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Sample records for residual gas analysis

  1. Residual gas analysis

    International Nuclear Information System (INIS)

    Berecz, I.

    1982-01-01

    Determination of the residual gas composition in vacuum systems by a special mass spectrometric method was presented. The quadrupole mass spectrometer (QMS) and its application in thin film technology was discussed. Results, partial pressure versus time curves as well as the line spectra of the residual gases in case of the vaporization of a Ti-Pd-Au alloy were demonstrated together with the possible construction schemes of QMS residual gas analysers. (Sz.J.)

  2. Analysis of residual swirl in tangentially-fired natural gas-boiler

    International Nuclear Information System (INIS)

    Hasril Hasini; Muhammad Azlan Muad; Mohd Zamri Yusoff; Norshah Hafeez Shuaib

    2010-01-01

    This paper describes the investigation on residual swirl flow in a 120 MW natural gas, full-scale, tangential-fired boiler. Emphasis is given towards the understanding of the behavior of the combustion gas flow pattern and temperature distribution as a result of the tangential firing system of the boiler. The analysis was carried out based on three-dimensional computational modeling on full scale boiler with validation from key design parameter as well as practical observation. Actual operating parameters of the actual boiler are taken as the boundary conditions for this modeling. The prediction of total heat flux was found to be in agreement with the key design parameter while the residual swirl predicted at the upper furnace agrees qualitatively with the practical observation. Based on this comparison, detail analysis was carried out for comprehensive understanding on the generation and destruction of the residual swirl behavior in boiler especially those with high capacity. (author)

  3. Analysis of residual toluene in food packaging via headspace extraction method using gas chromatography

    International Nuclear Information System (INIS)

    Lim, Ying Chin; Mohd Marsin Sanagi

    2008-01-01

    Polymeric materials are used in many food contact applications as packaging material. The presence of residual toluene in this food packaging material can migrate into food and thus affect the quality of food. In this study, a manual headspace analysis was successfully designed and developed. The determination of residual toluene was carried out with standard addition method and multiple headspace extraction, MHE) method using gas chromatography-flame ionization detector, GC-FID). Identification of toluene was performed by comparison of its retention time with standard toluene and GC-MS. It was found that the suitable heating temperature was 180 degree Celsius with an optimum heating time of 10 minutes. The study also found that the concentration of residual toluene in multicolored sample was higher compared to mono colored sample whereas residual toluene in sample analyzed using standard addition method was higher compared to MHE method. However, comparison with the results obtained from De Paris laboratory, France found that MHE method gave higher accuracy for sample with low analyte concentration. On the other hand, lower accuracy was obtained for sample with high concentration of residual toluene due to systematic errors. Comparison between determination methods showed that MHE method is more precise compared to standard addition method. (author)

  4. On residual gas analysis during high temperature baking of graphite tiles

    International Nuclear Information System (INIS)

    Prakash, A A; Chaudhuri, P; Khirwadkar, S; Reddy, D Chenna; Saxena, Y C; Chauhan, N; Raole, P M

    2008-01-01

    Steady-state Super-conducting Tokamak-1 (SST-1) is a medium size tokamak with major radius of 1.1 m and minor radius of 0.20 m. It is designed for plasma discharge duration of 1000 seconds to obtain fully steady-state plasma operation. Plasma Facing Components (PFC), consisting of divertors, passive stabilizers, baffles and poloidal limiters are also designed to be UHV compatible for steady state operation. All PFC are made up of graphite tiles mechanically attached to the copper alloy substrate. Graphite is one of the preferred first wall armour material in present day tokamaks. High thermal shock resistance and low atomic number of carbon are the most important properties of graphite for this application. High temperature vacuum baking of graphite tiles is the standard process to remove the impurities. Residual Gas Analyzer (RGA) has been used for qualitative and quantitative measurements of released gases from graphite tiles during baking. Surface Analysis of graphite tiles has also been done before and after baking. This paper describes the residual gas analysis during baking and surface analysis of graphite tiles

  5. On residual gas analysis during high temperature baking of graphite tiles

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, A A; Chaudhuri, P; Khirwadkar, S; Reddy, D Chenna; Saxena, Y C [Institute for Plasma Research, Bhat, Gandhinagar - 382 428 (India); Chauhan, N; Raole, P M [Facilitation Center for Industrial Plasma Technologies, IPR, Gandhinagar (India)], E-mail: arun@ipr.res.in

    2008-05-01

    Steady-state Super-conducting Tokamak-1 (SST-1) is a medium size tokamak with major radius of 1.1 m and minor radius of 0.20 m. It is designed for plasma discharge duration of 1000 seconds to obtain fully steady-state plasma operation. Plasma Facing Components (PFC), consisting of divertors, passive stabilizers, baffles and poloidal limiters are also designed to be UHV compatible for steady state operation. All PFC are made up of graphite tiles mechanically attached to the copper alloy substrate. Graphite is one of the preferred first wall armour material in present day tokamaks. High thermal shock resistance and low atomic number of carbon are the most important properties of graphite for this application. High temperature vacuum baking of graphite tiles is the standard process to remove the impurities. Residual Gas Analyzer (RGA) has been used for qualitative and quantitative measurements of released gases from graphite tiles during baking. Surface Analysis of graphite tiles has also been done before and after baking. This paper describes the residual gas analysis during baking and surface analysis of graphite tiles.

  6. Trace analysis of chloramphenicol residues in eggs, milk, and meat: comparison of gas chromatography radioimmunoassay

    International Nuclear Information System (INIS)

    Arnold, D.; Somgyi, A.

    1985-01-01

    A radioimmunological assay (RIA) to detect chloramphenicol (CAP) residues in eggs, milk, and meat is described. For tissues and other edible products of chloramphenicol-treated animals (chickens, cows, and pigs), the limit of detection is about 200 ng/kg. Residue levels above 1 μg/kg can easily be quantitated. When highly specific antisera produced in sheep were used, cross-reactivity was insignificant except for metabolites deviating from the parent compound in the acyl side chain only. Thiamphenicol fails to bind to the antisera; hence, it does not interfere with the assay. In the procedure described, the role of cleanup is merely to remove lipids. Thus, skim milk can be analyzed following appropriate dilution without cleanup. The results obtained by RIA were confirmed by gas chromatography with electron capture detection. The new RIA allows rapid, sensitive, and specific screening of large numbers of samples

  7. Evaluation of gas chromatography – electron ionization – full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mol, Hans G.J., E-mail: hans.mol@wur.nl; Tienstra, Marc; Zomer, Paul

    2016-09-07

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS based residue analysis, including the resolving power (15,000 to 120,000 FWHM at m/z 200), scan rate, dynamic range, selectivity, sensitivity, analyte identification, and utility of existing EI-libraries, are assessed and discussed in detail. The optimum acquisition conditions in full scan mode (m/z 50–500) were a resolving power of 60,000 and an automatic-gain-control target value of 3E6. These conditions provided (i) an optimum mass accuracy: within 2 ppm over a wide concentration range, with/without matrix, enabling the use of ±5 ppm mass extraction windows (ii) adequate scan speed: minimum 12 scans/peak, (iii) an intra-scan dynamic range sufficient to achieve LOD/LOQs ≤0.5 pg in fruit/vegetable matrices (corresponding to ≤0.5 μg kg{sup −1}) for most pesticides. EI-Orbitrap spectra were consistent over a very wide concentration range (5 orders) with good match values against NIST (EI-quadrupole) spectra. The applicability for quantitative residue analysis was verified by validation of 54 pesticides in three matrices (tomato, leek, orange) at 10 and 50 μg/kg. The method involved a QuEChERS-based extraction with a solvent switch into iso-octane, and 1 μL hot splitless injection into the GC-HRMS system. A recovery between 70 and 120% and a repeatability RSD <10% was obtained in most cases. Linearity was demonstrated for the range ≤5–250 μg kg{sup −1}. The pesticides could be identified according to the applicable EU criteria for GC-HRMS (SANTE/11945/2015). GC-EI-full scan Orbitrap HRMS was found to be highly suited for quantitative pesticide residue analysis. The potential of qualitative screening to extend the scope makes it an attractive

  8. Evaluation of gas chromatography – electron ionization – full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis

    International Nuclear Information System (INIS)

    Mol, Hans G.J.; Tienstra, Marc; Zomer, Paul

    2016-01-01

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS based residue analysis, including the resolving power (15,000 to 120,000 FWHM at m/z 200), scan rate, dynamic range, selectivity, sensitivity, analyte identification, and utility of existing EI-libraries, are assessed and discussed in detail. The optimum acquisition conditions in full scan mode (m/z 50–500) were a resolving power of 60,000 and an automatic-gain-control target value of 3E6. These conditions provided (i) an optimum mass accuracy: within 2 ppm over a wide concentration range, with/without matrix, enabling the use of ±5 ppm mass extraction windows (ii) adequate scan speed: minimum 12 scans/peak, (iii) an intra-scan dynamic range sufficient to achieve LOD/LOQs ≤0.5 pg in fruit/vegetable matrices (corresponding to ≤0.5 μg kg"−"1) for most pesticides. EI-Orbitrap spectra were consistent over a very wide concentration range (5 orders) with good match values against NIST (EI-quadrupole) spectra. The applicability for quantitative residue analysis was verified by validation of 54 pesticides in three matrices (tomato, leek, orange) at 10 and 50 μg/kg. The method involved a QuEChERS-based extraction with a solvent switch into iso-octane, and 1 μL hot splitless injection into the GC-HRMS system. A recovery between 70 and 120% and a repeatability RSD <10% was obtained in most cases. Linearity was demonstrated for the range ≤5–250 μg kg"−"1. The pesticides could be identified according to the applicable EU criteria for GC-HRMS (SANTE/11945/2015). GC-EI-full scan Orbitrap HRMS was found to be highly suited for quantitative pesticide residue analysis. The potential of qualitative screening to extend the scope makes it an attractive alternative to

  9. Gas-Phase Hydrogen-Deuterium Exchange Labeling of Select Peptide Ion Conformer Types: a Per-Residue Kinetics Analysis.

    Science.gov (United States)

    Khakinejad, Mahdiar; Kondalaji, Samaneh Ghassabi; Tafreshian, Amirmahdi; Valentine, Stephen J

    2015-07-01

    The per-residue, gas-phase hydrogen deuterium exchange (HDX) kinetics for individual amino acid residues on selected ion conformer types of the model peptide KKDDDDDIIKIIK have been examined using ion mobility spectrometry (IMS) and HDX-tandem mass spectrometry (MS/MS) techniques. The [M + 4H](4+) ions exhibit two major conformer types with collision cross sections of 418 Å(2) and 446 Å(2); the [M + 3H](3+) ions also yield two different conformer types having collision cross sections of 340 Å(2) and 367 Å(2). Kinetics plots of HDX for individual amino acid residues reveal fast- and slow-exchanging hydrogens. The contributions of each amino acid residue to the overall conformer type rate constant have been estimated. For this peptide, N- and C-terminal K residues exhibit the greatest contributions for all ion conformer types. Interior D and I residues show decreased contributions. Several charge state trends are observed. On average, the D residues of the [M + 3H](3+) ions show faster HDX rate contributions compared with [M + 4H](4+) ions. In contrast the interior I8 and I9 residues show increased accessibility to exchange for the more elongated [M + 4H](4+) ion conformer type. The contribution of each residue to the overall uptake rate showed a good correlation with a residue hydrogen accessibility score model calculated using a distance from charge site and initial incorporation site for nominal structures obtained from molecular dynamic simulations (MDS).

  10. Evaluation of the plasma hydrogen isotope content by residual gas analysis at JET and AUG

    Science.gov (United States)

    Drenik, A.; Alegre, D.; Brezinsek, S.; De Castro, A.; Kruezi, U.; Oberkofler, M.; Panjan, M.; Primc, G.; Reichbauer, T.; Resnik, M.; Rohde, V.; Seibt, M.; Schneider, P. A.; Wauters, T.; Zaplotnik, R.; ASDEX-Upgrade, the; EUROfusion MST1 Teams; contributors, JET

    2017-12-01

    The isotope content of the plasma reflects on the dynamics of isotope changeover experiments, efficiency of wall conditioning and the performance of a fusion device in the active phase of operation. The assessment of the isotope ratio of hydrogen and methane molecules is used as a novel method of assessing the plasma isotope ratios at JET and ASDEX-Upgrade (AUG). The isotope ratios of both molecules in general shows similar trends as the isotope ratio detected by other diagnostics. At JET, the absolute values of RGA signals are in relatively good agreement with each other and with spectroscopy data, while at AUG the deviation from neutral particle analyser data are larger, and the results show a consistent spatial distribution of the isotope ratio. It is further shown that the isotope ratio of the hydrogen molecule can be used to study the degree of dissociation of the injected gas during changeover experiments.

  11. Residual gas analysis of a cryostat vacuum chamber during the cool down of SST - 1 superconducting magnet field coil

    International Nuclear Information System (INIS)

    Semwal, P.; Joshi, K.S.; Thankey, P.L.; Pathan, F.S.; Raval, D.C.; Patel, R.J.; Pathak, H.A.

    2005-01-01

    One of the most important feature of Steady state Superconducting Tokamak -1 (SST-l) is the Nb-Ti superconducting magnet field coils. The coils will be kept in a high vacuum chamber (Cryostat) and liquid Helium will be flown through it to cool it down to its critical temperature of 4.5K. The coil along with its hydraulics has four types of joints (1) Stainless Steel (S.S.) to Copper (Cu) weld joints (2) S. S. to S. S. weld joints (3) Cu to Cu brazed joints and (4) G-10 to S. S. joints with Sti-cast as the binding material. The joints were leak tested with a Helium mass spectrometer leak detector in vacuum as well as in sniffer mode. However during the cool-down of the coil, these joints may develop leaks. This would deteriorate the vacuum inside the cryostat and coil cool-down would subsequently become more difficult. To study the effect of cooling on the vacuum condition of the Cryostat, a dummy Cryostat chamber was fabricated and a toroidal Field (TF) magnet was kept inside this chamber and cooled down to 4.5 K.A residual gas analyzer (RGA) was connected to the Cryostat chamber to study the behaviour of major gases inside this chamber with temperature. An analysis of the RGA data acquired during the coo-down has been presented in this chamber. (author)

  12. Trace analysis of multi-class pesticide residues in Chinese medicinal health wines using gas chromatography with electron capture detection

    Science.gov (United States)

    Kong, Wei-Jun; Liu, Qiu-Tao; Kong, Dan-Dan; Liu, Qian-Zhen; Ma, Xin-Ping; Yang, Mei-Hua

    2016-02-01

    A method is described for multi-residue, high-throughput determination of trace levels of 22 organochlorine pesticides (OCPs) and 5 pyrethroid pesticides (PYPs) in Chinese medicinal (CM) health wines using a QuEChERS (quick, easy, cheap, effective, rugged, and safe) based extraction method and gas chromatography-electron capture detection (GC-ECD). Several parameters were optimized to improve preparation and separation time while still maintaining high sensitivity. Validation tests of spiked samples showed good linearities for 27 pesticides (R = 0.9909-0.9996) over wide concentration ranges. Limits of detection (LODs) and quantification (LOQs) were measured at ng/L levels, 0.06-2 ng/L and 0.2-6 ng/L for OCPs and 0.02-3 ng/L and 0.06-7 ng/L for PYPs, respectively. Inter- and intra-day precision tests showed variations of 0.65-9.89% for OCPs and 0.98-13.99% for PYPs, respectively. Average recoveries were in the range of 47.74-120.31%, with relative standard deviations below 20%. The developed method was then applied to analyze 80 CM wine samples. Beta-BHC (Benzene hexachloride) was the most frequently detected pesticide at concentration levels of 5.67-31.55 mg/L, followed by delta-BHC, trans-chlordane, gamma-BHC, and alpha-BHC. The validated method is simple and economical, with adequate sensitivity for trace levels of multi-class pesticides. It could be adopted by laboratories for this and other types of complex matrices analysis.

  13. Liquid paraffin as new dilution medium for the analysis of high boiling point residual solvents with static headspace-gas chromatography.

    Science.gov (United States)

    D'Autry, Ward; Zheng, Chao; Bugalama, John; Wolfs, Kris; Hoogmartens, Jos; Adams, Erwin; Wang, Bochu; Van Schepdael, Ann

    2011-07-15

    Residual solvents are volatile organic compounds which can be present in pharmaceutical substances. A generic static headspace-gas chromatography analysis method for the identification and control of residual solvents is described in the European Pharmacopoeia. Although this method is proved to be suitable for the majority of samples and residual solvents, the method may lack sensitivity for high boiling point residual solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide and benzyl alcohol. In this study, liquid paraffin was investigated as new dilution medium for the analysis of these residual solvents. The headspace-gas chromatography method was developed and optimized taking the official Pharmacopoeia method as a starting point. The optimized method was validated according to ICH criteria. It was found that the detection limits were below 1μg/vial for each compound, indicating a drastically increased sensitivity compared to the Pharmacopoeia method, which failed to detect the compounds at their respective limit concentrations. Linearity was evaluated based on the R(2) values, which were above 0.997 for all compounds, and inspection of residual plots. Instrument and method precision were examined by calculating the relative standard deviations (RSD) of repeated analyses within the linearity and accuracy experiments, respectively. It was found that all RSD values were below 10%. Accuracy was checked by a recovery experiment at three different levels. Mean recovery values were all in the range 95-105%. Finally, the optimized method was applied to residual DMSO analysis in four different Kollicoat(®) sample batches. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Numerical calculation and analysis of natural convection removal of the spent fuel residual heat of 10 MW high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Wang Jinhua; Huang Yifan; Wu Bin

    2013-01-01

    The spent fuel of 10 MW High Temperature Gas Cooled Reactor (HTR-10) could be stored in the shielded tank, and the tank is stored in the concrete shielded canister in spent fuel storage room, the residual heat of the spent fuel could be removed by the air. The ability of residual heat removal is analyzed in the paper, and the temperature field is numerically calculated through FEA program ANSYS, the analysis and the calculation are used to validate the safety of the spent fuel and the tank, the ultimate temperature of the spent fuel and the tank should below the safety limit. The calculation shows that the maximum temperature locates in the middle of the fuel pebble bed in the spent fuel tank, and the temperature decreases gradually with radial distance, the temperature in the tank body is evenly distributed, and the temperature in the concrete shielded canister decreases gradually with radial distance. It is feasible to remove the residual heat of the spent fuel storage tank by natural ventilation, in natural ventilation condition, the temperature of the spent fuel and the tank is lower than the temperature limit, which provides theoretical evidence for the choice of the residual heat removal method. (authors)

  15. Profile Monitors Based on Residual Gas Interaction

    CERN Document Server

    Forck, P; Giacomini, T; Peters, A

    2005-01-01

    The precise determination of transverse beam profiles at high current hadron accelerators has to be performed non-interceptingly. Two methods will be discussed based on the excitation of the residual gas molecules by the beam particles: Firstly, by beam induced fluorescence (BIF) light is emitted from the residual gas molecules and is observed with an image intensified CCD camera. At most laboratories N2 gas is inserted, which has a large cross section for emission in the blue wave length region. Secondly, a larger signal strength is achieved by detecting the ionization products in an Ionization Profile Monitor (IPM). By applying an electric field all ionization products are accelerated toward a spatial resolving Micro-Channel Plate. The signal read-out can either be performed by observing the light from a phosphor screen behind the MCP or electronically by a wire array. Methods to achieve a high spatial resolution and a fast turn-by-turn readout capability are discussed. Even though various approaches at dif...

  16. Environmental performance, mechanical and microstructure analysis of concrete containing oil-based drilling cuttings pyrolysis residues of shale gas.

    Science.gov (United States)

    Wang, Chao-Qiang; Lin, Xiao-Yan; He, Ming; Wang, Dan; Zhang, Si-Lan

    2017-09-15

    The overall objective of this research project is to investigate the feasibility of incorporating oil-based drilling cuttings pyrolysis residues (ODPR) and fly ash serve as replacements for fine aggregates and cementitious materials in concrete. Mechanical and physical properties, detailed environmental performances, and microstructure analysis were carried out. Meanwhile, the early hydration process and hydrated products of ODPR concrete were analyzed with X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The results indicated that ODPR could not be categorize into hazardous wastes. ODPR had specific pozzolanic characteristic and the use of ODPR had certain influence on slump and compressive strength of concrete. The best workability and optimal compressive strength were achieved with the help of 35% ODPR. Environmental performance tests came to conclusion that ODPR as recycled aggregates and admixture for the preparation of concrete, from the technique perspective, were the substance of mere environmental contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Proposed systematic methodology for analysis of Pb-210 radioactivity in residues produced in Brazilian natural gas pipes

    International Nuclear Information System (INIS)

    Ferreira, Aloisio Cordilha

    2003-11-01

    Since the 80's, the potential radiological hazards due to the handling of solid wastes contaminated with Rn-222 long-lived progeny - Pb-210 in special - produced in gas pipes and removed by pig operations have been subject of growing concern abroad our country. Nevertheless, little or no attention has been paid to this matter in the Brazilian plants up to now, being these hazards frequently underestimated or even ignored. The main purpose of this work was to propose a systematic methodology for analysis of Pb-210 radioactivity in black powder samples from some Brazilian plants, through the evaluation of direct Pb-210 gamma spectrometry and Bi-210 beta counting technical viabilities. In both cases, one in five samples of black powder analysed showed relevant activity (above 1Bq/kg) of Pb-210, being these results probably related to particular features of each specific plant (production levels, reservoir geochemical profile, etc.), in such a way that a single pattern is not observed. For the proposed methodology, gamma spectrometry proved to be the most reliable technique, showing a 3.5% standard deviation, and, for a 95% confidence level, overall fitness in the range of Pb-210 concentration of activity presented in the standard sample reference sheet, provided by IAEA for intercomparison purposes. In the Brazilian scene, however, the availability of statistically supported evidences is insufficient to allow the potential radiological hazard due to the management of black powder to be discarded. Thus, further research efforts are recommended in order to detect the eventually critical regions or plants where gas exploration, production and processing practices will require a regular program of radiological surveillance, in the near future. (author)

  18. Application of acetone acetals as water scavengers and derivatization agents prior to the gas chromatographic analysis of polar residual solvents in aqueous samples.

    Science.gov (United States)

    van Boxtel, Niels; Wolfs, Kris; Van Schepdael, Ann; Adams, Erwin

    2015-12-18

    The sensitivity of gas chromatography (GC) combined with the full evaporation technique (FET) for the analysis of aqueous samples is limited due to the maximum tolerable sample volume in a headspace vial. Using an acetone acetal as water scavenger prior to FET-GC analysis proved to be a useful and versatile tool for the analysis of high boiling analytes in aqueous samples. 2,2-Dimethoxypropane (DMP) was used in this case resulting in methanol and acetone as reaction products with water. These solvents are relatively volatile and were easily removed by evaporation enabling sample enrichment leading to 10-fold improvement in sensitivity compared to the standard 10μL FET sample volumes for a selection of typical high boiling polar residual solvents in water. This could be improved even further if more sample is used. The method was applied for the determination of residual NMP in an aqueous solution of a cefotaxime analogue and proved to be considerably better than conventional static headspace (sHS) and the standard FET approach. The methodology was also applied to determine trace amounts of ethylene glycol (EG) in aqueous samples like contact lens fluids, where scavenging of the water would avoid laborious extraction prior to derivatization. During this experiment it was revealed that DMP reacts quantitatively with EG to form 2,2-dimethyl-1,3-dioxolane (2,2-DD) under the proposed reaction conditions. The relatively high volatility (bp 93°C) of 2,2-DD makes it possible to perform analysis of EG using the sHS methodology making additional derivatization reactions superfluous. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Variability of matrix effects in liquid and gas chromatography - mass spectrometry analysis of pesticide residues after QuEChERS sample preparation of different food crops

    Science.gov (United States)

    Gas and liquid chromatography (GC and LC) coupled to sophisticated mass spectrometry (MS) instruments are among the most powerful analytical tools currently available to monitor pesticide residues in food, among other applications. However, both GC-MS and LC-MS are susceptible to matrix effects whi...

  20. Determination of gas residues in uranium dioxide pellets

    International Nuclear Information System (INIS)

    Riella, H.G.

    1978-01-01

    The measurement of low amounts of residual gases, excluding water, in ceramic grade uranium dioxide pellets, using high temperature vacuum extraction technique, is dealt with. The high temperature extraction gas analysis apparatus was designed and assembled for sequential analysis of up to eight uranium dioxide pellets by run. The system consists of three major units, namely outgassing unit, transfer unit and analytical unit. The whole system is evacuated to a final pressure of less then 10 -5 torr. A weighed pellet is transfered into the outgassing unit for subsequent dropping into a Platinum-Rhodium crucible which is heated inductively up to 1600 0 C during 30 minutes. The released gases are imediately transfered from the outgassing to analytical unit passing through a cold trap at -95 0 C to remove water vapor. The gases are transfered to previously calibrated volumetric bulb where the total pressure and temperature are determined. An estimate of the gas content in the pellets at STP condition is obtained from the measured volume, pressure and temperature of the gas mixture by applying ideal gases equation. Analysis to two lots (fourteen samples) of uranium dioxide pellets by the method described here indicated a mean gas content of 0,060cm 3 /g UO 2 . The lower limit of this technique is 0,03cm 3 /g UO 2 (STP). The time required for the analysis of eight pellets is about 9 hours [pt

  1. Agricultural residues as fuel for producer gas generation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeglund, C

    1981-01-01

    This paper reports on results from a series of tests with four different types of agricultural residues as fuel for producer gas generation. The fuels are coconut shells, coconut husks, pelletized wheat-straw and pressed sugar cane. The tests were made with a 73 Hp (50 kW) agricultural tractor diesel engine equipped with a standard gasifier developed for wood chips in Sweden, and run on a testbed at the Swedish National Machinery Testing Institute. The engine was operated on approximately 10% diesel oil and 90% producer gas. The gas composition, its calorific value and temperature, the pressure drop and the engine power were monitored. Detailed elementary analysis of the fuel and gas were carried out. Observations were also made regarding the important aspects of bridging and slagging in the gasifier. The tests confirmed that coconut shells make an excellent fuel for producer gas generation. After 8 hours of running no problems with slags and bridging were experienced. Coconut husks showed no bridging but some slag formation. The gasifier operated satisfactorily for this fuel. Pelletized wheat straw and pressed sugar cane appeared unsuitable as fuel in the unmodified test gasifier (Type F 300) due to slag formation. It is important to note, however, that the present test results are not optimal for any of the fuels used, the gasifier being designed for wood-chips and not for the test-fuels used. Tests using approximately modified gasifiers are planned for the future.

  2. Computational fluid dynamics (CFD) analysis of the combustion process of a leather residuals gasification fuel gas: influence of fuel moisture content

    Energy Technology Data Exchange (ETDEWEB)

    Antonietti, Anderson Jose; Beskow, Arthur Bortolin; Silva, Cristiano Vitorino da [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Erechim, RS (Brazil)], E-mails: arthur@uricer.edu.br, mlsperb@unisinos.br; Indrusiak, Maria Luiza Sperb [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil)], E-mail: cristiano@uricer.edu.br

    2010-07-01

    This work presents a numerical study of the combustion process of leather residuals gasification gas, aiming the improvement of the process efficiency, considering different concentrations of water on the gas. The heating produced in this combustion process can be used to generation of thermal and/or electrical energy, for use at the leather industrial plant. However, the direct burning of this leather-residual-gas into the chambers is not straightforward. The alternative in development consists in processing this leather residuals by gasification or pyrolysis, separating the volatiles and products of incomplete combustion, for after use as fuel in a boiler. At these processes, different quantities of water can be used, resulting at different levels of moisture content in this fuel gas. This humidity can affect significantly the burning of this fuel, producing unburnt gases, as the carbon monoxide, or toxic gases as NOx, which must have their production minimized on the process, with the purpose of reducing the emission of pollutants to the atmosphere. Other environment-harmful-gases, remaining of the chemical treatment employed at leather manufacture, as cyanide, and hydrocarbons as toluene, must burn too, and the moisture content has influence on it. At this way, to increase understanding of the influence of moisture in the combustion process, it was made a numerical investigation study of reacting flow in the furnace, evaluating the temperature field, the chemical species concentration fields, flow mechanics and heat transfer at the process. The commercial CFD code CFX Ansys Inc. was used. Considering different moisture contents in the fuel used on the combustion process, with this study was possible to achieve the most efficient burning operation parameters, with improvement of combustion efficiency, and reduction of environmental harmful gases emissions. It was verified that the different moisture contents in the fuel gas demand different operation conditions

  3. [High throuput analysis of organophosphorus pesticide residues and their metabolites in animal original foods by dual gas chromatography-dual pulse flame photometric detection].

    Science.gov (United States)

    Yang, Lixin; Li, Heli; Miao, Hong; Zeng, Fangang; Li, Ruifeng; Chen, Huijing; Zhao, Yunfeng; Wu, Yongning

    2011-10-01

    A method was established for the quantitative determination of 54 organophosphorus pesticide residues and their metabolites in foods of animal origin by dual gas chromatography-dual pulse flame photometric detection. Homogenized samples were extracted with acetone and methylene chloride, and cleaned-up by gel permeation chromatography (GPC). The response of each analyte showed a good linearity with a correlation coefficient not less than 0. 99. The recovery experiments were performed by a blank sample spiked at low, medium and high fortification levels. The recoveries for beef, mutton, pork, chicken were in the range of 50. 5% -128. 1% with the relative standard deviations (n = 6) of 1. 1% -25. 5%, which demonstrated the good precision and accuracy of the present method. The limits of detection for the analytes were in the range of 0. 001 -0. 170 mg/kg, and the limits of quantification were in the range of 0. 002 -0. 455 mg/kg. Animal food samples collected from markets such as meat, liver and kidney were analyzed, and the residues of dichlorovos and disulfoton-sulfoxide were found in the some samples. The established method is sensitive and selective enough to detect organophosphorus pesticide residues in animal foods.

  4. Effect of residual gas on structural, electrical and mechanical properties of niobium films deposited by magnetron sputtering deposition

    Science.gov (United States)

    Wang, Lanruo; Zhong, Yuan; Li, Jinjin; Cao, Wenhui; Zhong, Qing; Wang, Xueshen; Li, Xu

    2018-04-01

    Magnetron sputtering is an important method in the superconducting thin films deposition. The residual gas inside the vacuum chamber will directly affect the quality of the superconducting films. In this paper, niobium films are deposited by magnetron sputtering under different chamber residual gas conditions. The influence of baking and sputtering process on residual gas are studied as well. Surface morphology, electrical and mechanical properties of the films are analysed. The residual gas analysis result before the sputtering process could be regarded as a reference condition to achieve high quality superconducting thin films.

  5. Residue management in the Bolivia-Brazil gas pipeline construction

    International Nuclear Information System (INIS)

    Freitas, Eduardo Lopes; Henrique, Paulo Roberto Pereira; Cantarino, Anderson Americo Alves

    2000-01-01

    The construction of the gas pipeline is a process sequential of assembly phases, where each one of those phases generates residues of the most varied types and amounts, being necessary the forecast of your generation in agreement with the activity that is being executed. During the accomplishment of the works they are generated a lot of times situations where are observed the inadequate disposition of the residues. Those practices, besides the environmental impact that they cause, it can cart in the future, the need of additional investments be proceeded in the recovery of the areas and removal of the residues. This work presents the Program of administration of Residues instituted during the construction of the pipeline Bolivia - Brazil, seeking, on a side to reduce to the minimum the generation of residues and of the other, moths handling guidelines and disposition, in way to minimize the environmental impacts caused by the same ones. (author)

  6. The emission of fluorine gas during incineration of fluoroborate residue

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yuheng, E-mail: fengyh@tongji.edu.cn [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); Jiang, Xuguang [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China); Chen, Dezhen [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China)

    2016-05-05

    Highlights: • Gaseous fluorine products were identified when combusting fluoroborate residue. • BF{sub 3} and SiF{sub 4} tend to be hydrolyzed into HF with the increase of temperature. • The emission of BF{sub 3} and SiF{sub 4} from the chamber could be negligible at 1100 °C. - Abstract: The emission behaviors of wastes from fluorine chemical industry during incineration have raised concerns because multiple fluorine products might danger human health. In this study, fluorine emission from a two-stage incineration system during the combustion of fluoroborate residue was examined. In a TG-FTIR analysis BF{sub 3}, SiF{sub 4} and HF were identified as the initial fluorine forms to be released, while fluorine gases of greenhouse effect such as CF{sub 4} and SF{sub 6} were not found. Below 700 °C, NaBF{sub 4} in the sample decomposed to generate BF{sub 3}. Then part of BF{sub 3} reacted with SiO{sub 2} in the system to form SiF{sub 4} or hydrolyzed to HF. At higher temperatures, the NaF left in the sample was gradually hydrolyzed to form HF. A lab-scale two-stage tube furnace is established to simulate the typical two-stage combustion chamber in China. Experimental tests proved that HF was the only fluorine gas in the flue gas, and emissions of BF{sub 3} and SiF{sub 4} can be negligible. Thermodynamic equilibrium model predicted that all SiF{sub 4} would be hydrolyzed at 1100 °C in the secondary-chamber, which agreed well with the experimental results.

  7. Fuel gas production from animal and agricultural residues and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Wise, D. L; Wentworth, R. L

    1978-05-30

    Progress was reported by all contractors. Topics presented include: solid waste to methane gas; pipeline fuel gas from an environmental cattle feed lot; heat treatment of organics for increasing anaerobic biodegradability; promoting faster anaerobic digestion; permselective membrane control of algae and wood digesters for increased production and chemicals recovery; anaerobic fermentation of agricultural residues; pilot plant demonstration of an anaerobic, fixed-film bioreactor for wastewater treatment; enhancement of methane production in the anaerobic diegestion of sewage; evaluation of agitation concepts for biogasification of sewage sludge; operation of a 50,000 gallon anaerobic digester; biological conversion of biomass to methane; dirt feedlot residue experiments; anaerobic fermentation of livestock and crop residues; current research on methanogenesis in Europe; and summary of EPA programs in digestion technology. (DC)

  8. CO2 storage in depleted gas reservoirs: A study on the effect of residual gas saturation

    Directory of Open Access Journals (Sweden)

    Arshad Raza

    2018-03-01

    Full Text Available Depleted gas reservoirs are recognized as the most promising candidate for carbon dioxide storage. Primary gas production followed by injection of carbon dioxide after depletion is the strategy adopted for secondary gas recovery and storage practices. This strategy, however, depends on the injection strategy, reservoir characteristics and operational parameters. There have been many studies to-date discussing critical factors influencing the storage performance in depleted gas reservoirs while little attention was given to the effect of residual gas. In this paper, an attempt was made to highlight the importance of residual gas on the capacity, injectivity, reservoir pressurization, and trapping mechanisms of storage sites through the use of numerical simulation. The results obtained indicated that the storage performance is proportionally linked to the amount of residual gas in the medium and reservoirs with low residual fluids are a better choice for storage purposes. Therefore, it would be wise to perform the secondary recovery before storage in order to have the least amount of residual gas in the medium. Although the results of this study are useful to screen depleted gas reservoirs for the storage purpose, more studies are required to confirm the finding presented in this paper.

  9. Accumulative effect of food residues on intestinal gas production.

    Science.gov (United States)

    Mego, M; Accarino, A; Malagelada, J-R; Guarner, F; Azpiroz, F

    2015-11-01

    As mean transit time in the colon is longer than the interval between meals, several consecutive meal loads accumulate, and contribute to colonic biomass. Our aim was to determine the summation effect of fermentable food residues on intestinal gas production. In eight healthy subjects, the volume of endogenous intestinal gas produced in the intestine over a 4-h period was measured by means of a wash-out technique, using an exogenous gas infusion into the jejunum (24 mL/min) and collection of the effluent via a rectal Foley catheter. The exogenous gas infused was labeled (5% SF6 ) to calculate the proportion of endogenous intestinal gas evacuated. In each subject, four experiments were performed ≥1 week apart combining a 1-day high- or low-flatulogenic diet with a test meal or fast. Basal conditions: on the low-flatulogenic diet, intestinal gas production during fasting over the 4-h study period was 609 ± 63 mL. Effect of diet: during fasting, intestinal gas production on the high-flatulogenic diet was 370 ± 146 mL greater than on the low-flatulogenic diet (p = 0.040). Effect of test meal: on the low-flatulogenic diet, intestinal gas production after the test meal was 681 ± 114 mL greater than during fasting (p = 0.001); a similar effect was observed on the high-flatulogenic diet (599 ± 174 mL more intestinal gas production after the test meal than during fasting; p = 0.021). Our data demonstrate temporal summation effects of food residues on intestinal gas production. Hence, intestinal gas production depends on pre-existing and on recent colonic loads of fermentable foodstuffs. © 2015 John Wiley & Sons Ltd.

  10. Residual stresses evaluation in a gas-pipeline crossing

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Maria Cindra [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Almeida, Manoel Messias [COMPAGAS, Curitiba, PR (Brazil); Rebello, Joao Marcos Alcoforado [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Souza Filho, Byron Goncalves de [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The X-rays diffraction technique is a well established and effectiveness method in the determination of the residual and applied stresses in fine grained crystalline materials. It allows to characterize and to quantify the magnitude and direction of the existing surface stresses in the studied point of the material. The objective of this work is the evaluation of the surface stresses in a 10 in diameter Natural Gas Distribution Pipeline manufactured from API 5 L Gr B steel of COMPAGAS company, in a crossing with a Natural Gas Transportation Pipeline, in Araucaria-PR. This kind of evaluation is important to establish weather you have to perform a repositioning of one of the pipeline or not. The measurements had been made in two transversal sections of the pipe, the one upstream (170 mm of the external wall of the pipeline) and another one downstream (840 mm of the external wall of the pipeline). Each transversal section measurements where carried out in 3 points: 9 hours, 12 hours and 3 hours. In each measured point of the pipe surface, the longitudinal and transversal stresses had been measured. The magnitude of the surface residual stresses in the pipe varied of +180 MPa at the -210 MPa. The residual stress state on the surface of the points 12 hours region is characterized by tensile stresses and by compressive stresses in the points of 3 and 9 hours region. The surface residual stresses in gas-pipeline have been measured using X-ray diffraction method, by double exposure technique, using a portable apparatus, with Cr-K-alpha radiation. (author)

  11. Tank 12H residuals sample analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shine, E. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Diprete, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coleman, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-06-11

    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to provide sample preparation and analysis of the Tank 12H final characterization samples to determine the residual tank inventory prior to grouting. Eleven Tank 12H floor and mound residual material samples and three cooling coil scrape samples were collected and delivered to SRNL between May and August of 2014.

  12. Development of Residual Gas Profile Monitors at GSI

    International Nuclear Information System (INIS)

    Giacomini, T.; Forck, P.; Barabin, S.; Liakin, D.; Skachkov, V.

    2004-01-01

    Beam profile measurements at modern ion synchrotrons and storage rings require high timing performances on a turn-by-turn basis. High spatial resolutions are essential for cold beams and beamwidth measurings. The currently used RGM supported very interesting measurements and applications. Due to the readout technology the spatial and time resolution is limited. To meet the expanded demands a more comprehensive device is under development. It will be an all-purpose residual gas monitor to cover the wide range of beam currents and transversal particle distributions. Due to the fast profile detection it will operate on primary electrons after residual gas ionization. A magnetic field of 100 mT binds them to the ionization point inside 0.1-mm orbits. The high-resolution mode will be read out by a digital CCD camera with an upstream MCP-phosphor screen assembly. It is planned to read out the fast turn-by-turn mode by an array of 100 photodiodes with a resolution of 1 mm. Every photodiode is equipped with an amplifier-digitizer device providing a frame rate of ∼ 10 MSamples/s

  13. Development of Residual Gas Profile Monitors at GSI

    Science.gov (United States)

    Giacomini, T.; Barabin, S.; Forck, P.; Liakin, D.; Skachkov, V.

    2004-11-01

    Beam profile measurements at modern ion synchrotrons and storage rings require high timing performances on a turn-by-turn basis. High spatial resolutions are essential for cold beams and beamwidth measurings. The currently used RGM supported very interesting measurements and applications. Due to the readout technology the spatial and time resolution is limited. To meet the expanded demands a more comprehensive device is under development. It will be an all-purpose residual gas monitor to cover the wide range of beam currents and transversal particle distributions. Due to the fast profile detection it will operate on primary electrons after residual gas ionization. A magnetic field of 100 mT binds them to the ionization point inside 0.1-mm orbits. The high-resolution mode will be read out by a digital CCD camera with an upstream MCP-phosphor screen assembly. It is planned to read out the fast turn-by-turn mode by an array of 100 photodiodes with a resolution of 1 mm. Every photodiode is equipped with an amplifier-digitizer device providing a frame rate of ˜ 10 MSamples/s.

  14. Residual stress concerns in containment analysis

    International Nuclear Information System (INIS)

    Costantini, F.; Kulak, R. F.; Pfeiffer, P. A.

    1997-01-01

    The manufacturing of steel containment vessels starts with the forming of flat plates into curved plates. A steel containment structure is made by welding individual plates together to form the sections that make up the complex shaped vessels. The metal forming and welding process leaves residual stresses in the vessel walls. Generally, the effect of metal forming residual stresses can be reduced or virtually eliminated by thermally stress relieving the vesseL In large containment vessels this may not be practical and thus the residual stresses due to manufacturing may become important. The residual stresses could possibly tiect the response of the vessel to internal pressurization. When the level of residual stresses is significant it will affect the vessel's response, for instance the yielding pressure and possibly the failure pressure. The paper will address the effect of metal forming residual stresses on the response of a generic pressure vessel to internal pressurization. A scoping analysis investigated the effect of residual forming stresses on the response of an internally pressurized vessel. A simple model was developed to gain understanding of the mechanics of the problem. Residual stresses due to the welding process were not considered in this investigation

  15. Self-activation of biochar from furfural residues by recycled pyrolysis gas.

    Science.gov (United States)

    Yin, Yulei; Gao, Yuan; Li, Aimin

    2018-04-17

    Biochar samples with controllable specific surface area and mesopore ratio were self-activated from furfural residues by recycled pyrolysis gas. The objective of this study was to develop a new cyclic utilization method for the gas produced by pyrolysis. The influences of preparation parameters on the resulting biochar were studied by varying the pyrolysis-gas flow rate, activation time and temperature. Structural characterization of the produced biochar was performed by analysis of nitrogen adsorption isotherms at 77 K and scanning electron microscope (SEM). The pyrolysis gas compositions before and after activation were determined by a gas chromatograph. The results indicated that the surface area of the biochar was increased from 167 m 2 /g to 567 m 2 /g, the total pore volume increased from 0.121 cm 3 /g to 0.380 cm 3 /g, and the ratio of the mesopore pore volume to the total pore volume increased 17-39.7%. The CO volume fraction of the pyrolysis gas changed from 34.66 to 62.29% and the CO 2 volume fraction decreased from 48.26% to 12.17% under different conditions of pyrolysis-gas flow rate, activation time and temperature. The calorific values of pyrolysis gas changed from 8.82 J/cm 3 to 14.00 J/cm 3 , which were higher than those of conventional pyrolysis gases. The slower pyrolysis-gas flow rate and higher activation time increased the efficiency of the reaction between carbon and pyrolysis gas. These results demonstrated the feasibility of treatment of the furfural residues to produce microporous and mesoporous biochar. The pyrolysis gas that results from the activation process could be used as fuel. Overall, this new self-activation method meets the development requirements of cyclic economy and cleaner production. Copyright © 2018. Published by Elsevier Ltd.

  16. Residual stress analysis in thick uranium films

    International Nuclear Information System (INIS)

    Hodge, A.M.; Foreman, R.J.; Gallegos, G.F.

    2005-01-01

    Residual stress analysis was performed on thick, 1-25 μm, depleted uranium (DU) films deposited on an Al substrate by magnetron sputtering. Two distinct characterization techniques were used to measure substrate curvature before and after deposition. Stress evaluation was performed using the Benabdi/Roche equation, which is based on beam theory of a bi-layer material. The residual stress evolution was studied as a function of coating thickness and applied negative bias voltage (0, -200, -300 V). The stresses developed were always compressive; however, increasing the coating thickness and applying a bias voltage presented a trend towards more tensile stresses and thus an overall reduction of residual stresses

  17. Multi-residue analysis of legacy POPs and emerging organic contaminants in Singapore's coastal waters using gas chromatography-triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Hui; Bayen, Stéphane; Kelly, Barry C

    2015-08-01

    A gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) based method was developed for determination of 86 hydrophobic organic compounds in seawater. Solid-phase extraction (SPE) was employed for sequestration of target analytes in the dissolved phase. Ultrasound assisted extraction (UAE) and florisil chromatography were utilized for determination of concentrations in suspended sediments (particulate phase). The target compounds included multi-class hydrophobic contaminants with a wide range of physical-chemical properties. This list includes several polycyclic and nitro-aromatic musks, brominated and chlorinated flame retardants, methyl triclosan, chlorobenzenes, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Spiked MilliQ water and seawater samples were used to evaluate the method performance. Analyte recoveries were generally good, with the exception of some of the more volatile target analytes (chlorobenzenes and bromobenzenes). The method is very sensitive, with method detection limits typically in the low parts per quadrillion (ppq) range. Analysis of 51 field-collected seawater samples (dissolved and particulate-bound phases) from four distinct coastal sites around Singapore showed trace detection of several polychlorinated biphenyl congeners and other legacy POPs, as well as several current-use emerging organic contaminants (EOCs). Polycyclic and nitro-aromatic musks, bromobenzenes, dechlorane plus isomers (syn-DP, anti-DP) and methyl triclosan were frequently detected at appreciable levels (2-20,000pgL(-1)). The observed concentrations of the monitored contaminants in Singapore's marine environment were generally comparable to previously reported levels in other coastal marine systems. To our knowledge, these are the first measurements of these emerging contaminants of concern in Singapore or Southeast Asia. The developed method may prove beneficial for future environmental monitoring of hydrophobic organic contaminants

  18. Determination of organophosphorus pesticide residues in tomatoes by gas chromatography

    International Nuclear Information System (INIS)

    Souissi, Sihem

    2010-01-01

    Chloropyriphos and malathion are two organophosphorus pesticides from many others pesticides widely used by famers in agriculture .Because of their bad effect on human health, officials standards are set by the international organisations and communities to ensure safer food for consumer .In the same way, scientists over the world are working hard to develop new detection techniques responding to the international requirements. In this study, an ' IAEA-ethylacetate method ', an adaptation of the popular QuEChERS multi residue method, was optimized to analyse chloropyriphos and Malathion residues in tomatoes .Ethyl-Acetate was used as an extraction solvent the PSA was kept for the clean up procedure. GC-NPD is used for samples analysis .The method optimized is specifique, selective with a recovery averaged more than 70 pour cent. A complete validation of the method is necessary to be used for routine analysis.

  19. QA/QC in pesticide residue analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ambrus, A [Agrochemicals Unit, Agency' s Laboratories, Seibersdorf (Austria)

    2002-07-01

    This paper outlines problems related to pesticide residue analysis in a regulatory laboratory that are related to: availability of reference materials, as over 1000 pesticide active ingredients are currently in use and over 400 crops represent a large part of a healthy diet; analysis time; availability of samples in sufficient numbers; uncertainties of the procedures.

  20. QA/QC in pesticide residue analysis

    International Nuclear Information System (INIS)

    Ambrus, A.

    2002-01-01

    This paper outlines problems related to pesticide residue analysis in a regulatory laboratory that are related to: availability of reference materials, as over 1000 pesticide active ingredients are currently in use and over 400 crops represent a large part of a healthy diet; analysis time; availability of samples in sufficient numbers; uncertainties of the procedures

  1. Determination of Profenofos Pesticidal Residue in Lettuce (Lactuca sativa L. by Gas Chromatographic Method

    Directory of Open Access Journals (Sweden)

    Yohannes Alen

    2015-05-01

    Full Text Available The determination of profenofos pesticidal residue in the lettuce (Lactuca sativa L. by using gas chromatography using flame photometric detector (FPD had been investigated. The lettuce was collected from Padang Luar area, Agam distric, West Sumatera. Sample for determination of profenofos residue divided into three groups: unwashed (A, washed with water (B, and washed with detergent (C. Maceration with sonication was used for the extraction using ethylacetateas a solvent. The results showed that profenofos pesticide residue in sample A, B and C were 0.204, 0.080 and 0.061 ppm, respectively. These profenofos pesticidal residue are over than the Maximum Residue Limits (MRL that established by The Japan Food Chemical Research Foundation (0.05 ppm even though World Health Organization (WHO has not established Maximum Residue Limits (MRL profenofos on lettuce. Based on the statistical analysis one-way method (Anova using SPSS 20.0 showed that there was a significant concentrations difference between lettuce A from lettuce B and lettuce C with p < 0.05.

  2. Hanford gas dispersion analysis

    International Nuclear Information System (INIS)

    Fujita, R.K.; Travis, J.R.

    1994-01-01

    An analysis was performed to verify the design of a waste gas exhauster for use in support of rotary core sampling activities at the Westinghouse Hanford Waste Tank Farm. The exhauster was designed to remove waste gases from waste storage tanks during the rotary core drilling process of the solid materials in the tank. Some of the waste gases potentially are very hazardous and must be monitored during the exhauster's operation. If the toxic gas concentrations in specific areas near the exhauster exceed minimum Threshold Limit Values (TLVs), personnel must be excluded from the area. The exhauster stack height is of interest because an increase in stack height will alter the gas concentrations at the critical locations. The exhaust stack is currently ∼4.6 m (15 ft) high. An equipment operator will be located within a 6.1 m (20 ft) radius of the exhaust stack, and his/her head will be at an elevation 3.7 m (12 ft) above ground level (AGL). Therefore, the maximum exhaust gas concentrations at this location must be below the TLV for the toxic gases. Also, the gas concentrations must be within the TLV at a 61 m (200 ft) radius from the stack. If the calculated gas concentrations are above the TLV, where the operator is working below the stack at the 61 m (200 ft) radius location, the stack height may need to be increased

  3. Quantification of residual solvents in antibody drug conjugates using gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Medley, Colin D., E-mail: medley.colin@gene.com [Genentech Inc., Small Molecule Pharmaceutical Sciences, 1 DNA Way, South San Francisco, CA 94080 (United States); Kay, Jacob [Research Pharmaceutical Services, 520 Virginia Dr. Fort, Washington, PA (United States); Li, Yi; Gruenhagen, Jason; Yehl, Peter; Chetwyn, Nik P. [Genentech Inc., Small Molecule Pharmaceutical Sciences, 1 DNA Way, South San Francisco, CA 94080 (United States)

    2014-11-19

    Highlights: • Sensitive residual solvents detection in ADCs. • 125 ppm QL for common conjugation solvents. • Generic and validatable method. - Abstract: The detection and quantification of residual solvents present in clinical and commercial pharmaceutical products is necessary from both patient safety and regulatory perspectives. Head-space gas chromatography is routinely used for quantitation of residual solvents for small molecule APIs produced through synthetic processes; however residual solvent analysis is generally not needed for protein based pharmaceuticals produced through cultured cell lines where solvents are not introduced. In contrast, antibody drug conjugates and other protein conjugates where a drug or other molecule is covalently bound to a protein typically use solvents such as N,N-dimethylacetamide (DMA), N,N‑dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or propylene glycol (PG) to dissolve the hydrophobic small molecule drug for conjugation to the protein. The levels of the solvent remaining following the conjugation step are therefore important to patient safety as these parental drug products are introduced directly into the patients bloodstream. We have developed a rapid sample preparation followed by a gas chromatography separation for the detection and quantification of several solvents typically used in these conjugation reactions. This generic method has been validated and can be easily implemented for use in quality control testing for clinical or commercial bioconjugated products.

  4. Chloroxyanion residues in cantaloupe and tomatoes after chlorine dioxide gas sanitation

    Science.gov (United States)

    Chlorine dioxide gas is effective at cleansing fruits and vegetables of bacterial pathogens and(or) rot organisms, but few data are available on chemical residues remaining subsequent to chlorine gas treatment. Therefore, studies were conducted to quantify chlorate and perchlorate residues after tom...

  5. Proposed systematic methodology for analysis of Pb-210 radioactivity in residues produced in Brazilian natural gas pipes; Proposicao de um modelo analitico sistematico da atividade de Pb-210 em residuos gerados em linhas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Aloisio Cordilha

    2003-11-15

    Since the 80's, the potential radiological hazards due to the handling of solid wastes contaminated with Rn-222 long-lived progeny - Pb-210 in special - produced in gas pipes and removed by pig operations have been subject of growing concern abroad our country. Nevertheless, little or no attention has been paid to this matter in the Brazilian plants up to now, being these hazards frequently underestimated or even ignored. The main purpose of this work was to propose a systematic methodology for analysis of Pb-210 radioactivity in black powder samples from some Brazilian plants, through the evaluation of direct Pb-210 gamma spectrometry and Bi-210 beta counting technical viabilities. In both cases, one in five samples of black powder analysed showed relevant activity (above 1Bq/kg) of Pb-210, being these results probably related to particular features of each specific plant (production levels, reservoir geochemical profile, etc.), in such a way that a single pattern is not observed. For the proposed methodology, gamma spectrometry proved to be the most reliable technique, showing a 3.5% standard deviation, and, for a 95% confidence level, overall fitness in the range of Pb-210 concentration of activity presented in the standard sample reference sheet, provided by IAEA for intercomparison purposes. In the Brazilian scene, however, the availability of statistically supported evidences is insufficient to allow the potential radiological hazard due to the management of black powder to be discarded. Thus, further research efforts are recommended in order to detect the eventually critical regions or plants where gas exploration, production and processing practices will require a regular program of radiological surveillance, in the near future. (author)

  6. Clean-up of cereal extracts for gas chromatography-tandem quadrupole mass spectrometry pesticide residues analysis using primary secondary amine and C18

    DEFF Research Database (Denmark)

    Herrmann, Susan Strange; Poulsen, Mette Erecius

    2015-01-01

    The level of co-extracted matrix in wheat and oat extracts obtained by the QuEChERS method (EN 15662) is high and the occurrence of free fatty acids generates a major matrix peak in TIC chromatograms (rt. 13-22min). Matrix can compromise the analytical performance in pesticide analysis using GC-M...

  7. Gas composition of sludge residue profiles in a sludge treatment reed bed between loadings

    DEFF Research Database (Denmark)

    Larsen, Julie Dam; Nielsen, Steen M; Scheutz, Charlotte

    2017-01-01

    Treatment of sludge in sludge treatment reed bed systems includes dewatering and mineralization. The mineralization process, which is driven by microorganisms, produces different gas species as by-products. The pore space composition of the gas species provides useful information on the biological...... processes occurring in the sludge residue. In this study, we measured the change in composition of gas species in the pore space at different depth levels in vertical sludge residue profiles during a resting period of 32 days. The gas composition of the pore space in the sludge residue changed during...

  8. Injection, flow, and mixing of CO2 in porous media with residual gas.

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C.M.; Doughty, C.A.

    2010-09-01

    Geologic structures associated with depleted natural gas reservoirs are desirable targets for geologic carbon sequestration (GCS) as evidenced by numerous pilot and industrial-scale GCS projects in these environments world-wide. One feature of these GCS targets that may affect injection is the presence of residual CH{sub 4}. It is well known that CH{sub 4} drastically alters supercritical CO{sub 2} density and viscosity. Furthermore, residual gas of any kind affects the relative permeability of the liquid and gas phases, with relative permeability of the gas phase strongly dependent on the time-history of imbibition or drainage, i.e., dependent on hysteretic relative permeability. In this study, the effects of residual CH{sub 4} on supercritical CO{sub 2} injection were investigated by numerical simulation in an idealized one-dimensional system under three scenarios: (1) with no residual gas; (2) with residual supercritical CO{sub 2}; and (3) with residual CH{sub 4}. We further compare results of simulations that use non-hysteretic and hysteretic relative permeability functions. The primary effect of residual gas is to decrease injectivity by decreasing liquid-phase relative permeability. Secondary effects arise from injected gas effectively incorporating residual gas and thereby extending the mobile gas plume relative to cases with no residual gas. Third-order effects arise from gas mixing and associated compositional effects on density that effectively create a larger plume per unit mass. Non-hysteretic models of relative permeability can be used to approximate some parts of the behavior of the system, but fully hysteretic formulations are needed to accurately model the entire system.

  9. Study of residual gas adsorption on GaN nanowire arrays photocathode

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Sihao; Liu, Lei, E-mail: liu1133_cn@sina.com.cn; Diao, Yu; Kong, Yike

    2017-05-01

    Highlights: • H{sub 2}O is more easily to absorb on the nanowire surface. • The work function increase after residual gas adsorption. • Bandgaps of the nanowire increase slightly. • Absorption coefficient is reduced and moves to higher energy side. - Abstract: In order to find out the influences of residual gas on GaN nanowire arrays photocathode, the optoelectronic properties of adsorption system are calculated on the basis of first principles. Results suggest that the residual gas adsorption will increase the work function and introduce a dipole moment with a direction from the nanowire to the adsorbates. The surface structures are changed and electrons transfer from nanowire to gas molecule. The bandgaps are enhanced after adsorption. Besides, the peak of absorption coefficients is reduced and moves to higher energy side. It is discovered that residual gas will drastically degrade the characteristics and lifetime of GaN nanowire arrays photocathode.

  10. Multi-class, multi-residue analysis of pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and novel flame retardants in fish using fast, low-pressure gas chromatography–tandem mass spectrometry

    International Nuclear Information System (INIS)

    Sapozhnikova, Yelena; Lehotay, Steven J.

    2013-01-01

    Highlights: ► A method for analysis of POPs and novel flame retardants in catfish was developed. ► The method is based on a QuEChERS extraction, d-SPE clean-up and low pressure GC/MS–MS. ► The method validation demonstrated good recoveries and low detection limits. ► The method was successfully applied for analysis of catfish samples from the market. - Abstract: A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated using fast low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS–MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with acetonitrile and dispersive solid-phase extraction (d-SPE) clean-up with zirconium-based sorbent prior to LP-GC/MS–MS analysis. The developed method was evaluated at 4 spiking levels and further validated by analysis of NIST Standard Reference Materials (SRMs) 1974B and 1947. Sample preparation for a batch of 10 homogenized samples took about 1 h/analyst, and LP-GC/MS–MS analysis provided fast separation of multiple analytes within 9 min achieving high throughput. With the use of isotopically labeled internal standards, recoveries of all but one analyte were between 70 and 120% with relative standard deviations less than 20% (n = 5). The measured values for both SRMs agreed with certified/reference values (72–119% accuracy) for the majority of analytes. The detection limits were 0.1–0.5 ng g −1 for PCBs, 0.5–10 ng g −1 for PBDEs, 0.5–5 ng g −1 for select pesticides and PAHs and 1–10 ng g −1 for flame retardants. The developed method was successfully applied for analysis of catfish samples from the market.

  11. Laboratory-based validation of the baseline sensors of the ITER diagnostic residual gas analyzer

    International Nuclear Information System (INIS)

    Klepper, C.C.; Biewer, T.M.; Marcus, C.; Graves, V.B.; Andrew, P.; Hughes, S.; Gardner, W.L.

    2017-01-01

    The divertor-specific ITER Diagnostic Residual Gas Analyzer (DRGA) will provide essential information relating to DT fusion plasma performance. This includes pulse-resolving measurements of the fuel isotopic mix reaching the pumping ducts, as well as the concentration of the helium generated as the ash of the fusion reaction. In the present baseline design, the cluster of sensors attached to this diagnostic's differentially pumped analysis chamber assembly includes a radiation compatible version of a commercial quadrupole mass spectrometer, as well as an optical gas analyzer using a plasma-based light excitation source. This paper reports on a laboratory study intended to validate the performance of this sensor cluster, with emphasis on the detection limit of the isotopic measurement. This validation study was carried out in a laboratory set-up that closely prototyped the analysis chamber assembly configuration of the baseline design. This includes an ITER-specific placement of the optical gas measurement downstream from the first turbine of the chamber's turbo-molecular pump to provide sufficient light emission while preserving the gas dynamics conditions that allow for /textasciitilde 1 s response time from the sensor cluster [1].

  12. Laboratory-based validation of the baseline sensors of the ITER diagnostic residual gas analyzer

    Science.gov (United States)

    Klepper, C. C.; Biewer, T. M.; Marcus, C.; Andrew, P.; Gardner, W. L.; Graves, V. B.; Hughes, S.

    2017-10-01

    The divertor-specific ITER Diagnostic Residual Gas Analyzer (DRGA) will provide essential information relating to DT fusion plasma performance. This includes pulse-resolving measurements of the fuel isotopic mix reaching the pumping ducts, as well as the concentration of the helium generated as the ash of the fusion reaction. In the present baseline design, the cluster of sensors attached to this diagnostic's differentially pumped analysis chamber assembly includes a radiation compatible version of a commercial quadrupole mass spectrometer, as well as an optical gas analyzer using a plasma-based light excitation source. This paper reports on a laboratory study intended to validate the performance of this sensor cluster, with emphasis on the detection limit of the isotopic measurement. This validation study was carried out in a laboratory set-up that closely prototyped the analysis chamber assembly configuration of the baseline design. This includes an ITER-specific placement of the optical gas measurement downstream from the first turbine of the chamber's turbo-molecular pump to provide sufficient light emission while preserving the gas dynamics conditions that allow for \\textasciitilde 1 s response time from the sensor cluster [1].

  13. Laboratory-based validation of the baseline sensors of the ITER diagnostic residual gas analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Biewer, Theodore M. [ORNL; Marcus, Chris [ORNL; Klepper, C Christopher [ORNL; Andrew, Philip [ITER Organization, Cadarache, France; Gardner, W. L. [United States ITER Project Office; Graves, Van B. [ORNL; Hughes, Shaun [ITER Organization, Saint Paul Lez Durance, France

    2017-10-01

    The divertor-specific ITER Diagnostic Residual Gas Analyzer (DRGA) will provide essential information relating to DT fusion plasma performance. This includes pulse-resolving measurements of the fuel isotopic mix reaching the pumping ducts, as well as the concentration of the helium generated as the ash of the fusion reaction. In the present baseline design, the cluster of sensors attached to this diagnostic's differentially pumped analysis chamber assembly includes a radiation compatible version of a commercial quadrupole mass spectrometer, as well as an optical gas analyzer using a plasma-based light excitation source. This paper reports on a laboratory study intended to validate the performance of this sensor cluster, with emphasis on the detection limit of the isotopic measurement. This validation study was carried out in a laboratory set-up that closely prototyped the analysis chamber assembly configuration of the baseline design. This includes an ITER-specific placement of the optical gas measurement downstream from the first turbine of the chamber's turbo-molecular pump to provide sufficient light emission while preserving the gas dynamics conditions that allow for \\textasciitilde 1 s response time from the sensor cluster [1].

  14. Residual energy applications program systems analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Yngve, P.W.

    1980-10-01

    Current DOE plans call for building an Energy Applied Systems Test (EAST) Facility at the Savannah River Plant in close proximity to the 140 to 150/sup 0/F waste heat from one of several operating nuclear reactors. The waste water flow from each reactor, approximately 165,000 gpm, provides a unique opportunity to test the performance and operating characteristics of large-scale waste heat power generation and heat pump system concepts. This report provides a preliminary description of the potential end-use market, parametric data on heat pump and the power generation system technology, a preliminary listing of EAST Facility requirements, and an example of an integrated industrial park utilizing the technology to maximize economic pay back. The parametric heat pump analysis concluded that dual-fluid Rankine cycle heat pumps with capacities as high as 400 x 10/sup 6/ Btu/h, can utilize large sources of low temperature residual heat to provide 300/sup 0/F saturatd steam for an industrial park. The before tax return on investment for this concept is 36.2%. The analysis also concluded that smaller modular heat pumps could fulfill the same objective while sacrificing only a moderate rate of return. The parametric power generation analysis concluded that multi-pressure Rankine cycle systems not only are superior to single pressure systems, but can also be developed for large systems (approx. = 17 MW/sub e/). This same technology is applicable to smaller systems at the sacrifice of higher investment per unit output.

  15. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper

    We define residuals for point process models fitted to spatial point pattern data, and propose diagnostic plots based on these residuals. The techniques apply to any Gibbs point process model, which may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Ou...... or covariate effects. Q-Q plots of the residuals are effective in diagnosing interpoint interaction. Some existing ad hoc statistics of point patterns (quadrat counts, scan statistic, kernel smoothed intensity, Berman's diagnostic) are recovered as special cases....

  16. Generation of low-Btu fuel gas from agricultural residues experiments with a laboratory scale gas producer

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R O

    1977-01-01

    Two successive laboratory-scale, downdraft gas producers were fabricated and tested. Agricultural and food processing residues including walnut shells, corn cobs, tree prunings, and cotton gin waste, were converted to a low Btu producer gas. The performance of 2 spark ignition engines, when running on producer gas, was highly satisfactory. The ability of the producer to maintain a continuous supply of good quality gas was determined largely by firebox configuration. Fuel handling and fuel flow control problems tended to be specific to individual types of residues. During each test run, air input, firebox temperature, fuel consumption rate, and pressure differential across the producer were monitored. An overall conversion efficiency of 65% was achieved.

  17. Residual lifetime assessment of uPVC gas pipes

    NARCIS (Netherlands)

    Visser, H.A.

    2010-01-01

    The Dutch gas distribution network consists of about 20% (22,500 km) of unplasticised poly(vinyl chloride) (uPVC) pipes, most of which have been installed from the mid-sixties up to the mid-seventies of the previous century and have been in service ever since. In the next decade the specified

  18. Gas composition of sludge residue profiles in a sludge treatment reed bed between loadings.

    Science.gov (United States)

    Larsen, Julie D; Nielsen, Steen M; Scheutz, Charlotte

    2017-11-01

    Treatment of sludge in sludge treatment reed bed systems includes dewatering and mineralization. The mineralization process, which is driven by microorganisms, produces different gas species as by-products. The pore space composition of the gas species provides useful information on the biological processes occurring in the sludge residue. In this study, we measured the change in composition of gas species in the pore space at different depth levels in vertical sludge residue profiles during a resting period of 32 days. The gas composition of the pore space in the sludge residue changed during the resting period. As the resting period proceeded, atmospheric air re-entered the pore space at all depth levels. The methane (CH 4 ) concentration was at its highest during the first part of the resting period, and then declined as the sludge residue became more dewatered and thereby aerated. In the pore space, the concentration of CH 4 often exceeded the concentration of carbon dioxide (CO 2 ). However, the total emission of CO 2 from the surface of the sludge residue exceeded the total emission of CH 4 , suggesting that CO 2 was mainly produced in the layer of newly applied sludge and/or that CO 2 was emitted from the sludge residue more readily compared to CH 4 .

  19. A survey of residual analysis and a new test of residual trend.

    Science.gov (United States)

    McDowell, J J; Calvin, Olivia L; Klapes, Bryan

    2016-05-01

    A survey of residual analysis in behavior-analytic research reveals that existing methods are problematic in one way or another. A new test for residual trends is proposed that avoids the problematic features of the existing methods. It entails fitting cubic polynomials to sets of residuals and comparing their effect sizes to those that would be expected if the sets of residuals were random. To this end, sampling distributions of effect sizes for fits of a cubic polynomial to random data were obtained by generating sets of random standardized residuals of various sizes, n. A cubic polynomial was then fitted to each set of residuals and its effect size was calculated. This yielded a sampling distribution of effect sizes for each n. To test for a residual trend in experimental data, the median effect size of cubic-polynomial fits to sets of experimental residuals can be compared to the median of the corresponding sampling distribution of effect sizes for random residuals using a sign test. An example from the literature, which entailed comparing mathematical and computational models of continuous choice, is used to illustrate the utility of the test. © 2016 Society for the Experimental Analysis of Behavior.

  20. Total and occluded residual gas content inside the nuclear fuel pellets

    International Nuclear Information System (INIS)

    Moura, Sergio C.; Fernandes, Carlos E.; Oliveira, Justine R.; Machado, Joyce F.; Guglielmo, Luisa M.; Bustillos, Oscar V.

