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Sample records for acetate-based multi-residue method

  1. Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce

    NARCIS (Netherlands)

    Mol, H.G.J.; Rooseboom, A.; Dam, R. van; Roding, M.; Arondeus, K.; Sunarto, S.

    2007-01-01

    The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary-secondary amine and graphitized carbon black) and large-volume (20 μL) injecti

  2. Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce

    NARCIS (Netherlands)

    Mol, J.G.J.; Rooseboom, A.; Dam, van R.; Roding, M.; Arondeus, K.; Sunarto, S.

    2007-01-01

    The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary¿secondary amine and graphitized carbon black) and large-volume (20 ¿L) injecti

  3. Guidelines for the validation of qualitative multi-residue methods used to detect pesticides in food

    NARCIS (Netherlands)

    Mol, J.G.J.; Reynolds, S.L.; Fussell, R.J.; Stajnbaher, D.

    2012-01-01

    There is a current trend for many laboratories to develop and use qualitative gas chromatography–mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) based multi-residue methods (MRMs) in order to greatly increase the number of pesticides that they can target. Before these q

  4. Rapid detection of pesticides not amenable to multi-residue methods by flow injection-tandem mass spectrometry

    NARCIS (Netherlands)

    Mol, J.G.J.; Dam, van R.C.J.

    2014-01-01

    Flow injection combined with tandem mass spectrometry (MS/MS) was investigated for the rapid detection of highly polar pesticides that are not amenable to multi-residue methods because they do not partition into organic solvents and require dedicated chromatographic conditions. The pesticides includ

  5. [Multi-residue method for determination of veterinary drugs and feed additives in meats by HPLC].

    Science.gov (United States)

    Chonan, Takao; Fujimoto, Toru; Ueno, Ken-Ichi; Tazawa, Teijiro; Ogawa, Hiroshi

    2007-10-01

    A simple and rapid multi-residue method was developed for the determination of 28 kinds of veterinary drugs and feed additives (drugs) in muscle of cattle, pig and chicken. The drugs were extracted with acetonitrile-water (95:5) in a homogenizer and ultrasonic generator. The extracted solution was poured into an alumina column and the drugs were eluted with acetonitrile-water (90:10). The eluate was washed with n-hexane saturated with acetonitrile and then evaporated. The drugs were separated on a Inertsil ODS-3V column (4.6 mm i.d. x 250 mm) with a gradient system of 0.1% phosphoric acid-acetonitrile as the mobile phase, with monitoring at 280 and 340 nm. The recoveries of the 26 kinds of drugs were over 60% from the meats fortified at 0.1 microg/g, and the quantification limits of most drugs were 0.01 microg/g. This proposed method was found to be effective and suitable for the screening of the above drugs in meats.

  6. Multi-residue method for the analysis of pesticides in Arabica coffee using liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Dias, Cláudia M; Oliveira, Fabiano A; Madureira, Fernando D; Silva, Gilsara; Souza, Wesley R; Cardeal, Zenilda L

    2013-01-01

    Coffee is a major tropical agricultural commodity and represents a significant fraction of the economy of many countries. However, certain plant and animal species can damage coffee crops, affecting trade. A solution to this issue is the use of pesticides, some of which are harmful to human health and the environment. This work consisted of the development of a multi-residue method for the analysis of pesticides in coffee by using LC-MS/MS. The QuEChERS extraction procedure was used. The following analytical parameters were optimised: selectivity, analytical range, linearity, LOD, LOQ, precision (RSD%) and recovery of the method. The results showed that the method is selective, as they were linear in the range of 10.0-100.0 µg kg(-1). The sensitivity, recovery and precision were adequate for the multi-residue analysis of pesticides in coffee. The method was applied to the analyses of 15 Brazilian coffee samples.

  7. Multi-residue method for detecting coccidiostats at carry-over level in feed by HPLC-MS/MS.

    Science.gov (United States)

    Delahaut, Ph; Pierret, G; Ralet, N; Dubois, M; Gillard, N

    2010-06-01

    A multi-residue HPLC-ESI-MS/MS method has been developed for the simultaneous extraction, detection and confirmation of the 11 coccidiostats referenced by Regulation 2009/8/EC (lasalocid sodium, narasin, salinomycin sodium, monensin sodium, semduramicin sodium, maduramicin ammonium alpha, robenidine hydrochloride, decoquinate, halofuginone hydrobromide, nicarbazin, and diclazuril) in feedstuffs at carry-over level. The sensitivity of the method allows quantification and confirmation for all coccidiostats below target concentration. The method was in-house validated and meets all criteria of European legislation (2002/657/EC). The precision of the method was determined under repeatability and within-laboratory reproducibility conditions; RSD(r) and RSD(R) were below the maximum permitted values for every tested concentration. The specificity was checked by analysing representative blank samples and blank samples fortified with potentially interfering substances (benzimidazoles, corticosteroides, triphenylmethane dyes, quinolones, nitrofurans, nitroimidazoles, phenicols); no interference were found. Concerning quantification, a quadratic regression model was fitted to every calibration curve with a regression coefficient r2 above 0.99 on each data set. Finally, the expanded uncertainty U was calculated with data obtained within the laboratory while applying the method during validation and in routine tests.

  8. Multi-residue method for the determination of antibiotics and some of their metabolites in seafood.

    Science.gov (United States)

    Serra-Compte, Albert; Álvarez-Muñoz, Diana; Rodríguez-Mozaz, Sara; Barceló, Damià

    2017-06-01

    The presence of antibiotics in seafood for human consumption may pose a risk for consumers. A methodology for the analysis of antibiotics in seafood based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction, followed by detection and quantification using liquid chromatography coupled to mass spectrometry was developed. The analytical method was evaluated for the determination of 23 antibiotics (including parent compounds and some metabolites) in fish, mussels and clams. Recoveries ranged between 30% and 70% for most of the compounds and method detection and quantification limits (MDLs and MQLs) were between 0.01 and 0.31 ng/g dry weigh (dw) and 0.02-1.03 ng/g (dw) respectively. Real seafood samples were analysed using this method. Nine antibiotics were found at levels above MDLs; however none of them exceed the maximum residue limits (MRL) established by the authorities. Tetracycline was the most ubiquitous compound, presenting also the highest concentration: 5.63 ng/g (dw) in fish from Netherlands. In addition, an alternative technique based on microbial growth inhibition was explored as semiquantitative detection method of antibiotics in seafood. This methodology could be applied as a fast screening technique for the detection of macrolides and β-lactams in seafood but further research is needed for other antibiotics families. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. A multi-residue method for characterization of endocrine disruptors in gaseous and particulate phases of ambient air

    Science.gov (United States)

    Alliot, Fabrice; Moreau-Guigon, Elodie; Bourges, Catherine; Desportes, Annie; Teil, Marie-Jeanne; Blanchard, Martine; Chevreuil, Marc

    2014-08-01

    A number of semi-volatile compounds occur in indoor air most of them being considered as potent endocrine disruptors and thus, exerting a possible impact upon health. To assess their concentration levels in indoor air, we developed and validated a method for sampling and multi-residue analysis of 58 compounds including phthalates, polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), parabens, bisphenol A (BPA) and tetrabromobisphenol A (TBBPA) in gaseous and particulate phases of air. We validated each step of procedures from extraction until analysis. Matrice spiking were performed at extraction, fractionation and purification stages. The more volatile compounds were analyzed with a gas chromatography system coupled with a mass spectrometer (GC/MS) or with a tandem mass spectrometer (GC/MS/MS). The less volatile compounds were analyzed with a liquid chromatography system coupled with a tandem mass spectrometer (LC/MS/MS). Labeled internal standard method was used ensuring high quantification accuracy. The instrumental detection limits were under 1 pg for all compounds and therefore, a limit of quantification averaging 1 pg m-3 for the gaseous and the particulate phases and a volume of 150 m3, except for phthalates, phenol compounds and BDE-209. Satisfactory recoveries were found except for phenol compounds. That method was successfully applied to several indoor air samples (office, apartment and day nursery) and most of the targeted compounds were quantified, mainly occurring in the gaseous phase. The most abundant were phthalates (up to 918 ng m-3 in total air), followed by PCBs > parabens > BPA > PAHs > PBDEs.

  10. Multi-residue and multi-class method for the determination of antibiotics in bovine muscle by ultra-high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Freitas, Andreia; Barbosa, Jorge; Ramos, Fernando

    2014-09-01

    A multi-residue quantitative screening method covering 41 antibiotics from 7 different families, by ultra-high-performance-liquid-chromatography tandem mass spectrometry (UHPLC-MS/MS), is described. Sulfonamides, trimethoprim, tetracyclines, macrolides, quinolones, penicillins and chloramphenicol are simultaneously detected after a simple sample preparation of bovine muscle optimized to achieve the best recovery for all compounds. A simple sample treatment was developed consisting in an extraction with a mixture of acetonitrile and ethylenediaminetetraacetic acid (EDTA), followed by a defatting step with n-hexane. The methodology was validated, in accordance with Decision 2002/657/EC by evaluating the required parameters: decision limit (CCα), detection capability (CCβ), specificity, repeatability and reproducibility. Precision in terms of relative standard deviation was under 20% for all compounds and the recoveries between 91% and 119%. CCα and CCβ were determined according the maximum residue limit (MRL) or the minimum required performance limit (MRPL), when required.

  11. Validation and application of a multi-residue method, using accelerated solvent extraction followed by gas chromatography, for pesticides quantification in soil.

    Science.gov (United States)

    Leyva-Morales, J B; Valdez-Torres, J B; Bastidas-Bastidas, P J; Betancourt-Lozano, M

    2015-01-01

    A multi-residue method was developed to determine different types of pesticides in soils. An extraction with pressure and temperature, through accelerated solvent extraction (dichloromethane:acetone, 50:50, v/v). The pesticides were determined by gas chromatography with several selective detectors: electron capture detector, pulsed flame photometric detector and thermionic specific detector. The following parameters were determined: limit of detection, limit of quantification, equipment linearity (working interval), method linearity as well as, method accuracy and precision. The average recoveries ranged between 76 and 106%, with the exception of chlorothalonil, which had an average recovery of 46%. Additionally, detection limits from 0.9 to 7.6ng g -: (1) and the quantification limits from 3.00 to 25.47ng g -: (1) were estimated. In terms of linearity and precision, the results obtained were in the ranges considered adequate (R(2) ≥ 0.98 and coefficient of variation (CV) ≤ 20%), with the exception of aldrin (R(2) = 0.946, CV = 35.79%), lindane (R(2) = 0.917, CV = 32.91%) and chlorothalonil (R(2) = 0.8184, CV = 81.35%). The proposed method was used to evaluate pesticides in real soil samples, detecting concentrations over 1000ng g -: (1) for some pesticides. The method was correctly validated and provided for the rapid determination of pesticides in soil.

  12. [Validation Study on a Multi-Residue Method for Determination of Pesticide Residues in Vegetables and Fruits by using General Matrix Standard Solutions].

    Science.gov (United States)

    Fukui, Naoki; Takatori, Satoshi; Yamaguchi, Satoko; Kitagawa, Yoko; Yoshimitsu, Masato; Osakada, Masakazu; Kajimura, Keiji; Obana, Hirotaka

    2015-01-01

    Quantitative methods using the matrix-matched standard solutions approach are widely used for multi-residue pesticide determination by GC-MS/MS to deal with the issue of matrix effects. However, preparing matrix-matched standard solutions in analyses of many kinds of samples is very time-consuming. In order to solve this problem, a method that employs general matrix standard solutions has been developed using polyethylene glycol (PEG), extract of vegetables-fruit juice (VFJm) and triphenyl phosphate (named the PEG-VFJm method). Here, a validation study for 168 pesticides was performed on three kinds of samples [potato, spinach and apple] at concentrations of 0.010 and 0.050 μg/g. In these three commodities, 144 to 158 pesticides satisfied the required criteria using the matrix-matched method and 129 to 149 pesticides satisfied the same criteria using the PEG-VFJm method. Our results suggest that application of general matrix standard solutions would enable rapid and effective analyses of pesticides.

  13. [Study of multi-residue method for determining pesticide residues in processed foods manufactured from agricultural products by LC-MS/MS].

    Science.gov (United States)

    Fukui, Naoki; Takatori, Satoshi; Kitagawa, Yoko; Okihashi, Masahiro; Kajimura, Keiji; Obana, Hirotaka

    2013-01-01

    A rapid multi-residue method for determination of pesticide residues in processed foods manufactured from agricultural products was examined. Five mL water was added to 5 g sample in a polypropylene tube, and the tube was left to stand at room temperature for 30 min. Then, 20 mL acetonitrile was added to the sample. The mixture was homogenized in a high-speed homogenizer, followed by salting out with 1 g NaCl and 4 g anhydrous MgSO4. After centrifugation, the organic layer was purified on a graphitized carbon/PSA cartridge column. After removal of the solvent, the extract was resolved in methanol-water and analyzed with LC-MS/MS. The recoveries of 93 pesticides fortified into 5 kinds of processed foods [Chinese cabbage kimchi, marmalade, raisin, umeboshi (pickled plum) and worcester sauce] were examined at the concentrations of 0.02 and 0.1 μg/g (n=5). The recoveries of 61 pesticides in all foods were 70-120% with relative standard deviation below 20% at both concentrations. Seventy-four processed foods obtained from markets in Japan were examined with this method. Pesticide residues over the maximum residue limit (0.01 μg/g) were detected in 2 processed foods.

  14. Development and comparison of two multi-residue methods for the analysis of select pesticides in honey bees, pollen, and wax by gas chromatography-quadrupole mass spectrometry.

    Science.gov (United States)

    Li, Yuanbo; Kelley, Rebecca A; Anderson, Troy D; Lydy, Michael J

    2015-08-01

    One of the hypotheses that may help explain the loss of honey bee colonies worldwide is the increasing potential for exposure of honey bees to complex mixtures of pesticides. To better understand this phenomenon, two multi-residue methods based on different extraction and cleanup procedures have been developed, and compared for the determination of 11 relevant pesticides in honey bees, pollen, and wax by gas chromatography-quadrupole mass spectrometry. Sample preparatory methods included solvent extraction followed by gel permeation chromatography (GPC) cleanup and cleanup using a dispersive solid-phase extraction with zirconium-based sorbents (Z-Sep). Matrix effects, method detection limits, recoveries, and reproducibility were evaluated and compared. Method detection limits (MDL) of the pesticides for the GPC method in honey bees, pollen, and wax ranged from 0.65 to 5.92 ng/g dw, 0.56 to 6.61 ng/g dw, and 0.40 to 8.30 ng/g dw, respectively, while MDLs for the Z-Sep method were from 0.33 to 4.47 ng/g dw, 0.42 to 5.37 ng/g dw, and 0.51 to 5.34 ng/g dw, respectively. The mean recoveries in all matrices and at three spiking concentrations ranged from 64.4% to 149.5% and 71.9% to 126.2% for the GPC and Z-Sep methods, with relative standard deviation between 1.5-25.3% and 1.3-15.9%, respectively. The results showed that the Z-Sep method was more suitable for the determination of the target pesticides, especially chlorothalonil, in bee hive samples. The Z-Sep method was then validated using a series of field-collected bee hive samples taken from honey bee colonies in Virginia.

  15. Development of a multi-residue analytical method for TBBP-A and PBDEs in various biological matrices using unique reduced size sample

    Energy Technology Data Exchange (ETDEWEB)

    Andre, F.; Cariou, R.; Antignac, J.P.; Le Bizec, B. [Ecole Nationale Veterinaire de Nantes (FR). Laboratoire d' Etudes des Residus et Contaminants dans les Aliments (LABERCA); Debrauwer, L.; Zalko, D. [Institut National de Recherches Agronomiques (INRA), 31-Toulouse (France). UMR 1089 Xenobiotiques

    2004-09-15

    The impact of brominated flame retardants on the environment and their potential risk for animal and human health is a present time concern for the scientific community. Numerous studies related to the detection of tetrabromobisphenol A (TBBP-A) and polybrominated diphenylethers (PBDEs) have been developed over the last few years; they were mainly based on GC-ECD, GC-NCI-MS or GC-EI-HRMS, and recently GC-EI-MS/MS. The sample treatment is usually derived from the analytical methods used for dioxins, but recently some authors proposed the utilisation of solid phase extraction (SPE) cartridges. In this study, a new analytical strategy is presented for the multi-residue analysis of TBBP-A and PBDEs from a unique reduced size sample. The main objective of this analytical development is to be applied for background exposure assessment of French population groups to brominated flame retardants, for which, to our knowledge, no data exist. A second objective is to provide an efficient analytical tool to study the transfer of these contaminants through the environment to living organisms, including degradation reactions and metabolic biotransformations.

  16. Simplified RP-HPLC method for multi-residue analysis of abamectin, emamectin benzoate and ivermectin in rice.

    Science.gov (United States)

    Xie, Xianchuan; Gong, Shu; Wang, Xiaorong; Wu, Yinxing; Zhao, Li

    2011-01-01

    A rapid, reliable and sensitive reverse-phase high-performance liquid chromatography method with fluorescence detection (RP-FLD-HPLC) was developed and validated for simultaneous analysis of the abamectin (ABA), emamectin (EMA) benzoate and ivermectin (IVM) residues in rice. After extraction with acetonitrile/water (2 : 1) with sonication, the avermectin (AVMs) residues were directly derivatised by N-methylimidazole (N-NMIM) and trifluoroacetic anhydride (TFAA) and then analysed on RP-FLD-HPLC. A good linear relationship (r(2 )> 0.99) was obtained for three AVMs ranging from 0.01 to 5 microg ml(-1), i.e. 0.01-5.0 microg g(-1) in rice matrix. The limit of detection (LOD) and the limit of quantification (LOQ) were between 0.001 and 0.002 microg g(-1) and between 0.004 and 0.006 microg g(-1), respectively. Recoveries were from 81.9% to 105.4% and precision less than 12.4%. The proposed method was successfully applied to routine analysis of the AVMs residues in rice.

  17. Development of a multi-residue method for the determination of human and veterinary pharmaceuticals and some of their metabolites in aqueous environmental matrices by SPE-UHPLC-MS/MS.

    Science.gov (United States)

    Paíga, P; Santos, L H M L M; Delerue-Matos, C

    2017-02-20

    The aim of the present work was to develop and validate a multi-residue method for the analysis of 33 human and veterinary pharmaceuticals (non-steroidal anti-inflammatory drugs (NSAIDs)/analgesics, antibiotics and psychiatric drugs), including some of their metabolites, in several aqueous environmental matrices: drinking water, surface water and wastewaters. The method is based on solid phase extraction (SPE) followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and it was validated for different aqueous matrices, namely bottled water, tap water, seawater, river water and wastewaters, showing recoveries between 50% and 112% for the majority of the target analytes. The developed analytical methodology allowed method detection limits in the low nanograms per liter level. Method intra- and inter-day precision was under 8% and 11%, respectively, expressed as relative standard deviation. The developed method was applied to the analysis of drinking water (bottled and tap water), surface waters (seawater and river water) and wastewaters (wastewater treatment plant (WWTP) influent and effluent). Due to the selectivity and sensitivity of the optimized method, it was possible to detect pharmaceuticals in all the aqueous environmental matrices considered, including in bottled water at concentrations up to 31ngL(-1) (salicylic acid). In general, non-steroidal anti-inflammatory drugs/analgesics was the therapeutic group most frequently detected, with the highest concentrations found in wastewaters (acetaminophen and the metabolite carboxyibuprofen at levels up to 615 and 120μgL(-1), respectively).

  18. Application of dispersive Liquid-Liquid microextraction based on solidification of floating organic droplet multi-residue method for the simultaneous determination of polychlorinated biphenyls, organochlorine, and pyrethroid pesticides in aqueous sample

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Mei; Li, Man-Liang [Enshi Prefecture Tobacco Company, Enshi, Hubei (China); Cheng, Jing; Matsadiq, Guzalnur; Liu, Lu; Zhang, Miao [Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan (China)

    2012-12-15

    Dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) technique was successfully applied for simultaneous assay of eight polychlorinated biphenyls, two organochlorine, and four pyrethroid pesticides multi-residue in aqueous samples by using GC-electron capture detection. The effects of various parameters such as kind of extractant and dispersant and volume of them, extraction time, effect of salt addition, and pH were optimized. As a result, 5.0 {mu}L 1-dodecanol was chosen as extraction solvent, 600 {mu}L methanol were used as dispersive solvent without salt addition, pH was adjusted to 7. Under the optimized conditions, the limits of detection (LOD) were ranged from 1.4 to 8.3 ng L{sup -1}. Satisfactory linear range was observed from 5.0 to 2000 ng L{sup -1} with correlation coefficient better than 0.9909. Good precisions were also acquired with RSD better than 13.6% for all target analytes. The enrichment factors of the method were ranged from 786 to 1427. The method can be successfully applied to simultaneous separation and determination of three class residues in real water samples and good recoveries were obtained ranging from 76 to 130, 73 to 129, and 78 to 130% for tap water, lake water, and industrial waste water, respectively. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. A multi-residue method for the determination of pesticides in tea using multi-walled carbon nanotubes as a dispersive solid phase extraction absorbent.

    Science.gov (United States)

    Hou, Xue; Lei, Shaorong; Qiu, Shiting; Guo, Lingan; Yi, Shengguo; Liu, Wei

    2014-06-15

    A modified QuEChERS (quick, easy, cheap, effective, rugged and safe) method using multi-walled carbon nanotubes (MWCNTs) as a dispersive solid phase extraction (d-SPE) absorbent was established for analysis of 78 pesticide residues in tea. A 6 mg MWCNT sample was selected as the optimised amount based on the distribution of pesticide recoveries and clean-up efficiency from 6 mL acetonitrile extracts. The matrix effects of the method were evaluated and matrix-matched calibration was recommended. The method was validated employing gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) at the spiked concentration levels of 0.05, 0.1 and 0.15 mg kg(-1). For most of the targeted pesticides, the percent recoveries range from 70% to 120%, with relative standard deviations (RSDs) absorbent with excellent cleanup efficiency, which could be widely applied for the analysis of pesticide residues.

  20. Development and validation of a multi-residue method for the detection of a wide range of hormonal anabolic compounds in hair using gas chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rambaud, Lauriane [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Monteau, Fabrice [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Deceuninck, Yoann [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Bichon, Emmanuelle [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Andre, Francois [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Le Bizec, Bruno [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France)]. E-mail: lebizec@vet-nantes.fr

    2007-03-14

    The monitoring of anabolic steroid residues in hair is undoubtedly one of the most efficient strategies to demonstrate the long-term administration of these molecules in meat production animals. A multi-residue sample preparation procedure was developed and validated for 28 steroids. A 100 mg hair sample was grinded into powder and extracted at 50 deg. C with methanol. After acidic hydrolysis and extraction with ethyl acetate, phenolsteroids, such as estrogens, resorcyclic acid lactones and stilbens in one hand, are separated from androgens and progestagens in the other hand. Solid phase extractions were performed before applying a specific derivatisation for each compound sub-group. Detection and identification were achieved using gas chromatography-tandem mass spectrometry with acquisition in the selected reaction monitoring mode after electron ionisation. The method was validated according to the 2002/657/EC guideline. Decision limits (CC{alpha}) for main steroids were in the 0.1-10 {mu}g kg{sup -1} range.

  1. Development of high-throughput multi-residue method for non-steroidal anti-inflammatory drugs monitoring in swine muscle by LC-MS/MS.

    Science.gov (United States)

    Castilhos, Tamara S; Barreto, Fabiano; Meneghini, Leonardo; Bergold, Ana Maria

    2016-07-01

    A reliable and simple method for the detection and quantification of residues of 14 non-steroidal anti-inflammatory drugs and a metamizole metabolite in swine muscle was developed using liquid chromatography-electrospray ionisation-tandem mass spectrometry (LC-ESI-MS/MS). The samples were extracted with acetonitrile (ACN) in solid-liquid extraction followed by a low-temperature partitioning (LLE-LTP) process at -20 ± 2°C. After evaporation to dryness, the residue was reconstituted with hexane and a mixture of water:acetonitrile (1:1). LC separation was achieved on a reversed-phase (RP18) column with gradient elution using water (phase A) and ACN (phase B) both containing 1 mmol l(-)(1) ammonium acetate (NH4COO) with 0.025% acetic acid. Analysis was carried out on a triple-quadrupole tandem mass spectrometer (LC-MS/MS) in multiple reaction monitoring mode using an electrospray interface in negative and positive mode in a single run. Method validation was performed according to the criteria of Commission Decision No. 2002/657/EC. The matrix effect and linearity were evaluated. Decision limit (CCα), detection capability (CCβ), accuracy and repeatability of the method are also reported. The proposed method proved to be simple, easy and adequate for high-throughput analysis and was applied to routine analysis by the Brazilian Ministry of Agriculture, Livestock and Food Supply.

  2. Multi-residue method for the determination of pesticides and pesticide metabolites in honeybees by liquid and gas chromatography coupled with tandem mass spectrometry--Honeybee poisoning incidents.

    Science.gov (United States)

    Kiljanek, Tomasz; Niewiadowska, Alicja; Semeniuk, Stanisław; Gaweł, Marta; Borzęcka, Milena; Posyniak, Andrzej

    2016-02-26

    A method for the determination of 200 pesticides and pesticide metabolites in honeybee samples has been developed and validated. Almost 98% of compounds included in this method are approved to use within European Union, as active substances of plant protection products or veterinary medicinal products used by beekeepers to control mites Varroa destructor in hives. Many significant metabolites, like metabolites of imidacloprid, thiacloprid, fipronil, methiocarb and amitraz, are also possible to detect. The sample preparation was based on the buffered QuEChERS method. Samples of bees were extracted with acetonitrile containing 1% acetic acid and then subjected to clean-up by dispersive solid phase extraction (dSPE) using a new Z-Sep+ sorbent and PSA. The majority of pesticides, including neonicotionoids and their metabolites, were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) but some of pesticides, especially pyrethroid insecticides, were analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS). The procedure was validated according to the Guidance document SANCO/12571/2013 at four concentration levels: 1, 5, 10 and 100 ng/g bees and verified in the international proficiency test. The analysis of bee samples spiked at the limit of quantification (LOQ) showed about 98% mean recovery value (trueness) and 97% of analytes showed recovery in the required range of 70-120% and RSDr (precision) below 20%. Linearity and matrix effects were also established. The LOQs of pesticides were in the range of 1-100 ng/g. The developed method allows determination of insecticides at concentrations of 10 ng/g or less, except abamectin and tebufenozide. LOQ values are lower than the median lethal doses LD50 for bees. The method was used to investigate more than 70 honeybee poisoning incidents. Data about detected pesticides and their metabolites are included.

  3. A multi-residue method for pesticides analysis in green coffee beans using gas chromatography-negative chemical ionization mass spectrometry in selective ion monitoring mode.

    Science.gov (United States)

    Pizzutti, Ionara R; de Kok, Andre; Dickow Cardoso, Carmem; Reichert, Bárbara; de Kroon, Marijke; Wind, Wouter; Weber Righi, Laís; Caiel da Silva, Rosselei

    2012-08-17

    In this study, a new gas chromatography-mass spectrometry (GC-MS) method, using the very selective negative chemical ionization (NCI) mode, was developed and applied in combination with a modified acetonitrile-based extraction method (QuEChERS) for the analysis of a large number of pesticide residues (51 pesticides, including isomers and degradation products) in green coffee beans. A previously developed integrated sample homogenization and extraction method for both pesticides and mycotoxins analysis was used. An homogeneous slurry of green milled coffee beans and water (ratio 1:4, w/w) was prepared and extracted with acetonitrile/acetic acid (1%), followed by magnesium sulfate addition for phase separation. Aliquots from this extract could be used directly for LC-MS/MS analysis of mycotoxins and LC-amenable pesticides. For GC-MS analysis, a further clean-up was necessary. C18- and PSA-bonded silica were tested as dispersive solid-phase extraction (d-SPE) sorbents, separate and as a mixture, and the best results were obtained using C18-bonded silica. For the optimal sensitivity and selectivity, GC-MS detection in the NCI-selected ion monitoring (SIM) mode had to be used to allow the fast analysis of the difficult coffee bean matrix. The validation was performed by analyzing recovery samples at three different spike concentrations, 10, 20 and 50 μg kg(-1), with 6 replicates (n=6) at each concentration. Linearity (r(2)) of calibration curves, estimated instrument and method limits of detection and limits of quantification (LOD(i), LOD(m), LOQ(i) and LOQ(m), respectively), accuracy (as recovery %), precision (as RSD%) and matrix effects (%) were determined for each individual pesticide. From the 51 analytes (42 parent pesticides, 4 isomers and 5 degradation products) determined by GC-MS (NCI-SIM), approximately 76% showed average recoveries between 70-120% and 75% and RSD ≤ 20% at the lowest spike concentration of 10 μg kg(-1), the target method LOQ. For the

  4. Multi-residue analysis method for analysis of pharmaceuticals using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS) in water sample

    Science.gov (United States)

    Al-Qaim, Fouad Fadhil; Abdullah, Md Pauzi; Othman, Mohamed Rozali

    2013-11-01

    In this work, a developed method using solid - phase extraction (SPE) followed by liquid chromatography - time of flight mass spectrometry (LC-ESI-TOF/MS) was developed and validated for quantification and confirmation of eleven pharmaceuticals with different therapeutic classes in water samples, Malaysia. These compounds are caffeine (CAF), prazosin (PRZ), enalapril (ENL), carbamazepine (CBZ), nifedipine (NFD), levonorgestrel (LNG), simvastatin (SMV), hydrochlorothiazide (HYD), gliclazide (GLIC), diclofenac-Na (DIC-Na) and mefenamic acid (MEF). LC was performed on a Dionex Ultimate 3000/LC 09115047 (USA) system. Chromatography was performed on a Thermo Scientific C18 (250 mm × 2.1 mm, i.d.: 5μm) column. Several parameters were optimised such as; mobile phase, gradient elution, collision energy and solvent elution for extraction of compounds from water. The recoveries obtained ranged from 30-148 % in river water. Five pharmaceutical compounds were detected in the surface water samples: caffeine, prazosin, enalpril, diclofenac-Na and mefenamic acid. The developed method is precise and accepted recoveries were got. In addition, this method is suitable to identify and quantify trace concentrations of pharmaceuticals in surface water.

  5. Evaluation and validation of a multi-residue method based on biochip technology for the simultaneous screening of six families of antibiotics in muscle and aquaculture products.

    Science.gov (United States)

    Gaudin, Valérie; Hedou, Celine; Soumet, Christophe; Verdon, Eric

    2016-01-01

    The Evidence Investigator™ system (Randox, UK) is a biochip and semi-automated system. The microarray kit II (AM II) is capable of detecting several compounds belonging to different families of antibiotics: quinolones, ceftiofur, thiamphenicol, streptomycin, tylosin and tetracyclines. The performance of this innovative system was evaluated for the detection of antibiotic residues in new matrices, in muscle of different animal species and in aquaculture products. The method was validated according to the European Decision No. EC/2002/657 and the European guideline for the validation of screening methods, which represents a complete initial validation. The false-positive rate was equal to 0% in muscle and in aquaculture products. The detection capabilities CCβ for 12 validated antibiotics (enrofloxacin, difloxacin, ceftiofur, desfuroyl ceftiofur cysteine disulfide, thiamphenicol, florfenicol, tylosin, tilmicosin, streptomycin, dihydrostreptomycin, tetracycline, doxycycline) were all lower than the respective maximum residue limits (MRLs) in muscle from different animal origins (bovine, ovine, porcine, poultry). No cross-reactions were observed with other antibiotics, neither with the six detected families nor with other families of antibiotics. The AM II kit could be applied to aquaculture products but with higher detection capabilities from those in muscle. The detection capabilities CCβ in aquaculture products were respectively at 0.25, 0.10 and 0.5 of the respective MRL in aquaculture products for enrofloxacin, tylosin and oxytetracycline. The performance of the AM II kit has been compared with other screening methods and with the performance characteristics previously determined in honey.

  6. Comparative evaluation of tensile bond strength of a polyvinyl acetate-based resilient liner following various denture base surface pre-treatment methods and immersion in artificial salivary medium: An in vitro study

    Directory of Open Access Journals (Sweden)

    Jacob M Philip

    2012-01-01

    Full Text Available Background and Aim: This study was formulated to evaluate and estimate the influence of various denture base resin surface pre-treatments (chemical and mechanical and combinations upon tensile bond strength between a poly vinyl acetate-based denture liner and a denture base resin. Materials and Methods: A universal testing machine was used for determining the bond strength of the liner to surface pre-treated acrylic resin blocks. The data was analyzed by one-way analysis of variance and the t-test (α =.05. Results: This study infers that denture base surface pre-treatment can improve the adhesive tensile bond strength between the liner and denture base specimens. The results of this study infer that chemical, mechanical, and mechano-chemical pre-treatments will have different effects on the bond strength of the acrylic soft resilient liner to the denture base. Conclusion: Among the various methods of pre-treatment of denture base resins, it was inferred that the mechano-chemical pre-treatment method with air-borne particle abrasion followed by monomer application exhibited superior bond strength than other methods with the resilient liner. Hence, this method could be effectively used to improve bond strength between liner and denture base and thus could minimize delamination of liner from the denture base during function.

  7. Development of an ELISA Method for Multi-Residue Detecting of Fluoroquinolones%氟喹诺酮类药物多残留酶联免疫检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    李新朋; 姜金庆; 钱爱东; 王自良; 范国英; 单晓峰; 康元环; 李艺

    2014-01-01

    释;反应温度均为37℃,标准品与单抗同时加入反应15 min,洗板后加二抗反应25 min;显色10 min,2H5细胞株腹水敏感性和广谱特异性最好,2H5的线性回归方程为y=-28.022x+56.219,R2=0.9782,对10种FQs的IC50值分别为环丙沙星(CPFX)1.67 ng·mL-1、诺氟沙星(NOR)1.82 ng·mL-1、培氟沙星(PEF)1.97 ng·mL-1、恩诺沙星(ENR)1.54 ng·mL-1、单诺沙星(DAN)2.79 ng·mL-1、洛美沙星(LOM)3.38 ng·mL-1、氧氟沙星(OFL)5.50 ng·mL-1、麻保沙星(MAR)4.40 ng·mL-1、沙拉沙星(SAR)11.76 ng·mL-1、二氟沙星(DIF)13.60 ng·mL-1,与10种FQs的交叉反应率为12.3%—108.4%,与非 FQs交叉反应率均低于0.01%,对10种FQs的检测限(LODs)为0.09 ng·mL-1—0.64 ng·mL-1。icELISA法鸡肉中10种FQs的回收率为80.5%—91.8%,HPLC法的回收率为85.1%—95.7%,二者变异系数均低于10.0%;两种检测方法差异不显著(P>0.05)。【结论】该试验获得了高效价、敏感、广谱特异性的mAbs,建立的icELISA方法可用于同时检测鸡肉中10种FQs。%Objective]Fluoroquinolones(FQs) are widely used in veterinary medicine for the treatment and prevention of bacterial infection. With the increasing use, FQs residues in animal edible tissues have caused serious public health problems and attracted serious attention by research scholars all over the world. The objective of this study was to produce class-specific monoclonal antibodies (mAbs) against fluoroquinolones (FQs), establish competitive indirect enzyme linked immunesorbent assay (icELISA), and in order to lay a foundation for detection of multi-residue FQs in animal foods.[Method]The aminobutyric acid was introduced to carboxyl of ciprofloxacin as hapten (CPFX-A) and was proved by (+) ESI-MS spectrum, which was conjugated to bovine serum albumin (BSA) as immunogen (CPFX-A-BSA) by the N,N'-Dicyclohexylcarbodiimide (DDC) method, and to ovalbumin (OVA) as coating antigen(CPFX-A-OVA) by

  8. Multi-residue methods for the determination of over four hundred pesticides in solid and liquid high sucrose content matrices by tandem mass spectrometry coupled with gas and liquid chromatograph.

    Science.gov (United States)

    Lozowicka, Bozena; Ilyasova, Gulzhakhan; Kaczynski, Piotr; Jankowska, Magdalena; Rutkowska, Ewa; Hrynko, Izabela; Mojsak, Patrycja; Szabunko, Julia

    2016-05-01

    For the first time three methods: matrix solid phase dispersion (MSPD), original and modified QuEChERS, with and without clean up step were studied in order to evaluate the extraction efficiency of various classes of pesticides from solid and liquid high sucrose content matrices. Determinations over four hundred pesticides were performed by gas and liquid chromatography with triple quadrupole mass spectrometry (GC/LC/MS/MS) using multiple reaction monitoring. The proposed methods were validated on sugar beets and their technological product beet molasses. In general, the recoveries obtained for the original QuEChERS and MSPD method were lower (gas and liquid chromatography. The most compounds showed signal enhancement and it was compensated by using matrix-matched calibration and modified QuEChERS characterized lower matrix effects. The confirmation of suitability citrate QuEChERS optimized method was to use for routine testing of several dozen samples determination and residue of epoxiconazole and tebuconazole (both at 0.01mgkg(-1)) in the samples of beet molasses and cyfluthrin (0.06mgkg(-1)) in sugar beet were found.

  9. Multi-residue analytical method for the determination of endocrine disruptors and related compounds in river and waste water using dual column liquid chromatography switching system coupled to mass spectrometry.

    Science.gov (United States)

    Gorga, Marina; Petrovic, Mira; Barceló, Damià

    2013-06-21

    The present study describes a novel, fully automated method, based on column switching using EQuan™ columns for an integrated sample preconcentration and liquid chromatography coupled to tandem mass spectrometry (LC-LC-MS/MS). The method allows the unequivocal identification and quantification of the most relevant environmental endocrine disruptors compounds (EDCs) and compounds suspected to be EDCs, such as natural and synthetic estrogens and their conjugates, antimicrobials, parabens, bisphenol A, alkylphenolic compounds, benzotriazoles, and organophosphorus flame retardants, in surface river water and wastewater samples. Applying this technique, water samples were directly injected into the chromatographic system and the target compounds were concentrated into the loading column. Thereafter, the analytes were transferred into the analytical column for subsequent detection by MS-MS (QqQ). A comparative study employing three types of columns, with different chemical modifications, was performed in order to determine the optimal column that allowed maximum retention and subsequent elution of the analytes. Using this new optimized methodology a fast and easy online methodology for the analysis of EDCs in surface river water and wastewater with low limits of quantification (LOQ) was obtained. LOQs ranged from 0.008 to 1.54 ng/L for surface river water and from 0.178/0.364 to 12.5/25.0 ng/L (except for alkylphenol monoethoxylates) for effluent/influent waste water. Moreover, employing approximately 1h, a complete analysis was performed which was significant improvement in comparison to other methods reported previously. This method was used to track the presence and fate of target compounds in the Ebro River which is the most important river in Spain whose intensive agricultural and industrial activities concentrate mainly close to the main cities in the basin, deteriorating soil and water quality.

  10. Multi-residue determination of 171 pesticides in cowpea using modified QuEChERS method with multi-walled carbon nanotubes as reversed-dispersive solid-phase extraction materials.

    Science.gov (United States)

    Han, Yongtao; Song, Le; Zou, Nan; Chen, Ronghua; Qin, Yuhong; Pan, Canping

    2016-09-15

    A rapid and sensitive method for the determination of 171 pesticides in cowpea was developed using multi-walled carbon nanotubes (MWCNTs) as reversed-dispersive solid-phase (r-DSPE) extraction materials. The clean-up performance of MWCNTs was proved to be obviously superior to PSA and GCB. This method was validated on cowpea spiked at 0.01 and 0.1mgkg(-1) with five replicates. The mean recoveries for 169 pesticides ranged from 74% to 129% with relative standard deviations (RSDs) (n=5) lower than 16.4%, except diflufenican and quizalofop-ethyl. Good linearity for all pesticides was obtained with the calibration curve coefficients (R(2)) larger than 0.9970. The limit of detection (LODs) and limit of quantification (LOQs) for the 171 pesticides ranged from 0.001 to 0.003mgkg(-1) and from 0.002 to 0.009mgkg(-1), respectively. The method was demonstrated to be reliable and sensitive for the routine monitoring of the 171 pesticides in cowpea samples.

  11. Development of a new multi-residue laser diode thermal desorption atmospheric pressure chemical ionization tandem mass spectrometry method for the detection and quantification of pesticides and pharmaceuticals in wastewater samples.

    Science.gov (United States)

    Boisvert, Michel; Fayad, Paul B; Sauvé, Sébastien

    2012-11-19

    A new solid phase extraction (SPE) method coupled to a high throughput sample analysis technique was developed for the simultaneous determination of nine selected emerging contaminants in wastewater (atrazine, desethylatrazine, 17β-estradiol, ethynylestradiol, norethindrone, caffeine, carbamazepine, diclofenac and sulfamethoxazole). We specifically included pharmaceutical compounds from multiple therapeutic classes, as well as pesticides. Sample pre-concentration and clean-up was performed using a mixed-mode SPE cartridge (Strata ABW) having both cation and anion exchange properties, followed by analysis by laser diode thermal desorption atmospheric pressure chemical ionization coupled to tandem mass spectrometry (LDTD-APCI-MS/MS). The LDTD interface is a new high-throughput sample introduction method, which reduces total analysis time to less than 15s per sample as compared to minutes with traditional liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS). Several SPE parameters were evaluated in order to optimize recovery efficiencies when extracting analytes from wastewater, such as the nature of the stationary phase, the loading flow rate, the extraction pH, the volume and composition of the washing solution and the initial sample volume. The method was successfully applied to real wastewater samples from the primary sedimentation tank of a municipal wastewater treatment plant. Recoveries of target compounds from wastewater ranged from 78% to 106%, the limit of detection ranged from 30 to 122ng L(-1) while the limit of quantification ranged from 90 to 370ng L(-1). Calibration curves in the wastewater matrix showed good linearity (R(2)≥0.991) for all target analytes and the intraday and interday coefficient of variation was below 15%, reflecting a good precision.

  12. Multi-residue method for determination of 58 pesticides, pharmaceuticals and personal care products in water using solvent demulsification dispersive liquid-liquid microextraction combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Caldas, Sergiane Souza; Rombaldi, Caroline; Arias, Jean Lucas de Oliveira; Marube, Liziane Cardoso; Primel, Ednei Gilberto

    2016-01-01

    A rapid and efficient sample pretreatment using solvent-based de-emulsification dispersive liquid-liquid microextraction (SD-DLLME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was studied for the extraction of 58 pharmaceuticals and personal care products (PPCPs) and pesticides from water samples. Type and volume of extraction and disperser solvents, pH, salt addition, amount of salt and type of demulsification solvent were evaluated. Limits of quantification (LOQ) in the range from 0.0125 to 1.25 µg L(-1) were reached, and linearity was in the range from the LOQ of each compound to 25 μg L(-1). Recoveries ranged from 60% to 120% for 84% of the compounds, with relative standard deviations lower than 29%. The proposed method demonstrated, for the first time, that sample preparation by SD-DLLME with determination by LC-MS/MS can be successfully used for the simultaneous extraction of 32 pesticides and 26 PPCPs from water samples. The entire procedure, including the extraction of 58 organic compounds from the aqueous sample solution and the breaking up of the emulsion after extraction with water, rather than with an organic solvent, was environmentally friendly. In addition, this technique was less expensive and faster than traditional techniques. Finally, the analytical method under study was successfully applied to the analysis of all 58 pesticides and PPCPs in surface water samples.

  13. A single-step pesticide extraction and clean-up multi-residue analytical method by selective pressurized liquid extraction followed by on-line solid phase extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry for complex matrices.

    Science.gov (United States)

    Rodrigues, Elsa Teresa; Pardal, Miguel Ângelo; Salgueiro-González, Noelia; Muniategui-Lorenzo, Soledad; Alpendurada, Maria Fátima

    2016-06-24

    Pesticides, a group of compounds linked to human activity, may, when in toxic levels, have a profound effect on water quality, and hence result in adverse consequences to aquatic life and ultimately to human health. Analytical challenges arise when successfully trying to determine these levels in environmental complex matrices. Therefore, fast, simple, sensitive and selective analytical methodologies for multi-residue determination of pesticides (atrazine, azoxystrobin, bentazon, λ-cyhalothrin, penoxsulam and terbuthylazine) in sediment, macrophytes (algae and aquatic plants) and aquatic animals were developed and validated. The established methods were matrix-dependent and were based on Selective Pressurized Liquid Extraction (SPLE) followed by on-line Solid Phase Extraction and Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (on-line SPE-UPLC-ESI-MS/MS). This cutting-edge research methodology uses a small amount of sample, is time saving and reduces the use of organic solvents in compliance with Green Chemistry principles. The analytical features were adequate for all compounds in all studied matrices. The established methodology was applied on real marine samples and no pesticide concentrations above their respective method quantification limits were measured in sediments or aquatic plants. However, terbuthylazine was found in the macroalgae Ulva spp. (108ngg(-1)dw) and all the prospected pesticides were measured above their respective method quantification limits in the bivalve Scrobicularia plana (atrazine: 48ngg(-1)dw, azoxystrobin: 64ngg(-1)dw, bentazon: 33ngg(-1)dw, λ-cyhalothrin: 2531ngg(-1)dw, penoxsulam: 50ngg(-1)dw, and terbuthylazine: 44ngg(-1)dw).

  14. Multi-class, multi-residue analysis of pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and novel flame retardants....mass spectrometry

    Science.gov (United States)

    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...

  15. Multi-residue determination of plant growth regulators in apples and tomatoes by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Xue, Jiaying; Wang, Suli; You, Xiangwei; Dong, Jiannan; Han, Lijun; Liu, Fengmao

    2011-11-15

    A sensitive and rapid multi-residue analytical method for plant growth regulators (PGRs) (i.e., chlormequat, mepiquat, paclobutrazol, uniconazole, ethephon and flumetralin) in apples and tomatoes was developed using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). A homogenised sample was extracted with a mixture of methanol/water (90:10, v/v) and adjusted to pH <3 with formic acid. Primary secondary amine (PSA) adsorbent was used to clean up the sample. The determination was performed using electrospray ionisation (ESI) and a triple quadrupole (QqQ) analyser. Under the optimised method, the results showed that, except for ethephon, the recoveries were 81.8-98.1% in apples and tomatoes at the spiked concentrations of 0.005 to 2 mg/kg, with relative standard deviations (RSDs) of less than 11.7%. The limits of quantification (LOQs) were lower than their maximum residue limits (MRLs). The procedure was concluded as a practical method to determine the PGR residues in fruit and vegetables and is also suitable for the simultaneous analysis of the amounts of samples for routine monitoring. The analytical method described herein demonstrates a strong potential for its application in the field of PGR multi-residue analysis to help assure food safety.

  16. 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.

