Science.gov

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

    SciTech Connect

    Wilson, J.W.; Ding, Y.; Tobey, M.

    1995-12-31

    The primary goal of the current physical coal cleaning process is to reduce the ash and sulfur content from the coal, that is, to remove the mineral particles from the coal. In order to separate mineral from coal particles efficiently, the finely disseminated mineral matter must be liberated from the coal matrix with the help of an ultrafine grinding operation. The coal becomes very difficult to dewater because of the small particle size produced. Difficulty in coal transportation as well as in its storage and handling at the utility plants are also problems associated with the small coal particles resulting from ultrafine grinding. During this project, 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 hydraulic compacting device. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Coal workers pneumoconiosis - stage II #2 (image)

    MedlinePlus

    ... distinct light areas. Diseases which may explain these X-ray findings include simple coal workers pneumoconiosis (CWP) - stage II, silico-tuberculosis, disseminated tuberculosis, metastatic lung cancer, and other diffuse infiltrative pulmonary diseases.

  10. 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.

  11. Rehabilitation using single stage implants

    PubMed Central

    Mohamed, Jumshad B.; Sudarsan, Sabitha; Arun, K. V.; Shivakumar, B.

    2009-01-01

    Implant related prosthesis has become an integral part of rehabilitation of edentulous areas. Single stage implant placement has become popular because of its ease of use and fairly predictable results. In this paper, we present a series of cases of single stage implants being used to rehabilitate different clinical situations. All the implants placed have been successfully restored and followed up for up to one year. PMID:20376239

  12. 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.

  13. Two stage coprocessing of waste tires and coal

    SciTech Connect

    Ying Tang; Curtis, C.W.

    1996-12-31

    Liquefaction of waste (recycled) tire and coal was studied as a two-stage process. Waste tires were liquefied, then the solids and carbon black were removed. In the second stage, the liquefied tire served as the solvent for the coal liquefaction.

  14. Single stage desulfurization of both organic and inorganic sulfur from Midwestern U.S. coals by binary mixtures of supercritical fluids

    SciTech Connect

    Azzam, F.O.; Lee, S.

    1993-12-31

    High sulfur containing Midwestern U.S. coals contain 3-7 percent sulfur by mass, which mainly consists of substantial amounts of organic, pyritic, and sulfatic sulfur forms. In order to meet the strict emission requirements imposed on coal burning utilities by the Clean Air Act Amendments of 1990, coals with high sulfur content must be cleaned before, during, or after combustion. Depending upon the mode of desulfurization, the methods may be classified as precombustion, concurrent, and post-combustion cleaning. The present study deals with a novel, precombustion coal cleaning process that has a unique feature in its process technology. Removal of pyritic sulfur has always been considered successful, since the gravitational separation technique has proven to be quite efficient. Despite the relative success of such operations, however, the efficiency of this type of desulfurization is grossly insufficient for the new compliance coal requirements that mandate SO{sub x} emission to be lower than 1.2 lb per one million BTU. The problem is normally more complicated due to the high abundance of organic sulfur in Midwestern and Eastern U.S. coals. There have been various attempts to selectively remove organic sulfur from coals. They normally involve solvent extraction processes, and once they are found to be successful they are coupled with gravitation separation of pyritic sulfur.

  15. Two-stage, close coupled catalytic liquefaction of coal

    SciTech Connect

    Comolli, A.G.; Johanson, E.S.; Panvelker, S.V.; Popper, G.A.; Smith, T.O.

    1990-09-01

    During the first quarter of 1990, work was carried out in the microautoclave, microreactor, and Bench-Scale units. An economics analysis on sub-bituminous coal processing at two space velocities was also completed. Several supported catalysts and a sample of iron oxide were screened in the microautoclave unsulfided and sulfided with DMDS and TNPS. A second shipment of Black Thunder coal from Wilsonville, oil agglomerated cleaned Illinois {number sign}6 coal from Homer City, OTISCA cleaned coal a New Mexico coal were evaluated for relative conversions with and without catalyst. Results of Bench-Scale developments with cleaned, oil agglomerated, Illinois {number sign}6 coal from Homer City(CC-6), Dispersed Catalyst/Supported Catalyst Two-Stage and reversed sequential operation (CC-7), on Black Thunder Coal (CC-7), and preliminary observations on OTISCA cleaned coal are presented. The oil agglomerated cleaned coal gave higher conversion and distillate production than the OTISCA cleaned coal. The Dispersed/Supported Two-Stage operation yielded higher gas production than the reverse sequence but also showed the higher coal conversion. Economic analysis of sub-bituminous coal processing at two space velocities showed a 3% higher return on investment with a 50% increase in space velocity. 13 tabs.

  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. The single electron chemistry of coals

    SciTech Connect

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

    1990-07-24

    TCNQ Charge Transfer Complexes with Coals. TCNQ can be readily deposited in coals from pyridine solution. IR spectra of TCNQ and TCNQ in Illinois No. 6 coal are shown in Fig. 1. It is clear that the stretching frequency has been shifted by the full 44 cm[sup [minus]1] caused by the transfer of a single electron. Similar behavior has been observed with a variety of coals, including lignites, subbituminous and a range of bituminous coals. There are two possible explanations for the observed shift. The simplest explanation is that there exist in coals structures which are excellent single electron donors capable of transferring an electron to TCNQ in the ground state. All of the TCNQ dissolved in the coal is shifted. No uncomplexed TCNQ remains in the sample, as demonstrated by the absence of the unaltered CN stretch at 2227 cm[sup [minus]1]. The spectrum shown is for TCNQ in coal in a molar concentration equivalent to approximately 20% of the PNA systems in this coal as deduced from the NMR studies of Solum et al. (1989). It is highly unlikely that 20% of the PNA systems in coal are such good electron donors that the charge transfer complex would have an electron transferred in the ground state. The second explanation is that cooperative interactions between the TCNQ and the aromatic systems in coal have led to the formation of an extended valance band structure, that the TCNQ LUMO is part of this band structure, and that the band is half filled.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. CHARACTERISTICS OF SINGLE PARTICLE COAL COMBUSTION

    EPA Science Inventory

    The paper discusses the measurement of the burning history of single coal particles, using a two-color optical pyrometer. rom intensity traces at two wavelengths, information on burning times and temperatures, the duration of a volatile flame, and projected areas was obtained for...

  3. 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.

  4. 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.

  5. The single electron chemistry of coals

    SciTech Connect

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

    1992-11-11

    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 will also be concerned with the decomposition of radical cations and the products formed as a result of the decomposition. In our last report we described that treatment of bibenzyl and neo-pentylbenzene with Fe(III) (1,10-phenanthroline)[sub 3](ClO[sub 4])[sub 3] (Fe(III)(PHEN)) in refluxing CH[sub 3]CN (82[degrees]C) failed to produce substantial bond cleavage [beta] to the aromatic ring. Because bond cleavage was not observed, we have continued our study by moving to compounds which have lower ionization potentials as well as study other oxidants.

  6. Multiple angle single stage scrubber

    SciTech Connect

    Ostlie, L.

    1982-02-02

    A scrubber for cleansing flue gases is disclosed. The scrubber includes a housing which defines a channel. The channel includes a scrubber stage wherein vertically spaced rows of deflecting members of l-shaped cross-section are disposed. In a given row of deflecting members, a plurality of flow paths are defined between horizontally adjacent deflecting members. Each deflecting member has an upper arm and a lower arm. The lowermost edge of the lower arms of the deflecting members in one row are disposed between vertical projections from the uppermost edges of upper arms of deflecting members in a row below the last mentioned row.

  7. Coal liquefaction laboratory studies. Volume 2. Two-stage variations: subbituminous coal

    SciTech Connect

    Bynum, R.; Carver, J.M.; Gir, S.; Paranjape, A.S.; Rhodes, D.E.

    1985-07-01

    Laboratory studies were made to evaluate the technical feasibility of new process concepts and advanced coal liquefaction processes at the bench-scale level to produce environmentally-acceptable fuel and other useable by-products. This report summarizes the results of batch reactor studies completed during the period of January through July 1983. The laboratory studies covered several wide ranging topics including temperature-staged coal dissolving, co-processing of coal and petroleum, disposable catalysts and heterocyclic solvents. Good coal conversions and distillate yields were obtained from Wyoming subbituminous coal by using temperature-staged dissolving in the presence of iron oxide as a disposable catalyst. Similarly, petroleum-based asphaltenes were successfully co-processed with subbituminous coal in the presence of iron oxide with high coal conversions. Use of heterocyclic compounds as a component of liquefaction solvent resulted in high losses of these compounds to products rather than remain with the recycle solvent. During these laboratory studies, a simple reproducible batch test was developed to provide fast evaluation and screening of different catalysts for hydrotreatment of different resids. 33 refs., 8 figs., 44 tabs.

  8. Combustion of coal-gas fuels in a staged combustor

    SciTech Connect

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

    1982-01-01

    Gaseous fuels produced from coal resources have been considered for use in industrial gas turbines. Such fuels generally have heating values much lower than the typical gaseous fuel, natural gas; the low heating value could result in unstable or inefficient combustion. Additionally, coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable NO/sub x/ exhaust emission levels. Previous investigations have indicated that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low NO/sub x/ emission operation for coal-derived liquid fuels containing up to 0.8-wt % nitrogen. An experimental program has been 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% ammonia are presented. The test results permit the following conclusions to be drawn: (1) Staged, rich-lean combustion represents the desirable approach to achieve ultra-low NO/sub x/ and CO emissions for coal gas fuels with heating values of 210 kJ/mol (238 Btu/scf) or higher. (2) Lean combustion represents the desirable approach to achieve ultra-low NO/sub x/ and CO emissions for coal gas fuels with low heating values (84 kJ/mol (95 Btu/scf)). (3) Staged combustion has the ability to limit NH/sub 3/ to NO/sub x/ conversion rates to less than 5%. NO/sub x/ emissions below the EPA limit can readily be achieved.

  9. Two-stage, close coupled catalytic liquefaction of coal

    SciTech Connect

    Comolli, A.G.; Johanson, E.S.; Lee, T.L.K.; Popper, G.A.; Stalzer, R.H.

    1992-04-01

    This quarterly report covers activities of the Two-Stage, Close- Coupled Catalytic Liquefaction of Coal program during the period January 1,--March 31,1992, at Hydrocarbon Research, Inc. in Lawrenceville and Princeton, New Jersey. This DOE contract period is from October 1, 1988 to September 30, 1992. The overall purpose of the program is to achieve higher yields of better quality transportation and turbine fuels and to lower the capital and production costs in order to make the products from direct coal liquefaction competitive with other fossil fuel products. The quarterly report covers work on Laboratory Testing, PDU Activities and Administration.

  10. 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.

  11. Coal liquefaction laboratory studies. Volume 1. Two-stage variations - bituminous coal

    SciTech Connect

    Bynum, R.; Carver, J.M.; Gir, S.; Paranjape, A.S.; Rhodes, D.E.

    1985-07-01

    Laboratory studies were conducted to provide guidance in the selection of process variable levels for the Liquefaction-section of the continuous coal liquefaction bench-scale unit operated at Kerr-McGee Cimarron Facility. Using the results of batch reactor tests made with Illinois No. 6 coal, an empirical correlation was developed to predict the distillate yield from a thermal-liquefaction at 825/sup 0/F reaction-temperature as a linear function of the reaction-time, recycle resid to MAF coal ratio and the initial hydrogen pressure. Several single-ring and multi-ring organonitrogen compounds were evaluated as liquefaction solvents. Data indicate that basic organonitrogen compounds, saturated or partially saturated, have a more pronounced effect on the conversion results and particularly on toluene-soluble coal conversions, thereby suggesting that the primary driving force for good conversions may be the unshared pair of electrons associated with the nitrogen atom in these compounds. A study of microautoclaves indicated that sufficient mixing of the contents is necessary to obtain good conversions. The THF-soluble coal conversions were studied as a function of the hydrogen donor concentration in the liquid phase. Variations in product work-up procedures could result in significant differences in the observed THF-soluble and/or toluene-soluble results. A direct comparison of data from different sources should be done with caution and should take into consideration the differences between the equipment and product work-up procedures used. 17 figs., 73 tabs.

  12. 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.

  13. 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.

  14. CaO interaction in the staged combustion of coal

    SciTech Connect

    Levy, A.; Merryman, E.L.; Rising, B.W.

    1983-12-19

    The LIMB (limestone injection multi-stage burner) process offers special potential for reducing NO/sub x/ and SO/sub x/ by at least 50 percent in coal combustion. This is to be accomplished by adding limestone with fuel and/or air in a low NO/sub x/ burner. This program has been directed to defining the chemistry and kinetics necessary to optimize sulfur capture in LIMB combustion. More specifically, this program has attempted to clarify the role of calcium sulfide in LIMB chemistry. When limestone is added in a staged burner, there is a strong possibility that under certain circumstances CaS is produced in the reducing (fuel-rich) zone of the burner. Since CaS is more stable than CaSO/sub 4/, this affords the opportunity to (1) operate the burner at a higher temperature, 2200 to 2500 F, (2) pass the CaS rapidly through the high temperature zone (before dissociation), and (3) complete the combustion in a lean (air-rich) region where the sulfur is finally retained in CaSO/sub 4/. For these reasons this program has concentrated on the high temperature chemistry and kinetics of CaS. To achieve the program objective, the program was divided into three tasks. These involved (1) a study of CaS formation, (2) a brief examination of CaS oxidation, and (3) a laboratory examination of the combustion of coal in the presence of CaO under first stage, fuel-rich conditions. In the most general sense, the study has shown that the formation of CaS in the reducing zones of the burner may be restricted by competing kinetics and thermodynamics. The addition of lime in LIMB will require special care to optimize the ability to capture sulfur. 36 references, 44 figures, 10 tables.

  15. Coal-fired generation staging a comeback. 2nd ed.

    SciTech Connect

    2007-07-01

    The report is an overview of the renewed U.S. market interest in coal-fired power generation. It provides a concise look at what is driving interest in coal-fired generation, the challenges faced in implementing coal-fired generation projects, and the current and future state of coal-fired generation. Topics covered in the report include: An overview of coal-fired generation including its history, the current market environment, and its future prospects; An analysis of the key business factors that are driving renewed interest in coal-fired generation; An analysis of the challenges that are hindering the implementation of coal-fired generation projects; A description of coal-fired generation technologies; A review of the economic drivers of coal-fired generation project success; An evaluation of coal-fired generation versus other generation technologies; A discussion of the key government initiatives supporting new coal-fired generation; and A listing of planned coal-fired generation projects. 13 figs., 12 tabs., 1 app.

  16. Single stage rocket concept selection and design

    NASA Astrophysics Data System (ADS)

    Copper, J. A.

    1992-03-01

    The paper compares three concepts of a single-stage rocket for use as a reusable safe and reliable launch system: (1) horizontal takeoff and landing; (2) vertical takeoff and landing (VTOL), and vertical takeoff and horizontal landing. These concepts were evaluated during Phase I using the following ground rules: the 1992 technology availability; 7 d turnaround between flights with 350 man-days servicing; a 400-km polar orbit, 600 fps maneuver capability on orbit; 10,000 lb payload; 1170 nmi crossrange; two-man crew, 4-day duration, 14.7 psi cabin pressure, 1000 cu ft crew volume, 3 g maximum acceleration; winds amounting to 200 fps ascent, 73 fps landing; and return payload to base after single engine failure. On the basis of the comparison (done on the basis of the lowest cost to acquire and operate, the least sensitivity to uncertainties in predicted weight and performance, and the operational flexibility) the VTOL concept with nose-first reentry was chosen.

  17. Multi-stage coal liquefaction and fractionation method

    SciTech Connect

    Gir, S.; Rhodes, D.E.

    1987-05-12

    A method is described of liquefying and fractionating coal comprising: mixing coal with a primary heavy solvent to form a coal-primary heavy solvent slurry; treating the coal-primary heavy solvent slurry under coal-liquefying conditions to form a primary feed solution; introducing at least a portion of the primary feed solution into a first primary separation zone to form a first light primary phase and a first heavy primary phase, separated by a liquid-liquid interface; and processing the separated first light primary phase in at least one primary separation zone successive to the first primary separation zone to separate, in a final successive primary separation zone, a final light primary phase and a final heavy primary phase.

  18. 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,...

  19. Chemical and toxicologic characterization of co-processing and two-stage direct coal liquefaction materials

    SciTech Connect

    Wright, C.W.; Stewart, D.L.; Mahlum, D.D.; Chess, E.K.; Wilson, B.W.

    1986-03-01

    Recent advances in coal liquefaction have included two-stage direct coal liquefaction processes and petroleum resid/coal co-processing technology. Two-stage coal liquefaction processes are generally comprised of a first-stage thermal or liquefaction reactor followed by a second-stage hydrogenation step. Petroleum resids and coal are simultaneously converted to liquefaction products in co-processing technology. The purpose of this paper is to report the prelimianry results of the chemical analysis and toxicological testing of a coal liquefaction co-processing sample set, and to compare these results to those obtained from two-stage coal liquefaction materials. Samples were chemically characterized by chemical class fractionation, gas chromatography, gas chromatography-mass spectrometry, and low-voltage probe-inlet mass spectrometry. Toxicological activity was measured using the standard histidine reversion microbial mutagenicity test and an initiation/promotion assay for mouse skin tumorigenesis. A brief description of these methods are presented and results are discussed. 9 refs., 2 figs., 3 tabs.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. High speed single- and dual-stage vertical positioners

    NASA Astrophysics Data System (ADS)

    Yong, Yuen K.; Wadikhaye, Sachin P.; Fleming, Andrew J.

    2016-08-01

    This article presents a high-speed single- and dual-stage vertical positioners for applications in optical systems. Each positioner employs a unique end-constraint method with orthogonal flexures to preload a piezoelectric stack actuator. This end-constraint method also significantly increases the first mechanical resonance frequency. The single-stage positioner has a displacement range of 7.6 μm and a first resonance frequency of 46.8 kHz. The dual-stage design consists of a long-range slow-stage and a short-range fast-stage. An inertial counterbalance technique was implemented on the fast-stage to cancel inertial forces resulting from high-speed motion. The dual-stage positioner has a combined travel range of approximately 10 μm and a first evident resonance frequency of 130 kHz.

  7. High speed single- and dual-stage vertical positioners.

    PubMed

    Yong, Yuen K; Wadikhaye, Sachin P; Fleming, Andrew J

    2016-08-01

    This article presents a high-speed single- and dual-stage vertical positioners for applications in optical systems. Each positioner employs a unique end-constraint method with orthogonal flexures to preload a piezoelectric stack actuator. This end-constraint method also significantly increases the first mechanical resonance frequency. The single-stage positioner has a displacement range of 7.6 μm and a first resonance frequency of 46.8 kHz. The dual-stage design consists of a long-range slow-stage and a short-range fast-stage. An inertial counterbalance technique was implemented on the fast-stage to cancel inertial forces resulting from high-speed motion. The dual-stage positioner has a combined travel range of approximately 10 μm and a first evident resonance frequency of 130 kHz. PMID:27587157

  8. Efficiency of single stage- and two stage pretreatment in biomass with different lignin content.

    PubMed

    Kärcher, M A; Iqbal, Y; Lewandowski, I; Senn, T

    2016-07-01

    In current study the enzymatic glucose yields of miscanthus and wheat straw were compared after single stage- and two stage pretreatment with dilute sulfuric acid at different pretreatment severities. Glucose yields after two stage pretreatment were higher than after single stage pretreatment in miscanthus. Whereas wheat straw had higher glucose yields after single stage pretreatment. The study shows that two stage pretreatment has a negative effect on glucose yield in biomass with low not-acid-degradable lignin content and a positive one in biomass with high not-acid-degradable lignin content. The not-acid-degradable lignin fraction offers a higher degree of protection of the whole lignin structure against chemical attacks by mineral acids. More severe pretreatment conditions were needed to achieve a sufficient breakup of the lignin structure. But more severe conditions enhance resin formation, leading to lower enzyme activity and reduced carbohydrate yields. PMID:27067673

  9. Single-stage depressed collectors for gyrotrons

    SciTech Connect

    Piosczyk, B.; Iatrou, C.T.; Dammertz, G.; Thumm, M. |

    1996-06-01

    Two 140 GHz gyrotrons with a single-step depressed collector have been operated. The different position of the isolating collector gap in the stray magnetic field causes the electron motion in the retarding region to be in one case adiabatic and in the other case nonadiabatic. The kind of motion within the retarding field influences strongly the behavior of the gyrotron with a depressed collector. In the case of nonadiabatic motion a significant amount of transverse momentum is given to the electrons reflected at the collector potential. This causes the reflected electrons to be trapped between the magnetic mirror and the collector. The electrons escape from the trap by diffusion across the magnetic field to the body of the tube thus contributing to the body current. Despite the high body current there is no observable influence of the collector voltage on the RF output power. In the case of adiabatic motion the reflected electrons do not gain a sufficient amount of transverse momentum to be trapped by the magnetic mirror. They pass the cavity toward the gun and they are trapped between the negative gun potential and the collector. The interaction with the RF field by electrons traveling through the cavity enhances the diffusion in the velocity space thus enabling the trapped electrons to overcome the potential barrier and escape toward the collector. Therefore the body current stays at low values since in this case the reflected electrons do not contribute to it. However, at higher collector voltages a reduction of RF power occurred and some noise in the electron beam was observed. The main motivation for the development of gyrotrons in the frequency range above 100 GHz with power levels in excess of several hundreds kW per tube, is the application in magnetic fusion devices for plasma heating and for electron current drive.

  10. 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.

  11. The braided single-stage protocol for quantum secure communication

    NASA Astrophysics Data System (ADS)

    Darunkar, Bhagyashri; Verma, Pramode K.

    2014-05-01

    This paper presents the concept and implementation of a Braided Single-stage Protocol for quantum secure communication. The braided single-stage protocol is a multi-photon tolerant secure protocol. This multi-photon tolerant protocol has been implemented in the laboratory using free-space optics technology. The proposed protocol capitalizes on strengths of the three-stage protocol and extends it with a new concept of braiding. This protocol overcomes the limitations associated with the three-stage protocol in the following ways: It uses the transmission channel only once as opposed to three times in the three-stage protocol, and it is invulnerable to man-in-the-middle attack. This paper also presents the error analysis resulting from the misalignment of the devices in the implementation. The experimental results validate the efficient use of transmission resources and improvement in the data transfer rate.

  12. 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.

  13. 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.

  14. 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.

  15. Initial stages of coal slag interaction with high chromia sesquioxide refractories

    SciTech Connect

    Rawers, James C.; Iverson, Larissa; Collins, Wesley K.

    2002-02-01

    Slagging coal gasifiers operate at temperatures as high as 1650◦C in a reducing environment, requiring combustion chambers to be lined with refractories. The liner materials of choice are semi-porous high chromia refractories. Recently, a new series of high-chromia aluminia sesquioxide refractories have been developed. Both long term and short term tests are being conducted to evaluate the performance of these materials. In this study, the initial stage of slag-refractory interactions was analyzed. Samples of gasifier slag were compacted and placed upon the surface of these new chromia refractories and the temperature was raised consistent with start-up operating conditions of commercial gasifiers. The slag was completely molten by the time the furnace achieved a temperature consistent with gasifier operation conditions: 1350◦C. Measurement of the slag contact angle, slag spread along the slag-refractory interface, and the loss of slag due to slag infusion into the refractory were monitored by camera. Analysis suggests a single phenomenon with an activation energy of approximately 54 kcal may be the controlling factor. Cross-section analysis of the sample and analysis of slag chemistry indicate that slag infusion preceded the slag-refractory interface front movement and that the iron component of the slag was becoming concentrated at the slag-refractory interface leading to the formation of a chromium-iron spinel phase. Results of these short term tests are critical in characterizing and understanding the results long term slag-refractory interactions.

  16. Initial stages of coal slag interaction with high chromia sesquioxide refractories

    SciTech Connect

    Rawers, J.C.; Iverson, L.; Collins, W.K.

    2002-02-01

    Slagging coal gasifiers operate at temperatures as high as 1650°C in a reducing environment, requiring combustion chambers to be lined with refractories. The liner materials of choice are semi-porous high chromia refractories. Recently, a new series of high-chromia aluminia sesquioxide refractories have been developed. Both long term and short term tests are being conducted to evaluate the performance of these materials. In this study, the initial stage of slag-refractory interactions was analyzed. Samples of gasifier slag were compacted and placed upon the surface of these new chromia refractories and the temperature was raised consistent with start-up operating conditions of commercial gasifiers. The slag was completely molten by the time the furnace achieved a temperature consistent with gasifier operation conditions: 1350°C. Measurement of the slag contact angle, slag spread along the slag-refractory interface, and the loss of slag due to slag infusion into the refractory were monitored by camera. Analysis suggests a single phenomenon with an activation energy of approximately 54 kcal may be the controlling factor. Cross-section analysis of the sample and analysis of slag chemistry indicate that slag infusion preceded the slag-refractory interface front movement and that the iron component of the slag was becoming concentrated at the slag-refractory interface leading to the formation of a chromium-iron spinel phase. Results of these short term tests are critical in characterizing and understanding the results long term slag-refractory interactions.

  17. 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…

  18. Single-Stage Flexor Tendon Grafting: Refining the Steps.

    PubMed

    Fletcher, Derek R; McClinton, Michael A

    2015-07-01

    Single-stage tendon grafting for reconstruction of zone I and II flexor tendon injuries is a challenging procedure in hand surgery. Careful patient selection, strict indications, and adherence to sound surgical principles are mandatory for return of digital motion. PMID:26026357

  19. 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.

  20. A catalyst tackles odors in a single-stage scrubber

    SciTech Connect

    Shelley, S.

    1995-05-01

    Chemical-oxidation systems are widely used to absorb and oxidize odorous organic compounds in industrial and municipal exhaust streams. By combining conventional chemical scrubbers with a proprietary catalytic treatment unit, ICI Katalco (Billingham, England) has produced a single-stage scrubber system that enhances removal efficiency during liquid-phase adsorption, and overcomes many of the process and cost disadvantages of a conventional scrubber. Organic vapors are absorbed by the sodium hypochlorite solution inside the single-column scrubber. The liquid leaving the tower is then passed through the fixed-bed Odorgard reactor, where absorbed organics are catalytically oxidized.

  1. 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.

  2. 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.

  3. 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)

  4. 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.

  5. Siderophile elements, oxygen and single-stage core formation

    NASA Astrophysics Data System (ADS)

    Corgne, A.; Siebert, J.; Badro, J.

    2009-12-01

    The abundances of siderophile elements in the bulk silicate Earth (BSE) indicate that its iron-rich core most probably form at high pressure and high temperature in a magma ocean (e.g. Walker et al. 1993; Hillgren et al. 1994; Thibault & Walter 1995; Li & Agee, 1996). This is consistent with physical models of planetary accretion (Davies 1985; Benz & Cameron 1990; Tonks & Melosh 1993). Metal-silicate partitioning experiments have proposed that the BSE concentrations of several siderophile elements are consistent with a scenario of single-stage equilibration at the base of a deep magma ocean (Li & Agee 1996; Righter et al 1997; Chabot & Agee 2003). More recent models using temperature sensitive partitioning data for V and Nb have casted doubt on the single-stage event hypothesis since the required basal temperature should greatly exceed that of the mantle solidus (Wade & Wood 2005; Corgne et al. 2008; Wood et al. 2008). This temperature mismatch is meaningless in the framework of the magma ocean theory because the temperature at the base of the magma ocean should approximate that of the mantle solidus. To resolve this anomaly, it has been suggested that the building materials of the Earth were initially reduced materials and then became progressively oxidized with time (Wade & Wood 2005; Corgne et al. 2008; Wood et al. 2008). Thus, rather than resulting from a single-stage event at relatively fixed conditions of high pressure and high temperature, the Earth’s core may in fact have formed in a more complex event, imprinted by heterogeneous accretion and the progressive growth of the planet and its magma ocean. Here, we present an alternative to the dynamic model by showing that a single-stage core formation event could explain the mantle contents of the best-constrained siderophile elements (Ni, Co, V, Mn, Cr, Nb) provided that the core contains a few weight percents of oxygen. Our calculations based on partitioning and metallurgy data reveal that V and Nb become

  6. The single electron chemistry of coals. Quarterly report, October 1, 1993--December 31, 1993

    SciTech Connect

    Larsen, J.W.; Rothenberg, S.E.

    1994-08-01

    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. The work here is concerned with the interactions of coals, such as Illinois No. 6, with tetracyanoethylene.

  7. The single electron chemistry of coals. Quarterly report, January 1, 1994--March 31, 1994

    SciTech Connect

    Larsen, J.W.; Rothenberg, S.E.

    1994-08-01

    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. The work here is concerned with the interactions of coals, such as Illinois No. 6, with tetracyanoethylene.

  8. 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).

  9. 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.

  10. 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).

  11. 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.

  12. 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.

  13. Evaluation of an automated single-channel sleep staging algorithm

    PubMed Central

    Wang, Ying; Loparo, Kenneth A; Kelly, Monica R; Kaplan, Richard F

    2015-01-01

    Background We previously published the performance evaluation of an automated electroencephalography (EEG)-based single-channel sleep–wake detection algorithm called Z-ALG used by the Zmachine® sleep monitoring system. The objective of this paper is to evaluate the performance of a new algorithm called Z-PLUS, which further differentiates sleep as detected by Z-ALG into Light Sleep, Deep Sleep, and Rapid Eye Movement (REM) Sleep, against laboratory polysomnography (PSG) using a consensus of expert visual scorers. Methods Single night, in-lab PSG recordings from 99 subjects (52F/47M, 18–60 years, median age 32.7 years), including both normal sleepers and those reporting a variety of sleep complaints consistent with chronic insomnia, sleep apnea, and restless leg syndrome, as well as those taking selective serotonin reuptake inhibitor/serotonin–norepinephrine reuptake inhibitor antidepressant medications, previously evaluated using Z-ALG were re-examined using Z-PLUS. EEG data collected from electrodes placed at the differential-mastoids (A1–A2) were processed by Z-ALG to determine wake and sleep, then those epochs detected as sleep were further processed by Z-PLUS to differentiate into Light Sleep, Deep Sleep, and REM. EEG data were visually scored by multiple certified polysomnographic technologists according to the Rechtschaffen and Kales criterion, and then combined using a majority-voting rule to create a PSG Consensus score file for each of the 99 subjects. Z-PLUS output was compared to the PSG Consensus score files for both epoch-by-epoch (eg, sensitivity, specificity, and kappa) and sleep stage-related statistics (eg, Latency to Deep Sleep, Latency to REM, Total Deep Sleep, and Total REM). Results Sensitivities of Z-PLUS compared to the PSG Consensus were 0.84 for Light Sleep, 0.74 for Deep Sleep, and 0.72 for REM. Similarly, positive predictive values were 0.85 for Light Sleep, 0.78 for Deep Sleep, and 0.73 for REM. Overall, kappa agreement of 0

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. The single electron chemistry of coals. [Quarterly] report, April 1, 1990--June 30, 1990

    SciTech Connect

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

    1990-07-24

    TCNQ Charge Transfer Complexes with Coals. TCNQ can be readily deposited in coals from pyridine solution. IR spectra of TCNQ and TCNQ in Illinois No. 6 coal are shown in Fig. 1. It is clear that the stretching frequency has been shifted by the full 44 cm{sup {minus}1} caused by the transfer of a single electron. Similar behavior has been observed with a variety of coals, including lignites, subbituminous and a range of bituminous coals. There are two possible explanations for the observed shift. The simplest explanation is that there exist in coals structures which are excellent single electron donors capable of transferring an electron to TCNQ in the ground state. All of the TCNQ dissolved in the coal is shifted. No uncomplexed TCNQ remains in the sample, as demonstrated by the absence of the unaltered CN stretch at 2227 cm{sup {minus}1}. The spectrum shown is for TCNQ in coal in a molar concentration equivalent to approximately 20% of the PNA systems in this coal as deduced from the NMR studies of Solum et al. (1989). It is highly unlikely that 20% of the PNA systems in coal are such good electron donors that the charge transfer complex would have an electron transferred in the ground state. The second explanation is that cooperative interactions between the TCNQ and the aromatic systems in coal have led to the formation of an extended valance band structure, that the TCNQ LUMO is part of this band structure, and that the band is half filled.