    2009-01-01

    This work describes three techniques available to measure total and occluded residual gases inside the UO 2 nuclear fuel pellets. Hydrogen is the major gas compound inside these pellets, due to sintering fabrication process but Nitrogen is present as well, due to storage atmosphere fuel. The total and occluded residual gas content inside these pellets is a mandatory requirement in a quality control to assure the well function of the pellets inside the nuclear reactor. This work describes the Gas Extractor System coupled with mass spectrometry GES/MS, the Gas Extractor System coupled with gas chromatography GES/GC and the total Hydrogen / Nitrogen H/N analyzer as well. In the GES, occlude gases in the UO 2 pellets is determinate using a high temperature vacuum extraction system, in which the minimum limit of detection is in the range 0.002 cc/g. The qualitative and quantitative determination of the amount of gaseous components employs a mass spectrometry or a gas chromatography technique. The total Hydrogen / Nitrogen analyzer employ a thermal conductivity gas detector linked to a gaseous extractor furnace which has a detection limit is in the range 0.005 cc/g. The specification for the residual gas analyses in the nuclear fuel pellets is 0.03 cc/g, all techniques satisfy the requirement but not the nature of the gases due to reaction with the reactor cladding. The present work details the chemical reaction among Hydrogen / Nitrogen and nuclear reactor cladding. (author)

  1. NMR and Chemometric Characterization of Vacuum Residues and Vacuum Gas Oils from Crude Oils of Different Origin

    Directory of Open Access Journals (Sweden)

    Jelena Parlov Vuković

    2015-03-01

    Full Text Available NMR spectroscopy in combination with statistical methods was used to study vacuum residues and vacuum gas oils from 32 crude oils of different origin. Two chemometric metodes were applied. Firstly, principal component analysis on complete spectra was used to perform classification of samples and clear distinction between vacuum residues and vacuum light and heavy gas oils were obtained. To quantitatively predict the composition of asphaltenes, principal component regression models using areas of resonance signals spaned by 11 frequency bins of the 1H NMR spectra were build. The first 5 principal components accounted for more than 94 % of variations in the input data set and coefficient of determination for correlation between measured and predicted values was R2 = 0.7421. Although this value is not significant, it shows the underlying linear dependence in the data. Pseudo two-dimensional DOSY NMR experiments were used to assess the composition and structural properties of asphaltenes in a selected crude oil and its vacuum residue on the basis of their different hydrodynamic behavior and translational diffusion coefficients. DOSY spectra showed the presence of several asphaltene aggregates differing in size and interactions they formed. The obtained results have shown that NMR techniques in combination with chemometrics are very useful to analyze vacuum residues and vacuum gas oils. Furthermore, we expect that our ongoing investigation of asphaltenes from crude oils of different origin will elucidate in more details composition, structure and properties of these complex molecular systems.

  2. A Study on Fatigue Design Automation of Plug- and Ring-type Gas-welded Joints of STS301L Taking Welded Residual Stress into Account

    International Nuclear Information System (INIS)

    Baek, Seung yeb; Yun, Ki Ho

    2010-01-01

    This paper presents a fatigue design method for plug- and ring-type gas-welded joints, which takes into account the effects of welding residual stress. To develop this method, we simulated the gas-welding process by performing nonlinear finite element analysis (FEA) To validate the FEA results, numerically calculated residual stresses in the gas welds were then compared with experimental results obtained by the hole-drilling method. To evaluate the fatigue strength of plug- and ring-type gas-welded joints influenced by welding residual stresses, the use of stress amplitude (σ a )R, which includes the welding residual stress in gas welds, is proposed (σ a )R on the basis of a modified Goodman equation that includes the residual stress effects. Using the stress amplitude (σ a )R at the hot spot point of gas weld, the relations obtained as the fatigue test results for plug and ring type gas welded joints having various dimensions and shapes were systematically rearranged to obtain the (σ a )R-N f relationship. It was found that more systematic and accurate evaluation of the fatigue strength of plug- and ring-type gas-welded joints can be achieved by using (σ a )R

  3. Autoresonant-spectrometric determination of the residual gas composition in the ALPHA experiment apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Amole, C.; Capra, A.; Menary, S. [Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3 (Canada); Ashkezari, M. D.; Hayden, M. E. [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Baquero-Ruiz, M.; Chapman, S.; Little, A.; Povilus, A.; So, C.; Turner, M. [Department of Physics, University of California, Berkeley, California 94720-7300 (United States); Bertsche, W. [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom and The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Butler, E. [Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Cesar, C. L.; Silveira, D. M. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil); Charlton, M.; Eriksson, S.; Isaac, C. A.; Madsen, N.; Napoli, S. C. [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Collaboration: ALPHA Collaboration; and others

    2013-06-15

    Knowledge of the residual gas composition in the ALPHA experiment apparatus is important in our studies of antihydrogen and nonneutral plasmas. A technique based on autoresonant ion extraction from an electrostatic potential well has been developed that enables the study of the vacuum in our trap. Computer simulations allow an interpretation of our measurements and provide the residual gas composition under operating conditions typical of those used in experiments to produce, trap, and study antihydrogen. The methods developed may also be applicable in a range of atomic and molecular trap experiments where Penning-Malmberg traps are used and where access is limited.

  4. Determination of insecticides malathion and lambda-cyhalothrin residues in zucchini by gas chromatography

    OpenAIRE

    Lofty, Hayam M.; Abd El-Aleem, Abd El-Aziz A.; Monir, Hany H.

    2013-01-01

    A sensitive gas chromatographic method has been developed for the determination of malathion and lambda-cyhalothrin (λ-cyhalothrin) insecticide residues in zucchini. The developed method consists of extraction with acetone, purification and partitioning with methylene chloride, column chromatographic clean-up, and finally capillary gas chromatographic determination of the insecticides. The recoveries of method were greater than 90% and limit of determination was 0.001 ppm for both insecticide...

  5. Design of a diagnostic residual gas analyzer for the ITER divertor

    Energy Technology Data Exchange (ETDEWEB)

    Klepper, C.C., E-mail: kleppercc@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Biewer, T.M.; Graves, V.B. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Andrew, P. [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France); Lukens, P.C. [US ITER Project Office, 1055 Commerce Park Dr #1, Oak Ridge, TN 37830 (United States); Marcus, C. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Shimada, M., E-mail: shimada.michiya@jaea.go.jp [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France); Hughes, S.; Boussier, B. [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France); Johnson, D.W. [US ITER Diagnostics Office, Princeton Plasma Physics Laboratory, Princeton, NJ 08540 (United States); Gardner, W.L. [US ITER Project Office, 1055 Commerce Park Dr #1, Oak Ridge, TN 37830 (United States); Hillis, D.L. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Vayakis, G.; Walsh, M. [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France)

    2015-10-15

    Highlights: • The divertor DRGA for ITER will measure neutral gas composition in the pumping ducts during plasma. • System must respond in timescales relevant to compositional changes in the divertor plasma. • It is shown that times can vary from 1 to 6 s for fuel (H2, D2, T2) up to 50 s for He (fusion reaction ash). • It is shown that present design delivers ∼ 1 s response even via an 8m long sampling pipe sampling. • Response time validated with VacTran{sup ®} over anticipated the 0.1–10 Pa pressure range in the ducts. - Abstract: One of the ITER diagnostics having reached an advanced design stage is a diagnostic RGA for the divertor, i.e. residual gas analysis system for the ITER divertor, which is intended to sample the divertor pumping duct region during the plasma pulse and to have a response time compatible with plasma particle and impurity lifetimes in the divertor region. Main emphasis is placed on helium (He) concentration in the ducts, as well as the relative concentration between the hydrogen isotopes (mainly in the form of diatomic molecules of H, D, and T). Measurement of the concentration of radiative gases, such as neon (Ne) and nitrogen (N{sub 2}), is also intended. Numerical modeling of the gas flow from the sampled region to the cluster of analysis sensors, through a long (∼8 m long, ∼110 mm diameter) sampling pipe originating from a pressure reducing orifice, confirm that the desired response time (∼1 s for He or D{sub 2}) is achieved with the present design.

  6. RESIDUAL GAS MOTIONS IN THE INTRACLUSTER MEDIUM AND BIAS IN HYDROSTATIC MEASUREMENTS OF MASS PROFILES OF CLUSTERS

    International Nuclear Information System (INIS)

    Lau, Erwin T.; Kravtsov, Andrey V.; Nagai, Daisuke

    2009-01-01

    We present analysis of bulk and random gas motions in the intracluster medium using high-resolution Eulerian cosmological simulations of 16 simulated clusters, including both very relaxed and unrelaxed systems and spanning a virial mass range of 5 x 10 13 - 2 x 10 15 h -1 M-odot. We investigate effects of the residual subsonic gas motions on the hydrostatic estimates of mass profiles and concentrations of galaxy clusters. In agreement with previous studies, we find that the gas motions contribute up to ∼5%-15% of the total pressure support in relaxed clusters with contribution increasing with the cluster-centric radius. The fractional pressure support is higher in unrelaxed systems. This contribution would not be accounted for in hydrostatic estimates of the total mass profile and would lead to systematic underestimate of mass. We demonstrate that total mass can be recovered accurately if pressure due to gas motions measured in simulations is explicitly taken into account in the equation of hydrostatic equilibrium. Given that the underestimate of mass is increasing at larger radii, where gas is less relaxed and contribution of gas motions to pressure is larger, the total density profile derived from hydrostatic analysis is more concentrated than the true profile. This may at least partially explain some high values of concentrations of clusters estimated from hydrostatic analysis of X-ray data.

  7. The effect of heat treatment on the magnitude and composition of residual gas in sealed silica glass ampoules

    Science.gov (United States)

    Palosz, W.; Szofran, F. R.; Lehoczky, S. L.

    1994-01-01

    The residual gas pressure and composition in sealed silica glass ampoules as a function of different treatment procedures has been investigated. The dependence of the residual gas on the outgassing and annealing parameters has been determined. The effects of the fused silica brand, of the ampoule fabrication, and of post-outgassing procedures have been evaluated.

  8. Residual solvent determination by head space gas chromatography with flame ionization detector in omeprazole API

    Directory of Open Access Journals (Sweden)

    Saurabh Pandey

    2011-06-01

    Full Text Available Residual solvents in pharmaceutical samples are monitored using gas chromatography with head space. Based on good manufacturing practices, measuring residual solvents is mandatory for the release testing of all active pharmaceutical ingredients (API. The analysis of residual organic solvents (methanol, acetone, cyclohexane, dichloromethane, toluene in Omeprazole, an active pharmaceutical ingredient was investigated. Omeprazole is a potent reversible inhibitor of the gastric proton pump H+/K+-ATPase. The Head space gas chromatography (HSGC method described in this investigation utilized a SPB TM-624, Supelco, 30 m long x 0.25 mm internal diameter, 1.4µm-thick column. Since Omeprazole is a thermally labile compound, the selection of the proper injector temperature is critical to the success of the analysis. The injector temperature was set at 170ºC to prevent degradation. The initial oven temperature was set at 40ºC for 12 min and programmed at a rate of 10ºC min-1 to a final temperature of 220ºC for 5 min. Nitrogen was used as a carrier gas. The sample solvent selected was N,N-dimethylacetamide. The method was validated to be specific, linear, precise, sensitive, rugged and showed excellent recovery.Solventes residuais em amostras farmacêuticas são monitoradas utilizando-se cromatografia a gás "headspace". Com base nas boas práticas de fabricação, a medida de solventes residuais é obrigatória para o teste de liberação de todos os ingredientes farmacêuticos (API. Efetuou-se a análise de solventes orgânicos residuais (metanol, acetona, cicloexano, diclorometano, tolueno em omeprazol, ingrediente farmacêutico ativo. O omeprazol é potente inibidor reversível da bomba de prótons H+/K+-ATPase. A cromatografia a gás "headspace" (HSGC descrita nessa pesquisa utilizou um SPB TM-624, Supelco, de 30 m de comprimento x 0,25 mm de diâmetro interno, e coluna de 1,4 µm de espessura. Considerando-se que o omeprazol é termicamente l

  9. Multiple responses optimization in the development of a headspace gas chromatography method for the determination of residual solvents in pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Carla M. Teglia

    2015-10-01

    Full Text Available An efficient generic static headspace gas chromatography (HSGC method was developed, optimized and validated for the routine determination of several residual solvents (RS in drug substance, using a strategy with two sets of calibration. Dimethylsulfoxide (DMSO was selected as the sample diluent and internal standards were used to minimize signal variations due to the preparative step. A gas chromatograph from Agilent Model 6890 equipped with flame ionization detector (FID and a DB-624 (30 m×0.53 mm i.d., 3.00 µm film thickness column was used. The inlet split ratio was 5:1. The influencing factors in the chromatographic separation of the analytes were determined through a fractional factorial experimental design. Significant variables: the initial temperature (IT, the final temperature (FT of the oven and the carrier gas flow rate (F were optimized using a central composite design. Response transformation and desirability function were applied to find out the optimal combination of the chromatographic variables to achieve an adequate resolution of the analytes and short analysis time. These conditions were 30 °C for IT, 158 °C for FT and 1.90 mL/min for F. The method was proven to be accurate, linear in a wide range and very sensitive for the analyzed solvents through a comprehensive validation according to the ICH guidelines. Keywords: Headspace gas chromatography, Residual solvents, Pharmaceuticals, Surface response methodology, Desirability function

  10. Buffer gas cooling and mixture analysis

    Science.gov (United States)

    Patterson, David S.; Doyle, John M.

    2018-03-06

    An apparatus for spectroscopy of a gas mixture is described. Such an apparatus includes a gas mixing system configured to mix a hot analyte gas that includes at least one analyte species in a gas phase into a cold buffer gas, thereby forming a supersaturated mixture to be provided for spectroscopic analysis.

  11. Removal of element mercury by medicine residue derived biochars in presence of various gas compositions

    International Nuclear Information System (INIS)

    Li, Guoliang; Shen, Boxiong; Li, Yongwang; Zhao, Bin; Wang, Fumei; He, Chuan; Wang, Yinyin; Zhang, Min

    2015-01-01

    Highlights: • Both physisorption and chemisorption of Hg 0 occurred on the surface of M6WN5. • Chemisorption process was an absolute predominant route for Hg 0 removal by M6WN5. • The effect of NO, H 2 O, SO 2 and O 2 on Hg 0 removal by M6WN5 was investigated. • M6WN5 demonstrated to be a promising Hg 0 sorbent in flue gas. - Abstract: Pyrolyzed biochars from an industrial medicinal residue waste were modified by microwave activation and NH 4 Cl impregnation. Mercury adsorption of different modified biochars was investigated in a quartz fixed-bed reactor. The results indicated that both physisorption and chemisorption of Hg 0 occurred on the surface of M6WN5 which was modified both microwave and 5 wt.% NH 4 Cl loading, and exothermic chemisorption process was a dominant route for Hg 0 removal. Microwave activation improved pore properties and NH 4 Cl impregnation introduced good active sites for biochars. The presence of NO and O 2 increased Hg 0 adsorption whereas H 2 O inhibited Hg 0 adsorption greatly. A converse effect of SO 2 was observed on Hg 0 removal, namely, low concentration of SO 2 promoted Hg 0 removal obviously whereas high concentration of SO 2 suppressed Hg 0 removal. The Hg 0 removal by M6WN5 was mainly due to the reaction of the C−Cl with Hg 0 to form HgCl 2 , and the active state of C−Cl * groups might be an intermediate group in this process. Thermodynamic analysis showed that mercury adsorption by the biochars was exothermic process and apparent adsorption energy was 43.3 kJ/mol in the range of chemisorption. In spite of low specific surface area, M6WN5 proved to be a promising Hg 0 sorbent in flue gas when compared with other sorbents

  12. Process for measuring the helium residual gas pressure and circuit for carrying out the process

    International Nuclear Information System (INIS)

    Schmidt, C.; Cesnak, L.

    1983-01-01

    In cryotechnic devices, the quality of the thermal insulation can be monitored by checking the pressure of the residual gas. A process is proposed in which a thin super-conducting wire or a superconducting layer acting as vacuum sensor has a heating pulse reaching the critical current applied to it, which produces a local normal conduction zone. The vacuum sensor has a measuring current of constant amount applied to it, which causes a voltage drop on its resistance during the time in which the normal conduction zone exists, the cooling time. The pressure of the residual gas is a function of the integral of the voltage drop and is measured by integrating the voltage during the cooling time. (orig./HP) [de

  13. Assessment of pesticide residues in some fruits using gas chromatography coupled with micro electron capture detector

    International Nuclear Information System (INIS)

    Latif, Y.; Sherazi, S.T.H.; Bhanger, M.I.

    2011-01-01

    A very sensitive analytical method for the determination of 26 pesticides in some fruits based on solid phase extraction (SPE) cleanup was developed using gas chromatography (GC) coupled with micro electron capture detector (mu ECD). The identity of the pesticides was confirmed by gas chromatography mass spectroscopy (GC-MS) using selected ion monitoring (SIM) mode. Ethyl acetate was used as a solvent for the extraction of pesticide residues with assistance of sonication. For cleanup an octadecyl, C18 SPE column was used. A linear response of mu ECD was observed for all pesticides with good correlation coefficients (>0.9992). Proposed method was successfully applied for the determination of pesticide residues in the orange, apple, and grape fruits. Average recoveries achieved for all of the pesticides at fortification levels of 0.05, 1.0 and 2.0 mu g g/sup -1/ in analyzed fruits were above 90% with relative standard deviations (RSD) less than 6%. (author)

  14. Development of residual gas ionization profile monitor for high intensity proton beams

    CERN Document Server

    Sato, Y; Hirose, E; Ieiri, M; Igarashi, Y; Inaba, S; Katoh, Y; Minakawa, M; Noumi, H; Saitó, M; Suzuki, Y; Takahashi, H; Takasaki, M; Tanaka, K; Toyoda, A; Yamada, Y; Yamanoi, Y; Watanabe, H

    2006-01-01

    Nondestructive beam profile monitor utilizing ionizations of residual gas has been developed for continuous monitoring of 3?0(J-PARC). Knock-on electrons produced in the ionizations of residual gas vacuumed to 1 Pa are collected with a uniform electric field applied between electrodes. Applying a uniform electric field parallel to the electric field is essential to reduce diffusion of electrons crossing over magnetic flux. A prototype monitor has been constructed and installed in EP2-C beam line at KEK 12 GeV proton synchrotron (12 Ge V-PS). The profiles measured with the present monitor agree with the ones measured with the existing destructive profile monitor. The present monitor shows sufficient performances as a candidate of the profile monitor at J-PARC. In the present article, the working principle of the present monitor, the results of test experiments, and further developments are described in detail.

  15. Residual Stress Analysis Based on Acoustic and Optical Methods

    Directory of Open Access Journals (Sweden)

    Sanichiro Yoshida

    2016-02-01

    Full Text Available Co-application of acoustoelasticity and optical interferometry to residual stress analysis is discussed. The underlying idea is to combine the advantages of both methods. Acoustoelasticity is capable of evaluating a residual stress absolutely but it is a single point measurement. Optical interferometry is able to measure deformation yielding two-dimensional, full-field data, but it is not suitable for absolute evaluation of residual stresses. By theoretically relating the deformation data to residual stresses, and calibrating it with absolute residual stress evaluated at a reference point, it is possible to measure residual stresses quantitatively, nondestructively and two-dimensionally. The feasibility of the idea has been tested with a butt-jointed dissimilar plate specimen. A steel plate 18.5 mm wide, 50 mm long and 3.37 mm thick is braze-jointed to a cemented carbide plate of the same dimension along the 18.5 mm-side. Acoustoelasticity evaluates the elastic modulus at reference points via acoustic velocity measurement. A tensile load is applied to the specimen at a constant pulling rate in a stress range substantially lower than the yield stress. Optical interferometry measures the resulting acceleration field. Based on the theory of harmonic oscillation, the acceleration field is correlated to compressive and tensile residual stresses qualitatively. The acoustic and optical results show reasonable agreement in the compressive and tensile residual stresses, indicating the feasibility of the idea.

  16. Mapping allostery through computational glycine scanning and correlation analysis of residue-residue contacts.

    Science.gov (United States)

    Johnson, Quentin R; Lindsay, Richard J; Nellas, Ricky B; Fernandez, Elias J; Shen, Tongye

    2015-02-24

    Understanding allosteric mechanisms is essential for the physical control of molecular switches and downstream cellular responses. However, it is difficult to decode essential allosteric motions in a high-throughput scheme. A general two-pronged approach to performing automatic data reduction of simulation trajectories is presented here. The first step involves coarse-graining and identifying the most dynamic residue-residue contacts. The second step is performing principal component analysis of these contacts and extracting the large-scale collective motions expressed via these residue-residue contacts. We demonstrated the method using a protein complex of nuclear receptors. Using atomistic modeling and simulation, we examined the protein complex and a set of 18 glycine point mutations of residues that constitute the binding pocket of the ligand effector. The important motions that are responsible for the allostery are reported. In contrast to conventional induced-fit and lock-and-key binding mechanisms, a novel "frustrated-fit" binding mechanism of RXR for allosteric control was revealed.

  17. Development Of A Permanent Magnet Residual Gas Profile Monitor With Fast Readout

    CERN Document Server

    Barabin, S; Giacomini, T; Liakin, D; Orlov, A; Skachkov, V S

    2004-01-01

    The beam profile measurements at modern ion synchrotrons and storage rings require high timing performances on a turn-by-turn basis. On the other hand, high spatial resolutions are very desirable for cooled beams. We are developing a residual gas monitor to cover the wide range of beam intensities and dimensions. It supplies the needed high-resolution and high-speed tools for beam profiling. The new residual gas monitor will operate on scattered residual gas electrons whose trajectories are localized within 0.1 mm filaments by using appropriate magnetic field. The required magnetic field of 100 mT will be excited by either a permanent or an electromagnet. The high resolution mode of 0.1 mm is provided by a CCD camera with upstream MCP-phosphor screen assembly. In the fast turn-by-turn mode the beam profile will be read out with a resolution of 1 mm by a 100-channel photodiode-amplifier-digitizer, which will be explained in detail.

  18. [Determination of residual solvents in 7-amino-3-chloro cephalosporanic acid by gas chromatography].

    Science.gov (United States)

    Ma, Li; Yao, Tong-wei

    2011-01-01

    To develop a gas chromatography method for determination of residual solvents in 7-amino-3-chloro cephalosporanic acid (7-ACCA). The residual levels of acetone, methanol, dichloromethane, ethyl acetate, isobutanol, pyridine and toluene in 7-ACCA were measured by gas chromatography using Agilent INNOWAX capillary column (30 m × 0.32 mm,0.5 μm). The initial column temperature was 70° maintained for 6 min and then raised (10°C/min) to 160°C for 1 min. Nitrogen gas was used as carrier and FID as detector. The flow of carrier was 1.0 ml/min, the temperature of injection port and detector was 200°C and 250°C, respectively. The limits of detection for acetone, methanol, dichloromethane, ethyl acetate, isobutanol, pyridine, toluene in 7-ACCA were 2.5 μg/ml, 1.5 μg/ml, 15 μg/ml, 2.5 μg/ml, 2.5 μg/ml, 2.5 μg/ml and 11 μg/ml, respectively. Only acetone was detected in the sample, and was less than the limits of Ch.P. The method can effectively detect the residual solvents in 7-ACCA.

  19. Residual Gas and Dust around Transition Objects and Weak T Tauri Stars

    Energy Technology Data Exchange (ETDEWEB)

    Doppmann, Greg W. [W. M. Keck Observatory, 65-1120 Mamalahoa Hwy., Kamuela, HI 96743 (United States); Najita, Joan R. [National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Carr, John S., E-mail: gdoppmann@keck.hawaii.edu, E-mail: najita@noao.edu, E-mail: carr@nrl.navy.mil [Naval Research Laboratory, Code 7213, Washington, DC 20375 (United States)

    2017-02-20

    Residual gas in disks around young stars can spin down stars, circularize the orbits of terrestrial planets, and whisk away the dusty debris that is expected to serve as a signpost of terrestrial planet formation. We have carried out a sensitive search for residual gas and dust in the terrestrial planet region surrounding young stars ranging in age from a few to ∼10 Myr. Using high-resolution 4.7 μ m spectra of transition objects (TOs) and weak T Tauri stars, we searched for weak continuum excesses and CO fundamental emission, after making a careful correction for the stellar contribution to the observed spectrum. We find that the CO emission from TOs is weaker and located farther from the star than CO emission from nontransition T Tauri stars with similar stellar accretion rates. The difference is possibly the result of chemical and/or dynamical effects (i.e., a low CO abundance or close-in low-mass planets). The weak T Tauri stars show no CO fundamental emission down to low flux levels (5 × 10{sup −20} to 10{sup −18} W m{sup −2}). We illustrate how our results can be used to constrain the residual disk gas content in these systems and discuss their potential implications for star and planet formation.

  20. A multi-residue method for the analysis of pesticides and pesticide degradates in water using HLB solid-phase extraction and gas chromatography-ion trap mass spectrometry

    Science.gov (United States)

    Hladik, M.L.; Smalling, K.L.; Kuivila, K.M.

    2008-01-01

    A method was developed for the analysis of over 60 pesticides and degradates in water by HLB solid-phase extraction and gas-chromatography/mass spectrometry. Method recoveries and detection limits were determined using two surface waters with different dissolved organic carbon (DOC) concentrations. In the lower DOC water, recoveries and detection limits were 80%-108% and 1-12 ng/L, respectively. In the higher DOC water, the detection limits were slightly higher (1-15 ng/L). Additionally, surface water samples from four sites were analyzed and 14 pesticides were detected with concentrations ranging from 4 to 1,200 ng/L. ?? 2008 Springer Science+Business Media, LLC.

  1. Manual of Standard Operating Procedures for Veterinary Drug Residue Analysis

    International Nuclear Information System (INIS)

    2016-01-01

    Laboratories are crucial to national veterinary drug residue monitoring programmes. However, one of the main challenges laboratories encounter is obtaining access to relevant methods of analysis. Thus, in addition to training, providing technical advice and transferring technology, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has resolved to develop clear and practical manuals to support Member State laboratories. The Coordinated Research Project (CRP) on Development of Radiometric and Allied Analytical Methods to Strengthen Residue Control Programs for Antibiotic and Anthelmintic Veterinary Drug Residues has developed a number of analytical methods as standard operating procedures (SOPs), which are now compiled here. This publication contains SOPs on chromatographic and spectrometric techniques, as well as radioimmunoassay and associated screening techniques, for various anthelmintic and antimicrobial veterinary drug residue analysis. Some analytical method validation protocols are also included. The publication is primarily aimed at food and environmental safety laboratories involved in testing veterinary drug residues, including under organized national residue monitoring programmes. It is expected to enhance laboratory capacity building and competence through the use of radiometric and complementary tools and techniques. The publication is also relevant for applied research on residues of veterinary drugs in food and environmental samples

  2. Greenhouse gas and energy analysis of substitute natural gas from biomass for space heat

    Energy Technology Data Exchange (ETDEWEB)

    Pucker, J.; Jungmeier, G. [JOANNEUM RESEARCH Forschungsgesellschaft mbH, RESOURCES - Institute for Water, Energy and Sustainability, Steyrergasse 17, 8010 Graz (Austria); Zwart, R. [Energy Research Centre of The Netherlands (ECN), Westerduinweg 3, 1755 LE Petten (Netherlands)

    2012-03-15

    In this paper, the greenhouse gas and energy balances of the production and use for space heating of substitute natural gas from biomass (bio-SNG) for space heat are analysed. These balances are compared to the use of natural gas and solid biomass as wood chips to provide the same service. The reduction of the greenhouse gas emissions (CO{sub 2}-eq.) - carbon dioxide, methane and nitrous oxide - and of the fossil primary energy use is investigated in a life cycle assessment (LCA). This assessment was performed for nine systems for bio-SNG; three types of gasification technologies (O{sub 2}-blown entrained flow, O{sub 2}-blown circulating fluidised bed and air-steam indirect gasification) with three different types of feedstock (forest residues, miscanthus and short rotation forestry). The greenhouse gas analysis shows that forest residues using the air-steam indirect gasification technology result in the lowest greenhouse gas emissions (in CO{sub 2}-eq. 32 kg MWh{sup -1} of heat output). This combination results in 80% reduction of greenhouse gas emissions when compared to natural gas and a 29% reduction of greenhouse gases if the forest residues were converted to wood chips and combusted. The gasification technologies O{sub 2}-blown entrained flow and O{sub 2}-blown circulating fluidised bed gasification have higher greenhouse gas emissions that range between in CO{sub 2}-eq. 41 to 75 kg MWh{sup -1} of heat output depending on the feedstock. When comparing feedstocks in the bio-SNG systems, miscanthus had the highest greenhouse gas emissions bio-SNG systems producing in CO2-eq. 57-75 kg MWh{sup -1} of heat output. Energy analysis shows that the total primary energy use is higher for bio-SNG systems (1.59-2.13 MWh MWh{sup -1} of heat output) than for the reference systems (in 1.37-1.51 MWh MWh{sup -1} of heat output). However, with bio-SNG the fossil primary energy consumption is reduced compared to natural gas. For example, fossil primary energy use is reduced by

  3. Life-cycle analysis of shale gas and natural gas.

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M. (Energy Systems); ( EVS)

    2012-01-27

    The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.

  4. Screening for estrogen residues in calf urine: Comparison of a validated yeast estrogen bioassay and gas chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Nielen, M.W.F.; Bovee, T.F.H.; Heskamp, H.H.; Lasaroms, J.J.P.; Sanders, M.B.; Rhijn, van J.A.; Groot, M.J.; Hoogenboom, L.A.P.

    2006-01-01

    Within the European Union, the control for residues of illegal hormones in food-producing animals is based on urine analysis for a few target analytes using gas chromatography/mass spectrometry and/or liquid chromatography¿tandem mass spectrometry. Recently, we developed a robust yeast bioassay

  5. [Simultaneous determination of seven residual solvents in bovis calculus artifactus by headspace gas chromatography].

    Science.gov (United States)

    Chi, Shuyao; Wu, Dike; Sun, Jinhong; Ye, Ruhan; Wang, Xiaoyan

    2014-05-01

    A headspace gas chromatography (HS-GC) method was developed for the simultaneous determination of seven residual solvents (petroleum ether (60-90 degrees C), acetone, ethyl acetate, methanol, methylene chloride, ethanol and butyl acetate) in bovis calculus artifactus. The DB-WAX capillary column and flame ionization detector (FID) were used for the separation and detection of the residual solvents, and the internal standard method was used for the quantification. The chromatographic conditions, such as equilibrium temperature and equilibrium time, were optimized. Under the optimized conditions, all of the seven residual solvents showed good linear relationships with good correlation coefficients (not less than 0.999 3) in the prescribed concentration range. At three spiked levels, the recoveries for the seven residual solvents were 94.7%-105.2% with the relative standard deviations (RSDs) less than 3.5%. The limits of detection (LODs) of the method were 0.43-5.23 mg/L, and the limits of quantification (LOQs) were 1.25-16.67 mg/L. The method is simple, rapid, sensitive and accurate, and is suitable for the simultaneous determination of the seven residual solvents in bovis calculus artifactus.

  6. A review of residual stress analysis using thermoelastic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, A F; Dulieu-Barton, J M; Quinn, S [University of Southampton, School of Engineering Sciences, Highfield, Southampton, SO17 1BJ (United Kingdom); Burguete, R L [Airbus UK Ltd., New Filton House, Filton, Bristol, BS99 7AR (United Kingdom)

    2009-08-01

    Thermoelastic Stress Analysis (TSA) is a full-field technique for experimental stress analysis that is based on infra-red thermography. The technique has proved to be extremely effective for studying elastic stress fields and is now well established. It is based on the measurement of the temperature change that occurs as a result of a stress change. As residual stress is essentially a mean stress it is accepted that the linear form of the TSA relationship cannot be used to evaluate residual stresses. However, there are situations where this linear relationship is not valid or departures in material properties due to manufacturing procedures have enabled evaluations of residual stresses. The purpose of this paper is to review the current status of using a TSA based approach for the evaluation of residual stresses and to provide some examples of where promising results have been obtained.

  7. A review of residual stress analysis using thermoelastic techniques

    International Nuclear Information System (INIS)

    Robinson, A F; Dulieu-Barton, J M; Quinn, S; Burguete, R L

    2009-01-01

    Thermoelastic Stress Analysis (TSA) is a full-field technique for experimental stress analysis that is based on infra-red thermography. The technique has proved to be extremely effective for studying elastic stress fields and is now well established. It is based on the measurement of the temperature change that occurs as a result of a stress change. As residual stress is essentially a mean stress it is accepted that the linear form of the TSA relationship cannot be used to evaluate residual stresses. However, there are situations where this linear relationship is not valid or departures in material properties due to manufacturing procedures have enabled evaluations of residual stresses. The purpose of this paper is to review the current status of using a TSA based approach for the evaluation of residual stresses and to provide some examples of where promising results have been obtained.

  8. Analysis of residual stresses in a long hollow cylinder

    International Nuclear Information System (INIS)

    Tokovyy, Yuriy V.; Ma, Chien-Ching

    2011-01-01

    This paper presents an analytical method for solving the axisymmetric stress problem for a long hollow cylinder subjected to locally-distributed residual (incompatible) strains. This method is based on direct integration of the equilibrium and compatibility equations, which thereby have been reduced to the set of two governing equations for two key functions with corresponding boundary and integral conditions. The governing equations were solved by making use of the Fourier integral transformation. Application of the method is illustrated with an analysis of the welding residual stresses in a butt-welded thick-walled pipe. - Highlights: → A solution to the axisymmetric stress problem for a hollow cylinder is constructed. → The cylinder is subjected to a field of locally-distributed residual strains. → The method is based on direct integration of the equilibrium equations. → An application of our solution to analysis of welding residual stresses is considered.

  9. The Continuation Study of the Measurement of Residual Monomer from theDenture Base After Three Month Worn by Gas Chromatography on the Radiationand Non Radiation Worker

    International Nuclear Information System (INIS)

    Isyuniarto; Winoto

    2000-01-01

    Residual monomer measurement on the radiation and non radiation workerafter three month worn the denture has been done. The aim of the research isto investigated residual monomer concentration on after three month worn. Thedenture base material, made of resin acrylic, sometimes is cause mucosairritation in the mouth, and dental irritation or allergic reaction, becauseof residual monomer that left on the mouth cavity. In this research two groupwere needed there are the radiation and non radiation worker, the level ofthe residual monomer count by gas chromatography analysis. The result of thisresearch showed that the level of residual monomer of two group are same orthere have same level of the limit value. The measurement result is in therange of 0.1783 ± 0.011 mg/l to 0.1790 ± 0.004 mg/l. (author)

  10. Evaluation of greenhouse gas emission risks from storage of wood residue

    International Nuclear Information System (INIS)

    Wihersaari, Margareta

    2005-01-01

    The use of renewable energy sources instead of fossil fuels is one of the most important means of limiting greenhouse gas emissions in the near future. In Finland, wood energy is considered to be a very important potential energy source in this sense. There might, however, still be some elements of uncertainty when evaluating biofuel production chains. By combining data from a stack of composting biodegradable materials and forest residue storage research there was an indication that rather great amounts of greenhouse gases maybe released during storage of wood chip, especially if there is rapid decomposition. Unfortunately, there have not been many evaluations of greenhouse gas emissions of biomass handling and storage heaps. The greenhouse gas emissions are probably methane, when the temperature in the fuel stack is above the ambient temperature, and nitrous oxide, when the temperature is falling and the decaying process is slowing down. Nowadays it is still rather unusual to store logging residue as chips, because the production is small, but in Finland storage of bark and other by-products from the forest industry is a normal process. The evaluations made indicate that greenhouse gas emissions from storage can, in some cases, be much greater than emissions from the rest of the biofuel production and transportation chain

  11. Finite Element Residual Stress Analysis of Planetary Gear Tooth

    Directory of Open Access Journals (Sweden)

    Jungang Wang

    2013-01-01

    Full Text Available A method to simulate residual stress field of planetary gear is proposed. In this method, the finite element model of planetary gear is established and divided to tooth zone and profile zone, whose different temperature field is set. The gear's residual stress simulation is realized by the thermal compression stress generated by the temperature difference. Based on the simulation, the finite element model of planetary gear train is established, the dynamic meshing process is simulated, and influence of residual stress on equivalent stress of addendum, pitch circle, and dedendum of internal and external meshing planetary gear tooth profile is analyzed, according to non-linear contact theory, thermodynamic theory, and finite element theory. The results show that the equivalent stresses of planetary gear at both meshing and nonmeshing surface are significantly and differently reduced by residual stress. The study benefits fatigue cracking analysis and dynamic optimization design of planetary gear train.

  12. Analysis of pesticide residues Or a needle in a barn

    International Nuclear Information System (INIS)

    Heinsen, H.; Cesio, V.

    2012-01-01

    This work is about the analysis of pesticide residues as well as the study of soil, air, water and organisms. The solvents used depend on the matrix, types of pesticides, analysis and the equipment. The chromatography engaged with mass spectrometry is one of the most used techniques.

  13. Determination of insecticides malathion and lambda-cyhalothrin residues in zucchini by gas chromatography

    Directory of Open Access Journals (Sweden)

    Hayam M. Lofty

    2013-12-01

    Full Text Available A sensitive gas chromatographic method has been developed for the determination of malathion and lambda-cyhalothrin (λ-cyhalothrin insecticide residues in zucchini. The developed method consists of extraction with acetone, purification and partitioning with methylene chloride, column chromatographic clean-up, and finally capillary gas chromatographic determination of the insecticides. The recoveries of method were greater than 90% and limit of determination was 0.001 ppm for both insecticides. The method was applied to determine residues and the rate of disappearance of malathion and λ-cyhalothrin from fruits of zucchini (open field treatment, 50 cc of Malason/Cormandel 57% EC (emulsifiable concentrate for 100 L of water, 20 cc of LAMBDA SUPER FOG 5% liquid for 100 L of water. The insecticide incorporated into the plants decreased rapidly with a half-life time around 0.77 day (18.5h for malathion and 4 days for λ-cyhalothrin. It is not recommended to use zucchini before 12 h of malathion application. For λ-cyhalothrin, the preharvest interval is 5 days. Four market samples were chosen from different regions from A.R.E. and all of them showed no residues of malathion or λ-cyhalothrin.

  14. Energy and greenhouse gas balance of the use of forest residues for bioenergy production in the UK

    International Nuclear Information System (INIS)

    Whittaker, Carly; Mortimer, Nigel; Murphy, Richard; Matthews, Robert

    2011-01-01

    Life cycle analysis is used to assess the energy requirements and greenhouse gas (GHG) emissions associated with extracting UK forest harvesting residues for use as a biomass resource. Three forest harvesting residues were examined (whole tree thinnings, roundwood and brash bales), and each have their own energy and emission profile. The whole forest rotation was examined, including original site establishment, forest road construction, biomass harvesting during thinning and final clear-fell events, chipping and transportation. Generally, higher yielding sites give lower GHG emissions per ‘oven dried tonne’ (ODT) forest residues, but GHG emissions ‘per hectare’ are higher as more biomass is extracted. Greater quantities of biomass, however, ultimately mean greater displacement of conventional fuels and therefore greater potential for GHG emission mitigation. Although forest road construction and site establishment are “one off” events they are highly energy-intensive operations associated with high diesel fuel consumption, when placed in context with the full forest rotation, however, their relative contributions to the overall energy requirements and GHG emissions are small. The lower bulk density of wood chips means that transportation energy requirements and GHG emissions are higher compared with roundwood logs and brash bales, suggesting that chipping should occur near the end-user of application. -- Highlights: ► GHGs and fuel consumption assessed for UK clear-fell conifer forest residues. ► Energy use and GHG emissions for forest road construction characterised. ► Lower energy requirements and GHG emissions per ODT for higher yielding sites. ► Transport energy and GHG emissions higher for wood chip than roundwood or brash bales. ► Results useful in predicting GHG mitigation potential from UK commercial conifer forest residues.

  15. Residual Displacements‘ Progresive Analysis of the Multisupported Beam

    Directory of Open Access Journals (Sweden)

    Liudas Liepa

    2014-12-01

    Full Text Available This paper focuses on a shakedown behaviour of the ideally elasto-plastic beams system under variable repeated load. The mathematical models of the analysis problems are created using numerical methods, extremum energy principles and mathematic programming. It is shown that during the shakedown process the residual displacements vary non-monotonically. By solving analysis problem, where the load locus is being progressively expanded, it is possible to determine the upper and lower bounds of residual displacements. Suggested methods are ilustrated by solving multisupported beam example problem. The results are obtained considering principle of the small displacements.

  16. Sampling and sample processing in pesticide residue analysis.

    Science.gov (United States)

    Lehotay, Steven J; Cook, Jo Marie

    2015-05-13

    Proper sampling and sample processing in pesticide residue analysis of food and soil have always been essential to obtain accurate results, but the subject is becoming a greater concern as approximately 100 mg test portions are being analyzed with automated high-throughput analytical methods by agrochemical industry and contract laboratories. As global food trade and the importance of monitoring increase, the food industry and regulatory laboratories are also considering miniaturized high-throughput methods. In conjunction with a summary of the symposium "Residues in Food and Feed - Going from Macro to Micro: The Future of Sample Processing in Residue Analytical Methods" held at the 13th IUPAC International Congress of Pesticide Chemistry, this is an opportune time to review sampling theory and sample processing for pesticide residue analysis. If collected samples and test portions do not adequately represent the actual lot from which they came and provide meaningful results, then all costs, time, and efforts involved in implementing programs using sophisticated analytical instruments and techniques are wasted and can actually yield misleading results. This paper is designed to briefly review the often-neglected but crucial topic of sample collection and processing and put the issue into perspective for the future of pesticide residue analysis. It also emphasizes that analysts should demonstrate the validity of their sample processing approaches for the analytes/matrices of interest and encourages further studies on sampling and sample mass reduction to produce a test portion.

  17. [Determination of buprofezin, methamidophos, acephate, and triazophos residues in Chinese tea samples by gas chromatography].

    Science.gov (United States)

    Zhang, Shuiba; Yi, Jun; Ye, Jianglei; Zheng, Wenhui; Cai, Xueqin; Gong, Zhenbin

    2004-03-01

    A method has been developed for the simultaneous determination of buprofezin, methamidophos, acephate and triazophos residues in Chinese tea samples. The pesticide residues were extracted from tea samples with a mixture of ethyl acetate and n-hexane (50:50, v/v) at 45 degrees C. The extracts were subsequently treated with a column packed with 40 mg of active carbon by gradient elution with ethyl acetate and n-hexane. Buprofenzin and the three organophosphorus pesticides were analyzed by gas chromatography using a DB-210 capillary column and a nitrogen-phosphorus detector. The recoveries for spiked standards were 73.4%-96.9%. The relative standard deviations were all within 4.63%. The limits of quantitation (3sigma) in the tea samples were about 7.0-12.0 microg/kg.

  18. Analysis of banned veterinary drugs and herbicide residues in shellfish by liquid chromatography-tandem mass spectrometry (LC/MS/MS) and gas chromatography-tandem mass spectrometry (GC/MS/MS)

    International Nuclear Information System (INIS)

    Chang, Geng-Ruei; Chen, Hui-Shan; Lin, Feng-Yi

    2016-01-01

    Seafood safety is a crucial public health concern for consumers. In this study, we applied a validated method to analyze the residue of banned veterinary drugs in shellfish, namely chloramphenicol, malachite green, leucomalachite green, and nitrofuran metabolites; additionally, the QuEChERS method was employed to detect 76 herbicides by LC/MS/MS and GC/MS/MS. In total, 42 shellfish samples, which included hard clams, freshwater clams, and oysters, were collected from aquafarms and production areas in Taiwan during 2012. Our results revealed 3.8 ng/g of chloramphenicol in one hard clam, 19.9–32.1 ng/g of ametryn in two hard clams, 16.1–60.1 ng/g of pendimethalin in four hard clams, and 17.0 ng/g of mefenacet in one oyster, indicating that 19.1% of the samples contained residues from banned veterinary drugs and pesticides. These data can be used to monitor the residue of veterinary drugs and pesticides in aquatic organisms and as a reference for food safety. - Highlights: • A certified method was employed for analyzing residues of banned veterinary drugs and herbicides in shellfish samples. • The trace levels of chloramphenicol, ametryn, pendimethalin were detected in hard clam samples. • For ensuring food safety, continual monitoring of aquatic products is necessary.

  19. Radionuclides in Bayer process residues: previous analysis for radiological protection

    International Nuclear Information System (INIS)

    Cuccia, Valeria; Rocha, Zildete; Oliveira, Arno H. de

    2011-01-01

    Natural occurring radionuclides are present in many natural resources. Human activities may enhance concentrations of radionuclides and/or enhance potential of exposure to naturally occurring radioactive material (NORM). The industrial residues containing radionuclides have been receiving a considerable global attention, because of the large amounts of NORM containing wastes and the potential long term risks of long-lived radionuclides. Included in this global concern, this work focuses on the characterization of radioactivity in the main residues of Bayer process for alumina production: red mud and sand samples. Usually, the residues of Bayer process are named red mud, in their totality. However, in the industry where the samples were collected, there is an additional residues separation: sand and red mud. The analytical techniques used were gamma spectrometry (HPGe detector) and neutron activation analysis. The concentrations of radionuclides are higher in the red mud than in the sand. These solid residues present activities concentrations enhanced, when compared to bauxite. Further uses for the residues as building material must be more evaluated from the radiological point of view, due to its potential of radiological exposure enhancement, specially caused by radon emission. (author)

  20. The use of solid phase extraction method for analysis of residues of pesticides used in banana production in Costa Rica

    International Nuclear Information System (INIS)

    Castillo, L.E.; Ruepert, C.; Alfaro, A.R.; Solis, E.

    1999-01-01

    Different solid phase extraction devices were tested for the analysis of residues of eleven pesticides used in banana production in Costa Rica. The analysis was performed by using gas chromatograph equipped with NPD and ECD detectors. In general low recoveries and high variation coefficients were found for chlorothalonil, imazalil, terbufos and thiabendazole. For the other pesticides recoveries ranged between 60 and over 100%. (author)

  1. Removal of element mercury by medicine residue derived biochars in presence of various gas compositions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guoliang [School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401 (China); College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Shen, Boxiong, E-mail: shenbx@nankai.edu.cn [School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401 (China); College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Li, Yongwang [College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Zhao, Bin [School of Chemical Engineering, Hebei University of Technology, Tianjin 300401 (China); Wang, Fumei; He, Chuan; Wang, Yinyin; Zhang, Min [College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

    2015-11-15

    Highlights: • Both physisorption and chemisorption of Hg{sup 0} occurred on the surface of M6WN5. • Chemisorption process was an absolute predominant route for Hg{sup 0} removal by M6WN5. • The effect of NO, H{sub 2}O, SO{sub 2} and O{sub 2} on Hg{sup 0} removal by M6WN5 was investigated. • M6WN5 demonstrated to be a promising Hg{sup 0} sorbent in flue gas. - Abstract: Pyrolyzed biochars from an industrial medicinal residue waste were modified by microwave activation and NH{sub 4}Cl impregnation. Mercury adsorption of different modified biochars was investigated in a quartz fixed-bed reactor. The results indicated that both physisorption and chemisorption of Hg{sup 0} occurred on the surface of M6WN5 which was modified both microwave and 5 wt.% NH{sub 4}Cl loading, and exothermic chemisorption process was a dominant route for Hg{sup 0} removal. Microwave activation improved pore properties and NH{sub 4}Cl impregnation introduced good active sites for biochars. The presence of NO and O{sub 2} increased Hg{sup 0} adsorption whereas H{sub 2}O inhibited Hg{sup 0} adsorption greatly. A converse effect of SO{sub 2} was observed on Hg{sup 0} removal, namely, low concentration of SO{sub 2} promoted Hg{sup 0} removal obviously whereas high concentration of SO{sub 2} suppressed Hg{sup 0} removal. The Hg{sup 0} removal by M6WN5 was mainly due to the reaction of the C−Cl with Hg{sup 0} to form HgCl{sub 2}, and the active state of C−Cl{sup *} groups might be an intermediate group in this process. Thermodynamic analysis showed that mercury adsorption by the biochars was exothermic process and apparent adsorption energy was 43.3 kJ/mol in the range of chemisorption. In spite of low specific surface area, M6WN5 proved to be a promising Hg{sup 0} sorbent in flue gas when compared with other sorbents.

  2. Different Analytical Procedures for the Study of Organic Residues in Archeological Ceramic Samples with the Use of Gas Chromatography-mass Spectrometry.

    Science.gov (United States)

    Kałużna-Czaplińska, Joanna; Rosiak, Angelina; Kwapińska, Marzena; Kwapiński, Witold

    2016-01-01

    The analysis of the composition of organic residues present in pottery is an important source of information for historians and archeologists. Chemical characterization of the materials provides information on diets, habits, technologies, and original use of the vessels. This review presents the problem of analytical studies of archeological materials with a special emphasis on organic residues. Current methods used in the determination of different organic compounds in archeological ceramics are presented. Particular attention is paid to the procedures of analysis of archeological ceramic samples used before gas chromatography-mass spectrometry. Advantages and disadvantages of different extraction methods and application of proper quality assurance/quality control procedures are discussed.

  3. Beam loss in HIRFL-CSR due to collisions with residual gas in vacuum

    International Nuclear Information System (INIS)

    Tang Jingyu; Lei Wen; Wang Yifang

    1998-01-01

    The author discusses the collision of heavy ions with residual gas atoms in the vacuum and the cross-sections of the collision processes. The method calculating beam transmission efficiency in vacuum is presented taking HIRFL and CSR machine as examples. Based on rich experimental data, a series of empirical formulae of calculating the cross-section of charge changing process is given. The transmission efficiency curves of different sections in HIRFL and CSR are also calculated, and thus the reasonable requirements for HIRFL and CSR vacuum systems are given. The calculation method has been checked by the measurements of vacuum and beam loss in HIRFL

  4. Pesticide residues determination in Polish organic crops in 2007-2010 applying gas chromatography-tandem quadrupole mass spectrometry.

    Science.gov (United States)

    Walorczyk, Stanisław; Drożdżyński, Dariusz; Kowalska, Jolanta; Remlein-Starosta, Dorota; Ziółkowski, Andrzej; Przewoźniak, Monika; Gnusowski, Bogusław

    2013-08-15

    A sensitive, accurate and reliable multiresidue method based on the application of gas chromatography-tandem quadrupole mass spectrometry (GC-QqQ-MS/MS) has been established for screening, identification and quantification of a large number of pesticide residues in produce. The method was accredited in compliance with PN-EN ISO/IEC 17025:2005 standard and it was operated under flexible scope as PB-11 method. The flexible scope of accreditation allowed for minor modifications and extension of the analytical scope while using the same analytical technique. During the years 2007-2010, the method was used for the purpose of verification of organic crop production by multiresidue analysis for the presence of pesticides. A total of 528 samples of differing matrices such as fruits, vegetables, cereals, plant leaves and other green parts were analysed, of which 4.4% samples contained pesticide residues above the threshold value of 0.01 mg/kg. A total of 20 different pesticide residues were determined in the samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Study of composition change and agglomeration of flue gas cleaning residue from a fluidized bed waste incinerator.

    Science.gov (United States)

    Lievens, P; Verbinnen, B; Bollaert, P; Alderweireldt, N; Mertens, G; Elsen, J; Vandecasteele, C

    2011-10-01

    Blocking of the collection hoppers of the baghouse filters in a fluidized bed incinerator for co-incineration of high calorific industrial solid waste and sludge was observed. The composition of the flue gas cleaning residue (FGCR), both from a blocked hopper and from a normal hopper, was investigated by (differential) thermogravimetric analysis, quantitative X-ray powder diffraction and wet chemical analysis. The lower elemental carbon concentration and the higher calcium carbonate concentration of the agglomerated sample was the result of oxidation of carbon and subsequent reaction of CO2 with CaO. The evolved heat causes a temperature increase, with the decomposition of CaOHCl as a consequence. The formation of calcite and calcium chloride and the evolution of heat caused agglomeration of the FGCR. Activated lignite coke was replaced by another adsorption agent with less carbon, so the auto-ignition temperature increased; since then no further block formation has occurred.

  6. Residual stress analysis of drive shafts after induction hardening

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Guilherme Vieira Braga; Rocha, Alexandre da Silva; Nunes, Rafael Menezes, E-mail: lemos_gl@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Algre, RS (Brazil); Hirsch, Thomas Karl [Stiftung Institut für Werkstofftechnik (IWT), Bremen (Germany)

    2014-08-15

    Typically, for automotive shafts, shape distortion manifests itself in most cases after the induction hardening by an effect known as bending. The distortion results in a boost of costs, especially due to machining parts in the hardened state to fabricate its final tolerances. In the present study, residual stress measurements were carried out on automotive drive shafts made of DIN 38B3 steel. The samples were selected in consequence of their different distortion properties by an industrial manufacturing line. One tested shaft was straightened, because of the considerable dimensional variation and the other one not. Firstly, the residual stress measurements were carried out by using a portable diffractometer, in order to avoid cutting the shafts and evaluate the original state of the stresses, and afterwards a more detailed analysis was realized by a conventional stationary diffractometer. The obtained results presented an overview of the surface residual stress profiles after induction hardening and displayed the influence of the straightening process on the redistribution of residual stresses. They also indicated that the effects of the straightening in the residual stresses cannot be neglected. (author)

  7. Analysis of fenbendazole residues in bovine milk by ELISA.

    Science.gov (United States)

    Brandon, David L; Bates, Anne H; Binder, Ronald G; Montague, William C; Whitehand, Linda C; Barker, Steven A

    2002-10-09

    Fenbendazole residues in bovine milk were analyzed by ELISAs using two monoclonal antibodies. One monoclonal antibody (MAb 587) bound the major benzimidazole anthelmintic drugs, including fenbendazole, oxfendazole, and fenbendazole sulfone. The other (MAb 591) was more specific for fenbendazole, with 13% cross-reactivity with the sulfone and no significant binding to the sulfoxide metabolite. The limit of detection of the ELISA method in the milk matrix was 7 ppb for MAb 587 and 3 ppb for MAb 591. Fenbendazole was administered in feed, drench, and paste form to three groups of dairy cattle. Milk was collected immediately before dosing and then every 12 h for 5 days. The ELISA indicated that residue levels varied widely among individual cows in each group. Fenbendazole levels peaked at approximately 12-24 h and declined rapidly thereafter. Metabolites were detected at much higher levels than the parent compound, peaked at approximately 24-36 h, and declined gradually. Residue levels were undetectable by 72 h. The ELISA data correlated well with the total residues determined by chromatographic analysis, but the use of the two separate ELISAs did not afford an advantage over ELISA with the single, broadly reactive MAb 587. The ELISA method could be used to flag high-residue samples in on-site monitoring of fenbendazole in milk and is a potential tool for studying drug pharmacokinetics.

  8. Gas chromatographic determination with electron capture detection of residual ethylene oxide in intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, H.; Nakamura, A.; Tsuji, K.

    1988-01-01

    A sensitive method is described to determine trace quantities of ethylene oxide (EO) in EO-sterilized intraocular lenses (IOLs). An IOL is dipped in ethanol containing 0.25 ppm propylene oxide (PO) in a 4 mL vial, 2 drops of freshly distilled hydrobromic acid is added through a septum, and the mixture is warmed at 50/sup 0/C for 24 h. It is then neutralized by vigorous shaking with sodium bicarbonate, dehydrated with anhydrous sodium sulfate, and filtered. The filtrate is injected into a gas chromatograph with electron-capture detection, and the peak height ratio of ethylene bromohydrin/propylene bromohydrin is measured. EO residue is calculated from the calibration curve obtained through a similar procedure with the standard EO/PO solutions. The limit of determination is 0.04 ..mu..g/lens (ca 2.0 ppm). When EO residue levels were determined for IOLs sampled at 3 different aeration periods after stabilization, the authors found that 9 days of aeration was necessary to meet the US Food and Drug Administration proposed limit for EO residue in IOLs.

  9. Assessment of Pesticide Residues in Some Fruits Using Gas Chromatography Coupled with Micro Electron Capture Detector

    Directory of Open Access Journals (Sweden)

    M. I. Bhanger

    2011-12-01

    Full Text Available A very sensitive analytical method for the determination of 26 pesticides in some fruits based on solid phase extraction (SPE cleanup was developed using gas chromatography (GC coupled with micro electron capture detector (μECD. The identity of the pesticides was confirmed by gas chromatography mass spectroscopy (GC-MS using selected ion monitoring (SIM mode. Ethyl acetate was used as a solvent for the extraction of pesticide residues with assistance of sonication. For cleanup an octadecyl, C18 SPE column was used. A linear response of μECD was observed for all pesticides with good correlation coefficients (>0.9992. Proposed method was successfully applied for the determination of pesticide residues in the orange, apple, and grape fruits. Average recoveries achieved for all of the pesticides at fortification levels of 0.05, 1.0 and 2.0 μg g-1 in analyzed fruits were above 90% with relative standard deviations (RSD less than 6

  10. Gas chromatography with flame photometric detection of 31 organophosphorus pesticide residues in Alpinia oxyphylla dried fruits.

    Science.gov (United States)

    Zhao, Xiangsheng; Kong, Weijun; Wei, Jianhe; Yang, Meihua

    2014-11-01

    A simple, rapid and effective gas chromatography-flame photometric detection method was established for simultaneous multi-component determination of 31 organophosphorus pesticides (OPPs) residues in Alpinia oxyphylla, which is widely consumed as a traditional medicine and food in China. Sample preparation was completed in a single step without any clean-up procedure. All pesticides expressed good linear relationships between 0.004 and 1.0 μg/mL with correlation coefficients higher than 0.9973. The method gave satisfactory recoveries for most pesticides. The limits of detection varied from 1 to 10 ng/mL, and the limits of quantification (LOQs) were between 4 and 30 ng/mL. The proposed method was successfully applied to 55 commercial samples purchased from five different areas. Five pesticide residues were detected in four (7.27%) samples. The positive samples were confirmed by gas chromatography with tandem mass spectrometry (GC-MS/MS). Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. [Determination of residual toluene diisocyanate in sponge bra by gas chromatography].

    Science.gov (United States)

    Wang, Aixia; Ye, Ping; Huang, Nan; Chen, Yan; Li, Xinggen

    2017-06-08

    A gas chromatography (GC) with internal standard method was developed for the determination of residual toluene diisocyanate (TDI) in sponge bra. The samples were extracted with ethyl acetate dehydrated, and cleaned up with 0.22 μm microfiltration membrane. The residual toluene diisocyanate was separated on a DB-624 capillary column using temperature programming. The flame ionization detector (FID) was used at 250 ℃. The inlet temperature was 180 ℃ with nitrogen as carrier gas. The linear range was 10-200 mg/L ( R 2 =0.9989) for TDI. The average recovery ranged from 80.5% to 91.6% with RSD not more than 7.9%( n =6). The limit of detection (LOD) and limit of quantification (LOQ) were 10 mg/kg and 100 mg/kg, respectively. The developed method was then utilized to analyse the 100 batches of sponge bra samples from the manufacturing enterprises, the entity shops and electric business platforms. The method is simple, time-saving and environment friendly with high sensitivity and good reproducibility, and has practical application value due to its low-cost and short-circle.

  12. Neutron activation analysis for noble metals in matte leach residues

    International Nuclear Information System (INIS)

    Hart, R.J.

    1978-01-01

    The development of the neutron activation analysis technique as a method for rapid and precise determinations of platinum group metals in matte leach residues depends on obtaining a method for effecting complete and homogeneous sample dilution. A simple method for solid dilution of metal samples is outlined in this study, which provided a basis for the accurate determination of all the noble metals by the Neutron Activation Analysis technique

  13. Flow analysis of heavy metals in a pilot-scale incinerator for residues from waste electrical and electronic equipment dismantling

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Ding, Wei-Xu; Shen, Dong-Sheng, E-mail: shends@zju.edu.cn

    2013-10-15

    Highlights: • Cu, Zn, Pb, and Ni are enriched in bottom ash from WEEE dismantling residues. • The heavy metal residual fraction restricts transfer in the incinerator. • Pre-treatment to remove heavy metals from WEEE residues would reduce emissions. -- Abstract: The large amount of residues generated from dismantling waste electrical and electronic equipment (WEEE) results in a considerable environmental burden. We used material flow analysis to investigate heavy metal behavior in an incineration plant in China used exclusively to incinerate residues from WEEE dismantling. The heavy metals tested were enriched in the bottom and fly ashes after incineration. However, the contents of heavy metals in the bottom ash, fly ash and exhaust gas do not have a significant correlation with that of the input waste. The evaporation and recondensation behavior of heavy metals caused their contents to differ with air pollution control equipment because of the temperature difference during gas venting. Among the heavy metals tested, Cd had the strongest tendency to transfer during incineration (T{sub Cd} = 69.5%) because it had the lowest melting point, followed by Cu, Ni, Pb and Zn. The exchangeable and residual fractions of heavy metals increased substantially in the incineration products compared with that of the input residues. Although the mass of residues from WEEE dismantling can be reduced by 70% by incineration, the safe disposal of the metal-enriched bottom and fly ashes is still required.

  14. Flow analysis of heavy metals in a pilot-scale incinerator for residues from waste electrical and electronic equipment dismantling

    International Nuclear Information System (INIS)

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Ding, Wei-Xu; Shen, Dong-Sheng

    2013-01-01

    Highlights: • Cu, Zn, Pb, and Ni are enriched in bottom ash from WEEE dismantling residues. • The heavy metal residual fraction restricts transfer in the incinerator. • Pre-treatment to remove heavy metals from WEEE residues would reduce emissions. -- Abstract: The large amount of residues generated from dismantling waste electrical and electronic equipment (WEEE) results in a considerable environmental burden. We used material flow analysis to investigate heavy metal behavior in an incineration plant in China used exclusively to incinerate residues from WEEE dismantling. The heavy metals tested were enriched in the bottom and fly ashes after incineration. However, the contents of heavy metals in the bottom ash, fly ash and exhaust gas do not have a significant correlation with that of the input waste. The evaporation and recondensation behavior of heavy metals caused their contents to differ with air pollution control equipment because of the temperature difference during gas venting. Among the heavy metals tested, Cd had the strongest tendency to transfer during incineration (T Cd = 69.5%) because it had the lowest melting point, followed by Cu, Ni, Pb and Zn. The exchangeable and residual fractions of heavy metals increased substantially in the incineration products compared with that of the input residues. Although the mass of residues from WEEE dismantling can be reduced by 70% by incineration, the safe disposal of the metal-enriched bottom and fly ashes is still required

  15. Validation of pestice multi residue analysis method on cucumber

    International Nuclear Information System (INIS)

    2011-01-01

    In this study we aimed to validate the method of multi pesticide residue analysis on cucumber. Before real sample injection, system suitability test was performed in gas chromatography (GC). For this purpose, a sensitive pesticide mixture was used for GC-NPD and estimated the performance parameters such as number of effective theoretical plates, resolution factor, asymmetry, tailing and selectivity. It was detected that the system was suitable for calibration and sample injection. Samples were fortified at the level of 0.02, 0.2, 0.8 and 1 mg/kg with mixture of dichlorvos, malathion and chloropyrifos pesticides. In the fortification step 1 4C-carbaryl was also added on homogenized analytical portions to make use of 1 4C labelled pesticides for the determining extraction efficiency. Then the basic analytical process, such as ethyl acetate extraction, filtration, evaporation and cleanup, were performed. The GPC calibration using 1 4C- carbaryl and fortification mixture (dichlorvos, malathion and chloropyrifos) showed that pesticide fraction come through the column between the 8-23 ml fractions. The recovery of 1 4C-carbaryl after the extraction and cleanup step were 92.63-111.73 % and 74.83-102.22 %, respectively. The stability of pesticides during analysis is an important factor. In this study, stability test was performed including matrix effect. Our calculation and t test results showed that above mentioned pesticides were not stabile during sample processing in our laboratory conditions and it was found that sample comminution with dry ice may improve stability. In the other part of the study, 1 4C-chloropyrifos was used to determine homogeneity of analytical portions taken from laboratory samples. Use of 1 4C labelled pesticides allows us for quick quantification analyte, even with out clean-up. The analytical results show that after sample processing with waring blender, analytical portions were homogenous. Sample processing uncertainty depending on quantity of

  16. Greenhouse gas and energy analysis of substitute natural gas from biomass for space heat

    International Nuclear Information System (INIS)

    Pucker, Johanna; Zwart, Robin; Jungmeier, Gerfried

    2012-01-01

    In this paper, the greenhouse gas and energy balances of the production and use for space heating of substitute natural gas from biomass (bio-SNG) for space heat are analysed. These balances are compared to the use of natural gas and solid biomass as wood chips to provide the same service. The reduction of the greenhouse gas emissions (CO 2 -eq.) – carbon dioxide, methane and nitrous oxide – and of the fossil primary energy use is investigated in a life cycle assessment (LCA). This assessment was performed for nine systems for bio-SNG; three types of gasification technologies (O 2 -blown entrained flow, O 2 -blown circulating fluidised bed and air–steam indirect gasification) with three different types of feedstock (forest residues, miscanthus and short rotation forestry). The greenhouse gas analysis shows that forest residues using the air–steam indirect gasification technology result in the lowest greenhouse gas emissions (in CO 2 -eq. 32 kg MWh −1 of heat output). This combination results in 80% reduction of greenhouse gas emissions when compared to natural gas and a 29% reduction of greenhouse gases if the forest residues were converted to wood chips and combusted. The gasification technologies O 2 -blown entrained flow and O 2 -blown circulating fluidised bed gasification have higher greenhouse gas emissions that range between in CO 2 -eq. 41 to 75 kg MWh −1 of heat output depending on the feedstock. When comparing feedstocks in the bio-SNG systems, miscanthus had the highest greenhouse gas emissions bio-SNG systems producing in CO 2 -eq. 57–75 kg MWh −1 of heat output. Energy analysis shows that the total primary energy use is higher for bio-SNG systems (1.59–2.13 MWh MWh −1 of heat output) than for the reference systems (in 1.37–1.51 MWh MWh −1 of heat output). However, with bio-SNG the fossil primary energy consumption is reduced compared to natural gas. For example, fossil primary energy use is reduced by 92% when air

  17. OPIC Greenhouse Gas Emissions Analysis Details

    Data.gov (United States)

    Overseas Private Investment Corporation — Summary project inventory with independent analysis to quantify the greenhouse gas ("GHG") emissions directly attributable to projects to which the Overseas Private...

  18. Computer simulation of void formation in residual gas atom free metals by dual beam irradiation experiments

    International Nuclear Information System (INIS)

    Shimomura, Y.; Nishiguchi, R.; La Rubia, T.D. de; Guinan, M.W.

    1992-01-01

    In our recent experiments (1), we found that voids nucleate at vacancy clusters which trap gas atoms such as hydrogen and helium in ion- and neutron-irradiated copper. A molecular dynamics computer simulation, which implements an empirical embedded atom method to calculate forces that act on atoms in metals, suggests that a void nucleation occurs in pure copper at six and seven vacancy clusters. The structure of six and seven vacancy clusters in copper fluctuates between a stacking fault tetrahedron and a void. When a hydrogen is trapped at voids of six and seven vacancy, a void can keep their structure for appreciably long time; that is, the void do not relax to a stacking fault tetrahedron and grows to a large void. In order to explore the detailed atomics of void formation, it is emphasized that dual-beam irradiation experiments that utilize beams of gas atoms and self-ions should be carried out with residual gas atom free metal specimens. (author)

  19. An Approach Using Gas Monitoring to Find the Residual TCE Location in the Unsaturated Zone of Woosan Industrial Complex (WIC), Korea

    Science.gov (United States)

    Koh, Y.; Lee, S.; Yang, J.; Lee, K.

    2012-12-01

    An area accommodating various industrial facilities has fairly high probability of groundwater contamination with multiple chlorinated solvents such as trichloroethene (TCE), carbon tetrachloride (CT), and chloroform (CF). Source tracing of chlorinated solvents in the unsaturated zone is an essential procedure for the management and remediation of contaminated area. From the previous study on seasonal variations in hydrological stresses and spatial variations in geologic conditions on a TCE plume, the existence of residual DNAPLs at or above the water table has proved. Since TCE is one of the frequently detected VOCs (Volatile Organic Compounds) in groundwater, residual TCE can be detected by gas monitoring. Therefore, monitoring of temporal and spatial variations in the gas phase TCE contaminant at an industrial complex in Wonju, Korea, were used to find the residual TCE locations. As pilot tests, TCE gas samples collected in the unsaturated zone at 4 different wells were analyzed using SPME (Solid Phase MicroExtraction) fiber and Gas Chromatography (GC). The results indicated that detecting TCE in gas phase was successful from these wells and TCE analysis on gas samples, collected from the unsaturated zone, will be useful for source area characterization. However, some values were too high to doubt the accuracy of the current method, which needs a preliminary lab test with known concentrations. The modified experiment setups using packer at different depths are in process to find residual TCE locations in the unsaturated zone. Meanwhile, several PVD (polyethylene-membrane Passive Vapor Diffusion) samplers were placed under water table to detect VOCs by equilibrium between air in the vial and VOCs in pore water.

