equation Spalart-Allmaras as well as the realizable k-epsilon models. Computations were performed using FLUENT for both a simplified steady-state and subsequent time-dependent formulation. Simulation results show larger scale structures across the entire sector angle

  14. Assessment of Advanced Coal Gasification Processes

    NASA Technical Reports Server (NTRS)

    McCarthy, John; Ferrall, Joseph; Charng, Thomas; Houseman, John

    1981-01-01

    This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process; Bell Single-Stage High Mass Flux (HMF) Process; Cities Service/Rockwell (CS/R) Hydrogasification Process; Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier. The report makes the following assessments: 1) while each process has significant potential as coal gasifiers, the CS/R and Exxon processes are better suited for SNG production; 2) the Exxon process is the closest to a commercial level for near-term SNG production; and 3) the SRT processes require significant development including scale-up and turndown demonstration, char processing and/or utilization demonstration, and reactor control and safety features development.

  15. Removal of sulfur and chlorine from Illinois coals by wet-grinding and selective flocculation

    SciTech Connect

    Chou, C.L.

    1999-07-01

    A coal-cleaning method for removing sulfur and chlorine from Illinois Basin coals was developed. The method includes four steps: (1) crushing raw coal to {minus}10 mesh, (2) using a concentrating table to remove pyrite and other minerals, (3) wet-grinding coal to an ultrafine particle size to liberate coal from pyrite and other minerals, and (4) conducting selective flocculation to separate coal from mineral particles and chlorine-containing water. A sample of Illinois Basin coal IBC-106 (9.0% ash and 3.77% sulfur) was ground to {minus}10 mesh and separated into five fractions on a concentrating table. The pyritic sulfur content decreased from 1.85% in feed coal to 1.49%, 0.85%, and 0.82% in clean, fine, and overflow fractions, respectively. Wet-grinding and selective flocculation tests were conducted on another sample of Illinois Basin coal IBC-105 (18.6% ash and 4.55% sulfur). The coal was ground in a stirred ball mill to generate a coal slurry with a particle size distribution of 90% <19 micrometer. The slurry was dispersed to make a complete suspension. Sodium metaphosphate was added as a dispersant. Various polymeric flocculants were tested to determine the selective flocculation performance of each. The acidity of the slurry (pH) and the flocculant dosage are critical in selective flocculation tests. When flocculant Calgon WCL-762 was used, the ash content decreased from 18.6% to 8.1% (56% reduction) in a single-stage flocculation process, and to 5.7% (69% reduction) in a two-stage process. Chlorine removal from coal was investigated on a high-chlorine coal sample IBC-109 (8.2% ash, 1.13% sulfur, and 0.42% chlorine). Wet-grinding the coal to 90% <20 micrometer, and subsequently dewatering the slurry by selective flocculation reduced the chlorine content from 0.42% to between 0.11% and 0.15% (64% to 74% reduction). In addition, ash content was reduced from 8.2% to between 4.0% and 5.4% (34% to 51% reduction) and pyritic sulfur content from 0.50% to between 0

  16. Advanced physical coal cleaning to comply with potential air toxic regulations. Quarterly report, 1 March 1995--31 May 1995

    SciTech Connect

    Honaker, R.Q.; Paul, B.C.; Mohanty, M.K.; Wang, D.

    1995-12-31

    Studies have indicated that the potentially hazardous trace elements found in coal have a strong affinity for coal pyrite. Thus, by maximizing the rejection of pyrite, one can minimize the trace element content of a given coal while also reducing sulfur emissions. The pyrite in most Illinois Basin coals, however, is finely disseminated within the coal matrix. Therefore, to remove the pyrite using physical coal cleaning techniques, the pyrite must be liberated by grinding the coal to ultrafine particle sizes. Fortunately, the coals being fed to pulverized coal boilers (PCB) are already ground to a very fine size, i.e., 70% passing 200 mesh. Therefore, this research project will investigate the use of advanced fine coal cleaning technologies for cleaning PCB feed as a compliance strategy. Work in this quarter has focused on the processing of a run-of-mine coal sample collected from Amax Coal Company`s Delta Coal mine using column flotation and an enhanced gravity separator as separate units and in circuitry arrangements. The {minus}60 mesh run-of-mine sample having an ash content of about 22% was cleaned to 6% while achieving a very high energy recovery of about 87% and a sulfur rejection value of 53% in a single stage column flotation operation. Enhanced gravity treatment is believed to be providing excellent total sulfur rejection values, although with inferior ash rejection for the {minus}400 mesh size fraction. The circuitry arrangement with the Falcon concentrator as the primary cleaner followed by the Packed-Column resulted in an excellent ash rejection performance, which out performed the release analysis. Trace element analyses of the samples collected from these tests will be conducted during the next report period.

  17. Coal pump

    DOEpatents

    Bonin, John H.; Meyer, John W.; Daniel, Jr., Arnold D.

    1983-01-01

    A device for pressurizing pulverized coal and circulating a carrier gas is disclosed. This device has utility in a coal gasification process and eliminates the need for a separate collection hopper and eliminates the separate compressor.

  18. Coal desulfurization

    NASA Technical Reports Server (NTRS)

    Corcoran, William H. (Inventor); Vasilakos, Nicholas P. (Inventor); Lawson, Daniel D. (Inventor)

    1982-01-01

    A method for enhancing solubilizing mass transport of reactive agents into and out of carbonaceous materials, such as coal. Solubility parameters of mass transfer and solvent media are matched to individual peaks in the solubility parameter spectrum of coals to enhance swelling and/or dissolution. Methanol containing reactive agent carriers are found particularly effective for removing organic sulfur from coals by chlorinolysis.

  19. Fixed-bed gasification research using US coals. Volume 17. Gasification and liquids recovery of four US coals

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-12-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and government agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) group. This report is the seventeenth in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This report describes the gasification and pyrolysis liquids recovery test for four different coals: Illinois No. 6, SUFCO, Indianhead lignite, and Hiawatha. This test series spanned from July 15, 1985, through July 28, 1985. 4 refs., 16 figs., 19 tabs.

  20. Fixed-bed gasification research using US coals. Volume 8. Gasification of River King Illinois No. 6 bituminous coal

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the eighth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of River King Illinois No. 6 bituminous coal. The period of gasification test was July 28 to August 19, 1983. 6 refs., 23 figs., 25 tabs.

  1. Fixed-bed gasification research using US coals. Volume 12. Gasification of Absaloka/Robinson subbituminous coal

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial particpants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the twelfth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. this specific reports describes the gasification of Absaloka/Robinson subbituminous coal. This volume covers the test period June 18, 1984 to June 30, 1984. 4 refs., 20 figs., 18 tabs.

  2. Coal liquefaction process with enhanced process solvent

    DOEpatents

    Givens, Edwin N.; Kang, Dohee

    1984-01-01

    In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

  3. Study of SSIN (single-stage interconnection networks) parallel-processing interconnection networks. Final report, 1 October 1987-30 September 1988

    SciTech Connect

    Agrawal, D.P.

    1988-10-31

    The increase in dynamic average path length (DAPL) with network size is moderate while it is significantly less than log(2)N, the number of stages needed in a MIN. The best performance in the case of no fault and single fault, is obtained for the modified Omega and the Zeta SSINs.

  4. A review of findings of a study of rocket based combined cycle engines applied to extensively axisymmetric single stage to orbit vehicles

    NASA Technical Reports Server (NTRS)

    Foster, Richard W.

    1992-01-01

    Extensively axisymmetric and non-axisymmetric Single Stage To Orbit (SSTO) vehicles are considered. The information is presented in viewgraph form and the following topics are presented: payload comparisons; payload as a percent of dry weight - a system hardware cost indicator; life cycle cost estimations; operations and support costs estimation; selected engine type; and rocket engine specific impulse calculation.

  5. Single Cell Proteomics Using Frog (Xenopus laevis) Blastomeres Isolated from Early Stage Embryos, Which Form a Geometric Progression in Protein Content.

    PubMed

    Sun, Liangliang; Dubiak, Kyle M; Peuchen, Elizabeth H; Zhang, Zhenbin; Zhu, Guijie; Huber, Paul W; Dovichi, Norman J

    2016-07-05

    Single cell analysis is required to understand cellular heterogeneity in biological systems. We propose that single cells (blastomeres) isolated from early stage invertebrate, amphibian, or fish embryos are ideal model systems for the development of technologies for single cell analysis. For these embryos, although cell cleavage is not exactly symmetric, the content per blastomere decreases roughly by half with each cell division, creating a geometric progression in cellular content. This progression forms a ladder of single-cell targets for the development of successively higher sensitivity instruments. In this manuscript, we performed bottom-up proteomics on single blastomeres isolated by microdissection from 2-, 4-, 8-, 16-, 32-, and 50-cell Xenopus laevis (African clawed frog) embryos. Over 1 400 protein groups were identified in single-run reversed-phase liquid chromatography-electrospray ionization-tandem mass spectrometry from single balstomeres isolated from a 16-cell embryo. When the mass of yolk-free proteins in single blastomeres decreased from ∼0.8 μg (16-cell embryo) to ∼0.2 μg (50-cell embryo), the number of protein group identifications declined from 1 466 to 644. Around 800 protein groups were quantified across four blastomeres isolated from a 16-cell embryo. By comparing the protein expression among different blastomeres, we observed that the blastomere-to-blastomere heterogeneity in 8-, 16-, 32-, and 50-cell embryos increases with development stage, presumably due to cellular differentiation. These results suggest that comprehensive quantitative proteomics on single blastomeres isolated from these early stage embryos can provide valuable insights into cellular differentiation and organ development.

  6. Carbon dioxide from coal combustion: Variation with rank of US coal

    USGS Publications Warehouse

    Quick, J.C.; Glick, D.C.

    2000-01-01

    Carbon dioxide from combustion of US coal systematically varies with ASTM rank indices, allowing the amount of CO2 produced per net unit of energy to be predicted for individual coals. No single predictive equation is applicable to all coals. Accordingly, we provide one equation for coals above high volatile bituminous rank and another for lower rank coals. When applied to public data for commercial coals from western US mines these equations show a 15% variation of kg CO2 (net GJ)-1. This range of variation suggests reduction of US CO2 emissions is possible by prudent selection of coal for combustion. Maceral and mineral content are shown to slightly affect CO2 emissions from US coal. We also suggest that CO2 emissions increased between 6 and 8% in instances where Midwestern US power plants stopped burning local, high-sulfur bituminous coal and started burning low-sulfur, subbituminous C rank coal from the western US.

  7. Coal combustion system

    DOEpatents

    Wilkes, Colin; Mongia, Hukam C.; Tramm, Peter C.

    1988-01-01

    In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature. The motive fluid is cooled in a dilution stage to an acceptable turbine inlet temperature before being transported to the turbine.

  8. Geomorphology of coal seam fires

    NASA Astrophysics Data System (ADS)

    Kuenzer, Claudia; Stracher, Glenn B.

    2012-02-01

    Coal fires occur in underground natural coal seams, in exposed surface seams, and in coal storage or waste piles. The fires ignite through spontaneous combustion or natural or anthropogenic causes. They are reported from China, India, USA, South Africa, Australia, and Russia, as well as many other countries. Coal fires lead to loss of a valuable resource (coal), the emission of greenhouse-relevant and toxic gases, and vegetation deterioration. A dangerous aspect of the fires is the threat to local mines, industries, and settlements through the volume loss underground. Surface collapse in coal fire areas is common. Thus, coal fires are significantly affecting the evolution of the landscape. Based on more than a decade of experience with in situ mapping of coal fire areas worldwide, a general classification system for coal fires is presented. Furthermore, coal seam fire geomorphology is explained in detail. The major landforms associated with, and induced by, these fires are presented. The landforms include manifestations resulting from bedrock surface fracturing, such as fissures, cracks, funnels, vents, and sponges. Further manifestations resulting from surface bedrock subsidence include sinkholes, trenches, depressions, partial surface subsidence, large surface subsidence, and slides. Additional geomorphologic coal fire manifestations include exposed ash layers, pyrometamorphic rocks, and fumarolic minerals. The origin, evolution, and possible future development of these features are explained, and examples from in situ surveys, as well as from high-resolution satellite data analyses, are presented. The geomorphology of coal fires has not been presented in a systematic manner. Knowledge of coal fire geomorphology enables the detection of underground coal fires based on distinct surface manifestations. Furthermore, it allows judgments about the safety of coal fire-affected terrain. Additionally, geomorphologic features are indicators of the burning stage of fires

  9. Single-stage evaluation of highly-loaded high-Mach-number compressor stages 5. Data and performance of baseline, corner-blow wall suction and combined corner blow wall suction stator

    NASA Technical Reports Server (NTRS)

    Nikkanen, J. P.; Brooky, J. P.

    1972-01-01

    A single-stage compressor with a rotor tip speed of 1600 ft/sec and a 0.5 hub tip ratio was used to investigate the effects of several stator endwall treatment methods on stage range and performance. These endwall treatment methods consisted of stator corner-blow, annular wall suction upstream of stator leading edge, and combined corner-blow and annular wall suction. The overall stage performance with corner blow was essentially the same as the baseline performance. The performance for the annular wall suction and the combined corner-blow and wall suction showed a reduction in peak efficiency of 2.5 percentage points compared to the baseline data.

  10. Staged single-tract minimally invasive percutaneous nephrolithotomy and flexible ureteroscopy in the treatment of staghorn stone in patients with solitary kidney.

    PubMed

    Xu, Guibin; Li, Xun; He, Yongzhong; He, Zhaohui

    2012-12-01

    The aim of this study was to evaluate the outcome of staged single-tract minimally invasive percutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy as a minimally invasive option in the treatment of staghorn stone in patients with a solitary kidney. A total of 24 patients with staghorn stone in a solitary kidney were treated with single-tract MPCNL and flexible ureteroscopy by a single surgeon. All the patients underwent single-tract MPCNL through a 20 F tract and had most of the intrarenal calculi removed at the first stage. The second stage of retrograde flexible ureteroscopy was performed 3-5 days later, after the drainage was cleared. The preoperative patient, characteristics, stone size, operative time, renal functional status and postoperative outcomes were then evaluated. Sixteen patients were partial staghorn (66.7 %), and other eight were complete staghorn (33.3 %). The overall stone-free rate was 83.3 % after the second-stage procedures, and only four patients had significant residue. The hemoglobin drop ranged from 1.1 to 3.7 g/dl, and three patients required blood transfusion. The mean serum creatinine value was 1.7 ± 0.5 mg/dl before surgery and 1.3 ± 0.4 mg/dl at the end of the follow-up period with statistical significance (P < 0.05). None of the patients had increased serum creatinine, and needed dialysis at the end of the follow-up period. Staged single-tract MPCNL and flexible ureteroscopy are safe and effective for the management of staghorn stone in patients with a solitary kidney and even in patients with impaired renal functions.

  11. Pulmonary retention of coal dusts

    SciTech Connect

    Morrow, P.E.; Gibb, F.R.; Beiter, H.; Amato, F.; Yuile, C.; Kilpper, R.W.

    1980-01-01

    The principal objectives of this study were: to determine, quantitatively, coal dust retention times in the dog lung; to test the appropriateness of a pulmonary retention model which incorporates first order rate coefficients obtained from in vitro and in vivo experiments on neutron-activated coal; to acquire a temporal description of the pulmonary disposition of the retained coal dust, and to compare the behavior of two different Pennsylvania coals in the foregoing regards. The principal findings include: retention half-times for both coals of approximately 2 years following single, hour-long exposures; a vivid association of the retained coal dust with the pulmonic lymphatics; and a general validation of the retention model.

  12. An evaluation of fine coal flotation at the Chaili Coal Washery

    SciTech Connect

    Zhang, R.Z.; Jiang, S.X.; Yu, Z.D.; Phillips, D.I.; Gebhardt, J.E.

    1995-12-31

    The potential application of flotation for the treatment and processing of a fine-particle coal stream was investigated for the Chaili Coal Washery of the Zaozhuang Coal Mine Administration, Shandong Province, China. A goal of the test work was to evaluate the application of the Microcel{trademark} flotation column and compare its performance to conventional flotation. Small-scale flotation tests were performed in the laboratory and on-site with fine coal slurry samples from the plant thickener underflow, i.e., the washing plant`s undersized reject material. Flotation tests were conducted on-site with a 7.6-cm diameter Microcel{trademark} column and with small-scale conventional cells. Column flotation tests were performed to determine a recovery-grade relationship for the fine coal feed, which contained about 24% ash, and to obtain sufficient data to enable scale-up to a large-diameter unit. A primary objective was to establish the maximum throughput capacity of a Microcel flotation column while operating to produce a clean coal product with ash content of 7.5--7.8%. Results of the test work indicate that this product quality could be achieved at feed rates of 15--19 tph to a 3-m diameter Microcel flotation column. Lower ash products, i.e. 5--7% ash, were obtained but at lower column throughput capacities. Comparative flotation tests, conducted with conventional flotation cells, indicated that a product ash of only 8% or greater was achieved in a single-stage test.

  13. Fixed-bed gasification research using US coals. Volume 19. Executive summary

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Liu, B.Y.H.; Pui, D.; Kittelson, D.

    1985-12-01

    A single-staged, fixed-bed, Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort under the Mining and Industrial Fuel Gas Group (MIFGA). This report is the nineteenth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This volume briefly summarizes the results of eighteen different gasification tests in which fourteen different fuels were gasified from May 1982 to August 1985. The design gasification performance of all coals evaluated are summarized. In addition, summary design and economic data for industrial coal gasification systems are presented. 28 refs., 2 figs., 22 tabs.

  14. 3-Port Single-Stage PV & Battery Converter Improves Efficiency and Cost in Combined PV/Battery Systems

    SciTech Connect

    Bundschuh, Paul

    2013-03-23

    industry’s first single-stage multi-port hybrid power converter. This unique low cost approach eliminates the hybrid power conversion bottlenecks when integrating batteries into PV systems. As result this product will significantly accelerate market adoption of these systems.