  1. 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%.

  2. Management of locoregional stage esophageal cancer: a single center experience.

    PubMed

    Javle, M M; Nwogu, C E; Donohue, K A; Iyer, R V; Brady, W E; Khemka, S V; Smith, J L; Demmy, T L; Yang, G Y; Nava, H R

    2006-01-01

    Therapeutic options for locoregional esophageal cancer (EC) include primary surgery, neoadjuvant or definitive chemoradiation and systemic chemotherapy. The role of surgery in these multimodal strategies has recently been debated and definitive chemoradiation is being offered as an alternative to surgery at many centers. We examined our results with multimodal therapy and surgery in this patient population. We conducted a retrospective analysis of 172 patients with locoregional (AJCC stages I-III) EC treated at RPCI between February 14, 1990 and September 20, 2002. Median age was 65 years (range, 36-95); there were 136 male patients. There were 100 regional (stages IIB-III), 69 local (stages I-IIA) and three in situ cases. Initial therapy was either combined modality (n = 122) or single modality (surgery) (n = 50). There was 0%, 30-day, postoperative mortality. Median survival for all patients was 25.3 months and was better for local stage with surgery alone (75 months) than with neoadjuvant (35.7 months) or definitive chemoradiation (19.1 months, P < 0.001). Survival for patients with regional disease treated with surgery alone, neoadjuvant or definitive chemoradiation was 21.5, 24.4 and 11.8 months, respectively (P = not significant). The associations of prognostic factors with overall survival were evaluated using Cox proportional hazards regression analysis and 2-sided Wald's chi-square test. On multivariate analysis, carefully selected patients treated with surgery alone had better outcomes compared with those treated with definitive chemoradiation (P < 0.001). Patients with locoregional esophageal cancer who are eligible for surgical resection either alone or as a part of multimodal therapy may have better outcomes than those treated with non-surgical approaches. PMID:16643174

  3. ENHANCED HYDROGEN PRODUCTION INTEGRATED WITH CO2 SEPARATION IN A SINGLE-STAGE REACTOR

    SciTech Connect

    Himanshu Gupta; Mahesh Iyer; Bartev Sakadjian; Liang-Shih Fan

    2005-03-10

    Hydrogen production cannot be maximized from fossil fuels (gas/coal) via the WGS reaction at high temperatures as the WGS-equilibrium constant K{sub WGS} (= [CO{sub 2}][H{sub 2}]/[CO][H{sub 2}O]), falls with increasing temperatures. However, CO{sub 2} removal down to ppm levels by the carbonation of CaO to CaCO{sub 3} in the temperature range 650-850 C, leads to the possibility of stoichiometric H{sub 2} production at high temperature/pressure conditions and at low steam to fuel ratios. Further, CO{sub 2} is also captured in the H{sub 2} generation process, making this coal to hydrogen process compatible with CO{sub 2} sequestration goals. While microporous CaO sorbents attain <50% conversion over cyclical carbonation-calcination, the OSU-patented, mesoporous CaO sorbents are able to achieve >95% conversion. Novel calcination techniques could lead to an ever-smaller footprint, single-stage reactors that achieve maximum theoretical H{sub 2} production at high temperatures and pressures for on/off site usage. Experimental results indicate that the PCC-CaO sorbent is able to achieve complete conversion of CO for 240 seconds as compared to only a few seconds with CaO derived from natural sources.

  4. Evaporation and heating of a single suspended coal-water slurry droplet in hot gas streams

    SciTech Connect

    Shi-chune, Y.; Liu, L.

    1982-01-01

    The evaporation, heating, and burning of single coal-water slurry droplets are studied. The coal selected in this study is Pittsburgh Seam number 8 coal which is a medium volatile caking bituminous coal. The droplet is suspended on a microthermocouple and exposed to a hot gas stream. Temperature measurement and microscopic observation are performed in the parametric studies. The duration of water evaporation in CWS droplets decreases with the reduction of the droplet size, increasing of coal weight fraction, and increasing of gas temperature and velocity. The duration of heat-up is always significant due to the agglomeration. The CWS droplets are generally observed to swell like popcorn during heating. A model for the formation of the popped swelling is proposed and discussed.

  5. 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.

  6. Technology requirements for affordable single-stage rocket launch vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Douglas O.; Piland, William M.

    1993-01-01

    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.

  7. 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.

  8. Development of Single Stage Stirling Cooler for Space Use

    NASA Astrophysics Data System (ADS)

    Narasaki, K.; Tsunematsu, S.; Kanao, K.; Otsuka, K.; Hoshika, S.; Fujioka, K.; Tsurumi, K.; Hirabayashi, M.

    2006-04-01

    A single-stage Stirling cooler has been developed and tested for space applications, which include instrument or detector cooling, and a supplemental cooler for the cryogenic system. The mechanical cooler is a free displacer type and consists of a compressor, a cold head and a connecting tube. The features of this cooler are a moving cylinder, clearance seal by diaphragm spring, twin pole magnet system and pneumatically driven displacer. The typical cooling power is 2 W at 80 K and the input power to the cooler is 50 W without driver electronics. The total weight of the cooler is 4.2 kg. The engineering and the flight models of the cooler have been fabricated and evaluated to verify the capability for three space missions. This paper describes the design of the cooler and the results from verification tests including cooler performance test, thermal vacuum test, vibration test and lifetime test.

  9. The single electron chemistry of coals. [Quarterly report], April 1--June 30, 1993

    SciTech Connect

    Larsen, J.W.; Rothenberg, S.E.

    1993-11-01

    Objective was to investigate the single electron reactions of alkyl and alkoxy aromatic compounds and the role of these reactions in the chemistry of coal. During this period, the reactions of Illinois No. 6 coal with tetracyanoethylene (TCNE) was studied using diffuse reflectance infrared spectra. Results showed that no chemical reaction occurred, either Diels-Alder or addition, even at 180 C; TCNE`s lowest unoccupied molecular orbital was still occupied 2/3 of an electron transferred by Illinois No. 6 coal.

  10. The single electron chemistry of coals. [Quarterly] report, July 1--September 30, 1993

    SciTech Connect

    Larsen, J.W.; Rothenberg, S.E.

    1993-12-31

    Tetracyanoethylene (TCNE) and Tetracyanoquinodimethane (TCNQ) were used earlier in an attempt to determine the single electron donating ability of aromatic groups in coals. The extent of electron transfer from coals to these compounds was measured by determining the frequency shift of the nitrile stretching bands in the Diffuse Reflectance (DR) infrared spectra. Our addition to this work will be to study the interactions of coals, such as Illinois No. 6, with TCNE. We will determine whether a Diels-Alder reaction or other addition reactions are occurring.

  11. 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.

  12. 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.

  13. 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.

  14. 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…

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

    SciTech Connect

    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.

  16. 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.

  17. Catalytic multi-stage liquefaction of coal. Eleventh quarterly progress report, April 1, 1995--June 30, 1995

    SciTech Connect

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

    1995-10-01

    This quarterly report covers the activities of Catalytic Multi-Stage Liquefaction of Coal during the Period April 1 - June 30, 1995, at Hydrocarbon Technologies, Inc. in Lawrenceville, 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.

  18. 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

  19. Two-stage, closed coupled catalytic liquefaction of coal. Sixteenth quarterly report, 1 July 1992--30 September 1992

    SciTech Connect

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

    1992-12-01

    This quarterly report covers activities of the Two-Stage, Close-Coupled Catalytic Liquefaction of Coal Program during the period of July 1--September 30, 1992, at Hydrocarbon Research, Inc., in Lawrenceville and Princeton, New Jersey. This DOE contract period is from October 1, 1998 to December 31, 1992. The overall purpose of the program is to achieve higher yields of better quality transportation and turbine fuels and to lower the capital and production costs in order to make the products from direct coal liquefaction competitive with other fossil fuel products. The quarterly report covers work on Laboratory testing, Bench Scale Studies and PDU Activities focusing on scale-up of the Catalytic Two-Stage Liquefaction (CTSL) processing of sub-bituminous Black Thunder Coal.

  20. 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.

  1. Mathematical modeling of a single stage ultrasonically assisted distillation process.

    PubMed

    Mahdi, Taha; Ahmad, Arshad; Ripin, Adnan; Abdullah, Tuan Amran Tuan; Nasef, Mohamed M; Ali, Mohamad W

    2015-05-01

    The ability of sonication phenomena in facilitating separation of azeotropic mixtures presents a promising approach for the development of more intensified and efficient distillation systems than conventional ones. To expedite the much-needed development, a mathematical model of the system based on conservation principles, vapor-liquid equilibrium and sonochemistry was developed in this study. The model that was founded on a single stage vapor-liquid equilibrium system and enhanced with ultrasonic waves was coded using MATLAB simulator and validated with experimental data for ethanol-ethyl acetate mixture. The effects of both ultrasonic frequency and intensity on the relative volatility and azeotropic point were examined, and the optimal conditions were obtained using genetic algorithm. The experimental data validated the model with a reasonable accuracy. The results of this study revealed that the azeotropic point of the mixture can be totally eliminated with the right combination of sonication parameters and this can be utilized in facilitating design efforts towards establishing a workable ultrasonically intensified distillation system. PMID:25432400

  2. Advanced technologies for rocket single-stage-to-orbit vehicles

    NASA Technical Reports Server (NTRS)

    Wilhite, Alan W.; Bush, Lance B.; Cruz, Christopher I.; Lepsch, Roger A.; Morris, W. Douglas; Stanley, Douglas O.; Wurster, Kathryn E.

    1991-01-01

    A single-stage-to-orbit vertical takeoff/horizontal landing rocket vehicle was studied to determine the benefits of advanced technology. Advanced technologies that were included in the study were variable mixture ratio oxygen/hydrogen rocket engines and materials, structures, and subsystem technologies currently being developed in the National Aero-Space Plane Program. The application of advanced technology results in an 85 percent reduction in vehicle dry weight. With advanced materials, an external thermal protection system, like the Space Shuttle tiles, was not required. Compared to an all-airbreathing horizontal takeoff/horizontal landing vehicle using the same advanced technologies and mission requirements, the rocket vehicle is lighter in dry weight and has fewer subsystems. To increase reliability and safety, operational features were included in the rocket vehicle-robust subsystems, 5 percent additional margin, no slush hydrogen, fail-operational with an engine out, and a crew escape module. The resulting vehicle grew in dry weight and was still lower in dry weight than the airbreathing vehicle.

  3. 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.

  4. Single-stage-to-orbit: Meeting the challenge

    NASA Astrophysics Data System (ADS)

    Freeman, Delma C., Jr.; Talay, Theodore A.; Austin, Robert Eugene

    1995-10-01

    There has been and continues to be significant discussion about the viability of fully reusable, single-stage-to-orbit (SSTO) concepts for delivery of payloads to orbit. Often, these discussions have focused in detail on performance and technology requirements relating to the technical feasibility of the concept, with only broad generalizations on how the SSTO will achieve its economic goals of greatly reduced vehicle ground and flight operations costs. With the current industry and NASA Reusable Launch Vehicle Technology Program efforts underway to mature and demonstrate technologies leading to a viable commercial launch system that also satisfies national needs, achieving acceptable recurring costs becomes a significant challenge. This paper reviews the current status of the Reusable Launch Vehicle Technology Program including the DC-XA, X-33, and X-34 flight systems and associated technology programs. The paper also examines lessons learned from the recently completed DC-X reusable rocket demonstrator program. It examines how these technologies and flight systems address the technical and operability challenges of SSTO whose solutions are necessary to reduce costs. The paper also discusses the management and operational approaches that address the challenge of a new cost-effective, reusable launch vehicle system.

  5. Single-stage-to-orbit — Meeting the challenge

    NASA Astrophysics Data System (ADS)

    Freeman, Delma C.; Talay, Theodore A.; Austin, Robert Eugene

    1996-02-01

    There has been and continues to be significant discussion about the viability of fully reusable, single-stage-to-orbit (SSTO) concepts for delivery of payloads to orbit. Often, these discussions have focused in detail on performance and technology requirements relating to the technical feasibility of the concept, with only broad generalizations on how the SSTO will achieve its economic goals of greatly reduced vehicle ground and flight operations costs. With the current industry and NASA Reusable Launch Vehicle Technology Program efforts underway to mature and demonstrate technologies leading to a viable commercial launch system that also satisfies national needs, achieving acceptable recurring costs becomes a significant challenge. This paper reviews the current status of the Reusable Launch Vehicle Technology Program including the DC-XA, X-33, X-34 flight systems and associated technology programs. The paper also examines lessons learned from the recently completed DC-X reusable rocket demonstrator program. It examines how these technologies and flight systems address the technical and operability challenges of SSTO whose solutions are necessary to reduce costs. The paper also discusses the management and operational approaches that address the challenge of a new cost-effective, reusable launch vehicle system.

  6. 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.

  7. The single electron chemistry of coals. [Quarterly], April 1--June 30, 1992

    SciTech Connect

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

    1992-10-01

    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 will also be concerned with the decomposition of radical cations and the products formed as a result of the decomposition.

  8. 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.

  9. Single-Stage Trans-mastoid Drainage of Otogenic Brain Abscess: A Single-Institution Experience.

    PubMed

    Mukherjee, Dwaipayan; Das, Chiranjib; Paul, Dipten

    2016-06-01

    Brain abscess is the ultimate otogenic complication, both in severity and difficulty of management. In developing countries with high incidence of cholesteatoma, brain abscess is not a rare complication. In India, brain abscesses constitute about 8 % of all intracranial lesions. The surgical treatment of brain abscess is very controversial. This prospective study was done in ENT department of a tertiary care hospital in Kolkata, during the period from May 2009 to April 2014. 22 such cases of otogenic brain abscess managed by single-stage trans-mastoid drainage along with meticulous mastoid clearance. On the basis of clinical, radiological and operative findings, data of all patients with otogenic brain abscess were analyzed. There was male predominance and 9 (40.91 %) of them were younger than 20 years. 15 (68.18 %) cases were of cerebellar abscess and in 7 (31.82 %) cases were of the temporal abscess. Lateral sinus thrombosis was the most common associated complication found (22.73 %) in our study. All the patients peri-operatively revealed cholesteatoma. All the patients recovered well and there was no recurrence of symptoms on a minimum 15 months follow-up. This approach suits the otologists in clearing the cause and effect of pathology, at the same sitting. This single-stage approach decreases the peri-operative morbidity and mortality of the two-stage procedure. It also decreases the hospital stay and financial burden. PMID:27340633

  10. Two-stage, close coupled catalytic liquefaction of coal. Fourteenth quarterly report, 1 January 1992--31 March 1992

    SciTech Connect

    Comolli, A.G.; Johanson, E.S.; Lee, T.L.K.; Popper, G.A.; Stalzer, R.H.

    1992-04-01

    This quarterly report covers activities of the Two-Stage, Close- Coupled Catalytic Liquefaction of Coal program during the period January 1,--March 31,1992, at Hydrocarbon Research, Inc. in Lawrenceville and Princeton, New Jersey. This DOE contract period is from October 1, 1988 to September 30, 1992. The overall purpose of the program is to achieve higher yields of better quality transportation and turbine fuels and to lower the capital and production costs in order to make the products from direct coal liquefaction competitive with other fossil fuel products. The quarterly report covers work on Laboratory Testing, PDU Activities and Administration.

  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. Wilsonville Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama. Topical report No. 14. Catalyst activity trends in two-stage coal liquefaction

    SciTech Connect

    Not Available

    1984-02-01

    The Two Stage Coal Liquefaction process became operational at Wilsonville in May 1981, with the inclusion of an H-OIL ebullated-bed catalytic reactor. The two stage process was initially operated in a nonintegrated mode and has recently been reconfigurated to fully integrate the thermal and the catalytic stages. This report focuses on catalyst activity trends observed in both modes of operation. A literature review of relevant catalyst screening studies in bench-scale and PDU units is presented. Existing kinetic and deactivation models were used to analyze process data over an extensive data base. Based on the analysis, three separate, application studies have been conducted. The first study seeks to elucidate the dependence of catalyst deactivation rate on type of coal feedstock used. A second study focuses on the significance of catalyst type and integration mode on SRC hydrotreatment. The third study presents characteristic deactivation trends observed in integrated operation with different first-stage thermal severities. In-depth analytical work was conducted at different research laboratories on aged catalyst samples from Run 242. Model hydrogenation and denitrogenation activity trends are compared with process activity trends and with changes observed in catalyst porosimetric properties. The accumulation of metals and coke deposits with increasing catalyst age, as well as their distribution across a pellet cross-section, are discussed. The effect of catalyst age and reactor temperature on the chemical composition of flashed bottoms product is addressed. Results from regenerating spent catalysts are also presented. 35 references, 31 figures, 18 tables.

  13. Reconfigured, close-coupled reconfigured, and Wyodak coal integrated two-stage coal liquefaction process materials from the Wilsonville facility: Chemical and toxicological evaluation

    SciTech Connect

    Wright, C.W.

    1987-03-01

    This document reports the results of the chemical analysis and toxicological testing of process materials sampled during the operation of the Advanced Coal Liquefaction Research and Development Facility (Wilsonville, AL) in the reconfigured, integrated (RITSL run No. 247), the close-coupled, reconfigured, integrated (CCRITSL run No. 249), and the Wyodak coal integrated (ITSL run No. 246) two-stage liquefaction operating modes. Chemical methods of analysis included proton nuclear magnetic resonance spectroscopy, adsorption column chromatography, high resolution gas chromatography, gas chromatography/mass spectrometry, and low-voltage probe-inlet mass spectrometry. Toxicological evaluation of the process materials included a histidine reversion assay for microbial mutagenicity, an initiation/promotion assay for tumorigenicity in mouse skin, and an aquatic toxicity assay using Daphnia magna. The results of these analyses and tests are compared to the previously reported results derived from the Illinois No. 6 coal ITSL and nonintegrated two-stage liquefaction (NTSL) process materials from the Wilsonville facility. 21 refs., 13 figs., 21 tabs.

  14. 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.

  15. Coal slurry combustion optimization on single cylinder engine

    SciTech Connect

    Not Available

    1992-09-01

    Under the sponsorship of the US Department of Energy, Morgantown Energy Technology Center, GE Transportation System has been conducting a proof of concept program to use coal water slurry (CWS) fuel to power a diesel engine locomotive since 1988. As reported earlier [1], a high pressure electronically controlled accumulator injector using a diamond compact insert nozzle was developed for this project. The improved reliability and durability of this new FIE allowed for an improved and more thorough study of combustion of CWS fuel in a diesel engine. It was decided to include a diesel pilot fuel injector in the combustion system mainly due to engine start and low load operation needs. BKM, Inc. of San Diego, CA was contracted to develop the electronic diesel fuel pilot/starting FIE for the research engine. As a result, the experimental combustion study was very much facilitated due to the ability of changing pilot/CWS injection timings and quantities without having to stop the engine. Other parameters studied included combustion chamber configuration (by changing CWS fuel injector nozzle hole number/shape/angle), as well as injection pressure. The initial phase of this combustion study is now complete. The results have been adopted into the design of a 12 cylinder engine FIE, to be tested in 1992. This paper summarizes the main findings of this study.

  16. 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.

  17. 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.

  18. Single-stage posterior-only approach treating single-segment thoracic tubercular spondylitis

    PubMed Central

    Shen, Xiongjie; Liu, Hongzhe; Wang, Guoping; Liu, Xiangyang

    2015-01-01

    There are quite a few controversies on surgical management of single-segment thoracic spinal tuberculosis (STB) with neurological deficits. The present study was to compare single-stage posterior-only transpedicular debridement, interbody fusion and posterior instrumentation (posterior-only surgery) with a combined posterior-anterior surgical approach for treatment of single-segment thoracic STB with neurological deficits and to determinethe clinical feasibility and effectiveness of posterior-only surgical treatment. Sixty patients with single-segment thoracic STB with neurological deficits were treated with one of two surgical procedures in our center from January 2003 to January 2013. Thirty patients were treated with posterior-only surgery (Group A) andthirty were treated with combined posterior-anterior surgery (Group B). The American Spinal Injury Association (ASIA) score system to evaluate the neurological deficits, thevisual analogue scale (VAS) to assess the degree of pain, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to judge the activity of tuberculosis (TB), surgery duration, intraoperative blood loss, length of hospitalization, bonyfusion rates, and kyphosis correction of the two groups were compared. The average follow-up period was 36.5 ± 9.2 months for Group A and 34.6 ± 10.2 months for Group B. Under the ASIA score system, all patients improved with treatment. STB was completely cured and grafted bones were fused within 5-11 months in allpatients. There were no persistent or recurrent infections orobvious differences in radiological results between thegroups. The kyphosis deformity was significantly corrected after surgical management. The average operative duration, blood loss, length of hospital stay, and postoperative complication rateof Group A were lower than those of Group B. In conclusions, posterior-only surgery is feasible and effective, resulting in better clinical outcomes than combined posterior-anterior surgeries

  19. Applications of the magnetocaloric effect in single-stage, multi-stage and continuous adiabatic demagnetization refrigerators

    NASA Astrophysics Data System (ADS)

    Shirron, Peter J.

    2014-07-01

    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 (6 × 6) 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.

  20. 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.

  1. 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.

  2. 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

  3. The single electron chemistry of coals. Quarterly report, July 1--September 30, 1992

    SciTech Connect

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

    1992-11-11

    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 will also be concerned with the decomposition of radical cations and the products formed as a result of the decomposition. In our last report we described that treatment of bibenzyl and neo-pentylbenzene with Fe(III) (1,10-phenanthroline){sub 3}(ClO{sub 4}){sub 3} (Fe(III)(PHEN)) in refluxing CH{sub 3}CN (82{degrees}C) failed to produce substantial bond cleavage {beta} to the aromatic ring. Because bond cleavage was not observed, we have continued our study by moving to compounds which have lower ionization potentials as well as study other oxidants.

  4. Catalytic multi-stage liquefaction of coal. Tenth quarterly report, January 1--March 31, 1995

    SciTech Connect

    Comolli, A.G.; Johanson, E.S.; Lee, L.K.; Pradhan, V.R.; Stalzer, R.H.

    1995-05-01

    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 report describes the following: (1) laboratory support for bench run CMSL-09, (2) the laboratory-scale efforts for development of suitable catalysts for hydrocracking/depolymerization of waste plastics, (3) analysis of TBP (true boiling point) fractions of distillates from CMSL-08, and (4) objectives and run-plan for bench run CMSL-09.

  5. 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.

  6. Composite engines for application to a single-stage-to-orbit vehicle

    NASA Technical Reports Server (NTRS)

    Bendot, J. G.; Brown, P. N.; Piercy, T. G.

    1975-01-01

    Seven composite engines were designed for application to a reusable single-stage-to-orbit vehicle. The engine designs were variations of the supercharged ejector ramjet engine. The resulting performance, weight, and drawings of each engine form a data base for establishing a potential of this class of composite engine to various missions, including the single-stage-to-orbit application. The impact of advanced technology in the design of the critical fan turbine was established.

  7. 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.

  8. 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%. PMID:25637013

  9. 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…

  10. Complex aortopulmonary window in a single ventricle setting: Technical considerations for staged palliation

    PubMed Central

    Salve, Gananjay G; Jain, Shreepal A; Katkade, Sandip S; Shivaprakash, Krishnanaik

    2016-01-01

    We report a successful surgical management of a case presented with a combination of aortopulmonary window (APW) with large ventricular septal defect (VSD) amounting to a single ventricle, with a view to highlight technical considerations during staged single-ventricle palliation. PMID:27212854

  11. Single exposure to heat induces stage-specific germ cell apoptosis in rats: role of intratesticular testosterone on stage specificity.

    PubMed

    Lue, Y H; Hikim, A P; Swerdloff, R S; Im, P; Taing, K S; Bui, T; Leung, A; Wang, C

    1999-04-01

    Short term exposure of the testis to heat causes degeneration of germ cells. However, the mechanisms underlying this process are poorly understood. The major objectives of this study were to determine whether the heat-induced loss of germ cells in the adult rat occurs via apoptosis, to document its stage-specific and cell-specific distribution, and to examine whether intratesticular testosterone (T) plays any role in the stage specificity of heat-induced germ cell death. Testes of adult male Sprague-Dawley rats were exposed to 22 C (control) or 43 C for 15 min. Animals were killed on days 1, 2, 9, and 56 after heat exposure. Germ cell apoptosis was characterized by DNA gel electrophoresis and in situ terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling assay. The incidence of germ cell apoptosis [apoptotic index (AI)] was quite low in control rats (AI = 0.04-0.1). Mild hyperthermia within 1 or 2 days resulted in a marked activation (AI = 4.7-5.6) of germ cell apoptosis predominantly at early (I-IV) and late (XII-XIV) stages. Stages V-VI and VII-VIII were relatively protected from heat-induced apoptosis. Spermatocytes, including pachytenes at stages I-IV and IX-XII, diplotene and dividing spermatocytes at stages XIII-XIV, and early (steps 1-4) spermatids, were most susceptible to heat. On day 9, the majority of the tubules were severely damaged and displayed only a few remaining apoptotic germ cells. By day 56, spermatogenesis was completely recovered, and the incidence of germ cell apoptosis was compatible with the control levels. To determine whether intratesticular T plays a role in protecting germ cells at stages VII-VIII against heat-induced cell death, adult rats were exposed to local testicular heating on day 2 or were given a daily sc injection of GnRH antagonist (GnRH-A) for 4 days with and without a single exposure of testes to heat applied on day 2. By day 4, the incidence of increased germ cell apoptosis at stages other than VII

  12. Short-range correlations in single-crystalline CoAl2O4

    NASA Astrophysics Data System (ADS)

    MacDougall, G. J.; Gout, D.; Zarestky, J. L.; Mandrus, D.; Nagler, S. E.

    2010-03-01

    The A-site spinels, where magnetic cations reside on a diamond sublattice, have been receiving much attention in recent years. Order can be frustrated in these systems due to competing nearest and further neighbor exchange, and theoretical studies suggest a number of interesting ground states and a central role for fluctuations. One such spinel, CoAl2O4, has been held up as a material of particular interest. Despite a large Curie-Weiss constant of θ˜104K, only a glassy transition is reported at T^*˜4-10K. Preliminary results on powders has been associated with novel spin liquid behavior, but careful studies of single crystals are needed. To this end, we have grown several large single crystals of CoAl2O4 at ORNL via the floating zone method, and studied them with neutron scattering using the HB-1a beamline at the High Flux Isotope Reactor. We will present the results of these neutron scattering experiments, and discuss both the evolution of magnetic properties in this system and implications for existing theories.

  13. 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.

  14. Cochlear implantation and management of chronic suppurative otitis media: single stage procedure?

    PubMed

    Basavaraj, S; Shanks, M; Sivaji, N; Allen, Agnes A

    2005-10-01

    In a series of 360 patients who underwent cochlear implantation at our center, four patients (five procedures) had cochlear implantation with obliteration of the mastoid cavity and management of cholesteatoma as a single-staged procedure. Three patients were bilaterally deaf secondary to CSOM and had bilateral mastoid cavities, and in one patient congenital cholesteatoma was identified during cochlear implantation. A mastoidectomy or revision mastoidectomy with obliteration of the mastoid cavity and cochlear implantation was performed as a single stage procedure. Cholesteatoma reoccurred in one patient 9 years after cochlear implantation. Surgical procedures, complications, follow-up and outcomes are discussed. PMID:15756568

  15. 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.}

  16. 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. PMID:23648266

  17. Synthesis of low-temperature, fast, single-firing body for porcelain stoneware tiles with coal gangue.

    PubMed

    Qiangwei Wei; Wenyuan Gao; Xinguo Sui

    2010-10-01

    Coal gangue is a major industrial solid waste in China, causing great environment pollution. According to phase diagram theory, a low-temperature, fast, single-firing body mix for porcelain stoneware tiles was designed in the quaternary system CaO--MgO--Al₂O₃--SiO₂, using coal gangue as the main raw material. The coal gangue was from Baishan city, Jilin province and mainly composed of kaolinite and quartz. Mineralogical compositions and microstructures of some selected samples sintered at different temperatures were identified with X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results indicated that the optimal body mix was the one containing 34 wt% coal gangue sintered at 1170°C for about 1 h, with rupture strength of 43 MPa and water absorption of 0.22%. The main crystalline phases of the sintered body were quartz, anorthite and mullite. PMID:19942651

  18. 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.

  19. 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.

  20. An experimental study of high-speed single stage magnetic fluid seals

    NASA Astrophysics Data System (ADS)

    Ozaki, K.; Fujiwara, T.

    1987-03-01

    Sealing performance, namely burst pressure difference and power loss, of the single stage magnetic fluid seals were experimentally studied to search for the optimal design of the magnetic fluid seals for flywheel systems. They were measured on a rotary shaft 120 mm in diameter, 12000 rpm at the maximum speed.

  1. Heat balance analysis of single stage Gifford-McMahon cycle cryorefrigerator

    NASA Astrophysics Data System (ADS)

    Thirumaleshwar, M.; Subramanyam, S. V.

    A heat balance analysis of single stage Gifford-McMahon cycle cryorefrigerator is presented. Ideal refrigeration, actual refrigeration, net refrigeration and the various losses are tabulated. It is observed that pressure-volume losses account for a major fraction of the total losses.

  2. Effects of multistage or single-stage incubation on broiler chick quality and performance.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single-stage (SS) incubation has benefit over multistage (MS) incubation by matching incubator environment to embryo needs. Eggs from a young breeder flock may be incubated diffeerently than eggs from old flocks. Information on chick quality and performance are scarce. The objective of this study...

  3. Limits of Single-stage Compression in Centrifugal Superchargers for Aircraft

    NASA Technical Reports Server (NTRS)

    Kollmann, K

    1940-01-01

    The limits of the single-stage compression in superchargers at the present state of development are determined by five factors. 1) by the rotor material; 2) by the formation of the flow; 3) by the manufacture of double shrouded rotors; 4) by the bearing problem; 5) by the drive method.

  4. The Maximum Delivery Pressure of Single-stage Radial Superchargers for Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Null, W Von Der

    1940-01-01

    With the aid of simple considerations and test results, an attempt is made to clear up some obscure points that still exist. The considerations are restricted to those cases where it is in fact of advantage to"force" the large delivery heads required for high altitude and high supercharge with a single-stage supercharger.

  5. High energy, high current neutral beam injector operation with single stage and two-stage multi-aperture extraction systems

    NASA Astrophysics Data System (ADS)

    Becherer, R.; Desmons, M.; Fumelli, M.; Raimbault, P.; Valckx, F. P. G.