  20. Multi-Residue Analysis of Pesticide Residues in Crude Pollens by UPLC-MS/MS

    Directory of Open Access Journals (Sweden)

    Zhou Tong

    2016-12-01

    Full Text Available A multi-residue method for the determination of 54 pesticide residues in pollens has been developed and validated. The proposed method was applied to the analysis of 48 crude pollen samples collected from eight provinces of China. The recovery of analytes ranged from 60% to 136% with relative standard deviations (RSDs below 30%. Of the 54 targeted compounds, 19 pesticides were detected. The major detection rates of each compound were 77.1% for carbendazim, 58.3% for fenpropathrin, 56.3% for chlorpyrifos, 50.0% for fluvalinate, 31.3% for chlorbenzuron, and 29.2% for triadimefon in crude pollen samples. The maximum values of each pesticide were 4516 ng/g for carbendazim, 162.8 ng/g for fenpropathrin, 176.6 ng/g for chlorpyrifos, 316.2 ng/g for fluvalinate, 437.2 ng/g for chlorbenzuron, 79.00 ng/g for triadimefon, and so on. This study provides basis for the research on the risks to honeybee health.

  1. Spectral Envelopes and Additive + Residual Analysis/Synthesis

    Science.gov (United States)

    Rodet, Xavier; Schwarz, Diemo

    The subject of this chapter is the estimation, representation, modification, and use of spectral envelopes in the context of sinusoidal-additive-plus-residual analysis/synthesis. A spectral envelope is an amplitude-vs-frequency function, which may be obtained from the envelope of a short-time spectrum (Rodet et al., 1987; Schwarz, 1998). [Precise definitions of such an envelope and short-time spectrum (STS) are given in Section 2.] The additive-plus-residual analysis/synthesis method is based on a representation of signals in terms of a sum of time-varying sinusoids and of a non-sinusoidal residual signal [e.g., see Serra (1989), Laroche et al. (1993), McAulay and Quatieri (1995), and Ding and Qian (1997)]. Many musical sound signals may be described as a combination of a nearly periodic waveform and colored noise. The nearly periodic part of the signal can be viewed as a sum of sinusoidal components, called partials, with time-varying frequency and amplitude. Such sinusoidal components are easily observed on a spectral analysis display (Fig. 5.1) as obtained, for instance, from a discrete Fourier transform.

  2. Pyrolysis of automotive shredder residue for the production of fuel-grade gas

    International Nuclear Information System (INIS)

    Sharp, L.L.; Ness, R.O. Jr.

    1993-01-01

    Every year eight to ten million cars and trucks are disposed of by shredding at one of the 200 auto shredders located in the United States. Automotive shredder residue (ASR) is a by-product created in the dismantling of automobiles. Figure 1 illustrates the process by which ASR is generated. An automobile is stripped of useful and/or hazardous items, such as the gas tank, battery, tires, and radiator. Although it is beneficial to have these items removed for safety and environmental concerns, this is not always accomplished. After removal of some or all of these items, the automobile is shredded to provide a material less than 4 inches in size and composed of approximately 50% organic and 50% inorganic fractions. Ferrous scrap is then separated out magnetically. This ferrous scrap supplies the steel industry with 12 to 14 million tons per year for electric arc furnace feedstock. Air cyclone separators isolate a low density open-quotes fluffclose quotes from the nonferrous fraction (aluminum, copper, etc.). This fluff (shredder residue) is composed of a variety of plastics, fabrics, foams, glass, rubber, and an assortment of contaminants. Fluff bulk density is approximately 20 lb/ft

  3. Analysis of lifetime and residual strength of wood

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1997-01-01

    The present paper is thought of as a working paper for the CTBA-seminar on Thematic network in the field for reliability based design of timber structures, Topic: Numerical methods for structural analysis. It is preliminary and quite informal in its structure. The intention is to present some wood...... technological problems which can be solved with respect to lifetime and residual strength by the so-called DVM-theory (Damaged Viscoelastic Material). The outlines of the paper is straight on: Expressions are presented by which the analysis is made. then some examples are considered with solutions presented...

  4. [Determination of lambda-cyhalothrin residue tea and soil using gas chromatography].

    Science.gov (United States)

    Chen, Linglong; Chen, Jiuxing; Ma, Ming; Chen, Lihua; Yang, Hui; Zhang, Guiqun

    2010-08-01

    A gas chromatographic (GC) method was established for the determination of lambda-cyhalothrin residue in tea and soil. Tea and soil samples were extracted with hexane, separated by capillary column and determined by gas chromatography-electron capture detector (GC-ECD). The average recoveries of lambda-cyhalothrin in tea and soil were 89.0% - 94.1% and 89.8% - 94.7%, respectively at the spiking levels of 0.02 to 2.00 mg/kg. The corresponding relative standard deviations (RSDs, n = 5) were 3.0% -4.9% and 2.5% -4.2%, respectively. The limit of detection (S/N = 3) was 0.002 mg/kg for lambda-cyhalothrin. The degradations of 2.5% lambda-cyhalothrin microemulsion in tea and soil in Changsha, Hunan were investigated and the degradation equations were Y = 3.199 6e(-0.339 4x) and Y = 0.122 4e(-0.103 6x) with the correlation coefficients of 0.995 6 and 0.924 7, respectively. The half-lives of lambda-cyhalothrin in tea and soil were 2.04 days and 6.69 days, respectively.

  5. Mining utilization of residues of exhaust gas cleaning from waste incinerators; Bergtechnische Verwertung von Abgasreinigungsrueckstaenden aus Verbrennungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Werthmann, Rainer [K+S Entsorgung GmbH, Kassel (Germany). Abfallchemie und Zulassungen

    2013-03-01

    The exhaust gas purification of a household incinerator or a substitute fuel power plant intends to remove dust, heavy metal compounds and acid harmful gases from the exhaust gas in order to comply with the immission-control legal limits. The particulate matter contains volatile heavy metal chlorides which precipitate as a solid matter. The enhanced amount of water-soluble salts is conspicuous. The concentration of soluble components is limited to 10,000 mg/L in the 1:10 eluate due to the landfill regulation. Thus, the residues of exhaust gas cleaning are predestined for an underground waste disposal in salt mines. Under this aspect, the author of the contribution under consideration reports on the mining utilization of residues of exhaust gas cleaning from waste incinerators.

  6. A gas conditioning and analysis system

    International Nuclear Information System (INIS)

    Busch, F.R.

    1974-01-01

    A system for carrying out a rapid analysis of explosive gas-mixtures is described. This system comprises a conduit connecting a sample taking point to a detection chamber, said chamber containing a mass of liquid into which the gas sample is discharged and being provided with a detecting unit for analyzing gases and with separate gas exit and liquid exit. The liquid is sent to a level-regulating chamber, whereas said gas exit sends the gas to a gas-stopping chamber which is in turn, connected to the conduit leading to a discharge point, and a vacuum pump for drawing up the gas sample into the system. This can be apply to nuclear power stations [fr

  7. Practical analysis of specificity-determining residues in protein families.

    Science.gov (United States)

    Chagoyen, Mónica; García-Martín, Juan A; Pazos, Florencio

    2016-03-01

    Determining the residues that are important for the molecular activity of a protein is a topic of broad interest in biomedicine and biotechnology. This knowledge can help understanding the protein's molecular mechanism as well as to fine-tune its natural function eventually with biotechnological or therapeutic implications. Some of the protein residues are essential for the function common to all members of a family of proteins, while others explain the particular specificities of certain subfamilies (like binding on different substrates or cofactors and distinct binding affinities). Owing to the difficulty in experimentally determining them, a number of computational methods were developed to detect these functional residues, generally known as 'specificity-determining positions' (or SDPs), from a collection of homologous protein sequences. These methods are mature enough for being routinely used by molecular biologists in directing experiments aimed at getting insight into the functional specificity of a family of proteins and eventually modifying it. In this review, we summarize some of the recent discoveries achieved through SDP computational identification in a number of relevant protein families, as well as the main approaches and software tools available to perform this type of analysis. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  8. Mineral analysis, anthocyanins and phenolic compounds in wine residues flour

    Directory of Open Access Journals (Sweden)

    Bennemann Gabriela Datsch

    2016-01-01

    Full Text Available This study analyzed the mineral content (N, P, K, S, Ca, Fe, Mg, Mn, Fe and Zn, anthocyanins and phenolic compounds in flours produced from residues of different grape cultivars from the wineries in the Southern region of Brazil. Mineral analysis showed a significant difference for all grape cultivar, with the exception for phosphorus content. Residues from cv. Seibel showed higher levels of N, Cu and Mg. The cultivars Ancelotta, Tanat and Bordô present higher contents of K, Zn, Mn, Fe and Ca. For the concentration of anthocyanins, cultivars Cabernet Sauvignon (114.7 mg / 100g, Tannat (88.5 mg / 100 g and Ancelotta (33.8 mg/100 g had the highest concentrations. The cultivars Pinot Noir (7.0 g AGE / 100 g, Tannat (4.3 g AGE / 100 g, and Ancelotta (3.9 g AGE / 100 g had the highest content of phenolic compounds. Considering these results, it became evident the potential of using the residue of winemaking to produce flour for human consumption, highlighting the grapes ‘Tannat' and ‘Ancellotta'.

  9. Quality control of residual solvents in [18F]FDG preparations by gas chromatography

    International Nuclear Information System (INIS)

    Lee, Hak Jeong; Jeong, Jae Min; Lee, Yun Sang; Kim, Hyung Woo; Chang, Young Soo; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

    2007-01-01

    Analysis of volatile organic solvents in 2-deoxy-2[ 18 F] fluoro-D-glucose ([ 18 F]FDG) preparations was performed by gas chromatography (GC), in accordance with USP. Analyses were carried out on a Hewlett-Packard 6890 gas chromatography equipped with an FID. We determined the amounts of ethanol and acetonitrile on every batch of our routine [ 18 F]FDG preparations, ranging between 5000 ppm and 100 ppm. In our routine preparation of [ 18 F]FDG, the amount of acetonitrile and ethanol in the final product were well below the maximum allowable limit described in the USP. Our [ 18 F]FDG preparations were in accordance with the suggested USP maximum allowable levels of the quality control analysis of volatile organic compounds

  10. Residual symptoms and functioning in depression, does the type of residual symptom matter? A post-hoc analysis

    Directory of Open Access Journals (Sweden)

    Romera Irene

    2013-02-01

    Full Text Available Abstract Background The degrees to which residual symptoms in major depressive disorder (MDD adversely affect patient functioning is not known. This post-hoc analysis explored the association between different residual symptoms and patient functioning. Methods Patients with MDD who responded (≥50% on the 17-item Hamilton Rating Scale for Depression; HAMD-17 after 3 months of treatment (624/930 were included. Residual core mood-symptoms (HAMD-17 core symptom subscale ≥1, residual insomnia-symptoms (HAMD-17 sleep subscale ≥1, residual anxiety-symptoms (HAMD-17-anxiety subscale ≥1, residual somatic-symptoms (HAMD-17 Item 13 ≥1, pain (Visual Analogue Scale ≥30, and functioning were assessed after 3 months treatment. A stepwise logistic regression model with normal functioning (Social and Occupational Functioning Assessment Scale ≥80 as the dependent variable was used. Results After 3 months, 59.5% of patients (371/624 achieved normal functioning and 66.0% (412/624 were in remission. Residual symptom prevalence was: core mood symptoms 72%; insomnia 63%; anxiety 78%; and somatic symptoms 41%. Pain reported in 18%. Factors associated with normal functioning were absence of core mood symptoms (odds ratio [OR] 8.7; 95% confidence interval [CI], 4.6–16.7, absence of insomnia symptoms (OR 1.8; 95% CI, 1.2–2.7, episode length (4–24 weeks vs. ≥24 weeks [OR 2.0; 95% CI, 1.1–3.6] and better baseline functioning (OR 1.0; 95% CI, 1.0–1.1. A significant interaction between residual anxiety symptoms and pain was found (p = 0.0080. Conclusions Different residual symptoms are associated to different degrees with patient functioning. To achieve normal functioning, specific residual symptoms domains might be targeted for treatment.

  11. Quantitative analysis of deuterium by gas chromatography

    International Nuclear Information System (INIS)

    Isomura, Shohei; Kaetsu, Hayato

    1981-01-01

    An analytical method for the determination of deuterium concentration in water and hydrogen gas by gas chromatography is described. HD and D 2 in a hydrogen gas sample were separated from H 2 by a column packed with Molecular Sieve 13X, using extra pure hydrogen gas as carrier. A thermal conductivity detector was used. Concentrations of deuterium were determined by comparison with standard samples. The error inherent to the present method was less a 1% on the basis of the calibration curves obtained with the standard samples. The average time required for the analysis was about 3 minutes. (author)

  12. Forensic analysis of explosive residues from hand swabs

    International Nuclear Information System (INIS)

    Umi Khairul Ahmad; Sumathy Rajendran; Syahidah Abu Hassan

    2008-01-01

    In the forensic examination of physical evidence for organic explosives, cotton swabs are often used to collect residue from surfaces, such as skin and post-blast debris. A preliminary study has been conducted to develop extraction method of a common energetic compound, pentaerythritol tetranitrate (PETN) from hand swabs followed by direct analysis of the resulting extract solution using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detector. Analysis was performed on an octadecylsilane-based (C 18 ) column using acetonitrile-water mixture (55:45) as mobile phase. The mobile phase was pumped at 1.0 mL/ min and separation affected using an isocratic mode with the detection wavelength of 230 nm. The explosive residue was extracted from cotton swabs using acetone in an ultrasonic cold bath. The developed method was later applied to the real hand swabs samples, which were taken from three army personnel who handled PETN during a munition disposal operation at Asahan Camp Military Firing range. The acetone extract obtained using sonication method was found to be effective in recovering PETN from cotton swabs with relatively high recovery (89.5 %) and good sensitivity with detection limit as low as 2 ng. The content of PETN in the real hand swab samples were found to be in the range of 4.7-130 mg. (author)

  13. Method for the Collection, Gravimetric and Chemical Analysis of Nonvolatile Residue (NVR) on Surfaces

    Science.gov (United States)

    Gordon, Keith; Rutherford, Gugu; Aranda, Denisse

    2017-01-01

    Nonvolatile residue (NVR), sometimes referred to as molecular contamination is the term used for the total composition of the inorganic and high boiling point organic components in particulates and molecular films deposited on critical surfaces surrounding space structures, with the particulate and NVR contamination originating primarily from pre-launch operations. The "nonvolatile" suggestion from the terminology NVR implies that the collected residue will not experience much loss under ambient conditions. NVR has been shown to have a dramatic impact on the ability to perform optical measurements from platforms based in space. Such contaminants can be detected early by the controlled application of various detection techniques and contamination analyses. Contamination analyses are the techniques used to determine if materials, components, and subsystems can be expected to meet the performance requirements of a system. Of particular concern is the quantity of NVR contaminants that might be deposited on critical payload surfaces from these sources. Subsequent chemical analysis of the contaminant samples by infrared spectroscopy and gas chromatography mass spectrometry identifies the components, gives semi-quantitative estimates of contaminant thickness, indicates possible sources of the NVR, and provides guidance for effective cleanup procedures. In this report, a method for the collection and determination of the mass of NVR was generated by the authors at NASA Langley Research Center. This report describes the method developed and implemented for collecting NVR contaminants, and procedures for gravimetric and chemical analysis of the residue obtained. The result of this NVR analysis collaboration will help pave the way for Langley's ability to certify flight hardware outgassing requirements in support of flight projects such as Stratospheric Aerosol and Gas Experiment III (SAGE III), Clouds and the Earth's Radiant Energy System (CERES), Materials International

  14. Longitudinal and transverse dynamics of ions from residual gas in an electron accelerator

    Science.gov (United States)

    Gamelin, A.; Bruni, C.; Radevych, D.

    2018-05-01

    The ion cloud produced from residual gas in an electron accelerator can degrade machine performances and produce instabilities. The ion dynamics in an accelerator is governed by the beam-ion interaction, magnetic fields and eventual mitigation strategies. Due to the fact that the beam has a nonuniform transverse size along its orbit, the ions move longitudinally and accumulate naturally at some points in the accelerator. In order to design effective mitigation strategies it is necessary to understand the ion dynamics not only in the transverse plane but also in the longitudinal direction. After introducing the physics behind the beam-ion interaction, we show how to get accumulation points for a realistic electron storage ring lattice. Simulations of the ion cloud dynamics, including the effect of magnetic fields on the ions, clearing electrodes and clearing gaps are shown. Longitudinal ion trapping due to the magnetic mirror effect in the dipole fringe fields is also detailed. Finally, the effectiveness of clearing electrode using longitudinal clearing fields is discussed and compared to clearing electrodes producing transverse field only.

  15. Sensitivity of Emissions to Uncertainties in Residual Gas Fraction Measurements in Automotive Engines: A Numerical Study

    Directory of Open Access Journals (Sweden)

    S. M. Aithal

    2018-01-01

    Full Text Available Initial conditions of the working fluid (air-fuel mixture within an engine cylinder, namely, mixture composition and temperature, greatly affect the combustion characteristics and emissions of an engine. In particular, the percentage of residual gas fraction (RGF in the engine cylinder can significantly alter the temperature and composition of the working fluid as compared with the air-fuel mixture inducted into the engine, thus affecting engine-out emissions. Accurate measurement of the RGF is cumbersome and expensive, thus making it hard to accurately characterize the initial mixture composition and temperature in any given engine cycle. This uncertainty can lead to challenges in accurately interpreting experimental emissions data and in implementing real-time control strategies. Quantifying the effects of the RGF can have important implications for the diagnostics and control of internal combustion engines. This paper reports on the use of a well-validated, two-zone quasi-dimensional model to compute the engine-out NO and CO emission in a gasoline engine. The effect of varying the RGF on the emissions under lean, near-stoichiometric, and rich engine conditions was investigated. Numerical results show that small uncertainties (~2–4% in the measured/computed values of the RGF can significantly affect the engine-out NO/CO emissions.

  16. Trends and advances in pesticide residue analysis | Yeboah ...

    African Journals Online (AJOL)

    The nature, origin and the economic significance of pesticide residues are reviewed to underscore the need for countries to develop the ability and capacity to monitor pesticide residues. An overview of pesticide residues analytical procedures is also presented with emphasis on thin layer chromatography (TLC) as an ...

  17. Image Analysis to Estimate Mulch Residue in Soil

    Directory of Open Access Journals (Sweden)

    Carmen Moreno

    2014-01-01

    Full Text Available Mulching is used to improve the condition of agricultural soils by covering the soil with different materials, mainly black polyethylene (PE. However, problems derived from its use are how to remove it from the field and, in the case of it remaining in the soil, the possible effects on it. One possible solution is to use biodegradable plastic (BD or paper (PP, as mulch, which could present an alternative, reducing nonrecyclable waste and decreasing the environmental pollution associated with it. Determination of mulch residues in the ground is one of the basic requirements to estimate the potential of each material to degrade. This study has the goal of evaluating the residue of several mulch materials over a crop campaign in Central Spain through image analysis. Color images were acquired under similar lighting conditions at the experimental field. Different thresholding methods were applied to binarize the histogram values of the image saturation plane in order to show the best contrast between soil and mulch. Then the percentage of white pixels (i.e., soil area was used to calculate the mulch deterioration. A comparison of thresholding methods and the different mulch materials based on percentage of bare soil area obtained is shown.

  18. Forensic Analysis of High Explosive Residues from Selected Cloth

    International Nuclear Information System (INIS)

    Mohamad Afiq Mohamed Huri; Umi Kalthom Ahmad

    2014-01-01

    Increased terrorist activities around the Asian region have resulted in the need for improved analytical techniques in forensic analysis. High explosive residues from post-blast clothing are often encountered as physical evidence submitted to a forensic laboratory. Therefore, this study was initiated to detect high explosives residues of cyclotrimethylenetrinitramine (RDX) and pentaerythritol tetranitrate (PETN) on selected cloth in this study. Cotton swabbing technique was employed as a simple and rapid method in recovering analytes from the sample matrix. Analytes were analyzed using Griess spot test, TLC and HPLC. TLC separation employed toluene-ethyl acetate (9:1) as a good solvent system. Reversed phase HPLC separation employed acetonitrile-water (65:35) as the mobile phase and analytes detected using a programmed wavelength. RDX was detected at 235 nm for the first 3.5 min and then switched to 215 nm for PETN. Limits of detection (LODs) of analytes were in the low ppm range (0.05 ppm for RDX and 0.25 ppm for PETN). Analyte recovery studies revealed that the type of cloth has a profound effect on the extraction efficiency. Analytes were recovered better for nylon as compared to cotton cloth. However, no analytes could be recovered from denim cloth. For post-blast samples, only RDX was detected in low concentration for both nylon and cotton cloth. (author)

  19. Determination of pesticide residues in animal origin baby foods by gas chromatography coupled with triple quadrupole mass spectrometry.

    Science.gov (United States)

    Amendola, Graziella; Pelosi, Patrizia; Attard Barbini, Danilo

    2015-01-01

    A simple, fast and multiresidue method for the determination of pesticide residues in baby foods of animal origin has been developed in order to check the compliance with the Maximum Residue Levels (MRLs) set at a general value of 0.01 mg/kg by Commission Directive 2006/125/EC for infant foods. The main classes of organochlorine, organophosphorus and pyrethroid compounds have been considered, which are mainly fat soluble pesticides. The analytical procedure consists in the extraction of baby food samples by acetonitrile (ACN) followed by a clean up using C18 solid-phase extraction column eluted with ACN. The compounds were determined by gas chromatography-triple quadrupole mass spectrometry equipped with a Programmed Temperature Vaporizer (PTV) injection and a backflush system. In order to compensate for matrix effects PTV and matrix matched standard calibrations have been used. The method has been fully validated for 57 pesticides according to the Document SANCO/12571/2013. Accuracy and precision (repeatability) have been studied by recoveries at two spiking levels, the Limit of Quantitation (LOQ) (0.003-0.008 mg/kg) and 10 time greater (0.03-0.08 mg/kg), and the results were in the acceptable range of 70-120% with Relative Standards Deviations (RSD) ≤20%. Selectivity, linearity, LOQ and uncertainty of measurement were also determined for all the compounds. The method has been also applied for the analysis of 18 baby food animal origin samples, bought form the local market in Rome (Italy), and no pesticide in the scope of the method has been found above the MRL or the LOQ.

  20. Residual stress analysis in BWR pressure vessel attachments

    International Nuclear Information System (INIS)

    Dexter, R.J.; Leung, C.P.; Pont, D.

    1992-06-01

    Residual stresses from welding processes can be the primary driving force for stress corrosion cracking (SCC) in BWR components. Thus, a better understanding of the causes and nature of these residual stresses can help assess and remedy SCC. Numerical welding simulation software, such as SYSWELD, and material property data have been used to quantify residual stresses for application to SCC assessments in BWR components. Furthermore, parametric studies using SYSWELD have revealed which variables significantly affect predicted residual stress. Overall, numerical modeling techniques can be used to evaluate residual stress for SCC assessments of BWR components and to identify and plan future SCC research

  1. Comparative analysis of different methods of extraction of present hydrocarbons in industrial residual waters

    International Nuclear Information System (INIS)

    Santa, Judith Rocio; Serrano, Martin; Stashenko, Elena

    2002-01-01

    A comparison among four extraction techniques such as: liquid - liquid (LLE) continuous and for lots, solid phase extraction (SPE), solid phase micro extraction (SPME) and static headspace (S-HS) was carried out. The main purpose of this research was to determine the highest recovery efficiencies and how reproducible the tests are while varying parameters such as time, extraction technique, type of solvents and others. Chromatographic parameters were optimized in order to carry out the analyses. Hydrocarbon's quantification of residual waters was achieved by using a high-resolution gas chromatography with a gas flame ionization detector (HRGC-FID). Validation of the method was carried out by analyzing real samples taken in different sampling places of the residual waters treatment plant of Ecopetrol - Barrancabermeja. The use of extraction methods that require big solvent quantities and long time for analysis are losing validity day by day. Techniques such as the HS-SPME and static HS are offered as alternatives for quantifying hydrocarbons. They show total lack of solvents, high sensibility, selectivity and the techniques are reproducible. Solid phase micro extraction (SPME) and static headspace (static HS) techniques were chosen as the extraction techniques to validate the method in real samples. Both techniques showed similar results for the determination of total hydrocarbons (in the gasoline range)

  2. Probabilistic Analysis of Gas Turbine Field Performance

    Science.gov (United States)

    Gorla, Rama S. R.; Pai, Shantaram S.; Rusick, Jeffrey J.

    2002-01-01

    A gas turbine thermodynamic cycle was computationally simulated and probabilistically evaluated in view of the several uncertainties in the performance parameters, which are indices of gas turbine health. Cumulative distribution functions and sensitivity factors were computed for the overall thermal efficiency and net specific power output due to the thermodynamic random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design, enhance performance, increase system availability and make it cost effective. The analysis leads to the selection of the appropriate measurements to be used in the gas turbine health determination and to the identification of both the most critical measurements and parameters. Probabilistic analysis aims at unifying and improving the control and health monitoring of gas turbine aero-engines by increasing the quality and quantity of information available about the engine's health and performance.

  3. Image Analysis to Estimate Mulch Residual on Soil

    Science.gov (United States)

    Moreno Valencia, Carmen; Moreno Valencia, Marta; Tarquis, Ana M.

    2014-05-01

    Organic farmers are currently allowed to use conventional polyethylene mulch, provided it is removed from the field at the end of the growing or harvest season. To some, such use represents a contradiction between the resource conservation goals of sustainable, organic agriculture and the waste generated from the use of polyethylene mulch. One possible solution is to use biodegradable plastic or paper as mulch, which could present an alternative to polyethylene in reducing non-recyclable waste and decreasing the environmental pollution associated with it. Determination of mulch residues on the ground is one of the basic requisites to estimate the potential of each material to degrade. Determination the extent of mulch residue on the field is an exhausting job while there is not a distinct and accurate criterion for its measurement. There are several indices for estimation the residue covers while most of them are not only laborious and time consuming but also impressed by human errors. Human vision system is fast and accurate enough in this case but the problem is that the magnitude must be stated numerically to be reported and to be used for comparison between several mulches or mulches in different times. Interpretation of the extent perceived by vision system to numerals is possible by simulation of human vision system. Machine vision comprising image processing system can afford these jobs. This study aimed to evaluate the residue of mulch materials over a crop campaign in a processing tomato (Solanum lycopersicon L.) crop in Central Spain through image analysis. The mulch materials used were standard black polyethylene (PE), two biodegradable plastic mulches (BD1 and BD2), and one paper (PP1) were compared. Meanwhile the initial appearance of most of the mulches was sort of black PE, at the end of the experiment the materials appeared somewhat discoloured, soil and/or crop residue was impregnated being very difficult to completely remove them. A digital camera

  4. Evaluation of Pentachlorophenol Residues in Some Hygienic Papers Prepared from Virgin and Secondary Pulp by Electron Capture Gas Chromatographic Method

    Directory of Open Access Journals (Sweden)

    Behrouz Akbari-adergani

    2016-01-01

    Full Text Available In this study, residual amount of pentachlorophenol (PCP as the most important paper preservative, which is extremely hazardous pollutant, was determined in some tissue papers and napkins. Twenty-five samples of two producing hygienic paper factories prepared from virgin and secondary pulp were analyzed for the presence of trace amount of PCP. The analytical procedure involved direct extraction of PCP from hygienic paper and its determination by gas chromatography with electron capture detection. The statistical results for the analysis of all samples revealed that there were significant differences between mean of PCP in hygienic papers prepared from virgin and secondary pulp (P<0.05. This method gave recoveries of 86-98% for hygienic paper made from virgin pulp and 79-92% for hygienic paper made from secondary pulp. The limit of detection (LOD and limit of quantification (LOQ for PCP were 6.3 and 21.0 mg/kg, respectively. The analytical method has the requisite sensitivity, accuracy, precision and specificity to assay PCP in hygienic papers. This study demonstrates a concern with exposition to PCP considering that hygienic paper is largely consumed in the society.

  5. Observations of changes in residual gas and surface composition with discharge cleaning in PLT

    International Nuclear Information System (INIS)

    Dylla, H.F.; Bol, K.; Cohen, S.A.; Hawryluk, R.J.; Meservey, E.B.; Rossnagel, S.M.

    1978-10-01

    Hydrogen discharge cleaning of the PLT vacuum vessel has been studied by mass spectroscopy of desorbed gases and surface analysis of exposed samples. Several modes of vessel conditioning have been studied to date: (1) a high power discharge cleaning (PDC) mode, with a peak power density to the vessel wall P/sub s/ approximately 0.6 w/cm 2 and a peak electron temperature T/sub e/ approximately 100 ev; (2) low power (Taylor-type) discharge cleaning (TDC) with P/sub s/ approximately 0.05 w/cm 2 and T/sub e/ equal to or less than 5 eV. The predominant residual gases produced during PDC are CH 4 (1-5 x 10 -6 torr) and CO (1-10 x 10 -7 torr), whereas TDC produced primarily H 2 O (1-2 x 10 -6 torr) and CH 4 (1-10 x 10 -7 torr). In situ surface analysis of hydrocarbon-covered stainless steel has shown significant decreases in carbon coverage occurring after 10 3 -10 4 pulses of either cleaning mode. Observed changes in oxygen coverage are more difficult to interpret because of the presence of the nascent oxide layer on the stainless steel substrates

  6. Longitudinal Analysis of Residual Feed Intake in Mink using Random Regression with Heterogeneous Residual Variance

    DEFF Research Database (Denmark)

    Shirali, Mahmoud; Nielsen, Vivi Hunnicke; Møller, Steen Henrik

    Heritability of residual feed intake (RFI) increased from low to high over the growing period in male and female mink. The lowest heritability for RFI (male: 0.04 ± 0.01 standard deviation (SD); female: 0.05 ± 0.01 SD) was in early and the highest heritability (male: 0.33 ± 0.02; female: 0.34 ± 0.......02 SD) was achieved at the late growth stages. The genetic correlation between different growth stages for RFI showed a high association (0.91 to 0.98) between early and late growing periods. However, phenotypic correlations were lower from 0.29 to 0.50. The residual variances were substantially higher...

  7. Isolation of residuals using trend surface analysis to magnetic data ...

    African Journals Online (AJOL)

    Polynomial surfaces of various degrees are fitted to a magnetic data of Awo area, southwestern Nigeria with the aim of isolating the residuals of the area associated with mineralogy. The fourth degree surface correlates better with the magnetic map of the study area. The residualized data were obtained by subtracting the ...

  8. Gas chromatographic determination of residual hydrazine and morpholine in boiler feed water and steam condensates

    International Nuclear Information System (INIS)

    Vatsala, S.; Bansal, V.; Tuli, D.K.; Rai, M.M.; Jain, S.K.; Srivastava, S.P.; Bhatnagar, A.K.

    1994-01-01

    Hydrazine, an oxygen scavenger in boiler water, was derivatised to the corresponding acetone azine and determined at the ng ml -1 level by gas chromatography. Morpholine, a corrosion inhibitor used in steam boilers, was estimated either directly (if >2.0 μg ml -1 ) or by quantitative preconcentration (0.1 ng-2.0 μg ml -1 ). To obtain symmetrical peaks for these amines, the column packing was coated with KOH. Use of a nitrogen-specific detector improved accuracy of estimation of hydrazine and morpholine, giving a RSD of 1.9-3.6%. Chromatographic analysis of these amines in boiler feed water and steam condensate samples collected from boilers servicing a pertroleum refinery is described. Environmental safety regulations calls for monitoring of hydrazine and the methods developed can easily be adapted for this purpose. (orig.)

  9. A Multi-Factor Analysis of Sustainable Agricultural Residue Removal Potential

    Energy Technology Data Exchange (ETDEWEB)

    Jared Abodeely; David Muth; Paul Adler; Eleanor Campbell; Kenneth Mark Bryden

    2012-10-01

    Agricultural residues have significant potential as a near term source of cellulosic biomass for bioenergy production, but sustainable removal of agricultural residues requires consideration of the critical roles that residues play in the agronomic system. Previous work has developed an integrated model to evaluate sustainable agricultural residue removal potential considering soil erosion, soil organic carbon, greenhouse gas emission, and long-term yield impacts of residue removal practices. The integrated model couples the environmental process models WEPS, RUSLE2, SCI, and DAYCENT. This study uses the integrated model to investigate the impact of interval removal practices in Boone County, Iowa, US. Residue removal of 4.5 Mg/ha was performed annually, bi-annually, and tri-annually and were compared to no residue removal. The study is performed at the soil type scale using a national soil survey database assuming a continuous corn rotation with reduced tillage. Results are aggregated across soil types to provide county level estimates of soil organic carbon changes and individual soil type soil organic matter content if interval residue removal were implemented. Results show interval residue removal is possible while improving soil organic matter. Implementation of interval removal practices provide greater increases in soil organic matter while still providing substantial residue for bioenergy production.

  10. Agricultural residues as fuel for producer gas generation. Report from a test series with coconut shells, coconut husks, wheat straw and sugar cane

    Energy Technology Data Exchange (ETDEWEB)

    Hoeglund, C

    1981-08-01

    This paper reports on results from a series of tests with four different types of agricultural residues as fuel for producer gas generation. The fuels are coconut shells, coconut husks, pelletized wheat straw and pressed sugar cane. The tests were made with a 73 Hp agricultural tractor diesel engine equipped with a standard gasifier developed for wood chips in Sweden, and run on a testbed at the Swedish National Machinery Testing Institute. The engine was operated on approximately 10 per cent diesel oil and 90 per cent producer gas. The gas composition, its calorific value and temperature, the pressure drop and the engine power were monitored. Detailed elementary analysis of the fuel and gas were carried out. Observations were also made regarding the important aspects of bridging and slagging in the gasifier. The tests confirmed that coconut shells make an excellent fuel for producer gas generation. After 8 hours of running no problems with slags and bridging were experienced. Coconut husks showed no bridging but some slag formation. The gasifier operated satisfactorily for this fuel. Pelletized wheat straw and pressed sugar cane appeared unsuitable as fuel in the unmodified test gasifier (Type F 300) due to slag formation. It is important to note, however, that the present results are not optimal for any of the fuel used, the gasifier being designed for wood-chips and not for the test-fuels used. Tests using appropriately modified gasifiers are planned for the future.

  11. 210Pb content in natural gas pipeline residues ('black-powder') and its correlation with the chemical composition

    International Nuclear Information System (INIS)

    Godoy, Jose Marcus; Carvalho, Franciane; Cordilha, Aloisio; Matta, Luiz Ernesto; Godoy, Maria Luiza

    2005-01-01

    The present work was carried out to assess the 210 Pb content in 'black-powder' found in pigging operations on gas pipelines in Brazil, in particular, on the Campos Basin gas pipeline. Additionally, the chemical composition of such deposits was determined and an eventual correlation with 210 Pb concentration evaluated. Typical 'black-powder' generated in the natural gas pipeline from Campos Basin oilfield contains mainly iron oxide (∼81%) and residual organic matter (∼9%). The 210 Pb content ranges from 4.9 to 0.04 kBq kg -1 and seems to be inversely correlated with the distance to the platforms. On the other hand, 226 Ra concentration is higher on the pipeline branch between the platform and the onshore installations. 228 Ra was only observed in few samples, in particular, in the samples with the highest 226 Ra content

  12. Residual stress analysis in reactor pressure vessel attachments

    International Nuclear Information System (INIS)

    Dexter, R.J.; Pont, D.

    1991-08-01

    Residual stresses in cladding and welded attachments could contribute to the problem of stress-corrosion cracking in boiling-water reactors (BWR). As part of a larger program aimed at quantifying residual stress in BWR components, models that would be applicable for predicting residual stress in BWR components are reviewed and documented. The review includes simple methods of estimating residual stresses as well as advanced finite-element software. In general, simple methods are capable of predicting peak magnitudes of residual stresses but are incapable of adequately characterizing the distribution of residual stresses. Ten groups of researchers using finite-element software are reviewed in detail. For each group, the assumptions of the model, possible simplifications, material property data, and specific applications are discussed. The most accurate results are obtained when a metallurgical simulation is performed, transformation plasticity effects are included, and the heating and cooling parts of the welding thermal cycle are simulated. Two models are identified which can provide these features. The present state of these models and the material property data available in the literature are adequate to quantify residual stress in BWR components

  13. Effectiveness of the compound chlorpyrifos+ cypermethrin+citronellal against Alphitobius diaperinus: laboratory analysis and residue determination in carcasses

    Directory of Open Access Journals (Sweden)

    GS Silva

    2007-09-01

    Full Text Available Effectiveness, biological security and the absence of residues in meat and/or eggs must be considered when recommending options for the control Alphitobius diaperinus in poultry production environments. This research study evaluated the effectiveness of cypermethrin+ chlorpyrifos+citronellal in the control of A. diaperinus, including analysis for the presence of residues of this compound in poultry carcasses (experimental farm. Two studies were carried out under laboratory conditions. One used paper filters a four dilutions of the compound, and the other used a container including with pulverized broiler litter and the compound. The analysis of carcasses for residues was conducted in broilers that raised in a broiler house treated (floor and/or litter with the compound at a dilution of 1:800. Birds were regularly sacrificed, submitted to necropsy, and liver, muscle and fat fragments were collected. Gas chromatography was used to identify the possible presence of any chemical residue in these samples. High effectiveness rates against A.diaperinus were observed in the two laboratory studies, as well as the absence of residues in the carcasses. This compound, used in the studied concentrations, can be recommended as a valuable alternative for the control and treatment of A. diaperinus.

  14. The nev diffractometer ARES for the analysis of residual stresses

    Czech Academy of Sciences Publication Activity Database

    Staron, P.; Ruhnau, H. U.; Marmotti, M.; Mikula, Pavol; Kampmann, R.

    276/278, - (2000), s. 158-159 ISSN 0921-4526 Institutional research plan: CEZ:AV0Z1048901 Keywords : neutron instruments * residual stress Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.893, year: 2000

  15. A miniaturized optical gas sensor for natural gas analysis

    NARCIS (Netherlands)

    Ayerden, N.P.

    2016-01-01

    The depletion of domestic reserves and the growing use of sustainable resources forces a transition from the locally produced natural gas with a well-known composition toward the ‘new’ gas with a more flexible composition in the Netherlands. For safe combustion and proper billing, the natural gas

  16. Screening of the presence organophosphates and organochlorines pesticide residues in vegetables and fruits using gas chromatography-mass spectrometry

    Science.gov (United States)

    Putri, Dillani; Aryana, Nurhani; Aristiawan, Yosi; Styarini, Dyah

    2017-01-01

    Pesticides is commonly used to improve the quality of agricultural product, especially in vegetables and fruits. Due to pesticide residues in the product become a concern to consumer health, monitoring and analysis of pesticide residues in agriculture product need to be established. The certified reference material (CRM) is often benefited to obtain accurate results in analysis. It is required as the quality control to improve quality assurance of the testing results. Unfortunately in Indonesia, the development of matrix CRM for the analysis of pesticide residues in vegetables and fruits is still limited. This study is aimed to determine the type of commodity and target analyte to be employed in the development of CRM for pesticides in vegetables and fruits. As the preliminary study, the screening of 11 commodities of fresh vegetables and fruits has been conducted to review the information about the presence of organophosphates (OPs) and organochlorines (OCs) in the sample. In this analysis, QuEChERS technique was used in the extraction process and the qualitative analysis was evaluated by using GC-MS. The results showed that strawberry and celery contain residues of pesticide chlorpyrifos. Further analysis of the commodity celery from seven different places has been conducted, resulting that from 3 of all 7 samples (43%) were positive containing chlorpyrifos. Therefore, the development of CRM for chlorpyrifos in celery will be our next research project.

  17. Direct gas-solid carbonation of serpentinite residues in the absence and presence of water vapor: a feasibility study for carbon dioxide sequestration.

    Science.gov (United States)

    Veetil, Sanoopkumar Puthiya; Pasquier, Louis-César; Blais, Jean-François; Cecchi, Emmanuelle; Kentish, Sandra; Mercier, Guy

    2015-09-01

    Mineral carbonation of serpentinite mining residue offers an environmentally secure and permanent storage of carbon dioxide. The strategy of using readily available mining residue for the direct treatment of flue gas could improve the energy demand and economics of CO2 sequestration by avoiding the mineral extraction and separate CO2 capture steps. The present is a laboratory scale study to assess the possibility of CO2 fixation in serpentinite mining residues via direct gas-solid reaction. The degree of carbonation is measured both in the absence and presence of water vapor in a batch reactor. The gas used is a simulated gas mixture reproducing an average cement flue gas CO2 composition of 18 vol.% CO2. The reaction parameters considered are temperature, total gas pressure, time, and concentration of water vapor. In the absence of water vapor, the gas-solid carbonation of serpentinite mining residues is negligible, but the residues removed CO2 from the feed gas possibly due to reversible adsorption. The presence of small amount of water vapor enhances the gas-solid carbonation, but the measured rates are too low for practical application. The maximum CO2 fixation obtained is 0.07 g CO2 when reacting 1 g of residue at 200 °C and 25 barg (pCO2 ≈ 4.7) in a gas mixture containing 18 vol.% CO2 and 10 vol.% water vapor in 1 h. The fixation is likely surface limited and restricted due to poor gas-solid interaction. It was identified that both the relative humidity and carbon dioxide-water vapor ratio have a role in CO2 fixation regardless of the percentage of water vapor.

  18. Natural gas product and strategic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Layne, A.W.; Duda, J.R.; Zammerilli, A.M.

    1993-12-31

    Product and strategic analysis at the Department of Energy (DOE)/Morgantown Energy Technology Center (METC) crosscuts all sectors of the natural gas industry. This includes the supply, transportation, and end-use sectors of the natural-gas market. Projects in the Natural Gas Resource and Extraction supply program have been integrated into a new product focus. Product development facilitates commercialization and technology transfer through DOE/industry cost-shared research, development, and demonstration (RD&D). Four products under the Resource and Extraction program include Resource and Reserves; Low Permeability Formations; Drilling, Completion, and Stimulation: and Natural Gas Upgrading. Engineering process analyses have been performed for the Slant Hole Completion Test project. These analyses focused on evaluation of horizontal-well recovery potential and applications of slant-hole technology. Figures 2 and 3 depict slant-well in situ stress conditions and hydraulic fracture configurations. Figure 4 presents Paludal Formation coal-gas production curves used to optimize the hydraulic fracture design for the slant well. Economic analyses have utilized data generated from vertical test wells to evaluate the profitability of horizontal technology for low-permeability formations in Yuma County, Colorado, and Maverick County, Texas.

  19. Analysis of residual solvents in PET radiopharmaceuticals by GC

    International Nuclear Information System (INIS)

    Li Yungang; Zhang Xiaojun; Liu Jian; Tian Jiahe; Zhang Jinming

    2013-01-01

    The residual solvents in PET radiopharmaceuticals were analyzed by GC, which were acetonitrile, ethanol, N, N-dimethylethanolamine (DMEA), dimethylsulfoxide (DMSO). The standard curves were established with the AT-624 capillary column at GC, and the sensitivity of acetonitrile and ethanol were 0.004-0.320 g/L and 0.010-0.120 g/L respectively. The residual solvents of acetonitrile, ethanol, DMEA and DMSO in PET radio- pharmaceuticals were analyzed by GC. The linearity were 0.9994, 0.9999, 0.9997, 0.999 6 respectively. The residual of acetonitrile were (0.0313±0.0433), (0.0829±0.0668), (0.0156±0.0059), (0.0254±0.0266) g/L in 18 F-FDG, 18 F-FLT, 11 C-CFT, 11 C-PIB respectively. The residual of ethanol was (0.0505±0.00528) g/L in 18 F-FDG. The residual of DMSO were (0.0331±0.0180) g/L, (0.0238±0.0100) g/L in 18 F-W372 and 11 C-DTBZ respectively. The residual of DMEA was (0.0348±0.0022) g/L in 11 C-Choline. The survived of organic solvent in PET radiopharmaceuticals can be analyzed with GC directly. The results showed that the QC should be done in PET radiopharmaceuticals purity with semi-HPLC to avoid the high residual. (authors)

  20. proximate and ultimate analysis of fuel pellets from oil palm residues

    African Journals Online (AJOL)

    HOD

    Keywords: Oil Palm Residues, Fuel Pellets, Proximate Analysis, Ultimate Analysis. 1. INTRODUCTION ... Pelletizing of this biomass resources into pellets is a way of ensuring a ... demand for pellets [3], and alternative feed-stocks such as palm kernel ... agro-residues, selection of the best pellets has to be made based on ...

  1. Radiation protection and management of NORM residues in the oil and gas industry

    International Nuclear Information System (INIS)

    Haridasan, P.P.; )

    2014-01-01

    The radionuclides in oil and gas streams belong to the decay chains of 238 U and 232 Th originate from the reservoir rock that contains oil, gas and formation water. Formation water contains significant concentrations of isotopes of radium dissolved from the reservoir rock. The parent isotopes of uranium and thorium are not mobilized from the rock and hence the radium isotopes appear in the water co-produced with the oil and gas. When the ions of Group II elements are present in the produced water, drops in pressure and temperature can lead to precipitation of sulphate and carbonate scales on the inner walls of production tubulars, well heads, valves, pumps, separators, water treatment vessels, gas treatment and oil storage tanks. The mixed stream of oil, gas and water carries the radon gas generated in the reservoir rock and in the production stream it preferentially follows the dry export gases. Consequently the equipment from gas treatment and transport facilities may accumulate a thin film of 210 Pb in the inner surfaces of gas lines. The radionuclide concentrations in produced water, hard scale and sludge will be presented. Indication on typical quantities of wastes generated and best practices followed in the industry in managing such wastes will be outlined. Information on external gamma exposure and potential internal exposure as well as global emerging issues will be discussed

  2. Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

    Science.gov (United States)

    Shams, Bilal; Yao, Jun; Zhang, Kai; Zhang, Lei

    2017-08-01

    Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulation-condensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources. In gas injection, the flooding pattern, injection timing and injection duration are key parameters to study an efficient EOR scenario in order to recover lost condensate. This work contains sensitivity analysis on different parameters to generate an accurate investigation about the effects on performance of different injection scenarios in homogeneous gas condensate system. In this paper, starting time of gas cycling and injection period are the parameters used to influence condensate recovery of a five-spot well pattern which has an injection pressure constraint of 3000 psi and production wells are constraint at 500 psi min. BHP. Starting injection times of 1 month, 4 months and 9 months after natural depletion areapplied in the first study. The second study is conducted by varying injection duration. Three durations are selected: 100 days, 400 days and 900 days. In miscible gas injection, miscibility and vaporization of condensate by injected gas is more efficient mechanism for condensate recovery. From this study, it is proven that the application of gas cycling on five-spot well pattern greatly enhances condensate recovery

  3. Pesticide residue quantification analysis by hyperspectral imaging sensors

    Science.gov (United States)

    Liao, Yuan-Hsun; Lo, Wei-Sheng; Guo, Horng-Yuh; Kao, Ching-Hua; Chou, Tau-Meu; Chen, Junne-Jih; Wen, Chia-Hsien; Lin, Chinsu; Chen, Hsian-Min; Ouyang, Yen-Chieh; Wu, Chao-Cheng; Chen, Shih-Yu; Chang, Chein-I.

    2015-05-01

    Pesticide residue detection in agriculture crops is a challenging issue and is even more difficult to quantify pesticide residue resident in agriculture produces and fruits. This paper conducts a series of base-line experiments which are particularly designed for three specific pesticides commonly used in Taiwan. The materials used for experiments are single leaves of vegetable produces which are being contaminated by various amount of concentration of pesticides. Two sensors are used to collected data. One is Fourier Transform Infrared (FTIR) spectroscopy. The other is a hyperspectral sensor, called Geophysical and Environmental Research (GER) 2600 spectroradiometer which is a batteryoperated field portable spectroradiometer with full real-time data acquisition from 350 nm to 2500 nm. In order to quantify data with different levels of pesticide residue concentration, several measures for spectral discrimination are developed. Mores specifically, new measures for calculating relative power between two sensors are particularly designed to be able to evaluate effectiveness of each of sensors in quantifying the used pesticide residues. The experimental results show that the GER is a better sensor than FTIR in the sense of pesticide residue quantification.

  4. Residual Stress Analysis of Aircraft Part using Neutron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Eun Joo; Seong, Baek Seok; Sim, Cheul Muu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    A precise measurement of the residual stress magnitude and distribution is an important factor to evaluate the lifetime or safety of the materials, because the residual stress affects the material properties, such as the strength, fatigue, etc. In the case of a fighter jet, the lifetime and safety of the parts of the landing gear are more important than that of a passenger airplane because of its frequent take offs and landings. In particular in the case of training a fighter jet, a precise evaluation of life time for the parts of the landing gear is strongly required for economic reason. In this study, the residual stress of a part of the landing gear of the training fighter jet which is used to fix the landing gear to the aircraft body was investigated. The part was used for 2000 hours of flight, which corresponds to 10 years. During this period, the fighter jet normally takes off and lands more than 2000 times. These frequent take off and landing can generate residual stress and cause a crack in the part. By measuring the neutron diffraction peaks, we evaluated the residual stress of the landing gear part

  5. A stochastic logical system approach to model and optimal control of cyclic variation of residual gas fraction in combustion engines

    International Nuclear Information System (INIS)

    Wu, Yuhu; Kumar, Madan; Shen, Tielong

    2016-01-01

    Highlights: • An in-cylinder pressure based measuring method for the RGF is derived. • A stochastic logical dynamical model is proposed to represent the transient behavior of the RGF. • The receding horizon controller is designed to reduce the variance of the RGF. • The effectiveness of the proposed model and control approach is validated by the experimental evidence. - Abstract: In four stroke internal combustion engines, residual gas from the previous cycle is an important factor influencing the combustion quality of the current cycle, and the residual gas fraction (RGF) is a popular index to monitor the influence of residual gas. This paper investigates the cycle-to-cycle transient behavior of the RGF in the view of systems theory and proposes a multi-valued logic-based control strategy for attenuation of RGF fluctuation. First, an in-cylinder pressure sensor-based method for measuring the RGF is provided by following the physics of the in-cylinder transient state of four-stroke internal combustion engines. Then, the stochastic property of the RGF is examined based on statistical data obtained by conducting experiments on a full-scale gasoline engine test bench. Based on the observation of the examination, a stochastic logical transient model is proposed to represent the cycle-to-cycle transient behavior of the RGF, and with the model an optimal feedback control law, which targets on rejection of the RGF fluctuation, is derived in the framework of stochastic logical system theory. Finally, experimental results are demonstrated to show the effectiveness of the proposed model and the control strategy.

  6. Evaluation of a recent product to remove lipids and other matrix co-extractives in the analysis of pesticide residues and environmental contaminants in foods

    Science.gov (United States)

    This study demonstrates the application of a novel lipid removal product to the residue analysis of 65 pesticides and 52 environmental contaminants in kale, pork, salmon, and avocado by fast, low pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS). Sample preparation involves QuEChE...

  7. Greenhouse gas reductions through enhanced use of residues in the life cycle of Malaysian palm oil derived biodiesel

    DEFF Research Database (Denmark)

    Hansen, Sune Balle; Olsen, Stig Irving; Ujang, Zaini

    2012-01-01

    This study identifies the potential greenhouse gas (GHG) reductions, which can be achieved by optimizing the use of residues in the life cycle of palm oil derived biodiesel. This is done through compilation of data on existing and prospective treatment technologies as well as practical experiments...... extraction from empty fruit bunches was found to be the most significant in the biodiesel production life cycle. All the studied waste treatment technologies performed significantly better than the conventional practices and with dedicated efforts of optimized use in the palm oil industry, the production...

  8. Validation of QuEChERS based method for determination of fenitrothion residues in tomatoes by gas chromatography-flame photometric detector: Decline pattern and risk assessment.

    Science.gov (United States)

    Malhat, Farag; Boulangé, Julien; Abdelraheem, Ehab; Abd Allah, Osama; Abd El-Hamid, Rania; Abd El-Salam, Shokr

    2017-08-15

    A simple and rapid gas chromatography with flame photometric detector (GC-FPD) determination method was developed to detect residue levels and investigate the dissipation pattern and safe use of fenitrothion in tomatoes. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) using an ethyl acetate-based extraction, followed by a dispersive solid-phase extraction (d-SPE) with primary-secondary amine (PSA) and graphite carbon black (GCB) for clean up, was applied prior to GC-FPD analysis. The method showed satisfactory linearity, recovery and precision. The limits of detection (LOD) and quantification (LOQ) were 0.005 and 0.01mg/kg, respectively. The residue levels of fenitrothion were best described by first order kinetics with a half-life of 2.2days in tomatoes. The potential health risks posed by fenitrothion were not significant, based on supervised residue trial data. The current findings could provide guidance for safe and reasonable use of fenitrothion in tomatoes and prevent health problems to consumers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. GAS CHROMATOGRAPHIC AND SPECTROSCOPIC ANALYSIS OF ...

    African Journals Online (AJOL)

    Peroxyformic acid prepared in-situ was employed for epoxidation of canola oil in the presence of toluene. Gas chromatographic analysis of the product revealed the following species: C16:0; C18:0; C18:1; C18:2; C18:3; monoepoxy C18:0; monoepoxy C18:1; monoepoxy C18:2; diepoxy C18:0; diepoxy C18:1 and triepoxy ...

  10. Analysis and modeling of simulated residual stress of mold injected plastic parts by using robust correlations

    OpenAIRE

    Vargas, Carlos; Sierra, Juan; Posada, Juan; Botero-Cadavid, Juan F.

    2017-01-01

    ABSTRACT The injection molding process is the most widely used processing technique for polymers. The analysis of residual stresses generated during this process is crucial for the part quality assessment. The present study evaluates the residual stresses in a tensile strength specimen using the simulation software Moldex3D for two polymers, polypropylene and polycarbonate. The residual stresses obtained under a simulated design of experiment were modeled using a robust multivariable regressi...

  11. Effect of sewage sludge content on gas quality and solid residues produced by cogasification in an updraft gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Seggiani, Maurizia, E-mail: m.seggiani@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Puccini, Monica, E-mail: m.puccini@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Raggio, Giovanni, E-mail: g.raggio@tiscali.it [Italprogetti Engineering SPA, Lungarno Pacinotti, 59/A, 56020 San Romano (Pisa) (Italy); Vitolo, Sandra, E-mail: s.vitolo@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Cogasification of sewage sludge with wood pellets in updraft gasifier was analysed. Black-Right-Pointing-Pointer The effects of sewage sludge content on the gasification process were examined. Black-Right-Pointing-Pointer Sewage sludge addition up to 30 wt.% reduces moderately the process performance. Black-Right-Pointing-Pointer At high sewage sludge content slagging and clinker formation occurred. Black-Right-Pointing-Pointer Solid residues produced resulted acceptable at landfills for non-hazardous waste. - Abstract: In the present work, the gasification with air of dehydrated sewage sludge (SS) with 20 wt.% moisture mixed with conventional woody biomass was investigated using a pilot fixed-bed updraft gasifier. Attention was focused on the effect of the SS content on the gasification performance and on the environmental impact of the process. The results showed that it is possible to co-gasify SS with wood pellets (WPs) in updraft fixed-bed gasification installations. However, at high content of sewage sludge the gasification process can become instable because of the very high ash content and low ash fusion temperatures of SS. At an equivalent ratio of 0.25, compared with wood pellets gasification, the addition of sewage sludge led to a reduction of gas yield in favor of an increase of condensate production with consequent cold gas efficiency decrease. Low concentrations of dioxins/furans and PAHs were measured in the gas produced by SS gasification, well below the limiting values for the exhaust gaseous emissions. NH{sub 3}, HCl and HF contents were very low because most of these compounds were retained in the wet scrubber systems. On the other hand, high H{sub 2}S levels were measured due to high sulfur content of SS. Heavy metals supplied with the feedstocks were mostly retained in gasification solid residues. The leachability tests performed according to European regulations showed that metals leachability was

  12. TOXRISK, Toxic Gas Release Accident Analysis

    International Nuclear Information System (INIS)

    Bennett, D.E.; Chanin, D.I.; Shiver, A.W.

    1993-01-01

    1 - Description of program or function: TOXRISK is an interactive program developed to aid in the evaluation of nuclear power plant control room habitability in the event of a nearby toxic material release. The program uses a model which is consistent with the approach described in the NRC Regulatory Guide 1.78. Release of the gas is treated as an initial puff followed by a continuous plume. The relative proportions of these as well as the plume release rate are supplied by the user. Transport of the gas is modeled as a Gaussian distribution and occurs through the action of a constant velocity, constant direction wind. Great flexibility is afforded the user in specifying the release description, meteorological conditions, relative geometry of the accident and plant, and the plant ventilation system characteristics. Two types of simulation can be performed: multiple case (parametric) studies and probabilistic analyses. Upon execution, TOXRISK presents a menu, and the user chooses between the Data Base Manager, the Multiple Case program, and the Probabilistic Study Program. The Data Base Manager provides a convenient means of storing, retrieving, and modifying blocks of data required by the analysis programs. The Multiple Case program calculates resultant gas concentrations inside the control room and presents a summary of information that describes the event for each set of conditions given. Optimally, a time history profile of inside and outside concentrations can also be produced. The Probabilistic Study program provides a means for estimating the annual probability of operator incapacitation due to toxic gas accidents on surrounding transportation routes and storage sites. 2 - Method of solution: Dispersion or diffusion of the gas during transport is described by modified Pasquill-Gifford dispersion coefficients

  13. Environmental analysis for pipeline gas demonstration plants

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, L.H.

    1978-09-01

    The Department of Energy (DOE) has implemented programs for encouraging the development and commercialization of coal-related technologies, which include coal gasification demonstration-scale activities. In support of commercialization activities the Environmental Analysis for Pipeline Gas Demonstration Plants has been prepared as a reference document to be used in evaluating potential environmental and socioeconomic effects from construction and operation of site- and process-specific projects. Effluents and associated impacts are identified for six coal gasification processes at three contrasting settings. In general, impacts from construction of a high-Btu gas demonstration plant are similar to those caused by the construction of any chemical plant of similar size. The operation of a high-Btu gas demonstration plant, however, has several unique aspects that differentiate it from other chemical plants. Offsite development (surface mining) and disposal of large quantities of waste solids constitute important sources of potential impact. In addition, air emissions require monitoring for trace metals, polycyclic aromatic hydrocarbons, phenols, and other emissions. Potential biological impacts from long-term exposure to these emissions are unknown, and additional research and data analysis may be necessary to determine such effects. Possible effects of pollutants on vegetation and human populations are discussed. The occurrence of chemical contaminants in liquid effluents and the bioaccumulation of these contaminants in aquatic organisms may lead to adverse ecological impact. Socioeconomic impacts are similar to those from a chemical plant of equivalent size and are summarized and contrasted for the three surrogate sites.

  14. The Effects of Rape Residue Mulching on Net Global Warming Potential and Greenhouse Gas Intensity from No-Tillage Paddy Fields

    Science.gov (United States)

    Zhang, Zhi-Sheng; Cao, Cou-Gui; Guo, Li-Jin; Li, Cheng-Fang

    2014-01-01

    A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha−1) during a rice-growing season after 3 years of oilseed rape-rice cultivation. Residue mulching treatments showed significantly more organic carbon (C) density for the 0–20 cm soil layer at harvesting than no residue treatment. During a rice-growing season, residue mulching treatments sequestered significantly more organic C from 687 kg C ha−1 season−1 to 1654 kg C ha−1 season−1 than no residue treatment. Residue mulching significantly increased emissions of CO2 and N2O but decreased CH4 emissions. Residue mulching treatments significantly increased GWP by 9–30% but significantly decreased net GWP by 33–71% and GHGI by 35–72% relative to no residue treatment. These results suggest that agricultural economic viability and GHG mitigation can be achieved simultaneously by residue mulching on NT paddy fields in central China. PMID:25140329

  15. The effects of rape residue mulching on net global warming potential and greenhouse gas intensity from no-tillage paddy fields.

    Science.gov (United States)

    Zhang, Zhi-Sheng; Cao, Cou-Gui; Guo, Li-Jin; Li, Cheng-Fang

    2014-01-01

    A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha(-1)) during a rice-growing season after 3 years of oilseed rape-rice cultivation. Residue mulching treatments showed significantly more organic carbon (C) density for the 0-20 cm soil layer at harvesting than no residue treatment. During a rice-growing season, residue mulching treatments sequestered significantly more organic C from 687 kg C ha(-1) season(-1) to 1654 kg C ha(-1) season(-1) than no residue treatment. Residue mulching significantly increased emissions of CO2 and N2O but decreased CH4 emissions. Residue mulching treatments significantly increased GWP by 9-30% but significantly decreased net GWP by 33-71% and GHGI by 35-72% relative to no residue treatment. These results suggest that agricultural economic viability and GHG mitigation can be achieved simultaneously by residue mulching on NT paddy fields in central China.

  16. Analysis and characterization of plutonium in pyrochemical salt residues

    International Nuclear Information System (INIS)

    Haschke, John M.; Phillips, Alan G.

    2000-01-01

    Quantitative measurement of hydrogen produced during salt-catalyzed hydrolysis of plutonium in pyrochemical salt residues show that the metal is present in concentrations of 10 ± 5 mass%. The analytical method is based on stoichiometric reaction of metal with water to form plutonium monoxide monohydride (PuOH) and hydrogen. Results of a kinetic model developed to describe the observed time dependence of the hydrolysis rate shows that metal is present predominately as particles with essentially spherical geometries and diameters near 1 mm. The presence of smaller metallic particles cannot be verified or excluded. Plutonium concentrations measured for residues stored in different configurations suggest that a sizable fraction of the metal has oxidized during storage. Application of the hydrolysis method in determining concentrations and dimensions of metallic plutonium in other nuclear waste forms is proposed

  17. Trends in the analysis of natural gas by capillary gas chromatography

    NARCIS (Netherlands)

    Cramers, C.A.M.G.; Rossum, van G.J.

    1986-01-01

    The importance of correct determination of physical and chemical properties of natural gas is evident. The calculation of calorific value or hydrocarbon dew point requires detailed analysis as can be provided by gas chromatography. Analysis by gas chromatography is a necessary complement to direct

  18. Evaluation of two fast and easy methods for pesticide residue analysis in fatty food matrixes.

    Science.gov (United States)

    Lehotay, Steven J; Mastovská, Katerina; Yun, Seon Jong

    2005-01-01

    Two rapid methods of sample preparation and analysis of fatty foods (e.g., milk, eggs, and avocado) were evaluated and compared for 32 pesticide residues representing a wide range of physicochemical properties. One method, dubbed the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for pesticide residue analysis, entailed extraction of 15 g sample with 15 mL acetonitrile (MeCN) containing 1% acetic acid followed by addition of 6 g anhydrous magnesium sulfate and 1.5 g sodium acetate. After centrifugation, 1 mL of the buffered MeCN extract underwent a cleanup step (in a technique known as dispersive solid-phase extraction) using 50 mg each of C18 and primary secondary amine sorbents plus 150 mg MgSO4. The second method incorporated a form of matrix solid-phase dispersion (MSPD), in which 0.5 g sample plus 2 g C18 and 2 g anhydrous sodium sulfate was mixed in a mortar and pestle and added above a 2 g Florisil column on a vacuum manifold. Then, 5 x 2 mL MeCN was used to elute the pesticide analytes from the sample into a collection tube, and the extract was concentrated to 0.5 mL by evaporation. Extracts in both methods were analyzed concurrently by gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry. The recoveries of semi-polar and polar pesticides were typically 100% in both methods (except that basic pesticides, such as thiabendazole and imazalil, were not recovered in the MSPD method), but recovery of nonpolar pesticides decreased as fat content of the sample increased. This trend was more pronounced in the QuEChERS method, in which case the most lipophilic analyte tested, hexachlorobenzene, gave 27 +/- 1% recovery (n=6) in avocado (15% fat) with a<10 ng/g limit of quantitation.

  19. Technology on In-Situ Gas Generation to Recover Residual Oil Reserves

    Energy Technology Data Exchange (ETDEWEB)

    Sayavur Bakhtiyarov

    2008-02-29

    This final technical report covers the period October 1, 1995 to February 29, 2008. This chapter begins with an overview of the history of Enhanced Oil Recovery techniques and specifically, CO2 flood. Subsequent chapters conform to the manner consistent with the Activities, Tasks, and Sub-tasks of the project as originally provided in Exhibit C1 in the Project Management Plan dated September 20, 1995. These chapters summarize the objectives, status and conclusions of the major project activities performed during the project period. The report concludes by describing technology transfer activities stemming from the project and providing a reference list of all publications of original research work generated by the project team or by others regarding this project. The overall objective of this project was a final research and development in the United States a technology that was developed at the Institute for Geology and Development of Fossil Fuels in Moscow, Russia. Before the technology can be convincingly adopted by United States oil and gas producers, the laboratory research was conducted at Mew Mexico Institute of Mining and Technology. The experimental studies were conducted to measure the volume and the pressure of the CO{sub 2} gas generated according to the new Russian technology. Two experimental devices were designed, built and used at New Mexico Tech facilities for these purposes. The designed setup allowed initiating and controlling the reaction between the 'gas-yielding' (GY) and 'gas-forming' (GF) agents proposed by Russian technology. The temperature was controlled, and the generated gas pressure and volume were recorded during the reaction process. Additionally, the effect of surfactant addition on the effectiveness of the process was studied. An alternative GY reactant was tested in order to increase the efficiency of the CO2 gas generation process. The slim tube and the core flood experimental studies were conducted to define

  20. Determination of daminozide residues in apples using gas chromatography with nitrogen-phosphorus detection

    NARCIS (Netherlands)

    Brinkman, J.H.W.; Dijk, A.G. van; Wagenaar, R.; Quirijns, J.K.

    1996-01-01

    A method was developed for the determination of daminozide in apples using gas chromatography (GC) with nitrogen-phosphorus detection (NPD). Daminozide is hydrolysed to 1,1-dimethylhydrazine (UDMH) by alkaline digestion. The UDMH generated is distilled from the apple matrix, derivatized with

  1. Conversion of forest residues to a clean gas for fuel or synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Feldmann, H.F.; Liu, K.T.; Longanbach, J.R.; Curran, L.M.; Chauhan, S.P.

    1979-01-01

    A program is described for developing a gasification system specifically for wood and other biomass materials which allows greatly increased gasifier throughputs and direct catalysis of wood. Wood ash, which is a by-product of a wood gasification plant, can be used as a gasification catalyst for wood, as it increases gasification rates and promotes the water-gas shift reaction. The high reactivity of even uncatalyzed biomass allows the potential of very high gasifier throughputs. However, the achievement of this potential requires that the gasifier operate at gas velocities higher than those attainable in conventional reactor systems. Stable and very smooth fluidization with uniform mixing and distribution of chips throughout the bed was observed on addition of an entrained sand phase to a fluidized bed of alumina and wood chips. Economc feasibility studies based on utilization of a proprietary Battelle gasification system which utilizes an entrained-phase heat carrier indicated that an intermediate-Btu gas can be produced in 1000 ton/day plants at a price competitive with liquefied natural gas and No. 2 heating oil.

  2. Potential ligand-binding residues in rat olfactory receptors identified by correlated mutation analysis

    Science.gov (United States)

    Singer, M. S.; Oliveira, L.; Vriend, G.; Shepherd, G. M.

    1995-01-01

    A family of G-protein-coupled receptors is believed to mediate the recognition of odor molecules. In order to identify potential ligand-binding residues, we have applied correlated mutation analysis to receptor sequences from the rat. This method identifies pairs of sequence positions where residues remain conserved or mutate in tandem, thereby suggesting structural or functional importance. The analysis supported molecular modeling studies in suggesting several residues in positions that were consistent with ligand-binding function. Two of these positions, dominated by histidine residues, may play important roles in ligand binding and could confer broad specificity to mammalian odor receptors. The presence of positive (overdominant) selection at some of the identified positions provides additional evidence for roles in ligand binding. Higher-order groups of correlated residues were also observed. Each group may interact with an individual ligand determinant, and combinations of these groups may provide a multi-dimensional mechanism for receptor diversity.

  3. Simple gas chromatographic method for furfural analysis.

    Science.gov (United States)

    Gaspar, Elvira M S M; Lopes, João F

    2009-04-03

    A new, simple, gas chromatographic method was developed for the direct analysis of 5-hydroxymethylfurfural (5-HMF), 2-furfural (2-F) and 5-methylfurfural (5-MF) in liquid and water soluble foods, using direct immersion SPME coupled to GC-FID and/or GC-TOF-MS. The fiber (DVB/CAR/PDMS) conditions were optimized: pH effect, temperature, adsorption and desorption times. The method is simple and accurate (RSDfurfurals will contribute to characterise and quantify their presence in the human diet.