  17. Multi-residue determination of pesticides in tropical fruits using liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Botero-Coy, A M; Marín, J M; Ibáñez, M; Sancho, J V; Hernández, F

    2012-03-01

    Monitoring pesticide residues in tropical fruits is of great interest for many countries, e.g., from South America, that base an important part of their economy on the exportation of these products. In this work, a LC-MS/MS multi-residue method using a triple quadrupole analyzer has been developed for around 30 pesticides in seven Colombian tropical fruits of high commercial value for domestic and international markets (uchuva, tamarillo, granadilla, gulupa, maracuya, papaya, and pithaya). After sample extraction with acetonitrile, an aliquot of the extract was diluted with water and directly injected into the HPLC-MS/MS system (electrospray interface) without any cleanup step. The formation of sodium adducts-of poor fragmentation-was minimized using 0.1% formic acid in the mobile phase, which favored the formation of the protonated molecule. However, the addition of ammonium acetate made the formation of the ammonium adducts in some particular cases possible, avoiding the presence of the sodium adducts. The highest sensitivity was observed in positive electrospray ionization for the wide majority of pesticides, with a few exceptions for acidic compounds that gave better response in the negative mode (e.g., 2,4-D, fluazinan). Thus, simultaneous acquisition on the positive/negative mode was applied. Two MS/MS transitions were acquired for each compound to ensure a reliable quantification and identification of the compounds detected in samples, although for malathion a third transition was acquired due to the presence of interfering isobaric compounds in the sample extracts. A detailed study of matrix effects was made by a comparison of standards in solvent and in matrix. Both ionization suppression and ionization enhancement were observed depending on the analyte/matrix combination tested. Correction of matrix effects was made by the application of calibration in matrix. Three matrices were selected (uchuva, maracuya, gulupa) to perform matrix calibration in the

  18. Multi-residue analysis of organic pollutants in hair and urine for matrices comparison.

    Science.gov (United States)

    Hardy, Emilie M; Duca, Radu C; Salquebre, Guillaume; Appenzeller, Brice M R

    2015-04-01

    Urine being currently the most classically used matrix for the assessment of human exposure to pesticides, a growing interest is yet observed in hair analysis for the detection of organic pollutants. The aim of the present work was to develop and to validate multi-residue analytical methods, as similar as possible, in order to determine pesticides and their metabolites in these two biological matrices despite their different nature. The list of parent compounds and their metabolites investigated here consisted of 56 compounds, including organochlorines, organophosphates, pyrethroids, carbamates, other pesticides and polychlorinated biphenyls (PCBs). Two different approaches were necessary for the analysis of non-polar compounds (mainly parents) on one hand and polar analytes (mainly metabolites) on the other hand. In the final procedure, extraction from hair was carried out with acetonitrile/water after sample decontamination and pulverization. Extract was split into two fractions, which were analyzed directly with solid phase microextraction (SPME) injection for non-polar compounds and after derivatization with liquid injection for polar compounds. In urine, non-polar compounds were analyzed directly using SPME. Polar compounds were analyzed after acidic hydrolysis, liquid-liquid extraction with acetonitrile-cyclohexane-ethyl acetate, derivatization and liquid injection. Analysis was performed with gas chromatography tandem mass spectrometry operating in negative chemical ionization (GC-MS/MS-NCI) for all the compounds (non-polar and polar) in the two matrices. In hair, limits of quantification (LOQ) ranged from 0.02 pg/mg for trifluralin to 5.5 pg/mg for diethylphosphate. In urine, LOQ ranged from 0.4 pg/mL for α-endosulfan to 4 ng/mL for dimethyldithiophosphate. The analysis of samples supplemented with standards and samples collected from an animal previously submitted to chronic exposure to pesticides confirmed that all the compounds were analyzable in both

  19. Development and validation of an immunochromatographic assay for rapid multi-residues detection of cephems in milk.

    Science.gov (United States)

    Xie, Huiling; Ma, Wei; Liu, Liqiang; Chen, Wei; Peng, Chifang; Xu, Chuanlai; Wang, Libing

    2009-02-16

    A one-step immunochromatographic assay (ICA) was developed for the detection of seven kinds of cephems in milk. Polyclonal antibodies (PcAb) with group-specific to cephems were raised in rabbits after immunization with cephalexin-keyhole limpet hemocyanin (KLH) conjugate. The specificity of anti-sera was determined by indirect competitive enzyme-linked immunosorbent assay (icELISA), and the 50% inhibitions (IC(50)) of cephalexin and cefadroxil were obtained at 1.5 ngmL(-1); IC(50) of cefatiofur, cefapirin, cefazolin, cefalothin and cefotaxine were 4, 3.7, 3.2, 4.5 and 5 ngmL(-1), respectively. The PcAb against cephems were conjugated to colloidal gold particles as the detection reagent for ICA strips to test for cephems. This method achieved semi-quantitative detection of cephems in milk samples. This method was compared with an enzyme-linked immunosorbent assay by testing 40 milk samples, and the positive samples were validated by a high-performance liquid chromatographic method, with an agreement rate of 100% for both comparisons. In conclusion, the method was rapid and accurate for the multi-residue detection of cephems in milk.

  20. [Validation study on a multi-residue analysis of pesticides in agricultural products by using phosphoric acid treatment and GC-MS/MS].

    Science.gov (United States)

    Makabe, Yuhki; Takahashi, Hiroshi; Enomoto, Tomoko; Aikawa, Takehiko

    2014-01-01

    A rapid method for multi-residue determination of pesticides in agricultural products was validated. The sample was cut into pieces and placed into a mixer cup containing half weight amount of 10% phosphoric acid in order to suppress degradation of easily degraded pesticides, represented by captan, and then homogenized. Pesticides in the phosphoric acid-treated sample were extracted with acetonitrile using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride. The extract was cleaned up on a C18 and graphite carbon black/PSA mini-cartridge column. Some pesticides gave tailing peaks, but these peaks became sharp and symmetrical when polyethylene glycol (PEG) 300 was added to the test solution. Recovery tests were performed on nine kinds of agricultural products (brown rice, soybean, spinach, cabbage, potato, orange, apple, strawberry, and Japanese pear) fortified with 170 pesticides at 0.01 and 0.1 μg/g. Each concentration of pesticide residue was extracted from 2 samples on 5 separate days. The trueness of the method for 147-164 pesticides in each sample was 70-120% with satisfactory repeatability and within-run reproducibility. This method is expected to useful for multi-residue analysis of pesticides in agricultural products.

  1. Multi-residue determination of pesticides in water using multi-walled carbon nanotubes solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Wang, Shuo; Zhao, Peng; Min, Guang; Fang, Guozhen

    2007-09-21

    A reliable multi-residue method which was based on solid-phase extraction (SPE) with multi-walled carbon nanotubes (MWCNTs) as adsorbent was developed for determination and quantitation of 12 pesticides (carbofuran, iprobenfos, parathion-methyl, prometryn, fenitrothion, parathion-ethyl, isocarbofos, phenthoate, methidathion, endrin, ethion, methoxychlor) in surface water by gas chromatography-mass spectrometry (GC-MS). Parameters that might influence the extraction efficiency such as the eluent volume, the sample flow rate and the sample loading volume were optimized. The experimental results showed the excellent linearity of 12 pesticides (R(2)>0.99) over the range of 0.04-4 microg L(-1), and the precisions (RSD) were 3.1-15.1% under the optimal conditions. The detection limits of proposed method could reach 0.01-0.03 microg L(-1) based on the ratio of chromatographic signal to base line noise (S/N=3). Good recoveries achieved with spiked water samples were in the range of 82.0-103.7%. The results indicated that MWCNTs have good adsorbability to the 12 pesticides tested in this study. With less cost, less analytical time and less solvent-consuming, the developed multi-residue method could be used to determine multi-class pesticides in water simultaneously.

  2. Multi-Residue Analysis of Pesticides in Pistachio Using Gas Chromatography-Mass Spectrometry (GC/MS

    Directory of Open Access Journals (Sweden)

    Azadeh Emami

    2014-12-01

    Full Text Available Background: Analysis of pesticide residues in food and other environmental commodities have become an essential requirement for consumers, producers, food inspectors and authorities. This study is focused on validation of an accurate, rapid and reliable method for multi-residual analysis of pesticides in pistachio as a strategic crop for export and one of the main nuts in Iranian food basket. Methods: We developed a "Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS method based on spiking blank samples and used the data for drawing calibration curves instead of standard solutions. Sample preparations were developed for determination of 12 pesticide residues in pistachio by gas chromatography-mass spectrometry (GC/MS. Results: Recovery of pesticides at 5 concentration levels (n=3 was in the range of 81.40% - 93.08 %. The method proved to be repeatable in the majority of samples with relative standard deviation (RSD of lower than 20%. The limits of detection and quantification for all pesticides were 2 ppb and 10 ppb, respectively. Conclusion: The calibration curves of pesticides were linear in the range of 10-500 (ng/g and correlation coefficient of entire pesticides was higher than 0.994. The recovery of pesticides at 5 concentration levels (n=3 was in range of 81.41- 91.80 %. The method was proved to be repeatable with the majority of RSDs being lower than 20%. The limits of detection and quantification for all pesticides were 2 and 10 ppb, respectively. The recoveries and repeatabilities were in accordance with the criteria set by SANCO Guideline (Commission of the European Communities, 2006.

  3. Multi-residue analysis of pesticides, plant hormones, veterinary drugs and mycotoxins using HILIC chromatography - MS/MS in various food matrices.

    Science.gov (United States)

    Danezis, G P; Anagnostopoulos, C J; Liapis, K; Koupparis, M A

    2016-10-26

    One of the recent trends in Analytical Chemistry is the development of economic, quick and easy hyphenated methods to be used in a field that includes analytes of different classes and physicochemical properties. In this work a multi-residue method was developed for the simultaneous determination of 28 xenobiotics (polar and hydrophilic) using hydrophilic interaction liquid chromatography technique (HILIC) coupled with triple quadrupole mass spectrometry (LC-MS/MS) technology. The scope of the method includes plant growth regulators (chlormequat, daminozide, diquat, maleic hydrazide, mepiquat, paraquat), pesticides (cyromazine, the metabolite of the fungicide propineb PTU (propylenethiourea), amitrole), various multiclass antibiotics (tetracyclines, sulfonamides quinolones, kasugamycin and mycotoxins (aflatoxin B1, B2, fumonisin B1 and ochratoxin A). Isolation of the analytes from the matrix was achieved with a fast and effective technique. The validation of the multi-residue method was performed at the levels: 10 μg/kg and 100 μg/kg in the following representative substrates: fruits-vegetables (apples, apricots, lettuce and onions), cereals and pulses (flour and chickpeas), animal products (milk and meat) and cereal based baby foods. The method was validated taking into consideration EU guidelines and showed acceptable linearity (r ≥ 0.99), accuracy with recoveries between 70 and 120% and precision with RSD ≤ 20% for the majority of the analytes studied. For the analytes that presented accuracy and precision values outside the acceptable limits the method still is able to serve as a semi-quantitative method. The matrix effect, the limits of detection and quantification were also estimated and compared with the current EU MRLs (Maximum Residue Levels) and FAO/WHO MLs (Maximum Levels) or CXLs (Codex Maximum Residue Limits). The combined and expanded uncertainty of the method for each analyte per substrate, was also estimated.

  4. Development of a molecular recognition based approach for multi-residue extraction of estrogenic endocrine disruptors from biological fluids coupled to liquid chromatography-tandem mass spectrometry measurement.

    Science.gov (United States)

    Bousoumah, Radia; Antignac, Jean Philippe; Camel, Valérie; Grimaldi, Marina; Balaguer, Patrick; Courant, Frederique; Bichon, Emmanuelle; Morvan, Marie-Line; Le Bizec, Bruno

    2015-11-01

    Multi-residue methods permitting the high-throughput and affordable simultaneous determination of an extended range of endocrine disrupting chemicals (EDCs) with reduced time and cost of analysis is of prime interest in order to characterize a whole set of bioactive compounds. Such a method based on UHPLC-MS/MS measurement and dedicated to 13 estrogenic EDCs was developed and applied to biological matrices. Two molecular recognition-based strategies, either molecular imprinted polymer (MIP) with phenolic template or estrogen receptors (ERα) immobilized on a sorbent, were assessed in terms of recovery and purification efficiency. Both approaches demonstrated their suitability to measure ultra-trace levels of estrogenic EDCs in aqueous samples. Applicability of the MIP procedure to urine and serum samples has also been demonstrated.

  5. MULTI-RESIDUE ANALYSIS OF PESTICIDES IN GRAPES IN BIJAPUR DISTRICT

    Directory of Open Access Journals (Sweden)

    U.S.Pujeri

    2010-10-01

    Full Text Available Fruit samples of grapes were analyzed for pesticide residues, employing multi-residue analysis by gas- liquid chromatography-mass spectrography (GC-MS/ LCMS/ MS. All the fruit samples showed the presence of pesticide residues with one or other group of pesticides. Some of the grape samples contain more than the minimum residue limit. The increasing interest in the study of pesticides in grapes is justified from an enological point of view, since some pesticides can interfere with fermentative microflora used in wine production, as well as affect consumer safety. There were no significant differences between some pesticide levels found in the whole grape (skin and pulp and in the grape skin. Chlorpyriphos, captan, dichlorovos, oxyfluorfen, fipronoil, 4- bromo-2-chlorophenol and indoxycarb were detected. Nevertheless, consumer intake of pesticides from grapes studied in this work should be decreased as a result of water washing of the grapes. In this paper, multiresidue determination of pesticides using GCMS/ LC-MS/MS are discussed.

  6. 36 CFR 1237.30 - How do agencies manage records on nitrocellulose-base and cellulose-acetate base film?

    Science.gov (United States)

    2010-07-01

    ... records on nitrocellulose-base and cellulose-acetate base film? 1237.30 Section 1237.30 Parks, Forests... and cellulose-acetate base film? (a) The nitrocellulose base, a substance akin to gun cotton, is... picture film and X-ray film—nitrocellulose base). (b) Agencies must inspect cellulose-acetate...

  7. Cellulose acetate-based molecularly imprinted polymeric membrane for separation of vanillin and o-vanillin

    OpenAIRE

    Chunjing Zhang; Shian Zhong; Zhengpeng Yang

    2008-01-01

    Cellulose acetate-based molecularly imprinted polymeric membranes were prepared using vanillin as template molecule. The microscopic structure of the resultant polymeric membranes was characterized by SEM and FTIR spectroscopy, and the selective binding properties and separation capacity of the membranes for vanillin and o-vanillin were tested with binding experiments and separate experiments, respectively. The results showed that the vanillin-imprinted polymeric membranes displayed higher bi...

  8. Multi-residue analysis of free and conjugated hormones and endocrine disruptors in rat testis by QuEChERS-based extraction and LC-MS/MS.

    Science.gov (United States)

    Pouech, Charlène; Tournier, Mikaël; Quignot, Nadia; Kiss, Agneta; Wiest, Laure; Lafay, Florent; Flament-Waton, Marie-Magdeleine; Lemazurier, Emmanuel; Cren-Olivé, Cécile

    2012-03-01

    Endocrine disrupting compounds (EDCs) are suspected to be responsible for many disorders of the human reproductive system. To establish a causality relationship between exposure to endocrine disruptors and disease, experiments on animals must be performed with improved or new analytical tools. Therefore, a simple, rapid, and effective multi-residue method was developed for the determination of four steroid hormones (i.e., testosterone, androstenedione, estrone, and estradiol), glucuronide and sulfate conjugates of estrone and estradiol and four endocrine disruptors in rat testis (i.e., bisphenol A, atrazine, and active metabolites of methoxychlor and vinclozolin). The sample preparation procedure was based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) approach. An analytical method was then developed to quantify these compounds at ultra-trace levels by liquid chromatography coupled to tandem mass spectrometry. The QuEChERS extraction was optimized with regard to the acetonitrile/water ratio used in the extraction step, the choice of the cleanup method and the acetonitrile/hexane ratio used in the cleanup step. The optimized extraction method exhibited recoveries between 89% and 108% for all tested compounds except the conjugates (31% to 58%). The detection limits of all compounds were below 20 ng g(-1) of wet weight of testis. The method was subsequently applied to determine the levels of hormones and EDCs in seven rat testis samples.

  9. Multi-residue analysis of 90 emerging contaminants in liquid and solid environmental matrices by ultra-high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Petrie, Bruce; Youdan, Jane; Barden, Ruth; Kasprzyk-Hordern, Barbara

    2016-01-29

    Reported herein is new analytical methodology for the determination of 90 emerging contaminants (ECs) in liquid environmental matrices (crude wastewater, final effluent and river water). The application of a novel buffer, ammonium fluoride improved signal response for several ECs determined in negative ionisation mode. Most notably the sensitivity of steroid estrogens was improved by 4-5 times in environmental extracts. Method recoveries ranged from 40 to 152% in all matrices and method quantitation limits (MQLs) achieved were <1ngL(-1) for numerous ECs. Development of a microwave assisted extraction (MAE) protocol as an additional sample extraction step for solid matrices enabled 63 ECs to be simultaneously analysed in digested sludge. To the authors knowledge this is considerably more than any previously reported MAE method. Here, MQLs ranged from 0.1-24.1ngg(-1) dry weight. The application of MAE offers several advantages over pressurized liquid extraction including faster sample preparation, lower solvent requirements, and the ability to perform several extractions simultaneously as well as lower purchasing and running costs. To demonstrate the method's sensitivity, application to environmental samples revealed 68 and 40 ECs to be above their respective MQL in liquid environmental samples and digested sludge, respectively. To date, this is the most comprehensive multi-residue analytical method reported in the literature for the determination of ECs in both liquid and solid environmental matrices.

  10. Automated multi-plug filtration cleanup for liquid chromatographic-tandem mass spectrometric pesticide multi-residue analysis in representative crop commodities.

    Science.gov (United States)

    Qin, Yuhong; Zhang, Jingru; Zhang, Yuan; Li, Fangbing; Han, Yongtao; Zou, Nan; Xu, Haowei; Qian, Meiyuan; Pan, Canping

    2016-09-01

    An automated multi-plug filtration cleanup (m-PFC) method on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts was developed. The automatic device was aimed to reduce labor-consuming manual operation workload in the cleanup steps. It could control the volume and the speed of pulling and pushing cycles accurately. In this work, m-PFC was based on multi-walled carbon nanotubes (MWCNTs) mixed with other sorbents and anhydrous magnesium sulfate (MgSO4) in a packed tip for analysis of pesticide multi-residues in crop commodities followed by liquid chromatography with tandem mass spectrometric (LC-MS/MS) detection. It was validated by analyzing 25 pesticides in six representative matrices spiked at two concentration levels of 10 and 100μg/kg. Salts, sorbents, m-PFC procedure, automated pulling and pushing volume, automated pulling speed, and pushing speed for each matrix were optimized. After optimization, two general automated m-PFC methods were introduced to relatively simple (apple, citrus fruit, peanut) and relatively complex (spinach, leek, green tea) matrices. Spike recoveries were within 83 and 108% and 1-14% RSD for most analytes in the tested matrices. Matrix-matched calibrations were performed with the coefficients of determination >0.997 between concentration levels of 10 and 1000μg/kg. The developed method was successfully applied to the determination of pesticide residues in market samples.

  11. Multi-residue off-flavour profiling in wine using stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Franc, Céline; David, Frank; de Revel, Gilles

    2009-04-10

    A multi-residue method (MRM) for the detection and quantification of eight compounds responsible for off-flavours in wine using stir bar sorptive extraction (SBSE) followed by thermal desorption (TD) and gas chromatography-mass spectrometry (GC-MS) analysis is presented. The extraction and desorption conditions were optimised in order to get the best compromise for the simultaneous analysis of the eight target solutes, belonging to different chemical classes. The analytical conditions enable the quantification of the solutes below their respective organoleptic perception thresholds in wine. The method displayed good linearity over the concentration ranges explored in wine as well as excellent repeatability (RSD below 6%) and good reproducibility (RSD below 24%). The developed methodology was applied to the analysis of several wines and showed good agreement with the results collected with headspace solid-phase microextraction (HS-SPME) or liquid-liquid extraction (LLE) followed by GC-MS or electron capture detection (ECD). Good correlation was also found between the analytical and sensory results.

  12. Preparation and properties of cyclic acetal based biodegradable gel by thiol-ene photopolymerization.

    Science.gov (United States)

    Wang, Kemin; Lu, Jian; Yin, Ruixue; Chen, Lu; Du, Shuang; Jiang, Yan; Yu, Qiang

    2013-04-01

    Synthetic, hydrolytically degradable biomaterials have been widely developed for biomedical use; however, most of them will form acidic products upon degradation of polymer backbone. In order to address this concern, we proposed to fabricate a biodegradable gel based on the crosslinking of a cyclic acetal monomer with reactable diallyl group and multifunctional thiols by thiol-ene photopolymerization. This gel produces diols and carbonyl end groups upon hydrolytic degradation and could be entirely devoid of acidic by-products. Real time infrared spectroscopy was employed to investigate the effect of different light intensities and concentrations of photoinitiator on the polymerization kinetics. With the increase of the concentration of photoinitiator and light intensity, both the rate of polymerization and final double bond conversion increased. Degradation of cyclic acetal based networks was investigated in PBS medium so as to simulate physiological conditions. The remaining mass of the materials after 25 days incubation was 84%. TGA analysis showed that the gels exhibited a typical weight loss (97.2%) at around 378 °C. In vitro cytotoxicity showed that the cyclic acetal based gels had non-toxicity to cell L-929 and had good biocompatibility.

  13. Multi-residue determination of micropollutants in Phragmites australis from constructed wetlands using microwave assisted extraction and ultra-high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Petrie, Bruce; Smith, Benjamin D; Youdan, Jane; Barden, Ruth; Kasprzyk-Hordern, Barbara

    2017-03-22

    In constructed wetlands micropollutants can be removed from water by phytoremediation. However, micropollutant uptake and metabolism by plants here is poorly understood due to the lack of good analytical approaches. Reported herein is the first methodology developed and validated for the multi-residue determination of 81 micropollutants (pharmaceuticals, personal care products and illicit drugs) in the emergent macrophyte Phragmites australis. The method involved extraction by microwave accelerated extraction (MAE), clean-up using off-line solid phase extraction and analysis by ultra-high-performance liquid chromatography tandem mass spectrometry. Development of the MAE method found the influence of studied variables on micropollutant recovery to be: extraction temperature > sample mass > solvent composition. Validation of the developed extraction protocol revealed method recoveries were in the range 80-120% for the majority of micropollutants. Method quantitation limits (MQLs) were generally <5 ng g(-1) dry weight demonstrating the sensitivity of the methodology. Application of the method to P. australis from a constructed wetland used to treat trickling filter effluent found 17 micropollutants above their MQL, up to concentrations of 200 ng g(-1). Other than uptake, the presence of several metabolites (carbamazepine 10,11 epoxide, desvenlafaxine, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, N-desmethyltramadol and norketamine) indicated metabolism within the plant may also occur. This new analytical methodology will enable a process mass balance of the constructed wetland to be attained for the first time, and thus help understand the role of phytoremediation in micropollutant removal by such systems.

  14. Multi-residue determination of 115 veterinary drugs and pharmaceutical residues in milk powder, butter, fish tissue and eggs using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dasenaki, Marilena E; Thomaidis, Nikolaos S

    2015-06-23

    A simple and sensitive multi-residue method for the determination of 115 veterinary drugs and pharmaceuticals, belonging in more than 20 different classes, in butter, milk powder, egg and fish tissue has been developed. The method involves a simple generic solid-liquid extraction step (solvent extraction, SE) with 0.1% formic acid in aqueous solution of EDTA 0.1% (w/v)-acetonitrile (ACN)-methanol (MeOH) (1:1:1, v/v) with additional ultrasonic-assisted extraction. Precipitation of lipids and proteins was promoted by subjecting the extracts at very low temperature (-23°C) for 12h. Further cleanup with hexane ensures fat removal from the matrix. Analysis was performed by liquid chromatography coupled with electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS). Two separate runs were performed for positive and negative ionization in multiple reaction monitoring mode (MRM). Particular attention was devoted to extraction optimization: different sample-to-extracting volume ratios, different concentrations of formic acid in the extraction solvent and different ultrasonic extraction temperatures were tested in butter, egg and milk powder samples. The method was also applied in fish tissue samples. It was validated, on the basis of international guidelines, for all four matrices. Quantitative analysis was performed by means of standard addition calibration. For over 80% of the analytes, the recoveries were between 50% and 120% in all matrices studied, with RSD values in the range of 1-18%. Limits of detection (LODs) and quantification (LOQs) ranged from 0.008 μg kg(-1) (oxfendazole in butter) to 3.15 μg kg(-1) (hydrochlorthiazide in egg). The evaluated method provides reliable screening, quantification, and identification of 115 veterinary drug and pharmaceutical residues in foods of animal origin and has been successfully applied in real samples.

  15. Application of a hybrid ordered mesoporous silica as sorbent for solid-phase multi-residue extraction of veterinary drugs in meat by ultra-high-performance liquid chromatography coupled to ion-trap tandem mass spectrometry.

    Science.gov (United States)

    Casado, Natalia; Morante-Zarcero, Sonia; Pérez-Quintanilla, Damián; Sierra, Isabel

    2016-08-12

    A quick, sensitive and selective analytical reversed-phase multi-residue method using ultra-high performance liquid chromatography coupled to an ion-trap mass spectrometry detector (UHPLC-IT-MS/MS) operating in both positive and negative ion mode was developed for the simultaneous determination of 23 veterinary drug residues (β-blockers, β-agonists and Non-Steroidal Anti-inflammatory Drugs (NSAIDs)) in meat samples. The sample treatment involved a liquid-solid extraction followed by a solid-phase extraction (SPE) procedure. SBA-15 type mesoporous silica was synthetized and modified with octadecylsilane, and the resulting hybrid material (denoted as SBA-15-C18) was applied and evaluated as SPE sorbent in the purification of samples. The materials were comprehensively characterized, and they showed a high surface area, high pore volume and a homogeneous distribution of the pores. Chromatographic conditions and extraction procedure were optimized, and the method was validated according to the Commission Decision 2002/657/EC. The method detection limits (MDLs) and the method quantification limits (MQLs) were determined for all the analytes in meat samples and found to range between 0.01-18.75μg/kg and 0.02-62.50μg/kg, respectively. Recoveries for 15 of the target analytes ranged from 71 to 98%. In addition, for comparative purpose SBA-15-C18 was evaluated towards commercial C18 amorphous silica. Results revealed that SBA-15-C18 was clearly more successful in the multi-residue extraction of the 23 mentioned analytes with higher recovery values. The method was successfully tested to analyze prepacked preparations of mince bovine meat. Traces of propranolol, ketoprofen and diclofenac were detected in some samples.

  16. Validação intralaboratorial de método quantitativo para determinação múltipla de resíduos de avermectinas em leite bovino por cromatografia líquida de alta eficiência com detecção de fluorescência In-house validation of a multi-residue method for determining residual avermectin in cow's milk by hplc coupled with fluorescence detection

    Directory of Open Access Journals (Sweden)

    Scheilla Vitorino Carvalho de Souza

    2007-12-01

    Full Text Available Um procedimento detalhado para validação intralaboratorial de métodos, incluindo delineamento experimental, estatísticas e avaliação de premissas foi proposto e aplicado à validação de um método para ensaio de avermectinas em leite bovino por cromatografia líquida de alta eficiência com detector de fluorescência. Foram realizados ensaios com curvas de solventes e de matriz, amostras de leite bovino brancas e adicionadas. As premissas relacionadas às estatísticas empregadas foram avaliadas e confirmadas. Linearidade foi obtida entre 25 e 150 ng.mL-1. Não foram observados efeitos de matriz significativos nesta faixa. As médias de recuperação aparente variaram de 87,2 a 101,4%. Desvios padrão relativos sob condições de repetitividade estiveram entre 3,3 e 11,2%, enquanto os desvios padrão relativos de reprodutibilidade parcial foram de 7,4 a 14,7%. Estes resultados indicaram exatidão e precisão do método entre 10 e 30 µg.L-1 para os quatro analitos estudados. Os limites de detecção e quantificação experimentais foram 5 e 10 µg.L-1, respectivamente. Limites de decisão (12,6 a 13,7 µg.L-1 e capacidades de detecção (15,1 a 17,4 µg.L-1 foram estimados, assumindo um limite máximo de resíduo de 10 µg.L-1.A detailed procedure for in-house validation of methods, including experimental design, statistics and evaluation of assumptions, was proposed and applied to the validation of a method for screening avermectins in cow's milk by high performance liquid chromatography coupled with fluorescence detection. Assays were performed with solvent and matrix-matched calibration curves, milk blanks and spiked samples. The assumptions about the statistics employed were evaluated and confirmed. Linearity was achieved between 25 and 150 ng.mL-1. No significant matrix effects were observed in this range. Mean apparent recoveries varied from 87.2 to 101.4%. The relative standard deviations under conditions of repeatability ranged

  17. 有机磷农药多残留检测化学发光标记物的合成及鉴定%Synthesis and identification of chemiluminescent markers used in the multi-residue determination of organophosphorus pesticides

    Institute of Scientific and Technical Information of China (English)

    刘涛; 孟超; 姚鑫; 李景娜; 程燕; 刘晓宇

    2014-01-01

    Objective Chemiluminescent markers were synthesized using O,O-diethylthiophosphoryl chloride and luminol for the multi-residue determination of organophosphorus pesticides. Methods Luminol and O, O-diethyl phosphoryl chloride were added to dichloromethane under ice-cooling with triethylamine as acid binding agent. After 8 h, the organic layer was separated and purified by column chromatography. Results The product was the chemiluminescent markers after indentation using UV and IR. It had a strong luminescent ability on the BPCL, and the maximum luminous intensity reached 9000 mV. Conclusion The chemilumi-nescent markers synthesized by this method had a strong luminescence capability, and it could be used in the multi-residue determination of organophosphorus pesticides.%目的:以 O,O-二乙基硫代磷酰氯和鲁米诺为原料,合成一种新型的化学发光标记物,用于后续的二乙氧基类有机磷农药多残留化学发光免疫法检测。方法取鲁米诺和O,O-二乙基硫代磷酰氯溶于二氯甲烷中,以三乙胺作为缚酸剂,冰浴下反应8h后分出有机层,产物经柱层析纯化,即得到化学发光标记物。结果产物经紫外、红外鉴定,实验结果表明反应产物即为所需的化学发光标记物,产物在BPCL上进行发光特性测定,表现出较强的发光能力,最大发光强度达到9000 mV。结论本方法合成的化学发光标记物具有较强的发光能力,能用于后续的二乙氧基类有机磷农药多残留的化学发光免疫检测。

  18. Multi-residue analysis of veterinary drugs, pesticides and mycotoxins in dairy products by liquid chromatography-tandem mass spectrometry using low-temperature cleanup and solid phase extraction.

    Science.gov (United States)

    Xie, Jie; Peng, Tao; Zhu, Ailing; He, Jianli; Chang, Qiaoying; Hu, Xueyan; Chen, Hui; Fan, Chunlin; Jiang, Wenxiao; Chen, Min; Li, Jiancheng; Ding, Shuangyang; Jiang, Haiyang

    2015-10-01

    A multi-class multi-residue analysis method for determination of veterinary drugs, pesticides and mycotoxins in dairy products by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been established. These 17 classes, a total of 40 kinds of target compounds were chosen because their administration to food-producing animals is banned or regulated in China and may be potentially abused or misused. Samples were extracted with acetonitrile-ethyl acetate-acetic acid (49.5+49.5+1, v/v/v). Most of lipids in the extract were removed by low-temperature cleanup, prior to solid phase extraction on HLB cartridges. The quantification and confirmation of the 40 analytes were performed by LC-MS/MS with electro-spray ionization (ESI) interface in multiple reaction monitoring (MRM) mode. The limits of detection (LODs) and limits of quantification (LOQs) were 0.006-0.3μg/kg and 0.02-1.0μg/kg, respectively. The spiked recoveries in milk, yogurt, milk powder and cheese samples were from 67.3% to 106.9%. The repeatability and the within-laboratory reproducibility were less than 12.7% and 13.9%. Applying this method, our results revealed the presences of chloramphenicol, cimeterol, and flunixin at the concentration of 0.027-0.452μg/kg in some samples.

  19. Comparative study of different chromatographic techniques for the analysis of multi-residues of some approved antimicrobials in fish tissues.

    Science.gov (United States)

    Riad, Safa'a M; Rezk, Mamdouh R; Khattab, Fatma I; Marzouk, Hoda M

    2015-01-01

    Two chromatographic methods were developed, optimized and validated for the simultaneous determination of three approved aquaculture antimicrobials, namely sulphadimethoxine sodium, trimethoprim and florphenicol in fish tissues. The developed methods were based on simple liquid extraction technique. The first method employs thin-layer chromatography as a clean-up procedure coupled with densitometric determination for the separated drugs. The second method is an HPLC one using X-Terra™ C18 column. Several mobile-phase systems and extracting solvents were tried to optimize the separation and the extraction procedures from fish tissues. The procedures were applied for the analysis of spiked fish tissue samples at three different concentration levels (10, 50 and 100 ppm). A comparative study was conducted between the proposed methods to discuss the advantage of each one. The methods were validated according to the international conference on harmonization guidelines. The proposed methods were successfully applied for the determination of the studied drugs in spiked fish tissues, pure powders and in their veterinary pharmaceutical formulation.

  20. Multi-residue analysis of 36 priority and emerging pollutants in marine echinoderms (Holothuria tubulosa) and marine sediments by solid-liquid extraction followed by dispersive solid phase extraction and liquid chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Martín, J; Zafra-Gómez, A; Hidalgo, F; Ibáñez-Yuste, A J; Alonso, E; Vilchez, J L

    2017-05-01

    Marine echinoderms are filter-feeding invertebrates widely distributed along the coasts, and which are therefore extensively exposed to anthropogenic xenobiotics. They can serve as good sentinels for monitoring a large variety of contaminants in marine ecosystems. In this context, a multi-residue analytical method has been validated and applied to Holothuria tubulosa specimens and marine sediments for the determination of 36 organic compounds, which belong to some of the most problematic groups of emerging and priority pollutants (perfluoroalkyl compounds, estrogens, parabens, benzophenones, plasticizers, surfactants, brominated flame retardants and alkylphenols). Lyophilization of samples prior to solvent extraction and clean-up of extracts with C18, followed by liquid chromatography-tandem mass spectrometry analysis, is proposed. A Box-Behnken design was used for optimization of the most influential variables affecting the extraction and clean-up steps. For validation, matrix-matched calibration and recovery assay were applied. Linearity (% r(2)) higher than 99%, recoveries between 80% and 114% (except in LAS and NP1EO), RSD (precision) lower than 15% and limits of quantification between 0.03 and 12.5ngg(-1) dry weight (d.w.) were achieved. The method was applied to nine samples of Holothuria collected along the coast of Granada (Spain), and to marine sediments around the animals. The results demonstrated high bioaccumulation of certain pollutants. A total of 25 out of the 36 studied compounds were quantified, being surfactants, alkylphenols, perfluoroalkyl compounds, triclocarban and parabens the most frequently detected. Nonylphenol was found in the highest concentration (340 and 323ngg(-1) d.w. in sediment and Holothuria samples, respectively).

  1. Liquid chromatography-mass spectrometry in applications of veterinary drugs multi-class and multi-residues analysis%液质联用技术在兽药多类别、多组分残留分析中的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    曲斌; 陈蓉; 耿士伟; 陆桂萍; 蒋天梅; 邵德佳; 姜加华

    2015-01-01

    Veterinary drug residue analysis (VDRA) was one of the most widely studied subjects in analytical laboratories working in the field of food safety, liquid chromatogaphy-mass spectrometry (LC-MS) has been the main technique of choice for VDRA. Except of the quantitative determination of several target compounds, the trend of VDRA was been as mainly simultaneous analysis of multi-class and multi-residuals based on mass spectrometry (MS) screening method in a single analysis. Liquid chromatography tandem triple quadrupole MS (LC-MS/MS) and liquid chromatography tandem high resolution MS (LC-HRMS) had many characteristics and advantages respectively, LC-MS multi-residue methods has been developed and applied to detect such as antibiotics in animal-derived foods by researchers all over the world. This paper was focused on the progress of the current LC-MS methods which applied to the veterinary multi-residue analysis.%兽药残留分析是食品安全实验室最广泛开展的分析项目之一,液质联用技术已成为兽药残留分析的关键技术和研究手段。除进行少数目标组分的定量测定外,多类别、多组分兽药的同时同步分析成为近年来兽药残留分析的发展趋势。液相色谱串联三级四极杆质谱和液相色谱串联高分辨质谱在兽药多残留分析中各有其特点和优势,各国研究者在牛奶、动物组织等动物源性食品中开展了抗生素等多残留的检测研究与应用工作。本文就目前液质联用技术及其在兽药多残留分析中的应用做一概述。

  2. Carbohydrate Bis-acetal-Based Substrates as Tunable Fluorescence-Quenched Probes for Monitoring exo-Glycosidase Activity.

    Science.gov (United States)

    Cecioni, Samy; Vocadlo, David J

    2017-06-28

    Tunable Förster resonance energy transfer (FRET)-quenched substrates are useful for monitoring the activity of various enzymes within their relevant physiological environments. Development of FRET-quenched substrates for exo-glycosidases, however, has been hindered by their constrained pocket-shaped active sites. Here we report the design of a new class of substrate that overcomes this problem. These Bis-Acetal-Based Substrates (BABS) bear a hemiacetal aglycon leaving group that tethers fluorochromes in close proximity, also positioning them distant from the active site pocket. Following cleavage of the glycosidic bond, the liberated hemiacetal spontaneously breaks down, leading to separation of the fluorophore and quencher. We detail the synthesis and characterization of GlcNAc-BABS, revealing a striking 99.9% quenching efficiency. These substrates are efficiently turned over by the human exo-glycosidase O-GlcNAcase (OGA). We find the hemiacetal leaving group rapidly breaks down, enabling quantitative monitoring of OGA activity. We expect this strategy to be broadly useful for the development of substrate probes for monitoring exo-glycosidases, as well as a range of other enzymes having constrained pocket-shaped active sites.

  3. Multi-residue analysis of anabolics in calf urine using high-performance liquid chromatography with diode-array detection

    NARCIS (Netherlands)

    Koole, A; Franke, J.P.; de Zeeuw, R.A

    1999-01-01

    We describe the development of an HPLC method with diode-array detection (DAD) for the analysis and identification of 20 substances with anabolic properties, that are considered as potential growth promoters, to be used for the analysis of extracts of calf urine samples. The substances are separated

  4. Multi-residue analysis of anabolics in calf urine using high-performance liquid chromatography with diode-array detection

    NARCIS (Netherlands)

    Koole, A; Franke, J.P.; de Zeeuw, R.A

    1999-01-01

    We describe the development of an HPLC method with diode-array detection (DAD) for the analysis and identification of 20 substances with anabolic properties, that are considered as potential growth promoters, to be used for the analysis of extracts of calf urine samples. The substances are separated

  5. Multi-residue analysis of eight thioamphetamine designer drugs in human urine by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Nieddu, Maria; Boatto, Gianpiero; Pirisi, Maria Antonietta; Baralla, Elena

    2009-10-01

    An analytical procedure for the simultaneous determination in human urine of several thioamphetamine designer drugs (2C-T and ALEPH series) is reported. The quantitative analysis was performed by liquid chromatography/tandem mass spectrometry and has been fully validated. The mass spectrometer was operated in positive-ion, selected reaction monitoring (SRM) mode. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid-phase extraction was introduced in the method as a clean-up step. The entire method was validated for selectivity, linearity, precision and accuracy. The method turned out to be specific, sensitive, and reliable for the analysis of amphetamine derivatives in urine samples. The calibration curves were linear over the concentration range of 1 to 100 ng mL(-1) for all drugs with correlation coefficients that exceeded 0.996. The lower limits of detection (LODs) and quantification (LOQs) ranged from 1.2 to 4.9 ng mL(-1) and from 3.2 to 9.6 ng mL(-1), respectively.

  6. Critical evaluation of monitoring strategy for the multi-residue determination of 90 chiral and achiral micropollutants in effluent wastewater.

    Science.gov (United States)

    Petrie, Bruce; Proctor, Kathryn; Youdan, Jane; Barden, Ruth; Kasprzyk-Hordern, Barbara

    2017-02-01

    It is essential to monitor the release of organic micropollutants from wastewater treatment plants (WWTPs) for developing environmental risk assessment and assessing compliance with legislative regulation. In this study the impact of sampling strategy on the quantitative determination of micropollutants in effluent wastewater was investigated. An extended list of 90 chiral and achiral micropollutants representing a broad range of biological and physico-chemical properties were studied simultaneously for the first time. During composite sample collection micropollutants can degrade resulting in the under-estimation of concentration. Cooling collected sub-samples to 4°C stabilised ≥81 of 90 micropollutants to acceptable levels (±20% of the initial concentration) in the studied effluents. However, achieving stability for all micropollutants will require an integrated approach to sample collection (i.e., multi-bottle sampling with more than one stabilisation method applied). Full-scale monitoring of effluent revealed time-paced composites attained similar information to volume-paced composites (influent wastewater requires a sampling mode responsive to flow variation). The option of monitoring effluent using time-paced composite samplers is advantageous as not all WWTPs have flow controlled samplers or suitable sites for deploying portable flow meters. There has been little research to date on the impact of monitoring strategy on the determination of chiral micropollutants at the enantiomeric level. Variability in wastewater flow results in a dynamic hydraulic retention time within the WWTP (and upstream sewerage system). Despite chiral micropollutants being susceptible to stereo-selective degradation, no diurnal variability in their enantiomeric distribution was observed. However, unused medication can be directly disposed into the sewer network creating short-term (e.g., daily) changes to their enantiomeric distribution. As enantio-specific toxicity is observed

  7. 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

    Energy Technology Data Exchange (ETDEWEB)

    Sapozhnikova, Yelena, E-mail: yelena.sapozhnikova@ars.usda.gov [US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 193038 (United States); Lehotay, Steven J. [US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 193038 (United States)

    2013-01-03

    Highlights: Black-Right-Pointing-Pointer A method for analysis of POPs and novel flame retardants in catfish was developed. Black-Right-Pointing-Pointer The method is based on a QuEChERS extraction, d-SPE clean-up and low pressure GC/MS-MS. Black-Right-Pointing-Pointer The method validation demonstrated good recoveries and low detection limits. Black-Right-Pointing-Pointer 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{sup -1} for PCBs, 0.5-10 ng g{sup -1} for PBDEs, 0.5-5 ng g{sup -1} for select pesticides and PAHs and 1-10 ng g{sup -1} for flame retardants. The developed method was successfully applied for analysis of catfish samples

  8. Comparison of electrospray ionization and atmospheric pressure chemical ionization for multi-residue analysis of biocides, UV-filters and benzothiazoles in aqueous matrices and activated sludge by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wick, Arne; Fink, Guido; Ternes, Thomas A

    2010-04-02

    This paper describes the development of a multi-residue method for the determination of 36 emerging organic pollutants (26 biocides, 5 UV-filters and 5 benzothiazoles) in raw and treated wastewater, activated sludge and surface water using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The target analytes were enriched from water samples adjusted to pH 6 by solid-phase extraction (SPE) on Oasis HLB 200mg cartridges and eluted with a mixture of methanol and acetone (60/40, v/v). Extraction of freeze-dried sludge samples was accomplished by pressurized liquid extraction (PLE) using a mixture of methanol and water (50/50, v/v) as extraction solvent followed by SPE. LC-tandem MS detection was compared using electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) in positive and negative ionization mode. ESI exhibited strong ion suppression for most target analytes, while APCI was generally less susceptible to ion suppression but partially leading to ion enhancement of up to a factor of 10. In general, matrix effects could be compensated using stable isotope-labeled surrogate standards, indicated by relative recoveries ranging from 70% to 130%. In wastewater, activated sludge and surface water up to 33 analytes were detected. Maximum concentrations up to 5.1 and 3.9mugL(-1) were found in raw wastewater for the water-soluble UV-filters benzophenone-4 (BZP-4) and phenylbenz-imidazole sulfonic acid (PBSA), respectively. For the first time, the anti-dandruff climbazole was detected in raw wastewater and in activated sludge with concentrations as high as 1.4 microg L(-1) and 1.2 microg gTSS(-1), respectively. Activated sludge is obviously a sink for four benzothiazoles and two isothiazolones, as concentrations were detected in activated sludge between 120 ng gTSS(-1) (2-n-octyl-4-isothiazolin-3-one, OIT) to 330 ng gTSS(-1) (benzothiazole-2-sulfonic acid, BTSA). Copyright (c) 2010 Elsevier B.V. All rights reserved.

  9. Multi-residue methods for the analysis of pesticides in airborne particulate matter by LC_MS/ and GC-MS/MS. Monitoring levels in the atmosphere

    OpenAIRE

    Coscollà Raga, Clara

    2011-01-01

    Los plaguicidas actualmente utilizados en agricultura (CUPs) pueden encontrarse en la atmósfera como consecuencia de su uso intensivo en zonas agrícolas sobre todo durante el periodo de aplicación. Más de 300 sustancias activas están actualmente aprobadas por la UE y pueden ser aplicadas en distintos cultivos según la Directiva 91/414/CEE. La cantidad total de plaguicidas utilizados en la (EU-27) durante el 2008 fue de unas 310.011 toneladas de sustancia activa, con Francia (25.3%), España (1...

  10. Isolation of ethyl acetic based AGF bio-nutrient and its application on the growth of Capsicum annum L. plants

    Science.gov (United States)

    Hendrawan, Sonjaya, Yaya; Khoerunnisa, Fitri; Musthapa, Iqbal; Nurmala, Astri Rizki

    2015-12-01

    The study aimed to obtain the bionutrient derived from extraction of AGF leafs in ethyl acetic solvents and to explore its application on the plant growth of capsicum annum L. (curly red chili). Particularly, the fraction of secondary metabolites groups composed bionutrient was intensively elucidated by liquid vacuum chromatography technique. The characterization of secondary metabolites groups was conducted through several methods, i.e. thin layer chromatography, phytochemical screening, and FTIR spectroscopy. The AGF extracts based bionutrient then was applied on capsicum annum L. plants with dosage of 2 and 10 mL/L. The ethyl acetic solvent and commercial nutrient of Phonska and pesticide of curacron (EC 500) were selected as a blank and a positive control to evaluate the growth pattern of capsicum annum L., respectively. The result showed that the CF 1 dan CF2 of AGF extract contained alkaloid and terpenoid of secondary metabolite group, the CF 3, and CF 4 of AGF extracts were dominated by alkaloid, flavonoid, and terpenoid, while the CF 5 of AGF extract contained alkaloid, tannin and terpenoid groups. The CF 2 of AGF extract has the highest growth rate constant of 0.1702 week-1 with the number and heaviest mass of the yield of 82 pieces and 186.60, respectively. It was also showed the significant bio-pesticide activity that should be useful to support plant growth, indicating that AGF extract can be applied as both bio-nutrient and bio-pesticide.

  11. The Cholesterol-Lowering Effect of Alisol Acetates Based on HMG-CoA Reductase and Its Molecular Mechanism

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2016-01-01

    Full Text Available This study measured the impact of alisol B 23-acetate and alisol A 24-acetate, the main active ingredients of the traditional Chinese medicine Alismatis rhizoma, on total cholesterol (TC, triglyceride (TG, high density lipoprotein-cholesterol (HDL-C, and low density lipoprotein-cholesterol (LDL-C levels of hyperlipidemic mice. The binding of alisol B 23-acetate and alisol A 24-acetate to the key enzyme involved in the metabolism of TC, 3-hydroxy-3-methylglutary-coenzyme A (HMG-CoA reductase, was studied using the reagent kit method and the western blotting technique combined with a molecular simulation technique. According to the results, alisol acetates significantly lower the TC, TG, and LDL-C concentrations of hyperlipidemic mice, while raising HDL-C concentrations. Alisol acetates lower HMG-CoA reductase activity in a dose-dependent fashion, both in vivo and in vitro. Neither of these alisol acetates significantly lower the protein expression of HMG-CoA. This suggests that alisol acetates lower the TC level via inhibiting the activity of HMG-CoA reductase by its prototype drug, which may exhibit an inhibition effect via directly and competitively binding to HMG-CoA. The side chain of the alisol acetate was the steering group via molecular simulation.

  12. Microbiological quality and other characteristics of refrigerated chicken meat in contact with cellulose acetate-based film incorporated with rosemary essential oil

    Directory of Open Access Journals (Sweden)

    Adriane Alexandre Machado de Melo

    2012-12-01

    Full Text Available Antimicrobial active packaging delays or inhibits microorganism growth in packed products, and it can be used in a variety of food systems. The objective of the present research was to develop packaging incorporated with natural antimicrobial agents (active film. The effects of the active film on the spoilage, pathogenic microorganism counts, pH and color of the refrigerated chicken breast cuts were analyzed. Cellulose acetate-based active films incorporating two concentrations (20% and 50%, v/w of rosemary (Rosmarinus officinalis L. essential oil were manufactured and placed in contact with the chicken breast cuts for six days. An analysis of variance and mean comparison tests (Tukey's test, p<0.05 were performed on the results. The films that contained 20% essential oil and were intercalated with chicken breast samples did not demonstrate significant effects on the control of psychrotrophic or total coliform microorganisms during the storage period; however, the films incorporated with 50% essential oil demonstrated efficacy toward the control of coliforms during the storage of the samples (6 days, 2 ± 2ºC. The pH was related to the psychrotrophic microorganism count and was not influenced by the treatment. The color was not influenced by the time of storage or the treatment. The results demonstrate that active films incorporating 50% rosemary essential oil are effective at controlling certain microorganisms in chicken breast cuts.