    1982-12-01

    Neutral beam development for JET injections at FAR laboratory has led to the study of properties of a single stage (triode) and a two-stage (tetrode) multi-aperture extraction system at ion beam powers exceeding the megawatt level and up to 80 keV beam energy. The results of the experimental measurements and of a numerical study of the beam optical qualities and grid power loadings of these systems are presented. Grid power loading levels of less than 1% of the high-voltage drain power were measured in both the triode and the tetrode accelerators. This would allow long pulse operation (10 s with water-cooling) as required for JET. The beam divergence angle (α ≅ 0.7°) and the transmission characteristics were almostidentical. At the same energy, higher current densities, at optimum perveance, were obtained with the triode at a lower electric field stress on the high-voltage gap. The triode offers the additional advantage of being simpler from the mechanical and electrical points of view. Operation of the injection line with an electrostatic beam dump associated with a grounded source is also demonstrated for a 25 ion beam up to 60 keV.

  6. Characterization of single coal particle combustion within oxygen-enriched environments using high-speed OH-PLIF

    NASA Astrophysics Data System (ADS)

    Köser, J.; Becker, L. G.; Vorobiev, N.; Schiemann, M.; Scherer, V.; Böhm, B.; Dreizler, A.

    2015-12-01

    This work presents first-of-its-kind high-speed planar laser-induced fluorescence measurements of the hydroxyl radical in the boundary layer of single coal particles. Experiments were performed in a laminar flow reactor providing an oxygen-enriched exhaust gas environment at elevated temperatures. Single coal particles in a sieve fraction of 90-125 µm and a significant amount of volatiles (36 wt%) were injected along the burner's centerline. Coherent anti-Stokes Raman spectroscopy measurements were taken to characterize the gas-phase temperature. Time-resolved imaging of the OH distribution at 10 kHz allowed identifying reaction and post-flame zones and gave access to the temporal evolution of burning coal particles. During volatile combustion, a symmetric diffusion flame was observed around the particle starting from a distance of ~150 µm from the particle surface. For subsequent char combustion, this distance decreased and the highest OH signals appeared close to the particle surface.

  7. Overlapping of the devolatilization and char combustion stages in the burning of coal particles

    SciTech Connect

    Veras, C.A.G.; Saastamoinen, J.; Aho, M.; Carvalho, J.A. Jr.

    1999-03-01

    The oxygen content at the surface of a fuel particle can significantly exceed zero during the devolatilization stage of combustion, despite the flux of volatiles from the surface and also gas phase reactions. This implies that char oxidation can take place simultaneously. This overlapping of the devolatilization and char combustion stages is studied by modeling. The rates of gas phase reactions around the particle influence the availability of oxygen at the surface of a burning particle and they are accounted for by using a two-step global model for combustion of volatiles. The effects of particle size, ambient temperature, and oxygen concentration on the degree of overlap are studied. The study provides theoretical and experimental evidence that the combustion time of a particle does not always increase with its size at constant ambient conditions, but there can be a specific particle size giving a maximum combustion rate.

  8. 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

  9. Single stage minimally invasive bilateral video assisted thoracoscopic surgery for simultaneous bilateral primary spontaneous pneumothorax.

    PubMed

    Sachithanandan, A; Nur Ezrin, I; Badmanaban, B

    2012-04-01

    Simultaneous bilateral spontaneous pneumothorax (SBSP) is a very rare life-threatening condition that requires rapid diagnosis and treatment. Most cases are secondary to various underlying lung pathology but a primary SBSP may occur due to rupture of subpleural blebs or bullae. Surgery via an open or minimally invasive approach provides definitive treatment and can be undertaken as a staged or simultaneous procedure. We report our experience with two such rare cases utilizing a single stage minimally invasive bilateral video assisted thoracoscopic (VATS) approach. The pathogenesis of this rare condition and intra-operative technical considerations for a successful outcome are discussed. PMID:22822653

  10. 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.

  11. 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

  12. Construction of a 150 t/d pilot plant for bituminous coal liquefaction

    SciTech Connect

    Ishibashi, Hirohito; Kobayashi, Masatoshi; Suzuki, Satoru

    1994-12-31

    This present paper covers bituminous coal liquefaction R and D carried out by Nippon Coal Oil Co., Ltd. (NCOL). Construction of a 150 ton/day bituminous coal liquefaction pilot plant will be presented. The NEDOL process is characterized by the wide applicability of various coal grades, such as low-rank bituminous coal, subbituminous coal and low-rank subbituminous coal, and a single-stage liquefaction method that combines the advantages of a hydrogen-donor solvent and a fine iron catalyst. A vacuum distillation system for solid-liquid separation is used to improve reliability. The simplicity of this process ensures a high degree of stability.

  13. 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. PMID:23399080

  14. Analysis and design of a high power factor, single-stage electronic dimming ballast

    SciTech Connect

    Wu, T.F.; Yu, T.H.

    1998-05-01

    This paper presents the analysis, design, and practical consideration of a single-stage electronic dimming ballast with unity power factor. The power stage of the ballast is derived from combining a buck-boost converter and a half-bridge series-resonant parallel-loaded inverter (SRPLI). With the plasma model of the lamp, the analysis of the ballast is carried out, from which the key equations used for dimming control are derived. Starting performance and dimming consideration are also addressed in the paper. In this dimming ballast, both pulsewidth modulation (PWM) and variable-frequency control strategies are employed. The discussed ballast with the controls can save a controller and a switch driver, reduce size and cost, and possibly increase system reliability over conventional two-stage systems in the applications with moderate power level. Simulated and experimental results of the ballast for an OSRAM T8 32-W lamp are used to verify the discussion.

  15. 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.

  16. 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.

  17. 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. PMID:25976710

  18. Single staged complete length excision of the holocord ependymoma: Team work.

    PubMed

    Bhaisora, Kamlesh S; Sharma, Pradeep; Srivastava, Arun Kumar; Mehrotra, Anant; Das, Kuntal Kanti; Sardhara, Jayesh; Behari, Sanjay; Jaiswal, A K; Sahu, R N

    2015-01-01

    The authors present a case of a 15-year-old male patient who presented with gradually progressive quadriparesis for 3 years. Magnetic resonance imaging of the spine was suggestive of heterogeneously enhancing mass lesion extending from cervicomedullary junction to conus. This holocord spinal tumor was excised in a single stage with standard microsurgical technique. In immediate postoperative period, the patient had deterioration in power in both lower limbs which improved in follow-up at 6 months. Histopathology of the tumor was suggestive of ependymoma. Holocord ependymoma is a rare entity; until now, only six cases have been described in the literature. To the author's best knowledge, this is only the second case of holocord ependymoma excised in a single stage. PMID:26962355

  19. Single staged complete length excision of the holocord ependymoma: Team work

    PubMed Central

    Bhaisora, Kamlesh S.; Sharma, Pradeep; Srivastava, Arun Kumar; Mehrotra, Anant; Das, Kuntal Kanti; Sardhara, Jayesh; Behari, Sanjay; Jaiswal, A. K.; Sahu, R. N.

    2015-01-01

    The authors present a case of a 15-year-old male patient who presented with gradually progressive quadriparesis for 3 years. Magnetic resonance imaging of the spine was suggestive of heterogeneously enhancing mass lesion extending from cervicomedullary junction to conus. This holocord spinal tumor was excised in a single stage with standard microsurgical technique. In immediate postoperative period, the patient had deterioration in power in both lower limbs which improved in follow-up at 6 months. Histopathology of the tumor was suggestive of ependymoma. Holocord ependymoma is a rare entity; until now, only six cases have been described in the literature. To the author's best knowledge, this is only the second case of holocord ependymoma excised in a single stage. PMID:26962355

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

    NASA Astrophysics Data System (ADS)

    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)NO3 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 percent. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. High Frequency Single-Stage Multi-Bypass Pulse Tube Cryocooler for 23.8K

    NASA Astrophysics Data System (ADS)

    Yang, Junling; Hou, Xiaofeng; Yang, Luwei; Zhou, Yuan; Zhang, Liang

    2008-03-01

    A below 30K single-stage high-frequency multi-bypass pulse tube cryocooler(PTC) is introduced in this paper. At present, the lowest temperature of 27.46K has been achieved with input power of 100W and 23.8K with input power of 200W. Experiments show that if the area of multi-bypass and the length of inertance tube matching well, a better performance of PTC will be obtained.

  6. Method of calculating gas dynamics and heat transfer in single stage refrigeration units

    NASA Technical Reports Server (NTRS)

    Zhitomirskiy, I. S.; Popolskiy, A. B.

    1974-01-01

    A generalized mathematical model of gas-dynamic and heat transfer processes in single-stage regenerative installations operating in Stirling, MacMahon, Gifford-MacMahon, and pulsating tube cycles is proposed. A numerical method os solving initial equations on a digital computer is given. This makes it possible to calculate the change in the thermodynamic parameters in the working cycle in different machine components, as well as the dependence of cold productivity on the temperature level in the steady regime.

  7. Parallel-burn options for dual-fuel single-stage orbital transports

    NASA Technical Reports Server (NTRS)

    Martin, J. A.

    1978-01-01

    A parallel-burn version of a single-stage vehicle for transport from the earth to low-earth orbit using two fuels and rocket propulsion is considered. New engine results were incorporated in vehicle performance and design studies. The results indicate that a hydrogen-cooled gas generator cycle engine provides attractive vehicle performance and that there is little incentive for increasing the chamber pressure beyond 27 MPa.

  8. 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.

  9. Single stage to orbit vertical takeoff and landing concept technology challenges

    NASA Astrophysics Data System (ADS)

    Heald, Daniel A.; Kessler, Thomas L.

    1991-10-01

    General Dynamics has developed a VTOL concept for a single-stage-to-orbit under contract to the Strategic Defense Initiative Organization. This paper briefly describes the configuration and its basic operations. Two key advanced technolgy areas are then discussed: high-performance rocket propulsion employing a plug nozzle arrangement and integrated health management to facilitate very rapid turnaround between flights, more like an aircraft than today's rockets.

  10. History of the Phoenix VTOL SSTO and recent developments in single-stage launch systems

    NASA Astrophysics Data System (ADS)

    Hudson, Gary C.

    The history of the VTOL SSTO (single stage to orbit) concept and the Phoenix designs is reviewed. The role the Phoenix concept played in stimulating consideration of the SSTO approach by the U.S. Government in ongoing SSTO concept studies is also discussed. It is pointed out that these studies are currently expected to lead to prototype hardware development aimed at demonstrating the SSTO approach by 1995-1997 in the form of the McDonnell-Douglas DC-Y.

  11. Single-stage small satellite launcher with combustible tank of polyethylene

    NASA Astrophysics Data System (ADS)

    Yemets, Vitaly; Sanin, Fedir; Dzhur, Yevgen; Masliany, Mykola; Kostritsyn, Oleg; Minteev, Grygory

    2009-01-01

    A solid propellant version of the single-stage launch vehicle with polyethylene case that consumed as fuel is considered as means for launching small satellites. Emphasis is on experimental investigating gasification of a polyethylene structure element by a chamber of special design. Photographs and the reference to electronic annex containing an experimental video record are included in the paper. Main previous experiments are also briefly reviewed. Conclusions concern improvements of the gasification chamber design and a speculation about next experiments.

  12. 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.

  13. 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

  14. 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.

  15. Treatment of strong domestic sewage in a 96 m3 UASB reactor operated at ambient temperatures: two-stage versus single-stage reactor.

    PubMed

    Halalsheh, M; Sawajneh, Z; Zu'bi, M; Zeeman, G; Lier, J; Fayyad, M; Lettinga, G

    2005-03-01

    A 96 m3 UASB reactor was operated for 2.5 years under different conditions to assess the feasibility of treating strong sewage (COD(tot) = 1531 mg/l) at ambient temperatures with averages of 18 and 25 degrees C for winter and summer respectively. During the first year, the reactor was operated as a two-stage system at OLRs in the range of 3.6-5.0 kg COD/m3 d for the first stage and 2.9-4.6 kg COD/m3 d for the second stage. The results of the first stage showed average removals of 51% and 60% for COD(tot) and COD(ss) respectively without significant effect of temperature. The second stage reactor was unstable. The temperature affected sludge stabilization. During the second year, the first stage was operated as a single-stage UASB reactor at half of the previous loading rates. The results showed an average removal efficiency of 62% for COD(tot) during summer, while it dropped to 51% during wintertime. However, the effluent suspended solids were stabilized with VSS/TSS ratio around 0.50 all over the year. The sludge in the single-stage reactor was well-stabilized and exerted an excellent settlability. During the last three months of research, sludge was discharged regularly from the single-stage UASB reactor. The results showed no significant improvement in the performance in terms of COD(tot). Based on the results of the experiment, a single-stage UASB reactor operated at relatively long HRT is preferred above two-stage system at the Jordanian conditions. PMID:15501665

  16. Fueling of magnetically confined plasmas by single- and two-stage repeating pneumatic pellet injectors

    SciTech Connect

    Gouge, M.J.; Combs, S.K.; Foust, C.R.; Milora, S.L.

    1990-01-01

    Advanced plasma fueling systems for magnetic fusion confinement experiments are under development at Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets to speeds in the kilometer-per-second range using single shot and repetitive pneumatic (light-gas gun) pellet injectors. The millimeter-to-centimeter size pellets enter the plasma and continuously ablate because of the plasma electron heat flux, depositing fuel atoms along the pellet trajectory. This fueling method allows direct fueling in the interior of the hot plasma and is more efficient than the alternative method of injecting room temperature fuel gas at the wall of the plasma vacuum chamber. Single-stage pneumatic injectors based on the light-gas gun concept have provided hydrogenic fuel pellets in the speed range of 1--2 km/s in single-shot injector designs. Repetition rates up to 5 Hz have been demonstrated in repetitive injector designs. Future fusion reactor-scale devices may need higher pellet velocities because of the larger plasma size and higher plasma temperatures. Repetitive two-stage pneumatic injectors are under development at ORNL to provide long-pulse plasma fueling in the 3--5 km/s speed range. Recently, a repeating, two-stage light-gas gun achieved repetitive operation at 1 Hz with speeds in the range of 2--3 km/s.

  17. Single stage transforaminal retrojugular tumor resection: The spinal keyhole for dumbbell tumors in the cervical spine

    PubMed Central

    Bobinski, Lukas; Henchoz, Yves; Sandu, Kishore; Duff, John Michael

    2015-01-01

    Background: Dumbbell tumors are defined as having an intradural and extradural component with an intermediate component within an expanded neural foramen. Complete resection of these lesions in the subaxial cervical spine is a challenge, and it has been achieved through a combined posterior/anterior or anterolateral approach. This study describes a single stage transforaminal retrojugular (TFR) approach for dumbbell tumors resection in the cervical spine. Methods: This is a retrospective review of a series of 17 patients treated for cervical benign tumors, 4 of which were “true” cervical dumbbell tumors operated by a simplified retrojugular approach. The TFR approach allows a single stage gross total resection of both the extraspinal and intraspinal/intradural components of the tumor, taking advantage of the expanded neural foramen. All patients were followed clinically and radiologically with magnetic resonance imaging (MRI). Results: Gross total resection was confirmed in all four patients by postoperative MRI. Minimal to no bone resection was performed. No fusion procedure was performed and no delayed instability was seen. At follow up, one patient had a persistent mild hand weakness and Horners syndrome following resection of a hemangioblastoma of the C8 nerve root. The other three patients were neurologically normal. Conclusions: The TFR approach appears to be a feasible surgical option for single stage resection in selective cases of dumbbell tumors of the cervical spine. PMID:25883845

  18. A single-stage GM-type pulse tube cryocooler operating at 10.6 K

    NASA Astrophysics Data System (ADS)

    Gan, Z. H.; Dong, W. Q.; Qiu, L. M.; Zhang, X. B.; Sun, H.; He, Y. L.; Radebaugh, R.

    2009-05-01

    In order to explore the lowest attainable refrigeration temperature and improve cooling performance at temperatures around 20 K for a single-stage G-M type pulse tube cryocooler (PTC), numerical and experimental studies were performed. The National Institute of Standards and Technology (NIST) numerical model known as REGEN was applied to the simulation of a G-M type PTC for the first time. Based on the calculation results, a single-stage G-M type PTC was designed, fabricated and tested. The performance improvement of the regenerator in the temperature range of 10-80 K was investigated. The calculations predicted a lowest temperature of 10 K. A lowest temperature of 10.6 K was achieved experimentally with an input power of 7.5 kW, which is the lowest temperature ever achieved by a single-stage PTC. Further more, the cryocooler can provide a cooling power of 20 W at 20.6 K and 39.5 W at 30 K, respectively.

  19. Nitrite reduction and methanogenesis in a single-stage UASB reactor.

    PubMed

    Borges, L I; López-Vazquez, C M; García, H; van Lier, J B

    2015-01-01

    In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO(2)(-)-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO(2)(-)-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO(2)(-)-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO(2)(-) reduction to N₂. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater. PMID:26676012

  20. Single stage and thrust augmented reusable launch vehicle stability and performance study

    NASA Astrophysics Data System (ADS)

    Tanck, Pamela A.; Steadman, Kimberly B.

    1998-01-01

    The requirement for routine, reliable, inexpensive launch service drives the interest in the development of a fully reusable launch vehicle (RLV). In theory, single-stage vehicle operations would resemble aircraft operations where high initial development costs are offset by relatively low recurring costs. However, the large size of a single-stage-to-orbit vehicle and the advanced engine and structural technology requirements could overshadow advantages gained through streamlined operations. This analysis explores the feasibility of using thrust augmentation on a fully reusable core vehicle in order to lessen the disadvantages of a fully single-stage vehicle. Advanced technology systems and two 86,000 kg solid strapon motors are incorporated into a vehicle designed to deliver an Atlas-class payload. This study shows that thrust augmentation significantly decreases vehicle size, decreases development risk and improves longitudinal stability characteristics. The thrust augmentation reduces vehicle insertion mass by 40% and reduces the vehicle's sensitivity to the increases in dry mass growth often experienced during development, thus reducing development risk. Thrust augmentation also moves the center of gravity location forward, thus improving longitudinal stability characteristics and maximizing the vehicle's reentry cross range capability.

  1. Design and optimization of a single stage centrifugal compressor for a solar dish-Brayton system

    NASA Astrophysics Data System (ADS)

    Wang, Yongsheng; Wang, Kai; Tong, Zhiting; Lin, Feng; Nie, Chaoqun; Engeda, Abraham

    2013-10-01

    According to the requirements of a solar dish-Brayton system, a centrifugal compressor stage with a minimum total pressure ratio of 5, an adiabatic efficiency above 75% and a surge margin more than 12% needs to be designed. A single stage, which consists of impeller, radial vaned diffuser, 90° crossover and two rows of axial stators, was chosen to satisfy this system. To achieve the stage performance, an impeller with a 6:1 total pressure ratio and an adiabatic efficiency of 90% was designed and its preliminary geometry came from an in-house one-dimensional program. Radial vaned diffuser was applied downstream of the impeller. Two rows of axial stators after 90° crossover were added to guide the flow into axial direction. Since jet-wake flow, shockwave and boundary layer separation coexisted in the impeller-diffuser region, optimization on the radius ratio of radial diffuser vane inlet to impeller exit, diffuser vane inlet blade angle and number of diffuser vanes was carried out at design point. Finally, an optimized centrifugal compressor stage fulfilled the high expectations and presented proper performance. Numerical simulation showed that at design point the stage adiabatic efficiency was 79.93% and the total pressure ratio was 5.6. The surge margin was 15%. The performance map including 80%, 90% and 100% design speed was also presented.

  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. Single- vs. multi-stage repair of proximal hypospadias: The dilemma continues

    PubMed Central

    Badawy, Haytham; Fahmy, Ahmed

    2013-01-01

    Introduction The surgical reconstruction of distal penile hypospadias in a single stage is the standard practice for managing anterior hypospadias. Unfortunately, it is not simple to extrapolate the same principle to proximal hypospadias. There is no consensus among hypospadiologists about whether a single- or multi-stage operation is the optimal treatment for proximal hypospadias. In this review, we assess the currently reported outcomes and complications of both techniques in proximal hypospadias repair. Methods We searched Medline, Pubmed, Scopus and Ovid for publications in the last 10 years (2002–2012) for relevant articles, using the terms ‘proximal hypospadias’, ‘posterior hypospadias’ ‘single stage’, ‘multiple stage’, and ‘complications’. Articles retrieved were analysed according to the technique of repair, follow-up, complications, success rate, number of included children, and re-operative rate. Results and conclusions The reported complications in both techniques were similar, including mostly minor complications in the form of fistula, meatal stenosis, partial glans dehiscence, and urethral diverticulum, with their easy surgical repair. The outcomes of single- and multistage repairs of proximal hypospadias are comparable; no technique can be considered better than any other. Thus, it is more judicious for a hypospadiologist to master a few of these procedures to achieve the best results, regardless of the technique used. PMID:26558078

  4. Monte Carlo Error Analysis Applied to Core Formation: The Single-stage Model Revived

    NASA Astrophysics Data System (ADS)

    Cottrell, E.; Walter, M. J.

    2009-12-01

    The last decade has witnessed an explosion of studies that scrutinize whether or not the siderophile element budget of the modern mantle can plausibly be explained by metal-silicate equilibration in a deep magma ocean during core formation. The single-stage equilibrium scenario is seductive because experiments that equilibrate metal and silicate can then serve as a proxy for the early earth, and the physical and chemical conditions of core formation can be identified. Recently, models have become more complex as they try to accommodate the proliferation of element partitioning data sets, each of which sets its own limits on the pressure, temperature, and chemistry of equilibration. The ability of single stage models to explain mantle chemistry has subsequently been challenged, resulting in the development of complex multi-stage core formation models. Here we show that the extent to which extant partitioning data are consistent with single-stage core formation depends heavily upon (1) the assumptions made when regressing experimental partitioning data (2) the certainty with which regression coefficients are known and (3) the certainty with which the core/mantle concentration ratios of the siderophile elements are known. We introduce a Monte Carlo algorithm coded in MATLAB that samples parameter space in pressure and oxygen fugacity for a given mantle composition (nbo/t) and liquidus, and returns the number of equilibrium single-stage liquidus “solutions” that are permissible, taking into account the uncertainty in regression parameters and range of acceptable core/mantle ratios. Here we explore the consequences of regression parameter uncertainty and the impact of regression construction on model outcomes. We find that the form of the partition coefficient (Kd with enforced valence state, or D) and the handling of the temperature effect (based on 1-atm free energy data or high P-T experimental observations) critically affects model outcomes. We consider the most

  5. 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.

  6. Single institution experience with the Ladd’s procedure in patients with heterotaxy and stage I palliated single-ventricle

    PubMed Central

    Piggott, Kurt D; George, Grace; Fakioglu, Harun; Blanco, Carlos; Narasimhulu, Sukumar Saguna; Pourmoghadam, Kamal; Munroe, Hamish; Decampli, William

    2016-01-01

    AIM To investigate and describe our current institutional management protocol for single-ventricle patients who must undergo a Ladd’s procedure. METHODS We retrospectively reviewed the charts of all patients from January 2005 to March 2014 who were diagnosed with heterotaxy syndrome and an associated intestinal rotation anomaly who carried a cardiac diagnosis of functional single ventricle and were status post stage I palliation. A total of 8 patients with a history of stage I single-ventricle palliation underwent Ladd’s procedure during this time period. We reviewed each patients chart to determine if significant intraoperative or post-operative morbidity or mortality occurred. We also described our protocolized management of these patients in the cardiac intensive care unit, which included pre-operative labs, echocardiography, milrinone infusion, as well as protocolized fluid administration and anticoagulation regimines. We also reviewed the literature to determine the reported morbidity and mortality associated with the Ladd’s procedure in this particular cardiac physiology and if other institutions have reported protocolized care of these patients. RESULTS A total of 8 patients were identified to have heterotaxy with an intestinal rotation anomaly and single-ventricle heart disease that was status post single ventricle palliation. Six of these patients were palliated with a Blaylock-Taussig shunt, one of whom underwent a Norwood procedure. The two other patients were palliated with a stent, which was placed in the ductus arteriosus. These eight patients all underwent elective Ladd’s procedure at the time of gastrostomy tube placement. Per our protocol, all patients remained on aspirin prior to surgery and had no period where they were without anticoagulation. All patients remained on milrinone during and after the procedure and received fluid administration upon arrival to the cardiac intensive care unit to account for losses. All 8 patients experienced

  7. 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. PMID:26210232

  8. On the modeling of a single-stage, entrained-flow gasifier using Aspen Custom Modeler (ACM)

    SciTech Connect

    Kasule, J.; Turton, R.; Bhattacharyya, D.; Zitney, S.

    2010-01-01

    Coal-fired gasifiers are the centerpiece of integrated gasification combined cycle (IGCC) power plants. The gasifier produces synthesis gas that is subsequently converted into electricity through combustion in a gas turbine. Several mathematical models have been developed to study the physical and chemical processes taking place inside the gasifier. Such models range from simple one-dimensional (1D) steady-state models to sophisticated dynamic 3D computational fluid dynamics (CFD) models that incorporate turbulence effects in the reactor. The practical operation of the gasifier is dynamic in nature but most 1D and some higher-dimensional models are often steady state. On the other hand, many higher order CFD-based models are dynamic in nature, but are too computationally expensive to be used directly in operability and controllability dynamic studies. They are also difficult to incorporate in the framework of process simulation software such as Aspen Plus Dynamics. Thus lower-dimensional dynamic models are still useful in these types of studies. In the current study, a 1D dynamic model for a single-stage, downward-firing, entrained-flow GE-type gasifier is developed using Aspen Custom Modeler{reg_sign} (ACM), which is a commercial equation-based simulator for creating, editing, and re-using models of process units. The gasifier model is based on mass, momentum, and energy balances for the solid and gas phases. The physical and chemical reactions considered in the model are drying, devolatilization/pyrolysis, gasification, combustion, and the homogeneous gas phase reactions. The dynamic gasifier model is being developed for use in a plant-wide dynamic model of an IGCC power plant. For dynamic simulation, the resulting highly nonlinear system of partial differential algebraic equations (PDAE) is solved in ACM using the well-known Method of Lines (MoL) approach. The MoL discretizes the space domain and leaves the time domain continuous, thereby converting the PDAE to

  9. Comparing a single-stage geocoding method to a multi-stage geocoding method: how much and where do they disagree?

    PubMed Central

    Lovasi, Gina S; Weiss, Jeremy C; Hoskins, Richard; Whitsel, Eric A; Rice, Kenneth; Erickson, Craig F; Psaty, Bruce M

    2007-01-01

    Background Geocoding methods vary among spatial epidemiology studies. Errors in the geocoding process and differential match rates may reduce study validity. We compared two geocoding methods using 8,157 Washington State addresses. The multi-stage geocoding method implemented by the state health department used a sequence of local and national reference files. The single-stage method used a single national reference file. For each address geocoded by both methods, we measured the distance between the locations assigned by each method. Area-level characteristics were collected from census data, and modeled as predictors of the discordance between geocoded address coordinates. Results The multi-stage method had a higher match rate than the single-stage method: 99% versus 95%. Of 7,686 addresses were geocoded by both methods, 96% were geocoded to the same census tract by both methods and 98% were geocoded to locations within 1 km of each other by the two methods. The distance between geocoded coordinates for the same address was higher in sparsely populated and low poverty areas, and counties with local reference files. Conclusion The multi-stage geocoding method had a higher match rate than the single-stage method. An examination of differences in the location assigned to the same address suggested that study results may be most sensitive to the choice of geocoding method in sparsely populated or low-poverty areas. PMID:17367520

  10. 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.

  11. Ornithodoros peropteryx (Acari: Argasidae) in Bolivia: an argasid tick with a single nymphal stage.

    PubMed

    Venzal, José M; Nava, Santiago; Terassini, Flavio A; Ogrzewalska, Maria; Camargo, Luis Marcelo A; Labruna, Marcelo B

    2013-10-01

    By the end of the 1960s, the argasid tick Ornithodoros peropteryx was described from larval specimens collected from the bat Peropteryx macrotis in Colombia. Since its original description, no additional record of O. peropteryx has been reported, and its post-larval stages have remained unknown. During July 2010, 18 larvae were collected from 9 bats (Centronycteris maximiliani), resulting in a mean infestation of 2.0 ± 2.2 ticks per bat (range 1-8). These bats were captured in a farm in northeastern Bolivia close to Guaporé River in the border with Brazil. Morphological examinations of the larvae revealed them to represent the species O. peropteryx. One engorged larva that was kept alive in the laboratory moulted to a nymph after 9 days. Fourteen days after the larval moulting, the nymph moulted to an adult female without taking any blood meal during the nymphal period. This adult female was used for a morphological description of the female stage of O. peropteryx. In addition, the larvae were used for a morphological redescription of this stage. One larva and two legs extirpated from the adult female were submitted to DNA extraction and PCR targeting a fragment of the mitochondrial 16S rDNA gene, which yielded DNA sequences at least 11 % divergent from any available argasid sequence in Genbank. We show that O. peropteryx ontogeny is characterized by a single, non-feeding, nymphal stage. This condition has never been reported for ticks. PMID:23543273

  12. 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. PMID:23566819

  13. Transient analysis of single stage GM type double inlet pulse tube cryocooler

    NASA Astrophysics Data System (ADS)

    Gujarati, P. B.; Desai, K. P.; Naik, H. B.; Atrey, M. D.

    2015-12-01

    Transient analysis of single stage GM type double inlet pulse tube cryocooler is carried out using a one dimensional numerical model based on real gas properties of helium. The model solves continuity, momentum and energy equation for gas and solid to analyse the physical process occurring inside of the pulse tube cryocooler. Finite volume method is applied to discretize the governing equations with realistic initial and boundary conditions. Input data required for solving the model are the design data and operating parameters viz. pressure waveform from the compressor, regenerator matrix data, and system geometry including pulse tube, regenerator size and operating frequency for pulse tube cryocooler. The model investigates the effect of orifice opening, double inlet opening, pressure ratio, system geometry on no load temperature and refrigeration power at various temperatures for different charging pressure. The results are compared with experimental data and reasonable agreement is observed. The model can further be extended for designing two stage pulse tube cryocooler.

  14. 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. PMID:23187266

  15. Off-design performance of a single-stage transonic turbine

    SciTech Connect

    Woinowsky-Krieger, M.; Lavoie, J.P.; Vlasic, E.P.; Moustapha, S.H.

    1999-04-01

    This paper presents results of rig testing of a transonic, single-stage turbine at off-design conditions. Mapping of the 3.4 pressure ratio, 1.9 stage loading turbine ranged from 70 through 120% of design speed and 75 to 125% of design pressure ratio. Results show expansion efficiency dropping over 4% from 100 to 80% of design speed at design pressure ratio, while remaining within half a percent from 90 to 110% of design pressure ratio at design speed. Efficiency lapse rate from equivalent sea-level to cruise altitude Reynolds numbers at the design point was measured and found to be worth over 1.5%. Analyses of test results using a viscous three-dimensional solver showed very good agreement for the efficiency change with speed.

  16. Immediate single-stage reconstruction of complex frontofaciobasal injuries: part I.

    PubMed

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

    2015-03-01

    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

  17. 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

  18. 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.

  19. 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.

  20. Single-stage surgical repair of airway gastric fistula after esophagectomy

    PubMed Central

    2014-01-01

    Airway gastric fistula (AGF) is a rare but catastrophic complication after esophagectomy. Surgical repair with viable tissue interposed between the airway and alimentary tracts remains the definitive treatment. However, it is challenging for surgeons, and only anecdotally described in sporadic case reports due to the complexity of the techniques necessary for successful surgical intervention. Here, we report two cases successfully managed via single-stage surgical re-exploration. On outpatient follow-up, the two Chinese patients were progressing satisfactorily without complaint of any dyspnea or dysphagia. PMID:24506968

  1. [Biological implant in single-stage reconstruction of mammary gland for cancer].