  4. Microfabricated Gas Phase Chemical Analysis Systems

    International Nuclear Information System (INIS)

    FRYE-MASON, GREGORY CHARLES; HELLER, EDWIN J.; HIETALA, VINCENT M.; KOTTENSTETTE, RICHARD; LEWIS, PATRICK R.; MANGINELL, RONALD P.; MATZKE, CAROLYN M.; WONG, CHUNGNIN C.

    1999-01-01

    A portable, autonomous, hand-held chemical laboratory ((micro)ChemLab(trademark)) is being developed for trace detection (ppb) of chemical warfare (CW) agents and explosives in real-world environments containing high concentrations of interfering compounds. Microfabrication is utilized to provide miniature, low-power components that are characterized by rapid, sensitive and selective response. Sensitivity and selectivity are enhanced using two parallel analysis channels, each containing the sequential connection of a front-end sample collector/concentrator, a gas chromatographic (GC) separator, and a surface acoustic wave (SAW) detector. Component design and fabrication and system performance are described

  5. Pyrolysis Gas as a Renewable Reducing Agent for the Recycling of Zinc- and Lead-Bearing Residues: A Status Report

    Science.gov (United States)

    Pichler, C.; Antrekowitsch, J.

    2017-04-01

    The topic "Zero Waste" has been in existence for several years in the industry, and the metallurgical industry has also made efforts to reduce the amounts of residues occurring and have started several investigations to cut down on metallurgical by-products which have to be landfilled. Especially, the additional costs for CO2 emissions in different metallurgical steps have led to investigations into alternative carbon carriers. Charcoal has been identified to serve as an ideal substitute due its CO2-neutrality. For the applications of this renewable carbon carrier in metallurgical processes, charcoal production by means of a carbonization process needs to be optimized. As a by-product during the heating of agricultural wastes or wood by excluding air, pyrolysis gas occurs. Due to the existence of combustible compounds in this gas, an application as a reduction agent instead of fossil carbon carriers in metallurgy is possible. Based on the prevention of dumping metallurgical by-products, an investigation has been developed to treat zinc- and lead-containing materials. To realize this, a dedicated process concept has been designed and developed. As the main focuses, the usage of the pyrolysis gas from charcoal production for the Waelz kiln process and the recycling of zinc- and lead-containing Waelz slag, resulting from the processing of steel mill dust in a vertical retort, have to be mentioned. Within this research, the process concept was executed from laboratory-scale up to pilot-scale testing, described in this article.

  6. Recycling of Zinc- and Lead-Bearing Residues with Pyrolysis Gas

    Science.gov (United States)

    Pichler, C.; Antrekowitsch, J.

    2015-09-01

    Efforts in the metallurgical industry for an approximation to the zero waste concept has led to many different investigations. Together with the greenhouse effect, CO2 emissions have caused additional costs for different process steps in the industry. For this reason, alternative carbon carriers have been sought, and charcoal was found to be an ideal substitute, due to its CO2 neutrality. In order to use it in the metallurgical industry, an optimization of the charcoal production through a carbonization process must be carried out. Beside the charcoal, pyrolysis gas also occurs during the heating of wood or agricultural wastes under the exclusion of air. Because of combustible compounds in this gas, it is possible to use it as a reduction agent instead of fossil carbon carriers. Together with the idea of preventing landfilling of metallurgical by-products, an investigation was carried out to treat zinc- and lead-containing materials. For this issue a special process concept was designed and developed. The main aspect was to recycle the zinc- and lead-containing Waelz slag, which results from the processing of steel mill dusts, in a vertical retort. Two different sizes of facilities were constructed to perform the reaction system of the solid Waelz slag with the gaseous reduction agent of pyrolysis gas.

  7. Residual stresses analysis of friction stir welding using one-way FSI simulation

    International Nuclear Information System (INIS)

    Kang, Sung Wook; Jang, Beom Seon; Song, Ha Cheol

    2015-01-01

    When certain mechanisms, such as plastic deformations and temperature gradients, occur and are released in a structure, stresses remain because of the shape of the structure and external constraints. These stresses are referred to as residual stresses. The base material locally expands during heating in the welding process. When the welding is completed and cooled to room temperature, the residual stresses are left at nearly the yield strength level. In the case of friction stir welding, the maximum temperature is 80% to 90% of the melting point of the materials. Thus, the residual stresses in the welding process are smaller than those in other fusion welding processes; these stresses have not been considered previously. However, friction stir welding residual stresses are sometimes measured at approximately 70% or above. These residual stresses significantly affect fatigue behavior and lifetime. The present study investigates the residual stress distributions in various welding conditions and shapes of friction stir welding. In addition, the asymmetric feature is considered in temperature and residual stress distribution. Heat transfer analysis is conducted using the commercial computational fluid dynamics program Fluent, and results are used in the finite element structural analysis with the ANSYS Multiphysics software. The calculated residual stresses are compared with experimental values using the X-ray diffraction method.

  8. Development of residual stress analysis procedure for fitness-for-service assessment of welded structure

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Jin, Tae Eun; Dong, P.; Prager, M.

    2003-01-01

    In this study, a state of art review of existing residual stress analysis techniques and representative solutions is presented in order to develop the residual stress analysis procedure for Fitness-For-Service(FFS) assessment of welded structure. Critical issues associated with existing residual stress solutions and their treatments in performing FFS are discussed. It should be recognized that detailed residual stress evolution is an extremely complicated phenomenon that typically involves material-specific thermomechanical/metallurgical response, welding process physics, and structural interactions within a component being welded. As a result, computational procedures can vary significantly from highly complicated numerical techniques intended only to elucidate a small part of the process physics to cost-effective procedures that are deemed adequate for capturing some of the important features in a final residual stress distribution. Residual stress analysis procedure for FFS purposes belongs to the latter category. With this in mind, both residual stress analysis techniques and their adequacy for FFS are assessed based on both literature data and analyses performed in this investigation

  9. Scanning electron microscope/energy dispersive x ray analysis of impact residues in LDEF tray clamps

    Science.gov (United States)

    Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

    1993-01-01

    Detailed optical scanning of tray clamps is being conducted in the Facility for the Optical Inspection of Large Surfaces at JSC to locate and document impacts as small as 40 microns in diameter. Residues from selected impacts are then being characterized by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis at CNES. Results from this analysis will be the initial step to classifying projectile residues into specific sources.

  10. Quantitative risk analysis preoperational of gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Manfredi, Carlos; Bispo, Gustavo G.; Esteves, Alvaro [Gie S.A., Buenos Aires (Argentina)

    2009-07-01

    The purpose of this analysis is to predict how it can be affected the individual risk and the public's general security due to the operation of a gas pipeline. In case that the single or social risks are considered intolerable, compared with the international standards, to be recommended measures of mitigation of the risk associated to the operation until levels that can be considered compatible with the best practices in the industry. The quantitative risk analysis calculates the probability of occurrence of an event based on the frequency of occurrence of the same one and it requires a complex mathematical treatment. The present work has as objective to develop a calculation methodology based on the previously mentioned publication. This calculation methodology is centered in defining the frequencies of occurrence of events, according to representative database of each case in study. Besides, it settles down the consequences particularly according to the considerations of each area and the different possibilities of interferences with the gas pipeline in study. For each one of the interferences a typical curve of ignition probabilities is developed in function from the distance to the pipe. (author)

  11. Texture, residual stress and structural analysis of thin films using a combined X-ray analysis

    International Nuclear Information System (INIS)

    Lutterotti, L.; Chateigner, D.; Ferrari, S.; Ricote, J.

    2004-01-01

    Advanced thin films for today's industrial and research needs require highly specialized methodologies for a successful quantitative characterization. In particular, in the case of multilayer and/or unknown phases a global approach is necessary to obtain some or all the required information. A full approach has been developed integrating novel texture and residual stress methodologies with the Rietveld method (Acta Cryst. 22 (1967) 151) (for crystal structure analysis) and it has been coupled with the reflectivity analysis. The complete analysis can be done at once and offers several benefits: the thicknesses obtained from reflectivity can be used to correct the diffraction spectra, the phase analysis help to identify the layers and to determine the electron density profile for reflectivity; quantitative texture is needed for quantitative phase and residual stress analyses; crystal structure determination benefits of the previous. To achieve this result, it was necessary to develop some new methods, especially for texture and residual stresses. So it was possible to integrate them in the Rietveld, full profile fitting of the patterns. The measurement of these spectra required a special reflectometer/diffractometer that combines a thin parallel beam (for reflectivity) and a texture/stress goniometer with a curved large position sensitive detector. This new diffraction/reflectivity X-ray machine has been used to test the combined approach. Several spectra and the reflectivity patterns have been collected at different tilting angles and processed at once by the special software incorporating the aforementioned methodologies. Some analysis examples will be given to show the possibilities offered by the method

  12. Solar-gas systems impact analysis study

    Science.gov (United States)

    Neill, C. P.; Hahn, E. F.; Loose, J. C.; Poe, T. E.; Hirshberg, A. S.; Haas, S.; Preble, B.; Halpin, J.

    1984-07-01

    The impacts of solar/gas technologies on gas consumers and on gas utilities were measured separately and compared against the impacts of competing gas and electric systems in four climatic regions of the U.S. A methodology was developed for measuring the benefits or penalties of solar/gas systems on a combined basis for consumers sand distribution companies. It is shown that the combined benefits associated with solar/gas systems are generally greatest when the systems are purchased by customers who would have otherwise chosen high-efficiency electric systems (were solar/gas systems not available in the market place). The role of gas utilities in encouraging consumer acceptance of solar/gas systems was also examined ion a qualitative fashion. A decision framework for analyzing the type and level of utility involvement in solar/gas technologies was developed.

  13. On-line gas chromatographic analysis of airborne particles

    Science.gov (United States)

    Hering, Susanne V [Berkeley, CA; Goldstein, Allen H [Orinda, CA

    2012-01-03

    A method and apparatus for the in-situ, chemical analysis of an aerosol. The method may include the steps of: collecting an aerosol; thermally desorbing the aerosol into a carrier gas to provide desorbed aerosol material; transporting the desorbed aerosol material onto the head of a gas chromatography column; analyzing the aerosol material using a gas chromatograph, and quantizing the aerosol material as it evolves from the gas chromatography column. The apparatus includes a collection and thermal desorption cell, a gas chromatograph including a gas chromatography column, heated transport lines coupling the cell and the column; and a quantization detector for aerosol material evolving from the gas chromatography column.

  14. Numerical analysis of residual stresses reconstruction for axisymmetric glass components

    Science.gov (United States)

    Tao, Bo; Xu, Shuang; Yao, Honghui

    2018-01-01

    A non-destructive measurement method for 3D stress state in a glass cylinder using photoelasticity has been analyzed by simulation in this research. Based on simulated stresses in a glass cylinder, intensity of the cylinder in a circular polariscope can be calculated by Jones calculus. Therefore, the isoclinic angle and optical retardation can be obtained by six steps phase shifting technique. Through the isoclinic angle and optical retardation, the magnitude and distribution of residual stresses inside the glass cylinder in cylindrical coordinate system can be reconstructed. Comparing the reconstructed stresses with numerical simulated stresses, the results verify this non-destructive method can be used to reconstruct the 3D stresses. However, there are some mismatches in axial stress, radial stress and circumferential stress.

  15. Analysis of Food Contaminants, Residues, and Chemical Constituents of Concern

    Science.gov (United States)

    Ismail, Baraem; Reuhs, Bradley L.; Nielsen, S. Suzanne

    The food chain that starts with farmers and ends with consumers can be complex, involving multiple stages of production and distribution (planting, harvesting, breeding, transporting, storing, importing, processing, packaging, distributing to retail markets, and shelf storing) (Fig. 18.1). Various practices can be employed at each stage in the food chain, which may include pesticide treatment, agricultural bioengineering, veterinary drug administration, environmental and storage conditions, processing applications, economic gain practices, use of food additives, choice of packaging material, etc. Each of these practices can play a major role in food quality and safety, due to the possibility of contamination with or introduction (intentionally and nonintentionally) of hazardous substances or constituents. Legislation and regulation to ensure food quality and safety are in place and continue to develop to protect the stakeholders, namely farmers, consumers, and industry. [Refer to reference (1) for information on regulations of food contaminants and residues.

  16. Analysis of residual stress in subsurface layers after precision hard machining of forging tools

    Directory of Open Access Journals (Sweden)

    Czan Andrej

    2018-01-01

    Full Text Available This paper is focused on analysis of residual stress of functional surfaces and subsurface layers created by precision technologies of hard machining for progressive constructional materials of forging tools. Methods of experiments are oriented on monitoring of residual stress in surface which is created by hard turning (roughing and finishing operations. Subsequently these surfaces were etched in thin layers by electro-chemical polishing. The residual stress was monitored in each etched layer. The measuring was executed by portable X-ray diffractometer for detection of residual stress and structural phases. The results significantly indicate rise and distribution of residual stress in surface and subsurface layers and their impact on functional properties of surface integrity.

  17. TOF-SIMS Analysis of Crater Residues from Wild 2 Cometary on Stardust Aluminum Foil

    Science.gov (United States)

    Leutner, Jan; Stephan, Thomas; Kearsley, T.; Horz, Friedrich; Flynn, George J.; Sandford, Scott A.

    2006-01-01

    Impact residues of cometary particles on aluminum foils from the Stardust mission were investigated with TOF-SIMS for their elemental and organic composition. The residual matter from comet 81P/Wild 2 shows a wide compositional range, from nearly monomineralic grains to polymict aggregates. Despite the comparably small analyzed sample volume, the average element composition of the investigated residues is similar to bulk CI chondritic values. Analysis of organic components in impact residues is complicated, due to fragmentation and alteration of the compounds during the impact process and by the presence of contaminants on the aluminum foils. Nevertheless, polycyclic aromatic hydrocarbons (PAHs) that are unambiguously associated with the impact residues were observed, and thus are most likely of cometary origin.

  18. An adjoint method of sensitivity analysis for residual vibrations of structures subject to impacts

    Science.gov (United States)

    Yan, Kun; Cheng, Gengdong

    2018-03-01

    For structures subject to impact loads, the residual vibration reduction is more and more important as the machines become faster and lighter. An efficient sensitivity analysis of residual vibration with respect to structural or operational parameters is indispensable for using a gradient based optimization algorithm, which reduces the residual vibration in either active or passive way. In this paper, an integrated quadratic performance index is used as the measure of the residual vibration, since it globally measures the residual vibration response and its calculation can be simplified greatly with Lyapunov equation. Several sensitivity analysis approaches for performance index were developed based on the assumption that the initial excitations of residual vibration were given and independent of structural design. Since the resulting excitations by the impact load often depend on structural design, this paper aims to propose a new efficient sensitivity analysis method for residual vibration of structures subject to impacts to consider the dependence. The new method is developed by combining two existing methods and using adjoint variable approach. Three numerical examples are carried out and demonstrate the accuracy of the proposed method. The numerical results show that the dependence of initial excitations on structural design variables may strongly affects the accuracy of sensitivities.

  19. Phyloproteomic Analysis of 11780 Six-Residue-Long Motifs Occurrences

    Directory of Open Access Journals (Sweden)

    O. V. Galzitskaya

    2015-01-01

    Full Text Available How is it possible to find good traits for phylogenetic reconstructions? Here, we present a new phyloproteomic criterion that is an occurrence of simple motifs which can be imprints of evolution history. We studied the occurrences of 11780 six-residue-long motifs consisting of two randomly located amino acids in 97 eukaryotic and 25 bacterial proteomes. For all eukaryotic proteomes, with the exception of the Amoebozoa, Stramenopiles, and Diplomonadida kingdoms, the number of proteins containing the motifs from the first group (one of the two amino acids occurs once at the terminal position made about 20%; in the case of motifs from the second (one of two amino acids occurs one time within the pattern and third (the two amino acids occur randomly groups, 30% and 50%, respectively. For bacterial proteomes, this relationship was 10%, 27%, and 63%, respectively. The matrices of correlation coefficients between numbers of proteins where a motif from the set of 11780 motifs appears at least once in 9 kingdoms and 5 phyla of bacteria were calculated. Among the correlation coefficients for eukaryotic proteomes, the correlation between the animal and fungi kingdoms (0.62 is higher than between fungi and plants (0.54. Our study provides support that animals and fungi are sibling kingdoms. Comparison of the frequencies of six-residue-long motifs in different proteomes allows obtaining phylogenetic relationships based on similarities between these frequencies: the Diplomonadida kingdoms are more close to Bacteria than to Eukaryota; Stramenopiles and Amoebozoa are more close to each other than to other kingdoms of Eukaryota.

  20. Validation of a new analytical procedure for determination of residual solvents in [18F]FDG by gas chromatography

    International Nuclear Information System (INIS)

    Costa, Flávia M.; Costa, Cassiano L.S.; Silva, Juliana B.; Ferreira, Soraya M.Z.M.D.

    2017-01-01

    Fludeoxyglucose F 18 ([ 18 F]FDG) is the most used radiopharmaceutical for positron emission tomography, especially on oncology. Organic solvents such as ether, ethanol and acetonitrile might be used in the synthesis of [ 18 F]FDG; however, they might not be completely removed during purification steps. The determination of residual solvents in [ 18 F]FDG is required in the European Pharmacopoeia (EP) and the United States Pharmacopeia (USP) monographs. While the procedure described in the EP is quite general, the one described in the USP requires a long runtime (about 13 minutes). In this work a simple and fast (4-minute) analytical procedure was developed and validated for determination of residual solvents in [ 18 F]FDG. Analyses were carried out in a Perkin Elmer gas chromatograph equipped with a flame ionization detector. The separation was obtained on a 0.53-mm x 30 m fused-silica column. Validation included the evaluation of various parameters, such as: specificity, linearity and range, limits of detection and quantitation, precision (repeatability and intermediate precision), accuracy, and robustness. Results were found to be within acceptable limits, indicating the developed procedure is suitable for its intended application. Considering the short half-life of fluorine-18 (109.7 minutes), this new method could be a valuable alternative for routine quality control of [ 18 F]FDG. (author)

  1. Validation of a new analytical procedure for determination of residual solvents in [{sup 18}F]FDG by gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Flávia M.; Costa, Cassiano L.S.; Silva, Juliana B.; Ferreira, Soraya M.Z.M.D., E-mail: flaviabiomedica@yahoo.com.br [Centro de Desenvolvimento da Tecnologia Nuclear (UPPR/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Produção de Radiofármacos

    2017-07-01

    Fludeoxyglucose F 18 ([{sup 18}F]FDG) is the most used radiopharmaceutical for positron emission tomography, especially on oncology. Organic solvents such as ether, ethanol and acetonitrile might be used in the synthesis of [{sup 18}F]FDG; however, they might not be completely removed during purification steps. The determination of residual solvents in [{sup 18}F]FDG is required in the European Pharmacopoeia (EP) and the United States Pharmacopeia (USP) monographs. While the procedure described in the EP is quite general, the one described in the USP requires a long runtime (about 13 minutes). In this work a simple and fast (4-minute) analytical procedure was developed and validated for determination of residual solvents in [{sup 18}F]FDG. Analyses were carried out in a Perkin Elmer gas chromatograph equipped with a flame ionization detector. The separation was obtained on a 0.53-mm x 30 m fused-silica column. Validation included the evaluation of various parameters, such as: specificity, linearity and range, limits of detection and quantitation, precision (repeatability and intermediate precision), accuracy, and robustness. Results were found to be within acceptable limits, indicating the developed procedure is suitable for its intended application. Considering the short half-life of fluorine-18 (109.7 minutes), this new method could be a valuable alternative for routine quality control of [{sup 18}F]FDG. (author)

  2. Spectroscopic evidence for gas-phase formation of successive beta-turns in a three-residue peptide chain.

    Science.gov (United States)

    Chin, Wutharath; Compagnon, Isabelle; Dognon, Jean-Pierre; Canuel, Clélia; Piuzzi, François; Dimicoli, Iliana; von Helden, Gert; Meijer, Gerard; Mons, Michel

    2005-02-09

    We report the first gas-phase spectroscopic study of a three-residue model of a peptide chain, Ac-Phe-Gly-Gly-NH2 (Ac = acetyl), using the IR/UV double resonance technique. The existence of at least five different conformers under supersonic expansion conditions is established, most of them exhibiting rather strong intramolecular H-bonds. One of the most populated conformers, however, exhibits a different H-bonding network characterized by two weak H-bonds. Comparison of the amide A and I/II experimental data with density functional theory calculations carried out on a series of selected conformations enables us to assign this conformer to two successive beta-turns along the peptide chain, the two H-bonds being of C10 type, i.e., each of them closing a 10-atom ring in the molecule. The corresponding form is found to be more stable than the 310 helix secondary structure (not observed), presumably because of specific effects due to the glycine residues.

  3. A novel optimised and validated method for analysis of multi-residues of pesticides in fruits and vegetables by microwave-assisted extraction (MAE)-dispersive solid-phase extraction (d-SPE)-retention time locked (RTL)-gas chromatography-mass spectrometry with Deconvolution reporting software (DRS).

    Science.gov (United States)

    Satpathy, Gouri; Tyagi, Yogesh Kumar; Gupta, Rajinder Kumar

    2011-08-01

    A rapid, effective and ecofriendly method for sensitive screening and quantification of 72 pesticides residue in fruits and vegetables, by microwave-assisted extraction (MAE) followed by dispersive solid-phase extraction (d-SPE), retention time locked (RTL) capillary gas-chromatographic separation in trace ion mode mass spectrometric determination has been validated as per ISO/IEC: 17025:2005. Identification and reporting with total and extracted ion chromatograms were facilitated to a great extent by Deconvolution reporting software (DRS). For all compounds LOD were 0.002-0.02mg/kg and LOQ were 0.025-0.100mg/kg. Correlation coefficients of the calibration curves in the range of 0.025-0.50mg/kg were >0.993. To validate matrix effects repeatability, reproducibility, recovery and overall uncertainty were calculated for the 35 matrices at 0.025, 0.050 and 0.100mg/kg. Recovery ranged between 72% and 114% with RSD of <20% for repeatability and intermediate precision. The reproducibility of the method was evaluated by an inter laboratory participation and Z score obtained within ±2. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. The analysis of residual monocrotophos in rice plants

    International Nuclear Information System (INIS)

    Santiago, E.C.

    1992-01-01

    The procedure of Ambrus et al. (2.3) for extraction and clean up was modified to apply specifically to the extraction of monocrotophos in rice plant for determination by gas chromatography using flame photometric detector. An effective clean up system was developed to remove unwanted substances as well as to separate monocrotophos from other organic phosphate pesticides that interfere in the determination. The extraction utilized acetone/methylene chloride with recovery ranging from 41-53% for standards, while clean up recovery averaged 94% for standards or an overall percentage recovery of 41-55%. (auth.). 5 refs.; 5 tabs.; 5 figs

  5. Multivariate study of parameters in the determination of pesticide residues in apple by headspace solid phase microextraction coupled to gas chromatography-mass spectrometry using experimental factorial design.

    Science.gov (United States)

    Abdulra'uf, Lukman Bola; Tan, Guan Huat

    2013-12-15

    Solid-phase microextraction (SPME) is a solvent-less sample preparation method which combines sample preparation, isolation, concentration and enrichment into one step. In this study, multivariate strategy was used to determine the significance of the factors affecting the solid phase microextraction of pesticide residues (fenobucarb, diazinon, chlorothalonil and chlorpyrifos) using a randomised factorial design. The interactions and effects of temperature, time and salt addition on the efficiency of the extraction of the pesticide residues were evaluated using 2(3) factorial designs. The analytes were extracted with 100 μm PDMS fibres according to the factorial design matrix and desorbed into a gas chromatography-mass spectrometry detector. The developed method was applied for the analysis of apple samples and the limits of detection were between 0.01 and 0.2 μg kg(-)(1), which were lower than the MRLs for apples. The relative standard deviations (RSD) were between 0.1% and 13.37% with average recovery of 80-105%. The linearity ranges from 0.5-50 μg kg(-)(1) with correlation coefficient greater than 0.99. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Headspace Solid Phase Microextraction in Pesticide Residues Analysis: 2. Apple Samples

    Directory of Open Access Journals (Sweden)

    Jelena Milinović

    2007-01-01

    Full Text Available Headspace solid phase microextraction method (HS/SPME, optimised previously for pesticide water solutions, was applied to trace residues of the pesticides chlorpyrifos, fenthion and bifenthrin in apple samples. One-hour extraction procedure was performed at 60oC extraction temperature. Nonpolar polydimethyl siloxane (PDMS fiber was used. Detection and quantification were carried out by gas chromatography/mass spectrometry (GC/MS. A non-pesticide treated apple sample was fortified with the pesticides over a 0.025-1.25 mg/kg concentration range in order to determine analytical parameters of the method applied. Linearity with regression coefficient (R values higher than 0.99 were obtained over the whole concentration range investigated for chlorpyrifos and fenthion, while linear dependence was observed in the 0.1-1.25 mg/kg range for bifenthrin. Relative recovery values for samples fortified at different levels were in the 56.68-82.91% range. Limit of detection (LOD values were determined as follows: 0.014 mg/kg for chlorpyrifos, 0.021 mg/kg for fenthion and 0.053 mg/kg for bifenthrin. Relative standard deviation (RSD values obtained for multiple analysis of the sample fortified at 0.6 mg/kg level were not higher than 20%.

  7. Manual of Standard Operating Procedures for Veterinary Drug Residue Analysis (Spanish Edition)

    International Nuclear Information System (INIS)

    2017-01-01

    Laboratories are crucial to national veterinary drug residue monitoring programmes. However, one of the main challenges laboratories encounter is obtaining access to relevant methods of analysis. Thus, in addition to training, providing technical advice and transferring technology, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has resolved to develop clear and practical manuals to support Member State laboratories. The Coordinated Research Project (CRP) on Development of Radiometric and Allied Analytical Methods to Strengthen Residue Control Programs for Antibiotic and Anthelmintic Veterinary Drug Residues has developed a number of analytical methods as standard operating procedures (SOPs), which are now compiled here. This publication contains SOPs on chromatographic and spectrometric techniques, as well as radioimmunoassay and associated screening techniques, for various anthelmintic and antimicrobial veterinary drug residue analysis. Some analytical method validation protocols are also included. The publication is primarily aimed at food and environmental safety laboratories involved in testing veterinary drug residues, including under organized national residue monitoring programmes. It is expected to enhance laboratory capacity building and competence through the use of radiometric and complementary tools and techniques. The publication is also relevant for applied research on residues of veterinary drugs in food and environmental samples

  8. Effects of weld residual stresses on crack-opening area analysis of pipes for LBB applications

    Energy Technology Data Exchange (ETDEWEB)

    Dong, P.; Rahman, S.; Wilkowski, G. [and others

    1997-04-01

    This paper summarizes four different studies undertaken to evaluate the effects of weld residual stresses on the crack-opening behavior of a circumferential through-wall crack in the center of a girth weld. The effect of weld residual stress on the crack-opening-area and leak-rate analyses of a pipe is not well understood. There are no simple analyses to account for these effects, and, therefore, they are frequently neglected. The four studies involved the following efforts: (1) Full-field thermoplastic finite element residual stress analyses of a crack in the center of a girth weld, (2) A comparison of the crack-opening displacements from a full-field thermoplastic residual stress analysis with a crack-face pressure elastic stress analysis to determine the residual stress effects on the crack-opening displacement, (3) The effects of hydrostatic testing on the residual stresses and the resulting crack-opening displacement, and (4) The effect of residual stresses on crack-opening displacement with different normal operating stresses.

  9. Effects of weld residual stresses on crack-opening area analysis of pipes for LBB applications

    International Nuclear Information System (INIS)

    Dong, P.; Rahman, S.; Wilkowski, G.

    1997-01-01

    This paper summarizes four different studies undertaken to evaluate the effects of weld residual stresses on the crack-opening behavior of a circumferential through-wall crack in the center of a girth weld. The effect of weld residual stress on the crack-opening-area and leak-rate analyses of a pipe is not well understood. There are no simple analyses to account for these effects, and, therefore, they are frequently neglected. The four studies involved the following efforts: (1) Full-field thermoplastic finite element residual stress analyses of a crack in the center of a girth weld, (2) A comparison of the crack-opening displacements from a full-field thermoplastic residual stress analysis with a crack-face pressure elastic stress analysis to determine the residual stress effects on the crack-opening displacement, (3) The effects of hydrostatic testing on the residual stresses and the resulting crack-opening displacement, and (4) The effect of residual stresses on crack-opening displacement with different normal operating stresses

  10. Manual of Standard Operating Procedures for Veterinary Drug Residue Analysis (French Edition)

    International Nuclear Information System (INIS)

    2017-01-01

    Laboratories are crucial to national veterinary drug residue monitoring programmes. However, one of the main challenges laboratories encounter is obtaining access to relevant methods of analysis. Thus, in addition to training, providing technical advice and transferring technology, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has resolved to develop clear and practical manuals to support Member State laboratories. The Coordinated Research Project (CRP) on Development of Radiometric and Allied Analytical Methods to Strengthen Residue Control Programs for Antibiotic and Anthelmintic Veterinary Drug Residues has developed a number of analytical methods as standard operating procedures (SOPs), which are now compiled here. This publication contains SOPs on chromatographic and spectrometric techniques, as well as radioimmunoassay and associated screening techniques, for various anthelmintic and antimicrobial veterinary drug residue analysis. Some analytical method validation protocols are also included. The publication is primarily aimed at food and environmental safety laboratories involved in testing veterinary drug residues, including under organized national residue monitoring programmes. It is expected to enhance laboratory capacity building and competence through the use of radiometric and complementary tools and techniques. The publication is also relevant for applied research on residues of veterinary drugs in food and environmental samples

  11. [Determination of acetanilide herbicide residues in tea by gas chromatography-mass spectrometry with two different ionization techniques].

    Science.gov (United States)

    Shen, Weijian; Xu, Jinzhong; Yang, Wenquan; Shen, Chongyu; Zhao, Zengyun; Ding, Tao; Wu, Bin

    2007-09-01

    An analytical method of solid phase extraction-gas chromatography-mass spectrometry with two different ionization techniques was established for simultaneous determination of 12 acetanilide herbicide residues in tea-leaves. Herbicides were extracted from tea-leaf samples with ethyl acetate. The extract was cleaned-up on an active carbon SPE column connected to a Florisil SPE column. Analytical screening was determined by the technique of gas chromatography (GC)-mass spectrometry (MS) in the selected ion monitoring (SIM) mode with either electron impact ionization (EI) or negative chemical ionization (NCI). It is reliable and stable that the recoveries of all herbicides were in the range from 50% to 110% at three spiked levels, 10 microg/kg, 20 microg/kg and 40 microg/kg, and the relative standard deviations (RSDs) were no more than 10.9%. The two different ionization techniques are complementary as more ion fragmentation information can be obtained from the EI mode while more molecular ion information from the NCI mode. By comparison of the two techniques, the selectivity of NCI-SIM was much better than that of EI-SIM method. The sensitivities of the both techniques were high, the limit of quantitative (LOQ) for each herbicide was no more than 2.0 microg/kg, and the limit of detection (LOD) with NCI-SIM technique was much lower than that of EI-SIM when analyzing herbicides with several halogen atoms in the molecule.

  12. Nondestructive fission gas release measurement and analysis

    International Nuclear Information System (INIS)

    O'Leary, P.M.; Packard, D.R.

    1993-01-01

    Siemens Power Corporation (SPC) has performed reactor poolside gamma scanning measurements of fuel rods for fission gas release (FGR) detection for more than 10 yr. The measurement system has been previously described. Over the years, the data acquisition system, the method of spectrum analysis, and the means of reducing spectrum interference have been significantly improved. A personal computer (PC)-based multichannel analyzer (MCA) package is used to collect, display, and store high-resolution gamma-ray spectra measured in the fuel rod plenum. A PC spread sheet is used to fit the measured spectra and compute sample count rates after Compton background subtraction. A Zircaloy plenum spacer is often used to reduce positron annihilation interference that can arise from the INCONEL reg-sign plenum spring used in SPC-manufactured fuel rods

  13. Thermal analysis of a gas centrifuge

    International Nuclear Information System (INIS)

    Andrade, D.A.; Bastos, J.L.F.; Maiorino, J.R.

    1996-01-01

    The centrifuge separation efficiency is the result of the composition of the centrifuge field to the secondary flow in the axial direction near to the rotor wall. For a given machine, the centrifuge field can not be altered and the effort to augment the separation efficiency should be concentrated on the secondary flow. The secondary flow has a mechanical and a thermal component. The mechanical component is due to the deceleration of the gas at the scoop region. The thermal component is due to the temperature differences at the rotor. This paper presents a thermal model of a centrifuge in order to understand the main heat transfer mechanisms and to establish the boundary conditions for a fluid flow computer code. The heat transfer analysis takes into account conduction at the structure parts of the rotor and shell, radiation with multi-reflections between the rotor and the shell, and convection to the ambient. (author)

  14. Tank 16 Annulus Cleanout Analysis Doses at Seepline from Transport of Residual Tc-99 Wastes

    International Nuclear Information System (INIS)

    Collard, L.B.

    1999-01-01

    An analysis of residual Tc-99 in the Tank 16 annulus was conducted to assess the potential benefit from cleaning the annulus. One analysis was performed for the as-is case to determine seepline doses if no clean out occurs. Another analysis was performed assuming that ninety percent of existing contaminants are removed. Characterization data for samples retrieved from the annulus were used in the analysis. Only Tc-99 was analyzed because preliminary modeling identified it as the highest dose contributor. The effect of residual waste in piping was not analyzed

  15. Calculation method for residual stress analysis of filament-wound spherical pressure vessels

    International Nuclear Information System (INIS)

    Knight, C.E. Jr.

    1976-01-01

    Filament wound spherical pressure vessels may be produced with very high performance factors. These performance factors are a calculation of contained pressure times enclosed volume divided by structure weight. A number of parameters are important in determining the level of performance achieved. One of these is the residual stress state in the fabricated unit. A significant level of an unfavorable residual stress state could seriously impair the performance of the vessel. Residual stresses are of more concern for vessels with relatively thick walls and/or vessels constructed with the highly anisotropic graphite or aramid fibers. A method is established for measuring these stresses. A theoretical model of the composite structure is required. Data collection procedures and techniques are developed. The data are reduced by means of the model and result in the residual stress analysis. The analysis method can be used in process parameter studies to establish the best fabrication procedures

  16. Internal laboratory control in residue analysis of chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The thesis contains a chapter on gaschromatographic system in which gas current, temperatures, separation system, detector system, recorder, dosing system and integrator are described. The chapter on reagents deals with standards and solvents, absorbents and other reagents. The chapter on laboratory equipment deals with general recommendations for apparatus, purification and total numerical result of blank test. The chapter ''Methods'' contains general references, aptitude for a special problem, common investigations and control by standard reference materials. The chapter on the work up of samples treats extraction, purification, concentrating the solution, internal standard, multiple determination and control samples. The chapter on measurement presents calibration, internal standard, multiple determination, securing the result and control samples. The chapter on evaluation consists of qualitative and quantitave evaluation, decision criteria and communication of the result. The chapter of documentation described routine investigations, tests and controls of internal laboratory control, preliminary works, maintenance and service works.

  17. Annotating Protein Functional Residues by Coupling High-Throughput Fitness Profile and Homologous-Structure Analysis.

    Science.gov (United States)

    Du, Yushen; Wu, Nicholas C; Jiang, Lin; Zhang, Tianhao; Gong, Danyang; Shu, Sara; Wu, Ting-Ting; Sun, Ren

    2016-11-01

    Identification and annotation of functional residues are fundamental questions in protein sequence analysis. Sequence and structure conservation provides valuable information to tackle these questions. It is, however, limited by the incomplete sampling of sequence space in natural evolution. Moreover, proteins often have multiple functions, with overlapping sequences that present challenges to accurate annotation of the exact functions of individual residues by conservation-based methods. Using the influenza A virus PB1 protein as an example, we developed a method to systematically identify and annotate functional residues. We used saturation mutagenesis and high-throughput sequencing to measure the replication capacity of single nucleotide mutations across the entire PB1 protein. After predicting protein stability upon mutations, we identified functional PB1 residues that are essential for viral replication. To further annotate the functional residues important to the canonical or noncanonical functions of viral RNA-dependent RNA polymerase (vRdRp), we performed a homologous-structure analysis with 16 different vRdRp structures. We achieved high sensitivity in annotating the known canonical polymerase functional residues. Moreover, we identified a cluster of noncanonical functional residues located in the loop region of the PB1 β-ribbon. We further demonstrated that these residues were important for PB1 protein nuclear import through the interaction with Ran-binding protein 5. In summary, we developed a systematic and sensitive method to identify and annotate functional residues that are not restrained by sequence conservation. Importantly, this method is generally applicable to other proteins about which homologous-structure information is available. To fully comprehend the diverse functions of a protein, it is essential to understand the functionality of individual residues. Current methods are highly dependent on evolutionary sequence conservation, which is

  18. Finite element analysis of residual stress in plasma-sprayed ceramic

    International Nuclear Information System (INIS)

    Mullen, R.L.; Hendricks, R.C.; McDonald, G.

    1985-01-01

    Residual stress in a ZrO 2 -Y 2 O 3 ceramic coating resulting from the plasma spraying operation is calculated. The calculations were done using the finite element method. Both thermal and mechanical analysis were performed. The resulting residual stress field was compared to the measurements obtained by Hendricks and McDonald. Reasonable agreement between the predicted and measured moment occurred. However, the resulting stress field is not in pure bending

  19. Residual Stress Analysis for Engineering Applications by Means of Neutron Diffraction

    International Nuclear Information System (INIS)

    Gndupel-Herold, Thomas; Brand, Paul C.; Prask, Henry J.

    1999-01-01

    The economic and scientific importance of neutron diffraction residual stress analysis has led to an increasing number of suitable instruments worldwide. Recently, a dedicated state-of-the-art diffractometer has been installed at the National Institute of Standards and Technology reactor. It has been used for a variety of measurements on basic and engineering stress problems. Among the most prominent examples that have been investigated are residual stresses in rails, weldments, and plasma-sprayed coatings

  20. Annotating Protein Functional Residues by Coupling High-Throughput Fitness Profile and Homologous-Structure Analysis

    Directory of Open Access Journals (Sweden)

    Yushen Du

    2016-11-01

    Full Text Available Identification and annotation of functional residues are fundamental questions in protein sequence analysis. Sequence and structure conservation provides valuable information to tackle these questions. It is, however, limited by the incomplete sampling of sequence space in natural evolution. Moreover, proteins often have multiple functions, with overlapping sequences that present challenges to accurate annotation of the exact functions of individual residues by conservation-based methods. Using the influenza A virus PB1 protein as an example, we developed a method to systematically identify and annotate functional residues. We used saturation mutagenesis and high-throughput sequencing to measure the replication capacity of single nucleotide mutations across the entire PB1 protein. After predicting protein stability upon mutations, we identified functional PB1 residues that are essential for viral replication. To further annotate the functional residues important to the canonical or noncanonical functions of viral RNA-dependent RNA polymerase (vRdRp, we performed a homologous-structure analysis with 16 different vRdRp structures. We achieved high sensitivity in annotating the known canonical polymerase functional residues. Moreover, we identified a cluster of noncanonical functional residues located in the loop region of the PB1 β-ribbon. We further demonstrated that these residues were important for PB1 protein nuclear import through the interaction with Ran-binding protein 5. In summary, we developed a systematic and sensitive method to identify and annotate functional residues that are not restrained by sequence conservation. Importantly, this method is generally applicable to other proteins about which homologous-structure information is available.

  1. Gas chromatographic analysis of volatiles in fluid and gas inclusions

    Science.gov (United States)

    Andrawes, F.; Holzer, G.; Roedder, E.; Gibson, E.K.; Oro, John

    1984-01-01

    Most geological samples and some synthetic materials contain fluid inclusions. These inclusions preserve for us tiny samples of the liquid and/or the gas phase that was present during formation, although in some cases they may have undergone significant changes from the original material. Studies of the current composition of the inclusions provide data on both the original composition and the change since trapping.These inclusions are seldom larger than 1 millimeter in diameter. The composition varies from a single major compound (e.g., water) in a single phase to a very complex mixture in one or more phases. The concentration of some of the compounds present may be at trace levels.We present here some analyses of inclusions in a variety of geological samples, including diamonds. We used a sample crusher and a gas chromatography—mass spectrometry (GC—MS) system to analyze for organic and inorganic volatiles present as major to trace constituents in inclusions. The crusher is a hardened stainless-steel piston cylinder apparatus with tungsten carbide crusing surfaces, and is operated in a pure helium atmosphere at a controlled temperature.Samples ranging from 1 mg to 1 g were crushed and the released volatiles were analyzed using multi-chromatographic columns and detectors, including the sensitive helium ionization detector. Identification of the GC peaks was carried out by GC—MS. This combination of procedures has been shown to provide geochemically useful information on the process involved in the history of the samples analyzed.

  2. Reduction of residual gas in a sputtering system by auxiliary sputter of rare-earth metal

    International Nuclear Information System (INIS)

    Li Dejie

    2002-01-01

    In film deposition by sputtering, the oxidation and nitrification of the sputtered material lead to degradation of film quality, particularly with respect to metal sulfide films. We propose to use auxiliary sputtering as a method to produce a fresh film of rare-earth metal, usually dysprosium (Dy), that absorbs the active gases in a sputtering system, greatly reducing the background pressure and protecting the film from oxidation and nitrification effectively. The influence of the auxiliary sputtering power consumption, sputtering time, and medium gas pressure on the background pressure in the vacuum chamber is investigated in detail. If the auxiliary sputtering power exceeds 120 W and the sputtering time is more than 4 min, the background pressure is only one fourth of the ultimate pressure pumped by an oil diffusion pump. The absorption activity of the sputtered Dy film continues at least an hour after completion of the auxiliary sputter. Applied to film deposition of Ti and ZnS, this technique has been proven to be effective. For the Ti film, the total content of N and O is reduced from 45% to 20% when the auxiliary sputtering power of Dy is 120 W, and the sputtering time is 20 min. In the case of ZnS, the content of O is reduced from 8% to 2%

  3. Reverse Conservation Analysis Reveals the Specificity Determining Residues of Cytochrome P450 Family 2 (CYP 2

    Directory of Open Access Journals (Sweden)

    Tai-Sung Lee

    2008-01-01

    Full Text Available The concept of conservation of amino acids is widely used to identify important alignment positions of orthologs. The assumption is that important amino acid residues will be conserved in the protein family during the evolutionary process. For paralog alignment, on the other hand, the opposite concept can be used to identify residues that are responsible for specificity. Assuming that the function-specific or ligand-specific residue positions will have higher diversity since they are under evolutionary pressure to fit the target specificity, these function-specific or ligand-specific residues positions will have a lower degree of conservation than other positions in a highly conserved paralog alignment. This study assessed the ability of reverse conservation analysis to identify function-specific and ligand-specific residue positions in closely related paralog. Reverse conservation analysis of paralog alignments successfully identified all six previously reported substrate recognition sites (SRSs in cytochrome P450 family 2 (CYP 2. Further analysis of each subfamily identified the specificity-determining residues (SDRs that have been experimentally found. New potential SDRs were also predicted and await confirmation by further experiments or modeling calculations. This concept may be also applied to identify SDRs in other protein families.

  4. Design of a compressed air modulator to be used in comprehensive multidimensional gas chromatography and its application in the determination of pesticide residues in grapes.

    Science.gov (United States)

    Pizzutti, Ionara R; Vreuls, René J J; de Kok, André; Roehrs, Rafael; Martel, Samile; Friggi, Caroline A; Zanella, Renato

    2009-04-10

    In this study, a new modulator that is simple, robust and presents low operation costs, was developed. This modulator uses compressed air to cool two small portions in the first centimeters of the second chromatographic column of a comprehensive multidimensional gas chromatography (GCxGC) system. The results show a variation in the peak area less than 3 and 5% to alkanes and pesticides, respectively. The standard deviations for the retention times in the first and second dimension are around 0.05 min and 0.05s for all the compounds. The system was optimized with n-alkanes. The GCxGC system proposed was applied in the determination of pyrethroid pesticides (bifenthrin, cypermethrin, deltamethrin, fenvalerate, esfenvalerate, cis- and trans-permethrin) in grape samples. Samples were extracted by the mini-Luke modified method and pesticides were quantified by comprehensive multidimensional gas chromatography with micro electron-capture detection (microECD). The values of method limit of quantification (LOQ) were 0.01-0.02 mg kg(-1) for all studied pyrethroid and the values of recovery were between 94.3 and 115.2%, with good precision (RSDcompressed air has the potential for application in the analysis of a wider range of pesticide residues in other commodities since it provides low values of LOQ with acceptable accuracy and precision.

  5. Improvement of the management of residual waste in areas without thermal treatment facilities: A life cycle analysis of an Italian management district

    Energy Technology Data Exchange (ETDEWEB)

    Di Maria, Francesco, E-mail: francesco.dimaria@unipg.it [LAR Laboratory, Dipartimento di Ingegneria, Via G. Duranti 93, Perugia (Italy); Micale, Caterina; Morettini, Emanuela [LAR Laboratory, Dipartimento di Ingegneria, Via G. Duranti 93, Perugia (Italy); Sisani, Luciano [TSA spa, Via Case Sparse 107, Magione (Italy); Damiano, Roberto [GESENU spa, Via della Molinella 7, Perugia (Italy)

    2015-10-15

    Highlights: • LCA analysis of two option for residual waste management. • Exploitation of mechanical physical sorting facility for extracting recyclable from RMSW. • Processing the mechanically sorted organic fraction in bioreactor landfill. • Sensitivity analysis demonstrate high influence for impact assessment of substitution ratio for recycle materials. - Abstract: Starting from an existing waste management district without thermal treatment facilities, two different management scenarios for residual waste were compared by life cycle assessment (LCA). The adoption of a bioreactor landfill for managing the mechanically sorted organic fraction instead of bio-stabilization led to reduction of global warming and fresh water eutrophication by 50% and 10%, respectively. Extraction of recyclables from residual waste led to avoided emissions for particulate matter, acidification and resource depletion impact categories. Marginal energy and the amount of energy recovered from landfill gas marginally affected the LCA results. On the contrary the quality of the recyclables extracted can significantly modify the eco profile of the management schemes.

  6. Residual subsidence analysis after the end of coal mine work. Example from Lorraine Colliery, France

    International Nuclear Information System (INIS)

    Al Heib, M.; Nicolas, M.; Noirel, J.F.; Wojtkowiak, F.

    2005-01-01

    This paper describes the residual movements associated with the deep coal mines. The studied case relates to works located into Lorraine coal basin. The paper is divided into two sections. The first one describes subsidence phenomena, especially the residual phase in terms of amplitude, duration and localization. The second one focus on Morsbach case: the total and residual subsidence measurements will be analyzed and compared to the state of the art as well as the currant knowledge. The results of the analysis show that the duration of residual movements does not exceed 24 months and their amplitude is about 5% of total subsidence. We analyze also the declarations of the mining damage during and after the mining period. Damages occur, after this period are probably due to late observations. (authors)

  7. Residue analysis of veterinary drugs and growth-promoting agents

    NARCIS (Netherlands)

    Stolker, A.A.M.; Zuidema, T.; Nielen, M.W.F.

    2007-01-01

    Two major trends are observed in the analysis of veterinary drugs and growth-promoting agents. First is the selection of sample material for monitoring the use of registered veterinary drugs. Traditionally meat, kidney and liver were analyzed but, due to the food scandals in which meat was very

  8. Evaluation And Analysis of Natural Gas Rates

    International Nuclear Information System (INIS)

    Taheri, Ali Akbar

    1999-01-01

    Natural gas is considered as a preferred fuel and its utility is growing every day in the country (Iran). The usage of natural gas has increased from 3.5 to 44 billion cubic meters from 1980 to 1997, respectively. Currently, 4 million residences and most of the industrial sector are being provided with the pipelined natural gas. Because of the tremendous increase in consumption, it is necessary to give the needed considerations to natural gas rate structure. The objective of the paper is to 1.Evaluate the fundamentals and principal methods used for rate structures. 2. Identification of effective components. 3. Analyze the current rates including connection fees and other customer charges

  9. Gas hydrates forming and decomposition conditions analysis

    Directory of Open Access Journals (Sweden)

    А. М. Павленко

    2017-07-01

    Full Text Available The concept of gas hydrates has been defined; their brief description has been given; factors that affect the formation and decomposition of the hydrates have been reported; their distribution, structure and thermodynamic conditions determining the gas hydrates formation disposition in gas pipelines have been considered. Advantages and disadvantages of the known methods for removing gas hydrate plugs in the pipeline have been analyzed, the necessity of their further studies has been proved. In addition to the negative impact on the process of gas extraction, the hydrates properties make it possible to outline the following possible fields of their industrial use: obtaining ultrahigh pressures in confined spaces at the hydrate decomposition; separating hydrocarbon mixtures by successive transfer of individual components through the hydrate given the mode; obtaining cold due to heat absorption at the hydrate decomposition; elimination of the open gas fountain by means of hydrate plugs in the bore hole of the gushing gasser; seawater desalination, based on the hydrate ability to only bind water molecules into the solid state; wastewater purification; gas storage in the hydrate state; dispersion of high temperature fog and clouds by means of hydrates; water-hydrates emulsion injection into the productive strata to raise the oil recovery factor; obtaining cold in the gas processing to cool the gas, etc.

  10. Failure Analysis of Nonvolatile Residue (NVR) Analyzer Model SP-1000

    Science.gov (United States)

    Potter, Joseph C.

    2011-01-01

    National Aeronautics and Space Administration (NASA) subcontractor Wiltech contacted the NASA Electrical Lab (NE-L) and requested a failure analysis of a Solvent Purity Meter; model SP-IOOO produced by the VerTis Instrument Company. The meter, used to measure the contaminate in a solvent to determine the relative contamination on spacecraft flight hardware and ground servicing equipment, had been inoperable and in storage for an unknown amount of time. NE-L was asked to troubleshoot the unit and make a determination on what may be required to make the unit operational. Through the use of general troubleshooting processes and the review of a unit in service at the time of analysis, the unit was found to be repairable but would need the replacement of multiple components.

  11. [Monitoring of the residue of fosthiazate in water samples using solid-phase extraction coupled with gas chromatography/mass spectrometry].

    Science.gov (United States)

    Zhu, Jing; Zhou, Xin; Fu, Chunmei; Liu, Sankang; Li, Zhangwan

    2004-11-01

    Solid-phase extraction (SPE) coupled with gas chromatography/mass spectrometry (GC/MS) was used to determine the fosthiazate residue in water samples. The water samples were first filtered through cellulose filters (0.45 microm pore size). A 100 mL volume of filtered water, in which 1 mL of methanol has been added, was then passed through a pre-conditioned 3 cm C18 cartridge at a flow-rate of 1.5 mL/min. Elution was performed by 1 mL of methanol. The eluant was finally dried under reduced pressure for solvent evaporation. The volume was quantitatively adjusted to 0.5 mL with methanol. The analysis was carried out on GC/MS. The mass spectrometer was operated in selected ion monitoring (SIM) mode. According to mass spectrum of fosthiazate, three selected ions at m/z of 126, 195, 283, respectively, were monitored for identification and quantification. High sensitivity and selectivity were achieved by using this method. The limit of detection for fosthiazate in water samples was determined to be 56.4 ng/L. The linearity was demonstrated over a wide range of concentrations covering from 0.282 to 141 microg/L. The recoveries were more than 85.5% and the relative standard deviations for the overall procedure were less than 4.42%. The fosthiazate residue was detected in the water samples from a pool near cropland where fosthiazate was used. The results demonstrate the suitability of the SPE-GC/MS approach for the analysis of fosthiazate in water.

  12. Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS).

    Science.gov (United States)

    Quirk, Emma; Doggett, Adrian; Bretnall, Alison

    2014-08-05

    Spray Dried Dispersions (SDD) are uniform mixtures of a specific ratio of amorphous active pharmaceutical ingredient (API) and polymer prepared via a spray drying process. Volatile solvents are employed during spray drying to facilitate the formation of the SDD material. Following manufacture, analytical methodology is required to determine residual levels of the spray drying solvent and its associated impurities. Due to the high level of polymer in the SDD samples, direct liquid injection with Gas Chromatography (GC) is not a viable option for analysis. This work describes the development and validation of an analytical approach to determine residual levels of acetone and acetone related impurities, mesityl oxide (MO) and diacetone alcohol (DAA), in drug product intermediates prepared as SDDs using GC with headspace (HS) autosampling. The method development for these analytes presented a number of analytical challenges which had to be overcome before the levels of the volatiles of interest could be accurately quantified. GCHS could be used after two critical factors were implemented; (1) calculation and application of conversion factors to 'correct' for the reactions occurring between acetone, MO and DAA during generation of the headspace volume for analysis, and the addition of an equivalent amount of polymer into all reference solutions used for quantitation to ensure comparability between the headspace volumes generated for both samples and external standards. This work describes the method development and optimisation of the standard preparation, the headspace autosampler operating parameters and the chromatographic conditions, together with a summary of the validation of the methodology. The approach has been demonstrated to be robust and suitable to accurately determine levels of acetone, MO and DAA in SDD materials over the linear concentration range 0.008-0.4μL/mL, with minimum quantitation limits of 20ppm for acetone and MO, and 80ppm for DAA. Copyright

  13. Review of statistical analysis of trapped gas

    International Nuclear Information System (INIS)

    Schmittroth, F.A.

    1996-01-01

    A review was conducted of trapped gas estimates in Hanford waste tanks. Tank waste levels were found to correlate with barometric pressure changes giving the possibility to infer amounts of trapped gas. Previous models of the tank waste level were extended to include other phenomena such as evaporation in a more complete description of tank level changes

  14. Analysis of Adsorbed Natural Gas Tank Technology

    Science.gov (United States)

    Knight, Ernest; Schultz, Conrad; Rash, Tyler; Dohnke, Elmar; Stalla, David; Gillespie, Andrew; Sweany, Mark; Seydel, Florian; Pfeifer, Peter

    With gasoline being an ever decreasing finite resource and with the desire to reduce humanity's carbon footprint, there has been an increasing focus on innovation of alternative fuel sources. Natural gas burns cleaner, is more abundant, and conforms to modern engines. However, storing compressed natural gas (CNG) requires large, heavy gas cylinders, which limits space and fuel efficiency. Adsorbed natural gas (ANG) technology allows for much greater fuel storage capacity and the ability to store the gas at a much lower pressure. Thus, ANG tanks are much more flexible in terms of their size, shape, and weight. Our ANG tank employs monolithic nanoporous activated carbon as its adsorbent material. Several different configurations of this Flat Panel Tank Assembly (FPTA) along with a Fuel Extraction System (FES) were examined to compare with the mass flow rate demands of an engine.

  15. Development of a natural Gas Systems Analysis Model (GSAM)

    International Nuclear Information System (INIS)

    Godec, M.; Haas, M.; Pepper, W.; Rose, J.

    1993-01-01

    Recent dramatic changes in natural gas markets have significant implications for the scope and direction of DOE's upstream as well as downstream natural gas R ampersand D. Open access transportation changes the way gas is bought and sold. The end of the gas deliverability surplus requires increased reserve development above recent levels. Increased gas demand for power generation and other new uses changes the overall demand picture in terms of volumes, locations and seasonality. DOE's Natural Gas Strategic Plan requires that its R ampersand D activities be evaluated for their ability to provide adequate supplies of reasonably priced gas. Potential R ampersand D projects are to be evaluated using a full fuel cycle, benefit-cost approach to estimate likely market impact as well as technical success. To assure R ampersand D projects are evaluated on a comparable basis, METC has undertaken the development of a comprehensive natural gas technology evaluation framework. Existing energy systems models lack the level of detail required to estimate the impact of specific upstream natural gas technologies across the known range of geological settings and likely market conditions. Gas Systems Analysis Model (GSAM) research during FY 1993 developed and implemented this comprehensive, consistent natural gas system evaluation framework. Rather than a isolated research activity, however, GSAM represents the integration of many prior and ongoing natural gas research efforts. When complete, it will incorporate the most current resource base description, reservoir modeling, technology characterization and other geologic and engineering aspects developed through recent METC and industry gas R ampersand D programs

  16. Chemical Analysis of Organic Residues Found in Hellenistic Time Amphorae from SE Bulgaria

    Science.gov (United States)

    Zlateva, B.; Rangelov, M.

    2015-05-01

    We have used IR spectroscopy, 1H NMR spectroscopy, high-performance liquid chromatography and thin-layer chromatography to study the composition of resin residues found in 22 amphorae from Apollonia Pontika (SE Bulgaria). In particular this analysis of the resin residues was aimed at discovering the content of the amphorae and to verify the hypothesis on the transport of wine, named "Retsina". Additionally this hypothesis has been confirmed by a similar analysis of the modern resin sample from Aleppo pine (Pinus Halepensis) growing in the Attica region (Greece).

  17. Analysis of Residual Stress and Deformation of Rolling Strengthen Crankshaft Fillet

    Directory of Open Access Journals (Sweden)

    Han Shaojun

    2016-01-01

    Full Text Available Based on the analysis of crankshaft fillet rolling process, used ANSYS finite element analysis software to conduct the elastic-plastic mechanical simulation of crankshaft rolling process, and gained the variation law of the residual stress and plastic deformation in the radial path of the fillet under different rolling laps and rolling pressure. Established the relationship between the rolling pressure and the plastic deformation and residual stress of the fillet, and provided theoretical support for the evaluation and detection of the crankshaft rolling quality.

  18. Chemical analysis of solid residue from liquid and solid fuel combustion: Method development and validation

    Energy Technology Data Exchange (ETDEWEB)

    Trkmic, M. [University of Zagreb, Faculty of Mechanical Engineering and Naval Architecturek Zagreb (Croatia); Curkovic, L. [University of Zagreb, Faculty of Chemical Engineering and Technology, Zagreb (Croatia); Asperger, D. [HEP-Proizvodnja, Thermal Power Plant Department, Zagreb (Croatia)

    2012-06-15

    This paper deals with the development and validation of methods for identifying the composition of solid residue after liquid and solid fuel combustion in thermal power plant furnaces. The methods were developed for energy dispersive X-ray fluorescence (EDXRF) spectrometer analysis. Due to the fuels used, the different composition and the location of creation of solid residue, it was necessary to develop two methods. The first method is used for identifying solid residue composition after fuel oil combustion (Method 1), while the second method is used for identifying solid residue composition after the combustion of solid fuels, i. e. coal (Method 2). Method calibration was performed on sets of 12 (Method 1) and 6 (Method 2) certified reference materials (CRM). CRMs and analysis test samples were prepared in pellet form using hydraulic press. For the purpose of method validation the linearity, accuracy, precision and specificity were determined, and the measurement uncertainty of methods for each analyte separately was assessed. The methods were applied in the analysis of real furnace residue samples. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. FEM Analysis and Measurement of Residual Stress by Neutron Diffraction on the Dissimilar Overlay Weld Pipe

    International Nuclear Information System (INIS)

    Kim, Kang Soo; Lee, Ho Jin; Woo, Wan Chuck; Seong, Baek Seok; Byeon, Jin Gwi; Park, Kwang Soo; Jung, In Chul

    2010-01-01

    Much research has been done to estimate the residual stress on a dissimilar metal weld. There are many methods to estimate the weld residual stress and FEM (Finite Element Method) is generally used due to the advantage of the parametric study. And the X-ray method and a Hole Drilling technique for an experimental method are also usually used. The aim of this paper is to develop the appropriate FEM model to estimate the residual stresses of the dissimilar overlay weld pipe. For this, firstly, the specimen of the dissimilar overlay weld pipe was manufactured. The SA 508 Gr3 nozzle, the SA 182 safe end and SA376 pipe were welded by the Alloy 182. And the overlay weld by the Alloy 52M was performed. The residual stress of this specimen was measured by using the Neutron Diffraction device in the HANARO (High-flux Advanced Neutron Application ReactOr) research reactor, KAERI (Korea Atomic Energy Research Institute). Secondly, FEM Model on the dissimilar overlay weld pipe was made and analyzed by the ABAQUS Code (ABAQUS, 2004). Thermal analysis and stress analysis were performed, and the residual stress was calculated. Thirdly, the results of the FEM analysis were compared with those of the experimental methods

  20. Reducing the impurity incorporation from residual gas by ion bombardment during high vacuum magnetron sputtering

    International Nuclear Information System (INIS)

    Rosen, Johanna; Widenkvist, Erika; Larsson, Karin; Kreissig, Ulrich; Mraz, Stanislav; Martinez, Carlos; Music, Denis; Schneider, J. M.

    2006-01-01

    The influence of ion energy on the hydrogen incorporation has been investigated for alumina thin films, deposited by reactive magnetron sputtering in an Ar/O 2 /H 2 O environment. Ar + with an average kinetic energy of ∼5 eV was determined to be the dominating species in the plasma. The films were analyzed with x-ray diffraction, x-ray photoelectron spectroscopy, and elastic recoil detection analysis, demonstrating evidence for amorphous films with stoichiometric O/Al ratio. As the substrate bias potential was increased from -15 V (floating potential) to -100 V, the hydrogen content decreased by ∼70%, from 9.1 to 2.8 at. %. Based on ab initio calculations, these results may be understood by thermodynamic principles, where a supply of energy enables surface diffusion, H 2 formation, and desorption [Rosen et al., J. Phys.: Condens. Matter 17, L137 (2005)]. These findings are of importance for the understanding of the correlation between ion energy and film composition and also show a pathway to reduce impurity incorporation during film growth in a high vacuum ambient

  1. Studies on the profile measurement of hadron beams by means of residual-gas luminescence and ionization

    International Nuclear Information System (INIS)

    Boehme, Christian Gerhard Heinrich

    2011-01-01

    Modern particle accelerators are applied for a long time no more only in the fundamental physical research but in ever larger extent also in the concrete application for instance in the tumor irradiation or the microprocessor fabrication. The precise knowledge of the beam profile is thereby of great importance for the success. But in intermediate-energy hadron accelerators it hitherto not satisfyingly succeeds to measure the beam profiles not disturbingly. These study presents two not beam-disturbing measuring methods, which are based on the ion beam-residual gas interactions of luminescence and ionization. They were developed for different framework conditions at the JESSICA beam place of the COSY accelerator of the Juelich research center, an advance experiment of the planned European Spallation Source (ESS), as well at the proton synchrotron COSY itself, and the iThemba Laboratory for Accelerator Based Science, Somerset West, South Africa. Thereby the studies consider a large range of possible configuration parameters: Particle momenta from 3 MeV/c to 3 GeV/c, pressures from 1 mbar to 10 -11 mbar and time structures from DC beam to beam bunches of 100 ns length. The experimental arrangement, the application ranges, and the advantages and disadvantages of both methods are explained in this book.

  2. Automated metabolic gas analysis systems: a review.

    Science.gov (United States)

    Macfarlane, D J

    2001-01-01

    The use of automated metabolic gas analysis systems or metabolic measurement carts (MMC) in exercise studies is common throughout the industrialised world. They have become essential tools for diagnosing many hospital patients, especially those with cardiorespiratory disease. Moreover, the measurement of maximal oxygen uptake (VO2max) is routine for many athletes in fitness laboratories and has become a defacto standard in spite of its limitations. The development of metabolic carts has also facilitated the noninvasive determination of the lactate threshold and cardiac output, respiratory gas exchange kinetics, as well as studies of outdoor activities via small portable systems that often use telemetry. Although the fundamental principles behind the measurement of oxygen uptake (VO2) and carbon dioxide production (VCO2) have not changed, the techniques used have, and indeed, some have almost turned through a full circle. Early scientists often employed a manual Douglas bag method together with separate chemical analyses, but the need for faster and more efficient techniques fuelled the development of semi- and full-automated systems by private and commercial institutions. Yet, recently some scientists are returning back to the traditional Douglas bag or Tissot-spirometer methods, or are using less complex automated systems to not only save capital costs, but also to have greater control over the measurement process. Over the last 40 years, a considerable number of automated systems have been developed, with over a dozen commercial manufacturers producing in excess of 20 different automated systems. The validity and reliability of all these different systems is not well known, with relatively few independent studies having been published in this area. For comparative studies to be possible and to facilitate greater consistency of measurements in test-retest or longitudinal studies of individuals, further knowledge about the performance characteristics of these

  3. Residual stress analysis for engineering applications by means of neutron diffraction

    International Nuclear Information System (INIS)

    Gnaeupel-Herold, T.; Brand, P.C.; Prask, H.J.

    1999-01-01

    Residual stresses originate from spatial differences in plastic deformation, temperature, or phase distribution, introduced by manufacturing processes or during service. Engineering parts and materials experience mechanical, thermal, and chemical loads during their service, and most of these loads introduce stresses that are superimposed on the already existing residual stresses. Residual stresses can therefore limit or improve life and strength of engineering parts; knowledge and understanding of these stresses is therefore critical for optimizing strength and durability. The economic and scientific importance of neutron diffraction residual stress analysis has led to an increasing number of suitable instruments worldwide. All of the major sources due in the next several years will have instruments for the sole purpose of performing residual stress and texture measurements. Recently, a dedicated, state-of-the-art diffractometer has been installed at the National Institute of Standards and Technology reactor. It has been used for a variety of measurements on basic and engineering stress problems. Among the most prominent examples that have been investigated in collaboration with industrial and academic partners are residual stresses in rails, weldments, and plasma-sprayed coatings

  4. Residual strain sensor using Al-packaged optical fiber and Brillouin optical correlation domain analysis.

    Science.gov (United States)

    Choi, Bo-Hun; Kwon, Il-Bum

    2015-03-09

    We propose a distributed residual strain sensor that uses an Al-packaged optical fiber for the first time. The residual strain which causes Brillouin frequency shifts in the optical fiber was measured using Brillouin optical correlation domain analysis with 2 cm spatial resolution. We quantified the Brillouin frequency shifts in the Al-packaged optical fiber by the tensile stress and compared them for a varying number of Al layers in the optical fiber. The Brillouin frequency shift of an optical fiber with one Al layer had a slope of 0.038 MHz/με with respect to tensile stress, which corresponds to 78% of that for an optical fiber without Al layers. After removal of the stress, 87% of the strain remained as residual strain. When different tensile stresses were randomly applied, the strain caused by the highest stress was the only one detected as residual strain. The residual strain was repeatedly measured for a time span of nine months for the purpose of reliability testing, and there was no change in the strain except for a 4% reduction, which is within the error tolerance of the experiment. A composite material plate equipped with our proposed Al-packaged optical fiber sensor was hammered for impact experiment and the residual strain in the plate was successfully detected. We suggest that the Al-packaged optical fiber can be adapted as a distributed strain sensor for smart structures, including aerospace structures.

  5. Residual stress analysis in carbon fiber-reinforced SiC ceramics

    International Nuclear Information System (INIS)

    Broda, M.

    1998-01-01

    Systematic residual stress analyses are reported, carried out in long-fiber reinforced SiC ceramics. The laminated C fiber /SiC matrix specimens used were prepared by polymer pyrolysis, and the structural component specimens used are industrial products. Various diffraction methods have been applied for non-destructive evaluation of residual stress fields, so as to completely detect the residual stresses and their distribution in the specimens. The residual stress fields at the surface (μm) have been measured using characteristic X-radiation and applying the sin 2 ψ method as well as the scatter vector method. For residual stress field analysis in the mass volume (cm), neutron diffraction has been applied. The stress fields in the fiber layers (approx. 250μm) have been measured as a function of their location within the laminated composite by using an energy-dispersive method and synchrotron radiation. By means of the systematic, process-accompanying residual stress and phase analyses, conclusions can be drawn as to possible approaches for optimization of fabrication parameters. (orig./CB) [de

  6. Microstructure and temperature dependence of intergranular strains on diffractometric macroscopic residual stress analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J.N., E-mail: Julia.Wagner@kit.edu [KNMF, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Hofmann, M. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), TU München, Lichtenbergstr. 1, 85747 Garching (Germany); Wimpory, R. [Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109 Berlin Wannsee (Germany); Krempaszky, C. [Christian-Doppler-Labor für Werkstoffmechanik von Hochleistungslegierungen, TU München, Boltzmannstr. 15, 85747 Garching (Germany); Lehrstuhl für Werkstoffkunde und Werkstoffmechanik, TU München, Boltzmannstr. 15, 85747 Garching (Germany); Stockinger, M. [Böhler Schmiedetechnik GmbH and Co KG, Mariazeller Straße 25, 8605 Kapfenberg (Austria)

    2014-11-17

    Knowledge of the macroscopic residual stresses in components of complex high performance alloys is crucial when it comes to considering the safety and manufacturing aspects of components. Diffraction experiments are one of the key methods for studying residual stresses. However a component of the residual strain determined by diffraction experiments, known as microstrain or intergranular residual strain, occurs over the length scale of the grains and thus plays only a minor role for the life time of such components. For the reliable determination of macroscopic strains (with the minimum influence of these intergranular residual strains), the ISO standard recommends the use of particular Bragg reflections. Here we compare the build-up of intergranular strain of two different precipitation hardened IN 718 (INCONEL 718) samples, with identical chemical composition. Since intergranular strains are also affected by temperature, results from room temperature measurement are compared to results at T=550 °C. It turned out that microstructural parameters, such as grain size or type of precipitates, have a larger effect on the intergranular strain evolution than the influence of temperature at the measurement temperature of T=550 °C. The results also show that the choice of Bragg reflections for the diffractometric residual stress analysis is dependent not only on its chemical composition, but also on the microstructure of the sample. In addition diffraction elastic constants (DECs) for all measured Bragg reflections are given.