  13. 77 FR 39895 - New Analytic Methods and Sampling Procedures for the United States National Residue Program for...

    Science.gov (United States)

    2012-07-06

    ... Service 9 CFR Parts 417 New Analytic Methods and Sampling Procedures for the United States National... sampling and scheduling, the Agency is implementing several multi-residue methods for analyzing samples of... analytical ] methods to devise a final sampling plan. FSIS publishes the final sampling plan in the...

  14. Rapid multi-residue and multi-class qualitative screening for veterinary drugs in foods of animal origin by UHPLC-MS/MS.

    Science.gov (United States)

    Robert, C; Gillard, N; Brasseur, P-Y; Pierret, G; Ralet, N; Dubois, M; Delahaut, Ph

    2013-01-01

    Multi-class UHPLC-MS/MS was developed for the analysis of more than 160 regulated or banned compounds of various classes: anthelmintics including benzimidazoles, avermectins and others; antibiotics including amphenicols, beta-lactams, macrolides, pyrimidines, quinolones, sulphonamides and tetracyclines; beta-agonists; corticosteroids; ionophores; nitroimidazoles; non-steroidal anti-inflammatory agents; steroids; and tranquillisers. Samples were extracted with acetonitrile, without any additional purification step, and analysed by using UHPLC-MS/MS. Validation was done in accordance with the guidelines laid down by European Commission Decision 2002/657/EC for qualitative screening methods. This simple method proved applicable to routine screening for residues in egg, honey, milk and muscle samples at half the maximum concentration permitted by the European Union for each drug. In most cases, the target value was set at 5 µg kg(-1) for unauthorised compounds.

  15. Determination of multi-residue for malachite green, gentian violet and their metabolites in aquatic products by high-performance liquid chromatography coupled with molecularly imprinted solid-phase extraction.

    Science.gov (United States)

    Long, Chaoyang; Mai, Zhibin; Yang, Yingfen; Zhu, Binghui; Xu, Xiumin; Lu, Lin; Zou, Xiaoyong

    2009-03-20

    A sorbent was synthesized and investigated for molecularly imprinted solid-phase extraction (MISPE). Molecularly imprinted polymers (MIPs) were synthesized via precipitation polymerization procedure, where methacrylic acid (MAA) was used as functional monomer and ethylene glycol dimethacrylate (EDMA) as cross-linking agent. The imprinting effect and selectivity of the MISPE were evaluated by elution experiments. The resulting MISPE showed high extraction selectivity to malachite green, gentian violet and their metabolites, which may be caused by both the ion exchange and the hydrophobic interactions. The determination of multi-residue for malachite green, gentian violet and their metabolites in aquatic products by HPLC coupled with MISPE was also investigated. The mean recoveries calculated by solvent calibration curve for malachite green (MG), gentian violet (GV), leucomalachite green (LMG) and leucogentian violet (LGV) were from 89.8% to 99.1% for grass carp, 90.6% to 101.2% for shrimp and 91.3% to 96.3% for shellfish. The decision limit (CCalpha) and the detection capability (CCbeta) obtained for MG, GV, LMG and LGV were in the range of 0.11-0.14 and 0.19-0.24 microg kg(-1) for grass carp, shrimp and shellfish. The MISPE was successfully used off-line for the determination of MG, GV and their metabolites in aquatic products.

  16. Multi-residue quantification of veterinary drugs in milk with a novel extraction and cleanup technique: salting out supported liquid extraction (SOSLE).

    Science.gov (United States)

    Kaufmann, A; Butcher, P; Maden, K; Walker, S; Widmer, M

    2014-04-11

    A quantitative liquid chromatography coupled with high-resolution mass spectrometry method was developed for the determination of more than one hundred compounds belonging to a variety of veterinary drug classes in bovine milk. Salting out supported liquid extraction (SOSLE), a novel extraction and cleanup technique, was introduced to ensure high extraction efficiency and good sample cleanup. The high salt (ammonium sulfate) concentration in the aqueous donor phase permits supported liquid/liquid extraction (SLE) with a relative polar organic acceptor phase (acetonitrile). This is different from traditional SLE, in which the need for phase separation results in the selection of organic solvents with intermediate polarities (e.g., ethyl acetate or dichloromethane). Hence, SOSLE is more efficient in recovering polar analytes than conventional SLE. SOSLE was also compared to classical approaches like solid phase extraction, QuEChERS and ultra-filtration. The proposed technique resulted in extracts of equal or superior cleanliness and with higher average recoveries than those obtained with QuEChERS or SPE. The recovery (median for all compounds) was 73% for QuEChERS, 83% for SPE and 91% for SOSLE. The most significant improvements were observed for polar analytes (penicillines, quinolones and tetracyclines) which are hardly recovered by QuEChERS. The chromatographic separation and detection was based on an ultra-high-performance liquid chromatography Q-Orbitrap system (Q-Exactive plus). The developed analytical method has been validated (based on the commission decision 2002/957/EC) as required for quantitative veterinary drug methods.

  17. Application of gas chromatography/tandem quadrupole mass spectrometry to the multi-residue analysis of pesticides in green leafy vegetables.

    Science.gov (United States)

    Walorczyk, Stanisław

    2008-12-01

    A new, sensitive and specific method has been developed for the simultaneous determination of 129 pesticides in lettuce and other green leafy vegetables. The samples were extracted with acetonitrile and co-extractives such as fatty acids and pigments were removed using dispersive solid-phase extraction (dispersive-SPE) with primary secondary amine (PSA) and graphitized carbon black (GCB). All pesticides were analyzed in a single injection gas chromatography/tandem quadrupole mass spectrometry (GC/MS/MS) acquisition method. Two multiple reaction monitoring (MRM) transitions of precursor ions fragmenting into product ions were recorded for the targeted pesticides, thus fulfilling the EU identification points system criteria for the identification of contaminants (2002/657/EC). Calibration curves were determined using matrix-matched standards, and exhibited excellent linearity at two orders of magnitude from 0.005 to 0.5 mg/kg for almost all the pesticides studied (R(2) > or = 0.99). The analytical performance was demonstrated by the analysis of lettuce samples spiked at five concentration levels ranging from 0.005 to 0.5 mg/kg for each pesticide. The recovery and repeatability results satisfied SANCO/2007/3131 criteria (i.e. average recoveries were in the range 70-120% with RSDs vegetable samples such as lettuce, cabbage and leek.

  18. Sol-gel type synthesis of Bi{sub 2}(Sr,Ta{sub 2})O{sub 9} using an acetate based system

    Science.gov (United States)

    Boyle, T.J.

    1997-11-04

    A method of forming a layered-perovskite bismuth-strontium-tantalum oxide (SBT) ferroelectric material is performed by dissolving a bismuth compound in a first solvent to form a first solution, mixing a strontium compound and a tantalum compound to form a binary mixture, dissolving the binary mixture in a second solvent to form a second solution, mixing the first solution with the second solution to form a SBT precursor solution, evaporating the first and second solvents to form a SBT precursor material and subsequently sintering said SBT precursor material in the presence of oxygen. 6 figs.

  19. Sol-gel type synthesis of Bi.sub.2 (Sr,Ta.sub.2)O.sub.9 using an acetate based system

    Science.gov (United States)

    Boyle, Timothy J.

    1997-01-01

    A method of forming a layered-perovskite bismuth-strontium-tantalum oxide (SBT) ferroelectric material is performed by dissolving a bismuth compound in a first solvent to form a first solution, mixing a strontium compound and a tantalum compound to form a binary mixture, dissolving the binary mixture in a second solvent to form a second solution, mixing the first solution with the second solution to form a SBT precursor solution, evaporating the first and second solvents to form a SBT precursor material and subsequently sintering said SBT precursor material in the presence of oxygen.

  20. Synthesis and study of nano-structured cellulose acetate based materials for energy applications; Synthese et etude de materiaux nanostructures a base d'acetate de cellulose pour applications energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, F

    2006-12-15

    Nano-structured materials have unique properties (high exchange areas, containment effect) because of their very low characteristic dimensions. The elaboration way set up in this PhD work consists in applying the classical processes for the preparation of aerogel-like materials (combining sol-gel synthesis and CO{sub 2} supercritical extraction) to cellulosic polymers. This work is divided in four parts: a literature review, the presentation and the study of the chemical synthesis that leads to cellulose acetate-based aerogel, the characterizations (chemical, structural and thermal) of the elaborated nano-materials, and finally the study of the first carbons that were obtained after pyrolysis of the organic matrix. The formulations and the sol-gel protocol lead to chemical gels by crosslinking cellulose acetate using a poly-functional iso-cyanate. The dry materials obtained after solvent extraction with supercritical CO{sub 2} are nano-structured and mainly meso-porous. Correlations between chemical synthesis parameters (reagent concentrations, crosslinking rate and degree of polymerisation) and porous properties (density, porosity, pore size distribution) were highlighted thanks to structural characterizations. An ultra-porous reference aerogel, with a density equals to 0,245 g.cm{sup -3} together with a meso-porous volume of 3,40 cm{sup 3}.g{sup -1} was elaborated. Once in granular shape, this material has a thermal conductivity of 0,029 W.m{sup -1}.K{sup -1}. In addition, carbon materials produced after pyrolysis of the organic matrix and after grinding are nano-structured and nano-porous, even if important structural modifications have occurred during the carbonization process. The elaborated materials are evaluated for applications in relation with energy such as thermal insulation (organic aerogels) but also for energy conversion and storage through electrochemical way (carbon aerogels). (author)

  1. Multi-residue analysis of 30 currently used pesticides in fine airborne particulate matter (PM 2.5) by microwave-assisted extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Coscollà, Clara; Yusà, Vicent; Beser, Ma Isabel; Pastor, Agustin

    2009-12-18

    A confirmatory and rapid procedure has been developed for the determination of 30 currently used pesticides (CUP) in fine airborne particulate matter (PM 2.5) at trace level. The proposed method includes extraction of PM 2.5-bound pesticides by microwave-assisted extraction (MAE) followed by a direct injection into LC-MS/MS. The main parameters affecting the MAE extraction (time, temperature and volume of solvent) were optimised using statistical design of experiments (DoE). The matrix effect was also evaluated. Recoveries ranged from 72 to 109% and the limit of quantification (LoQ) was 32.5 pg m(-3) for chlorpyrifos, 13.5 pg m(-3) for fenhexamid, imazalil and prochloraz, and 6.5 pg m(-3) for the rest of pesticides, when air volumes of 760 m(3) were collected. The method was applied to 54 samples collected from three stations of the atmospheric monitoring network of the Regional Valencia Government (Spain) during April-July 2009. Nineteen out of 30 pesticides investigated were found in at least one sample: omethoate, carbendazim, acetamiprid, thiabendazole, malathion, flusilazole, metalaxyl, azoxystrobin, iprovalicarb, myclobutanil, tebuconazole, triflumizole, cyprodinil, tebufenpyrad, buprofezin, pyriproxyfen, hexythiazox, flufenoxuron and fenazaquin. The measured concentrations ranged from 6.5 to 1208 pg m(-3). To our knowledge, 11 of the pesticides detected have been reported for the first time in ambient air.

  2. Multi-residue analysis of pharmaceuticals in aqueous environmental samples by online solid-phase extraction-ultra-high-performance liquid chromatography-tandem mass spectrometry: optimisation and matrix effects reduction by quick, easy, cheap, effective, rugged and safe extraction.

    Science.gov (United States)

    Bourdat-Deschamps, Marjolaine; Leang, Sokha; Bernet, Nathalie; Daudin, Jean-Jacques; Nélieu, Sylvie

    2014-07-04

    The aim of this study was to develop and optimise an analytical method for the quantification of a bactericide and 13 pharmaceutical products, including 8 antibiotics (fluoroquinolones, tetracyclines, sulfonamides, macrolide), in various aqueous environmental samples: soil water and aqueous fractions of pig slurry, digested pig slurry and sewage sludge. The analysis was performed by online solid-phase extraction coupled to ultra-high performance liquid chromatography with tandem mass spectrometry (online SPE-UHPLC-MS-MS). The main challenge was to minimize the matrix effects observed in mass spectrometry, mostly due to ion suppression. They depended on the dissolved organic carbon (DOC) content and its origin, and ranged between -22% and +20% and between -38% and -93% of the signal obtained without matrix, in soil water and slurry supernatant, respectively. The very variable levels of these matrix effects suggested DOC content cut-offs above which sample purification was required. These cut-offs depended on compounds, with concentrations ranging from 30 to 290mgC/L for antibiotics (except tylosine) up to 600-6400mgC/L for the most apolar compounds. A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction procedure was therefore optimised using an experimental design methodology, in order to purify samples with high DOC contents. Its performance led to a compromise, allowing fluoroquinolone and tetracycline analysis. The QuEChERS extraction salts consisted therefore of sodium acetate, sodium sulfate instead of magnesium sulfate, and sodium ethylenediaminetetraacetate (EDTA) as a ligand of divalent cations. The modified QuEChERS procedure employed for the extraction of pharmaceuticals in slurry and digested slurry liquid phases reduced the matrix effects for almost all the compounds, with extraction recoveries generally above 75%. The performance characteristics of the method were evaluated in terms of linearity, intra-day and inter

  3. Multi-residue determination of eleven anticoagulant rodenticides by high-performance liquid chromatography with diode array/fluorimetric detection: investigation of suspected animal poisoning in the period 2012-2013 in north-eastern Italy.

    Science.gov (United States)

    Gallocchio, Federica; Basilicata, Lara; Benetti, Cristiana; Angeletti, Roberto; Binato, Giovanni

    2014-11-01

    Misuse or deliberate abuse of anticoagulant rodenticides (AR) may often result in incidental or malicious non-target animal poisoning. This study presents preliminary results of the analysis of 561 real suspected samples, ranging from baits to livers and stomach contents, collected at the Istituto Zooprofilattico Sperimentale delle Venezie (official referral laboratory for the regions of north-eastern Italy), in the period 2012-2013. Samples were analyzed by a method based on a combination of liquid chromatography with diode array/fluorescence detection (HPLC-DAD/F) able to identify 11 different AR (brodifacoum, bromadiolone, chloropahacinone, coumachlor, coumafuryl, coumatetralyl, difenacoum, diphacinone, flocoumafen, pindone, warfarin). Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Preparation and characterization of amino functionalized nano-composite material and its application for multi-residue analysis of pesticides in cabbage by gas chromatography-triple quadrupole mass spectrometry.

    Science.gov (United States)

    Zhao, Yong-Gang; Shen, Hao-Yu; Shi, Jia-Wei; Chen, Xiao-Hong; Jin, Mi-Cong

    2011-08-19

    In this paper, a novel and recyclable amino-functionalized nano-composite material (NCM) using tetraethylenepentamine (TEPA) as a coupling agent was synthesized. The properties of the TEPA-NCM were characterized by transmission electron microscopy (TEM), Fourier transform infrared analysis (FTIR), thermogravimetric analysis (TGA) and elemental analysis (EA). An effective dispersive solid-phase extraction (dSPE) procedure using the TEPA-NCM was developed, and comparative studies were carried out among Carbon/NH₂ SPE, primary secondary amine (PSA) dSPE and TEPA-NCM dSPE. The results showed that TEPA-NCM dSPE was faster, easier and more effective to clean and enrich than the Carbon/NH₂ cartridges, and the TEPA-NCM was much more effective to remove the pigments in vegetable samples than the PSA materials. The TEPA-NCM could be reused at least five times without much sacrifice of the cleanup efficiency. Furthermore, a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS/MS) method was established for the simultaneous determination of 29 pesticides (such as organochlorine and organophosphorus pesticides) in vegetables by dSPE using acetonitrile as an extraction solvent and TEPA-NCM as an adsorbent instead of PSA. The recoveries were in the range of 75-114% for all analytes except for trans-chlordane. The RSDs were in the range of 2-17%. The linearities were in the range of 0.4-100.0 μg/kg with determination coefficients (r²) higher than 0.986 for all compounds. The limits of detection (LODs) for all pesticides were less than 0.29 μg/kg and the limits of quantification (LOQs) were between 0.17 and 0.95 μg/kg. The developed method was applied to fifteen real vegetable samples, and it was confirmed that the TEPA-NCM was one of a kind of highly effective dSPE materials used for the pesticides analyses.

  5. method

    Directory of Open Access Journals (Sweden)

    L. M. Kimball

    2002-01-01

    Full Text Available This paper presents an interior point algorithm to solve the multiperiod hydrothermal economic dispatch (HTED. The multiperiod HTED is a large scale nonlinear programming problem. Various optimization methods have been applied to the multiperiod HTED, but most neglect important network characteristics or require decomposition into thermal and hydro subproblems. The algorithm described here exploits the special bordered block diagonal structure and sparsity of the Newton system for the first order necessary conditions to result in a fast efficient algorithm that can account for all network aspects. Applying this new algorithm challenges a conventional method for the use of available hydro resources known as the peak shaving heuristic.

  6. Method

    Directory of Open Access Journals (Sweden)

    Xixin Wang

    2012-01-01

    Full Text Available ZrO2 nanotube arrays were prepared by anodization method in aqueous electrolyte containing (NH42SO4 and NH4F. The morphology and structure of nanotube arrays were characterized through scanning electron microscope, X-ray diffraction, and infrared spectra analysis. The zirconia nanotube arrays were used as catalyst in esterification reaction. The effects of calcination temperature and electrolyte concentration on catalytic esterification activity have been investigated in detail. Experiments indicate that nanotube arrays have highest catalytic activity when the concentration of (NH42SO4 is 1 mol/L, the concentration of NH4F is 1 wt%, and the calcination temperature is 400°C. Esterification reaction yield of as much as 97% could be obtained under optimal conditions.

  7. Method

    Directory of Open Access Journals (Sweden)

    Andrey Gnatov

    2015-01-01

    Full Text Available Recently repair and recovery vehicle body operations become more and more popular. A special place here is taken by equipment that provides performance of given repair operations. The most interesting things are methods for recovery of car body panels that allow the straightening without disassembling of car body panels and damaging of existing protective coating. Now, there are several technologies for repair and recovery of car body panels without their disassembly and dismantling. The most perspective is magnetic-pulse technology of external noncontact straightening. Basics of magnetic-pulse attraction, both ferromagnetic and nonferromagnetic thin-walled sheet metal, are explored. Inductor system calculation models of magnetic-pulse straightening tools are presented. Final analytical expressions for excited efforts calculation in the tools under consideration are introduced. According to the obtained analytical expressions, numerical evaluations of excited forces were executed. The volumetric epures of the attractive force radial distributions for different types of inductors were built. The practical testing of magnetic-pulse straightening with research tools is given. Using the results of the calculations we can create effective tools for an external magnetic-pulse straightening of car body panels.

  8. Performance characterization of a quantitative liquid chromatography-tandem mass spectrometric method for 12 macrolide and lincosamide antibiotics in salmon, shrimp and tilapia.

    Science.gov (United States)

    Dickson, Leslie C

    2014-09-15

    This paper describes an extension and performance characterization of a quantitative confirmatory multi-residue liquid chromatography-tandem mass spectrometric method for residues of macrolide and lincosamide antibiotics, originally validated for application to bovine kidney tissues, to tissues of salmon, shrimp and tilapia. The 12 analytes include clindamycin, erythromycin A, gamithromycin, josamycin, lincomycin, neospiramycin 1, oleandomycin, pirlimycin, spiramycin 1, tildipirosin, tilmicosin and tylosin A. The limit of detection was 0.5 μg/kg. Within-laboratory precision evaluated over the analytical range of 5.0-50.0 μg/kg ranged from 4 to 17%. The accuracy of the method ranged from 80 to 112%. Recoveries ranged from 47 to 99% with all but one recovery above 60%. This is the first report of a quantitative confirmatory method for gamithromycin, pirlimycin and tildipirosin in fish and shrimp.

  9. Using second-order calibration method based on trilinear decomposition algorithms coupled with high performance liquid chromatography with diode array detector for determination of quinolones in honey samples.

    Science.gov (United States)

    Yu, Yong-Jie; Wu, Hai-Long; Shao, Sheng-Zhi; Kang, Chao; Zhao, Juan; Wang, Yu; Zhu, Shao-Hua; Yu, Ru-Qin

    2011-09-15

    A novel strategy that combines the second-order calibration method based on the trilinear decomposition algorithms with high performance liquid chromatography with diode array detector (HPLC-DAD) was developed to mathematically separate the overlapped peaks and to quantify quinolones in honey samples. The HPLC-DAD data were obtained within a short time in isocratic mode. The developed method could be applied to determine 12 quinolones at the same time even in the presence of uncalibrated interfering components in complex background. To access the performance of the proposed strategy for the determination of quinolones in honey samples, the figures of merit were employed. The limits of quantitation for all analytes were within the range 1.2-56.7 μg kg(-1). The work presented in this paper illustrated the suitability and interesting potential of combining second-order calibration method with second-order analytical instrument for multi-residue analysis in honey samples.

  10. A confirmatory method for the simultaneous extraction, separation, identification and quantification of Tetracycline, Sulphonamide, Trimethoprim and Dapsone residues in muscle by ultra-high-performance liquid chromatography-tandem mass spectrometry according to Commission Decision 2002/657/EC.

    Science.gov (United States)

    McDonald, Mark; Mannion, Celine; Rafter, Paul

    2009-11-13

    A rapid confirmatory multi-residue method for the analysis of tetracyclines, sulphonamides, trimethoprim and dapsone by UPLC-MS/MS is described. The method is able to quantify and confirm the following 19 compounds, oxytetracycline, tetracycline, chlortetracycline, doxycycline, sulfadiazine, sulfathiazole, sulfapyridine, trimethoprim, sulfamerazine, sulfamethizole, sulfamethazine, sulfamethoxypyridazine, sulfamonomethoxine, sulfachlorpyridazine, dapsone, sulfamethoxazole, sulfisoxazole, sulfaquinoxaline and sulfadimethoxine. Samples are extracted with 0.1M EDTA and acetonitrile, which is then evaporated under a stream of nitrogen and reconstituted in water. Following centrifugation and filtering, an aliquot is analysed by UPLC-MS/MS using positive electrospray ionisation and multiple reaction monitoring. The method is deemed rapid as all analytes are extracted by a single extraction technique, with no solid-phase extraction clean up required. Validation is according to Commission Decision 2002/657/EC and was carried out for bovine, porcine, ovine and poultry species. Specificity, recovery, repeatability, reproducibility, CCalpha and CCbeta data is presented.

  11. Screening method for the detection of a range of nitrofurans in avian eyes by optical biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Colin S., E-mail: colin.thompson@afbini.gov.uk [Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast BT4 3SD, Northern Ireland (United Kingdom); Traynor, Imelda M.; Fodey, Terence L.; Crooks, Steven R.H.; Kennedy, D. Glenn [Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast BT4 3SD, Northern Ireland (United Kingdom)

    2011-08-26

    An immunobiosensor assay was developed for the multi-residue screening of a range of nitrofuran compounds in avian eyes. A polyclonal antibody which binds at least 5 of the major parent nitrofurans was raised in a rabbit after inoculation with a nitrofuran mimic-protein conjugate. Sample homogenates were extracted into 0.1 M hydrochloric acid and subjected to clean-up by solid phase extraction and micro-centrifugation prior to biosensor analysis. Validation data obtained from the analysis of 21 fortified samples has shown that the method has a detection capability (CC{beta}) of less than 1 ng eye{sup -1} for nitrofurazone (NFZ). In addition, cross-reactivity data and the analysis of a smaller number of fortified samples have shown that the method will also detect a range of other major parent nitrofurans including furazolidone (FZD), furaltadone (FTD), nitrofurantoin (NFA) and nifursol (NFS). Intra-assay variation (n = 10) was calculated at 12.9% and 10.1% at concentrations of 1 ng eye{sup -1} and 2 ng eye{sup -1} NFZ respectively. Inter-assay variation (n = 3) was determined to be 10.8% and 4.7% at the same NFZ concentrations respectively. The cross-reactivity profile and validation data for the detection of these nitrofurans are presented together with the results obtained following the analysis of a small number of incurred samples using the developed method.

  12. An Accurate Thermoviscoelastic Rheological Model for Ethylene Vinyl Acetate Based on Fractional Calculus

    Directory of Open Access Journals (Sweden)

    Marco Paggi

    2015-01-01

    Full Text Available The thermoviscoelastic rheological properties of ethylene vinyl acetate (EVA used to embed solar cells have to be accurately described to assess the deformation and the stress state of photovoltaic (PV modules and their durability. In the present work, considering the stress as dependent on a noninteger derivative of the strain, a two-parameter model is proposed to approximate the power-law relation between the relaxation modulus and time for a given temperature level. Experimental validation with EVA uniaxial relaxation data at different constant temperatures proves the great advantage of the proposed approach over classical rheological models based on exponential solutions.

  13. Ethylene vinyl acetate based radiation grafted hydrophilic matrices: Process parameter standardization, grafting kinetics and characterization

    Science.gov (United States)

    Chaudhari, C. V.; Mondal, R. K.; Dubey, K. A.; Grover, V.; Panicker, L.; Bhardwaj, Y. K.; Varshney, L.

    2016-08-01

    A transparent, elastomeric, grafted matrix for several potential applications was synthesized by single-step simultaneous radiation grafting of methacrylic acid onto ethylene vinyl acetate (EVA). CuSO4 was found to be the most suitable homo-polymerization inhibitor among different inhibitors tried. The grafting kinetics was found to be a strong function of dose rate (D) and monomer content (M) and an equation relating grafting rate Rg=Kg [M]1.13D0.23 was deduced. Crystallinity of the grafted matrices as assessed from XRD and DSC measurements indicated decrease in crystalline content with increase in grafting yield, suggesting crystalline domain of EVA get disrupted on grafting. Elastic modulus increased linearly with the increase in grafting yield, though elongation at break decreased precipitously from 900% to 30% at even ~9% grafting. Thermo-gravimetric analysis showed three step weight loss of the grafted EVA matrix. The grafting of MAA resulted in increase in surface energy mainly due to enhanced polar component.

  14. Multi residue screening of intact testosterone esters and boldenone undecylenate in bovine hair using liquid chromatography electrospray tandem mass spectrometry

    NARCIS (Netherlands)

    Nielen, M.W.F.; Lasaroms, J.J.P.; Mulder, P.P.J.; Hende, van J.; Rhijn, van J.A.; Groot, M.J.

    2006-01-01

    The abuse of esters of natural androgenic steroids in cattle fattening and sports is hard to control via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously present in urine. In veterinary control strange findings of 17ß-testosterone and 17¿-t

  15. Validation and robustness testing of a HPLC method for the determination of avermectins and moxidectin in animal liver samples using an alumina column clean-up.

    Science.gov (United States)

    Danaher, M; O'Keeffe, M; Glennon, J D

    2000-10-01

    A multi-residue method has been developed for the quantitative determination of moxidectin, abamectin, doramectin and ivermectin in liver samples, with capability for qualitative identification of the presence of eprinomectin. Liver samples are extracted with isooctane, followed by clean-up on alumina-N solid phase extraction (SPE) cartridges. Extracts are derivatised and determined by high-performance liquid chromatography (HPLC) with fluorescence detection. The method was validated using bovine liver fortified at levels of 4 and 20 micrograms kg-1 with the drugs. The mean recovery from bovine liver ranged between 90 and 96%. The intra and inter-assay variations showed RSD typically of < 5% and < 10%, respectively. The procedure was applied also to ovine and porcine liver, giving similar results. A robustness study, carried out on the alumina clean-up step, indicated that the step is relatively insensitive to method changes. However, significant differences overall were found for the type of alumina and/or commercial SPE cartridge used. The limit of quantitation of the method is 2 micrograms kg-1 (ppb).

  16. Analytical method for fast screening and confirmation of multi-class veterinary drug residues in fish and shrimp by LC-MS/MS.

    Science.gov (United States)

    Kim, Junghyun; Suh, Joon Hyuk; Cho, Hyun-Deok; Kang, Wonjae; Choi, Yong Seok; Han, Sang Beom

    2016-01-01

    A multi-class, multi-residue analytical method based on LC-MS/MS detection was developed for the screening and confirmation of 28 veterinary drug and metabolite residues in flatfish, shrimp and eel. The chosen veterinary drugs are prohibited or unauthorised compounds in Korea, which were categorised into various chemical classes including nitroimidazoles, benzimidazoles, sulfones, quinolones, macrolides, phenothiazines, pyrethroids and others. To achieve fast and simultaneous extraction of various analytes, a simple and generic liquid extraction procedure using EDTA-ammonium acetate buffer and acetonitrile, without further clean-up steps, was applied to sample preparation. The final extracts were analysed by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The method was validated for each compound in each matrix at three different concentrations (5, 10 and 20 ng g(-1)) in accordance with Codex guidelines (CAC/GL 71-2009). For most compounds, the recoveries were in the range of 60-110%, and precision, expressed as the relative standard deviation (RSD), was in the range of 5-15%. The detection capabilities (CCβs) were below or equal to 5 ng g(-1), which indicates that the developed method is sufficient to detect illegal fishery products containing the target compounds above the residue limit (10 ng g(-1)) of the new regulatory system (Positive List System - PLS).

  17. Development and validation of an ultra-high performance liquid chromatographic high resolution Q-Orbitrap mass spectrometric method for the simultaneous determination of steroidal endocrine disrupting compounds in aquatic matrices.

    Science.gov (United States)

    Huysman, Steve; Van Meulebroek, Lieven; Vanryckeghem, Francis; Van Langenhove, Herman; Demeestere, Kristof; Vanhaecke, Lynn

    2017-09-01

    The lack of adequate strategies for monitoring endocrine disrupting compounds (EDCs) in the aquatic environment is emphasized in the European Water Framework Directive. In this context, a new UHPLC-HR-Q-Orbirtrap-MS multi-residue method was developed for the simultaneous measurement of 70 steroidal EDCs in two aquatic matrices, i.e. sea and fresh water. First, an instrumental APCI-UHPLC-HR-Q-Orbitrap-MS was devised for separating and detecting the EDC isomers and mass analogues, within 12.5 min per run. Next, an appropriate extraction was statistically optimised using a three-strep workflow (95% confidence interval, p > 0.05); including fractional factorial resolution IV, simplex lattice, and response surface methodological designs. The fitness-for-purpose of the method was demonstrated through successful validation at relevant environmental concentrations, i.e. the low nano- and picogram range. Method quantification limits ranged for the androgens (n = 33), oestrogens (n = 14), progestins (n = 12), and corticosteroids (n = 11) between, respectively, 0.13 and 5.00 ng L(-1), 0.25 and 5.00 ng L(-1), 0.13 and 2.50 ng L(-1), and 0.50 and 5.00 ng L(-1). Good linearity (R(2) ≥ 0.99) and no lack of fit was observed (95% confidence interval, p > 0.05) for the 70 steroidal EDCs. In addition, good recovery (95-109%) and satisfactory repeatability (RSD < 8.5%, n = 18) and reproducibility (RSD < 10.5%, n = 12) were obtained. Finally, the applicability of the multi-residue method was demonstrated by measuring steroidal EDC in 28 sea water samples collected from four different locations during fall 2016 and winter 2017. Regarding the sea water samples, all the classes were ubiquitously present and included different metabolites, transformation product and or degradation products from the parent EDCs (n = 43). Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Development of a high-performance liquid chromatography method for the simultaneous quantification of four organoarsenic compounds in the feeds of swine and chicken.

    Science.gov (United States)

    Chen, Dongmei; Zhang, Huahai; Tao, Yanfei; Wang, Yulian; Huang, Lingli; Liu, Zhenli; Pan, Yuanhu; Peng, Dapeng; Wang, Xu; Dai, Menghong; Yuan, Zonghui

    2011-04-01

    A high-performance liquid chromatography (HPLC) method with UV detection was developed for the simultaneous determination of arsanilic acid, roxarsone, nitarsone, and carbarsone in the feeds of swine and chicken. Feed samples were extracted with methanol/1% acetic acid (90:10, v/v) in an ultrasonic bath and the protein was precipitated with 2% Cu(2)SO(4). The samples were further purified by solid phase extraction (SPE) on SAX cartridges. Separation was performed on a Zorbax SB-Aq C18 HPLC column using an isocratic procedure with methanol and 1% acetic acid (3:97, v/v) at a flow-rate of 0.7 mL min(-1), and the UV detector was set at a wavelength of 260 nm. The recoveries of organoarsenic compounds spiked at levels of 2, 20 and 200 μg g(-1) ranged from 81.2% to 91.3%; the inter-day relative standard deviation values were less than 7.0%. The limits of quantification for four organoarsenic compounds were 1.0-2.0 μg g(-1). This simple and fast method could be applied to the determination of multi-residues of organic arsenic compounds in animal feeds.

  19. Validation of a QuEChERS-based gas chromatographic method for analysis of pesticide residues in Cassia angustifolia (senna).

    Science.gov (United States)

    Tripathy, Vandana; Saha, Ajoy; Patel, Dilipkumar J; Basak, B B; Shah, Paresh G; Kumar, Jitendra

    2016-08-01

    A simple multi-residue method based on modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach was established for the determination of 17 organochlorine (OC), 15 organophosphorous (OP) and 7 synthetic pyrethroid (SP) pesticides in an economically important medicinal plant of India, Senna (Cassia angustifolia), by gas chromatography coupled to electron capture and flame thermionic detectors (GC/ECD/FTD) and confirmation of residues was done on gas chromatograph coupled with mass spectrometry (GC-MS). The developed method was validated by testing the following parameters: linearity, limit of detection (LOD), limit of quantification (LOQ), matrix effect, accuracy-precision and measurement uncertainty; the validation study clearly demonstrated the suitability of the method for its intended application. All pesticides showed good linearity in the range 0.01-1.0 μg mL(-1) for OCs and OPs and 0.05-2.5 μg mL(-1) for SPs with correlation coefficients higher than 0.98. The method gave good recoveries for most of the pesticides (70-120%) with intra-day and inter-day precision < 20% in most of the cases. The limits of detection varied from 0.003 to 0.03 mg kg(-1), and the LOQs were determined as 0.01-0.049 mg kg(-1). The expanded uncertainties were <30%, which was distinctively less than a maximum default value of ±50%. The proposed method was successfully applied to determine pesticide residues in 12 commercial market samples obtained from different locations in India.

  20. Method development and fate determination of pesticide-treated hops and their subsequent usage in the production of beer.

    Science.gov (United States)

    Hengel, Matt J; Shibamoto, Takayuki

    2002-06-05

    The fate of residues of seven agrochemicals (chlorfenapyr, quinoxyfen, tebuconazole, fenarimol, pyridaben, and E- and Z-dimethomorph) from the treatment on hops to the brewing of beer was studied. First, a multi-residue analytical method was developed for the determination of pesticide residues in spent hops, trub, wort, and beer. Each matrix was validated over at least two levels of fortification, for all seven compounds, in the ranges 0.05-5.0, 0.001-1.0, 0.001-0.05, and 0.0005-1.0 ppm for spent hops, trub, wort, and beer, respectively. Recoveries ranged from 73 to 136%. Second, the matrixes prepared from hops, which were treated under commercial practices with each compound, were analyzed using the method developed. The use of treated hops resulted in the carryover of 0.001 ppm of tebuconazole, 0.008 Z-dimethomorph, and 0.005 ppm of E-dimethomorph into the wort. The bulk of the remaining residues of all seven compounds was found on the spent hops. Following fermentation, all compounds were found in levels less than 0.0005 ppm in beer, except Z- (0.006 ppm) and E-dimethomorph (0.004 ppm). Third, when all seven pesticides were spiked prior to the pitching of yeast into clean wort, most of the nonpolar compounds (chlorfenapyr, quinoxyfen, and pyridaben) partitioned into the organic material (trub) which settled to the bottom, while the more polar compounds (fenarimol, tebuconazole, and E- and Z-dimethomorph) were generally distributed evenly between the beer and the trub.

  1. Trace analysis of three fungicides in animal origin foods with a modified QuEChERS method and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mu, Zhaobin; Feng, Xiaoxiao; Zhang, Yun; Zhang, Hongyan

    2016-02-01

    A multi-residue method based on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS), was developed and validated for the determination of three selected fungicides (propiconazole, pyraclostrobin, and isopyrazam) in seven animal origin foods. The overall recoveries at the three spiking levels of 0.005, 0.05, and 0.5 mg kg(-1) spanned between 72.3 and 101.4% with relative standard deviation (RSD) values between 0.7 and 14.9%. The method shows good linearity in the concentrations between 0.001 and 1 mg L(-1) with the coefficient of determination (R (2)) value >0.99 for each target analyte. The limit of detections (LODs) for target analytes were between 0.04 and 1.26 μg kg(-1), and the limit of quantifications (LOQs) were between 0.13 and 4.20 μg kg(-1). The matrix effect for each individual compound was evaluated through the study of ratios of the areas obtained in solvent and matrix standards. The optimized method provided a negligible matrix effect for propiconazole within 20%, whereas for pyraclostrobin and isopyrazam, the matrix effect was relatively significant with a maximum value of 49.8%. The developed method has been successfully applied to the analysis of 210 animal origin samples obtained from 16 provinces of China. The results suggested that the developed method was satisfactory for trace analysis of three fungicides in animal origin foods.

  2. Determination of pharmaceutical residues in drinking water in Poland using a new SPE-GC-MS(SIM) method based on Speedisk extraction disks and DIMETRIS derivatization.

    Science.gov (United States)

    Caban, Magda; Lis, Ewa; Kumirska, Jolanta; Stepnowski, Piotr

    2015-12-15

    The presence of pharmaceuticals in drinking water, even at very low concentrations, has raised concerns among stakeholders such as drinking-water regulators, governments, water suppliers and the public, with regard to the potential risks to humans. Despite this, the occurrence and the fate of pharmaceuticals in drinking waters of many countries (e.g. in Poland) remains unknown. There is a lack of sufficiently sensitive and reliable analytical methods for such analyses and a need for more in-depth hydrogeological analysis of the possible sources of drug residues in drinking water. In this paper, a multi-residual method for the simultaneous determination of seventeen human pharmaceuticals in drinking waters has been developed. Large-volume extractions using Speedisk extraction disks, and derivatization prior to GC-MS-SIM analysis using a new silylating agent DIMETRIS were applied. The method detection limits (MDLs) ranged from 0.9 to 5.7ng/L and the absolute recoveries of the target compounds were above 80% for most analytes. The developed method was successfully applied in the analysis of the target compounds in drinking water collected in Gdansk (Poland), and of the 17 pharmaceuticals, 6 compounds were detected at least once. During the investigation, the geomorphology of the site region was taken into account, possible sources of pharmaceuticals in the analysed drinking water samples were investigated, and the presence of the drugs in ground and surface waters, raw and treated drinking waters was determined. Concentrations were also compared with those observed in other countries. As a result, this study has not only developed a new analytical method for determining pharmaceuticals in drinking waters as well as rendering missing information for Poland (a country with one of the highest consumptions of pharmaceuticals in Europe), but it also presents a modelled in-depth hydrogeological analysis of the real sources of drugs in drinking waters.

  3. Perturbation methods

    CERN Document Server

    Nayfeh, Ali H

    2008-01-01

    1. Introduction 1 2. Straightforward Expansions and Sources of Nonuniformity 23 3. The Method of Strained Coordinates 56 4. The Methods of Matched and Composite Asymptotic Expansions 110 5. Variation of Parameters and Methods of Averaging 159 6. The Method of Multiple Scales 228 7. Asymptotic Solutions of Linear Equations 308 References and Author Index 387 Subject Index 417

  4. Synthesis and Structure of Supramolecular Compound with Ethyl 2-(4-Aminophenoxy)acetate Based on 18-Crown-6%Synthesis and Structure of Supramolecular Compound with Ethyl 2-(4-Aminophenoxy)acetate Based on 18-Crown-6

    Institute of Scientific and Technical Information of China (English)

    王文祥; 孙素文; 熊仁根

    2012-01-01

    The title ammonium compound ethyl 2-(4-aminophenoxy)acetate (C10 H13NO3, I) and its crown ether inclusion complex {[(CIoHI4NO3)·(18-crown-6)]·[PF6] , II} (18-crown-6 = 1,4,7,10,13,16-hexaoxacyclo-octadecane) were synthesized. The ammonium compound I was determined by 11-t NMR, IR and ESI-MS techiniques. X-ray crystal- lography reveals that compound I crystallizes in the triclinic system with space group of P-l, all the atoms in | are almost coplanar except H, and N--H…O hydrogen bonds lead to the formation of one dimensional chain. The ro- tator-stator-like compound 11 was crystallizes in the centrosymmetric monoclinic system with space group of P21/c. The supramolecular was formed via N--H…O hydrogen-bond interactions. Temperature-dependent dielectric constants of compound II were measured.

  5. Development of a gas chromatography-mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere.

    Science.gov (United States)

    Borrás, E; Sánchez, P; Muñoz, A; Tortajada-Genaro, L A

    2011-08-05

    A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography-mass spectrometry (GC-MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1). Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5±1%, a reproducibility of 13±3% and detection limits of 0.05-0.18 pg m(-3) for the particulate phase and 26-88 pg m(-3) for the gaseous phase. Finally, the methodology was successfully applied to rural and agricultural samples in the Mediterranean area.

  6. Vortex methods

    Energy Technology Data Exchange (ETDEWEB)

    Chorin, A.J. [California Univ., Berkeley, CA (United States). Dept. of Mathematics]|[Lawrence Berkeley Lab., CA (United States)

    1993-06-01

    Vortex methods originated from the observation that in incompressible inviscid flow vorticity (or, more accurately, circulation) is a conserved quantity, as can be readily deduced from the absence of tangential stresses. Thus, if the vorticity is known at time t=0, one can find the flow at a later time by simply following the vorticity. In this narrow context, a vortex method is a numerical method that follows vorticity. The author restricts himself in these lectures to a special class of numerical vortex methods, those that are based on a Lagrangian transport of vorticity in hydrodynamics by smoothed particles (blobs) and those whose analysis contributes to the understanding of blob methods. Blob methods started in the 1930`s.

  7. Mining Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Shik; Lee, Kyung Woon; Kim, Oak Hwan; Kim, Dae Kyung [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    The reducing coal market has been enforcing the coal industry to make exceptional rationalization and restructuring efforts since the end of the eighties. To the competition from crude oil and natural gas has been added the growing pressure from rising wages and rising production cost as the workings get deeper. To improve the competitive position of the coal mines against oil and gas through cost reduction, studies to improve mining system have been carried out. To find fields requiring improvements most, the technologies using in Tae Bak Colliery which was selected one of long running mines were investigated and analyzed. The mining method appeared the field needing improvements most to reduce the production cost. The present method, so-called inseam roadway caving method presently is using to extract the steep and thick seam. However, this method has several drawbacks. To solve the problems, two mining methods are suggested for a long term and short term method respectively. Inseam roadway caving method with long-hole blasting method is a variety of the present inseam roadway caving method modified by replacing timber sets with steel arch sets and the shovel loaders with chain conveyors. And long hole blasting is introduced to promote caving. And pillar caving method with chock supports method uses chock supports setting in the cross-cut from the hanging wall to the footwall. Two single chain conveyors are needed. One is installed in front of chock supports to clear coal from the cutting face. The other is installed behind the supports to transport caved coal from behind. This method is superior to the previous one in terms of safety from water-inrushes, production rate and productivity. The only drawback is that it needs more investment. (author). 14 tabs., 34 figs.

  8. Projection Methods

    DEFF Research Database (Denmark)

    Wagner, Falko Jens; Poulsen, Mikael Zebbelin

    1999-01-01

    When trying to solve a DAE problem of high index with more traditional methods, it often causes instability in some of the variables, and finally leads to breakdown of convergence and integration of the solution. This is nicely shown in [ESF98, p. 152 ff.].This chapter will introduce projection...... methods as a way of handling these special problems. It is assumed that we have methods for solving normal ODE systems and index-1 systems....

  9. Computing methods

    CERN Document Server

    Berezin, I S

    1965-01-01

    Computing Methods, Volume 2 is a five-chapter text that presents the numerical methods of solving sets of several mathematical equations. This volume includes computation sets of linear algebraic equations, high degree equations and transcendental equations, numerical methods of finding eigenvalues, and approximate methods of solving ordinary differential equations, partial differential equations and integral equations.The book is intended as a text-book for students in mechanical mathematical and physics-mathematical faculties specializing in computer mathematics and persons interested in the

  10. Method 59

    DEFF Research Database (Denmark)

    Kjellsson, G.

    1994-01-01

    OCDE/GD(94)41. Er supplerende rapport til rapport: The OECD Workshop on Methods for Monitoring Organisms in the Environment, Ottawa 14-17 September 1992. Environment Monograph 90.......OCDE/GD(94)41. Er supplerende rapport til rapport: The OECD Workshop on Methods for Monitoring Organisms in the Environment, Ottawa 14-17 September 1992. Environment Monograph 90....

  11. Method Mixins

    DEFF Research Database (Denmark)

    Ernst, Erik

    2005-01-01

    , where traditional invocation is optimized for as-is reuse of existing behavior. Tight coupling reduces flexibility, and traditional invocation tightly couples transfer of information and transfer of control. Method mixins decouple these two kinds of transfer, thereby opening the doors for new kinds......The world of programming has been conquered by the procedure call mechanism, including object-oriented method invocation which is a procedure call in context of an object. This paper presents an alternative, method mixin invocations, that is optimized for flexible creation of composite behavior...

  12. Method Mixins

    DEFF Research Database (Denmark)

    Ernst, Erik

    2002-01-01

    invocation is optimized for as-is reuse of existing behavior. Tight coupling reduces flexibility, and traditional invocation tightly couples transfer of information and transfer of control. Method mixins decouple these two kinds of transfer, thereby opening the doors for new kinds of abstraction and reuse......The procedure call mechanism has conquered the world of programming, with object-oriented method invocation being a procedure call in context of an object. This paper presents an alternative, method mixin invocations, that is optimized for flexible creation of composite behavior, where traditional...

  13. Validation and use of a fast sample preparation method and liquid chromatography-tandem mass spectrometry in analysis of ultra-trace levels of 98 organophosphorus pesticide and carbamate residues in a total diet study involving diversified food types.

    Science.gov (United States)

    Chung, Stephen W C; Chan, Benny T P

    2010-07-16

    This paper reports a comprehensive sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, identification and quantitation of 73 pesticides and their related products, a total of 98 analytes, belonging to organophosphorus pesticides (OPPs) and carbamates, in foods. The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rigged, and safe) procedure that combines isolation of the pesticides and sample clean-up in a single step. Analysis is performed by liquid chromatography-electrospray ionization-tandem mass spectrometry operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Two main fragment ions for each pesticide were obtained to achieve the identification according to the SANCO guidelines 10684/2009. The method was validated with various food samples, including edible oil, meat, egg, cheese, chocolate, coffee, rice, tree nuts, citric fruits, vegetables, etc. No significant matrix effect was observed for tested pesticides, therefore, matrix-matched calibration was not necessary. Calibration curves were linear and covered from 1 to 20 microg L(-1) for all compounds studied. The average recoveries, measured at 10 microg kg(-1), were in the range 70-120% for all of the compounds tested with relative standard deviations below 20%, while a value of 10 microg kg(-1) has been established as the method limit of quantitation (MLOQ) for all target analytes. Similar trueness and precision results were also obtained for spiking at 200 microg kg(-1). Expanded uncertainty values were in the range 21-27% while the HorRat ratios were below 1. The method has been successfully applied to the analysis of 700 food samples in the course of a baseline monitoring study of OPPs and carbamates.

