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Sample records for field amplified sample

  1. Acupuncture injection for field amplified sample stacking and glass microchip-based capillary gel electrophoresis.

    Science.gov (United States)

    Ha, Ji Won; Hahn, Jong Hoon

    2017-02-01

    Acupuncture sample injection is a simple method to deliver well-defined nanoliter-scale sample plugs in PDMS microfluidic channels. This acupuncture injection method in microchip CE has several advantages, including minimization of sample consumption, the capability of serial injections of different sample solutions into the same microchannel, and the capability of injecting sample plugs into any desired position of a microchannel. Herein, we demonstrate that the simple and cost-effective acupuncture sample injection method can be used for PDMS microchip-based field amplified sample stacking in the most simplified straight channel by applying a single potential. We achieved the increase in electropherogram signals for the case of sample stacking. Furthermore, we present that microchip CGE of ΦX174 DNA-HaeⅢ digest can be performed with the acupuncture injection method on a glass microchip while minimizing sample loss and voltage control hardware. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Determination of ephedrine and pseudoephedrine by field-amplified sample injection capillary electrophoresis.

    Science.gov (United States)

    Deng, Dongli; Deng, Hao; Zhang, Lichun; Su, Yingying

    2014-04-01

    A simple and rapid capillary electrophoresis method was developed for the separation and determination of ephedrine (E) and pseudoephedrine (PE) in a buffer solution containing 80 mM of NaH2PO4 (pH 3.0), 15 mM of β-cyclodextrin and 0.3% of hydroxypropyl methylcellulose. The field-amplified sample injection (FASI) technique was applied to the online concentration of the alkaloids. With FASI in the presence of a low conductivity solvent plug (water), an approximately 1,000-fold improvement in sensitivity was achieved without any loss of separation efficiency when compared to conventional sample injection. Under these optimized conditions, a baseline separation of the two analytes was achieved within 16 min and the detection limits for E and PE were 0.7 and 0.6 µg/L, respectively. Without expensive instruments or labeling of the compounds, the limits of detection for E and PE obtained by the proposed method are comparable with (or even lower than) those obtained by capillary electrophoresis laser-induced fluorescence, liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. The method was validated in terms of precision, linearity and accuracy, and successfully applied for the determination of the two alkaloids in Ephedra herbs.

  3. Sensitive determination of sertraline by capillary electrophoresis with dispersive liquid-liquid microextraction and field-amplified sample stacking.

    Science.gov (United States)

    Huang, Shiou-Wen; Hsieh, Ming-Mu; Chang, Sarah Y

    2012-11-15

    A novel method for the determination of sertraline using dispersive liquid-liquid microextraction (DLLME) coupled with capillary electrophoresis (CE) was developed. Acetone and dichloromethane were used as the disperser solvent and extraction solvent, respectively. A mixture of the extraction and disperser solvents was rapidly injected into a 1.0 mL aqueous sample to form a cloudy solution. After the extraction, sertraline was analyzed using CE that was equipped with UV detection. A 74-fold improvement in the sensitivity was observed when DLLME was used to extract sertraline. Since the DLLME extract residue was redissolved with 5 μL of water that contained 20% methanol, the detection sensitivity was further enhanced through the use of field-amplified sample stacking (FASS). A 11-fold improvement in the sensitivity was obtained when FASS was used to on-line concentrate sertraline. Under optimal extraction and stacking conditions, the calibration curve, which ranged from 0.01 to 1 μM was observed to be linear. The limit of detection (LOD) at a signal-to-noise ratio of 3 was 2.5 nM for sertraline. An approximately 814-fold improvement in the sensitivity was observed for sertraline compare with injection of standard solution without the DLLME and FASS procedures. This developed method was successfully applied to the determination of sertraline in human urine samples.

  4. Field-Amplified Sample Injection-Micellar Electrokinetic Chromatography for the Determination of Benzophenones in Food Simulants

    Directory of Open Access Journals (Sweden)

    Cristina Félez

    2015-07-01

    Full Text Available A field-amplified sample injection-micellar electrokinetic chromatography (FASI-MEKC method for the determination of 14 benzophenones (BPs in a food simulant used in migration studies of food packaging materials was developed, allowing almost baseline separation in less than 21 min. The use of a 10 mM sodium dodecyl sulfate (SDS solution as sample matrix was mandatory to achieve FASI enhancement of the analyzed BPs. A 21- to 784-fold sensitivity enhancement was achieved with FASI-MEKC, obtaining limits of detection down to 5.1–68.4 µg/L, with acceptable run-to-run precisions (RSD values lower than 22.3% and accuracy (relative errors lower than 21.0%. Method performance was evaluated by quantifying BPs in the food simulant spiked at 500 µg/L (bellow the established specific migration limit for BP (600 µg/L by EU legislation. For a 95% confidence level, no statistical differences were observed between found and spiked concentrations (probability at the confidence level, p value, of 0.55, showing that the proposed FASI-MEKC method is suitable for the analysis of BPs in food packaging migration studies at the levels established by EU legislation.

  5. Rapid and sensitive determination of strychnine and brucine in human urine by capillary electrophoresis with field-amplified sample stacking.

    Science.gov (United States)

    Li, Junmei; Jiang, Ye

    2010-02-01

    A simple, rapid, sensitive and low-cost method using capillary electrophoresis (CE) coupled with field-amplified sample stacking (FASS) has been developed and validated for the simultaneous determination of strychnine and brucine residues in human urine. Before sample loading, a water plug (3.5 kPa, 3 s) was injected to contain sample cations and to permit FASS. Electrokinetic injection at a voltage (20 kV, 25 s) was then used to introduce cations. Separation was performed using 20 mM acetate buffer (pH 3.8) with an applied voltage of 20 kV. The calibration curves were linear over a range of 8.00-2.56 infinity 10(2) ng/mL (r = 0.9995) for strychnine and 10.0-3.20 x 10(2) ng/mL (r = 0.9999) for brucine. Extraction recoveries in urine were greater than 79.6 and 82.8% for strychnine and brucine, respectively, with an RSD of less than 4.9%. The detection limits (signal-to-noise ratio 3) for strychnine and brucine were 2.00 and 2.50 ng/mL, respectively. A urine sample from one healthy female volunteer (26 years old, 50 kg) was pretreated and analyzed. Strychnine and brucine levels in urine could be detected 24 h after administration. On these grounds, this method was feasible for application to preliminary screening of trace levels of abused drugs for both doping control and forensic analysis. (c) 2009 John Wiley & Sons, Ltd.

  6. Sensitive determination of pyrrolizidine alkaloids in Tussilago farfara L. by field-amplified, sample-stacking, sweeping micellar electrokinetic chromatography.

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    Cao, Kun; Xu, Yi; Mu, Xiuni; Zhang, Qing; Wang, Renjie; Lv, Junjiang

    2016-11-01

    Pyrrolizidine alkaloids are the toxic components in Tussilago farfara L. Due to the lack of standard substances for quantitative analysis and traces of pyrrolizidine alkaloids in total alkaloids, the full quality control of Tussilago farfara L has been limited. In this study, we aimed to solve the difficulty of determination of pyrrolizidine alkaloids and identify more components in the total alkaloids. An on-line preconcentration method has been applied to improve determining sensitivity of pyrrolizidine alkaloids in Tussilago farfara L. in which included field-amplified sample stacking and sweeping in micellar electrokinetic capillary chromatography. The main parameters that affected separation and stacking efficiency were investigated in details. Under the optimal conditions, the sensitivity enhancement factors obtained by the developed method for the analytes were from 15- to 12-fold, the limits of detection of senkirkine and senecionine were 2∼5 μg/L. Senkirkine and senecionine have been detected in alkaloids (c) of Tussilago farfara L, along ferulic acid methyl ester and methyl caffeate. The developed method was also applied to the analysis of acid extraction (a) of Tussilago farfara L, and senkirkine could be detected directly. The results indicated that the developed method is feasible for the analysis of pyrrolizidine alkaloids in Tussilago farfara L with good recoveries.

  7. Field-amplified sample stacking capillary electrophoresis with electrochemiluminescence applied to the determination of illicit drugs on banknotes.

    Science.gov (United States)

    Xu, Yuanhong; Gao, Ying; Wei, Hui; Du, Yan; Wang, Erkang

    2006-05-19

    Capillary electrophoresis (CE) with Ru(bpy)3(2+) electrochemiluminescence (ECL) detection system was established to the determination of contamination of banknotes with controlled drugs and a high efficiency on-column field-amplified sample stacking (FASS) technique was also optimized to increase the ECL intensity. The method was illustrated using heroin and cocaine, which are two typical and popular illicit drugs. Highest sample stacking was obtained when 0.01 mM acetic acid was chosen for sample dissolution with electrokinetical injection for 6 s at 17 kV. Under the optimized conditions: ECL detection at 1.2 V, separation voltage 10.0 kV, 20 mM phosphate-acetate (pH 7.2) as running buffer, 5 mM Ru(bpy)3(2+) with 50 mM phosphate-acetate (pH 7.2) in the detection cell, the standard curves were linear in the range of 7.50x10(-8) to 1.00x10(-5) M for heroin and 2.50x10(-7) to 1.00x10(-4) M for cocaine and detection limits of 50 nM for heroin and 60 nM for cocaine were achieved (S/N = 3), respectively. Relative standard derivations of the ECL intensity and the migration time were 3.50 and 0.51% for heroin and 4.44 and 0.12% for cocaine, respectively. The developed method was successfully applied to the determination of heroin and cocaine on illicit drug contaminated banknotes without any damage of the paper currency. A baseline resolution for heroin and cocaine was achieved within 6 min.

  8. Simultaneous Separation of Eight Benzodiazepines in Human Urine Using Field-Amplified Sample Stacking Micellar Electrokinetic Chromatography.

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    Oledzka, Ilona; Kulińska, Zofia; Prahl, Adam; Baczek, Tomasz

    2015-01-01

    A novel approach for the simultaneous quantification of eight benzodiazepines (BZDs) using dispersive liquid-liquid microextraction (DLLME) and field-amplified sample stacking (FASS) combined with micellar electrokinetic chromatography (MEKC) was investigated and evaluated in the context of precision, accuracy, sensitivity, linearity, detection and limits of quantification (LOQ). The absolute recovery rates of BZDs were above 90.65%. The limits of detection (LOD) were 20 ng/mL for chlordiazepoxide, estazolam, temazepam and midazolam, and 30 ng/mL for clonazepam, lorazepam, lormetazepam and medazepam, while the LOQ was set at 50 ng/mL for chlordiazepoxide, estazolam, temazepam and midazolam, and 100 ng/mL for clonazepam, lorazepam, lormetazepam and medazepam. Linearity was confirmed in the range of 50-2,000 ng/mL for chlordiazepoxide, estazolam, temazepam and midazolam, and 100-2,000 ng/mL for clonazepam, lorazepam, lormetazepam and medazepam, with a correlation coefficient greater than 0.9987 for all analytes. The elaborated procedure meets all the requirements of analytical methods. During the extraction procedure, a mixture of 1 mL of ethanol and 500 µL of dichloromethane, used as the disperser and extraction solvent, respectively, was rapidly injected into 3 mL of a urine sample. A significant improvement in sensitivity was achieved when DLLME was used to extract BZDs from the urine sample and FASS as an on-line preconcentration technique was developed. For the best separation of analytes, the running buffer was composed of 30 mM SDS, 10 mM sodium tetraborate and 15% methanol (pH 8.8), whereas a sample buffer was composed of 10 mM SDS and 2 mM sodium tetraborate. Moreover, a fused-silica capillary [inner diameter (i.d.) of 75 µm and length of 50 cm], photodiode array detection, pneumatic injection for 15 s and a voltage of 23 kV were applied. The applicability of the method has been confirmed for the analysis of BZD in urine samples collected from patients who

  9. Solid-phase extraction and field-amplified sample injection-capillary zone electrophoresis for the analysis of benzophenone UV filters in environmental water samples.

    Science.gov (United States)

    Purrà, Miquel; Cinca, Roser; Legaz, Jessica; Núñez, Oscar

    2014-10-01

    A field-amplified sample injection-capillary zone electrophoresis (FASI-CZE) method for the analysis of benzophenone (BP) UV filters in environmental water samples was developed, allowing the separation of all compounds in less than 8 min. A 9- to 25-fold sensitivity enhancement was obtained with FASI-CZE, achieving limits of detection down to 21-59 μg/L for most of the analyzed BPs, with acceptable run-to-run and day-to-day precisions (relative standard deviations lower than 17%). In order to remove water sample salinity and to enhance FASI sensitivity, an off-line solid-phase extraction (SPE) procedure using a Strata X polymeric reversed-phase sorbent was used and afforded recoveries up to 72-90% for most BPs. With the combination of off-line SPE and FASI-CZE, limits of detection in the range 0.06-0.6 μg/L in a river water matrix, representing a 2,400- to 6,500-fold enhancement, were obtained. Method performance was evaluated by quantifying a blank river water sample spiked at 1 μg/L. For a 95% confidence level, no statistical differences were observed between found concentrations and spiked concentrations (probability at the confidence level, p value, of 0.60), showing that the proposed off-line SPE-FASI-CZE method is suitable for the analysis of BP UV filters in environmental water samples at low microgram per liter levels. The method was successfully applied to the analysis of BPs in river water samples collected up- and downstream of industrialized and urban areas, and in some drinking water samples.

  10. YANG-MILLS FIELD AMPLIFIER

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    Trunev A. P.

    2015-09-01

    Full Text Available The article presents a project of the Yang-Mills amplifier. Amplifier model is a multilayer spherical shell with increasing density towards the center. In the center of the amplifier is the core of high-density material. It is shown that in such a system, the amplitude of the Yang-Mills waves rises from the periphery to the center of several orders of magnitude. The role of the Yang-Mills field in the processes occurring in the nuclei of galaxies, stars and planets is discussed. The data modeling to strengthen the Yang-Mills field in the bowels of the planet, with an atomic explosion, and in some special devices such as the voltaic pile. To describe the mechanism of amplification chromodynamics field used as accurate results in Yang-Mills theory and numerical models developed based on an average and the exact equations as well. Among the exact solutions of the special role played by the centralsymmetric metric describing the contribution of the Yang-Mills field in the speed of recession of galaxies. Among the approximate numerical models can be noted the eight-scalar model we have developed for the simulation of non-linear color oscillations and chaos in the Yang-Mills theory. Earlier models were investigated spatio-temporal oscillations of the YangMills theory in the case of three and eight colors. The results of numerical simulation show that the nonlinear interaction does not lead to a spatial mixing of colors as it might be in the case of turbulent diffusion. Depending on the system parameters there is a suppression of the amplitude of the oscillations the first three by five colors or vice versa. The kinetic energy fluctuations or shared equally between the color components, or dominated by the kinetic energy of repressed groups of colors. In the present study, we found that amplification chromodynamic field leads to a sharp increase in the amplitude of the suppressed color, which can lead to an increase in entropy, excitation of nuclear

  11. Combining field-amplified sample stacking with moving reaction boundary electrophoresis on a paper chip for the preconcentration and separation of metal ions.

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    Ouyang, Liangfei; Liu, Qian; Liang, Heng

    2017-02-01

    A common drawback of paper-based separation devices is their poor detection limit. In this study, we combined field-amplified sample stacking with moving reaction boundary electrophoresis on a paper chip with six array channels for the parallel separation and concentration of multiple samples. With a new hyphenated technique, the brown I2 from the Fe(3+) /I(-) oxidation-reduction reaction emerged near the boundary between the dilute ethylene diamine tetraacetic acid and potassium iodide and highly concentrated KCl solutions. For the separation and concentration of three components, Cr(3+) , Cu(2+) , and Fe(3+) , the Fe(3+) detection limit was improved at least 266-fold by comparing the hyphenated technique with moving reaction boundary electrophoresis. The detection limit of Fe(3+) was found to be as low as 0.34 ng (20 μM) on the paper chip. We also demonstrated the analysis of a real sample of four metal ions, with detection limits as follows: 0.16 μg Cr(3+) , 1.5 μg Ni(2+) , 0.64 μg Cu(2+) , and 1.5 μg Co(2+) . The synergy of field-amplified sample stacking and moving reaction boundary electrophoresis in the micron paper-based array channels dramatically improved the detection limit and throughput of paper-based electrophoresis.

  12. Ultra-sensitive speciation analysis of mercury by CE-ICP-MS together with field-amplified sample stacking injection and dispersive solid-phase extraction.

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    Chen, YiQuan; Cheng, Xian; Mo, Fan; Huang, LiMei; Wu, Zujian; Wu, Yongning; Xu, LiangJun; Fu, FengFu

    2016-04-01

    A simple dispersive solid-phase extraction (DSPE) used to extract and preconcentrate ultra-trace MeHg, EtHg and Hg(2+) from water sample, and a sensitive method for the simultaneous analysis of MeHg, EtHg and Hg(2+) by using capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) with field-amplified sample stacking injection (FASI) were first reported in this study. The DSPE used thiol cotton particles as adsorbent, and is simple and effective. It can be used to extract and preconcentrate ultra-trace mercury compounds in water samples within 30 min with a satisfied recovery and no mercury species alteration during the process. The FASI enhanced the sensitivity of CE-ICP-MS with 25-fold, 29-fold and 27-fold for MeHg, EtHg and Hg(2+) , respectively. Using FASI-CE-ICP-MS together with DSPE, we have successfully determined ultra-trace MeHg, EtHg and Hg(2+) in tap water with a limits of quantification (LOQs) of 0.26-0.45 pg/mL, an RSD (n = 3) mercury.

  13. Analysis of urinary neurotransmitters by capillary electrophoresis: Sensitivity enhancement using field-amplified sample injection and molecular imprinted polymer solid phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Claude, Berengere, E-mail: berengere.claude@univ-orleans.fr [Institut de Chimie Organique et Analytique, CNRS FR 2708 UMR 6005, Universite d' Orleans, 45067 Orleans (France); Nehme, Reine; Morin, Philippe [Institut de Chimie Organique et Analytique, CNRS FR 2708 UMR 6005, Universite d' Orleans, 45067 Orleans (France)

    2011-08-12

    Highlights: {yields} Field-amplified sample injection (FASI) improves the sensitivity of capillary electrophoresis through the online pre-concentration samples. {yields} The cationic analytes are stacked at the capillary inlet between a zone of low conductivity - sample and pre-injection plug - and a zone of high conductivity - running buffer. {yields} The limits of quantification are 500 times lower than those obtained with hydrodynamic injection. {yields} The presence of salts in the matrix greatly reduces the sensitivity of the FASI/CE-UV method. - Abstract: Capillary electrophoresis (CE) has been investigated for the analysis of some neurotransmitters, dopamine (DA), 3-methoxytyramine (3-MT) and serotonin (5-hydroxytryptamine, 5-HT) at nanomolar concentrations in urine. Field-amplified sample injection (FASI) has been used to improve the sensitivity through the online pre-concentration samples. The cationic analytes were stacked at the capillary inlet between a zone of low conductivity - sample and pre-injection plug - and a zone of high conductivity - running buffer. Several FASI parameters have been optimized (ionic strength of the running buffer, concentration of the sample protonation agent, composition of the sample solvent and nature of the pre-injection plug). Best results were obtained using H{sub 3}PO{sub 4}-LiOH (pH 4, ionic strength of 80 mmol L{sup -1}) as running buffer, 100 {mu}mol L{sup -1} of H{sub 3}PO{sub 4} in methanol-water 90/10 (v/v) as sample solvent and 100 {mu}mol L{sup -1} of H{sub 3}PO{sub 4} in water for the pre-injection plug. In these conditions, the linearity was verified in the 50-300 nmol L{sup -1} concentration range for DA, 3-MT and 5-HT with a determination coefficient (r{sup 2}) higher than 0.99. The limits of quantification (10 nmol L{sup -1} for DA and 3-MT, 5.9 nmol L{sup -1} for 5-HT) were 500 times lower than those obtained with hydrodynamic injection. However, if this method is applied to the analysis of

  14. Monitoring of threo-methylphenidate enantiomers in oral fluid by capillary electrophoresis with head-column field-amplified sample injection.

    Science.gov (United States)

    Theurillat, Regula; Thormann, Wolfgang

    2014-04-01

    Threo-methylphenidate is a chiral psychostimulant drug widely prescribed to treat attention-deficit hyperactivity disorder in children and adolescents. An enantioselective CE-based assay with head-column field-amplified sample stacking for analysis of threo-methylphenidate enantiomers in liquid/liquid extracts of oral fluid is described. Analytes are electrokinetically injected across a short water plug placed at the capillary inlet and become stacked at the interface between plug and buffer. Enantiomeric separation occurs within a few minutes in a pH 3.0 phosphate/triethanolamine buffer containing 20 mg/mL (2-hydroxypropyl)-β-CD as chiral selector. The assay with six point multilevel internal calibration provides a linear response for each enantiomer in the 10-200 ng/mL concentration range, is simple, inexpensive, and reproducible, and has an LOQ of 5 ng/mL. It was applied to oral fluid patient samples that were collected up to 12 h after intake of an immediate release tablet and two different extended release formulations with racemic methylphenidate. Drug profiles could thereby be assessed in a stereoselective way. Almost no levorotary threo-methylphenidate enantiomer was detected after intake of the two extended release formulations, whereas this enantiomer was detected during the first 2.5 h after intake of the immediate release preparation. The noninvasive collection of oral fluid is an attractive alternative to plasma for the monitoring of methylphenidate exposure in the pediatric community.

  15. Analysis of urinary neurotransmitters by capillary electrophoresis: sensitivity enhancement using field-amplified sample injection and molecular imprinted polymer solid phase extraction.

    Science.gov (United States)

    Claude, Bérengère; Nehmé, Reine; Morin, Philippe

    2011-08-12

    Capillary electrophoresis (CE) has been investigated for the analysis of some neurotransmitters, dopamine (DA), 3-methoxytyramine (3-MT) and serotonin (5-hydroxytryptamine, 5-HT) at nanomolar concentrations in urine. Field-amplified sample injection (FASI) has been used to improve the sensitivity through the online pre-concentration samples. The cationic analytes were stacked at the capillary inlet between a zone of low conductivity - sample and pre-injection plug - and a zone of high conductivity - running buffer. Several FASI parameters have been optimized (ionic strength of the running buffer, concentration of the sample protonation agent, composition of the sample solvent and nature of the pre-injection plug). Best results were obtained using H(3)PO(4)-LiOH (pH 4, ionic strength of 80 mmol L(-1)) as running buffer, 100 μmol L(-1) of H(3)PO(4) in methanol-water 90/10 (v/v) as sample solvent and 100 μmol L(-1) of H(3)PO(4) in water for the pre-injection plug. In these conditions, the linearity was verified in the 50-300 nmol L(-1) concentration range for DA, 3-MT and 5-HT with a determination coefficient (r(2)) higher than 0.99. The limits of quantification (10 nmol L(-1) for DA and 3-MT, 5.9 nmol L(-1) for 5-HT) were 500 times lower than those obtained with hydrodynamic injection. However, if this method is applied to the analysis of neurotransmitters in urine, the presence of salts in the matrix greatly reduces the sensitivity of the FASI/CE-UV method.Therefore, a solid phase extraction (SPE) on a dedicated imprinted polymer (MIP) was developed to extract specific neurotransmitters, catecholamines, metanephrines and indolamines, from urine. Matrix salts were thus discarded after sample extraction on AFFINIMIP™ Catecholamine & Metanephrine (100mg) cartridge. Therefore, lower limits of quantification were determined in artificial urine (46 nmol L(-1) for DA, 11 nmol L(-1) for 3-MT and 6 nmol L(-1) for 5-HT).The application of this protocol MIP

  16. A novel capillary electrophoresis method with pressure assisted field amplified sample injection in determination of thiol collectors in flotation process waters.

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    Sihvonen, T; Aaltonen, A; Leppinen, J; Hiltunen, S; Sirén, H

    2014-01-17

    A new capillary electrophoresis method was developed for the quantification of diisobutyldithiophosphate (DTP), diisobutyldithiophosphinate (DTPI) and ethyl and isobutyl xanthates (EX, IBX) all of which are used as thiol collectors in froth flotation. This method uses pressure assisted field amplified sample injection (PA-FASI) to concentrate the analytes at the capillary inlet. The background electrolyte in electrophoretic separation was 60millimolar (mM) from 3-(cyclohexylamino)propane-1-sulfonic acid (CAPS) in 40mM NaOH solution. The similar CAPS electrolyte solution has earlier been used for screening for diuretics that contained sulphonamide and/or carboxylic groups. In this study, the functional groups are xanthate, phosphate and phosphinate. The method was developed using actual flotation process waters. The results showed that the water delivered from the plant did not contain significant amount of collectors; therefore, method development was accomplished by spiking analytes in these waters. Separation of analytes was achieved in 15min. The range of quantification was 0.27-66.6mg/L (R(2) 0.9991-0.9999) for all analytes other than ethyl xanthate, for which the range was 0.09-66.6mg/L (R(2) 0.9999). LOD (S/N=3) and LOQ (S/N=10) values for DTP, DTPI, IBX and EX were 0.05, 0.07, 0.06 and 0.01mg/L and 0.16, 0.25, 0.21 and 0.04mg/L, respectively. No interference from the matrices was observed, when the method was tested at a gold concentrator plant.

  17. Simultaneous determination of pyridine-triphenylborane anti-fouling agent and its degradation products in paint-waste samples using capillary zone electrophoresis with field-amplified sample injection.

    Science.gov (United States)

    Kaewchuay, Netnapit; Fukushi, Keiichi; Tsuboi, Ai; Okamura, Hideo; Saito, Keiitsu; Hirokawa, Takeshi

    2012-01-01

    We proposed a capillary zone electrophoresis (CZE) procedure using field-amplified sample injection (FASI) for the simultaneous determination of pyridine-triphenylborane (PTPB) and its degradation products: diphenylborinic acid (DPB), phenylboronic acid (MPB), and phenol. The LODs for PTPB, DPB, MPB, and phenol were, respectively, 0.85, 0.88, 44, and 28 μg L(-1). The RSDs (n = 4) for the analytes listed above were in respective ranges of 6.2 - 14, 5.9 - 10, and 0.49 - 0.62% for the peak area, peak height, and migration time. The compounds were extracted from paint-waste samples collected from shipyards using a siliga-gel column. The extract was dissolved with acetonitrile containing 1% (v/v) pyridine. The samples were then analyzed using CZE, revealing respective concentrations of 0.076 - 0.53, 0.015 - 0.36, 1.7 - 22, and 1.2 - 13 μg g(-1). The proposed FASI-CZE method is a simple and promising procedure that is expected to be useful for the determination of PTPB and its degradation products in paint wastes.

  18. Vortex-assisted liquid-liquid extraction combined with field-amplified sample injection and sweeping micellar electrokinetic chromatography for improved determination of β-blockers in human urine.

    Science.gov (United States)

    Jouyban, Abolghasem; Sorouraddin, Mohammad Hossein; Farajzadeh, Mir Ali; Somi, Mohammad Hossein; Fazeli-Bakhtiyari, Rana

    2016-01-01

    A new micellar electrokinetic chromatography (MEKC) method was developed and validated for the analysis of carvedilol and propranolol in human urine samples. In this study, vortex-assisted liquid-liquid extraction (VALLE) coupled with field-amplified sample injection and sweeping was employed for biological sample clean-up and sensitivity enhancement in MEKC. After VALLE, the urine samples were analyzed by MEKC. Tris-phosphate buffer (60mmolL(-1), pH 2.0) containing 40% (v/v) methanol was first filled into an uncoated fused-silica capillary (56cm, 50µm i.d.). The pretreated urine sample was loaded by electrokinetic injection (10kV, 250s). The stacking and separation were performed using Tris-phosphate buffer (30mmolL(-1), pH 3.0) containing 30% (v/v) methanol and 50mmolL(-1) sodium dodecyl sulfate (SDS) at -25kV. Detection was carried out at 195 and 214nm for carvedilol and propranolol, respectively. The suggested method is linear (r(2)≥0.997) over a dynamic range of 0.005-1µgmL(-1) in urine. The intra- and inter-day relative standard deviation and relative error values of the method were below 20%, which shows good precision and accuracy. Finally, this method was successfully applied to the analysis of real urine samples.

  19. Adaptation of a Digitally Predistorted RF Amplifier Using Selective Sampling

    Institute of Scientific and Technical Information of China (English)

    R. Neil Braithwaite

    2011-01-01

    In this paper, a reduced-cost method of measuring residual nonlinearities in an adaptive digitally predistorted amplifier is proposed. Measurements obtained by selective sampling of the amplifier output are integrated over the input envelope range to adapt a fourth-order polynomial predistorter with memory correction. Results for a WCDMA input with a 101 carrier configuration show that a transmitter using the proposed method can meet the adjacent channel leakage ratio (ACLR) specification. Inverse modeling of the nonlinearity is proposed as a future extension that will reduce the cost of the system further.

  20. Analysis of CMOS Transconductance Amplifiers for Sampling Mixers

    Science.gov (United States)

    Li, Ning; Chaivipas, Win; Okada, Kenichi; Matsuzawa, Akira

    In this paper the transfer function of a system with windowed current integration is discussed. This kind of integration is usually used in a sampling mixer and the current is generated by a transconductance amplifier (TA). The parasitic capacitance (Cp) and the output resistance of the TA (Ro,TA) before the sampling mixer heavily affect the performance. Calculations based on a model including the parasitic capacitance and the output resistance of the TA is carried out. Calculation results show that due to the parasitic capacitance, a notch at the sampling frequency appears, which is very harmful because it causes the gain near the sampling frequency to decrease greatly. The output resistance of the TA makes the depth of the notches shallow and decreases the gain near the sampling frequency. To suppress the effect of Cp and Ro,TA, an operational amplifier is introduced in parallel with the sampling capacitance (Cs). Simulation results show that there is a 17dB gain increase while Cs is 1pF, gm is 9mS, N is 8 with a clock rate of 800MHz.

  1. Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

    Science.gov (United States)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

    2008-01-01

    There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

  2. Dispersive liquid-liquid microextraction based on solidification of floating organic drop combined with field-amplified sample injection in capillary electrophoresis for the determination of beta(2)-agonists in bovine urine.

    Science.gov (United States)

    Us, Murat Faruk; Alshana, Usama; Lubbad, Ibrahim; Göğer, Nilgün G; Ertaş, Nusret

    2013-03-01

    Dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) was for the first time combined with field-amplified sample injection (FASI) in CE to determine four β(2)-agonists (cimbuterol, clenbuterol, mabuterol, and mapenterol) in bovine urine. Optimum BGE consisted of 20 mM borate buffer and 0.1 mM SDS. Using salting-out extraction, β(2)-agonists were extracted into ACN that was then used as the disperser solvent in DLLME-SFO. Optimum DLLME-SFO conditions were: 1.0 mL ACN, 50 μL 1-undecanol (extraction solvent), total extraction time 1.5 min, no salt addition. Back extraction into an aqueous solution (pH 2.0) facilitated direct injection of β(2)-agonists into CE. Compared to conventional CZE, DLLME-SFO-FASI-CE achieved sensitivity enhancement factors of 41-1046 resulting in LODs in the range of 1.80-37.0 μg L(-1). Linear dynamic ranges of 0.15-10.0 mg L(-1) for cimbuterol and 15-1000 μg L(-1) for the other analytes were obtained with coefficients of determination (R(2)) ≥ 0.9901 and RSD% ≤5.5 (n = 5). Finally, the applicability of the proposed method was successfully confirmed by determination of the four β(2)-agonists in spiked bovine urine samples and accuracy higher than 96.0% was obtained.

  3. Amplified Fermion Production from Overpopulated Bose Fields

    CERN Document Server

    Berges, J; Sexty, D

    2014-01-01

    We study the real-time dynamics of fermions coupled to scalar fields in a linear sigma model, which is often employed in the context of preheating after inflation or as a low-energy effective model for quantum chromodynamics. We find a dramatic amplification of fermion production in the presence of highly occupied bosonic quanta for weak as well as strong couplings. For this we consider the range of validity of different methods: lattice simulations with male/female fermions, the mode functions approach and the quantum 2PI effective action with its associated kinetic theory. For strongly coupled fermions we find a rapid approach to a Fermi-Dirac distribution with time-dependent temperature and chemical potential parameters, while the bosons are still far from equilibrium.

  4. All-optical sampling based on quantum-dot semiconductor optical amplifier

    Science.gov (United States)

    Wu, Chen; Wang, Yongjun; Wang, Lina

    2016-11-01

    In recent years, the all-optical signal processing system has become a hot research field of optical communication. This paper focused on the basic research of quantum-dot (QD) semiconductor optical amplifier (SOA) and studied its practical application to all-optical sampling. A multi-level dynamic physical model of QD-SOA is established, and its ultrafast dynamic characteristics are studied through theoretical and simulation research. For further study, an all-optical sampling scheme based on the nonlinear polarization rotation (NPR) effect of QD-SOA is also proposed. This paper analyzed the characteristics of optical switch window and investigated the influence of different control light pulses on switch performance. The presented optical sampling method has an important role in promoting the improvement of all-optical signal processing technology.

  5. Amplifiability of mitochondrial, microsatellite and amelogenin DNA loci from fecal samples of red brocket deer Mazama americana (Cetartiodactyla, Cervidae).

    Science.gov (United States)

    Oliveira, M L; Duarte, J M B

    2013-01-16

    We tried to amplify mitochondrial, microsatellite and amelogenin loci in DNA from fecal samples of a wild Mazama americana population. Fifty-two deer fecal samples were collected from a 600-ha seasonal semideciduous forest fragment in a subtropical region of Brazil (21°20'S, 47°17'W), with the help of a detection dog; then, stored in ethanol and georeferenced. Among these samples 16 were classified as "fresh" and 36 as "non-fresh". DNA was extracted using the QIAamp(®) DNA Stool Mini Kit. Mitochondrial loci were amplified in 49 of the 52 samples. Five microsatellite loci were amplified by PCR; success in amplification varied according to locus size and sample age. Successful amplifications were achieved in 10/16 of the fresh and in 13/36 of the non-fresh samples; a negative correlation (R = -0.82) was found between successful amplification and locus size. Amplification of the amelogenin locus was successful in 22 of the 52 samples. The difficulty of amplifying nuclear loci in DNA samples extracted from feces collected in the field was evident. Some methodological improvements, including collecting fresh samples, selecting primers for shorter loci and quantifying the extracted DNA by real-time PCR, are suggested to increase amplification success in future studies.

  6. Monolithic integration of widely tunable sampled grating DBR laser with tilted semiconductor optical amplifier

    Science.gov (United States)

    Ye, Nan; Liu, Yang; Wang, BaoJun; Zhou, DaiBing; Pang, JiaoQing; Zhao, LingJuan; Wang, Wei

    2011-01-01

    More than 11mW output powers for all wavelengths from the fiber and over 49 nm range tuning in sampled grating distributed Bragg reflector laser with an integrated semiconductor optical amplifier which is enabling access to 110 ITU 50GHz channels is demonstrated. Tilted amplifier and anti-reflection facet coating are used to suppress reflection.

  7. Monolithic integration of widely tunable sampled grating DBR laser with tilted semiconductor optical amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yang; Ye Nan; Wang Baojun; Zhou Daibing; An Xin; Bian Jing; Pan Jiaoqing; Zhao Lingjuan; Wang Wei, E-mail: matsu@semi.ac.c [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2010-07-15

    High output powers and wide range tuning have been achieved in a sampled grating distributed Bragg reflector laser with an integrated semiconductor optical amplifier. Tilted amplifier and anti-reflection facet coating are used to suppress reflection. We have demonstrated sampled grating DBR laser with a tuning range over 38 nm, good wavelength coverage and peak output powers of more than 9 mW for all wavelengths.

  8. A stimulated Raman scattering imager using high-speed lateral electric field modulator and lock-in pixels amplifiers

    Science.gov (United States)

    Mars, Kamel; Guseul, Beak; Han, Sang Man; Takasawa, Taishi; Yasutomi, Keita; Kagawa, Keiichiro; Hashimoto, Mamoru; Kawahito, Shoji

    2014-03-01

    A high speed Lateral Electric Field Modulator (LEFM) and lock-in pixels amplifiers for stimulated Raman scattering (SRS)imager is presented. Since the generated signal from the SRS process is very small compared to the offset signal, a technique suitable for extracting and amplifying the SRS signal is needed. The offset can be canceled by tuning the phase delay between the demodulated pixel output signal and the sampling clock. The small SRS signal in large offset is amplified by the differential integration. The proposed technique has been investigated with an implementation of 64x8 pixels array using a pinned photodiode LEFM an lock-in pixels amplifiers. Very small signal can be extracted from large offset signal. A ratio of the detected small SRS to offset signal of less 10-5 is achieved.

  9. Amplified fragment length polymorphism and pulsed field gel electrophoresis for subspecies differentiation of Serpulina pilosicoli

    DEFF Research Database (Denmark)

    Møller, Kristian; Jensen, Tim Kåre; Boye, Mette

    1999-01-01

    Pulsed field gel electrophoresis (PFGE) and amplified fragment length polymorphism (AFLP) were compared for their ability to differentiate between 50 porcine Serpulina pilosicoli isolates. Both techniques were highly sensitive, dividing the isolates into 36 and 38 groups, respectively. Due...

  10. Amplification of complex fields in Nd:YAG amplifiers

    Science.gov (United States)

    Chen, Xudong; Chang, Chengcheng; Pu, Jixiong

    2017-04-01

    High energy nanosecond vortex beams and cylindrically polarized beams are generated in Nd:YAG amplifiers. Vortex seed beams and cylindrically polarized seed beams are converted from a conventional Nd:YAG laser by spiral phase plate and polarization converter, respectively. Maximum output energy of optical vortex up to 995 mJ and cylindrically polarized beams up to 772 mJ have been achieved at 10 Hz in a 10-ns pulse, respectively. The amplification efficiency, the beam quality and pulse width of the amplification output are studied. Both the topological charge of the vortex seed beams and polarization state of cylindrically polarized beams are confirmed to be conserved during the amplification. The generation of high energy vortex beams and cylindrically polarized beams would be beneficial to laser material processing.

  11. Study of all-optical sampling using a semiconductor optical amplifier

    Science.gov (United States)

    Wu, Chen; Wang, Yongjun; Wang, Lina; Wang, Fu

    2016-08-01

    All-optical sampling is an important research content of all-optical signal processing. In recent years, the application of the semiconductor optical amplifier (SOA) in optical sampling has attracted lots of attention because of its small volume and large nonlinear coefficient. We propose an optical sampling model based on nonlinear polarization rotation effect of the SOA. The proposed scheme has the advantages of high sampling speed and small input pump power, and a transfer curve with good linearity was obtained through simulation. To evaluate the performance of sampling, we analyze the linearity and efficiency of sampling pulse considering the impact of pulse width and analog signal frequency. We achieve the sampling of analog signal to high frequency pulse and exchange the positions of probe light and pump light to study another sampling.

  12. A compact x-ray beam intensity monitor using gas amplified sample current measurement

    Science.gov (United States)

    Hayakawa, Shinjiro; Kobayashi, Kazuo; Gohshi, Yohichi

    2000-01-01

    Development of a compact beam intensity monitor using gas amplified sample current measurement is described. The monitor can be a powerful tool for x-ray spectroscopy and microscopy when the beam is defined by a small pinhole or slits and when the workspace around the sample is limited. The thickness of the monitor is as small as approximately 3 mm, and the dimension is 10 mm square. The photon flux is monitored by measuring x-ray excited current from an Al foil under atmospheric conditions. Emitted electrons from the Al foil can ionize surrounding air molecules, and the gas amplified current can be measured with the use of a biased grid that prevents created ion pairs from recombination.