  7. Using Willie's Acid-Base Box for Blood Gas Analysis

    Science.gov (United States)

    Dietz, John R.

    2011-01-01

    In this article, the author describes a method developed by Dr. William T. Lipscomb for teaching blood gas analysis of acid-base status and provides three examples using Willie's acid-base box. Willie's acid-base box is constructed using three of the parameters of standard arterial blood gas analysis: (1) pH; (2) bicarbonate; and (3) CO[subscript…

  8. Thermodynamic DFT analysis of natural gas.

    Science.gov (United States)

    Neto, Abel F G; Huda, Muhammad N; Marques, Francisco C; Borges, Rosivaldo S; Neto, Antonio M J C

    2017-08-01

    Density functional theory was performed for thermodynamic predictions on natural gas, whose B3LYP/6-311++G(d,p), B3LYP/6-31+G(d), CBS-QB3, G3, and G4 methods were applied. Additionally, we carried out thermodynamic predictions using G3/G4 averaged. The calculations were performed for each major component of seven kinds of natural gas and to their respective air + natural gas mixtures at a thermal equilibrium between room temperature and the initial temperature of a combustion chamber during the injection stage. The following thermodynamic properties were obtained: internal energy, enthalpy, Gibbs free energy and entropy, which enabled us to investigate the thermal resistance of fuels. Also, we estimated an important parameter, namely, the specific heat ratio of each natural gas; this allowed us to compare the results with the empirical functions of these parameters, where the B3LYP/6-311++G(d,p) and G3/G4 methods showed better agreements. In addition, relevant information on the thermal and mechanic resistance of natural gases were investigated, as well as the standard thermodynamic properties for the combustion of natural gas. Thus, we show that density functional theory can be useful for predicting the thermodynamic properties of natural gas, enabling the production of more efficient compositions for the investigated fuels. Graphical abstract Investigation of the thermodynamic properties of natural gas through the canonical ensemble model and the density functional theory.

  9. Experimental analysis of residual stresses in pre-straightened SAE 1045 steel

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Carla Adriana Theis Soares; Rocha, Alexandre da Silva, E-mail: carla.adriana@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Laboratorio de Formacao de Metais; Epp, Jérémy; Zoch, Hans-Werner [Stiftung Institut für Werkstofftechnik IWT, University of Bremen (Germany)

    2017-11-15

    This paper aims at analyzing the effects of the roller pre-straightening of wire-rods on residual stress distributions in SAE 1045 steel bars. The combined drawing process is used in industrial production of bars in order to obtain a good surface quality and improved mechanical properties complying with specifications of the final products. In this process, prior to the drawing step, a roller straightening of the steel wire-rod is essential, because it provides the minimum straightness necessary for drawing. Metallographic analysis and hardness test were done for selected samples after different processing steps. Also, residual stress analysis of pre-straightened wire-rods by X-ray diffraction and neutron diffraction were carried out. The hardness tests show higher values near the surface and lower in the center of the wire-rod. Besides, the residual stresses results show a big inhomogeneity from one peripheral position to another and also in the evaluated cross section. (author)

  10. Experimental analysis of residual stresses in pre-straightened SAE 1045 steel

    International Nuclear Information System (INIS)

    Diehl, Carla Adriana Theis Soares; Rocha, Alexandre da Silva

    2017-01-01

    This paper aims at analyzing the effects of the roller pre-straightening of wire-rods on residual stress distributions in SAE 1045 steel bars. The combined drawing process is used in industrial production of bars in order to obtain a good surface quality and improved mechanical properties complying with specifications of the final products. In this process, prior to the drawing step, a roller straightening of the steel wire-rod is essential, because it provides the minimum straightness necessary for drawing. Metallographic analysis and hardness test were done for selected samples after different processing steps. Also, residual stress analysis of pre-straightened wire-rods by X-ray diffraction and neutron diffraction were carried out. The hardness tests show higher values near the surface and lower in the center of the wire-rod. Besides, the residual stresses results show a big inhomogeneity from one peripheral position to another and also in the evaluated cross section. (author)

  11. Research Progress on Pesticide Residue Analysis Techniques in Agro-products

    Directory of Open Access Journals (Sweden)

    HE Ze-ying

    2016-07-01

    Full Text Available There are constant occurrences of acute pesticide poisoning among consumers and pesticide residue violations in agro-products import/export trading. Pesticide residue analysis is the important way to protect the food safety and the interest of import/export enterprises. There has been a rapid development in pesticide residue analysis techniques in recent years. In this review, the research progress in the past five years were discussed in the respects of samples preparation and instrument determination. The application, modification and development of the QuEChERS method in samples preparation and the application of tandem mass spectrometry and high resolution mass spectrometry were reviewed. And the implications for the future of the field were discussed.

  12. Viscoelastic finite element analysis of residual stresses in porcelain-veneered zirconia dental crowns.

    Science.gov (United States)

    Kim, Jeongho; Dhital, Sukirti; Zhivago, Paul; Kaizer, Marina R; Zhang, Yu

    2018-06-01

    The main problem of porcelain-veneered zirconia (PVZ) dental restorations is chipping and delamination of veneering porcelain owing to the development of deleterious residual stresses during the cooling phase of veneer firing. The aim of this study is to elucidate the effects of cooling rate, thermal contraction coefficient and elastic modulus on residual stresses developed in PVZ dental crowns using viscoelastic finite element methods (VFEM). A three-dimensional VFEM model has been developed to predict residual stresses in PVZ structures using ABAQUS finite element software and user subroutines. First, the newly established model was validated with experimentally measured residual stress profiles using Vickers indentation on flat PVZ specimens. An excellent agreement between the model prediction and experimental data was found. Then, the model was used to predict residual stresses in more complex anatomically-correct crown systems. Two PVZ crown systems with different thermal contraction coefficients and porcelain moduli were studied: VM9/Y-TZP and LAVA/Y-TZP. A sequential dual-step finite element analysis was performed: heat transfer analysis and viscoelastic stress analysis. Controlled and bench convection cooling rates were simulated by applying different convective heat transfer coefficients 1.7E-5 W/mm 2 °C (controlled cooling) and 0.6E-4 W/mm 2 °C (bench cooling) on the crown surfaces exposed to the air. Rigorous viscoelastic finite element analysis revealed that controlled cooling results in lower maximum stresses in both veneer and core layers for the two PVZ systems relative to bench cooling. Better compatibility of thermal contraction coefficients between porcelain and zirconia and a lower porcelain modulus reduce residual stresses in both layers. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Mapping residual stresses in PbWO4 crystals using photo-elastic analysis

    International Nuclear Information System (INIS)

    Lebeau, M.; Gobbi, L.; Majni, G.; Paone, N.; Pietroni, P.; Rinaldi, D.

    2005-01-01

    Large scintillating crystals are affected by internal stresses induced by the crystal growth temperature gradient remanence. Cutting boules (ingots) into finished crystal shapes allows for a partial tension relaxation but residual stresses remain the main cause of breaking. Quality control of residual stresses is essential in the application of Scintillating Crystals to high-energy physics calorimeters (e.g. CMS ECAL at CERN LHC). In this context the industrial process optimisation towards stress reduction is mandatory. We propose a fast technique for testing samples during the production process in order to evaluate the residual stress distribution after the first phases of mechanical processing. We mapped the stress distribution in PbWO 4 slabs cut from the same production boule. The analysis technique is based on the stress intensity determination using the photo-elastic properties of the samples. The stress distribution is mapped in each sample. The analysis shows that there are regions of high residual tension close to the seed position and at the boule periphery. These results should allow for adapting the industrial process to producing crystals with lower residual stresses

  14. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2002-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indirectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supplementary firing may be based on natural gas, biogas, or pyrolysis gas. {The interest in this cycle arise from a recent...... demonstration of a two-stage gasification process through construction of several plants.} A preliminary analysis of the ideal recuperated Brayton cycle shows that for this cycle any supplementary firing will have a marginal efficiency of unity per extra unit of fuel. The same result is obtained...

  15. Strength analysis of copper gas pipeline span

    OpenAIRE

    Ianevski, Philipp

    2016-01-01

    The purpose of the study was to analyze the stresses in a gas pipeline. While analyzing piping systems located inside building were used. Calculation of the strength of a gas pipeline is done by using information of the thickness of pipe walls, by choosing the suitable material, inner and outer diameter for the pipeline. Data for this thesis was collected through various internet sources and different books. From the study and research, the final results were reached and calculations were ...

  16. Least-Squares Linear Regression and Schrodinger's Cat: Perspectives on the Analysis of Regression Residuals.

    Science.gov (United States)

    Hecht, Jeffrey B.

    The analysis of regression residuals and detection of outliers are discussed, with emphasis on determining how deviant an individual data point must be to be considered an outlier and the impact that multiple suspected outlier data points have on the process of outlier determination and treatment. Only bivariate (one dependent and one independent)…

  17. Thermal decomposition characteristics of microwave liquefied rape straw residues using thermogravimetric analysis

    Science.gov (United States)

    Xingyan Huang; Cornelis F. De Hoop; Jiulong Xie; Chung-Yun Hse; Jinqiu Qi; Yuzhu Chen; Feng Li

    2017-01-01

    The thermal decomposition characteristics of microwave liquefied rape straw residues with respect to liquefaction condition and pyrolysis conversion were investigated using a thermogravimetric (TG) analyzer at the heating rates of 5, 20, 50 °C min-1. The hemicellulose decomposition peak was absent at the derivative thermogravimetric analysis (DTG...

  18. Analysis of natural gas supply strategies at Fort Drum

    International Nuclear Information System (INIS)

    Stucky, D.J.; Shankle, S.A.; Anderson, D.M.

    1992-07-01

    This analysis investigates strategies for Fort Drum to acquire a reliable natural gas supply while reducing its gas supply costs. The purpose of this study is to recommend an optimal supply mix based on the life-cycle costs of each strategy analyzed. In particular, this study is intended to provide initial guidance as to whether or not the building and operating of a propane-air mixing station is a feasible alternative to the current gas acquisition strategy. The analysis proceeded by defining the components of supply (gas purchase, gas transport, supplemental fuel supply); identifying alternative options for each supply component; constructing gas supply strategies from different combinations of the options available for each supply component and calculating the life-cycle costs of each supply strategy under a set of different scenarios reflecting the uncertainty of future events

  19. Finite element analysis for prediction of the residual stresses induced by shot peening II

    International Nuclear Information System (INIS)

    Kim, Cheol; Seok, Chang Sung; Yang, Won Ho; Ryu, Myung Hai

    2002-01-01

    Shot peening is a surface impact treatment widely used to improve the performance of metal parts and welded details subjected to fatigue loading, contact fatigue, stress corrosion and other damage mechanisms. The better performance of the peened parts is mainly due to the residual stresses resulting from the plastic deformation of the surface layers of the material caused by the impact of the shot. In this paper the simulation technique is applied to predict the magnitude and distribution of the residual stress and plastic deformation caused by shot peening with the help of finite element analysis

  20. Experimental stress analysis for determination of residual stresses and integrity monitoring of components and systems

    International Nuclear Information System (INIS)

    1993-01-01

    For an analysis of the safety-related significance of residual stresses, mechanical, magnetic as well as ultrasonic and diffraction methods can be applied as testing methods. The results of an interlaboratory test concerning the experimental determination of residual stresses in a railway track are included. Further, questions are analyzed concerning the in-service inspections of components and systems with regard to their operational safety and life. Measurement methods are explained by examples from power plant engineering, nuclear power plant engineering, construction and traffic engineering as well as aeronautics. (DG) [de

  1. Gas analysis during the chemical vapor deposition of carbon

    International Nuclear Information System (INIS)

    Lieberman, M.L.; Noles, G.T.

    1973-01-01

    Gas chromatographic analyses were performed during the chemical vapor deposition of carbon in both isothermal and thermal gradient systems. Such data offer insight into the gas phase processes which occur during deposition and the interrelations which exist between gas composition, deposition rate, and resultant structure of the deposit. The results support a carbon CVD model presented previously. The application of chromatographic analysis to research, development, and full-scale facilities is shown. (U.S.)

  2. The finite element analysis for prediction of residual stresses induced by shot peening

    International Nuclear Information System (INIS)

    Kim, Cheol; Yang, Won Ho; Sung, Ki Deug; Cho, Myoung Rae; Ko, Myung Hoon

    2000-01-01

    The shot peening is largely used for a surface treatment in which small spherical parts called shots are blasted on a surface of a metallic components with velocities up to 100m/s. This treatment leads to an improvement of fatigue behavior due to the developed compressive residual stresses, and so it has gained widespread acceptance in the automobile and aerospace industries. The residual stress profile on surface layer depends on the parameters of shot peening, which are, shot velocity, shot diameter, coverage, impact angle, material properties etc. and the method to confirm this profile is only measurement by X-ray diffractometer. Despite its importance to automobile and aerospace industries, little attention has been devoted to the accurate modeling of the process. In this paper, the simulation technique is applied to predict the magnitude and distribution of the residual stress and plastic deformation caused by shot peening with the help of the finite element analysis

  3. ELASTIC-PLASTIC AND RESIDUAL STRESS ANALYSIS OF AN ALUMINUM DISC UNDER INTERNAL PRESSURES

    Directory of Open Access Journals (Sweden)

    Numan Behlül BEKTAŞ

    2004-02-01

    Full Text Available This paper deals with elastic-plastic stress analysis of a thin aluminum disc under internal pressures. An analytical solution is performed for satisfying elastic-plastic stress-strain relations and boundary conditions for small plastic deformations. The Von-Mises Criterion is used as a yield criterion, and elastic perfectly plastic material is assumed. Elastic-plastic and residual stress distributions are obtained from inner radius to outer radius, and they are presented in tables and figures. All radial stress components, ?r, are compressive, and they are highest at the inner radius. All tangential stress components, ??, are tensile, and they are highest where the plastic deformation begins. Magnitude of the tangential residual stresses is higher than those the radial residual stresses.

  4. A Stirling engine analysis method based upon moving gas nodes

    Science.gov (United States)

    Martini, W. R.

    1986-01-01

    A Lagrangian nodal analysis method for Stirling engines (SEs) is described, validated, and applied to a conventional SE and an isothermalized SE (with fins in the hot and cold spaces). The analysis employs a constant-mass gas node (which moves with respect to the solid nodes during each time step) instead of the fixed gas nodes of Eulerian analysis. The isothermalized SE is found to have efficiency only slightly greater than that of a conventional SE.

  5. Efficient identification of critical residues based only on protein structure by network analysis.

    Directory of Open Access Journals (Sweden)

    Michael P Cusack

    2007-05-01

    Full Text Available Despite the increasing number of published protein structures, and the fact that each protein's function relies on its three-dimensional structure, there is limited access to automatic programs used for the identification of critical residues from the protein structure, compared with those based on protein sequence. Here we present a new algorithm based on network analysis applied exclusively on protein structures to identify critical residues. Our results show that this method identifies critical residues for protein function with high reliability and improves automatic sequence-based approaches and previous network-based approaches. The reliability of the method depends on the conformational diversity screened for the protein of interest. We have designed a web site to give access to this software at http://bis.ifc.unam.mx/jamming/. In summary, a new method is presented that relates critical residues for protein function with the most traversed residues in networks derived from protein structures. A unique feature of the method is the inclusion of the conformational diversity of proteins in the prediction, thus reproducing a basic feature of the structure/function relationship of proteins.

  6. Correlation between arterial blood gas analysis and peripheral blood gas analysis in acid-base unbalance state

    Directory of Open Access Journals (Sweden)

    Hyun Lee Kim

    2012-06-01

    Full Text Available Acid-base unbalance is most common problem in severe ill patient, especially in condition of abnormal renal function state. Acid-base unbalances are respiratory acidosis, respiratory alkalosis, metabolic acidosis, and metabolic alkalosis. Metabolic acidosis is frequently appeared in clinical state. Arterial blood gas analysis is considered as a basic test to the intensive care unit patient and emergency state. Recently some researches were done, comparing with arterial blood gas analysis and venous blood gas analysis. Because of venous blood sampling is safer than arterial blood gas analysis, and beside not so different among them for detecting pH, pCO2, HCO3, except pO2 measuring. This research was done in emergency room, and for explaining no different between arterial blood gas analysis and peripheral blood gas analysis result in acid-base unbalance state patient. Especially in kidney functions decreased state. : The study was done from March, 2010 to January, 2011. The object was 89 peoples who came to emergency room for treating internal medicine problem. (Women 53, average age: 66.7±12.1 Then compare between arterial blood gas analysis and peripheral blood gas analysis. Result: The mean arterial minus venous difference for pH, pCO2, and bicarbonate was −0.0170, 2.6528, and 0.6124. Bland-Altman plot was done for predicting agreement of two groups, and the scale was pH −2.95 to 4.17, pCO2 −4.45 to 9.76, bicarbonate −2.95 to 4.16, in 95% relative. Conclusion: The peripheral blood gas pH, pCO2, bicarbonate level is almost same as arterial blood gas analysis results. And enough to measuring acid-base unbalance state, in absent of arterial blood testing.

  7. Development of a micrometre-scale radiographic measuring method for residual stress analysis

    International Nuclear Information System (INIS)

    Moeller, D.

    1999-01-01

    The radiographic method described uses micrometre X-ray diffraction for high-resolution residual stress analysis in single crystals. The focus is on application of two x-ray optics (glass capillaries) for shaping a sufficiently fine and intensive primary beam. Due to application of a proper one-grain measuring and analysis method, the resolution results are applicable to the characteristic grain sizes of many materials. (orig.) [de

  8. Thermal analysis elements of liquefied gas storage tanks

    Science.gov (United States)

    Yanvarev, I. A.; Krupnikov, A. V.

    2017-08-01

    Tasks of solving energy and resource efficient usage problems, both for oil producing companies and for companies extracting and transporting natural gas, are associated with liquefied petroleum gas technology development. Improving the operation efficiency of liquefied products storages provides for conducting structural, functional, and appropriate thermal analysis of tank parks in the general case as complex dynamic thermal systems.

  9. State and trends of ionization gas analysis. 1

    International Nuclear Information System (INIS)

    Leonhardt, J.W.; Grosse, H.J.; Popp, P.

    1980-01-01

    The ionization gas analysis makes use of the fact that the ionization-induced conductivity of gases and gas mixtures changes with the composition of such mixtures. A general description is given of ionization detectors based on this principle and theory, properties, and main fields of application of electron capture detectors are discussed

  10. Improvement of gas chromatographic analysis for organic acids and ...

    African Journals Online (AJOL)

    Yomi

    2010-08-27

    Aug 27, 2010 ... short retention time and fair recognition peak of the compounds were obtained under the ... GC for acid and solvent analysis from ABE fermentation ... FID was kept at 230°C. Nitrogen gas was used as a carrier gas at a.

  11. State and trends of ionization gas analysis. 3

    International Nuclear Information System (INIS)

    Leonhardt, J.W.; Grosse, H.J.; Popp, P.

    1980-01-01

    Theory, properties, and main fields of application of noble gas detectors are discussed. The theory and design of the indirect electron mobility detector is presented. Conclusions are drawn with regard to possibilities of further development of detectors for the ionization gas analysis

  12. Design and analysis of a new passive residual heat removal system

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xing [Key Subject Laboratory of Nuclear Safety and Simulation Technology, Harbin Engineering University, Harbin, Heilongjiang 150001 (China); Peng, Minjun, E-mail: heupmj@163.com [Key Subject Laboratory of Nuclear Safety and Simulation Technology, Harbin Engineering University, Harbin, Heilongjiang 150001 (China); Yuan, Xiao [Guangxi Fangchenggang Nuclear Power Co., Ltd (China); Xia, Genglei [Key Subject Laboratory of Nuclear Safety and Simulation Technology, Harbin Engineering University, Harbin, Heilongjiang 150001 (China)

    2016-07-15

    Highlights: • An air cooling passive residual heat removal System (PRHRs) is designed. • Using RELAP5/MOD3.4 code to analyze the operation characteristics of the PRHRs. • Noncondensable gas is used to simulate the hydrodynamic behavior in the air cooling tower. • The natural circulations could respectively establish in the primary circuit and the PRHRs circuit. • The PRHRs could remove the residual heat effectively. - Abstract: The inherent safety functions will mitigate the consequences of the accidents, and it can be accomplished through the passive safety systems which employed in the typical pressurized water reactor (PWR). In this paper, a new passive residual heat removal system (PRHRS) is designed for a typical nuclear power plant. PRHRS consists of a steam generator (SG), a cooling tank with two groups of cooling pipes, an air-cooling heat exchanger (AHX), an air-cooling tower, corresponding pipes and valves. The cooling tank which works as an intermediate buffer device is used to transfer the core decay heat to the AHX, and then the core decay heat will be removed to the atmosphere finally. The RELAP5/MOD3.4 code is used to analyze the operation characteristics of PRHRS and the primary loop system. It shows PRHRS could remove the decay heat from the primary loop effectively, and the natural circulations can be established in the primary circuit and the PRHRS circuit respectively. Furthermore, the sensitivity study has also been done to research the effect of various factors on the heat removal capacity.

  13. Analysis Method for Pesticides Residues by GC/MS in Lebanese Apple

    International Nuclear Information System (INIS)

    Jaber, F.; Al Iskandarani, M.

    2008-01-01

    The apple's crop can be affected by many pests during the growing season, which requires careful monitoring. Both apple fruit and apple tree need to be treated by pesticides in order to protect them from pests. Such treatment often leads to the accumulation of stable pesticides inside the fruit. The local market provides a large variety of pesticides allowing farmers to use more than one active substance in order to protect their crop, often without proper advice. Monitoring pesticides on apples and other agricultural crops is the best way to protect consumers health from the hazards of pesticides residues. The development of new, rapid and effective method to analyze the multi pesticides residues at trace levels in apple samples is essential. This work describes the extraction procedure and the analytical method developed to detect the pesticide residues using the gas-chromatographic-mass spectrometric approach (GC-MS). The developed method was successfully applied to analyze apple samples collected from different Lebanese markets for a one year period in order to monitor the presence of pesticides and their stability in apple fruits during storage. (author)

  14. Analysis of the industrial treatment of gas

    Energy Technology Data Exchange (ETDEWEB)

    Shirkovskiy, A.I.; Belaya, N.N.; Nad, Z.

    1982-01-01

    Mathematical models, algorithms and programs are developed for calculation of the thermodynamic conditions of the operation of installations for low temperature separation, which made it possible, in an example of the gas condensate deposit of western Shatlyk, to predict the operation of low temperature separation installations to 1984.

  15. Numerical Analysis of Dusty-Gas Flows

    Science.gov (United States)

    Saito, T.

    2002-02-01

    This paper presents the development of a numerical code for simulating unsteady dusty-gas flows including shock and rarefaction waves. The numerical results obtained for a shock tube problem are used for validating the accuracy and performance of the code. The code is then extended for simulating two-dimensional problems. Since the interactions between the gas and particle phases are calculated with the operator splitting technique, we can choose numerical schemes independently for the different phases. A semi-analytical method is developed for the dust phase, while the TVD scheme of Harten and Yee is chosen for the gas phase. Throughout this study, computations are carried out on SGI Origin2000, a parallel computer with multiple of RISC based processors. The efficient use of the parallel computer system is an important issue and the code implementation on Origin2000 is also described. Flow profiles of both the gas and solid particles behind the steady shock wave are calculated by integrating the steady conservation equations. The good agreement between the pseudo-stationary solutions and those from the current numerical code validates the numerical approach and the actual coding. The pseudo-stationary shock profiles can also be used as initial conditions of unsteady multidimensional simulations.

  16. Gas-Cooled Fast Breeder Reactor Preliminary Safety Information Document, Amendment 10. GCFR residual heat removal system criteria, design, and performance

    International Nuclear Information System (INIS)

    1980-01-01

    This report presents a comprehensive set of safety design bases to support the conceptual design of the gas-cooled fast breeder reactor (GCFR) residual heat removal (RHR) systems. The report is structured to enable the Nuclear Regulatory Commission (NRC) to review and comment in the licensability of these design bases. This report also presents information concerning a specific plant design and its performance as an auxiliary part to assist the NRC in evaluating the safety design bases

  17. [Correlation analysis between residual displacement and hip function after reconstruction of acetabular fractures].

    Science.gov (United States)

    Ma, Kunlong; Fang, Yue; Luan, Fujun; Tu, Chongqi; Yang, Tianfu

    2012-03-01

    To investigate the relationships between residual displacement of weight-bearing and non weight-bearing zones (gap displacement and step displacement) and hip function by analyzing the CT images after reconstruction of acetabular fractures. The CT measures and clinical outcome were retrospectively analyzed from 48 patients with displaced acetabular fracture between June 2004 and June 2009. All patients were treated by open reduction and internal fixation, and were followed up 24 to 72 months (mean, 36 months); all fractures healed after operation. The residual displacement involved the weight-bearing zone in 30 cases (weight-bearing group), and involved the non weight-bearing zone in 18 cases (non weight-bearing group). The clinical outcomes were evaluated by Merle d'Aubigné-Postel criteria, and the reduction of articular surface by CT images, including the maximums of two indexes (gap displacement and step displacement). All the data were analyzed in accordance with the Spearman rank correlation coefficient analysis. There was strong negative correlation between the hip function and the residual displacement values in weight-bearing group (r(s) = -0.722, P = 0.001). But there was no correlation between the hip function and the residual displacement values in non weight-bearing group (r(s) = 0.481, P = 0.059). The results of clinical follow-up were similar to the correlation analysis results. In weight-bearing group, the hip function had strong negative correlation with step displacement (r(s) = 0.825, P = 0.002), but it had no correlation with gap displacement (r(s) = 0.577, P = 0.134). In patients with acetabular fracture, the hip function has correlation not only with the extent of the residual displacement but also with the location of the residual displacement, so the residual displacement of weight-bearing zone is a key factor to affect the hip function. In patients with residual displacement in weight-bearing zone, the bigger the step displacement is, the

  18. Effects of food processing on pesticide residues in fruits and vegetables: a meta-analysis approach.

    Science.gov (United States)

    Keikotlhaile, B M; Spanoghe, P; Steurbaut, W

    2010-01-01

    Pesticides are widely used in food production to increase food security despite the fact that they can have negative health effects on consumers. Pesticide residues have been found in various fruits and vegetables; both raw and processed. One of the most common routes of pesticide exposure in consumers is via food consumption. Most foods are consumed after passing through various culinary and processing treatments. A few literature reviews have indicated the general trend of reduction or concentration of pesticide residues by certain methods of food processing for a particular active ingredient. However, no review has focused on combining the obtained results from different studies on different active ingredients with differences in experimental designs, analysts and analysis equipment. In this paper, we present a meta-analysis of response ratios as a possible method of combining and quantifying effects of food processing on pesticide residue levels. Reduction of residue levels was indicated by blanching, boiling, canning, frying, juicing, peeling and washing of fruits and vegetables with an average response ratio ranging from 0.10 to 0.82. Baking, boiling, canning and juicing indicated both reduction and increases for the 95% and 99.5% confidence intervals. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. Fatigue life analysis of cracked gas receiver of emergency cut-off system in gas gathering station

    Science.gov (United States)

    Hu, Junzhi; Zhou, Jiyong; Li, Siyuan

    2017-06-01

    Small-scale air compressor and gas receiver are used as the driving gas of the emergency cut-off system in gas gathering station. Operation of block valve is ensured by starting and stopping compressor automatically. The frequent start-stop of compressor and the pressure fluctuation pose a threat to the service life of gas receiver, and then affect normal operation of the emergency cut-off system and security of gas gathering station. In this paper, the fatigue life of a pressure vessel with axial semi-elliptical surface crack in the inner wall is analyzed under the varying pressure by means of the theory of fracture mechanics. The influences of the amplitude of pressure fluctuation and the initial crack size on the residual life of gas receiver are discussed. It provides a basis for setting the working parameters of gas receiver of emergency cut-off system and determining the maintenance cycle.

  20. Gas Chromatography-Mass Spectrometric Analysis and Insecticidal ...

    African Journals Online (AJOL)

    HP

    Original Research Article. Gas Chromatography-Mass Spectrometric Analysis and ... into a natural fumigant/insecticide for the control of stored product insects. Keywords: Mallotus ..... stability as well as reduce cost. ACKNOWLEDGEMENT.

  1. Gas Chromatography-Mass Spectrometric Analysis of Nematicidal ...

    African Journals Online (AJOL)

    Gas Chromatography-Mass Spectrometric Analysis of Nematicidal Essential Oil of Valeriana ... Tropical Journal of Pharmaceutical Research ... have a potential to be developed to natural nematicides for the control of cereal cyst nematodes.

  2. Environmental analysis of natural gas life cycle

    International Nuclear Information System (INIS)

    Riva, A.; D'Angelosante, S.; Trebeschi, C.

    2000-01-01

    Life Cycle Assessment is a method aimed at identifying the environmental effects connected with a given product, process or activity during its whole life cycle. The evaluation of published studies and the application of the method to electricity production with fossil fuels, by using data from published databases and data collected by the gas industry, demonstrate the importance and difficulties to have reliable and updated data required for a significant life cycle assessment. The results show that the environmental advantages of natural gas over the other fossil fuels in the final use stage increase still further if the whole life cycle of the fuels, from production to final consumption, is taken into account [it

  3. Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography

    Science.gov (United States)

    Belisle, A.A.; Swineford, D.M.

    1988-01-01

    A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetone:methylene chloride (1:l,v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93 % for sediments extracted shortly after spiking, but decreased significantly as the samples aged.

  4. Gas analysis modeling system forecast for the Energy Modeling Forum North American Natural Gas Market Study

    International Nuclear Information System (INIS)

    Mariner-Volpe, B.; Trapmann, W.

    1989-01-01

    The Gas Analysis Modeling System is a large computer-based model for analyzing the complex US natural gas industry, including production, transportation, and consumption activities. The model was developed and first used in 1982 after the passage of the NGPA, which initiated a phased decontrol of most natural gas prices at the wellhead. The categorization of gas under the NGPA and the contractual nature of the natural gas market, which existed at the time, were primary factors in the development of the basic structure of the model. As laws and regulations concerning the natural gas market have changed, the model has evolved accordingly. Recent increases in competition in the wellhead market have also led to changes in the model. GAMS produces forecasts of natural gas production, consumption, and prices annually through 2010. It is an engineering-economic model that incorporates several different mathematical structures in order to represent the interaction of the key groups involved in the natural gas market. GAMS has separate supply and demand components that are equilibrated for each year of the forecast by means of a detailed transaction network

  5. Microstructuring of piezoresistive cantilevers for gas detection and analysis

    International Nuclear Information System (INIS)

    Sarov, Y.; Sarova, V.; Bitterlich, Ch.; Richter, O.; Guliyev, E.; Zoellner, J.-P.; Rangelow, I. W.; Andok, R.; Bencurova, A.

    2011-01-01

    In this work we report on a design and fabrication of cantilevers for gas detection and analysis. The cantilevers have expanded area of interaction with the gas, while the signal transduction is realized by an integrated piezoresistive deflection sensor, placed at the narrowed cantilever base with highest stress along the cantilever. Moreover, the cantilevers have integrated bimorph micro-actuator detection in a static and dynamic mode. The cantilevers are feasible as pressure, temperature and flow sensors and under chemical functionalization - for gas recognition, tracing and composition analysis. (authors)

  6. Reciprocally coupled residues crucial for protein kinase Pak2 activity calculated by statistical coupling analysis.

    Directory of Open Access Journals (Sweden)

    Yuan-Hao Hsu

    2010-03-01

    Full Text Available Regulation of Pak2 activity involves at least two mechanisms: (i phosphorylation of the conserved Thr(402 in the activation loop and (ii interaction of the autoinhibitory domain (AID with the catalytic domain. We collected 482 human protein kinase sequences from the kinome database and globally mapped the evolutionary interactions of the residues in the catalytic domain with Thr(402 by sequence-based statistical coupling analysis (SCA. Perturbation of Thr(402 (34.6% suggests a communication pathway between Thr(402 in the activation loop, and Phe(387 (DeltaDeltaE(387F,402T = 2.80 in the magnesium positioning loop, Trp(427 (DeltaDeltaE(427W,402T = 3.12 in the F-helix, and Val(404 (DeltaDeltaE(404V,402T = 4.43 and Gly(405 (DeltaDeltaE(405G,402T = 2.95 in the peptide positioning loop. When compared to the cAMP-dependent protein kinase (PKA and Src, the perturbation pattern of threonine phosphorylation in the activation loop of Pak2 is similar to that of PKA, and different from the tyrosine phosphorylation pattern of Src. Reciprocal coupling analysis by SCA showed the residues perturbed by Thr(402 and the reciprocal coupling pairs formed a network centered at Trp(427 in the F-helix. Nine pairs of reciprocal coupling residues crucial for enzymatic activity and structural stabilization were identified. Pak2, PKA and Src share four pairs. Reciprocal coupling residues exposed to the solvent line up as an activation groove. This is the inhibitor (PKI binding region in PKA and the activation groove for Pak2. This indicates these evolutionary conserved residues are crucial for the catalytic activity of PKA and Pak2.

  7. Numerical Analysis on Transient of Steam-gas Pressurizer

    International Nuclear Information System (INIS)

    Kim, Jong-Won; Lee, Yeon-Gun; Park, Goon-Cherl

    2008-01-01

    In nuclear reactors, various pressurizers are adopted to satisfy their characteristics and uses. The additional active systems such as heater, pressurizer cooler, spray and insulator are essential for a steam or a gas pressurizer. With a steam-gas pressurizer, additional systems are not required due to the use of steam and non-condensable gas as pressure-buffering materials. The steam-gas pressurizer in integrated small reactors experiences very complicated thermal-hydraulic phenomena. To ensure the integrity of this pressurizer type, the analysis on the transient behavior of the steam-gas pressure is indispensable. For this purpose, the steam-gas pressurizer model is introduced to predict the accurate system pressure. The proposed model includes bulk flashing, rainout, inter-region heat and mass transfer and wall condensation with non-condensable gas. However, the ideal gas law is not applied because of significant interaction at high pressure between steam and non-condensable gas. The results obtained from this proposed model agree with those from pressurizer tests. (authors)

  8. Residual analysis applied to S-N data of a surface rolled cast iron

    Directory of Open Access Journals (Sweden)

    Omar Maluf

    2005-09-01

    Full Text Available Surface rolling is a process extensively employed in the manufacture of ductile cast iron crankshafts, specifically in regions containing stress concentrators with the main aim to enhance fatigue strength. Such process hardens and introduces compressive residual stresses to the surface as a result of controlled strains, reducing cyclic tensile stresses near the surface of the part. The main purpose of this work was to apply the residual analysis to check the suitability of the S-N approach to describe the fatigue properties of a surface rolled cast iron. The analysis procedure proved to be very efficient and easy to implement and it can be applied in the verification of any other statistical model used to describe fatigue behavior. Results show that the conventional S-N methodology is able to model the high cycle fatigue behavior of surface rolled notch testpieces of a pearlitic ductile cast iron submitted to rotating bending fatigue tests.

  9. Analysis of martensitic transformation and residual tension in an 304L stainless steel

    International Nuclear Information System (INIS)

    Alves, Juciane Maria

    2014-01-01

    The relationship between plastic deformation and the strain induced phase transformation, that provides a practical route to the development of new engineering materials with excellent mechanical properties, characterize the TRIP effect 'Transformation Induced Plasticity'. Among the stainless steels, the metastable 304 L austenitic steel is susceptible to transformation of austenite-martensite phase from tensile tests at room temperature by increments of plastic deformation. It is of great technological and scientific interest the knowledge of the evolution of phase transformation and residual stress from different levels and rates of plastic deformation imposed to the material. It is also important to evaluate the interference of metallographic preparation in quantitative analyzes of this steel. The main techniques used in this study consisted of X-rays diffraction and Ferritoscopy for the quantitation phase, and XRD to residual stress analysis also. As observed, the phase transformation quantification has not suffered significant influence of the metallographic preparation and evolved from increments of plastic deformation due to different stop charges and strain rates, leading to a further strengthening of the austenite matrix. The evaluation of residual stress resulting from the martensitic transformation was susceptible to the metallographic preparation and increased its value on comparison to sample without metallographic preparation. It was also observed that the residual stress decreased with the increase of the fraction of transformed martensite. (author)

  10. Pyrolysis kinetics and thermodynamic parameters of castor (Ricinus communis) residue using thermogravimetric analysis.

    Science.gov (United States)

    Kaur, Ravneet; Gera, Poonam; Jha, Mithilesh Kumar; Bhaskar, Thallada

    2018-02-01

    Castor plant is a fast-growing, perennial shrub from Euphorbiaceae family. More than 50% of the residue is generated from its stems and leaves. The main aim of this work is to study the pyrolytic characteristics, kinetics and thermodynamic properties of castor residue. The TGA experiments were carried out from room temperature to 900 °C under an inert atmosphere at different heating rates of 5, 10, 15, 20, 30 and 40 °C/min. The kinetic analysis was carried using different models namely Kissinger, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS). The average E ɑ calculated by FWO and KAS methods were 167.10 and 165.86 kJ/mole respectively. Gibbs free energy varied from 150.62-154.33 to 150.59-154.65 kJ/mol for FWO and KAS respectively. The HHV of castor residue was 14.43 MJ/kg, considered as potential feedstock for bio-energy production. Kinetic and thermodynamic results will be useful input for the design of pyrolytic process using castor residue as feedstock. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. New tendencies in isotopic analysis of pesticide residues from wines by mass spectrometry in concordance with the European standards

    International Nuclear Information System (INIS)

    Costinel, Diana; Lazar, Roxana Elena; Vremera, Raluca; Irimescu, Rodica; Saros-Rogobete, Gili

    2006-01-01

    Multi-isotope analysis, the determination of isotope ratios by mass spectrometry or magnetic resonance spectroscopy, becomes increasingly used in the food industry and by national food control laboratories as a method of authenticating both raw materials and finished products. These highly sophisticated techniques are capable of determining the botanical and geographical origin of a wide variety of foodstuffs, thus providing a means of detecting product adulteration and controlling mislabelling practices which are virtually impossible to circumvent. The European Union has officially adopted the used of isotope analysis as a means of controlling sugar addition in wines. Its successful implementation in the wine-producing Member States has considerably reduced the financial losses which the Community had incurred due to over - capitalisation. Coupling mass spectrometer with gas chromatograph is used for quantitative and qualitative analysis of traces of pesticides from food. The presence of pesticides in foods is harmful for the nervous system, the cardiovascular apparatus and decreases the immunity of human body. In addition, ensuring the foods quality and safety is a requirement, which must be fulfilled for the integration in EU. The subject of this paper is the presentation of the tests results of the isotopic analysis for pesticide residues in wines, in concordance with European Standard. (authors)

  12. Residual stress distribution analysis of heat treated APS TBC using image based modelling.

    Science.gov (United States)

    Li, Chun; Zhang, Xun; Chen, Ying; Carr, James; Jacques, Simon; Behnsen, Julia; di Michiel, Marco; Xiao, Ping; Cernik, Robert

    2017-08-01

    We carried out a residual stress distribution analysis in a APS TBC throughout the depth of the coatings. The samples were heat treated at 1150 °C for 190 h and the data analysis used image based modelling based on the real 3D images measured by Computed Tomography (CT). The stress distribution in several 2D slices from the 3D model is included in this paper as well as the stress distribution along several paths shown on the slices. Our analysis can explain the occurrence of the "jump" features near the interface between the top coat and the bond coat. These features in the residual stress distribution trend were measured (as a function of depth) by high-energy synchrotron XRD (as shown in our related research article entitled 'Understanding the Residual Stress Distribution through the Thickness of Atmosphere Plasma Sprayed (APS) Thermal Barrier Coatings (TBCs) by high energy Synchrotron XRD; Digital Image Correlation (DIC) and Image Based Modelling') (Li et al., 2017) [1].

  13. Gas analysis by computer-controlled microwave rotational spectrometry

    International Nuclear Information System (INIS)

    Hrubesh, L.W.

    1978-01-01

    Microwave rotational spectrometry has inherently high resolution and is thus nearly ideal for qualitative gas mixture analysis. Quantitative gas analysis is also possible by a simplified method which utilizes the ease with which molecular rotational transitions can be saturated at low microwave power densities. This article describes a computer-controlled microwave spectrometer which is used to demonstrate for the first time a totally automated analysis of a complex gas mixture. Examples are shown for a complete qualitative and quantitative analysis, in which a search of over 100 different compounds is made in less than 7 min, with sensitivity for most compounds in the 10 to 100 ppm range. This technique is expected to find increased use in view of the reduced complexity and increased reliabiity of microwave spectrometers and because of new energy-related applications for analysis of mixtures of small molecules

  14. Analysis of explosive and other organic residues by laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lazic, V., E-mail: lazic@frascati.enea.i [ENEA, FIS-LAS, Via. E. Fermi 45, 00044 Frascati (RM) (Italy); Palucci, A. [ENEA, FIS-LAS, Via. E. Fermi 45, 00044 Frascati (RM) (Italy); Jovicevic, S. [Institute of Physics, 11080 Belgrade, Pregrevica 118 (Serbia); Poggi, C.; Buono, E. [ENEA, FIS-LAS, Via. E. Fermi 45, 00044 Frascati (RM) (Italy)

    2009-10-15

    With the aim of realizing a compact instrument for detection of energetic materials at trace levels, laser induced breakdown spectroscopy was applied on residues from nine explosives in air surroundings. Different potentially interfering organic materials were also analyzed. The residues were not uniformly distributed on an aluminum support and single-shot discrimination was attempted. For a single residue type, large shot-to-shot fluctuations of the line intensity ratios characteristic for organic samples were observed, which made material classification difficult. It was found that both atomic and molecular emission intensities, as well as their ratios, are strongly affected by an amount of the ablated support material, which mainly determines the plasma temperature. With respect to the spectra from the clean support, emission intensities of atomic oxygen and nitrogen are always reduced in the presence of an organic material, even if its molecules contain these elements. This was attributed to chemical reactions in a plasma containing carbon or its fragments. Hydrogen atomic emission depends strongly on the local humidity above the sampled point and its line intensity shows shot to shot variations up to 50%, also on a homogeneous sample. It is argued that shock waves generated by previous spatially and/or temporally close laser pulses blow away a relatively heavy water aerosol, which later diffuses slowly back towards the sampled point. C{sub 2} and CN exhibit a peak emission behavior with atomic Al emission, and their variable ratio indicates an existence of different formation or removal mechanisms from the plasma, depending on the plasma parameters and on the composition of the organic residue. On the basis of these observations, an attempt is made to establish a suitable procedure for data analysis and to determine the optimal experimental conditions, which would allow for discrimination of explosives from other, potentially interfering, residues.

  15. Scanning electron microscope/energy dispersive x ray analysis of impact residues on LDEF tray clamps

    Science.gov (United States)

    Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

    1992-01-01

    To better understand the nature of particulates in low-Earth orbit (LEO), and their effects on spacecraft hardware, we are analyzing residues found in impacts on the Long Duration Exposure Facility (LDEF) tray clamps. LDEF experiment trays were held in place by 6 to 8 chromic-anodized aluminum (6061-T6) clamps that were fastened to the spacecraft frame using three stainless steel hex bolts. Each clamp exposed an area of approximately 58 sq cm (4.8 cm x 12.7 cm x .45 cm, minus the bolt coverage). Some 337 out of 774 LDEF tray clamps were archived at JSC and are available through the Meteoroid & Debris Special Investigation Group (M&D SIG). Optical scanning of clamps, starting with Bay/Row A01 and working toward H25, is being conducted at JSC to locate and document impacts as small as 40 microns. These impacts are then inspected by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis (SEM/EDXA) to select those features which contain appreciable impact residue material. Based upon the composition of projectile remnants, and using criteria developed at JSC, we have made a preliminary discrimination between micrometeoroid and space debris residue-containing impact features. Presently, 13 impacts containing significant amounts of unmelted and semi-melted micrometeoritic residues were forwarded to Centre National d'Etudes Spatiales (CNES) in France. At the CNES facilities, the upgraded impacts were analyzed using a JEOL T330A SEM equipped with a NORAN Instruments, Voyager X-ray Analyzer. All residues were quantitatively characterized by composition (including oxygen and carbon) to help understand interplanetary dust as possibly being derived from comets and asteroids.

  16. Bioethanol production from forestry residues: A comparative techno-economic analysis

    International Nuclear Information System (INIS)

    Frankó, Balázs; Galbe, Mats; Wallberg, Ola

    2016-01-01

    Highlights: • A proposed cellulosic ethanol biorefinery in Sweden was simulated with Aspen Plus. • Forestry residues with different bark contents were evaluated as raw materials. • The bark content negatively influenced the minimum ethanol selling price. • Sensitivity analyses were performed to assess the influence of raw material cost. - Abstract: A techno-economic analysis was conducted to assess the feasibility of using forestry residues with different bark contents for bioethanol production. A proposed cellulosic ethanol biorefinery in Sweden was simulated with Aspen Plus. The plant was assumed to convert different forestry assortments (sawdust and shavings, fuel logs, early thinnings, tops and branches, hog fuel and pulpwood) to ethanol, pellets, biogas and electricity. The intention was not to obtain absolute ethanol production costs for future facilities, but to assess and compare the future potential of utilizing different forestry residues for bioethanol production. The same plant design and operating conditions were assumed in all cases, and the effect of including bark on the whole conversion process, especially how it influenced the ethanol production cost, was studied. While the energy efficiency (not including district heating) obtained for the whole process was between 67 and 69% regardless of the raw material used, the ethanol production cost differed considerably; the minimum ethanol selling price ranging from 0.77 to 1.52 USD/L. Under the basic assumptions, all the forestry residues apart from sawdust and shavings exhibited a negative net present value at current market prices. The profitability decreased with increasing bark content of the raw material. Sensitivity analyses showed that, at current market prices, the utilization of bark-containing forestry residues will not provide significant cost improvement compared with pulpwood unless the conversion of cellulose and hemicellulose to monomeric sugars is improved.

  17. Analysis of pollutants in air and water using gas chromatography and headspace gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, H.

    1980-01-01

    The combination 'personal sampling' with headspace gas chromatography to determine traces of formaldehyde, phenol and benzene in air is investigated in this work, with the aim of developing maximum workplace concentration values (MWL values). Further possible applications of gas chromatography in trace analysis in the environmentally protected area. The analysis of chromium in waste waters (Cr III as acetyl acetonate complex) is investigated as further possible application, whereby optimum conditions are obtained. A modified flame ionization detector was used to increase the detection sensitivity.

  18. Ambient Field Analysis at Groningen Gas Field

    Science.gov (United States)

    Spica, Z.; Nakata, N.; Beroza, G. C.

    2016-12-01

    We analyze continuous ambient-field data at Groningen gas field (Netherlands) through cross-correlation processing. The Groningen array is composed of 75 shallow boreholes with 6 km spacing, which contain a 3C surface accelerometer and four 5-Hz 3C borehole geophones spaced at 50 m depth intervals. We successfully retrieve coherent waves from ambient seismic field on the 9 components between stations. Results show high SNR signal in the frequency range of 0.125-1 Hz, and the ZZ, ZR, RZ, RR and TT components show much stronger wave energy than other components as expected. This poster discuss the different type of waves retrieved, the utility of the combination of borehole and surface observations, future development as well as the importance to compute the 9 components of the Green's tensor to better understand the wave field propriety with ambient noise.

  19. Suitability of selected free-gas and dissolved-gas sampling containers for carbon isotopic analysis.

    Science.gov (United States)

    Eby, P; Gibson, J J; Yi, Y

    2015-07-15

    Storage trials were conducted for 2 to 3 months using a hydrocarbon and carbon dioxide gas mixture with known carbon isotopic composition to simulate typical hold times for gas samples prior to isotopic analysis. A range of containers (both pierced and unpierced) was periodically sampled to test for δ(13)C isotopic fractionation. Seventeen containers were tested for free-gas storage (20°C, 1 atm pressure) and 7 containers were tested for dissolved-gas storage, the latter prepared by bubbling free gas through tap water until saturated (20°C, 1 atm) and then preserved to avoid biological activity by acidifying to pH 2 with phosphoric acid and stored in the dark at 5°C. Samples were extracted using valves or by piercing septa, and then introduced into an isotope ratio mass spectrometer for compound-specific δ(13)C measurements. For free gas, stainless steel canisters and crimp-top glass serum bottles with butyl septa were most effective at preventing isotopic fractionation (pierced and unpierced), whereas silicone and PTFE-butyl septa allowed significant isotopic fractionation. FlexFoil and Tedlar bags were found to be effective only for storage of up to 1 month. For dissolved gas, crimp-top glass serum bottles with butyl septa were again effective, whereas silicone and PTFE-butyl were not. FlexFoil bags were reliable for up to 2 months. Our results suggest a range of preferred containers as well as several that did not perform very well for isotopic analysis. Overall, the results help establish better QA/QC procedures to avoid isotopic fractionation when storing environmental gas samples. Recommended containers for air transportation include steel canisters and glass serum bottles with butyl septa (pierced and unpierced). Copyright © 2015 John Wiley & Sons, Ltd.

  20. Molecular gas analysis by Raman scattering in intracavity laser configuration

    International Nuclear Information System (INIS)

    Benner, R.E.; Andrade, J.D.; Van Wagenen, R.A.; Westenskow, D.R.

    1987-01-01

    A system is described for the near simultaneous analysis and quantitation of selected multiple polyatomic gases in a gas sample by Raman light scattering comprising in combination: (a) laser means capable of producing a polarized laser beam of a selected wavelength containing a laser cavity the laser cavity containing a plasma tube and wherein one end of the laser cavity contains a high reflectivity output coupler mirror; (b) a gas sampling cell located within the laser cavity between the plasma tube and the output coupler mirror, the cell having opposing parallel end windows interconnected by a continuous sidewall. The end windows and sidewall define a longitudinal gas chamber oriented such that, when the laser beam is activated, the laser beam is coincident with and traverses the axis of the longitudinal gas chamber, the end windows being positioned to be substantially normal to the axis of the longitudinal gas cell chamber. The cell also has opposing, aligned side windows in the sidewall parallel to and on either side of the axis of the longitudinal gas chamber. The gas cell further contains inlet and outlet means communicating with the chamber to pass a sample gas through the cell

  1. Exergy analysis of waste emissions from gas flaring

    Directory of Open Access Journals (Sweden)

    Olawale Saheed ISMAIL

    2016-07-01

    Full Text Available Gas flaring produces a stream of waste gases at high temperature and pressure which contains carbon monoxide, Hydrogen Sulphide etc. The resultant effect of which is detrimental to our planet and, consequently, to the life of both the living and the non-living things. It’s well known that gas flaring contributes in no small measure to the global warming. Exergy analysis is applied in this work to analyze waste emissions from gas flaring so as to have a model through which impact of gas flaring can be measured. The study considers both the thermo-mechanical exergy and the chemical exergy of these gases. Relevant data on gas flaring activities in the Niger-Delta region of Nigeria between the periods of fifteen (15 years was obtained from the Nigerian National Petroleum Corporation (NNPC. A computer program (Exergy Calculator was developed based on the equations generated in the Model. Exergy associated with gas flaring activities in Nigeria between the periods of 1998 through 2012 was calculated. The results show that 1 mscf (in thousand cubic feet of flared gases generate 0.000041 MWh of energy leading to a value of 440158.607 MWh of energy for the period under review.The analysis provides important conclusions and recommendations for improving oil platforms operationsin in order to safeguard the environment, health of the populace, and maximize recovered exergy from gas flaring.

  2. Gas Hydrate-Sediment Morphologies Revealed by Pressure Core Analysis

    Science.gov (United States)

    Holland, M.; Schultheiss, P.; Roberts, J.; Druce, M.

    2006-12-01

    Analysis of HYACINTH pressure cores collected on IODP Expedition 311 and NGHP Expedition 1 showed gas hydrate layers, lenses, and veins contained in fine-grained sediments as well as gas hydrate contained in coarse-grained layers. Pressure cores were recovered from sediments on the Cascadia Margin off the North American West Coast and in the Krishna-Godavari Basin in the Western Bay of Bengal in water depths of 800- 1400 meters. Recovered cores were transferred to laboratory chambers without loss of pressure and nondestructive measurements were made at in situ pressures and controlled temperatures. Gamma density, P-wave velocity, and X-ray images showed evidence of grain-displacing and pore-filling gas hydrate in the cores. Data highlights include X-ray images of fine-grained sediment cores showing wispy subvertical veins of gas hydrate and P-wave velocity excursions corresponding to grain-displacing layers and pore-filling layers of gas hydrate. Most cores were subjected to controlled depressurization experiments, where expelled gas was collected, analyzed for composition, and used to calculate gas hydrate saturation within the core. Selected cores were stored under pressure for postcruise analysis and subsampling.

  3. Gas generation and migration analysis for TRU waste disposal system

    International Nuclear Information System (INIS)

    Ando, Kenichi; Noda, Masaru; Yamamoto, Mikihiko; Mihara, Morihiro

    2005-09-01

    In TRU waste disposal system, significant quantities of gases may be generated due to metal corrosion, radiolysis effect and microorganism activities. It is therefore recommended that the potential impact of gas generation and migration on TRU waste repository should be evaluated. In this study, gas generation rates were calculated in the repository and gas migration analysis in the disposal system were carried out using two phase flow model with results of gas generation rates. First, the time dependencies of gas generation rate in each TRU waste repositories were evaluated based on amounts of metal, organic matter and radioactivity. Next, the accumulation pressure of gases and expelled pore water volume nuclides in the repository were calculated by TOUGH2 code. After that, the results showed that the increase of gas pressure was the range of 1.3 to 1.4 MPa. In the repository with and without buffer, the rate of expelled pore water was 0.006 - 0.009 m 3 /y and 0.018 - 0.24m 3 /y, respectively. In addition, the radioactive gas migration through the repository and geosphere are evaluated. And re-saturation analysis is also performed to evaluate the initial condition of the system. (author)

  4. The Use of Gas Chromatography for Biogas Analysis

    Science.gov (United States)

    Andersen, Amanda; Seeley, John; Aurandt, Jennifer

    2010-04-01

    Energy from natural gas accounts for 24 percent of energy consumed in the US. Natural gas is a robust form of energy which is rich in methane content and is low in impurities. This quality suggests that it is a very clean and safe gas; it can be used in providing heat, a source for cooking, and in powering vehicles. The downside is that it is a non-renewable resource. On the contrary, methane rich gas that is produced by the breakdown of organic material in an anaerobic environment, called biogas, is a renewable energy source. This research focuses on the gas analysis portion of the creation of the anaerobic digestion and verification laboratory where content and forensic analysis of biogas is performed. Gas Chromatography is implemented as the optimal analytical tool for quantifying the components of the biogas including methane, carbon dioxide, hydrogen sulfide and siloxanes. In addition, the problems associated with the undesirable components are discussed. Anaerobic digestion of primary sludge has consistently produced about 55 percent methane; future goals of this research include studying different substrates to increase the methane yield and decrease levels of impurities in the gas.

  5. Financial cost-benefit analysis of investment possibilities in district heating system on wood residues

    Directory of Open Access Journals (Sweden)

    Stošić Ivan

    2017-01-01

    Full Text Available The purpose of this research is to provide feasibility analysis of a long-term sustainable development concept for district heating based on wood residues. In this paper, the experimental study has been conducted starting from the data collected by field researches in municipality of Trstenik (town in Serbia with district heating system currently based on heavy fuel oil and lignite. Using the method of Financial Cost-Benefit Analysis, this study evaluates financial efficiency of investment in district heating plant based on wood residues and energy savings in district heating system. Findings show that such investment could be profitable from the financial point of view: Net Present Value of investment is positive, Financial Rate of Return is high (30.69%, and the pay-back period is relatively favourable (7 years. Moreover, the presented SWOT indicates that there are realistic prospects of implementation of district heating based on wood residues. However, this does not mean everything will go smoothly and easily, keeping in mind a number of challenges that each new concept of district heating contains immanently. Nevertheless, the results of this research could provide useful inputs for the decision makers when selecting appropriate models for improving performance of municipal district heating systems.

  6. Residue conservation and dimer-interface analysis of olfactory receptor molecular models

    Directory of Open Access Journals (Sweden)

    Ramanathan Sowdhamini

    2012-10-01

    Full Text Available Olfactory Receptors (ORs are members of the Class A rhodopsin like G-protein coupled receptors (GPCRs which are the initial players in the signal transduction cascade, leading to the generation of nerve impulses transmitted to the brain and resulting in the detection of odorant molecules. Despite the accumulation of thousands of olfactory receptor sequences, no crystal structures of ORs are known tο date. However, the recent availability of crystallographic models of a few GPCRs allows us to generate homology models of ORs and analyze their amino acid patterns, as there is a huge diversity in OR sequences. In this study, we have generated three-dimensional models of 100 representative ORs from Homo sapiens, Mus musculus, Drosophila melanogaster, Caenorhabditis elegans and Sacharomyces cerevisiae which were selected on the basis of a composite classification scheme and phylogenetic analysis. The crystal structure of bovine rhodopsin was used as a template and it was found that the full-length models have more than 90% of their residues in allowed regions of the Ramachandran plot. The structures were further used for analysis of conserved residues in the transmembrane and extracellular loop regions in order to identify functionally important residues. Several ORs are known to be functional as dimers and hence dimer interfaces were predicted for OR models to analyse their oligomeric functional state.

  7. Three-dimensional finite element analysis of residual magnetic field for ferromagnets under early damage

    International Nuclear Information System (INIS)

    Yao, Kai; Shen, Kai; Wang, Zheng-Dao; Wang, Yue-Sheng

    2014-01-01

    In this study, 3D finite element analysis is presented by calculating the residual magnetic field signals of ferromagnets under the plastic deformation. The contour maps of tangential and normal RMF gradients are given, and the 3D effect is discussed. The results show that the tangential peak–peak amplitude and normal peak–vale amplitude are remarkably different in 2D and 3D simulations, but the tangential peak–peak width and normal peak–vale width are similar. Moreover, some key points are capable of capturing the plastic-zone shape, especially when the lift-off is small enough. The present study suggests an effective defect identification method with Metal magnetic memory (MMM) technique. - Highlights: • Three-dimensional (3D) finite element analysis is presented by calculating the residual magnetic field signals of ferromagnets under the plastic deformation. • The contour maps of gradients of the tangential and normal residual magnetic fields are given, and the 3D effect is discussed. • The present study suggests an effective defect identification method with metal magnetic memory technique

  8. Residual Heat Removal System qualitative probabilistic safety analysis before and after auto closure interlock removal

    International Nuclear Information System (INIS)

    Mikulicic, V.; Simic, Z.

    1992-01-01

    The analysis evaluates the consequences of the removal of the auto closure interlock (ACI) on the Residual Heat Removal System (RHRS) suction/isolation valves at the nuclear power plant. The deletion of the RHRS ACI is in part based on a probabilistic safety analysis (PSA) which justifies the removal based on a criterion of increased availability and reliability. Three different areas to be examined in PSA: the likelihood of an interfacing system LOCA; RHRS availability and reliability; and low temperature overpressurization control. The paper emphasizes particularly the RHRS unavailability and reliability evaluation utilizing the current control circuitry configuration and then with the proposed modification to the control circuitry. (author)

  9. Void analysis of target residues at SPS energy -evidence of correlation with fractal behaviour

    International Nuclear Information System (INIS)

    Ghosh, Dipak; Deb, Argha; Das, Rupa . E-mail : dipakghosh_in@yahoo.com

    2007-01-01

    This paper presents an analysis of the target residues in 32 S -AgBr and 16 0 -AgBr interactions at 200 AGeV and 60AGeV respectively in terms of fractal moment by Takagi method and void probability scaling. The study reveals an interesting feature of the production process. In 16 O- AgBr interactions multifractal behaviour is present in both hemispheres and void probability does not show a scaling behaviour, but at high energy the situation changes. In 32 S -AgBr interactions for both hemisphere monofractal behaviour is indicated by that data and void probability also shows good scaling behaviour. This suggests that a possible correlation of void probability with fractal behaviour of target residues. (author)

  10. Distribution patterns of firearm discharge residues as revealed by neutron activation analysis

    International Nuclear Information System (INIS)

    Pillay, K.K.S.; Driscoll, D.C.; Jester, W.A.

    1975-01-01

    A systematic investigation using a variety of handguns has revealed the existence of distinguisable distribution patterns of firearm discharge residues on surfaces below the flight path of a bullet. The residues are identificable even at distances of 12 meters from the gun using nondestructive neutron activation analysis. The results of these investigations show that the distribution pattern for a gun is reproducible using similar ammunition and that there exist two distinct regions to the patterns developed between the firearm and the target-one with respect to the position of the gun and the other in the vicinity of the target. The judicious applications of these findings could be of significant value in criminal investigations. (T.G.)

  11. Phase space analysis of some interacting Chaplygin gas models

    Energy Technology Data Exchange (ETDEWEB)

    Khurshudyan, M. [Academy of Sciences of Armenia, Institute for Physical Research, Ashtarak (Armenia); Tomsk State University of Control Systems and Radioelectronics, Laboratory for Theoretical Cosmology, Tomsk (Russian Federation); Tomsk State Pedagogical University, Department of Theoretical Physics, Tomsk (Russian Federation); Myrzakulov, R. [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan)

    2017-02-15

    In this paper we discuss a phase space analysis of various interacting Chaplygin gas models in general relativity. Linear and nonlinear sign changeable interactions are considered. For each case appropriate late time attractors of field equations are found. The Chaplygin gas is one of the dark fluids actively considered in modern cosmology due to the fact that it is a joint model of dark energy and dark matter. (orig.)

  12. Analysis of hazardous organic residues from sodium hydrosulfite industry and utilization as raw materials in a novel solid lubricant production

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Jiwu [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Zhang, Yihe, E-mail: zyh@cugb.edu.cn [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Zhou, Fengshan; Lv, Fengzhu; Han, Feng; Lu, Jinbo; Meng, Xianghai [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Ye, Zhengfang [Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences of the Ministry of Education, Peking University, Beijing 100871 (China); Xing, Jing [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer The hazardous organic residual wastes produced by the sodium hydrosulfite industry are analyzed and the main compounds are found to be thiodiglycol and 2,2 Prime -dithiodiethanol. Black-Right-Pointing-Pointer The lubricity of the organic residues is subsequently studied and the homemade solid lubricant is observed to have good lubricity. Black-Right-Pointing-Pointer The clean process is expected to not only have commercial impact but also help to reduce environmental pollution. - Abstract: The hazardous organic residual wastes produced by the sodium hydrosulfite industry are demonstrated to be convertible into a novel solid lubricant. Identification and isolation of the organic residues are achieved by Fourier transform infrared (FTIR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR). FTIR and GC-MS provide important information about the residues and the two main components obtained by column chromatography are further analyzed by NMR. The main organic residues are found to be thiodiglycol and 2,2 Prime -dithiodiethanol which have potential applications in petroleum drilling because of their S-S and/or C-S functional groups. The lubricity of the organic residues is subsequently studied and the influence of different adsorbents on the lubricity is investigated and discussed. This homemade lubricant is observed to have good lubricity and by increasing the concentration of the commercial solid lubricant M, the lubricity diminishes. The process is expected to not only have commercial impact but also help to reduce environmental pollution.

  13. Analysis of hazardous organic residues from sodium hydrosulfite industry and utilization as raw materials in a novel solid lubricant production

    International Nuclear Information System (INIS)

    Shang, Jiwu; Zhang, Yihe; Zhou, Fengshan; Lv, Fengzhu; Han, Feng; Lu, Jinbo; Meng, Xianghai; Chu, Paul K.; Ye, Zhengfang; Xing, Jing

    2011-01-01

    Highlights: ► The hazardous organic residual wastes produced by the sodium hydrosulfite industry are analyzed and the main compounds are found to be thiodiglycol and 2,2′-dithiodiethanol. ► The lubricity of the organic residues is subsequently studied and the homemade solid lubricant is observed to have good lubricity. ► The clean process is expected to not only have commercial impact but also help to reduce environmental pollution. - Abstract: The hazardous organic residual wastes produced by the sodium hydrosulfite industry are demonstrated to be convertible into a novel solid lubricant. Identification and isolation of the organic residues are achieved by Fourier transform infrared (FTIR) spectroscopy, gas chromatography–mass spectrometry (GC–MS), and nuclear magnetic resonance (NMR). FTIR and GC–MS provide important information about the residues and the two main components obtained by column chromatography are further analyzed by NMR. The main organic residues are found to be thiodiglycol and 2,2′-dithiodiethanol which have potential applications in petroleum drilling because of their S–S and/or C–S functional groups. The lubricity of the organic residues is subsequently studied and the influence of different adsorbents on the lubricity is investigated and discussed. This homemade lubricant is observed to have good lubricity and by increasing the concentration of the commercial solid lubricant M, the lubricity diminishes. The process is expected to not only have commercial impact but also help to reduce environmental pollution.

  14. Fuel gas production from animal and agricultural residues and biomass. Quarterly coordination meeting, December 11-12, 1978, Denver, Colorado. Second Quarterly progress report

    Energy Technology Data Exchange (ETDEWEB)

    Wise, D L; Ashare, E; Wentworth, R L

    1979-01-05

    The tenth quarterly coordination meeting of the methane production group of the Fuels from Biomass Systems Branch, US Department of Energy was held at Denver, Colorado, December 11-12, 1978. Progress reports were presented by the contractors and a site visit was made to the Solar Energy Research Institute, Golden, Colorado. A meeting agenda, a list of attendees, and progress are presented. Report titles are: pipeline fuel gas from an environmental feedlot; operation of a 50,000 gallon anaerobic digester at the Monroe State Dairy Farm near Monroe, Washington; anaerobic fermentation of livestock and crop residues; anaerobic fermentation of agricultural residues - potential for improvement and implementation; heat treatment of organics for increasing anaerobic biodegradability; and biological conversion of biomass to methane. (DC)

  15. Analysis of gas and vaporizable compounds

    International Nuclear Information System (INIS)

    Linares, Bernard; Massot, Roger; Maman, Marcel; Valdener, Georges

    1975-01-01

    The principles of qualitative and quantitative analysis using a mass spectrometer are presented together with the principle of identification of organic molecules (relation between the mass spectrum and the structure of an organic molecule. (55 references) [fr

  16. Matrix effect in analysis of pesticide residues in fruits and vegetables by high performance liquid chromatography with quadrupole-time of flight mass spectrometry

    Directory of Open Access Journals (Sweden)

    Andoralov A.M.

    2017-03-01

    Full Text Available For modern food safety control are using techniques that allow to determinate a large number of components. So for determination of pesticide residues in fruits and vegetables commonly used methods of gas and liquid chromatography with time-of-flight mass-spectrometric detection. This system allows to carry out quantitative determination several hundreds of pesticides and their identification by the characteristic fragments of the mass spectrum. The main problem when using mass spectrometric detection is a matrix effect, which is caused by the influence of matrix components extracted with pesticides from the sample. In this work, attempts have been made to reduce the influence of the matrix in the analysis of pesticide residues by high performance liquid chromatography with time of flight mass spectrometry (HPLC / TOFMS.