  14. Dosimetry methods

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, A.; Kovacs, A.;

    2003-01-01

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application.......Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  15. Ensemble Methods

    Science.gov (United States)

    Re, Matteo; Valentini, Giorgio

    2012-03-01

    Ensemble methods are statistical and computational learning procedures reminiscent of the human social learning behavior of seeking several opinions before making any crucial decision. The idea of combining the opinions of different "experts" to obtain an overall “ensemble” decision is rooted in our culture at least from the classical age of ancient Greece, and it has been formalized during the Enlightenment with the Condorcet Jury Theorem[45]), which proved that the judgment of a committee is superior to those of individuals, provided the individuals have reasonable competence. Ensembles are sets of learning machines that combine in some way their decisions, or their learning algorithms, or different views of data, or other specific characteristics to obtain more reliable and more accurate predictions in supervised and unsupervised learning problems [48,116]. A simple example is represented by the majority vote ensemble, by which the decisions of different learning machines are combined, and the class that receives the majority of “votes” (i.e., the class predicted by the majority of the learning machines) is the class predicted by the overall ensemble [158]. In the literature, a plethora of terms other than ensembles has been used, such as fusion, combination, aggregation, and committee, to indicate sets of learning machines that work together to solve a machine learning problem [19,40,56,66,99,108,123], but in this chapter we maintain the term ensemble in its widest meaning, in order to include the whole range of combination methods. Nowadays, ensemble methods represent one of the main current research lines in machine learning [48,116], and the interest of the research community on ensemble methods is witnessed by conferences and workshops specifically devoted to ensembles, first of all the multiple classifier systems (MCS) conference organized by Roli, Kittler, Windeatt, and other researchers of this area [14,62,85,149,173]. Several theories have been

  16. Statistical methods

    CERN Document Server

    Szulc, Stefan

    1965-01-01

    Statistical Methods provides a discussion of the principles of the organization and technique of research, with emphasis on its application to the problems in social statistics. This book discusses branch statistics, which aims to develop practical ways of collecting and processing numerical data and to adapt general statistical methods to the objectives in a given field.Organized into five parts encompassing 22 chapters, this book begins with an overview of how to organize the collection of such information on individual units, primarily as accomplished by government agencies. This text then

  17. Sieve methods

    CERN Document Server

    Halberstam, Heine

    2011-01-01

    Derived from the techniques of analytic number theory, sieve theory employs methods from mathematical analysis to solve number-theoretical problems. This text by a noted pair of experts is regarded as the definitive work on the subject. It formulates the general sieve problem, explores the theoretical background, and illustrates significant applications.""For years to come, Sieve Methods will be vital to those seeking to work in the subject, and also to those seeking to make applications,"" noted prominent mathematician Hugh Montgomery in his review of this volume for the Bulletin of the Ameri

  18. Spectral Methods

    CERN Document Server

    Shen, Jie; Wang, Li-Lian

    2011-01-01

    Along with finite differences and finite elements, spectral methods are one of the three main methodologies for solving partial differential equations on computers. This book provides a detailed presentation of basic spectral algorithms, as well as a systematical presentation of basic convergence theory and error analysis for spectral methods. Readers of this book will be exposed to a unified framework for designing and analyzing spectral algorithms for a variety of problems, including in particular high-order differential equations and problems in unbounded domains. The book contains a large

  19. Statistical methods

    CERN Document Server

    Freund, Rudolf J; Wilson, William J

    2010-01-01

    Statistical Methods, 3e provides students with a working introduction to statistical methods offering a wide range of applications that emphasize the quantitative skills useful across many academic disciplines. This text takes a classic approach emphasizing concepts and techniques for working out problems and intepreting results. The book includes research projects, real-world case studies, numerous examples and data exercises organized by level of difficulty. This text requires that a student be familiar with algebra. New to this edition: NEW expansion of exercises a

  20. Digital Methods

    NARCIS (Netherlands)

    Rogers, R.

    2013-01-01

    In Digital Methods, Richard Rogers proposes a methodological outlook for social and cultural scholarly research on the Web that seeks to move Internet research beyond the study of online culture. It is not a toolkit for Internet research, or operating instructions for a software package; it deals wi

  1. Characterization methods

    Energy Technology Data Exchange (ETDEWEB)

    Glass, J.T. [North Carolina State Univ., Raleigh (United States)

    1993-01-01

    Methods discussed in this compilation of notes and diagrams are Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and other surface analysis techniques (auger electron spectroscopy, x-ray photoelectron spectroscopy, electron energy loss spectroscopy, and scanning tunnelling microscopy). A comparative evaluation of different techniques is performed. In-vacuo and in-situ analyses are described.

  2. Radiofluorination method

    DEFF Research Database (Denmark)

    2014-01-01

    A method of conducting radiofluorination of a substrate, comprising the steps of: (a) contacting an aqueous solution of [18F] fluoride with a polymer supported phosphazene base for sufficient time for trapping of [18F] fluoride on the polymer supported phosphazene base; and (b) contacting...

  3. Contraceptive Methods.

    Science.gov (United States)

    Colquitt, Charlie W; Martin, Tonya S

    2017-02-01

    The prevention of pregnancy remains an important part of the practice of medicine. Contraception can occur at a number of points in the basic reproductive biological process and through a number of contraceptive product options. Pharmacists are health care providers appropriately positioned to assist patients in suitable contraceptive product selection based on their personal situations and lifestyles. This article provides an overview of available products for prevention of pregnancy and associated risks and benefits. Contraceptive products are categorized by their hormonal content and method of action. Hormonal options include oral contraceptive pills, contraceptive patch, implants, injection, intravaginal, and intrauterine devices. Barrier products prevent pregnancy by creating a physical obstacle to the successful fertilization of an egg by sperm. All products and methods are associated with benefits and potential complications that must be considered as patients, and health care providers select the most satisfactory option.

  4. Numerical methods

    CERN Document Server

    Dahlquist, Germund

    2003-01-01

    ""Substantial, detailed and rigorous . . . readers for whom the book is intended are admirably served."" - MathSciNet (Mathematical Reviews on the Web), American Mathematical Society.Practical text strikes fine balance between students' requirements for theoretical treatment and needs of practitioners, with best methods for large- and small-scale computing. Prerequisites are minimal (calculus, linear algebra, and preferably some acquaintance with computer programming). Text includes many worked examples, problems, and an extensive bibliography.

  5. Development of a method for the analysis of hormones and pharmaceuticals in earthworms by quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    Science.gov (United States)

    Bergé, Alexandre; Vulliet, Emmanuelle

    2015-10-01

    The earthworm represents a kind of creature in contact with the soil surface and usually exposed to a variety of organic pollutants from human activities. Therefore, it can be considered as an organism of choice for identifying pollution or better understanding the input of contaminants in food chains in particular through the contributions of sludge. Moreover, the use of organisms such as soil invertebrates is to be developed for ecotoxicological risk assessment of pollutants. In this context, a simple, rapid and effective multi-residue method was developed for the determination of 31 compounds including 11 steroids, 14 veterinary antibiotics and 6 human contaminants (paracetamol, sulfamethoxazole, fluvoxamine, carbamazepine, ibuprofen, bisphenol A) in earthworm. The sample preparation procedure was based on a salting-out extraction with acetonitrile (QuEChERS approach) that was optimised with regard to the acetonitrile/water ratio used in the extraction step, the choice of the clean-up and the quantity of the matrix. The optimised extraction method exhibited recoveries that comprised between 44 and 98 % for all the tested compounds. The limits of detection of all compounds were below 14 ng g(-1) and the limits of quantification (LOQ) comprised between 1.6 and 40 ng g(-1) (wet weight). The method was therefore applied to determine the levels of pharmaceuticals and hormones in six earthworm samples collected in various soils. Concentrations up to 195 ng g(-1) for bisphenol A were determined, between a few nanograms per gram and 43.1 ng g(-1) (estriol) for hormones and between a few nanograms per gram and 73.5 ng g(-1) (florfenicol) for pharmaceuticals. Experiments were also conducted in laboratory conditions to evaluate the accumulation of the target substances by earthworm.

  6. Development of a multiple-class analytical method based on the use of synthetic matrices for the simultaneous determination of commonly used commercial surfactants in wastewater by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Alexandre, Bergé; Barbara, Giroud; Laure, Wiest; Bruno, Domenjoud; Adriana, Gonzalez-Ospina; Emmanuelle, Vulliet

    2016-06-10

    Discharges of surfactants from wastewater treatment plants are often considered as the principal vector of pollution into the environment. The analysis of complex matrices, such as urban wastewater, suspended solids and biological sludge requires careful preparation of the sample to obtain a sensitive, selective and reproducible analysis. A simple, fast, effective and multi-residue method based on the SPE (water) and QuEChERS (solid matrices) approaches using synthetic matrices for validation and quantification, has been developed for the determination of 16 surfactants in wastewater, suspended solids and biological sludge. This work resulted in an innovative method that was validated to detect and assess several classes of surfactants such as quaternary ammonium compounds, betaïns, alkylphenols and their ethoxylated or sulfated derivatives in urban wastewater and solid matrices. The optimised extraction method exhibited recoveries comprised between 83% and 120% for all the tested compounds in the dissolved matrix and between 50% and 109% for particulate matrix. The limits of quantification of all compounds were comprised between 0.1 and 1.0μg/L for dissolved matrix and between 2 and 1000ng/g (dry weight) in particulate matrix. Linearity was assessed for all compounds within the [LOQ-250LOQ] range. Confidence intervals were also computed in real matrices with less than 15% margin of error for all studied surfactants. This work has confirmed, first and foremost, that surfactants are indeed highly concentrated in urban wastewater. As expected, linear alkylbenzene sulfonates were present at significant concentrations (up to 1-2mg/L). In addition, although biological processing results in significant removal of the total pollution, the residual concentrations at output of WWTP remain significant (up to 100μg/L).

  7. Rapid determination of residues of pesticides in honey by µGC-ECD and GC-MS/MS: Method validation and estimation of measurement uncertainty according to document No. SANCO/12571/2013.

    Science.gov (United States)

    Paoloni, Angela; Alunni, Sabrina; Pelliccia, Alessandro; Pecorelli, Ivan

    2016-01-01

    A simple and straightforward method for simultaneous determination of residues of 13 pesticides in honey samples (acrinathrin, bifenthrin, bromopropylate, cyhalothrin-lambda, cypermethrin, chlorfenvinphos, chlorpyrifos, coumaphos, deltamethrin, fluvalinate-tau, malathion, permethrin and tetradifon) from different pesticide classes has been developed and validated. The analytical method provides dissolution of honey in water and an extraction of pesticide residues by n-Hexane followed by clean-up on a Florisil SPE column. The extract was evaporated and taken up by a solution of an injection internal standard (I-IS), ethion, and finally analyzed by capillary gas chromatography with electron capture detection (GC-µECD). Identification for qualitative purpose was conducted by gas chromatography with triple quadrupole mass spectrometer (GC-MS/MS). A matrix-matched calibration curve was performed for quantitative purposes by plotting the area ratio (analyte/I-IS) against concentration using a GC-µECD instrument. According to document No. SANCO/12571/2013, the method was validated by testing the following parameters: linearity, matrix effect, specificity, precision, trueness (bias) and measurement uncertainty. The analytical process was validated analyzing blank honey samples spiked at levels equal to and greater than 0.010 mg/kg (limit of quantification). All parameters were satisfactorily compared with the values established by document No. SANCO/12571/2013. The analytical performance was verified by participating in eight multi-residue proficiency tests organized by BIPEA, obtaining satisfactory z-scores in all 70 determinations. Measurement uncertainty was estimated according to the top-down approaches described in Appendix C of the SANCO document using the within-laboratory reproducibility relative standard deviation combined with laboratory bias using the proficiency test data.

  8. Development of a gas chromatography-mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Borras, E.; Sanchez, P.; Munoz, A. [Instituto Universitario Centro de Estudios Ambientales del Mediterraneo CEAM-UMH (Fundacion CEAM-UMH), 46980 Paterna, Valencia (Spain); Tortajada-Genaro, L.A., E-mail: luitorge@qim.upv.es [Instituto IDM, Departamento de Quimica, Universitat Politecnica de Valencia, Cami de Vera s/n 46022 Valencia (Spain)

    2011-08-05

    Highlights: {yields} An efficient method for the determination of sixteen pesticides in atmospheric samples. {yields} XAD-4 is an interesting support for collecting gas-phase pesticides, with similar performances than the conventional XAD-2. {yields} The ultrasonic extraction is cheaper, less aggressive and time-consuming with excellent analytical parameters. {yields} The method has been successfully tested by using high volume atmospheric simulation chamber and field campaigns. - Abstract: A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography-mass spectrometry (GC-MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1). Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5 {+-} 1%, a

  9. Core-shell LC-MS/MS method for quantification of second generation anticoagulant rodenticides diastereoisomers in rat liver in relationship with exposure of wild rats.

    Science.gov (United States)

    Fourel, Isabelle; Damin-Pernik, Marlène; Benoit, Etienne; Lattard, Virginie

    2017-01-15

    Second generation anticoagulant rodenticides (SGARs), pesticides used worldwide to control rodent populations, exist in two diastereoisomer chemical species because they own two stereogenic centers. A core-shell LC-MS/MS multi-residue method for comprehensive quantitative analysis of the diastereoisomers of five SGARs as well as three first generation anticoagulant rodenticide molecules has been fully validated in liver of rats according to a bioanalytical guideline. A core-shell column (superficially porous particles) has been chosen for its ability to separate the diastereomers of bromadiolone, difenacoum, brodifacoum, flocoumafen and difethialone and for its robustness to rat liver extracts. The highly selective chromatographic separation of the diastereoisomers contributes to good signal to noise ratios and then enhances the sensitivity of the method compared to the ones of fully porous columns. An elution gradient has been optimized with 10mM ammonium acetate and acetonitrile as aqueous/organic mobile phase respectively. Triple quadrupole mass detector has been used to achieve specifity and LLOQ from 0.92 to 2.2ng/g for each diastereoisomer, or first generation anticoagulant rodenticides. Then we evidenced diastereoisomeric ratios in liver of rats issued from not controlled exposure of wild rats (Rattus norvegicus) trapped in a French Parisian park through a campaign of rodent eradication. We compared them to diastereoisomeric ratios in SGARs commercial baits that contain both isomers, and showed that one of the two diastereoiomers had nearly disappeared in liver of rats. The proportions of cis-bromadiolone and trans-difenacoum were really lowered compared to the baits: 5/7 and 9/12 rats had only trans-bromadiolone and cis-difenacoum hepatic residues respectively. Liver persistence of the two diastereoisomers of bromadiolone and difenacoum was different due to differences in their pharmacokinetics in wild rats. The new core-shell LC-MS/MS method is

  10. Birth Control Methods

    Science.gov (United States)

    ... Home A-Z Health Topics Birth control methods Birth control methods > A-Z Health Topics Birth control methods ... To receive Publications email updates Enter email Submit Birth control methods Birth control (contraception) is any method, medicine, ...

  11. The clinical method and the scientific method

    Directory of Open Access Journals (Sweden)

    José Arteaga Herrera

    2010-12-01

    Full Text Available This paper is the chapter dedicated to the scientific method and the clinical method in the authors’ Handbook “Teaching of Clinics”. Philosophycal principles of the scientific method and its stages are presented as well as the clinical method as a scientific one and its stages. A relationship between the clinical method and the medical record is established, the role of technology in the clinical method is stated and the most frequent mistakes when applying it in clinical practice are provided. Finally, the teaching of the clinical method and the appropriate settings to do it are discussed.

  12. An Inexact Halley's Method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    An inexact Halley's method-Halley-PCG(preconditioned conjugate gradient) method is proposed for solving the systems of linear equations for improved Halley method either by Cholesky factorization exactly or by preconditioned conjugate gradient method approximately. The convergence result is given and the efficiency of the method compared to the improved Halley's method is shown.

  13. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation

    Directory of Open Access Journals (Sweden)

    Clara Casado-Coterillo

    2014-06-01

    Full Text Available Mixed matrix membranes (MMMs were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL to chitosan (CS polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials.

  14. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation.

    Science.gov (United States)

    Casado-Coterillo, Clara; Del Mar López-Guerrero, María; Irabien, Angel

    2014-06-19

    Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials.

  15. Meshless Methods Coupled with Other Numerical Methods

    Institute of Scientific and Technical Information of China (English)

    Y.T.GU; G.R.LIU

    2005-01-01

    Meshless or mesh-free (or shorten as MFree) methods have been proposed and achieved remarkable progress over the past few years. The idea of combining MFree methods with other existing numerical techniques such as the finite element method (FEM) and the boundary element method (BEM), is naturally of great interest in many practical applications. However, the shape functions used in some MFree methods do not have the Kronecker delta function property. In order to satisfy the combined conditions of displacement compatibility, two numerical techniques, using the hybrid displacement shape function and the modified variational form, are developed and discussed in this paper. In the first technique, the original MFree shape functions are modified to the hybrid forms that possess the Kronecker delta function property. In the second technique, the displacement compatibility is satisfied via a modified variational form based on the Lagrange multiplier method. Formulations of several coupled methods are presented. Numerical examples are presented to demonstrate the effectiveness of the present coupling methods.

  16. From Method to Post Method: A Panacea!

    Science.gov (United States)

    Masouleh, Nima Shakouri

    2012-01-01

    The foundation of language teaching has undergone many changes. The rise and fall of language teaching methods depends upon a variety of factors extrinsic to a method itself and often reflects the influence of profit-seekers and promoters, as well as the forces of the intellectual marketplace. There was always a source of contention among people…

  17. The Multidimensional WKB Method.

    Science.gov (United States)

    Knudson, Stephen K.; Noid, D. W.

    1989-01-01

    Discusses a new method for determining the eigenvalues of the Schroedinger equation when the potential energy function does not have a simple form. Describes the mathematical methods and provides an application. Lists limitations to the method. (MVL)

  18. ANALYSIS OF MULTISCALE METHODS

    Institute of Scientific and Technical Information of China (English)

    Wei-nan E; Ping-bing Ming

    2004-01-01

    The heterogeneous multiscale method gives a general framework for the analysis of multiscale methods. In this paper, we demonstrate this by applying this framework to two canonical problems: The elliptic problem with multiscale coefficients and the quasicontinuum method.

  19. Ensemble Data Mining Methods

    Data.gov (United States)

    National Aeronautics and Space Administration — Ensemble Data Mining Methods, also known as Committee Methods or Model Combiners, are machine learning methods that leverage the power of multiple models to achieve...

  20. Simplifications of CQC method and CCQC method

    Institute of Scientific and Technical Information of China (English)

    Yu Ruifang; Zhou Xiyuan

    2007-01-01

    The response-spectrum mode superposition method is widely used for seismic response analyses of linear systems. In using this method, the complete quadratic combination (CQC) is adopted for classically damped linear systems and the complex complete quadratic combination (CCQC) formula is adopted for non-classically damped linear systems.However, in both cases, the calculation of seismic response analyses is very time consuming. In this paper, the variation of the modal correlation coefficients of displacement, velocity and displacement-velocity with frequency and damping ratios of two modes of interest are studied, Moreover, the calculation errors generated by using CQC and square-root-of-the-sum-of-the-squares (SRSS) methods (or CCQC and CSRSS methods) for different damping combinations are compared. In these analyses,some boundary lines for classically and non-classically damped systems are plotted to distinguish the allowed minimum frequency ratio at given geometric mean of the damping ratios of both modes if their relativity is neglected. Furthermore,the simplified method, which is a special mode quadratic combination method considering only relativity of adjacent modes in CQC method and named simplified CQC or partial quadratic combination (PQC) method for classically damped linear system, is proposed to improve computational efficiency, and the criterion for determination of how many correlated modes should be adopted is proposed. Similarly, the simplified CCQC or complex partial quadratic combination (CPQC) method for the non-classically damped linear system and the corresponding criterion are also deduced. Finally, a numerical example is given to illustrate the applicability, computational accuracy and efficiency of the PQC and CPQC methods.

  1. Simulations using meshfree methods

    CERN Document Server

    P, Kirana Kumara

    2015-01-01

    In this paper, attempt is made to solve a few problems using the Polynomial Point Collocation Method (PPCM), the Radial Point Collocation Method (RPCM), Smoothed Particle Hydrodynamics (SPH), and the Finite Point Method (FPM). A few observations on the accuracy of these methods are recorded. All the simulations in this paper are three dimensional linear elastostatic simulations, without accounting for body forces.

  2. Numerical Methods for Multilattices

    CERN Document Server

    Abdulle, Assyr; Shapeev, Alexander V

    2011-01-01

    Among the efficient numerical methods based on atomistic models, the quasicontinuum (QC) method has attracted growing interest in recent years. The QC method was first developed for crystalline materials with Bravais lattice and was later extended to multilattices (Tadmor et al, 1999). Another existing numerical approach to modeling multilattices is homogenization. In the present paper we review the existing numerical methods for multilattices and propose another concurrent macro-to-micro method in the homogenization framework. We give a unified mathematical formulation of the new and the existing methods and show their equivalence. We then consider extensions of the proposed method to time-dependent problems and to random materials.

  3. Inflow Turbulence Generation Methods

    Science.gov (United States)

    Wu, Xiaohua

    2017-01-01

    Research activities on inflow turbulence generation methods have been vigorous over the past quarter century, accompanying advances in eddy-resolving computations of spatially developing turbulent flows with direct numerical simulation, large-eddy simulation (LES), and hybrid Reynolds-averaged Navier-Stokes–LES. The weak recycling method, rooted in scaling arguments on the canonical incompressible boundary layer, has been applied to supersonic boundary layer, rough surface boundary layer, and microscale urban canopy LES coupled with mesoscale numerical weather forecasting. Synthetic methods, originating from analytical approximation to homogeneous isotropic turbulence, have branched out into several robust methods, including the synthetic random Fourier method, synthetic digital filtering method, synthetic coherent eddy method, and synthetic volume forcing method. This article reviews major progress in inflow turbulence generation methods with an emphasis on fundamental ideas, key milestones, representative applications, and critical issues. Directions for future research in the field are also highlighted.

  4. Advanced differential quadrature methods

    CERN Document Server

    Zong, Zhi

    2009-01-01

    Modern Tools to Perform Numerical DifferentiationThe original direct differential quadrature (DQ) method has been known to fail for problems with strong nonlinearity and material discontinuity as well as for problems involving singularity, irregularity, and multiple scales. But now researchers in applied mathematics, computational mechanics, and engineering have developed a range of innovative DQ-based methods to overcome these shortcomings. Advanced Differential Quadrature Methods explores new DQ methods and uses these methods to solve problems beyond the capabilities of the direct DQ method.After a basic introduction to the direct DQ method, the book presents a number of DQ methods, including complex DQ, triangular DQ, multi-scale DQ, variable order DQ, multi-domain DQ, and localized DQ. It also provides a mathematical compendium that summarizes Gauss elimination, the Runge-Kutta method, complex analysis, and more. The final chapter contains three codes written in the FORTRAN language, enabling readers to q...

  5. Consumer Behavior Research Methods

    DEFF Research Database (Denmark)

    Chrysochou, Polymeros

    2017-01-01

    emphasizes the discussion of primary research methods. Based on the nature of the data primary research methods are further distinguished into qualitative and quantitative. The chapter describes the most important and popular qualitative and quantitative methods. It concludes with an overall evaluation......This chapter starts by distinguishing consumer behavior research methods based on the type of data used, being either secondary or primary. Most consumer behavior research studies phenomena that require researchers to enter the field and collect data on their own, and therefore the chapter...... of the methods and how to improve quality in consumer behavior research methods....

  6. Quality Control Analytical Methods: Method Validation.

    Science.gov (United States)

    Klang, Mark G; Williams, LaVonn A

    2016-01-01

    To properly determine the accuracy of a pharmaceutical product or compounded preparation, tests must be designed specifically for that evaluation. The procedures selected must be verified through a process referred to as method validation, an integral part of any good analytical practice. The results from a method validation procedure can be used to judge the quality, reliability, and consistency of analytical results. The purpose of this article is to deliver the message of the importance of validation of a pharmaceutical product or compounded preparation and to briefly discuss the results of a lack of such validation. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  7. Applied Bayesian Hierarchical Methods

    CERN Document Server

    Congdon, Peter D

    2010-01-01

    Bayesian methods facilitate the analysis of complex models and data structures. Emphasizing data applications, alternative modeling specifications, and computer implementation, this book provides a practical overview of methods for Bayesian analysis of hierarchical models.

  8. Dissolution Methods Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — For a drug product that does not have a dissolution test method in the United States Pharmacopeia (USP), the FDA Dissolution Methods Database provides information on...

  9. Dissolution Methods Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — For a drug product that does not have a dissolution test method in the United States Pharmacopeia (USP), the FDA Dissolution Methods Database provides information on...

  10. Simulated floating zone method

    OpenAIRE

    Ozawa, Ryo; Kato, Yasuyuki; Motome, Yukitoshi

    2016-01-01

    This paper provides the simulated floating zone (SFZ) method that is an efficient simulation technique to obtain thermal equilibrium states, especially useful when domain formation prevents the system from reaching a spatially-uniform stable state. In the SFZ method, the system is heated up locally, and the heated region is steadily shifted, similar to the floating zone method for growing a single crystal with less lattice defect and impurity in experiments. We demonstrate that the SFZ method...

  11. Mixed methods research.

    Science.gov (United States)

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  12. Geobacteraceae strains and methods

    Science.gov (United States)

    Lovley, Derek R.; Nevin, Kelly P.; Yi, Hana

    2015-07-07

    Embodiments of the present invention provide a method of producing genetically modified strains of electricigenic microbes that are specifically adapted for the production of electrical current in microbial fuel cells, as well as strains produced by such methods and fuel cells using such strains. In preferred embodiments, the present invention provides genetically modified strains of Geobacter sulfurreducens and methods of using such strains.

  13. Numerical methods using Matlab

    CERN Document Server

    Gupta, Abhishek

    2015-01-01

    Numerical Methods with MATLAB provides a highly-practical reference work to assist anyone working with numerical methods. A wide range of techniques are introduced, their merits discussed and fully working MATLAB code samples supplied to demonstrate how they can be coded and applied. Numerical methods have wide applicability across many scientific, mathematical, and engineering disciplines and are most often employed in situations where working out an exact answer to the problem by another method is impractical. Numerical Methods with MATLAB presents each topic in a concise and readable

  14. The Generalized Sturmian Method

    DEFF Research Database (Denmark)

    Avery, James Emil

    2011-01-01

    generations of researchers were left to work out how to achieve this ambitious goal for molecular systems of ever-increasing size. This book focuses on non-mainstream methods to solve the molecular electronic Schrödinger equation. Each method is based on a set of core ideas and this volume aims to explain...... these ideas clearly so that they become more accessible. By bringing together these non-standard methods, the book intends to inspire graduate students, postdoctoral researchers and academics to think of novel approaches. Is there a method out there that we have not thought of yet? Can we design a new method...

  15. Mimetic discretization methods

    CERN Document Server

    Castillo, Jose E

    2013-01-01

    To help solve physical and engineering problems, mimetic or compatible algebraic discretization methods employ discrete constructs to mimic the continuous identities and theorems found in vector calculus. Mimetic Discretization Methods focuses on the recent mimetic discretization method co-developed by the first author. Based on the Castillo-Grone operators, this simple mimetic discretization method is invariably valid for spatial dimensions no greater than three. The book also presents a numerical method for obtaining corresponding discrete operators that mimic the continuum differential and

  16. Methods for assessing geodiversity

    Science.gov (United States)

    Zwoliński, Zbigniew; Najwer, Alicja; Giardino, Marco

    2017-04-01

    The accepted systematics of geodiversity assessment methods will be presented in three categories: qualitative, quantitative and qualitative-quantitative. Qualitative methods are usually descriptive methods that are suited to nominal and ordinal data. Quantitative methods use a different set of parameters and indicators to determine the characteristics of geodiversity in the area being researched. Qualitative-quantitative methods are a good combination of the collection of quantitative data (i.e. digital) and cause-effect data (i.e. relational and explanatory). It seems that at the current stage of the development of geodiversity research methods, qualitative-quantitative methods are the most advanced and best assess the geodiversity of the study area. Their particular advantage is the integration of data from different sources and with different substantive content. Among the distinguishing features of the quantitative and qualitative-quantitative methods for assessing geodiversity are their wide use within geographic information systems, both at the stage of data collection and data integration, as well as numerical processing and their presentation. The unresolved problem for these methods, however, is the possibility of their validation. It seems that currently the best method of validation is direct filed confrontation. Looking to the next few years, the development of qualitative-quantitative methods connected with cognitive issues should be expected, oriented towards ontology and the Semantic Web.

  17. Design Methods in Practice

    DEFF Research Database (Denmark)

    Jensen, Torben Elgaard; Andreasen, Mogens Myrup

    2010-01-01

    The paper challenges the dominant and widespread view that a good design method will guarantee a systematic approach as well as certain results. First, it explores the substantial differences between on the one hand the conception of methods implied in Pahl & Beitz’s widely recognized text book...... subject to change; The goals of methods are less stable than assumed. The paper finally suggests that ethnomethodology and similar approaches direct our attention to the fact that method use is always a situated and socially interactive affair. It is crucial to attend to these dimensions of method use...... on engineering design, and on the other hand the understanding of method use, which has emerged from micro-sociological studies of practice (ethnomethodology). Second, it reviews a number of case studies conducted by engineering students, who were instructed to investigate the actual use of design methods...

  18. Consensus theoretic classification methods

    Science.gov (United States)

    Benediktsson, Jon A.; Swain, Philip H.

    1992-01-01

    Consensus theory is adopted as a means of classifying geographic data from multiple sources. The foundations and usefulness of different consensus theoretic methods are discussed in conjunction with pattern recognition. Weight selections for different data sources are considered and modeling of non-Gaussian data is investigated. The application of consensus theory in pattern recognition is tested on two data sets: 1) multisource remote sensing and geographic data and 2) very-high-dimensional remote sensing data. The results obtained using consensus theoretic methods are found to compare favorably with those obtained using well-known pattern recognition methods. The consensus theoretic methods can be applied in cases where the Gaussian maximum likelihood method cannot. Also, the consensus theoretic methods are computationally less demanding than the Gaussian maximum likelihood method and provide a means for weighting data sources differently.

  19. Methods of Software Verification

    Directory of Open Access Journals (Sweden)

    R. E. Gurin

    2015-01-01

    Full Text Available This article is devoted to the problem of software verification (SW. Methods of software verification designed to check the software for compliance with the stated requirements such as correctness, system security and system adaptability to small changes in the environment, portability and compatibility, etc. These are various methods both by the operation process and by the way of achieving result. The article describes the static and dynamic methods of software verification and paid attention to the method of symbolic execution. In its review of static analysis are discussed and described the deductive method, and methods for testing the model. A relevant issue of the pros and cons of a particular method is emphasized. The article considers classification of test techniques for each method. In this paper we present and analyze the characteristics and mechanisms of the static analysis of dependencies, as well as their views, which can reduce the number of false positives in situations where the current state of the program combines two or more states obtained both in different paths of execution and in working with multiple object values. Dependences connect various types of software objects: single variables, the elements of composite variables (structure fields, array elements, the size of the heap areas, the length of lines, the number of initialized array elements in the verification code using static methods. The article pays attention to the identification of dependencies within the framework of the abstract interpretation, as well as gives an overview and analysis of the inference tools.Methods of dynamic analysis such as testing, monitoring and profiling are presented and analyzed. Also some kinds of tools are considered which can be applied to the software when using the methods of dynamic analysis. Based on the work a conclusion is drawn, which describes the most relevant problems of analysis techniques, methods of their solutions and

  20. Gas chromatographic determination of acid herbicides in surface water samples with electron-capture detection and mass spectrometric confirmation

    NARCIS (Netherlands)

    Vink, M.; Poll, J.M. van der

    1996-01-01

    The development of a multi-residue method for the determination of eight polar acidic herbicides (MCPA, MCPB, mecoprop, 2,4-D, dichlorprop, bentazone, dicamba and dikegulac) in surface water is described. The method involves an off-line solid-phase extraction (SPE) procedure prior to instrumental an

  1. Performative Schizoid Method

    DEFF Research Database (Denmark)

    Svabo, Connie

    2016-01-01

    A performative schizoid method is developed as a method contribution to performance as research. The method is inspired by contemporary research in the human and social sciences urging experimentation and researcher engagement with creative and artistic practice. In the article, the method...... is presented and an example is provided of a first exploratory engagement with it. The method is used in a specific project Becoming Iris, making inquiry into arts-based knowledge creation during a three month visiting scholarship at a small, independent visual art academy. Using the performative schizoid...... method in Becoming Iris results in four audio-visual and performance-based productions, centered on an emergent theme of the scholartist as a bird in borrowed feathers. Interestingly, the moral lesson of the fable about the vain jackdaw, who dresses in borrowed peacock feathers and becomes a castout...

  2. Exoplanet Detection Methods

    CERN Document Server

    Wright, Jason T

    2012-01-01

    This chapter reviews various methods of detecting planetary companions to stars from an observational perspective, focusing on radial velocities, astrometry, direct imaging, transits, and gravitational microlensing. For each method, this chapter first derives or summarizes the basic observable phenomena that are used to infer the ex- istence of planetary companions, as well as the physical properties of the planets and host stars that can be derived from the measurement of these signals. This chapter then outlines the general experimental requirements to robustly detect the signals us- ing each method, by comparing their magnitude to the typical sources of measurement uncertainty. This chapter goes on to compare the various methods to each other by outlining the regions of planet and host star parameter space where each method is most sensitive, stressing the complementarity of the ensemble of the methods at our disposal. Finally, there is a brief review of the history of the young exoplanet field, from the f...

  3. Phenomenographic Research Method

    Directory of Open Access Journals (Sweden)

    Erdem ÇEKMEZ

    2012-12-01

    Full Text Available Phenomenography, an approach to educational research, emerged from the studies carried out by Ference Marton and his colleagues at the University of Göteborg, Sweden, in the early 1970s. Phenomenography is the empirical study of the different ways in which people experience, perceive, apprehend, understand, conceptualize various phenomena in the world around them. Not only this method has been used much in educational researches in Turkey, but also the books about research methods do not provide detailed information about this method in details. This study explains the aim, characteristics, historical background and how to ensure the generalization, validity and reliability of phenomenographic research outcomes, besides mentions to the studies in which phenomenographic research method was used. In addition, the differences and similarities between this method and methods similar to phenomenology are explained.

  4. The Schwinger Variational Method

    Science.gov (United States)

    Huo, Winifred M.

    1995-01-01

    Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions.

  5. Applied iterative methods

    CERN Document Server

    Hageman, Louis A

    2004-01-01

    This graduate-level text examines the practical use of iterative methods in solving large, sparse systems of linear algebraic equations and in resolving multidimensional boundary-value problems. Assuming minimal mathematical background, it profiles the relative merits of several general iterative procedures. Topics include polynomial acceleration of basic iterative methods, Chebyshev and conjugate gradient acceleration procedures applicable to partitioning the linear system into a "red/black" block form, adaptive computational algorithms for the successive overrelaxation (SOR) method, and comp

  6. Well testing: interpretation methods

    Energy Technology Data Exchange (ETDEWEB)

    Bourdarot, G. [Elf Aquitaine, 92 - Courbevoie (France)

    1998-12-31

    This book presents the different methods to use for interpreting well tests: conventional methods, type curves, derivative, according to the type of reservoir limits (faults, channels, secant faults, constant pressure limits, closed reservoir) and the well configuration (partial penetration, inclined, fractured, horizontal or injection well). It indicates the method to be used in the case of more complex reservoirs (fissured reservoirs, two-layered reservoirs), interference tests or pulse tests and when fluid produced is gas or polyphasic. (authors) 60 refs.

  7. Well testing: interpretation methods

    Energy Technology Data Exchange (ETDEWEB)

    Bourdarot, G. (Elf Aquitaine, 92 - Courbevoie (France))

    1998-01-01

    This book presents the different methods to use for interpreting well tests: conventional methods, type curves, derivative, according to the type of reservoir limits (faults, channels, secant faults, constant pressure limits, closed reservoir) and the well configuration (partial penetration, inclined, fractured, horizontal or injection well). It indicates the method to be used in the case of more complex reservoirs (fissured reservoirs, two-layered reservoirs), interference tests or pulse tests and when fluid produced is gas or polyphasic. (authors) 60 refs.

  8. The Box Method

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentum flow in the supply jets controls the air movement in the room and, therefore, it is very important that the inlet conditions and the numerical method can generate a satisfactor...... description of this momentum flow. The Box Method is a practical method for the description of an Air Terminal Device which will save grid points and ensure the right level of the momentum flow....

  9. Methods of inventory control.

    Science.gov (United States)

    Lindley, C; Mackowiak, J

    1985-01-01

    Various methods for controlling inventory are described, and the advantages and disadvantages of each are discussed. The open-to-buy (OTB) budget method limits purchases to a specific amount of funds available for purchasing pharmaceuticals during a specified period. The emphasis of the OTB method is financial control of the pharmacy inventory. Although it is useful in monitoring and adjusting the dollar value of the inventory, it should be combined with other methods for a total inventory control system. The primary emphasis of the short-list method is to provide accurate and timely inventory information to the person responsible for order placement. The short list identifies the items that are in short supply. It is the most common feedback and control mechanism in use, but it is best suited for settings where duplicate or reserve stock is maintained and monitored by more rigorous methods. The main objective of the minimum and maximum method is to determine when and how much to order of each item. It also provides limited dollar control. The major disadvantage of this method is the time it requires to establish the minimum and maximum levels and to update them regularly to reflect changes in demand. The stock record card method is used to record information on the movement of goods in and out of the storage area. Stock cards can also be used to monitor inventory levels and facilitate order initiation. It is probably the optimum method to be used alone. The most effective system of inventory control is one employing a combination of these methods tailored to meet the institution's needs and available resources.

  10. Methods for data classification

    Science.gov (United States)

    Garrity, George; Lilburn, Timothy G.

    2011-10-11

    The present invention provides methods for classifying data and uncovering and correcting annotation errors. In particular, the present invention provides a self-organizing, self-correcting algorithm for use in classifying data. Additionally, the present invention provides a method for classifying biological taxa.

  11. DISCOURSE ON METHODS.

    Science.gov (United States)

    BOUCHER, JOHN G.

    THE AUTHOR STATES THAT BEFORE PRESENT FOREIGN LANGUAGE TEACHING METHODS CAN BE DISCUSSED INTELLIGENTLY, THE RESEARCH IN PSYCHOLOGY AND LINGUISTICS WHICH HAS INFLUENCED THE DEVELOPMENT OF THESE METHODS MUST BE CONSIDERED. MANY FOREIGN LANGUAGE TEACHERS WERE BEGINNING TO FEEL COMFORTABLE WITH THE AUDIOLINGUAL APPROACH WHEN NOAM CHOMSKY, IN HIS 1966…

  12. Noise-Measuring Method

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A noise-measuring method based on the use of a calibrated noise generator and an output meter with a special scale is described. The method eliminates the effect of noise contributions occurring in the circuits following the device under test....

  13. Method of forming nanodielectrics

    Science.gov (United States)

    Tuncer, Enis [Knoxville, TN; Polyzos, Georgios [Oak Ridge, TN

    2014-01-07

    A method of making a nanoparticle filled dielectric material. The method includes mixing nanoparticle precursors with a polymer material and reacting the nanoparticle mixed with the polymer material to form nanoparticles dispersed within the polymer material to form a dielectric composite.

  14. Soybean allergen detection methods

    DEFF Research Database (Denmark)

    Pedersen, Mona H; Holzhauser, Thomas; Bisson, Caroline

    2008-01-01

    Soybean containing products are widely consumed, thus reliable methods for detection of soy in foods are needed in order to make appropriate risk assessment studies to adequately protect soy allergic patients. Six methods were compared using eight food products with a declared content of soy...

  15. The Method of Archimedes.

    Science.gov (United States)

    Del Grande, John

    1993-01-01

    Describes the method that Archimedes utilized to calculate the volumes of spheres and other solids. The method found the volume of a sphere by comparing the mass of parallel slices of a sphere and a cone with that of a cylinder of known mass. (MDH)

  16. Research Methods in Education

    Science.gov (United States)

    Check, Joseph; Schutt, Russell K.

    2011-01-01

    "Research Methods in Education" introduces research methods as an integrated set of techniques for investigating questions about the educational world. This lively, innovative text helps students connect technique and substance, appreciate the value of both qualitative and quantitative methodologies, and make ethical research decisions.…

  17. METHOD FOR MAKING CHEESE

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a method for making Cheddar type and Continental type cheese with an adjunct culture comprising a Lactobacillus helveticus strain.......The present invention relates to a method for making Cheddar type and Continental type cheese with an adjunct culture comprising a Lactobacillus helveticus strain....

  18. Improved nonlinear prediction method

    Science.gov (United States)

    Adenan, Nur Hamiza; Md Noorani, Mohd Salmi

    2014-06-01

    The analysis and prediction of time series data have been addressed by researchers. Many techniques have been developed to be applied in various areas, such as weather forecasting, financial markets and hydrological phenomena involving data that are contaminated by noise. Therefore, various techniques to improve the method have been introduced to analyze and predict time series data. In respect of the importance of analysis and the accuracy of the prediction result, a study was undertaken to test the effectiveness of the improved nonlinear prediction method for data that contain noise. The improved nonlinear prediction method involves the formation of composite serial data based on the successive differences of the time series. Then, the phase space reconstruction was performed on the composite data (one-dimensional) to reconstruct a number of space dimensions. Finally the local linear approximation method was employed to make a prediction based on the phase space. This improved method was tested with data series Logistics that contain 0%, 5%, 10%, 20% and 30% of noise. The results show that by using the improved method, the predictions were found to be in close agreement with the observed ones. The correlation coefficient was close to one when the improved method was applied on data with up to 10% noise. Thus, an improvement to analyze data with noise without involving any noise reduction method was introduced to predict the time series data.

  19. Data center cooling method

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Dang, Hien P.; Parida, Pritish R.; Schultz, Mark D.; Sharma, Arun

    2015-08-11

    A method aspect for removing heat from a data center may use liquid coolant cooled without vapor compression refrigeration on a liquid cooled information technology equipment rack. The method may also include regulating liquid coolant flow to the data center through a range of liquid coolant flow values with a controller-apparatus based upon information technology equipment temperature threshold of the data center.

  20. Studying Aid: Some Methods

    NARCIS (Netherlands)

    D.R. Gasper (Des)

    2003-01-01

    textabstractINVESTIGATING IDEAS, IDEOLOGIES AND PRACTICES This paper presents some methods for trying to make sense of international aid and of its study.1 Some of the methods may be deemed ethnographic; the others are important partners to them, but rather different. In the course of discussing q

  1. Research Methods in Education

    Science.gov (United States)

    Check, Joseph; Schutt, Russell K.

    2011-01-01

    "Research Methods in Education" introduces research methods as an integrated set of techniques for investigating questions about the educational world. This lively, innovative text helps students connect technique and substance, appreciate the value of both qualitative and quantitative methodologies, and make ethical research decisions.…

  2. METHODS OF MAGNETOTELLURIC ANALYSIS

    Science.gov (United States)

    Magnetotelluric prospecting is a method of geophysical exploration that makes use of the fluctuations in the natural electric and magnetic fields...function of the conductivity structure of the earth’s substrata. This report describes some new methods for analyzing and interpreting magnetotelluric

  3. Methods in Modern Biophysics

    CERN Document Server

    Nölting, Bengt

    2006-01-01

    Incorporating recent dramatic advances, this textbook presents a fresh and timely introduction to modern biophysical methods. An array of new, faster and higher-power biophysical methods now enables scientists to examine the mysteries of life at a molecular level. This innovative text surveys and explains the ten key biophysical methods, including those related to biophysical nanotechnology, scanning probe microscopy, X-ray crystallography, ion mobility spectrometry, mass spectrometry, proteomics, and protein folding and structure. Incorporating much information previously unavailable in tutorial form, Nölting employs worked examples and 267 illustrations to fully detail the techniques and their underlying mechanisms. Methods in Modern Biophysics is written for advanced undergraduate and graduate students, postdocs, researchers, lecturers and professors in biophysics, biochemistry and related fields. Special features in the 2nd edition: • Illustrates the high-resolution methods for ultrashort-living protei...

  4. Adaptive method of lines

    CERN Document Server

    Saucez, Ph

    2001-01-01

    The general Method of Lines (MOL) procedure provides a flexible format for the solution of all the major classes of partial differential equations (PDEs) and is particularly well suited to evolutionary, nonlinear wave PDEs. Despite its utility, however, there are relatively few texts that explore it at a more advanced level and reflect the method''s current state of development.Written by distinguished researchers in the field, Adaptive Method of Lines reflects the diversity of techniques and applications related to the MOL. Most of its chapters focus on a particular application but also provide a discussion of underlying philosophy and technique. Particular attention is paid to the concept of both temporal and spatial adaptivity in solving time-dependent PDEs. Many important ideas and methods are introduced, including moving grids and grid refinement, static and dynamic gridding, the equidistribution principle and the concept of a monitor function, the minimization of a functional, and the moving finite elem...

  5. Fast Distributed Gradient Methods

    CERN Document Server

    Jakovetic, Dusan; Moura, Jose M F

    2011-01-01

    The paper proposes new fast distributed optimization gradient methods and proves convergence to the exact solution at rate O(\\log k/k), much faster than existing distributed optimization (sub)gradient methods with convergence O(1/\\sqrt{k}), while incurring practically no additional communication nor computation cost overhead per iteration. We achieve this for convex (with at least one strongly convex,) coercive, three times differentiable and with Lipschitz continuous first derivative (private) cost functions. Our work recovers for distributed optimization similar convergence rate gains obtained by centralized Nesterov gradient and fast iterative shrinkage-thresholding algorithm (FISTA) methods over ordinary centralized gradient methods. We also present a constant step size distributed fast gradient algorithm for composite non-differentiable costs. A simulation illustrates the effectiveness of our distributed methods.

  6. Cooperative method development

    DEFF Research Database (Denmark)

    Dittrich, Yvonne; Rönkkö, Kari; Eriksson, Jeanette;

    2008-01-01

    research is not easily combined with the improvement orientation of an engineering discipline. During the last 6 years, we have applied an approach we call `cooperative method development', which combines qualitative social science fieldwork, with problem-oriented method, technique and process improvement....... The action research based approach focusing on shop floor software development practices allows an understanding of how contextual contingencies influence the deployment and applicability of methods, processes and techniques. This article summarizes the experiences and discusses the further development......The development of methods tools and process improvements is best to be based on the understanding of the development practice to be supported. Qualitative research has been proposed as a method for understanding the social and cooperative aspects of software development. However, qualitative...

  7. Engaging with mobile methods

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    2014-01-01

    This chapter showcases how mobile methods are more than calibrated techniques awaiting application by tourism researchers, but productive in the enactment of the mobile (Law and Urry, 2004). Drawing upon recent findings deriving from a PhD course on mobility and mobile methods it reveals...... the conceptual ambiguousness of the term ‘mobile methods’. In order to explore this ambiguousness the chapter provides a number of examples deriving from tourism research, to explore how mobile methods are always entangled in ideologies, predispositions, conventions and practice-realities. Accordingly......, the engagements with methods are acknowledged to be always political and contextual, reminding us to avoid essentialist discussions regarding research methods. Finally, the chapter draws on recent fieldwork to extend developments in mobilities-oriented tourism research, by employing auto-ethnography to call...

  8. Methods for age estimation

    Directory of Open Access Journals (Sweden)

    D. Sümeyra Demirkıran

    2014-03-01

    Full Text Available Concept of age estimation plays an important role on both civil law and regulation of criminal behaviors. In forensic medicine, age estimation is practiced for individual requests as well for request of the court. In this study it is aimed to compile the methods of age estimation and to make recommendations for the solution of the problems encountered. In radiological method the epiphyseal lines of the bones and views of the teeth are used. In order to estimate the age by comparing bone radiographs; Greulich-Pyle Atlas (GPA, Tanner-Whitehouse Atlas (TWA and “Adli Tıpta Yaş Tayini (ATYT” books are used. Bone age is found to be 2 years older averagely than chronologic age, especially in puberty, according to the forensic age estimations described in the ATYT book. For the age estimation with teeth, Demirjian method is used. In time different methods are developed by modifying Demirjian method. However no accurate method was found. Histopathological studies are done on bone marrow cellularity and dermis cells. No correlation was found between histopathoogical findings and choronologic age. Important ethical and legal issues are brought with current age estimation methods especially in teenage period. Therefore it is required to prepare atlases of bone age compatible with our society by collecting the findings of the studies in Turkey. Another recommendation could be to pay attention to the courts of age raising trials of teenage women and give special emphasis on birth and population records

  9. STATISTICAL METHODS IN HISTORY

    Directory of Open Access Journals (Sweden)

    Orlov A. I.