  15. Preliminary Sizing Completed for Single- Stage-To-Orbit Launch Vehicles Powered By Rocket-Based Combined Cycle Technology

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.

    2002-01-01

    Single-stage-to-orbit (SSTO) propulsion remains an elusive goal for launch vehicles. The physics of the problem is leading developers to a search for higher propulsion performance than is available with all-rocket power. Rocket-based combined cycle (RBCC) technology provides additional propulsion performance that may enable SSTO flight. Structural efficiency is also a major driving force in enabling SSTO flight. Increases in performance with RBCC propulsion are offset with the added size of the propulsion system. Geometrical considerations must be exploited to minimize the weight. Integration of the propulsion system with the vehicle must be carefully planned such that aeroperformance is not degraded and the air-breathing performance is enhanced. Consequently, the vehicle's structural architecture becomes one with the propulsion system architecture. Geometrical considerations applied to the integrated vehicle lead to low drag and high structural and volumetric efficiency. Sizing of the SSTO launch vehicle (GTX) is itself an elusive task. The weight of the vehicle depends strongly on the propellant required to meet the mission requirements. Changes in propellant requirements result in changes in the size of the vehicle, which in turn, affect the weight of the vehicle and change the propellant requirements. An iterative approach is necessary to size the vehicle to meet the flight requirements. GTX Sizer was developed to do exactly this. The governing geometry was built into a spreadsheet model along with scaling relationships. The scaling laws attempt to maintain structural integrity as the vehicle size is changed. Key aerodynamic relationships are maintained as the vehicle size is changed. The closed weight and center of gravity are displayed graphically on a plot of the synthesized vehicle. In addition, comprehensive tabular data of the subsystem weights and centers of gravity are generated. The model has been verified for accuracy with finite element analysis. The

  16. Rapid near-optimal trajectory generation and guidance law development for single-stage-to-orbit airbreathing vehicles

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Flandro, G. A.; Corban, J. E.

    1990-01-01

    General problems associated with on-board trajectory optimization, propulsion system cycle selection, and with the synthesis of guidance laws were addressed for an ascent to low-earth-orbit of an air-breathing single-stage-to-orbit vehicle. The NASA Generic Hypersonic Aerodynamic Model Example and the Langley Accelerator aerodynamic sets were acquired and implemented. Work related to the development of purely analytic aerodynamic models was also performed at a low level. A generic model of a multi-mode propulsion system was developed that includes turbojet, ramjet, scramjet, and rocket engine cycles. Provisions were made in the dynamic model for a component of thrust normal to the flight path. Computational results, which characterize the nonlinear sensitivity of scramjet performance to changes in vehicle angle of attack, were obtained and incorporated into the engine model. Additional trajectory constraints were introduced: maximum dynamic pressure; maximum aerodynamic heating rate per unit area; angle of attack and lift limits; and limits on acceleration both along and normal to the flight path. The remainder of the effort focused on required modifications to a previously derived algorithm when the model complexity cited above was added. In particular, analytic switching conditions were derived which, under appropriate assumptions, govern optimal transition from one propulsion mode to another for two cases: the case in which engine cycle operations can overlap, and the case in which engine cycle operations are mutually exclusive. The resulting guidance algorithm was implemented in software and exercised extensively. It was found that the approximations associated with the assumed time scale separation employed in this work are reasonable except over the Mach range from roughly 5 to 8. This phenomenon is due to the very large thrust capability of scramjets in this Mach regime when sized to meet the requirement for ascent to orbit. By accounting for flight path

  17. Chaotic Extension Neural Network Theory-Based XXY Stage Collision Fault Detection Using a Single Accelerometer Sensor

    PubMed Central

    Hsieh, Chin-Tsung; Yau, Her-Terng; Wu, Shang-Yi; Lin, Huo-Cheng

    2014-01-01

    The collision fault detection of a XXY stage is proposed for the first time in this paper. The stage characteristic signals are extracted and imported into the master and slave chaos error systems by signal filtering from the vibratory magnitude of the stage. The trajectory diagram is made from the chaos synchronization dynamic error signals E1 and E2. The distance between characteristic positive and negative centers of gravity, as well as the maximum and minimum distances of trajectory diagram, are captured as the characteristics of fault recognition by observing the variation in various signal trajectory diagrams. The matter-element model of normal status and collision status is built by an extension neural network. The correlation grade of various fault statuses of the XXY stage was calculated for diagnosis. The dSPACE is used for real-time analysis of stage fault status with an accelerometer sensor. Three stage fault statuses are detected in this study, including normal status, Y collision fault and X collision fault. It is shown that the scheme can have at least 75% diagnosis rate for collision faults of the XXY stage. As a result, the fault diagnosis system can be implemented using just one sensor, and consequently the hardware cost is significantly reduced. PMID:25405512

  18. Chaotic extension neural network theory-based XXY stage collision fault detection using a single accelerometer sensor.

    PubMed

    Hsieh, Chin-Tsung; Yau, Her-Terng; Wu, Shang-Yi; Lin, Huo-Cheng

    2014-11-14

    The collision fault detection of a XXY stage is proposed for the first time in this paper. The stage characteristic signals are extracted and imported into the master and slave chaos error systems by signal filtering from the vibratory magnitude of the stage. The trajectory diagram is made from the chaos synchronization dynamic error signals E1 and E2. The distance between characteristic positive and negative centers of gravity, as well as the maximum and minimum distances of trajectory diagram, are captured as the characteristics of fault recognition by observing the variation in various signal trajectory diagrams. The matter-element model of normal status and collision status is built by an extension neural network. The correlation grade of various fault statuses of the XXY stage was calculated for diagnosis. The dSPACE is used for real-time analysis of stage fault status with an accelerometer sensor. Three stage fault statuses are detected in this study, including normal status, Y collision fault and X collision fault. It is shown that the scheme can have at least 75% diagnosis rate for collision faults of the XXY stage. As a result, the fault diagnosis system can be implemented using just one sensor, and consequently the hardware cost is significantly reduced.

  19. Factors affecting gas content in coal beds

    SciTech Connect

    Scott, A.R.; Kaiser, W.R.

    1996-06-01

    Gas content is one of the most important controls on coalbed methane producibility because coal gas production becomes uneconomical if insufficient amounts of gas are sorbed onto the coal surface. Gas content in coal beds is not fixed but changes when equilibrium conditions within the reservoir are disrupted. Therefore, the distribution of gas content varies laterally within individual coal beds, vertically among coals within a single well, and vertically within thicker coal beds. The key hydrogeologic factors affecting gas content variability include gas generation, coal properties, and reservoir conditions. The potential for high gas content depends on thermogenic and secondary biogenic gas generation, which are controlled by burial history (coal rank), maceral composition, and basin hydrodynamics. Coal properties such as ash and moisture content, maceral type, permeability, and diffusion coefficient affect the sorption capacity and diffusion rates in coal beds and, therefore, the final gas content. Reservoir conditions such as pressure and temperature also affect the amount of gases sorbed to the coal surface, whereas coal geometry, hydrogeology, and the presence or absence of permeability barriers determine whether or not gas contents are increased or decreased. Stratigraphic and/or structural trapping concentrates coal gases, resulting in higher gas contents adjacent to permeability barriers; the presence of abnormally high gas contents in lower-rank coals indicates secondary biogenic gas generation and/or conventional trapping of thermogenic or biogenic gases. Gas content decreases in areas of active recharge caused by flushing or in areas of convergent flow where no trapping mechanisms (seals) are present.

  20. Pyrolysis of coal

    DOEpatents

    Babu, Suresh P.; Bair, Wilford G.

    1992-01-01

    A method for mild gasification of crushed coal in a single vertical elongated reaction vessel providing a fluidized bed reaction zone, a freeboard reaction zone, and an entrained reaction zone within the single vessel. Feed coal and gas may be fed separately to each of these reaction zones to provide different reaction temperatures and conditions in each reaction zone. The reactor and process of this invention provides for the complete utilization of a coal supply for gasification including utilization of caking and non-caking or agglomerating feeds in the same reactor. The products may be adjusted to provide significantly greater product economic value, especially with respect to desired production of char having high surface area.

  1. Health and safety evaluation of a modified tunnel-borer design for application to single-entry coal-mine development

    SciTech Connect

    Zimmerman, W. F.

    1982-02-15

    The health and safety analysis is part of an overall effort to identify and develop innovative underground coal extraction systems. The single-entry tunnel borer system was initially considered an innovative approach to underground mining because it exhibited a means of increasing the speed and efficiency of entry development by reducing the number of entries. However, to be considered a truly advanced system, the tunnel borer had to meet distinct safety criteria as well. The objective was to examine the tunnel borer design and determine whether it offset major health hazards, and satisfied the prescribed safety levels. As a baseline for comparison, the tunnel borer was compared against the continuous mining entry driving system. The results of the health analysis indicated that while the tunnel borer design offered improvements in dust control through the use of water sprays, a higher face ventilation rate, and the application of spalling rather than the conventional grinding process, it interjected an additional mutagenic is and toxic compound into the environment through the use of shotcrete. The tunnel borer system easily conformed with the prescribed fatality limit, but exceeded the required limits for disabling and overall injuries. It also exhibited projected disabling and overall injury rates considerably higher than existing continuous mining injury rates. Consequently, the tunnel borer system was not considered an advanced system.

  2. Biological upgrading of coal liquids

    SciTech Connect

    Not Available

    1992-01-01

    The objective of this project is to develop a simple biological process for the removal of nitrogen, oxygen, and sulfur heteroatoms from coal liquids, and simultaneously reducing aromaticity. Microorganisms, employing biocatalysts, are known to degrade aromatic heteroatom compounds in nature to NH[sub 3], SO[sub 4], and CO[sub 2]. Preliminary experiments in the ERI laboratories to determine the feasibility of biological removal of N, 0, and S from coal and shale oil liquids have shown up to 20 percent nitrogen removal, 40 percent sulfur removal, and 100 percent oxygen removal in a simple one stage incubation. This project will screen known bacteria and develop isolates for N, 0, and S removal and aromaticity reduction. The performance of the best of these cultures will be optimized for complete heteroatom removal in a single step go up. An outline of the protocol used to select pure cultures and isolates for their suitability in degrading heteroatom compounds is presented. Also shown is a listing of nine model compounds to be used in culture comparison and selection studies. Preliminary results with isolate ERI4 shows that the bacterium grows on phenol as its sole carbon source and rapidly depletes the compound from the medium. Similar results are shown for ERI5, which grows on pyridine as its sole carbon and nitrogen source and rapidly removes the compound from the medium.

  3. The World Coal Quality Inventory: South America

    USGS Publications Warehouse

    Karlsen, Alex W.; Tewalt, Susan J.; Bragg, Linda J.; Finkelman, Robert B.

    2006-01-01

    Executive Summary-Introduction: The concepts of a global environment and economy are strongly and irrevocably linked to global energy issues. Worldwide coal production and international coal trade are projected to increase during the next several decades in an international energy mix that is still strongly dependent on fossil fuels. Therefore, worldwide coal use will play an increasingly visible role in global environmental, economic, and energy forums. Policy makers require information on coal, including coal quality data, to make informed decisions regarding domestic coal resource allocation, import needs and export opportunities, foreign policy objectives, technology transfer policies, foreign investment prospects, environmental and health assessments, and byproduct use and disposal issues. The development of a worldwide, reliable, coal quality database would help ensure the most economically and environmentally efficient global use of coal. The U.S. Geological Survey (USGS), in cooperation with many agencies and scientists from the world's coal producing countries, originally undertook a project to obtain representative samples of coal from most of the world's producing coal provinces during a limited period of time (roughly 1998-2005), which is called the World Coal Quality Inventory (WoCQI). The multitude of producing coal mines, coal occurrences, or limited accessibility to sites in some countries can preclude collecting more than a single sample from a mine. In some areas, a single sample may represent an entire coal mining region or basin. Despite these limitations in sampling and uneven distribution of sample collection, the analytical results can still provide a general overview of world coal quality. The USGS intends to present the WoCQI data in reports and, when possible, in Geographic Information System (GIS) products that cover important coal bearing and producing regions.

  4. AN APPROACH TO REVEALING BLOOD FLUKE LIFE CYCLES, TAXONOMY, AND DIVERSITY: PROVISION OF KEY REFERENCE DATA INCLUDING DNA SEQUENCE FROM SINGLE LIFE CYCLE STAGES

    PubMed Central

    Brant, Sara V.; Morgan, Jess A. T.; Mkoji, Gerald M.; Snyder, Scott D.; Rajapakse, R. P. V. Jayanthe; Loker, Eric S.

    2008-01-01

    Revealing diversity among extant blood flukes, and the patterns of relationships among them, has been hindered by the difficulty of determining if specimens described from different life cycle stages, hosts, geographic localities, and times represent the same or different species. Persistent collection of all available life cycle stages and provision of exact collection localities, host identification, reference DNA sequences for the parasite, and voucher specimens eventually will provide the framework needed to piece together individual life cycles and facilitate reconciliation with classical taxonomic descriptions, including those based on single life cycle stages. It also provides a means to document unique or rare species that might only ever be recovered from a single life cycle stage. With an emphasis on the value of new information from field collections of any available life cycle stages, here we provide data for several blood fluke cercariae from freshwater snails from Kenya, Uganda, and Australia. Similar data are provided for adult worms of Macrobilharzia macrobilharzia and miracidia of Bivitellobilharzia nairi. Some schistosome and sanguinicolid cercariae that we recovered have peculiar morphological features, and our phylogenetic analyses (18S and 28S rDNA and mtDNA CO1) suggest that 2 of the new schistosome specimens likely represent previously unknown lineages. Our results also provide new insights into 2 of the 4 remaining schistosome genera yet to be extensively characterized with respect to their position in molecular phylogenies, Macrobilharzia and Bivitellobilharzia. The accessibility of each life cycle stage is likely to vary dramatically from one parasite species to the next, and our examples validate the potential usefulness of information gleaned from even one such stage, whatever it might be. PMID:16629320

  5. An approach to revealing blood fluke life cycles, taxonomy, and diversity: provision of key reference data including DNA sequence from single life cycle stages.

    PubMed

    Brant, Sara V; Morgan, Jess A T; Mkoji, Gerald M; Snyder, Scott D; Rajapakse, R P V Jayanthe; Loker, Eric S

    2006-02-01

    Revealing diversity among extant blood flukes, and the patterns of relationships among them, has been hindered by the difficulty of determining if specimens described from different life cycle stages, hosts, geographic localities, and times represent the same or different species. Persistent collection of all available life cycle stages and provision of exact collection localities, host identification, reference DNA sequences for the parasite, and voucher specimens eventually will provide the framework needed to piece together individual life cycles and facilitate reconciliation with classical taxonomic descriptions, including those based on single life cycle stages. It also provides a means to document unique or rare species that might only ever be recovered from a single life cycle stage. With an emphasis on the value of new information from field collections of any available life cycle stages, here we provide data for several blood fluke cercariae from freshwater snails from Kenya, Uganda, and Australia. Similar data are provided for adult worms of Macrobilharzia macrobilharzia and miracidia of Bivitellobilharzia nairi. Some schistosome and sanguinicolid cercariae that we recovered have peculiar morphological features, and our phylogenetic analyses (18S and 28S rDNA and mtDNA CO1) suggest that 2 of the new schistosome specimens likely represent previously unknown lineages. Our results also provide new insights into 2 of the 4 remaining schistosome genera yet to be extensively characterized with respect to their position in molecular phylogenies, Macrobilharzia and Bivitellobilharzia. The accessibility of each life cycle stage is likely to vary dramatically from one parasite species to the next, and our examples validate the potential usefulness of information gleaned from even one such stage, whatever it might be.

  6. High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

    SciTech Connect

    Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

    2011-07-31

    Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

  7. Effect of fuel properties on performance of a single aircraft turbojet combustor. [from coal and oil-shale derived syncrudes

    NASA Technical Reports Server (NTRS)

    Butze, H. F.; Ehlers, R. C.

    1975-01-01

    The performance of a single-can JT8D combustor was investigated with a number of fuels exhibiting wide variations in chemical composition and volatility. Performance parameters investigated were combustion efficiency, emissions of CO, unburned hydrocarbons and NOx, as well as liner temperatures and smoke. At the simulated idle condition no significant differences in performance were observed. At cruise, liner temperatures and smoke increased sharply with decreasing hydrogen content of the fuel. No significant differences were observed in the performance of an oil-shale derived JP-5 and a petroleum-based Jet A fuel except for emissions of NOx which were higher with the oil-shale JP-5. The difference is attributed to the higher concentration of fuel-bound nitrogen in the oil-shale JP-5.

  8. Direct liquefaction of low-rank coals

    SciTech Connect

    Rindt, J.R.; Hetland, M.D.; Knudson, C.L.; Willson, W.G.

    1988-04-01

    Co-processing of low-rank coals (LRCs) with petroleum resids under mild conditions may produce a product that extends petroleum refinery feeds with a partially coal-derived material. These co-processing products may also provide a lower-cost way to introduce coal-derived materials into the commercial market. In this staged process, the petroleum resid acts as a solvent, aiding in the solubilization of the coal during the first stage, and both the dissolved coal and the resid are upgraded during a second-stage catalytic hydrogenation. Another method of upgrading coal in a liquefaction process is the ChemCoal Process. The process uses chemical methods to transform coal into clean solid and liquid products. It features low-severity conversion of coal in a phenolic solvent, using an alkali promotor and carbon monoxide as the reductant. Oil agglomeration has been used to reduce the ash and mineral matter in bituminous coals to obtain a product with increased heating value, reduced moisture, and lower sulfur content. This method can be used to produce a clean coal feedstock for liquefaction. During agglomeration, an oil is used to preferentially wet the organic phases of the coal, and water is used to wet the minerals, resulting in a separation of ash and water from the coal. The primary objective of this project is to expand the scientific and engineering data base of LRC liquefaction by investigating direct liquefaction processes that will produce the most competitive feedstocks or liquid fuels. The work effort which was proposed for the second year of this cooperative agreement dealt primarily with co-processing and the ChemCoal Process.