    PubMed

    Zikiriakhodzhaev, A D; Ermoshchenkova, M V

    2015-01-01

    Brief literature review about features of biological implants application for mammary gland reconstruction is presented in the article. Possible complications after such materials use, first experience of acellular dermal matrix administration for single-stage mammary gland reconstruction in 6 patients with breast cancer are also described. We offered surgical techniques, complications and methods of its treatment. We presented advantages of biological implant use which are consisted in decrease of surgical damage and duration of surgery, opportunity for enlargement of pocket for implant, decrease of pain syndrome. PMID:25909549

  2. 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. PMID:26423975

  3. Design and cold-air test of single-stage uncooled turbine with high work output

    NASA Technical Reports Server (NTRS)

    Moffitt, T. P.; Szanca, E. M.; Whitney, W. J.; Behning, F. P.

    1980-01-01

    A solid version of a 50.8 cm single stage core turbine designed for high temperature was tested in cold air over a range of speed and pressure ratio. Design equivalent specific work was 76.84 J/g at an engine turbine tip speed of 579.1 m/sec. At design speed and pressure ratio, the total efficiency of the turbine was 88.6 percent, which is 0.6 point lower than the design value of 89.2 percent. The corresponding mass flow was 4.0 percent greater than design.

  4. 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.

  5. Propulsion system requirements for reusable single-stage-to-orbit rocket vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Douglas O.; Engelund, Walter C.; Lepsch, Roger

    1992-01-01

    The conceptual design of a single-stage-to-orbit (SSTO) vehicle using a wide variety of evolutionary technologies has recently been completed as a part of NASA's Advanced Manned Launch System (AMLS) study. The employment of new propulsion system technologies is critical to the design of a reasonably sized, operationally efficient SSTO vehicle. This paper presents the propulsion system requirements identified for this near-term AMLS SSTO vehicle. Sensitivities of the vehicle to changes in specific impulse and sea-level thrust-to-weight ratio are examined. The results of a variety of vehicle/propulsion system trades performed on the near-term AMLS SSTO vehicle are also presented.

  6. Propulsion requirements for reusable single-stage-to-orbit rocket vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Douglas O.; Engelund, Walter C.; Lepsch, Roger

    1994-01-01

    The conceptual design of a single-stage-to-orbit (SSTO) vehicle using a wide variety of evolutionary technologies has recently been completed as a part of NASA's Advanced Manned Launch System (AMLS) study. The employment of new propulsion system technologies is critical to the design of a reasonably sized, operationally efficient SSTO vehicle. This paper presents the propulsion system requirements identified for this near-term AMLS SSTO vehicle. Sensitivities of the vehicle to changes in specific impulse and sea-level thrust-to-weight ratio are examined. The results of a variety of vehicle/propulsion system trades performed on the near-term AMLS SSTO vehicle are also presented.

  7. Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

    NASA Astrophysics Data System (ADS)

    Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

    2015-10-01

    The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

  8. Coupled finite element simulation and optimization of single- and multi-stage sheet-forming processes

    NASA Astrophysics Data System (ADS)

    Tamasco, Cynthia M.; Rais-Rohani, Masoud; Buijk, Arjaan

    2013-03-01

    This article presents the development and application of a coupled finite element simulation and optimization framework that can be used for design and analysis of sheet-forming processes of varying complexity. The entire forming process from blank gripping and deep drawing to tool release and springback is modelled. The dies, holders, punch and workpiece are modelled with friction, temperature, holder force and punch speed controlled in the process simulation. Both single- and multi-stage sheet-forming processes are investigated. Process simulation is coupled with a nonlinear gradient-based optimization approach for optimizing single or multiple design objectives with imposed sheet-forming response constraints. A MATLAB program is developed and used for data-flow management between process simulation and optimization codes. Thinning, springback, damage and forming limit diagram are used to define failure in the forming process design optimization. Design sensitivity analysis and optimization results of the example problems are presented and discussed.

  9. 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.

  10. A True Single-Stage Reconstruction of a Projected Auricle for Concha-Type Microtia Incorporating Endoscopically Harvested Temporoparietal Fascia.

    PubMed

    Nataliya, Biskup; Martin, Mark C

    2015-09-01

    Reconstruction of microtia with autogenous costal cartilage that produces a well-projected ear in a single stage is a challenging endeavor. In this case report, we describe a single-stage, projected costal cartilage-based reconstruction of concha type mitoria. Due to the patient's low hairline, his hair-bearing scalp would encroach on the ear framework if placed subcutaneously in the standard fashion. Thus, a large TPF flap harvested with endoscopic assistance was planned to achieve both a color-matched hairless skin envelope and a well-projected ear in single stage. PMID:26147024

  11. Catalytic multi-stage liquefaction of coal twelth quarterly report for the period 1 July 1995--30 September 1995

    SciTech Connect

    Comolli, A.G.; Johanson, E.S.; Lee, L.K.; Pradhan, V.R.; Stalzer, R.H.

    1995-12-01

    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.

  12. 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

  13. Cheap spaceflight promised again: Is single-stage-to-orbit finally the answer?

    NASA Astrophysics Data System (ADS)

    Robertson, Donald F.

    Chemical rocket fuel is cheap, and rockets, in theory, are simple devices, but spaceflight remains one of Western civilization's most expensive activities. The problems are that it takes close to the maximum power that a chemical rocket can achieve just to lift a fuel tank, rocket engines, vehicle structure, and the diminishing quantity of fuel all the way to orbit. The solution to that problem causes the second. By staging a rocket, its performance is improved, but it vastly increases the complexity of the rocket. Three potential solutions are: (1) to improve the performance of the rocket engines, but performance equals cost and today's most efficient engines already yield fairly close to the best performance that chemical rockets can produce; (2) to reduce the weight and volume of the fuel that must be carried in the tank, which is the approach of the National Aerospace Plane project; and (3) to reduce the weight and complexity of the vehicle as a system, which is perhaps the most promising approach. Technical advances may allow what has been considered largely impractical: a chemical Earth-to-orbit rocket without stages, a Single-Stage-To-Orbit vehicle (SSTO) or Delta Clipper. The detailed program is addressed.

  14. 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.

  15. Dimension determination of precursive stall events in a single stage high speed compressor

    SciTech Connect

    Bright, M.M.; Qammar, H.K.; Hartley, T.T.

    1996-06-01

    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 undersireable event of rotating stall formation in high speed compressor cores. {copyright} {ital 1996 American Institute of Physics.}

  16. 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.

  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. 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.

  19. Inhibition of cytochrome bc1 as a strategy for single-dose, multi-stage antimalarial therapy.

    PubMed

    Stickles, Allison M; Ting, Li-Min; Morrisey, Joanne M; Li, Yuexin; Mather, Michael W; Meermeier, Erin; Pershing, April M; Forquer, Isaac P; Miley, Galen P; Pou, Sovitj; Winter, Rolf W; Hinrichs, David J; Kelly, Jane X; Kim, Kami; Vaidya, Akhil B; Riscoe, Michael K; Nilsen, Aaron

    2015-06-01

    Single-dose therapies for malaria have been proposed as a way to reduce the cost and increase the effectiveness of antimalarial treatment. However, no compound to date has shown single-dose activity against both the blood-stage Plasmodium parasites that cause disease and the liver-stage parasites that initiate malaria infection. Here, we describe a subset of cytochrome bc1 (cyt bc1) inhibitors, including the novel 4(1H)-quinolone ELQ-400, with single-dose activity against liver, blood, and transmission-stage parasites in mouse models of malaria. Although cyt bc1 inhibitors are generally classified as slow-onset antimalarials, we found that a single dose of ELQ-400 rapidly induced stasis in blood-stage parasites, which was associated with a rapid reduction in parasitemia in vivo. ELQ-400 also exhibited a low propensity for drug resistance and was active against atovaquone-resistant P. falciparum strains with point mutations in cyt bc1. Ultimately, ELQ-400 shows that cyt bc1 inhibitors can function as single-dose, blood-stage antimalarials and is the first compound to provide combined treatment, prophylaxis, and transmission blocking activity for malaria after a single oral administration. This remarkable multi-stage efficacy suggests that metabolic therapies, including cyt bc1 inhibitors, may be valuable additions to the collection of single-dose antimalarials in current development. PMID:25918204

  20. Inhibition of Cytochrome bc1 as a Strategy for Single-Dose, Multi-Stage Antimalarial Therapy

    PubMed Central

    Stickles, Allison M.; Ting, Li-Min; Morrisey, Joanne M.; Li, Yuexin; Mather, Michael W.; Meermeier, Erin; Pershing, April M.; Forquer, Isaac P.; Miley, Galen P.; Pou, Sovitj; Winter, Rolf W.; Hinrichs, David J.; Kelly, Jane X.; Kim, Kami; Vaidya, Akhil B.; Riscoe, Michael K.; Nilsen, Aaron

    2015-01-01

    Single-dose therapies for malaria have been proposed as a way to reduce the cost and increase the effectiveness of antimalarial treatment. However, no compound to date has shown single-dose activity against both the blood-stage Plasmodium parasites that cause disease and the liver-stage parasites that initiate malaria infection. Here, we describe a subset of cytochrome bc1 (cyt bc1) inhibitors, including the novel 4(1H)-quinolone ELQ-400, with single-dose activity against liver, blood, and transmission-stage parasites in mouse models of malaria. Although cyt bc1 inhibitors are generally classified as slow-onset antimalarials, we found that a single dose of ELQ-400 rapidly induced stasis in blood-stage parasites, which was associated with a rapid reduction in parasitemia in vivo. ELQ-400 also exhibited a low propensity for drug resistance and was active against atovaquone-resistant P. falciparum strains with point mutations in cyt bc1. Ultimately, ELQ-400 shows that cyt bc1 inhibitors can function as single-dose, blood-stage antimalarials and is the first compound to provide combined treatment, prophylaxis, and transmission blocking activity for malaria after a single oral administration. This remarkable multi-stage efficacy suggests that metabolic therapies, including cyt bc1 inhibitors, may be valuable additions to the collection of single-dose antimalarials in current development. PMID:25918204

  1. Clinical Outcomes and Risks of Single-stage Bilateral Unicompartmental Knee Arthroplasty via Oxford Phase III

    PubMed Central

    Ma, Tong; Tu, Yi-Hui; Xue, Hua-Ming; Wen, Tao; Cai, Min-Wei

    2015-01-01

    Background: Osteoarthritis often affects the joint bilaterally, and the single-stage (SS) unicompartmental knee arthroplasty (UKA) is advantageous in terms of a single anesthesia administration, a short hospital stay, lower medical costs, and enhanced patient convenience. However, the complication risk of SS UKA continues to be debated. The aim of this article was to evaluate the clinical effectiveness, complications, and functional recovery of SS and two-stage (TS) UKA. Methods: From January 2008 to December 2013, we compared a series of 36 SS UKA with 45 TS UKA for osteoarthritis. The mean age was 65.4 years (range: 55–75 years). The mean body mass index was 25.2 kg/m2 (range: 22–29 kg/m2). The pre- and post-operative Oxford Knee Scores (OKSs), complications, operative times, tourniquet times, the amount of drainage, and hemoglobin (Hb) were evaluated. The Chi-square test, Fisher's exact test, and paired and grouped t-tests were used in this study. Results: The mean follow-up was 50 months. No complications of death, fat embolism, deep vein thrombosis, and prosthetic infection were reported. Patients who underwent SS UKA had a shorter cumulative anesthesia time (113.5 vs. 133.0 min, P < 0.01). There were no significant variations between the values of the mean tourniquet time, the amount of drainage, pre- and post-operative Hb in the different groups. No patient required a blood transfusion. No statistical differences were found in the complications between two groups (P > 0.05). At the final follow-up, the mean OKS improved from 39.48 ± 5.69 to 18.83 ± 3.82 (P < 0.01), with no statistical differences between the two groups (P > 0.05). Patients who underwent SS UKA had a faster recovery. Conclusions: The single-staged UKA offers the benefits of a single anesthesia administration, reduced total anesthetic time, decreased overall rehabilitation time, and absence of an increase in perioperative mortality or complications compared with the TS bilateral UKA

  2. 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.

  3. Abort performance for a winged-body single-stage to orbit vehicle

    NASA Astrophysics Data System (ADS)

    Lyon, Jeffery A.

    1995-08-01

    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.

  4. 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.

  5. 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.

  6. Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

    NASA Astrophysics Data System (ADS)

    Wilcken, K. M.; Freeman, S. P. H. T.; Xu, S.; Dougans, A.

    2013-01-01

    A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such 14C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed 13C and 16O by improvising an additional Wien filter on our SSAMS deck. Also, 14C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the 14N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

  7. Single-Stage Minimally Invasive Surgery for Synchronous Primary Pulmonary Adenocarcinoma and Left Atrial Myxoma.

    PubMed

    van der Merwe, Johan; Beelen, Roel; Martens, Sebastiaan; Van Praet, Frank

    2015-12-01

    We report the first successful short-term outcome of single-stage combined video-assisted thoracoscopic surgery lobectomy and port access surgery in a patient with operable primary right lower lobe adenocarcinoma and a synchronous cardiac myxoma. The video-assisted thoracic surgery right lower lobectomy with systematic lymph node dissection was performed first, followed by myxoma excision by port access surgery through the same working port incision. The histopathologic analysis confirmed a pT2a N0 M0 R0 (TNM 7th edition) primary poorly differentiated pulmonary adenocarcinoma and a completely excised cardiac myxoma. Postoperative recovery was uneventful, and follow-up at 6 weeks confirmed an excellent surgical and oncologic outcome. PMID:26652533

  8. Single-stage-to-orbit performance enhancement from take-off thrust augmentation

    SciTech Connect

    Galati, T.; Elkins, T.

    1997-01-01

    Thrust augmentation offers the Single Stage to Orbit (SSTO) space launch vehicle improved payload capability while reducing vehicle weight and cost. Optimization of vehicle configuration and flight profile are studied. Using a 612,000 kg Gross Lift Off Weight (GLOW) SSTO with three Castor{sup {reg_sign}} strap-on motors, payloads in excess of 18,000 kg to Low Earth Orbit (LEO) are achievable. Emphasis is placed on finding vehicle optimums in the 9,000 kg payload range to capture over 80{percent} of commercial payloads. Strap-on boosters allow a small SSTO vehicle to fly with a mass fraction of only 0.88 and LOX/H{sub 2} engines operating at 445 sec vacuum specific impulse. Payload sensitivity due to variations of mass fraction, I{sub sp} and pitch rate are quantified. {copyright} {ital 1997 American Institute of Physics.}

  9. 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.

  10. Total Single-Stage Autologous Breast Reconstruction with Free Nipple Grafts.

    PubMed

    Schwartz, Jean-Claude D; Skowronski, Piotr P

    2015-12-01

    Outstanding results are difficult to achieve in postmastectomy reconstructions in obese ptotic patients. We describe an autologous single-stage reconstruction with free nipple grafts that is best suited for these difficult patients. This technique allows for delayed volume supplementation with implants or fat grafting but does not commit the patient to additional surgery. It avoids the common complications of immediate implant-based reconstructions. This technique is also an excellent option in patients with a known requirement for radiotherapy as it does not sacrifice a valuable autologous flap nor does it subject the patient to capsular contracture, infection, and extrusion. It also obviates the psychological trauma that many women suffer awaiting a reconstruction after radiotherapy. We believe it should be considered as a first-line reconstructive option. PMID:26894012

  11. 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.

  12. 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.

  13. RL-10 Based Combined Cycle For A Small Reusable Single-Stage-To-Orbit Launcher

    NASA Technical Reports Server (NTRS)

    Balepin, Vladimir; Price, John; Filipenco, Victor

    1999-01-01

    This paper discusses a new application of the combined propulsion known as the KLIN(TM) cycle, consisting of a thermally integrated deeply cooled turbojet (DCTJ) and liquid rocket engine (LRE). If based on the RL10 rocket engine family, the KLIN (TM) cycle makes a small single-stage-to-orbit (SSTO) reusable launcher feasible and economically very attractive. Considered in this paper are the concept and parameters of a small SSTO reusable launch vehicle (RLV) powered by the KLIN (TM) cycle (sSSTO(TM)) launcher. Also discussed are the benefits of the small launcher, the reusability, and the combined cycle application. This paper shows the significant reduction of the gross take off weight (GTOW) and dry weight of the KLIN(TM) cycle-powered launcher compared to an all-rocket launcher.

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

    SciTech Connect

    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 A{acute e}rospatiale 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. {copyright} {ital 1996 American Institute of Physics.}

  15. 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.

  16. 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.

  17. 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.

  18. Total Single-Stage Autologous Breast Reconstruction with Free Nipple Grafts

    PubMed Central

    Schwartz, Jean-Claude D.; Skowronski, Piotr P.

    2015-01-01

    Summary: Outstanding results are difficult to achieve in postmastectomy reconstructions in obese ptotic patients. We describe an autologous single-stage reconstruction with free nipple grafts that is best suited for these difficult patients. This technique allows for delayed volume supplementation with implants or fat grafting but does not commit the patient to additional surgery. It avoids the common complications of immediate implant-based reconstructions. This technique is also an excellent option in patients with a known requirement for radiotherapy as it does not sacrifice a valuable autologous flap nor does it subject the patient to capsular contracture, infection, and extrusion. It also obviates the psychological trauma that many women suffer awaiting a reconstruction after radiotherapy. We believe it should be considered as a first-line reconstructive option. PMID:26894012

  19. 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.

  20. Oxygen as a light element: A solution to single-stage core formation

    NASA Astrophysics Data System (ADS)

    Corgne, Alexandre; Siebert, Julien; Badro, James

    2009-10-01

    The abundances of siderophile elements in the silicate Earth indicate that Earth's iron-rich core probably formed at high pressure and high temperature. A popular model of core formation considers that the concentrations of several moderately siderophile elements are consistent with a scenario of simple single-stage equilibration at the base of a magma ocean. However, recent work using temperature sensitive partitioning data for V and Nb have casted doubt on this interpretation since the required basal temperature would greatly exceed that of the mantle solidus. Here we show that single-stage core formation event could explain the mantle contents of siderophile elements best constrained by experiment (Ni, Co, V, Mn, Cr, and Nb) provided that the core contains a few weight percents of oxygen. Our calculations, based on partitioning and metallurgy data, reveal that V and Nb become significantly less siderophile with increasing the O content of core-forming materials, while the behaviour of Ni, Co, Cr and Mn is little affected. Since the other likely light element candidates C, Si and S do not drastically influence the siderophile behaviour, we conclude that a simple-equilibration scenario is a viable hypothesis only if O contributes partially to the core density deficit. This interpretation is consistent with the W budget of the silicate Earth and recently published W metal-silicate partitioning data. The presence of a few weight percents of oxygen in the core is also in agreement with recent high-pressure high-temperature solubility measurements in molten iron equilibrated with perovskite and ferropericlase.

  1. 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.

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

    PubMed

    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

  3. 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

  4. 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

  5. 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.

  6. Molecular asymmetry in the 8-cell stage Xenopus tropicalis embryo described by single blastomere transcript sequencing

    PubMed Central

    De Domenico, Elena; Owens, Nick D.L.; Grant, Ian M.; Gomes-Faria, Rosa; Gilchrist, Michael J.

    2015-01-01

    Correct development of the vertebrate body plan requires the early definition of two asymmetric, perpendicular axes. The first axis is established during oocyte maturation, and the second is established by symmetry breaking shortly after fertilization. The physical processes generating the second asymmetric, or dorsal–ventral, axis are well understood, but the specific molecular determinants, presumed to be maternal gene products, are poorly characterized. Whilst enrichment of maternal mRNAs at the animal and vegetal poles in both the oocyte and the early embryo has been studied, little is known about the distribution of maternal mRNAs along either the dorsal–ventral or left–right axes during the early cleavage stages. Here we report an unbiased analysis of the distribution of maternal mRNA on all axes of the Xenopus tropicalis 8-cell stage embryo, based on sequencing of single blastomeres whose positions within the embryo are known. Analysis of pooled data from complete sets of blastomeres from four embryos has identified 908 mRNAs enriched in either the animal or vegetal blastomeres, of which 793 are not previously reported as enriched. In contrast, we find no evidence for asymmetric distribution along either the dorsal–ventral or left–right axes. We confirm that animal pole enrichment is on average distinctly lower than vegetal pole enrichment, and that considerable variation is found between reported enrichment levels in different studies. We use publicly available data to show that there is a significant association between genes with human disease annotation and enrichment at the animal pole. Mutations in the human ortholog of the most animally enriched novel gene, Slc35d1, are causative for Schneckenbecken dysplasia, and we show that a similar phenotype is produced by depletion of the orthologous protein in Xenopus embryos. PMID:26100918

  7. Adjuvant Radiotherapy Outcome of Stage I Testicular Seminoma: A Single Institution Study

    PubMed Central

    Lee, Hayoon; Kim, Jun Won; Hong, Sung Joon; Yang, Seung Choul; Choi, Young Deuk; Rha, Koon Ho

    2015-01-01

    Purpose To analyze treatment outcome and side effects of adjuvant radiotherapy using radiotherapy fields and doses which have evolved over the last two decades in a single institution. Materials and Methods Forty-one patients received radiotherapy after orchiectomy from 1996 to 2007. At our institution, the treatment field for stage I seminoma has changed from dog-leg (DL) field prior to 2003 to paraaortic (PA) field after 2003. Fifteen patients were treated with the classic fractionation scheme of 25.5 Gy at 1.5 Gy per fraction. Other patients had been treated with modified schedules of 25.05 Gy at 1.67 Gy per fraction (n=15) and 25.2 Gy at 1.8 Gy per fraction (n=11). Results With a median follow-up of 112 months, the 5-year and 10-year survival rates were 100% and 96%, respectively, and 5-year and 10-year relapse-free survival rates were both 97.1%. No in-field recurrence occurred. Contralateral seminoma occurred in one patient 5 years after treatment. No grade III-IV acute toxicity occurred. An increased rate of grade 1-2 acute hematologic toxicity was found in patients with longer overall treatment times due to 1.5 Gy per fraction. The rate of grade 2 acute gastrointestinal toxicity was significantly higher with DL field than with PA field and also higher in the 1.8-Gy group than in the 1.5-Gy and 1.67-Gy groups. Conclusion Patients with stage I seminoma were safely treated with PA-only radiotherapy with no pelvic failure. Optimal fractionation schedule needs to be explored further in order to minimize treatment-related toxicity. PMID:25510743

  8. Molecular asymmetry in the 8-cell stage Xenopus tropicalis embryo described by single blastomere transcript sequencing.

    PubMed

    De Domenico, Elena; Owens, Nick D L; Grant, Ian M; Gomes-Faria, Rosa; Gilchrist, Michael J

    2015-12-15

    Correct development of the vertebrate body plan requires the early definition of two asymmetric, perpendicular axes. The first axis is established during oocyte maturation, and the second is established by symmetry breaking shortly after fertilization. The physical processes generating the second asymmetric, or dorsal-ventral, axis are well understood, but the specific molecular determinants, presumed to be maternal gene products, are poorly characterized. Whilst enrichment of maternal mRNAs at the animal and vegetal poles in both the oocyte and the early embryo has been studied, little is known about the distribution of maternal mRNAs along either the dorsal-ventral or left-right axes during the early cleavage stages. Here we report an unbiased analysis of the distribution of maternal mRNA on all axes of the Xenopus tropicalis 8-cell stage embryo, based on sequencing of single blastomeres whose positions within the embryo are known. Analysis of pooled data from complete sets of blastomeres from four embryos has identified 908 mRNAs enriched in either the animal or vegetal blastomeres, of which 793 are not previously reported as enriched. In contrast, we find no evidence for asymmetric distribution along either the dorsal-ventral or left-right axes. We confirm that animal pole enrichment is on average distinctly lower than vegetal pole enrichment, and that considerable variation is found between reported enrichment levels in different studies. We use publicly available data to show that there is a significant association between genes with human disease annotation and enrichment at the animal pole. Mutations in the human ortholog of the most animally enriched novel gene, Slc35d1, are causative for Schneckenbecken dysplasia, and we show that a similar phenotype is produced by depletion of the orthologous protein in Xenopus embryos. PMID:26100918

  9. 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.

  10. 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.

  11. High-peak-power second-harmonic generation of single-stage Yb-doped fiber amplifiers

    NASA Astrophysics Data System (ADS)

    Horiuchi, Ryusuke; Saiki, Koichi; Adachi, Koji; Tei, Kazuyoku; Yamaguchi, Shigeru

    2008-05-01

    A high-peak-power and high-repetition-rate fiber laser architecture is successfully demonstrated using a single-stage fiber amplifier. Nonlinear optical effects in a fiber amplifier degrade the monochromaticity of amplified laser pulses. In general, it is difficult for a non-monochromatic laser pulse to realize high-order harmonic generation with bulk nonlinear optical crystals. To overcome this problem, a single-stage amplifier architecture and a gain fiber with a high cladding absorption coefficient are employed. Furthermore, single-stage amplification enables the use of a multi-longitudinal mode electro-optically (EO) Q-switched micro seed laser. This architecture can generate a peak power of 100 kW at 50 kHz and an average power of 10 W. A second-harmonic conversion efficiency of 51% is obtained using this architecture and a LiB3O5 (LBO) crystal.

  12. 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.

  13. 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.

  14. Outcomes of single-stage total arch replacement via clamshell incision

    PubMed Central

    2011-01-01

    Background Treatment of complex aortic pathologies involving the transverse arch with extensive involvement of the descending aorta remains a surgical challenge. Since clamshell incision provides superior exposure of the entire thoracic aorta, we evaluated the use of this technique for single-stage total arch replacement by arch vessel reconstruction. Methods The arch-first technique combined with clamshell incision was used in 38 cases of aneurysm and aortic disease in 2008 and 2009. Extensive total arch replacement was used with clamshell incision for reconstruction of arch vessels under deep hypothermic circulatory arrest. Results Overall 30-day mortality was 13%. The mean operating time was approximately 8 hours. Deep hypothermia resulted in mean CPB time exceeding 4.5 hours and mean duration of circulatory arrest was 25 minutes. The overall postoperative temporary and permanent neurologic dysfunction rates were 3% and 3% for elective and 3% and 0% for emergency surgery, respectively. All patients except the five who died in hospital were discharged without nursing care after an average post-operative hospital stay of 35 days. Conclusions The arch-first technique, combined with clamshell incision, provides expeditious replacement of the thoracic aorta with an acceptable duration of hypothermic circulatory arrest and minimizes the risk of retrograde atheroembolism by using antegrade perfusion. PMID:21933402

  15. 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.

  16. Orbital single particle tracking on a commercial confocal microscope using piezoelectric stage feedback

    NASA Astrophysics Data System (ADS)

    Lanzanò, L.; Gratton, E.

    2014-06-01

    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.

  17. Enhanced single-stage laser-driven electron acceleration by self-controlled ionization injection.

    PubMed

    Li, Song; Hafz, Nasr A M; Mirzaie, Mohammad; Sokollik, Thomas; Zeng, Ming; Chen, Min; Sheng, Zhengming; Zhang, Jie

    2014-12-01

    We report on overall enhancement of a single-stage laser wakefield acceleration (LWFA) using the ionization injection in a mixture of 0.3% nitrogen gas in 99.7% helium gas. Upon the interaction of 30-TW, 30-fs laser pulses with a gas jet of the above gas mixture, >300 MeV electron beams were generated at a helium plasma densities of 3.3-8.5 × 10(18) cm(-3). Compared with the uncontrolled electron self-injection in pure helium gas jet, the ionization injection process due to the presence of ultra-low nitrogen concentrations appears to be self-controlled; it has led to the generation of electron beams with higher energies, higher charge, lower density threshold for trapping, and a narrower energy spread without dark current (low energy electrons) or multiple bunches. It is foreseen that further optimization of such a scheme is expected to bring the electron beam energy-spread down to 1%, making them suitable for driving ultra-compact free-electron lasers. PMID:25606890

  18. 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. PMID:25256550

  19. 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.

  20. Citrullination as early-stage indicator of cell response to single-walled carbon nanotubes.

    PubMed

    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. PMID:23350031

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

    PubMed Central

    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. PMID:23350031

  2. 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.

  3. Study on a Single-Stage 120 HZ Pulse Tube Cryocooler

    NASA Astrophysics Data System (ADS)

    Wu, Y. Z.; Gan, Z. H.; Qiu, L. M.; Chen, J.; Li, Z. P.

    2010-04-01

    Miniaturization of pulse tube cryocoolers is required for some particular applications where size and mass for devices are limited. In order to pack more cooling power in a small volume, higher operating frequencies are commonly used for Stirling-type pulse tube cryocoolers. To maintain high efficiency of the regenerator with a higher frequency, a higher charging pressure, smaller hydraulic diameters of regenerator material and a shorter regenerator length should be applied. A rapid growth of research and development on pulse tube cryocoolers operating at a high frequency over 100 Hz in the last 3 years has occurred. In this study, a single stage pulse tube cryocooler with 120 Hz to provide 10 W of lift at 80 K has been developed by using the numerical model, known as REGEN 3.2. Experiments performed on this cryocooler driven by a CFIC linear compressor show that a no-load temperature of 49.6 K was achieved and the net refrigeration power at 78.5 K was 8.0 W. The effect of pulse tube orientation was tested, and the copper velvet as a regenerator matrix was proposed for high frequency operation.

  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. Solvent Carryover Characterization and Recovery for a 10-inch Single Stage Centrifugal Contactor

    SciTech Connect

    Lentsch, R.D.; Stephens, A.B.; Leung, D.T.; Baffling, K.E.; Harmon, H.D.; Suggs, P.C.

    2006-07-01

    A test program has been performed to characterize the organic solvent carryover and recovery from centrifugal contactors in the Caustic-side Solvent Extraction (CSSX) process. CSSX is the baseline design for removing cesium from salt solutions for Department of Energy (DOE) Savannah River Site's Salt Waste Processing Facility. CSSX uses a custom solvent to extract cesium from the salt solution in a series of single stage centrifugal contactors. Meeting the Waste Acceptance Criteria at the Defense Waste Processing Facility and Saltstone, as well as plant economics, dictate that solvent loss should be kept to a minimum. Solvent droplet size distribution in the aqueous outlet streams of the CSSX contactors is of particular importance to the design of solvent recovery equipment. Because insufficient solvent droplet size data existed to form a basis for the recovery system design, DOE funded the CSSX Solvent Carryover Characterization and Recovery Test (SCCRT). This paper presents the droplet size distribution of solvent and concentration in the contactor aqueous outlet streams as a function of rotor speed, bottom plate type, and flow rate. It also presents the performance data of a prototype coalescer. (authors)

  6. 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.

  7. 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.

  8. Fatigue crack growth behavior of a single crystal alloy as observed through an in situ fatigue loading stage

    NASA Technical Reports Server (NTRS)

    Telesman, Jack; Kantzos, Peter

    1988-01-01

    An in situ fatigue loading stage inside a scanning electron microscope (SEM) was used to determine the fatigue crack growth behavior of a PWA 1480 single-crystal nickel-based superalloy. The loading stage permits real-time viewing of the fatigue damage processes at high magnification. The PWA 1480 single-crystal, single-edge notch specimens were tested with the load axis parallel to the (100) orientation. Two distinct fatigue failure mechanisms were identified. The crack growth rate differed substantially when the failure occurred on a single slip system in comparison to multislip system failure. Two processes by which crack branching is produced were identified and are discussed. Also discussed are the observed crack closure mechanisms.