  13. Highly sensitive analysis of nucleic acids using capillary gel electrophoresis with ultraviolet detection based on the combination of matrix field-amplified and head-column field-amplified stacking injection.

    Science.gov (United States)

    Lian, Dong-Sheng; Zhao, Shu-Jin

    2015-01-26

    To develop a highly sensitive method for analyzing nucleic acids using capillary gel electrophoresis with ultraviolet detection (CGE-UV), we combined matrix field-amplified with head-column field-amplified stacking injection (C-FASI) to employ the advantages of two methods. Without diminishing the resolution, a limit of detection of 0.13 ng/ml (signal/noise=3) in a 300,000-fold diluted sample was obtained, the sensitivity is 102,308 times higher than that achieved with normal pressure injection, 3077 times that with normal electrokinetic injection, 154 times that with pressure field-amplified sample stacking injection, and 31 times that with matrix field-amplified stacking injection. After establishing the method, we tested the detection of a φX174-Hae III digest DNA product without purification and with a high ionic strength. At the lowest dilution of 5000-fold, sample at a concentration of 10 ng/ml was enriched and detected. The relative standard deviations for migration time and peak area (n=3) were 0.03-1.15 and 0.72-6.42, respectively. To further validate C-FASI was applicable for real sample, a 400 bp PCR product without purification was directly detected with a limit of detection at the concentration of 6000-fold dilution (signal/noise=3), The relative standard deviations for migration time and peak area (n=6) were 0.44 and 4.8, respectively. These results indicated that C-FASI had good qualitative and quantitative detection abilities and CGE-UV based on C-FASI is easy to perform, practical, highly-sensitive and robust for nucleic acid detection, which makes it a highly valuable tool for genetic diagnostics based on nucleic acid analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Rapid, Simple and Ultrasensitive Analysis of Paraquat in Drinking Water by Field-Amplified Sample Injection Combined with Pressure-Assisted Capillary Zone Electrophoresis%场放大样品进样-压力辅助毛细管区带电泳测定饮用水中的百草枯

    Institute of Scientific and Technical Information of China (English)

    王明明; 沈菁; 宋婷; 李胜清; 陈浩

    2012-01-01

    Field-amplified sample injection (FASI) combined with pressure-assisted capillary zone electrophoresis (CZE) was developed for the determination of paraquat in drinking water. High reproducibility in FASI-CZE process could be attained with constant pressure applied at both ends of capillary. Compared with conventional hydrodynamic injection, the enrichment factor of 1174 was achieved for paraquat by FASI. Several parameters including length of water plug, injection time and composition of sample solution were systematically optimized. Linearity, sensitivity, precision and accuracy were investigated to validate the proposed method. The result showed that the calibration curve was linear at the concentration of 1.0 100 (ig/L with a correlation coefficient of 0. 9975. The limit of detection was 0. 039 ng/L (S/N=3). Mean recovery of paraquat was ranged from 78. 4% to 94. 5% with relative standard deviation ranging from 3. 0% to 10. 4%. Finally, the method proposed was applied for the determination of paraquat in real drinking water.

  15. High-power microwave amplifier based on overcritical relativistic electron beam without external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kurkin, S. A., E-mail: KurkinSA@gmail.com; Koronovskii, A. A. [Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation); Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Frolov, N. S.; Hramov, A. E. [Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation); Rak, A. O. [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus); Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Kuraev, A. A. [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus)

    2015-04-13

    The high-power scheme for the amplification of powerful microwave signals based on the overcritical electron beam with a virtual cathode (virtual cathode amplifier) has been proposed and investigated numerically. General output characteristics of the virtual cathode amplifier including the dependencies of the power gain on the input signal frequency and amplitude have been obtained and analyzed. The possibility of the geometrical working frequency tuning over the range about 8%–10% has been shown. The obtained results demonstrate that the proposed virtual cathode amplifier scheme may be considered as the perspective high-power microwave amplifier with gain up to 18 dB, and with the following important advantages: the absence of external magnetic field, the simplicity of construction, the possibility of geometrical frequency tuning, and the amplification of relatively powerful microwave signals.

  16. 电堆集-场放大进样非水毛细管电泳法测定苦参中的三种生物碱%Determination of Three Alkaloids in Sophora flavescens by Nonaqueous Capillary Electrophoresis with Electrostacking-Field-Amplified Sample Injection

    Institute of Scientific and Technical Information of China (English)

    李利军; 孙科; 吴美艳; 罗应; 胡大春; 邓春燕; 李彦青

    2013-01-01

    建立了电堆集-场放大进样非水毛细管电泳法分离测定苦参中的槐定碱、苦参碱和氧化苦参碱.采用未涂层熔融石英毛细管(50 cm×50 μm i.d.,有效柱长36 cm),紫外检测波长为209 nm,运行缓冲溶液为50 mmol/L乙酸铵-20%乙腈-0.75%乙酸-55%甲醇,分离电压20 kV,电动进样20 kV、15s,重力进水柱时间20 s时达到最佳的分离效果.在优化条件下,上述三种生物碱均在15 min内出峰,峰面积的相对标准偏差(RSD)均小于5%.检出限分别达到2.02 μg/L、1.32 μg/L和1.01 μg/L.%An electrostacking-field-amplified sample injection ( FASI ) method was used for the simultaneous separation and determination of sophoridine, matrine and oxymatrine in Sophora flavescens. The result indicated that a best separation of the three alkaloids was obtained on a uncoated fused silica capillary column (50 cm × 50 μm i. d., effective length 36 cm) by using the background electrolyte containing 50 mmol/L ammonium acetate, 20% acetonitrile( by volume), 0. 75% acetic acid (by volume) and 55% methanoKby volume). The detection wavelength was set at 209 nm, separation voltage was 20 kV,sample injection voltage was 20 kV and injection time was 15 s,and injection time of water was 20 s. Under the optimum conditions,the three alkaloids were separated within 15 minutes with the relative standard deviations of peak areas less than 5%. The detection limits (S/N =3) of sophoridine,matrine and oxymatrine were 2. 02 μg/L,l. 32 μg/L and 1. 01 μg/L, respectively.

  17. Field techniques for sampling ants

    Science.gov (United States)

    Ants occur in most environments and ecologists ask a diverse array of questions involving ants. Thus, a key consideration in ant studies is to match the environment and question (and associated environmental variables) to the ant sampling technique. Since each technique has distinct limitations, usi...

  18. Use of non-amplified RNA samples for microarray analysis of gene expression.

    Directory of Open Access Journals (Sweden)

    Hiroko Sudo

    Full Text Available Demand for high quality gene expression data has driven the development of revolutionary microarray technologies. The quality of the data is affected by the performance of the microarray platform as well as how the nucleic acid targets are prepared. The most common method for target nucleic acid preparation includes in vitro transcription amplification of the sample RNA. Although this method requires a small amount of starting material and is reported to have high reproducibility, there are also technical disadvantages such as amplification bias and the long, laborious protocol. Using RNA derived from human brain, breast and colon, we demonstrate that a non-amplification method, which was previously shown to be inferior, could be transformed to a highly quantitative method with a dynamic range of five orders of magnitude. Furthermore, the correlation coefficient calculated by comparing microarray assays using non-amplified samples with qRT-PCR assays was approximately 0.9, a value much higher than when samples were prepared using amplification methods. Our results were also compared with data from various microarray platforms studied in the MicroArray Quality Control (MAQC project. In combination with micro-columnar 3D-Gene™ microarray, this non-amplification method is applicable to a variety of genetic analyses, including biomarker screening and diagnostic tests for cancer.

  19. Controlling the gain shape of Er3+-doped fluorozirconate fibre amplifier by a coherent field

    Institute of Scientific and Technical Information of China (English)

    张惠芳; 吴金辉; 高锦岳

    2003-01-01

    We proposed a four-level system to explore the quantum interference effects on optical amplification. We found that the gain of the probe, including positions and values of gain peaks, can be adjusted by changing the coherent field and the incoherent pumping. At the same time, we can also modify the absorption profile of electromagnetically induced transparency by the incoherent pump. The results provide a method to flatten the gain of Erbium-doped fibre amplifiers.

  20. Design and Simulation of the Recirculating Crossed-Field Planar Amplifier

    Science.gov (United States)

    Exelby, Steven; Greening, Geoffrey; Jordan, Nicholas; Simon, David; Lau, Yue Ying; Gilgenbach, Ronald; Hoff, Brad

    2016-10-01

    The Recirculating Planar Crossed-Field Amplifier (RPCFA) is a high power microwave device adapted from the Recirculating Planar Magnetron1, developed at the University of Michigan. A travelling-wave, rectangular, meander-line design has been developed in simulation that amplifies a 1.3 MW signal at 3 GHz to approximately 29 MW (13.5 dB) with nearly 53% electronic efficiency. Simulation also shows that the RPCFA is zero-drive stable, e.g., output of any appreciable power is dependent on the presence of an input RF signal. The amplifier was designed to be driven by the Michigan Electron Long Beam Accelerator (MELBA), which is currently configured to deliver a -300 kV, 1-10 kA, 0.3-1.0 µs pulse. Taking these parameters into consideration, a slow wave structure, cathode, and housing were designed using the finite element frequency domain code Ansys HFSS. The cold tube characteristics and RF field structures were then verified using the particle in cell code, MAGIC. Hot tube simulations on MAGIC were also run to calculate the RPCFA's performance, including gain and efficiency. Future work will include building a prototype RPCFA, cold testing, and performing experiments to verify the hot tube simulations. This work was supported by the AFOSR Grant FA9550-15-1-0097.

  1. Robust entanglement between a movable mirror and a cavity field system with an optical parametric amplifier

    Science.gov (United States)

    Mi, Xianwu; Bai, Jiangxiang; Ke-hui, Song

    2013-06-01

    Robust entanglement created between an optical cavity field mode and a macroscopic vibrating mirror with an optical parametric amplifier is shown. Increasing the gain of the optical parametric amplifier makes the line of the logarithmic negativity E N move to the range of the larger detuning and higher temperature. Such optomechanical entanglement can be generated even at room temperature with current experimental parameters. Compared with other proposals, we have considered the one-to-one correspondence between the detuning and the input power, which is reasonable with the fact that the mean shift of the cavity frequency is determined by the radiation pressure which is related to the input power. Such consideration may be valuable to current experiments.

  2. Entanglement of movable mirror and cavity field enhanced by an optical parametric amplifier

    Science.gov (United States)

    Cai-yun, Zhang; Hu, Li; Gui-xia, Pan; Zong-qiang, Sheng

    2016-07-01

    A scheme to generate entanglement in a cavity optomechanical system filled with an optical parametric amplifier is proposed. With the help of the optical parametric amplifier, the stationary macroscopic entanglement between the movable mirror and the cavity field can be notably enhanced, and the entanglement increases when the parametric gain increases. Moreover, for a given parametric gain, the degree of entanglement of the cavity optomechanical system increases with increasing input laser power. Project supported by the National Natural Science Foundation of China (Grant No. 11247001), the Scientific Research Foundation of the Higher Education Institutions of Anhui Province, China (Grant No. KJ2012A083), and the Doctor (Master) Fund of Anhui University of Science and Technology, China.

  3. 微乳液毛细管电动色谱-场放大富集法灵敏分析尿液中的9种麻醉剂类药物%Analysis of nine narcotics in urine by microemulsion electrokinetic chromatography-field amplified sample injection

    Institute of Scientific and Technical Information of China (English)

    张雨; 李琴; 卢明华; 张兰; 陈国南; 蔡宗苇

    2011-01-01

    建立了一种微乳液毛细管电动色谱(MEEKC) -场放大富集(FASI)分析尿液中多种麻醉剂(吗啡、可待因、纳洛酮、海洛因、蒂巴因、可卡因、哌替啶、芬太尼、美沙酮)的方法.考察了微乳液组成、分离电压等因素的影响,得到的最佳微乳液组成(质量分数)为0.6%十二烷基硫酸钠、1.2%正丁醇、0.6%乙酸乙酯和97.6% 10 mmol/L硼砂缓冲液(pH 9.5);分离电压为25 kV.在上述微乳体系中,9种化合物在15 min内得到了基线分离.采用场放大在线富集技术提高了分析灵敏度,检出限(S/N=3)低至0.3μg/L.模拟尿样样品中9种麻醉剂的加标回收率介于79.4% ~ 119.9%之间,日内相对标准偏差小于5.5%.将该方法应用于美沙酮大鼠体外代谢样品的测定,结果令人满意.%A simple, sensitive and reproducible method using microemulsion electrokinetic chromatography (MEEKC)-field amplified sample injection (FASI) was developed for the analysis of nine narcotics (morphine, codeine, naloxone, heroin, thebaine, cocaine, pethidine, fentanyl and methadone) in urine. In the MEEKC method, sodium dodecyl sulfate (SDS), 1-butanol and ethyl acetate were used as surfactant, co-surfactant and organic solvent, respectively. The effects of the acidity and concentration of borate buffer, SDS, 1-butanol and ethyl acetate contents were investigated. The optimum concentrations (by mass fraction) of microemulsion system were 0. 6% SDS, 1.2% 1-butanol, 0.6% ethyl acetate and 97. 6% 10 mmol/L Na2B4O7 buffer (pH 9. 5). The applied voltage was 25 kV. FASI was coupled with the MEEKC method to increase the sensitivity. Under the optimum conditions, the nine narcotics were baseline separated within 15 min and the detection limits (S/N = 3) were in the range of 0. 3 -8. 0 μg/L. The spiked recoveries in urine samples were between 79.4% and 119. 9% with the intraday relative standard deviations (ESDs) less than 5.5%. The developed method has been

  4. Genetic profiling of Klebsiella pneumoniae: comparison of pulsed field gel electrophoresis and random amplified polymorphic DNA

    Science.gov (United States)

    Ashayeri-Panah, Mitra; Eftekhar, Fereshteh; Ghamsari, Maryam Mobarak; Parvin, Mahmood; Feizabadi, Mohammad Mehdi

    2013-01-01

    In this study, the discriminatory power of pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) methods for subtyping of 54 clinical isolates of Klebsiella pneumoniae were compared. All isolates were typeable by RAPD, while 3.6% of them were not typeable by PFGE. The repeatability of both typing methods were 100% with satisfying reproducibility (≥ 95%). Although the discriminatory power of PFGE was greater than RAPD, both methods showed sufficient discriminatory power (DI > 0.95) which reflects the heterogeneity among the K. pneumoniae isolates. An optimized RAPD protocol is less technically demanding and time consuming that makes it a reliable typing method and competitive with PFGE. PMID:24516423

  5. Comparison of Haemophilus parasuis reference strains and field isolates by using random amplified polymorphic DNA and protein profiles

    Directory of Open Access Journals (Sweden)

    Zehr Emilie S

    2012-06-01

    Full Text Available Abstract Background Haemophilus parasuis is the causative agent of Glässer’s disease and is a pathogen of swine in high-health status herds. Reports on serotyping of field strains from outbreaks describe that approximately 30% of them are nontypeable and therefore cannot be traced. Molecular typing methods have been used as alternatives to serotyping. This study was done to compare random amplified polymorphic DNA (RAPD profiles and whole cell protein (WCP lysate profiles as methods for distinguishing H. parasuis reference strains and field isolates. Results The DNA and WCP lysate profiles of 15 reference strains and 31 field isolates of H. parasuis were analyzed using the Dice and neighbor joining algorithms. The results revealed unique and reproducible DNA and protein profiles among the reference strains and field isolates studied. Simpson’s index of diversity showed significant discrimination between isolates when three 10mer primers were combined for the RAPD method and also when both the RAPD and WCP lysate typing methods were combined. Conclusions The RAPD profiles seen among the reference strains and field isolates did not appear to change over time which may reflect a lack of DNA mutations in the genes of the samples. The recent field isolates had different WCP lysate profiles than the reference strains, possibly because the number of passages of the type strains may affect their protein expression.

  6. Sampling Criterion for EMC Near Field Measurements

    DEFF Research Database (Denmark)

    Franek, Ondrej; Sørensen, Morten; Ebert, Hans;

    2012-01-01

    An alternative, quasi-empirical sampling criterion for EMC near field measurements intended for close coupling investigations is proposed. The criterion is based on maximum error caused by sub-optimal sampling of near fields in the vicinity of an elementary dipole, which is suggested as a worst......-case representative of a signal trace on a typical printed circuit board. It has been found that the sampling density derived in this way is in fact very similar to that given by the antenna near field sampling theorem, if an error less than 1 dB is required. The principal advantage of the proposed formulation is its...... parametrization with respect to the desired maximum error in measurements. This allows the engineer performing the near field scan to choose a suitable compromise between accuracy and measurement time....

  7. Bioaerosol sampling: sampling mechanisms, bioefficiency and field studies.

    Science.gov (United States)

    Haig, C W; Mackay, W G; Walker, J T; Williams, C

    2016-07-01

    Investigations into the suspected airborne transmission of pathogens in healthcare environments have posed a challenge to researchers for more than a century. With each pathogen demonstrating a unique response to environmental conditions and the mechanical stresses it experiences, the choice of sampling device is not obvious. Our aim was to review bioaerosol sampling, sampling equipment, and methodology. A comprehensive literature search was performed, using electronic databases to retrieve English language papers on bioaerosol sampling. The review describes the mechanisms of popular bioaerosol sampling devices such as impingers, cyclones, impactors, and filters, explaining both their strengths and weaknesses, and the consequences for microbial bioefficiency. Numerous successful studies are described that point to best practice in bioaerosol sampling, from the use of small personal samplers to monitor workers' pathogen exposure through to large static samplers collecting airborne microbes in various healthcare settings. Of primary importance is the requirement that studies should commence by determining the bioefficiency of the chosen sampler and the pathogen under investigation within laboratory conditions. From such foundations, sampling for bioaerosol material in the complexity of the field holds greater certainty of successful capture of low-concentration airborne pathogens. From the laboratory to use in the field, this review enables the investigator to make informed decisions about the choice of bioaerosol sampler and its application.

  8. Sampling Criterion for EMC Near Field Measurements

    DEFF Research Database (Denmark)

    Franek, Ondrej; Sørensen, Morten; Ebert, Hans

    2012-01-01

    -case representative of a signal trace on a typical printed circuit board. It has been found that the sampling density derived in this way is in fact very similar to that given by the antenna near field sampling theorem, if an error less than 1 dB is required. The principal advantage of the proposed formulation is its...

  9. Field Sampling from a Segmented Image

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-06-01

    Full Text Available Image Debba, Stein, van der Meer, Carranza, Lucieer Objective Study Site Methods The ICM Algorithm Sampling Per Category Sample Size Per Category Fitness Function Per Category Simulated Annealing Per Category Results Experiment Case... Study Conclusions Field Sampling from a Segmented Image P. Debba1 A. Stein2 F.D. van der Meer2 E.J.M. Carranza2 A. Lucieer3 1The Council for Scientific and Industrial Research (CSIR), Logistics and Quantitative Methods, CSIR Built Environment, P...

  10. Visual Sample Plan (VSP) - FIELDS Integration

    Energy Technology Data Exchange (ETDEWEB)

    Pulsipher, Brent A.; Wilson, John E.; Gilbert, Richard O.; Hassig, Nancy L.; Carlson, Deborah K.; Bing-Canar, John; Cooper, Brian; Roth, Chuck

    2003-04-19

    Two software packages, VSP 2.1 and FIELDS 3.5, are being used by environmental scientists to plan the number and type of samples required to meet project objectives, display those samples on maps, query a database of past sample results, produce spatial models of the data, and analyze the data in order to arrive at defensible decisions. VSP 2.0 is an interactive tool to calculate optimal sample size and optimal sample location based on user goals, risk tolerance, and variability in the environment and in lab methods. FIELDS 3.0 is a set of tools to explore the sample results in a variety of ways to make defensible decisions with quantified levels of risk and uncertainty. However, FIELDS 3.0 has a small sample design module. VSP 2.0, on the other hand, has over 20 sampling goals, allowing the user to input site-specific assumptions such as non-normality of sample results, separate variability between field and laboratory measurements, make two-sample comparisons, perform confidence interval estimation, use sequential search sampling methods, and much more. Over 1,000 copies of VSP are in use today. FIELDS is used in nine of the ten U.S. EPA regions, by state regulatory agencies, and most recently by several international countries. Both software packages have been peer-reviewed, enjoy broad usage, and have been accepted by regulatory agencies as well as site project managers as key tools to help collect data and make environmental cleanup decisions. Recently, the two software packages were integrated, allowing the user to take advantage of the many design options of VSP, and the analysis and modeling options of FIELDS. The transition between the two is simple for the user – VSP can be called from within FIELDS, automatically passing a map to VSP and automatically retrieving sample locations and design information when the user returns to FIELDS. This paper will describe the integration, give a demonstration of the integrated package, and give users download

  11. Fabrication of Tunable Sampled Grating DBR Laser Integrated Monolithically with Optical Semiconductor Amplifier Using Planar Buried Heterostructure

    Science.gov (United States)

    Oh, Su Hwan; Lee, Ji-Myon; Kim, Soo; Ko, Hyunsung; Lee, Chul-Wook; Park, Sahnggi; Park, Moon-Ho

    2004-10-01

    We have demonstrated a high-power widely tunable sampled grating (SG) DBR laser integrated monolithically with optical semiconductor amplifier (SOA), using planar buried heterostructure (PBH). The measured threshold current was 5 mA on average with 60 chips randomly selected which is lowest among the typical average values. Fiber-coupled output power was 12.4 dBm and the output power variation was ˜1 dB for the whole tuning range.

  12. Genetic profiling of Klebsiella pneumoniae: comparison of pulsed field gel electrophoresis and random amplified polymorphic DNA

    Directory of Open Access Journals (Sweden)

    Mitra Ashayeri-Panah

    2013-09-01

    Full Text Available In this study, the discriminatory power of pulsed field gel electrophoresis (PFGE and random amplified polymorphic DNA (RAPD methods for subtyping of 54 clinical isolates of Klebsiella pneumoniae were compared. All isolates were typeable by RAPD, while 3.6% of them were not typeable by PFGE. The repeatability of both typing methods were 100% with satisfying reproducibility (≥ 95%. Although the discriminatory power of PFGE was greater than RAPD, both methods showed sufficient discriminatory power (DI > 0.95 which reflects the heterogeneity among the K. pneumoniae isolates. An optimized RAPD protocol is less technically demanding and time consuming that makes it a reliable typing method and competitive with PFGE.

  13. Soil Sampling Techniques For Alabama Grain Fields

    Science.gov (United States)

    Thompson, A. N.; Shaw, J. N.; Mask, P. L.; Touchton, J. T.; Rickman, D.

    2003-01-01

    Characterizing the spatial variability of nutrients facilitates precision soil sampling. Questions exist regarding the best technique for directed soil sampling based on a priori knowledge of soil and crop patterns. The objective of this study was to evaluate zone delineation techniques for Alabama grain fields to determine which method best minimized the soil test variability. Site one (25.8 ha) and site three (20.0 ha) were located in the Tennessee Valley region, and site two (24.2 ha) was located in the Coastal Plain region of Alabama. Tennessee Valley soils ranged from well drained Rhodic and Typic Paleudults to somewhat poorly drained Aquic Paleudults and Fluventic Dystrudepts. Coastal Plain s o i l s ranged from coarse-loamy Rhodic Kandiudults to loamy Arenic Kandiudults. Soils were sampled by grid soil sampling methods (grid sizes of 0.40 ha and 1 ha) consisting of: 1) twenty composited cores collected randomly throughout each grid (grid-cell sampling) and, 2) six composited cores collected randomly from a -3x3 m area at the center of each grid (grid-point sampling). Zones were established from 1) an Order 1 Soil Survey, 2) corn (Zea mays L.) yield maps, and 3) airborne remote sensing images. All soil properties were moderately to strongly spatially dependent as per semivariogram analyses. Differences in grid-point and grid-cell soil test values suggested grid-point sampling does not accurately represent grid values. Zones created by soil survey, yield data, and remote sensing images displayed lower coefficient of variations (8CV) for soil test values than overall field values, suggesting these techniques group soil test variability. However, few differences were observed between the three zone delineation techniques. Results suggest directed sampling using zone delineation techniques outlined in this paper would result in more efficient soil sampling for these Alabama grain fields.

  14. GLASS: The Grism Lens-Amplified Survey From Space. HST Grism Spectroscopy of the Frontier Fields

    Science.gov (United States)

    Schmidt, Kasper B.; Schmidt

    The Grism Lens-Amplified Survey From Space (GLASS) is a 140 orbit spectroscopic survey of 10 massive galaxy clusters, including the six Hubble Frontier Fields. GLASS has observed the cluster cores with the HST-WFC3 G102 and G141 grisms providing a wide wavelength coverage in the near-infrared from roughly 0.8-1.7μm. The parallel fields were observed through the optical ACS G800L grism. Taking advantage of the lensing magnification of the clusters, GLASS reaches intrinsic spectroscopic 1σ flux limits of roughly 10-18erg/s/cm2 and improved spatial resolution for lensed sources behind the clusters. These features are particularly useful for the three main science drivers of GLASS which are, I) exploring the universe at the epoch of reionization, II) describe how metals cycle in and out of galaxies, and III) asses the environmental dependence of galaxy evolution. The former two benefit highly from the improved depth and increased resolution provided by the cluster lensing. Apart from the main science drivers, a slew of ancillary science has been enabled by the survey, including improving cluster lens modeling and searches for supernovae. Here we present the survey and the GLASS data releases, which are continuously being made available to the community through https://archive.stsci.edu/prepds/glass/. For further information we refer to Schmidt et al. (2014), Treu et al. (2015), and http://glass.physics.ucsb.edu.

  15. Genotypic characterization of Salmonella by multilocus sequence typing, pulsed-field gel electrophoresis and amplified fragment length polymorphism

    DEFF Research Database (Denmark)

    Torpdahl, Mia; Skov, Marianne N.; Sandvang, Dorthe

    2005-01-01

    subspecies enterica isolates. A total of 25 serotypes were investigated that had been isolated from humans or veterinary sources in Denmark between 1995 and 2001. All isolates were genotyped by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and amplified fragment length...

  16. Nonreciprocal Microwave Signal Processing with a Field-Programmable Josephson Amplifier

    Science.gov (United States)

    Lecocq, F.; Ranzani, L.; Peterson, G. A.; Cicak, K.; Simmonds, R. W.; Teufel, J. D.; Aumentado, J.

    2017-02-01

    We report on the design and implementation of a field-programmable Josephson amplifier (FPJA)—a compact and lossless superconducting circuit that can be programmed in situ by a set of microwave drives to perform reciprocal and nonreciprocal frequency conversion and amplification. In this work, we demonstrate four modes of operation: frequency conversion (transmission of -0.5 dB, reflection of -30 dB), circulation (transmission of -0.5 dB, reflection of -30 dB, isolation of 30 dB), phase-preserving amplification (gain >20 dB , one photon of added noise) and directional phase-preserving amplification (reflection of -10 dB, forward gain of 18 dB, reverse isolation of 8 dB, one photon of added noise). The system exhibits quantitative agreement with the theoretical prediction. Based on a gradiometric superconducting quantum-interference device with Nb /Al -Al Ox/Nb Josephson junctions, the FPJA is first-order insensitive to flux noise and can be operated without magnetic shielding at low temperature. Owing to its flexible design and compatibility with existing superconducting fabrication techniques, the FPJA offers a straightforward route toward on-chip integration with superconducting quantum circuits such as qubits and microwave optomechanical systems.

  17. MOA—The Magnetic Field Amplified Thruster, a Novel Concept for a Pulsed Plasma Accelerator

    Science.gov (United States)

    Frischauf, Norbert; Hettmer, Manfred; Grassauer, Andreas; Bartusch, Tobias; Koudelka, Otto

    2008-01-01

    More than 60 years after the later Nobel laureate Hannes Alfvén had published a letter stating that oscillating magnetic fields can accelerate ionised matter via magneto-hydrodynamic interactions in a wave like fashion, the technical implementation of Alfvén waves for propulsive purposes has been proposed, patented and examined for the first time by a group of inventors. The name of the concept is MOA—Magnetic field Oscillating Amplified thruster. Based on computer simulations, MOA is a highly flexible propulsion system, whose performance parameters might easily be adapted, by changing the mass flow and/or the power level. As such the system is capable to deliver a maximum specific impulse of 13116 s (12.87 mN) at a power level of 11.16 kW, using Xe as propellant, but can also be attuned to provide a thrust of 236.5 mN (2411 s) at 6.15 kW of power. While space propulsion is expected to be the prime application for MOA and is supported by numerous applications such as Solar and/or Nuclear Electric Propulsion or even as an `afterburner system' for Nuclear Thermal Propulsion, other terrestrial applications can be thought of as well, making the system highly suited for a common space-terrestrial application research and utilisation strategy. This paper presents the recent developments of the MOA Thruster R&D activities at QASAR (www.qasar.at), the company in Vienna, which has been set up to further develop and test the Alfvén wave technology and its applications.

  18. GLASS: The Grism Lens-Amplified Survey From Space. HST Grism Spectroscopy of the Frontier Fields.

    Science.gov (United States)

    Borello Schmidt, Kasper

    2015-08-01

    The Grism Lens-Amplified Survey From Space (GLASS) is a 140 orbit spectroscopic survey of 10 massive galaxy clusters, including the six Hubble Frontier Fields. GLASS has observed the cluster cores in the HST-WFC3 G102 and G141 grisms providing a wide wavelength coverage in the near-infrared from roughly 0.8 - 1.7 μm. The parallel fields were observed through the optical ACS G800L grism. Taking advantage of the lensing magnification of the clusters, GLASS reaches excellent spectroscopic limits of ˜10-18 erg/s/cm2 and improved spatial resolution for lensed sources behind the clusters. These features are particularly useful for the three main science drivers of GLASS, which are: I) Use the hundreds of spectra of galaxies at z>6 to shed light on the epoch of reionization, the role galaxies play in reionizing the universe, and the Lyα escape fraction at the cosmic dawn. II) Study gas accretion, star formation, and outflows by spatially mapping resolved star formation and determine metallicity gradients from emission lines at z˜2. III) Explore the environmental dependence of galaxy evolution using the first comprehensive census of spatially resolved star formation in dense environments, i.e., the cluster cores as well as the cluster infall regions. The former two benefit highly from the improved depth and increased resolution provided by the cluster lensing. Apart from the main science drivers, a slew of ancillary science has been enabled by the survey. One particularly interesting example is the search for supernovae in the more than 40 GLASS visits, which resulted in the detection of the first multiple imaged supernova, SN Refsdal. I will present the survey, give an update on the current science results, in particular on the GLASS galaxies at the epoch of reionization, and provide a status report on the GLASS data releases, which are continuously being made available to the community.

  19. Brownian Optogenetic-Noise-Photostimulation on the Brain Amplifies Somatosensory-Evoked Field Potentials.

    Science.gov (United States)

    Huidobro, Nayeli; Mendez-Fernandez, Abraham; Mendez-Balbuena, Ignacio; Gutierrez, Ranier; Kristeva, Rumyana; Manjarrez, Elias

    2017-01-01

    Stochastic resonance (SR) is an inherent and counter-intuitive mechanism of signal-to-noise ratio (SNR) facilitation in biological systems associated with the application of an intermediate level of noise. As a first step to investigate in detail this phenomenon in the somatosensory system, here we examined whether the direct application of noisy light on pyramidal neurons from the mouse-barrel cortex expressing a light-gated channel channelrhodopsin-2 (ChR2) can produce facilitation in somatosensory evoked field potentials. Using anesthetized Thy1-ChR2-YFP transgenic mice, and a new neural technology, that we called Brownian optogenetic-noise-photostimulation (BONP), we provide evidence for how BONP directly applied on the barrel cortex modulates the SNR in the amplitude of whisker-evoked field potentials (whisker-EFP). In all transgenic mice, we found that the SNR in the amplitude of whisker-EFP (at 30% of the maximal whisker-EFP) exhibited an inverted U-like shape as a function of the BONP level. As a control, we also applied the same experimental paradigm, but in wild-type mice, as expected, we did not find any facilitation effects. Our results show that the application of an intermediate intensity of BONP on the barrel cortex of ChR2 transgenic mice amplifies the SNR of somatosensory whisker-EFPs. This result may be relevant to explain the improvements found in sensory detection in humans produced by the application of transcranial-random-noise-stimulation (tRNS) on the scalp.

  20. Mars Analogue Field Research and Sample Analysis

    Science.gov (United States)

    Foing, Bernard H.

    2016-07-01

    We describe results from the data analysis from a series of field research campaigns (ILEWG EuroMoonMars campaigns 2009 to 2016) in the Utah desert and in other extreme environments (Iceland, Eifel, La Reunion) relevant to habitability and astrobiology in Mars environments, and in order to help in the interpretation of Mars missions measurements from orbit (MEX, MRO) or from the surface (MER, MSL). We discuss results relevant to the scientific study of the habitability factors influenced by the properties of dust, organics, water history and the diagnostics and characterisation of microbial life. We also discuss perspectives for the preparation of future lander and sample return missions. We deployed at Mars Desert Research station, Utah, a suite of instruments and techniques including sample collection, context imaging from remote to local and microscale, drilling, spectrometers and life sensors. We analyzed how geological and geochemical evolution affected local parameters (mineralogy, organics content, environment variations) and the habitability and signature of organics and biota. We find high diversity in the composition of soil samples even when collected in close proximity, the low abundances of detectable PAHs and amino acids and the presence of biota of all three domains of life with significant heterogeneity. An extraordinary variety of putative extremophiles was observed. A dominant factor seems to be soil porosity and lower clay-sized particle content. A protocol was developed for sterile sampling, contamination issues, and the diagnostics of biodiversity via PCR and DGGE analysis in soils and rocks samples. We compare campaign results from 2009-2013 campaigns in Utah and other sites to new measurements concerning: the comparison between remote sensing and in-situ measurements; the study of minerals; the detection of organics and signs of life.

  1. Fluorescence amplified fragment length polymorphism compared to pulsed field gel electrophoresis for Listeria monocytogenes subtyping

    Directory of Open Access Journals (Sweden)

    Roussel Sophie

    2013-01-01

    Full Text Available Abstract Background Listeriosis is a severe infection which mainly affects pregnant women, neonates and immuno-compromised adults. ANSES’s Laboratory for Food safety has been the European Union Reference Laboratory (EURL for L. monocytogenes in the food chain since 2006. Pulsed Field Gel Electrophoresis (PFGE is routinely used in the EURL for the surveillance of L. monocytogenes isolated from foods, animals and the environment. One of the main EURL activities is to evaluate alternative molecular subtyping methods to PFGE, and integrate their use within the National Reference Laboratories (NRL network. Since 2008, the United Kingdom (UK-NRL for L. monocytogenes at the Health Protection Agency (HPA, London, has used fluorescent Amplified Fragment Length Polymorphism (fAFLP for the routine surveillance of L. monocytogenes isolated from human clinical cases, food and food processing environments in the UK. This study compares fAFLP with PFGE for subtyping L. monocytogenes. Results A panel of 109 L. monocytogenes isolates from either human cases of listeriosis, foods, food processing environments and animals were used for the comparative evaluation. Among these, 2 strains were tested from duplicate culture by both methods. The panel also included field isolates, isolates associated with outbreaks or sporadic cases and reference strains. The two strains tested in duplicate displayed the same fAFLP and PFGE types. Strains known to be epidemiologically associated with one another were found to have unique PFGE and fAFLP types. FAFLP and PFGE divided the strains into 76 and 82 distinct profiles, or types, respectively. The discriminatory index calculated was 0.993 and 0.996 for fAFLP and PFGE, respectively. Conclusions The discriminatory ability of fAFLP was similar to that of PFGE for the subtyping of L. monocytogenes isolates. As a less labour intensive technique fAFLP may be a better method to use than PFGE in investigating outbreaks of human

  2. Temperature-Accelerated Sampling and Amplified Collective Motion with Adiabatic Reweighting to Obtain Canonical Distributions and Ensemble Averages.

    Science.gov (United States)

    Hu, Yue; Hong, Wei; Shi, Yunyu; Liu, Haiyan

    2012-10-09

    In molecular simulations, accelerated sampling can be achieved efficiently by raising the temperature of a small number of coordinates. For collective coordinates, the temperature-accelerated molecular dynamics method or TAMD has been previously proposed, in which the system is extended by introducing virtual variables that are coupled to these coordinates and simulated at higher temperatures (Maragliano, L.; Vanden-Eijnden, E. Chem. Phys. Lett.2005, 426, 168-175). In such accelerated simulations, steady state or equilibrium distributions may exist but deviate from the canonical Boltzmann one. We show that by assuming adiabatic decoupling between the subsystems simulated at different temperatures, correct canonical distributions and ensemble averages can be obtained through reweighting. The method makes use of the low-dimensional free energy surfaces that are estimated as Gaussian mixture probability densities through maximum likelihood and expectation maximization. Previously, we proposed the amplified collective motion method or ACM. The method employs the coarse-grained elastic network model or ANM to extract collective coordinates for accelerated sampling. Here, we combine the ideas of ACM and of TAMD to develop a general technique that can achieve canonical sampling through reweighting under the adiabatic approximation. To test the validity and accuracy of adiabatic reweighting, first we consider a single n-butane molecule in a canonical stochastic heat bath. Then, we use explicitly solvated alanine dipeptide and GB1 peptide as model systems to demonstrate the proposed approaches. With alanine dipeptide, it is shown that sampling can be accelerated by more than an order of magnitude with TAMD while correct distributions and canonical ensemble averages can be recovered, necessarily through adiabatic reweighting. For the GB1 peptide, the conformational distribution sampled by ACM-TAMD, after adiabatic reweighting, suggested that a normal simulation suffered

  3. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including t...

  4. Attosecond nanoscale near-field sampling

    Science.gov (United States)

    Förg, B.; Schötz, J.; Süßmann, F.; Förster, M.; Krüger, M.; Ahn, B.; Okell, W. A.; Wintersperger, K.; Zherebtsov, S.; Guggenmos, A.; Pervak, V.; Kessel, A.; Trushin, S. A.; Azzeer, A. M.; Stockman, M. I.; Kim, D.; Krausz, F.; Hommelhoff, P.; Kling, M. F.

    2016-01-01

    The promise of ultrafast light-field-driven electronic nanocircuits has stimulated the development of the new research field of attosecond nanophysics. An essential prerequisite for advancing this new area is the ability to characterize optical near fields from light interaction with nanostructures, with sub-cycle resolution. Here we experimentally demonstrate attosecond near-field retrieval for a tapered gold nanowire. By comparison of the results to those obtained from noble gas experiments and trajectory simulations, the spectral response of the nanotaper near field arising from laser excitation can be extracted. PMID:27241851

  5. Attosecond nanoscale near-field sampling

    CERN Document Server

    Förg, Benjamin; Suessmann, Frederik; Foerster, Michael; Krueger, Michael; Ahn, Byung-Nam; Wintersperger, Karen; Zherebtsov, Sergey; Guggenmos, Alexander; Pervak, Vladimir; Kessel, Alexander; Trushin, Sergei; Azzeer, Abdallah; Stockman, Mark; Kim, Dong-Eon; Krausz, Ferenc; Hommelhoff, Peter; Kling, Matthias

    2015-01-01

    The promise of ultrafast light field driven electronic nanocircuits has stimulated the development of the new research field of attosecond nanophysics. An essential prerequisite for advancing this new area is the ability to characterize optical nearfields from light interaction with nanostructures with sub cycle resolution. Here, we experimentally demonstrate attosecond nearfield retrieval with a gold nanotip using streaking spectroscopy. By comparison of the results from gold nanotips to those obtained for a noble gas, the spectral response of the nanotip near field arising from laser excitation can be extracted. Monte Carlo MC trajectory simulations in near fields obtained with the macroscopic Maxwells equations elucidate the streaking mechanism on the nanoscale.