  17. Analysis of martensitic transformation and residual tension in an 304L stainless steel; Analise da transformacao martensitica e tensao residual em um aco inoxidavel 304L

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Juciane Maria

    2014-07-01

    The relationship between plastic deformation and the strain induced phase transformation, that provides a practical route to the development of new engineering materials with excellent mechanical properties, characterize the TRIP effect 'Transformation Induced Plasticity'. Among the stainless steels, the metastable 304 L austenitic steel is susceptible to transformation of austenite-martensite phase from tensile tests at room temperature by increments of plastic deformation. It is of great technological and scientific interest the knowledge of the evolution of phase transformation and residual stress from different levels and rates of plastic deformation imposed to the material. It is also important to evaluate the interference of metallographic preparation in quantitative analyzes of this steel. The main techniques used in this study consisted of X-rays diffraction and Ferritoscopy for the quantitation phase, and XRD to residual stress analysis also. As observed, the phase transformation quantification has not suffered significant influence of the metallographic preparation and evolved from increments of plastic deformation due to different stop charges and strain rates, leading to a further strengthening of the austenite matrix. The evaluation of residual stress resulting from the martensitic transformation was susceptible to the metallographic preparation and increased its value on comparison to sample without metallographic preparation. It was also observed that the residual stress decreased with the increase of the fraction of transformed martensite. (author)

  18. Determination of residues of fipronil and its metabolites in cauliflower by using gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Duhan, Anil; Kumari, Beena; Duhan, Saroj

    2015-02-01

    Fipronil is a widely used insecticide with a well-described toxicological pathway. Recently it has been widely used in India to control vegetable pests. The present study has been carried out to observe the persistence pattern of fipronil and its metabolites-fipronil sulfone, fipronil sulfide, fipronil desulfinyl in cauliflower and soil so as to know the potential risk if any to consumers and environment. Fipronil was applied @ 56 g a.i. ha(-1). Samples of cauliflower and soil were collected periodically; processed using QuEChERS method and analyzed by GCMS/MS. In cauliflower, residues of fipronil and its metabolites reached below detectable level before 30 days of application whereas in soil about 95% of total fipronil residues got degraded within same time period. Washing and washing followed by cooking or boiling was found effective in reducing residues. A safe waiting period of 15 days is therefore suggested before consuming cauliflower.

  19. Greenhouse gas emission measurement and economic analysis of Iran natural gas fired power plants

    International Nuclear Information System (INIS)

    Shahsavari Alavijeh, H.; Kiyoumarsioskouei, A.; Asheri, M.H.; Naemi, S.; Shahsavari Alavije, H.; Basirat Tabrizi, H.

    2013-01-01

    This study attempts to examine the natural gas fired power plants in Iran. The required data from natural gas fired power plants were gathered during 2008. The characteristics of thirty two gas turbine power plants and twenty steam power plants have been measured. Their emission factor values were then compared with the standards of Energy Protection Agency, Euro Union and World Bank. Emission factors of gas turbine and steam power plants show that gas turbine power plants have a better performance than steam power plants. For economic analysis, fuel consumption and environmental damages caused by the emitted pollutants are considered as cost functions; and electricity sales revenue are taken as benefit functions. All of these functions have been obtained according to the capacity factor. Total revenue functions show that gas turbine and steam power plants are economically efficient at 98.15% and 90.89% of capacity factor, respectively; this indicates that long operating years of power plants leads to reduction of optimum capacity factor. The stated method could be implemented to assess the economic status of a country’s power plants where as efficient capacity factor close to one means that power plant works in much better condition. - Highlights: • CO 2 and NO x emissions of Iran natural gas fired power plants have been studied. • CO 2 and NO x emission factors are compared with EPA, EU and World Bank standards. • Costs and benefit as economic functions are obtained according to capacity factor. • Maximum economic profit is obtained for gas turbine and steam power plants. • Investment in CO 2 reduction is recommended instead of investment in NO x reduction

  20. MSPD procedure for determining buprofezin, tetradifon, vinclozolin, and bifenthrin residues in propolis by gas chromatography-mass spectrometry.

    Science.gov (United States)

    dos Santos, Thaíse Fernanda Santana; Aquino, Adriano; Dórea, Haroldo Silveira; Navickiene, Sandro

    2008-03-01

    A simple and effective extraction method based on matrix solid-phase dispersion (MSPD) was developed to determine bifenthrin, buprofezin, tetradifon, and vinclozolin in propolis using gas chromatography-mass spectrometry in selected ion monitoring mode (GC-MS, SIM). Different method conditions were evaluated, for example type of solid phase (C(18), alumina, silica, and Florisil), the amount of solid phase and eluent (n-hexane, dichloromethane, dichloromethane-n-hexane (8:2 and 1:1, v/v) and dichloromethane-ethyl acetate (9:1, 8:2 and 7:3, v/v)). The best results were obtained using 0.5 g propolis, 1.0 g silica as dispersant sorbent, 1.0 g Florisil as clean-up sorbent, and dichloromethane-ethyl acetate (9:1, v/v) as eluting solvent. The method was validated by analysis of propolis samples fortified at different concentration levels (0.25 to 1.0 mg kg(-1)). Average recoveries (four replicates) ranged from 67% to 175% with relative standard deviation between 5.6% and 12.1%. Detection and quantification limits ranged from 0.05 to 0.10 mg kg(-1) and 0.15 to 0.25 mg kg(-1) propolis, respectively.

  1. The Energy Conversion Analysis of HTR Gas Turbine System

    International Nuclear Information System (INIS)

    Utaja

    2000-01-01

    The energy conversion analysis of HTR gas turbine system by hand calculation is tedious work and need much time. This difficulty comes from the repeated thermodynamic process calculation, both on compression or expansion of the cycle. To make the analysis faster and wider variable analyzed, HTR-1 programme is used. In this paper, the energy conversion analysis of HTR gas turbine system by HTR-1 will be described. The result is displayed as efficiency curve and block diagram with the input and output temperature of the component. This HTR-1 programme is developed by Basic language programming and be compiled by Visual Basic 5.0 . By this HTR-1 programme, the efficiency, specific power and effective compression of the amount of gas can be recognized fast. For example, for CO 2 gas between 40 o C and 700 o C, the compression on maximum efficiency is 4.6 and the energy specific is 18.9 kcal/kg, while the temperature changing on input and output of the component can be traced on monitor. This process take less than one second, while the manual calculation take more than one hour. It can be concluded, that the energy conversion analysis of the HTR gas turbine system by HTR-1 can be done faster and more variable analyzed. (author)

  2. Mid-infrared spectroscopy and multivariate analysis for determination of tetracycline residues in cow's milk

    Directory of Open Access Journals (Sweden)

    Lizeth Mariel Casarrubias-Torres

    2018-01-01

    Full Text Available Mid-infrared spectroscopy and chemometric analysis were tested to determine tetracycline's residues in cow's milk. Cow's milk samples (n = 30 were spiked with tetracycline, chlortetracycline, and oxytetracycline in the range of 10-400 µg/l. Chemometric models to quantify each of the tetracycline's residues were developed by applying Partial Components Regression and Partial Least Squares algorithms. The Soft Independent Modeling of Class Analogy model was used to differentiate between pure milk and milk sample with tetracycline residues. The best models for predicting the levels of these antibiotics were obtained using Partial Least Square 1 algorithm (coefficient of determination between 0.997-0.999 and the standard error of calibration from 1.81 to 2.95. The Soft Independent Modeling of Class Analogy model showed well-separated groups allowing classification of milk samples and milk sample with antibiotics. The obtained results demonstrate the great analytical potential of chemometrics coupled with mid-infrared spectroscopy for the prediction of antibiotic in cow's milk at a concentration of microgram per litre (µg/l. This technique can be used to verify the safety of the milk rapidly and reliably.

  3. Analysis and measurement of residual stress distribution of vanadium/ceramics joints for fusion reactor applications

    International Nuclear Information System (INIS)

    Nemoto, Y.; Ueda, K.

    1998-01-01

    Vanadium alloys are considered as candidate structural materials for fusion reactor system. When vanadium alloys are used in fusion reactor system, joining with ceramics for insulating is one of material issues to be solved to make component of fusion reactor. In the application of ceramics/metal jointing and coating, residual stress caused by difference of thermal expansion rate between ceramics and metals is an important factor in obtaining good bonding strength and soundness of coating. In this work, residual stress distribution in direct diffusion bonded vanadium/alumina joint (jointing temperature: 1400 C) was measured by small area X-ray diffraction method. And the comparison of finite element method (FEM) analysis and actual stress distribution was carried out. Tensile stress concentration at the edge of the boundary of the joint in alumina was observed. The residual stress concentration may cause cracks in alumina, or failure of bonding. Actually, cracks in alumina caused by thermal stress after bonding at 1500 C was observed. The stress concentration of the joint must be reduced to obtain good bonded joint. Lower bonding temperature or to devise the shape of the outer surface of the joint will reduce the stress concentration. (orig.)

  4. Determination of hexachlorocyclohexane pesticide residues in wool fat by a combined high-performance liquid chromatographic-gas-liquid chromatographic method

    International Nuclear Information System (INIS)

    Ali, S.L.

    1978-01-01

    Beta- and gamma-hexachlorocyclohexane residues were determined in twelve wool fat samples by using a combined high-performance liquid chromatographic (HPLC)-gas-liquid chromatographic (GLC) method. After extraction and chromatographic clean-up on a silca-gel column, the sample was further purified by HPLC on a reversed-phase C-18 column with methanol as the mobile phase. The final determination was effected by GLC with a 1-mCi nickel-63 electron-capture detector. The analytical method was checked by addition of carbon-14-labelled lindane and measurement of the radioactivity in a liquid scintillation counter. (Auth.)

  5. Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

    Directory of Open Access Journals (Sweden)

    Shams Bilal

    2017-08-01

    Full Text Available Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulation-condensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources.

  6. Thermodynamic analysis of steam-injected advanced gas turbine cycles

    Science.gov (United States)

    Pandey, Devendra; Bade, Mukund H.

    2017-12-01

    This paper deals with thermodynamic analysis of steam-injected gas turbine (STIGT) cycle. To analyse the thermodynamic performance of steam-injected gas turbine (STIGT) cycles, a methodology based on pinch analysis is proposed. This graphical methodology is a systematic approach proposed for a selection of gas turbine with steam injection. The developed graphs are useful for selection of steam-injected gas turbine (STIGT) for optimal operation of it and helps designer to take appropriate decision. The selection of steam-injected gas turbine (STIGT) cycle can be done either at minimum steam ratio (ratio of mass flow rate of steam to air) with maximum efficiency or at maximum steam ratio with maximum net work conditions based on the objective of plants designer. Operating the steam injection based advanced gas turbine plant at minimum steam ratio improves efficiency, resulting in reduction of pollution caused by the emission of flue gases. On the other hand, operating plant at maximum steam ratio can result in maximum work output and hence higher available power.

  7. Identifying Plant Part Composition of Forest Logging Residue Using Infrared Spectral Data and Linear Discriminant Analysis

    Directory of Open Access Journals (Sweden)

    Gifty E. Acquah

    2016-08-01

    Full Text Available As new markets, technologies and economies evolve in the low carbon bioeconomy, forest logging residue, a largely untapped renewable resource will play a vital role. The feedstock can however be variable depending on plant species and plant part component. This heterogeneity can influence the physical, chemical and thermochemical properties of the material, and thus the final yield and quality of products. Although it is challenging to control compositional variability of a batch of feedstock, it is feasible to monitor this heterogeneity and make the necessary changes in process parameters. Such a system will be a first step towards optimization, quality assurance and cost-effectiveness of processes in the emerging biofuel/chemical industry. The objective of this study was therefore to qualitatively classify forest logging residue made up of different plant parts using both near infrared spectroscopy (NIRS and Fourier transform infrared spectroscopy (FTIRS together with linear discriminant analysis (LDA. Forest logging residue harvested from several Pinus taeda (loblolly pine plantations in Alabama, USA, were classified into three plant part components: clean wood, wood and bark and slash (i.e., limbs and foliage. Five-fold cross-validated linear discriminant functions had classification accuracies of over 96% for both NIRS and FTIRS based models. An extra factor/principal component (PC was however needed to achieve this in FTIRS modeling. Analysis of factor loadings of both NIR and FTIR spectra showed that, the statistically different amount of cellulose in the three plant part components of logging residue contributed to their initial separation. This study demonstrated that NIR or FTIR spectroscopy coupled with PCA and LDA has the potential to be used as a high throughput tool in classifying the plant part makeup of a batch of forest logging residue feedstock. Thus, NIR/FTIR could be employed as a tool to rapidly probe/monitor the variability

  8. Establishment of analysis method for methane detection by gas chromatography

    Science.gov (United States)

    Liu, Xinyuan; Yang, Jie; Ye, Tianyi; Han, Zeyu

    2018-02-01

    The study focused on the establishment of analysis method for methane determination by gas chromatography. Methane was detected by hydrogen flame ionization detector, and the quantitative relationship was determined by working curve of y=2041.2x+2187 with correlation coefficient of 0.9979. The relative standard deviation of 2.60-6.33% and the recovery rate of 96.36%∼105.89% were obtained during the parallel determination of standard gas. This method was not quite suitable for biogas content analysis because methane content in biogas would be over the measurement range in this method.

  9. Gas quality analysis and evaluation program for project Gasbuggy

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C F [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Experimental results of the gas quality analysis program for Project Gasbuggy through August 1969 are presented graphically, addressing the questions raised by the preshot program goals. The chemical composition and the concentrations of tritium, krypton-85, carbon-14 and argon-37, 39 are presented as a function of time and gas production from the nuclear chimney. Chemically, the presence of CO{sub 2}, CO and H{sub 2} served to dilute the formation gas and caused reactions which significantly altered the gas composition at early times. The radionuclide content of the chimney gas at reentry was some 800 pCi/cm{sup 3} of which about 80% was CH{sub 3}T. Lesser quantities of tritium were observed as HT, C{sub 2}H{sub 5}T and C{sub 3}H{sub 7}T. The other major contaminant was Kr{sup 85} which was present at about one-fifth the level of CH{sub 3}T. Small quantities of carbon-14 and argon-39 were also identified. The only other radionuclides identified in the gas were relatively short-lived rare gases. During the production testing, about two and one-half chimney volumes of gas at formation pressure were removed. This removal, accompanied by dilution, has reduced the radionuclide concentrations to about 7% of their levels at reentry. The production characteristics of the Gasbuggy environment prevented an adequate test of the effectiveness of chimney flushing. However, the rapid drawdown concept is supported by the available data as an effective means of reducing contaminant levels. The changes in composition during production or testing are seen to be consistent with a model involving a non-uniform gas influx rate and flow distribution over the chimney region. Mixing times are estimated to be on the order of a few days, so that increasing concentrations following a sudden gas influx can be explained. (author)

  10. Assessment of a residual life evaluation tool for gas turbine blades and vanes based on microstructural evolution of a NiCoCrAlY+Re coating

    Energy Technology Data Exchange (ETDEWEB)

    Barbareschi, E.; Bonadei, A.; Costa, A.; Guarnone, P.; Vacchieri, E. [Ansaldo Energia S.p.A., Genoa (Italy)

    2010-07-01

    Life management of hot gas path components is a fundamental topic in gas turbine for power generation. The gas turbine components have to withstand severe service conditions in term of high temperature oxidation, corrosion and creep-fatigue. The resistance to environmental conditions is assured by metallic coatings of the MCrAlY family. {beta} phase, NiAl, present as secondary phase, is the source of protection against oxidation. Among MCrAlY coatings, NiCoCrAlY + Re have a complex microstructure with a higher number of phases than the standard ones; these phases are subjected to transformations during service. The addition of Re is effective against the diffusion of protective elements, as Al and Cr, toward the base material. For the estimation of residual life a first approach has been developed using the decrease of {beta} phase amount after static oxidation test at high temperature and for long time. This type of prediction tool is not complete for the assessment of the hot gas path components life management and a deep study focused on the transformation of the other phases is necessary. Experimental tests have been performed to identify the phase stability range by annealing at different temperatures and durations. Moreover after static oxidation tests a systematic data collection of phase evolution has been carried out through EDS, XRD and EBSD techniques in order to define the kinetic laws that rule the phase transformations. The tuning of thermodynamic and kinetic results allows to build up another residual life tool that, even if it is more complex, is more reliable in temperature evaluation in GT components. Both models have been applied to a component after service and a comparison between the different models evaluation has been conducted. (orig.)

  11. Gas conditioning and gas balance in tokamak

    International Nuclear Information System (INIS)

    Grisolia, C.; Bonnel, P.; Grosman, A.; Rodriguez, L.; Bardon, J.

    1990-01-01

    An accurate barometry is very helpful in analysing the plasma wall interaction processes in controlled fusion devices. In Tore Supra, residual gas analysis and various types of pressure gauges allow to monitor the various conditioning processes and the global particle balance. In this paper, measurements are described and analysis of two examples is given [fr

  12. Theoretical conformational analysis of the bovine adrenal medulla 12 residue peptide molecule

    Science.gov (United States)

    Akhmedov, N. A.; Tagiyev, Z. H.; Hasanov, E. M.; Akverdieva, G. A.

    2003-02-01

    The spatial structure and conformational properties of the bovine adrenal medulla 12 residue peptide Tyr1-Gly2-Gly3-Phe4-Met5-Arg6-Arg7-Val8-Gly9-Arg10-Pro11-Glu12 (BAM-12P) molecule were studied by theoretical conformational analysis. It is revealed that this molecule can exist in several stable states. The energy and geometrical parameters for the low-energy conformations are obtained. The conformationally rigid and labile segments of this molecule were revealed.

  13. XRF intermediate thickness layer technique for analysis of residue of hard to dissolve materials

    International Nuclear Information System (INIS)

    Mzyk, Z.; Mzyk, J.; Buzek, L.; Baranowska, I.

    1998-01-01

    This work presents a quick method for lead and silver determination in materials, such as slags from silver metallurgy and slimes from copper electrorefining, which are very difficult to dissolve, even using a microwave technique. The idea was to dissolve the possibly greatest amount of the sample using acids. Insoluble deposit was filtered out. Silver content in the solution was analysed by potentiometric titration or AAS, lead content by XRS, while sediment deposit on filter - by XRF intermediate thickness technique. The results of silver and lead analysis obtained by this method were compared with those obtained by classical method, i.e. melting the residue with sodium peroxide. (author)

  14. Shutdown risk analysis for a BWR plant (residual heat removal systems)

    International Nuclear Information System (INIS)

    Rebollo Garcia, C.; Merino Teillet, A.; Cerezo, L.

    1994-01-01

    This report analyses the different risk situations which may arise during refuelling outage at Cofrentes NPP. The most critical situations are determined in terms of the small amount of coolant available and the lowest number of heat removal and water make-up systems available. The available times before the boiling point of the coolant is reached and the subsequent moment when the fuel elements are left uncovered in the event of the failure of the normal heat removal functions are determined. The analysis identifies the alternative systems which can be used besides those required by the technical specification and their capacity for residual heat removal and coolant make-up functions. (Author)

  15. Determined analysis of safety, viability and residual service life on criteria of crack mechanics

    International Nuclear Information System (INIS)

    Matvienko, Yu.G.

    1997-01-01

    Unified methods used in analysis of reliability, vulnerability, and residual lifetime of equipment with crack damage are considered, an increase in the desired lifetime is proven in the framework of vulnerability concept that allows crack developing with regard to the given level of reliability. The problem of reliability, vulnerability, and the lifetime is shown to be an interrelated problem. Optimal combination of the strength value, plasticity and resistance to crack developing results from the criteria of reliability and vulnerability based, in turn, on the principles of the mechanics of cracks. Structural features of technical systems can hinder the crack developing and prevent drastic damages of the equipment thus increasing the lifetime

  16. Failure Modes and Effects Analysis (FMEA) of the Residual Heat Removal System

    International Nuclear Information System (INIS)

    Eggleston, F.T.

    1976-01-01

    The Residual Heat Removal System (RHRS) transfer heat from the Reactor Coolant System (RCS) to the reactor plant Component Cooling System (CCS) to reduce the temperature of the RCS at a controlled rate during the second part of normal plant cooldown and maintains the desired temperature until the plant is restarted. By the use of an analytic tool, the Failure Modes and Effects Analysis, it is shown that the RHRS, because of its redundant two train design, is able to accommodate any credible component single failure with the only effect being an extension in the required cooldown time, thus demonstrating the reliability of the RHRS to perform its intended function

  17. Bias due to two-stage residual-outcome regression analysis in genetic association studies.

    Science.gov (United States)

    Demissie, Serkalem; Cupples, L Adrienne

    2011-11-01

    Association studies of risk factors and complex diseases require careful assessment of potential confounding factors. Two-stage regression analysis, sometimes referred to as residual- or adjusted-outcome analysis, has been increasingly used in association studies of single nucleotide polymorphisms (SNPs) and quantitative traits. In this analysis, first, a residual-outcome is calculated from a regression of the outcome variable on covariates and then the relationship between the adjusted-outcome and the SNP is evaluated by a simple linear regression of the adjusted-outcome on the SNP. In this article, we examine the performance of this two-stage analysis as compared with multiple linear regression (MLR) analysis. Our findings show that when a SNP and a covariate are correlated, the two-stage approach results in biased genotypic effect and loss of power. Bias is always toward the null and increases with the squared-correlation between the SNP and the covariate (). For example, for , 0.1, and 0.5, two-stage analysis results in, respectively, 0, 10, and 50% attenuation in the SNP effect. As expected, MLR was always unbiased. Since individual SNPs often show little or no correlation with covariates, a two-stage analysis is expected to perform as well as MLR in many genetic studies; however, it produces considerably different results from MLR and may lead to incorrect conclusions when independent variables are highly correlated. While a useful alternative to MLR under , the two -stage approach has serious limitations. Its use as a simple substitute for MLR should be avoided. © 2011 Wiley Periodicals, Inc.

  18. Ethanol production process from banana fruit and its lignocellulosic residues: Energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez-Arredondo, H.I. [Grupo de Investigacion Bioprocesos y Flujos Reactivos, Universidad Nacional de Colombia, Sede Medellin, Calle 59 A N 63-20 (Colombia); Departamento de Engenharia Mecanica, Escola Politecnica, Universidade de Sao Paulo, Avenida Professor Mello Moraes 2231 (Brazil); Ruiz-Colorado, A.A. [Grupo de Investigacion Bioprocesos y Flujos Reactivos, Universidad Nacional de Colombia, Sede Medellin, Calle 59 A N 63-20 (Colombia); De Oliveira, S. Jr. [Departamento de Engenharia Mecanica, Escola Politecnica, Universidade de Sao Paulo, Avenida Professor Mello Moraes 2231 (Brazil)

    2010-07-15

    Tropical countries, such as Brazil and Colombia, have the possibility of using agricultural lands for growing biomass to produce bio-fuels such as biodiesel and ethanol. This study applies an energy analysis to the production process of anhydrous ethanol obtained from the hydrolysis of starch and cellulosic and hemicellulosic material present in the banana fruit and its residual biomass. Four different production routes were analyzed: acid hydrolysis of amylaceous material (banana pulp and banana fruit) and enzymatic hydrolysis of lignocellulosic material (flower stalk and banana skin). The analysis considered banana plant cultivation, feedstock transport, hydrolysis, fermentation, distillation, dehydration, residue treatment and utility plant. The best indexes were obtained for amylaceous material for which mass performance varied from 346.5 L/t to 388.7 L/t, Net Energy Value (NEV) ranged from 9.86 MJ/L to 9.94 MJ/L and the energy ratio was 1.9 MJ/MJ. For lignocellulosic materials, the figures were less favorable; mass performance varied from 86.1 to 123.5 L/t, NEV from 5.24 to 8.79 MJ/L and energy ratio from 1.3 to 1.6 MJ/MJ. The analysis showed, however, that both processes can be considered energetically feasible. (author)

  19. Evaluation of Some Pesticide Residues in Stored Beans in Jos ...

    African Journals Online (AJOL)

    Qualitative and quantitative analysis were performed by gas chromatography with electron capture and flame ionization. All the 3 samples (100%) contained pesticide residues beyond the allowed beans maximum residue levels (MRLs) of 0.01 mg/kg and 0.2 mg/kg, respectively, for chlorpyrifos and endosulfan. The present ...

  20. Greenhouse gas emissions in Hawaii. Household and visitor expenditure analysis

    International Nuclear Information System (INIS)

    Konan, Denise Eby; Chan, Hing Ling

    2010-01-01

    This paper focuses on petroleum use and greenhouse gas emissions associated with economic activities in Hawaii. Data on economic activity, petroleum consumption by type (gasoline, diesel, aviation fuel, residual, propane), and emissions factors are compiled and analyzed. In the baseline year 1997, emissions are estimated to total approximately 23.2 million metric tons of carbon, 181 thousand metric tons of nitrous oxide, and 31 thousand metric tons of methane in terms of carbon-equivalent global warming potential over a 100-year horizon. Air transportation, electricity, and other transportation are the key economic activity responsible for GHG emissions associated with fossil fuel use. More than 22% of total emissions are attributed to visitor expenditures. On a per person per annum basis, emission rates generated by visitor demand are estimated to be higher than that of residents by a factor of 4.3 for carbon, 3.2 for methane, and 4.8 for nitrous oxide. (author)

  1. Meta-Analysis of Microarray Data Identifies GAS6 Expression as an Independent Predictor of Poor Survival in Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Michelle Buehler

    2013-01-01

    Full Text Available Seeking new biomarkers for epithelial ovarian cancer, the fifth most common cause of death from all cancers in women and the leading cause of death from gynaecological malignancies, we performed a meta-analysis of three independent studies and compared the results in regard to clinicopathological parameters. This analysis revealed that GAS6 was highly expressed in ovarian cancer and therefore was selected as our candidate of choice. GAS6 encodes a secreted protein involved in physiological processes including cell proliferation, chemotaxis, and cell survival. We performed immunohistochemistry on various ovarian cancer tissues and found that GAS6 expression was elevated in tumour tissue samples compared to healthy control samples (. In addition, GAS6 expression was also higher in tumours from patients with residual disease compared to those without. Our data propose GAS6 as an independent predictor of poor survival, suggesting GAS6, both on the mRNA and on the protein level, as a potential biomarker for ovarian cancer. In clinical practice, the staining of a tumour biopsy for GAS6 may be useful to assess cancer prognosis and/or to monitor disease progression.

  2. gRINN: a tool for calculation of residue interaction energies and protein energy network analysis of molecular dynamics simulations.

    Science.gov (United States)

    Serçinoglu, Onur; Ozbek, Pemra

    2018-05-25

    Atomistic molecular dynamics (MD) simulations generate a wealth of information related to the dynamics of proteins. If properly analyzed, this information can lead to new insights regarding protein function and assist wet-lab experiments. Aiming to identify interactions between individual amino acid residues and the role played by each in the context of MD simulations, we present a stand-alone software called gRINN (get Residue Interaction eNergies and Networks). gRINN features graphical user interfaces (GUIs) and a command-line interface for generating and analyzing pairwise residue interaction energies and energy correlations from protein MD simulation trajectories. gRINN utilizes the features of NAMD or GROMACS MD simulation packages and automatizes the steps necessary to extract residue-residue interaction energies from user-supplied simulation trajectories, greatly simplifying the analysis for the end-user. A GUI, including an embedded molecular viewer, is provided for visualization of interaction energy time-series, distributions, an interaction energy matrix, interaction energy correlations and a residue correlation matrix. gRINN additionally offers construction and analysis of Protein Energy Networks, providing residue-based metrics such as degrees, betweenness-centralities, closeness centralities as well as shortest path analysis. gRINN is free and open to all users without login requirement at http://grinn.readthedocs.io.

  3. Exergy analysis of a gas-hydrate cool storage system

    International Nuclear Information System (INIS)

    Bi, Yuehong; Liu, Xiao; Jiang, Minghe

    2014-01-01

    Based on exergy analysis of charging and discharging processes in a gas-hydrate cool storage system, the formulas for exergy efficiency at the sensible heat transfer stage and the phase change stage corresponding to gas-hydrate charging and discharging processes are obtained. Furthermore, the overall exergy efficiency expressions of charging, discharging processes and the thermodynamic cycle of the gas-hydrate cool storage system are obtained. By using the above expressions, the effects of number of transfer units, the inlet temperatures of the cooling medium and the heating medium on exergy efficiencies of the gas-hydrate cool storage system are emphatically analyzed. The research results can be directly used to evaluate the performance of gas-hydrate cool storage systems and design more efficient energy systems by reducing the sources of inefficiency in gas-hydrate cool storage systems. - Highlights: • Formulas for exergy efficiency at four stages are obtained. • Exergy efficiency expressions of two processes and one cycle are obtained. • Three mainly influencing factors on exergy efficiencies are analyzed. • With increasing the inlet temperature of cooling medium, exergy efficiency increases. • With decreasing the inlet temperature of heating medium, exergy efficiency increases

  4. Finite element analysis and measurement for residual stress of dissimilar metal weld in pressurizer safety nozzle mockup

    International Nuclear Information System (INIS)

    Lee, Kyoung Soo; Kim, W.; Lee, Jeong Geun; Park, Chi Yong; Yang, Jun Seok; Kim, Tae Ryong; Park, Jai Hak

    2009-01-01

    Finite element (FE) analysis and experiment for weld residual stress (WRS) in the pressurizer safety nozzle mockup is described in various processes and results. Foremost of which is the dissimilar simulation metal welding (DMW) between carbon steel and austenitic stainless steel. Thermal and structural analyses were compared with actual residual stress, and actual measurements of. Magnitude and distribution of WRS in the nozzle mockup were assessed. Two measurement methods were used: hole-drilling method (HDM) with strain gauge for residual stress on the surface of the mockup, and block removal and splitting layer (BRSL) method for through-thickness. FE analysis and measurement data showed good agreement. In conclusion, the characteristics of weld residual stress of DMW could be well understood and the simplified FE analysis was verified as acceptable for estimating WRS

  5. Finite element analysis and measurement for residual stress of dissimilar metal weld in pressurizer safety nozzle mockup

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyoung Soo; Kim, W.; Lee, Jeong Geun; Park, Chi Yong; Yang, Jun Seok; Kim, Tae Ryong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Park, Jai Hak [Chungbuk University, Cheongju (Korea, Republic of)

    2009-11-15

    Finite element (FE) analysis and experiment for weld residual stress (WRS) in the pressurizer safety nozzle mockup is described in various processes and results. Foremost of which is the dissimilar simulation metal welding (DMW) between carbon steel and austenitic stainless steel. Thermal and structural analyses were compared with actual residual stress, and actual measurements of. Magnitude and distribution of WRS in the nozzle mockup were assessed. Two measurement methods were used: hole-drilling method (HDM) with strain gauge for residual stress on the surface of the mockup, and block removal and splitting layer (BRSL) method for through-thickness. FE analysis and measurement data showed good agreement. In conclusion, the characteristics of weld residual stress of DMW could be well understood and the simplified FE analysis was verified as acceptable for estimating WRS

  6. High sensitivity analysis of atmospheric gas elements

    International Nuclear Information System (INIS)

    Miwa, Shiro; Nomachi, Ichiro; Kitajima, Hideo

    2006-01-01

    We have investigated the detection limit of H, C and O in Si, GaAs and InP using a Cameca IMS-4f instrument equipped with a modified vacuum system to improve the detection limit with a lower sputtering rate We found that the detection limits for H, O and C are improved by employing a primary ion bombardment before the analysis. Background levels of 1 x 10 17 atoms/cm 3 for H, of 3 x 10 16 atoms/cm 3 for C and of 2 x 10 16 atoms/cm 3 for O could be achieved in silicon with a sputtering rate of 2 nm/s after a primary ion bombardment for 160 h. We also found that the use of a 20 K He cryo-panel near the sample holder was effective for obtaining better detection limits in a shorter time, although the final detection limits using the panel are identical to those achieved without it

  7. High sensitivity analysis of atmospheric gas elements

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, Shiro [Materials Analysis Lab., Sony Corporation, 4-16-1 Okata, Atsugi 243-0021 (Japan)]. E-mail: Shiro.Miwa@jp.sony.com; Nomachi, Ichiro [Materials Analysis Lab., Sony Corporation, 4-16-1 Okata, Atsugi 243-0021 (Japan); Kitajima, Hideo [Nanotechnos Corp., 5-4-30 Nishihashimoto, Sagamihara 229-1131 (Japan)

    2006-07-30

    We have investigated the detection limit of H, C and O in Si, GaAs and InP using a Cameca IMS-4f instrument equipped with a modified vacuum system to improve the detection limit with a lower sputtering rate We found that the detection limits for H, O and C are improved by employing a primary ion bombardment before the analysis. Background levels of 1 x 10{sup 17} atoms/cm{sup 3} for H, of 3 x 10{sup 16} atoms/cm{sup 3} for C and of 2 x 10{sup 16} atoms/cm{sup 3} for O could be achieved in silicon with a sputtering rate of 2 nm/s after a primary ion bombardment for 160 h. We also found that the use of a 20 K He cryo-panel near the sample holder was effective for obtaining better detection limits in a shorter time, although the final detection limits using the panel are identical to those achieved without it.

  8. Gas-cooled reactor safety and accident analysis

    International Nuclear Information System (INIS)

    1985-12-01

    The Specialists' Meeting on Gas-Cooled Reactor Safety and Accident Analysis was convened by the International Atomic Energy Agency in Oak Ridge on the invitation of the Department of Energy in Washington, USA. The meeting was hosted by the Oak Ridge National Laboratory. The purpose of the meeting was to provide an opportunity to compare and discuss results of safety and accident analysis of gas-cooled reactors under development, construction or in operation, to review their lay-out, design, and their operational performance, and to identify areas in which additional research and development are needed. The meeting emphasized the high safety margins of gas-cooled reactors and gave particular attention to the inherent safety features of small reactor units. The meeting was subdivided into four technical sessions: Safety and Related Experience with Operating Gas-Cooled Reactors (4 papers); Risk and Safety Analysis (11 papers); Accident Analysis (9 papers); Miscellaneous Related Topics (5 papers). A separate abstract was prepared for each of these papers

  9. Gas Chromatographic-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    Purpose: To analyze the essential oil composition of the flower of Jasminum officinale L. var. grandifloroum L. (Jasminum grandiflorum) by gas chromatography-mass spectrometry (GC-MS). Methods: The optimum GC-MS conditions used for the analysis were 250 oC inlet temperature, 150 oC MSD detector temperature, ...

  10. Gas chromatographic column for the Viking 1975 molecular analysis experiment

    Science.gov (United States)

    Novotny, M.; Hayes, J. M.; Bruner, F.; Simmonds, P. G.

    1975-01-01

    A gas chromatographic column has been developed for use in the remote analysis of the Martian surface. The column, which utilizes a liquid-modified organic adsorbent (Tenax) as the stationary phase, provides efficient transmission and resolution of nanogram quantities of organic materials in the presence of millionfold excesses of water and carbon dioxide.

  11. LC-MS/MS analysis of neonicotinoid insecticides: Residue findings in chilean honeys

    Directory of Open Access Journals (Sweden)

    Raquel Bridi

    Full Text Available ABSTRACT Neonicotinoids are a relatively new generation of insecticides that have been used for control of pests such as aphids, leafhoppers and whiteflies. This paper presents for the first time a determination of residues of four neonicotinoid insecticides (acetamiprid, thiamethoxam, thiacloprid and imidacloprid in Chilean honey using QuEChERS extraction and UHPLC-MS/MS analysis. The limits of detection and quantification found for all analytes ranging from 0.34 to 1.43 μg kg-1 and from 0.30 to 4.76 μg kg-1, respectively. The extraction using QuEChERS method provided recoveries over 79% and the precision showed coefficient of variation lower than 20%. These data are in agreement with the international criteria that recommend general recovery limits of 70 - 120%. Of the 16 samples analyzed, in three honey samples neonicotinoids pesticides were detected. These three samples were collected from the same geographical area (Rengo. Fruit and grain production characterize the province of Rengo. The analysis of the botanical origin of these honeys showed the absence of pollen grains of crops and the majority presence of pollen grains of weeds such as Medicago sativa, Galega officinalis and Brassica rapa, which could be associated with crops. Although the residue levels found were low, the results also confirm the actual occurrence of a transfer of neonicotinoid insecticides from exposed honeybees into honey.

  12. Fracture mechanics and residual fatigue life analysis for complex stress fields. Technical report

    International Nuclear Information System (INIS)

    Besuner, P.M.

    1975-07-01

    This report reviews the development and application of an influence function method for calculating stress intensity factors and residual fatigue life for two- and three-dimensional structures with complex stress fields and geometries. Through elastic superposition, the method properly accounts for redistribution of stress as the crack grows through the structure. The analytical methods used and the computer programs necessary for computation and application of load independent influence functions are presented. A new exact solution is obtained for the buried elliptical crack, under an arbitrary Mode I stress field, for stress intensity factors at four positions around the crack front. The IF method is then applied to two fracture mechanics problems with complex stress fields and geometries. These problems are of current interest to the electric power generating industry and include (1) the fatigue analysis of a crack in a pipe weld under nominal and residual stresses and (2) fatigue analysis of a reactor pressure vessel nozzle corner crack under a complex bivariate stress field

  13. Analysis of gas turbine systems for sustainable energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Anheden, Marie

    2000-02-01

    Increased energy demands and fear of global warming due to the emission of greenhouse gases call for development of new efficient power generation systems with low or no carbon dioxide (CO{sub 2}) emissions. In this thesis, two different gas turbine power generation systems, which are designed with these issues in mind, are theoretically investigated and analyzed. In the first gas turbine system, the fuel is combusted using a metal oxide as an oxidant instead of oxygen in the air. This process is known as Chemical Looping Combustion (CLC). CLC is claimed to decrease combustion exergy destruction and increase the power generation efficiency. Another advantage is the possibility to separate CO{sub 2} without a costly and energy demanding gas separation process. The system analysis presented includes computer-based simulations of CLC gas turbine systems with different metal oxides as oxygen carriers and different fuels. An exergy analysis comparing the exergy destruction of the gas turbine system with CLC and conventional combustion is also presented. The results show that it is theoretically possible to increase the power generation efficiency of a simple gas turbine system by introducing CLC. A combined gas/steam turbine cycle system with CLC is, however, estimated to reach a similar efficiency as the conventional combined cycle system. If the benefit of easy and energy-efficient CO{sub 2} separation is accounted for, a CLC combined cycle system has a potential to be favorable compared to a combined cycle system with CO{sub 2} separation. In the second investigation, a solid, CO{sub 2}-neutral biomass fuel is used in a small-scale externally fired gas turbine system for cogeneration of power and district heating. Both open and closed gas turbines with different working fluids are simulated and analyzed regarding thermodynamic performance, equipment size, and economics. The results show that it is possible to reach high power generation efficiency and total (power

  14. Organic Rankine Cycle for Residual Heat to Power Conversion in Natural Gas Compressor Station. Part I: Modelling and Optimisation Framework

    Science.gov (United States)

    Chaczykowski, Maciej

    2016-06-01

    Basic organic Rankine cycle (ORC), and two variants of regenerative ORC have been considered for the recovery of exhaust heat from natural gas compressor station. The modelling framework for ORC systems has been presented and the optimisation of the systems was carried out with turbine power output as the variable to be maximized. The determination of ORC system design parameters was accomplished by means of the genetic algorithm. The study was aimed at estimating the thermodynamic potential of different ORC configurations with several working fluids employed. The first part of this paper describes the ORC equipment models which are employed to build a NLP formulation to tackle design problems representative for waste energy recovery on gas turbines driving natural gas pipeline compressors.

  15. Static Structural and Modal Analysis of Gas Turbine Blade

    Science.gov (United States)

    Ranjan Kumar, Ravi; Pandey, K. M., Prof.

    2017-08-01

    Gas turbine is one of the most versatile items of turbo machinery nowadays. It is used in different modes such as power generation, oil and gas, process plants, aviation, domestic and related small industries. This paper is based on the problems concerning blade profile selection, material selection and turbine rotor blade vibration that seriously impact the induced stress-deformation and structural functioning of developmental gas turbine engine. In this paper for generating specific power by rotating blade at specific RPM, blade profile and material has been decided by static structural analysis. Gas turbine rotating blade RPM is decided by Modal Analysis so that the natural frequency of blade should not match with the excitation frequency. For the above blade profile has been modeled in SOLIDWORKS and analysis has been done in ANSYS WORKBENCH 14. Existing NACA6409 profile has been selected as base model and then it is modified by bending it through 72.5° and 145°. Hence these three different blade profiles have been analyzed for three different materials viz. Super Alloy X, Nimonic 80A and Inconel 625 at three different speed viz. 20000, 40000 and 60000RPM. It is found that NACA6409 with 72.5° bent gives best result for all material at all speed. Among all the material Inconel 625 gives best result. Hence Blade of Inconel 625 having 72.5° bent profile is the best combination for all RPM.

  16. Certain questions about analysis of natural gas disolved in brine

    Energy Technology Data Exchange (ETDEWEB)

    Tezuka, M; Nakamura, M; Omi, K

    1983-01-01

    The composition of the gaseous phase of stratum brines is determined and the analysis technique is described. Ordinary analysis is performed with the assumptions that the contents of small components (excluding C02 and N2) are ignorably small and that the gas contains no 02. The determined concentrations of 02 and the proportional share of N2 are calculated from results of analysis as bound with pollutants. The high sensitivity of modern analytical methods makes it possible to identify quite small and trace concentrations of components, but corrections for air contamination may partially depreciate these results. Data are cited from gas chromatographic identifications of the components of gases disolved in the stratum brines of a Japanese deposit. C2H6 is established in all samples and C3H8 in two thirds of the samples, where H2 and helium were not detected anywhere. The concentrations of the gas phase on the whole in the brine were low. 02 falls into the samples in a water dissolved state; this demands the use of unconventional proportion of 02 to N2 (1 to 3.55), which is characteristic for air and a proportion of 1 to 2 which is characteristic for disolved air. With the conventional ordinary technique the consideration of the air contamination leads to a substantial underestimate of the N2 results. At the same time, the incorrect introduction of corrections for N2 has no effect on the heat creativity of the disolved gas.

  17. An alternative methodology for the analysis of electrical resistivity data from a soil gas study

    Science.gov (United States)

    Johansson, Sara; Rosqvist, Hâkan; Svensson, Mats; Dahlin, Torleif; Leroux, Virginie

    2011-08-01

    The aim of this paper is to present an alternative method for the analysis of resistivity data. The methodology was developed during a study to evaluate if electrical resistivity can be used as a tool for analysing subsurface gas dynamics and gas emissions from landfills. The main assumption of this study was that variations in time of resistivity data correspond to variations in the relative amount of gas and water in the soil pores. Field measurements of electrical resistivity, static chamber gas flux and weather data were collected at a landfill in Helsingborg, Sweden. The resistivity survey arrangement consisted of nine lines each with 21 electrodes in an investigation area of 16 ×20 m. The ABEM Lund Imaging System provided vertical and horizontal resistivity profiles every second hour. The data were inverted in Res3Dinv using L1-norm-based optimization method with a standard least-squares formulation. Each horizontal soil layer was then represented as a linear interpolated raster model. Different areas underneath the gas flux measurement points were defined in the resistivity model of the uppermost soil layer, and the vertical extension of the zones could be followed at greater depths in deeper layer models. The average resistivity values of the defined areas were calculated and plotted on a time axis, to provide graphs of the variation in resistivity with time in a specific section of the ground. Residual variation of resistivity was calculated by subtracting the resistivity variations caused by the diurnal temperature variations from the measured resistivity data. The resulting residual resistivity graphs were compared with field data of soil moisture, precipitation, soil temperature and methane flux. The results of the study were qualitative, but promising indications of relationships between electrical resistivity and variations in the relative amount of gas and water in the soil pores were found. Even though more research and better data quality is

  18. Analysis of antibiotic residues in foodstuffs in Tunisia: The tetracyclines, quinolones, and Sulphonamides

    International Nuclear Information System (INIS)

    Rezgui, Adel

    2009-01-01

    The first part of the work was to detect antibiotic residues in animal nutriment: chicken, fish, eggs and milk, by methods of screening. The second part covered the development of a new kit for the detection of antibiotic residues. (Author)

  19. Residual strength evaluation of corroded pipelines with long defects based upon limit load analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chiodo, Mario S.G.; Ruggieri, Claudio [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Arquitetura Naval e Engenharia Oceanica

    2009-07-01

    Accurate evaluation of the residual strength for corroded pipes remains essential in fitness for service analyses, including repair decisions and life-extension programs, of onshore and offshore oil and gas transportation. As the pipeline infrastructure ages, material loss due to corrosion represents one of the main degradation factors of steel pipes which leads to strength reduction and potential catastrophic failures. Current high resolution methods can precisely measure the geometry of corrosion defects. Despite the improvement of those techniques, they are insufficient to ensure high levels of reliability in the burst pressure assessment because the recognized semi-empirical nature of conventional procedures. This work studies the applicability of a stress based criterion based upon plastic instability to predict the burst pressure of pipelines with axial corrosion defects. Verification studies based on experimental burst tests of large diameter pipes made of API X65 and X100 steels with different defect length showed the effectiveness of the proposed criterion based on {sigma}{sup ref} ={eta}{sigma}{sub u} in failure predictions, even though the {eta} factor exhibits a potential strong dependence of the defect geometry and material properties. In general, the results presented here provide an effective support to the ability of the proposed stress based criterion in the integrity assessment of corroded pipelines. (author)

  20. Geospatial Analysis of Oil and Gas Wells in California

    Science.gov (United States)

    Riqueros, N. S.; Kang, M.; Jackson, R. B.

    2015-12-01

    California currently ranks third in oil production by U.S. state and more than 200,000 wells have been drilled in the state. Oil and gas wells provide a potential pathway for subsurface migration, leading to groundwater contamination and emissions of methane and other fluids to the atmosphere. Here we compile available public databases on oil and gas wells from the California Department of Conservation's Division of Oil, Gas, and Geothermal Resources, the U.S. Geological Survey, and other state and federal sources. We perform geospatial analysis at the county and field levels to characterize depths, producing formations, spud/completion/abandonment dates, land cover, population, and land ownership of active, idle, buried, abandoned, and plugged wells in California. The compiled database is designed to serve as a quantitative platform for developing field-based groundwater and air emission monitoring plans.

  1. PIXE analysis of exhaust gas from diesel engine

    International Nuclear Information System (INIS)

    Miyake, Hirosi; Michijima, Masami; Onishi, Masayuki; Fujitani, Tatsuya.

    1986-01-01

    The variation of elemental concentrations in exhaust gas of a Diesel engine with the outputs was studied. Particulates in high temperature gas were collected on silica fiber filters and analyzed by PIXE method. Concentrations of S and V were nearly proportional to particulate masses and fuel consumption rates per discharging rates of exhaust gas respectively. While, concentrations of Fe and Mn were markedly increased together with engine outputs, and Mn/Fe ratios were nearly equal to those of the material of piston rings and the cylinder liner. Concentrations of the elements contained in lubricant, such as Ca and Mo, were also conspicuously increased with the outputs. It was shown that PIXE analysis is a useful tool for engine diagonostics owing to its high sensitive multi-elemental availability without chemical treatments. (author)

  2. Exergy analysis of gas turbine with air bottoming cycle

    International Nuclear Information System (INIS)

    Ghazikhani, M.; Khazaee, I.; Abdekhodaie, E.

    2014-01-01

    In this paper, the exergy analysis of a conventional gas turbine and a gas turbine with air bottoming cycle (ABC) is presented in order to study the important parameters involved in improving the performance characteristics of the ABC based on the Second Law of thermodynamics. In this study, work output, specific fuel consumption (SFC) and the exergy destruction of the components are investigated using a computer model. The variations of the ABC cycle exergy parameters are comprehensively discussed and compared with those of the simple gas turbine. The results indicate that the amount of the exhaust exergy recovery in different operating conditions varies between 8.6 and 14.1% of the fuel exergy, while the exergy destruction due to the extra components in the ABC makes up only 4.7–7.4% of the fuel exergy. This is the reason why the SFC of the ABC is averagely 13.3% less and the specific work 15.4% more than those of the simple gas turbine. The results also reveal that in the ABC cycle, at a small value of pressure ratio, a higher specific work with lower SFC can be achieved in comparison with those of the simple gas turbine. - Highlights: • Exhaust exergy recovery in ABC gas turbine varies with 8.6–14.1% of the fuel exergy. • Irreversibility of the extra devices in ABC makes up 4.7–7.4% of the fuel exergy. • SFC in ABC is poor due to exergy recovery more than extra devices irreversibility. • At the same TIT and R c , specific work in the ABC is more than simple gas turbine. • The recuperator has the largest contribution in the irreversibility of the ABC

  3. Screening of antibiotics and chemical analysis of penicillin residue in fresh milk and traditional dairy products in Oyo state, Nigeria

    Directory of Open Access Journals (Sweden)

    Isaac Olufemi Olatoye

    2016-09-01

    Full Text Available Background and Aim: There are global public health and economic concerns on chemical residues in food of animal origin. The use of antibiotics in dairy cattle for the treatment of diseases such as mastitis has contributed to the presence of residues in dairy products. Penicillin residues as low as 1 ppb can lead to allergic reactions and shift of resistance patterns in microbial population as well as interfere with the processing of several dairy products. Antibiotic monitoring is an essential quality control measure in safe milk production. This study was aimed at determining antibiotic residue contamination and the level of penicillin in dairy products from Fulani cattle herds in Oyo State. Materials and Methods: The presence of antibiotic residues in 328 samples of fresh milk, 180 local cheese (wara, and 90 fermented milk (nono from Southwest, Nigeria were determined using Premi® test kit (R-Biopharm AG, Germany followed by high-performance liquid chromatography analysis of penicillin-G residue. Results: Antibiotic residues were obtained in 40.8%, 24.4% and 62.3% fresh milk, wara and nono, respectively. Penicillin-G residue was also detected in 41.1% fresh milk, 40.2% nono and 24.4% wara at mean concentrations of 15.22±0.61, 8.24±0.50 and 7.6±0.60 μg/L with 39.3%, 36.7% and 21.1%, respectively, containing penicillin residue above recommended Codex maximum residue limit (MRL of 5 μg/L in dairy. There was no significant difference between the mean penicillin residues in all the dairy products in this study. Conclusion: The results are of food safety concern since the bulk of the samples and substantial quantities of dairy products in Oyo state contained violative levels of antibiotic residues including penicillin residues in concentrations above the MRL. This could be due to indiscriminate and unregulated administration of antibiotics to dairy cattle. Regulatory control of antibiotic use, rapid screening of milk and dairy farmers

  4. System analysis and planning of a gas distribution network

    Energy Technology Data Exchange (ETDEWEB)

    Salas, Edwin F.M.; Farias, Helio Monteiro [AUTOMIND, Rio de Janeiro, RJ (Brazil); Costa, Carla V.R. [Universidade Salvador (UNIFACS), BA (Brazil)

    2009-07-01

    The increase in demand by gas consumers require that projects or improvements in gas distribution networks be made carefully and safely to ensure a continuous, efficient and economical supply. Gas distribution companies must ensure that the networks and equipment involved are defined and designed at the appropriate time to attend to the demands of the market. To do that a gas distribution network analysis and planning tool should use distribution networks and transmission models for the current situation and the future changes to be implemented. These models are used to evaluate project options and help in making appropriate decisions in order to minimize the capital investment in new components or simple changes in operational procedures. Gas demands are increasing and it is important that gas distribute design new distribution systems to ensure this growth, considering financial constraints of the company, as well as local legislation and regulation. In this study some steps of developing a flexible system that attends to those needs will be described. The analysis of distribution requires geographically referenced data for the models as well as an accurate connectivity and the attributes of the equipment. GIS systems are often used as a deposit center that holds the majority of this information. GIS systems are constantly updated as distribution network equipment is modified. The distribution network modeling gathered from this system ensures that the model represents the current network condition. The benefits of this architecture drastically reduce the creation and maintenance cost of the network models, because network components data are conveniently made available to populate the distribution network. This architecture ensures that the models are continually reflecting the reality of the distribution network. (author)

  5. Economic Impacts Analysis of Shale Gas Investment in China

    Science.gov (United States)

    Han, Shangfeng; Zhang, Baosheng; Wang, Xuecheng

    2018-01-01

    Chinese government has announced an ambitious shale gas extraction plan, which requires significant investment. This has the potential to draw investment from other areas and may affect the whole China’s economy. There is few study to date has quantified these shale gas investment’s effects on Chinese economy. The aim of this paper is to quantify the economic effect and figures out whether shale gas investment in China is a good choice or not. Input-output analysis has been utilized in this study to estimate the economic impacts in four different Chinese regions. Our findings show that shale gas investment will result in approximately 868, 427, 115 and 42 Billion RMB economic impacts in Sichuan, Chongqing, Inner Mongolia and Guizhou, respectively. The total economic impact is only around 1453 Billion RMB, which is not significant compared to the economic impact of coalbed methane investment. Considering the potential risks of environmental issues, we suggest that it may be a better strategy for the government, at least in the current situation, to slow down shale gas development investment.

  6. Impact-disrupted gunshot residue: A sub-micron analysis using a novel collection protocol

    Directory of Open Access Journals (Sweden)

    V. Spathis

    2017-06-01

    Full Text Available The analysis of gunshot residue (GSR has played an integral role within the legal system in relation to shooting cases. With a characteristic elemental composition of lead, antimony, barium, and a typically discriminative spheroidal morphology, the presence and distribution of GSR can aid in firearm investigations. In this experiment, three shots of low velocity rim-fire ammunition were fired over polished silicon collection substrates placed at six intervals over a 100 cm range. The samples were analysed using a Field Emission Gun Scanning Electron Microscope (FEG-SEM in conjunction with an X-flash Energy Dispersive X-ray (EDX detector, allowing for GSR particle analyses of composition and structure at the sub-micron level. The results of this experiment indicate that although classic spheroidal particles are present consistently throughout the entire range of samples their sizes vary significantly, and at certain distances from the firearm particles with an irregular morphology were discerned, forming “impact-disrupted” GSR particles, henceforth colloquially referred to as “splats”. Upon further analysis, trends with regards to the formation of these splat particles were distinguished. An increase in splat frequency was observed starting at 10 cm from the firearm, with 147 mm−2 splat density, reaching a maximal flux at 40 cm (451 mm−2, followed by a gradual decrease to the maximum range sampled. Moreover, the structural morphology of the splats changes throughout the sampling range. At the distances closest to the firearm, molten-looking particles were formed, demonstrating the metallic residues were in a liquid state when their flight path was disrupted. However, at increased distances-primarily where the discharge plume was at maximum dispersion and moving away from the firearm, the residues have had time to cool in-fight resulting in semi-congealed and solid particles that subsequently disrupted upon impact, forming more

  7. Analysis of the Residual Stresses in Helical Cylindrical Springs at High Temperature

    Directory of Open Access Journals (Sweden)

    H. Sun

    2015-01-01

    Full Text Available Creep is one of the basic properties of materials, its speed significantly depends on the temperature. Helical cylindrical springs are widely used in the elements of heating systems. This results in necessity of taking into account the effect of temperature on the stress-strain state of the spring. The object of research is a helical cylindrical spring used at high temperatures. Under this condition the spring state stability should be ensured.The paper studies relaxation of stress state and generation of residual stresses. Calculations are carried out in ABAQUS environment. The purpose of this work is to discuss the law of relaxation and residual stress in the spring.This paper describes the basic creep theories of helical cylindrical spring material. The calculation formulas of shear stress relaxation for a fixed compression ratio are obtained. Distribution and character of stress contour lines in the cross section of spring are presented. The stress relaxation – time relationships are discussed. The approximate formula for calculating relaxation shear stresses in the cross section of helical springs is obtained.The paper investigates creep ratio and law of residual stress variation in the cross-section of spring at 650℃. Computer simulation in ABAQUS environment was used. Research presents a finite element model of the spring creep in the cross-section.The paper conducts analysis of the stress changes for the creep under constant load. Under constant load stresses are quickly decreased in the around area of cross-section and are increased in the centre, i.e. the maximum and minimum stresses come close with time. Research work shows the possibility for using the approximate formula to calculate the relaxation shear stress in the cross section of spring and can provide a theoretical basis for predicting the service life of spring at high temperatures.In research relaxation processes of stress state are studied. Finite element model is cre

  8. Pesticide residues in canned foods, fruits, and vegetables: the application of Supercritical Fluid Extraction and chromatographic techniques in the analysis.

    Science.gov (United States)

    El-Saeid, Mohamed H

    2003-12-11

    Multiple pesticide residues have been observed in some samples of canned foods, frozen vegetables, and fruit jam, which put the health of the consumers at risk of adverse effects. It is quite apparent that such a state of affairs calls for the need of more accurate, cost-effective, and rapid analytical techniques capable of detecting the minimum concentrations of the multiple pesticide residues. The aims of this paper were first, to determine the effectiveness of the use of Supercritical Fluid Extraction (SFE) and Supercritical Fluid Chromatography (SFC) techniques in the analysis of the levels of pesticide residues in canned foods, vegetables, and fruits; and second, to contribute to the promotion of consumer safety by excluding pesticide residue contamination from markets. Fifteen different types of imported canned and frozen fruits and vegetables samples obtained from the Houston local food markets were investigated. The major types of pesticides tested were pyrethroids, herbicides, fungicides, and carbamates. By using these techniques, the overall data showed 60.82% of the food samples had no detection of any pesticide residues under this investigation. On the other hand, 39.15% different food samples were contaminated by four different pyrethroid residues +/- RSD% ranging from 0.03 +/- 0.005 to 0.05 +/- 0.03 ppm, of which most of the pyrethroid residues were detected in frozen vegetables and strawberry jam. Herbicide residues in test samples ranged from 0.03 +/- 0.005 to 0.8 +/- 0.01 ppm. Five different fungicides, ranging from 0.05 +/- 0.02 to 0.8 +/- 0.1 ppm, were found in five different frozen vegetable samples. Carbamate residues were not detected in 60% of investigated food samples. It was concluded that SFE and SFC techniques were accurate, reliable, less time consuming, and cost effective in the analysis of imported canned foods, fruits, and vegetables and are recommended for the monitoring of pesticide contaminations.

  9. Pesticide Residues in Canned Foods, Fruits, and Vegetables: The Application of Supercritical Fluid Extraction and Chromatographic Techniques in the Analysis

    Directory of Open Access Journals (Sweden)

    Mohamed H. EL-Saeid

    2003-01-01

    Full Text Available Multiple pesticide residues have been observed in some samples of canned foods, frozen vegetables, and fruit jam, which put the health of the consumers at risk of adverse effects. It is quite apparent that such a state of affairs calls for the need of more accurate, cost-effective, and rapid analytical techniques capable of detecting the minimum concentrations of the multiple pesticide residues. The aims of this paper were first, to determine the effectiveness of the use of Supercritical Fluid Extraction (SFE and Supercritical Fluid Chromatography (SFC techniques in the analysis of the levels of pesticide residues in canned foods, vegetables, and fruits; and second, to contribute to the promotion of consumer safety by excluding pesticide residue contamination from markets. Fifteen different types of imported canned and frozen fruits and vegetables samples obtained from the Houston local food markets were investigated. The major types of pesticides tested were pyrethroids, herbicides, fungicides, and carbamates.By using these techniques, the overall data showed 60.82% of the food samples had no detection of any pesticide residues under this investigation. On the other hand, 39.15% different food samples were contaminated by four different pyrethroid residues ± RSD% ranging from 0.03 ± 0.005 to 0.05 ± 0.03 ppm, of which most of the pyrethroid residues were detected in frozen vegetables and strawberry jam. Herbicide residues in test samples ranged from 0.03 ± 0.005 to 0.8 ± 0.01 ppm. Five different fungicides, ranging from 0.05 ± 0.02 to 0.8 ±0.1 ppm, were found in five different frozen vegetable samples. Carbamate residues were not detected in 60% of investigated food samples. It was concluded that SFE and SFC techniques were accurate, reliable, less time consuming, and cost effective in the analysis of imported canned foods, fruits, and vegetables and are recommended for the monitoring of pesticide contaminations.

  10. Logistics cost analysis of rice residues for second generation bioenergy production in Ghana.

    Science.gov (United States)

    Vijay Ramamurthi, Pooja; Cristina Fernandes, Maria; Sieverts Nielsen, Per; Pedro Nunes, Clemente

    2014-12-01

    This study explores the techno-economic potential of rice residues as a bioenergy resource to meet Ghana's energy demands. Major rice growing regions of Ghana have 70-90% of residues available for bioenergy production. To ensure cost-effective biomass logistics, a thorough cost analysis was made for two bioenergy routes. Logistics costs for a 5 MWe straw combustion plant were 39.01, 47.52 and 47.89 USD/t for Northern, Ashanti and Volta regions respectively. Logistics cost for a 0.25 MWe husk gasification plant (with roundtrip distance 10 km) was 2.64 USD/t in all regions. Capital cost (66-72%) contributes significantly to total logistics costs of straw, however for husk logistics, staff (40%) and operation and maintenance costs (46%) dominate. Baling is the major processing logistic cost for straw, contributing to 46-48% of total costs. Scale of straw unit does not have a large impact on logistic costs. Transport distance of husks has considerable impact on logistic costs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Logistics cost analysis of rice residues for second generation bioenergy production in Ghana

    DEFF Research Database (Denmark)

    Vijay Ramamurthi, Pooja; Cristina Fernandes, Maria; Nielsen, Per Sieverts

    2014-01-01

    This study explores the techno-economic potential of rice residues as a bioenergy resource to meet Ghana’s energy demands. Major rice growing regions of Ghana have 70–90% of residues available for bioenergy production. To ensure cost-effective biomass logistics, a thorough cost analysis was made...... for two bioenergy routes. Logistics costs for a 5MWe straw combustion plant were 39.01, 47.52 and 47.89USD/t for Northern, Ashanti and Volta regions respectively. Logistics cost for a 0.25MWe husk gasification plant (with roundtrip distance 10km) was 2.64USD/t in all regions. Capital cost (66......–72%) contributes significantly to total logistics costs of straw, however for husk logistics, staff (40%) and operation and maintenance costs (46%) dominate. Baling is the major processing logistic cost for straw, contributing to 46–48% of total costs. Scale of straw unit does not have a large impact on logistic...

  12. Analysis of glyphosate residues in cereals using liquid chromatography-mass spectrometry (LC-MS/MS)

    DEFF Research Database (Denmark)

    Granby, Kit; Johannesen, S.; Gabrielsen, Martin Vahl

    2003-01-01

    A fast and specific method for the determination of glyphosate in cereals is described. The method is based on extraction with water by ultrasonication. The samples are cleaned up and separated by high-performance liquid chromatography on a polystyrene-based reverse-phase column (clean-up) in ser......A fast and specific method for the determination of glyphosate in cereals is described. The method is based on extraction with water by ultrasonication. The samples are cleaned up and separated by high-performance liquid chromatography on a polystyrene-based reverse-phase column (clean...... monitored m/z 168--> 150 (glyphosate) and 170-->152 (internal standard 2- 13 (CN)-N-15-glyphosate) for quantification. The mean recovery was 85% ( n =32) at spiking levels from 0.03 to 0.33 mg kg(-1) . From 1998 to 2001, from the analysis of about 50 samples per annum, a reduction in the glyphosate residues...... was observed owing to a Danish trade decision not to use grain with glyphosate residues for milling or bread production....

  13. Multiclass analysis of antibiotic residues in honey by ultraperformance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Vidal, Jose Luis Martínez; Aguilera-Luiz, María Del Mar; Romero-González, Roberto; Frenich, Antonia Garrido

    2009-03-11

    A method has been developed and validated for the simultaneous analysis of different veterinary drug residues (macrolides, tetracyclines, quinolones, and sulfonamides) in honey. Honey samples were dissolved with Na(2)EDTA, and veterinary residues were extracted from the supernatant by solid-phase extraction (SPE), using OASIS HLB cartridges. The separation and determination was carried out by ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS), using an electrospay ionization source (ESI) in positive mode. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring (MRM) of two ion transitions per compound to provide a high degree of sensitivity and specificity. The method was validated, and mean recoveries were evaluated at three concentration levels (10, 50, and 100 microg/kg), ranging from 70 to 120% except for doxycycline, erythromycin, and tylmicosin with recovery higher than 50% at the three levels assayed. Relative standard deviations (RSDs) of the recoveries were less than 20% within the intraday precision and less than 25% within the interday precision. The limits of quantification (LOQs) were always lower than 4 microg/kg. The developed procedure was applied to 16 honey samples, and erythromycin, sarafloxacin, and tylosin were found in a few samples.

  14. Joining U.S. NRC international round robin for weld residual stress analysis. Stress analysis and validation in PWSCC mitigation program

    International Nuclear Information System (INIS)

    Maekawa, Akira; Serizawa, Hisashi; Murakawa, Hidekazu

    2012-01-01

    It is necessary to establish properly reliable weld residual stress analysis methods for accurate crack initiation and growth assessment of primary water stress corrosion cracking (PWSCC), which may occur in nickel-based dissimilar metal welds in pressurized water reactors. The U.S. Nuclear Regulatory Commission conducted an international round robin for weld residual stress analysis to improve stress analysis methods and to examine the uncertainties involved in the calculated stress values. In this paper, the results from the authors' participation in the round robin were reported. In the round robin, the weld residual stress in a nickel-based dissimilar metal weld of a pressurizer surge nozzle mock-up was computed under various analysis conditions. Based on these residual stress analysis results, a welding simulation code currently being developed that uses the iterative substructure method was validated and affecting factors on the analysis results were identified. (author)

  15. Possibilities of gas-phase radio-chromatography application to permanent-gas analysis

    International Nuclear Information System (INIS)

    Dupuis, M.C.; Charrier, G.; Alba, C.; Massimino, D.

    1970-01-01

    The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H 2 , O 2 , N 2 , A, Kr, Xe, CO, CH 4 ) labelled with radioactive indicators ( 3 H, 37 A, 85 Kr, 133 Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm 3 . The minimum detectable activity is of the order of 10 -4 μC for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [fr

  16. Residue Geometry Networks: A Rigidity-Based Approach to the Amino Acid Network and Evolutionary Rate Analysis

    Science.gov (United States)

    Fokas, Alexander S.; Cole, Daniel J.; Ahnert, Sebastian E.; Chin, Alex W.

    2016-01-01

    Amino acid networks (AANs) abstract the protein structure by recording the amino acid contacts and can provide insight into protein function. Herein, we describe a novel AAN construction technique that employs the rigidity analysis tool, FIRST, to build the AAN, which we refer to as the residue geometry network (RGN). We show that this new construction can be combined with network theory methods to include the effects of allowed conformal motions and local chemical environments. Importantly, this is done without costly molecular dynamics simulations required by other AAN-related methods, which allows us to analyse large proteins and/or data sets. We have calculated the centrality of the residues belonging to 795 proteins. The results display a strong, negative correlation between residue centrality and the evolutionary rate. Furthermore, among residues with high closeness, those with low degree were particularly strongly conserved. Random walk simulations using the RGN were also successful in identifying allosteric residues in proteins involved in GPCR signalling. The dynamic function of these residues largely remain hidden in the traditional distance-cutoff construction technique. Despite being constructed from only the crystal structure, the results in this paper suggests that the RGN can identify residues that fulfil a dynamical function. PMID:27623708

  17. Impacts of soil incorporation of pre-incubated silica-rich rice residue on soil biogeochemistry and greenhouse gas fluxes under flooding and drying.

    Science.gov (United States)

    Gutekunst, Madison Y; Vargas, Rodrigo; Seyfferth, Angelia L

    2017-09-01

    Incorporation of silica-rich rice husk residue into flooded paddy soil decreases arsenic uptake by rice. However, the impact of this practice on soil greenhouse gas (GHG) emissions and elemental cycling is unresolved particularly as amended soils experience recurrent flooding and drying cycles. We evaluated the impact of pre-incubated silica-rich rice residue incorporation to soils on pore water chemistry and soil GHG fluxes (i.e., CO 2 , CH 4 , N 2 O) over a flooding and drying cycle typical of flooded rice cultivation. Soils pre-incubated with rice husk had 4-fold higher pore water Si than control and 2-fold higher than soils pre-incubated with rice straw, whereas the pore water As and Fe concentrations in soils amended with pre-incubated straw and husk were unexpectedly similar (maximum ~0.85μM and ~450μM levels, respectively). Pre-incubation of residues did not affect Si but did affect the pore water levels of As and Fe compared to previous studies using fresh residues where straw amended soils had higher As and Fe in pore water. The global warming potential (GWP) of soil GHG emissions decreased in the order straw (612±76g CO 2 -eqm -2 )>husk (367±42gCO 2 -eqm -2 )>ashed husk=ashed straw (251±26 and 278±28gCO 2 -eqm -2 )>control (186±23gCO 2 -eqm -2 ). The GWP increase due to pre-incubated straw amendment was due to: a) larger N 2 O fluxes during re-flooding; b) smaller contributions from larger CH 4 fluxes during flooded periods; and c) higher CH 4 and CO 2 fluxes at the onset of drainage. In contrast, the GWP of the husk amendment was dominated by CO 2 and CH 4 emissions during flooded and drainage periods, while ashed amendments increased CO 2 emissions particularly during drainage. This experiment shows that ashed residues and husk addition minimizes GWP of flooded soils and enhances pore water Si compared to straw addition even after pre-incubation. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Bioaccumulation and distribution of organochlorine residues across ...