  9. Fatique crack growth behavior of a single crystal alloy as observed through an in situ fatigue loading stage

    NASA Technical Reports Server (NTRS)

    Telesman, Jack; Kantzos, Peter

    1988-01-01

    An in situ fatigue loading stage inside a scanning electron microscope (SEM) was used to determine the fatigue crack growth behavior of a PWA 1480 single-crystal nickel-based superalloy. The loading stage permits real-time viewing of the fatigue damage processes at high magnification. The PWA 1480 single-crystal, single-edge notch specimens were tested with the load axis parallel to the (100) orientation. Two distinct fatigue failure mechanisms were identified. The crack growth rate differed substantially when the failure occurred on a single slip system in comparison to multislip system failure. Two processes by which crack branching is produced were identified and are discussed. Also discussed are the observed crack closure mechanisms.

  10. 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

  11. 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.

  12. Preoperative Single Fraction Partial Breast Radiotherapy for Early-Stage Breast Cancer

    SciTech Connect

    Palta, Manisha; Yoo, Sua; Adamson, Justus D.; Prosnitz, Leonard R.; Horton, Janet K.

    2012-01-01

    Purpose: Several recent series evaluating external beam accelerated partial breast irradiation (PBI) have reported adverse cosmetic outcomes, possibly related to large volumes of normal tissue receiving near-prescription doses. We hypothesized that delivery of external beam PBI in a single fraction to the preoperative tumor volume would be feasible and result in a decreased dose to the uninvolved breast compared with institutional postoperative PBI historical controls. Methods and Materials: A total of 17 patients with unifocal Stage T1 breast cancer were identified. Contrast-enhanced subtraction magnetic resonance images were loaded into an Eclipse treatment planning system and used to define the target volumes. A 'virtual plan' was created using four photon beams in a noncoplanar beam arrangement and optimized to deliver 15 Gy to the planning target volume. Results: The median breast volume was 1,713 cm{sup 3} (range: 1,014-2,140), and the median clinical target volume was 44 cm{sup 3} (range: 26-73). In all cases, 100% of the prescription dose covered 95% of the clinical target volume. The median conformity index was 0.86 (range: 0.70-1.12). The median percentage of the ipsilateral breast volume receiving 100% and 50% of the prescribed dose was 3.8% (range: 2.2-6.9) and 13.3% (range: 7.5-20.8) compared with 18% (range: 3-42) and 53% (range: 24-65) in the institutional historical controls treated with postoperative external beam PBI (p = .002). The median maximum skin dose was 9 Gy. The median dose to 1 and 10 cm{sup 3} of skin was 6.7 and 4.9 Gy. The doses to the heart and ipsilateral lung were negligible. Conclusion: Preoperative PBI resulted in a substantial reduction in ipsilateral breast tissue dose compared with postoperative PBI. The skin dose appeared reasonable, given the small volumes. A prospective Phase I trial evaluating this technique is ongoing.

  13. 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.

  14. 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.

  15. Single stage ventral onlay buccal mucosal graft urethroplasty for navicular fossa strictures

    PubMed Central

    Chowdhury, Puskar Shyam; Nayak, Prasant; Mallick, Sujata; Gurumurthy, Srinivasan; David, Deepak; Mossadeq, A.

    2014-01-01

    Introduction: The correction of fossa navicularis strictures poses a distinct reconstructive challenge as it requires attention to cosmesis, in addition to urethral patency. Different graft and flap based repairs have been described with variable success rates. However, the ideal management remains unclear. The feasibility and efficacy of a single stage ventral onlay buccal mucosa graft urethroplasty (VOBMGU) for navicular fossa strictures (NFS) was evaluated in the present study. Subjects and Methods: All patients with NFS attending urology out-patient department from March, 2009 onward accepting VOBMGU were evaluated prospectively. Patients with minimum 1 year of follow-up were included for analysis. The technique involves opening the diseased stenosed meatus ventrally up to the corona. The diseased mucosa is excised leaving a midline strip of native urethral mucosa on the dorsal side. The buccal mucosal graft (BMG) is fixed on either side of this strip over a 24 Fr. silicone catheter. The glans wings are apposed in midline taking anchoring bites on the mucosal graft ventrally. Post-operatively patients were reviewed at 1, 3, 6 and 12 months and annually thereafter. Cosmetic acceptance and splaying of the urinary stream was assessed with individual questionnaires. Results: A total of six patients underwent VOBMGU. Average flow rate at 3 months post-operatively was 12 ml/s. The end result was cosmetically highly acceptable. There was no fistula in any of the cases. With a median follow-up of 37 months, only one patient had a recurrence of stricture in a proximal site. Conclusions: VOBMGU is a viable technique for reconstruction of NFS with promising short term results. However, long-term follow-up is necessary. PMID:24497676

  16. 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

  17. In Vitro Assessment of the Assisted Bidirectional Glenn Procedure for Stage One Single Ventricle Repair.

    PubMed

    Zhou, Jian; Esmaily-Moghadam, Mahdi; Conover, Timothy A; Hsia, Tain-Yen; Marsden, Alison L; Figliola, Richard S

    2015-09-01

    This in vitro study compares the hemodynamic performance of the Norwood and the Glenn circulations to assess the performance of a novel assisted bidirectional Glenn (ABG) procedure for stage one single ventricle surgery. In the ABG, the flow in a bidirectional Glenn procedure is assisted by injection of a high-energy flow stream from the systemic circulation using an aorta-caval shunt with nozzle. The aim is to explore experimentally the potential of the ABG as a surgical alternative to current surgical practice. The experiments are directly compared against previously published numerical simulations. A multiscale mock circulatory system was used to measure the hemodynamic performance of the three circulations. For each circulation, the system was tested using both low and high values of pulmonary vascular resistance. Resulting parameters measured were: pressure and flow rate at left/right pulmonary artery and superior vena cava (SVC). Systemic oxygen delivery (OD) was calculated. A parametric study of the ratio of ABG nozzle to shunt diameter was done. We report time-based comparisons with numerical simulations for the three surgical variants tested. The ABG circulation demonstrated an increase of 30-38% in pulmonary flow with a 2-3.7 mmHg increase in SVC pressure compared to the Glenn and a 4-14% higher systemic OD than either the Norwood or the Glenn. The nozzle/shunt diameter ratio affected the local hemodynamics. These experimental results agreed with those of the numerical model: mean flow values were not significantly different (p > 0.05) while mean pressures were comparable within 1.2 mmHg. The results verify the approaches providing two tools to study this complicated circulation. Using a realistic experimental model we demonstrate the performance of a novel surgical procedure with potential to improve patient hemodynamics in early palliation of the univentricular circulation. PMID:26577359

  18. 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. PMID:11379106

  19. 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

  20. 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

    2016-01-01

    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. PMID:26967119

  1. 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.

  2. 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.

  3. Fixed-bed gasification research using US coals. Volume 13. Gasification of Blind Canyon 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 thirteenth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Blind Canyon bituminous coal, from July 31, 1984 to August 11, 1984. 6 refs., 22 figs., 20 tabs.

  4. Fixed-bed gasification research using US coals. Volume 15. Gasification of ''fresh'' Rosebud subbituminous coal

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-09-01

    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 fifteenth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Rosebud subbituminous coal, from June 17, 1985 to June 24, 1985. 4 refs., 20 figs., 15 tabs.

  5. Single stage management of a unique variant of congenital pouch colon with triplet fistula and normal anus.

    PubMed

    Pandey, Vaibhav; Gangopadhyay, Ajay Narayan; Gupta, Dinesh Kumar; Sharma, Shiv Prasad

    2015-01-01

    Congenital pouch colon (CPC) in the female patient presents with highly variable and anomalous anatomy. We herein report the first case of CPC with uterus didelphys having normal anal opening, H-type vestibular fistula, two other fistulous communications between pouch colon and two vagina managed in a single stage with excellent postoperative outcome. PMID:26166988

  6. Single stage management of a unique variant of congenital pouch colon with triplet fistula and normal anus

    PubMed Central

    Pandey, Vaibhav; Gangopadhyay, Ajay Narayan; Gupta, Dinesh Kumar; Sharma, Shiv Prasad

    2015-01-01

    Congenital pouch colon (CPC) in the female patient presents with highly variable and anomalous anatomy. We herein report the first case of CPC with uterus didelphys having normal anal opening, H-type vestibular fistula, two other fistulous communications between pouch colon and two vagina managed in a single stage with excellent postoperative outcome. PMID:26166988

  7. 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.

  8. 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.

  9. A portable high-power diode laser-based single-stage ceramic tile grout sealing system

    NASA Astrophysics Data System (ADS)

    Lawrence, J.; Schmidt, M. J. J.; Li, L.; Edwards, R. E.; Gale, A. W.

    2002-02-01

    By means of a 60 W high-power diode laser (HPDL) and a specially developed grout material the void between adjoining ceramic tiles has been successfully sealed. A single-stage process has been developed which uses a crushed ceramic tile mix to act as a tough, inexpensive bulk substrate and a glazed enamel surface to provide an impervious surface glaze. The single-stage ceramic tile grout sealing process yielded seals produced in normal atmospheric conditions that displayed no discernible cracks and porosities. The single-stage grout is simple to formulate and easy to apply. Tiles were successfully sealed with power densities as low as 200 kW/ mm2 and at rates of up to 600 mm/ min. Bonding of the enamel to the crushed ceramic tile mix was identified as being primarily due to van der Waals forces and, on a very small scale, some of the crushed ceramic tile mix material dissolving into the glaze. In terms of mechanical, physical and chemical characteristics, the single-stage ceramic tile grout was found to be far superior to the conventional epoxy tile grout and, in many instances, matched and occasionally surpassed that of the ceramic tiles themselves. What is more, the development of a hand-held HPDL beam delivery unit and the related procedures necessary to lead to the commercialisation of the single-stage ceramic tile grout sealing process are presented. Further, an appraisal of the potential hazards associated with the use of the HPDL in an industrial environment and the solutions implemented to ensure that the system complies with the relevant safety standards are given.

  10. 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

  11. 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

  12. Long-term trends in gender, T-stage, subsite and treatment for laryngeal cancer at a single center.

    PubMed

    Brandstorp-Boesen, Jesper; Falk, Ragnhild Sørum; Boysen, Morten; Brøndbo, Kjell

    2014-12-01

    To investigate the changes in the epidemiology of laryngeal squamous cell carcinoma (LSCC) regarding gender, T-stage and subsite distribution, and to identify the potential effect of introducing new therapeutic alternatives for early and advanced stage LSCC. A prospective cohort study of LSCC patients diagnosed and treated at a single tertiary referral center in Norway. Retrospective analysis of prospectively recorded data from 1,616 patients treated for LSCC in all subsites of the larynx during 1983-2010. Females represented an increasing proportion of cases throughout the study (p < 0.01) and presented more often than men with supraglottic cancer (p < 0.01). Marked changes in the distribution of T-stages over time were observed in both early and advanced stage LSCC. T1a glottic tumors constituted 56 % of all early-stage LSCC and were predominantly treated by transoral endoscopic laser surgery. The introduction of chemoradiotherapy for advanced stage LSCC offers a distinct advantage for laryngeal preservation. The increasing proportion of females with LSCC may be explained by changes in smoking habits. The proportion of T1a glottic LSCC gradually increased over time, while T4 supraglottic LSCC became less frequent. Videostroboscopy should be considered mandatory in the diagnosis and follow-up of LSCC. Transoral laser microsurgery is the standard first-line treatment for T1a glottic tumors. Chemoradiotherapy has reduced the number of total laryngectomies and is now regarded as the primary treatment for advanced stage tumors. PMID:24871863

  13. 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.

  14. 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.

  15. 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.

  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. Real Power and Reactive Power Control of a Three-Phase Single-Stage-PV System and PV voltage Stability

    SciTech Connect

    Li, Huijuan; Xu, Yan; Adhikari, Sarina; Rizy, D Tom; Li, Fangxing; Irminger, Philip

    2012-01-01

    Grid-connected photovoltaic (PV) systems with power electronic interfaces can provide both real and reactive power to meet power system needs with appropriate control algorithms. This paper presents the control algorithm design for a three-phase single-stage grid-connected PV inverter to achieve either maximum power point tracking (MPPT) or a certain amount of real power injection, as well as the voltage/var control. The switching between MPPT control mode and a certain amount of real power control mode is automatic and seamless. Without the DC-to-DC booster stage, PV DC voltage stability is an important issue in the control design especially when the PV inverter is operating at maximum power point (MPP) with voltage/var control. The PV DC voltage collapse phenomenon and its reason are discussed. The method based on dynamic correction of the PV inverter output is proposed to ensure PV DC voltage stability. Simulation results of the single-stage PV system during system disturbances and fast solar irradiation changes confirm that the proposed control algorithm for single-stage PV inverters can provide appropriate real and reactive power services and ensure PV DC voltage stability during dynamic system operation and atmospheric conditions.

  18. Risk Factors for Prolonged Length of Stay Following the Stage II Procedure in the Single Ventricle Reconstruction Trial

    PubMed Central

    Schwartz, Steven M.; Lu, Minmin; Ohye, Richard G.; Hill, Kevin D.; Atz, Andrew M.; Naim, Maryam Y.; Williams, Ismee A.; Goldberg, Caren S.; Lewis, Alan; Pigula, Frank; Manning, Peter; Pizarro, Christian; Chai, Paul; McCandless, Rachel; Dunbar-Masterson, Carolyn; Kaltman, Jonathan R.; Kanter, Kirk; Sleeper, Lynn A.; Schonbeck, Julie V.; Ghanayem, Nancy

    2013-01-01

    Objectives The Single Ventricle Reconstruction trial randomized patients with single right ventricle lesions to a modified Blalock-Taussig or right ventricle-to-pulmonary artery shunt at the Norwood. This analysis describes outcomes at the stage II procedure and factors associated with a longer hospital length of stay (LOS). Methods We examined the association of shunt type with stage II hospital outcomes. Cox regression and bootstrapping were used to evaluate risk factors for longer LOS. We also examined characteristics associated with in-hospital death. Results There were 393 subjects in the analytic cohort. Median stage II procedure hospital LOS (8 days, IQR (6,14)), hospital mortality (4.3%), transplantation (0.8%), median ventilator time (2 days, IQR (1,3)), median intensive care unit LOS (4 days (IQR (3,7)), number of additional cardiac procedures or complications and serious adverse events did not differ by shunt type. Longer LOS was associated (R2=0.26) with center, longer post-Norwood LOS (HR 1.93 per log day, P<0.001), non-elective timing of the stage II procedure (HR 1.78, P<0.001) and pulmonary artery (PA) stenosis (HR 1.56, P<0.001). By univariate analysis, non-elective stage II (65% vs. 32%, P=0.009), ≥ moderate atrioventricular valve (AVV) regurgitation (75% vs. 24%, P<0.001) and AVV repair (53% vs. 9%, P<0.001) were among the risk factors associated with in-hospital death. Conclusions Norwood LOS, PA stenoses and non-elective stage II procedure, but not shunt type, are independently associated with longer LOS. Non-elective stage II, >moderate AVV regurgitation and need for AVV repair are among the risk factors for death. PMID:24075564

  19. 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.

  20. The single electron chemistry of coals. [Quarterly] report, January 1--March 31, 1993

    SciTech Connect

    Larsen, J.W.; Rothenberg, S.E.

    1993-09-01

    Following the position of the nitrile band and using the assumption that there is a linear relationship for between the extent of charge transfer and frequency, a 69% charge transfer was obtained and successfully replicates Flowers` results. If a Diels-Alder reaction occurred, we would expect the position of nitrile group to have shifted down field to the 2260-2240 cm{sup {minus}1} range for a saturated alkyl nitrile. There is no evidence for this type of reaction under these conditions since we obtained a shift upfield from 2229 cm{sup {minus}1} to 2200 cm{sup {minus}1}. There are some peaks of interest in the 1660-1300 cm{sup {minus}1} range of the deposited coals which will be investigated. The TCNE-Illinois No. 6 reaction mixture will be heated from room temperature to 180{degrees}C within the Harrick cell during IR analysis to see if a Diels-Alder or other additions reaction could occur.

  1. Spin liquid in a single crystal of the frustrated diamond lattice antiferromagnet CoAl2O4

    NASA Astrophysics Data System (ADS)

    Zaharko, O.; Christensen, N. B.; Cervellino, A.; Tsurkan, V.; Maljuk, A.; Stuhr, U.; Niedermayer, C.; Yokaichiya, F.; Argyriou, D. N.; Boehm, M.; Loidl, A.

    2011-09-01

    We study the evidence for spin liquid in the frustrated diamond lattice antiferromagnet CoAl2O4 by means of single-crystal neutron scattering in zero and applied magnetic fields. The magnetically ordered phase appearing below TN=8 K remains nonconventional down to 1.5 K. The magnetic Bragg peaks at the q=0 positions are broad and their line shapes have strong Lorentzian contributions. Additionally, the peaks are connected by weak diffuse streaks oriented along the <111> directions. The observed short-range magnetic correlations are explained within the spiral spin-liquid model. The specific shape of the energy landscape of the system, with an extremely flat energy minimum around q=0 and many low-lying excited spiral states with q=<111>, results in thermal population of this manifold at finite temperatures. The agreement between the experimental results and the spiral spin-liquid model is only qualitative, indicating that microstructure effects might be important to achieve quantitative agreement. Application of a magnetic field significantly perturbs the spiral spin-liquid correlations. The magnetic peaks remain broad but acquire more Gaussian line shapes and increase in intensity. The 1.5 K static magnetic moment increases from 1.58 μB/Co at zero field to 2.08 μB/Co at 10 T. The magnetic excitations appear rather conventional at zero field. Analysis using classical spin-wave theory yields values of the nearest- and next-nearest-neighbor exchange parameters J1=0.92(1) meV and J2=0.101(2) meV and an additional anisotropy term D=-0.0089(2) meV for CoAl2O4. In the presence of a magnetic field, the spin excitations broaden considerably and become nearly featureless at the zone center.

  2. 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...

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. CT for Assessment of Thrombosis and Pulmonary Embolism in Multiple Stages of Single-Ventricle Palliation: Challenges and Suggested Protocols.

    PubMed

    Ghadimi Mahani, Maryam; Agarwal, Prachi P; Rigsby, Cynthia K; Lu, Jimmy C; Fazeli Dehkordy, Soudabeh; Wright, Robyn A; Dorfman, Adam L; Krishnamurthy, Rajesh

    2016-01-01

    The total cavopulmonary connection (TCPC), or Fontan procedure, diverts systemic venous blood directly into the pulmonary arteries and is the palliative surgery of choice for patients with a wide variety of congenital heart diseases with single-ventricle physiologic characteristics. Pulmonary embolism and thrombosis are known complications and are among the major causes of morbidity and mortality in patients after TCPC. Magnetic resonance (MR) imaging is usually performed for postoperative evaluation of patients after single-ventricle repair; however, screening for thrombosis or embolism with MR imaging is not always feasible because of the emergent nature of the clinical presentation or because of artifacts from metallic devices or coils. Computed tomographic (CT) angiography is an effective method for diagnosing pulmonary embolism in children. However, because of altered hemodynamics after single-ventricle palliation, there are unique challenges in achieving optimal opacification of the pulmonary arteries and Fontan circuit that can result in nondiagnostic CT angiographic studies or erroneous image interpretation. Radiologists should be familiar with the multiple stages of single-ventricle palliation, understand the technique for performing pulmonary CT angiography at each stage, and recognize common pitfalls in obtaining and interpreting pulmonary CT angiographic images in patients who have undergone single-ventricle repair. Online supplemental material is available for this article. (©)RSNA, 2016. PMID:27618316

  10. 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.

  11. An evaluation of composite propulsion for single-stage-to-orbit vehicles designed for horizontal take-off

    NASA Technical Reports Server (NTRS)

    Martin, J. A.

    1977-01-01

    Composite propulsion was analyzed for single-stage-to-orbit vehicles designed for horizontal take-off. Trajectory, geometric, and mass analyses were performed to establish the orbital payload capability of six engines. The results indicated that none of the engines performed adequately to deliver payloads to orbit as analyzed. The single-stage turbine and oxidizer-rich gas generator resulted in a low engine specific impulse, and the performance increment of the ejector subsystem was less than that of a separate rocket system with a high combustion pressure. There was a benefit from incorporating a fan into the engine, and removal of the fan from the airstream during the ramjet mode increased the orbital payload capability.

  12. 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.

  13. 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.

  14. Determination of the archaeal and bacterial communities in two-phase and single-stage anaerobic systems by 454 pyrosequencing.

    PubMed

    Maspolim, Yogananda; Zhou, Yan; Guo, Chenghong; Xiao, Keke; Ng, Wun Jern

    2015-10-01

    2-Phase anaerobic digestion (AD), where the acidogenic phase was operated at 2day hydraulic retention time (HRT) and the methanogenic phase at 10days HRT, had been evaluated to determine if it could provide higher organic reduction and methane production than the conventional single-stage AD (also operated at 12days HRT). 454 pyrosequencing was performed to determine and compare the microbial communities. The acidogenic reactor of the 2-phase system yielded a unique bacterial community of the lowest richness and diversity, while bacterial profiles of the methanogenic reactor closely followed the single-stage reactor. All reactors were predominated by hydrogenotrophic methanogens, mainly Methanolinea. Unusually, the acidogenic reactor contributed up to 24% of total methane production in the 2-phase system. This could be explained by the presence of Methanosarcina and Methanobrevibacter, and their activities could also help regulate reactor alkalinity during high loading conditions through carbon dioxide production. The enrichment of hydrolytic and acidogenic Porphyromonadaceae, Prevotellaceae, Ruminococcaceae and unclassified Bacteroidetes in the acidogenic reactor would have contributed to the improved sludge volatile solids degradation, and ultimately the overall 2-phase system's performance. Syntrophic acetogenic microorganisms were absent in the acidogenic reactor but present in the downstream methanogenic reactor, indicating the retention of various metabolic pathways also found in a single-stage system. The determination of key microorganisms further expands our understanding of the complex biological functions in AD process. PMID:26456614

  15. Single-Stage Posterior Subtotal Corpectomy and Circumferential Reconstruction for the Treatment of Unstable Thoracolumbar Burst Fractures

    PubMed Central

    Jo, Dae-Jean; Kim, Ki-Tack; Kim, Sung-Min; Lee, Sang-Hun; Cho, Myung-Guk

    2016-01-01

    Objective To illustrate the technique of single-stage posterior subtotal corpectomy and circumferential reconstruction for the treatment of unstable thoracolumbar burst fractures and to evaluate the radiographical and clinical outcomes of patients treated using this technique. Methods 16 consecutive patients with unstable thoracolumbar burst fractures were treated with single-stage posterior subtotal corpectomy and circumferential reconstruction. The mean patient age was 54.8 years. The mean follower up period was 25 months. Five patients suffered from T12 fractures, 10 from L1, 1 from L2. The segmental kyphosis, neurologic status, visual analogue scale for back pain was evaluated before surgery and at follow up. Results The segmental kyphotic angle improved from 18.5 degrees before surgery to -9.2 degrees at the last follow up. The mean correction angle was 28.9 degrees. The mean surgical time was 255 minutes, and a mean intraoperative blood loss was 1073 mL. Intraoperative complications included two dural tears, and a superficial wound infection. There were no other severe complications. The mean visual analog scale of back pain decreased from a mean value of 6.6 to 2 at the last follow up. Conclusion The single-stage posterior subtotal corpectomy and circumferential reconstruction achieved satisfactory kyphosis correction with direct visualization of the circumferentially decompressed spinal cord, as well as good fusion with less blood loss and complications. It is a safe and reliable surgical treatment option for unstable thoracolumbar burst fractures. PMID:26962417

  16. ENHANCED HYDROGEN PRODUCTION INTEGRATED WITH CO2 SEPARATION IN A SINGLE-STAGE REACTOR

    SciTech Connect

    Himanshu Gupta; Mahesh Iyer; Bartev Sakadjian; Liang-Shih Fan

    2005-03-10

    The water gas shift reaction (WGSR) plays a major role in increasing the hydrogen production from fossil fuels. However, the enhanced hydrogen production is limited by thermodynamic constrains posed by equilibrium limitations of WGSR. This project aims at using a mesoporous, tailored, highly reactive calcium based sorbent system for incessantly removing the CO{sub 2} product which drives the equilibrium limited WGSR forward. In addition, a pure sequestration ready CO{sub 2} stream is produced simultaneously. A detailed project vision with the description of integration of this concept with an existing coal gasification process for hydrogen production is presented. Conceptual reactor designs for investigating the simultaneous water gas shift and the CaO carbonation reactions are presented. In addition, the options for conducting in-situ sorbent regeneration under vacuum or steam are also reported. Preliminary, water gas shift reactions using high temperature shift catalyst and without any sorbent confirmed the equilibrium limitation beyond 600 C demonstrating a carbon monoxide conversion of about 80%. From detailed thermodynamic analyses performed for fuel gas streams from typical gasifiers the optimal operating temperature range to prevent CaO hydration and to effect its carbonation is between 575-830 C.

  17. 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. PMID:11893424

  18. 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. PMID:25047279

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

    NASA Astrophysics Data System (ADS)

    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.

  20. 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.

  1. 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.

  2. Single-Stage Anterior Debridement and Fibular Allograft Implantation Followed by Posterior Instrumentation for Complicated Infectious Spondylitis

    PubMed Central

    Chung, Tzu-Chun; Yang, Shih-Chieh; Chen, Hung-Shu; Kao, Yu-Hsien; Tu, Yuan-Kun; Chen, Wen-Jer

    2014-01-01

    Abstract Complicated infectious spondylitis is an infrequent infection with severe spinal destruction, and is indicated for combined anterior and posterior surgeries. Staged debridement and subsequent reconstruction is advocated in the literature. The purpose of this study is to evaluate the feasibility and clinical outcome of patients who underwent single-stage combined anterior debridement and fibular allograft implantation followed by supplemental posterior fixation for complicated infectious spondylitis. We retrospectively reviewed the medical records of 20 patients who underwent single-stage combined anterior and posterior surgeries for complicated infectious spondylitis from January 2005 to December 2010. Complicated infectious spondylitis was defined as at least 1 vertebral osteomyelitis with pathological fracture or severe bony destruction and adjacent discitis, based on imaging studies. The severity of the neurological status was evaluated using the Frankel scale. The clinical outcomes were assessed by careful physical examination and regular serological tests to determine the visual analog scale (VAS) score and Macnab criteria. Correction of the sagittal Cobb angle on radiography was also compared before and after surgery. The Wilcoxon signed-rank test was used to analyze patient surgical prognosis and radiological findings. All patients with complicated infectious spondylitis were successfully treated by single-stage combined anterior and posterior surgeries. No patients experienced neurologic deterioration. The average VAS score was 7.8 before surgery and significantly decreased to 2.1 at discharge. Three patients had excellent outcomes and 17 had good outcomes, based on Macnab criteria. The average length of the allograft for reconstruction was 64.0 mm. Kyphotic deformity improved in all patients, with an average correction angle of 13.4°. There was no implant breakage or allograft dislodgement during at least 36 months of follow-up. Single-stage

  3. 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. PMID:27074090

  4. 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.

  5. 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.

  6. 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.

  7. Design of a single-stage single-switch PFC circuit with a small output current ripple for an LED lamp

    NASA Astrophysics Data System (ADS)

    Li, Yi; Han, Gyung-Seok; Kim, Hee-Jun

    2014-07-01

    A new single-stage power factor correction (PFC) circuit for driving a light-emitting diode (LED) is proposed in this paper. This circuit makes it possible to have a low output ripple due to the energy storage capacitor on the primary side. The proposed circuit is compatible with a primaryside regulation (PSR) chip. The operating principle of the proposed circuit is analyzed, design guidelines for the proposed circuit are presented, and prototype of the proposed circuit was built. The results of the experiment showed that this proposed circuit could achieve a significant reduction in the LED current ripple and could maintain a reasonable efficiency and power factor.

  8. Extents of alkane combustion during rapid compression leading to single and two stage ignition

    SciTech Connect

    Cox, A.; Griffiths, J.F.; Mohamed, C.; Curran, H.; Pitz, W.J.; Westbrook, C.K.

    1996-02-01

    Extents of reactant consumption have been measured during the course of spontaneous ignition following rapid compression of N-pentane and N-heptane and also of PRF 60 (N-heptane = i-octane, 2.2.4 trimethylpentane) in stoichiometric mixtures with air. Compressed gas temperatures of 720-750 K and 845-875 K were studied at reactant densities of 131 mol m{sup minus 3}. At the lower gas temperature there was no evidence of reactant consumption during the course of the compression stroke. Two-stage ignition occurred at these temperatures, but only modest proportions of n-pentane were consumed during the first stage (< 15%) whereas about 40% of proportions of n- heptane reacted under the same conditions. At the higher compressed gas temperature the oxidation of n-pentane began only after the piston had stopped, whereas more than 30% of the n-heptane had already been consumed in the final stage of the compression stroke. The behavior of the PRF 60 mixture differed somewhat from that of N- pentane despite the similarly of the research octane numbers. Although there was a preferential oxidation of n-heptane at T{sub c} = 850K, which persisted throughout the early development of spontaneous ignition during the post-compression period, oxidation of both components of the PRF 60 mixture began before the piston had stopped. Numerical simulations of the spontaneous ignition under conditions resembling those of the rapid compression experiments show that the predicted reactivity from detailed kinetics are consistent with the observed features. Insights into the kinetic interactions that give rise to the relative reactivities of the primary reference fuel components are established

  9. 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 ...

  10. Laparoscopic fertility-sparing surgery for early stage ovarian cancer: a single-centre case series and systematic literature review

    PubMed Central

    2014-01-01

    Background There is as yet limited evidence about fertility-sparing surgery for early ovarian cancer (EOC) carried out laparoscopically. We sought to analyze recurrence patterns and fertility outcome in a cohort of ovarian cancer patients who underwent fertility-saving laparoscopic surgical staging. Methods We conducted a retrospective analysis of prospectively collected data on all patients undergoing fertility-sparing laparoscopic staging procedures for presumed EOC at a single gynecologic oncology service. Oncologic safety and reproductive outcome were the main outcome measures. The pertinent literature is reviewed. Results The study cohort consisted of 12 women. Cases included 5 invasive epithelial tumors and 7 nonepithelial tumors. The disease was reclassified to a higher stage in one woman. After a median follow up period of 38 months (range: 14–108), the overall survival was 100% and recurrence-free survival 90.9%. Five (100%) of patients who attempted pregnancy conceived spontaneously. Three of them had uneventful term pregnancy delivering healthy babies. The literature search yielded 62 cases of laparoscopic fertility conserving surgery for ovarian cancer. There were 4 (6.2%) recurrences. Cumulative pregnancy and live birth rate were not estimable as earlier publications lack essential data. Conclusions Laparoscopic staging may represent a viable option for premenopausal women seeking fertility preservation in the setting of early ovarian cancer. More research is needed to determine whether laparoscopy may offer reproductive benefits to this particular population. PMID:24917888

  11. Hydrogen Isotope Separation Factor Measurement for Single Stage Hydrogen Separators and Parameters for a Large-Scale Separation System

    SciTech Connect

    Luo, D.L.; Xiong, Y.F.; Song, J.F.; Huang, G.Q.