  6. Switched-capacitor multiply-by-two amplifier with reduced capacitor mismatches sensitivity and full swing sample signal common-mode voltage

    Institute of Scientific and Technical Information of China (English)

    Xu Xinnan; Yao Suying; Xu Jiangtao; Nie Kaiming

    2012-01-01

    A switched-capacitor amplifier with an accurate gain of two that is insensitive to component mismatch is proposed.This structure is based on associating two sets of two capacitors in cross series during the amplification phase.This circuit permits the common-mode voltage of the sample signal to reach full swing.Using the chargecomplement technique,the proposed amplifier can reduce the impact of parasitic capacitors on the gain accuracy effectively.Simulation results show that as sample signal common-mode voltage changes,the difference between the minimum and maximum gain error is less than 0.03%.When the capacitor mismatch is increased from 0 to 0.2%,the gain error is deteriorated by 0.00015 %.In all simulations,the gain of amplifier is 69 dB.

  7. Designing optimal sampling schemes for field visits

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-10-01

    Full Text Available This is a presentation of a statistical method for deriving optimal spatial sampling schemes. The research focuses on ground verification of minerals derived from hyperspectral data. Spectral angle mapper (SAM) and spectral feature fitting (SFF...

  8. Field sampling scheme optimization using simulated annealing

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2010-10-01

    Full Text Available to derive optimal sampling schemes. 2. Hyperspectral remote sensing In the study of electro-magnetic physics, when energy in the form of light interacts with a material, part of the energy at certain wavelength is absorbed, transmitted, emitted... in order to derive optimal sampling schemes. 2. Hyperspectral remote sensing In the study of electro-magnetic physics, when energy in the form of light interacts with a material, part of the energy at certain wavelength is absorbed, transmitted, emitted...

  9. Optimal sampling schemes for vegetation and geological field visits

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2012-07-01

    Full Text Available The presentation made to Wits Statistics Department was on common classification methods used in the field of remote sensing, and the use of remote sensing to design optimal sampling schemes for field visits with applications in vegetation...

  10. Using remotely-sensed data for optimal field sampling

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-09-01

    Full Text Available to carry out a fieldwork sample is an important issue as it avoids subjective judgement and can save on time and costs in the field. STATISTICAL SAMPLING, USING DATA OBTAINED FROM REMOTE SENSING, FINDS APPLICATION IN A VARIETY OF FIELDS... M B E R 2 0 0 8 15 USING REMOTELY- SENSED DATA FOR OPTIMAL FIELD SAMPLING BY DR PRAVESH DEBBA STATISTICS IS THE SCIENCE pertaining to the collection, summary, analysis, interpretation and presentation of data. It is often impractical...

  11. Micromagnetic insight into a magnetoreceptor in birds: existence of magnetic field amplifiers in the beak

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2009-01-01

    The Earth's magnetic field provides an important source of directional information for many living organisms, especially birds, but the sensory receptor responsible for magnetic field detection still has to be identified. Recently, magnetic iron oxide particles were detected in dendritic endings...... of the ophthalmic nerves in the skin of the upper beak of homing pigeons and were shown to fulfill the special prerequisites of a biological receptor. Here we study the proposed receptor theoretically and formulate the criteria for which it becomes operational and can be used for registering the weak magnetic...

  12. Wireless Josephson amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Narla, A.; Sliwa, K. M.; Hatridge, M.; Shankar, S.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

    2014-06-09

    Josephson junction parametric amplifiers are playing a crucial role in the readout chain in superconducting quantum information experiments. However, their integration with current 3D cavity implementations poses the problem of transitioning between waveguide, coax cables, and planar circuits. Moreover, Josephson amplifiers require auxiliary microwave components, like directional couplers and/or hybrids, that are sources of spurious losses and impedance mismatches that limit measurement efficiency and amplifier tunability. We have developed a wireless architecture for these parametric amplifiers that eliminates superfluous microwave components and interconnects. This greatly simplifies their assembly and integration into experiments. We present an experimental realization of such a device operating in the 9–11 GHz band with about 100 MHz of amplitude gain-bandwidth product, on par with devices mounted in conventional sample holders. The simpler impedance environment presented to the amplifier also results in increased amplifier tunability.

  13. Klystrons, traveling wave tubes, magnetrons, crossed-field amplifiers, and gyrotrons

    CERN Document Server

    Gilmour, A S

    2011-01-01

    Microwave tubes are vacuum electron devices used for the generation and amplification of radio frequencies in the microwave range. An established technology area, the use of tubes remains essential in the field today for high-power applications. The culmination of the author's 50 years of industry experience, this authoritative resource offers you a thorough understanding of the operations and major classes of microwave tubes.Minimizing the use of advanced mathematics, the book places emphasis on clear qualitative explanations of phenomena. This practical reference serves as an excellent intro

  14. Coherent addition of gratings for chirped-pulse-amplified lasers based on near-field and far-field measurements

    Institute of Scientific and Technical Information of China (English)

    Yuchuan Yang; Hui Luo; Xiao Wang; Fuquan Li; Xiaojun Huang; Bin Feng; Feng Jing

    2011-01-01

    @@ The development of phased-array grating compressor is a crucial issue for high-energy, ultra-short pulse petawatt-class lasers.Almost all systems have adopted a tiled-grating approach to meet the size require-ments for the compression gratings.We present a computer-control test system utilizing near-field interfer-ence and far-field focusing capable of monitoring and fast correcting tiled errors of the grating compressor.In this system, the tilt/tip errors between the two gratings are determined by the Fourier transform (FT)of the individual inteiference fringe, and the piston errors are determined by the ratio of the two primary peaks formed in the far-field pattern as a function of the piston difference.Monochromatic grating phasing is achieved experimentally and pulse compression is demonstrated with a tiled grating system.%The development of phased-array grating compressor is a crucial issue for high-energy, ultra-short pulse petawatt-class lasers. Almost all systems have adopted a tiled-grating approach to meet the size requirements for the compression gratings. We present a computer-control test system utilizing near-field interference and far-field focusing capable of monitoring and fast correcting tiled errors of the grating compressor.In this system, the tilt/tip errors between the two gratings are determined by the Fourier transform (FT)of the individual inter ference fringe, and the piston errors are determined by the ratio of the two primary peaks formed in the far-field pattern as a function of the piston difference. Monochromatic grating phasing is achieved experimentally and pulse compression is demonstrated with a tiled grating system.

  15. High-resolution genotyping of Listeria monocytogenes by fluorescent amplified fragment length polymorphism analysis compared to pulsed-field gel electrophoresis, random amplified polymorphic DNA analysis, ribotyping, and PCR-restriction fragment length polymorphism analysis

    DEFF Research Database (Denmark)

    Vogel, Birte Fonnesbech; Fussing, V.; Ojeniyi, B.

    2004-01-01

    of different origin. The AFLP technique was compared with three other molecular typing methods - ribotyping, random amplified polymorphic DNA analysis (RAPD), and pulsed-field gel electrophoresis (PFGE) - in terms of discriminatory ability. PCR-restriction fragment length polymorphism was included......The purpose of this study was to evaluate fluorescent amplified fragment length polymorphism (AFLP) analysis for the inter- and intraspecies differentiation of a collection of 96 strains of Listeria monocytogenes and 10 non- L. monocytogenes strains representing six other Listeria species...... for virulence gene allele characterization. The 96 L. monocytogenes strains were divided into two major clusters by AFLP fingerprinting at a similarity level of 82% in concordance with the results of PFGE, RAPD, and ribotyping. One main cluster consisted of all of the 24 L. monocytogenes hly allele 1 strains...

  16. Astronaut Neil Armstrong studies rock samples during geological field trip

    Science.gov (United States)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, studies rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  17. Direct sampling of electric-field vacuum fluctuations

    National Research Council Canada - National Science Library

    Riek, C; Seletskiy, D V; Moskalenko, A S; Schmidt, J F; Krauspe, P; Eckart, S; Eggert, S; Burkard, G; Leitenstorfer, A

    2015-01-01

    .... The ground-state electric-field variance is inversely proportional to the four-dimensional space-time volume, which we sampled electro-optically with tightly focused laser pulses lasting a few femtoseconds...

  18. Characterization of Mycoplasma hyosynoviae strains by amplified fragment length polymorphism analysis, pulsed-field gel electrophoresis and 16S ribosomal DNA sequencing

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Friis, N.F.; Ahrens, Peter

    2002-01-01

    , were investigated by analysis of amplified fragment length polymorphisms of the Bgl II and Mfe I restriction sites and by pulsed-field gel electrophoresis of a Bss HII digest of chromosomal DNA. Both methods allowed unambiguous differentiation of the analysed strains and showed similar discriminatory...

  19. Molecular epidemiology of contagious bovine pleuropneumonia in Tanzania based on amplified fragment length polymorphism and pulsed-field gel electrophoresis analysis

    DEFF Research Database (Denmark)

    Kusiluka, L.J.M.; Ojeniyi, B.; Friis, N.F.

    2001-01-01

    . The strains were analysed fur variations in the EcoRI and Csp6I restriction sites in the genomic DNA using the amplified fragment length polymorphism (AFLP) technique, and variations in the BamHI restriction sites using pulscd-field gel electrophoresis (PFGE). Six AFLP I) pes were detected among the analysed...

  20. Operational amplifiers

    CERN Document Server

    Dostal, Jiri

    1993-01-01

    This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

  1. Operational Amplifiers.

    Science.gov (United States)

    Foxcroft, G. E.

    1986-01-01

    Addresses the introduction of low cost equipment into high school and college physical science classes. Examines the properties of an "ideal" operational amplifier and discusses how it might be used under saturated and non-saturated conditions. Notes the action of a "real" operational amplifier. (TW)

  2. Extended Characterization of the Common-Source and Common-Gate Amplifiers using a Metal-Ferroelectric-Semiconductor Field Effect Transistor

    Science.gov (United States)

    Hunt, Mitchell; Sayyah, Rana; Mitchell, Cody; Laws, Crystal; MacLeod, Todd C.; Ho, Fat D.

    2013-01-01

    Collected data for both common-source and common-gate amplifiers is presented in this paper. Characterizations of the two amplifier circuits using metal-ferroelectric-semiconductor field effect transistors (MFSFETs) are developed with wider input frequency ranges and varying device sizes compared to earlier characterizations. The effects of the ferroelectric layer's capacitance and variation load, quiescent point, or input signal on each circuit are discussed. Comparisons between the MFSFET and MOSFET circuit operation and performance are discussed at length as well as applications and advantages for the MFSFETs.

  3. Magnetostatic modes in ferromagnetic samples with inhomogeneous internal fields

    Science.gov (United States)

    Arias, Rodrigo

    2015-03-01

    Magnetostatic modes in ferromagnetic samples are very well characterized and understood in samples with uniform internal magnetic fields. More recently interest has shifted to the study of magnetization modes in ferromagnetic samples with inhomogeneous internal fields. The present work shows that under the magnetostatic approximation and for samples of arbitrary shape and/or arbitrary inhomogeneous internal magnetic fields the modes can be classified as elliptic or hyperbolic, and their associated frequency spectrum can be delimited. This results from the analysis of the character of the second order partial differential equation for the magnetostatic potential under these general conditions. In general, a sample with an inhomogeneous internal field and at a given frequency, may have regions of elliptic and hyperbolic character separated by a boundary. In the elliptic regions the magnetostatic modes have a smooth monotonic character (generally decaying form the surfaces (a ``tunneling'' behavior)) and in hyperbolic regions an oscillatory wave-like character. A simple local criterion distinguishes hyperbolic from elliptic regions: the sign of a susceptibility parameter. This study shows that one may control to some extent magnetostatic modes via external fields or geometry. R.E.A. acknowledges Financiamiento Basal para Centros Cientificos y Tecnologicos de Excelencia under Project No. FB 0807 (Chile), Grant No. ICM P10-061-F by Fondo de Innovacion para la Competitividad-MINECON, and Proyecto Fondecyt 1130192.

  4. Design of a Sample and Hold Circuit using Rail to Rail Low Voltage Compact Operational Amplifier and bootstrap Switching

    Directory of Open Access Journals (Sweden)

    Annu Saini

    2014-09-01

    Full Text Available This paper presents a low power high performance and higher sampling speed sample and hold circuit. The proposed circuit is designed at 180 nm technology and has high linearity. The circuit can be used for the ADC frontend applications and supports double sampling architecture. The proposed sample and hold circuit has common mode range beyond rail to rail and uses two differential pairs transistor stages connected in parallel as its input stage.

  5. Rotating sample magnetometer for cryogenic temperatures and high magnetic fields.

    Science.gov (United States)

    Eisterer, M; Hengstberger, F; Voutsinas, C S; Hörhager, N; Sorta, S; Hecher, J; Weber, H W

    2011-06-01

    We report on the design and implementation of a rotating sample magnetometer (RSM) operating in the variable temperature insert (VTI) of a cryostat equipped with a high-field magnet. The limited space and the cryogenic temperatures impose the most critical design parameters: the small bore size of the magnet requires a very compact pick-up coil system and the low temperatures demand a very careful design of the bearings. Despite these difficulties the RSM achieves excellent resolution at high magnetic field sweep rates, exceeding that of a typical vibrating sample magnetometer by about a factor of ten. In addition the gas-flow cryostat and the high-field superconducting magnet provide a temperature and magnetic field range unprecedented for this type of magnetometer.

  6. Long-Term Ecological Monitoring Field Sampling Plan for 2007

    Energy Technology Data Exchange (ETDEWEB)

    T. Haney

    2007-07-31

    This field sampling plan describes the field investigations planned for the Long-Term Ecological Monitoring Project at the Idaho National Laboratory Site in 2007. This plan and the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions constitute the sampling and analysis plan supporting long-term ecological monitoring sampling in 2007. The data collected under this plan will become part of the long-term ecological monitoring data set that is being collected annually. The data will be used t determine the requirements for the subsequent long-term ecological monitoring. This plan guides the 2007 investigations, including sampling, quality assurance, quality control, analytical procedures, and data management. As such, this plan will help to ensure that the resulting monitoring data will be scientifically valid, defensible, and of known and acceptable quality.

  7. Piezoelectric Sensor for Determination of Genetically Modified Soybean Roundup Readyâ in Samples not Amplified by PCR

    Directory of Open Access Journals (Sweden)

    Hanna Radecka

    2007-08-01

    Full Text Available The chemically modified piezoelectrodes were utilized to develop relativelycheap and easy to use biosensor for determination of genetically modified Roundup Readysoybean (RR soybean. The biosensor relies on the immobilization onto goldpiezoelectrodes of the 21-mer single stranded oligonucleotide (probes related to5-enolpyruvylshikimate-3-phosphate synthase (EPSPS gene, which is an active componentof an insert integrated into RR soybean genome. The hybridization reaction between theprobe and the target complementary sequence in solution was monitored. The system wasoptimized using synthetic oligonucleotides, which were applied for EPSPS gene detectionin DNA samples extracted from animal feed containing 30% RR soybean amplified by thePCR and nonamplified by PCR. The detection limit for genomic DNA was in the range of4.7·105 numbers of genom copies contained EPSPS gene in the QCM cell. The propertiessuch as sensitivity and selectivity of piezoelectric senor presented here indicated that it could be applied for the direct determination of genetically modified RR soybean in the samples non-amplified by PCR.

  8. Phase noise in RF and microwave amplifiers.

    Science.gov (United States)

    Boudot, Rodolphe; Rubiola, Enrico

    2012-12-01

    Understanding amplifier phase noise is a critical issue in many fields of engineering and physics, such as oscillators, frequency synthesis, telecommunication, radar, and spectroscopy; in the emerging domain of microwave photonics; and in exotic fields, such as radio astronomy, particle accelerators, etc. Focusing on the two main types of base noise in amplifiers, white and flicker, the power spectral density of the random phase φ(t) is Sφ(f) = b(0) + b(-1)/f. White phase noise results from adding white noise to the RF spectrum in the carrier region. For a given RF noise level, b(0) is proportional to the reciprocal of the carrier power P(0). By contrast, flicker results from a near-dc 1/f noise-present in all electronic devices-which modulates the carrier through some parametric effect in the semiconductor. Thus, b(-1) is a parameter of the amplifier, constant in a wide range of P(0). The consequences are the following: Connecting m equal amplifiers in parallel, b(-1) is 1/m times that of one device. Cascading m equal amplifiers, b(-1) is m times that of one amplifier. Recirculating the signal in an amplifier so that the gain increases by a power of m (a factor of m in decibels) as a result of positive feedback (regeneration), we find that b(-1) is m(2) times that of the amplifier alone. The feedforward amplifier exhibits extremely low b(-1) because the carrier is ideally nulled at the input of its internal error amplifier. Starting with an extensive review of the literature, this article introduces a system-oriented model which describes the phase flickering. Several amplifier architectures (cascaded, parallel, etc.) are analyzed systematically, deriving the phase noise from the general model. There follow numerous measurements of amplifiers using different technologies, including some old samples, and in a wide frequency range (HF to microwaves), which validate the theory. In turn, theory and results provide design guidelines and give suggestions for CAD and

  9. Astronauts Armstrong and Aldrin study rock samples during field trip

    Science.gov (United States)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, and Astronaut Edwin Aldrin, Lunar module pilot for Apollo 11, study rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  10. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Field Sampling Plan

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

    1995-03-01

    The Environmental Management Division (EMD) of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland (Figure 1. 1). Since World War II activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). Considerable archival information about J-Field exists as a result of efforts by APG staff to characterize the hazards associated with the site. Contamination of J-Field was first detected during an environmental survey of the Edgewood Area conducted in 1977 and 1978 by the US Army Toxic and Hazardous Materials Agency (USATHAMA) (predecessor to the US Army Environmental Center [AEC]). As part of a subsequent USATHAMA -environmental survey, 11 wells were installed and sampled at J-Field. Contamination at J-Field was also detected during a munitions disposal survey conducted by Princeton Aqua Science in 1983. The Princeton Aqua Science investigation involved the installation and sampling of nine wells and the collection and analysis of surficial and deep composite soil samples. In 1986, a Resource Conservation and Recovery Act (RCRA) permit (MD3-21-002-1355) requiring a basewide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field was issued by the US Environmental Protection Agency (EPA). In 1987, the US Geological Survey (USGS) began a two-phased hydrogeologic assessment in data were collected to model, groundwater flow at J-Field. Soil gas investigations were conducted, several well clusters were installed, a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today.

  11. Genotyping whole-genome-amplified DNA from 3- to 25-year-old neonatal dried blood spot samples with reference to fresh genomic DNA.

    Science.gov (United States)

    Hollegaard, Mads Vilhelm; Thorsen, Poul; Norgaard-Pedersen, Bent; Hougaard, David Michael

    2009-07-01

    Stored surplus of dried blood spot (DBS) samples from neonatal screening programs constitute a vast potential for large genetic epidemiological studies. However, age of the samples and the small amounts of DNA available may limit their usage. In this study we validate genotyping accuracy and efficiency of whole-genome-amplified DNA (wgaDNA) obtained from stored DBS samples, with reference to fresh genomic DNA from the same individuals. DBS samples from 29 volunteers, stored for up to 25 years, in the Danish Neonatal Screening Biobank were included and three DNA extraction methods, each using one 3.2 mm disk, were evaluated. Four whole-genome amplification kits, and one re-amplification kit, were used. Thirty-one SNPs were genotyped using the Sequenom platform and the wgaDNA samples calls were compared with their references for accuracy and efficiency evaluation. The genotype calls done blinded by the user had in many setups a 100% call- and concordance rate. Our results showed that genotyping performance is dependent on the combination of extraction procedure and amplification method, whereas years of storage did not seem to influence in this study. Based on these results we conclude that DBS samples should be considered a reliable and potential resource for future genotyping studies.

  12. Sampling atmospheric pesticides with SPME: Laboratory developments and field study

    Energy Technology Data Exchange (ETDEWEB)

    Wang Junxia [EPCA-Institut des Sciences Moleculaires, UMR 5255 CNRS-Universite Bordeaux 1, ISM, Site universitaire, 24019 Perigueux Cedex (France); Tuduri, Ludovic [EPCA-Institut des Sciences Moleculaires, UMR 5255 CNRS-Universite Bordeaux 1, ISM, Site universitaire, 24019 Perigueux Cedex (France)], E-mail: l.tuduri@ism.u-bordeaux1.fr; Mercury, Maud [EPCA-Institut des Sciences Moleculaires, UMR 5255 CNRS-Universite Bordeaux 1, ISM, Site universitaire, 24019 Perigueux Cedex (France); Universites d' Aix-Marseille I, II et III-CNRS UMR 6264: Laboratoire Chimie Provence, Equipe Instrumentation et Reactivite Atmospherique (IRA), Universite de Provence Centre de Saint Jerome, Avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20 (France); Millet, Maurice [Centre de Geochimie de la Surface UMR 7517 CNRS-Universite Louis Pasteur (ULP), LPCA, 1 rue Blessig, 67084 Strasbourg Cedex (France); Briand, Olivier [AFSSET, 253 avenue du General Leclerc, 94701 Maisons-Alfort Cedex (France); Montury, Michel [EPCA-Institut des Sciences Moleculaires, UMR 5255 CNRS-Universite Bordeaux 1, ISM, Site universitaire, 24019 Perigueux Cedex (France)

    2009-02-15

    To estimate the atmospheric exposure of the greenhouse workers to pesticides, solid phase microextraction (SPME) was used under non-equilibrium conditions. Using Fick's law of diffusion, the concentrations of pesticides in the greenhouse can be calculated using pre-determined sampling rates (SRs). Thus the sampling rates (SRs) of two modes of SPME in the lab and in the field were determined and compared. The SRs for six pesticides in the lab were 20.4-48.3 mL min{sup -1} for the exposed fiber and 0.166-0.929 mL min{sup -1} for the retracted fiber. In field sampling, two pesticides, dichlorvos and cyprodinil were detected with exposed SPME. SR with exposed SPME for dichlorvos in the field (32.4 mL min{sup -1}) was consistent with that in the lab (34.5 mL min{sup -1}). SR for dichlorvos in the field (32.4 mL min{sup -1}) was consistent with that in the lab (34.5 mL min{sup -1}). The trends of temporal concentration and the inhalation exposure were also obtained. - SPME was proved to be a powerful and simple tool for determining pesticides' atmospheric concentration.

  13. Field-Flow Fractionation Analysis of Complex Biological Samples

    Directory of Open Access Journals (Sweden)

    Mijić, I.

    2014-03-01

    Full Text Available Normal analytical methods have difficulties when analysing complex samples containing particles of different size. In the 1960s, a new analytical technique was developed, which was able to overcome those difficulties. This new, Field-Flow Fractionation (FFF technique has been primarily used in the separation of large particles such as macromolecules and colloids. The development and improvement of the FFF technique led to the coupling of the technique with other specific and sensitive analytical methods which resulted in the FFF technique becoming very useful in isolation, separation and analysis of various complex samples, such as powders, emulsions, colloids, geological sediments, biopolymers, complex proteins, polysaccharides, synthetic polymers, and many others. The separation field in the FFF technique is a thin, empty flow chamber called a channel. The structure of the ribbonlike channel with view of the parabolic flow can be seen in Fig. 1. Separation is achieved by the interaction of sample components with an externally generated field, which is applied perpendicularly to the direction of the mobile flow inside the channel. Sample components, which differ in molar mass, size or other properties are pushed by the applied perpendicular field into different velocity regions within the parabolic flow profile of the mobile phase across the channel. The flow has different velocity depending on the position within the channel; the velocity at the walls is zero and it increases towards the centre of the channel. Samples are carried downstream through the channel at different velocities and exit the channel after different retention times. The relative distribution of samples in the parabolic flow determines the separation characteristics. Different operating modes have different types of distributions. The most frequently used mechanisms of FFF separation are listed in Fig. 2. Based on the characteristics of analysed particles and applied outer

  14. Serum Dried Samples to Detect Dengue Antibodies: A Field Study

    Directory of Open Access Journals (Sweden)

    Angelica Maldonado-Rodríguez

    2017-01-01

    Full Text Available Background. Dried blood and serum samples are useful resources for detecting antiviral antibodies. The conditions for elution of the sample need to be optimized for each disease. Dengue is a widespread disease in Mexico which requires continuous surveillance. In this study, we standardized and validated a protocol for the specific detection of dengue antibodies from dried serum spots (DSSs. Methods. Paired serum and DSS samples from 66 suspected cases of dengue were collected in a clinic in Veracruz, Mexico. Samples were sent to our laboratory, where the conditions for optimal elution of DSSs were established. The presence of anti-dengue antibodies was determined in the paired samples. Results. DSS elution conditions were standardized as follows: 1 h at 4°C in 200 µl of DNase-, RNase-, and protease-free PBS (1x. The optimal volume of DSS eluate to be used in the IgG assay was 40 µl. Sensitivity of 94%, specificity of 93.3%, and kappa concordance of 0.87 were obtained when comparing the antidengue reactivity between DSSs and serum samples. Conclusion. DSS samples are useful for detecting anti-dengue IgG antibodies in the field.

  15. DESIGN, DEVELOPMENT AND FIELD DEPLOYMENT OF A TELEOPERATED SAMPLING SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Dalmaso, M; Robert Fogle, R; Tony Hicks, T; Larry Harpring, L; Daniel Odell, D

    2007-11-09

    A teleoperated sampling system for the identification, collection and retrieval of samples following the detonation of an Improvised Nuclear Device (IND) or Radiological Dispersion Devise (RDD) has been developed and tested in numerous field exercises. The system has been developed as part of the Defense Threat Reduction Agency's (DTRA) National Technical Nuclear Forensic (NTNF) Program. The system is based on a Remotec ANDROS Mark V-A1 platform. Extensive modifications and additions have been incorporated into the platform to enable it to meet the mission requirements. The Defense Science Board Task Force on Unconventional Nuclear Warfare Defense, 2000 Summer Study Volume III report recommended the Department of Defense (DOD) improve nuclear forensics capabilities to achieve accurate and fast identification and attribution. One of the strongest elements of protection is deterrence through the threat of reprisal, but to accomplish this objective a more rapid and authoritative attribution system is needed. The NTNF program provides the capability for attribution. Early on in the NTNF program, it was recognized that there would be a desire to collect debris samples for analysis as soon as possible after a nuclear event. Based on nuclear test experience, it was recognized that mean radiation fields associated with even low yield events could be several thousand R/Hr near the detonation point for some time after the detonation. In anticipation of pressures to rapidly sample debris near the crater, considerable effort is being devoted to developing a remotely controlled vehicle that could enter the high radiation field area and collect one or more samples for subsequent analysis.

  16. Scanning Electron Microscopy with Samples in an Electric Field

    Science.gov (United States)

    Frank, Ludĕk; Hovorka, Miloš; Mikmeková, Šárka; Mikmeková, Eliška; Müllerová, Ilona; Pokorná, Zuzana

    2012-01-01

    The high negative bias of a sample in a scanning electron microscope constitutes the “cathode lens” with a strong electric field just above the sample surface. This mode offers a convenient tool for controlling the landing energy of electrons down to units or even fractions of electronvolts with only slight readjustments of the column. Moreover, the field accelerates and collimates the signal electrons to earthed detectors above and below the sample, thereby assuring high collection efficiency and high amplification of the image signal. One important feature is the ability to acquire the complete emission of the backscattered electrons, including those emitted at high angles with respect to the surface normal. The cathode lens aberrations are proportional to the landing energy of electrons so the spot size becomes nearly constant throughout the full energy scale. At low energies and with their complete angular distribution acquired, the backscattered electron images offer enhanced information about crystalline and electronic structures thanks to contrast mechanisms that are otherwise unavailable. Examples from various areas of materials science are presented.

  17. Electric field-modulated amplified spontaneous emission in organo-lead halide perovskite CH3NH3PbI3

    Science.gov (United States)

    Yuan, Fang; Wu, Zhaoxin; Dong, Hua; Xia, Bin; Xi, Jun; Ning, Shuya; Ma, Lin; Hou, Xun

    2015-12-01

    The electric field-modulation of the spontaneous emission (SE) and amplified spontaneous emission (ASE) in organo-lead halide perovskite CH3NH3PbI3 (aliased as MAPbI3) layer has been investigated. With the increase of the external applied electric field, the electric field-induced quenching of the SE and ASE intensity was observed, accompanying with a blue-shift of the ASE emission peaks, which can be attributed to field-induced ionization of photogenerated excitons in the MAPbI3 layer. Based on the analysis of quenching factor and the dielectric constant, we estimated an exciton binding energy ˜36 meV at room temperature, which will provide useful insights into the optical-electrical characteristics of MAPbI3 and pave the way for the future optoelectronic applications.

  18. Sampling Hyperpolarized Molecules Utilizing a 1 Tesla Permanent Magnetic Field.

    Science.gov (United States)

    Tee, Sui Seng; DiGialleonardo, Valentina; Eskandari, Roozbeh; Jeong, Sangmoo; Granlund, Kristin L; Miloushev, Vesselin; Poot, Alex J; Truong, Steven; Alvarez, Julio A; Aldeborgh, Hannah N; Keshari, Kayvan R

    2016-09-06

    Hyperpolarized magnetic resonance spectroscopy (HP MRS) using dynamic nuclear polarization (DNP) is a technique that has greatly enhanced the sensitivity of detecting (13)C nuclei. However, the HP MRS polarization decays in the liquid state according to the spin-lattice relaxation time (T1) of the nucleus. Sampling of the signal also destroys polarization, resulting in a limited temporal ability to observe biologically interesting reactions. In this study, we demonstrate that sampling hyperpolarized signals using a permanent magnet at 1 Tesla (1T) is a simple and cost-effective method to increase T1s without sacrificing signal-to-noise. Biologically-relevant information may be obtained with a permanent magnet using enzyme solutions and in whole cells. Of significance, our findings indicate that changes in pyruvate metabolism can also be quantified in a xenograft model at this field strength.

  19. Sampling Hyperpolarized Molecules Utilizing a 1 Tesla Permanent Magnetic Field

    Science.gov (United States)

    Tee, Sui Seng; Digialleonardo, Valentina; Eskandari, Roozbeh; Jeong, Sangmoo; Granlund, Kristin L.; Miloushev, Vesselin; Poot, Alex J.; Truong, Steven; Alvarez, Julio A.; Aldeborgh, Hannah N.; Keshari, Kayvan R.

    2016-09-01

    Hyperpolarized magnetic resonance spectroscopy (HP MRS) using dynamic nuclear polarization (DNP) is a technique that has greatly enhanced the sensitivity of detecting 13C nuclei. However, the HP MRS polarization decays in the liquid state according to the spin-lattice relaxation time (T1) of the nucleus. Sampling of the signal also destroys polarization, resulting in a limited temporal ability to observe biologically interesting reactions. In this study, we demonstrate that sampling hyperpolarized signals using a permanent magnet at 1 Tesla (1T) is a simple and cost-effective method to increase T1s without sacrificing signal-to-noise. Biologically-relevant information may be obtained with a permanent magnet using enzyme solutions and in whole cells. Of significance, our findings indicate that changes in pyruvate metabolism can also be quantified in a xenograft model at this field strength.

  20. Mathematical Models of the Common-Source and Common-Gate Amplifiers using a Metal-Ferroelectric-Semiconductor Field effect Transistor

    Science.gov (United States)

    Hunt, Mitchell; Sayyah, Rana; Mitchell, Cody; Laws, Crystal; MacLeod, Todd C.; Ho, Fat D.

    2013-01-01

    Mathematical models of the common-source and common-gate amplifiers using metal-ferroelectric- semiconductor field effect transistors (MOSFETs) are developed in this paper. The models are compared against data collected with MOSFETs of varying channel lengths and widths, and circuit parameters such as biasing conditions are varied as well. Considerations are made for the capacitance formed by the ferroelectric layer present between the gate and substrate of the transistors. Comparisons between the modeled and measured data are presented in depth as well as differences and advantages as compared to the performance of each circuit using a MOSFET.

  1. Field assisted hot pressing of sintering Inconel 718 MIM samples

    Science.gov (United States)

    Dugauguez, Olivier; Torralba, Jose Manuel; Barriere, Thierry; Gelin, Jean-Claude

    2016-10-01

    In this investigation on samples obtained by Metal Injection Molding (MIM), the conventional way of sintering in a furnace will be compared to Field Assisted Hot pressing (FAHP) sintering. The difficulty of this method is to be able to control the shrinkage of the sample and so its shape. It has yet not been investigated with a super alloy powder and so, the effects of a high sintering rate. By accelerating the sintering kinetics, the thermal behavior may be modified. Hence, the behavior of the Inconel 718 sintered by FAHP has been investigated. The sintered samples were all injected from a feedstock composed of a fine particle Inconel powder and a binder principally composed of Cellulose Acetate Butyrate CAB and Poly-Ethylene Glycol PEG. The effects of the two methods on the microstructure and the mechanical properties are then compared. There was no difference in distribution of pores between the conventional sintering and the FAHP sintering but a finer grain size showed better hardness.

  2. Amplified voltammetric detection of miRNA from serum samples of glioma patients via combination of conducting magnetic microbeads and ferrocene-capped gold nanoparticle/streptavidin conjugates.

    Science.gov (United States)

    Lu, Zhixuan; Tang, Hailin; Wu, Daohong; Xia, Yonghong; Wu, Minghua; Yi, Xinyao; Li, Hengfeng; Wang, Jianxiu

    2016-12-15

    MicroRNA (miRNA) plays a key regulatory role in many biological processes, emerging as an important biomarker for a large variety of cancer diseases. Employing gold nanoparticle (AuNP)-coated magnetic microbeads (AuNP-MMBs) as an immobilization matrix for higher loading density of hairpin-structured DNA probes and then ferrocene (Fc)-capped gold nanoparticle/streptavidin conjugates, amplified electrochemical assay of miRNA has been performed. In the presence of target miRNA, a novel assembly was formed via linking biotinylated hairpin DNA probe-covered AuNP-MMBs with Fc-capped gold nanoparticle/streptavidin conjugates and then collected by magnetic electrodes for voltammetric detection. The enlarged surface area, good conductivity of AuNP-MMBs and the multiple Fc tags on the electrode surface ensure high sensitivity of the method. The oxidation peak current of Fc tags is proportional to the concentrations of miRNA ranging from 5 fM to 100 fM, and a detection limit of 0.14 fM was achieved. The proposed assay is highly selective and reproducible, serving as a viable alternative for the detection of miRNA-182 from serum samples of glioma patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. PID Controller with Operational Amplifier

    Directory of Open Access Journals (Sweden)

    Cristian Paul Chioncel

    2009-01-01

    Full Text Available The paper presents a PID controller made with LM741 operational amplifier that implement the PID controllers laws and allow for a widerange of applications of in the field of automatic control of technicalprocesses and systems.

  4. Integral Field Spectroscopy of a sample of nearby galaxies. I. Sample, Observations and Data Reduction

    CERN Document Server

    Marmol-Queralto, E; Marino, R A; Mast, D; Viironen, K; de Paz, A Gil; Iglesias-Paramo, J; Rosales-Ortega, F F; Vilchez, J M

    2011-01-01

    Aims: Integral Field Spectroscopy (IFS) is a powerful approach for the study of nearby galaxies since it enables a detailed analysis of their resolved physical properties. Here we present the sample of nearby galaxies selected to exploit the two dimensional information provided by the IFS. Methods: We observed a sample of 48 galaxies from the Local Universe with the PPAK Integral Field Spectroscopy unit (IFU), of the PMAS spectrograph, mounted at the 3.5m telescope at Calar Alto Observatory (Almeria, Spain). Two different setups were used during these studies (low -V300- and medium -V600- resolution mode) covering a spectral range of around 3700-7000 Angs. We developed a full automatic pipeline for the data reduction, that includes an analysis of the quality of the final data products. We applied a decoupling method to obtain the ionised gas and stellar content of these galaxies, and to derive the main physical properties of the galaxies. To asses the accuracy in the measurements of the different parameters, ...

  5. Standard Practice for Field Sampling of Aerospace Fluids in Containers

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice covers field sampling of fluids from hermetically sealed containers and other fluid containers of 208-L volume maximum. It may be utilized at manufacturing, storage, or use levels for obtaining representative fluid samples for chemical, physical, or particulate matter determinations. 1.2 Use of this practice depends upon variables such as fluid toxicity, restrictive fluid odors, fluid flammability, and so forth. It is suitable for most hydraulic fluids; however, care should be exercised in determining compatibility before use. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For hazard statement, see 6.5.1.

  6. Detection of genetically modified ingredients in seed samples from Heilongjiang soybean field

    Institute of Scientific and Technical Information of China (English)

    JIANG Haiyan; WANG Jianhua; WU Peng; LI Yongchun; WANG Guoying

    2005-01-01

    A total of 210 soybean samples collected from different areas of Heilongjiang Province were analyzed by PCR to detect the presence of RR (Roundup Ready) soybean ingredient. Results showed that CaMV35S promoter was not detected in all samples. CP4-EPSPS gene was amplified in 13 samples, but all of them were proved to be false positives in restriction endonuclease digestion analysis of PCR products. Further analysis by nested PCR indicated that there were no RR soybean ingredients in the samples. Besides, the amplified fragments of 0x1 by CP4-EPSPS primers were sequenced, and the results confirmed again the fact that this fragment was not from CP4-EPSPS gene.

  7. The Grism Lens-Amplified Survey from Space (GLASS). VI. Comparing the Mass and Light in MACSJ0416.1-2403 using Frontier Field imaging and GLASS spectroscopy

    CERN Document Server

    Hoag, Austin; Treu, Tommaso; Bradač, Maruša; Schmidt, Kasper B; Wang, Xin; Brammer, Gabriel B; Broussard, Adam; Amorin, Ricardo; Castellano, Marco; Fontana, Adriano; Merlin, Emiliano; Schrabback, Tim; Trenti, Michele; Vulcani, Benedetta

    2016-01-01

    We present a strong and weak gravitational lens model of the galaxy cluster MACSJ0416.1-2403, constrained using spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) and Hubble Frontier Fields (HFF) imaging data. We search for emission lines in known multiply imaged sources in the GLASS spectra, obtaining secure spectroscopic redshifts of 31 multiple images belonging to 16 distinct source galaxies. The GLASS spectra provide the first spectroscopic measurements for 6 of the source galaxies. The weak lensing signal is acquired from 884 galaxies in the F606W HFF image. By combining the weak lensing constraints with 15 multiple image systems with spectroscopic redshifts and 9 multiple image systems with photometric redshifts, we reconstruct the gravitational potential of the cluster on an adaptive grid. The resulting total mass density map is compared with a stellar mass density map obtained from the deep Spitzer Frontier Fields imaging data to study the relative distribution of stellar and total m...