    2016-01-01

    Full Text Available We have given a critical analysis of statistical models and methods for processing text information in historical records to establish the times when there were certain events, ie, to build science-based chronology. There are three main kinds of sources of knowledge of ancient history: ancient texts, the remains of material culture and traditions. The specific date of the extracted by archaeologists objects in most cases can not be found. The group of Academician A.T. Fomenko has developed and applied new statistical methods for analysis of historical texts (Chronicle, based on the intensive use of computer technology. Two major scientific results were: the majority of historical records that we know now, are duplicated (in particular, chronicles, describing the so-called "Ancient Rome" and "Middle Ages", talking about the same events; the known historical chronicles tell us about real events, separated from the present time for not more than 1000 years. It was found that chronicles describing the history of "ancient times" and "Middle Ages" and the chronicle of Chinese history and the history of various European countries do not talk about different, but about the same events. We have the attempt of a new dating of historical events and restoring the true history of human society based on new data. From the standpoint of statistical methods of historical records and images of their fragments – they are special cases of non-numeric objects of nature. Therefore, developed by the group of A.T. Fomenko computer-statistical methods are the part of non-numerical statistics. We have considered some methods of statistical analysis of chronicles applied by the group of A.T. Fomenko: correlation method of maximums; dynasties method; the method of attenuation frequency; questionnaire method codes. New chronology allows us to understand much of the battle of ideas in modern science and mass consciousness. It becomes clear the root cause of cautious

  10. The Prescribed Velocity Method

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The- velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentum flow in the supply jets controls the air movement in the room and, therefore, it is very important that the inlet conditions and the numerical method can generate a satisfactory...... description of this momentum flow. The Prescribed Velocity Method is a practical method for the description of an Air Terminal Device which will save grid points close to the opening and ensure the right level of the momentum flow....

  11. Methods in mummy research

    DEFF Research Database (Denmark)

    Lynnerup, Niels

    2009-01-01

    Mummies are human remains with preservation of non-bony tissue. Many mummy studies focus on the development and application of non-destructive methods for examining mummies, including radiography, CT-scanning with advanced 3-dimensional visualisations, and endoscopic techniques, as well as minima......Mummies are human remains with preservation of non-bony tissue. Many mummy studies focus on the development and application of non-destructive methods for examining mummies, including radiography, CT-scanning with advanced 3-dimensional visualisations, and endoscopic techniques, as well...... as minimally-destructive chemical, physical and biological methods for, e.g., stable isotopes, trace metals and DNA....

  12. Modern diffraction methods

    CERN Document Server

    Mittemeijer, E J

    2013-01-01

    The role of diffraction methods for the solid-state sciences has been pivotal to determining the (micro)structure of a material. Particularly, the expanding activities in materials science have led to the development of new methods for analysis by diffraction. This book offers an authoritative overview of the new developments in the field of analysis of matter by (in particular X-ray, electron and neutron) diffraction. It is composed of chapters written by leading experts on 'modern diffraction methods'. The focus in the various chapters of this book is on the current forefront of research on

  13. Methods in Bioengineering

    CERN Document Server

    Jayaraman, Arul

    2009-01-01

    This volume provides a detailed look at the two main aspects of systems biology: the design of sophisticated experimental methods and the development of complex models to analyze the data. Focusing on methods that are being used to solve current problems in biomedical science and engineering, this comprehensive, richly illustrated resource shows you how to design of state-of-the art methods for analyzing biological systems, implement experimental approaches for investigating cellular behavior in health and disease, use algorithms and modeling techniques for quantitatively describing biomedical

  14. Montessori Method and ICTs

    Directory of Open Access Journals (Sweden)

    Athanasios Drigas

    2016-03-01

    Full Text Available This article bridges the gap between the Montessori Method and Information and Communication Technologies (ICTs in contemporary education. It reviews recent research works which recall the Montessori philosophy, principles and didactical tools applying to today’s computers and supporting technologies in children’s learning process. This article reviews how important the stimulation of human senses in the learning process is, as well as the development of Montessori materials using the body and the hand in particular, all according to the Montessori Method along with recent researches over ICTs. Montessori Method within information society age acquires new perspectives, new functionality and new efficacy.

  15. Numerical methods using Matlab

    CERN Document Server

    Lindfield, George

    2012-01-01

    Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of useful and important numerical algorithms that can be implemented into MATLAB for a graphical interpretation to help researchers analyze a particular outcome. Many worked examples are given together with exercises and solutions to illustrate how numerical methods can be used to study problems that have applications in the biosciences, chaos, optimization, engineering and science across the board. Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of use

  16. Methods of flash sintering

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Rishi; Cologna, Marco; Francis, John S.

    2016-05-10

    This disclosure provides methods of flash sintering and compositions created by these methods. Methods for sintering multilayered bodies are provided in which a sintered body is produced in less than one minute. In one aspect, each layer is of a different composition, and may be constituted wholly from a ceramic or from a combination of ceramic and metallic particles. When the body includes a layer of an anode composition, a layer of an electrolyte composition and a layer of a cathode composition, the sintered body can be used to produce a solid oxide fuel cell.

  17. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature......The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...

  18. Generalized subspace correction methods

    Energy Technology Data Exchange (ETDEWEB)

    Kolm, P. [Royal Institute of Technology, Stockholm (Sweden); Arbenz, P.; Gander, W. [Eidgenoessiche Technische Hochschule, Zuerich (Switzerland)

    1996-12-31

    A fundamental problem in scientific computing is the solution of large sparse systems of linear equations. Often these systems arise from the discretization of differential equations by finite difference, finite volume or finite element methods. Iterative methods exploiting these sparse structures have proven to be very effective on conventional computers for a wide area of applications. Due to the rapid development and increasing demand for the large computing powers of parallel computers, it has become important to design iterative methods specialized for these new architectures.

  19. Ensemble Data Mining Methods

    Science.gov (United States)

    Oza, Nikunj C.

    2004-01-01

    Ensemble Data Mining Methods, also known as Committee Methods or Model Combiners, are machine learning methods that leverage the power of multiple models to achieve better prediction accuracy than any of the individual models could on their own. The basic goal when designing an ensemble is the same as when establishing a committee of people: each member of the committee should be as competent as possible, but the members should be complementary to one another. If the members are not complementary, Le., if they always agree, then the committee is unnecessary---any one member is sufficient. If the members are complementary, then when one or a few members make an error, the probability is high that the remaining members can correct this error. Research in ensemble methods has largely revolved around designing ensembles consisting of competent yet complementary models.

  20. Adaptive Algebraic Multigrid Methods

    Energy Technology Data Exchange (ETDEWEB)

    Brezina, M; Falgout, R; MacLachlan, S; Manteuffel, T; McCormick, S; Ruge, J

    2004-04-09

    Our ability to simulate physical processes numerically is constrained by our ability to solve the resulting linear systems, prompting substantial research into the development of multiscale iterative methods capable of solving these linear systems with an optimal amount of effort. Overcoming the limitations of geometric multigrid methods to simple geometries and differential equations, algebraic multigrid methods construct the multigrid hierarchy based only on the given matrix. While this allows for efficient black-box solution of the linear systems associated with discretizations of many elliptic differential equations, it also results in a lack of robustness due to assumptions made on the near-null spaces of these matrices. This paper introduces an extension to algebraic multigrid methods that removes the need to make such assumptions by utilizing an adaptive process. The principles which guide the adaptivity are highlighted, as well as their application to algebraic multigrid solution of certain symmetric positive-definite linear systems.

  1. Methods for cellobiosan utilization

    Energy Technology Data Exchange (ETDEWEB)

    Linger, Jeffrey; Beckham, Gregg T.

    2017-07-11

    Disclosed herein are enzymes useful for the degradation of cellobiosan in materials such a pyrolysis oils. Methods of degrading cellobiosan using enzymes or organisms expressing the same are also disclosed.

  2. Compressive Spectral Renormalization Method

    CERN Document Server

    Bayindir, Cihan

    2016-01-01

    In this paper a novel numerical scheme for finding the sparse self-localized states of a nonlinear system of equations with missing spectral data is introduced. As in the Petviashivili's and the spectral renormalization method, the governing equation is transformed into Fourier domain, but the iterations are performed for far fewer number of spectral components (M) than classical versions of the these methods with higher number of spectral components (N). After the converge criteria is achieved for M components, N component signal is reconstructed from M components by using the l1 minimization technique of the compressive sampling. This method can be named as compressive spectral renormalization (CSRM) method. The main advantage of the CSRM is that, it is capable of finding the sparse self-localized states of the evolution equation(s) with many spectral data missing.

  3. Iii. Sleep assessment methods.

    Science.gov (United States)

    Sadeh, Avi

    2015-03-01

    Sleep is a complex phenomenon that could be understood and assessed at many levels. Sleep could be described at the behavioral level (relative lack of movements and awareness and responsiveness) and at the brain level (based on EEG activity). Sleep could be characterized by its duration, by its distribution during the 24-hr day period, and by its quality (e.g., consolidated versus fragmented). Different methods have been developed to assess various aspects of sleep. This chapter covers the most established and common methods used to assess sleep in infants and children. These methods include polysomnography, videosomnography, actigraphy, direct observations, sleep diaries, and questionnaires. The advantages and disadvantages of each method are highlighted.

  4. Stochastic optimization methods

    CERN Document Server

    Marti, Kurt

    2005-01-01

    Optimization problems arising in practice involve random parameters. For the computation of robust optimal solutions, i.e., optimal solutions being insensitive with respect to random parameter variations, deterministic substitute problems are needed. Based on the distribution of the random data, and using decision theoretical concepts, optimization problems under stochastic uncertainty are converted into deterministic substitute problems. Due to the occurring probabilities and expectations, approximative solution techniques must be applied. Deterministic and stochastic approximation methods and their analytical properties are provided: Taylor expansion, regression and response surface methods, probability inequalities, First Order Reliability Methods, convex approximation/deterministic descent directions/efficient points, stochastic approximation methods, differentiation of probability and mean value functions. Convergence results of the resulting iterative solution procedures are given.

  5. Methods for euclidean geometry

    CERN Document Server

    Byer, Owen; Smeltzer, Deirdre L

    2010-01-01

    Euclidean plane geometry is one of the oldest and most beautiful topics in mathematics. Instead of carefully building geometries from axiom sets, this book uses a wealth of methods to solve problems in Euclidean geometry. Many of these methods arose where existing techniques proved inadequate. In several cases, the new ideas used in solving specific problems later developed into independent areas of mathematics. This book is primarily a geometry textbook, but studying geometry in this way will also develop students' appreciation of the subject and of mathematics as a whole. For instance, despite the fact that the analytic method has been part of mathematics for four centuries, it is rarely a tool a student considers using when faced with a geometry problem. Methods for Euclidean Geometry explores the application of a broad range of mathematical topics to the solution of Euclidean problems.

  6. Methods in Modern Biophysics

    CERN Document Server

    Nölting, Bengt

    2010-01-01

    Incorporating recent dramatic advances, this textbook presents a fresh and timely introduction to modern biophysical methods. An array of new, faster and higher-power biophysical methods now enables scientists to examine the mysteries of life at a molecular level. This innovative text surveys and explains the ten key biophysical methods, including those related to biophysical nanotechnology, scanning probe microscopy, X-ray crystallography, ion mobility spectrometry, mass spectrometry, proteomics, and protein folding and structure. Incorporating much information previously unavailable in tutorial form, Nölting employs worked examples and about 270 illustrations to fully detail the techniques and their underlying mechanisms. Methods in Modern Biophysics is written for advanced undergraduate and graduate students, postdocs, researchers, lecturers, and professors in biophysics, biochemistry and related fields. Special features in the 3rd edition: Introduces rapid partial protein ladder sequencing - an important...

  7. Concrete compositions and methods

    Science.gov (United States)

    Chen, Irvin; Lee, Patricia Tung; Patterson, Joshua

    2015-06-23

    Provided herein are compositions, methods, and systems for cementitious compositions containing calcium carbonate compositions and aggregate. The compositions find use in a variety of applications, including use in a variety of building materials and building applications.

  8. Monte Carlo methods

    OpenAIRE

    Bardenet, R.

    2012-01-01

    ISBN:978-2-7598-1032-1; International audience; Bayesian inference often requires integrating some function with respect to a posterior distribution. Monte Carlo methods are sampling algorithms that allow to compute these integrals numerically when they are not analytically tractable. We review here the basic principles and the most common Monte Carlo algorithms, among which rejection sampling, importance sampling and Monte Carlo Markov chain (MCMC) methods. We give intuition on the theoretic...

  9. Business forecasting methods

    OpenAIRE

    Skribans, V.

    2002-01-01

    The paper comprises three parts: description of the forecasting conception, classification of forecasting methods, and the general forecasting model. The first part deals with the definition of business forecasting, the second classifies and deals in more detail with the most frequently practiced forecasting methods and comes up with recommendations how to apply them in specific situations. The third part present the analysis of newly established forecasting model.

  10. Bidirectional beam propagation method

    Science.gov (United States)

    Kaczmarski, P.; Lagasse, P. E.

    1988-05-01

    A bidirectional extension of the beam propagation method (BPM) to optical waveguides with a longitudinal discontinuity is presented. The algorithm is verified by computing a reflection of the TE(0) mode from a semiconductor laser facet. The bidirectional BPM is applicable to other configurations such as totally reflecting waveguide mirrors, an abruption transition in a waveguide, or a waveguide with many discontinuities generating multiple reflections. The method can also be adapted to TM polarization.

  11. Method of treating depression

    Energy Technology Data Exchange (ETDEWEB)

    Henn, Fritz

    2013-04-09

    Methods for treatment of depression-related mood disorders in mammals, particularly humans are disclosed. The methods of the invention include administration of compounds capable of enhancing glutamate transporter activity in the brain of mammals suffering from depression. ATP-sensitive K.sup.+ channel openers and .beta.-lactam antibiotics are used to enhance glutamate transport and to treat depression-related mood disorders and depressive symptoms.

  12. Method of treating depression

    Science.gov (United States)

    Henn, Fritz [East Patchogue, NY

    2012-01-24

    Methods for treatment of depression-related mood disorders in mammals, particularly humans are disclosed. The methods of the invention include administration of compounds capable of enhancing glutamate transporter activity in the brain of mammals suffering from depression. ATP-sensitive K.sup.+ channel openers and .beta.-lactam antibiotics are used to enhance glutamate transport and to treat depression-related mood disorders and depressive symptoms.

  13. On Danish Legal Method

    DEFF Research Database (Denmark)

    Schaumburg-Müller, Sten

    2014-01-01

    On the basis on 1) the Danish legal writer A.S.Ørsted (1778-1860) and 2) an enquete among present day Danish legal scholars, the contribution deals with special traits in Danish legal method......On the basis on 1) the Danish legal writer A.S.Ørsted (1778-1860) and 2) an enquete among present day Danish legal scholars, the contribution deals with special traits in Danish legal method...

  14. Methods for polymer synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Simoneau, Christopher A.; Keefe, William D.; Conuel, Jeff R.

    2016-12-06

    The present invention provides methods for reducing induction periods in epoxide-CO.sub.2 copolymerizations. In certain embodiments, the methods include the step of contacting an epoxide with CO.sub.2 in the presence of two catalysts: an epoxide hydrolysis catalyst and an epoxide CO.sub.2 copolymerization catalyst. In another aspect, the invention provides catalyst compositions comprising a mixture of an epoxide hydrolysis catalyst and an epoxide CO.sub.2 copolymerization catalyst.

  15. Modern Methods in Marketing

    OpenAIRE

    Jandová, Pavlína

    2007-01-01

    Traditional marketing methods are losing their effectiveness and credibility. It has been worse and worse to communicate with customers, and marketers are therefore looking for new techniques and way how to appeal buyers. They turn to the use of modern marketing methods, which typical features are possibility of accurate targeting and low costs, and, also, the fact that they are still not considered being a classic promotion. In the theoretical part of the diploma thesis the alternative marke...

  16. Painful Bile Extraction Methods

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It was only in the past 20 years that countries in Asia began to search for an alternative to protect moon bears from being killed for their bile and other body parts. In the early 1980s, a new method of extracting bile from living bears was developed in North Korea. In 1983, Chinese scientists imported this technique from North Korea. According to the Animals Asia Foundation, the most original method of bile extraction is to embed a latex catheter, a narrow rubber

  17. [Unproven methods in oncology].

    Science.gov (United States)

    Jallut, O; Guex, P; Barrelet, L

    1984-09-08

    As in some other chronic diseases (rheumatism, multiple sclerosis, etc.), unproven methods of diagnosis and treatment have long been current in cancer. Since 1960 the American Cancer Society has published an abundant literature on these "unproven methods", which serves as a basis for a historical review: some substances (Krebiozen, Laetrile) have enjoyed tremendous if shortlived success. The present trend is back to nature and "mild medicine". The proponents of this so-called natural medicine are often disciples of a pseudoscientific religion using irrational arguments. Direct attacks on these erroneous theories and their public refutation fail to convince the adepts, who trust in these methods and are not amenable to a scientific approach. Study of their psychological motivations reveals that in fact they seek something more reassuring than plain medical explanation which is aware of its limits. They feel reassured by theories which often bear some resemblance to the old popular medicine. To protect patients against these dangerous methods and all the disillusionment they entail, the Swiss Society of Oncology and the Swiss Cancer League have decided to gather information and draw up a descriptive list of the commonest unproven methods in Switzerland (our File No. 2, "Total anti-cancer cure", is given as an example). The files are published in French, German and English and are available to physicians, nursing teams, and also patients who wish to have more objective information on these methods.

  18. Multicriteria identification sets method

    Science.gov (United States)

    Kamenev, G. K.

    2016-11-01

    A multicriteria identification and prediction method for mathematical models of simulation type in the case of several identification criteria (error functions) is proposed. The necessity of the multicriteria formulation arises, for example, when one needs to take into account errors of completely different origins (not reducible to a single characteristic) or when there is no information on the class of noise in the data to be analyzed. An identification sets method is described based on the approximation and visualization of the multidimensional graph of the identification error function and sets of suboptimal parameters. This method allows for additional advantages of the multicriteria approach, namely, the construction and visual analysis of the frontier and the effective identification set (frontier and the Pareto set for identification criteria), various representations of the sets of Pareto effective and subeffective parameter combinations, and the corresponding predictive trajectory tubes. The approximation is based on the deep holes method, which yields metric ɛ-coverings with nearly optimal properties, and on multiphase approximation methods for the Edgeworth-Pareto hull. The visualization relies on the approach of interactive decision maps. With the use of the multicriteria method, multiple-choice solutions of identification and prediction problems can be produced and justified by analyzing the stability of the optimal solution not only with respect to the parameters (robustness with respect to data) but also with respect to the chosen set of identification criteria (robustness with respect to the given collection of functionals).

  19. [Barrier methods of contraception].

    Science.gov (United States)

    Goldsmith, A; Edelman, D A

    1982-01-01

    Vaginal methods of contraception were the earliest types used and some references to them date back to antiquity. Most of the vaginal contraceptive agents identified by the ancient Greeks, Indians, Japanese, and Chinese have been found in modern laboratory tests to have spermicidal properties, but it is doubtful that the methods were fully reliable or were used by many people. During the 19th century the condom, vaginal spermicides, and diaphragm became available. The development of nonoxynol-9 and other nonirritating but effective spermicidal agents improved vaginal contraceptives greatly by the 1950s, but starting in the 1960s newer methods began to replace the vaginal methods. Interest in barrier methods has been reawakened somewhat by concern about the health effects of hormonal methods. At present all barrier methods leave something to be desired. Failure rates of 3-30% for barrier methods in general have been estimated, but the higher rates are believed due to incorrect or inconsistent use. Theoretical failure rates of condoms and diaphragms have been estimated at 3/100 women-years, but in actual use failure rates may reach 15 for condoms and 13 for diaphragms used with spermicides. Use-effectiveness rates are greatly influenced by motivation. For a variety of reasons, the acceptability of barrier methods is low, especially in developing countries. New developments in spermicidal agents include sperm inhibitors, which impede the fertilizing capacity of sperm rather than attempting a spermicidal effect; a number of such agents have been studied and have proven more effective in animal tests than conventional spermicides. Neosampoon, a new spermicidal foam, has attracted an increasing number of users, especially in developing countries. A new condom, made of thin polymers and containing a standard dose of nonoxynol-9, has been designed to dissolve in the vaginal fluid. Further studies are needed of its acceptability, efficacy, and side effects before it becomes

  20. The ICARE Method

    Science.gov (United States)

    Henke, Luke

    2010-01-01

    The ICARE method is a flexible, widely applicable method for systems engineers to solve problems and resolve issues in a complete and comprehensive manner. The method can be tailored by diverse users for direct application to their function (e.g. system integrators, design engineers, technical discipline leads, analysts, etc.). The clever acronym, ICARE, instills the attitude of accountability, safety, technical rigor and engagement in the problem resolution: Identify, Communicate, Assess, Report, Execute (ICARE). This method was developed through observation of Space Shuttle Propulsion Systems Engineering and Integration (PSE&I) office personnel approach in an attempt to succinctly describe the actions of an effective systems engineer. Additionally it evolved from an effort to make a broadly-defined checklist for a PSE&I worker to perform their responsibilities in an iterative and recursive manner. The National Aeronautics and Space Administration (NASA) Systems Engineering Handbook states, engineering of NASA systems requires a systematic and disciplined set of processes that are applied recursively and iteratively for the design, development, operation, maintenance, and closeout of systems throughout the life cycle of the programs and projects. ICARE is a method that can be applied within the boundaries and requirements of NASA s systems engineering set of processes to provide an elevated sense of duty and responsibility to crew and vehicle safety. The importance of a disciplined set of processes and a safety-conscious mindset increases with the complexity of the system. Moreover, the larger the system and the larger the workforce, the more important it is to encourage the usage of the ICARE method as widely as possible. According to the NASA Systems Engineering Handbook, elements of a system can include people, hardware, software, facilities, policies and documents; all things required to produce system-level results, qualities, properties, characteristics

  1. VALUATION METHODS- LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    Dorisz Talas

    2015-07-01

    Full Text Available This paper is a theoretical overview of the often used valuation methods with the help of which the value of a firm or its equity is calculated. Many experts (including Aswath Damodaran, Guochang Zhang and CA Hozefa Natalwala classify the methods. The basic models are based on discounted cash flows. The main method uses the free cash flow for valuation, but there are some newer methods that reveal and correct the weaknesses of the traditional models. The valuation of flexibility of management can be conducted mainly with real options. This paper briefly describes the essence of the Dividend Discount Model, the Free Cash Flow Model, the benefit from using real options and the Residual Income Model. There are a few words about the Adjusted Present Value approach as well. Different models uses different premises, and an overall truth is that if the required premises are real and correct, the value will be appropriately accurate. Another important condition is that experts, analysts should choose between the models on the basis of the purpose of valuation. Thus there are no good or bad methods, only methods that fit different goals and aims. The main task is to define exactly the purpose, then to find the most appropriate valuation technique. All the methods originates from the premise that the value of an asset is the present value of its future cash flows. According to the different points of view of different techniques the resulted values can be also differed from each other. Valuation models and techniques should be adapted to the rapidly changing world, but the basic statements remain the same. On the other hand there is a need for more accurate models in order to help investors get as many information as they could. Today information is one of the most important resources and financial models should keep up with this trend.

  2. Application of gas chromatography–(triple quadrupole) massspectrometry with atmospheric pressure chemical ionization for thedetermination of multiclass pesticides in fruits and vegetables

    NARCIS (Netherlands)

    Cherta, L.; Portoles, T.; Beltran, J.; Pitarch, E.; Mol, J.G.J.; Hernandez, F.

    2013-01-01

    A multi-residue method for the determination of 142 pesticide residues in fruits and vegetables has been developed using a new atmospheric pressure chemical ionization (APCI) source for coupling gas chromatography (GC) to tandem mass spectrometry (MS). Selected reaction monitoring (SRM) mode has bee

  3. Analysis of Turf Fungicides in Snow Melt Runoff by LC/MS

    Science.gov (United States)

    Fungicides are applied on turf grass, in autumn, to control snow mold in the north-central United States. Fungicides of varying chemical classes have been detected in snow melt runoff from turf. A multi-residue method for simultaneous sample extraction and analysis is needed to process a large quant...

  4. Molecular methods for biofilms

    KAUST Repository

    Ferrera, Isabel

    2014-08-30

    This chapter deals with both classical and modern molecular methods that can be useful for the identification of microorganisms, elucidation and comparison of microbial communities, and investigation of their diversity and functions. The most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples; these are discussed in the first part. The second part provides an overview over DNA polymerase chain reaction (PCR) amplification and DNA sequencing methods. Protocols and analysis software as well as potential pitfalls associated with application of these methods are discussed. Community fingerprinting analyses that can be used to compare multiple microbial communities are discussed in the third part. This part focuses on Denaturing Gradient Gel Electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP) and Automated rRNA Intergenic Spacer Analysis (ARISA) methods. In addition, classical and next-generation metagenomics methods are presented. These are limited to bacterial artificial chromosome and Fosmid libraries and Sanger and next-generation 454 sequencing, as these methods are currently the most frequently used in research. Isolation of nucleic acids: This chapter discusses, the most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples. Nucleic acid isolation methods generally include three steps: cell lysis, removal of unwanted substances, and a final step of DNA purification and recovery. The first critical step is the cell lysis, which can be achieved by enzymatic or mechanical procedures. Removal of proteins, polysaccharides and other unwanted substances is likewise important to avoid their interference in subsequent analyses. Phenol-chloroform-isoamyl alcohol is commonly used to recover DNA, since it separates nucleic acids into an aqueous phase and precipitates proteins and

  5. New oligosaccharyltransferase assay method.

    Science.gov (United States)

    Kohda, Daisuke; Yamada, Masaki; Igura, Mayumi; Kamishikiryo, Jun; Maenaka, Katsumi

    2007-11-01

    We developed a new in vitro assay for oligosaccharyltransferase (OST), which catalyzes the transfer of preassembled oligosaccharides on lipid carriers onto asparagine residues in polypeptide chains. The asparagine residues reside in the sequon, Asn-X-Thr/Ser, where X can be any amino acid residue except Pro. We demonstrate the potency of our assay using the OST from yeast. In our method, polyacrylamide gel electrophoresis is used to separate the glycopeptide products from the peptide substrates. The substrate peptide is fluorescently labeled and the formation of glycopeptides is analyzed by fluorescence gel imaging. Two in vitro OST assay methods are now widely used, but both the methods depend on previous knowledge of the oligosaccharide moiety: One method uses lectin binding as the separation mechanism and the other method uses biosynthetically or chemoenzymatically synthesized lipid-linked oligosaccharides as donors. N-linked protein glycosylation is found in all three domains of life, but little is known about the N-glycosylation in Archaea. Thus, our new assay, which does not require a priori knowledge of the oligosaccharides, will be useful in such cases. Indeed, we have detected the OST activity in the membrane fraction from a hyperthermophilic archaeon, Pyrococcus furiosus.

  6. Methods for Neutron Spectrometry

    Science.gov (United States)

    Brockhouse, Bertram N.

    1961-01-09

    The appropriate theories and the general philosophy of methods of measurement and treatment of data neutron spectrometry are discussed. Methods of analysis of results for liquids using the Van Hove formulation, and for crystals using the Born-von Karman theory, are reviewed. The most useful of the available methods of measurement are considered to be the crystal spectrometer methods and the pulsed monoenergetic beam/time-of-flight method. Pulsed-beam spectrometers have the advantage of higher counting rates than crystal spectrometers, especially in view of the fact that simultaneous measurements in several counters at different angles of scattering are possible in pulsed-beam spectrometers. The crystal spectrometer permits several valuable new types of specialized experiments to be performed, especially energy distribution measurements at constant momentum transfer. The Chalk River triple-axis crystal-spectrometer is discussed, with reference to its use in making the specialized experiments. The Chalk River rotating crystal (pulsed-beam) spectrometer is described, and a comparison of this type instrument with other pulsed-beam spectrometers is made. A partial outline of the theory of operation of rotating-crystal spectrometers is presented. The use of quartz-crystal filters for fast neutron elimination and for order elimination is discussed. (auth)

  7. The lod score method.

    Science.gov (United States)

    Rice, J P; Saccone, N L; Corbett, J

    2001-01-01

    The lod score method originated in a seminal article by Newton Morton in 1955. The method is broadly concerned with issues of power and the posterior probability of linkage, ensuring that a reported linkage has a high probability of being a true linkage. In addition, the method is sequential, so that pedigrees or lod curves may be combined from published reports to pool data for analysis. This approach has been remarkably successful for 50 years in identifying disease genes for Mendelian disorders. After discussing these issues, we consider the situation for complex disorders, where the maximum lod score (MLS) statistic shares some of the advantages of the traditional lod score approach but is limited by unknown power and the lack of sharing of the primary data needed to optimally combine analytic results. We may still learn from the lod score method as we explore new methods in molecular biology and genetic analysis to utilize the complete human DNA sequence and the cataloging of all human genes.

  8. Fashion, Mediations & Method Assemblages

    DEFF Research Database (Denmark)

    Sommerlund, Julie; Jespersen, Astrid Pernille

    , respectively. The paper thus takes on aesthetics and the social in a manner closely related to a core argument of STS - namely that the scientific fact, and the social processes of constructing, distributing, and using that fact, are co-constructed (Callon, 1986; Latour, 1993). The paper thus contributes......, it is an important ambition of this paper to go into a methodological discussion of how "that which effectively happens" can be approached. To this end, the paper will combine Hennion's term of the "mediator" with John Laws methodological term of "method assemblages". Method assemblages is a suggested as a way...... of handling multiple, fluid realities with multiple, fluid methods. Empirically, the paper works with mediation in fashion - that is efforts the active shaping of relations between producer and consumer through communication, marketing and PR. Fashion mediation is by no means simple, but organise complex...

  9. Cytoskeleton - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-03-01

    Full Text Available Cytoskeleton - Methods and ProtocolsSecond edition, 2010; Ray H. Gavin (Ed; Springer Protocols methods in molecular biology, vol. 586 Humana press, Totowa, New Jersey (USA; Pages: 390; €95.44; ISBN: 978-1-60761-375-6Ray H. Gavin, from the Brooklyn College of The City University of New York, Brooklyn, NY, USA, wrote a few line as preface of this book. This is quite understandable: there is not a great need of words when there are facts that sustain and favour the dissemination of a cultural product. This is the case of the second edition of Cytoskeleton - Methods and Protocols, which appears just ten years after the first edition...

  10. Geostatistical Methods in R

    Directory of Open Access Journals (Sweden)

    Adéla Volfová

    2012-10-01

    Full Text Available Geostatistics is a scientific field which provides methods for processing spatial data.  In our project, geostatistics is used as a tool for describing spatial continuity and making predictions of some natural phenomena. An open source statistical project called R is used for all calculations. Listeners will be provided with a brief introduction to R and its geostatistical packages and basic principles of kriging and cokriging methods. Heavy mathematical background is omitted due to its complexity. In the second part of the presentation, several examples are shown of how to make a prediction in the whole area of interest where observations were made in just a few points. Results of these methods are compared.

  11. Robust iterative methods

    Energy Technology Data Exchange (ETDEWEB)

    Saadd, Y.

    1994-12-31

    In spite of the tremendous progress achieved in recent years in the general area of iterative solution techniques, there are still a few obstacles to the acceptance of iterative methods in a number of applications. These applications give rise to very indefinite or highly ill-conditioned non Hermitian matrices. Trying to solve these systems with the simple-minded standard preconditioned Krylov subspace methods can be a frustrating experience. With the mathematical and physical models becoming more sophisticated, the typical linear systems which we encounter today are far more difficult to solve than those of just a few years ago. This trend is likely to accentuate. This workshop will discuss (1) these applications and the types of problems that they give rise to; and (2) recent progress in solving these problems with iterative methods. The workshop will end with a hopefully stimulating panel discussion with the speakers.

  12. Energy methods in dynamics

    CERN Document Server

    Le, Khanh Chau

    2012-01-01

    The above examples should make clear the necessity of understanding the mechanism of vibrations and waves in order to control them in an optimal way. However vibrations and waves are governed by differential equations which require, as a rule, rather complicated mathematical methods for their analysis. The aim of this textbook is to help students acquire both a good grasp of the first principles from which the governing equations can be derived, and the adequate mathematical methods for their solving. Its distinctive features, as seen from the title, lie in the systematic and intensive use of Hamilton's variational principle and its generalizations for deriving the governing equations of conservative and dissipative mechanical systems, and also in providing the direct variational-asymptotic analysis, whenever available, of the energy and dissipation for the solution of these equations. It will be demonstrated that many well-known methods in dynamics like those of Lindstedt-Poincare, Bogoliubov-Mitropolsky, Ko...

  13. Energy methods in dynamics

    CERN Document Server

    Le, Khanh Chau

    2014-01-01

    Energy Methods in Dynamics is a textbook based on the lectures given by the first author at Ruhr University Bochum, Germany. Its aim is to help students acquire both a good grasp of the first principles from which the governing equations can be derived, and the adequate mathematical methods for their solving. Its distinctive features, as seen from the title, lie in the systematic and intensive use of Hamilton's variational principle and its generalizations for deriving the governing equations of conservative and dissipative mechanical systems, and also in providing the direct variational-asymptotic analysis, whenever available, of the energy and dissipation for the solution of these equations. It demonstrates that many well-known methods in dynamics like those of Lindstedt-Poincare, Bogoliubov-Mitropolsky, Kolmogorov-Arnold-Moser (KAM), Wentzel–Kramers–Brillouin (WKB),  and Whitham are derivable from this variational-asymptotic analysis.   This second edition includes the solutions to all exercises as w...

  14. Sampling system and method

    Energy Technology Data Exchange (ETDEWEB)

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2017-03-07

    In one embodiment, the present disclosure provides an apparatus and method for supporting a tubing bundle during installation or removal. The apparatus includes a clamp for securing the tubing bundle to an external wireline. In various examples, the clamp is external to the tubing bundle or integral with the tubing bundle. According to one method, a tubing bundle and wireline are deployed together and the tubing bundle periodically secured to the wireline using a clamp. In another embodiment, the present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit. In a specific example, one or more clamps are used to connect the first and/or second conduits to an external wireline.

  15. Grid generation methods

    CERN Document Server

    Liseikin, Vladimir D

    2017-01-01

    This new edition provides a description of current developments relating to grid methods, grid codes, and their applications to actual problems. Grid generation methods are indispensable for the numerical solution of differential equations. Adaptive grid-mapping techniques, in particular, are the main focus and represent a promising tool to deal with systems with singularities. This 3rd edition includes three new chapters on numerical implementations (10), control of grid properties (11), and applications to mechanical, fluid, and plasma related problems (13). Also the other chapters have been updated including new topics, such as curvatures of discrete surfaces (3). Concise descriptions of hybrid mesh generation, drag and sweeping methods, parallel algorithms for mesh generation have been included too. This new edition addresses a broad range of readers: students, researchers, and practitioners in applied mathematics, mechanics, engineering, physics and other areas of applications.

  16. Method of treating wells

    Energy Technology Data Exchange (ETDEWEB)

    Knox, J.A.; Lasater, R.M.

    1966-11-22

    Chemical compositions and methods are provided for treating underground formations to render their surfaces water-repellent or preferentially oil-wettable. Previous methods have provided only temporary water-repellency because they do not actually act chemically with the reservoir rock. This improvement is obtained by using a treating agent which does not form a precipitate upon hydrolysis with water, such as a liquid organo-halogen- silane or its ester. A water-soluble anhydrous solvent which is nonreactive with the silane is used as a carrier. This method may be used for treating non-oil-bearing aquifers for increasing the flow rate of water, such as in water supply wells, or in water input rate, such as in water disposal wells. (10 claims)

  17. Methods for RNA Analysis

    DEFF Research Database (Denmark)

    Olivarius, Signe

    of the transcriptome, 5’ end capture of RNA is combined with next-generation sequencing for high-throughput quantitative assessment of transcription start sites by two different methods. The methods presented here allow for functional investigation of coding as well as noncoding RNA and contribute to future......While increasing evidence appoints diverse types of RNA as key players in the regulatory networks underlying cellular differentiation and metabolism, the potential functions of thousands of conserved RNA structures encoded in mammalian genomes remain to be determined. Since the functions of most...... RNAs rely on interactions with proteins, the establishment of protein-binding profiles is essential for the characterization of RNAs. Aiming to facilitate RNA analysis, this thesis introduces proteomics- as well as transcriptomics-based methods for the functional characterization of RNA. First, RNA...

  18. Model Correction Factor Method

    DEFF Research Database (Denmark)

    Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes

    1997-01-01

    The model correction factor method is proposed as an alternative to traditional polynomial based response surface techniques in structural reliability considering a computationally time consuming limit state procedure as a 'black box'. The class of polynomial functions is replaced by a limit...... statebased on an idealized mechanical model to be adapted to the original limit state by the model correction factor. Reliable approximations are obtained by iterative use of gradient information on the original limit state function analogously to previous response surface approaches. However, the strength...... of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods...

  19. Splines and variational methods

    CERN Document Server

    Prenter, P M

    2008-01-01

    One of the clearest available introductions to variational methods, this text requires only a minimal background in calculus and linear algebra. Its self-contained treatment explains the application of theoretic notions to the kinds of physical problems that engineers regularly encounter. The text's first half concerns approximation theoretic notions, exploring the theory and computation of one- and two-dimensional polynomial and other spline functions. Later chapters examine variational methods in the solution of operator equations, focusing on boundary value problems in one and two dimension

  20. Nonparametric statistical methods

    CERN Document Server

    Hollander, Myles; Chicken, Eric

    2013-01-01

    Praise for the Second Edition"This book should be an essential part of the personal library of every practicing statistician."-Technometrics  Thoroughly revised and updated, the new edition of Nonparametric Statistical Methods includes additional modern topics and procedures, more practical data sets, and new problems from real-life situations. The book continues to emphasize the importance of nonparametric methods as a significant branch of modern statistics and equips readers with the conceptual and technical skills necessary to select and apply the appropriate procedures for any given sit

  1. METHOD OF ROLLING URANIUM

    Science.gov (United States)

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  2. Electrorheological fluids and methods

    Energy Technology Data Exchange (ETDEWEB)

    Green, Peter F.; McIntyre, Ernest C.

    2015-06-02

    Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.

  3. Tautomerism methods and theories

    CERN Document Server

    Antonov, Liudmil

    2013-01-01

    Covering the gap between basic textbooks and over-specialized scientific publications, this is the first reference available to describe this interdisciplinary topic for PhD students and scientists starting in the field. The result is an introductory description providing suitable practical examples of the basic methods used to study tautomeric processes, as well as the theories describing the tautomerism and proton transfer phenomena. It also includes different spectroscopic methods for examining tautomerism, such as UV-VIs, time-resolved fluorescence spectroscopy, and NMR spectrosc

  4. Unorthodox theoretical methods

    Energy Technology Data Exchange (ETDEWEB)

    Nedd, Sean [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    The use of the ReaxFF force field to correlate with NMR mobilities of amine catalytic substituents on a mesoporous silica nanosphere surface is considered. The interfacing of the ReaxFF force field within the Surface Integrated Molecular Orbital/Molecular Mechanics (SIMOMM) method, in order to replicate earlier SIMOMM published data and to compare with the ReaxFF data, is discussed. The development of a new correlation consistent Composite Approach (ccCA) is presented, which incorporates the completely renormalized coupled cluster method with singles, doubles and non-iterative triples corrections towards the determination of heats of formations and reaction pathways which contain biradical species.

  5. Exploring Monte Carlo methods

    CERN Document Server

    Dunn, William L

    2012-01-01

    Exploring Monte Carlo Methods is a basic text that describes the numerical methods that have come to be known as "Monte Carlo." The book treats the subject generically through the first eight chapters and, thus, should be of use to anyone who wants to learn to use Monte Carlo. The next two chapters focus on applications in nuclear engineering, which are illustrative of uses in other fields. Five appendices are included, which provide useful information on probability distributions, general-purpose Monte Carlo codes for radiation transport, and other matters. The famous "Buffon's needle proble

  6. Method through motion

    DEFF Research Database (Denmark)

    Steijn, Arthur

    2016-01-01

    Contemporary scenography often consists of video-projected motion graphics. The field is lacking in academic methods and rigour: descriptions and models relevant for the creation as well as in the analysis of existing works. In order to understand the phenomenon of motion graphics in a scenographic...... construction as a support to working systematically practice-led research project. The design model is being developed through design laboratories and workshops with students and professionals who provide feedback that lead to incremental improvements. Working with this model construction-as-method reveals...

  7. Methods of visualizing graphs

    Science.gov (United States)

    Wong, Pak C.; Mackey, Patrick S.; Perrine, Kenneth A.; Foote, Harlan P.; Thomas, James J.

    2008-12-23

    Methods for visualizing a graph by automatically drawing elements of the graph as labels are disclosed. In one embodiment, the method comprises receiving node information and edge information from an input device and/or communication interface, constructing a graph layout based at least in part on that information, wherein the edges are automatically drawn as labels, and displaying the graph on a display device according to the graph layout. In some embodiments, the nodes are automatically drawn as labels instead of, or in addition to, the label-edges.

  8. Methods of Multivariate Analysis

    CERN Document Server

    Rencher, Alvin C

    2012-01-01

    Praise for the Second Edition "This book is a systematic, well-written, well-organized text on multivariate analysis packed with intuition and insight . . . There is much practical wisdom in this book that is hard to find elsewhere."-IIE Transactions Filled with new and timely content, Methods of Multivariate Analysis, Third Edition provides examples and exercises based on more than sixty real data sets from a wide variety of scientific fields. It takes a "methods" approach to the subject, placing an emphasis on how students and practitioners can employ multivariate analysis in real-life sit

  9. Methods for pretreating biomass

    Science.gov (United States)

    Balan, Venkatesh; Dale, Bruce E; Chundawat, Shishir; Sousa, Leonardo

    2017-05-09

    A method for pretreating biomass is provided, which includes, in a reactor, allowing gaseous ammonia to condense on the biomass and react with water present in the biomass to produce pretreated biomass, wherein reactivity of polysaccharides in the biomass is increased during subsequent biological conversion as compared to the reactivity of polysaccharides in biomass which has not been pretreated. A method for pretreating biomass with a liquid ammonia and recovering the liquid ammonia is also provided. Related systems which include a biochemical or biofuel production facility are also disclosed.

  10. Apoptosis - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-03-01

    Full Text Available Apoptosis - Methods and ProtocolsSecond edition, 2009; Peter Erhardt and Ambrus Toth (Eds; Springer Protocols - Methods in molecular biology, vol. 559; Humana press, Totowa, New Jersey (USA; Pages: 400; €88.35; ISBN: 978-1-60327-016-8The editors rightly begin the preface telling us that: “The ability to detect and quantify apoptosis, to understand its biochemistry and to identify its regulatory genes and proteins is crucial to biomedical research”. Nowadays this is a grounding concept of biology and medicine. What is particularly remarkable...

  11. Practical methods of optimization

    CERN Document Server

    Fletcher, R

    2013-01-01

    Fully describes optimization methods that are currently most valuable in solving real-life problems. Since optimization has applications in almost every branch of science and technology, the text emphasizes their practical aspects in conjunction with the heuristics useful in making them perform more reliably and efficiently. To this end, it presents comparative numerical studies to give readers a feel for possibile applications and to illustrate the problems in assessing evidence. Also provides theoretical background which provides insights into how methods are derived. This edition offers rev

  12. Essential numerical computer methods

    CERN Document Server

    Johnson, Michael L

    2010-01-01

    The use of computers and computational methods has become ubiquitous in biological and biomedical research. During the last 2 decades most basic algorithms have not changed, but what has is the huge increase in computer speed and ease of use, along with the corresponding orders of magnitude decrease in cost. A general perception exists that the only applications of computers and computer methods in biological and biomedical research are either basic statistical analysis or the searching of DNA sequence data bases. While these are important applications they only scratch the surface

  13. Analogue computing methods

    CERN Document Server

    Welbourne, D

    1965-01-01

    Analogue Computing Methods presents the field of analogue computation and simulation in a compact and convenient form, providing an outline of models and analogues that have been produced to solve physical problems for the engineer and how to use and program the electronic analogue computer. This book consists of six chapters. The first chapter provides an introduction to analogue computation and discusses certain mathematical techniques. The electronic equipment of an analogue computer is covered in Chapter 2, while its use to solve simple problems, including the method of scaling is elaborat

  14. Making Methods Choices.

    Science.gov (United States)

    Patton, Michael Quinn

    1980-01-01

    Methodological paradigms in evaluation research are discussed. This article is a response to the attacks on paradigmatic perspectives made by Reichardt and Cook in the opening chapter of their edited book, "Qualitative and Quantitative Methods in Evaluation Research." (Author/GK)

  15. communication method and apparatus

    DEFF Research Database (Denmark)

    2005-01-01

    The present invention relates to a non-lingual communication method and apparatus, wherein a physical or physiological signal consciously created by a first subject (1) is detected and converted into a transmitted output signal presented to a second subject (7) in order to communicate information...

  16. METHOD OF CENTRIFUGE OPERATION

    Science.gov (United States)

    Cohen, K.

    1960-05-10

    A method of isotope separation is described in which two streams are flowed axially of, and countercurrently through, a cylindrical centrifuge bowl. Under the influence of a centrifugal field, the light fraction is concentrated in a stream flowing through the central portion of the bowl, whereas the heavy fraction is concentrated in a stream at the periphery thereof.

  17. Ferrari's Method and Technology

    Science.gov (United States)

    Althoen, Steve

    2005-01-01

    Some tips that combine knowledge of mathematics history and technology for adapting Ferrar's method to factor quintics with a TI-83 graphing calculator are presented. A demonstration on the use of the root finder and regression capabilities of the graphing calculator are presented, so that the tips can be easily adapted for any graphing calculator…

  18. The Mnemonic Keyword Method.

    Science.gov (United States)

    Pressley, Michael; And Others

    1982-01-01

    Available experimental evidence is reviewed concerning the keyword method, a two-stage procedure for remembering materials having an associative component. The review examines subjects' memory for definitions, given vocabulary words; subjects' learning of other aspects of vocabulary, given definitions; group-administered keyword studies; and…

  19. Modern Reduction Methods

    CERN Document Server

    Andersson, Pher G

    2008-01-01

    With its comprehensive overview of modern reduction methods, this book features high quality contributions allowing readers to find reliable solutions quickly and easily. The monograph treats the reduction of carbonyles, alkenes, imines and alkynes, as well as reductive aminations and cross and heck couplings, before finishing off with sections on kinetic resolutions and hydrogenolysis. An indispensable lab companion for every chemist.

  20. Analysis of numerical methods

    CERN Document Server

    Isaacson, Eugene

    1994-01-01

    This excellent text for advanced undergraduates and graduate students covers norms, numerical solution of linear systems and matrix factoring, iterative solutions of nonlinear equations, eigenvalues and eigenvectors, polynomial approximation, and other topics. It offers a careful analysis and stresses techniques for developing new methods, plus many examples and problems. 1966 edition.

  1. The Method of "Currere."

    Science.gov (United States)

    Pinar, William Frederick

    In this presentation the author paints a conceptual portrait of his evolving relationships to his formal studies and thereby describes a method by which educators can reconceptualize the meaning of curriculum. By taking oneself and one's existential experience as a data source and using the psychoanalytical technique of free association, one can…

  2. Universal Image Steganalytic Method

    Directory of Open Access Journals (Sweden)

    V. Banoci

    2014-12-01

    Full Text Available In the paper we introduce a new universal steganalytic method in JPEG file format that is detecting well-known and also newly developed steganographic methods. The steganalytic model is trained by MHF-DZ steganographic algorithm previously designed by the same authors. The calibration technique with the Feature Based Steganalysis (FBS was employed in order to identify statistical changes caused by embedding a secret data into original image. The steganalyzer concept utilizes Support Vector Machine (SVM classification for training a model that is later used by the same steganalyzer in order to identify between a clean (cover and steganographic image. The aim of the paper was to analyze the variety in accuracy of detection results (ACR while detecting testing steganographic algorithms as F5, Outguess, Model Based Steganography without deblocking, JP Hide and Seek which represent the generally used steganographic tools. The comparison of four feature vectors with different lengths FBS (22, FBS (66 FBS(274 and FBS(285 shows promising results of proposed universal steganalytic method comparing to binary methods.