    2005-07-15

    A Concept design for large-scale hydrogen ISS based on a single Pd alloy membrane separator cascade has been presented. Separators to investigate the feasibility of the Pd membrane separator cascade concept have been designed and the separation performance of the separators is given. Results show that the separation factors, which are between 1.4 and 1.8 at the operation temperature, are large enough for a practical separation system design. Estimation results indicate that a 2.0m{sup 2} Pd membrane is needed for a 20mol/h and 12 stages batch ISS, and an approximately 50m{sup 2} Pd membrane is needed for a 200mol/h and 26 stages ISS. It is clear that the separator cascade concept is both reasonable and practicable for large-scale hydrogen isotope separation.

  12. Unsteady three-dimensional flow in a single-stage transonic fan: Part 2: Unsteady stator exit flow field

    SciTech Connect

    Cherrett, M.A.; Bryce, J.D.; Ginder, R.B.

    1995-10-01

    Detailed unsteady aerodynamic measurements have been taken in a single-stage transonic fan with a very high stage-hub loading. Two-dimensional dynamic yawmeter probes, capable of measuring mean levels and fluctuations in stagnation pressure, static pressure, and yaw angle have been traversed at rotor exit and downstream of the stator, along with several types of pneumatic three-dimensional probe. Part 1 describes measurements taken at rotor exit. This paper, Part 2, describes measurements taken at stator exit when the fan was operating at near-peak efficiency, on the design speed characteristic. The measurements indicate the effects of rotor-stator interaction on the development of the viscous endwall-corner flows at the hub and casing. In addition, they illustrate that significant changes in stagnation pressure level occur within much of the stator exit flow field during the rotor passing cycle.

  13. 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.

  14. 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.

  15. 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. PMID:24480620

  16. Single-port one-stage bilateral thoracoscopic sympathicotomy for severe hyperhidrosis: prospective analysis of a standardized approach

    PubMed Central

    2013-01-01

    Background Primary palmar and/or axillary focal hyperhidrosis is a frequent disorder characterized by excessive sweating beyond physiological needs, often leading to a substantial impairment of quality of life. Over the years several minimally invasive surgical treatments have been described, however results vary, and due to a lack of uniform surgical approach, technique and nomenclature are often difficult to compare. In this prospective study we sought to evaluate the safety and effectiveness of our standardized technique of single-port, one-stage bilateral thoracoscopic sympathicotomy. Methods On a prospective basis a hundred consecutive patients with severe or intolerable primary hyperhidrosis underwent one-stage bilateral single-port thoracoscopic sympathicotomy. Primary outcome was measured in pre- vs. post-operative Hyperhidrosis Disease Severity Scale scores. Location and extend of compensatory hyperhidrosis, and satisfaction with the procedure were registered. Results A significant reduction in mean Hyperhidrosis Disease Severity Scale score (3.69 ± 0.47 preoperatively vs. 1.06 ± 0.34 postoperatively) (p < 0.001) was observed. In 97 (97%) out of the 100 enrolled patients a >80% reduction in sweat production was achieved. Compensatory hyperhidrosis was seen in 27 patients (27%). It was rated as mild by 21 patients (78%) and as moderate by 6 (22%) of these patients. No severe compensatory hyperhidrosis was reported. Major complications, such as intraoperative bleeding, infections, and Horner’s syndrome were not observed. Conclusions Highly selective sympathicotomy at well-defined levels with a one-stage bilateral single-port transaxillary thoracoscopic approach is a save procedure, with excellent and reproducible immediate results in the treatment of primary palmar and/or axillary hyperhidrosis. PMID:24279511

  17. Outcome of single-stage transanal endorectal pull through for short segment Hirschsprung's disease in neonates and infants.

    PubMed

    Shahjahan, M; Ferdous, M N; Nag, U K; Ullah, M S; Rahman, M A; Islam, M K

    2014-01-01

    Hirschsprung's disease (HD) is developmental disorder of the enteric nervous system. Diagnosis can be confirmed by rectal biopsy. The surgical management of HD includes so many procedures. The purpose of this study was to evaluate the out come of single-stage transanal endorectal pull-through operation for short segment HD in neonates and infants. This prospective study was carried out in the Department of Pediatric Surgery, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh during the period from January 2004 to December 2009. The study included neonates & infants (age 1 day to 1 year) of both sex, who were clinically suspected and biopsy proven HD with barium enema suggesting rectosigmoid HD. We excluded patients with short segment HD who had associated anomalies, and with hugely dilated proximal colon, operated cases with less than 6 months' follow up. During study period, single-stage transanal endorectal pull through (TEP) operation done in 68 neonates and infants patients (8 excluded) of short segment HD. The mean operative time, postoperative hospital stay, followed up time were 120 minutes, 7.94 days and 12 months respectively. Transeverse colostomy was needed in 4 patients because of anastomotic leakage and they were complicated with anastomotic stenosis, however managed by progressive dilatation. Overall parents' satisfaction was achieved. Single-stage primary transnanl endorectal pull-through for short segment HD is feasible in neonates and infants. It preserves all the advantages of minimally invasive surgery. TEP is a better option in terms of comfort, operative success, postoperative morbidity, cosmetic appearance and parents' satisfaction. PMID:24584376

  18. Pulmonary Hemodynamics Simulations Before Stage 2 Single Ventricle Surgery: Patient-Specific Parameter Identification and Clinical Data Assessment.

    PubMed

    Arbia, Gregory; Corsini, Chiara; Baker, Catriona; Pennati, Giancarlo; Hsia, Tain-Yen; Vignon-Clementel, Irene E

    2015-09-01

    Single ventricle heart defects involve pathologies in which the heart has only one functional pumping chamber. In these conditions, treatment consists of three staged procedures. At stage 1 pulmonary flow is provided through an artificial shunt from the systemic circulation. Representative hemodynamics models able to explore different virtual surgical options can be built based on pre-operative imaging and patient data. In this context, the specification of boundary conditions is necessary to compute pressure and flow in the entire domain. However, these boundary conditions are rarely the measured variables. Moreover, to take into account the rest of the circulation outside of the three-dimensional modeled domain, a number of reduced order models exist. A simplified method is presented to iteratively, but automatically, tune reduced model parameters from hemodynamic data clinically measured before stage 2 surgery. Patient-specific local hemodynamics around the distal systemic-to-pulmonary shunt anastomosis and the connected pulmonary arteries are also analyzed. Multi-scale models of pre-stage 2 single ventricle patients are developed, including a 3D model of shunt-pulmonary connection and a number of pulmonary arteries. For each pulmonary outlet a total downstream resistance is identified, consistent with measured flow split and pressures. Target pressures such as minimum, maximum or average over one or both lungs are considered, depending on the clinical measurement. When possible, both steady and pulsatile identifications are performed. The methodology is demonstrated with six patient-specific models: the clinical target data are well-matched, except for one case where clinical data were subsequently found inconsistent. Inhomogeneous pressure, swirling blood flow patterns and very high wall shear stress 3D maps highlight similarities and differences among patients. Steady and pulsatile tuning results are similar. This work demonstrates (1) how to use routine

  19. 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

  20. 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.

  1. 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.

  2. Effect of coal briquetting on overall plant costs for a large low-Btu gas application. Task II final topical report. Addendum. [Two-stage gasification plant with briquetting

    SciTech Connect

    Baker, R.L.; Cassidy, H.P.

    1983-03-02

    This report presents the results of a study to determine the technical and economic aspects of coal briquetting, when the coal briquettes are used as feed coal to a coal gasification facility. Gas from the coal gasification facility was used as the fuel source for an iron ore pelletizing facility. The gasifier for this plant was a two-stage, fixed-bed gasifier. The product gas was 20 x 10/sup 9/ Btu per day (833.3 x 10/sup 6/ Btu/hour), HHV, to be sent to an iron ore pelletizing facility. The product gas was a clean low-Btu gas produced at approximately atmospheric pressure. The evaluations were based on installing the gasifiers at the existing Erie Mining Company iron ore pelletizing plant at Hoyt Lakes, Minnesota. Thus, the designs use existing facilities where possible, and produce or purchase other needs. The briquetting/gasification design presented is technically feasible. The estimated fuel gas price is $10.00 per million Btu with a 12 percent DCF-ROR. The fuel cost is higher than the present price of natural gas at Hoyt Lakes, $3.52 per million Btu, and higher than the $7.70 per million Btu obtainable through substitution of Winkler fluidized-bed gasifiers for the two-stage fixed bed gasifiers. Not included in the study were considerations of intrinsic factors, such as the interruptible nature of natural gas supplies and future changes in the prices of natural gas and coal. 3 references, 16 figures, 16 tables.

  3. Sludge incineration in single stage combustor with gas scrubbing followed by afterburning and heat recovery

    SciTech Connect

    Albertson, O.E.; Baturay, A.

    1990-04-17

    This patent describes the method for disposal of waste organic sludge of the type which contains at least one certain waste material that is either a low melting eutectic that softens or heavy metal that fumes at the highest temperature required to effect incineration of the sludge and cleansing by burning of the resultant gases. It comprises: the steps of combusting the sludge in a single combustion mass overlain by a gas-filled freeboard thereby to effect burning of substantially the entire content of combustible solids while yielding wet gases which contain entrained particulates as well as combustible and non-combustible constituents, volatiles and condensible matter.

  4. 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. PMID:16621273

  5. Multi-omics maps of cotton fibre reveal epigenetic basis for staged single-cell differentiation.

    PubMed

    Wang, Maojun; Wang, Pengcheng; Tu, Lili; Zhu, Sitao; Zhang, Lin; Li, Zhonghua; Zhang, Qinghua; Yuan, Daojun; Zhang, Xianlong

    2016-05-19

    Epigenetic modifications are highlighted for their great importance in regulating plant development, but their function associated with single-cell differentiation remains undetermined. Here, we used the cotton fibre, which is the epidermal hair on the cotton ovule, as a model to investigate the regulatory role of DNA methylation in cell differentiation. The level of CHH (H = A, T, or C) DNA methylation level was found to increase during fibre development, accompanied by a decrease in RNA-directed DNA methylation (RdDM). Examination of nucleosome positioning revealed a gradual transition from euchromatin to heterochromatin for chromatin dynamics in developing fibres, which could shape the DNA methylation landscape. The observed increase in DNA methylation in fibres, compared with other ovule tissue, was demonstrated to be mediated predominantly by an active H3K9me2-dependent pathway rather than the RdDM pathway, which was inactive. Furthermore, integrated multi-omics analyses revealed that dynamic DNA methylation played a role in the regulation of lipid biosynthesis and spatio-temporal modulation of reactive oxygen species during fibre differentiation. Our study illustrates two divergent pathways mediating a continuous increase of DNA methylation and also sheds further light on the epigenetic basis for single-cell differentiation in plants. These data and analyses are made available to the wider research community through a comprehensive web portal. PMID:27067544

  6. Multi-omics maps of cotton fibre reveal epigenetic basis for staged single-cell differentiation

    PubMed Central

    Wang, Maojun; Wang, Pengcheng; Tu, Lili; Zhu, Sitao; Zhang, Lin; Li, Zhonghua; Zhang, Qinghua; Yuan, Daojun; Zhang, Xianlong

    2016-01-01

    Epigenetic modifications are highlighted for their great importance in regulating plant development, but their function associated with single-cell differentiation remains undetermined. Here, we used the cotton fibre, which is the epidermal hair on the cotton ovule, as a model to investigate the regulatory role of DNA methylation in cell differentiation. The level of CHH (H = A, T, or C) DNA methylation level was found to increase during fibre development, accompanied by a decrease in RNA-directed DNA methylation (RdDM). Examination of nucleosome positioning revealed a gradual transition from euchromatin to heterochromatin for chromatin dynamics in developing fibres, which could shape the DNA methylation landscape. The observed increase in DNA methylation in fibres, compared with other ovule tissue, was demonstrated to be mediated predominantly by an active H3K9me2-dependent pathway rather than the RdDM pathway, which was inactive. Furthermore, integrated multi-omics analyses revealed that dynamic DNA methylation played a role in the regulation of lipid biosynthesis and spatio-temporal modulation of reactive oxygen species during fibre differentiation. Our study illustrates two divergent pathways mediating a continuous increase of DNA methylation and also sheds further light on the epigenetic basis for single-cell differentiation in plants. These data and analyses are made available to the wider research community through a comprehensive web portal. PMID:27067544

  7. Modification of the Koyanagi Technique for the Single-Stage Repair of Proximal Hypospadias.

    PubMed

    Chen, Yuhong; Zhang, Jinming; Ji, Chenyang; Liang, Weiqiang; Pan, Shujuan; Wu, Biying

    2016-06-01

    We describe a modification of the Koyanagi technique for hypospadias in an attempt to reduce complications and improve results. Between January 2005 and July 2012, 21 patients underwent treatment of proximal hypospadias using a modified hypospadias repair. The procedure involved making a U-incision similar to that in a Thiersch-Duplay repair to preserve the blood supply to the tubular neourethra. The neourethra was reconstructed by island penile skin. An M-incision was made in the glans, and the meatus was attached to tip of glans. Flaps were harvested from both sides of the penis preventing postoperative penile turn. Cosmetic and functional, long-term (mean, 12 months) recovery was excellent. Complications consisted of 3 cases of urethrocutaneous fistula (14.2%), which were corrected surgically, and 2 cases of penile skin necrosis. There were no instances of meatal stenosis, diverticulum, or urethral stricture. Bifid scrotum was present in 6 patients, and associated penoscrotal transposition was present in 15 patients. Both of these associated defects were corrected at the time of surgery. The modified technique permits 1-stage repair of proximal hypospadias with a low complication rate, the satisfactory recovery. PMID:27176562

  8. 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. PMID:22942578

  9. Cost analysis for single-stage (SSTO) reusable ballistic launch vehicles

    NASA Astrophysics Data System (ADS)

    Koelle, Dietrich E.

    The ballistic SSTO Vehicle seems to be the prime candidate for a future reusable launch system for medium-size cargo due to its inherent technical and operational simplicity by limiting the number of stages to just one, and by using conventional rocket propulsion. Based on the MBB vehicle studies from 1969/70 and 1986 (BETA II) and taking into account requirements of the recent SDIO-Contract ("Delta Clipper") a cost and cost driver analysis is presented using the TRANSCOST Model. First, the potential development cost for ballistic SSTO vehicles in the range of 200 to 1000 tons propellant mass are presented and the main influencal parameters - including the so-called "non-technical" factors - are discussed. The results are compared with actual total development cost of other launch systems. Then the potential ground and flight operations cost are discussed, based on the proposed "Standardized Launch Cost Definition (SLC, Level I, Level II Cost). In this case especially the impact of annual launch frequency on the cost per launch is shown, and the expected specific transportation cost compared with the present values of expendable launchers. A substantial cost reduction is to be expected, even under non-optimistic assumptions.

  10. Technology requirements for advanced earth-orbital transportation systems: Summary report. [single stage to orbit vehicles

    NASA Technical Reports Server (NTRS)

    Haefeli, R. C.; Littler, E. G.; Hurley, J. B.; Winter, M. G.

    1977-01-01

    Areas of advanced technology that are either critical or offer significant benefits to the development of future Earth-orbit transportation systems were identified. Technology assessment was based on the application of these technologies to fully reusable, single-state-to-orbit (SSTO) vehicle concepts with horizontal landing capability. Study guidelines included mission requirements similar to space shuttle, an operational capability beginning in 1995, and main propulsion to be advanced hydrogen-fueled rocket engines. The technical and economic feasibility of this class of SSTO concepts were evaluated as well as the comparative features of three operational take-off modes, which were vertical boost, horizontal sled launch, and horizontal take-off with subsequent inflight fueling. Projections of both normal and accelerated technology growth were made. Figures of merit were derived to provide relative rankings of technology areas. The influence of selected accelerated areas on vehicle design and program costs was analyzed by developing near-optimum point designs.

  11. 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.

  12. 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

  13. 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.

  14. 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. PMID:25889805

  15. 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.

  16. 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

    2016-09-01

    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. PMID:27527879

  17. Design and experimental investigation of a single-stage turbine with a rotor entering relative Mach number of 2

    NASA Technical Reports Server (NTRS)

    Moffitt, Thomas P

    1958-01-01

    The design and experimental investigation of a single-stage supersonic turbine are presented herein. The turbine was designed for a rotor entering relative Mach number of 2. The maximum equivalent specific work output of the turbine at design speed and approximately design over-all pressure ratio was 32.9 BTU per pound at a static efficiency of 0.414. This static efficiency gave good verification to an independent reference that indicated theoretical static efficiencies for similar single-stage turbines within the range 0.40 to 0.45. An experimental ratio of effective rotor blade momentum thickness to mean camber length was determined to be 0.0014, which compares favorably with the results obtained from several transonic and subsonic turbines. The design procedure for this turbine would have been improved by allowing for more rotor losses by assuming a value of this momentum parameter comparable with those obtained from transonic turbines. Removing a large portion of the rotor suction surface enabled a lower static pressure to be felt at the stator exit, at the expense of higher rotor losses. The net result was an improvement in turbine work output of about 3 percent at design setting conditions. No problems associated with supersonic starting were encountered even under the worst conditions of turbine operation with respect to this problem.

  18. 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.

  19. Determine the operational boundary of a pilot-scale single-stage partial nitritation/anammox system with granular sludge.

    PubMed

    Yang, Yandong; Zhang, Liang; Han, Xiaoyu; Zhang, Shujun; Li, Baikun; Peng, Yongzhen

    2016-01-01

    The partial nitritation/anammox (PN/A) process has been applied to ammonium-rich wastewater treatment, but the operational boundary has not been well determined for long-term stability. This pilot-scale study was targeted at a single-stage PN/A process using a sequencing batch reactor (SBR) (volume: 53 m(3)) and granulated activated sludge. The maximum nitrogen removal rate reached 0.83 kg N/(m(3)·d). Microbial analysis suggested that ammonium oxidizing bacteria were mainly present in small sludge flocs while anammox bacteria were prone to grow in large sludge granules. The PN/A performance was enhanced when dissolved oxygen (DO) was increased from 0.25 to 0.76 mg/L, and deteriorated at DO higher than 1.15 mg/L. The PN/A was inhibited at free ammonia (FA) over 77.0 mg/L. High DO or FA concentrations inhibited anammox activity and further induced high and inhibitory nitrite concentrations. Therefore, appropriate DO and FA concentrations should be controlled to achieve single-stage PN/A in SBRs. PMID:27148709

  20. 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.

  1. 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.

  2. Cell death stages in single apoptotic and necrotic cells monitored by Raman microspectroscopy

    PubMed Central

    Brauchle, Eva; Thude, Sibylle; Brucker, Sara Y.; Schenke-Layland, Katja

    2014-01-01

    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. PMID:24732136

  3. 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.

  4. 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

  5. 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.

  6. 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. PMID:20050661

  7. 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.

  8. 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

  9. 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

  10. Coal systems analysis: A new approach to the understanding of coal formation, coal quality and environmental considerations, and coal as a source rock for hydrocarbons

    USGS Publications Warehouse

    Warwick, P.D.

    2005-01-01

    Coal is an important and required energy source for today's world. Current rates of world coal consumption are projected to continue at approximately the same (or greater) levels well into the twenty-first century. This paper will provide an introduction to the concept of coal systems analysis and the accompanying volume of papers will provide examples of how coal systems analysis can be used to understand, characterize, and evaluate coal and coal gas resources. Coal systems analysis incorporates the various disciplines of coal geology to provide a complete characterization of the resource. The coal system is divided into four stages: (1) accumulation, (2) preservation-burial, (3) diagenesis-coalification, and (4) coal and hydrocarbon resources. These stages are briefly discussed and key references and examples of the application of coal systems analysis are provided. ??2005 Geological Society of America.

  11. A Rocket Powered Single-Stage-to-Orbit Launch Vehicle With U.S. and Soviet Engineers

    NASA Technical Reports Server (NTRS)

    MacConochie, Ian O.; Stnaley, Douglas O.

    1991-01-01

    A single-stage-to-orbit launch vehicle is used to assess the applicability of Soviet Energia high-pressure-hydrocarbon engine to advanced U.S. manned space transportation systems. Two of the Soviet engines are used with three Space Shuttle Main Engines. When applied to a baseline vehicle that utilized advanced hydrocarbon engines, the higher weight of the Soviet engines resulted in a 20 percent loss of payload capability and necessitated a change in the crew compartment size and location from mid-body to forebody in order to balance the vehicle. Various combinations of Soviet and Shuttle engines were evaluated for comparison purposes, including an all hydrogen system using all Space Shuttle Main Engines. Operational aspects of the baseline vehicle are also discussed. A new mass properties program entitles Weights and Moments of Inertia (WAMI) is used in the study.

  12. Effects of dissolved oxygen on microbial community of single-stage autotrophic nitrogen removal system treating simulating mature landfill leachate.

    PubMed

    Wen, Xin; Zhou, Jian; Wang, Jiale; Qing, Xiaoxia; He, Qiang

    2016-10-01

    The performance of four identical sequencing biofilm batch reactors (SBBR) for autotrophic nitrogen removal was investigated with 2000mg/L ammonia-containing mature landfill leachate at 30°C. The main objective of this study was to evaluate the effects of dissolved oxygen (DO) on the performance and microbial community of single-stage nitrogen removal using anammox and partial nitritation (SNAP) system. At an applied load of 0.5kgNm(-3)d(-1), average total nitrogen removal efficiency (TNRE) above 90% was long-term achieved with an optimal DO concentration of 2.7mg/L. The microelectrode-measured profiles showed the microenvironments inside the biofilms. 16S ribosomal Ribonucleic Acid (rRNA) amplicon pyrosequencing and denaturing gradient gel electrophoresis (DGGE) were used to analyze the microbial variations of different DO concentrations and different positions inside one reactor. PMID:27450126

  13. Application of a compliant foil bearing for the thrust force estimation in the single stage radial blower

    NASA Astrophysics Data System (ADS)

    Łagodzinski, Jakub; Miazga, Kacper; Musiał, Izabela

    2015-08-01

    The paper presents the application of a compliant foil bearing for estimation of the thrust force in a single stage radial blower under operational conditions. The bump foil of the thrust bearing behaves as a nonlinear spring. The knowledge of the spring deflection curve allows estimation of the actual thrust force for a measured bump deflection at the given rotational speed. To acquire the deflection curve, static calibration of the axial shaft displacement sensor was performed. During the calibration, the information about voltage signals of the sensor for the given loading force was collected. The measured voltage values at different speeds and loadswere then converted into the thrust force. The results were verified by comparison to the thrust force resulting from the pressure distribution on the impeller.

  14. Irreducible Atlanto-Axial Dislocation in Neglected Odontoid Fracture Treated with Single Stage Anterior Release and Posterior Instrumented Fusion

    PubMed Central

    Rathod, Ashok Keshav; Chaudhary, Kshitij Subhash

    2016-01-01

    It is a well-know fact that type 2 odontoid fractures frequently go into nonunion. If left untreated, patients may develop irreducible atlantoaxial dislocation (AAD). We describe the surgical management of two patients with neglected odontoid fractures and irreducible AAD treated with single stage anterior release followed by posterior instrumented fusion. Both patients presented with history of neglected trauma and progressive myelopathy. Traction under anesthesia failed to achieve reduction of AAD. Anterior release was done by trans-oral approach in one patient and retrophayngeal approach in the other. Posterior fixation was performed with transarticular screws in both the patients. Both patients had full neurological recovery and demonstrated fusion at follow-up. Anterior release followed by posterior instrumented correction may be an effective alternative to the traditional means of treating irreducible dislocations associated with neglected odontoid fractures. PMID:27114778

  15. 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.

  16. 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.

  17. Outcompeting nitrite-oxidizing bacteria in single-stage nitrogen removal in sewage treatment plants: a model-based study.

    PubMed

    Pérez, Julio; Lotti, Tommaso; Kleerebezem, Robbert; Picioreanu, Cristian; van Loosdrecht, Mark C M

    2014-12-01

    This model-based study investigated the mechanisms and operational window for efficient repression of nitrite oxidizing bacteria (NOB) in an autotrophic nitrogen removal process. The operation of a continuous single-stage granular sludge process was simulated for nitrogen removal from pretreated sewage at 10 °C. The effects of the residual ammonium concentration were explicitly analyzed with the model. Competition for oxygen between ammonia-oxidizing bacteria (AOB) and NOB was found to be essential for NOB repression even when the suppression of nitrite oxidation is assisted by nitrite reduction by anammox (AMX). The nitrite half-saturation coefficient of NOB and AMX proved non-sensitive for the model output. The maximum specific growth rate of AMX bacteria proved a sensitive process parameter, because higher rates would provide a competitive advantage for AMX. PMID:25216301

  18. High OSNR watt-level single-frequency one-stage PM-MOPA fiber laser at 1083 nm.

    PubMed

    Yang, Changsheng; Xu, Shanhui; Yang, Qi; Mo, Shupei; Li, Can; He, Xin; Feng, Zhouming; Yang, Zhongmin; Jiang, Zhonghong

    2014-01-13

    A 1.03 W optical signal-to-noise ratio (OSNR) of > 70 dB single-frequency polarization-maintained master-oscillator power amplifier (PM-MOPA) laser at 1083 nm was demonstrated. The seed laser of this laser system was a distributed Bragg reflector short cavity Yb-doped phosphate fiber oscillator. A one-stage core-pumped amplification configuration was employed, in which the typical gain is 9.7 dB and the optical-to-optical conversion efficiency is 68.7%. The estimated laser linewidth is less than 3.5 kHz, the measured polarization-extinction ratio is greater than 25 dB, and the obtained relative intensity noise of fiber laser for frequencies of over 2 MHz is less than -130 dB/Hz. PMID:24515078

  19. Unsteady three-dimensional flow in a single-stage transonic fan. Part 1: Unsteady rotor exit flow field

    SciTech Connect

    Cherrett, M.A.; Bryce, J.D.; Ginder, R.B.

    1995-10-01

    Detailed unsteady aerodynamic measurements have been taken in a single-stage transonic fan with a very high stator-hub loading. Two-dimensional dynamic yawmeter probes, capable of measuring mean and fluctuating levels of stagnation pressure, static pressure, and yaw angle have been traversed at rotor exit, and downstream of the stator along with several types of pneumatic three-dimensional probe. Part 1 of this paper describes the dynamic yawmeters and their performance, and presents ensemble-averaged stagnation pressure and random stagnation pressure unsteadiness measurements taken at rotor exit. These are used to illustrate the salient features of the rotor flow field, and the effects of compressor aerodynamic loading. Part 2 presents measurements taken at stator exit.

  20. A rapid method for optimization of the rocket propulsion system for single-stage-to-orbit vehicles

    NASA Technical Reports Server (NTRS)

    Eldred, C. H.; Gordon, S. V.

    1976-01-01

    A rapid analytical method for the optimization of rocket propulsion systems is presented for a vertical take-off, horizontal landing, single-stage-to-orbit launch vehicle. This method utilizes trade-offs between propulsion characteristics affecting flight performance and engine system mass. The performance results from a point-mass trajectory optimization program are combined with a linearized sizing program to establish vehicle sizing trends caused by propulsion system variations. The linearized sizing technique was developed for the class of vehicle systems studied herein. The specific examples treated are the optimization of nozzle expansion ratio and lift-off thrust-to-weight ratio to achieve either minimum gross mass or minimum dry mass. Assumed propulsion system characteristics are high chamber pressure, liquid oxygen and liquid hydrogen propellants, conventional bell nozzles, and the same fixed nozzle expansion ratio for all engines on a vehicle.

  1. 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.

  2. 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

  3. Studies on mixed populations of human intestinal bacteria grown in single-stage and multistage continuous culture systems.

    PubMed Central

    Allison, C; McFarlan, C; MacFarlane, G T

    1989-01-01

    Mixed intestinal bacteria were grown for 336 h in two identical single-stage chemostats at low growth rates in a carbohydrate-limited medium. Complex bacterial populations were maintained and anaerobes always outnumbered aerobes. The predominant organisms belonged to the genera Bacteroides, Bifidobacterium, Lactobacillus, Clostridium, Eubacterium, Propionbacterium, Peptococcus, and Peptostreptococcus. Bacteroides species predominated in both fermentors, particularly B. ovatus and B. thetaiotaomicron. A high degree of reproducibility of bacteriological and fermentation product data was obtained in these experiments. When gut contents were inoculated into a five-stage continuous culture system (retention time of 79 or 38 h) containing soya bran, the medium flow rate had little quantitative effect on the formation of acidic fermentation products; however, more oxidized fermentation acids were produced at the higher retention time. Diverse bacterial populations were maintained in every vessel at each flow rate. Bacteroides fragilis group organisms, especially B. ovatus, were numerically the most important. The viability of bacteria decreased through the system, especially at a retention time of 79 h, when the bacteria were growing under severely nutrient-limited conditions. PMID:2930171

  4. Cooperative research program in coal liquefaction

    SciTech Connect

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

    1990-01-01

    Cooperative research in coal liquefaction is presented. Topics include: Sulfate-promoted metal oxides as direct coal liquefaction catalysts; low temperature depolymerization and liquefaction of premium US coal samples; construction of continuous flow-through gas reactor for liquefaction investigations; examination of ferric sulfide as a liquefaction catalyst; generic structural characterization and liquefaction research; spectroscopic studies of coal macerals depolymerization catalyzed by iron chloride; characterization of catalysts used in coal hydrogenation systems; coal structure/liquefaction yield correlation by means of advanced NMR techniques; mass spectrometry of coal derived liquids: determination of molecular weight distributions; catalyst cracking, hydrogenation and liquefaction of coals under milder conditions; ENDOR investigations of coal liquefaction under mild conditions; direct determination of hydroaromatic structures in coal and coal conversion products by catalytic dehydrogenation; surface characterization of APCSB coals by XPS; computation chemistry of model compounds and molecular fragments of relevance to coal liquefaction; chemical characterization and hydrogenation reactions of single coal particles; the role of hydrogen during liquefaction using donor and non-donor solvents; solvent sorption and FTIR studies on the effect of catalytic depolymerization reactions in coal; bioprocessing of coal; chemical routes to breaking bonds: new approaches to low-temperature liquefaction; an investigation into the reactivity of isotetralin and tetralin using molecular orbital calculations; coal liquefaction modification for enhanced reactivity; 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; and improved catalysts for coal liquefaction and coprocessing.

  5. 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.

  6. Linguistic Knowledge at Early Stage I; Evidence from Successive Single Word Utterances. Papers and Reports on Child Language Development, No. 12.

    ERIC Educational Resources Information Center

    Horgan, Dianne

    A study was conducted to determine whether the child expresses linguistic knowledge during the single-word period. The order of mention in 65 sets of successive single-word utterances from five children at Stage 1, two to four years old, were analyzed. To elicit speech, the children were shown line drawings representing such situations as animate…

  7. 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.

  8. 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.

  9. Single cell analysis facilitates staging of Blimp1-dependent primordial germ cells derived from mouse embryonic stem cells.