  9. Upgrading and refurbishing coal-handling systems

    SciTech Connect

    Strauss, S.D.

    1983-03-01

    Case histories presented at the Coal Technology '82 meetings are singled out in this article as examples of integrated attacks on coal-handling problems. At the Ohio Edison Co. Sammis Plant the conveyor passed over a public highway, and fugitive coal rained on passing vehicles. Four belt cleaners and a modified gas reducer were installed. Belt-cleaning systems were then installed throughout the plant. At the Con Edison Arthur Kill station coal-receiving facilities, coal conveyors, and ash-handling systems were upgraded. The rotary dumper was modified, the coal-thawing equipment modernized. In the breaker house a rotary breaker was replaced by a ring-type coal crusher. The outmoded pneumatic type ash-handling system was replaced by a drag-chain conveyor. Such concerted plantwide efforts are still the exception, where coal-handling equipment is cared for on a day-to-day patchwork basis.

  10. Treatment of real coal gasification wastewater using a novel integrated system of anoxic hybrid two stage aerobic processes: performance and the role of pure oxygen microbubble.

    PubMed

    Zhuang, Haifeng; Han, Hongjun; Shan, Shengdao

    2016-06-01

    A novel integrated system of anoxic-pure oxygen microbubble-activated sludge reactor-moving bed biofilm reactor was employed in treatment of real coal gasification wastewater. The results showed the integrated system had efficient performance of pollutants removal in short hydraulic retention time. While pure oxygen microbubble with the flow rate of 1.5 L/h and NaHCO3 dosage ratio of 2:1 (amount NaHCO3 to NH4 (+)-N ratio, mol: mol) were used, the removal efficiencies of COD, total phenols (TPh) and NH4 (+)-N reached 90, 95, and 95 %, respectively, with the influent loading rates of 3.4 kg COD/(m(3) d), 0.81 kg TPh/(m(3) d), and 0.28 kg NH4 (+)-N/(m(3) d). With the recycle ratio of 300 %, the concentrations of NO2 (-)-N and NO3 (-)-N in effluent decreased to 12 and 59 mg/L, respectively. Meanwhile, pure oxygen microbubble significantly improved the enzymatic activities and affected the effluent organic compositions and reduced the foam expansion. Thus, the novel integrated system with efficient, stable, and economical advantages was suitable for engineering application.

  11. Comparison of a 250 kV single-stage accelerator mass spectrometer with a 5 MV tandem accelerator mass spectrometer--fitness for purpose in bioanalysis.

    PubMed

    Young, G C; Corless, S; Felgate, C C; Colthup, P V

    2008-12-01

    The introduction of 'compact' accelerator mass spectrometers into biomedical science, including use in drug metabolism and bioanalytical applications, is an exciting recent development. Comparisons are presented here between a more established and relatively large tandem accelerator which operates at up to 5 MV and a conventional laboratory-sized 250 kV single-stage accelerator mass spectrometer. Biological samples were enriched with low levels of radiocarbon, then converted into graphite prior to analysis on each of the two instruments. The data obtained showed the single-stage instrument to be capable of delivering comparable results, and thus able to provide similar study support, with that provided by the 5 MV instrument, without the significant overheads and complexities which are inherent to the operation of the larger instrument. We believe that the advent of these laboratory-sized accelerator mass spectrometry (AMS) instruments represents a real turning point in the potential for application of AMS by a wider user group.

  12. Accounting for uncertainty in the historical response rate of the standard treatment in single-arm two-stage designs based on Bayesian power functions.

    PubMed

    Matano, Francesca; Sambucini, Valeria

    2016-11-01

    In phase II single-arm studies, the response rate of the experimental treatment is typically compared with a fixed target value that should ideally represent the true response rate for the standard of care therapy. Generally, this target value is estimated through previous data, but the inherent variability in the historical response rate is not taken into account. In this paper, we present a Bayesian procedure to construct single-arm two-stage designs that allows to incorporate uncertainty in the response rate of the standard treatment. In both stages, the sample size determination criterion is based on the concepts of conditional and predictive Bayesian power functions. Different kinds of prior distributions, which play different roles in the designs, are introduced, and some guidelines for their elicitation are described. Finally, some numerical results about the performance of the designs are provided and a real data example is illustrated. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Single cell oil production by Mortierella isabellina from steam exploded corn stover degraded by three-stage enzymatic hydrolysis in the context of on-site enzyme production.

    PubMed

    Fang, Hao; Zhao, Chen; Chen, Shaolin

    2016-09-01

    Single cell oil (SCO), promising as alternative oil source, was produced from steam exploded corn stover (SECS) by Mortierella isabellina. Different bioprocesses from SECS to SCO were compared and the bioprocess C using the three-stage enzymatic hydrolysis was found to be the most efficient one. The bioprocess C used the lowest enzyme input 20FPIU cellulase/g glucan and the shortest time 222h, but produced 44.94g dry cell biomass and 25.77g lipid from 327.63g dry SECS. It had the highest lipid content 57.34%, and its productivities and yields were much higher than those of the bioprocess B and comparable to the bioprocess A, indicating that the three-stage enzymatic hydrolysis could greatly improve the efficiency of the bioprocess from high solid loading SECS to SCO by Mortierella isabellina. This work testified the application value of three-stage enzymatic hydrolysis in lignocellulose-based bioprocesses.

  14. Hybrid coal gasification

    SciTech Connect

    Moore, K.

    2007-01-15

    Retrofitting gas, oil and coal-fired boilers can reduce operating costs and meet EPA's Clean Air Interstate Rules (CAIR) when firing most Eastern and Midwest bituminous coals. The trademarked Clean Combustion System (CCS) concept, conceived at Rockwell International, evolved from a confluence of advanced combustion modelling know-how, experience in coal gasification and wet-bottom boiler operation and design. The CCS is a high temperature air-feed entrained flow gasifier that replaces a boiler's existing burners. It fires pulverized coal with some limestone added to provide calcium to capture sulfur and provide a clean hot fuel-rich gas to the boiler furnace. Subsequent over-fire air (OFA) staging completes the combustion. A 'sulfur bearing glass' waste product results from the coal ash and the calcium sulfide. The CCS process prevents formation of NOx from fuel-bound nitrogen. The initial commercialisation of CCS is the update and retrofit an industrial stoker design boiler. Steps for the retrofit are described in the article. 2 figs., 1 photo.

  15. Single-stage Reconstruction of Elbow Flexion Associated with Massive Soft-Tissue Defect Using the Latissimus Dorsi Muscle Bipolar Rotational Transfer.

    PubMed

    Stevanovic, Milan V; Cuéllar, Vanessa G; Ghiassi, Alidad; Sharpe, Frances

    2016-09-01

    In the upper extremity, the latissimus dorsi muscle can be used as an ipsilateral rotational muscle flap for soft-tissue coverage or functional reconstruction of arm and elbow. Patients who have both major soft-tissue loss and functional deficits can be successfully treated with a single-stage functional latissimus dorsi rotational muscle transfer that provides simultaneous soft-tissue coverage and functional reconstruction.

  16. Static aerodynamic characteristics of a single-stage-to-orbit vehicle with low planform loading at Mach numbers from 0.3 to 4.63

    NASA Technical Reports Server (NTRS)

    Freeman, D. C., Jr.; Fournier, R. H.

    1977-01-01

    Transonic pressure and wind tunnel studies were performed to determine the longitudinal and lateral aerodynamic characteristics of a single-stage-to-orbit vehicle which utilizes an all metallic, hot structure, thermal protection system resulting in low planform loading. The model was tested over a Mach number range from 0.3 to 4.63 for angles of attack from -4 deg to 32 deg at both 0 deg and 5 deg sideslip.

  17. Comparative assessment of the methanogenic steps of single and two-stage processes without or with a previous hydrolysis of cassava distillage.

    PubMed

    Zhang, Qinghua; Zhu, Xiangdong; Kong, Lingbao; Yuan, Ganjun; Zhai, Zhijun; Liu, Haoju; Guo, Xiaoyan

    2013-11-01

    In this study, cassava distillage with a high solid content was digested in an anaerobic sequencing batch reactor (ASBR) without or with a previous hydrolytic step by a cellulolytic microbial consortium (i.e., single or two-stage process). The methanogenic steps of these processes were compared and evaluated through observation of the methanogenic stability and methane yield under different organic loading rates (OLRs). It was found the methanogenic reactor can be stably performed with the OLRs lower than 20 g COD L(-1) d(-1) in the two-stage process, where a specific methane yield (0.147 L CH4 g(-1) CODremoved) could be achieved, which was 17.6% higher than that of the single-stage process (0.125 L CH4 g(-1) CODremoved). The above results indicated that the degradation of cassava distillage in a two-stage process with a previous hydrolytic step can assure the methanogenic process proceeds with greater stability and generates higher methane yield.

  18. Exploratory Research on Novel Coal

    SciTech Connect

    Winschel, R.A.; Brandes, S.D.

    1998-05-01

    The report presents the findings of work performed under DOE Contract No. DE-AC22 -95PC95050, Task 3 - Flow Sheet Development. A novel direct coal liquefaction technology was investigated in a program being conducted by CONSOL Inc. with the University of Kentucky Center for Applied Energy Research and LDP Associates. The process concept explored consists of a first-stage coal dissolution step in which the coal is solubilized by hydride ion donation. In the second stage, the products are catalytically upgraded to refinery feedstocks. Integrated first-stage and solids-separation steps were used to prepare feedstocks for second-stage catalytic upgrading. An engineering and economic evaluation was conducted concurrently with experimental work throughout the program. Parameters were established for a low-cost, low-severity first-stage reaction system. A hydride ion reagent system was used to effect high coal conversions of Black Thunder Mine Wyoming subbituminous coal. An integrated first-stage and filtration step was successfully demonstrated and used to produce product filtrates with extremely low solids contents. High filtration rates previously measured off-line in Task 2 studies were obtained in the integrated system. Resid conversions of first-stage products in the second stage were found to be consistently greater than for conventional two-stage liquefaction resids. In Task 5, elementally balanced material balance data were derived from experimental results and an integrated liquefaction system balance was completed. The economic analysis indicates that the production of refined product (gasoline) via this novel direct liquefaction technology is higher than the cost associated with conventional two-stage liquefaction technologies. However, several approaches to reduce costs for the conceptual commercial plant were recommended. These approaches will be investigated in the next task (Task 4) of the program.

  19. Coal gasification cogeneration process

    SciTech Connect

    Marten, J.H.

    1990-10-16

    This patent describes a process for the coproduction of a combustible first gas stream usable as an energy source, a sulfur-dioxide-containing second gas stream usable as a source for oxidant in the gasification of coal and a sulfur-dioxide-containing third gas stream usable as a feedstock for the production of sulfuric acid. It comprises: reacting coal in a coal gasification zone in the presence of an oxidant under partial coal-gasifying conditions to produce carbonaceous char and a crude gas stream; separating sulfur-containing compounds from the crude gas stream in a sulfur recovery zone to produce a combustible first gas stream and elemental sulfur; reacting the carbonaceous char and gypsum in a reaction zone in proportions such that the non-gypsum portion of the carbonaceous char and gypsum mixture contains sufficient reducing potential to reduce sulfur in the gypsum to gaseous compounds of sulfur in a +4 or lower oxidation state under reducing conditions to produce first a sulfur-dioxide-containing second gas stream which contains weaker SO{sub 2} produced in an early stage of the reaction zone and removed from the reaction zone, and then a sulfur-dioxide-containing third gas stream which contains concentrated SO{sub 2} recovered from a later stage of the reaction zone.

  20. Lexical Access in Early Stages of Visual Word Processing: A Single-Trial Correlational MEG Study of Heteronym Recognition

    ERIC Educational Resources Information Center

    Solomyak, Olla; Marantz, Alec

    2009-01-01

    We present an MEG study of heteronym recognition, aiming to distinguish between two theories of lexical access: the "early access" theory, which entails that lexical access occurs at early (pre 200 ms) stages of processing, and the "late access" theory, which interprets this early activity as orthographic word-form identification rather than…

  1. Recent advances in the perchloroethylene coal cleaning system

    SciTech Connect

    Fullerton, K.L.; Lee, S.; Kulik, C.J.

    1994-12-31

    The perchloroethylene coal desulfurization process has been shown to selectively remove both inorganic and organic sulfur as well as mineral matter from high sulfur Midwestern coals. The process consists of four stages: a wet grinding of the coal to {minus}200 mesh, an extraction stage used to remove organic sulfur, a float sink stage to remove pyritic sulfur and mineral matter, and finally, a steam stripping stage to remove residual perchloroethylene from the coal. Using this process, up to 70% of the organic sulfur and over 90% of the pyritic sulfur can be removed from the coal. Recent work has studied the effects of parameters such as type of coal, particle size, moisture content, process temperatures, etc., on the sulfur removal efficiency. In addition, a kinetic relation was established for several types of Midwestern coals and minimum extraction time was established. The kinetic study was also used to conduct simulation studies of batch, plug flow reactor, and continuous stirred tank reactor.

  2. Novel single stripper with side-draw to remove ammonia and sour gas simultaneously for coal-gasification wastewater treatment and the industrial implementation

    SciTech Connect

    Feng, D.C.; Yu, Z.J.; Chen, Y.; Qian, Y.

    2009-06-15

    A large amount of wastewater is produced in the Lurgi coal-gasification process with the complex compounds carbon dioxide, ammonia, phenol, etc., which cause a serious environmental problem. In this paper, a novel stripper operated at elevated pressure is designed to improve the pretreatment process. In this technology, two noticeable improvements were established. First, the carbon dioxide and ammonia were removed simultaneously in a single stripper where sour gas (mainly carbon dioxide) is removed from the tower top and the ammonia vapor is drawn from the side and recovered by partial condensation. Second, the ammonia is removed before the phenol recovery to reduce the pH value of the subsequent extraction units, so as the phenol removal performance of the extraction is greatly improved. To ensure the operational efficiency, some key operational parameters are analyzed and optimized though simulation. It is shown that when the top temperature is kept at 40 C and the weight ratio of the side draw to the feed is above 9%, the elevated pressures can ensure the removal efficiency of NH{sub 3} and carbon dioxide and the desired purified water as the bottom product of the unit is obtained. A real industrial application demonstrates the attractiveness of the new technique: it removes 99.9% CO{sub 2} and 99.6% ammonia, compared to known techniques which remove 66.5% and 94.4%, respectively. As a result, the pH value of the wastewater is reduced from above 9 to below 7. This ensures that the phenol removal ratio is above 93% in the following extraction units. The operating cost is lower than that of known techniques, and the operation is simplified.

  3. Hydroliquefaction of coal

    DOEpatents

    Sze, Morgan C.; Schindler, Harvey D.

    1982-01-01

    Coal is catalytically hydroliquefied by passing coal dispersed in a liquefaction solvent and hydrogen upwardly through a plurality of parallel expanded catalyst beds, in a single reactor, in separate streams, each having a cross-sectional flow area of no greater than 255 inches square, with each of the streams through each of the catalyst beds having a length and a liquid and gas superficial velocity to maintain an expanded catalyst bed and provide a Peclet Number of at least 3. If recycle is employed, the ratio of recycle to total feed (coal and liquefaction solvent) is no greater than 2:1, based on volume. Such conditions provide for improved selectivity to liquid product to thereby reduce hydrogen consumption. The plurality of beds are formed by partitions in the reactor.

  4. Chemical analysis and mutational assay of distilled oils from the H-coal direct liquefaction process: a status report

    SciTech Connect

    Wilson, B.W.; Later, D.W.; Wright, C.W.; Stewart, D.L.

    1985-01-01

    Samples from the H-Coal process, a catalytic, single-stage, coal liquefaction technology, were chemically characterized and screened for microbial mutagenicity. For these investigations, a blend of light and heavy H-Coal process oils was fractionally distilled into 50/sup 0/F boiling point cuts. The chemical analyses and biological testing results presented in this status report deal primarily with the blended material and the distillate fractions boiling above 650/sup 0/F. Results from the microbial mutagenicity assays indicated that onset of biological activity in the crude materials occurred above 700/sup 0/F. Similar trends have been observed for Solvent Refined Coal (SRC) I, SRC II, Integrated Two-Stage Liquefaction (ITSL) and Exxon EDS process materials. After chemical class fractionation, the primary source of microbial mutagenicity of the crude boiling point cuts was the nitrogen-containing polycyclic aromatic compound (N-PAC) fractions. Amino polycyclic aromatic hydrocarbons (amino-PAH) were present at sufficient concentration levels in the N-PAC fractions to account for the observed mutagenic responses. In general, the chemical composition of the H-Coal materials studied was similar to that of other single-stage liquefaction materials. The degree of alkylation in these materials was determined to be greater than in the SRC and less than in the EDS process distillate cuts. 13 references, 8 figures, 11 tables.

  5. Synchronous development of Eimeria tenella in chicken caeca and utility of laser microdissection for purification of single stage schizont RNA.

    PubMed

    Matsubayashi, M; Hatta, T; Miyoshi, T; Anisuzzaman; Alim, M A; Yamaji, K; Shimura, K; Isobe, T; Tsuji, N

    2012-10-01

    Eimeria tenella is recognized worldwide as a significant pathogen in the poultry industry. However, a lack of methods for isolating developing schizonts has hindered the use of transcriptome analyses to discover novel and developmentally regulated genes. In the present study, we characterized the long-term successive development of E. tenella in infected chicken caeca and assessed the utility of laser microdissection (LMD) for the isolation of schizont RNA. Developmental stages, including those of the first, second, and third-generation schizonts and gametocytes, were synchronous. Using LMD, only the mature second-generation schizonts were successfully excised from the lamina propria, and non-degraded RNA was purified from the schizonts. E. tenella-specific genes were amplified by reverse transcription polymerase chain reaction (RT-PCR). These results augment our understanding of the E. tenella life cycle, and reveal LMD as a potentially useful tool for gene expression analyses of the intracellular stages of E. tenella.