  3. Methods Evolved by Observation

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    Montessori's idea of the child's nature and the teacher's perceptiveness begins with amazing simplicity, and when she speaks of "methods evolved," she is unveiling a methodological system for observation. She begins with the early childhood explosion into writing, which is a familiar child phenomenon that Montessori has written about…

  4. Method card design dimensions

    DEFF Research Database (Denmark)

    Wölfel, Christiane; Merritt, T.

    2013-01-01

    . The card-based tools are explained in terms of five design dimensions including the intended purpose and scope of use, duration of use, methodology, customization, and formal/material qualities. Our analysis suggests three design patterns or archetypes for existing card-based design method tools...

  5. Statistical methods in astronomy

    OpenAIRE

    Long, James P.; de Souza, Rafael S.

    2017-01-01

    We present a review of data types and statistical methods often encountered in astronomy. The aim is to provide an introduction to statistical applications in astronomy for statisticians and computer scientists. We highlight the complex, often hierarchical, nature of many astronomy inference problems and advocate for cross-disciplinary collaborations to address these challenges.

  6. Methods of materiality

    DEFF Research Database (Denmark)

    Aagaard, Jesper; Matthiesen, Noomi

    2016-01-01

    , and the method of participant observation is suggested as a viable approach to achieve this end. An empirical example of how authority is produced in a parent-teacher conference, not only through language but also through material objects and embodied being, is then presented. The article concludes by suggesting...

  7. Research Methods in Sociolinguistics

    Science.gov (United States)

    Hernández-Campoy, Juan Manuel

    2014-01-01

    The development of Sociolinguistics has been qualitatively and quantitatively outstanding within Linguistic Science since its beginning in the 1950s, with a steady growth in both theoretical and methodological developments as well as in its interdisciplinary directions within the spectrum of language and society. Field methods in sociolinguistic…

  8. Ergonomics research methods

    Science.gov (United States)

    Uspenskiy, S. I.; Yermakova, S. V.; Chaynova, L. D.; Mitkin, A. A.; Gushcheva, T. M.; Strelkov, Y. K.; Tsvetkova, N. F.

    1973-01-01

    Various factors used in ergonomic research are given. They are: (1) anthrometric measurement, (2) polyeffector method of assessing the functional state of man, (3) galvanic skin reaction, (4) pneumography, (5) electromyography, (6) electrooculography, and (7) tachestoscopy. A brief summary is given of each factor and includes instrumentation and results.

  9. A method for sintering

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention provides a method for sintering, comprising in the following order the steps of: providing a body in the green state or in the pre-sintered state on a support; providing a load on at least one spacer on the support such that the load is located above said body in the green...

  10. Biomass treatment method

    Science.gov (United States)

    Friend, Julie; Elander, Richard T.; Tucker, III; Melvin P.; Lyons, Robert C.

    2010-10-26

    A method for treating biomass was developed that uses an apparatus which moves a biomass and dilute aqueous ammonia mixture through reaction chambers without compaction. The apparatus moves the biomass using a non-compressing piston. The resulting treated biomass is saccharified to produce fermentable sugars.

  11. Truth and Methods.

    Science.gov (United States)

    Dasenbrock, Reed Way

    1995-01-01

    Examines literary theory's displacing of "method" in the New Historicist criticism. Argues that Stephen Greenblatt and Lee Paterson imply that no objective historical truth is possible and as a result do not give methodology its due weight in their criticism. Questions the theory of "truth" advanced in this vein of literary…

  12. Software specification methods

    CERN Document Server

    Habrias, Henri

    2010-01-01

    This title provides a clear overview of the main methods, and has a practical focus that allows the reader to apply their knowledge to real-life situations. The following are just some of the techniques covered: UML, Z, TLA+, SAZ, B, OMT, VHDL, Estelle, SDL and LOTOS.

  13. Progress in variational methods

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The International Conference on Variational Methods (ICVAM) was held from May 20th to 26th in 2007 at the Chern Institute of Mathematics, Nankai University, Tianjin, China. Twenty eight invited speakers from ten countries and areas worldwide gave their lectures at the conference.

  14. Heart imaging method

    Science.gov (United States)

    Collins, H. Dale; Gribble, R. Parks; Busse, Lawrence J.

    1991-01-01

    A method for providing an image of the human heart's electrical system derives time-of-flight data from an array of EKG electrodes and this data is transformed into phase information. The phase information, treated as a hologram, is reconstructed to provide an image in one or two dimensions of the electrical system of the functioning heart.

  15. Quality of regularization methods

    NARCIS (Netherlands)

    Bouwman, J.

    1998-01-01

    The solution of ill-posed problems is non-trivial in the sense that frequently applied methods like least-squares fail. The ill-posedness of the problem is refiected by very small changes in the input data which may result in very large changes in the output data. Hence, some sort of stabilization

  16. Methods of materiality

    DEFF Research Database (Denmark)

    Aagaard, Jesper; Matthiesen, Noomi

    2016-01-01

    , and the method of participant observation is suggested as a viable approach to achieve this end. An empirical example of how authority is produced in a parent-teacher conference, not only through language but also through material objects and embodied being, is then presented. The article concludes by suggesting...

  17. Proven Weight Loss Methods

    Science.gov (United States)

    Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. ... limiting calories) usually isn’t enough to cause weight loss. But exercise plays an important part in helping ...

  18. Research Methods in Sociolinguistics

    Science.gov (United States)

    Hernández-Campoy, Juan Manuel

    2014-01-01

    The development of Sociolinguistics has been qualitatively and quantitatively outstanding within Linguistic Science since its beginning in the 1950s, with a steady growth in both theoretical and methodological developments as well as in its interdisciplinary directions within the spectrum of language and society. Field methods in sociolinguistic…

  19. Sampling system and method

    Science.gov (United States)

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2013-04-16

    The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

  20. Photothermal methods in medicine

    Science.gov (United States)

    Murphy, John C.

    2000-10-01

    Photothermal imaging and spectroscopy are being applied to a variety of medical problems for diagnosis and therapy. This paper reviews some aspects of this field including the opportunities presented by non-optical sources and by use of detection methods targeted to the application.

  1. Quality of regularization methods

    NARCIS (Netherlands)

    Bouwman, J.

    1998-01-01

    The solution of ill-posed problems is non-trivial in the sense that frequently applied methods like least-squares fail. The ill-posedness of the problem is refiected by very small changes in the input data which may result in very large changes in the output data. Hence, some sort of stabilization o

  2. Project execution methods

    National Research Council Canada - National Science Library

    John C Pfeiffer

    2004-01-01

      In the design/build (D/B) method of implementing plant construction projects, the owner contracts with the engineer/contractor or contractor/engineer company or team-depending upon who takes the lead in the project to develop...

  3. The Effective Equation Method

    Science.gov (United States)

    Kuksin, Sergei; Maiocchi, Alberto

    In this chapter we present a general method of constructing the effective equation which describes the behavior of small-amplitude solutions for a nonlinear PDE in finite volume, provided that the linear part of the equation is a hamiltonian system with a pure imaginary discrete spectrum. The effective equation is obtained by retaining only the resonant terms of the nonlinearity (which may be hamiltonian, or may be not); the assertion that it describes the limiting behavior of small-amplitude solutions is a rigorous mathematical theorem. In particular, the method applies to the three- and four-wave systems. We demonstrate that different possible types of energy transport are covered by this method, depending on whether the set of resonances splits into finite clusters (this happens, e.g. in case of the Charney-Hasegawa-Mima equation), or is connected (this happens, e.g. in the case of the NLS equation if the space-dimension is at least two). For equations of the first type the energy transition to high frequencies does not hold, while for equations of the second type it may take place. Our method applies to various weakly nonlinear wave systems, appearing in plasma, meteorology and oceanography.

  4. Teaching Materials and Methods.

    Science.gov (United States)

    Physiologist, 1987

    1987-01-01

    Contains abstracts of presented papers which deal with teaching materials and methods in physiology. Includes papers on preconceptual notions in physiology, somatosensory activity recorded in the dorsal root ganglion of the bull frog, and the use of the Apple Macintosh microcomputer in teaching human anatomy and physiology. (TW)

  5. Convergence of Arnoldi method

    Energy Technology Data Exchange (ETDEWEB)

    Nevanlinna, O. [Helsinki Univ. of Technology, Espoo (Finland)

    1994-12-31

    This note summarizes some results on (a monitored version of) the Arnoldi method in Hilbert spaces. The interest in working in infinite dimensional spaces comes partly from the fact that only then can one have meaningful asymptotical statements (which hopefully give some light to the convergence of Arnoldi in large dimensional problems with iteration indices far less than the dimension).

  6. Photovoltaic device and method

    Science.gov (United States)

    Cleereman, Robert; Lesniak, Michael J.; Keenihan, James R.; Langmaid, Joe A.; Gaston, Ryan; Eurich, Gerald K.; Boven, Michelle L.

    2015-11-24

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  7. Water-budget methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    A water budget is an accounting of water movement into and out of, and storage change within, some control volume. Universal and adaptable are adjectives that reflect key features of water-budget methods for estimating recharge. The universal concept of mass conservation of water implies that water-budget methods are applicable over any space and time scales (Healy et al., 2007). The water budget of a soil column in a laboratory can be studied at scales of millimeters and seconds. A water-budget equation is also an integral component of atmospheric general circulation models used to predict global climates over periods of decades or more. Water-budget equations can be easily customized by adding or removing terms to accurately portray the peculiarities of any hydrologic system. The equations are generally not bound by assumptions on mechanisms by which water moves into, through, and out of the control volume of interest. So water-budget methods can be used to estimate both diffuse and focused recharge, and recharge estimates are unaffected by phenomena such as preferential flow paths within the unsaturated zone. Water-budget methods represent the largest class of techniques for estimating recharge. Most hydrologic models are derived from a water-budget equation and can therefore be classified as water-budget models. It is not feasible to address all water-budget methods in a single chapter. This chapter is limited to discussion of the “residual” water-budget approach, whereby all variables in a water-budget equation, except for recharge, are independently measured or estimated and recharge is set equal to the residual. This chapter is closely linked with Chapter 3, on modeling methods, because the equations presented here form the basis of many models and because models are often used to estimate individual components in water-budget studies. Water budgets for streams and other surface-water bodies are addressed in Chapter 4. The use of soil-water budgets and

  8. Nonhazardous Urine Pretreatment Method

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.

    2012-01-01

    A method combines solid phase acidification with two non-toxic biocides to prevent ammonia volatilization and microbial proliferation. The safe, non-oxidizing biocide combination consists of a quaternary amine and a food preservative. This combination has exhibited excellent stabilization of both acidified and unacidified urine. During pretreatment tests, composite urine collected from donors was challenged with a microorganism known to proliferate in urine, and then was processed using the nonhazardous urine pre-treatment method. The challenge microorganisms included Escherichia coli, a common gram-negative bacteria; Enterococcus faecalis, a ureolytic gram-positive bacteria; Candida albicans, a yeast commonly found in urine; and Aspergillus niger, a problematic mold that resists urine pre-treatment. Urine processed in this manner remained microbially stable for over 57 days. Such effective urine stabilization was achieved using non-toxic, non-oxidizing biocides at higher pH (3.6 to 5.8) than previous methods in use or projected for use aboard the International Space Station (ISS). ISS urine pretreatment methods employ strong oxidants including ozone and hexavalent chromium (Cr(VI)), a carcinogenic material, under very acidic conditions (pH = 1.8 to 2.4). The method described here offers a much more benign chemical environment than previous pretreatment methods, and will lower equivalent system mass (ESM) by reducing containment volume and mass, system complexity, and crew time needed to handle pre-treatment chemicals. The biocides, being non-oxidizing, minimize the potential for chemical reactions with urine constituents to produce volatile, airborne contaminants such as cyanogen chloride. Additionally, the biocides are active under significantly less acidic conditions than those used in the current system, thereby reducing the degree of required acidification. A simple flow-through solid phase acidification (SPA) bed is employed to overcome the natural buffering

  9. Developments in Surrogating Methods

    Directory of Open Access Journals (Sweden)

    Hans van Dormolen

    2005-11-01

    Full Text Available In this paper, I would like to talk about the developments in surrogating methods for preservation. My main focus will be on the technical aspects of preservation surrogates. This means that I will tell you something about my job as Quality Manager Microfilming for the Netherlands’ national preservation program, Metamorfoze, which is coordinated by the National Library. I am responsible for the quality of the preservation microfilms, which are produced for Metamorfoze. Firstly, I will elaborate on developments in preservation methods in relation to the following subjects: · Preservation microfilms · Scanning of preservation microfilms · Preservation scanning · Computer Output Microfilm. In the closing paragraphs of this paper, I would like to tell you something about the methylene blue test. This is an important test for long-term storage of preservation microfilms. Also, I will give you a brief report on the Cellulose Acetate Microfilm Conference that was held in the British Library in London, May 2005.

  10. Motor degradation prediction methods

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  11. Mitosis Methods & Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-06-01

    Full Text Available Mitosis Methods & Protocols Andrew D. McAinsh (Edt Humana press, Totowa, New Jersey (USA Series: Springer Protocols Methods in Molecular Biology, Volume 545, 2009 ISBN: 978-1-60327-992-5   It is quite clear from the contents of this book that the remarkably fascinating phenomenon of mitosis (that captured, and still is capturing, the attention of entire generations of scientists is still open to research. This is mainly due to our lack of knowledge of so many multifaced events of this extraordinarly complex process. The reader giving a glace through the Contents and Contributors sections is speechless: All of the first-class models (i.e., budding yeast, Caenorabditis, Drosophila, Xenopus and Human are presented..... 

  12. Method card design dimensions

    DEFF Research Database (Denmark)

    Wölfel, Christiane; Merritt, T.

    2013-01-01

    . The card-based tools are explained in terms of five design dimensions including the intended purpose and scope of use, duration of use, methodology, customization, and formal/material qualities. Our analysis suggests three design patterns or archetypes for existing card-based design method tools...... and highlights unexplored areas in the design space. The paper concludes with recommendations for the future development of card-based methods for the field of interaction design.......There are many examples of cards used to assist or provide structure to the design process, yet there has not been a thorough articulation of the strengths and weaknesses of the various examples. We review eighteen card-based design tools in order to understand how they might benefit designers...

  13. Jet vortex methods

    CERN Document Server

    Holm, Darryl D

    2015-01-01

    Vortex blob methods are typically characterized by a regularization length scale, below which the the dynamics are trivial for isolated blobs. In this article we will find that the dynamics need not be trivial if one is willing to consider distributional derivatives of Dirac delta functionals as valid vorticity distributions. More specifically, a new singular vortex theory is presented for regularised Euler fluid equations of ideal incompressible flow in the plane. We determine the conditions under which such regularised Euler fluid equations may admit vorticity singularities which are stronger than delta functions, e.g., derivatives of delta functions. We also characterise the Hamiltonian dynamics of the higher-order singular vortices. Applications to the design of numerical meth- ods similar to vortex blob methods are also discussed. Such findings shed light onto the rich dynamics which occur below the regularization length scale and enlighten our perspective on the multiscale aspects of regularized fluid m...

  14. The Montessori Method

    Directory of Open Access Journals (Sweden)

    Cathleen Haskins

    2010-06-01

    Full Text Available Dr. Maria Montessori provided the world with a powerful philosophy and practice for the advancement of humanity: change how we educate children and we change the world. She understood two things very clearly: One, that we can build a better world, a more just and peaceful place, when we educate for the realization of the individual and collective human potential; and two, that the only way to create an educational system that will that will serve this end is to scrap the current system entirely and replace it with a completely new system. She gave us a system through which to accomplish that goal: The Montessori Method. The following is a personal and professional account of the Montessori Method of educating children.

  15. in the DSMC Method

    Directory of Open Access Journals (Sweden)

    Fong-Zhi Chen

    2001-01-01

    Full Text Available In this study, the Plücker coordinates representation is used to formulate the ruled surface and the molecular path for pumping speed performance evaluation of a molecular vacuum pump. The ruled surface represented by the Pliicker coordinates is used to develop a criterion for when gas molecules hit the pump surface wall. The criterion is applied to analyze the flow rate of a new developed vacuum pump in transition regimes by using the DSMC (Direct Simulation Monte Carlo method. When a molecule flies in a neutral electrical field its path is a straight line. If the molecular path and the generators of a ruled surface are both represented by the Pliicker coordinates, the position of the molecular hit on the wall can be verified by the reciprocal condition of the lines. The Plücker coordinates representation is quite convenient in the DSMC method for this three-dimensional molecular flow simulation.

  16. Anthropological methods in ethnopharmacology.

    Science.gov (United States)

    Etkin, N L

    1993-03-01

    This paper reviews anthropological methods in ethnopharmacology to advance a critical and biobehavioral perspective for the construction of primary data in the light of indigenous paradigms of health and therapeutics. The unique contributions of anthropology are the conceptual and practical tools that allow one to develop the ethnography of plant use in sufficient depth to correlate with laboratory and clinical investigations of plant constituents and activities. This serves an ethnopharmacology that links bioscientific research to traditional empirical knowledge. Specific methods discussed include: key respondents, participant observation, focus groups, structured and unstructured interviews, survey instruments and questionnaires, lexical and semantic studies, and discourse and content analysis. The accommodation of rapid ethnographic techniques for ethnopharmacologic research is described, and several problem orientations based on assessments of efficacy are offered.

  17. INNOVATIVE SALES METHODS

    Directory of Open Access Journals (Sweden)

    Roxana L. IONESCU

    2014-06-01

    Full Text Available Companies operating in a global economy that is constantly changing and developming, especially during the financial crisis and political instability. It is necessary to adapt and develop sales methods in such environment. For large companies who base their activity on sales it has become a necessity to learn different types of sales approaches because their knowledge enables them to grow the number of customers and therefore the sales and the turnover. This paper aims to exame the most effective sales methods used on the highly sensitive economic and social environment – the insurance market. In the field of insurances, the sales process is even more important because sellers need to sell an intangible product that may materialize in the future, but there is no certainty.

  18. Dynamic encryption method

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is a method of transmitting a data set using encryption, wherein the method comprises the steps of: selecting a first encryption technique, wherein said first encryption technique comprises a first encryption algorithm for encrypting plain data into cipher data, and a first decryption...... algorithm for on provision of a specific key, decrypting cipher data and reproduce plain data; encrypting the first data package comprising plain data, using a first encryption program implementing the first encryption algorithm of said first encryption technique, creating a first encrypted data package...... comprising cipher data; obtaining a first decryption program; and transmitting said first decryption program and said first encrypted data package to a receiver, wherein the first decryption, upon provision of the specific key and the first encrypted data package, will decrypt the cipher data in the first...

  19. by Lifting Line Method

    Directory of Open Access Journals (Sweden)

    Horia Dumitrescu

    1998-01-01

    Full Text Available The vortex model of propellers is modified and applied to the high-speed horizontal axis turbines. The turbine blades are replaced by lifting lines and trailing vortices which shed along the blade span. The model is not a free wake model, but it is still a nonlinear one which should be solved iteratively. In addition to the regular case where the trailing vortices are constrained to distribute along a helical surface, another version, where each trailing vortex sheding from the blade grows as a free helical vortex line, is also included. Performance parameters are calculated by application of the Biot-Savart law along with the Kutta-Joukowski theorem. Predictions are, shown to compare favorably with existing numerical data from more involved free wake methods, but require less computational effort. Thereby, the present method may be a very useful tool for calculating the aerodynamic loads on horizontal-axis wind turbine blades.

  20. THE ACTION RESEARCH METHOD

    Directory of Open Access Journals (Sweden)

    Petre GEORGIEVSKI

    1999-05-01

    Full Text Available The effort in this work to elaborate an action research method as a central research problem considering the recent contemporary sociological and educa­tional literature. The author begins with the statement that the method is a complex notion, composed of three main components: approach to the research problem, data gathering procedures and data analysis procedures. This point of view is further applied and elaborated in the author's text, emphasizing the action research characteristics: interruption with the positive tradition in social research and the divided of the objective and subjective, application of the qualitative data. The sub­stantial difference between the action research in regard with the other kinds of research, is not only in getting to new knowledge's, but also in problem solving or a change in the situation in a concrete social context.

  1. Nanoscale waveguiding methods.

    Science.gov (United States)

    Wang, Chia-Jean; Lin, Lih Y

    2007-05-01

    While 32 nm lithography technology is on the horizon for integrated circuit (IC) fabrication, matching the pace for miniaturization with optics has been hampered by the diffraction limit. However, development of nanoscale components and guiding methods is burgeoning through advances in fabrication techniques and materials processing. As waveguiding presents the fundamental issue and cornerstone for ultra-high density photonic ICs, we examine the current state of methods in the field. Namely, plasmonic, metal slot and negative dielectric based waveguides as well as a few sub-micrometer techniques such as nanoribbons, high-index contrast and photonic crystals waveguides are investigated in terms of construction, transmission, and limitations. Furthermore, we discuss in detail quantum dot (QD) arrays as a gain-enabled and flexible means to transmit energy through straight paths and sharp bends. Modeling, fabrication and test results are provided and show that the QD waveguide may be effective as an alternate means to transfer light on sub-diffraction dimensions.

  2. Methods for forming particles

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  3. Methods for forming particles

    Science.gov (United States)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  4. The random projection method

    CERN Document Server

    Vempala, Santosh S

    2005-01-01

    Random projection is a simple geometric technique for reducing the dimensionality of a set of points in Euclidean space while preserving pairwise distances approximately. The technique plays a key role in several breakthrough developments in the field of algorithms. In other cases, it provides elegant alternative proofs. The book begins with an elementary description of the technique and its basic properties. Then it develops the method in the context of applications, which are divided into three groups. The first group consists of combinatorial optimization problems such as maxcut, graph coloring, minimum multicut, graph bandwidth and VLSI layout. Presented in this context is the theory of Euclidean embeddings of graphs. The next group is machine learning problems, specifically, learning intersections of halfspaces and learning large margin hypotheses. The projection method is further refined for the latter application. The last set consists of problems inspired by information retrieval, namely, nearest neig...

  5. Glycoconjugates and methods

    Energy Technology Data Exchange (ETDEWEB)

    Bertozzi, Carolyn C. (Albany, CA); Yarema, Kevin J. (Albany, CA); Mahal; Lara K. (Berkeley, CA)

    2008-04-01

    Methods for making the functionalized glycoconjugates include (a) contacting a cell with a first monosaccharide, and (b) incubating the cell under conditions whereby the cell (i) internalizes the first monosaccharide, (ii) biochemically processes the first monosaccharide into a second saccharide, (iii) conjugates the saccharide to a carrier to form a glycoconjugate, and (iv) extracellularly expresses the glycoconjugate to form an extracellular glycoconjugate comprising a selectively reactive functional group. Methods for forming products at a cell further comprise contacting the functional group of the extracellularly expressed glycoconjugate with an agent which selectively reacts with the functional group to form a product. Subject compositions include cyto-compatible monosaccharides comprising a nitrogen or ether linked functional group selectively reactive at a cell surface and compositions and cells comprising such saccharides.

  6. Statistical Methods for Astronomy

    CERN Document Server

    Feigelson, Eric D

    2012-01-01

    This review outlines concepts of mathematical statistics, elements of probability theory, hypothesis tests and point estimation for use in the analysis of modern astronomical data. Least squares, maximum likelihood, and Bayesian approaches to statistical inference are treated. Resampling methods, particularly the bootstrap, provide valuable procedures when distributions functions of statistics are not known. Several approaches to model selection and good- ness of fit are considered. Applied statistics relevant to astronomical research are briefly discussed: nonparametric methods for use when little is known about the behavior of the astronomical populations or processes; data smoothing with kernel density estimation and nonparametric regression; unsupervised clustering and supervised classification procedures for multivariate problems; survival analysis for astronomical datasets with nondetections; time- and frequency-domain times series analysis for light curves; and spatial statistics to interpret the spati...

  7. MIXED METHOD RESEARCH

    Directory of Open Access Journals (Sweden)

    Masrizal Masrizal

    2012-03-01

    Full Text Available Mixed Method Research adalah metode penelitian yang diaplikasikan bila peneliti memiliki pertanyaan yang perlu diuji dari segi outcomes dan prosesnya, serta menyangkut kombinasi antara metode kuantitatif dan kualitatif dalam satu penelitian. Karena berfokus pada outcomes dan proses, maka desain MMR biasa digunakan dalam penelitian evaluasi program. Namun sekarang, MMR sudah sering digunakan untuk ilmu-ilmu sosial, seperti: konseling, psikologi social manajemen, dan pengorganisasian perilaku.

  8. MIXED METHOD RESEARCH

    OpenAIRE

    Masrizal Masrizal

    2012-01-01

    Mixed Method Research adalah metode penelitian yang diaplikasikan bila peneliti memiliki pertanyaan yang perlu diuji dari segi outcomes dan prosesnya, serta menyangkut kombinasi antara metode kuantitatif dan kualitatif dalam satu penelitian. Karena berfokus pada outcomes dan proses, maka desain MMR biasa digunakan dalam penelitian evaluasi program. Namun sekarang, MMR sudah sering digunakan untuk ilmu-ilmu sosial, seperti: konseling, psikologi social manajemen, dan pengorganisasian perilaku.

  9. Method for scavenging mercury

    Science.gov (United States)

    Chang, Shih-ger; Liu, Shou-heng; Liu, Zhao-rong; Yan, Naiqiang

    2009-01-20

    Disclosed herein is a method for removing mercury from a gas stream comprising contacting the gas stream with a getter composition comprising bromine, bromochloride, sulphur bromide, sulphur dichloride or sulphur monochloride and mixtures thereof. In one preferred embodiment the getter composition is adsorbed onto a sorbent. The sorbent may be selected from the group consisting of flyash, limestone, lime, calcium sulphate, calcium sulfite, activated carbon, charcoal, silicate, alumina and mixtures thereof. Preferred is flyash, activated carbon and silica.

  10. Statokinesigram normalization method.

    Science.gov (United States)

    de Oliveira, José Magalhães

    2017-02-01

    Stabilometry is a technique that aims to study the body sway of human subjects, employing a force platform. The signal obtained from this technique refers to the position of the foot base ground-reaction vector, known as the center of pressure (CoP). The parameters calculated from the signal are used to quantify the displacement of the CoP over time; there is a large variability, both between and within subjects, which prevents the definition of normative values. The intersubject variability is related to differences between subjects in terms of their anthropometry, in conjunction with their muscle activation patterns (biomechanics); and the intrasubject variability can be caused by a learning effect or fatigue. Age and foot placement on the platform are also known to influence variability. Normalization is the main method used to decrease this variability and to bring distributions of adjusted values into alignment. In 1996, O'Malley proposed three normalization techniques to eliminate the effect of age and anthropometric factors from temporal-distance parameters of gait. These techniques were adopted to normalize the stabilometric signal by some authors. This paper proposes a new method of normalization of stabilometric signals to be applied in balance studies. The method was applied to a data set collected in a previous study, and the results of normalized and nonnormalized signals were compared. The results showed that the new method, if used in a well-designed experiment, can eliminate undesirable correlations between the analyzed parameters and the subjects' characteristics and show only the experimental conditions' effects.

  11. Comments on PDF methods

    Science.gov (United States)

    Chen, J.-Y.

    1992-01-01

    Viewgraphs are presented on the following topics: the grand challenge of combustion engineering; research of probability density function (PDF) methods at Sandia; experiments of turbulent jet flames (Masri and Dibble, 1988); departures from chemical equilibrium; modeling turbulent reacting flows; superequilibrium OH radical; pdf modeling of turbulent jet flames; scatter plot for CH4 (methane) and O2 (oxygen); methanol turbulent jet flames; comparisons between predictions and experimental data; and turbulent C2H4 jet flames.

  12. Situational method engineering

    CERN Document Server

    Henderson-Sellers, Brian; Ågerfalk, Pär J; Rossi, Matti

    2014-01-01

    While previously available methodologies for software ? like those published in the early days of object technology ? claimed to be appropriate for every conceivable project, situational method engineering (SME) acknowledges that most projects typically have individual characteristics and situations. Thus, finding the most effective methodology for a particular project needs specific tailoring to that situation. Such a tailored software development methodology needs to take into account all the bits and pieces needed for an organization to develop software, including the software process, the

  13. Polymer compositions and methods

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Willkomm, Wayne R.

    2016-09-27

    The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: ##STR00001## In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.

  14. Nearshore Pipeline Installation Methods.

    Science.gov (United States)

    1981-08-01

    179. 5. Aldridge, R. G., and Bomba , J. G., "Deep Water Pipelines - Interdependence of Design and Construction", ASCE Paper. 6. American Society Civil...October 13, 1967. 24. Bomba , J. G. and Seeds, K. J., "Pipelining in 600 feet of water .... A Case Study of Washington Natural Gas Company’s Puget Sound...Crossing", Offshore Technology Conference, paper OTC 1188, 1970. 25. Bomba , J., "Submarine Pipe Construction Methods", Petroleum Engineer, Vol. 32

  15. Methods in Bioengineering

    CERN Document Server

    Rege, Kaushal

    2009-01-01

    Filling a critical gap in the current literature, this new resource presents practical, step-by-step methods to help you synthesize, characterize, biofunctionalize and apply the nanomaterial that is most suitable for handling a given nanoscale bioengineering problem. Written and presented by leading scientists and engineers in their respective fields, the authors offer a clear and detailed understanding of how to carry out nanoparticle functionalization with biomolecules (including enzymes), nanoparticle analysis and characterization, in vitro evaluation of nanoparticles using different cell l

  16. Method of infusion extraction

    Science.gov (United States)

    Chang-Diaz, Franklin R. (Inventor)

    1989-01-01

    Apparatus and method of removing desirable constituents from an infusible material by infusion extraction, where a piston operating in a first chamber draws a solvent into the first chamber where it may be heated, and then moves the heated solvent into a second chamber containing the infusible material, and where infusion extraction takes place. The piston then moves the solvent containing the extract through a filter into the first chamber, leaving the extraction residue in the second chamber.

  17. Method for detecting biomolecules

    Science.gov (United States)

    Huo, Qisheng; Liu, Jun

    2008-08-12

    A method for detecting and measuring the concentration of biomolecules in solution, utilizing a conducting electrode in contact with a solution containing target biomolecules, with a film with controllable pore size distribution characteristics applied to at least one surface of the conducting electrode. The film is functionalized with probe molecules that chemically interact with the target biomolecules at the film surface, blocking indicator molecules present in solution from diffusing from the solution to the electrode, thereby changing the electrochemical response of the electrode

  18. Method for scavenging mercury

    Science.gov (United States)

    Chang, Shih-ger; Liu, Shou-heng; Liu, Zhao-rong; Yan, Naiqiang

    2010-07-13

    Disclosed herein is a method for removing mercury from a gas stream comprising contacting the gas stream with a getter composition comprising bromine, bromochloride, sulphur bromide, sulphur dichloride or sulphur monochloride and mixtures thereof. In one preferred embodiment the getter composition is adsorbed onto a sorbent. The sorbent may be selected from the group consisting flyash, limestone, lime, calcium sulphate, calcium sulfite, activated carbon, charcoal, silicate, alumina and mixtures thereof. Preferred is flyash, activated carbon and silica.

  19. Method of producing imines

    Science.gov (United States)

    Sithambaram, Shanthakumar; Son, Young-Chan; Suib, Steven L.

    2008-04-08

    A method for forming an imine comprises reacting a first reactant comprising a hydroxyl functionality, a carbonyl functionality, or both a hydroxyl functionality and a carbonyl functionality with a second reactant having an amine functionality in the presence of ordered porous manganese-based octahedral molecular sieves and an oxygen containing gas at a temperature and for a time sufficient for the imine to be produced.

  20. Methods in Bioengineering

    CERN Document Server

    Zahn, Jeffrey D

    2009-01-01

    This unique volume presents leading-edge microfluidics methods used to handle, manipulate, and analyze cells, particles, and biological components (e.g., proteins and DNA) for microdiagnostics. The authors offer clear and detailed guidance on microfabrication techniques utilized to create microfluidic devices and on-chip flow control and mixing Microsystems, protein and DNA handling devices for electrophoretic and isoelectric separations in microchromatography columns, microfluidic manipulations of droplets via electrowetting and particles via dielectrophoresis for separations and chemical rea

  1. Chromosome doubling method

    Science.gov (United States)

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  2. Montessori Method and ICTs

    OpenAIRE

    Athanasios Drigas; Eugenia Gkeka

    2016-01-01

    This article bridges the gap between the Montessori Method and Information and Communication Technologies (ICTs) in contemporary education. It reviews recent research works which recall the Montessori philosophy, principles and didactical tools applying to today’s computers and supporting technologies in children’s learning process. This article reviews how important the stimulation of human senses in the learning process is, as well as the development of Montessori materials using the body a...

  3. Geometrical method of decoupling

    Science.gov (United States)

    Baumgarten, C.

    2012-12-01

    The computation of tunes and matched beam distributions are essential steps in the analysis of circular accelerators. If certain symmetries—like midplane symmetry—are present, then it is possible to treat the betatron motion in the horizontal, the vertical plane, and (under certain circumstances) the longitudinal motion separately using the well-known Courant-Snyder theory, or to apply transformations that have been described previously as, for instance, the method of Teng and Edwards. In a preceding paper, it has been shown that this method requires a modification for the treatment of isochronous cyclotrons with non-negligible space charge forces. Unfortunately, the modification was numerically not as stable as desired and it was still unclear, if the extension would work for all conceivable cases. Hence, a systematic derivation of a more general treatment seemed advisable. In a second paper, the author suggested the use of real Dirac matrices as basic tools for coupled linear optics and gave a straightforward recipe to decouple positive definite Hamiltonians with imaginary eigenvalues. In this article this method is generalized and simplified in order to formulate a straightforward method to decouple Hamiltonian matrices with eigenvalues on the real and the imaginary axis. The decoupling of symplectic matrices which are exponentials of such Hamiltonian matrices can be deduced from this in a few steps. It is shown that this algebraic decoupling is closely related to a geometric “decoupling” by the orthogonalization of the vectors E→, B→, and P→, which were introduced with the so-called “electromechanical equivalence.” A mathematical analysis of the problem can be traced down to the task of finding a structure-preserving block diagonalization of symplectic or Hamiltonian matrices. Structure preservation means in this context that the (sequence of) transformations must be symplectic and hence canonical. When used iteratively, the decoupling

  4. Electron cryomicroscopy methods.

    Science.gov (United States)

    Unger, V M

    2001-10-01

    Electron cryomicroscopy methods comprise a rapidly expanding field providing insights into the structure and function of biological macromolecules and their supramolecular assemblies. The 3.8 A resolution structure of the membrane protein aquaporin, a view of the herpesvirus capsid at 8.5 A and the 10 A resolution structure of the spliceosomal U1 small nuclear ribonucleoprotein complex are three outstanding examples emphasizing the versatility of this technique.

  5. Method for making nanomaterials

    Science.gov (United States)

    Fan, Hongyou; Wu, Huimeng

    2013-06-04

    A method of making a nanostructure by preparing a face centered cubic-ordered metal nanoparticle film from metal nanoparticles, such as gold and silver nanoparticles, exerting a hydrostatic pressure upon the film at pressures of several gigapascals, followed by applying a non-hydrostatic stress perpendicularly at a pressure greater than approximately 10 GPA to form an array of nanowires with individual nanowires having a relatively uniform length, average diameter and density.

  6. Bering Mission Navigation Method

    OpenAIRE

    2003-01-01

    "Bering", after the name of the famous Danish explorer, is a near Earth object (NEO) and main belt asteroids mapping mission envisaged by a consortium of Danish universities and research institutes. To achieve the ambitious goals set forth by this mission, while containing the costs and risks, "Bering" sports several new technological enhancements and advanced instruments under development at the Technical University of Denmark (DTU). The autonomous on-board orbit determination method is part...

  7. Methods of celestial mechanics

    CERN Document Server

    Brouwer, Dirk

    2013-01-01

    Methods of Celestial Mechanics provides a comprehensive background of celestial mechanics for practical applications. Celestial mechanics is the branch of astronomy that is devoted to the motions of celestial bodies. This book is composed of 17 chapters, and begins with the concept of elliptic motion and its expansion. The subsequent chapters are devoted to other aspects of celestial mechanics, including gravity, numerical integration of orbit, stellar aberration, lunar theory, and celestial coordinates. Considerable chapters explore the principles and application of various mathematical metho

  8. ARK methods: some recent developments

    Science.gov (United States)

    Moir, Nicolette

    2005-03-01

    Almost Runge-Kutta methods are a sub-class of the family of methods known as general linear methods, used for solving ordinary differential equations. They combine many of the favourable properties of traditional Runge-Kutta methods with some additional advantages. We will introduce these methods, concentrating on methods of order four, and present some recent results.

  9. Multigrid methods III

    CERN Document Server

    Trottenberg, U; Third European Conference on Multigrid Methods

    1991-01-01

    These proceedings contain a selection of papers presented at the Third European Conference on Multigrid Methods which was held in Bonn on October 1-4, 1990. Following conferences in 1981 and 1985, a platform for the presentation of new Multigrid results was provided for a third time. Multigrid methods no longer have problems being accepted by numerical analysts and users of numerical methods; on the contrary, they have been further developed in such a successful way that they have penetrated a variety of new fields of application. The high number of 154 participants from 18 countries and 76 presented papers show the need to continue the series of the European Multigrid Conferences. The papers of this volume give a survey on the current Multigrid situation; in particular, they correspond to those fields where new developments can be observed. For example, se­ veral papers study the appropriate treatment of time dependent problems. Improvements can also be noticed in the Multigrid approach for semiconductor eq...

  10. Stochastic Methods in Biology

    CERN Document Server

    Kallianpur, Gopinath; Hida, Takeyuki

    1987-01-01

    The use of probabilistic methods in the biological sciences has been so well established by now that mathematical biology is regarded by many as a distinct dis­ cipline with its own repertoire of techniques. The purpose of the Workshop on sto­ chastic methods in biology held at Nagoya University during the week of July 8-12, 1985, was to enable biologists and probabilists from Japan and the U. S. to discuss the latest developments in their respective fields and to exchange ideas on the ap­ plicability of the more recent developments in stochastic process theory to problems in biology. Eighteen papers were presented at the Workshop and have been grouped under the following headings: I. Population genetics (five papers) II. Measure valued diffusion processes related to population genetics (three papers) III. Neurophysiology (two papers) IV. Fluctuation in living cells (two papers) V. Mathematical methods related to other problems in biology, epidemiology, population dynamics, etc. (six papers) An important f...

  11. Validation of analytical methods

    Directory of Open Access Journals (Sweden)

    Xavier Rius, F.

    2002-03-01

    Full Text Available In this paper we shall discuss the concept of method validation, describe the various elements and explain its close relationship with fitness for purpose. Method validation is based on the assumption that a series of requirements are fulfilled and we shall explain how these requirements are selected, the way in which evidence is supplied and what work has to be carried out in the laboratory. The basic principles of method validation and the different ways to validate a methodology, by inter-laboratory comparison or performing an in-house validation, are also described.En este artículo se discute el concepto de validación del método, se describen los elementos que la componen y se explica la fuerte relación entre la validación y las características de ajuste. El método de validación se basa en el cumplimiento de una serie de requerimientos, se explica como seleccionar esos requerimientos, la forma en que se suministran evidencias, y que trabajo se debe llevar a cabo en el laboratorio. También se describen, los principios básicos del método de validación y los diferentes caminos para validar una metodología, tanto en la comparación entre laboratorios o como cuando se lleva a cabo una validación dentro del laboratorio.

  12. Generalized Agile Estimation Method

    Directory of Open Access Journals (Sweden)

    Shilpa Bahlerao

    2011-01-01

    Full Text Available Agile cost estimation process always possesses research prospects due to lack of algorithmic approaches for estimating cost, size and duration. Existing algorithmic approach i.e. Constructive Agile Estimation Algorithm (CAEA is an iterative estimation method that incorporates various vital factors affecting the estimates of the project. This method has lots of advantages but at the same time has some limitations also. These limitations may due to some factors such as number of vital factors and uncertainty involved in agile projects etc. However, a generalized agile estimation may generate realistic estimates and eliminates the need of experts. In this paper, we have proposed iterative Generalized Estimation Method (GEM and presented algorithm based on it for agile with case studies. GEM  based algorithm various project domain classes and vital factors with prioritization level. Further, it incorporates uncertainty factor to quantify the risk of project for estimating cost, size and duration. It also provides flexibility to project managers for deciding on number of vital factors, uncertainty level and project domains thereby maintaining the agility.

  13. Method Engineering: Engineering of Information Systems Development Methods and Tools

    NARCIS (Netherlands)

    Brinkkemper, J.N.; Brinkkemper, Sjaak

    1996-01-01

    This paper proposes the term method engineering for the research field of the construction of information systems development methods and tools. Some research issues in method engineering are identified. One major research topic in method engineering is discussed in depth: situational methods, i.e.

  14. The data embedding method

    Energy Technology Data Exchange (ETDEWEB)

    Sandford, M.T. II; Bradley, J.N.; Handel, T.G.

    1996-06-01

    Data embedding is a new steganographic method for combining digital information sets. This paper describes the data embedding method and gives examples of its application using software written in the C-programming language. Sandford and Handel produced a computer program (BMPEMBED, Ver. 1.51 written for IBM PC/AT or compatible, MS/DOS Ver. 3.3 or later) that implements data embedding in an application for digital imagery. Information is embedded into, and extracted from, Truecolor or color-pallet images in Microsoft{reg_sign} bitmap (.BMP) format. Hiding data in the noise component of a host, by means of an algorithm that modifies or replaces the noise bits, is termed {open_quote}steganography.{close_quote} Data embedding differs markedly from conventional steganography, because it uses the noise component of the host to insert information with few or no modifications to the host data values or their statistical properties. Consequently, the entropy of the host data is affected little by using data embedding to add information. The data embedding method applies to host data compressed with transform, or {open_quote}lossy{close_quote} compression algorithms, as for example ones based on discrete cosine transform and wavelet functions. Analysis of the host noise generates a key required for embedding and extracting the auxiliary data from the combined data. The key is stored easily in the combined data. Images without the key cannot be processed to extract the embedded information. To provide security for the embedded data, one can remove the key from the combined data and manage it separately. The image key can be encrypted and stored in the combined data or transmitted separately as a ciphertext much smaller in size than the embedded data. The key size is typically ten to one-hundred bytes, and it is in data an analysis algorithm.

  15. Data embedding method

    Science.gov (United States)

    Sandford, Maxwell T., II; Bradley, Jonathan N.; Handel, Theodore G.

    1996-01-01

    Data embedding is a new steganographic method for combining digital information sets. This paper describes the data embedding method and gives examples of its application using software written in the C-programming language. Sandford and Handel produced a computer program (BMPEMBED, Ver. 1.51 written for IBM PC/AT or compatible, MS/DOS Ver. 3.3 or later) that implements data embedding in an application for digital imagery. Information is embedded into, and extracted from, Truecolor or color-pallet images in MicrosoftTM bitmap (BMP) format. Hiding data in the noise component of a host, by means of an algorithm that modifies or replaces the noise bits, is termed `steganography.' Data embedding differs markedly from conventional steganography, because it uses the noise component of the host to insert information with few or no modifications to the host data values or their statistical properties. Consequently, the entropy of the host data is affected little by using data embedding to add information. The data embedding method applies to host data compressed with transform, or `lossy' compression algorithms, as for example ones based on discrete cosine transform and wavelet functions. Analysis of the host noise generates a key required for embedding and extracting the auxiliary data from the combined data. The key is stored easily in the combined data. Images without the key cannot be processed to extract the embedded information. To provide security for the embedded data, one can remove the key from the combined data and manage it separately. The image key can be encrypted and stored in the combined data or transmitted separately as a ciphertext much smaller in size than the embedded data. The key size is typically ten to one-hundred bytes, and it is derived from the original host data by an analysis algorithm.

  16. ZIRCONIUM PHOSPHATE ADSORPTION METHOD

    Science.gov (United States)

    Russell, E.R.; Adamson, A.S.; Schubert, J.; Boyd, G.E.

    1958-11-01

    A method is presented for separating plutonium values from fission product values in aqueous acidic solution. This is accomplished by flowing the solutlon containing such values through a bed of zirconium orthophosphate. Any fission products adsorbed can subsequently be eluted by washing the column with a solution of 2N HNO/sub 3/ and O.lN H/sub 3/PO/sub 4/. Plutonium values may subsequently be desorbed by contacting the column with a solution of 7N HNO/sub 3/ .

  17. Methods of graded rings

    CERN Document Server

    Nastasescu, Constantin

    2004-01-01

    The topic of this book, graded algebra, has developed in the past decade to a vast subject with new applications in noncommutative geometry and physics. Classical aspects relating to group actions and gradings have been complemented by new insights stemming from Hopf algebra theory. Old and new methods are presented in full detail and in a self-contained way. Graduate students as well as researchers in algebra, geometry, will find in this book a useful toolbox. Exercises, with hints for solution, provide a direct link to recent research publications. The book is suitable for courses on Master level or textbook for seminars.

  18. Control system design method

    Science.gov (United States)

    Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  19. Calcium measurement methods

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-09-01

    Full Text Available Rightly stressed by prof. Wolfgang Walz in the Preface to the series Neuromethods series, the “careful application of methods is probably the most important step in the process of scientific inquiry”. Thus, I strongly suggest to all those interested in calcium signaling and especially to the new-comers in the hot topic of neuroscience (which has so much space even in science-society debate for its implications in legal issues and in the judge-decision process to take profit from this so well edited book. I am saying this since prof. Verkhratsky and prof. Petersen......

  20. Methods of thermodynamics

    CERN Document Server

    Reiss, Howard

    1997-01-01

    Since there is no shortage of excellent general books on elementary thermodynamics, this book takes a different approach, focusing attention on the problem areas of understanding of concept and especially on the overwhelming but usually hidden role of ""constraints"" in thermodynamics, as well as on the lucid exposition of the significance, construction, and use (in the case of arbitrary systems) of the thermodynamic potential. It will be especially useful as an auxiliary text to be used along with any standard treatment.Unlike some texts, Methods of Thermodynamics does not use statistical m

  1. Geometrical method of decoupling

    Directory of Open Access Journals (Sweden)

    C. Baumgarten

    2012-12-01

    Full Text Available The computation of tunes and matched beam distributions are essential steps in the analysis of circular accelerators. If certain symmetries—like midplane symmetry—are present, then it is possible to treat the betatron motion in the horizontal, the vertical plane, and (under certain circumstances the longitudinal motion separately using the well-known Courant-Snyder theory, or to apply transformations that have been described previously as, for instance, the method of Teng and Edwards. In a preceding paper, it has been shown that this method requires a modification for the treatment of isochronous cyclotrons with non-negligible space charge forces. Unfortunately, the modification was numerically not as stable as desired and it was still unclear, if the extension would work for all conceivable cases. Hence, a systematic derivation of a more general treatment seemed advisable. In a second paper, the author suggested the use of real Dirac matrices as basic tools for coupled linear optics and gave a straightforward recipe to decouple positive definite Hamiltonians with imaginary eigenvalues. In this article this method is generalized and simplified in order to formulate a straightforward method to decouple Hamiltonian matrices with eigenvalues on the real and the imaginary axis. The decoupling of symplectic matrices which are exponentials of such Hamiltonian matrices can be deduced from this in a few steps. It is shown that this algebraic decoupling is closely related to a geometric “decoupling” by the orthogonalization of the vectors E[over →], B[over →], and P[over →], which were introduced with the so-called “electromechanical equivalence.” A mathematical analysis of the problem can be traced down to the task of finding a structure-preserving block diagonalization of symplectic or Hamiltonian matrices. Structure preservation means in this context that the (sequence of transformations must be symplectic and hence canonical. When

  2. Method of joining ceramics

    Science.gov (United States)

    Henager, Jr., Charles H.; Brimhall, John L.

    2000-01-01

    According to the method of the present invention, joining a first bi-element carbide to a second bi-element carbide, has the steps of: (a) forming a bond agent containing a metal carbide and silicon; (b) placing the bond agent between the first and second bi-element carbides to form a pre-assembly; and (c) pressing and heating the pre-assembly in a non-oxidizing atmosphere to a temperature effective to induce a displacement reaction creating a metal silicon phase bonding the first and second bi-element carbides.