    PubMed

    Vincent, John J; Li, Ziwei; Lee, Serena A; Liu, Xian; Etter, Marisabel O; Diaz-Perez, Silvia V; Taylor, Sara K; Gkountela, Sofia; Lindgren, Anne G; Clark, Amander T

    2011-01-01

    The cell intrinsic programming that regulates mammalian primordial germ cell (PGC) development in the pre-gonadal stage is challenging to investigate. To overcome this we created a transgene-free method for generating PGCs in vitro (iPGCs) from mouse embryonic stem cells (ESCs). Using labeling for SSEA1 and cKit, two cell surface molecules used previously to isolate presumptive iPGCs, we show that not all SSEA1+/cKit+ double positive cells exhibit a PGC identity. Instead, we determined that selecting for cKit(bright) cells within the SSEA1+ fraction significantly enriches for the putative iPGC population. Single cell analysis comparing SSEA1+/cKit(bright) iPGCs to ESCs and embryonic PGCs demonstrates that 97% of single iPGCs co-express PGC signature genes Blimp1, Stella, Dnd1, Prdm14 and Dazl at similar levels to e9.5-10.5 PGCs, whereas 90% of single mouse ESC do not co-express PGC signature genes. For the 10% of ESCs that co-express PGC signature genes, the levels are significantly lower than iPGCs. Microarray analysis shows that iPGCs are transcriptionally distinct from ESCs and repress gene ontology groups associated with mesoderm and heart development. At the level of chromatin, iPGCs contain 5-methyl cytosine bases in their DNA at imprinted and non-imprinted loci, and are enriched in histone H3 lysine 27 trimethylation, yet do not have detectable levels of Mvh protein, consistent with a Blimp1-positive pre-gonadal PGC identity. In order to determine whether iPGC formation is dependent upon Blimp1, we generated Blimp1 null ESCs and found that loss of Blimp1 significantly depletes SSEA1/cKit(bright) iPGCs. Taken together, the generation of Blimp1-positive iPGCs from ESCs constitutes a robust model for examining cell-intrinsic regulation of PGCs during the Blimp1-positive stage of development. PMID:22194959

  10. Transmission electron microscopy (TEM) study of minerals in coal

    SciTech Connect

    Hsieh, Kuang-Chien

    1982-01-01

    Minerals in eight coals from different mines were characterized in the micron-size range by using analytical transmission electron microscopy. Specimens were thinned by ion-milling wafers cut from these coals; a cold stage cooled by liquid nitrogen was used to reduce thermal degradation of the minerals by the ion-beam. Different mineral compounds were observed in different coals. The major minerals are clays, sulfides, oxides, carbonates and some minor-element-bearing phosphates. Clays (kaolinite, illite and others) have been most commonly found as either flat sheets or round globules. Iron sulfide was mostly found in the No. 5 and No. 6 coals from Illinois, distributed as massive polycrystals, as clusters of single crystals (framboids) or as isolated single crystals with size range down to some 0.25 microns. Other sulfides and some oxides were found in other coals with particle size as small as some 200 angstroms. Quartz, titanium oxides and many other carbonates and phosphate compounds were also characterized. Brief TEM work in the organic mass of coal was also introduced to study the nature of the coal macerals.

  11. Study of a solvent/binder combination for viscosity reduction of Orimulsion in fine coal dewatering

    SciTech Connect

    Kan, S.W.; Wilson, J.W.; Dharman, T.; Aksoy, B.S.

    1998-04-01

    To effectively liberate finely disseminated minerals from a coal matrix, a pulverization operation is needed. In this process fine coal particles are formed that possess large surface areas that are difficult to dewater, and create transportation, storage and handling problems at coal cleaning and utility plants. Using both laboratory and pilot scale models, research work conducted at the Department of Mining Engineering at University of Missouri - Rolla (UMR) on a single-stage fine coal dewatering and briquetting technique, has shown the potential of briquetting to enhance the handling, transportation, and storage of fine coal. The operation uses a hydrophobic binder as the dewatering and briquetting agent and requires a compaction device, specifically, a commercial-scale briquetting machine. In the single-stage dewatering/briquetting process, a bitumen-in-water emulsion (Orimulsion), which has high viscosity even at room temperature, was selected as the binder. Due to the tacky nature of the binder, it was felt that by reducing its viscosity using a solvent, the binder could more effectively coat the fine coal surfaces. This study investigated the efficiency of a solvent/binder combination for reducing the viscosity of the Orimulsion for the dewatering of fine coal, and making robust briquettes from predominantly -400 mesh coal particles.

  12. An efficient continuous-wave and Q-switched single-pass two-stage Ho:YLF MOPA system

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, Jacek; Jabczynski, Jan Karol; Zendzian, Waldemar

    2015-04-01

    We report on the efficient operation of an Ho:YLF laser single-pass in-band pumped by a Tm-doped fiber laser. The research in a continuous-wave (CW) operation in an oscillator scheme was done for a crystal of 0.5 at% Ho dopant concentration and the length of 30 mm for the output coupler transmittances of TOC=10%, 20%, 30% and 40%. At room temperature, for the output coupling transmission of 20%, the maximum CW output power of 24.5 W for 82.5 W of incident pump power, corresponding to the slope efficiency of 35.4% and optical-to-optical conversion efficiency of 29.7% was achieved. The highest slope efficiency of 81.6% with respect to absorbed pump power was obtained. Carrying out the measurements of the laser spectrum, for the out-coupling transmittance of TOC=30%, we observed a very short time wavelength shift between 2051.5 and 2062.4 nm in an Ho:YLF laser operation. Trying to fully utilize the pump power unabsorbed by the active crystal in an oscillator stage, an amplifier system based on two additional Ho:YLF crystals was developed. For the output coupling transmission of 40% the slope efficiency increased from 31.5% in an oscillator scheme to 47.3% with respect to the incident pump power in a two-stage amplifier scheme with a beam quality parameter of M2 better than 1.1. For a Q-switched operation, for the maximum incident pump power and the pulse repetition frequency (PRF) of 1 kHz, pulse energies of 18.5 mJ with a 22 ns FWHM pulse width corresponding to 841 kW peak power in the amplifier system were recorded.

  13. 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

  14. 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.)

  15. TNM staging of pancreatic neuroendocrine tumors: an observational analysis and comparison by both AJCC and ENETS systems from 1 single institution.

    PubMed

    Yang, Min; Zeng, Lin; Zhang, Yi; Wang, Wei-guo; Wang, Li; Ke, Neng-wen; Liu, Xu-bao; Tian, Bo-le

    2015-03-01

    We aimed to analyze the clinical characteristics and compare the surgical outcome of pancreatic neuroendocrine tumors (p-NETs) using the 2 tumor-node-metastasis (TNM) systems by both the American Joint Committee on Cancer (AJCC) Staging Manual (seventh edition) and the European Neuroendocrine Tumor Society (ENETS). Moreover, we sought to validate the prognostic value of the new AJCC criterion. Data of 145 consecutive patients who were all surgically treated and histologically diagnosed as p-NETs from January 2002 to June 2013 in our single institution were retrospectively collected and analyzed. The 5-year overall survival (OS) rates for AJCC classifications of stages I, II, III, and IV were 79.5%, 63.1%, 15.0%, and NA, respectively, (P < 0.005). As for the ENETS system, the OS rates at 5 years for stages I, II, III, and IV were 75.5%, 72.7%, 29.0%, and NA, respectively, (P < 0.005). Both criteria present no statistically notable difference between stage I and stage II (P > 0.05) but between stage I and stages III and IV (P < 0.05), as well as those between stage II and stages III and IV (P < 0.05). Difference between stage III and IV by ENETS was significant (P = 0.031), whereas that by the AJCC was not (P = 0.144). What's more, the AJCC Staging Manual (seventh edition) was statistically significant in both uni- and multivariate analyses by Cox regression (P < 0.005 and P = 0.025, respectively). Our study indicated that the ENETS TNM staging system might be superior to the AJCC Staging Manual (seventh edition) for the clinical practice of p-NETs. Together with tumor grade and radical resection, the new AJCC system was also validated to be an independent predictor for p-NETs. PMID:25816036

  16. Test and evaluate the tri-gas low-Btu coal-gasification process. Final report, October 21, 1977-October 31, 1980

    SciTech Connect

    Zabetakis, M.G.

    1980-12-01

    This report describes the continuation of work done to develop the BCR TRI-GAS multiple fluidized-bed gasification process. The objective is the gasification of all ranks of coals with the only product being a clean, low-Btu fuel gas. Design and construction of a 100 lb/h process and equipment development unit (PEDU) was completed on the previous contract. The process consists of three fluid-bed reactors in series, each having a specific function: Stage 1 - pretreatment; Stage 2- - gasification; Stage 3 - maximization of carbon utilization. Under the present contract, 59 PEDU tests have been conducted. A number of these were single-stage tests, mostly in Stage 1; however, integrated PEDU tests were conducted with a western coal (Rosebud) and two eastern coals (Illinois No. 6 and Pittsburgh seam). Both Rosebud and Pittsburgh seam coals were gasified with the PEDU operating in the design mode. Operation with Illinois No. 6 seam coal was also very promising; however, time limitations precluded further testing with this coal. One of the crucial tasks was to operate the Stage 1 reactor to pretreat and devolatilize caking coals. By adding a small amount of air to the fluidizing gas, the caking properties of the coal can be eliminated. However, it was also desirable to release a high percentage of the volatile matter from the coal in this vessel. To accomplish this, the reactor had to be operated above the agglomerating temperature of caking coals. By maintaining a low ratio of fresh to treated coal, this objective was achieved. Both Illinois No. 6 and Pittsburgh seam coals were treated at temperatures of 800 to 900 F without agglomerating in the vessel.

  17. 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.

  18. Single stage treatment of saline wastewater with marine bacterial-microalgae consortia in a fixed-bed photobioreactor.

    PubMed

    Babatsouli, P; Fodelianakis, S; Paranychianakis, N; Venieri, D; Dialynas, M; Kalogerakis, N

    2015-07-15

    Currently, the treatment of aquaculture-origin effluents is mainly performed through land-based recirculating aquaculture systems (RAS). In this study, we evaluate and introduce a novel immobilized/packed bed bioreactor which uses a synthetic textile as the support medium. A marine microbial consortium was developed on the textile by its inoculation with the microalgae Picochlorum sp. The bioreactor was tested with variable loadings of C and N and showed outstanding performance approaching removal rates up to 95% within a few hours (4-5h) of operation. Pyrosequencing analysis revealed a novel microbial consortium consisting mainly of chitrinomycetes, Pseudomonas sp. and the absence of β-proteobacteria, which is the Class encompassing autotrophic nitrifiers. Quantitative polymerase chain reaction further confirmed these findings suggesting heterotrophic nitrification and aerobic denitrification as the principal mechanisms of N-removal from the bioreactor. Overall our findings reveal the potential of the AdvanTex System for the treatment of marine aquaculture effluents-COD reduction and N-removal, in a single stage. PMID:25804790

  19. Modeling the catalytic action of supersaturated Ni droplets for the initial stage of growth of single-walled nanotubes

    NASA Astrophysics Data System (ADS)

    Chaudhuri, I.; Yu, M.; Jayanthi, C. S.; Wu, S. Y.

    2006-03-01

    Transition metal nanoparticles are the catalysis of choice for the growth of single-walled carbon nanotubes because of the high miscibility of carbon atoms with their supersaturated liquid droplets. This suggests that, at least for modeling the initial stage of growth, the droplets may be represented by the jellium medium and catalytic action of the droplets may be modeled by the electron redistribution for carbon atoms mediated by the medium. We have tested this scenario by comparing stable configurations of cage-structured C clusters in vacuum with those in jellium, with an average charge transfer from the jellium to C atoms nav 0.2e to model the effect of nickel atoms. The structural optimization was carried out using the semi-empirical self-consistent and environment- dependent Hamiltonian in the framework of linear combination of atomic orbitals developed by our group [1]. Our results showed that the pentagons are more stable with substantial charge transfer occurrence in the defects in the vicinity of pentagons, consistent with previous results [2]. We also found that for a cage-structured cluster of a given size, increasing nav tends to elongate the hexagonal rings. Thus it appears that the catalytic action provided by Ni-droplet may be modeled by the charge fluctuations on C atoms mediated by the jellium. [1] S. Y. Wu et.al. Handbook of Material Modeling Vol. I, p.2935 (2005). [2] X. Fan et. al. Phys. Rev. Lett. 90, 145501 (2003).

  20. 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.

  1. 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.

  2. A single channel, 6-bit 410-MS/s 3bits/stage asynchronous SAR ADC based on resistive DAC

    NASA Astrophysics Data System (ADS)

    Xue, Han; Qi, Wei; Huazhong, Yang; Hui, Wang

    2015-05-01

    This paper presents a single channel, low power 6-bit 410-MS/s asynchronous successive approximation register analog-to-digital converter (SAR ADC) for ultrawide bandwidth (UWB) communication, prototyped in a SMIC 65-nm process. Based on the 3 bits/stage structure, resistive DAC, and the modified asynchronous successive approximation register control logic, the proposed ADC attains a peak spurious-free dynamic range (SFDR) of 41.95 dB, and a signal-to-noise and distortion ratio (SNDR) of 28.52 dB for 370 MS/s. At the sampling rate of 410 MS/s, this design still performs well with a 40.71-dB SFDR and 30.02-dB SNDR. A four-input dynamic comparator is designed so as to decrease the power consumption. The measurement results indicate that this SAR ADC consumes 2.03 mW, corresponding to a figure of merit of 189.17 fJ/step at 410 MS/s. Project supported by the National Science Foundation for Young Scientists of China (No. 61306029) and the National High Technology Research and Development Program of China (No. 2013AA014103).

  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.

    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.

  4. 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.

  5. Temperature and concentration fields in a generator integrated to single stage heat transformer using Water/Carrol mixture

    NASA Astrophysics Data System (ADS)

    Gómez-Arias, E.; Ibarra-Bahena, J.; Velazquez-Avelar, L.; Romero, R. J.; Rodríguez-Martínez, A.; Montiel-González, M.

    2014-12-01

    The generator is the starter device of single stage heat transformer ( SSHT) and its characteristics have main effects on the overall efficiency of this kind of absorption machines. This article reports a study of the generation of steam and changes in the concentration of the working solution (Water/Carrol mixture) into a plate heat exchanger as a function of its horizontal and vertical position by gravity effect. It is considered the analysis of six experimental tests; two were evaluated in a plate heat exchanger in a horizontal position and four in a vertical position (90 degree inclination). The generation of steam and increased concentration of the working solution are more sensitive to the vertical position of exchanger than in horizontal position. The results of numerical-experimental analysis indicates that a heat exchanger in horizontal position, the steam generation and the change in the concentration of the working solution occurring in the middle of the plate (or at greater distance depending to the thermodynamic conditions) and instantly in vertical position (at the input of the plate).

  6. 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.

  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. PMID:25314667

  8. The Effect of Rotor Blade Speed to the Best Efficiency Point of Single Stage Axial Flow Compressor

    NASA Astrophysics Data System (ADS)

    Sukri, Mohamad Firdaus; Wasbari, Faizil; Mat, Shafizal

    2010-06-01

    The best efficiency point is ideal operational point for any turbomachinery. Selections of turbomachines in industry such as pump, turbine, compressor, etc are basically based on their operating point. The best efficiency point is a point at the highest efficiency. Therefore, turbomachines with nearest operating point to best efficiency point will be chosen due to higher efficiency thus produce great reduction in cost saving. Different speed of rotor blade will cause effect to the best efficiency point, as well as different in rotor and stator blade angle. If angle of rotor and stator blade constant while speed of rotor blade increased, the net head produced by the compressor will also increased. Thus, it will increase the brake horse power and fluid horse power. Although the efficiency of the compressor increases if fluid horse power increased, the increasing in brake horse power will produce lower efficiency. In this paper, the effect of rotor blade speed on best efficiency point of an axial flow compressor will be investigated and discussed. Through this paper, the highest efficiency is only 73 %, achieved at rotor blade speed of 750 rpm with net head of 9.4 mmWG, and air volumetric flow rate of 0.56m3/s. For higher net head, the rotor blade speed must be increased, but the efficiency will decrease simultaneously. The type of compressor used in this research is single stage axial flow compressor; model Dixson FM36, manufactured by Dixson FA Engineering Sdn. Bhd.

  9. 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.

  10. [Single-stage autotrophic nitrogen removal reactor with self-generated granular sludge for treating sludge dewatering effluent].

    PubMed

    Cao, Jian-ping; Du, Bing; Liu, Yin; Qin, Yong-sheng

    2009-10-15

    Single-stage autotrophic nitrogen removal (SANR) has been observed in a long-term operated nitrosation air-lift reactor for treating digested sludge dewatering effluent from sewage wastewater treatment plant. A kind of so called self-generated granular sludge which undertake the SANR reaction has oriented formed. The performance of SANR reactor cultivated above sludge for treating sludge dewatering effluent has been tested and better results have been reached. When the influent total nitrogen (TN) was kept about 350 mg/L (mainly ammonium nitrogen), the average TN removal efficiency and nitrogen removal load were 74.8% (maximum 86.92%) and 0.68 kg x (m3 x d)(-1) [maximum 0.9 kg x (m3 x d)(-1)] respectively. The operation stability and nitrogen removal efficiency have been enforced after adding a certain quantity powered activated carbon. The influent ammonium concentration, nitrogen load and aeration rate have a great effect on SANR reactor as well as the influent organic compound, pH, alkalinity have a relatively low effect. The parameters such as the ratios of aeration rate/deltaTN, aeration rate/deltaNH4+ -N, deltaALK/deltaTN can be used for better controlling the reaction. PMID:19968119

  11. 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. PMID:26196419

  12. 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

  13. 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.

  14. 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.

  15. Fixed-bed gasification research using US coals. Volume 7. Gasification of Piney Tipple 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 seventh volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Piney Tipple bituminous coal. The period of the gasification test was July 18-24, 1983. 6 refs., 20 figs., 17 tabs.

  16. Fixed-bed gasification research using US coals. Volume 5. Gasification of Stahlman Stoker bituminous 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 fifth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Stahlman Stoker bituminous coal from Clarion County, PA. The period of the gasification test was April 30 to May 4, 1983. 4 refs., 16 figs., 10 tabs.

  17. 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.

  18. Single Stage Repair for Aortic Coarctation associated with Intracardiac Defects Using Extra-Anatomic Bypass Graft in Adults

    PubMed Central

    Ates, Mehmet Sanser; Onuk, Burak Emre; Bakkaloglu, Beyhan; Sungur, Umit Pinar; Kurtoglu, Murat; Karagoz, Yahya Halidun

    2016-01-01

    Background and Objectives Coarctation of the aorta in adulthood is generally associated with other cardiovascular disorders requiring surgical management. An extra anatomic bypass grafting from the ascending to descending aorta by posterior pericardial approach via median sternotomy could be a reasonable single stage surgical strategy for these patients. Subjects and Methods Seven male patients aged between 14-41 years underwent an extra anatomic bypass grafting for coarctation repair concomitantly with the surgical management of the associated cardiovascular disorders via median sternotomy. Preoperative mean systolic arterial blood pressure was 161.8±24.5 mmHg, although the patients were under treatment of different combinations of antihypertensive agents. Additional surgical procedures were: aortic valve replacement (n=4), ventricular septal defect (VSD) closure (n=2), ascending aortic replacement (n=3) and Bentall procedure (n=1). None of our patients have been previously diagnosed or operated on for coarctation. Data were evaluated during their hospital stay and in post-operative follow-up. Results The post-operative course was uneventful in all but one patient was re-operated on due to bleeding. There was neither mortality nor significant morbidity during the in-hospital period and all patients were discharged within 5-9 (mean: 6.3±1.5) days. The mean follow up period was 71.83±23 months (range: 23-95 months). Unfortunately one of our patients could not be contacted for a follow up period because of invalid personal data. Conclusion Coarctation of the aorta in adulthood associated with other cardiovascular disorders can be operated on simultaneously via an extra anatomic bypass grafting technique with low morbidity and mortality. PMID:27482266

  19. Application of single-stage Orbitrap mass spectrometry and differential analysis software to nontargeted analysis of contaminants in dog food: detection, identification, and quantification of glycoalkaloids.

    PubMed

    Lohne, Jack J; Turnipseed, Sherri B; Andersen, Wendy C; Storey, Joseph; Madson, Mark R

    2015-05-20

    The objective of this study was to perform a preliminary investigation of the nontargeted search and quantitative capabilities of a single-stage Exactive High-Resolution Mass Spectrometer (HRMS). To do this, the instrument and its associated software performed a non-targeted search for deleterious substances in a dog food sample suspected of causing gastrointestinal problems in dogs. A single-stage Orbitrap/high-performance liquid chromatography method and differential expression analysis software (Sieve) was used to detect and identify, and subsequently quantify, nontargeted compounds occurring only in the suspect dog food sample. When combined with an online database (ChemSpider), a preliminary identification of one of the nontargeted compounds was determined to be potato glycoalkaloids. The diagnostic product ion ratios and quantitative data accuracy generated by the single-stage Orbitrap MS were shown to be similar to results obtained using a triple quadrupole LC-MS/MS. Additionally, the ability of the single-stage Orbitrap instrument to provide precursor and product ion accurate masses and isotope patterns was also investigated. PMID:25912523

  20. 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.

  1. 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

    2016-07-01

    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. PMID:27314579

  2. 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.

  3. Coal-based synthetic asphalts

    SciTech Connect

    Kang, J.H.

    1986-01-01

    The study investigated the technical and economic feasibility of producing a specification-grade, local-based asphalt from a raw coal available in the United States. Bench-scale hydrogenation experiments were performed in a one-gallon autoclave to produce asphalts from Illinois No. 6 bituminous coal and Clovis Point subbituminous coal. Samples from the process streams of a continuous coal liquefaction pilot plant at Wilsonville, AL were also evaluated to determine the potential for making a paving asphalt. The results showed that coal-based asphalts have a higher age-hardening rate than petroleum asphalts; also, they have a higher viscosity-temperature susceptibility (VTS) number. The high age-hardening rate of coal-based asphalts could be offset satisfactorily via catalytic hydrogenation. The VTS of these asphalts could be markedly reduced by adding a certain amount of styrene/butadiene copolymer. As a result, a specification grade, coal-based asphalt was successfully made via catalytic hydrogenation of coal combined with the incorporation of ca. 3 wt% styrene/butadiene copolymer into the coal-based asphalt. Marshall stability testing showed that coal based asphalt/aggregate compacted mixes had excellent resistance to plastic flow. Immersion compression testing revealed that the compacted mixes had a high initial compression strength and retained strength. A two-stage coal-based asphalt process was designed for producing 1000 tons/day. Economic analyses showed that the coal-based asphalt would be more expensive than currently used petroleum asphalt.

  4. Enhanced coal liquefaction with ammonia and amines in single and binary solvent systems. Quarterly report, September 20-December 19, 1983

    SciTech Connect

    Chen, W.Y.

    1984-01-12

    The program objective is to evaluate the process potential of coal liquefaction by using supercritical solvent systems. The solvent system will include at least one nitrogen-containing compound: ammonia or aliphatic amines. Recent discovery of the nucleophilic attack capability of nitrogen-containing compounds provides the incentive for this choice of solvent. Kinetics and thermodynamics of the process are examined. A tubing-bomb batch reactor has been designed, assembled and tested. The reactor is designed to allow independent control of temperature, pressure (solvent density) and residence time. Condensed products are separated into oil, asphaltene, preasphaltene, and residue fractions depending on their solubilities in hexane, benzene, and pyridine. A Louisiana lignite was used in the test runs. Results from subcritical ammonia experiments showed 2 to 4% conversion to ammonia soluble materials. Sequential elution of condensed products did not yield significant soluble compounds, but it confirmed a previous report on pore enlargement by ammonia. 29 references, 2 figures, 2 tables.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. Infrared Microspectroscopy Of Coals

    NASA Astrophysics Data System (ADS)

    Brenner, Douglas

    1983-11-01

    Coals consist of a wide range of plant matter which has undergone metamorphosis, as well as various minerals. The organic matter in the coal contains the remnants of a variety of parts of plants such as trunks, bark, roots, stems, leaves, spores, and so forth. The various coherent remnant organic bodies in the coal, which are generally of microscopic dimensions, are termed "macerals." Most analyses of the chemical functionalities in coals use the coal in a ground-up particulate form which contains a huge variety of different macerals as well as minerals. Such analyses give only averaged information, rather than being characteristic of any individual component of the coal. Now, however, a new microscopic IR (infrared) spectroscopy technique makes possible the chemical analysis of individual macerals of coal. Areas as small as 25 micrometers across can be analyzed. The technique utilizes a computer-controlled IR microspectrophotometer (which is now commercially available) in conjunction with newly-developed procedures for preparing uncontaminated thin sections of coals. The sample preparation technique utilizes a hydrocarbon-soluble adhesive to cement the coal to a glass slide for final grinding. This enables removal of the adhesive with a solvent to produce an uncontaminated specimen. A suitable thickness for the specimens has been found to he roughly 15 micrometers. Using this technique variations from specimen to specimen within a given maceral type, or even heterogeneities within a single maceral, can be determined. Preliminary experiments using this new technique have been made on single macerals of homogeneous vitrinite and liptinite in Illinois No. 6 coal. The spectra clearly contrasted the more aromatic and hydroxyl-containing structure of the vitrinite to the more aliphatic structure of the liptinite. In this paper, details of this new technique are discussed, and recent results, including representative spectra, are presented.

  13. Which Stage of ADPKD Is More Appropriate for Decortication? A Retrospective Study of 137 Patients from a Single Clinic

    PubMed Central

    Li, Ruipeng; Liu, Hailong; Kong, Xiangjie; Duan, Liujian; Qi, Jun

    2015-01-01

    Objective To study retrospectively the efficacy of decortication in patients with different stages of ADPKD and to determine which stage for decortication is more appropriate. Materials and Methods We analyzed 137 patients with ADPKD from 2001 to 2010. All patients were divided into three stages. A total of 70 patients underwent decortication, and we studied intraoperative indicators and postoperative indicators at 1 and 3 years follow-up. Results In 70 patients who underwent decortication, significant differences were observed in operative duration and bleeding volume between patients with stage I and II ADPKD (P<0.05), but no significant differences were observed in intestinal recovery time, pain medication dose, and the days of postoperative hospitalization (P > 0.05). The total complication occurrence rate was significantly different between them (P < 0.05). The serum creatinine (Scr) levels in patients with stage I ADPKD were within normal limits 1 and 3 years postoperatively and did not differ significantly (P > 0.05). Scr levels were significantly decreased in patients with stage II ADPKD in the 1st postoperative year (P < 0.05), but these were not significant differences in the 3rd postoperative year (P > 0.05). In the 1st postoperative year, VAS value, blood pressure and renal volume significantly differed (P < 0.05). However, no significant differences were observed 3 years later (P > 0.05). Conclusions Decortication in patients with stage I ADPKD can alleviate back pain symptoms and decrease blood pressure within 1 year, but the long-term efficacy is not ideal. Scr levels can be maintained within normal limits, suggesting that decortication does not lead to deterioration of renal function. For patients with stage II ADPKD, decortication can significantly improve renal function over the short term. However, after 3 years, renal function returns to the preoperative level, and surgical difficulties and complications also increase. PMID:25939015

  14. Coal slurry combustion optimization on single cylinder engine. Task 1.1.2.2.2, Combustion R&D

    SciTech Connect

    Not Available

    1992-09-01

    Under the sponsorship of the US Department of Energy, Morgantown Energy Technology Center, GE Transportation System has been conducting a proof of concept program to use coal water slurry (CWS) fuel to power a diesel engine locomotive since 1988. As reported earlier [1], a high pressure electronically controlled accumulator injector using a diamond compact insert nozzle was developed for this project. The improved reliability and durability of this new FIE allowed for an improved and more thorough study of combustion of CWS fuel in a diesel engine. It was decided to include a diesel pilot fuel injector in the combustion system mainly due to engine start and low load operation needs. BKM, Inc. of San Diego, CA was contracted to develop the electronic diesel fuel pilot/starting FIE for the research engine. As a result, the experimental combustion study was very much facilitated due to the ability of changing pilot/CWS injection timings and quantities without having to stop the engine. Other parameters studied included combustion chamber configuration (by changing CWS fuel injector nozzle hole number/shape/angle), as well as injection pressure. The initial phase of this combustion study is now complete. The results have been adopted into the design of a 12 cylinder engine FIE, to be tested in 1992. This paper summarizes the main findings of this study.

  15. Petrology and shock metamorphism of the olivine-phyric shergottite Yamato 980459 - Evidence for a two-stage cooling and a single-stage ejection history

    NASA Astrophysics Data System (ADS)

    Greshake, Ansgar; Fritz, Jörg; Stöffler, Dieter

    2004-05-01

    The basaltic Martian meteorite Yamato 980459 consists of large olivine phenocrysts and often prismatic pyroxenes set into a fine-grained groundmass of smaller more Fe-rich olivine, chromite, and an interstitial residual material displaying quenching textures of dendritic olivine, chain-like augite and sulfide droplets in a glassy matrix. Yamato 980459 is, thus, the only Martian meteorite without plagioclase/maskelynite. Olivine is compositionally zoned from a Mg-rich core to a Fe-rich rim with the outer few micrometers being especially rich in iron. With Fo 84 the cores are the most magnesian olivines found in Martian meteorites so far. Pyroxenes are also mostly composite crystals of large orthopyroxene cores and thin Ca-rich overgrowths. Separate pigeonite and augites are rare. On basis of the mineral compositions, the cooling rates determined from crystal morphologies, and crystal grain size distributions it is deduced that the parent magma of Yamato 980459 initially cooled under near equilibrium conditions e.g., in a magma chamber allowing chromite and the Mg-rich silicates to form as cumulus phases. Fractional crystallization at higher cooling rates and a low degree of undercooling let to the formation of the Ca-, Al-, and Fe-rich overgrowths on olivine and orthopyroxene while the magma was ascending towards the Martian surface. Finally and before plagioclase and also phosphates could precipitate, the magma was very quickly erupted quenching the remaining melt to glass, dendritic silicates and sulfide droplets. The shape preferred orientation of olivine and pyroxene suggests a quick, thin outflow of lava. According to the shock effects found in the minerals of Yamato 980459, the meteorite experienced an equilibration shock pressure of about 20-25 GPa. Its near surface position allowed the ejection from the planet's surface already by a single impact event and at relatively low shock pressures.

  16. 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.

  17. 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. PMID:27343451

  18. 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. PMID:23989035

  19. Efficacy of Single-stage Revision with Aggressive Debridement Using Intra-articular Antibiotics in the Treatment of Infected Joint Prosthesis

    PubMed Central

    Antony, Suresh J; Westbrook, Richard S; Jackson, John S; Heydemann, Jacob S; Nelson, Jenny L

    2015-01-01

    Prosthetic joint infections (PJI) of the hip and knee are uncommon, but result in significant morbidity and mortality when they do occur. Current management consists of a combination of either single- or two-stage exchange of the prosthesis and/or exchange of polymer components with intravenous (IV) antibiotics (4–6 weeks) and intraoperative debridement of the joint prior to reimplantation. However, failure rate, morbidity, and expense associated with current management are high, especially if the infection involves resistant pathogens and/or osteomyelitis. Also, the current use of systemic antibiotics does not allow for high local concentrations of the drug and biofilm penetration of the infected prosthesis. To overcome these difficulties, we examined the outcomes of aggressive operative debridement of the infected prosthesis. This was achieved through the use of a single-stage revision and administration of high concentrations of local intra-articular antibiotics via Hickman catheters. We present 57 patients with PJI who were treated with intra-articular antibiotics and single-stage revisions. Minimal systemic toxicity was observed along with a 100% microbiologic cure rate and 89% without relapse at 11-month follow-up despite isolation of multidrug resistant pathogens. This is the largest study to date using this method in the treatment of PJI. PMID:26279625

  20. High cell density lipid rich cultivation of a novel microalgal isolate Chlorella sorokiniana FC6 IITG in a single-stage fed-batch mode under mixotrophic condition.