  8. 100  kHz Yb-fiber laser pumped 3  μm optical parametric amplifier for probing solid-state systems in the strong field regime.

    Science.gov (United States)

    Archipovaite, Giedre Marija; Petit, Stéphane; Delagnes, Jean-Christophe; Cormier, Eric

    2017-03-01

    We report on a laser source operating at 100 kHz repetition rate and delivering 8 μJ few-cycle mid-IR pulses at 3 μm. The system is based on optical parametric amplification pumped by a high repetition rate Yb-doped femtosecond fiber-chirped amplifier. This high-intensity ultrafast system is a promising tool for strong-field experiments (up to 50 GV/m and 186 T) in low ionization potential atomic and molecular systems, or solid-state physics with coincidence measurements. As a proof of principle, up to the sixth harmonic has been generated in a 1 mm zinc selenide sample.

  9. The Grism lens-amplified survey from space (GLASS). VII. The diversity of the distribution of star formation in cluster and field galaxies at 0.3

    CERN Document Server

    Vulcani, Benedetta; Schmidt, Kasper B; Morishita, Takahiro; Dressler, Alan; Poggianti, Bianca M; Abramson, Louis; Bradač, Marusa; Brammer, Gabriel B; Hoag, Austin; Malkan, Matthew; Pentericci, Laura; Trenti, Michele

    2016-01-01

    Exploiting the slitless spectroscopy taken as part of the Grism Lens-Amplified Survey from Space (GLASS), we present an extended analysis of the spatial distribution of star formation in 76 galaxies in 10 clusters at 0.3< z <0.7. We use 85 foreground and background galaxies in the same redshift range as a field sample. The samples are well matched in stellar mass (10^8-10^11 M_sun) and star formation rate (0.5-50 M_sun/yr). We visually classify galaxies in terms of broad-band morphology, Halpha morphology and likely physical process acting on the galaxy. Most Halpha emitters have a spiral morphology (41+/-8% in clusters, 51+/-8% in the field), followed by mergers/interactions (28+/-8%, 31+/-7%, respectively) and early-type galaxies (remarkably as high as 29+/-8% in clusters and 15+/-6% in the field). A diversity of Halpha morphologies is detected, suggesting a diversity of physical processes. In clusters, 30+/-8% of the galaxies present a regular morphology, mostly consistent with star formation diffuse...

  10. European Research on THz Vacuum Amplifiers

    DEFF Research Database (Denmark)

    Brunetti, F.; Cojocarua, C.-S.; de Rossi, A.

    2010-01-01

    The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the Eu...... of the European research, academy and industry in vacuum electronics. This paper describes the status of the project and progress towards the THz amplifier realization....

  11. European Research on THz Vacuum Amplifiers

    DEFF Research Database (Denmark)

    Brunetti, F.; Cojocarua, C.-S.; de Rossi, A.

    2010-01-01

    The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the Eu...... of the European research, academy and industry in vacuum electronics. This paper describes the status of the project and progress towards the THz amplifier realization....

  12. Magnetic Fields in a Sample of Nearby Spiral Galaxies

    CERN Document Server

    Van Eck, Cameron; Shukurov, Anvar; Fletcher, Andrew

    2014-01-01

    Both observations and modelling of magnetic fields in the diffuse interstellar gas of spiral galaxies are well developed but the theory has been confronted with observations for only a handful of individual galaxies. There is now sufficient data to consider statistical properties of galactic magnetic fields. We have collected data from the literature on the magnetic fields and interstellar media (ISM) of 20 spiral galaxies, and tested for various physically motivated correlations between magnetic field and ISM parameters. Clear correlations emerge between the total magnetic field strength and molecular gas density as well as the star formation rate. The magnetic pitch angle exhibits correlations with the total gas density, the star formation rate and the strength of the axisymmetric component of the mean magnetic field. The total and mean magnetic field strengths exhibit noticeable degree of correlation, suggesting a universal behaviour of the degree of order in galactic magnetic fields. We also compare the p...

  13. Quantum Noise in Amplifiers and Hawking/Dumb-Hole Radiation as Amplifier Noise

    CERN Document Server

    Unruh, W G

    2011-01-01

    The quantum noise in a linear amplifier is shown to be thermal noise. The theory of linear amplifiers is applied first to the simplest, single or double oscillator model of an amplifier, and then to linear model of an amplifier with continuous fields and input and outputs. Finally it is shown that the thermal noise emitted by black holes first demonstrated by Hawking, and of dumb holes (sonic and other analogs to black holes), arises from the same analysis as for linear amplifiers. The amplifier noise of black holes acting as amplifiers on the quantum fields living in the spacetime surrounding the black hole is the radiation discovered by Hawking. For any amplifier, that quantum noise is completely characterized by the attributes of the system regarded as a classical amplifier, and arises out of those classical amplification factors and the commutation relations of quantum mechanics.

  14. Use of pulsed field gel electrophoresis (PFGE and single-enzyme amplified fragment length polymorphism(SE-AFLP to subtype isolates of Salmonella entericaserotype enteritidis

    Directory of Open Access Journals (Sweden)

    Caterina Mammina

    2005-03-01

    Full Text Available

    Serotype Enteritidis is still the main serotype infecting humans and poultry worldwide. Subtyping of isolates belonging to this serotype is difficult, because of the wide clonal circulation of a few bacterial clones.

    This study presents the results of the characterization of 49 isolates of S. Enteritidis identified at the southern Italy Centre for Enteric Pathogens (CEPIM during the years 2002-2003 by the methods of Pulsed Field Gel Electrophoresis (PFGE and Single-Enzyme Amplified Fragment Length Polymorphism (SE-AFLP.

    Clustering of the strains by SE-AFLP and PFGE is very similar, but the first technique is more rapid and user-friendly and does not require sophisticated equipment. Further work is needed for a more accurate assessment of SEAFLP, but preliminary results suggest it could be a promising support to epidemiological investigations.

  15. Device and Circuit Codesign Strategy for Application to Low-Noise Amplifier Based on Silicon Nanowire Metal-Oxide-Semiconductor Field Effect Transistors

    Science.gov (United States)

    Seongjae Cho,; Hee-Sauk Jhon,; Jung Hoon Lee,; Se Hwan Park,; Hyungcheol Shin,; Byung-Gook Park,

    2010-04-01

    In this study, a full-range approach from device level to circuit level design is performed for RF application of silicon nanowire (SNW) metal-oxide-semiconductor field effect transistors (MOSFETs). Both DC and AC analyses have been conducted to confirm the advantages of an SNW MOSFET over the conventional planar (CPL) MOSFET device having dimensional equivalence. Besides the intrinsic characteristic parameters, the extrinsic resistance and capacitance caused by wiring components are extracted from each device. On the basis of these intrinsic and extrinsic parameters, a multi-fingered 5.8 GHz low-noise amplifier (LNA) design adopting SNW MOSFETs has been achieved, which shows an improved gain of 17.5 dB and a noise figure of 3.1 dB over a CPL MOSFET LNA.

  16. MAGNETIC FIELDS IN A SAMPLE OF NEARBY SPIRAL GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Van Eck, C. L. [Department of Astrophysics, Faculty of Science, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Brown, J. C. [Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4 (Canada); Shukurov, A.; Fletcher, A., E-mail: c.vaneck@astro.ru.nl, E-mail: jocat@ucalgary.ca, E-mail: anvar.shukurov@ncl.ac.uk, E-mail: andrew.fletcher@ncl.ac.uk [School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2015-01-20

    Both observations and modeling of magnetic fields in the diffuse interstellar gas of spiral galaxies are well developed, but the theory has been confronted with observations for only a handful of individual galaxies. There is now sufficient data to consider the statistical properties of galactic magnetic fields. We have collected data from the literature on the magnetic fields and interstellar media of 20 spiral galaxies, and tested for various physically motivated correlations between magnetic field and interstellar medium parameters. Clear correlations emerge between the total magnetic field strength and molecular gas density as well as the star formation rate. The magnetic pitch angle exhibits correlations with the total gas density, the star formation rate, and the strength of the axisymmetric component of the mean magnetic field. The total and mean magnetic field strengths exhibit a noticeable degree of correlation, suggesting a universal behavior of the degree of order in galactic magnetic fields. We also compare the predictions of galactic dynamo theory to observed magnetic field parameters and identify directions in which theory and observations might be usefully developed.

  17. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  18. Multi-field Pattern Matching based on Sparse Feature Sampling.

    Science.gov (United States)

    Wang, Zhongjie; Seidel, Hans-Peter; Weinkauf, Tino

    2016-01-01

    We present an approach to pattern matching in 3D multi-field scalar data. Existing pattern matching algorithms work on single scalar or vector fields only, yet many numerical simulations output multi-field data where only a joint analysis of multiple fields describes the underlying phenomenon fully. Our method takes this into account by bundling information from multiple fields into the description of a pattern. First, we extract a sparse set of features for each 3D scalar field using the 3D SIFT algorithm (Scale-Invariant Feature Transform). This allows for a memory-saving description of prominent features in the data with invariance to translation, rotation, and scaling. Second, the user defines a pattern as a set of SIFT features in multiple fields by e.g. brushing a region of interest. Third, we locate and rank matching patterns in the entire data set. Experiments show that our algorithm is efficient in terms of required memory and computational efforts.

  19. Field evaluation of personal sampling methods for multiple bioaerosols.

    Directory of Open Access Journals (Sweden)

    Chi-Hsun Wang

    Full Text Available Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min. Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols.

  20. Field evaluation of personal sampling methods for multiple bioaerosols.

    Science.gov (United States)

    Wang, Chi-Hsun; Chen, Bean T; Han, Bor-Cheng; Liu, Andrew Chi-Yeu; Hung, Po-Chen; Chen, Chih-Yong; Chao, Hsing Jasmine

    2015-01-01

    Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC) filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters) and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min). Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols.

  1. Development of a field sampling method based on magnetic nanoparticles for the enrichment of pesticides in aqueous samples.

    Science.gov (United States)

    Zhang, Lingyi; Sheng, Xiaoling; Zhang, Runsheng; Xiong, Zhichao; Wu, Zhongping; Yan, Songmao; Zhang, Yurong; Zhang, Weibing

    2014-12-07

    A field sampling method based on magnetic core-shell silica nanoparticles was developed for field sampling and the enrichment of low concentrations of pesticides in aqueous samples. The magnetic nanoparticles could be easily extracted from water samples by a custom-made magnetic nanoparticle collector. The recovery of 15 mg of magnetic particles from a 500 mL water sample was 90.8%. Mixtures of seven pesticides spiked into pure water and pond water were used as marker samples to evaluate the field sampling method. The average recoveries at three levels of spiking were in the range 60.0-104.7% with relative standard deviations method has good linearity with a correlation coefficient >0.9990 in the concentration range 0.5-15 μg L(-1). The results of the analysis of a sample of poisoned pond water indicate that this method is fast, convenient and efficient for the field sampling and enrichment of pesticides in aqueous samples.

  2. Sampling Strategies for Fast Updating of Gaussian Markov Random Fields

    OpenAIRE

    Brown, D. Andrew; McMahan, Christopher S.

    2017-01-01

    Gaussian Markov random fields (GMRFs) are popular for modeling temporal or spatial dependence in large areal datasets due to their ease of interpretation and computational convenience afforded by conditional independence and their sparse precision matrices needed for random variable generation. Using such models inside a Markov chain Monte Carlo algorithm requires repeatedly simulating random fields. This is a nontrivial issue, especially when the full conditional precision matrix depends on ...

  3. Every base matters: assessing small subunit rRNA primers for marine microbiomes with mock communities, time series and global field samples.

    Science.gov (United States)

    Parada, Alma E; Needham, David M; Fuhrman, Jed A

    2016-05-01

    Microbial community analysis via high-throughput sequencing of amplified 16S rRNA genes is an essential microbiology tool. We found the popular primer pair 515F (515F-C) and 806R greatly underestimated (e.g. SAR11) or overestimated (e.g. Gammaproteobacteria) common marine taxa. We evaluated marine samples and mock communities (containing 11 or 27 marine 16S clones), showing alternative primers 515F-Y (5'-GTGYCAGCMGCCGCGGTAA) and 926R (5'-CCGYCAATTYMTTTRAGTTT) yield more accurate estimates of mock community abundances, produce longer amplicons that can differentiate taxa unresolvable with 515F-C/806R, and amplify eukaryotic 18S rRNA. Mock communities amplified with 515F-Y/926R yielded closer observed community composition versus expected (r(2)  = 0.95) compared with 515F-Y/806R (r(2)  ∼ 0.5). Unexpectedly, biases with 515F-Y/806R against SAR11 in field samples (∼4-10-fold) were stronger than in mock communities (∼2-fold). Correcting a mismatch to Thaumarchaea in the 515F-C increased their apparent abundance in field samples, but not as much as using 926R rather than 806R. With plankton samples rich in eukaryotic DNA (> 1 μm size fraction), 18S sequences averaged ∼17% of all sequences. A single mismatch can strongly bias amplification, but even perfectly matched primers can exhibit preferential amplification. We show that beyond in silico predictions, testing with mock communities and field samples is important in primer selection.

  4. Using remote sensing images to design optimal field sampling schemes

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-08-01

    Full Text Available At this presentation, the author discussed a statistical method for deriving optimal spatial sampling schemes. First I focus on ground verification of minerals derived from hyperspectral data. Spectral angle mapper (SAM) and spectral feature fitting...

  5. Estimation of the Relative Abundance of Different Bacteroides and Prevotella Ribotypes in Gut Samples by Restriction Enzyme Profiling of PCR-Amplified 16S rRNA Gene Sequences

    Science.gov (United States)

    Wood, Jacqueline; Scott, Karen P.; Avguštin, Gorazd; Newbold, C. James; Flint, Harry J.

    1998-01-01

    We describe an approach for determining the genetic composition of Bacteroides and Prevotella populations in gut contents based on selective amplification of 16S rRNA gene sequences (rDNA) followed by cleavage of the amplified material with restriction enzymes. The relative contributions of different ribotypes to total Bacteroides and Prevotella 16S rDNA are estimated after end labelling of one of the PCR primers, and the contribution of Bacteroides and Prevotella sequences to total eubacterial 16S rDNA is estimated by measuring the binding of oligonucleotide probes to amplified DNA. Bacteroides and Prevotella 16S rDNA accounted for between 12 and 62% of total eubacterial 16S rDNA in samples of ruminal contents from six sheep and a cow. Ribotypes 4, 5, 6, and 7, which include most cultivated rumen Prevotella strains, together accounted for between 20 and 86% of the total amplified Bacteroides and Prevotella rDNA in these samples. The most abundant Bacteroides or Prevotella ribotype in four animals, however, was ribotype 8, for which there is only one known cultured isolate, while ribotypes 1 and 2, which include many colonic Bacteroides spp., were the most abundant in two animals. This indicates that some abundant Bacteroides and Prevotella groups in the rumen are underrepresented among cultured rumen Prevotella isolates. The approach described here provides a rapid, convenient, and widely applicable method for comparing the genotypic composition of bacterial populations in gut samples. PMID:9758785

  6. Coherent amplified optical coherence tomography

    Science.gov (United States)

    Zhang, Jun; Rao, Bin; Chen, Zhongping

    2007-07-01

    A technique to improve the signal-to-noise ratio (SNR) of a high speed 1300 nm swept source optical coherence tomography (SSOCT) system was demonstrated. A semiconductor optical amplifier (SOA) was employed in the sample arm to coherently amplify the weak light back-scattered from sample tissue without increasing laser power illuminated on the sample. The image quality improvement was visualized and quantified by imaging the anterior segment of a rabbit eye at imaging speed of 20,000 A-lines per second. The theory analysis of SNR gain is given followed by the discussion on the technologies that can further improve the SNR gain.

  7. Interactive Editing of GigaSample Terrain Fields

    KAUST Repository

    Treib, Marc

    2012-05-01

    Previous terrain rendering approaches have addressed the aspect of data compression and fast decoding for rendering, but applications where the terrain is repeatedly modified and needs to be buffered on disk have not been considered so far. Such applications require both decoding and encoding to be faster than disk transfer. We present a novel approach for editing gigasample terrain fields at interactive rates and high quality. To achieve high decoding and encoding throughput, we employ a compression scheme for height and pixel maps based on a sparse wavelet representation. On recent GPUs it can encode and decode up to 270 and 730 MPix/s of color data, respectively, at compression rates and quality superior to JPEG, and it achieves more than twice these rates for lossless height field compression. The construction and rendering of a height field triangulation is avoided by using GPU ray-casting directly on the regular grid underlying the compression scheme. We show the efficiency of our method for interactive editing and continuous level-of-detail rendering of terrain fields comprised of several hundreds of gigasamples. © 2012 The Author(s).

  8. The OPTHER Project: Progress toward the THz Amplifier

    DEFF Research Database (Denmark)

    Paoloni, C; Brunetti, F; Di Carlo, A

    2011-01-01

    This paper describes the status of the OPTHER (OPtically driven TeraHertz AmplifiERs) project and progress toward the THz amplifier realization. This project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within th...

  9. Fuzzy logic scheme for tip-sample distance control for a low cost near field optical microscope

    Directory of Open Access Journals (Sweden)

    J.A. Márquez

    2013-12-01

    Full Text Available The control of the distance between the surface and the tip-sample of a Scanning Near Field Optical Microscope (SNOM is essential for a reliable surface mapping. The control algorithm should be able to maintain the system in a constant distance between the tip and the surface. In this system, nanometric adjustments should be made in order to sense topographies at the same scale with an appropriate resolution. These kinds of devices varies its properties through short periods of time, and it is required a control algorithm capable of handle these changes. In this work a fuzzy logic control scheme is proposed in order to manage the changes the device might have through the time, and to counter the effects of the non-linearity as well. Two inputs are used to program the rules inside the fuzzy logic controller, the difference between the reference signal and the sample signal (error, and the speed in which it decreases or increases. A lock-in amplifier is used as data acquisition hardware to sample the high frequency signals used to produce the tuning fork oscillations. Once these variables are read the control algorithm calculate a voltage output to move the piezoelectric device, approaching or removing the tip-probe from the sample analyzed.

  10. Influence of the probe-sample interaction on scanning near-field optical microscopic images in the far field

    Institute of Scientific and Technical Information of China (English)

    Li Zhi; Zhang Jia-Sen; Yang Jing; Gong Qi-Huang

    2006-01-01

    We have studied the influence of probe-sample interaction in a scanning near-field optical microscopy (SNOM) in the far field by using samples with a step structure. For a sample with a step height of ~λ/4, the SNOM image contrast between the two sides of the step changes periodically at different scan heights. For a step height of ~λ/2, the image contrast remains approximately the same. The probe-sample interaction determines the SNOM image contrast here. The influence of different refractive indices of the sample has been also analysed by using a simple theoretical model.

  11. Tackling field-portable Raman spectroscopy of real world samples

    Science.gov (United States)

    Shand, Neil C.

    2008-10-01

    A major challenge confronting first responders, customs authorities and other security-related organisations is the accurate, rapid, and safe identification of potentially hazardous chemicals outside a laboratory environment. Currently, a range of hand portable Raman equipment is commercially available that is low cost and increasingly more sophisticated. These systems are generally based on the 785nm Stokes shifted Raman technique with many using dispersive grating spectrometers. This technique offers a broad range of capabilities including the ability to analyse illicit drugs, explosives, chemical weapons and pre-cursors but still has some fundamental constraints. 'Real world' samples, such as those found at a crime scene, will often not be presented in the most accessible manner. Simple issues such as glass fluorescence can make an otherwise tractable sample impossible to analyse in-situ. A new generation of portable Raman equipment is currently being developed to address these issues. Consideration is given to the use of longer wavelength for fluorescence reduction. Alternative optical designs are being tested to compensate for the signal reduction incurred by moving to longer wavelengths. Furthermore, the use of anti-Stokes spectroscopy is being considered as well as investigating the robustness and portability of traditional Fourier Transform interferometer designs along with future advances in detector technology and ultra small spectrometers.

  12. Cone fields and topological sampling in manifolds with bounded curvature

    CERN Document Server

    Turner, Katharine

    2011-01-01

    Often noisy point clouds are given as an approximation of a particular compact set of interest. A finite point cloud is a compact set. This paper proves a reconstruction theorem which gives a sufficient condition, as a bound on the Hausdorff distance between two compact sets, for when certain offsets of these two sets are homotopic in terms of the absence of {\\mu}-critical points in an annular region. Since an offset of a set deformation retracts to the set itself provided that there are no critical points of the distance function nearby, we can use this theorem to show when the offset of a point cloud is homotopy equivalent to the set it is sampled from. The ambient space can be any Riemannian manifold but we focus on ambient manifolds which have nowhere negative curvature. In the process, we prove stability theorems for {\\mu}-critical points when the ambient space is a manifold.

  13. Cross-differential amplifier

    Science.gov (United States)

    Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

    2013-01-01

    A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

  14. Field evaluation of broiler gait score using different sampling methods

    Directory of Open Access Journals (Sweden)

    AFS Cordeiro

    2009-09-01

    Full Text Available Brazil is today the world's largest broiler meat exporter; however, in order to keep this position, it must comply with welfare regulations while maintaining low production costs. Locomotion problems restrain bird movements, limiting their access to drinking and feeding equipment, and therefore their survival and productivity. The objective of this study was to evaluate locomotion deficiency in broiler chickens reared under stressful temperature conditions using three different sampling methods of birds from three different ages. The experiment consisted in determining the gait score of 28, 35, 42 and 49-day-old broilers using three different known gait scoring methods: M1, birds were randomly selected, enclosed in a circle, and then stimulated to walk out of the circle; M2, ten birds were randomly selected and gait scored; and M3, birds were randomly selected, enclosed in a circle, and then observed while walking away from the circle without stimulus to walking. Environmental temperature, relative humidity, and light intensity inside the poultry houses were recorded. No evidence of interaction between scoring method and age was found however, both method and age influenced gait score. Gait score was found to be lower at 28 days of age. The evaluation using the ten randomly selected birds within the house was the method that presented the less reliable results. Gait score results when birds were stimulated to walk were lower than when they were not simulated, independently of age. The gait scores obtained with the three tested methods and ages were higher than those considered acceptable. The highest frequency of normal gait score (0 represented 50% of the flock. These results may be related to heat stress during rearing. Average gait score incresead with average ambient temperature, relative humidity, and light intensity. The evaluation of gait score to detect locomotion problems of broilers under rearing conditions seems subjective and

  15. Portable musical instrument amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Christian, David E. (Danbury, CT)

    1990-07-24

    The present invention relates to a musical instrument amplifier which is particularly useful for electric guitars. The amplifier has a rigid body for housing both the electronic system for amplifying and processing signals from the guitar and the system's power supply. An input plug connected to and projecting from the body is electrically coupled to the signal amplifying and processing system. When the plug is inserted into an output jack for an electric guitar, the body is rigidly carried by the guitar, and the guitar is operatively connected to the electrical amplifying and signal processing system without use of a loose interconnection cable. The amplifier is provided with an output jack, into which headphones are plugged to receive amplified signals from the guitar. By eliminating the conventional interconnection cable, the amplifier of the present invention can be used by musicians with increased flexibility and greater freedom of movement.

  16. CALIFA: a diameter-selected sample for an integral field spectroscopy galaxy survey

    NARCIS (Netherlands)

    Walcher, C. J.; Wisotzki, L.; Bekeraité, S.; Husemann, B.; Iglesias-Páramo, J.; Backsmann, N.; Barrera Ballesteros, J.; Catalán-Torrecilla, C.; Cortijo, C.; del Olmo, A.; Garcia Lorenzo, B.; Falcón-Barroso, J.; Jilkova, L.; Kalinova, V.; Mast, D.; Marino, R. A.; Méndez-Abreu, J.; Pasquali, A.; Sánchez, S. F.; Trager, S.; Zibetti, S.; Aguerri, J. A. L.; Alves, J.; Bland-Hawthorn, J.; Boselli, A.; Castillo Morales, A.; Cid Fernandes, R.; Flores, H.; Galbany, L.; Gallazzi, A.; García-Benito, R.; Gil de Paz, A.; González-Delgado, R. M.; Jahnke, K.; Jungwiert, B.; Kehrig, C.; Lyubenova, M.; Márquez Perez, I.; Masegosa, J.; Monreal Ibero, A.; Pérez, E.; Quirrenbach, A.; Rosales-Ortega, F. F.; Roth, M. M.; Sanchez-Blazquez, P.; Spekkens, K.; Tundo, E.; van de Ven, G.; Verheijen, M. A. W.; Vilchez, J. V.; Ziegler, B.

    2014-01-01

    We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area (CALIFA) survey, a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital

  17. Communication: Multiple atomistic force fields in a single enhanced sampling simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hoang Viet, Man [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States); Derreumaux, Philippe, E-mail: philippe.derreumaux@ibpc.fr [Laboratoire de Biochimie Théorique, UPR 9080, CNRS, Université Denis Diderot, Sorbonne Paris Cité IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France); Institut Universitaire de France, 103 Bvd Saint-Germain, 75005 Paris (France); Nguyen, Phuong H., E-mail: phuong.nguyen@ibpc.fr [Laboratoire de Biochimie Théorique, UPR 9080, CNRS, Université Denis Diderot, Sorbonne Paris Cité IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France)

    2015-07-14

    The main concerns of biomolecular dynamics simulations are the convergence of the conformational sampling and the dependence of the results on the force fields. While the first issue can be addressed by employing enhanced sampling techniques such as simulated tempering or replica exchange molecular dynamics, repeating these simulations with different force fields is very time consuming. Here, we propose an automatic method that includes different force fields into a single advanced sampling simulation. Conformational sampling using three all-atom force fields is enhanced by simulated tempering and by formulating the weight parameters of the simulated tempering method in terms of the energy fluctuations, the system is able to perform random walk in both temperature and force field spaces. The method is first demonstrated on a 1D system and then validated by the folding of the 10-residue chignolin peptide in explicit water.

  18. How do you feel? Sampling of experiences within a mobile field trip support system.

    NARCIS (Netherlands)

    Tabuenca, Bernardo; Börner, Dirk

    2013-01-01

    Tabuenca, B., & Börner, D. (2013, 30 May). How do you feel? Sampling of experiences within a mobile field trip support system. Workshop presentation at the 9th Joint European Summer School on Technology Enhanced Learning, Limassol, Cyprus.

  19. Guidelines for collection and field analysis of water-quality samples from streams in Texas

    Science.gov (United States)

    Wells, F.C.; Gibbons, W.J.; Dorsey, M.E.

    1990-01-01

    This manual provides standardized guidelines and quality-control procedures for the collection and preservation of water-quality samples and defines procedures for making field analyses of unstable constituents or properties.

  20. Field Sampling and Selecting On-Site Analytical Methods for Explosives in Soil

    Science.gov (United States)

    The purpose of this issue paper is to provide guidance to Remedial Project Managers regarding field sampling and on-site analytical methods fordetecting and quantifying secondary explosive compounds in soils.

  1. Feasible sampling plan for Bemisia tabaci control decision-making in watermelon fields.

    Science.gov (United States)

    Lima, Carlos Ho; Sarmento, Renato A; Pereira, Poliana S; Galdino, Tarcísio Vs; Santos, Fábio A; Silva, Joedna; Picanço, Marcelo C

    2017-05-23

    The silverleaf whitefly Bemisia tabaci is one of the most important pests of watermelon fields worldwide. Conventional sampling plans are the starting point for the generation of decision-making systems of integrated pest management programs. The aim of this study was to determine a conventional sampling plan for B. tabaci in watermelon fields. The optimal leaf for B. tabaci adult sampling was the 6(th) most apical leaf. Direct counting was the best pest sampling technique. Crop pest densities fitted the negative binomial distribution and had a common aggregation parameter (Kcommon ). The sampling plan consisted of evaluating 103 samples per plot. This sampling plan was conducted for 56 min, costing US$ 2.22 per sampling and with a 10% maximum evaluation error. The sampling plan determined in this study can be adopted by farmers because it enables the adequate evaluation of B. tabaci populations in watermelon fields (10% maximum evaluation error) and is a low-cost (US$ 2.22 per sampling), fast (56 min per sampling) and feasible (because it may be used in a standardized way throughout the crop cycle) technique. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. Analysis of a copper sample for the CLIC ACS study in a field emission scanning microscope

    CERN Document Server

    Muranaka, Tomoko; Leifer, Klaus; Ziemann, Volker; Navitski, Aliaksandr; Müller, Günter

    2011-01-01

    We report measurements on a diamond turned Copper sample of material intended for the CLIC accelerating structures. The first part of the measurements was performed at Bergische Universität Wuppertal using a field emission scanning microscope to localize and characterize strong emission sites. In a second part the sample was investigated in an optical microscope, a white-light profilometer and scanning electron microscope in the microstructure laboratory in Uppsala to attempt to identify the features responsible for the field emission.

  3. Sample cell for in-field X-ray diffraction experiments

    Directory of Open Access Journals (Sweden)

    Viktor Höglin

    2015-01-01

    Full Text Available A sample cell making it possible to perform synchrotron radiation X-ray powder diffraction experiments in a magnetic field of 0.35 T has been constructed. The device is an add-on to an existing sample cell and contains a strong permanent magnet of NdFeB-type. Experiments have shown that the setup is working satisfactory making it possible to perform in-field measurements.

  4. Sampling and Reconstruction of the Pupil and Electric Field for Phase Retrieval

    Science.gov (United States)

    Dean, Bruce; Smith, Jeffrey; Aronstein, David

    2012-01-01

    This technology is based on sampling considerations for a band-limited function, which has application to optical estimation generally, and to phase retrieval specifically. The analysis begins with the observation that the Fourier transform of an optical aperture function (pupil) can be implemented with minimal aliasing for Q values down to Q = 1. The sampling ratio, Q, is defined as the ratio of the sampling frequency to the band-limited cut-off frequency. The analytical results are given using a 1-d aperture function, and with the electric field defined by the band-limited sinc(x) function. Perfect reconstruction of the Fourier transform (electric field) is derived using the Whittaker-Shannon sampling theorem for 1sampling ratio such that 1field with no aliasing, which has been extended to 2-d optical apertures.

  5. Sampling of high amounts of bioaerosols using a high-volume electrostatic field sampler

    DEFF Research Database (Denmark)

    Madsen, A. M.; Sharma, Anoop Kumar

    2008-01-01

    by the electrostatic field sampler and 11.8 mg m(-3) when measured by the GSP inhalable dust sampler. The quantity (amount per mg dust) of total fungi, Aspergillus fumigatus, total bacteria, endotoxin and mesophilic actinomycetes sampled by the electrostatic field samplers and the Gravikon samplers varied within...

  6. Sampling Strategies for Soil Available K and P at Field Scale

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Field nutrient distribution maps obtained from the study on soil variations within fields are the basis of precision agriculture. The quality of these maps for management depends on the accuracy of the predicted values, which depends on the initial sampling. To produce reliable predictions efficiently the minimal sampling size and combination should be decided firstly, which could avoid the misspent funds for field sampling work.A 7.9 hectare silage field close to the Agricultural Research Institute at Hillsborough, Northern Ireland, was selected for the study. Soil samples were collected from the field at 25 m intervals in a rectangular grid to provide a database of selected soil properties. Different data combinations were subsequently abstracted from this database for comparison purposes, and ordinary kriging used to produce interpolated soil maps.These predicted data groups were compared using least significant difference (LSD) test method. The results showed that the 62 sampling sizes of triangle arrangement for soil available K were sufficient to reach the required accuracy. The triangular sample combination proved to be superior to a rectangular one of similar sample size.

  7. Norm in soil and sludge samples in Dukhan oil Field, Qatar state

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kinani, A.T.; Hushari, M.; Al-Sulaiti, Huda; Alsadig, I.A., E-mail: mmhushari@moe.gov.qa [Radiation and Chemical Protection Department, Ministry of Environment, Doha (Qatar)

    2015-07-01

    The main objective of this work is to measure the activity concentrations of Naturally Occurring radioactive Materials (NORM) produced as a buy products in oil production. The analyses of NORM give available information for guidelines concerning radiation protection. Recently NORM subjected to restricted regulation issued by high legal authority at Qatar state. Twenty five samples of soil from Dukhan onshore oil field and 10 sludge samples collected from 2 offshore fields at Qatar state. High resolution low-level gamma-ray spectrometry used to measure gamma emitters of NORM. The activity concentrations of natural radionuclide in 22 samples from Dukhan oil field, were with average worldwide values . Only three soil samples have high activity concentration of Ra-226 which is more than 185 Bq/kg the exempted level for NORM in the Quatrain regulation. The natural radionuclide activity concentrations of 10 sludge samples from offshore oil fields was greater than 1100Bq/kg the exempted values of NORM set by Quatrain regulation so the sludge need special treatments. The average hazards indices (H{sub ex} , D , and Ra{sub eq}), for the 22 samples were below the word permissible values .This means that the human exposure to such material not impose any radiation risk. The average hazards indices (H{sub ex} , D , and Ra{sub eq}), for 3 soil samples and sludge samples are higher than the published maximal permissible. Thus human exposure to such material impose radiation risk. (author)

  8. Accuracy and Effort of Interpolation and Sampling: Can GIS Help Lower Field Costs?

    Directory of Open Access Journals (Sweden)

    Greg Simpson

    2014-12-01

    Full Text Available Sedimentation is a problem for all reservoirs in the Black Hills of South Dakota. Before working on sediment removal, a survey on the extent and distribution of the sediment is needed. Two sample lakes were used to determine which of three interpolation methods gave the most accurate volume results. A secondary goal was to see if fewer samples could be taken while still providing similar results. The smaller samples would mean less field time and thus lower costs. Subsamples of 50%, 33% and 25% were taken from the total samples and evaluated for the lowest Root Mean Squared Error values. Throughout the trials, the larger sample sizes generally showed better accuracy than smaller samples. Graphing the sediment volume estimates of the full sample, 50%, 33% and 25% showed little improvement after a sample of approximately 40%–50% when comparing the asymptote of the separate samples. When we used smaller subsamples the predicted sediment volumes were normally greater than the full sample volumes. It is suggested that when planning future sediment surveys, workers plan on gathering data at approximately every 5.21 meters. These sample sizes can be cut in half and still retain relative accuracy if time savings are needed. Volume estimates may slightly suffer with these reduced samples sizes, but the field work savings can be of benefit. Results from these surveys are used in prioritization of available funds for reclamation efforts.

  9. Design, analysis, and interpretation of field quality-control data for water-sampling projects

    Science.gov (United States)

    Mueller, David K.; Schertz, Terry L.; Martin, Jeffrey D.; Sandstrom, Mark W.

    2015-01-01

    The process of obtaining and analyzing water samples from the environment includes a number of steps that can affect the reported result. The equipment used to collect and filter samples, the bottles used for specific subsamples, any added preservatives, sample storage in the field, and shipment to the laboratory have the potential to affect how accurately samples represent the environment from which they were collected. During the early 1990s, the U.S. Geological Survey implemented policies to include the routine collection of quality-control samples in order to evaluate these effects and to ensure that water-quality data were adequately representing environmental conditions. Since that time, the U.S. Geological Survey Office of Water Quality has provided training in how to design effective field quality-control sampling programs and how to evaluate the resultant quality-control data. This report documents that training material and provides a reference for methods used to analyze quality-control data.

  10. From Field to the Web: Management and Publication of Geoscience Samples in CSIRO Mineral Resources

    Science.gov (United States)

    Devaraju, A.; Klump, J. F.; Tey, V.; Fraser, R.; Reid, N.; Brown, A.; Golodoniuc, P.

    2016-12-01

    Inaccessible samples are an obstacle to the reproducibility of research and may cause waste of time and resources through duplication of sample collection and management. Within the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources there are various research communities who collect or generate physical samples as part of their field studies and analytical processes. Materials can be varied and could be rock, soil, plant materials, water, and even synthetic materials. Given the wide range of applications in CSIRO, each researcher or project may follow their own method of collecting, curating and documenting samples. In many cases samples and their documentation are often only available to the sample collector. For example, the Australian Resources Research Centre stores rock samples and research collections dating as far back as the 1970s. Collecting these samples again would be prohibitively expensive and in some cases impossible because the site has been mined out. These samples would not be easily discoverable by others without an online sample catalog. We identify some of the organizational and technical challenges to provide unambiguous and systematic access to geoscience samples, and present their solutions (e.g., workflow, persistent identifier and tools). We present the workflow starting from field sampling to sample publication on the Web, and describe how the International Geo Sample Number (IGSN) can be applied to identify samples along the process. In our test case geoscientific samples are collected as part of the Capricorn Distal Footprints project, a collaboration project between the CSIRO, the Geological Survey of Western Australia, academic institutions and industry partners. We conclude by summarizing the values of our solutions in terms of sample management and publication.

  11. Oscillators and operational amplifiers

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2005-01-01

    A generalized approach to the design of oscillators using operational amplifiers as active elements is presented. A piecewise-linear model of the amplifier is used so that it make sense to investigate the eigenvalues of the Jacobian of the differential equations. The characteristic equation...

  12. Detection of Non-Amplified Genomic DNA

    CERN Document Server

    Corradini, Roberto

    2012-01-01

    This book offers a state-of-the-art overview on non amplified DNA detection methods and provides chemists, biochemists, biotechnologists and material scientists with an introduction to these methods. In fact all these fields have dedicated resources to the problem of nucleic acid detection, each contributing with their own specific methods and concepts. This book will explain the basic principles of the different non amplified DNA detection methods available, highlighting their respective advantages and limitations. The importance of non-amplified DNA sequencing technologies will be also discussed. Non-amplified DNA detection can be achieved by adopting different techniques. Such techniques have allowed the commercialization of innovative platforms for DNA detection that are expected to break into the DNA diagnostics market. The enhanced sensitivity required for the detection of non amplified genomic DNA has prompted new strategies that can achieve ultrasensitivity by combining specific materials with specifi...

  13. Sampling High-Dimensional Bandlimited Fields on Low-Dimensional Manifolds

    CERN Document Server

    Unnikrishnan, Jayakrishnan

    2011-01-01

    Consider the task of sampling and reconstructing a bandlimited spatial field in $\\Re^2$ using moving sensors that take measurements along their path. It is inexpensive to increase the sampling rate along the paths of the sensors but more expensive to increase the total distance traveled by the sensors per unit area, which we call the \\emph{path density}. In this paper we introduce the problem of designing sensor trajectories that are minimal in path density subject to the condition that the measurements of the field on these trajectories admit perfect reconstruction of bandlimited fields. We study various possible designs of sampling trajectories. Generalizing some ideas from the classical theory of sampling on lattices, we obtain necessary and sufficient conditions on certain configurations of straight line trajectories for perfect reconstruction. We show that a single set of equispaced parallel lines has the lowest path density from certain restricted classes of trajectories that admit perfect reconstructio...

  14. QC of sampling processes- a first overview: from field to test portion.

    Science.gov (United States)

    Esbensen, Kim H; Ramsey, Charles A

    2015-01-01

    Quality control (QC) is a systematic approach for estimating and minimizing significant error contributions to the measurement uncertainty from the full sampling and analysis process. Many types of QC measures can be implemented; the three dealt with here are primary sampling reproducibility, sample processing reproducibility, and contamination. Sampling processes can be subject to QC by applying a replication experiment, used either from the top by replication of the entire sampling/ preparation/analysis process, or in a hierarchical fashion successively at each subsequent sampling stage. The analytical repeatability is necessarily always included in either alternative. The replication experiment results in a quality index, the Relative Sampling Variability, which is used to assess the total error associated with the full field-to-analysis pathway. Contamination can occur at essentially all locations in the sampling regimen in the food/feed realm, affecting sample containers, sampling tools, sample processing equipment, environmental conditions, and sampling personnel. QC events to determine contamination should always be included where appropriate, but is of most concern for low concentration and/or volatile analytes. It is also of key importance in the development of new sampling protocols or carried-over protocols intended for use on new types of materials/lots than the ones for which they were originally developed. We here establish a first practical framework for QC as applied to the sampling context.