  6. Single and joint toxic effects of five selected pesticides on the early life stages of zebrafish (Denio rerio).

    PubMed

    Wang, Yanhua; Lv, Lu; Yu, Yijun; Yang, Guiling; Xu, Zhenlan; Wang, Qiang; Cai, Leiming

    2017-03-01

    Instead of individual ones, pesticides are usually detected in water environment as mixtures of contaminants. Laboratory tests were conducted in order to investigate the effects of individual and joint pesticides (phoxim, atrazine, chlorpyrifos, butachlor and λ-cyhalothrin) on zebrafish (Denio rerio). Results from 96-h semi-static toxicity test indicated that λ-cyhalothrin had the greatest toxicity to the three life stages (embryonic, larval and juvenile stages) of D. rerio with LC50 values ranging from 0.0031 (0.0017-0.0042) to 0.38 (0.21-0.53) mg a.i. L(-1), followed by butachlor and chlorpyrifos with LC50 values ranging from 0.45 (0.31-0.59) to 1.93 (1.37-3.55) and from 0.28 (0.13-0.38) to 13.03 (7.54-19.71) mg a.i. L(-1), respectively. In contrast, atrazine showed the least toxicity with LC50 values ranging from 6.09 (3.34-8.35) to 34.19 (24.42-51.9) mg a.i. L(-1). The larval stage of D. rerio was a vulnerable period to most of the selected pesticides in the multiple life stages tested. Pesticide mixtures containing phoxim and λ-cyhalothrin exerted synergistic effects on the larvae of D. rerio. Moreover, the binary mixture of phoxim-atrazine also displayed synergistic response to zebrafish. It has been assumed that most chemicals are additive in toxicity. Therefore, it is crucial to clarify the synergistic interaction for pesticide regulators and environment managers. In the present study, our data provided a clear picture on ecological risk of these pesticide mixtures to aquatic organisms. Moreover, joint effects play a more important role than individual ones, which require more attention when defining standard for water environment quality and risk assessment protocols.

  7. Enamel pits in hamster molars, formed by a single high fluoride dose, are associated with a perturbation of transitional stage ameloblasts

    PubMed Central

    Lyaruu, D.M.; Vermeulen, L.; Stienen, N.; Bervoets, T.J.M.; DenBesten, P.K.; Bronckers, A.L.J.J.

    2013-01-01

    Excessive intake of fluoride (F) by young children results in formation of enamel subsurface porosities and pits, called enamel fluorosis. In this study, we used a single high dose of fluoride administered to hamster pups, to determine the stage of ameloblasts most affected by fluoride, and whether pit formation was related to F-related sub-ameloblastic cyst formation. Hamster pups received a single subcutaneous injection of either 20 mg or 40 mg NaF/kg body weights, were sacrificed 24 h later, and the number of cysts formed in the first molars counted. Other pups were sacrificed 8 days after F-injection when the first molars had just erupted, to score for enamel defects. All F-injected pups formed enamel defects in the upper half of the cusps in a dose-dependent way. After injection of 20 mg NaF/kg an average of 2.2 white spots per molar was found but no pits. At 40 mg NaF/kg, almost 4.5 spots per molar were counted as well as 2 pits per molar. The defects in erupted enamel were located in the upper half of the cusps, sites where cysts had formed at the transition stage of ameloblast differentiation. These results suggest that transitional ameloblasts, located between secretory and maturation stage ameloblasts, are most sensitive to the effects of a single high dose of fluoride. Fluoride- induced cysts formed earlier at the pre-secretory stage were not correlated to either white spots or enamel pits, suggesting that damaged ameloblasts overlying a fluoride induced cyst regenerate and continue to form enamel. PMID:22947666

  8. Targeting multiple chorismate-utilizing enzymes with a single inhibitor: validation of a three-stage design.

    PubMed

    Ziebart, Kristin T; Dixon, Seth M; Avila, Belem; El-Badri, Mohamed H; Guggenheim, Kathryn G; Kurth, Mark J; Toney, Michael D

    2010-05-13

    Chorismate-utilizing enzymes are attractive antimicrobial drug targets due to their absence in humans and their central role in bacterial survival and virulence. The structural and mechanistic homology of a group of these inspired the goal of discovering inhibitors that target multiple enzymes. Previously, we discovered seven inhibitors of 4-amino-4-deoxychorismate synthase (ADCS) in an on-bead, fluorescent-based screen of a 2304-member one-bead-one-compound combinatorial library. The inhibitors comprise PAYLOAD and COMBI stages, which interact with active site and surface residues, respectively, and are linked by a SPACER stage. These seven compounds, and six derivatives thereof, also inhibit two other enzymes in this family, isochorismate synthase (IS) and anthranilate synthase (AS). The best binding compound inhibits ADCS, IS, and AS with K(i) values of 720, 56, and 80 microM, respectively. Inhibitors with varying SPACER lengths show the original choice of lysine to be optimal. Lastly, inhibition data confirm the PAYLOAD stage directs the inhibitors to the ADCS active site.

  9. Difference of Postoperative Stool Frequency in Hirschsprung Disease According to Anastomosis Level in a Single-Stage, Laparoscopy-Assisted Transanal Endorectal Pull-Through Procedure

    PubMed Central

    Oh, Chaeyoun; Lee, Sanghoon; Lee, Suk-Koo; Seo, Jeong-Meen

    2016-01-01

    Abstract Anorectal innervation that governs sensation, motor function, and rectal accommodation can be influenced by the type of surgical procedure used to treat children with Hirschsprung disease. At our institution, we began to perform single-stage, laparoscopy-assisted transanal endorectal pull-through (LATEP) with submucosal dissection and anastomosis of the ganglionated bowel at 2 different levels relative to the dentate line. This retrospective study describes postoperative stool frequency changes in response to this procedure. Forty infants who underwent single-stage LATEP between September 2003 and April 2012 in a single center by the same surgeon were included in our analysis. The patients were divided in 2 groups: Group A (n = 23) underwent submucosal dissection and anastomosis at 2 mm above the dentate line, and Group B (n = 17) underwent the same procedure with anastomosis 15 mm above the dentate line. Clinical characteristics, clinical findings on the first postoperative visit, and instances of coexisting anomalies did not differ between the 2 groups. Aganglionic segments were found in the rectosigmoid colon in 18 cases (78.2%) in Group A and in 15 cases (88.2%) in Group B. Although the stool frequency was no different at 1, 3, 6, and 12 months after the operation, Group B showed significantly fewer bowel movements than Group A after 2 years (3.77 in Group A vs 2.0 in Group B; P = 0.035) and after 3 years (3.92 vs 1.29; P = 0.009) in patients who had aganglionosis of the rectosigmoid colon. The mean follow-up period was 65.87 ± 28.08 months for Group A and 35.59 ± 18.68 for Group B. The level of submucosal dissection and anastomosis in single-stage LATEP influenced the stool frequency in rectosigmoid aganglionosis. PMID:27057833

  10. Goal-oriented cognitive rehabilitation in early-stage dementia: study protocol for a multi-centre single-blind randomised controlled trial (GREAT)

    PubMed Central

    2013-01-01

    Background Preliminary evidence suggests that goal-oriented cognitive rehabilitation (CR) may be a clinically effective intervention for people with early-stage Alzheimer’s disease, vascular or mixed dementia and their carers. This study aims to establish whether CR is a clinically effective and cost-effective intervention for people with early-stage dementia and their carers. Methods/design In this multi-centre, single-blind randomised controlled trial, 480 people with early-stage dementia, each with a carer, will be randomised to receive either treatment as usual or cognitive rehabilitation (10 therapy sessions over 3 months, followed by 4 maintenance sessions over 6 months). We will compare the effectiveness of cognitive rehabilitation with that of treatment as usual with regard to improving self-reported and carer-rated goal performance in areas identified as causing concern by people with early-stage dementia; improving quality of life, self-efficacy, mood and cognition of people with early-stage dementia; and reducing stress levels and ameliorating quality of life for carers of participants with early-stage dementia. The incremental cost-effectiveness of goal-oriented cognitive rehabilitation compared to treatment as usual will also be examined. Discussion If the study confirms the benefits and cost-effectiveness of cognitive rehabilitation, it will be important to examine how the goal-oriented cognitive rehabilitation approach can most effectively be integrated into routine health-care provision. Our aim is to provide training and develop materials to support the implementation of this approach following trial completion. Trial registration Current Controlled Trials ISRCTN21027481 PMID:23710796

  11. Single-stage technogy for granulated foam glass production based on the composition of tripoli and technogical microsilica

    NASA Astrophysics Data System (ADS)

    Kazmina, O.; Volkova, A.; Vereschagin, V.; Rymanova, I.

    2016-09-01

    The possibility of foam glass production by means of one-stage technology based on the natural tripoli and technogenic silica is determined. 45 % sodium hydroxide solution is used for the synthesis of foam glass. The addition of microsilica as an extra component in an amount of 10 to 50 wt. % in batch component increases the strength of the obtained material to 4 MPa and reduces foaming temperature from 870 to 830 °C. The increased mechanical strength of the material is due to the residual quartz dissolution and cristobalite crystallization. The samples obtained from batch with 30 wt. % microsilica have maximum strength.

  12. Milliken Clean Coal Demonstration Project: A DOE Assessment

    SciTech Connect

    National Energy Technology Laboratory

    2001-08-15

    The goal of the U.S. Department of Energy's (DOE) Clean Coal Technology (CCT) program is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal-utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage.

  13. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Harris, G.; Sotillo, F.; Diao, J. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, Weibai; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. )

    1990-08-15

    The primary objective of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from six major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Work this quarter concentrated on the following: washability studies, which included particle size distribution of the washability samples, and chemical analysis of washability test samples; characterization studies of induction time measurements, correlation between yield, combustible-material recovery (CMR), and heating-value recovery (HVR), and QA/QC for standard flotation tests and coal analyses; surface modification and control including testing of surface-modifying reagents, restoration of hydrophobicity to lab-oxidized coals, pH effects on coal flotation, and depression of pyritic sulfur in which pyrite depression with calcium cyanide and pyrite depression with xanthated reagents was investigated; flotation optimization and circuitry included staged reagent addition, cleaning and scavenging, and scavenging and middling recycling. Weathering studies are also discussed. 19 figs., 28 tabs.

  14. High-Energy Extracorporeal Shock Wave for Early Stage Osteonecrosis of the Femoral Head: A Single-Center Case Series

    PubMed Central

    Gao, Fuqiang; Sun, Wei; Li, Zirong; Guo, Wanshou; Wang, Weiguo; Cheng, Liming; Wang, Bailiang

    2015-01-01

    Our retrospective study assessed the effects of treatment of early stage ONFH with extracorporeal shock wave therapy. 335 patients (528 hips) were treated with shockwave therapy in our institution. Each patient underwent two sessions. The hips were divided into two groups according to whether the lateral pillar of the femoral head (LPFH) was preserved: LPFH and non-LPFH groups. Patients were followed up at 3, 6, and 12 months after the treatment. Most of the patients (83.9% hips) demonstrated pain reduction and improved mobility of the treated joint (visual analogue scale score, P = 0.00006; Harris hip score, P = 0.00091). During the follow-up period, 16 hips failed following femoral head collapse and required hip arthroplasty (2 hips in LPFH group and 14 hips in non-LPFH group). The lesion size decreased after ESWT. However, the differences were statistically not significant (LPFH group, P = 0.091; non-LPFH group, P = 0.087). A significant reduction in bone marrow edema was observed after treatment (LPFH group, P = 0.007; non-LPFH group, P = 0.016). High-energy extracorporeal shock wave therapy resulted in considerable improvement in early stage ONFH, which can effectively relieve pain and improve the function of the hip. PMID:26609311

  15. Production of activated carbon from bagasse and rice husk by a single-stage chemical activation method at low retention times.

    PubMed

    Kalderis, Dimitrios; Bethanis, Sophia; Paraskeva, Panagiota; Diamadopoulos, Evan

    2008-10-01

    The production of activated carbon from bagasse and rice husk by a single-stage chemical activation method in short retention times (30-60min) was examined in this study. The raw materials were subjected to a chemical pretreatment and were fed to the reactor in the form of a paste (75% moisture). Chemicals examined were ZnCl2, NaOH and H3PO4, for temperatures of 600, 700 and 800 degrees C. Of the three chemical reagents under evaluation only ZnCl2 produced activated carbons with high surface areas. BET surface areas for rice husk were up to 750m2/g for 1:1 ZnCl2:rice husk ratio. BET surface areas for bagasse were up to 674m2/g for 0.75:1 ZnCl2:bagasse ratio. Results were compared to regular two-stage physical activation methods.

  16. Trappean magmatism as the basic cause of coal metamorphism and hydrocarbon generation in the Tungus Coal Basin

    SciTech Connect

    Pavlov, A.L.; Khomenko, A.V.; Gordeeva, A.O.

    2005-11-15

    A survey is presented for coal reserves and possible amounts of methane and other gases in the Tungus Coal Basin, where brown coal is metamorphized to various (down to anthracites) stages under the action of heat generated by many trappean intrusions. There is a presumption that some hydrocarbon gases are in a fossil state.

  17. Thermo-fluid dynamic design study of single and double-inflow radial and single-stage axial steam turbines for open-cycle thermal energy conversion net power-producing experiment facility in Hawaii

    SciTech Connect

    Schlbeiri, T. . Dept. of Mechanical Engineering)

    1990-03-01

    The results of the study of the optimum thermo-fluid dynamic design concept are presented for turbine units operating within the open-cycle ocean thermal energy conversion (OC-OTEC) systems. The concept is applied to the first OC-OTEC net power producing experiment (NPPE) facility to be installed at Hawaii's natural energy laboratory. Detailed efficiency and performance calculations were performed for the radial turbine design concept with single and double-inflow arrangements. To complete the study, the calculation results for a single-stage axial steam turbine design are also presented. In contrast to the axial flow design with a relatively low unit efficiency, higher efficiency was achieved for single-inflow turbines. Highest efficiency was calculated for a double-inflow radial design, which opens new perspectives for energy generation from OC-OTEC systems.

  18. Single-stage osseointegrated reconstruction and rehabilitation of lower limb amputees: the Osseointegration Group of Australia Accelerated Protocol-2 (OGAAP-2) for a prospective cohort study

    PubMed Central

    Al Muderis, Munjed; Lu, William; Tetsworth, Kevin; Bosley, Belinda; Li, Jiao Jiao

    2017-01-01

    Introduction Lower limb amputations have detrimental influences on the quality of life, function and body image of the affected patients. Following amputation, prolonged rehabilitation is required for patients to be fitted with traditional socket prostheses, and many patients experience symptomatic socket–residuum interface problems which lead to reduced prosthetic use and quality of life. Osseointegration has recently emerged as a novel approach for the reconstruction of amputated limbs, which overcomes many of the socket-related problems by directly attaching the prosthesis to the skeletal residuum. To date, the vast majority of osseointegration procedures worldwide have been performed in 2 stages, which require at least 4 months and up to 18 months for the completion of reconstruction and rehabilitation from the time of the initial surgery. The current prospective cohort study evaluates the safety and efficacy of a single-stage osseointegration procedure performed under the Osseointegration Group of Australia Accelerated Protocol-2 (OGAAP-2), which dramatically reduces the time of recovery to ∼3–6 weeks. Methods and analysis The inclusion criteria for osseointegrated reconstruction under the OGAAP-2 procedure are age over 18 years, unilateral transfemoral amputation and experiencing problems or difficulties in using socket prostheses. All patients receive osseointegrated implants which are press-fitted into the residual bone. Functional and quality-of-life outcome measures are recorded preoperatively and at defined postoperative follow-up intervals up to 2 years. Postoperative adverse events are also recorded. The preoperative and postoperative values are compared for each outcome measure, and the benefits and harms of the single-stage OGAAP-2 procedure will be compared with the results obtained using a previously employed 2-stage procedure. Ethics and dissemination This study has received ethics approval from the University of Notre Dame, Sydney

  19. Rosebud SynCoal Partnership, SynCoal{reg_sign} demonstration technology update

    SciTech Connect

    Sheldon, R.W.

    1997-12-31

    An Advanced Coal Conversion Process (ACCP) technology being demonstrated in eastern Montana (USA) at the heart of one of the world`s largest coal deposits is providing evidence that the molecular structure of low-rank coals can be altered successfully to produce a unique product for a variety of utility and industrial applications. The product is called SynCoal{reg_sign} and the process has been developed by the Rosebud SynCoal Partnership (RSCP) through the US Department of Energy`s multi-million dollar Clean Coal Technology Program. The ACCP demonstration process uses low-pressure, superheated gases to process coal in vibrating fluidized beds. Two vibratory fluidized processing stages are used to heat and convert the coal. This is followed by a water spray quench and a vibratory fluidized stage to cool the coal. Pneumatic separators remove the solid impurities from the dried coal. There are three major steps to the SynCoal{reg_sign} process: (1) thermal treatment of the coal in an inert atmosphere, (2) inert gas cooling of the hot coal, and (3) removal of ash minerals. When operated continuously, the demonstration plant produces over 1,000 tons per day (up to 300,000 tons per year) of SynCoal{reg_sign} with a 2% moisture content, approximately 11,800b Btu/lb and less than 1.0 pound of SO{sub 2} per million Btu. This product is obtained from Rosebud Mine sub-bituminous coal which starts with 25% moisture, 8,600 Btu/lb and approximately 1.6 pounds of SO{sub 2} per million Btu.