    PubMed

    Kumar, Vikram; Muthuraj, Muthusivaramapandian; Palabhanvi, Basavaraj; Ghoshal, Aloke Kumar; Das, Debasish

    2014-10-01

    A single-stage mixotrophic cultivation strategy was developed with a novel microalgal isolate Chlorella sorokiniana FC6 IITG for high cell density lipid-rich biomass generation. The strain was evaluated for growth and lipid content under different physico-chemical parameters, nutritional conditions and trophic modes. Finally, a single-stage mixotrophic fed-batch cultivation strategy was demonstrated with intermittent feeding of key nutrients along with dynamic increase in light intensity for high cell density biomass and sodium acetate as elicitor for lipid enrichment. The key findings: (i) glucose and sodium acetate was identified as growth supporting and lipid inducing nutrients, respectively; (ii) mixotrophic batch cultivation resulted in maximum biomass and lipid productivity (mgL(-1)day(-1)) of 455.5 and 111.85, respectively; (iii) single-stage mixotrophic fed-batch cultivation showed maximum biomass productivity of 1.93gL(-1)day(-1) (biomass titer 15.81gL(-1)) and lipid productivity of 550mgL(-1)day(-1); (iv) biodiesel properties were in accordance with international standards. PMID:25125198

  1. 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.

  2. 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…

  3. New regents for coal desulfurization

    SciTech Connect

    Buchanan, D.H.; Kalembasa, S.; Olson, D.; Wang, S.; Warfel, L.

    1991-01-01

    The primary goal of this project was development and exploration of potential new desulfurization reagents for the removal of organic sulfur'' from Illinois coals by mild chemical methods. Potential new desulfurization reagents were investigated using organic sulfur compounds of the types thought to be present in coals. Reagents included low-valent metal complexes based on nickel and on iron as well as possible Single Electron Transfer reagents. Soluble coal extracts served as second generation model compounds during this reagent development project.

  4. 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.

  5. 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.

  6. Transcatheter Arterial Chemoembolization With Gelatin Sponge Microparticles Treated for BCLC Stage B Hepatocellular Carcinoma: A Single Center Retrospective Study.

    PubMed

    Kamran, Asad Ullah; Liu, Ying; Li, Feng E; Liu, Song; Wu, Jian Lin; Zhang, Yue Wei

    2015-12-01

    Gelatin sponge particles are commonly used in the conventional transarterial chemoembolization (c-TACE) as an adjuvant embolizing agent for hepatocellular carcinoma (HCC). However, there are few reports regarding the clinical applications of gelatin sponge microparticles (GSMs) as a main embolizing agent in the treatment of HCC. This retrospective study aim to evaluate the efficacy and safety of patients with Barcelona Clinic Liver Cancer (BCLC) stage B HCC treated with intra-arterial injection of 350 to 560 μm GSMs mixed with anticancer agents.Twenty-four patients with unresectable BCLC stage B HCC without any prior treatment underwent transarterial chemoembolization with gelatin sponge microparticles (GSMs-TACE) of diameter 350 to 560 μm mixed with lobaplatin. The mixture was injected into tumor-feeding arteries until the sluggish flow in selective artery. Safety was measured by assessing complication rate, and efficacy was reflected by assessing response to mRECIST therapy and overall survival. The survival rate was calculated using the Kaplan-Meier method.All 24 BCLC stage B HCC patients showed good tolerance to the procedure. The mean follow-up period was 27 months and mean number of TACE treatments per patient was 3.7 sessions (range 1-10) during the follow-up period. Postprocedure complications were mild and treated by symptomatic treatment. Six months and 1 year overall survival rates were 100% and 87.5%, respectively. Overall median survival time was 25 months (95%CI: 21.06-28.95 months).GSMs-TACE is a safe and effective method for BCLC stage B HCC patients. PMID:26717358

  7. A single-stage video-assisted thoracoscopic surgery procedure for simultaneous bilateral spontaneous pneumothorax in a supine position.

    PubMed

    Watanabe, S-I; Nakamura, Y; Kariatsumari, K; Sakasegawa, K-I; Mukaihara, K; Sakata, R

    2003-04-01

    We report on the case of a 23-year-old man with simultaneous bilateral spontaneous pneumothorax (SBSP), treated with bilateral video-assisted thoracoscopic surgery (VATS) in a supine position. SBSP is a very rare condition that can be life-threatening when therapeutic techniques fail. We performed a unique operative procedure for SBSP using one-stage bilateral VATS in a supine position. This procedure is less invasive, more effective, and safer for the treatment of SBSP. PMID:12730822

  8. 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.

  9. 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.

  10. 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.

  11. Fixed-bed gasification research using US coals. Volume 3. Gasification of Rosebud sub-bituminous 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 third volume in a series of documents prepared by Black, Sivalls and Bryson, Incorporated and describes the gasification of Rosebud subbituminous coal during the time period November 2-20, 1982. Test results and data are presented for the gasification of the coal and the operation of a slipstream tar scrubber to cool the gas and remove condensed tar. 5 refs., 29 figs., 18 tabs.

  12. A propeller flap for single-stage nose reconstruction in selected patients: supratrochlear artery axial propeller flap.

    PubMed

    Cordova, Adriana; D'Arpa, Salvatore; Massimiliano, Tripoli; Toia, Francesca; Moschella, Francesco

    2014-06-01

    The paramedian forehead flap is the gold standard technique for nose reconstruction. It requires two different surgical operations which prolonged the postoperative dressing and care. We present our 5-year experience with a propeller flap based on the supratrochlear artery, which allows one-stage transfer of the forehead skin to the nose without the need for pedicle division. This technique is indicated in a selected group of patients who are not suitable for multiple-stage reconstructions because they have concurrent medical conditions, reduced mobility, or live far away from specialized medical centers. We have renamed this procedure as supratrochlear artery axial propeller flap, from the acronym STAAP flap, to stress the axial, well known and constant, vascularization of the flap. In the past 5 years, we have been performing 25 STAAP flaps; full-thickness nasal reconstruction was performed in 11 cases. The patients were 16 males and 9 females, with a mean age of 79.5 years. All patients had multiple comorbidities. Complete flap survival was observed in 23 cases and healing was complete in 7 days. In two cases, there was a partial distal necrosis of the flap treated conservatively. Cosmetic results were good and the patient's satisfaction was significant. These results indicate that the STAAP flap is a reliable and useful technique in selected cases, as old or noncompliant patients who benefit from a one-stage technique of nose reconstruction. PMID:24918712

  13. 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.

  14. Difference of Postoperative Stool Frequency in Hirschsprung Disease According to Anastomosis Level in a Single-Stage, Laparoscopy-Assisted Transanal Endorectal Pull-Through Procedure.

    PubMed

    Oh, Chaeyoun; Lee, Sanghoon; Lee, Suk-Koo; Seo, Jeong-Meen

    2016-04-01

    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

  15. 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.

  16. 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.

  17. 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

  18. 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. PMID:26961523

  19. Voidage and pressure profile characteristics of sand-iron ore-coal-FCC single-particle systems in the riser of a pilot plant circulating fluidized bed

    SciTech Connect

    Das, M.; Meikap, B.C.; Saha, R.K.

    2008-06-15

    Hydrodynamic behaviors of single system of particles were investigated in a circulating fluidized bed (CFB) unit. Particles belonging to Geldart groups A and B like sand of various sizes (90, 300, 417, 522, 599, and 622 mu m), FCC catalyst (120 mu m), iron ore (166 and 140 {mu} m), and coal (335 and 168 {mu} m) were used to study the hydrodynamic characteristics. Superficial air velocity used in the present study ranged between 2.01 and 4.681 m/s and corresponding mass fluxes were 12.5-50 kg/(m{sup 2} s). A CFB needs the creation of some special hydrodynamic conditions, namely a certain combination of superficial gas velocity, solids circulation rate, particle diameter, density of particle, etc. which can give rise to a state wherein the solid particles are subjected to an upward velocity greater than the terminal or free fall velocity of the majority of the individual particles. The hydrodynamics of the bed was investigated in depth and theoretical analysis is presented to support the findings. Based on gas-solid momentum balance in the riser, a distinction between apparent and real voidage has been made. The effects of acceleration and friction on the real voidage have been estimated. Results indicated a 0.995 voidage for higher superficial gas velocity of 4.681. m/s.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  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. 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.

  8. Hepatitis B Vaccination in End-Stage Pulmonary Disease Patients Evaluated for Lung Transplantation: A Retrospective Single-Center Evaluation.

    PubMed

    Wald, Alexandra; Deterding, Lea; Maier, Melanie; Liebert, Uwe G; Berg, Thomas; Wirtz, Hubert; Wiegand, Johannes

    2016-01-01

    BACKGROUND In times of limited organs for transplantation, anti-HBc-positive organs can be accepted for lung transplantation to increase the number of donors. Transplant recipients should be vaccinated against hepatitis B to prevent HBV infection. However, response after HBV vaccination has only been poorly evaluated in patients with end-stage pulmonary disease. MATERIAL AND METHODS Anti-HBs titers of 40 anti-HBc negative patients with end-stage pulmonary disease evaluated for lung transplantation were analyzed with the Architect® system (Abbott, Germany). Responders, partial responders, or non-responders after HBV vaccination were defined by anti-HBs titers >100 IU/L, 10-100 IU/L, and <10 IU/L, respectively. RESULTS There were 34/40 individuals (85%) vaccinated against hepatitis B, and 6 were not vaccinated. Response, partial response, and non-response after vaccination were observed in 10/34 (29.4%), 11/34 (32.4%), and 13/34 (38.2%) of patients, respectively. Response to vaccination did not correlate with sex, pulmonary disease, comorbidities, immunosuppressive therapy, or smoking status. CONCLUSIONS Although 85% of patients evaluated for lung transplantation were vaccinated against hepatitis B, 38.2% did not show an anti-HBs titer >10 IU/L. Thus, anti-HBs titers should be regularly monitored. Nonresponders should be considered for booster vaccinations, alternative vaccination schedules, or prophylactic treatment with a nucleos(t)ide analogue in case of transplantation of an anti-HBc-positive organ. PMID:27297788

  9. 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.

  10. 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.

  11. Burning coal refuse in fluid beds

    SciTech Connect

    Kleinau, J.H.; Sneyd, R.J.; Lombardi, C.E.

    1985-01-01

    This paper deals with the application of fluid bed combustion technology to the burning of coal-mining waste. The designs of two stage fluid bed combustors/dryers are demonstrated as useful in the drying of coal, slag and coke, using coal and coal refuse (gob) as fuel. Anthracite mining refuse (culm) is more than abundant in Northeastern Pennsylvania. After demonstration at Shamokin, Pennsylvania, a full commercial-sized fluid bed boiler using culm is used for district heating in Wilkes-Barre, Pennsylvania. Limited research work has shown the utility of using fine coal as filter aid in sludge incineration. With the rising avenues of the suitability of coal as auxiliary fuel in fluid bed sludge incineration, an expansion of these concepts combines the use of coal or coal refuse as filter aid and auxiliary fuel. Limestone addition controls SO/sub 2/ emission.

  12. 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.

  13. 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.

  14. 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

  15. Static Strain Aging Behavior of a Manganese-Silicon Steel After Single and Multi-stage Straining

    NASA Astrophysics Data System (ADS)

    Seraj, P.; Serajzadeh, S.

    2016-03-01

    In this work, static strain aging behavior of an alloy steel containing high amounts of silicon and manganese was examined while the influences of initial microstructure and pre-strain on the aging kinetics were evaluated as well. The rate of strain aging in a low carbon steel was also determined and compared with that occurred in the alloy steel. The rates of static strain aging in the steels were defined at room temperature and at 95 °C by means of double-hit tensile testing and hardness measurements. In addition, three-stage aging experiments at 80 °C were carried out to estimate aging behavior under multi-pass deformation processing. The results showed that in-solution manganese and silicon atoms could significantly affect the aging behavior of the steel and reduce the kinetics of static strain aging as compared to the low carbon steel. The initial microstructure also played an important role on the aging behavior. The rapidly cooled steel having mean ferrite grain size of 9.7 μm showed the least aging susceptibility index during the aging experiments. Accordingly, the activation energies for static strain aging were calculated as 93.2 and 85.7 kJ/mole for the alloy steel having fine and coarse ferrite-pearlite structures, respectively while it was computed as 79.1 kJ/mole for the low carbon steel with ferrite mean grain size of about 16.2 μm.

  16. 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

  17. Distribution and microbial community structure analysis of a single-stage partial nitritation/anammox granular sludge bioreactor operating at low temperature.

    PubMed

    Rodriguez-Sanchez, Alejandro; Purswani, Jessica; Lotti, Tommaso; Maza-Marquez, Paula; van Loosdrecht, M C M; Vahala, Riku; Gonzalez-Martinez, Alejandro

    2016-09-01

    In the last decade, autotrophic nitrogen removal technologies based on anammox metabolism have become state of the art in urban and industrial wastewater treatment systems, due to their advantages over traditional nitrogen removal processes. However, their application is currently limited to the treatment of warm wastewater (25-40°C) mainly due to the low growth rate of the anammox bacteria. The extension of the application field to wastewater characterized by lower temperatures (8-20°C), such as those typical for municipal sewage, allows the design of treatment systems with a net energy production. In this study, the distribution and bacterial community structure of a lab-scale single-stage partial nitritation/anammox (PN/A) granular sludge bioreactor operating at low temperatures was analysed using next-generation sequencing techniques. The presence of ammonium-oxidizing bacteria and anammox bacteria was found, but the appearance of other bacterial species shows a complex microbial ecosystem. Evaluation of ecological roles of representative species inside the single-stage PN/A bioreactor was accomplished. Results obtained will be helpful for the future design and operation of PN/A systems performing at low temperatures. PMID:26829222

  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. 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. PMID:25864735

  20. [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

  1. 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.

  2. Coal plasticity at high heating rates and temperatures

    SciTech Connect

    Gerjarusak, S.; Peters, W.A.; Howard, J.B.

    1992-05-01

    The potential influence of gas bubbles on the viscosity of molten coal at elevated temperatures was estimated by calculations, using literature models for the viscosity of two and three phase suspensions. In one approach, gas bubbles in molten coal were approximated as the dispersed phase of deformable liquid globules in G.I. Taylor's model of emulsion viscosity. This model was incorporated into different models for the viscosity of solid-in-liquid suspensions, in which the dispersed solids are approximated as rigid spheres. Calculations show that in the presence of gas bubbles, the apparent viscosity of molten coal increases roughly in proportion to the volume fraction of gas with respect to the liquid continuum phase. It is experimentally and mathematically difficult to accurately determine gas volume fractions throughout the softening stage of coal pyrolysis. Our current plan is therefore to assume that the apparent viscosity of molten coal can be reasonably modeled in terms of a single liquid continuum phase and one dispersed phase consisting only of solids, using for example the two phase suspension viscosity model of Hatschek or of Frankel and Acrivos. In this approximation, gas bubble effects would force the model to underestimate metaplast concentrations and to overpredict the contribution of the dispersed solids to increase the viscosity of the liquid continuum.

  3. 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.

  4. Single Phase 40Ar/39Ar Dating of Rajahmundry Trap Basalts Contemporaneous With Late Stage Deccan Trap Volcanism

    NASA Astrophysics Data System (ADS)

    Knight, K. B.; Knight, K. B.; Renne, P. R.; Renne, P. R.; Halkett, A.; White, N.

    2001-12-01

    The Rajahmundry Traps of eastern peninsular India, often considered to be outliers of the Deccan Traps, occupy ~35 km2 centered on the Krishna-Godavari Basin and extending offshore in the sub-surface. Onshore exposures average 60m in thickness, including a laterally continuous sedimentary interlayer of laterite, limestone and shale ( ~2m thick, total) separating `upper' flows from `lower' flows. 40Ar/39Ar CO2 laser incremental heating analysis of twelve plagioclase separates from Rajahmundry Trap basalts reveal an age of ~64.6 Ma for the entire sequence based on the FCs standard at 28.02 Ma. Flows chosen for dating include 8 sites spanning both the `upper' and `lower' flow sequences. Paleontological studies of sediments adjacent to the basalt at depth in Krishna-Godavari Basin, e.g. Jaiprakash et al. (1993), suggest that the period of time covered by the two flows and intertrappean sediments is up to ca. 6 myr. Dates obtained for this study, however, show that ages for both upper and lower flows are indistinguishable within 2σ error from one another, and span ~2 Ma at most, pointing to a substantial hiatus in the sedimentary record at the top of the upper basalt flows. Extremely high Ca/K ratios (up to ~400) in several samples limits precision due to error propagation attending the large correction necessary for reactor produced 36Ar from Ca. However, plateau ages as precise as 64.8 +/- 0.4 and 65.5 +/- 0.8 from above and below (respectively, 2σ errors) the sedimentary interlayer have been obtained. Samples with both high and low Ca/K ratios confirm rapid eruption of the entire Rajahmundry Trap sequence. A petrogenetic link between these basalts and the Deccan Trap basalts (the remains of which lie over 300 km from the nearest exposure of Rajahmundry Trap) has been suggested but has yet to be substantiated. These new data clearly place the eruption of the Rajahmundry Traps temporally close to the K-T boundary, coincident with late stage Deccan volcanism and

  5. 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.

  6. Correlative 99mTc-Labeled Tropane Derivative Single Photon Emission Computer Tomography and Clinical Assessment in the Staging of Parkinson Disease

    PubMed Central

    Shinto, Ajit S.; Antony, Joppy; Kamaleshwaran, Koramadai; Vijayan, Krishnan; Selvan, Arul; Korde, Aruna; Kameshwaran, Mythili; Samuel, Grace

    2014-01-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by a selective loss of dopamine in the striatum. Problems remain in the accurate diagnosis of PD. The diagnosis of idiopathic PD is based on the interpretation of clinical signs and symptoms could be incorrect at the time of initial presentation. In vivo imaging of the dopaminergic system has the potential to improve the diagnosis of PD in its early stages. The imaging of dopamine transporter (DAT) with 99mTc-labeled tropane derivative (TRODAT-1) single photon emission computer tomography/computer tomography (SPECT/CT) has been proposed to be a valuable and feasible means of assessment of the integrity of dopamine neurons. The purpose of this study was to investigate the potential usefulness of 99mTc-TRODAT-1 imaging in the evaluation of patients with PD and classify into different stages of the disease. SPECT imaging with 99mTc-TRODAT-1 was conducted in 16 consecutive PD patients (9 men; 7 women) and in 6 age matched healthy volunteers (4 men; 2 women). The images were obtained 3 h after the intra-venous injection of the tracer. Specific uptake in the striatum and its sub-regions, including the putamen and caudate nucleus was calculated and the ratios of specific striatal binding to nonspecific occipital binding were calculated. ANOVA with Dunnett C post-hoc analysis was conducted using SPSS 20. A stepwise reduction in specific striatal uptake of 99mTc-TRODAT-1 with increasing disease severity between healthy control versus Stage I versus Stage II versus Stage III was found in PD patients (i.e., 3.77 vs. 2.56 vs. 1.57 vs. 0.63, P < 0.05). The changes were magnified by measurement of specific putaminal uptake (1.43 vs. 0.79 vs. 0.54 vs. 0.19, P < 0.05) and specific caudate uptake (1.90 vs. 1.47 vs. 0.73 vs. 0.27, P < 0.05). No remarkable adverse reactions were found in either healthy volunteers or PD patients during or after imaging. 99mTc-TRODAT-1 is accurate and widely available

  7. The single dynamin family protein in the primitive protozoan Giardia lamblia is essential for stage conversion and endocytic transport.

    PubMed

    Gaechter, Verena; Schraner, Elisabeth; Wild, Peter; Hehl, Adrian B

    2008-01-01

    Dynamins are universally conserved large guanosine triphosphatases, which function as mechanoenzymes in membrane scission. The primitive protozoan Giardia lamblia has a single dynamin-related protein (GlDRP) with an unusual domain structure. Giardia lacks a Golgi apparatus but generates transient Golgi-like delay compartments dubbed encystation-specific vesicles (ESVs), which serve to accumulate and mature cyst wall proteins during differentiation to infectious cyst forms. Here, we analyze the function of GlDRP during growth and encystation and demonstrate that it relocalizes from peripheral endosomal-lysosomal compartments to nascent ESVs. We show that GlDRP is necessary for secretion of the cyst wall material and ESV homeostasis. Expression of a dominant-negative GlDRP variant does not interfere with ESV formation but blocks cyst formation completely prior to regulated exocytosis. GlDRP colocalizes with clathrin at the cell periphery and is necessary for endocytosis of surface proteins to endosomal-lysosomal organelles in trophozoites. Electron microscopy and live cell imaging reveal gross morphological changes as well as functional impairment of the endocytic system in cells expressing the dominant-negative GlDRP. Thus, giardial DRP plays a key role in two distinct trafficking pathways and in organelle homeostasis, both essential functions for the proliferation of the parasite in the gut and its transmission to a new host. PMID:17892527

  8. Source identification of nitrous oxide emission pathways from a single-stage nitritation-anammox granular reactor.

    PubMed

    Ali, Muhammad; Rathnayake, Rathnayake M L D; Zhang, Lei; Ishii, Satoshi; Kindaichi, Tomonori; Satoh, Hisashi; Toyoda, Sakae; Yoshida, Naohiro; Okabe, Satoshi

    2016-10-01

    Nitrous oxide (N2O) production pathway in a signal-stage nitritation-anammox sequencing batch reactor (SBR) was investigated based on a multilateral approach including real-time N2O monitoring, N2O isotopic composition analysis, and in-situ analyses of spatial distribution of N2O production rate and microbial populations in granular biomass. N2O emission rate was high in the initial phase of the operation cycle and gradually decreased with decreasing NH4(+) concentration. The average emission of N2O was 0.98 ± 0.42% and 1.35 ± 0.72% of the incoming nitrogen load and removed nitrogen, respectively. The N2O isotopic composition analysis revealed that N2O was produced via NH2OH oxidation and NO2(-) reduction pathways equally, although there is an unknown influence from N2O reduction and/or anammox N2O production. However, the N2O isotopomer analysis could not discriminate the relative contribution of nitrifier denitrification and heterotrophic denitrification in the NO2(-) reduction pathway. Various in-situ techniques (e.g. microsensor measurements and FISH (fluorescent in-situ hybridization) analysis) were therefore applied to further identify N2O producers. Microsensor measurements revealed that approximately 70% of N2O was produced in the oxic surface zone, where nitrifiers were predominantly localized. Thus, NH2OH oxidation and NO2 reduction by nitrifiers (nitrifier-denitrification) could be responsible for the N2O production in the oxic zone. The rest of N2O (ca. 30%) was produced in the anammox bacteria-dominated anoxic zone, probably suggesting that NO2(-) reduction by coexisting putative heterotrophic denitrifiers and some other unknown pathway(s) including the possibility of anammox process account for the anaerobic N2O production. Further study is required to identify the anaerobic N2O production pathways. Our multilateral approach can be useful to quantitatively examine the relative contributions of N2O production pathways. Good understanding of the

  9. Periodic Peritoneal Dialysis in End Stage Renal Disease: Is it Still Relevant? A Single Center Study from India

    PubMed Central

    Gandhi, K; Prasad, D; Malhotra, V; Agrawal, D; Beniwal, P; Mathur, M

    2015-01-01

    Background: High cost of maintenance hemodialysis (HD) and continuous ambulatory peritoneal dialysis (PD) in India has made renal replacement therapy out of reach of many patients with end stage renal disease (ESRD). Repeated puncture PD although inferior to HD biochemically, is easily and freely available across Rajasthan, India, and is simple to perform, and does not require sophisticated machines, thus making it an attractive option for dialysis for ESRD. Aim: To analyze the outcomes of periodic PD in patients with ESRD requiring dialysis support. Subjects and Methods: A prospective study analyzing the data of patients who underwent PD between August 2010 and January 2013 in Sawai Man Singh Hospital, Jaipur, India was conducted. Patients were divided into three groups based on the time period between first and second session of PD. Detailed demographic and clinical data during the study period were collected along with PD related complications. The main outcome studied was technique survival 1 year post initiation of PD. Results: 234 patients received an initial session of PD, of which 174 had a good response and were included in the study. 19 patients received the second PD within 7 days of first (Group 1), 45 patients within 8–14 days (Group 2) and 110 patients within 15–21 days (Group 3). The overall 1 year technique survival was 68.4% (91/133), with a rate of 50% (5/10), 56.8% (21/37), and 75.6% (65/86) for Group 1, Group 2, and Group 3, respectively. The time duration between first and second PD proved to be reliable indicator of the subsequent response, with a technique survival rate significantly lower in Group 1 patients compared to Groups 2 and 3 (P = 0.04). Median dialysis free days were 11, 16 and 21 days in Group 1, Group 2, and Group 3, respectively. Peritonitis rate observed was 2.1% (49/2261) during the study period. Conclusion: Periodic PD is a simple, safe and cheap procedure, which can be considered as used as a palliative measure in

  10. 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.

  11. Urochordate Ascidians Possess a Single Isoform of Aurora Kinase That Localizes to the Midbody via TPX2 in Eggs and Cleavage Stage Embryos

    PubMed Central

    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

  12. A single short session of media perfusion induces osteogenesis in hBMSCs cultured in porous scaffolds, dependent on cell differentiation stage.

    PubMed

    Filipowska, Joanna; Reilly, Gwendolen C; Osyczka, Anna M

    2016-08-01

    Perfusing culture media through porous cell-seeded scaffolds is now a common approach within many tissue engineering strategies. Human bone-marrow derived mesenchymal stem cells (hBMSC) are a clinically valuable source of osteoprogenitors that respond to mechanical stimuli. However, the optimal mechanical conditions for their osteogenic stimulation in vitro have not been defined. Whereas the effects of short durations of media fluid flow have been studied in monolayers of osteoblastic cells, in 3D culture continuous or repeated perfusion is usually applied. Here, we investigated whether a short, single perfusion session applied to hBMSCs cultured in 3D would enhance their osteogenesis in vitro. We cultured hBMSCs on gelatine-coated, porous polyurethane scaffolds with osteogenic supplements and stimulated them with a single 2-h session of unidirectional, steady, 2.5 mL/min media perfusion, at either early or late stages of culture in 3D. Some cells were pre-treated in monolayer with osteogenic supplements to advance cell differentiation, followed by 3D culture also with the osteogenic supplements. We report that this single, short session of media perfusion can markedly enhance the expression of bone-related transcription and growth factors, and matrix components, by hBMSCs but that it is more effective when cells reach the pre-osteoblast or osteoblast differentiation stage. These findings could aid in the optimization of 3D culture protocols for efficient bone tissue engineering. Biotechnol. Bioeng. 2016;113: 1814-1824. © 2016 Wiley Periodicals, Inc. PMID:26806539

  13. Stage-independent, single lead EEG sleep spindle detection using the continuous wavelet transform and local weighted smoothing

    PubMed Central

    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. PMID:25926784

  14. 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. PMID:25926784

  15. Single and Multiple Level One Stage Posterior Hemivertebrectomy and Short Segment Fixation: Experience with 22 Cases and Comparison of Single vs. Multilevel Procedures with Minimum 2-Year Follow-Up

    PubMed Central

    Basu, Saumyajit; Malik, Farid H.; Ghosh, Jay Deep; Jain, Mantu; Sarangi, Trinanjan

    2016-01-01

    Study Design Data of 22 patients with congenital scoliosis who underwent single stage posterior hemivertebrectomies and short segment fixation with a minimum follow-up of 2 years in our centre were studied retrospectively. Purpose To report the efficacy of posterior hemivertebrectomy in single vs multiple level hemivertebra and compare their results. Overview of Literature Single stage hemivertebrectomy is a standard procedure for single level hemivertebra. Results of multiple level hemivertebrectomies have not been reported. Methods Twenty-two patients (9 male and 13 female) with the mean age of 11.2 years (range, 2 years 4 months to 24 years 10 months) and a mean follow up of 32 months (range, 4 to 73 months) were studied retrospectively and their results were compared. Results Average number of hemivertebrae removed was 1.46 (range, 1 to 3). Mean preoperative and postoperative coronal cob angle was 48.7° (range, 22° to 80°) and 24.2° (range, 7° to 41°), respectively (p<0.001). Mean preoperative and postoperative sagittal cobb angle was 32.1° (range, 7° to 76°) and 13.6° (range, 0° to 23°), respectively (p<0.005). Mean coronal and sagittal cob correction percentage achieved was 50.2% and 51.8% respectively. Mean follow-up was 49 months (range, 30 to 84 months). Mean loss of coronal and sagittal correction at final follow-up was 4% (0% to 13.6%) degrees and 3.5% (0% to 20%), respectively. Conclusions Posterior hemivertebrectomy in congenital scoliosis is a safe treatment option for up to 3-level hemivertebrae. Excision of thoracolumbar hemivertebrae results in better correction than thoracic and lumbar hemivertebrae. PMID:27340519

  16. [Coal fineness effect on primary particulate matter features during pulverized coal combustion].

    PubMed

    Lü, Jian-yi; Li, Ding-kai

    2007-09-01

    Three kinds of coal differed from fineness were burned in a laboratory-scale drop tube furnace for combustion test, and an 8-stage Andersen particle impactor was employed for sampling the primary particulate matter (PM), in order to study coal fineness effect on primary PM features during pulverized coal combustion. It has been shown that the finer the coal was, the finer the PM produced. PM, emission amount augmented with coal fineness decreased, and the amount of PM10 increased from 13 mg/g to 21 mg/g respectively generated by coarse coal and fine coal. The amount of PM2.5 increased from 2 mg/g to 8 mg/g at the same condition. Constituents and content in bulk ash varied little after three different fineness coal combustion, while the appearance of grading PM differed visibly. The value of R(EE) increased while the coal fineness deceased. The volatility of trace elements which were investigated was Pb > Cr > Zn > Cu > Ni in turn. The concentration of poisonous trace elements was higher which generated from fine coal combustion. The volatilization capacity was influenced little by coal fineness, but the volatilization extent was influenced differently by coal fineness. Fine coal combustion affects worse environment than coarse coal does. PMID:17990536

  17. Fixed-bed gasification research using US coals. Volume 10. Gasification of Benton lignite

    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 tenth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Benton lignite. The period of gasification test was November 1-8, 1983. 16 refs., 22 figs., 19 tabs.

  18. 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.

  19. Transportation: A vital element in coal's future

    SciTech Connect

    Smith, J.P.

    1982-10-01

    This paper explains how economical coal transportation, particulary from vast western reserves, is becoming an increasingly difficult but compelling challenge for both the country and the coal industry. In controlling transportation costs, coal producers must rely on a delicate balance between product demand, competition among carriers, federal regulation, and a symbiotic relationship with coal transporters. Studies by the National Coal Association show that 85% of the coal carried by railroads has no practical alternative means of movement. Captive coal shipments, those in which a mine and a customer are serviced by a single, dedicated carrier, are common in the West. An FERC study revealed that captive coal shipments (which account for 14% of all coal shipped to US utilities) are usually more expensive than noncaptive shipments. Other factors affecting coal's price per ton include tonnage, distance, type of transport equipment used, carrier, and geographic considerations. Need for competing modes is shown by the fact that while railroad coal tonnage remained essentially unchanged from 1980 to 1981, railroad revenues for coal shipping increased 18%. Evaluates coal slurry transportation.

  20. Coal liquefaction with coal tar solvent

    SciTech Connect

    Gir, S.; Rhodes, D.E.

    1986-12-16

    A method is described of liquefying coal, comprising: mixing solid coal with a process solvent comprising coal tar material which has been at least partially hydrogenated under conditions which selectively hydrogenate aromatic coal tar components to hydroaromatics and which preserve the integrity of organonitrogen coal tar components, to produce a coal-solvent slurry; treating the coal-solvent slurry under coal-liquefying conditions in a liquefaction zone to produce a solution containing coal liquefaction products; and recovering coal liquefaction products from the solution.