  15. Auto-Zero Differential Amplifier

    Science.gov (United States)

    Quilligan, Gerard T. (Inventor); Aslam, Shahid (Inventor)

    2017-01-01

    An autozero amplifier may include a window comparator network to monitor an output offset of a differential amplifier. The autozero amplifier may also include an integrator to receive a signal from a latched window comparator network, and send an adjustment signal back to the differential amplifier to reduce an offset of the differential amplifier.

  16. Risk Attitudes, Sample Selection and Attrition in a Longitudinal Field Experiment

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten Igel

    Longitudinal experiments allow one to compare inferences about behavior over time for the same individuals, and evaluate the temporal stability of latent preferences. But longitudinal experiments entail the possibility of sample selection and sample attrition over time, confounding inferences about...... to findings of temporal stability in overall risk aversion. However, that stability is around different levels of risk aversion than one might naively infer without the controls for sample selection and attrition we are able to implement. This evidence of “randomization bias” from sample selection...... is important given the popularity of field experiments that rely on randomization, and the effects that risk attitudes have for economic behavior in general....

  17. Quantum electronics maser amplifiers and oscillators

    CERN Document Server

    Fain, V M; Sanders, J H

    2013-01-01

    Quantum Electronics, Volume 2: Maser Amplifiers and Oscillators deals with the experimental and theoretical aspects of maser amplifiers and oscillators which are based on the principles of quantum electronics. It shows how the concepts and equations used in quantum electronics follow from the basic principles of theoretical physics.Comprised of three chapters, this volume begins with a discussion on the elements of the theory of quantum oscillators and amplifiers working in the microwave region, along with the practical achievements in this field. Attention is paid to two-level paramagnetic ma

  18. Small Sample Whole-Genome Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Hara, C A; Nguyen, C P; Wheeler, E K; Sorensen, K J; Arroyo, E S; Vrankovich, G P; Christian, A T

    2005-09-20

    Many challenges arise when trying to amplify and analyze human samples collected in the field due to limitations in sample quantity, and contamination of the starting material. Tests such as DNA fingerprinting and mitochondrial typing require a certain sample size and are carried out in large volume reactions; in cases where insufficient sample is present whole genome amplification (WGA) can be used. WGA allows very small quantities of DNA to be amplified in a way that enables subsequent DNA-based tests to be performed. A limiting step to WGA is sample preparation. To minimize the necessary sample size, we have developed two modifications of WGA: the first allows for an increase in amplified product from small, nanoscale, purified samples with the use of carrier DNA while the second is a single-step method for cleaning and amplifying samples all in one column. Conventional DNA cleanup involves binding the DNA to silica, washing away impurities, and then releasing the DNA for subsequent testing. We have eliminated losses associated with incomplete sample release, thereby decreasing the required amount of starting template for DNA testing. Both techniques address the limitations of sample size by providing ample copies of genomic samples. Carrier DNA, included in our WGA reactions, can be used when amplifying samples with the standard purification method, or can be used in conjunction with our single-step DNA purification technique to potentially further decrease the amount of starting sample necessary for future forensic DNA-based assays.

  19. Elastic fields of stationary and moving dislocations in three dimensional finite samples

    OpenAIRE

    1997-01-01

    Integral expressions are determined for the elastic displacement and stress fields due to stationary or moving dislocation loops in three dimensional, not necessarily isotropic, finite samples. A line integral representation is found for the stress field, thus satisfying the expectation that stresses should depend on the location of the dislocation loop, but not on the location of surfaces bounded by such loops that are devoid of physical significance. In the stationary case the line integral...

  20. Theoretical Description for the Focused Parametric Field After Inserting a Sample

    Institute of Scientific and Technical Information of China (English)

    陆荣荣; 龚秀芬; 章东

    2001-01-01

    In the parabolic and quasi-linear approximations, a theoretical description for the acoustical parametric field from a focusing source after inserting a sample is derived by using the superposition method of Gaussian beams. This model takes into consideration the attenuation, diffraction and nonlinear effects. The namerical computations of the axial sound pressure amplitude curves for the difference frequency sounds after the insertion of a sample are presented. The results indicate that this new model can be extended to measure or image the nonlinear parameter in the focused field.

  1. Field sampling and selecting on-site analytical methods for explosives in soil

    Energy Technology Data Exchange (ETDEWEB)

    Crockett, A.B.; Craig, H.D.; Jenkins, T.F.; Sisk, W.E.

    1996-12-01

    A large number of defense-related sites are contaminated with elevated levels of secondary explosives. Levels of contamination range from barely detectable to levels above 10% that need special handling because of the detonation potential. Characterization of explosives-contaminated sites is particularly difficult because of the very heterogeneous distribution of contamination in the environment and within samples. To improve site characterization, several options exist including collecting more samples, providing on-site analytical data to help direct the investigation, compositing samples, improving homogenization of the samples, and extracting larger samples. This publication is intended to provide guidance to Remedial Project Managers regarding field sampling and on-site analytical methods for detecting and quantifying secondary explosive compounds in soils, and is not intended to include discussions of the safety issues associated with sites contaminated with explosive residues.

  2. Application of Nonredundant Sampling Representations of Electromagnetic Fields to NF-FF Transformation Techniques

    Directory of Open Access Journals (Sweden)

    Ovidio M. Bucci

    2012-01-01

    Full Text Available An overview of the application of the band-limitation properties and nonredundant sampling representations of electromagnetic fields to NF-FF transformations is presented. The progresses achieved by applying them to data acquired on conventional NF scanning surfaces are discussed, outlining the remarkable reduction in the number of needed NF samples and measurement time. An optimal sampling interpolation expansion for reconstructing the probe response on a rotational scanning surface from a non-redundant number of its samples is also discussed. A unified theory of the NF-FF transformations with spiral scannings, which allow a remarkable reduction of the measurement time, is then reviewed by describing a sampling representation of the voltage on a quite arbitrary rotational surface from its nonredundant samples collected on a proper spiral wrapping it. Some numerical and experimental results assessing the effectiveness of the considered NF-FF transformations are shown too.

  3. A simple and novel method for retrieval of Pasteurellaceae from swab samples collected in the field

    DEFF Research Database (Denmark)

    Hansen, Mie J; Bertelsen, Mads F; Dietz, Rune

    2013-01-01

    Traditionally it has been difficult or impossible to collect and preserve bacterial samples of especially fastidious bacteria in mixed primary cultures, unless the samples could be transported to a laboratory within approximately 24 h. Therefore, a simple novel method for preserving swab samples...... until bacterial isolation can be completed in the laboratory was developed and evaluated. Pasteurellaceae bacteria were used as a representative for fastidious bacteria. A 7.5% glucose serum medium was used as freeze medium. Swab samples were soaked in the medium a maximum of 2 h after collection...... and 30 days prior to plating. From a field setting in Greenland, eight polar bear samples were collected and subsequently stored for 240 to 259 days at -20°C before incubation. Pasteurellaceae bacteria were isolated and genotyped from all samples stored in the freeze medium, indicating that the medium...

  4. Optoisolators simplify amplifier design

    Science.gov (United States)

    Ting, Joseph Wee

    2007-09-01

    Simplicity and low parts count are key virtues to this high voltage amplifier. Optoisolators replace complex high voltage transistor biasing schemes. This amplifier employs only 2 optoisolators, 16 high voltage mosfets transistors, 2 low voltage ones, 6 linear IC's and a score of passive components. Yet it can amplify opamp signals to 5 kV peak-to-peak from DC to sine waves up to 20 kHz. Resistor feedback guarantees the fidelity of the signal. It can source and sink 10 mA of output current. This amplifier was conceived to power ion traps for biological whole cell mass measurements. It is a versatile tool for a variety of applications.

  5. Guided transect sampling - a new design combining prior information and field surveying

    Science.gov (United States)

    Anna Ringvall; Goran Stahl; Tomas Lamas

    2000-01-01

    Guided transect sampling is a two-stage sampling design in which prior information is used to guide the field survey in the second stage. In the first stage, broad strips are randomly selected and divided into grid-cells. For each cell a covariate value is estimated from remote sensing data, for example. The covariate is the basis for subsampling of a transect through...

  6. Charge-sensitive amplifier

    Directory of Open Access Journals (Sweden)

    Startsev V. I.

    2008-02-01

    Full Text Available The authors consider design and circuit design techniques of reduction of the influence of the pyroelectric effect on operation of the charge sensitive amplifiers. The presented experimental results confirm the validity of the measures taken to reduce the impact of pyroelectric currents. Pyroelectric currents are caused by the influence of the temperature gradient on the piezoelectric sensor and on the output voltage of charge sensitive amplifiers.

  7. RF Power Amplifier Analysis

    Directory of Open Access Journals (Sweden)

    M. Lokay

    1993-04-01

    Full Text Available The special program is presented for the demonstration of RF power transistor amplifiers for the purposes of the high-school education in courses of radio transmitters. The program is written in Turbo Pascal 6. 0 and enables to study the waveforms in selected points of the amplifier and to draw the trajectories of the working point in a plot of output transistor characteristics.

  8. Self Field Measurements by Hall Sensors on the SeCRETS Long Sample CICCs in SULTAN

    NARCIS (Netherlands)

    Ilyin, Yu. A.; Nijhuis, A.; Kate, ten H.H.J.; Bruzzone, P.

    2002-01-01

    The aim of this work is to determine the existence and degree of the current unbalance of two types of cable-in-conduit conductors (CICC) of the SeCRETS long sample experiment, and its influence on the conductors' performance. The self-field measurements are performed by using six sets of annular Ha

  9. Minimal BRDF Sampling for Two-Shot Near-Field Reflectance Acquisition

    DEFF Research Database (Denmark)

    Xu, Zexiang; Nielsen, Jannik Boll; Yu, Jiyang

    2016-01-01

    We develop a method to acquire the BRDF of a homogeneous flat sample from only two images, taken by a near-field perspective camera, and lit by a directional light source. Our method uses the MERL BRDF database to determine the optimal set of lightview pairs for data-driven reflectance acquisition...

  10. Modification and application of a leaf blower-vac for field sampling of arthropods

    NARCIS (Netherlands)

    Zou, Yi; Telgen, van Mario D.; Chen, Junhui; Xiao, Haijun; Kraker, de Joop; Bianchi, Felix J.J.A.; Werf, van der Wopke

    2016-01-01

    Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure,

  11. Water sampling at the Berge Helene FPSO at Chinguetti field in Mauritania using passive samplers

    NARCIS (Netherlands)

    Korytar, P.; Galien, van der W.

    2007-01-01

    Three rounds of water sampling were performed at the Berge Helene FPSO at the Chinguetti field in Mauritania using passive samplers attached to the FPSO to determine the levels of contamination that could potentially accumulate in organisms. Two rounds were carried out prior to the commencement of

  12. Working without accumulation membrane in flow field-flow fractionation. Effect of sample loading on retention.

    Science.gov (United States)

    Melucci, Dora; Zattoni, Andrea; Casolari, Sonia; Reggiani, Matteo; Sanz, Ramses; Reschiglian, Pierluigi; Torsi, Giancarlo

    2004-03-01

    Membraneless hyperlayer flow field-flow fractionation (Hyp FIFFF) has shown improved performance with respect to Hyp FIFFF with membrane. The conditions for high recovery and recovery independent of sample loading in membraneless Hyp FIFFF have been previously determined. The effect of sample loading should be also investigated in order to optimize the form of the peaks for real samples. The effect of sample loading on peak retention parameters is of prime importance in applications such as the conversion of peaks into particle size distributions. In this paper, a systematic experimental work is performed in order to study the effect of sample loading on retention parameters. A procedure to regenerate the frit operating as accumulation wall is described. High reproducibility is obtained with low system conditioning time.

  13. Field quality control of an earth dam: random versus purposive sampling

    Energy Technology Data Exchange (ETDEWEB)

    Kotzias, P.C.; Stamatopoulos, A.C.

    1996-08-01

    Two sampling operations, the random and purposive techniques, for field quality control of an earth dam were presented. Each technique was analyzed and their similarities and differences were compared. Each took into consideration the attributes or variables such as strength, temperature, slump, air content, density, and water content. The purposive operation needed much less field sampling and testing than the random operation. The advantages and disadvantages of each technique were described. It was concluded that both techniques could be used individually or jointly on the same project as long as the extent of the application, with all rules and underlying assumptions, were recognized for each case and were strictly adhered to in the field. 19 refs., 4 tabs., 2 figs.

  14. Sampling the sound field in auditoria using large natural-scale array measurements.

    Science.gov (United States)

    Witew, Ingo B; Vorländer, Michael; Xiang, Ning

    2017-03-01

    Suitable data for spatial wave field analyses in concert halls need to satisfy the sampling theorem and hence requires densely spaced measurement positions over extended regions. The described measurement apparatus is capable of automatically sampling the sound field in auditoria over a surface of 5.30 m × 8.00 m to any appointed resolutions. In addition to discussing design features, a case study based on measured impulse responses is presented. The experimental data allow wave field animations demonstrating how sound propagating at grazing incidence over theater seating is scattered from rows of chairs (seat-dip effect). The visualized data of reflections and scattering from an auditorium's boundaries give insights and opportunities for advanced analyses.

  15. A simplified sampling procedure for the estimation of methane emission in rice fields.

    Science.gov (United States)

    Khokhar, Nadar Hussain; Park, Jae-Woo

    2017-08-24

    Manual closed chamber methods are widely used for CH4 measurement from rice paddies. Despite diurnal and seasonal variations in CH4 emissions, fixed sampling times, usually during the day, are used. Here, we monitored CH4 emission from rice paddies for one complete rice-growing season. Daytime CH4 emission increased from 0800 h, and maximal emission was observed at 1200 h. Daily averaged CH4 flux increased during plant growth or fertilizer application and decreased upon drainage of plants. CH4 measurement results were linearly interpolated and matched with the daily averaged CH4 emission calculated from the measured results. The time when daily averaged emission and the interpolated CH4 curve coincided during the daytime was largely invariant within each of the five distinctive periods. One-hourly sampling during each of these five periods was utilized to estimate the emission during each period, and we found that five one-hourly samples during the season accurately reflected the CH4 emission calculated based on all 136 hourly samples. This new sampling scheme is simple and more efficient than current sampling practices. Previously reported sampling schemes yielded estimates 9 to 32% higher than the measured CH4 emission, while our suggested scheme yielded an estimate that was only 5% different from that based on all 136-h samples. The sampling scheme proposed in this study can be used in rice paddy fields in Korea and extended worldwide to countries that use similar farming practices. This sampling scheme will help in producing more accurate global methane budget from rice paddy fields.

  16. Note: A high dynamic range, linear response transimpedance amplifier.

    Science.gov (United States)

    Eckel, S; Sushkov, A O; Lamoreaux, S K

    2012-02-01

    We have built a high dynamic range (nine decade) transimpedance amplifier with a linear response. The amplifier uses junction-gate field effect transistors (JFETs) to switch between three different resistors in the feedback of a low input bias current operational amplifier. This allows for the creation of multiple outputs, each with a linear response and a different transimpedance gain. The overall bandwidth of the transimpedance amplifier is set by the bandwidth of the most sensitive range. For our application, we demonstrate a three-stage amplifier with transimpedance gains of approximately 10(9)Ω, 3 × 10(7)Ω, and 10(4)Ω with a bandwidth of 100 Hz.

  17. Direct Contact Sorptive Extraction: A Robust Method for Sampling Plant Volatiles in the Field.

    Science.gov (United States)

    Kfoury, Nicole; Scott, Eric; Orians, Colin; Robbat, Albert

    2017-09-27

    Plants produce volatile organic compounds (VOCs) with diverse structures and functions, which change in response to environmental stimuli and have important consequences for interactions with other organisms. To understand these changes, in situ sampling is necessary. In contrast to dynamic headspace (DHS), which is the most often employed method, direct contact sampling employing a magnetic stir bar held in place by a magnet eliminates artifacts produced by enclosing plant materials in glass or plastic chambers. Direct-contact sorptive extraction (DCSE) using polydimethylsiloxane coated stir bars (Twisters) coated stir bars is more sensitive than DHS, captures a wider range of compounds, minimizes VOC collection from neighboring plants, and distinguishes the effects of herbivory in controlled and field conditions. Because DCSE is relatively inexpensive and simple to employ, scalability of field trials can be expanded concomitant with increased sample replication. The sensitivity of DCSE combined with the spectral deconvolution data analysis software makes the two ideal for comprehensive, in situ profiling of plant volatiles.

  18. Modification and Application of a Leaf Blower-vac for Field Sampling of Arthropods.

    Science.gov (United States)

    Zou, Yi; van Telgen, Mario D; Chen, Junhui; Xiao, Haijun; de Kraker, Joop; Bianchi, Felix J J A; van der Werf, Wopke

    2016-08-10

    Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as numbers per standardized sampling area. The sampling efficiency depends critically on the sampling duration. In a mature rice crop, a two-minute sampling in an enclosure of 0.13 m(2) yields more than 90% of the arthropod population. The device also allows sampling of arthropods dwelling on the water surface or the soil in rice paddies, but it is not suitable for sampling fast flying insects, such as predatory Odonata or larger hymenopterous parasitoids. The modified blower-vac is simple to construct, and cheaper and easier to handle than traditional suction sampling devices, such as D-vac. The low cost makes the modified blower-vac also accessible to researchers in developing countries.

  19. Modification and Application of a Leaf Blower-vac for Field Sampling of Arthropods

    Science.gov (United States)

    Zou, Yi; van Telgen, Mario D.; Chen, Junhui; Xiao, Haijun; de Kraker, Joop; Bianchi, Felix J. J. A.; van der Werf, Wopke

    2016-01-01

    Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as numbers per standardized sampling area. The sampling efficiency depends critically on the sampling duration. In a mature rice crop, a two-minute sampling in an enclosure of 0.13 m2 yields more than 90% of the arthropod population. The device also allows sampling of arthropods dwelling on the water surface or the soil in rice paddies, but it is not suitable for sampling fast flying insects, such as predatory Odonata or larger hymenopterous parasitoids. The modified blower-vac is simple to construct, and cheaper and easier to handle than traditional suction sampling devices, such as D-vac. The low cost makes the modified blower-vac also accessible to researchers in developing countries. PMID:27584040

  20. Size-resolved culturable airborne bacteria sampled in rice field, sanitary landfill, and waste incineration sites.

    Science.gov (United States)

    Heo, Yongju; Park, Jiyeon; Lim, Sung-Il; Hur, Hor-Gil; Kim, Daesung; Park, Kihong

    2010-08-01

    Size-resolved bacterial concentrations in atmospheric aerosols sampled by using a six stage viable impactor at rice field, sanitary landfill, and waste incinerator sites were determined. Culture-based and Polymerase Chain Reaction (PCR) methods were used to identify the airborne bacteria. The culturable bacteria concentration in total suspended particles (TSP) was found to be the highest (848 Colony Forming Unit (CFU)/m(3)) at the sanitary landfill sampling site, while the rice field sampling site has the lowest (125 CFU/m(3)). The closed landfill would be the main source of the observed bacteria concentration at the sanitary landfill. The rice field sampling site was fully covered by rice grain with wetted conditions before harvest and had no significant contribution to the airborne bacteria concentration. This might occur because the dry conditions favor suspension of soil particles and this area had limited personnel and vehicle flow. The respirable fraction calculated by particles less than 3.3 mum was highest (26%) at the sanitary landfill sampling site followed by waste incinerator (19%) and rice field (10%), which showed a lower level of respiratory fraction compared to previous literature values. We identified 58 species in 23 genera of culturable bacteria, and the Microbacterium, Staphylococcus, and Micrococcus were the most abundant genera at the sanitary landfill, waste incinerator, and rice field sites, respectively. An antibiotic resistant test for the above bacteria (Micrococcus sp., Microbacterium sp., and Staphylococcus sp.) showed that the Staphylococcus sp. had the strongest resistance to both antibiotics (25.0% resistance for 32 microg ml(-1) of Chloramphenicol and 62.5% resistance for 4 microg ml(-1) of Gentamicin).

  1. Electrospun amplified fiber optics.

    Science.gov (United States)

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-03-11

    All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ∼20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics.

  2. High-resolution distributed sampling of bandlimited fields with fixed-precision sensors

    CERN Document Server

    Kumar, Animesh; Ramchandran, Kannan

    2007-01-01

    The problem of sampling a discrete-time sequence of spatially bandlimited fields with a bounded dynamic range, in a distributed, communication-constrained, processing environment is addressed. A central unit, having access to the data gathered by a dense network of fixed-precision sensors, operating under stringent inter-node communication constraints, is required to reconstruct the field snapshots to maximum accuracy. Both deterministic and stochastic field models are considered. For stochastic fields, results are established in the almost-sure sense. The feasibility of having a flexible tradeoff between the oversampling rate (sensor density) and the analog-to-digital converter (ADC) precision, while achieving an exponential accuracy in the number of bits per Nyquist-interval is demonstrated. This exposes an underlying ``conservation of bits'' principle: the bit-budget per Nyquist-interval per snapshot (the rate) can be distributed along the amplitude axis (sensor-precision) and space (sensor density) in an ...

  3. Recent developments on field gas extraction and sample preparation methods for radiokrypton dating of groundwater

    Science.gov (United States)

    Yokochi, Reika

    2016-09-01

    Current and foreseen population growths will lead to an increased demand in freshwater, large quantities of which is stored as groundwater. The ventilation age is crucial to the assessment of groundwater resources, complementing the hydrological model approach based on hydrogeological parameters. Ultra-trace radioactive isotopes of Kr (81 Kr and 85 Kr) possess the ideal physical and chemical properties for groundwater dating. The recent advent of atom trap trace analyses (ATTA) has enabled determination of ultra-trace noble gas radioisotope abundances using 5-10 μ L of pure Kr. Anticipated developments will enable ATTA to analyze radiokrypton isotope abundances at high sample throughput, which necessitates simple and efficient sample preparation techniques that are adaptable to various sample chemistries. Recent developments of field gas extraction devices and simple and rapid Kr separation method at the University of Chicago are presented herein. Two field gas extraction devices optimized for different sampling conditions were recently designed and constructed, aiming at operational simplicity and portability. A newly developed Kr purification system enriches Kr by flowing a sample gas through a moderately cooled (138 K) activated charcoal column, followed by a gentle fractionating desorption. This simple process uses a single adsorbent and separates 99% of the bulk atmospheric gases from Kr without significant loss. The subsequent two stages of gas chromatographic separation and a hot Ti sponge getter further purify the Kr-enriched gas. Abundant CH4 necessitates multiple passages through one of the gas chromatographic separation columns. The presented Kr separation system has a demonstrated capability of extracting Kr with > 90% yield and 99% purity within 75 min from 1.2 to 26.8 L STP of atmospheric air with various concentrations of CH4. The apparatuses have successfully been deployed for sampling in the field and purification of groundwater samples.

  4. An Evaluation of Plotless Sampling Using Vegetation Simulations and Field Data from a Mangrove Forest.

    Directory of Open Access Journals (Sweden)

    Renske Hijbeek

    Full Text Available In vegetation science and forest management, tree density is often used as a variable. To determine the value of this variable, reliable field methods are necessary. When vegetation is sparse or not easily accessible, the use of sample plots is not feasible in the field. Therefore, plotless methods, like the Point Centred Quarter Method, are often used as an alternative. In this study we investigate the accuracy of different plotless sampling methods. To this end, tree densities of a mangrove forest were determined and compared with estimates provided by several plotless methods. None of these methods proved accurate across all field sites with mean underestimations up to 97% and mean overestimations up to 53% in the field. Applying the methods to different vegetation patterns shows that when random spatial distributions were used the true density was included within the 95% confidence limits of all the plotless methods tested. It was also found that, besides aggregation and regularity, density trends often found in mangroves contribute to the unreliability. This outcome raises questions about the use of plotless sampling in forest monitoring and management, as well as for estimates of density-based carbon sequestration. We give recommendations to minimize errors in vegetation surveys and recommendations for further in-depth research.

  5. Fractionated dynamic headspace sampling in the analysis of matrices of vegetable origin in the food field.

    Science.gov (United States)

    Liberto, Erica; Cagliero, Cecilia; Cordero, Chiara; Rubiolo, Patrizia; Bicchi, Carlo; Sgorbini, Barbara

    2017-03-17

    Recent technological advances in dynamic headspace sampling (D-HS) and the possibility to automate this sampling method have lead to a marked improvement in its the performance, a strong renewal of interest in it, and have extended its fields of application. The introduction of in-parallel and in-series automatic multi-sampling and of new trapping materials, plus the possibility to design an effective sampling process by correctly applying the breakthrough volume theory, have make profiling more representative, and have enhanced selectivity, and flexibility, also offering the possibility of fractionated enrichment in particular for high-volatility compounds. This study deals with fractionated D-HS ability to produce a sample representative of the volatile fraction of solid or liquid matrices. Experiments were carried out on a model equimolar (0.5mM) EtOH/water solution, comprising 16 compounds with different polarities and volatilities, structures ranging from C5 to C15 and vapor pressures from 4.15kPa (2,3-pentandione) to 0.004kPa (t-β-caryophyllene), and on an Arabica roasted coffee powder. Three trapping materials were considered: Tenax TA™ (TX), Polydimethylsiloxane foam (PDMS), and a three-carbon cartridge Carbopack B/Carbopack C/Carbosieve S-III™ (CBS). The influence of several parameters on the design of successful fractionated D-HS sampling. Including the physical and chemical characteristics of analytes and matrix, trapping material, analyte breakthrough, purge gas volumes, and sampling temperature, were investigated. The results show that, by appropriately choosing sampling conditions, fractionated D-HS sampling, based on component volatility, can produce a fast and representative profile of the matrix volatile fraction, with total recoveries comparable to those obtained by full evaporation D-HS for liquid samples, and very high concentration factors for solid samples.

  6. Single conversion stage amplifier - SICAM

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2005-12-15

    especially the so called isolated SICAM with non-modulated transformer voltages. The latter is found to be the most interesting isolated SICAM solution for the modern multichannel audio power amplification systems, since all of the output stages corresponding to the different audio channels can reuse the same input stage and transformer core. While the proposed approach tends to be very simple from topological perspective and allows for reduction of reactive component count, the commutation of the load current in the output bridge and the bridge itself are much more complicated than their Class D predecessors. The main contribution of the thesis can be found in the thorough analysis of the present topologies for isolated SICAMs, as well as the numerous structural improvements and several newly proposed control methods for alleviating the problem of load current commutation and high-performance control of the whole SICAM. Another significant contribution is the presentation of several interesting topologies and associated control principles in the field of non-isolated SICAMs for mains-connected and portable audio amplifiers. (au)

  7. Near-field ablation threshold of cellular samples at mid-IR wavelengths

    CERN Document Server

    Raghu, Deepa; Gamari, Benjamin; Reeves, M E

    2012-01-01

    We report the near-field ablation of material from cellulose acetate coverslips in water and my- oblast cell samples in growth media, with a spot size as small as 1.5 {\\mu}m under 3 {\\mu}m wavelength radiation. The power dependence of the ablation process has been studied and comparisons have been made to models of photomechanical and plasma-induced ablation. The ablation mechanism is mainly dependent on the acoustic relaxation time and optical properties of the materials. We find that for all near-field experiments, the ablation thresholds are very high, pointing to plasma-induced ablation as the dominant mechanism.

  8. Field portable mobile phone based fluorescence microscopy for detection of Giardia lamblia cysts in water samples

    Science.gov (United States)

    Ceylan Koydemir, Hatice; Gorocs, Zoltan; McLeod, Euan; Tseng, Derek; Ozcan, Aydogan

    2015-03-01

    Giardia lamblia is a waterborne parasite that causes an intestinal infection, known as giardiasis, and it is found not only in countries with inadequate sanitation and unsafe water but also streams and lakes of developed countries. Simple, sensitive, and rapid detection of this pathogen is important for monitoring of drinking water. Here we present a cost-effective and field portable mobile-phone based fluorescence microscopy platform designed for automated detection of Giardia lamblia cysts in large volume water samples (i.e., 10 ml) to be used in low-resource field settings. This fluorescence microscope is integrated with a disposable water-sampling cassette, which is based on a flow-through porous polycarbonate membrane and provides a wide surface area for fluorescence imaging and enumeration of the captured Giardia cysts on the membrane. Water sample of interest, containing fluorescently labeled Giardia cysts, is introduced into the absorbent pads that are in contact with the membrane in the cassette by capillary action, which eliminates the need for electrically driven flow for sample processing. Our fluorescence microscope weighs ~170 grams in total and has all the components of a regular microscope, capable of detecting individual fluorescently labeled cysts under light-emitting-diode (LED) based excitation. Including all the sample preparation, labeling and imaging steps, the entire measurement takes less than one hour for a sample volume of 10 ml. This mobile phone based compact and cost-effective fluorescent imaging platform together with its machine learning based cyst counting interface is easy to use and can even work in resource limited and field settings for spatio-temporal monitoring of water quality.

  9. The Dust Content and Radiation Fields of Sample of Galaxies in the ELAIS-N1 Field

    CERN Document Server

    Shalima, P; Pathak, Amit; Misra, Ranjeev; Gupta, Ranjan; Vaidya, D B

    2015-01-01

    The Mid-IR colors ($F_{8}/F_{24}$) of galaxies together with their IR-UV luminosity correlations can be used to get some insight into the relative abundance of the different dust grain populations present in them. The ELAIS-N1 field contains thousands of galaxies which do not have optical spectra but have been observed in the Mid-IR by {\\it Spitzer} and UV by {\\it GALEX} making it ideal for these studies. As part of this work we have selected a sample of galaxies from the ELAIS-N1 field which have photometric observations in the MIR and UV as well as photometric redshifts from the SDSS database. We put the constraint that the redshifts are $\\le$ 0.1, thereby giving us a total of 309 galaxies. We find that the majority of the galaxies in the sample are PAH dominated due to their high MIR flux ratio. We also find a reasonable correlation between the Mid-IR and the UV luminosities out of which the Mid-IR emission from PAHs at 8 $\\mu$m is marginally better correlated than the 24 $\\mu$m VSG emission with the UV lu...

  10. A contemporary decennial global Landsat sample of changing agricultural field sizes

    Science.gov (United States)

    White, Emma; Roy, David

    2014-05-01

    Agriculture has caused significant human induced Land Cover Land Use (LCLU) change, with dramatic cropland expansion in the last century and significant increases in productivity over the past few decades. Satellite data have been used for agricultural applications including cropland distribution mapping, crop condition monitoring, crop production assessment and yield prediction. Satellite based agricultural applications are less reliable when the sensor spatial resolution is small relative to the field size. However, to date, studies of agricultural field size distributions and their change have been limited, even though this information is needed to inform the design of agricultural satellite monitoring systems. Moreover, the size of agricultural fields is a fundamental description of rural landscapes and provides an insight into the drivers of rural LCLU change. In many parts of the world field sizes may have increased. Increasing field sizes cause a subsequent decrease in the number of fields and therefore decreased landscape spatial complexity with impacts on biodiversity, habitat, soil erosion, plant-pollinator interactions, and impacts on the diffusion of herbicides, pesticides, disease pathogens, and pests. The Landsat series of satellites provide the longest record of global land observations, with 30m observations available since 1982. Landsat data are used to examine contemporary field size changes in a period (1980 to 2010) when significant global agricultural changes have occurred. A multi-scale sampling approach is used to locate global hotspots of field size change by examination of a recent global agricultural yield map and literature review. Nine hotspots are selected where significant field size change is apparent and where change has been driven by technological advancements (Argentina and U.S.), abrupt societal changes (Albania and Zimbabwe), government land use and agricultural policy changes (China, Malaysia, Brazil), and/or constrained by

  11. Validation of in Situ Networks Via Field Sampling: Case Study in the South Fork Experimental Watershed

    Science.gov (United States)

    Cosh, M. H.; McKee, L.; Bindlish, R.; Coopersmith, E. J.; Jackson, T. J.; Prueger, J. H.

    2014-12-01

    The calibration and validation of soil moisture remote sensing products is complicated by the logistics of installing a soil moisture network for a long term period in an active landscape. Therefore, these stations are located along field boundaries or in non-representative sites with regards to soil type or soil moisture. The representative character of this network can only be established by large scale field sampling to provide a calibration dataset. A team of samplers were deployed twice a week for the summer of 2014 to collect surface soil moisture data across a variety of land covers at 44 sites. These samples were compared and scaled to the domain to get a better understanding of the large scale soil moisture distributions and dynamics. In addition, comparisons are made to the Soil Moisture Ocean Salinity (SMOS) soil moisture product for the length of the network installation.

  12. CALIFA: a diameter-selected sample for an integral field spectroscopy galaxy survey

    Science.gov (United States)

    Walcher, C. J.; Wisotzki, L.; Bekeraité, S.; Husemann, B.; Iglesias-Páramo, J.; Backsmann, N.; Barrera Ballesteros, J.; Catalán-Torrecilla, C.; Cortijo, C.; del Olmo, A.; Garcia Lorenzo, B.; Falcón-Barroso, J.; Jilkova, L.; Kalinova, V.; Mast, D.; Marino, R. A.; Méndez-Abreu, J.; Pasquali, A.; Sánchez, S. F.; Trager, S.; Zibetti, S.; Aguerri, J. A. L.; Alves, J.; Bland-Hawthorn, J.; Boselli, A.; Castillo Morales, A.; Cid Fernandes, R.; Flores, H.; Galbany, L.; Gallazzi, A.; García-Benito, R.; Gil de Paz, A.; González-Delgado, R. M.; Jahnke, K.; Jungwiert, B.; Kehrig, C.; Lyubenova, M.; Márquez Perez, I.; Masegosa, J.; Monreal Ibero, A.; Pérez, E.; Quirrenbach, A.; Rosales-Ortega, F. F.; Roth, M. M.; Sanchez-Blazquez, P.; Spekkens, K.; Tundo, E.; van de Ven, G.; Verheijen, M. A. W.; Vilchez, J. V.; Ziegler, B.

    2014-09-01

    We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area (CALIFA) survey, a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalogue to include all galaxies with an r-band isophotal major axis between 45'' and 79.2'' and with a redshift 0.005 Mr > -23.1 and over a stellar mass range between 109.7 and 1011.4 M⊙. In particular, within these ranges, the diameter selection does not lead to any significant bias against - or in favour of - intrinsically large or small galaxies. Only below luminosities of Mr = -19 (or stellar masses CSIC). Publically released data products from CALIFA are made available on the webpage http://www.caha.es/CALIFA

  13. Ratio methods for cost-effective field sampling of commercial radioactive low-level wastes

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, L.L.; Simmons, M.A.; Thomas, J.M.

    1985-07-01

    In many field studies to determine the quantities of radioactivity at commercial low-level radioactive waste sites, preliminary appraisals are made with field radiation detectors, or other relatively inaccurate devices. More accurate determinations are subsequently made with procedures requiring chemical separations or other expensive analyses. Costs of these laboratory determinations are often large, so that adequate sampling may not be achieved due to budget limitations. In this report, we propose double sampling as a way to combine the expensive and inexpensive aproaches to substantially reduce overall costs. The underlying theory was developed for human and agricultural surveys, and is partially based on assumptions that are not appropriate for commercial low-level waste sites. Consequently, extensive computer simulations were conducted to determine whether the results can be applied in circumstances of importance to the Nuclear Regulatory Commission. This report gives the simulation details, and concludes that the principal equations are appropriate for most studies at commercial low-level waste sites. A few points require further research, using actual commercial low-level radioactive waste site data. The final section of the report provides some guidance (via an example) for the field use of double sampling. Details of the simulation programs are available from the authors. Major findings are listed in the Executive Summary. 9 refs., 9 figs., 30 tabs.

  14. Field Scale Variation in Water Dispersible Colloids from Aggregates and Intact Soil Samples

    DEFF Research Database (Denmark)

    Nørgaard, Trine; Møldrup, Per; Ferré, Ty P A

    Colloid-facilitated transport can play an important role in the transport of chemicals through the soil profile. The negative surface charge and large surface area makes colloids perfect carriers for strongly sorbing chemicals, like phosphorus and certain pesticides, in highly structured soils....... It is, however, difficult to quantify the amount of colloids ready available to participate in colloid-facilitated transport. In literature, the part of the colloidal fraction that readily disperses into suspension is referred to as water-dispersible clay (WDC). In this study we used two methods...... cm intact soil columns sampled from the same field grid also showed that the largest mass of particles and phosphorus leached from this part of the field. Thus, the presented WDC method comparison and results seem highly relevant in regard to field-scale mapping of leaching risk in regard to colloid...

  15. Field Scale Variation in Water Dispersible Colloids from Aggregates and Intact Soil Samples

    DEFF Research Database (Denmark)

    Nørgaard, Trine; Møldrup, Per; Ferré, Ty P A;

    Colloid-facilitated transport can play an important role in the transport of chemicals through the soil profile. The negative surface charge and large surface area makes colloids perfect carriers for strongly sorbing chemicals, like phosphorus and certain pesticides, in highly structured soils....... It is, however, difficult to quantify the amount of colloids ready available to participate in colloid-facilitated transport. In literature, the part of the colloidal fraction that readily disperses into suspension is referred to as water-dispersible clay (WDC). In this study we used two methods...... cm intact soil columns sampled from the same field grid also showed that the largest mass of particles and phosphorus leached from this part of the field. Thus, the presented WDC method comparison and results seem highly relevant in regard to field-scale mapping of leaching risk in regard to colloid...

  16. Fourier plane image amplifier

    Science.gov (United States)

    Hackel, L.A.; Hermann, M.R.; Dane, C.B.; Tiszauer, D.H.

    1995-12-12

    A solid state laser is frequency tripled to 0.3 {micro}m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only about 1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power. 1 fig.

  17. Fourier plane image amplifier

    Science.gov (United States)

    Hackel, Lloyd A.; Hermann, Mark R.; Dane, C. Brent; Tiszauer, Detlev H.

    1995-01-01

    A solid state laser is frequency tripled to 0.3 .mu.m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only .about.1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power.

  18. Realistic sampling of amino acid geometries for a multipolar polarizable force field.

    Science.gov (United States)

    Hughes, Timothy J; Cardamone, Salvatore; Popelier, Paul L A

    2015-09-15

    The Quantum Chemical Topological Force Field (QCTFF) uses the machine learning method kriging to map atomic multipole moments to the coordinates of all atoms in the molecular system. It is important that kriging operates on relevant and realistic training sets of molecular geometries. Therefore, we sampled single amino acid geometries directly from protein crystal structures stored in the Protein Databank (PDB). This sampling enhances the conformational realism (in terms of dihedral angles) of the training geometries. However, these geometries can be fraught with inaccurate bond lengths and valence angles due to artefacts of the refinement process of the X-ray diffraction patterns, combined with experimentally invisible hydrogen atoms. This is why we developed a hybrid PDB/nonstationary normal modes (NM) sampling approach called PDB/NM. This method is superior over standard NM sampling, which captures only geometries optimized from the stationary points of single amino acids in the gas phase. Indeed, PDB/NM combines the sampling of relevant dihedral angles with chemically correct local geometries. Geometries sampled using PDB/NM were used to build kriging models for alanine and lysine, and their prediction accuracy was compared to models built from geometries sampled from three other sampling approaches. Bond length variation, as opposed to variation in dihedral angles, puts pressure on prediction accuracy, potentially lowering it. Hence, the larger coverage of dihedral angles of the PDB/NM method does not deteriorate the predictive accuracy of kriging models, compared to the NM sampling around local energetic minima used so far in the development of QCTFF.