    African Journals Online (AJOL)

    Eighteen organochlorine pesticide (OCP) residues were measured in the water, sediment, plankton, benthic invertebrates and fish in various sections of the Lagos Lagoon in 2014 to investigate their bioaccumulation and distribution in the food web. The analysis was done using gas chromatography with an electron capture ...

  19. The application of probabilistic fracture analysis to residual life evaluation of embrittled reactor vessels

    International Nuclear Information System (INIS)

    Dickson, T.L.; Simonen, F.A.

    1992-01-01

    Probabilistic fracture mechanics analysis is a major element of the comprehensive probabilistic methodology on which current NRC regulatory requirements for pressurized water reactor vessel integrity evaluation are based. Computer codes such as OCA-P and VISA-11 perform probabilistic fracture analyses to estimate the increase in vessel failure probability that occurs as the vessel material accumulates radiation damage over the operating life of the vessel. The results of such analyses, when compared with limits of acceptable failure probabilities, provide an estimation of the residual life of a vessel. Such codes can be applied to evaluate the potential benefits of plant-specific mitigating actions designed to reduce the probability of failure of a reactor vessel

  20. The application of probabilistic fracture analysis to residual life evaluation of embrittled reactor vessels

    International Nuclear Information System (INIS)

    Dickson, T.L.; Simonen, F.A.

    1992-01-01

    Probabilistic fracture mechanics analysis is a major element of comprehensive probabilistic methodology on which current NRC regulatory requirements for pressurized water reactor vessel integrity evaluation are based. Computer codes such as OCA-P and VISA-II perform probabilistic fracture analyses to estimate the increase in vessel failure probability that occurs as the vessel material accumulates radiation damage over the operating life of the vessel. The results of such analyses, when compared with limits of acceptable failure probabilities, provide an estimation of the residual life of a vessel. Such codes can be applied to evaluate the potential benefits of plant-specific mitigating actions designed to reduce the probability of failure of a reactor vessel. 10 refs

  1. Multi-residue pesticide analysis (gas chromatography-tandem mass spectrometry detection)-Improvement of the quick, easy, cheap, effective, rugged, and safe method for dried fruits and fat-rich cereals-Benefit and limit of a standardized apple purée calibration (screening).

    Science.gov (United States)

    Rasche, Claudia; Fournes, Britta; Dirks, Uwe; Speer, Karl

    2015-07-17

    Some steps of the QuEChERS method for the analysis of pesticides with GC-MS/MS in cereals and dried fruits were improved or simplified. For the latter, a mixing vessel with stator-rotor-system proved to be advantageous. The extraction procedure of dried fruits is much easier and safer than the Ultra Turrax and results in excellent validation data at a concentration level of 0.01mg/kg (116 of 118 analytes with recoveries in the range of 70-120%, 117 of 118 analytes with RSD 7%), predominantly organochlorines showed recoveries of apple purée extract in combination with analyte protectants, allowed for a qualitative and quantitative analysis of 120 pesticides in different matrix extracts (tomato, red pepper, sour cherries, dried apples, black currant powder, raisins, wheat flour, rolled oats, wheat germ). The analyte protectants leveled the differences in the matrix-induced protection effect of the analyzed extracts over a wide range. The majority of the pesticides were analyzed with good analytical results (recoveries in the range of 70-120% and RSD <20%). Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Gas chromatographic isolation technique for compound-specific radiocarbon analysis

    International Nuclear Information System (INIS)

    Uchida, M.; Kumamoto, Y.; Shibata, Y.; Yoneda, M.; Morita, M.; Kawamura, K.

    2002-01-01

    Full text: We present here a gas chromatographic isolation technique for the compound-specific radiocarbon analysis of biomarkers from the marine sediments. The biomarkers of fatty acids, hydrocarbon and sterols were isolated with enough amount for radiocarbon analysis using a preparative capillary gas chromatograph (PCGC) system. The PCGC systems used here is composed of an HP 6890 GC with FID, a cooled injection system (CIS, Gerstel, Germany), a zero-dead-volume effluent splitter, and a cryogenic preparative collection device (PFC, Gerstel). For AMS analysis, we need to separate and recover sufficient quantity of target individual compounds (>50 μgC). Yields of target compounds from C 14 n-alkanes to C 40 to C 30 n-alkanes and approximately that of 80% for higher molecular weights compounds more than C 30 n-alkanes. Compound specific radiocarbon analysis of organic compounds, as well as compound-specific stable isotope analysis, provide valuable information on the origins and carbon cycling in marine system. Above PCGC conditions, we applied compound-specific radiocarbon analysis to the marine sediments from western north Pacific, which showed the possibility of a useful chronology tool for estimating the age of sediment using organic matter in paleoceanographic study, in the area where enough amounts of planktonic foraminifera for radiocarbon analysis by accelerator mass spectrometry (AMS) are difficult to obtain due to dissolution of calcium carbonate. (author)

  3. Identification of homemade inorganic explosives by ion chromatographic analysis of post-blast residues.

    Science.gov (United States)

    Johns, Cameron; Shellie, Robert A; Potter, Oscar G; O'Reilly, John W; Hutchinson, Joseph P; Guijt, Rosanne M; Breadmore, Michael C; Hilder, Emily F; Dicinoski, Greg W; Haddad, Paul R

    2008-02-29

    Anions and cations of interest for the post-blast identification of homemade inorganic explosives were separated and detected by ion chromatographic (IC) methods. The ionic analytes used for identification of explosives in this study comprised 18 anions (acetate, benzoate, bromate, carbonate, chlorate, chloride, chlorite, chromate, cyanate, fluoride, formate, nitrate, nitrite, perchlorate, phosphate, sulfate, thiocyanate and thiosulfate) and 12 cations (ammonium, barium(II), calcium(II), chromium(III), ethylammonium, magnesium(II), manganese(II), methylammonium, potassium(I), sodium(I), strontium(II), and zinc(II)). Two IC separations are presented, using suppressed IC on a Dionex AS20 column with potassium hydroxide as eluent for anions, and non-suppressed IC for cations using a Dionex SCS 1 column with oxalic acid/acetonitrile as eluent. Conductivity detection was used in both cases. Detection limits for anions were in the range 2-27.4ppb, and for cations were in the range 13-115ppb. These methods allowed the explosive residue ions to be identified and separated from background ions likely to be present in the environment. Linearity (over a calibration range of 0.05-50ppm) was evaluated for both methods, with r(2) values ranging from 0.9889 to 1.000. Reproducibility over 10 consecutive injections of a 5ppm standard ranged from 0.01 to 0.22% relative standard deviation (RSD) for retention time and 0.29 to 2.16%RSD for peak area. The anion and cation separations were performed simultaneously by using two Dionex ICS-2000 chromatographs served by a single autoinjector. The efficacy of the developed methods was demonstrated by analysis of residue samples taken from witness plates and soils collected following the controlled detonation of a series of different inorganic homemade explosives. The results obtained were also confirmed by parallel analysis of the same samples by capillary electrophoresis (CE) with excellent agreement being obtained.

  4. Attenuated total reflectance-FT-IR spectroscopy for gunshot residue analysis: potential for ammunition determination.

    Science.gov (United States)

    Bueno, Justin; Sikirzhytski, Vitali; Lednev, Igor K

    2013-08-06

    The ability to link a suspect to a particular shooting incident is a principal task for many forensic investigators. Here, we attempt to achieve this goal by analysis of gunshot residue (GSR) through the use of attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FT-IR) combined with statistical analysis. The firearm discharge process is analogous to a complex chemical process. Therefore, the products of this process (GSR) will vary based upon numerous factors, including the specific combination of the firearm and ammunition which was discharged. Differentiation of FT-IR data, collected from GSR particles originating from three different firearm-ammunition combinations (0.38 in., 0.40 in., and 9 mm calibers), was achieved using projection to latent structures discriminant analysis (PLS-DA). The technique was cross (leave-one-out), both internally and externally, validated. External validation was achieved via assignment (caliber identification) of unknown FT-IR spectra from unknown GSR particles. The results demonstrate great potential for ATR-FT-IR spectroscopic analysis of GSR for forensic purposes.

  5. Residual stress analysis in linear friction welded in-service Inconel 718 superalloy via neutron diffraction and contour method approaches

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M. [University of British Columbia – Okanagan, School of Engineering, 3333 University Way, Kelowna, Canada V1V 1V7 (Canada); Levesque, J.-B. [Institut de recherche d' Hydro-Québec (IREQ), 1800 Lionel-Boulet Blvd., Varennes, Canada J3X 1S1 (Canada); Bichler, L., E-mail: lukas.bichler@ubc.ca [University of British Columbia – Okanagan, School of Engineering, 3333 University Way, Kelowna, Canada V1V 1V7 (Canada); Sediako, D. [Canadian Nuclear Laboratories, Building 459, Station 18, Chalk River, Canada K0J 1J0 (Canada); Gholipour, J.; Wanjara, P. [National Research Council of Canada, Aerospace 5145 Decelles Ave., Montreal, Canada H3T 2B2 (Canada)

    2017-04-13

    In this study, an analysis of elastic residual stress in Inconel{sup ®} 718 (IN 718) linear friction welds (LFWs) was carried out. In particular, the suitability of LFW for manufacturing and repair of aero engine components was emulated by joining virgin and in-service (extracted from a turbine disk) materials. The evolution in the residual strains and stresses in the heat-affected zone (HAZ), thermomechanically affected zone (TMAZ) and dynamically recrystallized zone (DRX) of the weld was characterized using the neutron diffraction and contour methods. The results provided insight into diverse challenges in quantitative analysis of residual stresses in welded IN 718 using diffraction techniques. Specifically, judicious selection of the beam width, height and stress-free lattice spacing were seen to be crucial to minimize measurement error and increase accuracy. Further, the contour method – a destructive technique relying on capturing the stress relaxation after electrical discharge machining – was used to characterize the residual stress distribution on two-dimensional plane sections of the welds. Both techniques suggested an increasing magnitude of residual stress originating from the base metal that reached a peak at the weld interface. Both methods indicated that the peak magnitude of residual stresses were below the yield stress of IN 718.

  6. Determination of some selected pesticide residues in apple juice by solid-phase microextraction coupled to gas chromatography – mass spectrometry

    Directory of Open Access Journals (Sweden)

    Andrea Hercegová

    2011-01-01

    Full Text Available The performance of solid phase microextraction (SPME for enrichment of pesticides from apple juice was investigated. Samples were diluted with water, extracted by solid-phase microextraction and analysed by gas chromatography using mass-spectrometry detector (MSD in selected ion monitoring mode (SIM. The method was tested for the following pesticides used mostly in fruit culturing at Slovakia: tebuthylazine, fenitrothion, chlorpyrifos, myclobutanil, cyprodinil, phosalone, pyrimethanil, tebuconazole, kresoxim-methyl, methidathion, penconazole. All pesticides were extracted with polydimethylsiloxane fibre 100 μm thickness. The linear concentration range of application was 0.05 μg dm−3–10 μg dm−3. The method described provides detectabilities complying with the maximum residue levels (MRLs set by regulatory organizations for pesticides in apple juice matrices. The solvent – free SPME procedure was found to be quicker and more cost effective then the solvent extraction methods commonly used.

  7. Gas chromatography and isotope ratio mass spectrometry of Pinot Noir wine volatile compounds (δ13C) and solid residues (δ13C, δ15N) for the reassessment of vineyard water-status.

    Science.gov (United States)

    Spangenberg, Jorge E; Vogiatzaki, Maria; Zufferey, Vivian

    2017-09-29

    This paper describes a novel approach to reassess the water status in vineyards based on compound-specific isotope analysis (CSIA) of wine volatile organic compounds (δ 13 C VOC/VPDB ) and bulk carbon and nitrogen isotopes, and the C/N molar ratios of the wine solid residues (δ 13 C SR/VPDB , δ 15 N SR/Air-N2 ). These analyses link gas chromatography/combustion and elemental analysis to isotope ratio mass spectrometry (GC/C/IRMS, EA/IRMS). Field-grown cultivars of Pinot Noir grapevines were exposed during six growing seasons (2009-2014) to controlled soil water availability, while maintaining identical the other environmental variables and agricultural techniques. Wines were produced from the grapes by the same oenological protocol. This permitted for the assessment of the effects in the biochemistry of wines solely induced by the changes in the plant-soil water status. This mimicked the more recurrent and prolonged periods of soil water deficiency due to climate changes. Water stress in grapevine was assessed by the measurement of the predawn leaf water potential (Ψ pd ) and the stable carbon isotope composition of the berry sugars during harvest (must sugars). For quantitation purposes and the normalization of the measured stable carbon isotope ratios of the VOCs, the wine samples were spiked with three standard compounds with known concentration and δ 13 C VPDB values. VOCs were extracted by liquid-liquid extraction and analyzed by gas chromatography/flame ionization detection (GC/FID), gas chromatography/mass spectrometry (GC/MS), and GC/C/IRMS. δ 13 C values were obtained for eighteen VOCs. The solid residues were obtained by freeze-drying wine aliquots and were analyzed for their C and N content and isotope composition by EA/IRMS. All the isotopic ratios (δ 13 C SR , δ 15 N SR , δ 13 C VOC ) are highly correlated with the Ψ pd values, indicating that the proposed gas chromatography and isotope ratio mass spectrometry approach is a useful tool to

  8. Statistically generated weighted curve fit of residual functions for modal analysis of structures

    Science.gov (United States)

    Bookout, P. S.

    1995-01-01

    A statistically generated weighting function for a second-order polynomial curve fit of residual functions has been developed. The residual flexibility test method, from which a residual function is generated, is a procedure for modal testing large structures in an external constraint-free environment to measure the effects of higher order modes and interface stiffness. This test method is applicable to structures with distinct degree-of-freedom interfaces to other system components. A theoretical residual function in the displacement/force domain has the characteristics of a relatively flat line in the lower frequencies and a slight upward curvature in the higher frequency range. In the test residual function, the above-mentioned characteristics can be seen in the data, but due to the present limitations in the modal parameter evaluation (natural frequencies and mode shapes) of test data, the residual function has regions of ragged data. A second order polynomial curve fit is required to obtain the residual flexibility term. A weighting function of the data is generated by examining the variances between neighboring data points. From a weighted second-order polynomial curve fit, an accurate residual flexibility value can be obtained. The residual flexibility value and free-free modes from testing are used to improve a mathematical model of the structure. The residual flexibility modal test method is applied to a straight beam with a trunnion appendage and a space shuttle payload pallet simulator.

  9. Mutational analysis to identify the residues essential for the inhibition of N-acetyl glutamate kinase of Corynebacterium glutamicum.

    Science.gov (United States)

    Huang, Yuanyuan; Zhang, Hao; Tian, Hongming; Li, Cheng; Han, Shuangyan; Lin, Ying; Zheng, Suiping

    2015-09-01

    N-acetyl glutamate kinase (NAGK) is a key enzyme in the synthesis of L-arginine that is inhibited by its end product L-arginine in Corynebacterium glutamicum (C. glutamicum). In this study, the potential binding sites of arginine and the residues essential for its inhibition were identified by homology modeling, inhibitor docking, and site-directed mutagenesis. The allosteric inhibition of NAGK was successfully alleviated by a mutation, as determined through analysis of mutant enzymes, which were overexpressed in vivo in C. glutamicum ATCC14067. Analysis of the mutant enzymes and docking analysis demonstrated that residue W23 positions an arginine molecule, and the interaction between arginine and residues L282, L283, and T284 may play an important role in the remote inhibitory process. Based on the results of the docking analysis of the effective mutants, we propose a linkage mechanism for the remote allosteric regulation of NAGK activity, in which residue R209 may play an essential role. In this study, the structure of the arginine-binding site of C. glutamicum NAGK (CgNAGK) was successfully predicted and the roles of the relevant residues were identified, providing new insight into the allosteric regulation of CgNAGK activity and a solid platform for the future construction of an optimized L-arginine producing strain.

  10. Designing and analysis study of uranium enrichment with gas centrifuge

    International Nuclear Information System (INIS)

    Tsunetoshi Kai

    2006-01-01

    This note concerns a designing and analysis study of uranium enrichment with a gas centrifuge. At first, one dimensional model is presented and a conventional analytical method is applied to grasp the general idea of a centrifuge performance. Secondly, two-dimensional numerical method is adopted to describe the diffusion phenomena with assumption of simple flow patterns. Parametric surveys are made on the dimension of a centrifuge rotor, the gas feed, withdrawal and circulation system, and operation variables such as feed flow rate, cut and so on. Thirdly, full numerical solutions are obtained for the flow and diffusion equations in static state, using a modified version of the Newton method without neglect of any non-linear term. The numerical results are compared with the experimental data made by Beams et al. and Zippe, and found to be in good agreement. Further, the theoretical pressure and separative power are compared respectively with experimental ones on a comparatively recent centrifuge. The results reveal that the characteristics of separation performance of a centrifuge can be fully described by the present method. Some of inevitable problems are tackled regarding UF 6 gas isotope separation by centrifugation. To examine the influence of the extraneous light gas, the diffusion equations for ternary mixture are solved and also the flow field of binary mixture with large mass difference is obtained to simultaneously solve the Navier-Stokes equations and the diffusion equation.for binary case. Since the gas in the interior region of the rotor is so rarefied that the Navier-Stokes equations cease to be valid, the Burnett equations are solved.for gas flow in a rotating cylinder. Considering that the uranium recovered at a reprocessing plant includes 236 U besides 235 U and 238 U, the concentration distributions of the ternary gas isotopes are determined and a value function is defined for the evaluation of separative work for the multi-component mixture

  11. Determination of ethephon residues in water by gas chromatography with cubic mass spectrometry after ion-exchange purification and derivatisation with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide.

    Science.gov (United States)

    Royer, A; Laporte, F; Bouchonnet, S; Communal, P-Y

    2006-03-03

    An analytical method has been developed for the determination of residues of ethephon (2-chloroethyl phosphonic acid) in drinking and surface water. The procedure is based on de-ionisation with an anion/cation-exchange resin, solid phase extraction by means of anion-exchange polystyrene-divinylbenzene extraction disks, elution with a mixture of methanol and 10 M hydrochloric acid (98/2, v/v), redisolution into acetonitrile after evaporation and silylation with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA). Quantification is performed by gas chromatography with ion-trap cubic mass spectrometric detection in the electron impact mode (GC-EI-MS3). Method validation was conducted using samples of mineral, tap, and river water that were fortified with ethephon at concentration levels ranging from 0.1 to 1.0 microg/L. The mean recovery from all the fortified samples (n = 36) amounted to 88% with a relative standard deviation of 17%. The method, therefore, was shown to allow accurate determination of ethephon residues in drinking and surface water with a limit of quantification of 0.1 microg/L.

  12. Determination and maintenance of DE minimis risk for migration of residual tritium (3H) from the 1969 Project Rulison nuclear test to nearby hydraulically fractured natural gas wells.

    Science.gov (United States)

    Daniels, Jeffrey I; Chapman, Jenny B

    2013-05-01

    The Project Rulison underground nuclear test was a proof-of-concept experiment that was conducted under the Plowshare Program in 1969 in the Williams Fork Formation of the Piceance Basin in west-central Colorado. Today, commercial production of natural gas is possible from low permeability, natural gas bearing formations like that of the Williams Fork Formation using modern hydraulic fracturing techniques. With natural gas exploration and production active in the Project Rulison area, this human health risk assessment was performed in order to add a human health perspective for site stewardship. Tritium (H) is the radionuclide of concern with respect to potential induced migration from the test cavity leading to subsequent exposure during gas-flaring activities. This analysis assumes gas flaring would occur for up to 30 d and produce atmospheric H activity concentrations either as low as 2.2 × 10 Bq m (6 × 10 pCi m) from the minimum detectable activity concentration in produced water or as high as 20.7 Bq m (560 pCi m), which equals the highest atmospheric measurement reported during gas-flaring operations conducted at the time of Project Rulison. The lifetime morbidity (fatal and nonfatal) cancer risks calculated for adults (residents and workers) and children (residents) from inhalation and dermal exposures to such activity concentrations are all below 1 × 10 and considered de minimis. The implications for monitoring production water for conforming health-protective, risk-based action levels also are examined.

  13. Performance analysis and optimization of power plants with gas turbines

    Science.gov (United States)

    Besharati-Givi, Maryam

    The gas turbine is one of the most important applications for power generation. The purpose of this research is performance analysis and optimization of power plants by using different design systems at different operation conditions. In this research, accurate efficiency calculation and finding optimum values of efficiency for design of chiller inlet cooling and blade cooled gas turbine are investigated. This research shows how it is possible to find the optimum design for different operation conditions, like ambient temperature, relative humidity, turbine inlet temperature, and compressor pressure ratio. The simulated designs include the chiller, with varied COP and fogging cooling for a compressor. In addition, the overall thermal efficiency is improved by adding some design systems like reheat and regenerative heating. The other goal of this research focuses on the blade-cooled gas turbine for higher turbine inlet temperature, and consequently, higher efficiency. New film cooling equations, along with changing film cooling effectiveness for optimum cooling air requirement at the first-stage blades, and an internal and trailing edge cooling for the second stage, are innovated for optimal efficiency calculation. This research sets the groundwork for using the optimum value of efficiency calculation, while using inlet cooling and blade cooling designs. In the final step, the designed systems in the gas cycles are combined with a steam cycle for performance improvement.

  14. Review of sample preparation techniques for the analysis of pesticide residues in soil.

    Science.gov (United States)

    Tadeo, José L; Pérez, Rosa Ana; Albero, Beatriz; García-Valcárcel, Ana I; Sánchez-Brunete, Consuelo

    2012-01-01

    This paper reviews the sample preparation techniques used for the analysis of pesticides in soil. The present status and recent advances made during the last 5 years in these methods are discussed. The analysis of pesticide residues in soil requires the extraction of analytes from this matrix, followed by a cleanup procedure, when necessary, prior to their instrumental determination. The optimization of sample preparation is a very important part of the method development that can reduce the analysis time, the amount of solvent, and the size of samples. This review considers all aspects of sample preparation, including extraction and cleanup. Classical extraction techniques, such as shaking, Soxhlet, and ultrasonic-assisted extraction, and modern techniques like pressurized liquid extraction, microwave-assisted extraction, solid-phase microextraction and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) are reviewed. The different cleanup strategies applied for the purification of soil extracts are also discussed. In addition, the application of these techniques to environmental studies is considered.

  15. [Pollen analysis of the post-emergence residue of Centris tarsata Smith (Hymenoptera: Apidae, Centridini) nests].

    Science.gov (United States)

    Dórea, Marcos da C; Dos Santos, Francisco de A R; Lima, Luciene C de L E; Figueroa, Luís E R

    2009-01-01

    A new treatment protocol was developed to analyze pollen residues found in nests of Centris tarsata Smith harvested from nest-traps. The study area was located in the Canudos Biological Station in the municipality of Canudos (09 masculine56'34'S; 38 masculine59'17'W), in the northeastern micro-region of Bahia State, Brazil. The local vegetation is an open caatinga (deciduous dryland vegetation), the regional climate is semi-arid, the average annual temperature is 24.1 masculineC, and the annual regional rainfall rate is 454 mm. Ten nests of C. tarsata were collected in trap-nests during the first semester of 2004. Pollen analysis from the nests required the development of a new methodology that combined techniques of palynological sediment analysis with the more common pollinic analysis by acetolysis. Microscopic analyses employed optical microscopy techniques. The pollinic spectrum of the samples from C. tarsata indicated the presence of 17 pollen types from seven plant families, which were present in assemblage of five to eleven pollen types, pointed to the plants used by bees to feed on their offspring. The most represented plant families were Leguminosae (49.3%) and Solanaceae (43.2%). The most frequent pollen types in the samples were from Solanum paniculatum (43.8%) and Senna rizzini (32.1%). The protocol developed provides a new tool for diet assessment of Centris and other groups of solitary bees.

  16. Analysis of residual stress state in sheet metal parts processed by single point incremental forming

    Science.gov (United States)

    Maaß, F.; Gies, S.; Dobecki, M.; Brömmelhoff, K.; Tekkaya, A. E.; Reimers, W.

    2018-05-01

    The mechanical properties of formed metal components are highly affected by the prevailing residual stress state. A selective induction of residual compressive stresses in the component, can improve the product properties such as the fatigue strength. By means of single point incremental forming (SPIF), the residual stress state can be influenced by adjusting the process parameters during the manufacturing process. To achieve a fundamental understanding of the residual stress formation caused by the SPIF process, a valid numerical process model is essential. Within the scope of this paper the significance of kinematic hardening effects on the determined residual stress state is presented based on numerical simulations. The effect of the unclamping step after the manufacturing process is also analyzed. An average deviation of the residual stress amplitudes in the clamped and unclamped condition of 18 % reveals, that the unclamping step needs to be considered to reach a high numerical prediction quality.

  17. Comparative Analysis of Processes for Recovery of Rare Earths from Bauxite Residue

    Science.gov (United States)

    Borra, Chenna Rao; Blanpain, Bart; Pontikes, Yiannis; Binnemans, Koen; Van Gerven, Tom

    2016-11-01

    Environmental concerns and lack of space suggest that the management of bauxite residue needs to be re-adressed. The utilization of the residue has thus become a topic high on the agenda for both academia and industry, yet, up to date, it is only rarely used. Nonetheless, recovery of rare earth elements (REEs) with or without other metals from bauxite residue, and utilization of the left-over residue in other applications like building materials may be a viable alternative to storage. Hence, different processes developed by the authors for recovery of REEs and other metals from bauxite residue were compared. In this study, preliminary energy and cost analyses were carried out to assess the feasibility of the processes. These analyses show that the combination of alkali roasting-smelting-quenching-leaching is a promising process for the treatment of bauxite residue and that it is justified to study this process at a pilot scale.

  18. Novel method for the rapid and specific extraction of multiple β2 -agonist residues in food by tailor-made Monolith-MIPs extraction disks and detection by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Liu, Haibo; Gan, Ning; Chen, Yinji; Ding, Qingqing; Huang, Jie; Lin, Saichai; Cao, Yuting; Li, Tianhua

    2016-09-01

    A quick and specific pretreatment method based on a series of extraction clean-up disks, consisting of molecularly imprinted polymer monoliths and C18 adsorbent, was developed for the specific enrichment of salbutamol and clenbuterol residues in food. The molecularly imprinted monolithic polymer disk was synthesized using salbutamol as a template through a one-step synthesis process. It can simultaneously and specifically recognize salbutamol and clenbuterol. The monolithic polymer disk and series of C18 disks were assembled with a syringe to form a set of tailor-made devices for the extraction of target molecules. In a single run, salbutamol and clenbuterol can be specifically extracted, cleaned, and eluted by methanol/acetic acid/H2 O. The target molecules, after a silylation derivatization reaction were detected by gas chromatography-mass spectrometry. The parameters including solvent desorption, sample pH, and the cycles of reloading were investigated and discussed. Under the optimized extraction and clean-up conditions, the limits of detection and quantitation were determined as 0.018-0.022 and 0.042-0.049 ng/g for salbutamol and clenbuterol, respectively. The assay described was convenient, rapid, and specific; thereby potentially efficient in the high-throughput analysis of β2 -agonists residues in real food samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Regional versus detailed velocity analysis to quantify hydrate and free gas in marine sediments : the south Shetland margin case study

    Energy Technology Data Exchange (ETDEWEB)

    Tinivella, U.; Loreto, M.F.; Accaino, F. [Inst. Nazionale di Oceanografia di Geofisica Sperimentale, Trieste (Italy)

    2008-07-01

    The presence of gas hydrate and free gas within marine sediments, deposited along the South Shetland margin, offshore the Antarctic Peninsula, was confirmed by low and high resolution geophysical data, acquired during three research cruises in 1989-1990. Seismic data analysis has demonstrated the presence of a bottom simulating reflector that is very strong and continuous in the eastern part of the margin. This seismic dataset was used in the past to extract detailed velocity information of the shallow structures by using traditional tomographic inversion and jointly tomographic inversion and pre-stack depth migration tool. This paper presented a method to obtain a regional seismic velocity field and information about hydrate and free gas presence in the marine sediments, by using an improved method of the standard analysis of the pre-stack depth migration output. The velocity field was obtained with a layer stripping approach and tomographic inversion of the reflections observed in common image gathering. The paper presented the seismic data and regional and detailed velocity analysis. The results of residual semblance analyses were also presented. Gas phase concentrations were then discussed. The velocity analysis revealed the presence of three main layers characterizing the first kilometer of sediments below the sea floor. In addition, velocity models and related gas-phase sections showed that gas was concentrated in different parts of the profile than where the hydrate was concentrated. This observation confirmed that geological structures and sedimentary processes controlled the gas and hydrate distribution, as observed along other margins. 7 refs., 5 figs.

  20. X-ray residual stress analysis on machined and tempered HPSN-ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Immelmann, S.; Welle, E.; Reimers, W. [Hahn-Meitner-Institut Berlin GmbH (Germany)

    1997-11-15

    The residual stress state induced by grinding and tempering of hot pressed silicon nitride (HPSN) samples is studied by X-ray diffraction. The results reveal that the residual stress values at the surface of the samples as well as their gradient within the penetration depth of the X-rays depend on the sintering aid and thus, on the glassy phase content of the HPSN. Tempering of the ground HPSN reduces the residual stress values due to microplastic deformation, whereas an oxidation of the glassy phase leads to the formation of compressive residual stresses. (orig.) 35 refs.

  1. Gas Hydrate Investigations Using Pressure Core Analysis: Current Practice

    Science.gov (United States)

    Schultheiss, P.; Holland, M.; Roberts, J.; Druce, M.

    2006-12-01

    Recently there have been a number of major gas hydrate expeditions, both academic and commercially oriented, that have benefited from advances in the practice of pressure coring and pressure core analysis, especially using the HYACINTH pressure coring systems. We report on the now mature process of pressure core acquisition, pressure core handling and pressure core analysis and the results from the analysis of pressure cores, which have revealed important in situ properties along with some remarkable views of gas hydrate morphologies. Pressure coring success rates have improved as the tools have been modified and adapted for use on different drilling platforms. To ensure that pressure cores remain within the hydrate stability zone, tool deployment, recovery and on-deck handling procedures now mitigate against unwanted temperature rises. Core analysis has been integrated into the core transfer protocol and automated nondestructive measurements, including P-wave velocity, gamma density, and X-ray imaging, are routinely made on cores. Pressure cores can be subjected to controlled depressurization experiments while nondestructive measurements are being made, or cores can be stored at in situ conditions for further analysis and subsampling.

  2. Multiresidue Analysis of 86 Pesticides Using Gas Chromatography Mass Spectrometry: II-Nonleafy Vegetables

    Directory of Open Access Journals (Sweden)

    M. H. EL-Saeid

    2013-01-01

    Full Text Available A total of 1057 samples of fresh vegetables from import and domestic production were analyzed (cold pepper, egg plant, carrot, cucumber, potato, hot pepper, cultivation tomato, squash, beans, okra, onions, cauliflower, and green house tomato. The aim of this study was to investigate pesticide residues in market foods in Riyadh, which have been collected from Riyadh Development Company (Al-Tamer Vegetables Market. Pesticide residues were determined by gas chromatography with mass selective detector (GC-MSD. A multiresidue method was developed and described for simultaneous determination of 86 pesticides commonly used in crop protection. This method used to determine 86 pesticide residues with a broad range of physicochemical properties in fresh vegetables related to organophosphorus (OPP, organochlorines (OCP, pyrethroids, and carbamates mainly used in agriculture. Sample extract was cleaned up by using AOAC method. Pesticide residues above the maximum residue limits (MRL were detected in 15.89% of the total samples (168 from 1057 samples, but 83.90% of the total samples (887 from 1057 samples has no residues or contained pesticide residues at or below MRL. The detected and most frequently found pesticide residues were permethrin (45 times and endosulfan (34 times followed by deltamethrin (27 times. The findings of this study pointed to the following recommendations: the need for a monitoring program for pesticide residues in imported food crops.

  3. Spectroscopic analysis of femtosecond laser-induced gas breakdown

    International Nuclear Information System (INIS)

    Hermann, J.; Bruneau, S.; Sentis, M.

    2004-01-01

    The plasma generated by the interaction of a femtosecond laser pulse with gas has been analyzed using time- and space-resolved emission spectroscopy. The laser beam has been focused with a microscope objective into different gases (air, Ar, He) at pressures ranging from 10 2 to 10 5 Pa. From the analysis of spectral line emission from ions and neutral atoms, the plasma parameters and the plasma composition have been determined as a function of time and space. Furthermore, the generation of fast electrons and/or VUV radiation by the femtosecond laser interaction with the gas was brought to the fore. From the time- and space-evolution of the plasma parameters, a rough estimation of initial values of electron density and refraction index in the focal volume has been performed. These results are compared to analysis of the laser beam transmitted by the plasma. The latter show that only a small fraction of the laser energy is absorbed by the plasma while the spatial distribution of the transmitted laser beam is strongly perturbed by the plasma, which acts like a defocusing lens. However, in ambient helium, the plasma defocusing is weak due to the high ionization potential of helium. The understanding of femtosecond laser-induced gas breakdown is useful for process optimization in femtosecond laser applications like micromachining or surface microanalysis, etc

  4. Analysis of Maisotsenko open gas turbine bottoming cycle

    International Nuclear Information System (INIS)

    Saghafifar, Mohammad; Gadalla, Mohamed

    2015-01-01

    Maisotsenko gas turbine cycle (MGTC) is a recently proposed humid air turbine cycle. An air saturator is employed for air heating and humidification purposes in MGTC. In this paper, MGTC is integrated as the bottoming cycle to a topping simple gas turbine as Maisotsenko bottoming cycle (MBC). A thermodynamic optimization is performed to illustrate the advantages and disadvantages of MBC as compared with air bottoming cycle (ABC). Furthermore, detailed sensitivity analysis is reported to present the effect of different operating parameters on the proposed configurations' performance. Efficiency enhancement of 3.7% is reported which results in more than 2600 tonne of natural gas fuel savings per year. - Highlights: • Developed an accurate air saturator model. • Introduced Maisotsenko bottoming cycle (MBC) as a power generation cycle. • Performed Thermodynamic optimization for MBC and air bottoming cycle (ABC). • Performed detailed sensitivity analysis for MBC under different operating conditions. • MBC has higher efficiency and specific net work output as compared to ABC

  5. Commercial sector gas cooling technology frontier and market share analysis

    International Nuclear Information System (INIS)

    Pine, G.D.; Mac Donald, J.M.; McLain, H.A.

    1990-01-01

    This paper describes a method, developed for the Gas Research Institute of the United States, that can assist planning for commercial sector natural gas cooling systems R and D. These systems are higher in first cost than conventional electric chillers. Yet, engine-driven chiller designs exist which are currently competitive in U.S. markets typified by high electricity or demand charges. Section II describes a scenario analysis approach used to develop and test the method. Section III defines the technology frontier, a conceptual tool for identifying new designs with sales potential. Section IV describes a discrete choice method for predicting market shares of technologies with sales potential. Section V shows how the method predicts operating parameter, cost, and/or performance goals for technologies without current sales potential (or for enhancing a frontier technology's sales potential). Section VI concludes with an illustrative example for the Chicago office building retrofit market

  6. Startup analysis for a high temperature gas loaded heat pipe

    Science.gov (United States)

    Sockol, P. M.

    1973-01-01

    A model for the rapid startup of a high-temperature gas-loaded heat pipe is presented. A two-dimensional diffusion analysis is used to determine the rate of energy transport by the vapor between the hot and cold zones of the pipe. The vapor transport rate is then incorporated in a simple thermal model of the startup of a radiation-cooled heat pipe. Numerical results for an argon-lithium system show that radial diffusion to the cold wall can produce large vapor flow rates during a rapid startup. The results also show that startup is not initiated until the vapor pressure p sub v in the hot zone reaches a precise value proportional to the initial gas pressure p sub i. Through proper choice of p sub i, startup can be delayed until p sub v is large enough to support a heat-transfer rate sufficient to overcome a thermal load on the heat pipe.

  7. Multiplex gas chromatography: an alternative concept for gas chromatographic analysis of planetary atmospheres

    Science.gov (United States)

    Valentin, J. R.

    1989-01-01

    -Cassini entry probe, which is being jointly planned by NASA and the European Space Agency (ESA), might be launched as early as 1994. As in the Pioneer mission, limited time--perhaps only 3-4 h--will be available for the completion of all analyses while the probe descends through the atmosphere. A conventional GC or GC-MS system would be able to analyze no more than two aerosol and two gas samples during the probe's descent. Conventional GC also is limited by the sensitivity of the detector and by the sample volume. For the Titan mission, the sensitivity problems will be worse because the atmospheric pressure at the time of instrument deployment is expected to be of such limitations, alternative GC analysis techniques have been investigated for future NASA missions. Multiplex gas chromatography has been investigated as a possible candidate for chemical analysis within a spacecraft or other restricted environment, and chemical modulators have been developed and used when needed with this technique to reduce the size and weight of the instrumentation. Also, several new multiplex techniques have been developed for use in specific applications.

  8. Safety analysis of a high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Shimazu, Akira; Morimoto, Toshio

    1975-01-01

    In recent years, in order to satisfy the social requirements of environment and safety and also to cope with the current energy stringency, the installation of safe nuclear power plants is indispensable. Herein, safety analysis and evaluation to confirm quantitatively the safety design of a nuclear power plant become more and more important. The safety analysis and its methods for a high temperature gas-cooled reactor are described, with emphasis placed on the practices by Fuji Electric Manufacturing Co. Fundamental rule of securing plant safety ; safety analysis in normal operation regarding plant dynamic characteristics and radioactivity evaluation ; and safety analysis at the time of accidents regarding plant response to the accidents and radioactivity evaluation are explained. (Mori, K.)

  9. Pesticide residues in locally available cereals and vegetables

    International Nuclear Information System (INIS)

    Cunanan, S.A.; Santos, F.L.; Bonoan, L.S.

    1976-03-01

    Vegetable samples (pechay, cabbage, lettuce, green beans and tomatoes) bought from public markets in the Metro Manila area were analyzed for pesticide residues using gas chromatography. The samples analyzed in 1968-69 contained high levels of chlorinated pesticides such as DDT, Aldrin, Endrin, and Thiodan, while in the samples analyzed in January 1976, no chlorinated and organophosphate pesticides were detected. Cereal samples (rice, corn and sorghum) were obtained from the National Grains Authority and analyzed for pesticide residues and bromine residues. Total bromine residues was determined by neutron activation analysis. In most of the samples analyzed, the concentrations of pesticide residues were below the tolerance levels set by the FAO/WHO Committee on Pesticide Residues in Foods. An exception was one rice sample from Thailand, the bromine residue content (110ppm) of which exceeds the tolerance level of 50ppm

  10. A rapid, solid phase extraction (SPE technique for the extraction and gas chromatographic determination lindane pesticide residue in tissue and milk

    Directory of Open Access Journals (Sweden)

    Yuningsih

    2006-03-01

    Full Text Available Organochlorine pesticide contamination in feed can cause residue in animal product (tissue and milk, so its become a problem in food safety. Solid phase extraction (SPE has been carried out for determination organochlorine pesticide residues in food animal production. The technique was rapid, not costly and produce limited amount of hazardous-waste. Samples were homogenized with acetonitrile trough cartridge C18, eluted in fluorocyl column with 2% ether-petroleum or acetonitrile fortissue and milk samples respectively. The recoveries of tissue sample by addition lindane standard solution: 0.50 and 1.00 μg are 85.10 and 103.10% respectively, while that of milk with the addition of 0.50, 1.00 and 1.50 μg are 83.80, 88.69 and 91.24% respectively. Three replicates were carried out for every sample. According of validation criteria of FAO/IAEA the recovery for analysis of pesticide residues was 70-110%. Therefore, the method is applicable.

  11. The residuals analysis project: Evaluating disposal options for treated mixed low-level waste

    International Nuclear Information System (INIS)

    Waters, R.D.; Gruebel, M.M.; Case, J.T.; Letourneau, M.J.

    1997-01-01

    For almost four years, the U.S. Department of Energy (DOE) through its Federal Facility Compliance Act Disposal Workgroup has been working with state regulators and governors' offices to develop an acceptable configuration for disposal of its mixed low-level waste (MLLW). These interactions have resulted in screening the universe of potential disposal sites from 49 to 15 and conducting ''performance evaluations'' for those fifteen sites to estimate their technical capabilities for disposal of MLLW. In the residuals analysis project, we estimated the volume of DOE's MLLW that will require disposal after treatment and the concentrations of radionuclides in the treated waste. We then compared the radionuclide concentrations with the disposal limits determined in the performance evaluation project for each of the fifteen sites. The results are a scoping-level estimate of the required volumetric capacity for MLLW disposal and the identification of waste streams that may pose problems for disposal based on current treatment plans. The analysis provides technical information for continued discussions between the DOE and affected States about disposal of MLLW and systematic input to waste treatment developers on disposal issues

  12. An analysis of producing ethanol and electric power from woody residues and agricultural crops in East Texas

    Science.gov (United States)

    Ismayilova, Rubaba Mammad

    The increasing U.S. dependence on imported oil; the contribution of fossil fuels to the greenhouse gas emissions and the climate change issue; the current level of energy prices and other environmental concerns have increased world interest in renewable energy sources. Biomass is a large, diverse, readily exploitable resource. This dissertation examines the biomass potential in Eastern Texas by examining a 44 county region. This examination considers the potential establishment of a 100-megawatt (MW) power plant and a 20 million gallon per year (MMGY) ethanol plant using lignocellulosic biomass. The biomass sources considered are switchgrass, sugarcane bagasse, and logging residues. In the case of electricity generation, co-firing scenarios are also investigated. The research analyzes the key indicators involved with economic costs and benefits, environmental and social impacts. The bioenergy production possibilities considered here were biofeedstock supported electric power and cellulosic ethanol production. The results were integrated into a comprehensive set of information that addresses the effects of biomass energy development in the region. The analysis indicates that none of the counties in East Texas have sufficient biomass to individually sustain either a 100% biomass fired power plant or the cellulosic ethanol plant. Such plants would only be feasible at the regional level. Co-firing biomass with coal, however, does provide a most attractive alternative for the study region. The results indicate further that basing the decision solely on economics of feedstock availability and costs would suggest that bioenergy, as a renewable energy, is not a viable energy alternative. Accounting for some environmental and social benefits accruing to the region from bioenergy production together with the feedstock economics, however, suggests that government subsidies, up to the amount of accruing benefits, could make the bioenergies an attractive business opportunity

  13. Noble Gas Measurement and Analysis Technique for Monitoring Reprocessing Facilities

    International Nuclear Information System (INIS)

    William S. Charlton

    1999-01-01

    An environmental monitoring technique using analysis of stable noble gas isotopic ratios on-stack at a reprocessing facility was developed. This technique integrates existing technologies to strengthen safeguards at reprocessing facilities. The isotopic ratios are measured using a mass spectrometry system and are compared to a database of calculated isotopic ratios using a Bayesian data analysis method to determine specific fuel parameters (e.g., burnup, fuel type, fuel age, etc.). These inferred parameters can be used by investigators to verify operator declarations. A user-friendly software application (named NOVA) was developed for the application of this technique. NOVA included a Visual Basic user interface coupling a Bayesian data analysis procedure to a reactor physics database (calculated using the Monteburns 3.01 code system). The integrated system (mass spectrometry, reactor modeling, and data analysis) was validated using on-stack measurements during the reprocessing of target fuel from a U.S. production reactor and gas samples from the processing of EBR-II fast breeder reactor driver fuel. These measurements led to an inferred burnup that matched the declared burnup with sufficient accuracy and consistency for most safeguards applications. The NOVA code was also tested using numerous light water reactor measurements from the literature. NOVA was capable of accurately determining spent fuel type, burnup, and fuel age for these experimental results. Work should continue to demonstrate the robustness of this system for production, power, and research reactor fuels

  14. Gas

    International Nuclear Information System (INIS)

    1996-01-01

    The French government has decided to modify the conditions of extension of local natural gas authorities to neighbouring districts. The European Union is studying the conditions of internal gas market with the objective of more open markets although considering public service requirements

  15. Consensus guidelines on plasma cell myeloma minimal residual disease analysis and reporting.

    Science.gov (United States)

    Arroz, Maria; Came, Neil; Lin, Pei; Chen, Weina; Yuan, Constance; Lagoo, Anand; Monreal, Mariela; de Tute, Ruth; Vergilio, Jo-Anne; Rawstron, Andy C; Paiva, Bruno

    2016-01-01

    Major heterogeneity between laboratories in flow cytometry (FC) minimal residual disease (MRD) testing in multiple myeloma (MM) must be overcome. Cytometry societies such as the International Clinical Cytometry Society and the European Society for Clinical Cell Analysis recognize a strong need to establish minimally acceptable requirements and recommendations to perform such complex testing. A group of 11 flow cytometrists currently performing FC testing in MM using different instrumentation, panel designs (≥ 6-color) and analysis software compared the procedures between their respective laboratories and reviewed the literature to propose a consensus guideline on flow-MRD analysis and reporting in MM. Consensus guidelines support i) the use of minimum of five initial gating parameters (CD38, CD138, CD45, forward, and sideward light scatter) within the same aliquot for accurate identification of the total plasma cell compartment; ii) the analysis of potentially aberrant phenotypic markers and to report the antigen expression pattern on neoplastic plasma cells as being reduced, normal or increased, when compared to a normal reference plasma cell immunophenotype (obtained using the same instrument and parameters); and iii) the percentage of total bone marrow plasma cells plus the percentages of both normal and neoplastic plasma cells within the total bone marrow plasma cell compartment, and over total bone marrow cells. Consensus guidelines on minimal current and future MRD analyses should target a lower limit of detection of 0.001%, and ideally a limit of quantification of 0.001%, which requires at least 3 × 10(6) and 5 × 10(6) bone marrow cells to be measured, respectively. © 2015 International Clinical Cytometry Society.

  16. Numerical analysis of cavitating flow characteristics in impeller of residual heat removal pump

    NARCIS (Netherlands)

    Hong, Feng; Yuan, Jianping; Zhou, Banglun

    2016-01-01

    In order to investigate internal cavitating flow characteristics of the impeller in residual heat removal pumps, the three-dimensional cavitating flow in a residual heat removal model pump is numerically calculated by using the homogeneous mixture cavitation model based on the Rayleigh-Plesset

  17. Residual fatigue life evaluation of rail at squats seeds using 3D explicit finite element analysis

    NARCIS (Netherlands)

    Deng, X.; Naeimi, M.; Li, Z.; Qian, Z.

    2014-01-01

    A modeling procedure to predict the residual fatigue life of rail at squats seeds is developed in this article. Two models are involved: a 3D explicit Finite Element (FE) model to compute the stress and strain at squats in rail, and the J-S fatigue damage model to determine the residual fatigue life

  18. Productivity and cost analysis of a mobile pyrolysis system deployed to convert mill residues into biochar

    Science.gov (United States)

    Woodam Chung; Dongyeob Kim; Nathaniel Anderson

    2012-01-01

    Forest and mill residues are a promising source of biomass feedstock for the production of bioenergy, biofuels and bioproducts. However, high costs of transportation and handling of feedstock often make utilization of forest residues, such as logging slash, financially unviable. As a result, these materials are often considered waste and left on site to decompose or...

  19. Fate of iprovalicarb, indoxacarb, and boscalid residues in grapes and wine by GC-ITMS analysis.

    Science.gov (United States)

    Angioni, Alberto; Dedola, Fabrizio; Garau, Vincenzo Luigi; Schirra, Mario; Caboni, Pierluigi

    2011-06-22

    The behavior in field and the transfer from grapes to wine during winemaking of iprovalicarb, indoxacarb, and boscalid was studied. The residue levels found in grapes were far below the MRLs set for grapes in EU, accounting at harvest time 0.81, 0.43, and 4.23 mg/kg for iprovalicarb, indoxacarb, and boscalid, respectively. The residue levels in the samples treated with boscalid may have residual problems (due to an accumulation effect) if repeated field treatments will be performed. Winemaking experiments showed a complete transfer of all pesticide from grapes to the must, while in wine the residues were low or negligible due to the adsorbing effect of lees and pomace. The clarification experiments showed a good removal of pesticide residues from the wine media, for all pesticides. The GC-ITMS method showed good performance with adequate recoveries ranging from 75 to 115%, and good method limits of quantitation (LOQs) and of determination (LODs) far below MRLs.

  20. Depth-resolved X-ray residual stress analysis in PVD (Ti, Cr) N hard coatings

    CERN Document Server

    Genzel, C

    2003-01-01

    Physical vapour deposition (PVD) of thin hard coatings on TiN basis is usually performed at rather low temperatures (T sub D < 500 C) far from thermal equilibrium, which leads to high intrinsic residual stresses in the growing film. In contrast to the extrinsic thermal residual stresses which can easily be estimated from the difference of the coefficients of thermal expansion between the substrate and the coating, a theoretical prediction of the intrinsic residual stresses is difficult, because their amount as well as their distribution within the film depend in a very complex way on the deposition kinetics. By the example of strongly fibre-textured PVD (Ti, Cr)N coatings which have been prepared under defined variation of the deposition parameters in order to adjust the residual stress distribution within the coatings, the paper compares different X-ray diffraction techniques with respect to their applicability for detecting residual stresses which are non-uniform over the coating thickness. (orig.)

  1. Indoor air quality inspection and analysis system based on gas sensor array

    Science.gov (United States)

    Gao, Xiang; Wang, Mingjiang; Fan, Binwen

    2017-08-01

    A detection and analysis system capable of measuring the concentration of four major gases in indoor air is designed. It uses four gas sensors constitute a gas sensor array, to achieve four indoor gas concentration detection, while the detection of data for further processing to reduce the cross-sensitivity between the gas sensor to improve the accuracy of detection.

  2. Potential application of gas chromatography to the analysis of hydrogen isotopes

    International Nuclear Information System (INIS)

    Warner, D.K.; Sprague, R.E.; Bohl, D.R.

    1976-01-01

    Gas chromatography is used at Mound Laboratory for the analysis of hydrogen isotopic impurities in gas mixtures. This instrumentation was used to study the applicability of the gas chromatography technique to the determination of the major components of hydrogen isotopic gas mixtures. The results of this study, including chromatograms and precision data, are presented

  3. Collimator system for the stabilization of the dynamical residual-gas pressure in the heavy-ion synchrotron SIS18; Kollimatorsystem zur Stabilisierung des dynamischen Restgasdruckes im Schwerionensynchrotron SIS18

    Energy Technology Data Exchange (ETDEWEB)

    Omet, Carsten

    2009-01-15

    In order to achieve higher beam intensities of heavy ion beams in ring accelerators, low charge state ions can be used. By lowering the charge state, the space charge limit is shifted to higher particle numbers and stripping losses can be avoided. During test operation of the SIS18 at GSI with high intensity low charge state heavy ion beams, strong intensity dependent beam losses have been observed. It was found that these beam losses are originated to a large extent by the change of charge state of the circulating ions during collisions with residual gas atoms. The resulting deviation of m/q relative to the reference ion leads, in combination with dispersive elements in the ion optic lattice, to a modified trajectory, followed by the loss of the ion on the beam pipe. At the impact position, loosely bound residual gas molecules are released by ion stimulated desorption which increases the residual gas pressure locally. This pressure rise itself enhances the charge exchange rate, which can develop into a self amplifying process of pressure rise and subsequent beam loss. A method for the stabilization of the dynamic residual gas pressure is the use of special catcher systems, which minimize the production of desorption gases and remove them by strong pumping. Therefore, the pressure on the beam axis should remain as stable as possible. Other processes, e.g. Coulomb scattering of the beam ions by residual gas particles and unavoidable systematic beam losses can increase the gas pressure additionally. The pressure in the accelerator is further subjected to ionization of the residual gas atoms themselves, thermal out gassing of the beam pipes, insertions and pumps. In this work, a detailed numerical model of the interplay between the residual gas pressure dynamics in the accelerator, possible stabilization measures, e.g. by catchers and the resulting beam life time has been developed. The forecasted beam life times and pressures are verified by machine experiments, as

  4. On possibility of using E, H - crossed fields and gas-dynamic flowing of argon in the processes of degassing by the method of ion-stimulated desorption of residual gas in the KUTI-20

    International Nuclear Information System (INIS)

    Sharapov, V.E.

    1985-01-01

    In the project considered if the possibility to use the degassing of an adhezatior chamber inner walls, using the method of ion-stimulated desorption (ISD) of residual gas in the glow discharge is considered. It is suggested that the experiment should be realized using the model or the KUTI (PKUTI) prototype to decrease operation pressure to p -7 Pa (2x10 -9 Tor) at the expense of introduction of the technology described and certain modifications in the processes of leak-in and pumping. The use of crossed E,H-fields and gasodynamic regime of argon flow in the process of preliminary degassing of the adhezator chamber by the glow discharge is the main idea of the project

  5. Welding Residual Stress Analysis and Fatigue Strength Assessment at Elevated Temperature for Multi-pass Dissimilar Material Weld Between Alloy 617 and P92 Steel

    Science.gov (United States)

    Lee, Juhwa; Hwang, Jeongho; Bae, Dongho

    2018-03-01

    In this paper, welding residual stress analysis and fatigue strength assessment were performed at elevated temperature for multi-pass dissimilar material weld between Alloy 617 and P92 steel, which are used in thermal power plant. Multi-pass welding between Alloy 617 and P92 steel was performed under optimized welding condition determined from repeated pre-test welding. In particular, for improving dissimilar material weld-ability, the buttering welding technique was applied on the P92 steel side before multi-pass welding. Welding residual stress distribution at the dissimilar material weld joint was numerically analyzed by using the finite element method, and compared with experimental results which were obtained by the hole-drilling method. Additionally, fatigue strength of dissimilar material weld joint was assessed at the room temperature (R.T), 300, 500, and 700 °C. In finite element analysis results, numerical peak values; longitudinal (410 MPa), transverse (345 MPa) were higher than those of experiments; longitudinal (298 MPa), transverse (245 MPa). There are quantitatively big differences between numerical and experimental results, due to some assumption about the thermal conductivity, specific heat, effects of enforced convection of the molten pool, dilution, and volume change during phase transformation caused by actual shield gas. The low fatigue limit at R.T, 300 °C, 500 °C and 700 °C was assessed to be 368, 276, 173 and 137 MPa respectively.

  6. Welding Residual Stress Analysis and Fatigue Strength Assessment at Elevated Temperature for Multi-pass Dissimilar Material Weld Between Alloy 617 and P92 Steel

    Science.gov (United States)

    Lee, Juhwa; Hwang, Jeongho; Bae, Dongho

    2018-07-01

    In this paper, welding residual stress analysis and fatigue strength assessment were performed at elevated temperature for multi-pass dissimilar material weld between Alloy 617 and P92 steel, which are used in thermal power plant. Multi-pass welding between Alloy 617 and P92 steel was performed under optimized welding condition determined from repeated pre-test welding. In particular, for improving dissimilar material weld-ability, the buttering welding technique was applied on the P92 steel side before multi-pass welding. Welding residual stress distribution at the dissimilar material weld joint was numerically analyzed by using the finite element method, and compared with experimental results which were obtained by the hole-drilling method. Additionally, fatigue strength of dissimilar material weld joint was assessed at the room temperature (R.T), 300, 500, and 700 °C. In finite element analysis results, numerical peak values; longitudinal (410 MPa), transverse (345 MPa) were higher than those of experiments; longitudinal (298 MPa), transverse (245 MPa). There are quantitatively big differences between numerical and experimental results, due to some assumption about the thermal conductivity, specific heat, effects of enforced convection of the molten pool, dilution, and volume change during phase transformation caused by actual shield gas. The low fatigue limit at R.T, 300 °C, 500 °C and 700 °C was assessed to be 368, 276, 173 and 137 MPa respectively.

  7. Analysis of the Retained Gas Sample (RGS) Extruder Assembly

    International Nuclear Information System (INIS)

    Coverdell, B.L.

    1995-09-01

    In order for the Retained Gas Sample (RGS) Extruder Assembly to be safely used it was determined by the cognizant engineer that analysis was necessary. The use of the finite-element analysis (FEA) progarm COSMOS/M version 1.71 permitted a quick, easy, and detailed stress analysis of the RGS Extruder Assembly. The FEA model is a three dimensional model using the SHELL4T element type. From the results of the FEA, the cognizant engineer determined that the RGS extruder would be rated at 10,000 lbf and load tested to 12,000 lbf. The respective input and output files for the model are EXTR02.GFM and EXTR02.OUT and can be found on the attached tape

  8. Gas chromatographic analysis of extractive solvent in reprocessing plants

    International Nuclear Information System (INIS)

    Marlet, B.

    1984-01-01

    Operation of a reprocessing plant using the Purex process is recalled and analytical controls for optimum performance are specified. The aim of this thesis is the development of analytical methods using gas chromatography required to follow the evolution of the extraction solvent during spent fuel reprocessing. The solvent at different concentrations, is analysed along the reprocessing lines in organic or aqueous phases. Solvent degradation interferes with extraction and decomposition products are analysed. The solvent becomes less and less efficient, also it is distilled and quality is checked. Traces of solvent should also be checked in waste water. Analysis are made as simple as possible to facilitate handling of radioactive samples [fr

  9. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2003-01-01

    to result in a high marginal efficiency. The paper shows that depending on the application, this is not always the case. The interest in this cycle arises from a recent demonstration of the feasibility of a two-stage gasification process through construction of several plants. The gas from this process...... could be divided into two streams, one for primary and one for supplementary firing. A preliminary analysis of the ideal, recuperated Brayton cycle shows that for this cycle any supplementary firing will have a marginal efficiency of unity per extra unit of fuel. The same result is obtained...

  10. Tag gas burnup based on three-dimensional FTR analysis

    International Nuclear Information System (INIS)

    Kidman, R.B.

    1976-01-01

    Flux spectra from a three-dimensional diffusion theory analysis of the Fast Test Reactor (FTR) are used to predict gas tag ratio changes, as a function of exposure, for each FTR fuel and absorber subassembly plenum. These flux spectra are also used to predict Xe-125 equilibrium activities in absorber plena in order to assess the feasibility of using Xe-125 gamma rays to detect and distinguish control rod failures from fuel rod failures. Worst case tag burnup changes are used in conjunction with burnup and mass spectrometer uncertainties to establish the minimum spacing of tags which allows the tags to be unambiguously identified

  11. Applications of stable isotope analysis to atmospheric trace gas budgets

    Directory of Open Access Journals (Sweden)

    Brenninkmeijer C. A.M.

    2009-02-01

    Full Text Available Stable isotope analysis has become established as a useful method for tracing the budgets of atmospheric trace gases and even atmospheric oxygen. Several new developments are briefly discussed in a systematic way to give a practical guide to the scope of recent work. Emphasis is on applications and not on instrumental developments. Processes and reactions are less considered than applications to resolve trace gas budgets. Several new developments are promising and applications hitherto not considered to be possible may allow new uses.

  12. A generic approach for a linear elastic fracture mechanics analysis of components containing residual stress

    International Nuclear Information System (INIS)

    Lee, Hyeong Y.; Nikbin, Kamran M.; O'Dowd, Noel P.

    2005-01-01

    A review of through thickness transverse residual stress distribution measurements in a number of components, manufactured from a range of steels, has been carried out. Residual stresses introduced by welding and mechanical deformation have been considered. The geometries consisted of welded T-plate joints, pipe butt joints, tube-on-plate joints, tubular Y-joints and tubular T-joints as well as cold bent tubes and repair welds. In addition, the collected data cover a range of engineering steels including ferritic, austenitic, C-Mn and Cr-Mo steels. The methods used to measure the residual stresses also varied. These included neutron diffraction, X-ray diffraction and deep hole drilling techniques. Measured residual stress data, normalised by their respective yield stress have shown an inverse linear correlation versus the normalised depth of the region containing the residual stress (up to 0.5 of the component thickness). A simplified generic residual stress profile based on a linear fit to the data is proposed for the case of a transverse residual tensile stress field. Whereas the profiles in assessment procedures are case specific the proposed linear profile can be varied to produce a combination of membrane and bending stress distributions to give lower or higher levels of conservatism on stress intensity factors, depending on the amount of case specific data available or the degree of safety required

  13. Performance analysis of solar energy integrated with natural-gas-to-methanol process

    International Nuclear Information System (INIS)

    Yang, Sheng; Liu, Zhiqiang; Tang, Zhiyong; Wang, Yifan; Chen, Qianqian; Sun, Yuhan

    2017-01-01

    Highlights: • Solar energy integrated with natural-gas-to-methanol process is proposed. • The two processes are modeled and simulated. • Performance analysis of the two processes are conducted. • The proposed process can cut down the greenhouse gas emission. • The proposed process can save natural gas consumption. - Abstract: Methanol is an important platform chemical. Methanol production using natural gas as raw material has short processing route and well developed equipment and technology. However, natural gas reserves are not large in China. Solar energy power generation system integrated with natural-gas-to-methanol (NGTM) process is developed, which may provide a technical routine for methanol production in the future. The solar energy power generation produces electricity for reforming unit and system consumption in solar energy integrated natural-gas-to-methanol system (SGTM). Performance analysis of conventional natural-gas-to-methanol process and solar energy integrated with natural-gas-to-methanol process are presented based on simulation results. Performance analysis was conducted considering carbon efficiency, production cost, solar energy price, natural gas price, and carbon tax. Results indicate that solar energy integrated with natural-gas-to-methanol process is able to cut down the greenhouse gas (GHG) emission. In addition, solar energy can replace natural gas as fuel. This can reduce the consumption of natural gas, which equals to 9.2% of the total consumed natural gas. However, it is not economical considering the current technology readiness level, compared with conventional natural-gas-to-methanol process.

  14. [Situation analysis and standard formulation of pesticide residues in traditional Chinese medicines].

    Science.gov (United States)

    Yang, Wan-Zhen; Kang, Chuan-Zhi; Ji, Rui-Feng; Zhou, L I; Wang, Sheng; Li, Zhen-Hao; Ma, Zhong-Hua; Guo, Lan-Ping

    2017-06-01

    Chinese Pharmacopoeia provides nine pesticide Maximum Residual Limits(MRLs) of traditional Chinese medicines(TCMs), The number of pesticides used in production are far more than those listed in pharmacopoeia. The lack of the standards make it's hard to reflect the real situation of pesticide residues in TCMs correctly. The paper is aimed to analyze the data of pesticide residues in TCMs from 7 089 items in 140 reports, and judging the exceedance rate of pesticides in TCMs using the MRLs of European pharmacopoeia,which is widely accepted in many countries. The results show that:①Pesticide residues in 18 kinds of TCMs are higher than MRLs,while in 137 kinds are below MRLs, such as Atractylodis Macrocephalae Rhizoma, Menthae Haplocalycis Herba and Fritillariae Thunbergii Bulbus. The average exceedance rate of all TCMs is 1.72%. The average exceedance rates of organochlorine, organophosphorus and pyrethroid are 2.26%, 1.51%, 0.37%,respectively. ②The average exceedance rate of pesticides is 2.00%, and the exceedance rate is more than 5%, accounting for 8.33%, the exceedance rate is between 1%-5%, accounting for 18.75%. the exceedance rate is between 0%-1%, accounting for 18.75%. The remaining 29 kinds of pesticides were not exceeded, accounting for 60.42%.Some reports like Greenpeace's organization exaggerated the pesticide residues in TCMs.But the pesticide residue question is still worthy of attention, so we proposed to amend the Chinese Pharmacopoeia pesticide residues standards, to increase the pesticide species of traditional Chinese medicine in production on the basis of retaining the existing types of pesticide residues, to strengthen the system research of pesticide residues in TCMs, providing a basis for making standard and promoting import and export trade in TCMs. Copyright© by the Chinese Pharmaceutical Association.

  15. The analysis, by atomic-absorption spectrophotometry, of matte-leach residues

    International Nuclear Information System (INIS)

    Mallett, R.C.; Ring, E.J.; Middleton, H.R.; Dubois, M.

    1973-01-01

    Alternative methods for the analysis of matte-leach residues by atomic-absorption spectrophotometry were investigated. For the determination of the platinum-group metals, gold, and certain of the base metals, a fusion with sodium peroxide, followed by the separation of gold by reverse-phase chromatography and of the platinum-group metals by ion-exchange, is proposed. The noble metals are then determined in a solution that is free of most base metals including the sodium present as a result of the fusion. Copper, nickel, iron, calcium, magnesium, and aluminium can be determined after they have been removed from the ion-exchange column. Arsenic, selenium, tellurium, bismuth, tin, silver, lead, manganese, zinc, and cobalt can be determined in a separate sample after dissolution by a sealed-tube method. This is also an alternative method for the determination of copper, nickel, and iron. Chromium is determined separately after fusion with sodium peroxide, and silver can also be determined in this way. The laboratory method for these procedures is given as an appendix [af

  16. Determination of barium and antimony in gun shot residues by neutron activation analysis

    International Nuclear Information System (INIS)

    Charuchinda, A.

    1975-01-01

    The antimony contents on both hands of 7 persons before and after firing an automatic pistol were determined by instrumental neutron activation analysis. The gun shot residues were removed from hands by a 4% solution of cellulose acetate in acetone. The average content of antimony on both hands before firing obtained from 70 measurements (35 from each hand) was 0.040 ± 0.010 micro gram, whereas the average contents on the right and the left hands after 1 firing were 0.385 ± 0.036 and 0.144 ± 0.029 micro gram respectively. The ration of the antimony contents after 1 firing to the normal level (before firing) was 9.9 for the right and 3.6 for the left. No significant difference was observed between male and female, smoker and non-smoker. The antimony content after several firings was not much different from that of 1 firing and it reduced to the normal level within 2 days after firing. The barium contents before and after firing were studied from one person. Barium was precipitated as Ba SO 4 before counting. An average contents of 0.936 ± 0.551 micro gram for both hands before firing, 4.092 ± 2.687 micro gram for the right hand and 1.363 ± 0.879 micro gram for the left hand after 1 firing were found

  17. Residual life assessment of French PWR vessel head penetrations through metallurgical analysis

    International Nuclear Information System (INIS)

    Pichon, C.; Boudot, R.; Benhamou, C.; Gelpi, A.

    1994-01-01

    In September 1991, a vessel head penetration was found leaking at Bugey 3 plant during the hydrotest included in the framework of decennial In Service Inspections. Non destructive examinations performed afterwards on several other plants have shown some cracked penetrations. Destructive expertise confirmed quickly that again this new problem is related to stress corrosion cracking of Alloy 600 used as base material. During the last 15 years, similar cracking have been met in steam generator tubes and secondly in pressurizer instrumentation tubes. In spite of all the work performed since that time an extension appears to be necessary for explaining the features of this new event; however material sensitivity, stress and temperature still remain the key parameters governing the behavior of Alloy 600 in PWR environment. In this paper, only the material sensitivity of vessel head penetrations is examined through metallurgical analysis in relation with SCC tests. On the basis of vessel head field experience in combination with thermomechanical process used for fabrication of original bars criteria for a sensitivity ranking of penetrations are proposed. Metallurgical investigations and SCC tests were carried out to support this sensitivity ranking. The final aim is to use such information among those quoted above for assessment of vessel heads residual life. This document is an overview of the work performed in France concerning the material sensitivity of forged Alloy 600. It represents an important part of the assessments and investigations undertaken in France on the stress corrosion cracking phenomenon affecting the reactor vessel head penetrations in PWR's

  18. Recent Advances and Uses of Monolithic Columns for the Analysis of Residues and Contaminants in Food

    Directory of Open Access Journals (Sweden)

    Mónica Díaz-Bao

    2015-02-01

    Full Text Available Monolithic columns are gaining interest as excellent substitutes to conventional particle-packed columns. These columns show higher permeability and lower flow resistance than conventional liquid chromatography columns, providing high-throughput performance, resolution and separation in short run times. Monoliths possess also great potential for the clean-up and preparation of complex mixtures. In situ polymerization inside appropriate supports allows the development of several microextraction formats, such as in-tube solid-phase and pipette tip-based extractions. These techniques using porous monoliths offer several advantages, including miniaturization and on-line coupling with analytical instruments. Additionally, monoliths are ideal support media for imprinting template-specific sites, resulting in the so-called molecularly-imprinted monoliths, with ultra-high selectivity. In this review, time-saving LC columns and preparative applications applied to the analysis of residues and contaminants in food in 2010–2014 are described, focusing on recent improvements in design and with emphasis in automated on-line systems and innovative materials and formats.