  20. Results of Single-Staged Posterior Decompression and Circumferential Fusion Using a Transpedicular Approach to Correct a Kyphotic Deformity due to Thoracolumbar Spinal Tuberculosis

    PubMed Central

    Modi, Jayprakash; Soman, Shardul; Patel, Harshil; Dhanani, Shrikant

    2016-01-01

    Study Design This is a prospective study. Purpose The aim of this study was to investigate the results of single-staged posterior decompression and circumferential fusion using a transpedicular approach to correct a kyphotic deformity due to thoracolumbar spinal tuberculosis. Overview of Literature Surgical management is frequently an imperative choice to achieve spinal decompression and deformity correction due to tuberculosis to relieve pain, improve neurology, and reconstruct the spine stability. Since the time anterior radical debridement and noninstrumented fusion was described, it has become apparent that even anterior debridement and bone grafting was often unsatisfactory in correcting or preventing the progression of kyphosis deformity. With the advent of modern segmental spinal instrumentation systems, isolated posterior instrumentation; combined anterior and posterior fusion; and single-staged posterior decompression and circumferential fusion have been described by many authors for correcting angular deformity and stabilizing the spine; however, there is a lack of consensus regarding the most effective means of correcting the deformity due to thoracolumbar spinal tuberculosis. Methods This is a prospective study of 20 patients with thoracolumbar spinal tuberculosis who underwent surgery at our institute. Results Twenty patients who were started on antituberculosis treatment underwent surgery using a single-staged posterior approach involving fixation, decompression, and kyphosis correction. Preoperatively, all patients had varying degrees of neurological deficit and a 27.45° average kyphotic angle, which improved. At the 1-year follow-up, correction was maintained at 6.9°, and 55% of patients showed neurological improvement. None of the patients experienced neurological deterioration. Two patients with lumbar spine tuberculosis underwent revision surgery because of nonunion. Conclusions The procedure of posterior decompression, fixation, and

  1. Modeling Single Ventricle Physiology: Review of Engineering Tools to Study First Stage Palliation of Hypoplastic Left Heart Syndrome

    PubMed Central

    Biglino, Giovanni; Giardini, Alessandro; Hsia, Tain-Yen; Figliola, Richard; Taylor, Andrew M.; Schievano, Silvia

    2013-01-01

    First stage palliation of hypoplastic left heart syndrome, i.e., the Norwood operation, results in a complex physiological arrangement, involving different shunting options (modified Blalock-Taussig, RV-PA conduit, central shunt from the ascending aorta) and enlargement of the hypoplastic ascending aorta. Engineering techniques, both computational and experimental, can aid in the understanding of the Norwood physiology and their correct implementation can potentially lead to refinement of the decision-making process, by means of patient-specific simulations. This paper presents some of the available tools that can corroborate clinical evidence by providing detailed insight into the fluid dynamics of the Norwood circulation as well as alternative surgical scenarios (i.e., virtual surgery). Patient-specific anatomies can be manufactured by means of rapid prototyping and such models can be inserted in experimental set-ups (mock circulatory loops) that can provide a valuable source of validation data as well as hydrodynamic information. Such models can be tuned to respond to differing the patient physiologies. Experimental set-ups can also be compatible with visualization techniques, like particle image velocimetry and cardiovascular magnetic resonance, further adding to the knowledge of the local fluid dynamics. Multi-scale computational models include detailed three-dimensional (3D) anatomical information coupled to a lumped parameter network representing the remainder of the circulation. These models output both overall hemodynamic parameters while also enabling to investigate the local fluid dynamics of the aortic arch or the shunt. As an alternative, pure lumped parameter models can also be employed to model Stage 1 palliation, taking advantage of a much lower computational cost, albeit missing the 3D anatomical component. Finally, analytical techniques, such as wave intensity analysis, can be employed to study the Norwood physiology, providing a mechanistic

  2. Modeling single ventricle physiology: review of engineering tools to study first stage palliation of hypoplastic left heart syndrome.

    PubMed

    Biglino, Giovanni; Giardini, Alessandro; Hsia, Tain-Yen; Figliola, Richard; Taylor, Andrew M; Schievano, Silvia

    2013-10-30

    First stage palliation of hypoplastic left heart syndrome, i.e., the Norwood operation, results in a complex physiological arrangement, involving different shunting options (modified Blalock-Taussig, RV-PA conduit, central shunt from the ascending aorta) and enlargement of the hypoplastic ascending aorta. Engineering techniques, both computational and experimental, can aid in the understanding of the Norwood physiology and their correct implementation can potentially lead to refinement of the decision-making process, by means of patient-specific simulations. This paper presents some of the available tools that can corroborate clinical evidence by providing detailed insight into the fluid dynamics of the Norwood circulation as well as alternative surgical scenarios (i.e., virtual surgery). Patient-specific anatomies can be manufactured by means of rapid prototyping and such models can be inserted in experimental set-ups (mock circulatory loops) that can provide a valuable source of validation data as well as hydrodynamic information. Such models can be tuned to respond to differing the patient physiologies. Experimental set-ups can also be compatible with visualization techniques, like particle image velocimetry and cardiovascular magnetic resonance, further adding to the knowledge of the local fluid dynamics. Multi-scale computational models include detailed three-dimensional (3D) anatomical information coupled to a lumped parameter network representing the remainder of the circulation. These models output both overall hemodynamic parameters while also enabling to investigate the local fluid dynamics of the aortic arch or the shunt. As an alternative, pure lumped parameter models can also be employed to model Stage 1 palliation, taking advantage of a much lower computational cost, albeit missing the 3D anatomical component. Finally, analytical techniques, such as wave intensity analysis, can be employed to study the Norwood physiology, providing a mechanistic

  3. The Effect of Inlet Pressure and Temperature on the Efficiency of a Single-stage Impulse Turbine Having an 11.0-inch Pitch-line Diameter Wheel

    NASA Technical Reports Server (NTRS)

    Gabriel, David S.; Carmen, Robert L.; Trautwein, Elmer E

    1945-01-01

    Efficiency tests have been conducted on a single-stage impulse engine having an 11-inch pitch-line diameter wheel with inserted buckets and a fabricated nozzle diaphragm. The tests were made to determine the effect of inlet pressure, Inlet temperature, speed, and pressure ratio on the turbine efficiency. An analysis is presented that relates the effect of inlet pressure and temperature to the Reynolds number of the flow. The agreement between the analysis and the experimental data indicates that the changes in turbine efficiency with Inlet pressure and temperature may be principally a Reynolds number effect.

  4. Single-Stage Repair of Thoracic Aortic Aneurysm through a Median Sternotomy in a Patient with Pseudocoarctation of the Aorta and Severe Aortic Valve Stenosis.

    PubMed

    Yamane, Yoshitaka; Morimoto, Hironobu; Mukai, Shogo

    2015-01-01

    Pseudocoarctation of the aorta is a rare anomaly and considered a benign condition. Pseudocoarctation of the aorta has been associated with aneurysm formation in the thoracic aorta, which may cause sudden rupture or dissection. Thus, the presence of an aneurysm in combination with pseudocoarctation of the aorta is thought to be an indication for surgery. We present a case of pseudocoarctation of the aorta associated with thoracic aortic aneurysm and severe aortic valve stenosis with a bicuspid aortic valve. In our case, single-stage repair was performed through a median sternotomy using our "pleural-window approach."

  5. Clean Coal Diesel Demonstration Project

    SciTech Connect

    Robert Wilson

    2006-10-31

    A Clean Coal Diesel project was undertaken to demonstrate a new Clean Coal Technology that offers technical, economic and environmental advantages over conventional power generating methods. This innovative technology (developed to the prototype stage in an earlier DOE project completed in 1992) enables utilization of pre-processed clean coal fuel in large-bore, medium-speed, diesel engines. The diesel engines are conventional modern engines in many respects, except they are specially fitted with hardened parts to be compatible with the traces of abrasive ash in the coal-slurry fuel. Industrial and Municipal power generating applications in the 10 to 100 megawatt size range are the target applications. There are hundreds of such reciprocating engine power-plants operating throughout the world today on natural gas and/or heavy fuel oil.

  6. Liquefaction of sub-bituminous coal

    DOEpatents

    Schindler, Harvey D.; Chen, James M.

    1986-01-01

    Sub-bituminous coal is directly liquefied in two stages by use of a liquefaction solvent containing insoluble material as well as 850.degree. F.+ material and 850.degree. F.- material derived from the second stage, and controlled temperature and conversion in the second stage. The process is in hydrogen balance.

  7. Generation of 130 W narrow-linewidth high-peak-power picosecond pulses directly from a compact Yb-doped single-stage fiber amplifier

    NASA Astrophysics Data System (ADS)

    Qi, Yaoyao; Yu, Haijuan; Zhang, Jingyuan; Wang, Lei; Zhang, Ling; Lin, Xuechun

    2015-09-01

    We report a compact, 130-W single-stage master oscillator power amplifier with a high peak power of 51.3 kW and a narrow spectral linewidth of 0.1 nm. The seed source is a single-mode, passively mode-locked solid-state laser at 1064 nm with an average power of 2 W. At a repetition rate of 73.5 MHz, the pulse duration is 30 ps. After amplification, it stretches to 34.5 ps. The experiment enables the optical-to-optical conversion efficiency to reach 75%. To the best of our knowledge, this is the first report of such a high-power, narrow spectral linewidth, high peak power picosecond-pulse fiber amplifier based on a continuous-wave, mode-locked solid-state seeding laser. No amplified spontaneous emission and stimulated Raman scattering were observed when the pump was increased.

  8. A 900mV Single-Stage Class-AB Amplifier for a ∑-Δ Modulator with the Switched-Opamp Technique

    NASA Astrophysics Data System (ADS)

    Kwon, Oh Jun; Kwack, Kae Dal

    A 900mV single-stage class-AB amplifier suitable for the Switched-Opamp technique is presented. To improve the slew-limited characteristics, a Dynamic Current Source (DCS) circuit which boosts the tail currents of the amplifier is proposed. The tail current of the proposed circuit is well defined and independent of technology parameters and supply variations. The tail current of the amplifier is 40µA with zero differential voltages, while the maximum output current is nearly 900µA. A single-loop 3rd order Σ-Δ modulator with the proposed amplifier was designed. For a 260mV 15.625kHz sinusoidal input signal, the simulated dynamic range of the modulator is 89dB.

  9. Advanced physical coal cleaning to comply with potential air toxic regulations. Quarterly report, 1 December 1994--28 February 1995

    SciTech Connect

    Honaker, R.Q.; Paul, B.C.; Wang, D.

    1995-12-31

    Studies have indicated that the potentially hazardous trace elements found in coal have a strong affinity for coal pyrite. Thus, by maximizing the rejection of pyrite, one can minimize the trace element content of a given coal while also reducing sulfur emissions. The pyrite in most Illinois Basin coals, however, is finely disseminated within the coal matrix. Therefore, to remove the pyrite using physical coal cleaning techniques, the pyrite must be liberated by grinding the coal to ultrafine particle sizes. Fortunately, the coals being fed to pulverized coal boilers (PCB) are already ground to a very fine size, i.e., 70% passing 200 mesh. Therefore, this research project will investigate the use of advanced fine coal cleaning technologies for cleaning PCB feed as a compliance strategy. Work in this quarter has focused on the processing of a PCB feed sample collected from Central Illinois Power`s Newton Power Station using column flotation and an enhanced gravity separator as separate units and in a circuitry arrangement. The PCB feed sample having a low ash content of about 12% was further cleaned to 6% while achieving a very high energy recovery of about 90% in a single stage column flotation operation. Enhanced gravity treatment is believed to be providing excellent total sulfur rejection values, although with inferior ash rejection for the {minus}400 mesh size fraction. The circuitry arrangement with the Falcon concentrator as the primary cleaner followed by the Microcel column resulted in an excellent ash rejection performance, which out performed the release analysis. Trace element analyses of the samples collected from these tests will be conducted during the next report period.

  10. 30 Gy or 34 Gy? Comparing 2 Single-Fraction SBRT Dose Schedules for Stage I Medically Inoperable Non-Small Cell Lung Cancer

    SciTech Connect

    Videtic, Gregory M.M. Stephans, Kevin L.; Woody, Neil M.; Reddy, Chandana A.; Zhuang, Tingliang; Magnelli, Anthony; Djemil, Toufik

    2014-09-01

    Purpose: To review outcomes of 2 single-fraction lung stereotactic body radiation therapy (SBRT) schedules used for medically inoperable early stage lung cancer. Methods and Materials: Patients in our institution have been treated on and off protocols using single-fraction SBRT (30 Gy and 34 Gy, respectively). All patients had node-negative lung cancer measuring ≤5 cm and lying ≥2 cm beyond the trachea-bronchial tree and were treated on a Novalis/BrainLAB system with the ExactTrac positioning system for daily image guidance. Results: For the interval from 2009 to 2012, 80 patients with 82 lesions were treated with single-fraction lung SBRT. Fifty-five patients (69%) and 25 patients (31%) received 30 Gy and 34 Gy, respectively. In a comparison of 30 Gy and 34 Gy cohorts, patient and tumor characteristics were balanced and median follow-up in months was 18.7 and 17.8, respectively. The average heterogeneity-corrected mean doses to the target were 33.75 Gy and 37.94 Gy for the 30-Gy and 34-Gy prescriptions, respectively. Comparing 30-Gy and 34-Gy cohorts, 92.7% and 84.0% of patients, respectively, experienced no toxicity (P was not significant), and had neither grade 3 nor higher toxicities. For the 30-Gy and 34-Gy patients, rates of 1-year local failure, overall survival, and lung cancer-specific mortality were 2.0% versus 13.8%, 75.0% versus 64.0%, and 2. 1% versus 16.0%, respectively (P values for differences were not significant). Conclusions: This is the largest single-fraction lung SBRT series yet reported. and it confirms the safety, efficacy, and minimal toxicity of this schedule for inoperable early stage lung cancer.

  11. Clinical characteristics and outcome of patients with stage III esophageal carcinoma: a single-center experience from Turkey.

    PubMed

    Ugur, Vahide I; Kara, Sakire P; Kucukplakci, Bulent; Demirkasimoglu, Taciser; Misirlioglu, Cem; Ozgen, Aytul; Elgin, Yesim; Sanri, Ergun; Altundag, Kadri; Ozdamar, Nadi

    2008-01-01

    Esophageal carcinoma is an extremely deadly disease, and prognosis is poor. We retrospectively evaluated stage III esophageal carcinoma patients in our center. Median age of the patients was 52. Men to women ratio were 3/1. Epidermoid carcinoma was the major histology. Incidence of esophageal carcinoma was higher in the distal and middle third of the esophagus. In 19 patients tumor size was more than 5 cm. In total of 17 of the patients were operated. About 58 patients were irradiated. About 45 of the patients were irradiated with curative intent, 31 of them were primarily irradiated and 14 of them were irradiated postoperatively. Only 13 of the patients received concurrent chemoradiotherapy. Overall 1, 2, 3, and 4 year survival rates were 38.9%, 11.1%, 5.6%, and %1.9, respectively and median survival was 12 months. Median survival for tumors located in cervical esophageal, middle esophagus, and distal esophagus were 23, 8, and 14 months, respectively. One, 2, 3, 4 year survival rates of operated patients were 58.8%, 29.4%, 17.6%, 5.9%, respectively and median survival was 23 months. For inoperable patients 1 and 2 year survival rates were 29.7% and 2.7% and median survival was 8 months. Differences between operable and inoperable patients were statistically significant (P: 0.0003). One, 2, 3, 4 years survival results of patients treated with surgery and postoperative radiotherapy was 62.5%, 25%, 12.5%, 12.5% and median survival was 21 months, 1, 2, 3, 4 years survival results of patients treated with surgery and concurrent chemoradiotherapy was 55.6%, 33.3%, 22.2%, and 0% and median survival was 27 months. There was no statistically significant difference between groups (P: 0.5390). During the therapy, disphagia was the major side effect observed in seven patients. Fatigue, pain, and mild weight loss were the other side effects. Three patients could not tolerate the treatment and left the therapy. We demonstrated that stage III esophageal carcinoma is an extremely

  12. Intraoperative radiation therapy delivered prior to lumpectomy for early-stage breast cancer: a single institution study

    PubMed Central

    Yu, Wei; Lin, Zhi; Ju, Zhong-Jian; Li, Xi-Ru; Zhang, Yan-Jun; Kong, Qing-Long; Gong, Han-Shun; Wang, Jian-Dong; Ma, Lin

    2015-01-01

    Objective: To evaluate the safety, cosmesis, and clinical outcome of intraoperative electron radiation therapy (IOERT) delivered prior to lumpectomy for early-stage breast cancer. Methods: From December 2008 to March 2012, 75 breast cancer patients (ages 34-66 years) were treated with IOERT during breast conservative surgery. IOERT was delivered using a mobile linear accelerator. Suitable energy and applicator size were chosen to ensure coverage of the tumor with anterior and posterior margins of 1 cm and lateral margins of 2 cm. Patients with sentinel node metastases or younger than 40 years received 8 Gy as boost followed by post-operative external beam radiation therapy of 50 Gy/25F; the others had 15 Gy, prescribed to the 90% isodose depth. Adjuvant treatment consisted of chemotherapy (55 patients), hormonal therapy (59 patients), or combined chemotherapy and hormonal therapy (41 patients). The safety, cosmesis, and short-term outcome were evaluated. Results: Median follow-up was 54 months (range: 30-66 months). Two (2.7%) patients developed post-surgical hematoma. Six (8.0%) patients developed mild breast fibrosis. Eight (10.7%) patients suffered from local pain. One (1.2%) patient experienced a post-operative infection. Sixteen (21.3%) patients developed Grade 1 pulmonary fibrosis. Forty-three (57.3%) patients had an excellent cosmetic result and 23 (30.7%) had a good cosmetic result. Three patients had an ipsilateral breast recurrence, with an actual 3-year local recurrence rate of 4.0%. One patient had an ipsilateral axillary recurrence, resulting in a 3-year regional recurrence rate of 1.3%. No distant metastases or deaths were observed. The 3-year disease free survival was 94.6%. Conclusions: Intraoperative electron radiation therapy delivered prior to lumpectomy is safe and feasible for selected patients with early-stage breast cancer. Early side effects, cosmesis and short-term efficacy are acceptable, but a longer follow-up is needed for evaluation of

  13. Nitrogen release during coal combustion

    SciTech Connect

    Baxter, L.L.; Mitchell, R.E.; Fletcher, T.H.; Hurt, R.H.