  19. Some Notes on Wideband Feedback Amplifiers

    Science.gov (United States)

    Fitch, V.

    1949-03-16

    The extension of the passband of wideband amplifiers is a highly important problem to the designer of electronic circuits. Throughout the electronics industry and in many research programs in physics and allied fields where extensive use is made of video amplifiers, the foremost requirement is a passband of maximum width. This is necessary if it is desired to achieve a more faithful reproduction of transient wave forms, a better time resolution in physical measurements, or perhaps just a wider band gain-frequency response to sine wave signals. The art of electronics is continually faced with this omnipresent amplifier problem. In particular, the instrumentation techniques of nuclear physics require amplifiers with short rise times, a high degree of gain stability, and a linear response to high signal levels. While the distributed amplifier may solve the problems of those seeking only a wide passband, the requirements of stability and linearity necessitate using feedback circuits. This paper considers feedback amplifiers from the standpoint of high-frequency performance. The circuit conditions for optimum steady-state (sinusoidal) and transient response are derived and practical circuits (both interstage and output) are presented which fulfill these conditions. In general, the results obtained may be applied to the low-frequency end.

  20. Genus-Specific Primers for Study of Fusarium Communities in Field Samples.

    Science.gov (United States)

    Karlsson, Ida; Edel-Hermann, Véronique; Gautheron, Nadine; Durling, Mikael Brandström; Kolseth, Anna-Karin; Steinberg, Christian; Persson, Paula; Friberg, Hanna

    2015-10-30

    Fusarium is a large and diverse genus of fungi of great agricultural and economic importance, containing many plant pathogens and mycotoxin producers. To date, high-throughput sequencing of Fusarium communities has been limited by the lack of genus-specific primers targeting regions with high discriminatory power at the species level. In the present study, we evaluated two Fusarium-specific primer pairs targeting translation elongation factor 1 (TEF1). We also present the new primer pair Fa+7/Ra+6. Mock Fusarium communities reflecting phylogenetic diversity were used to evaluate the accuracy of the primers in reflecting the relative abundance of the species. TEF1 amplicons were subjected to 454 high-throughput sequencing to characterize Fusarium communities. Field samples from soil and wheat kernels were included to test the method on more-complex material. For kernel samples, a single PCR was sufficient, while for soil samples, nested PCR was necessary. The newly developed primer pairs Fa+7/Ra+6 and Fa/Ra accurately reflected Fusarium species composition in mock DNA communities. In field samples, 47 Fusarium operational taxonomic units were identified, with the highest Fusarium diversity in soil. The Fusarium community in soil was dominated by members of the Fusarium incarnatum-Fusarium equiseti species complex, contradicting findings in previous studies. The method was successfully applied to analyze Fusarium communities in soil and plant material and can facilitate further studies of Fusarium ecology.

  1. Detection of Microbial Life in Glacial Samples - Laboratories Studies and Development for Field use

    Science.gov (United States)

    Barnett, M. J.; Cullen, D. C.; Telling, J.; Wadham, J. L.; Holt, J.; Sims, M.

    2007-12-01

    Adenosine triphosphate (ATP) is frequently used as a proxy for bulk microbial biomass in environmental sciences and, in the food and health industries. Despite successful ATP detection in a variety of ecosystems, very little data are available on ATP levels in the glacial system. In this study, protocols for ATP detection on glacial ice and sediment samples are investigated, in order to aid in the development of a single-use device for in-field life detection, and also to increase the available data on biomass estimates in the cryosphere. ATP detection in two glacial samples reveals concentrations indistinguishable from internal blanks. Therefore, the samples were centrifuged and their particulate loads were subjected to four different extraction processes. Applying these extraction methods resulted in higher ATP concentration than samples with no extraction process; the different techniques increase the ATP detected between 5 and 15 times (also relative to an internal standard). Concurrent with the laboratory based development of extraction protocols is the development of a single-use device for the detection of ATP at the sampling site, in icy environments. The device is microfluidic-based, using commercially available reagents for the detection of ATP by bioluminescence. In order to produce a robust measure of biomass, both laboratory and field based analyses need to be carried out. This work shows the potential of ATP detection in glacial samples and the early development of a device for in situ life detection. The quantification of ATP in microfluidic format is being developed as the preliminary target for an integrated life detection and characterisation device.

  2. Sampling Strategies for Evaluating the Rate of Adventitious Transgene Presence in Non-Genetically Modified Crop Fields.

    Science.gov (United States)

    Makowski, David; Bancal, Rémi; Bensadoun, Arnaud; Monod, Hervé; Messéan, Antoine

    2017-02-23

    According to E.U. regulations, the maximum allowable rate of adventitious transgene presence in non-genetically modified (GM) crops is 0.9%. We compared four sampling methods for the detection of transgenic material in agricultural non-GM maize fields: random sampling, stratified sampling, random sampling + ratio reweighting, random sampling + regression reweighting. Random sampling involves simply sampling maize grains from different locations selected at random from the field concerned. The stratified and reweighting sampling methods make use of an auxiliary variable corresponding to the output of a gene-flow model (a zero-inflated Poisson model) simulating cross-pollination as a function of wind speed, wind direction, and distance to the closest GM maize field. With the stratified sampling method, an auxiliary variable is used to define several strata with contrasting transgene presence rates, and grains are then sampled at random from each stratum. With the two methods involving reweighting, grains are first sampled at random from various locations within the field, and the observations are then reweighted according to the auxiliary variable. Data collected from three maize fields were used to compare the four sampling methods, and the results were used to determine the extent to which transgene presence rate estimation was improved by the use of stratified and reweighting sampling methods. We found that transgene rate estimates were more accurate and that substantially smaller samples could be used with sampling strategies based on an auxiliary variable derived from a gene-flow model.

  3. Detection of Campylobacter in human and animal field samples in Cambodia.

    Science.gov (United States)

    Osbjer, Kristina; Tano, Eva; Chhayheng, Leang; Mac-Kwashie, Akofa Olivia; Fernström, Lise-Lotte; Ellström, Patrik; Sokerya, Seng; Sokheng, Choup; Mom, Veng; Chheng, Kannarath; San, Sorn; Davun, Holl; Boqvist, Sofia; Rautelin, Hilpi; Magnusson, Ulf

    2016-06-01

    Campylobacter are zoonotic bacteria and a leading cause of human gastroenteritis worldwide with Campylobacter jejuni and C. coli being the most commonly detected species. The aim of this study was to detect Campylobacter in humans and livestock (chickens, ducks, pigs, cattle, water buffalo, quail, pigeons and geese) in rural households by routine culturing and multiplex PCR in faecal samples frozen before analysis. Of 681 human samples, 82 (12%) tested positive by PCR (C. jejuni in 66 samples and C. coli in 16), but none by routine culture. Children were more commonly Campylobacter positive (19%) than adult males (8%) and females (7%). Of 853 livestock samples, 106 (12%) tested positive by routine culture and 352 (41%) by PCR. Campylobacter jejuni was more frequent in chickens and ducks and C. coli in pigs. In conclusion, Campylobacter proved to be highly prevalent by PCR in children (19%), ducks (24%), chickens (56%) and pigs (72%). Routine culturing was insufficiently sensitive in detecting Campylobacter in field samples frozen before analysis. These findings suggest that PCR should be the preferred diagnostic method for detection of Campylobacter in humans and livestock where timely culture is not feasible. © 2016 The Authors. APMIS published by John Wiley & Sons Ltd on behalf of Scandinavian Societies for Medical Microbiology and Pathology.

  4. A conditional random fields method for RNA sequence-structure relationship modeling and conformation sampling.

    Science.gov (United States)

    Wang, Zhiyong; Xu, Jinbo

    2011-07-01

    Accurate tertiary structures are very important for the functional study of non-coding RNA molecules. However, predicting RNA tertiary structures is extremely challenging, because of a large conformation space to be explored and lack of an accurate scoring function differentiating the native structure from decoys. The fragment-based conformation sampling method (e.g. FARNA) bears shortcomings that the limited size of a fragment library makes it infeasible to represent all possible conformations well. A recent dynamic Bayesian network method, BARNACLE, overcomes the issue of fragment assembly. In addition, neither of these methods makes use of sequence information in sampling conformations. Here, we present a new probabilistic graphical model, conditional random fields (CRFs), to model RNA sequence-structure relationship, which enables us to accurately estimate the probability of an RNA conformation from sequence. Coupled with a novel tree-guided sampling scheme, our CRF model is then applied to RNA conformation sampling. Experimental results show that our CRF method can model RNA sequence-structure relationship well and sequence information is important for conformation sampling. Our method, named as TreeFolder, generates a much higher percentage of native-like decoys than FARNA and BARNACLE, although we use the same simple energy function as BARNACLE. zywang@ttic.edu; j3xu@ttic.edu Supplementary data are available at Bioinformatics online.

  5. Confirmatory analysis of field-presumptive GSR test sample using SEM/EDS

    Science.gov (United States)

    Toal, Sarah J.; Niemeyer, Wayne D.; Conte, Sean; Montgomery, Daniel D.; Erikson, Gregory S.

    2014-09-01

    RedXDefense has developed an automated red-light/green-light field presumptive lead test using a sampling pad which can be subsequently processed in a Scanning Electron Microscope for GSR confirmation. The XCAT's sampling card is used to acquire a sample from a suspect's hands on the scene and give investigators an immediate presumptive as to the presence of lead possibly from primer residue. Positive results can be obtained after firing as little as one shot. The same sampling card can then be sent to a crime lab and processed on the SEM for GSR following ASTM E-1588-10 Standard Guide for Gunshot Residue Analysis by Scanning Electron Microscopy/Energy Dispersive X-Ray Spectrometry, in the same manner as the existing tape lifts currently used in the field. Detection of GSR-characteristic particles (fused lead, barium, and antimony) as small as 0.8 microns (0.5 micron resolution) has been achieved using a JEOL JSM-6480LV SEM equipped with an Oxford Instruments INCA EDS system with a 50mm2 SDD detector, 350X magnification, in low-vacuum mode and in high vacuum mode after coating with carbon in a sputter coater. GSR particles remain stable on the sampling pad for a minimum of two months after chemical exposure (long term stability tests are in progress). The presumptive result provided by the XCAT yields immediate actionable intelligence to law enforcement to facilitate their investigation, without compromising the confirmatory test necessary to further support the investigation and legal case.

  6. Virtual MEG Helmet: Computer Simulation of an Approach to Neuromagnetic Field Sampling.

    Science.gov (United States)

    Medvedovsky, Mordekhay; Nenonen, Jukka; Koptelova, Alexandra; Butorina, Anna; Paetau, Ritva; Mäkelä, Jyrki P; Ahonen, Antti; Simola, Juha; Gazit, Tomer; Taulu, Samu

    2016-03-01

    Head movements during an MEG recording are commonly considered an obstacle. In this computer simulation study, we introduce an approach, the virtual MEG helmet (VMH), which employs the head movements for data quality improvement. With a VMH, a denser MEG helmet is constructed by adding new sensors corresponding to different head positions. Based on the Shannon's theory of communication, we calculated the total information as a figure of merit for comparing the actual 306-sensor Elekta Neuromag helmet to several types of the VMH. As source models, we used simulated randomly distributed source current (RDSC), simulated auditory and somatosensory evoked fields. Using the RDSC model with the simulation of 360 recorded events, the total information (bits/sample) was 989 for the most informative single head position and up to 1272 for the VMH (addition of 28.6%). Using simulated AEFs, the additional contribution of a VMH was 12.6% and using simulated SEF only 1.1%. For the distributed and bilateral sources, a VMH can provide a more informative sampling of the neuromagnetic field during the same recording time than measuring the MEG from one head position. VMH can, in some situations, improve source localization of the neuromagnetic fields related to the normal and pathological brain activity. This should be investigated further employing real MEG recordings.

  7. Field sampling of soil pore water to evaluate trace element mobility and associated environmental risk

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Jimenez, Eduardo, E-mail: eduardo.moreno@uam.es [Departamento de Quimica Agricola, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Beesley, Luke [James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom); Lepp, Nicholas W. [35, Victoria Road, Formby, Liverpool L37 7DH (United Kingdom); Dickinson, Nicholas M. [Department of Ecology, Lincoln University, Lincoln 7647, PO Box 84 (New Zealand); Hartley, William [School of Computing, Science and Engineering, University of Salford, Cockcroft Building, Salford, M5 4WT (United Kingdom); Clemente, Rafael [Dep. of Soil and Water Conservation and Organic Waste Management, CEBAS-CSIC, Campus Universitario de Espinardo, PO Box 164, 30100 Espinardo, Murcia (Spain)

    2011-10-15

    Monitoring soil pollution is a key aspect in sustainable management of contaminated land but there is often debate over what should be monitored to assess ecological risk. Soil pore water, containing the most labile pollutant fraction in soils, can be easily collected in situ offering a routine way to monitor this risk. We present a compilation of data on concentration of trace elements (As, Cd, Cu, Pb, and Zn) in soil pore water collected in field conditions from a range of polluted and non-polluted soils in Spain and the UK during single and repeated monitoring, and propose a simple eco-toxicity test using this media. Sufficient pore water could be extracted for analysis both under semi-arid and temperate conditions, and eco-toxicity comparisons could be effectively made between polluted and non-polluted soils. We propose that in-situ pore water extraction could enhance the realism of risk assessment at some contaminated sites. - Highlights: > In situ pore water sampling successfully evaluates trace elements mobility in soils. > Field sampling proved robust for different soils, sites and climatic regimes. > Measurements may be directly related to ecotoxicological assays. > Both short and long-term monitoring of polluted lands may be achieved. > This method complements other widely used assays for environmental risk assessment. - In situ pore water sampling from a wide variety of soils proves to be a beneficial application to monitor the stability of pollutants in soils and subsequent risk through mobility.

  8. Geographical variation in inorganic arsenic in paddy field samples and commercial rice from the Iberian Peninsula.

    Science.gov (United States)

    Signes-Pastor, Antonio J; Carey, Manus; Carbonell-Barrachina, Angel A; Moreno-Jiménez, Eduardo; Green, Andy J; Meharg, Andrew A

    2016-07-01

    This study investigated total arsenic and arsenic speciation in rice using ion chromatography with mass spectrometric detection (IC-ICP-MS), covering the main rice-growing regions of the Iberian Peninsula in Europe. The main arsenic species found were inorganic and dimethylarsinic acid. Samples surveyed were soil, shoots and field-collected rice grain. From this information soil to plant arsenic transfer was investigated plus the distribution of arsenic in rice across the geographical regions of Spain and Portugal. Commercial polished rice was also obtained from each region and tested for arsenic speciation, showing a positive correlation with field-obtained rice grain. Commercial polished rice had the lowest i-As content in Andalucia, Murcia and Valencia while Extremadura had the highest concentrations. About 26% of commercial rice samples exceeded the permissible concentration for infant food production as governed by the European Commission. Some cadmium data is also presented, available with ICP-MS analyses, and show low concentration in rice samples.

  9. Field portable low temperature porous layer open tubular cryoadsorption headspace sampling and analysis part II: Applications.

    Science.gov (United States)

    Harries, Megan; Bukovsky-Reyes, Santiago; Bruno, Thomas J

    2016-01-15

    This paper details the sampling methods used with the field portable porous layer open tubular cryoadsorption (PLOT-cryo) approach, described in Part I of this two-part series, applied to several analytes of interest. We conducted tests with coumarin and 2,4,6-trinitrotoluene (two solutes that were used in initial development of PLOT-cryo technology), naphthalene, aviation turbine kerosene, and diesel fuel, on a variety of matrices and test beds. We demonstrated that these analytes can be easily detected and reliably identified using the portable unit for analyte collection. By leveraging efficiency-boosting temperature control and the high flow rate multiple capillary wafer, very short collection times (as low as 3s) yielded accurate detection. For diesel fuel spiked on glass beads, we determined a method detection limit below 1 ppm. We observed greater variability among separate samples analyzed with the portable unit than previously documented in work using the laboratory-based PLOT-cryo technology. We identify three likely sources that may help explain the additional variation: the use of a compressed air source to generate suction, matrix geometry, and variability in the local vapor concentration around the sampling probe as solute depletion occurs both locally around the probe and in the test bed as a whole. This field-portable adaptation of the PLOT-cryo approach has numerous and diverse potential applications.

  10. CALIFA: a diameter-selected sample for an integral field spectroscopy galaxy survey

    CERN Document Server

    Walcher, C J; Bekeraité, S; Husemann, B; Iglesias-Páramo, J; Backsmann, N; Ballesteros, J Barrera; Catalán-Torrecilla, C; Cortijo, C; del Olmo, A; Lorenzo, B Garcia; Falcón-Barroso, J; Jilkova, L; Kalinova, V; Mast, D; Marino, R A; Méndez-Abreu, J; Pasquali, A; Sánchez, S F; Trager, S; Zibetti, S; Aguerri, J A L; Alves, J; Bland-Hawthorn, J; Boselli, A; Morales, A Castillo; Fernandes, R Cid; Flores, H; Galbany, L; Gallazzi, A; García-Benito, R; de Paz, A Gil; González-Delgado, R M; Jahnke, K; Jungwiert, B; Kehrig, C; Lyubenova, M; Perez, I Márquez; Masegosa, J; Ibero, A Monreal; Pérez, E; Quirrenbach, A; Rosales-Ortega, F F; Roth, M M; Sanchez-Blazquez, P; Spekkens, K; Tundo, E; van de Ven, G; Verheijen, M A W; Vilchez, J V; Ziegler, B

    2014-01-01

    We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area Survey (CALIFA), a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalogue to include all galaxies with an r-band isophotal major axis between 45" and 79.2" and with a redshift 0.005 Mr > -23.1 and over a stellar mass range between 10^9.7 and 10^11.4Msun. In particular, within these ranges, the diameter selection does not lead to any significant bias against - or in favour of - intrinsically large or small galaxies. Only below luminosities of Mr = -19 (or stellar masses < 10^9.7Msun) is there a prevalence of galaxies with larger isophotal sizes, especially of nearly edge-on late-type galaxies, but such galaxies form < 10% of the full sample. We estimate volume-corrected distribution functions in luminosities and sizes and show that these ...

  11. Chopper amplifier circuit with CMOS switches and amplifier FETs

    NARCIS (Netherlands)

    Huijsing, J.H.; Bakker, A.

    1997-01-01

    Abstract of NL 1001231 (C2) The input voltage is fed to the inputs of an operational amplifier via a chopping reversal switchThe CMOS operational amplifier has a current source and a current mirror. The operational amplifier output is fed to an output circuit. The possible offset voltage is supp

  12. Amplifying genetic logic gates.

    Science.gov (United States)

    Bonnet, Jerome; Yin, Peter; Ortiz, Monica E; Subsoontorn, Pakpoom; Endy, Drew

    2013-05-03

    Organisms must process information encoded via developmental and environmental signals to survive and reproduce. Researchers have also engineered synthetic genetic logic to realize simpler, independent control of biological processes. We developed a three-terminal device architecture, termed the transcriptor, that uses bacteriophage serine integrases to control the flow of RNA polymerase along DNA. Integrase-mediated inversion or deletion of DNA encoding transcription terminators or a promoter modulates transcription rates. We realized permanent amplifying AND, NAND, OR, XOR, NOR, and XNOR gates actuated across common control signal ranges and sequential logic supporting autonomous cell-cell communication of DNA encoding distinct logic-gate states. The single-layer digital logic architecture developed here enables engineering of amplifying logic gates to control transcription rates within and across diverse organisms.

  13. Optimization of plasma amplifiers

    Science.gov (United States)

    Sadler, James D.; Trines, Raoul M. Â. G. Â. M.; Tabak, Max; Haberberger, Dan; Froula, Dustin H.; Davies, Andrew S.; Bucht, Sara; Silva, Luís O.; Alves, E. Paulo; Fiúza, Frederico; Ceurvorst, Luke; Ratan, Naren; Kasim, Muhammad F.; Bingham, Robert; Norreys, Peter A.

    2017-05-01

    Plasma amplifiers offer a route to side-step limitations on chirped pulse amplification and generate laser pulses at the power frontier. They compress long pulses by transferring energy to a shorter pulse via the Raman or Brillouin instabilities. We present an extensive kinetic numerical study of the three-dimensional parameter space for the Raman case. Further particle-in-cell simulations find the optimal seed pulse parameters for experimentally relevant constraints. The high-efficiency self-similar behavior is observed only for seeds shorter than the linear Raman growth time. A test case similar to an upcoming experiment at the Laboratory for Laser Energetics is found to maintain good transverse coherence and high-energy efficiency. Effective compression of a 10 kJ , nanosecond-long driver pulse is also demonstrated in a 15-cm-long amplifier.

  14. STABILIZED TRANSISTOR AMPLIFIER

    Science.gov (United States)

    Noe, J.B.

    1963-05-01

    A temperature stabilized transistor amplifier having a pair of transistors coupled in cascade relation that are capable of providing amplification through a temperature range of - 100 un. Concent 85% F to 400 un. Concent 85% F described. The stabilization of the amplifier is attained by coupling a feedback signal taken from the emitter of second transistor at a junction between two serially arranged biasing resistances in the circuit of the emitter of the second transistor to the base of the first transistor. Thus, a change in the emitter current of the second transistor is automatically corrected by the feedback adjustment of the base-emitter potential of the first transistor and by a corresponding change in the base-emitter potential of the second transistor. (AEC)

  15. Lensless coherent imaging by sampling of the optical field with digital micromirror device

    Science.gov (United States)

    Vdovin, G.; Gong, H.; Soloviev, O.; Pozzi, P.; Verhaegen, M.

    2015-12-01

    We have experimentally demonstrated a lensless coherent microscope based on direct registration of the complex optical field by sampling the pupil with a sequence of two-point interferometers formed by a digital micromirror device. Complete registration of the complex amplitude in the pupil of the imaging system, without any reference beam, provides a convenient link between the experimental and computational optics. Unlike other approaches to digital holography, our method does not require any external reference beam, resulting in a simple and robust registration setup. Computer analysis of the experimentally registered field allows for focusing the image in the whole range from zero to infinity, and for virtual correction of the aberrations present in the real optical system, by applying the adaptive wavefront corrections to its virtual model.

  16. Multiscale displacement field measurements of compressed mineral-wool samples by digital image correlation

    Science.gov (United States)

    Hild, Francois; Raka, Bumedijen; Baudequin, Maud; Roux, Stephane; Cantelaube, Florence

    2002-11-01

    We propose a multiscale approach to determine the displacement field by digital image correlation. The displacement field is first estimated on a coarse resolution image and progressively finer details are introduced in the analysis as the displacement is more and more securely and accurately determined. Such a scheme has been developed to increase the robustness, accuracy, and reliability of the image-matching algorithm. The procedure is used on two different types of examples. The first one deals with a representative image that is deformed precisely and purposefully to assess the intrinsic performances. In particular, the maximum measurable strain is determined. The second case deals with a series of pictures taken during compression experiments on mineral-wool samples. The different steps of the procedure are analyzed and their respective role is assessed. Both reflection and transmission images are tested.

  17. Review of concepts useful for maintaining quality of male reproductive field samples for laboratory study

    Science.gov (United States)

    Jenkins, Jill A.

    2011-01-01

    Investigations into cellular and molecular characteristics of male gametes obtained from fish in natural ecosystems require careful sample handling and shipping in order to minimize artifacts. Maintaining sample integrity engenders confident assessments of ecosystem health, whereby animal condition is often reflected by gamete biomarkers - indicators that respond in measurable ways to changes. A number of our investigations have addressed the hypothesis that biomarkers from fish along a pollution gradient are reflective of site location. Species biology and the selected biological endpoints direct choice of parameters such as: temperature, buffer osmolality, time in transit, fixation, cryoprotectants, protease inhibition, and antibiotic inclusion in extender. This paper will highlight case studies, and outline parameters and thoughts on approaches for use by field and laboratory researchers.

  18. GeoLab's First Field Trials, 2010 Desert RATS: Evaluating Tools for Early Sample Characterization

    Science.gov (United States)

    Evans, Cindy A.; Bell, M. S.; Calaway, M. J.; Graff, Trevor; Young, Kelsey

    2011-01-01

    As part of an accelerated prototyping project to support science operations tests for future exploration missions, we designed and built a geological laboratory, GeoLab, that was integrated into NASA's first generation Habitat Demonstration Unit-1/Pressurized Excursion Module (HDU1-PEM). GeoLab includes a pressurized glovebox for transferring and handling samples collected on geological traverses, and a suite of instruments for collecting preliminary data to help characterize those samples. The GeoLab and the HDU1-PEM were tested for the first time as part of the 2010 Desert Research and Technology Studies (DRATS), NASA's analog field exercise for testing mission technologies. The HDU1- PEM and GeoLab participated in two weeks of joint operations in northern Arizona with two crewed rovers and the DRATS science team.

  19. Principal modes in fiber amplifiers

    CERN Document Server

    Fridman, Moti; Dubinskii, Mark; Friesem, Asher A; Davidson, Nir

    2010-01-01

    The dynamics of the state of polarization in single mode and multimode fiber amplifiers are presented. The experimental results reveal that although the state of polarizations at the output can vary over a large range when changing the temperatures of the fiber amplifiers, the variations are significantly reduced when resorting to the principal states of polarization in single mode fiber amplifiers and principal modes in multimode fiber amplifiers.

  20. Feynman diagrams sampling for quantum field theories on the QPACE 2 supercomputer

    Energy Technology Data Exchange (ETDEWEB)

    Rappl, Florian

    2016-08-01

    This work discusses the application of Feynman diagram sampling in quantum field theories. The method uses a computer simulation to sample the diagrammatic space obtained in a series expansion. For running large physical simulations powerful computers are obligatory, effectively splitting the thesis in two parts. The first part deals with the method of Feynman diagram sampling. Here the theoretical background of the method itself is discussed. Additionally, important statistical concepts and the theory of the strong force, quantum chromodynamics, are introduced. This sets the context of the simulations. We create and evaluate a variety of models to estimate the applicability of diagrammatic methods. The method is then applied to sample the perturbative expansion of the vertex correction. In the end we obtain the value for the anomalous magnetic moment of the electron. The second part looks at the QPACE 2 supercomputer. This includes a short introduction to supercomputers in general, as well as a closer look at the architecture and the cooling system of QPACE 2. Guiding benchmarks of the InfiniBand network are presented. At the core of this part, a collection of best practices and useful programming concepts are outlined, which enables the development of efficient, yet easily portable, applications for the QPACE 2 system.

  1. Comparison of dust sampling methods in Estonia and Sweden--a field study.

    Science.gov (United States)

    Berg, P; Jaakmees, V; Bodin, L

    1999-09-01

    The purpose of this field study was to compare an Estonian dust sampling method, a method also used in other former East Block countries, with a Swedish method and to estimate inter-method agreement with statistical analyses. The Estonian standard method (ESM), used to assess exposure in Estonia since the early 1950s, is based on a strategy where air samples are collected for 10 minutes every hour over a full shift. This method was compared to a Swedish standard method (SSM), a modified NIOSH method, comparable to international standards, where one air sample is collected during a full shift. The study was carried out at a cement plant that in the beginning of the 1990s was subjected to an epidemiological study, including collection of exposure data. The results of the analysis from 31 clusters of parallel samples of the two methods, when dust consisting of Portland cement was collected, showed a relatively weak correlation between the SSM and the ESM, ri = 0.81 (Pearson's intra-class correlation coefficient). A conversion factor between the two methods was estimated, where SSM is 0.69 times ESM and the limits of agreement are 0.25 and 1.84, respectively. These results indicate a substantial inter-method difference. We therefore recommend that measurements obtained from the two methods should not be used interchangeably. Because the present study is of limited extent, our findings are confined to the operations studied and further studies covering other exposure situations will be needed.

  2. Tetracycline residues in meat and bone meals. Part 1: methodology and examination of field samples.

    Science.gov (United States)

    Körner, U; Kühne, M; Wenzel, S

    2001-04-01

    The incidence of tetracycline residues in commercially available samples of meat meals and meat and bone meals was investigated. Four different methods were used on each of the 87 samples from nine different rendering plants in Germany: examination using a screening fluorescence test; examination by high performance liquid chromatography analysis using three different extraction procedures (succinate buffer, hydrochloric acid, hydrochloric acid after sedimentation of bone particles). Tetracyclines were found in 100% of the samples by one or more of the extraction procedures. The highest concentrations found in meat meals were 2048 microgkg(-1), 1393 microgkg(-1) and 608 microgkg(-1) for oxytetracycline, tetracycline and chlortetracycline, respectively. In meat and bone meals the highest concentrations were 2295 microg oxytetracycline kg(-1) 848 microg tetracycline kg(-1) and 1274 microg chlortetracycline kg(-1). The extraction after sedimentation was the most effective of the applied extraction procedures and exposed the highest total tetracycline concentrations. The results of this investigation showed that considerable amounts of tetracyclines have to be expected in field samples. Further research has to be done on the heat stability of bound tetracycline residues.

  3. Multiple pass laser amplifier system

    Science.gov (United States)

    Brueckner, Keith A.; Jorna, Siebe; Moncur, N. Kent

    1977-01-01

    A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

  4. Radio Frequency Solid State Amplifiers

    CERN Document Server

    Jacob, J

    2015-01-01

    Solid state amplifiers are being increasingly used instead of electronic vacuum tubes to feed accelerating cavities with radio frequency power in the 100 kW range. Power is obtained from the combination of hundreds of transistor amplifier modules. This paper summarizes a one hour lecture on solid state amplifiers for accelerator applications.

  5. Polarization effect in parametric amplifier

    Institute of Scientific and Technical Information of China (English)

    Junhe Zhou; Jianping Chen; Xinwan Li; Guiling Wu; Yiping Wang

    2005-01-01

    @@ Polarization effect in parametric amplifiers is studied. Coupled equations are derived from the basic propagation equations and numerical solutions are given for both one-wavelength-pump and two-wavelengthpump systems. Several parametric amplifiers driven by pumps at one wavelength and two wavelengths are analyzed and the polarization independent parametric amplifier is proposed.

  6. Improved-Bandwidth Transimpedance Amplifier

    Science.gov (United States)

    Chapsky, Jacob

    2009-01-01

    The widest available operational amplifier, with the best voltage and current noise characteristics, is considered for transimpedance amplifier (TIA) applications where wide bandwidth is required to handle fast rising input signals (as for time-of-flight measurement cases). The added amplifier inside the TIA feedback loop can be configured to have slightly lower voltage gain than the bandwidth reduction factor.

  7. The left visual-field advantage in rapid visual presentation is amplified rather than reduced by posterior-parietal rTMS

    DEFF Research Database (Denmark)

    Verleger, Rolf; Möller, Friderike; Kuniecki, Michal

    2010-01-01

    by the right over the left hemisphere. If so, then repetitive transcranial magnetic stimulation (rTMS) to the right parietal cortex might release the left hemisphere from right-hemispheric control, thereby improving T2 identification in the right visual field. Alternatively or additionally, the asymmetry in T2...... identification might reflect capacity limitations of the left hemisphere, which might be aggravated by rTMS to the left parietal cortex. Therefore, rTMS pulses were applied during each trial, beginning simultaneously with T1 presentation. rTMS was directed either to P4 or to P3 (right or left parietal cortex...

  8. Classification of underwater targets from autonomous underwater vehicle sampled bistatic acoustic scattered fields.

    Science.gov (United States)

    Fischell, Erin M; Schmidt, Henrik

    2015-12-01

    One of the long term goals of autonomous underwater vehicle (AUV) minehunting is to have multiple inexpensive AUVs in a harbor autonomously classify hazards. Existing acoustic methods for target classification using AUV-based sensing, such as sidescan and synthetic aperture sonar, require an expensive payload on each outfitted vehicle and post-processing and/or image interpretation. A vehicle payload and machine learning classification methodology using bistatic angle dependence of target scattering amplitudes between a fixed acoustic source and target has been developed for onboard, fully autonomous classification with lower cost-per-vehicle. To achieve the high-quality, densely sampled three-dimensional (3D) bistatic scattering data required by this research, vehicle sampling behaviors and an acoustic payload for precision timed data acquisition with a 16 element nose array were demonstrated. 3D bistatic scattered field data were collected by an AUV around spherical and cylindrical targets insonified by a 7-9 kHz fixed source. The collected data were compared to simulated scattering models. Classification and confidence estimation were shown for the sphere versus cylinder case on the resulting real and simulated bistatic amplitude data. The final models were used for classification of simulated targets in real time in the LAMSS MOOS-IvP simulation package [M. Benjamin, H. Schmidt, P. Newman, and J. Leonard, J. Field Rob. 27, 834-875 (2010)].

  9. Integrating field sampling, geostatistics and remote sensing to map wetland vegetation in the Pantanal, Brazil

    Science.gov (United States)

    Arieira, J.; Karssenberg, D.; de Jong, S. M.; Addink, E. A.; Couto, E. G.; Nunes da Cunha, C.; Skøien, J. O.

    2011-03-01

    Development of efficient methodologies for mapping wetland vegetation is of key importance to wetland conservation. Here we propose the integration of a number of statistical techniques, in particular cluster analysis, universal kriging and error propagation modelling, to integrate observations from remote sensing and field sampling for mapping vegetation communities and estimating uncertainty. The approach results in seven vegetation communities with a known floral composition that can be mapped over large areas using remotely sensed data. The relationship between remotely sensed data and vegetation patterns, captured in four factorial axes, were described using multiple linear regression models. There were then used in a universal kriging procedure to reduce the mapping uncertainty. Cross-validation procedures and Monte Carlo simulations were used to quantify the uncertainty in the resulting map. Cross-validation showed that accuracy in classification varies according with the community type, as a result of sampling density and configuration. A map of uncertainty derived from Monte Carlo simulations revealed significant spatial variation in classification, but this had little impact on the proportion and arrangement of the communities observed. These results suggested that mapping improvement could be achieved by increasing the number of field observations of those communities with a scattered and small patch size distribution; or by including a larger number of digital images as explanatory variables in the model. Comparison of the resulting plant community map with a flood duration map, revealed that flooding duration is an important driver of vegetation zonation. This mapping approach is able to integrate field point data and high-resolution remote-sensing images, providing a new basis to map wetland vegetation and allow its future application in habitat management, conservation assessment and long-term ecological monitoring in wetland landscapes.

  10. Sign determination of dipolar couplings in field-oriented bicelles by variable angle sample spinning (VASS)

    Energy Technology Data Exchange (ETDEWEB)

    Tian, F.; Losonczi, J.A.; Fischer, M.W.F.; Prestegard, J.H. [University of Georgia, Complex Carbohydrate Research Center (United States)

    1999-10-15

    Residual dipolar couplings are being increasingly used as structural constraints for NMR studies of biomolecules. A problem arises when dipolar coupling contributions are larger than scalar contributions for a given spin pair, as is commonly observed in solid state NMR studies, in that signs of dipolar couplings cannot easily be determined. Here the sign ambiguities of dipolar couplings in field-oriented bicelles are resolved by variable angle sample spinning (VASS) techniques. The director behavior of field-oriented bicelles (DMPC/DHPC, DMPC/CHAPSO) in VASS is studied by {sup 31}P NMR. A stable configuration occurs when the spinning angle is smaller than the magic angle, 54.7 deg., and the director (or bicelle normal) of the disks is mainly distributed in a plane perpendicular to the rotation axis. Since the dipolar couplings depend on how the bicelles are oriented with respect to the magnetic field, it is shown that the dipolar interaction can be scaled to the same order as the J-coupling by moving the spinning axis from 0 deg. toward 54.7 deg. Thus the relative sign of dipolar and scalar couplings can be determined.

  11. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  12. Simplified design of IC amplifiers

    CERN Document Server

    Lenk, John

    1996-01-01

    Simplified Design of IC Amplifiers has something for everyone involved in electronics. No matter what skill level, this book shows how to design and experiment with IC amplifiers. For experimenters, students, and serious hobbyists, this book provides sufficient information to design and build IC amplifier circuits from 'scratch'. For working engineers who design amplifier circuits or select IC amplifiers, the book provides a variety of circuit configurations to make designing easier.Provides basics for all phases of practical design.Covers the most popular forms for amplif

  13. Wideband amplifier design

    CERN Document Server

    Hollister, Allen L

    2007-01-01

    In this book, the theory needed to understand wideband amplifier design using the simplest models possible will be developed. This theory will be used to develop algebraic equations that describe particular circuits used in high frequency design so that the reader develops a ""gut level"" understanding of the process and circuit. SPICE and Genesys simulations will be performed to show the accuracy of the algebraic models. By looking at differences between the algebraic equations and the simulations, new algebraic models will be developed that include parameters originally left out of the model

  14. Building valve amplifiers

    CERN Document Server

    Jones, Morgan

    2013-01-01

    Building Valve Amplifiers is a unique hands-on guide for anyone working with tube audio equipment--as an electronics hobbyist, audiophile or audio engineer. This 2nd Edition builds on the success of the first with technology and technique revisions throughout and, significantly, a major new self-build project, worked through step-by-step, which puts into practice the principles and techniques introduced throughout the book. Particular attention has been paid to answering questions commonly asked by newcomers to the world of the valve, whether audio enthusiasts tackling their first build or

  15. REGENERATIVE TRANSISTOR AMPLIFIER

    Science.gov (United States)

    Kabell, L.J.

    1958-11-25

    Electrical circults for use in computers and the like are described. particularly a regenerative bistable transistor amplifler which is iurned on by a clock signal when an information signal permits and is turned off by the clock signal. The amplifier porforms the above function with reduced power requirements for the clock signal and circuit operation. The power requirements are reduced in one way by employing transformer coupling which increases the collector circuit efficiency by eliminating the loss of power in the collector load resistor.

  16. Wideband pulse amplifiers for the NECTAr chip

    Science.gov (United States)

    Sanuy, A.; Delagnes, E.; Gascon, D.; Sieiro, X.; Bolmont, J.; Corona, P.; Feinstein, F.; Glicenstein, J.-F.; Naumann, C. L.; Nayman, P.; Ribó, M.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

    2012-12-01

    The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

  17. Wideband pulse amplifiers for the NECTAr chip

    Energy Technology Data Exchange (ETDEWEB)

    Sanuy, A., E-mail: asanuy@ecm.ub.es [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Delagnes, E. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Gascon, D. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Sieiro, X. [Departament d' Electronica, Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Bolmont, J.; Corona, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Feinstein, F. [LUPM, Universite Montpellier II and IN2P3/CNRS, CC072, bat. 13, place Eugene Bataillon, 34095 Montpellier (France); Glicenstein, J-F. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Naumann, C.L.; Nayman, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Ribo, M. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); and others

    2012-12-11

    The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

  18. Layered-nanomaterial-amplified chemiluminescence systems and their analytical applications.

    Science.gov (United States)

    Zhong, Jinpan; Yuan, Zhiqin; Lu, Chao

    2016-12-01

    Layered nanomaterial has become a popular hierarchical material for amplifying chemiluminescence (CL) in recent years, mainly because of its ease of preparation and modification, large specific surface area, and high catalytic activity. In this review, we mainly discuss layered-nanomaterial-amplified CL systems based on graphene and its derivatives, layered double hydroxides, and clay. Detection mechanisms and strategies of layered-nanomaterial-amplified CL systems are provided to show the basic concepts for designing sensitive and selective sensing systems. Strategies for expanding the applications of layered-nanomaterial-amplified CL systems by combination with surfactants, quantum dots, organic dyes, and nanoparticles are introduced for the analysis of various analytes in real samples. The challenges and future trends of layered-nanomaterial-amplified CL systems are discussed at the end of the review. Graphical Abstract Schematic illustration of layered nanomaterial amplified chemiluminescence.