  19. Nonparametric Bayesian inference for mean residual life functions in survival analysis.

    Science.gov (United States)

    Poynor, Valerie; Kottas, Athanasios

    2018-01-19

    Modeling and inference for survival analysis problems typically revolves around different functions related to the survival distribution. Here, we focus on the mean residual life (MRL) function, which provides the expected remaining lifetime given that a subject has survived (i.e. is event-free) up to a particular time. This function is of direct interest in reliability, medical, and actuarial fields. In addition to its practical interpretation, the MRL function characterizes the survival distribution. We develop general Bayesian nonparametric inference for MRL functions built from a Dirichlet process mixture model for the associated survival distribution. The resulting model for the MRL function admits a representation as a mixture of the kernel MRL functions with time-dependent mixture weights. This model structure allows for a wide range of shapes for the MRL function. Particular emphasis is placed on the selection of the mixture kernel, taken to be a gamma distribution, to obtain desirable properties for the MRL function arising from the mixture model. The inference method is illustrated with a data set of two experimental groups and a data set involving right censoring. The supplementary material available at Biostatistics online provides further results on empirical performance of the model, using simulated data examples. © The Author 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. A method for the estimation of the residual error in the SALP approach for fault tree analysis

    International Nuclear Information System (INIS)

    Astolfi, M.; Contini, S.

    1980-01-01

    The aim of this report is the illustration of the algorithms implemented in the SALP-MP code for the estimation of the residual error. These algorithms are of more general use, and it would be possible to implement them on all codes of the series SALP previously developed, as well as, with minor modifications, to analysis procedures based on 'top-down' approaches. At the time, combined 'top-down' - 'bottom up' procedures are being studied in order to take advantage from both approaches for further reduction of computer time and better estimation of the residual error, for which the developed algorithms are still applicable

  1. Pyrolysis behaviors and kinetic studies on Eucalyptus residues using thermogravimetric analysis

    International Nuclear Information System (INIS)

    Chen, Zhihua; Zhu, Quanjie; Wang, Xun; Xiao, Bo; Liu, Shiming

    2015-01-01

    Highlights: • The first study on pyrolysis characteristics and kinetic of Eucalyptus residues. • Pyrolysis process can be divided into three stages using differential DTG method. • A new modified discrete DAEM showed better than Gaussian DAEM for kinetic studies. • Variations of activation energy reveal the mechanism change during pyrolysis process. - Abstract: The pyrolysis behaviors and kinetics of Eucalyptus leaves (EL), Eucalyptus bark (EB) and Eucalyptus sawdust (ESD) were investigated by using thermogravimetric analysis (TGA) technique. Three stages for EL, EB and ESD pyrolysis have been divided using differential derivative thermogravimetric (DDTG) method and the second stage is the main pyrolysis process with approximately 86.93% (EL), 88.96% (EB) and 97.84% (ESD) weight loss percentages. Kinetic parameters of Gaussian distributed activation energy model (DAEM) for EL, EB and ESD pyrolysis are: distributed centers (E_0) of 141.15 kJ/mol (EL), 149.21 kJ/mol (EB), 175.79 kJ/mol (ESD), standard deviations (σ) of 18.35 kJ/mol (EL), 18.37 kJ/mol (EB), 14.41 kJ/mol (ESD) and pre-exponential factors (A) of 1.15E+10 s"−"1 (EL), 4.34E+10 s"−"1 (EB), 7.44E+12 s"−"1 (ESD). A new modified discrete DAEM was performed and showed excellent fits to experimental data than Gaussian DAEM. According to the modified discrete DAEM, the activation energies are in ranges of 122.67–308.64 kJ/mol, 118.72–410.80 kJ/mol and 108.39–192.93 kJ/mol for EL, EB and ESD pyrolysis, respectively. The pre-exponential factors of discrete DAEM have wide ranges of 4.84E+13–6.12E+22 s"−"1 (EL), 1.91E+12–4.51E+25 s"−"1 (EB) and 63.43–4.36E+11 s"−"1 (ESD). The variation of activation energy versus conversion reveals the mechanism change during pyrolysis process. The kinetic data would be of immense benefit to model, design and develop suitable thermo-chemical systems for the application of Eucalyptus residues.

  2. Development of Circular Disk Model for Polymeric Nanocomposites and Micromechanical Analysis of Residual Stresses in Reinforced Fibers with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    A. R. Ghasemi

    2017-02-01

    Full Text Available In this study, Circular Disk Model (CDM has been developed to determine the residual stresses in twophase and three- phase unit cell. The two-phase unit cell is consisting of carbon fiber and matrix. The three-phase unit cell is consisting of carbon fiber, carbon nanotubes and matrix in which the carbon fiber is reinforced with the carbon nanotube using electrophoresis method. For different volume fractions of carbon nanotubes, thermal properties of the carbon fiber and carbon nanotube in different linear and lateral directions and also different placement conditions of carbon nanotubes have been considered. Also, residual stresses distribution in two and three phases has been studied, separately. Results of micromechanical analysis of residual stresses obtained from Finite Element Method and CDM, confirms the evaluation and development of three dimensional CDM.

  3. Analysis of Corrosion Residues Collected from the Aluminum Basket Rails of the High-Burnup Demonstration Cask.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    On September, 2015, an inspection was performed on the TN-32B cask that will be used for the high-burnup demonstration project. During the survey, wooden cribbing that had been placed within the cask eleven years earlier to prevent shifting of the basket during transport was removed, revealing two areas of residue on the aluminum basket rails, where they had contacted the cribbing. The residue appeared to be a corrosion product, and concerns were raised that similar attack could exist at more difficult-to-inspect locations in the canister. Accordingly, when the canister was reopened, samples of the residue were collected for analysis. This report presents the results of that assessment, which determined that the corrosion was due to the presence of the cribbing. The corrosion was associated with fungal material, and fungal activity likely contributed to an aggressive chemical environment. Once the cask has been cleaned, there will be no risk of further corrosion.

  4. Analysis of shot-peening and residual stress relaxation in the nickel-based superalloy RR1000

    International Nuclear Information System (INIS)

    Foss, B.J.; Gray, S.; Hardy, M.C.; Stekovic, S.; McPhail, D.S.; Shollock, B.A.

    2013-01-01

    This work assesses the residual stress relaxation of the nickel-based alloy RR1000 due to thermal exposure and dwell-fatigue loading. A number of different characterization methods, including X-ray residual stress analysis, electron back-scattered diffraction, microhardness testing and focused ion beam secondary electron imaging, contributed to a detailed study of the shot-peened region. Thermal exposure at 700 °C resulted in a large reduction in the residual stresses and work-hardening effects in the alloy, but the subsurface remained in a beneficial compressive state. Oxidizing environments caused recrystallization in the near surface, but did not affect the residual stress-relaxation behaviour. Dwell-fatigue loading caused the residual stresses to return to approximately zero at nearly all depths. This work forms part of an ongoing investigation to determine the effects of shot-peening in this alloy with the motivation to improve the fatigue and oxidation resistance at 700 °C

  5. Residual lifetime prediction for lithium-ion battery based on functional principal component analysis and Bayesian approach

    International Nuclear Information System (INIS)

    Cheng, Yujie; Lu, Chen; Li, Tieying; Tao, Laifa

    2015-01-01

    Existing methods for predicting lithium-ion (Li-ion) battery residual lifetime mostly depend on a priori knowledge on aging mechanism, the use of chemical or physical formulation and analytical battery models. This dependence is usually difficult to determine in practice, which restricts the application of these methods. In this study, we propose a new prediction method for Li-ion battery residual lifetime evaluation based on FPCA (functional principal component analysis) and Bayesian approach. The proposed method utilizes FPCA to construct a nonparametric degradation model for Li-ion battery, based on which the residual lifetime and the corresponding confidence interval can be evaluated. Furthermore, an empirical Bayes approach is utilized to achieve real-time updating of the degradation model and concurrently determine residual lifetime distribution. Based on Bayesian updating, a more accurate prediction result and a more precise confidence interval are obtained. Experiments are implemented based on data provided by the NASA Ames Prognostics Center of Excellence. Results confirm that the proposed prediction method performs well in real-time battery residual lifetime prediction. - Highlights: • Capacity is considered functional and FPCA is utilized to extract more information. • No features required which avoids drawbacks induced by feature extraction. • A good combination of both population and individual information. • Avoiding complex aging mechanism and accurate analytical models of batteries. • Easily applicable to different batteries for life prediction and RLD calculation.

  6. Analysis of residual stresses on the transverse beam of a casting stand by means of drilling method

    Directory of Open Access Journals (Sweden)

    P. Frankovský

    2014-10-01

    Full Text Available The presented paper demonstrates the application of drilling method in the analysis of residual stresses on the transverse beam of a casting stand. In the initial stage of the analysis the determination of strains was done for individual steps of drilling in the area which was determined by means of numerical analysis. The drilling was carried out gradually by 0,5 mm up to the depth of 5 mm, while the diameter of the drilled hole was 3,2 mm. During the analysis we used the drilling device RS-200, strain indicator P3 and SGD 1-RY21-3/120. The paper presents the development of residual stresses throughout the depth of the drilled hole which were determined according to standard ASTM E837-01, by means of integral method, power series method and by means of Power Series method.

  7. The mining of toxin-like polypeptides from EST database by single residue distribution analysis.

    Science.gov (United States)

    Kozlov, Sergey; Grishin, Eugene

    2011-01-31

    Novel high throughput sequencing technologies require permanent development of bioinformatics data processing methods. Among them, rapid and reliable identification of encoded proteins plays a pivotal role. To search for particular protein families, the amino acid sequence motifs suitable for selective screening of nucleotide sequence databases may be used. In this work, we suggest a novel method for simplified representation of protein amino acid sequences named Single Residue Distribution Analysis, which is applicable both for homology search and database screening. Using the procedure developed, a search for amino acid sequence motifs in sea anemone polypeptides was performed, and 14 different motifs with broad and low specificity were discriminated. The adequacy of motifs for mining toxin-like sequences was confirmed by their ability to identify 100% toxin-like anemone polypeptides in the reference polypeptide database. The employment of novel motifs for the search of polypeptide toxins in Anemonia viridis EST dataset allowed us to identify 89 putative toxin precursors. The translated and modified ESTs were scanned using a special algorithm. In addition to direct comparison with the motifs developed, the putative signal peptides were predicted and homology with known structures was examined. The suggested method may be used to retrieve structures of interest from the EST databases using simple amino acid sequence motifs as templates. The efficiency of the procedure for directed search of polypeptides is higher than that of most currently used methods. Analysis of 39939 ESTs of sea anemone Anemonia viridis resulted in identification of five protein precursors of earlier described toxins, discovery of 43 novel polypeptide toxins, and prediction of 39 putative polypeptide toxin sequences. In addition, two precursors of novel peptides presumably displaying neuronal function were disclosed.

  8. The mining of toxin-like polypeptides from EST database by single residue distribution analysis

    Directory of Open Access Journals (Sweden)

    Grishin Eugene

    2011-01-01

    Full Text Available Abstract Background Novel high throughput sequencing technologies require permanent development of bioinformatics data processing methods. Among them, rapid and reliable identification of encoded proteins plays a pivotal role. To search for particular protein families, the amino acid sequence motifs suitable for selective screening of nucleotide sequence databases may be used. In this work, we suggest a novel method for simplified representation of protein amino acid sequences named Single Residue Distribution Analysis, which is applicable both for homology search and database screening. Results Using the procedure developed, a search for amino acid sequence motifs in sea anemone polypeptides was performed, and 14 different motifs with broad and low specificity were discriminated. The adequacy of motifs for mining toxin-like sequences was confirmed by their ability to identify 100% toxin-like anemone polypeptides in the reference polypeptide database. The employment of novel motifs for the search of polypeptide toxins in Anemonia viridis EST dataset allowed us to identify 89 putative toxin precursors. The translated and modified ESTs were scanned using a special algorithm. In addition to direct comparison with the motifs developed, the putative signal peptides were predicted and homology with known structures was examined. Conclusions The suggested method may be used to retrieve structures of interest from the EST databases using simple amino acid sequence motifs as templates. The efficiency of the procedure for directed search of polypeptides is higher than that of most currently used methods. Analysis of 39939 ESTs of sea anemone Anemonia viridis resulted in identification of five protein precursors of earlier described toxins, discovery of 43 novel polypeptide toxins, and prediction of 39 putative polypeptide toxin sequences. In addition, two precursors of novel peptides presumably displaying neuronal function were disclosed.

  9. Consistency Analysis and Data Consultation of Gas System of Gas-Electricity Network of Latvia

    Science.gov (United States)

    Zemite, L.; Kutjuns, A.; Bode, I.; Kunickis, M.; Zeltins, N.

    2018-02-01

    In the present research, the main critical points of gas transmission and storage system of Latvia have been determined to ensure secure and reliable gas supply among the Baltic States to fulfil the core objectives of the EU energy policies. Technical data of critical points of the gas transmission and storage system of Latvia have been collected and analysed with the SWOT method and solutions have been provided to increase the reliability of the regional natural gas system.

  10. Development of an enzyme-linked immunosorbent assay for residue analysis of the insecticide emamectin benzoate in agricultural products.

    Science.gov (United States)

    Kondo, Mika; Yamashita, Hiroshi; Uchigashima, Mikiko; Kono, Takeshi; Takemoto, Toshihide; Fujita, Masahiro; Saka, Machiko; Iwasa, Seiji; Ito, Shigekazu; Miyake, Shiro

    2009-01-28

    A direct competitive enzyme-linked immunosorbent assay (dc-ELISA) for the analysis of emamectin residues in agricultural products was developed using a prepared mouse monoclonal antibody. The working range was 0.3-3.0 ng/mL, and the 50% inhibition concentration (IC(50)) was 1.0 ng/mL. The assay was sufficiently sensitive for analysis of the maximum residue limits in agricultural products in Japan (>0.1 microg/g). Emamectin residues contain the following metabolites: the 4''-epi-amino analogue, the 4''-epi-(N-formyl)amino analogue, the 4''-epi-(N-formyl-N-methyl)amino analogue, and the 8,9-Z isomer. The dc-ELISA reacted with these compounds at ratios of 113, 55, 38, and 9.1% of the IC(50) value of emamectin benzoate. Seven kinds of vegetables were spiked with emamectin benzoate at concentrations of 15-300 ng/g, and the recoveries were 91-117% in the dc-ELISA. The dc-ELISA results agreed reasonably well with results obtained by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using spiked samples and actual (incurred) samples. The results indicate that the dc-ELISA was useful for the analysis of emamectin benzoate residues in agricultural products.

  11. Greenhouse gas emission analysis of an Egyptian rice straw biomass-to-energy chain

    NARCIS (Netherlands)

    Poppens, R.P.; Bakker, R.

    2012-01-01

    A common practice in Egypt has been the burning of rice straw, as a measure to prepare agricultural land for follow-up crops. This practice has caused significant greenhouse gas emissions, in addition to aerial pollution. By using straw residue for the production of pellets and shipping these

  12. NUMERICAL AND EXPERIMENTAL ANALYSIS OF RESIDUAL STRESSES GENERATED DURING HARDENING OFAISI 4140 BAR

    Directory of Open Access Journals (Sweden)

    Edwan Anderson Ariza Echeverri

    2012-09-01

    Full Text Available The aim of this work is to analyze the distribution of residual stresses resulting from the combination of volumetric changes due to heat gradients and phase changes occurring during the quenching process of an AISI/SAE 4140 steel cylinder. The mathematical model used for this objective is the AC3 modeling software of thermal treatments (transformation curves, cooling curves and microstructure, whose results were input in an finite element model, considering thermalmechanical coupling and non-linear elastic-plastic behavior, aiming the assessment of residual stresses in quenched 4140 steel cylinders. The observed microstructure confirms quantitatively and qualitatively the previsions of the AC3 Software. The results of the modeling are compared with the residual stresses measurements made using X-Ray diffraction techniques. The finite element numerical simulation shows the existence of 350 MPa compressive residual stresses in the surface region and indicates that the most significant stresses are tangential.

  13. Analysis of residual chlorine in simple drinking water distribution system with intermittent water supply

    Science.gov (United States)

    Goyal, Roopali V.; Patel, H. M.

    2015-09-01

    Knowledge of residual chlorine concentration at various locations in drinking water distribution system is essential final check to the quality of water supplied to the consumers. This paper presents a methodology to find out the residual chlorine concentration at various locations in simple branch network by integrating the hydraulic and water quality model using first-order chlorine decay equation with booster chlorination nodes for intermittent water supply. The explicit equations are developed to compute the residual chlorine in network with a long distribution pipe line at critical nodes. These equations are applicable to Indian conditions where intermittent water supply is the most common system of water supply. It is observed that in intermittent water supply, the residual chlorine at farthest node is sensitive to water supply hours and travelling time of chlorine. Thus, the travelling time of chlorine can be considered to justify the requirement of booster chlorination for intermittent water supply.

  14. US Department of Energy investments in natural gas R ampersand D: An analysis of the gas industry proposal

    International Nuclear Information System (INIS)

    Sutherland, R.J.

    1992-01-01

    The natural gas industry has proposed an increase in the DOE gas R ampersand D budget from about $100 million to about $250 million per year for each of the next 10 years. The proposal includes four programs: natural gas supplies, fuel cells, natural gas vehicles and stationary combustion systems. This paper is a qualitative assessment of the gas industry proposal and recommends a natural gas R ampersand D strategy for the DOE. The methodology is a conceptual framework based on an analysis of market failures and the energy policy objectives of the DOE's (1991) National Energy Strategy. This framework would assist the DOE in constructing an R ampersand D portfolio that achieves energy policy objectives. The natural gas supply program is recommended to the extent that it contributes to energy price stability. Stationary combustion programs are supported on grounds of economic efficiency and environmental quality. The fuel cell program is supported on grounds of environmental quality. The natural gas vehicle program may potentially contribute to environmental quality and energy price stability. The R ampersand D programs in natural gas vehicles and in fuel cells should be complemented with policies that encourage the commercialization and use of the technology, not merely its development

  15. Adjust of the residuals of the Arima model by means of the analysis of the residuals of the explanatory variables by means of the analysis of main components

    International Nuclear Information System (INIS)

    Bernal Suarez, Nestor Ricardo; Montealegre Bocanegra, Jose Edgar

    2000-01-01

    Based on the previous knowledge and understanding of the causality relationships between the fields of surface temperature of the Pacific and North and South tropical Atlantic oceans and rainfall behaviour in Colombia, we purport to model those relations with a (statistical) transfer model. This work is aimed at improving the adjustment of the model for the monthly mean rainfall registered in Funza (nearby the Capital Bogota). The residues of ARIMA models with six explanatory variables may contribute some percentage to the explanation of the total variability of rainfall as a consequence of their interrelationship. Such effect can be represented as a summary of the six variables, which can be achieved with principal components, taking into account that they are not mutually dependent, since they are white noise time series

  16. Analysis of residual stress relief mechanisms in post-weld heat treatment

    International Nuclear Information System (INIS)

    Dong, Pingsha; Song, Shaopin; Zhang, Jinmiao

    2014-01-01

    This paper presents a recent study on weld residual stress relief mechanisms associated with furnace-based uniform post-weld heat treatment (PWHT). Both finite element and analytical methods are used to quantitatively examine how plastic deformation and creep relaxation contribute to residual stress relief process at different stages of PWHT process. The key contribution of this work to an improved understanding of furnace based uniform PWHT can be summarized as follows: (1)Plastic deformation induced stress relief during PWHT can be analytically expressed by the change in material elastic deformation capacity (or elastic deformation limit) measured in terms of material yield strength to Young's modulus ratio, which has a rather limited role in overall residual stress relief during furnace based uniform PWHT. (2)The most dominant stress relief mechanism is creep strain induced stress relaxation, as expected. However, a rapid creep strain development accompanied by a rapid residual stress reduction during heating stage before reaching PWHT temperature is shown to contribute to most of the stress relief seen in overall PWHT process, suggesting PWHT hold time can be significantly reduced as far as residual stress relief is concerned. (3)A simple engineering scheme for estimating residual stress reduction is proposed based on this study by relating material type, PWHT temperature, and component wall thickness. - Highlights: • The paper clarified effects of plastic deformation and creep relaxation on weld residual stress relief during uniform PWHT. • Creep strain development is far more important than plastic strain, mostly completed even before hold time starts. • Plastic strain development is insignificant and be analytically described by a material elastic deformation capacity parameter. • An engineering estimation scheme is proposed for determining residual stress reduction resulted from furnace based PWHT

  17. A study on the bonding residual thermal stress analysis of dissimilar materials using boundary element method

    International Nuclear Information System (INIS)

    Yi, Won; Yu, Yeong Chul; Jeong, Eui Seob; Lee, Chang Ho

    1995-01-01

    It is very important to evaluate the bonding residual thermal stress in dissimilar materials such as LSI package. In this study, the bonding residual thermal stress was calculated using the boundary element method, varing with the sub-element, geometry of specimen and adhesive thickness. The present results reveal a stress singularity at the edge of the interface, therefore the bonding strength of metal/resin interface can be estimated by taking into account it.

  18. Quantitative analysis of residual protein contamination of podiatry instruments reprocessed through local and central decontamination units.

    Science.gov (United States)

    Smith, Gordon Wg; Goldie, Frank; Long, Steven; Lappin, David F; Ramage, Gordon; Smith, Andrew J

    2011-01-10

    The cleaning stage of the instrument decontamination process has come under increased scrutiny due to the increasing complexity of surgical instruments and the adverse affects of residual protein contamination on surgical instruments. Instruments used in the podiatry field have a complex surface topography and are exposed to a wide range of biological contamination. Currently, podiatry instruments are reprocessed locally within surgeries while national strategies are favouring a move toward reprocessing in central facilities. The aim of this study was to determine the efficacy of local and central reprocessing on podiatry instruments by measuring residual protein contamination of instruments reprocessed by both methods. The residual protein of 189 instruments reprocessed centrally and 189 instruments reprocessed locally was determined using a fluorescent assay based on the reaction of proteins with o-phthaldialdehyde/sodium 2-mercaptoethanesulfonate. Residual protein was detected on 72% (n = 136) of instruments reprocessed centrally and 90% (n = 170) of instruments reprocessed locally. Significantly less protein (p podiatry instruments when protein contamination is considered, though no significant difference was found in residual protein between local decontamination unit and central decontamination unit processes for Blacks files. Further research is needed to undertake qualitative identification of protein contamination to identify any cross contamination risks and a standard for acceptable residual protein contamination applicable to different instruments and specialities should be considered as a matter of urgency.

  19. Pesticide residue analysis of soil, water, and grain of IPM basmati rice.

    Science.gov (United States)

    Arora, Sumitra; Mukherji, Irani; Kumar, Aman; Tanwar, R K

    2014-12-01

    The main aim of the present investigations was to compare the pesticide load in integrated pest management (IPM) with non-IPM crops of rice fields. The harvest samples of Basmati rice grain, soil, and irrigation water, from IPM and non-IPM field trials, at villages in northern India, were analyzed using multi-pesticide residue method. The field experiments were conducted for three consecutive years (2008-2011) for the successful validation of the modules, synthesized for Basmati rice, at these locations. Residues of tricyclazole, propiconazole, hexconazole, lambda cyhalothrin, pretilachlor chlorpyrifos, DDVP, carbendazim, and imidacloprid were analyzed from two locations, Dudhli village of Dehradun, Uttrakhand and Saboli and Aterna village of Sonepat, Haryana. The pesticide residues were observed below detectable limit (BDL) (water samples (2008-09). Residues of tricyclazole and carbendazim, analyzed from same locations, revealed pesticide residues as BDL (water samples (2009-2010). The residues of tricyclazole, propioconazole, chlorpyrifos, hexaconazole, pretilachlor, and λ-cyhalothrin were also found as BDL (water samples (<0.001-0.05 μg/L) (2010-2011).

  20. Quantitative analysis of residual protein contamination of podiatry instruments reprocessed through local and central decontamination units

    Directory of Open Access Journals (Sweden)

    Ramage Gordon

    2011-01-01

    Full Text Available Abstract Background The cleaning stage of the instrument decontamination process has come under increased scrutiny due to the increasing complexity of surgical instruments and the adverse affects of residual protein contamination on surgical instruments. Instruments used in the podiatry field have a complex surface topography and are exposed to a wide range of biological contamination. Currently, podiatry instruments are reprocessed locally within surgeries while national strategies are favouring a move toward reprocessing in central facilities. The aim of this study was to determine the efficacy of local and central reprocessing on podiatry instruments by measuring residual protein contamination of instruments reprocessed by both methods. Methods The residual protein of 189 instruments reprocessed centrally and 189 instruments reprocessed locally was determined using a fluorescent assay based on the reaction of proteins with o-phthaldialdehyde/sodium 2-mercaptoethanesulfonate. Results Residual protein was detected on 72% (n = 136 of instruments reprocessed centrally and 90% (n = 170 of instruments reprocessed locally. Significantly less protein (p Conclusions Overall, the results show the superiority of central reprocessing for complex podiatry instruments when protein contamination is considered, though no significant difference was found in residual protein between local decontamination unit and central decontamination unit processes for Blacks files. Further research is needed to undertake qualitative identification of protein contamination to identify any cross contamination risks and a standard for acceptable residual protein contamination applicable to different instruments and specialities should be considered as a matter of urgency.

  1. Structural decomposition analysis of Australia's greenhouse gas emissions

    International Nuclear Information System (INIS)

    Wood, Richard

    2009-01-01

    A complex system of production links our greenhouse gas emissions to our consumer demands. Whilst progress may be made in improving efficiency, other changes in the production structure may easily annul global improvements. Utilising a structural decomposition analysis, a comparative-static technique of input-output analysis, over a time period of around 30 years, net greenhouse emissions are decomposed in this study into the effects, due to changes in industrial efficiency, forward linkages, inter-industry structure, backward linkages, type of final demand, cause of final demand, population affluence, population size, and mix and level of exports. Historically, significant competing forces at both the whole of economy and industrial scale have been mitigating potential improvements. Key sectors and structural influences are identified that have historically shown the greatest potential for change, and would likely have the greatest net impact. Results clearly reinforce that the current dichotomy of growth and exports are the key problems in need of address.

  2. Practical approach on gas pipeline compression system availability analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Sidney Pereira dos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Kurz, Rainer; Lubomirsky, Matvey [Solar Turbines, San Diego, CA (United States)

    2009-12-19

    Gas pipeline projects traditionally have been designed based on load factor and steady state flow. This approach exposes project sponsors to project sustainability risks due to potential losses of revenues and transportation contract penalties related to pipeline capacity shortage as consequence of compressor unit's unavailability. Such unavailability should previously be quantified during the design phase. This paper presents a case study and a methodology that highlights the practical benefits of applying Monte Carlo simulation for the compression system availability analysis in conjunction with quantitative risk analysis and economic feasibility study. Project economics main variables and their impacts on the project NPV (Net Present Value) are evaluated with their respective statistics distribution to quantify risk and support decision makers to adopt mitigating measures to guarantee competitiveness while protecting project sponsors from otherwise unpredictable risks. This practical approach is compared to load factor approach and the results are presented and evaluated. (author)

  3. Numerical analysis of the non-contacting gas face seals

    Science.gov (United States)

    Blasiak, S.

    2017-08-01

    The non-contacting gas face seals are used in high-performance devices where the main requirements are safety and reliability. Compliance with these requirements is made possible by careful research and analysis of physical processes related to, inter alia, fluid flow through the radial gap and ring oscillations susceptible to being housed in the enclosure under the influence of rotor kinematic forces. Elaborating and developing mathematical models describing these phenomena allows for more and more accurate analysis results. The paper presents results of studies on stationary ring oscillations made of different types of materials. The presented results of the research allow to determine which of the materials used causes the greatest amplitude of the vibration of the system fluid film-working rings.

  4. Minimal Residual Disease Evaluation in Childhood Acute Lymphoblastic Leukemia: An Economic Analysis.

    Science.gov (United States)

    2016-01-01

    Minimal residual disease (MRD) testing by higher performance techniques such as flow cytometry and polymerase chain reaction (PCR) can be used to detect the proportion of remaining leukemic cells in bone marrow or peripheral blood during and after the first phases of chemotherapy in children with acute lymphoblastic leukemia (ALL). The results of MRD testing are used to reclassify these patients and guide changes in treatment according to their future risk of relapse. We conducted a systematic review of the economic literature, cost-effectiveness analysis, and budget-impact analysis to ascertain the cost-effectiveness and economic impact of MRD testing by flow cytometry for management of childhood precursor B-cell ALL in Ontario. A systematic literature search (1998-2014) identified studies that examined the incremental cost-effectiveness of MRD testing by either flow cytometry or PCR. We developed a lifetime state-transition (Markov) microsimulation model to quantify the cost-effectiveness of MRD testing followed by risk-directed therapy to no MRD testing and to estimate its marginal effect on health outcomes and on costs. Model input parameters were based on the literature, expert opinion, and data from the Pediatric Oncology Group of Ontario Networked Information System. Using predictions from our Markov model, we estimated the 1-year cost burden of MRD testing versus no testing and forecasted its economic impact over 3 and 5 years. In a base-case cost-effectiveness analysis, compared with no testing, MRD testing by flow cytometry at the end of induction and consolidation was associated with an increased discounted survival of 0.0958 quality-adjusted life-years (QALYs) and increased discounted costs of $4,180, yielding an incremental cost-effectiveness ratio (ICER) of $43,613/QALY gained. After accounting for parameter uncertainty, incremental cost-effectiveness of MRD testing was associated with an ICER of $50,249/QALY gained. In the budget-impact analysis, the

  5. Minimal Residual Disease Evaluation in Childhood Acute Lymphoblastic Leukemia: An Economic Analysis

    Science.gov (United States)

    Gajic-Veljanoski, O.; Pham, B.; Pechlivanoglou, P.; Krahn, M.; Higgins, Caroline; Bielecki, Joanna

    2016-01-01

    Background Minimal residual disease (MRD) testing by higher performance techniques such as flow cytometry and polymerase chain reaction (PCR) can be used to detect the proportion of remaining leukemic cells in bone marrow or peripheral blood during and after the first phases of chemotherapy in children with acute lymphoblastic leukemia (ALL). The results of MRD testing are used to reclassify these patients and guide changes in treatment according to their future risk of relapse. We conducted a systematic review of the economic literature, cost-effectiveness analysis, and budget-impact analysis to ascertain the cost-effectiveness and economic impact of MRD testing by flow cytometry for management of childhood precursor B-cell ALL in Ontario. Methods A systematic literature search (1998–2014) identified studies that examined the incremental cost-effectiveness of MRD testing by either flow cytometry or PCR. We developed a lifetime state-transition (Markov) microsimulation model to quantify the cost-effectiveness of MRD testing followed by risk-directed therapy to no MRD testing and to estimate its marginal effect on health outcomes and on costs. Model input parameters were based on the literature, expert opinion, and data from the Pediatric Oncology Group of Ontario Networked Information System. Using predictions from our Markov model, we estimated the 1-year cost burden of MRD testing versus no testing and forecasted its economic impact over 3 and 5 years. Results In a base-case cost-effectiveness analysis, compared with no testing, MRD testing by flow cytometry at the end of induction and consolidation was associated with an increased discounted survival of 0.0958 quality-adjusted life-years (QALYs) and increased discounted costs of $4,180, yielding an incremental cost-effectiveness ratio (ICER) of $43,613/QALY gained. After accounting for parameter uncertainty, incremental cost-effectiveness of MRD testing was associated with an ICER of $50,249/QALY gained. In

  6. Analysis of Halogen-Mercury Reactions in Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Paula Buitrago; Geoffrey Silcox; Constance Senior; Brydger Van Otten

    2010-01-01

    Oxidized mercury species may be formed in combustion systems through gas-phase reactions between elemental mercury and halogens, such as chorine or bromine. This study examines how bromine species affect mercury oxidation in the gas phase and examines the effects of mixtures of bromine and chlorine on extents of oxidation. Experiments were conducted in a bench-scale, laminar flow, methane-fired (300 W), quartz-lined reactor in which gas composition (HCl, HBr, NO{sub x}, SO{sub 2}) and temperature profile were varied. In the experiments, the post-combustion gases were quenched from flame temperatures to about 350 C, and then speciated mercury was measured using a wet conditioning system and continuous emissions monitor (CEM). Supporting kinetic calculations were performed and compared with measured levels of oxidation. A significant portion of this report is devoted to sample conditioning as part of the mercury analysis system. In combustion systems with significant amounts of Br{sub 2} in the flue gas, the impinger solutions used to speciate mercury may be biased and care must be taken in interpreting mercury oxidation results. The stannous chloride solution used in the CEM conditioning system to convert all mercury to total mercury did not provide complete conversion of oxidized mercury to elemental, when bromine was added to the combustion system, resulting in a low bias for the total mercury measurement. The use of a hydroxylamine hydrochloride and sodium hydroxide solution instead of stannous chloride showed a significant improvement in the measurement of total mercury. Bromine was shown to be much more effective in the post-flame, homogeneous oxidation of mercury than chlorine, on an equivalent molar basis. Addition of NO to the flame (up to 400 ppmv) had no impact on mercury oxidation by chlorine or bromine. Addition of SO{sub 2} had no effect on mercury oxidation by chlorine at SO{sub 2} concentrations below about 400 ppmv; some increase in mercury oxidation

  7. Life-Cycle Energy Use and Greenhouse Gas Emissions Analysis for Bio-Liquid Jet Fuel from Open Pond-Based Micro-Algae under China Conditions

    OpenAIRE

    Xunmin Ou; Xiaoyu Yan; Xu Zhang; Xiliang Zhang

    2013-01-01

    A life-cycle analysis (LCA) of greenhouse gas (GHG) emissions and energy use was performed to study bio-jet fuel (BJF) production from micro-algae grown in open ponds under Chinese conditions using the Tsinghua University LCA Model (TLCAM). Attention was paid to energy recovery through biogas production and cogeneration of heat and power (CHP) from the residual biomass after oil extraction, including fugitive methane (CH 4 ) emissions during the production of biogas and nitrous oxide (N 2 O) ...

  8. Single particle analysis of ice crystal residuals observed in orographic wave clouds over Scandinavia during INTACC experiment

    Directory of Open Access Journals (Sweden)

    A. C. Targino

    2006-01-01

    Full Text Available Individual ice crystal residual particles collected over Scandinavia during the INTACC (INTeraction of Aerosol and Cold Clouds experiment in October 1999 were analyzed by Scanning Electron Microscopy (SEM equipped with Energy-Dispersive X-ray Analysis (EDX. Samples were collected onboard the British Met Office Hercules C-130 aircraft using a Counterflow Virtual Impactor (CVI. This study is based on six samples collected in orographic clouds. The main aim of this study is to characterize cloud residual elemental composition in conditions affected by different airmasses. In total 609 particles larger than 0.1 μm diameter were analyzed and their elemental composition and morphology were determined. Thereafter a hierarchical cluster analysis was performed on the signal detected with SEM-EDX in order to identify the major particle classes and their abundance. A cluster containing mineral dust, represented by aluminosilicates, Fe-rich and Si-rich particles, was the dominating class of particles, accounting for about 57.5% of the particles analyzed, followed by low-Z particles, 23.3% (presumably organic material and sea salt (6.7%. Sulfur was detected often across all groups, indicating ageing and in-cloud processing of particles. A detailed inspection of samples individually unveiled a relationship between ice crystal residual composition and airmass origin. Cloud residual samples from clean airmasses (that is, trajectories confined to the Atlantic and Arctic Oceans and/or with source altitude in the free troposphere were dominated primarily by low-Z and sea salt particles, while continentally-influenced airmasses (with trajectories that originated or traveled over continental areas and with source altitude in the continental boundary layer contained mainly mineral dust residuals. Comparison of residual composition for similar cloud ambient temperatures around –27°C revealed that supercooled clouds are more likely to persist in conditions where

  9. REVIEW ARTICLE: MODELLING AND ANALYSIS OF A GASOLINE ENGINE EXHAUST GAS SYSTEMS

    OpenAIRE

    Barhm Mohamad

    2018-01-01

    The engine exhaust gas behaviour is strongly influencing the engine performance. This paper presents the modelling and analysis of four stroke - gasoline engine exhaust gas systems. An automotive example is considered whereby the pulsating exhausts gas flow through an exhaust pipe and silencer are considered over a wide range of speeds. Analytical procedures are outlined enabling the general analysis and modelling of vehicle engine exhaust gas systems also in this paper present...

  10. Determination of residual volatile organic compounds migrated from polystyrene food packaging into food simulant by headspace solid phase micro extraction-gas chromatography

    International Nuclear Information System (INIS)

    Mohd Marsin Sanagi; Ling, Susie Lu; Zalilah Nasir; Wan Aini Wan Ibrahim; Abu Naim, Ahmedy

    2008-01-01

    The residual styrene and other volatile organic compounds (VOCs) present in the polystyrene food packaging are of concern as these compounds have the potential to migrate into the food in contact. This work describes a method for quantitative determination of VOCs, namely styrene, toluene, ethyl benzene, iso-propylbenzene and n-propylbenzene that have migrated from polystyrene food packaging into food stimulant by gas chromatography-flame ionization detection (GC-FID). Headspace solid phase micro extraction (HS-SPME) technique was applied for migration test using water as food stimulant. The effects of extraction variables including sample volume, eluotropic strength, extraction temperature, extraction time, desorption time, sample agitation, and salt addition on the amounts of the extracted analyses were studied to obtain the optimal HS-SPME conditions. The optimized method was applied to test the VOCs migrated from polystyrene bowls and cups at storage temperatures ranging from 24 to 80 degree Celsius for 30 min. Styrene and ethyl benzene were found to migrate from the samples into the food stimulant. The migration of analyze was found to be strongly dependent upon the storage temperature. The HS-SPME is useful as an alternative method to determine the migration of VOCs from food packaging material into food stimulant. (author)

  11. A Robust Transform Estimator Based on Residual Analysis and Its Application on UAV Aerial Images

    Directory of Open Access Journals (Sweden)

    Guorong Cai

    2018-02-01

    Full Text Available Estimating the transformation between two images from the same scene is a fundamental step for image registration, image stitching and 3D reconstruction. State-of-the-art methods are mainly based on sorted residual for generating hypotheses. This scheme has acquired encouraging results in many remote sensing applications. Unfortunately, mainstream residual based methods may fail in estimating the transform between Unmanned Aerial Vehicle (UAV low altitude remote sensing images, due to the fact that UAV images always have repetitive patterns and severe viewpoint changes, which produce lower inlier rate and higher pseudo outlier rate than other tasks. We performed extensive experiments and found the main reason is that these methods compute feature pair similarity within a fixed window, making them sensitive to the size of residual window. To solve this problem, three schemes that based on the distribution of residuals are proposed, which are called Relational Window (RW, Sliding Window (SW, Reverse Residual Order (RRO, respectively. Specially, RW employs a relaxation residual window size to evaluate the highest similarity within a relaxation model length. SW fixes the number of overlap models while varying the length of window size. RRO takes the permutation of residual values into consideration to measure similarity, not only including the number of overlap structures, but also giving penalty to reverse number within the overlap structures. Experimental results conducted on our own built UAV high resolution remote sensing images show that the proposed three strategies all outperform traditional methods in the presence of severe perspective distortion due to viewpoint change.

  12. Probabilistic fracture mechanics analysis of reactor vessel for pressurized thermal shock: the effect of residual stress and fracture toughness

    International Nuclear Information System (INIS)

    Jung, Sung Gyu; Jin, Tae Eun; Jhung, Myung Jo; Choi, Young Hwan

    2003-01-01

    The structural integrity of the reactor vessel with the approaching end of life must be assured for pressurized thermal shock. The regulation specifies the screening criteria for this and requires that specific analysis be performed for the reactor vessel which is anticipated to exceed the screening criteria at the end of plant life. In case the screening criteria is exceeded by the deterministic analysis, probabilistic analysis must be performed to show that failure probability is within the limit. In this study, probabilistic fracture mechanics analysis of the reactor vessel for pressurized thermal shock is performed and the effects of residual stress and master curve on the failure probability are investigated

  13. Residual stress analysis in carbon fiber-reinforced SiC ceramics; Eigenspannungsanalyse in kohlenstoffaserverstaerkten SiC-Keramiken

    Energy Technology Data Exchange (ETDEWEB)

    Broda, M.

    1998-12-31

    Systematic residual stress analyses are reported, carried out in long-fiber reinforced SiC ceramics. The laminated C{sub fiber}/SiC{sub matrix} specimens used were prepared by polymer pyrolysis, and the structural component specimens used are industrial products. Various diffraction methods have been applied for non-destructive evaluation of residual stress fields, so as to completely detect the residual stresses and their distribution in the specimens. The residual stress fields at the surface ({mu}m) have been measured using characteristic X-radiation and applying the sin {sup 2}{psi} method as well as the scatter vector method. For residual stress field analysis in the mass volume (cm), neutron diffraction has been applied. The stress fields in the fiber layers (approx. 250{mu}m) have been measured as a function of their location within the laminated composite by using an energy-dispersive method and synchrotron radiation. By means of the systematic, process-accompanying residual stress and phase analyses, conclusions can be drawn as to possible approaches for optimization of fabrication parameters. (orig./CB) [Deutsch] Im Rahmen der Arbeit werden systematische Eigenspannungsanalysen an langfaserverstaerkten SiC-Keramiken durchgefuehrt. Hierbei werden polymerpyrolytisch abgeleitete, laminierte C{sub Faser}/SiC{sub Matrix} Proben und Bauteile untersucht, welche industriell gefertigt wurden. Fuer die zerstoerungsfreie Eigenspannungsermittlung kommen verschiedene Beugungsverfahren zum Einsatz. Dadurch kann die Eigenspannungsverteilung in diesen Proben vollstaendig erfasst werden, d.h. der Eigenspannungszustand im Oberflaechenbereich ({mu}m) wird mit Hilfe charakteristischer Roentgenstrahlung unter Nutzung der sin{sup 2}{psi}-Methode als auch der Streuvektor-Methode beschrieben. Fuer die Analyse der Eigenspannungen im Volumen (cm) wird die Neutronenbeugung herangezogen. Um den Spannungszustand in den einzelnen Fasermatten (ca. 250 {mu}m) in Abhaengigkeit ihrer Lage

  14. Analysis of a multicomponent gas absorption system with carrier gas coabsorption

    International Nuclear Information System (INIS)

    Merriman, J.R.

    1975-03-01

    Conventional integrated versions of the packed gas absorber design equations do not account for significant coabsorption of the carrier gas along with the dilute transferring species. These equations, as a result, also neglect the relationship between dilute component transfer and carrier gas coabsorption. In the absorption of Kr and Xe from various carrier gases, using CCl 2 F 2 as the process solvent, carrier coabsorption is substantial. Consequently, a design package was developed to deal with multicomponent gas absorption in systems characterized by carrier gas coabsorption. Developed within the general film theory framework, the basic feature of this design approach is a view of dilute component mass-transfer as a conventional diffusive transfer superimposed on a net flux caused by carrier absorption. Other supporting elements of the design package include predictive techniques for various fluid properties, estimating procedures for carrier gas equilibrium constants, and correlations for carrier gas and dilute gas mass-transfer coefficients. When applied to systems using CCl 2 F 2 as the solvent; He, N 2 , air, or Ar as the carrier gas; and Kr or Xe as the dilute gas; the design approach gave good results, even when extended to conditions well beyond those of its development. (U.S.)

  15. Sensitivity Analysis for Residual Stress on DVI (Direct Vessel Injection) Nozzle Welded Joint

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Byeong Wook; Chung, Sung Ho; Lee, Jung Hun; Kim, Oak Sug [DOOSAN Heavy Industries and Construction Co. LTD, Reactor Design Team, 555 Guygok-dong Changwon (Korea, Republic of)

    2008-07-01

    Generally, any welding process produces high compressive or tensile residual stresses in the heat affected zone depending on the method, shape and procedures of the weldment. In particular, the tensile residual stresses have a considerable effect on the material strength, fatigue strength and corrosion cracking. For this reason, it is important that some knowledge of the internal stress state be deduced either from measurements or from modeling predictions. In this study, the residual stresses after a multi-pass welding process for DVI nozzle welding joint were evaluated by a numerical simulation method. The welding joint considered three weld joint angles of 40 deg., 6 deg. and 2 deg. Computations were made using a 2-D finite element model based on the simulation of cooling from the heat treatment temperature to room temperature with two cooling conditions at the inside surface. In these results, it is shown that the residual stress increased at the inner surface, when water cooling was applied to the inner surface, and axial compressive residual stress increased at the inner surface when the joint angle was decreased. (authors)

  16. Sensitivity Analysis for Residual Stress on DVI (Direct Vessel Injection) Nozzle Welded Joint

    International Nuclear Information System (INIS)

    Noh, Byeong Wook; Chung, Sung Ho; Lee, Jung Hun; Kim, Oak Sug

    2008-01-01

    Generally, any welding process produces high compressive or tensile residual stresses in the heat affected zone depending on the method, shape and procedures of the weldment. In particular, the tensile residual stresses have a considerable effect on the material strength, fatigue strength and corrosion cracking. For this reason, it is important that some knowledge of the internal stress state be deduced either from measurements or from modeling predictions. In this study, the residual stresses after a multi-pass welding process for DVI nozzle welding joint were evaluated by a numerical simulation method. The welding joint considered three weld joint angles of 40 deg., 6 deg. and 2 deg. Computations were made using a 2-D finite element model based on the simulation of cooling from the heat treatment temperature to room temperature with two cooling conditions at the inside surface. In these results, it is shown that the residual stress increased at the inner surface, when water cooling was applied to the inner surface, and axial compressive residual stress increased at the inner surface when the joint angle was decreased. (authors)

  17. Joining of molybdenum disilicide to stainless steel using amorphous metal brazes - residual stress analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, R.U.; Gallegos, D.E.; Kautz, D.D. [Los Alamos National Lab. (United States)

    2007-07-01

    Molybdenum disilicide (MoSi{sub 2})/stainless steel 316 L joints were produced by high temperature brazing using a cobalt-based metallic-glass (METGLAS trademark 2714A). Successful joining was completed in two different ways; either by feeding excess braze into the braze gap upon heating or by constraining the MoSi{sub 2}/stainless steel assembly with an alumina (Al{sub 2}O{sub 3}) fixture during the heating cycle. These steps were necessary to ensure the production of a high quality void free joint. Residual stress measurements were completed on these joints. Indentation results show higher tensile residual stresses in the stainless steel for the joint with the external constraint, in comparison to the unconstrained state. In contrast, the compressive residual stresses in the MoSi{sub 2} (as measured by X-ray diffraction) were lower in the constrained state relative to the unconstrained state. These results and a lack of residual stress balance indicate that the stress state in the braze is significantly different under the two joining conditions and the volume of the braze plays an important role in the development of the residual stresses. Push-out tests carried out on these joints gave higher joint strengths in the unconstrained as compared to the constrained condition. The results of this study have important implications on the selection of the appropriate joining process (use of constraint versus extra braze). (orig.)

  18. Life cycle analysis of biogas from residues; Livscykelanalys av biogas fraan restprodukter

    Energy Technology Data Exchange (ETDEWEB)

    Tufvesson, Linda; Lantz, Mikael [Dep. for Miljoe- och Energisystem, Lunds Tekniska Hoegskola, Lund (Sweden)

    2012-06-15

    The purpose of this study is to carry out life cycle assessments for different biogas systems where biogas is produced from different residues. The investigated residues are distiller's waste, rapeseed cake, whey permeate, concentrated whey permeate, fodder milk, fish residues, bakery residues and glycerol. The environmental impact categories included are climate change, eutrophication, acidification, photochemical ozone creation potential, particles and energy balance. The calculations include emissions from technical systems, especially the energy input in various operations and processes. A general conclusion is that all studied residues are very well suited for production of biogas if there is no demand for them as animal feed today. All biogas systems also reduce the emissions of greenhouse gases compared to petrol and diesel and meet the requirements presented in the EU renewable energy directive (RED). The results of the study also show that the investigated biogas systems are complex and many different parameters affect the result. These parameters are both integrated in the life cycle assessment method, but also in the inventory data used.

  19. Residual stresses analysis in ball end milling of nickel-based superalloy Inconel 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junteng; Zhang, Dinghua; Wu, Baohai; Luo, Ming [Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Northwestern Polytechnical University (China)

    2017-11-15

    Inconel 718 is widely used in the aviation, space, automotive and biomedical industries because of its outstanding properties. Near-surface residual stresses that are induced by ball end milling in Inconel 718 can be crucial for the performance and service time of the machined parts. In this paper, the influences of cutting conditions, including the use of cutting parameters, cutting fluid and spindle angles, on the residual stresses in the ball end milling process of Inconel 718 alloy were investigated experimentally. X-ray diffraction measurements reveal that residual stress distributions are highly influenced by cutting parameters, especially the depth of cut and cutting speed. The milling operation with cooling induces more compressive stresses trend and the magnitude of the residual stresses increases in the tensile direction with the increase of spindle angles. These cutting induced effects were further discussed with respect to thermal- mechanical coupling theory and some observations made by optical microscopy. From this investigation, it is suggested that the machining process parameters are not the smaller the better for the control of residual stresses in the ball end milling process of Inconel 718. (author)

  20. Non-destructive Residual Stress Analysis Around The Weld-Joint of Fuel Cladding Materials of ZrNbMoGe Alloys

    Directory of Open Access Journals (Sweden)

    Parikin

    2003-08-01

    Full Text Available The residual stress measurements around weld-joint of ZrNbMoGe alloy have been carried out by using X-ray diffraction technique in PTBIN-BATAN. The research was performed to investigate the structure of a cladding material with high temperature corrosion resistance and good weldability. The equivalent composition of the specimens (in %wt. was 97.5%Zr1%Nb1%Mo½%Ge. Welding was carried out by using TIG (tungsten inert gas technique that completed butt-joint with a current 20 amperes. Three region tests were taken in specimen while diffraction scanning, While diffraction scanning, tests were performed on three regions, i.e., the weldcore, the heat-affected zone (HAZ and the base metal. The reference region was determined at the base metal to be compared with other regions of the specimen, in obtaining refinement structure parameters. Base metal, HAZ and weldcore were diffracted by X-ray, and lattice strain changes were calculated by using Rietveld analysis program. The results show that while the quantity of minor phases tend to increase in the direction from the base metal to the HAZ and to the weldcore, the quantity of the ZrGe phase in the HAZ is less than the quantity of the ZrMo2 phase due to tGe element evaporation. The residual stress behavior in the material shows that minor phases, i.e., Zr3Ge and ZrMo2, are more dominant than the Zr matrix. The Zr3Ge and ZrMo2 experienced sharp straining, while the Zr phase was weak-lined from HAZ to weldcore. The hydrostatic residual stress ( in around weld-joint of ZrNbMoGe alloy is compressive stress which has minimum value at about -2.73 GPa in weldcore region

  1. Risk analysis for a local gas distribution network

    International Nuclear Information System (INIS)

    Peters, J.W.

    1991-01-01

    Cost control and service reliability are popular topics when discussing strategic issues facing local distribution companies (LDCs) in the 1990s. The ability to provide secure and uninterrupted gas service is crucial for growth and company image, both with the public and regulatory agencies. At the same time, the industry is facing unprecedented competition from alternate fuels, and cost control is essential for maintaining a competitive edge in the market. On the surface, it would appear that cost control and service reliability are contradictory terms. Improvement in service reliability should cost something, or does it? Risk analysis can provide the answer from a distribution design perspective. From a gas distribution engineer's perspective, projects such as loops, backfeeds and even valve placement are designed to reduce, minimize and/or eliminate potential customer outages. These projects improve service reliability by acting as backups should a failure occur on a component of the distribution network. These contingency projects are cost-effective but their longterm benefit or true value is under question. Their purpose is to maintain supply to an area in the distribution network in the event of a failure somewhere else. Two phrases, potential customer outages and in the event of failure, identify uncertainty

  2. Environmental risk analysis for offshore oil and gas activities

    Energy Technology Data Exchange (ETDEWEB)

    Brude, Odd Willy; Aspholm, Ole O.; Rudberg, Anders [Det Norske Veritas (Brazil)

    2008-07-01

    Offshore oil and gas activities always have a risk for environmental impact due to potential accidental releases of oil and gas. The environmental risk can be calculated as a combination of the frequency of such accidents to occur and their environmental consequences in terms of environmental damage to habitats or populations. A method for conducting environmental risk analysis has been in use in Norwegian offshore waters for a decade, with a continuously refinement of methodology over the past years. This paper outlines the principles in the MIRA method and gives examples and discussions regarding use in different environmental compartments. The risk assessment starts with identification of oil spill scenarios with frequencies of potential release rates and spill durations. The next step is to model the oil drift for each accidental oil spill scenario. Drift and fate of oil is modeled probabilistic. Based on the oil spill scenarios and their probability of oil pollution, the potential environmental damage is quantified for each scenario. The endpoint of environmental damage is reduction of a population and the resulting recovery time (in years) for various species and habitats. Environmental risk levels are then evaluated against the operating companies' environmental acceptance criteria. (author)

  3. Segmentation of Residential Gas Consumers Using Clustering Analysis

    Directory of Open Access Journals (Sweden)

    Marta P. Fernandes

    2017-12-01

    Full Text Available The growing environmental concerns and liberalization of energy markets have resulted in an increased competition between utilities and a strong focus on efficiency. To develop new energy efficiency measures and optimize operations, utilities seek new market-related insights and customer engagement strategies. This paper proposes a clustering-based methodology to define the segmentation of residential gas consumers. The segments of gas consumers are obtained through a detailed clustering analysis using smart metering data. Insights are derived from the segmentation, where the segments result from the clustering process and are characterized based on the consumption profiles, as well as according to information regarding consumers’ socio-economic and household key features. The study is based on a sample of approximately one thousand households over one year. The representative load profiles of consumers are essentially characterized by two evident consumption peaks, one in the morning and the other in the evening, and an off-peak consumption. Significant insights can be derived from this methodology regarding typical consumption curves of the different segments of consumers in the population. This knowledge can assist energy utilities and policy makers in the development of consumer engagement strategies, demand forecasting tools and in the design of more sophisticated tariff systems.

  4. Thermal hydrodynamic analysis of a countercurrent gas centrifuge

    International Nuclear Information System (INIS)

    Andrade, Delvonei Alves de

    1999-01-01

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  5. Regional quality control survey of blood-gas analysis.

    Science.gov (United States)

    Minty, B D; Nunn, J F

    1977-09-01

    We undertook an external quality control survey of blood-gas analysis in 16 laboratories at 13 hospitals. All samples were prepared in the laboratories under investigation by equilibration of blood or serum with gas mixtures of known composition. pH of serum was measured with no significant bias but with an SD of random error 0.026 pH units, which was almost twice the SD of the reference range (0.015). An acceptable random error (half SD of reference range) was not obtained in a longitudinal internal quality control suvey although there were acceptable results for buffer pH in both field and internal surveys. Blood PO2 was measured with no significant bias but with SD of random error 1.38 kPa which reduced to 0.72 kPa by excluding one egregious result. The latter value was just over half of the SD of the reference range (1.2 kPa). PCO2 of blood was also measured without significant bias but with a much smaller SD of random error of 0.28 kPa (by excluding one egregious result), which was again just over half the SD of the reference range (0.51 kPa). Measurements of blood PO2 and PCO2 seem generally acceptable in relation to their respective reference ranges but measurements of pH were unsatisfactory in both internal and external trials.

  6. Gas storage services and regulation in Italy. A Delphi analysis

    International Nuclear Information System (INIS)

    Bonacina, Monica; Creti, Anna; Sileo, Antonio

    2009-01-01

    The objective of this paper is to assess to which extent gas market inefficiencies, such as weak competition, import dependence and lack of flexibility tools, affect operation and usage of storage services in Italy in the aftermath of the EU liberalization process. The analysis is supported by the empirical results of a Delphi survey that we have conducted to investigate storage service provision and regulation in Italy. We argue that the Italian storage sector is at a crossroads. The policy-driven phase of liberalization is ending and the market-driven phase has just begun. The former phase has granted fair access to storage, narrowed the likelihood of strategic behaviour by the incumbent and secured residential users against supply disruptions, but it has proved dynamically inefficient. Cost-reflective tariffs and low penalties for unbalances have both lowered incentives to expand the range of flexibility tools and penalized industrial customers demand. The market-driven phase has just started. The expected increase in working capacity and the entry of newcomers in the authorization process for new facilities are a progress towards the commercial use of storage. To this end, however, a further change in gas market design is needed: the creation of a well functioning spot market. (author)

  7. CFD analysis of gas explosions vented through relief pipes.

    Science.gov (United States)

    Ferrara, G; Di Benedetto, A; Salzano, E; Russo, G

    2006-09-21

    Vent devices for gas and dust explosions are often ducted to safe locations by means of relief pipes. However, the presence of the duct increases the severity of explosion if compared to simply vented vessels (i.e. compared to cases where no duct is present). Besides, the identification of the key phenomena controlling the violence of explosion has not yet been gained. Multidimensional models coupling, mass, momentum and energy conservation equations can be valuable tools for the analysis of such complex explosion phenomena. In this work, gas explosions vented through ducts have been modelled by a two-dimensional (2D) axi-symmetric computational fluid dynamic (CFD) model based on the unsteady Reynolds Averaged Navier Stokes (RANS) approach in which the laminar, flamelet and distributed combustion models have been implemented. Numerical test have been carried out by varying ignition position, duct diameter and length. Results have evidenced that the severity of ducted explosions is mainly driven by the vigorous secondary explosion occurring in the duct (burn-up) rather than by the duct flow resistance or acoustic enhancement. Moreover, it has been found out that the burn-up affects explosion severity due to the reduction of venting rate rather than to the burning rate enhancement through turbulization.

  8. Metaphysics methods development for high temperature gas cooled reactor analysis

    International Nuclear Information System (INIS)

    Seker, V.; Downar, T. J.

    2007-01-01

    Gas cooled reactors have been characterized as one of the most promising nuclear reactor concepts in the Generation-IV technology road map. Considerable research has been performed on the design and safety analysis of these reactors. However, the calculational tools being used to perform these analyses are not state-of-the-art and are not capable of performing detailed three-dimensional analyses. This paper presents the results of an effort to develop an improved thermal-hydraulic solver for the pebble bed type high temperature gas cooled reactors. The solution method is based on the porous medium approach and the momentum equation including the modified Ergun's resistance model for pebble bed is solved in three-dimensional geometry. The heat transfer in the pebble bed is modeled considering the local thermal non-equilibrium between the solid and gas, which results in two separate energy equations for each medium. The effective thermal conductivity of the pebble-bed can be calculated both from Zehner-Schluender and Robold correlations. Both the fluid flow and the heat transfer are modeled in three dimensional cylindrical coordinates and can be solved in steady-state and time dependent. The spatial discretization is performed using the finite volume method and the theta-method is used in the temporal discretization. A preliminary verification was performed by comparing the results with the experiments conducted at the SANA test facility. This facility is located at the Institute for Safety Research and Reactor Technology (ISR), Julich, Germany. Various experimental cases are modeled and good agreement in the gas and solid temperatures is observed. An on-going effort is to model the control rod ejection scenarios as described in the OECD/NEA/NSC PBMR-400 benchmark problem. In order to perform these analyses PARCS reactor simulator code will be coupled with the new thermal-hydraulic solver. Furthermore, some of the other anticipated accident scenarios in the benchmark

  9. Analysis of hydrodynamic regimes of operation of a gas pipeline from the Samotlor field to the Nizhnevartovsk gas refinery

    Energy Technology Data Exchange (ETDEWEB)

    Al' tshular, S A; Bragunov, N I; Ivanov, V N; Izmaylov, I Ye; Koroleva, L N

    1979-01-01

    Results are presented from studying the hydraulic losses of a gas-transport system. Oil gas in the first stage of separation of the Samotlor field according to the plan is transported on two gas pipelines to the Nizhnevartovsk and Belozersk gas refinery. On the route of the first gas pipeline in order to remove the released condensate, 12 gas-separator and condensate-settling tanks are installed. The second gas pipeline in the beginning, middle and end has asemblies for additional separation (separation (separator, drop-separator, condensate-collector). The studied material is presented in the form of the dependence of actual calculatedcoefficients of hydraulic resistance on the rate of gas supply in the range 80,000-230,000 m/sup 3//h (Re-(0.82.0) X 10/sup -6/. It has been established that with Re=1.6 X 10/sup -6/ the calculated and actual coeffic-ients of resistance become the same, while with smaller values of Re, the actual values exceed the calculated by 20-40%. In the opinion of the authors this difference is due to the effect of the liquid phase with low velocities of gas and the formation of stable foam. As a result of transillumination it was also established that the regime of flow on the ascending part is dispersion-ring and dispersion-semiring, and on the descending part stratified. Analysis of the transport of the gas-condensate stream with ring regime of flow permitted the authors to hypothesize transporting of gas without removal of the condensate. A certain increase in the coefficients of resistance for the case where the condensate is not removed from the gas pipeline is noted with experimental realization of the proposed variant. It is explained by the low velocities of gas in the beginning of the gas pipeline. It is stressed that the actual and calculated pressure differentials are distinguished less than the calculated and actual coefficients of resistance and that this indicates the practical preservation of the throughput of the gas pipeline.

  10. Observation and analysis of tidal and residual current in the North Yellow Sea in the spring

    Science.gov (United States)

    Miao, Qingsheng; Yang, Jinkun; Yang, Yang; Wan, Fangfang; Yu, Jia

    2018-02-01

    In order to study the current characteristics of the North Yellow Sea (NYS), 4 moored ADCPs (Acoustic Doppler Current Profilers) were deployed and Current characteristics were analyzed based on the observations. Results show that tidal current is the dominant and M2 is the main constituent. Shallow water constituents are obvious in the near-shore area, and tidal current ellipses directions have relations with topography. Residual currents in the Bohai Strait point to the Bohai Sea interior and the magnitude have a connection with terrain. Residual current in south NYS can be divided into two layers, and energy of residual current only accounts for about 13% of the total energy. Barotropic eddy kinetic energy plays a major role and the average in NYS accounts for 87%, baroclinic mean kinetic energy is larger in north NYS, in other regions barotropic mean kinetic energy take the leading position.

  11. Analysis of hollow fibre membrane systems for multicomponent gas separation

    KAUST Repository

    Khalilpour, Rajab; Abbas, Ali; Lai, Zhiping; Pinnau, Ingo

    2013-01-01

    nonlinear differential algebraic equation system is solved via a combination of backward differentiation and Gauss-Seidel methods. Natural gas sweetening problem is investigated as a case study. Model parametric analyses of variables, namely feed gas quality

  12. Headspace Solid Phase Microextraction in Pesticide Residues Analysis:1. Optimisation of Extraction Conditions

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2007-01-01

    Full Text Available The method of headspace solid phase microextraction (HS/SPME was successfully used in a simultaneous multicomponent analysis of hexachlorobenzene (HCB, tefluthrin, heptachlor, aldrin, chlorpyrifos, fenthion and bifenthrin in aqueous medium. Measurementswere performed using a nonpolar polydimethyl siloxane (PDMS fiber. Detection and quantification were done by gas chromatography/mass spectrometry (GC/MS.Optimal conditions for HS/SPME were determined both by performing extraction at different temperatures and examining extraction time profiles at constant temperature. Optimal extraction temperature for each pesticide studied was determined as follows: 60°C for HCB and for heptachlor, 80°C for aldrin and for chlorpyrifos, fenthion and tefluthrin, and temperature exceeding 80°C for bifenthrin. For the pesticide mixture studied, 60°C was identified as the optimum extraction temperature.Based on the time profiles obtained, it was confirmed that satisfactory extraction sensitivity can be obtained even for extraction times shorter than the time required to reach a sorption equilibrium. This conclusion was confirmed by linear concentration profiles obtained for the following ranges: 0.05-10 ng/ml (HCB, 0.05-25 ng/ml (tefluthrin, 0.05-40 ng/ml (heptachlor, 0.05-40 ng/ml (aldrin, 0.05-25 ng/ml (chlorpyrifos, 0.05-25 ng/ml (fenthionand 0.05-25 ng/ml (bifenthrin.Relative standard deviation (RSD values for triplicate measurements did not exceed 15%.

  13. Greenhouse gas emission inventory based on full energy chain analysis

    International Nuclear Information System (INIS)

    Dones, R.; Hirschberg, S.; Knoepfel, I.

    1996-01-01

    Methodology, characteristics, features and results obtained for greenhouse gases within the recent Swiss LCA study 'Environmental Life-Cycle Inventories of Energy Systems' are presented. The focus of the study is on existing average Full Energy Chains (FENCHs) in the electricity generation mixes in Europe and in Switzerland. The systems, including coal (hard coal and lignite), oil, natural gas, nuclear and hydro, are discussed one by one as well as part of the electricity mixes. Photovoltaic systems are covered separately since they are not included in the electricity mixes. A sensitivity analysis on methane leakage during long-range transport via pipeline is shown. Whilst within the current study emissions are not attributed to specific countries, the main sectors contributing to the total GHGs emissions calculated for the various FENCHs are specified. (author). 10 refs, 10 figs, 9 tabs

  14. Greenhouse gas emission inventory based on full energy chain analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dones, R; Hirschberg, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Knoepfel, I [Federal Inst. of Technology Zurich, Zurich (Switzerland)

    1996-07-01

    Methodology, characteristics, features and results obtained for greenhouse gases within the recent Swiss LCA study `Environmental Life-Cycle Inventories of Energy Systems` are presented. The focus of the study is on existing average Full Energy Chains (FENCHs) in the electricity generation mixes in Europe and in Switzerland. The systems, including coal (hard coal and lignite), oil, natural gas, nuclear and hydro, are discussed one by one as well as part of the electricity mixes. Photovoltaic systems are covered separately since they are not included in the electricity mixes. A sensitivity analysis on methane leakage during long-range transport via pipeline is shown. Whilst within the current study emissions are not attributed to specific countries, the main sectors contributing to the total GHGs emissions calculated for the various FENCHs are specified. (author). 10 refs, 10 figs, 9 tabs.

  15. Impact damage and residual strength analysis of composite panels with bonded stiffeners. [for primary aircraft structures

    Science.gov (United States)

    Madan, Ram C.; Shuart, Mark J.

    1990-01-01

    Blade-stiffened, compression-loaded cover panels were designed, manufactured, analyzed, and tested. All panels were fabricated from IM6/1808I interleafed graphite-epoxy. An orthotropic blade stiffener and an orthotropic skin were selected to satisfy the design requirements for an advanced aircraft configuration. All specimens were impact damaged prior to testing. Experimental results were obtained for three- and five-stiffener panels. Analytical results described interlaminar forces caused by impact and predicted specimen residual strength. The analytical results compared reasonably with the experimental results for residual strength of the specimens.

  16. BOOK REVIEW: Analysis of Residual Stress by Diffraction Using Neutron and Synchrotron Radiation

    Science.gov (United States)

    Fitzpatrick, ed M. E.; Lodini, A.

    2003-09-01

    The presence of residual stresses within engineering components is often a key feature in determining their usable lifetimes and failure characteristics. Residual surface compression can, for example, restrict the propagation of surface cracks through the bulk. As a consequence, it is essential to characterize the magnitude and spatial distribution of residual stresses and, at least for non-destructive testing, this is most widely achieved using diffraction of neutron and high energy synchrotron radiations. This book aims to provide a detailed description of the methodology used to determine residual stresses. The major emphasis is placed on the neutron method, this being the more widely established approach at present. It contains 20 chapters contributed by 23 authors, divided into five major parts. The overall layout is very logical, with the first part giving a general introduction to the use of neutrons and x-rays for materials research and summarizing the methods used for their production. Part 2 considers the more specific aspects of extracting the residual stress distribution within a bulk sample and includes some valuable comments on a number of potential experimental problems, such as the determination of the stress-free lattice parameter and the effects of broadening of the Bragg peaks. The experimental facilities currently available or under development are described in part 3, with the remaining two parts devoted to general and specific applications of the residual stress measurement technique. As expected with such a large number of different authors, there is some variation in style and quality. However, the text is generally easy to follow and, more importantly, it is largely free of the problems of inconsistent notation and dupication of material that can afflict multi-authored texts. My only negative comment concerns the latter portion of the book devoted to specific applications of the technique, which is illustrative rather than comprehensive. In

  17. Analysis of core-periphery organization in protein contact networks reveals groups of structurally and functionally critical residues.

    Science.gov (United States)

    Isaac, Arnold Emerson; Sinha, Sitabhra

    2015-10-01

    The representation of proteins as networks of interacting amino acids, referred to as protein contact networks (PCN), and their subsequent analyses using graph theoretic tools, can provide novel insights into the key functional roles of specific groups of residues. We have characterized the networks corresponding to the native states of 66 proteins (belonging to different families) in terms of their core-periphery organization. The resulting hierarchical classification of the amino acid constituents of a protein arranges the residues into successive layers - having higher core order - with increasing connection density, ranging from a sparsely linked periphery to a densely intra-connected core (distinct from the earlier concept of protein core defined in terms of the three-dimensional geometry of the native state, which has least solvent acce