    1995-02-01

    Experiments in entrained flow reactors at combustion temperatures are performed to resolve the rank dependence of nitrogen release on an elemental basis for a suite of 15 U.S. coals ranging from lignite to low-volatile bituminous. Data were obtained as a function of particle conversion, with overall mass loss up to 99% on a dry, ash-free basis. Nitrogen release rates are presented relative to both carbon loss and overall mass loss. During devolatilization, fractional nitrogen release from low-rank coals is much slower than fractional mass release and noticeably slower than fractional carbon release. As coal rank increases, fractional nitrogen release rate relative to that of carbon and mass increases, with fractional nitrogen release rates exceeding fractional mass and fractional carbon release rates during devolatilization for high-rank (low-volatile bituminous) coals. At the onset of combustion, nitrogen release rates increase significantly. For all coals investigated, cumulative fractional nitrogen loss rates relative to those of mass and carbon passes through a maximum during the earliest stages of oxidation. The mechanism for generating this maximum is postulated to involve nascent thermal rupture of nitrogen-containing compounds and possible preferential oxidation of nitrogen sites. During later stages of oxidation, the cumulative fractional loss of nitrogen approaches that of carbon for all coals. Changes in the relative release rates of nitrogen compared to those of both overall mass and carbon during all stages of combustion are attributed to a combination of the chemical structure of coals, temperature histories during combustion, and char chemistry.

  14. Coal preparation process using true-heavy-liquid separation

    SciTech Connect

    Baltich, L.K.; Malhotra, D.

    1990-12-20

    The Pittsburgh Energy Technology Center (PETC) is supporting work to develop advanced fine-coal cleaning processes including the exploitation of differences in specific gravity through the use of heavy-liquid media in hydrocyclones. The true-heavy-liquid media used for this program are solutions of sulfuric acid (H{sub 2}SO{sub 4}) and water. This concept takes advantage of the miscibility of the acid water to produce a range of heavy liquids up to a specific gravity of 1.84 for pure sulfuric acid. The main objective of this research program was to develop a true-heavy-liquid separation process to clean ultrafine coal using smelter-guide sulfuric acid. Three bituminous coals and one subbituminous coal were selected for testing. In general, single-stage true-heavy-liquid hydrocyclone process demonstrated similar performance characteristics to heavy-media separation processes under study by other investigators. True-heavy-liquid media has the advantage of allowing additional separation steps at other specific gravities for cleaning and scavenging without the introduction of another heavy liquid to the flowsheet. In addition, sulfuric acid is inorganic and can be neutralized and disposed of without the toxicity problems associated with the other type of heavy liquids under consideration. Preliminary economics analysis indicates that the cost for sulfuric acid makeup to the process may be prohibitive. 4 refs., 11 figs., 61 tabs.

  15. Modeling of hyperbaric filtration and dewatering of coal

    NASA Astrophysics Data System (ADS)

    Ranjan, Sushil

    Generalized models have been developed for continuous hyperbaric filtration to evaluate cake formation, filter capacity/filter area, cake dewatering, air consumption and residual cake saturation/residual cake moisture. Emphasis has been placed on cake structure as being a major controlling factor in fine coal dewatering by filtration. The effects of cake structure, as defined by the distributions of pore size and shape, have been reviewed. A simple model relating cake structure to feed particle characteristics is presented and applied to a practical case of fine coal dewatering. A binary packing model has been proposed to explain the existence of compressibility in non-compressible cakes. This model proposes an inner open-structure in the main cake, with the inner layer being compressible. The variation in the inner cake porosity with applied pressure has been used to explain the change in specific cake resistance and filter capacity (solids cake throughput). Process simulations have been conducted for a single stage and a two stage process, wherein the original feed has been split into a coarse fraction and a fine fraction (and then each fraction processed separately). The process simulations for a two stage process show a lot of promise as this leads to a lowering of the required filter area and the residual cake moisture. The required filter area increases, while the residual cake moisture decreases as the cut size for the two stage process is increased. However, the advantages of a two stage process are adversely affected by an inefficient separation process, which leads to an increased filter area and a higher residual cake moisture and the two stage process approaches a single stage process.

  16. Chemical characteristics of Victorian brown coal

    SciTech Connect

    Perry, G.J.; Allardice, D.J.; Kiss, L.T.

    1983-08-01

    Extensive deposits of soft brown coal exist in Tertiary age sediments in a number of areas in Victoria and the largest single deposit occurs in the Latrobe Valley, about 150 kilometers east of Melbourne. In this region the coal seams often exceed 150 metres in thickness, with an overburden to coal ratio usually better than 1:2 making the coal ideally suited for large-scale open-cut mining. A recent study (1) has estimated the State's brown coal resources to be almost 200,000 million tonnes with approximately 52,000 million tonnes defined as usable reserves. About 85% of this coal is located in the Latrobe Valley. Since 1920 Latrobe Valley brown coal has been developed for power generation. The State Electricity Commission of Victoria (SECV) wins coal from two major open cuts at Yallourn and Morwell and operates coal fired power stations which presently consume approximately 35 million tonnes per annum. In addition to power generation, small quantities of brown coal are used for briquette manufacture and char production. Brown coal accounts for about 95% of Victoria's non-renewable energy reserves and it is now recognized that with suitable up-grading, primarily drying, it has the potential to become the basis of the supply of energy in a variety of forms.

  17. Effects of sludge recirculation rate and mixing time on performance of a prototype single-stage anaerobic digester for conversion of food wastes to biogas and energy recovery.

    PubMed

    Ratanatamskul, Chavalit; Saleart, Tawinan

    2016-04-01

    Food wastes have been recognized as the largest waste stream and accounts for 39.25 % of total municipal solid waste in Thailand. Chulalongkorn University has participated in the program of in situ energy recovery from food wastes under the Ministry of Energy (MOE), Thailand. This research aims to develop a prototype single-stage anaerobic digestion system for biogas production and energy recovery from food wastes inside Chulalongkorn University. Here, the effects of sludge recirculation rate and mixing time were investigated as the main key parameters for the system design and operation. From the results obtained in this study, it was found that the sludge recirculation rate of 100 % and the mixing time of 60 min per day were the most suitable design parameters to achieve high efficiencies in terms of chemical oxygen demand (COD), total solids (TS), and total volatile solid (TVS) removal and also biogas production by this prototype anaerobic digester. The obtained biogas production was found to be 0.71 m(3)/kg COD and the composition of methane was 61.6 %. Moreover, the efficiencies of COD removal were as high as 82.9 % and TVS removal could reach 83.9 % at the optimal condition. Therefore, the developed prototype single-stage anaerobic digester can be highly promising for university canteen application to recover energy from food wastes via biogas production.

  18. Single stage, low noise, advanced technology fan. Volume 5: Fan acoustics. Section 2: One-third octave data tabulations and selected narrowband traces

    NASA Technical Reports Server (NTRS)

    Jutras, R. R.

    1976-01-01

    The raw-acoustic data corrected to standard day, from acoustic tests performed on a 0.508-scale fan vehicle of a 111,300 newton thrust, full-size engine, which has application on an advanced transport aircraft, are presented. The single-stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec to achieve the desired pressure ratio in a single-stage fan with low radius ratio, and to maintain adequate stall margin. The two basic approaches taken in the acoustic design were: (1) minimization of noise at the source, and (2) suppression of the generated noise in the inlet and bypass exhaust duct. Suppression of the generated noise was accomplished in the inlet through use of the hybrid concept (wall acoustic treatment plus airflow acceleration suppression) and in the exhaust duct with extensive acoustic treatment including a splitter. The goal of the design was attainment of twenty effective perceived noise decibels. The suppression goal of FAR 36-20 was not reached, but improvements in the technology of both front and aft fan-noise suppression were realized.

  19. Harvesting on a stage-structured single population model with mature individuals in a polluted environment and pulse input of environmental toxin.

    PubMed

    Jiao, Jianjun; Yang, Xiaosong; Chen, Lansun

    2009-09-01

    In the natural world, there are many species whose individual members have a life history that they take them with two distinct stages: immaturity and maturity. In particular, we have in mind mammalian populations and some amphibious animals. We improve the assumption of a single population as a whole. It is assumed that the immature individuals and mature individuals are divided by a fixed period. This paper concentrates on the study of a stage-structured single population model with mature individuals in a polluted environment and pulse input of environmental toxin at fixed moments. Furthermore, the mature individuals are harvested continuously. We show that the population goes extinct if the harvesting rate is beyond a critical threshold. Conditions for the extended permanence of the population are also examined. From the biological point of view, it is easy to protect species by controlling the harvesting amount, impulsive period of the exogenous input of toxin and toxin impulsive input amount, etc. Our results provide reasonable tactics for biological resource management.

  20. β-Catenin stabilization stalls the transition from double-positive to single-positive stage and predisposes thymocytes to malignant transformation

    PubMed Central

    Guo, Zhuyan; Dose, Marei; Kovalovsky, Damian; Chang, Rui; O'Neil, Jennifer; Look, A. Thomas; von Boehmer, Harald; Khazaie, Khashayarsha

    2007-01-01

    Activation of β-catenin has been causatively linked to the etiology of colon cancer. Conditional stabilization of this molecule in pro-T cells promotes thymocyte development without the requirement for pre-TCR signaling. We show here that activated β-catenin stalls the developmental transition from the double-positive (DP) to the single-positive (SP) thymocyte stage and predisposes DP thymocytes to transformation. β-Catenin–induced thymic lymphomas have a leukemic arrest at the early DP stage. Lymphomagenesis requires Rag activity, which peaks at this developmental stage, as well as additional secondary genetic events. A consistent secondary event is the transcriptional up-regulation of c-Myc, whose activity is required for transformation because its conditional ablation abrogates lymphomagenesis. In contrast, the expression of Notch receptors as well as targets is reduced in DP thymocytes with stabilized β-catenin and remains low in the lymphomas, indicating that Notch activation is not required or selected for in β-catenin–induced lymphomas. Thus, β-catenin activation may provide a mechanism for the induction of T-cell–acute lymphoblastic leukemia (T-ALL) that does not depend on Notch activation. PMID:17317856

  1. [ORP in the Main Anoxic Stage as the Control Parameter for Nitrogen and Phosphorus Removal in the Single Sludge System with a Continuous Flow].

    PubMed

    Wang, Xiao-ling; Song, Tie-hong; Yin, Bao-yong; Li Jing-wen; Li, Zi-qi; Yu, Yong

    2015-07-01

    To optimize the performance of nitrogen and phosphorus removal, based on test results and mass balance, the feasibility of control for nitrogen and phosphorus removal in the single sludge system with a continuous flow using ORP in the main anoxic stage (ORPm) was investigated, meanwhile, the objective laws of conversion for nitrogen and phosphorus under different ORPm were expounded. During the experiments, nitration liquid internal circulation flow rate was controlled as the variable. The OPRm was controlled by PLC automatically, and the other operation parameters remained unchanged. The experiments tested six different ORPs in main anoxic stage affecting nitrogen and phosphorus removal, i.e., -143, -123, -105, -95, -72, and -57 mV. The ammonia concentration changed a little in effluent under the condition of different ORP.s, however, the TN and TP concentrations changed obviously. When the ORPm was controlled as -95 mV, the active sludge reached the maximal nitrogen and phosphorus removal with the continuous flow. According to mass balance calculation, when ORPm increased from -143 mV to -57 mV, (1) In the main anoxic stage, nitrate nitrogen reaction rates were 214. 40, 235. 16, 241. 16, 244. 02, 240. 90 and 233. 65 mg.h-1, respectively; the amount of total nitrogen conversions were 244. 92, 255. 85, 328. 04, 347. 45, 336. 42 and 320. 60 mg.h-1, respectively; both reaction rates reached the peak at the ORPm of -95 mV; (2)Phosphorus release rates in anaerobic stage were -214. 12, -228. 64, -259. 26, -264.54, -256.92 and -252.84 mg.h-1, respectively; total phosphorus absorption rates were 252. 15, 275.85, 332. 25, 338. 10, 336. 15 and 324. 30 mg.h-1, respectively, and phosphorus absorption rates were 30. 27, 62. 14, 124. 58, 154. 41, 150. 41 and 138. 30 mg.h-1, respectively, in the main anoxic stage; phosphorus absorption rates reached the peak when ORPm was -95 mV. The experiments revealed that ORPm could be used as the control parameter of nitrogen and phosphorus

  2. A 2-Stage Genome-Wide Association Study to Identify Single Nucleotide Polymorphisms Associated With Development of Erectile Dysfunction Following Radiation Therapy for Prostate Cancer

    SciTech Connect

    Kerns, Sarah L.; Stock, Richard; Stone, Nelson; Buckstein, Michael; Shao, Yongzhao; Campbell, Christopher; Rath, Lynda; De Ruysscher, Dirk; Lammering, Guido; Hixson, Rosetta; Cesaretti, Jamie; Terk, Mitchell; Ostrer, Harry; Rosenstein, Barry S.

    2013-01-01

    Purpose: To identify single nucleotide polymorphisms (SNPs) associated with development of erectile dysfunction (ED) among prostate cancer patients treated with radiation therapy. Methods and Materials: A 2-stage genome-wide association study was performed. Patients were split randomly into a stage I discovery cohort (132 cases, 103 controls) and a stage II replication cohort (128 cases, 102 controls). The discovery cohort was genotyped using Affymetrix 6.0 genome-wide arrays. The 940 top ranking SNPs selected from the discovery cohort were genotyped in the replication cohort using Illumina iSelect custom SNP arrays. Results: Twelve SNPs identified in the discovery cohort and validated in the replication cohort were associated with development of ED following radiation therapy (Fisher combined P values 2.1 Multiplication-Sign 10{sup -5} to 6.2 Multiplication-Sign 10{sup -4}). Notably, these 12 SNPs lie in or near genes involved in erectile function or other normal cellular functions (adhesion and signaling) rather than DNA damage repair. In a multivariable model including nongenetic risk factors, the odds ratios for these SNPs ranged from 1.6 to 5.6 in the pooled cohort. There was a striking relationship between the cumulative number of SNP risk alleles an individual possessed and ED status (Sommers' D P value = 1.7 Multiplication-Sign 10{sup -29}). A 1-allele increase in cumulative SNP score increased the odds for developing ED by a factor of 2.2 (P value = 2.1 Multiplication-Sign 10{sup -19}). The cumulative SNP score model had a sensitivity of 84% and specificity of 75% for prediction of developing ED at the radiation therapy planning stage. Conclusions: This genome-wide association study identified a set of SNPs that are associated with development of ED following radiation therapy. These candidate genetic predictors warrant more definitive validation in an independent cohort.

  3. A single center kidney transplant experience among ten Caucasian females with end-stage renal disease due to scleroderma
.

    PubMed

    Saxena, Nishkarsh; Djamali, Arjang; Astor, Brad C; Mohamed, Maha; Mandelbrot, Didier; Parajuli, Sandesh

    2017-04-13

    There is limited information on kidney transplant recipients with end-stage renal disease (ESRD) due to scleroderma. We conducted an observational study on kidney transplant recipients with ESRD due to scleroderma who received kidney transplant at our center between 01/1994 and 06/2013. During the study period, there were 10 kidney transplant recipients, all of whom were Caucasian females. Seven of them were living-donor kidney transplant recipients, and the mean age at time of transplant was 56.6 ± 11.99 years. The mean post-transplant follow-up was 76.75 ± 56.18 months; the mean dialysis vintage was 46.4 ± 80.35 months, ranging from 8 to 272 months; and the mean serum creatinine (Cr) levels at 3, 6, and 12 months were 1.31 ± 0.47 mg/dL, 1.35 ± 0.51 mg/dL, and 1.34 ± 0.49 mg/dL, respectively. There were 5 graft failures with median graft survival of 101 months. None had recurrence of scleroderma renal crisis. In those without graft failure, the mean serum Cr at last follow-up was 0.96 ± 0.39 mg/dL. Six patients were on angiotensin converting enzyme inhibitors (ACE-I) after transplant. In univariate analysis, none of the factors including, age at time of transplant, dialysis vintage, use of ACE-I, living-donor transplant, cytomegalovirus infection, and serum Cr at 1 year were predictive of graft failure. In our study, we hoped to find outcomes and various factors associated with graft failure in these patients. We found a wide variation in outcomes after kidney transplantation. More studies are needed to assess the factors that may influence the graft survival in this rare disease.
.

  4. Urochordate ascidians possess a single isoform of Aurora kinase that localizes to the midbody via TPX2 in eggs and cleavage stage embryos.