  19. Planning the sampling of a condensed-gas field with an oil fringe at the Benoi field

    Energy Technology Data Exchange (ETDEWEB)

    Siuniaev, Y.K.; Trubaev, V.L.

    1981-01-01

    In order to obtain data for determining gas, condensate and oil reserves, planning field development, and monitoring the operation of condensed gas wells in fields, a system of gas-hydrodynamic and specialized studies is developed.

  20. Using analog field and sample data to understand remote data of Mars

    Science.gov (United States)

    Wright, Shawn

    2015-04-01

    The primary geologic processes on Mars are basaltic volcanism, sedimentation, impact cratering, and alteration. All potentially create amorphous materials and complex mineralogies, and these must be measured by rovers sent to Mars to characterize the geology. This paper addresses the field measurements and sample analyses of a terrestrial analog impact crater to interpret rover and perhaps orbital data of Mars. Motivation: OMEGA and CRISM have shown alteration minerals in Martian ejecta blankets. These phyllosilicates may represent altered crust that was excavated, and only exposed, by the impact, or could represent ejecta that was altered in part during impact or fractured/fragmented material that was altered at higher rate than surrounding terrain after ejecta emplacement. Study Site and Geologic History: Lonar Crater, India is a young (~570 ka), ~1.8 km impact site emplaced in ~65 Ma Deccan basalt, which is an excellent analog material for Mars with ~45-50% labradorite and ~35% augite/pigeonite before lower flows were altered and then excavated and/or shocked. Pre-impact stratigraphy was not complex: 3 flows of fresh basalt overlying 3 flows of aqueously-altered basalt, and both are found as impact breccia clasts in a ~8 m thick lithic (unshocked, "throw out") and ~1 m suevite (all ranges of shock pressure, "fall out") breccia units in the ejecta. Two geologic histories for shocked clasts in the Lonar suevite breccia are compared: 1.) the alteration of impactites (impact glasses and melts) of a range of shock pressures ("post-impact alteration"), which likely increase the rate of alteration and affects the order of alteration where compared to pristine, igneous minerals, and 2.) the existence of altered basalt protoliths ("pre-impact alteration") now vitrified as in-situ breccia clasts or float. Both of these geologic histories and their alteration pathways are compared to those of unshocked fresh and unshocked altered basalts found in the lithic breccia and

  1. Amplified somatosensory and visual cortical projections to a core auditory area, the anterior auditory field, following early- and late-onset deafness.

    Science.gov (United States)

    Wong, Carmen; Chabot, Nicole; Kok, Melanie A; Lomber, Stephen G

    2015-09-01

    Cross-modal reorganization following the loss of input from a sensory modality can recruit sensory-deprived cortical areas to process information from the remaining senses. Specifically, in early-deaf cats, the anterior auditory field (AAF) is unresponsive to auditory stimuli but can be activated by somatosensory and visual stimuli. Similarly, AAF neurons respond to tactile input in adult-deafened animals. To examine anatomical changes that may underlie this functional adaptation following early or late deafness, afferent projections to AAF were examined in hearing cats, and cats with early- or adult-onset deafness. Unilateral deposits of biotinylated dextran amine were made in AAF to retrogradely label cortical and thalamic afferents to AAF. In early-deaf cats, ipsilateral neuronal labeling in visual and somatosensory cortices increased by 329% and 101%, respectively. The largest increases arose from the anterior ectosylvian visual area and the anterolateral lateral suprasylvian visual area, as well as somatosensory areas S2 and S4. Consequently, labeling in auditory areas was reduced by 36%. The age of deafness onset appeared to influence afferent connectivity, with less marked differences observed in late-deaf cats. Profound changes to visual and somatosensory afferent connectivity following deafness may reflect corticocortical rewiring affording acoustically deprived AAF with cross-modal functionality.

  2. Comparison of aerosol backscatter and wind field estimates from the REAL and the SAMPLE

    Science.gov (United States)

    Mayor, Shane D.; Dérian, Pierre; Mauzey, Christopher F.; Spuler, Scott M.; Ponsardin, Patrick; Pruitt, Jeff; Ramsey, Darrell; Higdon, Noah S.

    2015-09-01

    Although operating at the same near-infrared 1.5- m wavelength, the Raman-shifted Eye-safe Aerosol Lidar (REAL) and the Scanning Aerosol Micro-Pulse Lidar-Eye-safe (SAMPLE) are very different in how they generate and detect laser radiation. We present results from an experiment where the REAL and the SAMPLE were operated side-by-side in Chico, California, in March of 2015. During the non-continuous, eleven day test period, the SAMPLE instrument was operated at maximum pulse repetition frequency (15 kHz) and integrated over the interpulse period of the REAL (0.1 s). Operation at the high pulse repetition frequency resulted in second trip echoes which contaminated portions of the data. The performance of the SAMPLE instrument varied with background brightness--as expected with a photon counting receiver|--yet showed equal or larger backscatter intensity signal to noise ratio throughout the intercomparison experiment. We show that a modest low-pass filter or smooth applied to the REAL raw waveforms (that have 5x higher range resolution) results in significant increases in raw signal-to-noise ratio and image signal-to-noise ratio--a measure of coherent aerosol feature content in the images resulting from the scans. Examples of wind fields and time series of wind estimates from both systems are presented. We conclude by reviewing the advantages and disadvantages of each system and sketch a plan for future research and development activities to optimize the design of future systems.

  3. Uniform field loop-gap resonator and rectangular TEU02 for aqueous sample EPR at 94GHz.

    Science.gov (United States)

    Sidabras, Jason W; Sarna, Tadeusz; Mett, Richard R; Hyde, James S

    2017-09-01

    In this work we present the design and implementation of two uniform-field resonators: a seven-loop-six-gap loop-gap resonator (LGR) and a rectangular TEU02 cavity resonator. Each resonator has uniform-field-producing end-sections. These resonators have been designed for electron paramagnetic resonance (EPR) of aqueous samples at 94GHz. The LGR geometry employs low-loss Rexolite end-sections to improve the field homogeneity over a 3mm sample region-of-interest from near-cosine distribution to 90% uniform. The LGR was designed to accommodate large degassable Polytetrafluorethylen (PTFE) tubes (0.81mm O.D.; 0.25mm I.D.) for aqueous samples. Additionally, field modulation slots are designed for uniform 100kHz field modulation incident at the sample. Experiments using a point sample of lithium phthalocyanine (LiPC) were performed to measure both the uniformity of the microwave magnetic field and 100kHz field modulation, and confirm simulations. The rectangular TEU02 cavity resonator employs over-sized end-sections with sample shielding to provide an 87% uniform field for a 0.1×2×6mm(3) sample geometry. An evanescent slotted window was designed for light access to irradiate 90% of the sample volume. A novel dual-slot iris was used to minimize microwave magnetic field perturbations and maintain cross-sectional uniformity. Practical EPR experiments using the application of light irradiated rose bengal (4,5,6,7-tetrachloro-2',4',5',7'-tetraiodofluorescein) were performed in the TEU02 cavity. The implementation of these geometries providing a practical designs for uniform field resonators that continue resonator advancements towards quantitative EPR spectroscopy. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Whole arm manipulation planning based on feedback velocity fields and sampling-based techniques.

    Science.gov (United States)

    Talaei, B; Abdollahi, F; Talebi, H A; Omidi Karkani, E

    2013-09-01

    Changing the configuration of a cooperative whole arm manipulator is not easy while enclosing an object. This difficulty is mainly because of risk of jamming caused by kinematic constraints. To reduce this risk, this paper proposes a feedback manipulation planning algorithm that takes grasp kinematics into account. The idea is based on a vector field that imposes perturbation in object motion inducing directions when the movement is considerably along manipulator redundant directions. Obstacle avoidance problem is then considered by combining the algorithm with sampling-based techniques. As experimental results confirm, the proposed algorithm is effective in avoiding jamming as well as obstacles for a 6-DOF dual arm whole arm manipulator. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Some implications of sampling choices on comparisons between satellite and model aerosol optical depth fields

    Directory of Open Access Journals (Sweden)

    A. M. Sayer

    2010-11-01

    Full Text Available The comparison of satellite and model aerosol optical depth (AOD fields provides useful information on the strengths and weaknesses of both. However, the sampling of satellite and models is very different and some subjective decisions about data selection and aggregation must be made in order to perform such comparisons. This work examines some implications of these decisions, using GlobAerosol AOD retrievals at 550 nm from Advanced Along-Track Scanning Radiometer (AATSR measurements, and aerosol fields from the GEOS-Chem chemistry transport model. It is recommended to sample the model only where the satellite flies over on a particular day; neglecting this can cause regional differences in model AOD of up to 0.1 on monthly and annual timescales. The comparison is observed to depend strongly upon thresholds for sparsity of satellite retrievals in the model grid cells. Requiring at least 25% coverage of the model grid cell by satellite data decreases the observed difference between the two by approximately half over land. The impact over ocean is smaller. In both model and satellite datasets, there is an anticorrelation between the proportion p of a model grid cell covered by satellite retrievals and the AOD. This is attributed to small p typically occuring due to high cloud cover and lower AODs being found in large clear-sky regions. Daily median AATSR AODs were found to be closer to GEOS-Chem AODs than daily means (with the root mean squared difference being approximately 0.05 smaller. This is due to the decreased sensitivity of medians to outliers such as cloud-contaminated retrievals, or aerosol point sources not included in the model.

  6. Polymorphic amplified typing sequences (PATS) and pulsed-field gel electrophoresis (PFGE) yield comparable results in the strain typing of a diverse set of bovine Escherichia coli O157 isolates

    Science.gov (United States)

    The PCR-based Escherichia coli O157 (O157) strain typing system, Polymorphic Amplified Typing Sequences (PATS), targets insertions-deletions (Indels) and single nucleotide polymorphisms (SNPs) at the XbaI and AvrII(BlnI) restriction enzyme sites, respectively, besides amplifying four known virulenc...

  7. FIELD-DEPLOYABLE SAMPLING TOOLS FOR SPENT NUCLEAR FUEL INTERROGATION IN LIQUID STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Berry, T.; Milliken, C.; Martinez-Rodriguez, M.; Hathcock, D.; Heitkamp, M.

    2012-09-12

    Methodology and field deployable tools (test kits) to analyze the chemical and microbiological condition of aqueous spent fuel storage basins and determine the oxide thickness on the spent fuel basin materials were developed to assess the corrosion potential of a basin. this assessment can then be used to determine the amount of time fuel has spent in a storage basin to ascertain if the operation of the reactor and storage basin is consistent with safeguard declarations or expectations and assist in evaluating general storage basin operations. The test kit was developed based on the identification of key physical, chemical and microbiological parameters identified using a review of the scientific and basin operations literature. The parameters were used to design bench scale test cells for additional corrosion analyses, and then tools were purchased to analyze the key parameters. The tools were used to characterize an active spent fuel basin, the Savannah River Site (SRS) L-Area basin. The sampling kit consisted of a total organic carbon analyzer, an YSI multiprobe, and a thickness probe. The tools were field tested to determine their ease of use, reliability, and determine the quality of data that each tool could provide. Characterization confirmed that the L Area basin is a well operated facility with low corrosion potential.

  8. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling.

    Science.gov (United States)

    Aerts, Sam; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-01

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information-inside hotspots or in search of them-based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km2. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96.

  9. Exponentially Biased Ground-State Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians

    Science.gov (United States)

    Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G.

    2017-02-01

    We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009), 10.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.

  10. Integral field spectroscopy of a sample of nearby galaxies: II. Properties of the H ii regions

    CERN Document Server

    Sanchez, S F; Marino, R A; Iglesias-Paramo, J; Vilchez, J M; Kennicutt, R C; Diaz, A I; Mast, D; Monreal-Ibero, A; Garcia-Benito, R; Bland-Hawthorn, J; Perez, E; Delgado, R Gonzalez; Husemann, B; Lopez-Sanchez, A R; Fernandes, R Cid; Kehrig, C; Walcher, C J; de Paz, A Gil; Ellis, S

    2012-01-01

    In this work we analyze the spectroscopic properties of a large number of H ii regions, \\sim2600, located in 38 galaxies. The sample of galaxies has been assembled from the face-on spirals in the PINGS survey and a sample described in M\\'armol-Queralt\\'o (2011, henceforth Paper I). All the galaxies were observed using Integral Field Spectroscopy with a similar setup, covering their optical extension up to \\sim2.4 effective radii within a wavelength range from \\sim3700 to \\sim6900{\\AA}. We develop a new automatic procedure to detect H ii regions, based on the contrast of the H{\\alpha} intensity maps. Once detected, the procedure provides us with the integrated spectra of each individual segmented region. A well-tested automatic decoupling procedure has been applied to remove the underlying stellar population, deriving the main proper- ties of the strongest emission lines in the considered wavelength range (covering from [O ii] {\\lambda}3727 to [S ii] {\\lambda}6731). A final catalogue of the spectroscopic prope...

  11. Design of the sample cell in near-field surface-enhanced Raman scattering by finite difference time domain method

    Institute of Scientific and Technical Information of China (English)

    Yaqin Li; Guoshu Jian; Shifa Wu

    2006-01-01

    The rational design of the sample cell may improve the sensitivity of surface-enhanced Raman scattering(SERS) detection in a high degree. Finite difference time domain (FDTD) simulations of the configurationof Ag film-Ag particles illuminated by plane wave and evanescent wave are performed to provide physicalinsight for design of the sample cell. Numerical solutions indicate that the sample cell can provide more"hot spots" and the massive field intensity enhancement occurs in these "hot spots". More information onthe nanometer character of the sample can be got because of gradient-field Raman (GFR) of evanescentwave.

  12. Hazard surveillance for workplace magnetic fields. 1: Walkaround sampling method for measuring ambient field magnitude; 2: Field characteristics from waveform measurements

    Energy Technology Data Exchange (ETDEWEB)

    Methner, M.M.; Bowman, J.D.

    1998-03-01

    Recent epidemiologic research has suggested that exposure to extremely low frequency (ELF) magnetic fields (MF) may be associated with leukemia, brain cancer, spontaneous abortions, and Alzheimer`s disease. A walkaround sampling method for measuring ambient ELF-MF levels was developed for use in conducting occupational hazard surveillance. This survey was designed to determine the range of MF levels at different industrial facilities so they could be categorized by MF levels and identified for possible subsequent personal exposure assessments. Industries were selected based on their annual electric power consumption in accordance with the hypothesis that large power consumers would have higher ambient MFs when compared with lower power consumers. Sixty-two facilities within thirteen 2-digit Standard Industrial Classifications (SIC) were selected based on their willingness to participate. A traditional industrial hygiene walkaround survey was conducted to identify MF sources, with a special emphasis on work stations.

  13. Assessing five field sampling methods to monitor Yellowstone National Park's northern ungulate winter range: the advantages and disadvantages of implementing a new sampling protocol

    Science.gov (United States)

    Pamela G. Sikkink; Roy Renkin; Geneva Chong; Art Sikkink

    2013-01-01

    The five field sampling methods tested for this study differed in richness and Simpson's Index values calculated from the raw data. How much the methods differed, and which ones were most similar to each other, depended on which diversity measure and which type of data were used for comparisons. When the number of species (richness) was used as a measure of...

  14. Development of sampling approaches for the determination of the presence of genetically modified organisms at the field level.

    Science.gov (United States)

    Sustar-Vozlic, Jelka; Rostohar, Katja; Blejec, Andrej; Kozjak, Petra; Cergan, Zoran; Meglic, Vladimir

    2010-03-01

    In order to comply with the European Union regulatory threshold for the adventitious presence of genetically modified organisms (GMOs) in food and feed, it is important to trace GMOs from the field. Appropriate sampling methods are needed to accurately predict the presence of GMOs at the field level. A 2-year field experiment with two maize varieties differing in kernel colour was conducted in Slovenia. Based on the results of data mining analyses and modelling, it was concluded that spatial relations between the donor and receptor field were the most important factors influencing the distribution of outcrossing rate (OCR) in the field. The approach for estimation fitting function parameters in the receptor (non-GM) field at two distances from the donor (GM) field (10 and 25 m) for estimation of the OCR (GMO content) in the whole receptor field was developed. Different sampling schemes were tested; a systematic random scheme in rows was proposed to be applied for sampling at the two distances for the estimation of fitting function parameters for determination of OCR. The sampling approach had already been validated with some other OCR data and was practically applied in the 2009 harvest in Poland. The developed approach can be used for determination of the GMO presence at the field level and for making appropriate labelling decisions. The importance of this approach lies in its possibility to also address other threshold levels beside the currently prescribed labelling threshold of 0.9% for food and feed.

  15. Nanoscale electromechanical parametric amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Aleman, Benjamin Jose; Zettl, Alexander

    2016-09-20

    This disclosure provides systems, methods, and apparatus related to a parametric amplifier. In one aspect, a device includes an electron source electrode, a counter electrode, and a pumping electrode. The electron source electrode may include a conductive base and a flexible conductor. The flexible conductor may have a first end and a second end, with the second end of the flexible conductor being coupled to the conductive base. A cross-sectional dimension of the flexible conductor may be less than about 100 nanometers. The counter electrode may be disposed proximate the first end of the flexible conductor and spaced a first distance from the first end of the flexible conductor. The pumping electrode may be disposed proximate a length of the flexible conductor and spaced a second distance from the flexible conductor.

  16. Nanoscale electromechanical parametric amplifier

    Science.gov (United States)

    Aleman, Benjamin Jose; Zettl, Alexander

    2016-09-20

    This disclosure provides systems, methods, and apparatus related to a parametric amplifier. In one aspect, a device includes an electron source electrode, a counter electrode, and a pumping electrode. The electron source electrode may include a conductive base and a flexible conductor. The flexible conductor may have a first end and a second end, with the second end of the flexible conductor being coupled to the conductive base. A cross-sectional dimension of the flexible conductor may be less than about 100 nanometers. The counter electrode may be disposed proximate the first end of the flexible conductor and spaced a first distance from the first end of the flexible conductor. The pumping electrode may be disposed proximate a length of the flexible conductor and spaced a second distance from the flexible conductor.

  17. Modeling of semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Bischoff, Svend; Berg, Tommy Winther

    We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed.......We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed....

  18. Polymorphic Amplified Typing Sequences and Pulsed-Field Gel Electrophoresis Yield Comparable Results in the Strain Typing of a Diverse Set of Bovine Escherichia coli O157:H7 Isolates

    Directory of Open Access Journals (Sweden)

    Indira T. Kudva

    2012-01-01

    Full Text Available Polymorphic amplified typing sequences (PATS, a PCR-based Escherichia coli O157:H7 (O157 strain typing system, targets insertions-deletions and single nucleotide polymorphisms at XbaI and AvrII restriction enzyme sites, respectively, and the virulence genes (stx1, stx2, eae, hlyA in the O157 genome. In this study, the ability of PATS to discriminate O157 isolates associated with cattle was evaluated. An in-depth comparison of 25 bovine O157 isolates, from different geographic locations across Northwest United States, showed that about 85% of these isolates shared the same dendogram clade by PATS and pulsed-field gel electrophoresis (PFGE, irrespective of the restriction enzyme sites targeted. The Pearson’s correlation coefficient, r, calculated at about 0.4, 0.3, and 0.4 for XbaI-based, AvrII-based and combined-enzymes PATS and PFGE similarities, respectively, indicating that these profiles shared a good but not high correlation, an expected inference given that the two techniques discriminate differently. Isolates that grouped differently were better matched to their locations using PATS. Overall, PATS discriminated the bovine O157 isolates without interpretive biases or sophisticated analytical software, and effectively complemented while not duplicating PFGE. With its quick turnaround time, PATS has excellent potential as a convenient tool for early epidemiological or food safety investigations, enabling rapid notification/implementation of quarantine measures.

  19. DNase SISPA-next generation sequencing confirms Schmallenberg virus in Belgian field samples and identifies genetic variation in Europe.

    Directory of Open Access Journals (Sweden)

    Toon Rosseel

    Full Text Available In 2011, a novel Orthobunyavirus was identified in cattle and sheep in Germany and The Netherlands. This virus was named Schmallenberg virus (SBV. Later, presence of the virus was confirmed using real time RT-PCR in cases of congenital malformations of bovines and ovines in several European countries, including Belgium. In the absence of specific sequencing protocols for this novel virus we confirmed its presence in RT-qPCR positive field samples using DNase SISPA-next generation sequencing (NGS, a virus discovery method based on random amplification and next generation sequencing. An in vitro transcribed RNA was used to construct a standard curve allowing the quantification of viral RNA in the field samples. Two field samples of aborted lambs containing 7.66 and 7.64 log(10 RNA copies per µL total RNA allowed unambiguous identification of SBV. One sample yielded 192 SBV reads covering about 81% of the L segment, 56% of the M segment and 13% of the S segment. The other sample resulted in 8 reads distributed over the L and M segments. Three weak positive field samples (one from an aborted calf, two from aborted lambs containing virus quantities equivalent to 4.27-4.89 log(10 RNA copies per µL did not allow identification using DNase SISPA-NGS. This partial sequence information was compared to the whole genome sequence of SBV isolated from bovines in Germany, identifying several sequence differences. The applied viral discovery method allowed the confirmation of SBV in RT-qPCR positive brain samples. However, the failure to confirm SBV in weak PCR-positive samples illustrates the importance of the selection of properly targeted and fresh field samples in any virus discovery method. The partial sequences derived from the field samples showed several differences compared to the sequences from bovines in Germany, indicating sequence divergence within the epidemic.

  20. Field Study of Filter Sampling Artifacts for Inorganic and Organic Aerosol Species

    Science.gov (United States)

    Maenhaut, W.; Wang, W.; Chi, X.

    2009-12-01

    It is well-known that the collection of carbonaceous aerosols on quartz fibre filters is prone to both positive and negative artifacts (e.g., Turpin et al., 2000). In studies on these artifacts, one normally concentrates on organic carbon (OC) as a whole or occasionally on water-soluble OC (WSOC). It is rare that studies are carried on individual organic species. Examples of the latter type of study are those by Limbeck et al. (2001; 2005), who used a low-volume tandem filter set-up at a rural background site in South Africa and at the urban site Vienna in Austria, and measured dicarboxylic acids (DCAs) on the front and back filters. We conducted a similar study as those of Limbeck et al. (2001; 2005). For our study we collected high-volume PM2.5 samples during summer field campaigns at three European forested sites, i.e., in Hungary, Belgium, and Finland. The front and back filters of our samples were analysed for OC with a thermal-optical transmission technique (Birch & Cary, 1996), for WSOC as described by Viana et al. (2006), and for water-soluble inorganic cationic and anionic species and organic anionic species by suppressed ion chromatography with conductometric detection. The organic species measured included methanesulphonic acid (MSA) and the four major DCAs, i.e., oxalic, malonic, succinic, and glutaric. The median back/front percentage ratios for ammonium and sulphate were low, below 5% and 1%, respectively, but for nitrate they were around 25-30%. That undenuded filter samplings for nitrate are prone to artifacts is well-documented (e.g., Schaap et al., 2004). For OC the median back/front percentage ratios were around 15% and for WSOC around 20%. For MSA and the four DCAs, they increased in the following order: oxalic (1.5%), succinic (3%), MSA (4%), malonic (2-9%), glutaric (7-26%). Our back/front ratios for three of the four DCAs are lower to much lower than these found by Limbeck et al. (2001; 2005); for malonic, however, we found higher back

  1. Spatially-Optimized Sequential Sampling Plan for Cabbage Aphids Brevicoryne brassicae L. (Hemiptera: Aphididae) in Canola Fields.

    Science.gov (United States)

    Severtson, Dustin; Flower, Ken; Nansen, Christian

    2016-08-01

    The cabbage aphid is a significant pest worldwide in brassica crops, including canola. This pest has shown considerable ability to develop resistance to insecticides, so these should only be applied on a "when and where needed" basis. Thus, optimized sampling plans to accurately assess cabbage aphid densities are critically important to determine the potential need for pesticide applications. In this study, we developed a spatially optimized binomial sequential sampling plan for cabbage aphids in canola fields. Based on five sampled canola fields, sampling plans were developed using 0.1, 0.2, and 0.3 proportions of plants infested as action thresholds. Average sample numbers required to make a decision ranged from 10 to 25 plants. Decreasing acceptable error from 10 to 5% was not considered practically feasible, as it substantially increased the number of samples required to reach a decision. We determined the relationship between the proportions of canola plants infested and cabbage aphid densities per plant, and proposed a spatially optimized sequential sampling plan for cabbage aphids in canola fields, in which spatial features (i.e., edge effects) and optimization of sampling effort (i.e., sequential sampling) are combined. Two forms of stratification were performed to reduce spatial variability caused by edge effects and large field sizes. Spatially optimized sampling, starting at the edge of fields, reduced spatial variability and therefore increased the accuracy of infested plant density estimates. The proposed spatially optimized sampling plan may be used to spatially target insecticide applications, resulting in cost savings, insecticide resistance mitigation, conservation of natural enemies, and reduced environmental impact.

  2. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

    Energy Technology Data Exchange (ETDEWEB)

    Aerts, Sam, E-mail: sam.aerts@intec.ugent.be; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-15

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km{sup 2}. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an

  3. DEVELOPMENT OF METHODOLOGY AND FIELD DEPLOYABLE SAMPLING TOOLS FOR SPENT NUCLEAR FUEL INTERROGATION IN LIQUID STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Berry, T.; Milliken, C.; Martinez-Rodriguez, M.; Hathcock, D.; Heitkamp, M.

    2012-06-04

    This project developed methodology and field deployable tools (test kits) to analyze the chemical and microbiological condition of the fuel storage medium and determine the oxide thickness on the spent fuel basin materials. The overall objective of this project was to determine the amount of time fuel has spent in a storage basin to determine if the operation of the reactor and storage basin is consistent with safeguard declarations or expectations. This project developed and validated forensic tools that can be used to predict the age and condition of spent nuclear fuels stored in liquid basins based on key physical, chemical and microbiological basin characteristics. Key parameters were identified based on a literature review, the parameters were used to design test cells for corrosion analyses, tools were purchased to analyze the key parameters, and these were used to characterize an active spent fuel basin, the Savannah River Site (SRS) L-Area basin. The key parameters identified in the literature review included chloride concentration, conductivity, and total organic carbon level. Focus was also placed on aluminum based cladding because of their application to weapons production. The literature review was helpful in identifying important parameters, but relationships between these parameters and corrosion rates were not available. Bench scale test systems were designed, operated, harvested, and analyzed to determine corrosion relationships between water parameters and water conditions, chemistry and microbiological conditions. The data from the bench scale system indicated that corrosion rates were dependent on total organic carbon levels and chloride concentrations. The highest corrosion rates were observed in test cells amended with sediment, a large microbial inoculum and an organic carbon source. A complete characterization test kit was field tested to characterize the SRS L-Area spent fuel basin. The sampling kit consisted of a TOC analyzer, a YSI

  4. The Grism Lens-Amplified Survey from Space (GLASS). VI. Comparing the Mass and Light in MACS J0416.1-2403 Using Frontier Field Imaging and GLASS Spectroscopy

    Science.gov (United States)

    Hoag, A.; Huang, K.-H.; Treu, T.; Bradač, M.; Schmidt, K. B.; Wang, X.; Brammer, G. B.; Broussard, A.; Amorin, R.; Castellano, M.; Fontana, A.; Merlin, E.; Schrabback, T.; Trenti, M.; Vulcani, B.

    2016-11-01

    We present a model using both strong and weak gravitational lensing of the galaxy cluster MACS J0416.1-2403, constrained using spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) and Hubble Frontier Fields (HFF) imaging data. We search for emission lines in known multiply imaged sources in the GLASS spectra, obtaining secure spectroscopic redshifts of 30 multiple images belonging to 15 distinct source galaxies. The GLASS spectra provide the first spectroscopic measurements for five of the source galaxies. The weak lensing signal is acquired from 884 galaxies in the F606W HFF image. By combining the weak lensing constraints with 15 multiple image systems with spectroscopic redshifts and nine multiple image systems with photometric redshifts, we reconstruct the gravitational potential of the cluster on an adaptive grid. The resulting map of total mass density is compared with a map of stellar mass density obtained from the deep Spitzer Frontier Fields imaging data to study the relative distribution of stellar and total mass in the cluster. We find that the projected stellar mass to total mass ratio, f ⋆, varies considerably with the stellar surface mass density. The mean projected stellar mass to total mass ratio is =0.009+/- 0.003 (stat.), but with a systematic error as large as 0.004-0.005, dominated by the choice of the initial mass function. We find agreement with several recent measurements of f ⋆ in massive cluster environments. The lensing maps of convergence, shear, and magnification are made available to the broader community in the standard HFF format.

  5. Pre-Mission Input Requirements to Enable Successful Sample Collection by A Remote Field/EVA Team

    Science.gov (United States)

    Cohen, B. A.; Lim, D. S. S.; Young, K. E.; Brunner, A.; Elphic, R. E.; Horne, A.; Kerrigan, M. C.; Osinski, G. R.; Skok, J. R.; Squyres, S. W.; Saint-Jacques, D.; Heldmann, J. L.

    2016-01-01

    The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team, part of the Solar System Exploration Virtual Institute (SSERVI), is a field-based research program aimed at generating strategic knowledge in preparation for human and robotic exploration of the Moon, near-Earth asteroids, Phobos and Deimos, and beyond. In contract to other technology-driven NASA analog studies, The FINESSE WCIS activity is science-focused and, moreover, is sampling-focused with the explicit intent to return the best samples for geochronology studies in the laboratory. We used the FINESSE field excursion to the West Clearwater Lake Impact structure (WCIS) as an opportunity to test factors related to sampling decisions. We examined the in situ sample characterization and real-time decision-making process of the astronauts, with a guiding hypothesis that pre-mission training that included detailed background information on the analytical fate of a sample would better enable future astronauts to select samples that would best meet science requirements. We conducted three tests of this hypothesis over several days in the field. Our investigation was designed to document processes, tools and procedures for crew sampling of planetary targets. This was not meant to be a blind, controlled test of crew efficacy, but rather an effort to explicitly recognize the relevant variables that enter into sampling protocol and to be able to develop recommendations for crew and backroom training in future endeavors.

  6. Ca II Triplet Spectroscopy of Small Magellanic Cloud Red Giants. IV. Abundances for a Large Sample of Field Stars and Comparison with the Cluster Sample

    Science.gov (United States)

    Parisi, M. C.; Geisler, D.; Carraro, G.; Clariá, J. J.; Villanova, S.; Gramajo, L. V.; Sarajedini, A.; Grocholski, A. J.

    2016-09-01

    This paper represents a major step forward in the systematic and homogeneous study of Small Magellanic Cloud (SMC) star clusters and field stars carried out by applying the calcium triplet technique. We present in this work the radial velocity and metallicity of approximately 400 red giant stars in 15 SMC fields, with typical errors of about 7 km s-1 and 0.16 dex, respectively. We added to this information our previously determined metallicity values for 29 clusters and approximately 350 field stars using the identical techniques. Using this enlarged sample, we analyze the metallicity distribution and gradient in this galaxy. We also compare the chemical properties of the clusters and of their surrounding fields. We find a number of surprising results. While the clusters, taken as a whole, show no strong evidence for a metallicity gradient (MG), the field stars exhibit a clear negative gradient in the inner region of the SMC, consistent with the recent results of Dobbie et al. For distances to the center of the galaxy less than 4°, field stars show a considerably smaller metallicity dispersion than that of the clusters. However, in the external SMC regions, clusters and field stars exhibit similar metallicity dispersions. Moreover, in the inner region of the SMC, clusters appear to be concentrated in two groups: one more metal-poor and another more metal-rich than field stars. Individually considered, neither cluster group presents an MG. Most surprisingly, the MG for both stellar populations (clusters and field stars) appears to reverse sign in the outer regions of the SMC. The difference between the cluster metallicity and the mean metallicity of the surrounding field stars turns out to be a strong function of the cluster metallicity. These results could be indicating different chemical evolution histories for these two SMC stellar populations. They could also indicate variations in the chemical behavior of the SMC in its internal and external regions.

  7. Microcystin-Bound Protein Patterns in Different Cultures of Microcystis aeruginosa and Field Samples

    Science.gov (United States)

    Wei, Nian; Hu, Lili; Song, Lirong; Gan, Nanqin

    2016-01-01

    Micocystin (MC) exists in Microcystis cells in two different forms, free and protein-bound. We examined the dynamic change in extracellular free MCs, intracellular free MCs and protein-bound MCs in both batch cultures and semi-continuous cultures, using high performance liquid chromatography and Western blot. The results showed that the free MC per cell remained constant, while the quantity of protein-bound MCs increased with the growth of Microcystis cells in both kinds of culture. Significant changes in the dominant MC-bound proteins occurred in the late exponential growth phase of batch cultures, while the dominant MC-bound proteins in semi-continuous cultures remained the same. In field samples collected at different months in Lake Taihu, the dominant MC-bound proteins were shown to be similar, but the amount of protein-bound MC varied and correlated with the intracellular MC content. We identified MC-bound proteins by two-dimensional electrophoresis immunoblots and mass spectrometry. The 60 kDa chaperonin GroEL was a prominent MC-bound protein. Three essential glycolytic enzymes and ATP synthase alpha subunit were also major targets of MC-binding, which might contribute to sustained growth in semi-continuous culture. Our results indicate that protein-bound MC may be important for sustaining growth and adaptation of Microcystis sp. PMID:27754336

  8. Theoretically informed Monte Carlo simulation of liquid crystals by sampling of alignment-tensor fields.

    Energy Technology Data Exchange (ETDEWEB)

    Armas-Perez, Julio C.; Londono-Hurtado, Alejandro; Guzman, Orlando; Hernandez-Ortiz, Juan P.; de Pablo, Juan J.

    2015-07-27

    A theoretically informed coarse-grained Monte Carlo method is proposed for studying liquid crystals. The free energy functional of the system is described in the framework of the Landau-de Gennes formalism. The alignment field and its gradients are approximated by finite differences, and the free energy is minimized through a stochastic sampling technique. The validity of the proposed method is established by comparing the results of the proposed approach to those of traditional free energy minimization techniques. Its usefulness is illustrated in the context of three systems, namely, a nematic liquid crystal confined in a slit channel, a nematic liquid crystal droplet, and a chiral liquid crystal in the bulk. It is found that for systems that exhibit multiple metastable morphologies, the proposed Monte Carlo method is generally able to identify lower free energy states that are often missed by traditional approaches. Importantly, the Monte Carlo method identifies such states from random initial configurations, thereby obviating the need for educated initial guesses that can be difficult to formulate.

  9. Theoretically informed Monte Carlo simulation of liquid crystals by sampling of alignment-tensor fields

    Energy Technology Data Exchange (ETDEWEB)

    Armas-Pérez, Julio C.; Londono-Hurtado, Alejandro [Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637 (United States); Guzmán, Orlando [Departamento de Física, Universidad Autónoma Metropolitana, Iztapalapa, DF 09340, México (Mexico); Hernández-Ortiz, Juan P. [Departamento de Materiales y Minerales, Universidad Nacional de Colombia, Sede Medellín, Medellín (Colombia); Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637 (United States); Pablo, Juan J. de, E-mail: depablo@uchicago.edu [Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637 (United States); Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2015-07-28

    A theoretically informed coarse-grained Monte Carlo method is proposed for studying liquid crystals. The free energy functional of the system is described in the framework of the Landau-de Gennes formalism. The alignment field and its gradients are approximated by finite differences, and the free energy is minimized through a stochastic sampling technique. The validity of the proposed method is established by comparing the results of the proposed approach to those of traditional free energy minimization techniques. Its usefulness is illustrated in the context of three systems, namely, a nematic liquid crystal confined in a slit channel, a nematic liquid crystal droplet, and a chiral liquid crystal in the bulk. It is found that for systems that exhibit multiple metastable morphologies, the proposed Monte Carlo method is generally able to identify lower free energy states that are often missed by traditional approaches. Importantly, the Monte Carlo method identifies such states from random initial configurations, thereby obviating the need for educated initial guesses that can be difficult to formulate.

  10. Choice of sample size for high transport critical current density in a granular superconductor: percolation versus self-field effects

    Energy Technology Data Exchange (ETDEWEB)

    Mulet, R.; Diaz, O.; Altshuler, E. [Superconductivity Laboratory, IMRE-Physics Faculty, University of Havana, La Habana (Cuba)

    1997-10-01

    The percolative character of the current paths and the self-field effects were considered to estimate optimal sample dimensions for the transport current of a granular superconductor by means of a Monte Carlo algorithm and critical-state model calculations. We showed that, under certain conditions, self-field effects are negligible and the J{sub c} dependence on sample dimensions is determined by the percolative character of the current. Optimal dimensions are demonstrated to be a function of the fraction of superconducting phase in the sample. (author)

  11. Chaotic behaviors of operational amplifiers.

    Science.gov (United States)

    Yim, Geo-Su; Ryu, Jung-Wan; Park, Young-Jai; Rim, Sunghwan; Lee, Soo-Young; Kye, Won-Ho; Kim, Chil-Min

    2004-04-01

    We investigate nonlinear dynamical behaviors of operational amplifiers. When the output terminal of an operational amplifier is connected to the inverting input terminal, the circuit exhibits period-doubling bifurcation, chaos, and periodic windows, depending on the voltages of the positive and the negative power supplies. We study these nonlinear dynamical characteristics of this electronic circuit experimentally.

  12. Field geologic observation and sample collection strategies for planetary surface exploration: Insights from the 2010 Desert RATS geologist crewmembers

    Science.gov (United States)

    Hurtado, José M.; Young, Kelsey; Bleacher, Jacob E.; Garry, W. Brent; Rice, James W.

    2013-10-01

    Observation is the primary role of all field geologists, and geologic observations put into an evolving conceptual context will be the most important data stream that will be relayed to Earth during a planetary exploration mission. Sample collection is also an important planetary field activity, and its success is closely tied to the quality of contextual observations. To test protocols for doing effective planetary geologic fieldwork, the Desert RATS (Research and Technology Studies) project deployed two prototype rovers for two weeks of simulated exploratory traverses in the San Francisco volcanic field of northern Arizona. The authors of this paper represent the geologist crewmembers who participated in the 2010 field test. We document the procedures adopted for Desert RATS 2010 and report on our experiences regarding these protocols. Careful consideration must be made of various issues that impact the interplay between field geologic observations and sample collection, including time management; strategies related to duplication of samples and observations; logistical constraints on the volume and mass of samples and the volume/transfer of data collected; and paradigms for evaluation of mission success. We find that the 2010 field protocols brought to light important aspects of each of these issues, and we recommend best practices and modifications to training and operational protocols to address them. Underlying our recommendations is the recognition that the capacity of the crew to "flexibly execute" their activities is paramount. Careful design of mission parameters, especially field geologic protocols, is critical for enabling the crews to successfully meet their science objectives.