  3. Object oriented methods

    CERN Document Server

    Graham, Ian

    1994-01-01

    This book is a revision of Ian Graham's successful survey of the whole area of object technology. It covers object- oriented programming, object-oriented design, object- oriented analysis, object-oriented databases and treats several related technologies. New to this edition are more applications of object-oriented methods and more coverage of object-oriented database products available. Graham has also doubled the design and analysis material that examines over 60 different approaches - making this the most comprehensive book on the market. Also new is the foreword by Grady Booch.

  4. Electrical estimating methods

    CERN Document Server

    Del Pico, Wayne J

    2014-01-01

    Simplify the estimating process with the latest data, materials, and practices Electrical Estimating Methods, Fourth Edition is a comprehensive guide to estimating electrical costs, with data provided by leading construction database RS Means. The book covers the materials and processes encountered by the modern contractor, and provides all the information professionals need to make the most precise estimate. The fourth edition has been updated to reflect the changing materials, techniques, and practices in the field, and provides the most recent Means cost data available. The complexity of el

  5. Introduction to Numerical Methods

    Energy Technology Data Exchange (ETDEWEB)

    Schoonover, Joseph A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-14

    These are slides for a lecture for the Parallel Computing Summer Research Internship at the National Security Education Center. This gives an introduction to numerical methods. Repetitive algorithms are used to obtain approximate solutions to mathematical problems, using sorting, searching, root finding, optimization, interpolation, extrapolation, least squares regresion, Eigenvalue problems, ordinary differential equations, and partial differential equations. Many equations are shown. Discretizations allow us to approximate solutions to mathematical models of physical systems using a repetitive algorithm and introduce errors that can lead to numerical instabilities if we are not careful.

  6. Epitope prediction methods

    DEFF Research Database (Denmark)

    Karosiene, Edita

    on machine learning techniques. Several MHC class I binding prediction algorithms have been developed and due to their high accuracy they are used by many immunologists to facilitate the conventional experimental process of epitope discovery. However, the accuracy of these methods depends on data defining...... the NetMHCIIpan-3.0 predictor based on artificial neural networks, which is capable of giving binding affinities to any human MHC class II molecule. Chapter 4 of this thesis gives an overview of bioinformatics tools developed by the Immunological Bioinformatics group at Center for Biological Sequence...

  7. Formal Methods in Industry

    Directory of Open Access Journals (Sweden)

    Alexei Serna A.

    2012-12-01

    Full Text Available The application of formal methods in industry has progressed extensively over the past decade and the results are promising. But despite these achievements and it have been documented in numerous studies, it is still very common the skepticism about its usefulness and applicability. The goal of this paper is to show that its evolution over the past decade exceeds all previous processes and each time they do a better job to satisfy industrial needs. This is achieved by the description of some experiments and the result of various applications in industry and through an analyzing of the needs of companies that must be satisfy the research community in this field.

  8. Interval methods: An introduction

    DEFF Research Database (Denmark)

    Achenie, L.E.K.; Kreinovich, V.; Madsen, Kaj

    2006-01-01

    This chapter contains selected papers presented at the Minisymposium on Interval Methods of the PARA'04 Workshop '' State-of-the-Art in Scientific Computing ''. The emphasis of the workshop was on high-performance computing (HPC). The ongoing development of ever more advanced computers provides....... An important characteristic of the computer performance in scientific computing is the accuracy of the Computation results. Often, we can estimate this accuracy by using traditional statistical techniques. However, in many practical situations, we do not know the probability distributions of different...... '' techniques, and the applications of these techniques to various problems of scientific computing....

  9. Hydraulic mining method

    Science.gov (United States)

    Huffman, Lester H.; Knoke, Gerald S.

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  10. QUATERNIONIC JACOBI METHOD APPLICATIONS

    OpenAIRE

    SANCREY RODRIGUES ALVES

    2008-01-01

    O método tipo-Jacobi quaterniônico foi proposto em 1993. Vários estudos provaram sua convergência e melhoram a teoria proposta desde então. O presente trabalho realiza uma síntese do método tipo- Jacobi quaterniônico, apresentando aplicações do mesmo a diferentes tipos de matrizes. The quaternionic Jacobi method was proposed on 1993. Lots of studies has proved his convergence and also has improved the theory proposed. This document makes a survey of this me...

  11. Methods in Bioengineering

    CERN Document Server

    Nahmias, Yaakov

    2009-01-01

    Offering a practical look into the field, this volume presents the science behind microscale device design and the engineering of its fabrication. Supported with dozens of full-color illustrations, this book offers you clear, step-by-step methods for the cell capture from whole blood, high-throughput study of transcriptional dynamics in living cells, temporal control of cell-cell interaction, nanoscale measurements of cellular forces, immobilizing living c. elegans, optical and electrical on-chip cell sorting and human-on-chip modeling of drug metabolism.

  12. Interior-point methods

    Science.gov (United States)

    Potra, Florian A.; Wright, Stephen J.

    2000-12-01

    The modern era of interior-point methods dates to 1984, when Karmarkar proposed his algorithm for linear programming. In the years since then, algorithms and software for linear programming have become quite sophisticated, while extensions to more general classes of problems, such as convex quadratic programming, semi-definite programming, and nonconvex and nonlinear problems, have reached varying levels of maturity. We review some of the key developments in the area, including comments on both the complexity theory and practical algorithms for linear programming, semi-definite programming, monotone linear complementarity, and convex programming over sets that can be characterized by self-concordant barrier functions.

  13. Mathematical methods for physicists

    CERN Document Server

    Arfken, George B

    1985-01-01

    Mathematical Methods for Physicists, Third Edition provides an advanced undergraduate and beginning graduate study in physical science, focusing on the mathematics of theoretical physics. This edition includes sections on the non-Cartesian tensors, dispersion theory, first-order differential equations, numerical application of Chebyshev polynomials, the fast Fourier transform, and transfer functions. Many of the physical examples provided in this book, which are used to illustrate the applications of mathematics, are taken from the fields of electromagnetic theory and quantum mechanics. The He

  14. Crystallographic Lattice Boltzmann Method

    Science.gov (United States)

    Namburi, Manjusha; Krithivasan, Siddharth; Ansumali, Santosh

    2016-01-01

    Current approaches to Direct Numerical Simulation (DNS) are computationally quite expensive for most realistic scientific and engineering applications of Fluid Dynamics such as automobiles or atmospheric flows. The Lattice Boltzmann Method (LBM), with its simplified kinetic descriptions, has emerged as an important tool for simulating hydrodynamics. In a heterogeneous computing environment, it is often preferred due to its flexibility and better parallel scaling. However, direct simulation of realistic applications, without the use of turbulence models, remains a distant dream even with highly efficient methods such as LBM. In LBM, a fictitious lattice with suitable isotropy in the velocity space is considered to recover Navier-Stokes hydrodynamics in macroscopic limit. The same lattice is mapped onto a cartesian grid for spatial discretization of the kinetic equation. In this paper, we present an inverted argument of the LBM, by making spatial discretization as the central theme. We argue that the optimal spatial discretization for LBM is a Body Centered Cubic (BCC) arrangement of grid points. We illustrate an order-of-magnitude gain in efficiency for LBM and thus a significant progress towards feasibility of DNS for realistic flows. PMID:27251098

  15. Research methods in information

    CERN Document Server

    Pickard, Alison Jane

    2013-01-01

    The long-awaited 2nd edition of this best-selling research methods handbook is fully updated and includes brand new coverage of online research methods and techniques, mixed methodology and qualitative analysis. There is an entire chapter contributed by Professor Julie McLeod, Sue Childs and Elizabeth Lomas focusing on research data management, applying evidence from the recent JISC funded 'DATUM' project. The first to focus entirely on the needs of the information and communications community, it guides the would-be researcher through the variety of possibilities open to them under the heading "research" and provides students with the confidence to embark on their dissertations. The focus here is on the 'doing' and although the philosophy and theory of research is explored to provide context, this is essentially a practical exploration of the whole research process with each chapter fully supported by examples and exercises tried and tested over a whole teaching career. The book will take readers through eac...

  16. Nanoscale waveguiding methods

    Directory of Open Access Journals (Sweden)

    Wang Chia-Jean

    2007-01-01

    Full Text Available AbstractWhile 32 nm lithography technology is on the horizon for integrated circuit (IC fabrication, matching the pace for miniaturization with optics has been hampered by the diffraction limit. However, development of nanoscale components and guiding methods is burgeoning through advances in fabrication techniques and materials processing. As waveguiding presents the fundamental issue and cornerstone for ultra-high density photonic ICs, we examine the current state of methods in the field. Namely, plasmonic, metal slot and negative dielectric based waveguides as well as a few sub-micrometer techniques such as nanoribbons, high-index contrast and photonic crystals waveguides are investigated in terms of construction, transmission, and limitations. Furthermore, we discuss in detail quantum dot (QD arrays as a gain-enabled and flexible means to transmit energy through straight paths and sharp bends. Modeling, fabrication and test results are provided and show that the QD waveguide may be effective as an alternate means to transfer light on sub-diffraction dimensions.

  17. Recombinant methods and materials

    Energy Technology Data Exchange (ETDEWEB)

    Roizman, B.; Post, L.E.

    1988-09-06

    This patent describes a method for stably effecting the insertion or deletion of a selected DNA sequence at a specific site in a viral genome. The method consists of: (1) isolating from the genome a linear DNA fragment comprising both (a) the specific site determined for insertion or deletion of selected DNA sequence and (b) flanking DNA sequences normally preceding and following the site; (2) preparing first and second altered genome fragments from the fragment isolated in step (1). (a) the first altered fragment comprising the fragment comprising a thymidine kinase gene in a position intermediate the ends of the fragment, and (b) the second altered fragment comprising the fragment having the selected DNA sequence inserted therein or deleted therefrom; (3) contacting the genome with the first altered fragment under conditions permitting recombination at sites of DNA sequence homology, selecting for a recombinant genome comprising the thymidine kinase gene, and isolating the recombinant genome; and (4) contacting the recombinant genome isolated in step (3) with the second altered fragment under conditions permitting recombination at sites of DNA sequence homology, selecting for a recombinant genome lacking the thymidine kinase gene, and isolating the recombinant genome product.

  18. Methods of Endotoxin Detection.

    Science.gov (United States)

    Su, Wenqiong; Ding, Xianting

    2015-08-01

    Endotoxin, present in the outer membrane of all gram-negative bacteria, can pose serious risks to human health, from irreversible shock to death. Therefore, it is essential to develop sensitive, accurate, and rapid methods for its detection. The rabbit pyrogen test is the first standard technique for endotoxin detection and, nowadays, has been replaced by the Limulus Amoebocyte Lysate test, which is the most popular detection technique for endotoxin. With in-depth understanding of endotoxin, biosensors based on endotoxin-sensing components are promising alternatives to pursue in developing low-cost, easy-operation, and fast-response endotoxin detection techniques. This article summarizes the recent advances of endotoxin detection methods with a particular emphasis on optical and electrochemical biosensors based on various sensing elements ranging from nature biomolecules to artificial materials. As the research and technological revolution continues, the highly integrated and miniaturized commercial devices for sensitively and reliably detecting endotoxin will provide a wide range of applications in people's daily life.

  19. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  20. Microencapsulation system and method

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    2009-01-01

    A microencapsulation apparatus is provided which is configured to form co-axial multi-lamellar microcapsules from materials discharged from first and second microsphere dispensers of the apparatus. A method of fabricating and processing microcapsules is also provided which includes forming distinct droplets comprising one or more materials and introducing the droplets directly into a solution bath to form a membrane around the droplets such that a plurality of microcapsules are formed. A microencapsulation system is provided which includes a microcapsule production unit, a fluidized passage for washing and harvesting microcapsules dispensed from the microcapsule production unit and a flow sensor for sizing and counting the microcapsules. In some embodiments, the microencapsulation system may further include a controller configured to simultaneously operate the microcapsule production unit, fluidized passage and flow sensor to process the microcapsules in a continuous manner.

  1. Introduction to perturbation methods

    CERN Document Server

    Holmes, M

    1995-01-01

    This book is an introductory graduate text dealing with many of the perturbation methods currently used by applied mathematicians, scientists, and engineers. The author has based his book on a graduate course he has taught several times over the last ten years to students in applied mathematics, engineering sciences, and physics. The only prerequisite for the course is a background in differential equations. Each chapter begins with an introductory development involving ordinary differential equations. The book covers traditional topics, such as boundary layers and multiple scales. However, it also contains material arising from current research interest. This includes homogenization, slender body theory, symbolic computing, and discrete equations. One of the more important features of this book is contained in the exercises. Many are derived from problems of up- to-date research and are from a wide range of application areas.

  2. Extending the MINLO method

    CERN Document Server

    Frederix, Rikkert

    2015-01-01

    We consider improving POWHEG+MINLO simulations, so as to also render them NLO accurate in the description of observables receiving contributions from events with lower parton multiplicity than present in their underlying NLO calculation. On a conceptual level we follow the strategy of the so-called MINLO' programs. Whereas the existing MINLO' framework requires explicit analytic input from higher order resummation, here we derive an effective numerical approximation to these ingredients, by imposing unitarity. This offers a way of extending the MINLO' method to more complex processes, complementary to the known route which uses explicit computations of high-accuracy resummation inputs. Specifically, we have focused on Higgs-plus-two-jet production (HJJ) and related processes. We also consider how one can cover three units of multiplicity at NLO accuracy, i.e. we consider how the HJJ-MINLO simulation may yield NLO accuracy for inclusive H, HJ, and HJJ quantities. We perform a feasibility study assessing the po...

  3. Data mining methods

    CERN Document Server

    Chattamvelli, Rajan

    2015-01-01

    DATA MINING METHODS, Second Edition discusses both theoretical foundation and practical applications of datamining in a web field including banking, e-commerce, medicine, engineering and management. This book starts byintroducing data and information, basic data type, data category and applications of data mining. The second chapterbriefly reviews data visualization technology and importance in data mining. Fundamentals of probability and statisticsare discussed in chapter 3, and novel algorithm for sample covariants are derived. The next two chapters give an indepthand useful discussion of data warehousing and OLAP. Decision trees are clearly explained and a new tabularmethod for decision tree building is discussed. The chapter on association rules discusses popular algorithms andcompares various algorithms in summary table form. An interesting application of genetic algorithm is introduced inthe next chapter. Foundations of neural networks are built from scratch and the back propagation algorithm is derived...

  4. New methods in cytogenetics.

    Science.gov (United States)

    Buckle, V J; Kearney, L

    1994-06-01

    Developments in the technique of fluorescence in situ hybridization (FISH) now permit hybridization of sequences ranging from 1 kb to whole genomes. The technique can be used in applications from coarse mapping of whole chromosomes to high-resolution analysis of extended strands of DNA. The complexity, and hence the coverage, of 'paints' prepared by amplification is being improved to the extent that such methods are used in cloning strategies for the generation of region-specific probes. Interphase analysis and comparative genomic hybridization are becoming important tools in cancer cytogenetics, and the potential for routine analysis of fetal cells obtained from maternal blood may provide a fresh approach to prenatal cytogenetic screening. Functional studies of gene activity and nuclear organization are now also possible.

  5. Electrochemical catalyst recovery method

    Science.gov (United States)

    Silva, Laura J.; Bray, Lane A.

    1995-01-01

    A method of recovering catalyst material from latent catalyst material solids includes: a) combining latent catalyst material solids with a liquid acid anolyte solution and a redox material which is soluble in the acid anolyte solution to form a mixture; b) electrochemically oxidizing the redox material within the mixture into a dissolved oxidant, the oxidant having a potential for oxidation which is effectively higher than that of the latent catalyst material; c) reacting the oxidant with the latent catalyst material to oxidize the latent catalyst material into at least one oxidized catalyst species which is soluble within the mixture and to reduce the oxidant back into dissolved redox material; and d) recovering catalyst material from the oxidized catalyst species of the mixture. The invention is expected to be particularly useful in recovering spent catalyst material from petroleum hydroprocessing reaction waste products having adhered sulfides, carbon, hydrocarbons, and undesired metals, and as well as in other industrial applications.

  6. Floating Silicon Method

    Energy Technology Data Exchange (ETDEWEB)

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  7. Cyclostationarity theory and methods

    CERN Document Server

    Leśkow, Jacek; Napolitano, Antonio; Sanchez-Ramirez, Andrea

    2014-01-01

    In the last decade the research in signal analysis was dominated by models that encompass nonstationarity as an important feature. This book presents the results of a workshop held in Grodek—Poland in February 2013 which was dedicated to the investigation of cyclostationary signals. Its main objective is to highlight the strong interactions between theory and applications of cyclostationary signals with the use of modern statistical tools. An important application of cyclostationary signals is the analysis of mechanical signals generated by a vibrating mechanism. Cyclostationary models are very important to perform basic operations on signals in both time and frequency domains. One of the fundamental problems in diagnosis of rotating machine is the identification of significant modulating frequencies that contribute to the cyclostationary nature of the signals. The book shows that there are modern tools available for analyzing cyclostationary signals without the assumption of gaussianity. Those methods are...

  8. METHOD OF RECOVERING THORIUM

    Science.gov (United States)

    Fisher, R.W.

    1957-12-10

    A method is described for recovering thorium from impurities found in a slag containing thorium and said impurities, comprising leaching a composition containing thorium with water, removing the water solution, treating the residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting its acidity to 1 to 3 normal, adding oxalic acid, and thereafter separating the precipitated thorium oxalate digesting the residue from the hydrochloric acid treatment with a strong solution of sodium hydroxide at an elevated temperature, removing said solution and treating the insoluble residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting the acidity of this solution to 1 to 3 normal, adding nitric acid to oxidize the iron present, adding oxalic acid and thereafter separating the thorium oxalate thus precipitated.

  9. Ticks and control methods.

    Science.gov (United States)

    Jongejan, F; Uilenberg, G

    1994-12-01

    Ticks are the most important ectoparasites of livestock in tropical and sub-tropical areas, and are responsible for severe economic losses both through the direct effects of blood sucking and indirectly as vectors of pathogens and toxins. Feeding by large numbers of ticks causes reduction in live weight gain and anaemia among domestic animals, while tick bites also reduce the quality of hides. However, the major losses caused by ticks are due to the ability to transmit protozoan, rickettsial and viral diseases of livestock, which are of great economic importance world-wide. The authors review general aspects of tick biology, the taxonomy, pathogenic effects and vector role of these species, and methods for the control of ticks. The distribution of ticks is continuously changing, as illustrated by the spread of the African tick Amblyomma variegatum in the Caribbean, where a large-scale eradication campaign is now under way.

  10. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

    Although the field of radioactive air sampling has matured and evolved over decades, it has lacked a single resource that assimilates technical and background information on its many facets. Edited by experts and with contributions from top practitioners and researchers, Radioactive Air Sampling Methods provides authoritative guidance on measuring airborne radioactivity from industrial, research, and nuclear power operations, as well as naturally occuring radioactivity in the environment. Designed for industrial hygienists, air quality experts, and heath physicists, the book delves into the applied research advancing and transforming practice with improvements to measurement equipment, human dose modeling of inhaled radioactivity, and radiation safety regulations. To present a wide picture of the field, it covers the international and national standards that guide the quality of air sampling measurements and equipment. It discusses emergency response issues, including radioactive fallout and the assets used ...

  11. Parametric lattice Boltzmann method

    Science.gov (United States)

    Shim, Jae Wan

    2017-06-01

    The discretized equilibrium distributions of the lattice Boltzmann method are presented by using the coefficients of the Lagrange interpolating polynomials that pass through the points related to discrete velocities and using moments of the Maxwell-Boltzmann distribution. The ranges of flow velocity and temperature providing positive valued distributions vary with regulating discrete velocities as parameters. New isothermal and thermal compressible models are proposed for flows of the level of the isothermal and thermal compressible Navier-Stokes equations. Thermal compressible shock tube flows are simulated by only five on-lattice discrete velocities. Two-dimensional isothermal and thermal vortices provoked by the Kelvin-Helmholtz instability are simulated by the parametric models.

  12. Method for radioactivity monitoring

    Science.gov (United States)

    Umbarger, C. John; Cowder, Leo R.

    1976-10-26

    The disclosure relates to a method for analyzing uranium and/or thorium contents of liquid effluents preferably utilizing a sample containing counting chamber. Basically, 185.7-keV gamma rays following .sup.235 U alpha decay to .sup.231 Th which indicate .sup.235 U content and a 63-keV gamma ray doublet found in the nucleus of .sup.234 Pa, a granddaughter of .sup.238 U, are monitored and the ratio thereof taken to derive uranium content and isotopic enrichment .sup.235 U/.sup.235 U + .sup.238 U) in the liquid effluent. Thorium content is determined by monitoring the intensity of 238-keV gamma rays from the nucleus of .sup.212 Bi in the decay chain of .sup.232 Th.

  13. Method for synthesizing HMX

    Science.gov (United States)

    McGuire, Raymond R.; Coon, Clifford L.; Harrar, Jackson E.; Pearson, Richard K.

    1984-01-01

    A method and apparatus for electrochemically synthesizing N.sub.2 O.sub.5 cludes oxidizing a solution of N.sub.2 O.sub.4 /HNO.sub.3 at an anode, while maintaining a controlled potential between the N.sub.2 O.sub.4 /HNO.sub.3 solution and the anode. A potential of about 1.35 to 2.0 V vs. SCE is preferred, while a potential of about 1.80 V vs. SCE is most preferred. Thereafter, the N.sub.2 O.sub.5 is reacted with either 1.5-diacetyl-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DADN) or 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane (TAT) to form cyclotetramethylenetetraamine (HMX).

  14. The Algebraic Method

    CERN Document Server

    Grassi, P A; Steinhauser, M

    2001-01-01

    Combining the effect of an intermediate renormalization prescription (zero momentum subtraction) and the background field method (BFM), we show that the algebraic renormalization procedure needed for the computation of radiative corrections within non-invariant regularization schemes is drastically simplified. The present technique is suitable for gauge models and, here, is applied to the Standard Model. The use of the BFM allows a powerful organization of the counterterms and avoids complicated Slavnov-Taylor identities. Furthermore, the Becchi-Rouet-Stora-Tyutin (BRST) variation of background fields plays a special role in disentangling Ward-Takahashi identities (WTI) and Slavnov-Taylor identities (STI). Finally, the strategy to be applied to physical processes is exemplified for the process $b\\to s\\gamma$.

  15. Unconventional methods for clustering

    Science.gov (United States)

    Kotyrba, Martin

    2016-06-01

    Cluster analysis or clustering is a task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense or another) to each other than to those in other groups (clusters). It is the main task of exploratory data mining and a common technique for statistical data analysis used in many fields, including machine learning, pattern recognition, image analysis, information retrieval, and bioinformatics. The topic of this paper is one of the modern methods of clustering namely SOM (Self Organising Map). The paper describes the theory needed to understand the principle of clustering and descriptions of algorithm used with clustering in our experiments.

  16. Dominant modal decomposition method

    Science.gov (United States)

    Dombovari, Zoltan

    2017-03-01

    The paper deals with the automatic decomposition of experimental frequency response functions (FRF's) of mechanical structures. The decomposition of FRF's is based on the Green function representation of free vibratory systems. After the determination of the impulse dynamic subspace, the system matrix is formulated and the poles are calculated directly. By means of the corresponding eigenvectors, the contribution of each element of the impulse dynamic subspace is determined and the sufficient decomposition of the corresponding FRF is carried out. With the presented dominant modal decomposition (DMD) method, the mode shapes, the modal participation vectors and the modal scaling factors are identified using the decomposed FRF's. Analytical example is presented along with experimental case studies taken from machine tool industry.

  17. Method for maskless lithography

    Science.gov (United States)

    Sweatt, William C.; Stulen, Richard H.

    2000-01-01

    The present invention provides a method for maskless lithography. A plurality of individually addressable and rotatable micromirrors together comprise a two-dimensional array of micromirrors. Each micromirror in the two-dimensional array can be envisioned as an individually addressable element in the picture that comprises the circuit pattern desired. As each micromirror is addressed it rotates so as to reflect light from a light source onto a portion of the photoresist coated wafer thereby forming a pixel within the circuit pattern. By electronically addressing a two-dimensional array of these micromirrors in the proper sequence a circuit pattern that is comprised of these individual pixels can be constructed on a microchip. The reflecting surface of the micromirror is configured in such a way as to overcome coherence and diffraction effects in order to produce circuit elements having straight sides.

  18. Geophysical Methods: an Overview

    Science.gov (United States)

    Becker, A.; Goldstein, N. E.; Lee, K. H.; Majer, E. L.; Morrison, H. F.; Myer, L.

    1992-01-01

    Geophysics is expected to have a major role in lunar resource assessment when manned systems return to the Moon. Geophysical measurements made from a lunar rover will contribute to a number of key studies: estimating regolith thickness, detection of possible large-diameter lava tubes within maria basalts, detection of possible subsurface ice in polar regions, detection of conductive minerals that formed directly from a melt (orthomagmatic sulfides of Cu, Ni, Co), and mapping lunar geology beneath the regolith. The techniques that can be used are dictated both by objectives and by our abilities to adapt current technology to lunar conditions. Instrument size, weight, power requirements, and freedom from orientation errors are factors we have considered. Among the geophysical methods we believe to be appropriate for a lunar resource assessment are magnetics, including gradiometry, time-domain magnetic induction, ground-penetrating radar, seismic reflection, and gravimetry.

  19. Mathematical methods in engineering

    CERN Document Server

    Machado, José

    2014-01-01

    This book presents a careful selection of the contributions presented at the Mathematical Methods in Engineering (MME10) International Symposium, held at the Polytechnic Institute of Coimbra- Engineering Institute of Coimbra (IPC/ISEC), Portugal, October 21-24, 2010. The volume discusses recent developments about theoretical and applied mathematics toward the solution of engineering problems, thus covering a wide range of topics, such as:  Automatic Control, Autonomous Systems, Computer Science, Dynamical Systems and Control,  Electronics, Finance and Economics, Fluid Mechanics and Heat Transfer, Fractional Mathematics, Fractional Transforms and Their Applications,  Fuzzy Sets and Systems, Image and Signal Analysis, Image Processing, Mechanics, Mechatronics, Motor Control and Human Movement Analysis, Nonlinear Dynamics, Partial Differential Equations, Robotics, Acoustics, Vibration and Control, and Wavelets.

  20. Remanufacturability and Assessment Method

    Institute of Scientific and Technical Information of China (English)

    ZHU Sheng; CUI Pei-zhi; YAO Ju-kun

    2004-01-01

    Remanufacturing represents the combination of "three Rs" (reduce, reuse, recycle) into a single activity, which restores a wide variety of worn-out, discarded durable products to like-new condition, prolonging theit useful life,protecting the environment. The application of surface engineering has promoted the development of remanufacturing.Remanufacturing is an environmentally and economically sound way to achieve many of the goals of sustainable development. Through developing study of product design for remanufacturing, it can promote the surface technologies application in the remanufacturing, and markedly enhance the efficiency of remanufacturing. This paper gives some relative concepts about product design for remanufacturing, such as remanufacturability, and brings forward the remanufacturability research contents and assessment method of used product.

  1. Acoustophoresis separation method

    Science.gov (United States)

    Heyman, Joseph S. (Inventor)

    1993-01-01

    A method and apparatus are provided for acoustophoresis, i.e., the separation of species via acoustic waves. An ultrasonic transducer applies an acoustic wave to one end of a sample container containing at least two species having different acoustic absorptions. The wave has a frequency tuned to or harmonized with the point of resonance of the species to be separated. This wave causes the species to be driven to an opposite end of the sample container for removal. A second ultrasonic transducer may be provided to apply a second, oppositely directed acoustic wave to prevent undesired streaming. In addition, a radio frequency tuned to the mechanical resonance and coupled with a magnetic field can serve to identify a species in a medium comprising species with similar absorption coefficients, whereby an acoustic wave having a frequency corresponding to this gyrational rate can then be applied to sweep the identified species to one end of the container for removal.

  2. Remanufacturability and Assessment Method

    Institute of Scientific and Technical Information of China (English)

    ZHUSheng; CUIPei-zhi; YAOJu-kun

    2004-01-01

    Remanufacturing represents the combination of "three Rs" (reduce, reuse, recycle) into a single activity, which restores a wide variety of worn-out, discarded durable products to like-new condition, prolonging their useful life, protecting the environment. The application of surface engineering has promoted the development of remanufacturing. Remanufacturing is an environmentally and economically sound way to achieve many of the goals of sustainable development. Through developing study of product design for remanufacturing, it can promote the surface technologies application in the remanufacturing, and markedly enhance the efficiency of remanufacturing. This paper gives some relative concepts about product design for remanufacturing, such as remanufacturability, and brings forward the remanufacturability research contents and assessment method of used product.

  3. Gas centrifuge purge method

    Science.gov (United States)

    Theurich, Gordon R.

    1976-01-01

    1. In a method of separating isotopes in a high speed gas centrifuge wherein a vertically oriented cylindrical rotor bowl is adapted to rotate about its axis within an evacuated chamber, and wherein an annular molecular pump having an intake end and a discharge end encircles the uppermost portion of said rotor bowl, said molecular pump being attached along its periphery in a leak-tight manner to said evacuated chamber, and wherein end cap closure means are affixed to the upper end of said rotor bowl, and a process gas withdrawal and insertion system enters said bowl through said end cap closure means, said evacuated chamber, molecular pump and end cap defining an upper zone at the discharge end of said molecular pump, said evacuated chamber, molecular pump and rotor bowl defining a lower annular zone at the intake end of said molecular pump, a method for removing gases from said upper and lower zones during centrifuge operation with a minimum loss of process gas from said rotor bowl, comprising, in combination: continuously measuring the pressure in said upper zone, pumping gas from said lower zone from the time the pressure in said upper zone equals a first preselected value until the pressure in said upper zone is equal to a second preselected value, said first preselected value being greater than said second preselected value, and continuously pumping gas from said upper zone from the time the pressure in said upper zone equals a third preselected value until the pressure in said upper zone is equal to a fourth preselected value, said third preselected value being greater than said first, second and fourth preselected values.

  4. Characterization Methods of Encapsulates

    Science.gov (United States)

    Zhang, Zhibing; Law, Daniel; Lian, Guoping

    , reliable methods which can be used to characterize these properties of encapsulates are vital. In this chapter, the state-of-art of these methods, their principles and applications, and release mechanisms are described as follows.

  5. Location predicting methods for UAVs

    Science.gov (United States)

    Peng, Xiaodong; Zhang, Yu

    2017-08-01

    Location prediction of unmanned aerial vehicle (UAV) is important for fighting with its enemy and ensuring its normal operation. This paper presents the motion model of UAVs and reduces the state space into 7 dimensions. The Bayesian Network, Markov Chain, Curve Fitting and Neural Network are introduced for designing predicting methods. Then Curve Fitting Predicting method, Markov Chain Predicting method, Bayesian Network Predicting method and Neural Network Predicting method are designed for UAVs. The simulation result shows that 1) Neural Network Predicting method has highest predicting accuracy; 2) Markov Chain Predicting method and Bayesian Network Predicting method methods have similar performance and both are better than Bayesian Network Predicting method methods; 3) Neural Network Predicting method is the first choice when predicting the locations of UAVs.

  6. Section for qualitative methods (Letter)

    OpenAIRE

    Todd, Z.; Madill, A.

    2004-01-01

    Qualitative research methods are increasingly used in all areas of psychology. We have proposed a new Section – the Qualitative Methods in Psychology Section – for anyone with an interest in using these research methods.

  7. Methods and Technologies Branch (MTB)

    Science.gov (United States)

    The Methods and Technologies Branch focuses on methods to address epidemiologic data collection, study design and analysis, and to modify technological approaches to better understand cancer susceptibility.

  8. 40 years of formal methods

    DEFF Research Database (Denmark)

    Bjørner, Dines; Havelund, Klaus

    2014-01-01

    In this "40 years of formal methods" essay we shall first delineate, Sect. 1, what we mean by method, formal method, computer science, computing science, software engineering, and model-oriented and algebraic methods. Based on this, we shall characterize a spectrum from specification-oriented met......In this "40 years of formal methods" essay we shall first delineate, Sect. 1, what we mean by method, formal method, computer science, computing science, software engineering, and model-oriented and algebraic methods. Based on this, we shall characterize a spectrum from specification...

  9. Comparative law as method and the method of comparative law

    NARCIS (Netherlands)

    Hage, J.C.; Adams, M.; Heirbaut, D.

    2014-01-01

    This article addresses both the justificatory role of comparative law within legal research (comparative law as method) and the method of comparative law itself. In this connection two questions will be answered: 1. Is comparative law a method, or a set of methods, for legal research? 2. Does compar

  10. Production Methods for Hyaluronan

    Directory of Open Access Journals (Sweden)

    Carmen G. Boeriu

    2013-01-01

    Full Text Available Hyaluronan is a polysaccharide with multiple functions in the human body being involved in creating flexible and protective layers in tissues and in many signalling pathways during embryonic development, wound healing, inflammation, and cancer. Hyaluronan is an important component of active pharmaceutical ingredients for treatment of, for example, arthritis and osteoarthritis, and its commercial value far exceeds that of other microbial extracellular polysaccharides. Traditionally hyaluronan is extracted from animal waste which is a well-established process now. However, biotechnological synthesis of biopolymers provides a wealth of new possibilities. Therefore, genetic/metabolic engineering has been applied in the area of tailor-made hyaluronan synthesis. Another approach is the controlled artificial (in vitro synthesis of hyaluronan by enzymes. Advantage of using microbial and enzymatic synthesis for hyaluronan production is the simpler downstream processing and a reduced risk of viral contamination. In this paper an overview of the different methods used to produce hyaluronan is presented. Emphasis is on the advancements made in the field of the synthesis of bioengineered hyaluronan.

  11. Conference on Logical Methods

    CERN Document Server

    Remmel, Jeffrey; Shore, Richard; Sweedler, Moss; Progress in Computer Science and Applied Logic

    1993-01-01

    The twenty-six papers in this volume reflect the wide and still expanding range of Anil Nerode's work. A conference on Logical Methods was held in honor of Nerode's sixtieth birthday (4 June 1992) at the Mathematical Sciences Institute, Cornell University, 1-3 June 1992. Some of the conference papers are here, but others are from students, co-workers and other colleagues. The intention of the conference was to look forward, and to see the directions currently being pursued, in the development of work by, or with, Nerode. Here is a brief summary of the contents of this book. We give a retrospective view of Nerode's work. A number of specific areas are readily discerned: recursive equivalence types, recursive algebra and model theory, the theory of Turing degrees and r.e. sets, polynomial-time computability and computer science. Nerode began with automata theory and has also taken a keen interest in the history of mathematics. All these areas are represented. The one area missing is Nerode's applied mathematica...

  12. Statistical methods for forecasting

    CERN Document Server

    Abraham, Bovas

    2009-01-01

    The Wiley-Interscience Paperback Series consists of selected books that have been made more accessible to consumers in an effort to increase global appeal and general circulation. With these new unabridged softcover volumes, Wiley hopes to extend the lives of these works by making them available to future generations of statisticians, mathematicians, and scientists."This book, it must be said, lives up to the words on its advertising cover: ''Bridging the gap between introductory, descriptive approaches and highly advanced theoretical treatises, it provides a practical, intermediate level discussion of a variety of forecasting tools, and explains how they relate to one another, both in theory and practice.'' It does just that!"-Journal of the Royal Statistical Society"A well-written work that deals with statistical methods and models that can be used to produce short-term forecasts, this book has wide-ranging applications. It could be used in the context of a study of regression, forecasting, and time series ...

  13. Acoustic data transmission method

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, A.

    1991-09-17

    This patent describes a method for transmitting time line data through a drillstring having drill pipe sections connected end-to-end by joints from a first location below the surface of the earth to a second location at or near the surface of the earth, the length and cross-sectional area of the drill pipe sections being different from the length and cross-sectional area of the joints. It comprises generating acoustic data signals having a single frequency content in at least one passband of the drillstring; transmitting the data signals through the drillstring from either the first location to the second location or from the second location to the first location during a time period prior to the onset of reflective interference caused by the data signals reflecting from along the length of the drillstring, the time period being equal to or less than the time for the data signals to travel three lengths of the drillstring; stopping the transmission of data signals at the onset of the reflective interference and allowing the acoustic signals to substantially attenuate; and detecting the data signals at the respective first or second location.

  14. NCSX Plasma Heating Methods

    Energy Technology Data Exchange (ETDEWEB)

    H.W. Kugel; D. Spong; R. Majeski; M. Zarnstorff

    2003-02-28

    The NCSX (National Compact Stellarator Experiment) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral-beam injection, and radio-frequency. Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The plan is to provide 3 MW of 50 keV balanced neutral-beam tangential injection with pulse lengths of 500 msec for initial experiments, and to be upgradeable to pulse lengths of 1.5 sec. Subsequent upgrades will add 3 MW of neutral-beam injection. This Chapter discusses the NCSX neutral-beam injection requirements and design issues, and shows how these are provided by the candidate PBX-M (Princeton Beta Experiment-Modification) neutral-beam injection system. In addition, estimations are given for beam-heating efficiencies, scaling of heating efficiency with machine size an d magnetic field level, parameter studies of the optimum beam-injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of radio-frequency heating by mode-conversion ion-Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron-cyclotron heating. The initial MCIBW heating technique and the design of the radio-frequency system lend themselves to current drive, so that if current drive became desirable for any reason only minor modifications to the heating system described here would be needed. The radio-frequency system will also be capable of localized ion heating (bulk or tail), and possibly ion-Bernstein-wave-generated sheared flows.

  15. NCSX Plasma Heating Methods

    Energy Technology Data Exchange (ETDEWEB)

    Kugel, H. W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-18

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possiblyIBW-generated sheared flows.

  16. A method cache for Patmos

    DEFF Research Database (Denmark)

    Degasperi, Philipp; Hepp, Stefan; Puffitsch, Wolfgang;

    2014-01-01

    For real-time systems we need time-predictable processors. This paper presents a method cache as a time-predictable solution for instruction caching. The method cache caches whole methods (or functions) and simplifies worst-case execution time analysis. We have integrated the method cache...

  17. Methods of bicycle users’ survey

    OpenAIRE

    Tokmylenko, Olena

    2015-01-01

    The paper provides a review of data collection methods that can be used for bicycling modeling and planning. The review includes fifteen international studies that use different methods of data collection. The main advantages and disadvantages of each method are listed and the recommendations on when to use particular method are provided.

  18. Explorative methods in linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2004-01-01

    The author has developed the H-method of mathematical modeling that builds up the model by parts, where each part is optimized with respect to prediction. Besides providing with better predictions than traditional methods, these methods provide with graphic procedures for analyzing different feat...... features in data. These graphic methods extend the well-known methods and results of Principal Component Analysis to any linear model. Here the graphic procedures are applied to linear regression and Ridge Regression....

  19. Explorative methods in linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2004-01-01

    The author has developed the H-method of mathematical modeling that builds up the model by parts, where each part is optimized with respect to prediction. Besides providing with better predictions than traditional methods, these methods provide with graphic procedures for analyzing different...... features in data. These graphic methods extend the well-known methods and results of Principal Component Analysis to any linear model. Here the graphic procedures are applied to linear regression and Ridge Regression....

  20. Method Points: towards a metric for method complexity

    Directory of Open Access Journals (Sweden)

    Graham McLeod

    1998-11-01

    Full Text Available A metric for method complexity is proposed as an aid to choosing between competing methods, as well as in validating the effects of method integration or the products of method engineering work. It is based upon a generic method representation model previously developed by the author and adaptation of concepts used in the popular Function Point metric for system size. The proposed technique is illustrated by comparing two popular I.E. deliverables with counterparts in the object oriented Unified Modeling Language (UML. The paper recommends ways to improve the practical adoption of new methods.

  1. NEW ACCELERATION METHODS

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, A.M.

    1984-07-01

    But a glance at the Livingston chart, Fig. 1, of accelerator particle energy as a function of time shows that the energy has steadily, exponentially, increased. Equally significant is the fact that this increase is the envelope of diverse technologies. If one is to stay on, or even near, the Livingston curve in future years then new acceleration techniques need to be developed. What are the new acceleration methods? In these two lectures I would like to sketch some of these new ideas. I am well aware that they will probably not result in high energy accelerators within this or the next decade, but conversely, it is likely that these ideas will form the basis for the accelerators of the next century. Anyway, the ideas are stimulating and suffice to show that accelerator physicists are not just 'engineers', but genuine scientists deserving to be welcomed into the company of high energy physicists. I believe that outsiders will find this field surprisingly fertile and, certainly fun. To put it more personally, I very much enjoy working in this field and lecturing on it. There are a number of review articles which should be consulted for references to the original literature. In addition there are three books on the subject. Given this material, I feel free to not completely reference the material in the remainder of this article; consultation of the review articles and books will be adequate as an introduction to the literature for references abound (hundreds are given). At last, by way of introduction, I should like to quote from the end of Ref. 2 for I think the remarks made there are most germane. Remember that the talk was addressed to accelerator physicists: 'Finally, it is often said, I think by physicists who are not well-informed, that accelerator builders have used up their capital and now are bereft of ideas, and as a result, high energy physics will eventually--rather soon, in fact--come to a halt. After all, one can't build too many

  2. Dianhydrides, polyimides, methods of making each, and methods of use

    KAUST Repository

    Ma, Xiaohua

    2015-01-08

    Embodiments of the present disclosure provide for an aromatic dianhydride, a method of making an aromatic dianhydride, an aromatic dianhydride-based polyimide, a method of making an aromatic dianhydride-based polyimide, and the like.

  3. Alternative methods in toxicology: pre-validated and validated methods

    OpenAIRE

    2011-01-01

    The development of alternative methods to animal experimentation has progressed rapidly over the last 20 years. Today, in vitro and in silico methods have an important role in the hazard identification and assessment of toxicology profile of compounds. Advanced alternative methods and their combinations are also used for safety assessment of final products. Several alternative methods, which were scientifically validated and accepted by competent regulatory bodies, can be used for regulatory ...

  4. The Value of Mixed Methods Research: A Mixed Methods Study

    Science.gov (United States)

    McKim, Courtney A.

    2017-01-01

    The purpose of this explanatory mixed methods study was to examine the perceived value of mixed methods research for graduate students. The quantitative phase was an experiment examining the effect of a passage's methodology on students' perceived value. Results indicated students scored the mixed methods passage as more valuable than those who…

  5. Catalysts, methods of making catalysts, and methods of use

    KAUST Repository

    Renard, Laetitia

    2014-03-06

    Embodiments of the present disclosure provide for catalysts, methods of making catalysts, methods of using catalysts, and the like. In an embodiment, the method of making the catalysts can be performed in a single step with a metal nanoparticle precursor and a metal oxide precursor, where a separate stabilizing agent is not needed.

  6. Multiple Methods: Research Methods in Education Projects at NSF

    Science.gov (United States)

    Suter, Larry E.

    2005-01-01

    Projects on science and mathematics education research supported by the National Science Foundation (US government) rarely employ a single method of study. Studies of educational practices that use experimental design are very rare. The most common research method is the case study method and the second most common is some form of experimental…

  7. Stated preference methods using R

    CERN Document Server

    Aizaki, Hideo; Sato, Kazuo

    2014-01-01

    Stated Preference Methods Using R explains how to use stated preference (SP) methods, which are a family of survey methods, to measure people's preferences based on decision making in hypothetical choice situations. Along with giving introductory explanations of the methods, the book collates information on existing R functions and packages as well as those prepared by the authors. It focuses on core SP methods, including contingent valuation (CV), discrete choice experiments (DCEs), and best-worst scaling (BWS). Several example data sets illustrate empirical applications of each method with R

  8. Lectures on Monte Carlo methods

    CERN Document Server

    Madras, Neal

    2001-01-01

    Monte Carlo methods form an experimental branch of mathematics that employs simulations driven by random number generators. These methods are often used when others fail, since they are much less sensitive to the "curse of dimensionality", which plagues deterministic methods in problems with a large number of variables. Monte Carlo methods are used in many fields: mathematics, statistics, physics, chemistry, finance, computer science, and biology, for instance. This book is an introduction to Monte Carlo methods for anyone who would like to use these methods to study various kinds of mathemati

  9. Blindman-Walking Optimization Method

    Directory of Open Access Journals (Sweden)

    Chunming Li

    2010-12-01

    Full Text Available Optimization methods are all implemented with the hypothesis of unknowing the mathematic express of objective objection. Using the human analogy innovative method, the one-dimension blind-walking optimal method is proposed in this paper. The theory and the algorithm of this method includes halving, doubling, reversing probing step and verifying the applicability condition. Double-step is available to make current point moving to the extremum point. Half-step is available to accelerate convergence. In order to improve the optimization, the applicability condition decides whether update current point or not. The operation process, algorithmic flow chart and characteristic analysis of the method were given. Two optimization problems with unimodal or multimodal objective function were solved by the proposed method respectively. The simulation result shows that the proposed method is better than the ordinary method. The proposed method has the merit of rapid convergence, little calculation capacity, wide applicable range, etc. Taking the method as innovative kernel, the random research method, feasible direction method and complex shape method were improved. Taking the innovative content of this paper as innovative kernel, a monograph was published. The other innovations of the monograph are listed, such as applied algorithm of Karush-Kuhn-Tucker (KKT qualifications on judging the restriction extremum point, the design step of computing software, the complementarity and derivation of Powell criterion, the method of keeping the complex shape not to deduce dimension and the analysis of gradual optimization characteristic, the reinforced wall of inner point punish function method, the analysis of problem with constrained monstrosity extremum point, the improvement of Newton method and the validation of optimization idea of blind walking repeatedly, the explanation of later-day optimization method, the conformity of seeking algorithm needing the

  10. Numerical Methods for Stochastic Computations A Spectral Method Approach

    CERN Document Server

    Xiu, Dongbin

    2010-01-01

    The first graduate-level textbook to focus on fundamental aspects of numerical methods for stochastic computations, this book describes the class of numerical methods based on generalized polynomial chaos (gPC). These fast, efficient, and accurate methods are an extension of the classical spectral methods of high-dimensional random spaces. Designed to simulate complex systems subject to random inputs, these methods are widely used in many areas of computer science and engineering. The book introduces polynomial approximation theory and probability theory; describes the basic theory of gPC meth

  11. Birth control - slow release methods

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007555.htm Birth control - slow release methods To use the sharing features on this page, please enable JavaScript. Certain birth control methods contain man-made forms of hormones. These ...

  12. Mixed methods research for TESOL

    CERN Document Server

    Brown, James; Farr, Fiona

    2014-01-01

    Defining and discussing the relevance of theoretical and practical issues involved in mixed methods research. Covering the basics of research methodology, this textbook shows you how to choose and combine quantitative and qualitative research methods to b

  13. Analytic Methods in Investigative Geometry.

    Science.gov (United States)

    Dobbs, David E.

    2001-01-01

    Suggests an alternative proof by analytic methods, which is more accessible than rigorous proof based on Euclid's Elements, in which students need only apply standard methods of trigonometry to the data without introducing new points or lines. (KHR)

  14. Operator theory and numerical methods

    CERN Document Server

    Fujita, H; Suzuki, T

    2001-01-01

    In accordance with the developments in computation, theoretical studies on numerical schemes are now fruitful and highly needed. In 1991 an article on the finite element method applied to evolutionary problems was published. Following the method, basically this book studies various schemes from operator theoretical points of view. Many parts are devoted to the finite element method, but other schemes and problems (charge simulation method, domain decomposition method, nonlinear problems, and so forth) are also discussed, motivated by the observation that practically useful schemes have fine mathematical structures and the converses are also true. This book has the following chapters: 1. Boundary Value Problems and FEM. 2. Semigroup Theory and FEM. 3. Evolution Equations and FEM. 4. Other Methods in Time Discretization. 5. Other Methods in Space Discretization. 6. Nonlinear Problems. 7. Domain Decomposition Method.