    PubMed

    Hebras, Celine; McDougall, Alex

    2012-01-01

    Aurora kinases are key proteins found throughout the eukaryotes that control mitotic progression. Vertebrate Aurora-A and B kinases are thought to have evolved from a single Aurora-kinase isoform closest to that found in present day urochordates. In urochordate ascidians Aurora binds both TPX2 (a vertebrate AURKA partner) and INCENP (a vertebrate AURKB partner) and localizes to centrosomes and spindle microtubules as well as chromosomes and midbody during both meiosis and mitosis. Ascidian Aurora also displays this localization pattern during mitosis in echinoderms, strengthening the idea that non-vertebrate deuterostomes such as the urochordates and echinoderms possess a single form of Aurora kinase that has properties of vertebrate Aurora-kinase A and B. In the ascidian, TPX2 localizes to the centrosome and the spindle poles also as in vertebrates. However, we were surprised to find that TPX2 also localized strongly to the midbody in ascidian eggs and embryos. We thus examined more closely Aurora localization to the midbody by creating two separate point mutations of ascidian Aurora predicted to perturb binding to TPX2. Both forms of mutated Aurora behaved as predicted: neither localized to spindle poles where TPX2 is enriched. Interestingly, neither form of mutated Aurora localized to the midbody where TPX2 is also enriched, suggesting that ascidian Aurora midbody localization required TPX2 binding in ascidians. Functional analysis revealed that inhibition of Aurora kinase with a pharmacological inhibitor or with a dominant negative kinase dead form of Aurora caused cytokinesis failure and perturbed midbody formation during polar body extrusion. Our data support the view that vertebrate Aurora-A and B kinases evolved from a single non-vertebrate deuterostome ancestor. Moreover, since TPX2 localizes to the midbody in ascidian eggs and cleavage stage embryos it may be worthwhile re-assessing whether Aurora A kinase or TPX2 localize to the midbody in eggs and

  5. Single-stage multilevel soft-tissue surgery in the lower limbs with spastic cerebral palsy: Experience from a rehabilitation unit

    PubMed Central

    Gupta, Anupam; Srivastava, Abhishek; Taly, Arun B; Murali, Thyloth

    2008-01-01

    Background: To assess the effect of single-stage multilevel soft-tissue surgery (Single Event Multiple Level Resections, SEMLR) on deformities and locomotion in patients with cerebral palsy (CP) with static contracture(s) in lower limbs. Patients and Methods: Study included 34 patients (M:F, 23:11) with mean age of 9.53 ± 3.92 years (4–16 years). Among them 22 had diplegia and four each had quadriplegia and right and left hemiplegia. Fourteen patients (41.2%) had their intelligence quotient (IQ) in the normal range (IQ ≥ 80), while others had mental retardation (MR) of varying severity: borderline MR (IQ = 70–79) in 12, mild MR (IQ = 50–69) in 5, and moderate MR (IQ = 35–49) in patients 3. All patients underwent surgery (total number of procedures 153, average 4.5 procedures/patient) over a period of 30 months (April 2005 to September 2007). Improvement in functional abilities and locomotion was assessed using Gross Motor Functional Classification Scale (GMFCS) scores and by physical examination. Results: Significant improvement in function was observed (P = 0.000) after surgery when comparing the preoperative and postoperative GMFCS scores. All patients were maintaining ambulation at a mean follow-up duration of 13.12 ± 6.07 months (3–24 months), with five patients using knee-ankle-foot orthoses (KAFO), 22 using ankle-foot orthoses (AFO), and six patients using knee gaiters. Sixteen patients were using walker, and two were using crutches as assistive devices. Conclusion: This study suggests that CP patients with good trunk control and static contractures at multiple joints in the lower limbs can be made ambulant with single-stage multilevel soft-tissue surgery. It has to be a team effort of the surgeon and the rehabilitation team in the postoperative period for the attainment of satisfactory goal. PMID:19753234

  6. Stage-independent, single lead EEG sleep spindle detection using the continuous wavelet transform and local weighted smoothing.

    PubMed

    Tsanas, Athanasios; Clifford, Gari D

    2015-01-01

    Sleep spindles are critical in characterizing sleep and have been associated with cognitive function and pathophysiological assessment. Typically, their detection relies on the subjective and time-consuming visual examination of electroencephalogram (EEG) signal(s) by experts, and has led to large inter-rater variability as a result of poor definition of sleep spindle characteristics. Hitherto, many algorithmic spindle detectors inherently make signal stationarity assumptions (e.g., Fourier transform-based approaches) which are inappropriate for EEG signals, and frequently rely on additional information which may not be readily available in many practical settings (e.g., more than one EEG channels, or prior hypnogram assessment). This study proposes a novel signal processing methodology relying solely on a single EEG channel, and provides objective, accurate means toward probabilistically assessing the presence of sleep spindles in EEG signals. We use the intuitively appealing continuous wavelet transform (CWT) with a Morlet basis function, identifying regions of interest where the power of the CWT coefficients corresponding to the frequencies of spindles (11-16 Hz) is large. The potential for assessing the signal segment as a spindle is refined using local weighted smoothing techniques. We evaluate our findings on two databases: the MASS database comprising 19 healthy controls and the DREAMS sleep spindle database comprising eight participants diagnosed with various sleep pathologies. We demonstrate that we can replicate the experts' sleep spindles assessment accurately in both databases (MASS database: sensitivity: 84%, specificity: 90%, false discovery rate 83%, DREAMS database: sensitivity: 76%, specificity: 92%, false discovery rate: 67%), outperforming six competing automatic sleep spindle detection algorithms in terms of correctly replicating the experts' assessment of detected spindles.

  7. The effect of selective absorption on coal conversion, October--December 1991

    SciTech Connect

    Larsen, J.W.; Lazarov, L.; Amui, J.

    1992-05-01

    The objectives of this report are to (1) determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; (2) determine the composition of the solvent absorbed by and present within the coal in the first stage of direct coal liquefaction.

  8. Selective solvent absorption in coal conversion. Quarterly report, July 1, 1991--September 30, 1991

    SciTech Connect

    Larsen, J.W.; Lapucha, A.; Lazarov, L.; Amui, J.

    1992-04-01

    The objectives of this project are: (1) to determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; and (2) to determine the composition of the solvent absorbed by and present within the coal in the first stage of direct coal liquefaction.

  9. Oxy-coal Combustion Studies

    SciTech Connect

    Wendt, J.; Eddings, E.; Lighty, J.; Ring, T.; Smith, P.; Thornock, J.; Y Jia, W. Morris; Pedel, J.; Rezeai, D.; Wang, L.; Zhang, J.; Kelly, K.

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  10. Laser ignition of pulverized coals

    SciTech Connect

    Chen, J.C.; Taniguchi, Masayuki; Narato, Kiyoshi; Ito, Kazuyuki . Hitachi Research Lab.)

    1994-04-01

    The authors present a novel experiment to study the ignition of pulverized coal. A dilute stream of particles is dropped into a laminar, upward-flow wind tunnel with a quartz test section. The gas stream is not preheated. A single pulse from a Nd:YAG laser is focused through the tunnel and ignites the fuel. The transparent test section and cool walls allow for optical detection of the ignition process. In this article they describe the experiment and demonstrate its capabilities by observing the ignition behavior of spherical, amorphous-carbon particles and two coal: an anthracite and a high-volatile bituminous coal. The ignition behaviors of the carbon spheres and the anthracite are as expected for heterogeneous ignition, while the mechanism of the bituminous coal is uncertain. Calculations are also presented to describe the physical behavior of a laser-heated particle, and the heat transfer and chemistry of heterogeneous ignition.

  11. Advanced coal gasification system for electric power generation. Third quarterly progress report, April 1-June 30, 1980

    SciTech Connect

    1980-07-25

    The operation, maintenance and modifications to the Westinghouse gasification process development unit during the quarter are reviewed. The tests of the gasifier-agglomerator included direct coal feed as well as oxygen-blown gasification of a char or coal bed. Then the whole system was tested in single and double stage operation. Laboratory support involved fluidized bed test facilities at ambient temperature and at design temperature for devolatilization and gasification studies. Other laboratory systems were related to thermal analysis and pressurized high temperature studies of gasification and gas cleaning. (LTN)

  12. Fixed-bed gasification research using US coals. Volume 11. Gasification of Minnesota peat. [Peat pellets and peat sods

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a coooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the eleventh volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of peat pellets and peat sods during 3 different test periods. 2 refs., 20 figs., 13 tabs.

  13. Prevention of acid drainage from stored coal

    SciTech Connect

    Olem, H.

    1983-01-01

    It was found that application of a 50-mg/l solution of the detergent sodium lauryl sulphate to a coal stockpile inhibited the activity of the bacteria causing acid formation and leaching and kept the drainage neutral for 60 days. The cost of a single application would be 0.4 cents/t of coal.

  14. Improved Supercritical-Solvent Extraction of Coal

    NASA Technical Reports Server (NTRS)

    Compton, L.

    1982-01-01

    Raw coal upgraded by supercritical-solvent extraction system that uses two materials instead of one. System achieved extraction yields of 20 to 49 weight percent. Single-solvent yields are about 25 weight percent. Experimental results show extraction yields may be timedependent. Observed decreases in weight of coal agreed well with increases in ash content of residue.

  15. Coal: special report number 2

    USGS Publications Warehouse

    Keenlyne, Kent D.

    1977-01-01

    The Fish and Wildlife Service has extensive biological expertise within the Department of Interior and exerts national leadership in the management and protection of the nation's fish and wildlife resources, their habitat, and environment. Specifically, the Office of Biological Services obtains and assimilates biological and environmental data and identifies additional informational needs and means to provide environmental and biological input into major natural resource decisions. Coal Coordinators assist in carrying out Fish and Wildlife Service involvement in the Interior Department Coal Leasing Program through a multi-stage process designed to assemble existing fish and wildlife inventory data and to prioritize fish and wildlife values in areas subject to coal leasing and associated development. This report is designed to identify possible areas of concern for wildlife and its habitat in Wyoming in the development of coal and the associate implication of land use changes. This report summarizes past and present development of the coal resource in Wyoming in anticipation of future identification of data needs for making sound resource decisions in the development of coal.

  16. Single microparticle launching method using two-stage light-gas gun for simulating hypervelocity impacts of micrometeoroids and space debris.

    PubMed

    Kawai, Nobuaki; Tsurui, Kenji; Hasegawa, Sunao; Sato, Eiichi

    2010-11-01

    A single microparticle launching method is described to simulate the hypervelocity impacts of micrometeoroids and microdebris on space structures at the Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency. A microparticle placed in a sabot with slits is accelerated using a rifled two-stage light-gas gun. The centrifugal force provided by the rifling in the launch tube separates the sabot. The sabot-separation distance and the impact-point deviation are strongly affected by the combination of the sabot diameter and the bore diameter, and by the projectile diameter. Using this method, spherical projectiles of 1.0-0.1 mm diameter were launched at up to 7 km/s.

  17. Determination of blade-to-coolant heat-transfer coefficients on a forced-convection, water-cooled, single-stage turbine

    NASA Technical Reports Server (NTRS)

    Freche, John C; Schum, Eugene F

    1951-01-01

    Blade-to-coolant convective heat-transfer coefficients were obtained on a forced-convection water-cooled single-stage turbine over a large laminar flow range and over a portion of the transition range between laminar and turbulent flow. The convective coefficients were correlated by the general relation for forced-convection heat transfer with laminar flow. Natural-convection heat transfer was negligible for this turbine over the Grashof number range investigated. Comparison of turbine data with stationary tube data for the laminar flow of heated liquids showed good agreement. Calculated average midspan blade temperatures using theoretical gas-to-blade coefficients and blade-to-coolant coefficients from stationary-tube data resulted in close agreement with experimental data.

  18. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 94, Group ESH-19. Progress report

    SciTech Connect

    Conrad, R.; Childs, M.; Lyons, C.R.; Coriz, F.

    1996-08-01

    ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory during FY94 to characterize possible contaminant movement out of Area G through surface-water and sediment runoff. These samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. Ten metals were also analyzed on selected soils using analytical laboratory techniques. All radiochemical data are compared with analogous samples collected during FY 93 and reported in LA-12986. Baseline concentrations for future disposal operations were established for metals and radionuclides by a sampling program in the proposed Area G Expansion Area. Considering the amount of radioactive waste that has been disposed at Area G, there is evidence of only low concentrations of radionuclides on perimeter surface soils. Consequently, little radioactivity is leaving the confines of Area G via the surface water runoff pathway.

  19. Effect of insurance payer status on the surgical treatment of early stage breast cancer: data analysis from a single health system.

    PubMed

    Adepoju, Linda; Wanjiku, Stephen; Brown, Megan; Qu, Weikai; Williams, Mallory; Redfern, Roberta E; Sferra, Joseph J

    2013-06-01

    The effect of insurance payer status on surgical treatment of early stage breast cancer is unclear. This retrospective study examined the effect of insurance payer on mastectomy rates of 1539 women treated within a single health system. Women with Medicaid had significantly larger tumors compared with those with private insurance (PI) at diagnosis (3.3 cm vs 2.1 cm, P < .05) and were more likely to be treated with mastectomy for larger tumors compared with women with PI. However, women with PI were more likely to have mastectomy for smaller tumors; among women with tumors less than 2 cm, 11% with Medicaid underwent mastectomy compared with 47% with PI (P < .05). Overall, when compared with those with PI, women with Medicaid were more likely to receive mastectomy (60% vs 39%, P < .05).

  20. High-resolution X-ray phase-contrast tomography from single-distance radiographs applied to developmental stages of Xenopus laevis

    NASA Astrophysics Data System (ADS)

    Moosmann, J.; Altapova, V.; Helfen, L.; Hänschke, D.; Hofmann, R.; Baumbach, T.

    2013-03-01

    Considering a pure and not necessarily weak phase object, we review a noniterative and nonlinear single-distance phase-retrieval algorithm. The latter exploits the fact that a well-known linear contrast-transfer function, which incorporates all orders in object-detector distance, can be modified to yield a quasiparticle dispersion. Accepting a small loss of information, this algorithm also retrieves the high-frequency parts of the phase in an artefact free way. We point out an extension of this highly resolving quasiparticle approach for mixed objects by assuming a global attenuation-phase duality. Tomographically reconstructing two developmental stages in Xenopus laevis, we compare our approach with a linear algorithm, based on the transport-of-intensity equation, which suppresses high-frequency information.

  1. Temperature and orientation dependent plasticity features of Cu and Al single crystals under axial compression. 1: Lattice rotation effects and true hardening stages

    SciTech Connect

    Mecif, A.; Bacroix, B.; Franciosi, P.

    1997-01-01

    Compressive axial loadings are performed on differently oriented aluminium and copper single crystals between room temperature and 0.9 times the melting temperature. In this first part of the work, attention is paid to the influence on the hardening evolution of the type of active strain mechanisms and the associated lattice rotations. The lattice rotation amplitudes for unstable orientations decrease when the temperature increases and almost vanish above 0.7 T{sub m}. Octahedral straight slip traces evolve into weavy and distant ones, and occurrence of non-octahedral slip is observed. The stress-strain curves are resolved on the dominant octahedral slip system. The comparison for different orientations of this reference hardening modulus allows to separate lattice rotation effects and true hardening stages. This representation allows to estimate to what extent hardening characteristics can be considered as orientation independent. Part II, devoted to quantitative analyses on these hardening parameters, will follow.

  2. The Effect of Inlet Temperature and Pressure on the Efficiency of a Single-stage Impulse Turbine Having a 13.2-inch Pitch-line Diameter Wheel

    NASA Technical Reports Server (NTRS)

    Chanes, Ernest R.; Carman, L. Robert

    1945-01-01

    Efficiency tests have been conducted on a single-stage impulse turbine having a 13.2-inch pitch-line diameter wheel and a cast nozzle diaphram over a range of turbine speeds from 3000 to 17,000 rpm, pressure ratios from 1.5 to 5.0, inlet total temperatures from 1200 deg to 2000 deg R, and inlet total pressures from 18 to 59 inches of mercury absolute. The effect of inlet temperature and pressure on turbine efficiency for constant pressure ration and blade-to-jet speed ration is correlated against a factor derived from the equation for Reynolds number. The degree of correlation indicates that the change in turbine efficiency with inlet temperature and [ressure for constant pressure ration and blade-to-jet speed ration is principally a Reynolds number effect.

  3. [Effects of two typical substrates as the sole carbon source on biological phosphorus removal with a single-stage oxic process].

    PubMed

    Liu, Yi-Lin; Wang, Dong-Bo; Li, Xiao-Ming; Yang, Qi; Zou, Gao-Long; Jia, Bin; Zeng, Tian-Jing; Ding, Yan; Zeng, Guang-Ming

    2010-01-01

    To investigate the performances of phosphorus removal in a sequencing batch reactor (SBR) with single-stage oxic process using synthetical wastewater, glucose (R1) and acetate (R2) were fed to two SBRs as the sole carbon source, respectively. The operation run mode was determined to be: influent --> aeration (4 h) --> settling (8 h) --> effluent. The results showed that the performance of phosphorus removal in R1 was higher than that in R2 after steady-operation. Total phosphorus (TP) removed per MLVSS in R1 and R2 were 7.2-7.7 and 3.8-4.6 mg x g(-1) during aeration, respectively, but the rate of phosphorus release at the two reactors were 3.6-3.8 and 2.7-3.1 mg x g(-1) during the idle zone, respectively. The energy storage of poly-beta-hydroxyalkanoates (PHA) was constant nearly in R1 during the whole period, but glycogen was accumulated to the maximum value at 30 minutes of aeration, and then was decreased to the initial level. However in R2, PHA and glycogen were both accumulated at about 45 minutes of aeration. This phenomenon suggested that glycogen is the main energy source for metabolism during aerobic period in R1, and the main energy resource come from the decomposition of PHA and the hydrolysis of glycogen in R2. The facts showed that glycogen could replace PHAs to supply energy for phosphate uptake and polyphosphate accumulation in such a single-stage oxic process. Since glycogen accumulated in R1 was more than that in R2, the efficiency of phosphorus removal in R1 was higher than that in R2.

  4. Single-stage Reconstruction of Elbow Flexion Associated with Massive Soft-Tissue Defect Using the Latissimus Dorsi Muscle Bipolar Rotational Transfer

    PubMed Central

    Cuéllar, Vanessa G.; Ghiassi, Alidad; Sharpe, Frances

    2016-01-01

    Introduction: In the upper extremity, the latissimus dorsi muscle can be used as an ipsilateral rotational muscle flap for soft-tissue coverage or functional reconstruction of arm and elbow. Patients who have both major soft-tissue loss and functional deficits can be successfully treated with a single-stage functional latissimus dorsi rotational muscle transfer that provides simultaneous soft-tissue coverage and functional reconstruction. Methods: Our data base was queried for all patients undergoing a rotational latissimus dorsi muscle transfer for simultaneous soft-tissue coverage and functional reconstruction of elbow flexion. Four patients were identified. A chart review documented the mechanism of injury, associated injuries, soft-tissue defect size, number of surgical procedures, length of follow-up, last elbow range of motion, and flexion strength. Results: Four patients with loss of elbow flexion due to traumatic loss of the anterior compartment muscles and the overlying soft tissue underwent simultaneous soft-tissue coverage and elbow flexorplasty using the ipsilateral latissimus dorsi as a bipolar muscle rotational tissue transfer. All flaps survived and had a recovery of Medical Research Council Grade 4/5 elbow flexion strength. No additional procedures were required for elbow flexion. The surgical technique is described and supplemented with surgical technique video and patient outcome. Conclusions: This patient series augments the data provided in other series supporting the safety and efficacy of this procedure which provides both soft-tissue coverage and functional restoration of elbow flexion as a single-stage procedure in the setting of massive traumatic soft-tissue loss of the arm. PMID:27757363

  5. Evaluation of single and two-stage adaptive sampling designs for estimation of density and abundance of freshwater mussels in a large river

    USGS Publications Warehouse

    Smith, D.R.; Rogala, J.T.; Gray, B.R.; Zigler, S.J.; Newton, T.J.

    2011-01-01

    Reliable estimates of abundance are needed to assess consequences of proposed habitat restoration and enhancement projects on freshwater mussels in the Upper Mississippi River (UMR). Although there is general guidance on sampling techniques for population assessment of freshwater mussels, the actual performance of sampling designs can depend critically on the population density and spatial distribution at the project site. To evaluate various sampling designs, we simulated sampling of populations, which varied in density and degree of spatial clustering. Because of logistics and costs of large river sampling and spatial clustering of freshwater mussels, we focused on adaptive and non-adaptive versions of single and two-stage sampling. The candidate designs performed similarly in terms of precision (CV) and probability of species detection for fixed sample size. Both CV and species detection were determined largely by density, spatial distribution and sample size. However, designs did differ in the rate that occupied quadrats were encountered. Occupied units had a higher probability of selection using adaptive designs than conventional designs. We used two measures of cost: sample size (i.e. number of quadrats) and distance travelled between the quadrats. Adaptive and two-stage designs tended to reduce distance between sampling units, and thus performed better when distance travelled was considered. Based on the comparisons, we provide general recommendations on the sampling designs for the freshwater mussels in the UMR, and presumably other large rivers.

  6. Single-cell analysis of differences in transcriptomic profiles of oocytes and cumulus cells at GV, MI, MII stages from PCOS patients.

    PubMed

    Liu, Qiwei; Li, Yumei; Feng, Yun; Liu, Chaojie; Ma, Jieliang; Li, Yifei; Xiang, Huifen; Ji, Yazhong; Cao, Yunxia; Tong, Xiaowen; Xue, Zhigang

    2016-12-22

    Polycystic ovary syndrome (PCOS) is a common frequent endocrine disorder among women of reproductive age. Although assisted reproductive techniques (ARTs) are used to address subfertility in PCOS women, their effectiveness is not clear. Our aim was to compare transcriptomic profiles of oocytes and cumulus cells (CCs) between women with and without PCOS, and assess the effectiveness of ARTs in treating PCOS patients. We collected oocytes and CCs from 16 patients with and without PCOS patients to categorize them into 6 groups according to oocyte nuclear maturation. Transcriptional gene expression of oocyte and CCs was determined via single-cell RNA sequencing. The ratio of fertilization and cleavage was higher in PCOS patients than in non-PCOS patients undergoing ARTs, and there was no difference in the number of high-quality embryos between the groups. Differentially expressed genes including PPP2R1A, PDGFRA, EGFR, GJA1, PTGS2, TNFAIP6, TGF-β1, CAV1, INHBB et al. were investigated as potential causes of PCOS oocytes and CCs disorder at early stages, but their expression returned to the normal level at the metaphase II (MII) stage via ARTs. In conclusion, ARTs can improve the quality of cumulus-oocyte complex (COC) and increase the ratio of fertilization and cleavage in PCOS women.

  7. The treatment of advanced stage favorable histology non-Hodgkin's lymphoma: a preliminary report of a randomized trial comparing single agent chemotherapy, combination chemotherapy, and whole body irradiation

    SciTech Connect

    Hoppe, R.T.; Kushlan, P.; Kaplan, H.S.; Rosenberg, S.A.; Brown, B.W.

    1981-09-01

    Between 1975 and 1978, 51 patients with favorable histology non-Hodgkin's lymphomas, pathologic stage III-IV, were treated prospectively on a randomized treatment protocol. Treatment options were single alkylating agent chemotherapy, combination chemotherapy with cyclophosphamide, vincristine, and prednisone (CVP), or fractionated whole body irradiation followed by low dose involved field irradiation. The median follow-up interval in this group of patients is not 41 mo. Actuarial survival is excellent, 84% at 4 yr for the entire group, with similar survival observed for each of the three treatment options. Initial complete remission rates (64%, 88%, and 71%) were not significantly different in the three treatment arms. Frequent relapse after initial remission induction was noted, however, with a freedom from relapse at 4 yr of only 25%. The toxicities of the three therapies were acceptable. Acute complications of therapy were most numerous in the group of patients treated with CVP; however, long-term hematologic depression was most commonly observed in patients treated with whole body irradiation. In general, hematologic complications were more frequent among patients who had marrow involvement and intact spleens at the time of initial therapy. The relationship of this study to other clinical trials in the management of patients with advanced stage favorable histology lymphomas and its implications for future clinical trials are discussed.

  8. Single-cell analysis of differences in transcriptomic profiles of oocytes and cumulus cells at GV, MI, MII stages from PCOS patients

    PubMed Central

    Liu, Qiwei; Li, Yumei; Feng, Yun; Liu, Chaojie; Ma, Jieliang; Li, Yifei; Xiang, Huifen; Ji, Yazhong; Cao, Yunxia; Tong, Xiaowen; Xue, Zhigang

    2016-01-01

    Polycystic ovary syndrome (PCOS) is a common frequent endocrine disorder among women of reproductive age. Although assisted reproductive techniques (ARTs) are used to address subfertility in PCOS women, their effectiveness is not clear. Our aim was to compare transcriptomic profiles of oocytes and cumulus cells (CCs) between women with and without PCOS, and assess the effectiveness of ARTs in treating PCOS patients. We collected oocytes and CCs from 16 patients with and without PCOS patients to categorize them into 6 groups according to oocyte nuclear maturation. Transcriptional gene expression of oocyte and CCs was determined via single-cell RNA sequencing. The ratio of fertilization and cleavage was higher in PCOS patients than in non-PCOS patients undergoing ARTs, and there was no difference in the number of high-quality embryos between the groups. Differentially expressed genes including PPP2R1A, PDGFRA, EGFR, GJA1, PTGS2, TNFAIP6, TGF-β1, CAV1, INHBB et al. were investigated as potential causes of PCOS oocytes and CCs disorder at early stages, but their expression returned to the normal level at the metaphase II (MII) stage via ARTs. In conclusion, ARTs can improve the quality of cumulus-oocyte complex (COC) and increase the ratio of fertilization and cleavage in PCOS women. PMID:28004769

  9. Determination of the separation efficiencies of a single-stage cryogenic distillation setup to remove krypton out of xenon by using a (83m)Kr tracer method.

    PubMed

    Rosendahl, S; Brown, E; Cristescu, I; Fieguth, A; Huhmann, C; Lebeda, O; Murra, M; Weinheimer, C

    2015-11-01

    The separation of krypton and xenon is of particular importance for the field of direct dark matter search with liquid xenon detectors. The intrinsic contamination of the xenon with radioactive (85)Kr makes a significant background for these kinds of low count-rate experiments and has to be removed beforehand. This can be achieved by cryogenic distillation, a technique widely used in industry, using the different vapor pressures of krypton and xenon. In this paper, we present an investigation on the separation performance of a single stage distillation system using a radioactive (83m)Kr-tracer method. The separation characteristics under different operation conditions are determined for very low concentrations of krypton in xenon at the level of (83m)Kr/Xe = 1.9 ⋅ 10(-15), demonstrating, that cryogenic distillation in this regime is working. The observed separation is in agreement with the expectation from the different volatilities of krypton and xenon. This cryogenic distillation station is the first step on the way to a multi-stage cryogenic distillation column for the next generation of direct dark matter experiment XENON1T.

  10. Anaerobic digestion of municipal solid waste composed of food waste, wastepaper, and plastic in a single-stage system: performance and microbial community structure characterization.

    PubMed

    Wan, Shungang; Sun, Lei; Douieb, Yaniv; Sun, Jian; Luo, Wensui

    2013-10-01

    The performance of municipal organic solid waste anaerobic digestion was investigated using a single-stage bioreactor, and the microbial community structures were characterized during the digestion. The results showed that the biogas and methane production rates were 592.4 and 370.1L/kg with volatile solid added at the ratio of 2:1:1 for food waste, wastepaper, and plastic based on dry weight. The methane volume concentration fluctuated between 44.3% and 75.4% at steady stage. Acetic acid, propionic acid, and butyric acid were the major volatile fatty acids produced during the digestion process. The anaerobic process was not inhibited by the accumulation of ammonia and free ammonia. The bacterial community was found to consist of at least 21 bands of bacteria and 12 bands of archaea at the steady state. All of the results indicated that the mixture of food waste, wastepaper, and plastic could be efficiently co-digested using the anaerobic digestion system.

  11. Development of pressurized coal partial combustor

    SciTech Connect

    Yoshida, K.; Ino, T.; Yamamoto, T.; Kimura, N.

    1995-12-31

    The integrated gasification combined cycle (IGCC), an environment-friendly power generation system of high thermal efficiency, is being developed via various approaches around the world. The oxygen-blown entrained flow gasification process is a relatively simple method of producing medium calorie coal gas suitable for application to gas turbines. Various systems for this process have been developed to a demonstration level in Europe and America. Japan has actively been developing the air-blown process. However, taking stable molten slag discharge into consideration, coal must be supplied at two stages to raise the combustor temperature in ash molten part. Only two reports have been presented regarding two-stage coal supply. One is the report on an experiment with the Hycol gasifier, in which air feed ratio is varied, with coal feed fixed. The other is report on a simulation study with various gasifier coal feed ratios, conducted at Central Research Institute of Electric Power Industry. It seems that the appropriate feed ratio has not yet been established. Through this activity, a unique furnace construction has been established, and these influences of stoichiometric air ratio, of oxygen enrichment, of char recycling and of coal types on performance have been clarified. The purpose of the present study is to apply this developed CPC techniques to a Pressurized CPC (PCPC), thereby improving the IGCC technology. For the present study, we conducted systematic experiments on the air-blown process with a two stage dry feed system, using a 7 t/d-coal bench scale PCPC test facility, operated at the pressure of 0.4 MPa, and clarified the influence of coal feed ratio on coal gasification performance. This report describes the above-mentioned bench scale test procedures and results, and also some informations about a plan of a 25 t/d-coal pilot test system.

  12. Assessment of coal liquids as refinery feedstocks

    SciTech Connect

    Zhou, P.

    1992-02-01

    The R D of direct coal liquefaction has reached such a stage that current two-stage processes can produce coal liquids with high yields and improved quality at a reasonable cost. To fully realize the potential value, these coal liquids should be refined into high-value liquid transportation fuels. The purpose of this study is to assess coal liquids as feedstocks to be processed by modern petroleum refining technologies. After the introduction, Section 2.0 summarizes ASTM specifications for major transportation fuels: gasoline, jet fuel, and diesel fuel, which serve as a target for coal-liquid refining. A concise description of modern refining processes follows with an emphasis on the requirements for the raw materials. These provide criteria to judge the quality of coal liquids as a refinery feedstock for the production of marketable liquid fuels. Section 3.0 surveys the properties of coal liquids produced by various liquefaction processes. Compared with typical petroleum oils, the current two-stage coal liquids are: Light in boiling range and free of resids and metals; very low in sulfur but relatively high in oxygen; relatively low in hydrogen and high in cyclics content; and essentially toxicologically inactive when end point is lower than 650[degrees]F, particularly after hydroprocessing. Despite these characteristics, the coal liquids are basically similar to petroleum. The modern refining technology is capable of processing coal liquids into transportation fuels meeting all specifications, and hydroprocessinq is obviously the major tool. The important point is the determination of a reasonable product slate and an appropriate refining scheme.

  13. Assessment of coal liquids as refinery feedstocks

    SciTech Connect

    Zhou, P.

    1992-02-01

    The R&D of direct coal liquefaction has reached such a stage that current two-stage processes can produce coal liquids with high yields and improved quality at a reasonable cost. To fully realize the potential value, these coal liquids should be refined into high-value liquid transportation fuels. The purpose of this study is to assess coal liquids as feedstocks to be processed by modern petroleum refining technologies. After the introduction, Section 2.0 summarizes ASTM specifications for major transportation fuels: gasoline, jet fuel, and diesel fuel, which serve as a target for coal-liquid refining. A concise description of modern refining processes follows with an emphasis on the requirements for the raw materials. These provide criteria to judge the quality of coal liquids as a refinery feedstock for the production of marketable liquid fuels. Section 3.0 surveys the properties of coal liquids produced by various liquefaction processes. Compared with typical petroleum oils, the current two-stage coal liquids are: Light in boiling range and free of resids and metals; very low in sulfur but relatively high in oxygen; relatively low in hydrogen and high in cyclics content; and essentially toxicologically inactive when end point is lower than 650{degrees}F, particularly after hydroprocessing. Despite these characteristics, the coal liquids are basically similar to petroleum. The modern refining technology is capable of processing coal liquids into transportation fuels meeting all specifications, and hydroprocessinq is obviously the major tool. The important point is the determination of a reasonable product slate and an appropriate refining scheme.

  14. Coal industry annual 1997

    SciTech Connect

    1998-12-01

    Coal Industry Annual 1997 provides comprehensive information about US coal production, number of mines, prices, productivity, employment, productive capacity, and recoverable reserves. US Coal production for 1997 and previous years is based on the annual survey EIA-7A, Coal Production Report. This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report includes a national total coal consumption for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. 14 figs., 145 tabs.

  15. Coal Industry Annual 1995

    SciTech Connect

    1996-10-01

    This report presents data on coal consumption, coal distribution, coal stocks, coal prices, coal quality, and emissions for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report does not include coal consumption data for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. Consumption for nonutility power producers not included in this report is estimated to be 21 million short tons for 1995.

  16. Coal industry annual 1996

    SciTech Connect

    1997-11-01

    This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality, and emissions for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States.This report does not include coal consumption data for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. Consumption for nonutility power producers not included in this report is estimated to be 24 million short tons for 1996. 14 figs., 145 tabs.

  17. Carbon foams from different coals

    SciTech Connect

    Montserrat Calvo; Roberto Garcia; Sabino R. Moinelo

    2008-09-15

    Carbon foams were obtained from several bituminous coals with different plasticity and volatile matter content by a two-stage thermal process. The first stage, a controlled carbonization treatment under pressure at 450-500 {sup o}C, is responsible for the final textural properties of the foam. In the second stage, the carbonization product was baked at 1100{sup o}C. The foams produced display a macroporous texture with fluidity, volatile matter content, and maceral composition of the precursor coals, having an influence on the apparent density and the pore size of the resultant porous products. Coals with low fluidity, volatile matter content, and liptinite content give rise to foams with lower pore size and lower apparent density. In the case of high fluidity coals, their foams display an increase of flexural strength with the increasing relative density. In general, the carbon foams obtained in this study display good electrical properties (electrical resistivity comparable to that of commercial foams). 27 refs., 7 figs., 4 tabs.

  18. Coal and Energy.

    ERIC Educational Resources Information Center

    Bryant, Reba; And Others

    This teaching unit explores coal as an energy resource. Goals, student objectives, background information, and activity options are presented for each major section. The sections are: (1) an introduction to coal (which describes how and where coal was formed and explains the types of coal); (2) the mining of coal (including the methods and ways of…

  19. Microbial solubilization of coal

    DOEpatents

    Strandberg, G.W.; Lewis, S.N.

    1988-01-21

    The present invention relates to a cell-free preparation and process for the microbial solubilization of coal into solubilized coal products. More specifically, the present invention relates to bacterial solubilization of coal into solubilized coal products and a cell-free bacterial byproduct useful for solubilizing coal. 5 tabs.

  20. Evaluating the influence of laser wavelength and detection stage geometry on optical detection efficiency in a single-particle mass spectrometer

    NASA Astrophysics Data System (ADS)

    Marsden, Nicholas; Flynn, Michael J.; Taylor, Jonathan W.; Allan, James D.; Coe, Hugh

    2016-12-01

    Single-particle mass spectrometry (SPMS) is a useful tool for the online study of aerosols with the ability to measure size-resolved chemical composition with a temporal resolution relevant to atmospheric processes. In SPMS, optical particle detection is used for the effective temporal alignment of an ablation laser pulse with the presence of a particle in the ion source, and it gives the option of aerodynamic sizing by measuring the offset of particle arrival times between two detection stages. The efficiency of the optical detection stage has a strong influence on the overall instrument performance. A custom detection laser system consisting of a high-powered fibre-coupled Nd:YAG solid-state laser with a collimated beam was implemented in the detection stage of a laser ablation aerosol particle time-of-flight (LAAP-TOF) single-particle mass spectrometer without major modifications to instrument geometry. The use of a collimated laser beam permitted the construction of a numerical model that predicts the effects of detection laser wavelength, output power, beam focussing characteristics, light collection angle, particle size, and refractive index on the effective detection radius (R) of the detection laser beam. We compare the model predictions with an ambient data set acquired during the Ice in Clouds Experiment - Dust (ICE-D) project. The new laser system resulted in an order-of-magnitude improvement in instrument sensitivity to spherical particles in the size range 500-800 nm compared to a focussed 405 nm laser diode system. The model demonstrates that the limit of detection in terms of particle size is determined by the scattering cross section (Csca) as predicted by Mie theory. In addition, if light is collected over a narrow collection angle, oscillations in the magnitude of Csca with respect to particle diameter result in a variation in R, resulting in large particle-size-dependent variation in detection efficiency across the particle transmission range