  15. International Conference eXtended Discretization MethodS

    CERN Document Server

    Benvenuti, Elena

    2016-01-01

    This book gathers selected contributions on emerging research work presented at the International Conference eXtended Discretization MethodS (X-DMS), held in Ferrara in September 2015. It highlights the most relevant advances made at the international level in the context of expanding classical discretization methods, like finite elements, to the numerical analysis of a variety of physical problems. The improvements are intended to achieve higher computational efficiency and to account for special features of the solution directly in the approximation space and/or in the discretization procedure. The methods described include, among others, partition of unity methods (meshfree, XFEM, GFEM), virtual element methods, fictitious domain methods, and special techniques for static and evolving interfaces. The uniting feature of all contributions is the direct link between computational methodologies and their application to different engineering areas.

  16. Alternative methods in toxicology: pre-validated and validated methods.

    Science.gov (United States)

    Kandárová, Helena; Letašiová, Silvia

    2011-09-01

    The development of alternative methods to animal experimentation has progressed rapidly over the last 20 years. Today, in vitro and in silico methods have an important role in the hazard identification and assessment of toxicology profile of compounds. Advanced alternative methods and their combinations are also used for safety assessment of final products. Several alternative methods, which were scientifically validated and accepted by competent regulatory bodies, can be used for regulatory toxicology purposes, thus reducing or fully replacing living animals in toxicology experimentation. The acceptance of the alternative methods as valuable tools of modern toxicology has been recognized by regulators, including OECD, FDA and EPA.This paper provides a brief overview of the topic "alternative methods in toxicology" and focuses on pre-validated and validated alternative methods and their position in the modern toxicology.

  17. SYMPLECTIC RK METHODS AND SYMPLECTIC PRK METHODS WITH REAL EIGENVALUES

    Institute of Scientific and Technical Information of China (English)

    Hong-yu Liu; Geng Sun

    2004-01-01

    Properties of symplectic Runge-Kutta (RK) methods and symplectic partitioned RungeKutta (PRK) methods with real eigenvalues are discussed in this paper. It is shown that an s stage such method can't reach order more than s + 1. Particularly, we prove that no symplectic RK method with real eigenvalues exists in stage s of order s + 1 when s is even. But an example constructed by using the W-transformation shows that PRK method of this type does not necessarily meet this order barrier. Another useful way other than W-transformation to construct symplectic PRK method with real eigenvalues is then presented. Finally, a class of efficient symplectic methods is recommended.

  18. Mining method selection by integrated AHP and PROMETHEE method.

    Science.gov (United States)

    Bogdanovic, Dejan; Nikolic, Djordje; Ilic, Ivana

    2012-03-01

    Selecting the best mining method among many alternatives is a multicriteria decision making problem. The aim of this paper is to demonstrate the implementation of an integrated approach that employs AHP and PROMETHEE together for selecting the most suitable mining method for the "Coka Marin" underground mine in Serbia. The related problem includes five possible mining methods and eleven criteria to evaluate them. Criteria are accurately chosen in order to cover the most important parameters that impact on the mining method selection, such as geological and geotechnical properties, economic parameters and geographical factors. The AHP is used to analyze the structure of the mining method selection problem and to determine weights of the criteria, and PROMETHEE method is used to obtain the final ranking and to make a sensitivity analysis by changing the weights. The results have shown that the proposed integrated method can be successfully used in solving mining engineering problems.

  19. Methods for Equating Mental Tests.

    Science.gov (United States)

    1984-11-01

    1983) compared conventional and IRT methods for equating the Test of English as a Foreign Language ( TOEFL ) after chaining. Three conventional and...three IRT equating methods were examined in this study; two sections of TOEFL were each (separately) equated. The IRT methods included the following: (a...group. A separate base form was established for each of the six equating methods. Instead of equating the base-form TOEFL to itself, the last (eighth

  20. Physics-compatible numerical methods

    OpenAIRE

    Barry, Koren; Abgrall, Remi; Pavel, Bochev; Jason, Frank; Blair, Perrot

    2014-01-01

    International audience; Physics-compatible numerical methods are methods that aim to preserve key mathematical and physical properties of continuum physics models in their finite-dimensional algebraic representations. They include methods which preserve properties such as energy, monotonicity, maximum principles, symmetries, and involutions of the continuum models. Examples are mimetic methods for spatial discretizations, variational and geometric integrators, conservative finite-volume and f...

  1. Probabilistic methods for rotordynamics analysis

    Science.gov (United States)

    Wu, Y.-T.; Torng, T. Y.; Millwater, H. R.; Fossum, A. F.; Rheinfurth, M. H.

    1991-01-01

    This paper summarizes the development of the methods and a computer program to compute the probability of instability of dynamic systems that can be represented by a system of second-order ordinary linear differential equations. Two instability criteria based upon the eigenvalues or Routh-Hurwitz test functions are investigated. Computational methods based on a fast probability integration concept and an efficient adaptive importance sampling method are proposed to perform efficient probabilistic analysis. A numerical example is provided to demonstrate the methods.

  2. Formal Methods in Knowledge Engineering

    NARCIS (Netherlands)

    Harmelen, van F.A.H.; Fensel, D.

    1995-01-01

    This paper presents a general discussion of the role of formal methods in Knowledge Engineering. We give an historical account of the development of the field of Knowledge Engineering towards the use of formal methods. Subsequently, we discuss the pro's and cons of formal methods. We do this by summ

  3. Methods of analyzing crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Cooks, Robert Graham; Jjunju, Fred Paul Mark; Li, Anyin; Rogan, Iman S.

    2017-08-15

    The invention generally relates to methods of analyzing crude oil. In certain embodiments, methods of the invention involve obtaining a crude oil sample, and subjecting the crude oil sample to mass spectrometry analysis. In certain embodiments, the method is performed without any sample pre-purification steps.

  4. Chemical control methods and tools

    Science.gov (United States)

    Steven Manning; James. Miller

    2011-01-01

    After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

  5. Extraction Methods, Variability Encountered in

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Bias in DNA extractions methods; Variation in DNA extraction methods Definition The variability in extraction methods is defined as differences in quality and quantity of DNA observed using various extraction protocols, leading to differences in outcome of microbial community composition

  6. Indirect methods in nuclear astrophysics

    CERN Document Server

    Bertulani, C A; Mukhamedzhanov, A; Kadyrov, A S; Kruppa, A; Pang, D Y

    2015-01-01

    We discuss recent developments in indirect methods used in nuclear astrophysics to determine the capture cross sections and subsequent rates of various stellar burning processes, when it is difficult to perform the corresponding direct measurements. We discuss in brief, the basic concepts of Asymptotic Normalization Coefficients, the Trojan Horse Method, the Coulomb Dissociation Method, (d,p), and charge-exchange reactions.

  7. Multistep method for controlling chaos

    Science.gov (United States)

    Starobinets, Igor M.; Pikovsky, Arkady S.

    1993-10-01

    We present a multistep control method where the trajectory on a chaotic attractor is directed by small perturbations towards a chosen fixed point. The method gives a significant reduction of the chaotic transient preceding the controlled motion as compared with the Ott-Grebogi-Yorke method. Transition from local to global control, when chaotic transients disappear, is discussed.

  8. Rapid Statistical Methods: Part 1.

    Science.gov (United States)

    Lyon, A. J.

    1980-01-01

    Discusses some rapid statistical methods which are intended for use by physics teachers. Part one of this article gives some of the simplest and most commonly useful rapid methods. Part two gives references to the relevant theory together with some alternative and additional methods. (HM)

  9. Formal Methods in Knowledge Engineering

    NARCIS (Netherlands)

    Harmelen, van F.A.H.; Fensel, D.

    1995-01-01

    This paper presents a general discussion of the role of formal methods in Knowledge Engineering. We give an historical account of the development of the field of Knowledge Engineering towards the use of formal methods. Subsequently, we discuss the pro's and cons of formal methods. We do this by

  10. Activity based costing (ABC Method

    Directory of Open Access Journals (Sweden)

    Prof. Ph.D. Saveta Tudorache

    2008-05-01

    Full Text Available In the present paper the need and advantages are presented of using the Activity BasedCosting method, need arising from the need of solving the information pertinence issue. This issue has occurreddue to the limitation of classic methods in this field, limitation also reflected by the disadvantages ofsuch classic methods in establishing complete costs.

  11. Method for alignment of microwires

    Energy Technology Data Exchange (ETDEWEB)

    Beardslee, Joseph A.; Lewis, Nathan S.; Sadtler, Bryce

    2017-01-24

    A method of aligning microwires includes modifying the microwires so they are more responsive to a magnetic field. The method also includes using a magnetic field so as to magnetically align the microwires. The method can further include capturing the microwires in a solid support structure that retains the longitudinal alignment of the microwires when the magnetic field is not applied to the microwires.

  12. Another Form for LAMBDA Method

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yangmei; LIU Jingnan

    2003-01-01

    The LAMBDA methodthat was proposed by Teunissen is introduced. Then, on the basis of both the back-sequential conditional LS technique and the upper-triangular Cholesky decomposition, another form for LAMBDA method is proposed.This new form for LAMBDA method has the same principle and calculation speed as the traditional LAMBDA method.

  13. Reduced basis heterogeneous multiscale methods

    OpenAIRE

    Abdulle, Assyr

    2015-01-01

    Numerical methods for partial differential equations with multiple scales that combine numerical homogenization methods with reduced order modeling techniques are discussed. These numerical methods can be applied to a variety of problems including multiscale nonlinear elliptic and parabolic problems or Stokes flow in heterogenenous media.

  14. Extraction Methods, Variability Encountered in

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Bias in DNA extractions methods; Variation in DNA extraction methods Definition The variability in extraction methods is defined as differences in quality and quantity of DNA observed using various extraction protocols, leading to differences in outcome of microbial community composition as

  15. Mixed Method Research: An Overview

    Directory of Open Access Journals (Sweden)

    Dewan Mahboob HOSSAIN

    2012-12-01

    Full Text Available This article gives a general overview of mixed method research. In mixed method, the researchers combine both qualitative and quantitative approaches in a single research project. The article first attempts to define mixed method research. Then it gives a comparison of qualitative and quantitative approaches. It also introduces the well-known controversy among the researchers: which of these approaches is superior? By explaining this controversy, the article identifies the need for mixed method research. Lastly, the article describes the process of mixed method research.

  16. Immersed interface methods. Final report

    Energy Technology Data Exchange (ETDEWEB)

    LeVeque, R.J.; Adams, L.M.; Bube, K.P.

    1996-11-01

    Cartesian grid methods encompass a wide variety of techniques used to solve partial differential equations in more than one space dimension on uniform Cartesian grids even when the underlying geometry is complex and not aligned with the grid. The authors` groups work on Immersed Interface Methods (IIM) was originally motivated by the desire to understand and improve the ``Immersed Boundary Method``, developed by Charles Peskin to solve incompressible Navier-Stokes equations in complicated geometries with moving elastic boundaries. This report briefly discusses the development of the Immersed Interface Methods and gives examples of application of the method in solving several partial differential equations.

  17. Excitation Methods for Bridge Structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

    1999-02-08

    This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

  18. 40 years of formal methods

    DEFF Research Database (Denmark)

    Bjørner, Dines; Havelund, Klaus

    2014-01-01

    -oriented methods to analysis-oriented methods. Then, Sect. 2, we shall provide a "survey": which are the 'prerequisite works' that have enabled formal methods, Sect. 2.1, and which are, to us, the, by now, classical 'formal methods', Sect. 2.2. We then ask ourselves the question: have formal methods for software......" is complemented, in Sect. 3.4, by a "looking forward" at some promising developments-besides the alleviation of the (eighth or more) hindrances! © 2014 Springer International Publishing Switzerland....

  19. Factorization method of quadratic template

    Science.gov (United States)

    Kotyrba, Martin

    2017-07-01

    Multiplication of two numbers is a one-way function in mathematics. Any attempt to distribute the outcome to its roots is called factorization. There are many methods such as Fermat's factorization, Dixońs method or quadratic sieve and GNFS, which use sophisticated techniques fast factorization. All the above methods use the same basic formula differing only in its use. This article discusses a newly designed factorization method. Effective implementation of this method in programs is not important, it only represents and clearly defines its properties.

  20. Overview of paint removal methods

    Science.gov (United States)

    Foster, Terry

    1995-04-01

    With the introduction of strict environmental regulations governing the use and disposal of methylene chloride and phenols, major components of chemical paint strippers, there have been many new environmentally safe and effective methods of paint removal developed. The new methods developed for removing coatings from aircraft and aircraft components include: mechanical methods using abrasive media such as plastic, wheat starch, walnut shells, ice and dry ice, environmentally safe chemical strippers and paint softeners, and optical methods such as lasers and flash lamps. Each method has its advantages and disadvantages, and some have unique applications. For example, mechanical and abrasive methods can damage sensitive surfaces such as composite materials and strict control of blast parameters and conditions are required. Optical methods can be slow, leaving paint residues, and chemical methods may not remove all of the coating or require special coating formulations to be effective. As an introduction to environmentally safe and effective methods of paint removal, this paper is an overview of the various methods available. The purpose of this overview is to introduce the various paint removal methods available.

  1. Method of making alkyl esters

    Science.gov (United States)

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  2. An Extended Keyword Extraction Method

    Science.gov (United States)

    Hong, Bao; Zhen, Deng

    Among numerous Chinese keyword extraction methods, Chinese characteristics were shortly considered. This phenomenon going against the precision enhancement of the Chinese keyword extraction. An extended term frequency based method(Extended TF) is proposed in this paper which combined Chinese linguistic characteristics with basic TF method. Unary, binary and ternary grammars for the candidate keyword extraction as well as other linguistic features were all taken into account. The method establishes classification model using support vector machine. Tests show that the proposed extraction method improved key words precision and recall rate significantly. We applied the key words extracted by the extended TF method into the text file classification. Results show that the key words extracted by the proposed method contributed greatly to raising the precision of text file classification.

  3. Compositions, antibodies, asthma diagnosis methods, and methods for preparing antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hongjun; Zangar, Richard C.

    2017-01-17

    Methods for preparing an antibody are provided with the method including incorporating 3-bromo-4-hydroxy-benzoic acid into a protein to form an antigen, immunizing a mammalian host with the antigen, and recovering an antibody having an affinity for the antigen from the host. Antibodies having a binding affinity for a monohalotyrosine are provided as well as composition comprising an antibody bound with monohalotyrosine. Compositions comprising a protein having a 3-bromo-4-hydroxy-benzoic acid moiety are also provided. Methods for evaluating the severity of asthma are provide with the methods including analyzing sputum of a patient using an antibody having a binding affinity for monohalotyrosine, and measuring the amount of antibody bound to protein. Methods for determining eosinophil activity in bodily fluid are also provided with the methods including exposing bodily fluid to an antibody having a binding affinity for monohalotyrosine, and measuring the amount of bound antibody to determine the eosinophil activity.

  4. User interface inspection methods a user-centered design method

    CERN Document Server

    Wilson, Chauncey

    2014-01-01

    User Interface Inspection Methods succinctly covers five inspection methods: heuristic evaluation, perspective-based user interface inspection, cognitive walkthrough, pluralistic walkthrough, and formal usability inspections. Heuristic evaluation is perhaps the best-known inspection method, requiring a group of evaluators to review a product against a set of general principles. The perspective-based user interface inspection is based on the principle that different perspectives will find different problems in a user interface. In the related persona-based inspection, colleagues assume the

  5. The Monte Carlo method the method of statistical trials

    CERN Document Server

    Shreider, YuA

    1966-01-01

    The Monte Carlo Method: The Method of Statistical Trials is a systematic account of the fundamental concepts and techniques of the Monte Carlo method, together with its range of applications. Some of these applications include the computation of definite integrals, neutron physics, and in the investigation of servicing processes. This volume is comprised of seven chapters and begins with an overview of the basic features of the Monte Carlo method and typical examples of its application to simple problems in computational mathematics. The next chapter examines the computation of multi-dimensio

  6. From the scientific method to the clinical method: theoretical considerations

    Directory of Open Access Journals (Sweden)

    Roberto Hernández Hernández

    2010-12-01

    Full Text Available The scientific method is a general method composed of several stages necessary for the development of any scientific research. It is the focus to approach reality and to study natural phenomenon, reality itself and thoughts in order to find their essence and interrelationships. The clinical method is the particular application of the scientific method and in the present economic conditions its use is crucial because of the advantages that it reports from this point of view, as well as for the wellbeing of the patient.

  7. Efficient and accurate fragmentation methods.

    Science.gov (United States)

    Pruitt, Spencer R; Bertoni, Colleen; Brorsen, Kurt R; Gordon, Mark S

    2014-09-16

    Conspectus Three novel fragmentation methods that are available in the electronic structure program GAMESS (general atomic and molecular electronic structure system) are discussed in this Account. The fragment molecular orbital (FMO) method can be combined with any electronic structure method to perform accurate calculations on large molecular species with no reliance on capping atoms or empirical parameters. The FMO method is highly scalable and can take advantage of massively parallel computer systems. For example, the method has been shown to scale nearly linearly on up to 131 000 processor cores for calculations on large water clusters. There have been many applications of the FMO method to large molecular clusters, to biomolecules (e.g., proteins), and to materials that are used as heterogeneous catalysts. The effective fragment potential (EFP) method is a model potential approach that is fully derived from first principles and has no empirically fitted parameters. Consequently, an EFP can be generated for any molecule by a simple preparatory GAMESS calculation. The EFP method provides accurate descriptions of all types of intermolecular interactions, including Coulombic interactions, polarization/induction, exchange repulsion, dispersion, and charge transfer. The EFP method has been applied successfully to the study of liquid water, π-stacking in substituted benzenes and in DNA base pairs, solvent effects on positive and negative ions, electronic spectra and dynamics, non-adiabatic phenomena in electronic excited states, and nonlinear excited state properties. The effective fragment molecular orbital (EFMO) method is a merger of the FMO and EFP methods, in which interfragment interactions are described by the EFP potential, rather than the less accurate electrostatic potential. The use of EFP in this manner facilitates the use of a smaller value for the distance cut-off (Rcut). Rcut determines the distance at which EFP interactions replace fully quantum

  8. Analytical Method Development & Validation for Related Substances Method of Busulfan Injection by Ion Chromatography Method

    Directory of Open Access Journals (Sweden)

    Rewaria S

    2013-05-01

    Full Text Available A new simple, accurate, precise and reproducible Ion chromatography method has been developed forthe estimation of Methane sulfonic acid in Busulfan injectable dosage. The method which is developedis also validated in complete compliance with the current regulatory guidelines by using well developedanalytical method validation techniques and tools which comprises with the analytical method validationparameters like Linearity, LOD and LOQ determination, Accuracy, Method precision, Specificity,System suitability, Robustness, Ruggedness etc. by adopting the current method the linearity obtained isnear to 0.999 and thus this shows that the method is capable to give a good detector response, therecovery calculated was within the range of 85% to 115% of the specification limits.

  9. Shuttle onboard IMU alignment methods

    Science.gov (United States)

    Henderson, D. M.

    1976-01-01

    The current approach to the shuttle IMU alignment is based solely on the Apollo Deterministic Method. This method is simple, fast, reliable and provides an accurate estimate for the present cluster to mean of 1,950 transformation matrix. If four or more star sightings are available, the application of least squares analysis can be utilized. The least squares method offers the next level of sophistication to the IMU alignment solution. The least squares method studied shows that a more accurate estimate for the misalignment angles is computed, and the IMU drift rates are a free by-product of the analysis. Core storage requirements are considerably more; estimated 20 to 30 times the core required for the Apollo Deterministic Method. The least squares method offers an intermediate solution utilizing as much data that is available without a complete statistical analysis as in Kalman filtering.

  10. Microencapsulation and Electrostatic Processing Method

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2000-01-01

    Methods are provided for forming spherical multilamellar microcapsules having alternating hydrophilic and hydrophobic liquid layers, surrounded by flexible, semi-permeable hydrophobic or hydrophilic outer membranes which can be tailored specifically to control the diffusion rate. The methods of the invention rely on low shear mixing and liquid-liquid diffusion process and are particularly well suited for forming microcapsules containing both hydrophilic and hydrophobic drugs. These methods can be carried out in the absence of gravity and do not rely on density-driven phase separation, mechanical mixing or solvent evaporation phases. The methods include the process of forming, washing and filtering microcapsules. In addition, the methods contemplate coating microcapsules with ancillary coatings using an electrostatic field and free fluid electrophoresis of the microcapsules. The microcapsules produced by such methods are particularly useful in the delivery of pharmaceutical compositions.

  11. Mixed methods in gerontological research.

    Science.gov (United States)

    Happ, Mary Beth

    2009-04-01

    This article distinguishes between parallel and integrated mixed methods research approaches. Barriers to integrated mixed methods approaches in gerontological research are discussed and critiqued. The author presents examples of mixed methods gerontological research to highlight approaches to data integration at the levels of data analysis, interpretation, and research reporting. As a summary of the methodological literature, four basic levels of mixed methods data combination are proposed. Opportunities for mixing qualitative and quantitative data are explored using contemporary examples from published studies. Data transformation and visual display, judiciously applied, are proposed as pathways to fuller mixed methods data integration and analysis. Finally, practical strategies for mixing qualitative and quantitative data types are explicated, as gerontological research moves beyond parallel mixed methods approaches to achieve data integration.

  12. Reflexive Learning through Visual Methods

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth

    2014-01-01

    What. This chapter concerns how visual methods and visual materials can support visually oriented, collaborative, and creative learning processes in education. The focus is on facilitation (guiding, teaching) with visual methods in learning processes that are designerly or involve design. Visual...... or professional, to facilitate with visual methods in a critical, reflective, and experimental way. The chapter offers recommendations for facilitating with visual methods to support playful, emergent designerly processes. The chapter also has a critical, situated perspective. Where. This chapter offers case...... methods are exemplified through two university classroom cases about collaborative idea generation processes. The visual methods and materials in the cases are photo elicitation using photo cards, and modeling with LEGO Serious Play sets. Why. The goal is to encourage the reader, whether student...

  13. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch

    1997-01-01

    Measurements of corrosion rates and other parameters connected with corrosion processes are important, first as indicators of the corrosion resistance of metallic materials and second because such measurements are based on general and fundamental physical, chemical, and electrochemical relations....... Hence improvements and innovations in methods applied in corrosion research are likeliy to benefit basic disciplines as well. A method for corrosion measurements can only provide reliable data if the beckground of the method is fully understood. Failure of a method to give correct data indicates a need...... to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...

  14. Adjunct methods for caries detection

    DEFF Research Database (Denmark)

    Twetman, Svante; Axelsson, Susanna Bihari; Dahlén, Gunnar

    2012-01-01

    evidence for diagnostic accuracy regarding fiber-optic methods and quantitative light-induced fluorescence (+OOO). The electrical methods and laser fluorescence could be useful adjuncts to visual-tactile and radiographic examinations, especially on occlusal surfaces in permanent and primary molars......Abstract Objective. To assess the diagnostic accuracy of adjunct methods used to detect and quantify dental caries. Study design. A systematic literature search for relevant papers was conducted with pre-determined inclusion and exclusion criteria. Abstracts and full text articles were assessed...... independently by two reviewers. The study characteristics were compiled in tables and quality graded according to the QUADAS tool. The level of evidence for each diagnostic technology (fiber-optic methods, fluorescence methods, electrical methods) was based on studies of high or moderate quality according...

  15. Monte Carlo methods for electromagnetics

    CERN Document Server

    Sadiku, Matthew NO

    2009-01-01

    Until now, novices had to painstakingly dig through the literature to discover how to use Monte Carlo techniques for solving electromagnetic problems. Written by one of the foremost researchers in the field, Monte Carlo Methods for Electromagnetics provides a solid understanding of these methods and their applications in electromagnetic computation. Including much of his own work, the author brings together essential information from several different publications.Using a simple, clear writing style, the author begins with a historical background and review of electromagnetic theory. After addressing probability and statistics, he introduces the finite difference method as well as the fixed and floating random walk Monte Carlo methods. The text then applies the Exodus method to Laplace's and Poisson's equations and presents Monte Carlo techniques for handing Neumann problems. It also deals with whole field computation using the Markov chain, applies Monte Carlo methods to time-varying diffusion problems, and ...

  16. Methods of rock burst prediction

    Energy Technology Data Exchange (ETDEWEB)

    Genkin, V.A.; Minin, Yu.Ya.; Morozov, G.D.; Proskuryakov, V.M.; Cmirnov, V.A.

    1979-07-01

    Some methods of predicting rock bursts in underground coal and iron ore mines are evaluated: using BP-18 indenters and the MGD indenter with automatic recording; seismic method consisting in measuring the speed of shock waves travelling through various layers (apparatus SB-20 is designed for use in coal mines); electrometric method (measuring resistance between two electrodes when electric currents flow through coal and rocks). The design of the AEhSSh-1 measuring instrument, used in the electrometric method in coal mines is also described. Each of the methods is described and mathematical fomulae used as their theoretical basis are presented. The calculating process is explained and brief information on the design and use of the measuring instrument is given. The methods are evaluated from the viewpoint of precision. (In Russian)

  17. Numerical methods for phase retrieval

    CERN Document Server

    Osherovich, Eliyahu

    2012-01-01

    In this work we consider the problem of reconstruction of a signal from the magnitude of its Fourier transform, also known as phase retrieval. The problem arises in many areas of astronomy, crystallography, optics, and coherent diffraction imaging (CDI). Our main goal is to develop an efficient reconstruction method based on continuous optimization techniques. Unlike current reconstruction methods, which are based on alternating projections, our approach leads to a much faster and more robust method. However, all previous attempts to employ continuous optimization methods, such as Newton-type algorithms, to the phase retrieval problem failed. In this work we provide an explanation for this failure, and based on this explanation we devise a sufficient condition that allows development of new reconstruction methods---approximately known Fourier phase. We demonstrate that a rough (up to $\\pi/2$ radians) Fourier phase estimate practically guarantees successful reconstruction by any reasonable method. We also pres...

  18. Factorization Method in Quantum Mechanics

    CERN Document Server

    Dong, Shi-Hai

    2007-01-01

    This Work introduces the factorization method in quantum mechanics at an advanced level with an aim to put mathematical and physical concepts and techniques like the factorization method, Lie algebras, matrix elements and quantum control at the Reader’s disposal. For this purpose a comprehensive description is provided of the factorization method and its wide applications in quantum mechanics which complements the traditional coverage found in the existing quantum mechanics textbooks. Related to this classic method are the supersymmetric quantum mechanics, shape invariant potentials and group theoretical approaches. It is no exaggeration to say that this method has become the milestone of these approaches. In fact the Author’s driving force has been his desire to provide a comprehensive review volume that includes some new and significant results about the factorization method in quantum mechanics since the literature is inundated with scattered articles in this field, and to pave the Reader’s way into ...

  19. The Plastic Tension Field Method

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    . The emphasis is attached to the presentation of a design method based on the diagonal tension field theory. Also, how to determine the load-carrying capacity of a given steel plate girder with transverse web stiffeners, is briefly presented. The load-carrying capacity may be predicted by applying both...... method. The method is based on the theory of plasticity and is analogous to the so-called diagonal compression field method developed for reinforced concrete beams with transverse stirrups, which is adopted in the common European concrete code (Eurocode 2). Many other theories have been developed......, but the method presented differs from these theories by incorporating the strength of the transverse stiffeners and by the assumption that the tensile bands may pass the transverse stiffeners, which often is observed in tests. Other methods have only dealt with a single web field between two stiffeners...

  20. "Phenomenology" and qualitative research methods.

    Science.gov (United States)

    Nakayama, Y

    1994-01-01

    Phenomenology is generally based on phenomenological tradition from Husserl to Heidegger and Merleau-Ponty. As philosophical stances provide the assumptions in research methods, different philosophical stances produce different methods. However, the term "phenomenology" is used in various ways without the definition being given, such as phenomenological approach, phenomenological method, phenomenological research, etc. The term "phenomenology" is sometimes used as a paradigm and it is sometimes even viewed as synonymous with qualitative methods. As a result, the term "phenomenology" leads to conceptual confusions in qualitative research methods. The purpose of this paper is to examine the term "phenomenology" and explore philosophical assumptions, and discuss the relationship between philosophical stance and phenomenology as a qualitative research method in nursing.

  1. Negotiating a Systems Development Method

    Science.gov (United States)

    Karlsson, Fredrik; Hedström, Karin

    Systems development methods (or methods) are often applied in tailored version to fit the actual situation. Method tailoring is in most the existing literature viewed as either (a) a highly rational process with the method engineer as the driver where the project members are passive information providers or (b) an unstructured process where the systems developer makes individual choices, a selection process without any driver. The purpose of this chapter is to illustrate that important design decisions during method tailoring are made by project members through negotiation. The study has been carried out using the perspective of actor-network theory. Our narratives depict method tailoring as more complex than (a) and (b) show the driver role rotates between the project members, and design decisions are based on influences from several project members. However, these design decisions are not consensus decisions.

  2. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch

    1997-01-01

    Measurements of corrosion rates and other parameters connected with corrosion processes are important, first as indicators of the corrosion resistance of metallic materials and second because such measurements are based on general and fundamental physical, chemical, and electrochemical relations....... Hence improvements and innovations in methods applied in corrosion research are likeliy to benefit basic disciplines as well. A method for corrosion measurements can only provide reliable data if the beckground of the method is fully understood. Failure of a method to give correct data indicates a need...... to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...

  3. Mapping Mixed Methods Research: Methods, Measures, and Meaning

    Science.gov (United States)

    Wheeldon, J.

    2010-01-01

    This article explores how concept maps and mind maps can be used as data collection tools in mixed methods research to combine the clarity of quantitative counts with the nuance of qualitative reflections. Based on more traditional mixed methods approaches, this article details how the use of pre/post concept maps can be used to design qualitative…

  4. Mapping Mixed Methods Research: Methods, Measures, and Meaning

    Science.gov (United States)

    Wheeldon, J.

    2010-01-01

    This article explores how concept maps and mind maps can be used as data collection tools in mixed methods research to combine the clarity of quantitative counts with the nuance of qualitative reflections. Based on more traditional mixed methods approaches, this article details how the use of pre/post concept maps can be used to design qualitative…

  5. A Moral Method? Thoughts on Cultivating Empathy through Method Acting.

    Science.gov (United States)

    Verducci, Susan

    2000-01-01

    Using Nel Noddings ethic of Care, contends that this model of empathy has elements in common with the type of empathy method actors employ. Discusses the agreements between Caring's empathy and dramatic empathy focusing on three skills method actors use and the three differences that possess moral implications. (CMK)

  6. Sur Quatre Methodes Audio-Visuelles (On Four Audiovisual Methods)

    Science.gov (United States)

    Porquier, Remy; Vives, Robert

    1974-01-01

    This is a critical examination of four audiovisual methods for the teaching of French as a Foreign Language. The methods have as a common basis the interrelationship of image, dialogue, situation, and give grammar priority over vocabulary. (Text is in French.) (AM)

  7. Mixed Method Research: An Overview

    OpenAIRE

    Hossain, Dewan Mahboob

    2012-01-01

    This article gives a general overview of mixed method research. In mixed method, the researchers combine both qualitative and quantitative approaches in a single research project. The article first attempts to define mixed method research. Then it gives a comparison of qualitative and quantitative approaches. It also introduces the well-known controversy among the researchers: which of these approaches is superior? By explaining this controversy, the article identifies the need for mixed meth...

  8. Mixed Method Research: An Overview

    OpenAIRE

    Hossain, Dewan Mahboob

    2012-01-01

    This article gives a general overview of mixed method research. In mixed method, the researchers combine both qualitative and quantitative approaches in a single research project. The article first attempts to define mixed method research. Then it gives a comparison of qualitative and quantitative approaches. It also introduces the well-known controversy among the researchers: which of these approaches is superior? By explaining this controversy, the article identifies the need for mixed meth...

  9. Transport methods for energetic particles

    Institute of Scientific and Technical Information of China (English)

    WuHong-Lu; YangChui-Hsu

    1997-01-01

    In order to estimate radiation risk assessment for astronaut's radiation safety in space activities.transport codes for high energy particles have been created.Two of the transport methods,perturbation and Green function methods,for high energy particles are reviewed in this paper,and some of the calculated results with the perturbation method are presented.Finally,the low energy transport in the regard of the biological effects by low energy ions in also briefly discussed.

  10. Regression methods for medical research

    CERN Document Server

    Tai, Bee Choo

    2013-01-01

    Regression Methods for Medical Research provides medical researchers with the skills they need to critically read and interpret research using more advanced statistical methods. The statistical requirements of interpreting and publishing in medical journals, together with rapid changes in science and technology, increasingly demands an understanding of more complex and sophisticated analytic procedures.The text explains the application of statistical models to a wide variety of practical medical investigative studies and clinical trials. Regression methods are used to appropriately answer the

  11. Methods of forming CIGS films

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, Lorelle; Ramanathan, Kannan

    2017-09-19

    Methods for forming CIGS films are provided. According to an aspect of the invention, a method of forming a CIGS film includes a precursor step, which includes simultaneously evaporating Cu, In, Ga, Se, and Sb onto a substrate. The Se is incident on the substrate at a rate of at least 20 .ANG./s. The method also includes a selenization step, which includes evaporating Se over the substrate after the precursor step.

  12. A Voltage Quality Detection Method

    DEFF Research Database (Denmark)

    Chen, Zhe; Wei, Mu

    2008-01-01

    This paper presents a voltage quality detection method based on a phase-locked loop (PLL) technique. The technique can detect the voltage magnitude and phase angle of each individual phase under both normal and fault power system conditions. The proposed method has the potential to evaluate vario...... power quality disturbances, such as interruptions, sags and imbalances. Simulation studies have been performed. The effectiveness of the proposed method has been demonstrated under the simulated typical power disturbances....

  13. Statistical Methods in Integrative Genomics

    OpenAIRE

    Richardson, Sylvia; Tseng, George C.; Sun, Wei

    2016-01-01

    Statistical methods in integrative genomics aim to answer important biology questions by jointly analyzing multiple types of genomic data (vertical integration) or aggregating the same type of data across multiple studies (horizontal integration). In this article, we introduce different types of genomic data and data resources, and then review statistical methods of integrative genomics, with emphasis on the motivation and rationale of these methods. We conclude with some summary points and f...

  14. Local method for detecting communities

    Science.gov (United States)

    Bagrow, James P.; Bollt, Erik M.

    2005-10-01

    We propose a method of community detection that is computationally inexpensive and possesses physical significance to a member of a social network. This method is unlike many divisive and agglomerative techniques and is local in the sense that a community can be detected within a network without requiring knowledge of the entire network. A global application of this method is also introduced. Several artificial and real-world networks, including the famous Zachary karate club, are analyzed.

  15. Method of manufacturing superconductor wire

    Science.gov (United States)

    Motowidlo, Leszek

    2014-09-16

    A method for forming Nb.sub.3Sn superconducting wire is provided. The method employs a powder-in-tube process using a high-tin intermetallic compound, such as MnSn.sub.2, for producing the Nb.sub.3Sn. The use of a high-tin intermetallic compound enables the process to perform hot extrusion without melting the high-tin intermetallic compound. Alternatively, the method may entail drawing the wire without hot extrusion.

  16. Chebyshev and Fourier spectral methods

    CERN Document Server

    Boyd, John P

    2001-01-01

    Completely revised text focuses on use of spectral methods to solve boundary value, eigenvalue, and time-dependent problems, but also covers Hermite, Laguerre, rational Chebyshev, sinc, and spherical harmonic functions, as well as cardinal functions, linear eigenvalue problems, matrix-solving methods, coordinate transformations, methods for unbounded intervals, spherical and cylindrical geometry, and much more. 7 Appendices. Glossary. Bibliography. Index. Over 160 text figures.

  17. Comparison of Topographic Correction Methods

    Directory of Open Access Journals (Sweden)

    Rudolf Richter

    2009-07-01

    Full Text Available A comparison of topographic correction methods is conducted for Landsat-5 TM, Landsat-7 ETM+, and SPOT-5 imagery from different geographic areas and seasons. Three successful and known methods are compared: the semi-empirical C correction, the Gamma correction depending on the incidence and exitance angles, and a modified Minnaert approach. In the majority of cases the modified Minnaert approach performed best, but no method is superior in all cases.

  18. Bayesian Methods for Statistical Analysis

    OpenAIRE

    Puza, Borek

    2015-01-01

    Bayesian methods for statistical analysis is a book on statistical methods for analysing a wide variety of data. The book consists of 12 chapters, starting with basic concepts and covering numerous topics, including Bayesian estimation, decision theory, prediction, hypothesis testing, hierarchical models, Markov chain Monte Carlo methods, finite population inference, biased sampling and nonignorable nonresponse. The book contains many exercises, all with worked solutions, including complete c...

  19. Algebraic Methods to Design Signals

    Science.gov (United States)

    2015-08-27

    AFRL-AFOSR-VA-TR-2015-0257 Algebraic Methods to Design Signals Krishnasany Arasu WRIGHT STATE UNIVERSITY Final Report 08/27/2015 DISTRIBUTION A...REPORT TYPE FINAL 3. DATES COVERED (From - To) June 2012 - May 2015 4. TITLE AND SUBTITLE ALGEBRAIC METHODS TO DESIGN SIGNALS 5a. CONTRACT NUMBER...to date on designing signals using algebraic and combinatorial methods. Mathematical tools from algebraic number theory, representation theory and

  20. Entropy-based benchmarking methods

    OpenAIRE

    2012-01-01

    We argue that benchmarking sign-volatile series should be based on the principle of movement and sign preservation, which states that a bench-marked series should reproduce the movement and signs in the original series. We show that the widely used variants of Denton (1971) method and the growth preservation method of Causey and Trager (1981) may violate this principle, while its requirements are explicitly taken into account in the pro-posed entropy-based benchmarking methods. Our illustrati...

  1. The WST method, a fracture mechanics test method for FRC

    DEFF Research Database (Denmark)

    Lofgren, I.; Stang, Henrik; Olesen, John Forbes

    2008-01-01

    FRC compositions. Furthermore, for the WST method, two different specimen sizes have been investigated. Results from this investigation demonstrate the applicability of the WST method and show that the scatter of the test results is lower than for the 3PBT. Through inverse analysis, stress......The applicability of the wedge-splitting test method (WST), for determining fracture properties of fibre-reinforced concrete, is discussed. Experimental results, using the WST method, are compared with results from uniaxial tension tests (UTT) and three-point bending tests (3PBT) for five different......-crack opening (sigma-w) relationships have been determined for each mix and test method. For the two WST specimen sizes, there is no apparent difference either in the number of fibres (per cm(2)) crossing the fracture plane or in the fracture properties. The major factor contributing to the scatter in the test...

  2. Methods for Precise Submesh Allocation

    Directory of Open Access Journals (Sweden)

    Craig Morgenstern

    1994-01-01

    Full Text Available In this article we describe and compare several recently proposed algorithms for precise submesh allocation in a two-dimensional mesh connected system. The methods surveyed include various frame sliding strategies, the maximum boundary value heuristic, and interval set scan techniques. In addition, a new enhancement to the interval set scan method is described. This enhancement results in an algorithm that has better allocation and run-time performance under a FCFS scheduling policy than any of the other proposed methods. We present results drawn from an extensive simulation study to illustrate the relative efficiency of the various methods.

  3. Methods in Logic Based Control

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    1999-01-01

    Desing and theory of Logic Based Control systems.Boolean Algebra, Karnaugh Map, Quine McClusky's algorithm. Sequential control design. Logic Based Control Method, Cascade Control Method. Implementation techniques: relay, pneumatic, TTL/CMOS,PAL and PLC- and Soft_PLC implementation. PLC-design met......Desing and theory of Logic Based Control systems.Boolean Algebra, Karnaugh Map, Quine McClusky's algorithm. Sequential control design. Logic Based Control Method, Cascade Control Method. Implementation techniques: relay, pneumatic, TTL/CMOS,PAL and PLC- and Soft_PLC implementation. PLC...

  4. Methods for Obfuscating Java Programs

    Directory of Open Access Journals (Sweden)

    Florin Buzatu

    2012-03-01

    Full Text Available Java programs distributed through internet are suffering of problems like reverse engineering, algorithms theft and unauthorized functional changes. The reason for this issue is that the bytecode from Java class file holds enough information to be decompiled into source code that resembles the original. In this paper, I discuss some practical obfuscation methods that make difficult the understanding of the decompiled programs. The methods analyzed are: lexical obfuscation, data obfuscation, control flow obfuscation, obfuscation methods that make use of the discrepancy between bytecode and source code. In order to evaluate the usefulness of these methods, some metrics will be described.

  5. An introduction to g methods.

    Science.gov (United States)

    Naimi, Ashley I; Cole, Stephen R; Kennedy, Edward H

    2017-04-01

    Robins' generalized methods (g methods) provide consistent estimates of contrasts (e.g. differences, ratios) of potential outcomes under a less restrictive set of identification conditions than do standard regression methods (e.g. linear, logistic, Cox regression). Uptake of g methods by epidemiologists has been hampered by limitations in understanding both conceptual and technical details. We present a simple worked example that illustrates basic concepts, while minimizing technical complications. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  6. Comparison of photopeak integration methods

    Science.gov (United States)

    Kennedy, G.

    1990-12-01

    Several methods for the calculation of gamma-ray photopeak areas have been compared for the case of a small peak on a high Compton background. 980 similar spectra were accumulated with a germanium detector using a weak 137Cs source to produce a peak at 662 keV on a Compton background generated by a 60Co source. A computer program was written to calculate the area of the 662 keV peak using the total- and partial-peak-area methods, a modification of Sterlinski's method, Loska's method and least-squares fitting of Gaussian peak shapes with linear and quadratic background. The precision attained was highly dependent on the number of channels used to estimate the background, and the best precision, about 9.5%, was obtained with the partial-peak-area method, the modified Sterlinski method and least-squares fitting with variable peak position, fixed peak width and linear background. The methods were also evaluated for their sensitivity to uncertainty in the peak centroid position. Considering precision, ease of use, reliability and universal applicability, the total-peak-area method using several channels for background estimation and the least-squares-fitting method are recommended.

  7. Comparison of photopeak integration methods

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, G. (Ecole Polytechnique, Montreal, PQ (Canada). Energy Engineering Inst.)

    1990-12-20

    Several methods for the calculation of gamma-ray photopeak areas have been compared for the case of a small peak on a high Compton background. 980 similar spectra were accumulated with a germanium detector using a weak {sup 137}Cs source to produce a peak at 662 keV on a Compton background generated by a {sup 60}Co source. A computer program was written to calculate the area of the 662 keV peak using the total- and partial-peak-area methods, a modification of Sterlinski's method, Loska's method and least-squares fitting of Gaussian peak shapes with linear and quadratic background. The precision attained was highly dependent on the number of channels used to estimate the background, and the best precision, about 9.5%, was obtained with the partial-peak-area method, the modified Sterlinski method and least-squares fitting with variable peak position, fixed peak width and linear background. The methods were also evaluated for their sensitivity to uncertainty in the peak centroid position. Considering precision, ease of use, reliability and universal applicability, the total-peak-area method using several channels for background estimation and the least-squares-fitting method are recommended. (orig.).

  8. Methods for Predicting Stock Indexes

    Directory of Open Access Journals (Sweden)

    Martha Cecilia García

    2013-11-01

    Full Text Available This paper presents a literature review on methods that have been used in the last two decades to predict Stock Market Indexes. Methods studied range from those enabling to grab the linear characteristics present in the stock market indexes, going through those that focus on non-linear features and finally hybrid methods that are more robust, since they capture linear and non-linear features. In addition, this research includes methods that use macroeconomic variables to predict indexes from different stock exchanges around the world.

  9. Optimization of Medical Teaching Methods

    Directory of Open Access Journals (Sweden)

    Wang Fei

    2015-12-01

    Full Text Available In order to achieve the goal of medical education, medicine and adapt to changes in the way doctors work, with the rapid medical teaching methods of modern science and technology must be reformed. Based on the current status of teaching in medical colleges method to analyze the formation and development of medical teaching methods, characteristics, about how to achieve optimal medical teaching methods for medical education teachers and management workers comprehensive and thorough change teaching ideas and teaching concepts provide a theoretical basis.

  10. Methods of making microfluidic devices

    KAUST Repository

    Buttner, Ulrich

    2017-06-01

    Microfluidics has advanced in terms of designs and structures, however, fabrication methods are either time consuming or expensive to produce, in terms of the facilities and equipment needed. A fast and economically viable method is provided to allow, for example, research groups to have access to microfluidic fabrication. Unlike most fabrication methods, a method is provided to fabricate a microfluidic device in one step. In an embodiment, a resolution of 50 micrometers was achieved by using maskless high-resolution digital light projection (MDLP). Bonding and channel fabrication of complex or simple structures can be rapidly incorporated to fabricate the microfluidic devices.

  11. Quantitative vs qualitative research methods.

    Science.gov (United States)

    Lakshman, M; Sinha, L; Biswas, M; Charles, M; Arora, N K

    2000-05-01

    Quantitative methods have been widely used because of the fact that things that can be measured or counted gain scientific credibility over the unmeasurable. But the extent of biological abnormality, severity, consequences and the impact of illness cannot be satisfactorily captured and answered by the quantitative research alone. In such situations qualitative methods take a holistic perspective preserving the complexities of human behavior by addressing the "why" and "how" questions. In this paper an attempt has been made to highlight the strengths and weaknesses of both the methods and also that a balanced mix of both qualitative as well as quantitative methods yield the most valid and reliable results.

  12. Metathesis catalysts and methods thereof

    Energy Technology Data Exchange (ETDEWEB)

    Schrock, Richard Royce; Yuan, Jian

    2016-04-19

    The present application provides, among other things, novel compounds for metathesis reactions, and methods for preparing and using provided compounds. In some embodiments, the present invention provides compounds having the structure of formula I or II. In some embodiments, the present invention provides methods for preparing a compound of formula I or II. In some embodiments, the present invention provides methods for using a provided compound. In some embodiments, a provided compound is useful for stereoselective ring-opening metathesis polymerization. In some embodiments, a provided metathesis method provides cis and/or isotactic polymers.

  13. Mixed-Methods Research Methodologies

    Science.gov (United States)

    Terrell, Steven R.

    2012-01-01

    Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

  14. Sometimes "Newton's Method" Always "Cycles"

    Science.gov (United States)

    Latulippe, Joe; Switkes, Jennifer

    2012-01-01

    Are there functions for which Newton's method cycles for all non-trivial initial guesses? We construct and solve a differential equation whose solution is a real-valued function that two-cycles under Newton iteration. Higher-order cycles of Newton's method iterates are explored in the complex plane using complex powers of "x." We find a class of…

  15. Method of making optoelectric devices

    DEFF Research Database (Denmark)

    2012-01-01

    A method of preparing an optoelectric device, comprising: (a) providing a substrate on which is formed a first electrode layer; (b) forming an electron transport layer according to the following method: i) forming a film of a coating ink comprising zinc acetate in aqueous solution; ii) drying...

  16. The mGPC method:

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    2009-01-01

    We adapt concepts from matched filtering to propose a method for generating rapidly reconfigurable multiple beams. As a phase-only spatially filtering extension of the Generalized Phase Contrast (GPC) technique, the proposed method coined mGPC can yield dynamically reconfigurable optical beam arr...... arrays with high light efficiency for optical manipulation, high-speed sorting and other parallel spatial light applications [1]....

  17. Sparsity Methods for Networked Control

    OpenAIRE

    Nagahara, Masaaki

    2014-01-01

    In this presentation, we introduce sparsity methods for networked control systems and show the effectiveness of sparse control. In networked control, efficient data transmission is important since transmission delay and error can critically deteriorate the stability and performance. We will show that this problem is solved by sparse control designed by recent sparse optimization methods.

  18. Laboratory method used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  19. Bioluminescence methods for enzymatic determinations

    Science.gov (United States)

    Bostick, William D.; Denton, Mark S.; Dinsmore, Stanley R.

    1982-01-01

    An enzymatic method for continuous, on-line and rapid detection of diagnostically useful biomarkers, which are symptomatic of disease or trauma-related tissue damage, is disclosed. The method is characterized by operability on authentic samples of complex biological fluids which contain the biomarkers.

  20. Recent Progress of Thioester Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction The availability of site-specifically modified peptides is of vitalimportance for biochemical and biophysical studies. Biological methods, such as expression using bacteria, are useful. They are, however, not always applicable to the synthesis of peptides with sitespecific modifications. Chemical methods can be viable alternatives to those biological approaches.