  13. Fast Electrocardiogram Amplifier Recovery after Defibrillation Shock

    Directory of Open Access Journals (Sweden)

    Ivan Dotsinsky

    2005-04-01

    Full Text Available A procedure for fast ECG amplifier recovery after defibrillation shocks was developed and simulated in the MATLAB environment. Exponentially decaying post-shock voltages have been recorded. Signals from the AHA database are taken and mixed with the recorded exponential disturbances. The algorithm applies moving averaging (comb filter on the compound input signal, thereby obtaining the samples of the disturbance. They are currently subtracted from the input signal. The results obtained show that its recovery is practically instantaneous.

  14. The Use of Satellite Imagery to Guide Field Plot Sampling Scheme for Biomass Estimation in Ghanaian Forest

    Science.gov (United States)

    Sah, B. P.; Hämäläinen, J. M.; Sah, A. K.; Honji, K.; Foli, E. G.; Awudi, C.

    2012-07-01

    Accurate and reliable estimation of biomass in tropical forest has been a challenging task because a large proportion of forests are difficult to access or inaccessible. So, for effective implementation of REDD+ and fair benefit sharing, the proper designing of field plot sampling schemes plays a significant role in achieving robust biomass estimation. The existing forest inventory protocols using various field plot sampling schemes, including FAO's regular grid concept of sampling for land cover inventory at national level, are time and human resource intensive. Wall to wall LiDAR scanning is, however, a better approach to assess biomass with high precision and spatial resolution even though this approach suffers from high costs. Considering the above, in this study a sampling design based on a LiDAR strips sampling scheme has been devised for Ghanaian forests to support field plot sampling. Using Top-of-Atmosphere (TOA) reflectance value of satellite data, Land Use classification was carried out in accordance with IPCC definitions and the resulting classes were further stratified, incorporating existing GIS data of ecological zones in the study area. Employing this result, LiDAR sampling strips were allocated using systematic sampling techniques. The resulting LiDAR strips represented all forest categories, as well as other Land Use classes, with their distribution adequately representing the areal share of each category. In this way, out of at total area of 15,153km2 of the study area, LiDAR scanning was required for only 770 km2 (sampling intensity being 5.1%). We conclude that this systematic LiDAR sampling design is likely to adequately cover variation in above-ground biomass densities and serve as sufficient a-priori data, together with the Land Use classification produced, for designing efficient field plot sampling over the seven ecological zones.

  15. THE IMPORTANCE OF THE MAGNETIC FIELD FROM AN SMA-CSO-COMBINED SAMPLE OF STAR-FORMING REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Patrick M.; Tang, Ya-Wen; Ho, Paul T. P.; Chen, Huei-Ru Vivien; Liu, Hau-Yu Baobab; Yen, Hsi-Wei; Lai, Shih-Ping [Academia Sinica, Institute of Astronomy and Astrophysics, Taipei, Taiwan (China); Zhang, Qizhou; Chen, How-Huan; Ching, Tao-Chung [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Girart, Josep M. [Institut de Ciències de l' Espai, CSIC-IEEC, Campus UAB, Facultat de Ciències, C5p 2, 08193 Bellaterra, Catalonia (Spain); Frau, Pau [Observatorio Astronómico Nacional, Alfonso XII, 3 E-28014 Madrid (Spain); Li, Hua-Bai [Department of Physics, The Chinese University of Hong Kong (Hong Kong); Li, Zhi-Yun [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Padovani, Marco [Laboratoire Univers et Particules de Montpellier, UMR 5299 du CNRS, Université de Montpellier II, place E. Bataillon, cc072, F-34095 Montpellier (France); Qiu, Keping [School of Astronomy and Space Science, Nanjing University, 22 Hankou Road, Nanjiing 210093 (China); Rao, Ramprasad, E-mail: pmkoch@asiaa.sinica.edu.tw [Academia Sinica, Institute of Astronomy and Astrophysics, 645 N. Aohoku Place, Hilo, HI 96720 (United States)

    2014-12-20

    Submillimeter dust polarization measurements of a sample of 50 star-forming regions, observed with the Submillimeter Array (SMA) and the Caltech Submillimeter Observatory (CSO) covering parsec-scale clouds to milliparsec-scale cores, are analyzed in order to quantify the magnetic field importance. The magnetic field misalignment δ—the local angle between magnetic field and dust emission gradient—is found to be a prime observable, revealing distinct distributions for sources where the magnetic field is preferentially aligned with or perpendicular to the source minor axis. Source-averaged misalignment angles (|δ|) fall into systematically different ranges, reflecting the different source-magnetic field configurations. Possible bimodal (|δ|) distributions are found for the separate SMA and CSO samples. Combining both samples broadens the distribution with a wide maximum peak at small (|δ|) values. Assuming the 50 sources to be representative, the prevailing source-magnetic field configuration is one that statistically prefers small magnetic field misalignments |δ|. When interpreting |δ| together with a magnetohydrodynamics force equation, as developed in the framework of the polarization-intensity gradient method, a sample-based log-linear scaling fits the magnetic field tension-to-gravity force ratio (Σ {sub B}) versus (|δ|) with (Σ {sub B}) = 0.116 · exp (0.047 · (|δ|)) ± 0.20 (mean error), providing a way to estimate the relative importance of the magnetic field, only based on measurable field misalignments |δ|. The force ratio Σ {sub B} discriminates systems that are collapsible on average ((Σ {sub B}) < 1) from other molecular clouds where the magnetic field still provides enough resistance against gravitational collapse ((Σ {sub B}) > 1). The sample-wide trend shows a transition around (|δ|) ≈ 45°. Defining an effective gravitational force ∼1 – (Σ {sub B}), the average magnetic-field-reduced star formation efficiency is at least a

  16. Digital Lock-in Amplifier Based on Microcontroller

    Institute of Scientific and Technical Information of China (English)

    An-li TAO; Guo-dong XU; Ke-xue LUO; Gang-ling ZHANG

    2010-01-01

    A method of implementing high cost-effective and highly integrated digital lock-in amplifier with microcontroller is discussed. And the digital lock-in amplifier is more suitable for measuring low-frequency weak signal.Digital signal sequence is obtained through sampling signal measured over an integer number of signal periods, but digital reference sequence is acquired through mathematical operation, then digital phase sensitive detection can be implemented by calculating the cross-correlation function of digital signal sequence and digital reference sequence.In addition, the frequency response and phase character of the digital lock-in amplifier is analyzed. Finally, the designed digital lock-in amplifier is achieved. Experimental results show that the digital lock-in amplifier can be used for measuring weak signal with low ignal-to-noise ratio.

  17. Integrating field sampling, spatial statistics and remote sensing to map wetland vegetation in the Pantanal, Brazil

    Science.gov (United States)

    Arieira, J.; Karssenberg, D.; de Jong, S. M.; Addink, E. A.; Couto, E. G.; Nunes da Cunha, C.; Skøien, J. O.

    2010-09-01

    To improve the protection of wetlands, it is imperative to have a thorough understanding of their structuring elements and of the identification of efficient methods to describe and monitor them. This article uses sophisticated statistical classification, interpolation and error propagation techniques, in order to describe vegetation spatial patterns, map plant community distribution and evaluate the capability of statistical approaches to produce high-quality vegetation maps. The approach results in seven vegetation communities with a known floral composition that can be mapped over large areas using remotely sensed data. The relations between remotely sensing data and vegetation patterns, captured in four factorial axes, were formalized mathematically in multiple linear regression models and used in a universal kriging procedure to reduce the uncertainty in mapped communities. Universal kriging has shown to be a valuable interpolation technique because parts of vegetation variability not explained by the images could be modeled as spatially correlated residuals, increasing prediction accuracy. Differences in spatial dependence of the vegetation gradients evidenced the multi-scale nature of vegetation communities. Cross validation procedures and Monte Carlo simulations were used to quantify the uncertainty in the resulting map. Cross-validation showed that accuracy in classification varies according with the community type, as a result of sampling density and configuration. A map of uncertainty resulted from Monte Carlo simulations displayed the spatial variation in classification accuracy, showing that the quality of classification varies spatially, even though the proportion and arrangement of communities observed in the original map is preserved to a great extent. These results suggested that mapping improvement could be achieved by increasing the number of field observations of those communities with a scattered and small patch size distribution; or by

  18. Optimized Field Sampling and Monitoring of Airborne Hazardous Transport Plumes; A Geostatistical Simulation Approach

    Energy Technology Data Exchange (ETDEWEB)

    Chen, DI-WEN

    2001-11-21

    Airborne hazardous plumes inadvertently released during nuclear/chemical/biological incidents are mostly of unknown composition and concentration until measurements are taken of post-accident ground concentrations from plume-ground deposition of constituents. Unfortunately, measurements often are days post-incident and rely on hazardous manned air-vehicle measurements. Before this happens, computational plume migration models are the only source of information on the plume characteristics, constituents, concentrations, directions of travel, ground deposition, etc. A mobile ''lighter than air'' (LTA) system is being developed at Oak Ridge National Laboratory that will be part of the first response in emergency conditions. These interactive and remote unmanned air vehicles will carry light-weight detectors and weather instrumentation to measure the conditions during and after plume release. This requires a cooperative computationally organized, GPS-controlled set of LTA's that self-coordinate around the objectives in an emergency situation in restricted time frames. A critical step before an optimum and cost-effective field sampling and monitoring program proceeds is the collection of data that provides statistically significant information, collected in a reliable and expeditious manner. Efficient aerial arrangements of the detectors taking the data (for active airborne release conditions) are necessary for plume identification, computational 3-dimensional reconstruction, and source distribution functions. This report describes the application of stochastic or geostatistical simulations to delineate the plume for guiding subsequent sampling and monitoring designs. A case study is presented of building digital plume images, based on existing ''hard'' experimental data and ''soft'' preliminary transport modeling results of Prairie Grass Trials Site. Markov Bayes Simulation, a coupled Bayesian

  19. Surveying immigrants without sampling frames - evaluating the success of alternative field methods.

    Science.gov (United States)

    Reichel, David; Morales, Laura

    2017-01-01

    This paper evaluates the sampling methods of an international survey, the Immigrant Citizens Survey, which aimed at surveying immigrants from outside the European Union (EU) in 15 cities in seven EU countries. In five countries, no sample frame was available for the target population. Consequently, alternative ways to obtain a representative sample had to be found. In three countries 'location sampling' was employed, while in two countries traditional methods were used with adaptations to reach the target population. The paper assesses the main methodological challenges of carrying out a survey among a group of immigrants for whom no sampling frame exists. The samples of the survey in these five countries are compared to results of official statistics in order to assess the accuracy of the samples obtained through the different sampling methods. It can be shown that alternative sampling methods can provide meaningful results in terms of core demographic characteristics although some estimates differ to some extent from the census results.

  20. Partitioning of alcohol ethoxylates and polyethylene glycols in the marine environment: Field samplings vs laboratory experiments

    Energy Technology Data Exchange (ETDEWEB)

    Traverso-Soto, Juan M. [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain); Brownawell, Bruce J. [School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000 (United States); González-Mazo, Eduardo [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain); Lara-Martín, Pablo A., E-mail: pablo.lara@uca.es [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain)

    2014-08-15

    Nowadays, alcohol ethoxylates (AEOs) constitute the most important group of non-ionic surfactants, used in a wide range of applications such as household cleaners and detergents. Significant amounts of these compounds and their degradation products (polyethylene glycols, PEGs, which are also used for many other applications) reach aquatic environments, and are eliminated from the water column by degradation and sorption processes. This work deals with the environmental distribution of AEOs and PEGs in the Long Island Sound Estuary, a setting impacted by sewage discharges from New York City (NYC). The distribution of target compounds in seawater was influenced by tides, consistent with salinity differences, and concentrations in suspended solid samples ranged from 1.5 to 20.5 μg/g. The more hydrophobic AEOs were mostly attached to the particulate matter whereas the more polar PEGs were predominant in the dissolved form. Later, the sorption of these chemicals was characterized in the laboratory. Experimental and environmental sorption coefficients for AEOs and PEGs showed average values from 3607 to 164,994 L/kg and from 74 to 32,862 L/kg, respectively. The sorption data were fitted to a Freundlich isotherm model with parameters n and log K{sub F} between 0.8–1.2 and 1.46–4.39 L/kg, respectively. AEO and PEG sorptions on marine sediment were also found to be mostly not affected by changes in salinity. - Highlights: • AEO and PEG levels in estuaries are influenced by tides and suspended solids. • Sediment–water partition coefficients in the lab and in the field are comparable. • Sorption is depending on both hydrophilic and hydrophobic interactions. • Sorption data fits Freundlich isotherms, showing K{sub F} values from 29 to 24,892 L/kg. • Sorption is very weakly influenced by salinity changes.

  1. Trapped field of YBCO single-domain samples using pulse magnetization from 77K to 20K

    Energy Technology Data Exchange (ETDEWEB)

    Chaud, X [CNRS/CRETA, 25 avenue des martyrs, 38042 Grenoble Cedex 09 (France); Haanappel, E [LNCMP, 143 avenue de Rangueil, 31400 Toulouse (France); Noudem, J G; Horvath, D [CRISMAT/ENSICAEN, 6 bd Marechal Juin, 14050 Caen (France)], E-mail: xavier.chaud@grenoble.cnrs.fr

    2008-02-01

    ReBCO single-domain bulk superconductors have been shown to trap significant magnetic field at 77K and below. They can advantageously replace permanent magnets in cryogenic motors; more power in a smaller volume can be achieved. But practically, their magnetization has to be performed in situ. Usually it implies the use of pulse magnetization which is severe for the samples. This technique generates heat and stress on the superconductors. The magnetic-flux-trapping capabilities of YBCO single-domain samples were explored using the pulse-field facilities at the LNCMP (National Pulsed Magnetic Field Laboratory) at Toulouse, France. The flux dynamic was monitored during magnetic pulses by measuring the surface induction with a Hall probe on top of the samples at different temperatures from 77K to 20K. The samples were 16 mm in diameter and about 10 mm in height. The best one trapped 400 mT at 77K and 2.5T at 20K. The trapped field increases almost linearly down to 40K. The magnetic pulse is seen to generate heat. The temperature rise increases with decreasing temperature dwell because of lower heat capacity. The achieved trapped field is a compromise between the temperature rise and the applied field, and depends greatly of the magnetization history.

  2. Risk Attitudes, Sample Selection and Attrition in a Longitudinal Field Experiment

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten Igel

    Longitudinal experiments allow one to compare inferences about behavior over time for the same individuals, and evaluate the temporal stability of latent preferences. But longitudinal experiments entail the possibility of sample selection and sample attrition over time, confounding inferences abo...

  3. Capacities of quantum amplifier channels

    Science.gov (United States)

    Qi, Haoyu; Wilde, Mark M.

    2017-01-01

    Quantum amplifier channels are at the core of several physical processes. Not only do they model the optical process of spontaneous parametric down-conversion, but the transformation corresponding to an amplifier channel also describes the physics of the dynamical Casimir effect in superconducting circuits, the Unruh effect, and Hawking radiation. Here we study the communication capabilities of quantum amplifier channels. Invoking a recently established minimum output-entropy theorem for single-mode phase-insensitive Gaussian channels, we determine capacities of quantum-limited amplifier channels in three different scenarios. First, we establish the capacities of quantum-limited amplifier channels for one of the most general communication tasks, characterized by the trade-off between classical communication, quantum communication, and entanglement generation or consumption. Second, we establish capacities of quantum-limited amplifier channels for the trade-off between public classical communication, private classical communication, and secret key generation. Third, we determine the capacity region for a broadcast channel induced by the quantum-limited amplifier channel, and we also show that a fully quantum strategy outperforms those achieved by classical coherent-detection strategies. In all three scenarios, we find that the capacities significantly outperform communication rates achieved with a naive time-sharing strategy.

  4. Get the most out of blow hormones: validation of sampling materials, field storage and extraction techniques for whale respiratory vapour samples.

    Science.gov (United States)

    Burgess, Elizabeth A; Hunt, Kathleen E; Kraus, Scott D; Rolland, Rosalind M

    2016-01-01

    Studies are progressively showing that vital physiological data may be contained in the respiratory vapour (blow) of cetaceans. Nonetheless, fundamental methodological issues need to be addressed before hormone analysis of blow can become a reliable technique. In this study, we performed controlled experiments in a laboratory setting, using known doses of pure parent hormones, to validate several technical factors that may play a crucial role in hormone analyses. We evaluated the following factors: (i) practical field storage of samples on small boats during daylong trips; (ii) efficiency of hormone extraction methods; and (iii) assay interference of different sampler types (i.e. veil nylon, nitex nylon mesh and polystyrene dish). Sampling materials were dosed with mock blow samples of known mixed hormone concentrations (progesterone, 17β-estradiol, testosterone, cortisol, aldosterone and triiodothyronine), designed to mimic endocrine profiles characteristic of pregnant females, adult males, an adrenal glucocorticoid response or a zero-hormone control (distilled H2O). Results showed that storage of samples in a cooler on ice preserved hormone integrity for at least 6 h (P = 0.18). All sampling materials and extraction methods yielded the correct relative patterns for all six hormones. However, veil and nitex mesh produced detectable assay interference (mean 0.22 ± 0.04 and 0.18 ± 0.03 ng/ml, respectively), possibly caused by some nylon-based component affecting antibody binding. Polystyrene dishes were the most efficacious sampler for accuracy and precision (P samples obtained from field collections of whale blow.

  5. Introduction to RF power amplifier design and simulation

    CERN Document Server

    Eroglu, Abdullah

    2015-01-01

    Introduction to RF Power Amplifier Design and Simulation fills a gap in the existing literature by providing step-by-step guidance for the design of radio frequency (RF) power amplifiers, from analytical formulation to simulation, implementation, and measurement. Featuring numerous illustrations and examples of real-world engineering applications, this book:Gives an overview of intermodulation and elaborates on the difference between linear and nonlinear amplifiersDescribes the high-frequency model and transient characteristics of metal-oxide-semiconductor field-effect transistorsDetails activ

  6. Small signal microwave amplifier design

    CERN Document Server

    Grosch, Theodore

    2000-01-01

    This book explains techniques and examples for designing stable amplifiers for high-frequency applications in which the signal is small and the amplifier circuit is linear. An in-depth discussion of linear network theory provides the foundation needed to develop actual designs. Examples throughout the book will show you how to apply the knowledge gained in each chapter leading to the complex design of low noise amplifiers. Many exercises at the end of each chapter will help students to practice their skills. The solutions to these design problems are available in an accompanying solutions book

  7. Fundamentals of fiber lasers and fiber amplifiers

    CERN Document Server

    Ter-Mikirtychev, Valerii (Vartan)

    2014-01-01

    This book covers the fundamental aspects of fiber lasers and fiber amplifiers, and includes a wide range of material from laser physics fundamentals to state-of-the-art topics in this rapidly growing field of quantum electronics. Emphasis is placed on the nonlinear processes taking place in fiber lasers and amplifiers, their similarities, differences to, and their advantages over other solid-state lasers. The reader will learn basic principles of solid-state physics and optical spectroscopy of laser active centers in fibers, main operational laser regimes, and practical recommendations and suggestions on fiber laser research, laser applications, and laser product development. The book will be useful for students, researchers, and professionals who work with lasers, in the optical communications, chemical and biological industries, etc.

  8. Method Evaluation And Field Sample Measurements For The Rate Of Movement Of The Oxidation Front In Saltstone

    Energy Technology Data Exchange (ETDEWEB)

    Almond, P. M. [Savannah River Site (SRS), Aiken, SC (United States); Kaplan, D. I. [Savannah River Site (SRS), Aiken, SC (United States); Langton, C. A. [Savannah River Site (SRS), Aiken, SC (United States); Stefanko, D. B. [Savannah River Site (SRS), Aiken, SC (United States); Spencer, W. A. [Savannah River Site (SRS), Aiken, SC (United States); Hatfield, A. [Clemson University, Clemson, SC (United States); Arai, Y. [Clemson University, Clemson, SC (United States)

    2012-08-23

    The objective of this work was to develop and evaluate a series of methods and validate their capability to measure differences in oxidized versus reduced saltstone. Validated methods were then applied to samples cured under field conditions to simulate Performance Assessment (PA) needs for the Saltstone Disposal Facility (SDF). Four analytical approaches were evaluated using laboratory-cured saltstone samples. These methods were X-ray absorption spectroscopy (XAS), diffuse reflectance spectroscopy (DRS), chemical redox indicators, and thin-section leaching methods. XAS and thin-section leaching methods were validated as viable methods for studying oxidation movement in saltstone. Each method used samples that were spiked with chromium (Cr) as a tracer for oxidation of the saltstone. The two methods were subsequently applied to field-cured samples containing chromium to characterize the oxidation state of chromium as a function of distance from the exposed air/cementitious material surface.

  9. On the dual symmetry between absorbing and amplifying random media

    Indian Academy of Sciences (India)

    S Anantha Ramakrishna

    2004-06-01

    We re-examine the dual symmetry between absorbing and amplifying random media. By analysing the physically allowed choice of the sign of the square root to determine the complex wave vector in a medium, we draw a broad set of conclusions that enables us to resolve the apparent paradox of the dual symmetry and also to anticipate the large local electromagnetic field enhancements in amplifying random media.

  10. International Standardization Activities for Optical Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Haruo Okamura

    2003-01-01

    International standardization activities for Optical Amplifiers at IECTC86 and ITU-T SG15 are reviewed. Current discussions include Optical Amplifier safety guideline, Reliability standard, Rest methods of Noise and PMD, Definitions of Raman amplifier parameters and OA classification.

  11. Behavioral modeling of Digitally Adjustable Current Amplifier

    Directory of Open Access Journals (Sweden)

    Josef Polak

    2015-03-01

    Full Text Available This article presents the digitally adjustable current amplifier (DACA and its analog behavioral model (ABM, which is suitable for both ideal and advanced analyses of the function block using DACA as active element. There are four levels of this model, each being suitable for simulation of a certain degree of electronic circuits design (e.g. filters, oscillators, generators. Each model is presented through a schematic wiring in the simulation program OrCAD, including a description of equations representing specific functions in the given level of the simulation model. The design of individual levels is always verified using PSpice simulations. The ABM model has been developed based on practically measured values of a number of DACA amplifier samples. The simulation results for proposed levels of the ABM model are shown and compared with the results of the real easurements of the active element DACA.

  12. Pre-Mission Input Requirements to Enable Successful Sample Collection by a Remote Field/EVA Team

    Science.gov (United States)

    Cohen, B. A.; Young, K. E.; Lim, D. S.

    2015-01-01

    This paper is intended to evaluate the sample collection process with respect to sample characterization and decision making. In some cases, it may be sufficient to know whether a given outcrop or hand sample is the same as or different from previous sampling localities or samples. In other cases, it may be important to have more in-depth characterization of the sample, such as basic composition, mineralogy, and petrology, in order to effectively identify the best sample. Contextual field observations, in situ/handheld analysis, and backroom evaluation may all play a role in understanding field lithologies and their importance for return. For example, whether a rock is a breccia or a clast-laden impact melt may be difficult based on a single sample, but becomes clear as exploration of a field site puts it into context. The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team is a new activity focused on a science and exploration field based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, near-Earth asteroids (NEAs) and Phobos and Deimos. We used the FINESSE field excursion to the West Clearwater Lake Impact structure (WCIS) as an opportunity to test factors related to sampling decisions. In contract to other technology-driven NASA analog studies, The FINESSE WCIS activity is science-focused, and moreover, is sampling-focused, with the explicit intent to return the best samples for geochronology studies in the laboratory. This specific objective effectively reduces the number of variables in the goals of the field test and enables a more controlled investigation of the role of the crewmember in selecting samples. We formulated one hypothesis to test: that providing details regarding the analytical fate of the samples (e.g. geochronology, XRF/XRD, etc.) to the crew prior to their traverse will result in samples that are more likely to meet specific analytical

  13. Operational amplifiers theory and design

    CERN Document Server

    Huijsing, Johan

    2017-01-01

    This proven textbook guides readers to a thorough understanding of the theory and design of operational amplifiers (OpAmps). The core of the book presents systematically the design of operational amplifiers, classifying them into a periodic system of nine main overall configurations, ranging from one gain stage up to four or more stages. This division enables circuit designers to recognize quickly, understand, and choose optimal configurations. Characterization of operational amplifiers is given by macro models and error matrices, together with measurement techniques for their parameters. Definitions are given for four types of operational amplifiers depending on the grounding of their input and output ports. Many famous designs are evaluated in depth, using a carefully structured approach enhanced by numerous figures. In order to reinforce the concepts introduced and facilitate self-evaluation of design skills, the author includes problems with detailed solutions, as well as simulation exercises. Provides te...

  14. Characterization of SLUG microwave amplifiers

    Science.gov (United States)

    Hoi, I.-C.; Zhu, S.; Thorbeck, T.; McDermott, R.; Mutus, J.; Jeffrey, E.; Barends, R.; Chen, Y.; Roushan, P.; Fowler, A.; Sank, D.; White, T.; Campbell, B.; Chen, Z.; Chiaro, B.; Dunsworth, A.; Kelly, J.; Megrant, A.; Neill, C.; O'Malley, P. J. J.; Quintana, C.; Vainsencher, A.; Wenner, J.; Martinis, J. M.

    2015-03-01

    With the rapid growth of superconducting circuits quantum technology, a near quantum-limited amplifier at GHz frequency is needed to enable high fidelity measurements. We describe such an amplifier, the SQUID based, superconducting low inductance undulatory galvanometer (SLUG) amplifier. We measure the full scattering matrix of the SLUG. In particular, we measure both forward and reverse gain, as well as reflection. We see 15dB forward gain with added noise from one quanta to several quanta. The -1 dB compression point is around -95 dBm, about two orders of magnitude higher than that of typical Josephson parametric amplifiers. With these properties, SLUG is well suited for the high fidelity, simultaneous multiplexed readout of superconducting qubits.

  15. New Packaging for Amplifier Slabs

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thorsness, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suratwala, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Steele, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rogowski, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-18

    The following memo provides a discussion and detailed procedure for a new finished amplifier slab shipping and storage container. The new package is designed to maintain an environment of <5% RH to minimize weathering.

  16. A Transformer Class E Amplifier

    Directory of Open Access Journals (Sweden)

    Mikolajewski Miroslaw

    2014-12-01

    Full Text Available In a high-efficiency Class E ZVS resonant amplifier a matching and isolation transformer can replace some or even all inductive components of the amplifier thus simplifying the circuit and reducing its cost. In the paper a theoretical analysis, a design example and its experimental verification for a transformer Class E amplifier are presented. In the experimental amplifier with a transformer as the only inductive component in the circuit high efficiency ηMAX = 0.95 was achieved for supply voltage VI = 36 V, maximum output power POMAX = 100 W and the switching frequency f = 300 kHz. Measured parameters and waveforms showed a good agreement with theoretical predictions. Moreover, the relative bandwidth of the switching frequency was only 19% to obtain output power control from 4.8 W to POMAX with efficiency not less than 0.9 in the regulation range.

  17. TARC: Carlo Rubbia's Energy Amplifier

    CERN Multimedia

    Laurent Guiraud

    1997-01-01

    Transmutation by Adiabatic Resonance Crossing (TARC) is Carlo Rubbia's energy amplifier. This CERN experiment demonstrated that long-lived fission fragments, such as 99-TC, can be efficiently destroyed.

  18. A KIND OF NEW AMPLIFIER

    Institute of Scientific and Technical Information of China (English)

    YIN XUN-HE; FENG RU-PENG; REN YONG

    2000-01-01

    Chaotic characteristics in the iteration of logistic map (one-dimensional discrete dynamic system) are simulatedand analyzed. The circuit implementation of a kind of chaotic amplifier model is based on the chaotic characteristicsthat chaos is sensitively dependent on its initial conditions, and the circuit simulation result is given using simulationprogram with integrated circuit emphasis for personal computer (PSPICE), and is compared with linear amplifier.Advantages and disadvantages of such a model are indicated.

  19. Multi-wavelength fiber ring laser based on semiconductor optical amplifier and sampled fiber Bragg grating in a Sagnac loop interferometer%基于半导体光放大器和取样光纤光栅结合Sagnac环的多波长光纤激光器

    Institute of Scientific and Technical Information of China (English)

    冯素春; 许鸥; 鲁韶华; 宁提纲; 简水生

    2009-01-01

    Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.

  20. High-frequency isotopic analysis of liquid water samples in the field - initial results from continuous water sampling and cavity ring-down spectroscopy

    Science.gov (United States)

    von Freyberg, Jana; Studer, Bjørn; Kirchner, James

    2016-04-01

    Studying rapidly changing hydrochemical signals in catchments can help to improve our mechanistic understanding of their water flow pathways and travel times. For these purposes, stable water isotopes (18O and 2H) are commonly used as natural tracers. However, high-frequency isotopic analyses of liquid water samples are challenging. One must capture highly dynamic behavior with high precision and accuracy, but the lab workload (and sample storage artifacts) involved in collecting and analyzing thousands of bottled samples should also be avoided. Therefore, we have tested Picarro, Inc.'s newly developed Continuous Water Sampler Module (CoWS), which is coupled to their L2130-i Cavity Ring-Down Spectrometer to enable real-time on-line measurements of 18O and 2H in liquid water samples. We coupled this isotope analysis system to a dual-channel ion chomatograph (Metrohm AG, Herisau, Switzerland) for analysis of major cations and anions, as well as a UV-Vis spectroscopy system (s::can Messtechnik GmbH, Vienna, Austria) and electrochemical probes for characterization of basic water quality parameters. The system was run unattended for up to a week at a time in the laboratory and at a small catchment. At the field site, stream-water and precipitation samples were analyzed, alternating at sub-hourly intervals. We observed that measured isotope ratios were highly sensitive to the liquid water flow rate in the CoWS, and thus to the hydraulic head difference between the CoWS and the samples from which water was drawn. We used a programmable high-precision dosing pump to control the injection flow rate and eliminate this flow-rate artifact. Our experiments showed that the precision of the CoWS-L2130-i-system for 2-minute average values was typically better than 0.06‰ for δ18O and 0.16‰ for δ2H. Carryover effects were 1% or less between isotopically contrasting water samples for 30-minute sampling intervals. Instrument drift could be minimized through periodic analysis of

  1. Occurrence of Ditylenchus weischeri and Not D. dipsaci in Field Pea Harvest Samples and Cirsium arvense in the Canadian Prairies.

    Science.gov (United States)

    Tenuta, Mario; Madani, Mehrdad; Briar, Shabeg; Molina, Oscar; Gulden, Robert; Subbotin, Sergei A

    2014-12-01

    The stem nematode, a parasite of the herbaceous perennial weed, Cirsium arvense (L.) Scop. and identified as Ditylenchus dipsaci (Kühn) Filipjev, was reported in the Canadian prairies in 1979. Recently, D. weischeri Chizhov parasitizing Cirsium arvense was described in Russia, and it has been shown that this species is not an agricultural pest. In this study, we examined Ditylenchus species found in field pea (Pisum sativum L.) grain harvest samples in 2009 and 2010 and from C. arvense shoots in pea fields in the Saskatchewan, Alberta, and Manitoba provinces. Samples from 538 fields (mainly yellow pea) were provided by 151 growers throughout the main pea-growing area of the Canadian prairies. Of the samples collected, 2% were positive for Ditylenchus. The population density of the nematode ranged between 4 and 1,500 nematodes kg(-1) pea harvest sample and related to presence of C. arvense seeds. Positive samples occurred in 2009 but not in 2010 and were from throughout the pea-growing area of the Canadian prairies and not related to cropping history. C. arvense collected from yellow pea fields in Saskatchewan and Manitoba, but not Alberta, were infested with Ditylenchus. Morphological and molecular (ITS-PCR-RFLP) traits indicated that this species belongs to D. weischeri. The results indicated the stem nematode found in yellow pea grain is D. weischeri which resided with C. arvense seeds and debris to pea samples. Unlike D. dipsaci, D. weischeri is not a nematode pest of economic importance; therefore, its presence in the pea harvest samples was not a concern.

  2. An Importance Sampling Scheme for Models in a Strong External Field

    CERN Document Server

    Molkaraie, Mehdi

    2015-01-01

    We propose Monte Carlo methods to estimate the partition function of the two-dimensional Ising model in the presence of an external magnetic field. The estimation is done in the dual of the Forney factor graph representing the model. The proposed methods can efficiently compute an estimate of the partition function in a wide range of model parameters. As an example, we consider models that are in a strong external field.

  3. Backward Raman Amplifier for Laser Wakefield Accelerator

    Science.gov (United States)

    Ludwig, Joshua; Masson-Laborde, Paul-Edouard; Huller, Stefan; Rozmus, Wojciech; Wilks, Scott C.

    2016-10-01

    Particle in cell simulations via SCPIC and theoretical work on Raman amplification and laser wake field acceleration will be presented. Laser energy depletion has been shown to be a limiting factor during wake field acceleration. This work focuses on optimizing parameters for Raman amplification to work in conjunction with wake field acceleration in order in order to sustain an accelerating laser pulse as it generates plasma waves. It has been shown that laser pulses undergo red shifting during wake generation. Our work demonstrates that this red shifting results in a detuning between pump and seed in the backward Raman Amplifier. This detuning limits the amount of energy that can be transferred from the pump to the seed, and places new limits on backward Raman amplification. To overcome this limiting factor, this study makes use of a chirped pump allowing for extended coupling to the accelerating pulse. Three wave coupling model of Raman amplifier with a frequency shift term due to wake field will also be discussed and compared with PIC simulations.

  4. Amplified Dispersive Optical Tomography

    CERN Document Server

    Goda, Keisuke; Jalali, Bahram

    2008-01-01

    Optical coherence tomography (OCT) has proven to be a powerful technique for studying tissue morphology in ophthalmology, cardiology, and endomicroscopy. Its performance is limited by the fundamental trade-off between the imaging sensitivity and acquisition speed -- a predicament common in virtually all imaging systems. In this paper, we circumvent this limit by using distributed Raman post-amplification of the reflection from the sample. We combine the amplification with simultaneously performed dispersive Fourier transformation, a process that maps the optical spectrum into an easily measured time-domain waveform. The Raman amplification enables measurement of weak signals which are otherwise buried in noise. It extends the depth range without sacrificing the acquisition speed or causing damage to the sample. As proof of concept, single-shot imaging with 15 dB improvement in sensitivity at an axial scan rate of 36.6 MHz is demonstrated.

  5. Charge sensitive amplifies. The state of arts

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kunishiro [Clear Pulse Co., Tokyo (Japan)

    1996-07-01

    In the radiation detectors, signals are essentially brought with charges produced by radiation, then it is naturally the best way to use a charge sensitive amplifier (CSA) system to extract those signals. The CSA is thought to be the best amplifier suitable to almost all the radiation detectors, if neglecting economical points of view. The CSA has been only applied to special fields like radiation detection because the concept of `charges` is not so universal against the concepts of `voltage` and `current`. The CSA, however, is low in noise and a high speed amplifier and may be applicable not only to radiation measurement but also piezoelectric devices and also bolometers. In this article, noise in the CSA, basic circuit on the CSA, concepts of `equivalent noise charge` (ENC), a method for the ENC, and importance of the `open-loop gain` in the CSA to achieve better performance of it and how to realize in a practical CSA were described. And, characteristics on a counting rate of the CSA, various circuit used in the CSA, and CSAs which are commercially available at present and special purpose CSAs were also introduced. (G.K.)

  6. A GENERALIZED SAMPLING THEOREM OVER GALOIS FIELD DOMAINS FOR EXPERIMENTAL DESIGN

    Directory of Open Access Journals (Sweden)

    Yoshifumi Ukita

    2015-12-01

    Full Text Available In this paper, the sampling theorem for bandlimited functions over domains is generalized to one over ∏ domains. The generalized theorem is applicable to the experimental design model in which each factor has a different number of levels and enables us to estimate the parameters in the model by using Fourier transforms. Moreover, the relationship between the proposed sampling theorem and orthogonal arrays is also provided. KEY

  7. A novel low-E field coil to minimize heating of biological samples in solid-state multinuclear NMR experiments

    Science.gov (United States)

    Dillmann, Baudouin; Elbayed, Karim; Zeiger, Heinz; Weingertner, Marie-Catherine; Piotto, Martial; Engelke, Frank

    2007-07-01

    A novel coil, called Z coil, is presented. Its function is to reduce the strong thermal effects produced by rf heating at high frequencies. The results obtained at 500 MHz in a 50 μl sample prove that the Z coil can cope with salt concentrations that are one order of magnitude higher than in traditional solenoidal coils. The evaluation of the rf field is performed by numerical analysis based on first principles and by carrying out rf field measurements. Reduction of rf heating is probed with a DMPC/DHPC membrane prepared in buffers of increasing salt concentrations. The intricate correlation that exists between the magnetic and electric field is presented. It is demonstrated that, in a multiply tuned traditional MAS coil, the rf electric field E1 cannot be reduced without altering the rf magnetic field. Since the detailed distribution differs when changing the coil geometry, a comparison involving the following three distinct designs is discussed: (1) a regular coil of 5.5 turns, (2) a variable pitch coil with the same number of turns, (3) the new Z coil structure. For each of these coils loaded with samples of different salt concentrations, the nutation fields obtained at a certain power level provide a basis to discuss the impact of the dielectric and conductive losses on the rf efficiency.

  8. A novel low-E field coil to minimize heating of biological samples in solid-state multinuclear NMR experiments.

    Science.gov (United States)

    Dillmann, Baudouin; Elbayed, Karim; Zeiger, Heinz; Weingertner, Marie-Catherine; Piotto, Martial; Engelke, Frank

    2007-07-01

    A novel coil, called Z coil, is presented. Its function is to reduce the strong thermal effects produced by rf heating at high frequencies. The results obtained at 500MHz in a 50 microl sample prove that the Z coil can cope with salt concentrations that are one order of magnitude higher than in traditional solenoidal coils. The evaluation of the rf field is performed by numerical analysis based on first principles and by carrying out rf field measurements. Reduction of rf heating is probed with a DMPC/DHPC membrane prepared in buffers of increasing salt concentrations. The intricate correlation that exists between the magnetic and electric field is presented. It is demonstrated that, in a multiply tuned traditional MAS coil, the rf electric field E(1) cannot be reduced without altering the rf magnetic field. Since the detailed distribution differs when changing the coil geometry, a comparison involving the following three distinct designs is discussed: (1) a regular coil of 5.5 turns, (2) a variable pitch coil with the same number of turns, (3) the new Z coil structure. For each of these coils loaded with samples of different salt concentrations, the nutation fields obtained at a certain power level provide a basis to discuss the impact of the dielectric and conductive losses on the rf efficiency.

  9. Selectivity and limitations of carbon sorption tubes for capturing siloxanes in biogas during field sampling.

    Science.gov (United States)

    Tansel, Berrin; Surita, Sharon C

    2016-06-01

    Siloxane levels in biogas can jeopardize the warranties of the engines used at the biogas to energy facilities. The chemical structure of siloxanes consists of silicon and oxygen atoms, alternating in position, with hydrocarbon groups attached to the silicon side chain. Siloxanes can be either in cyclic (D) or linear (L) configuration and referred with a letter corresponding to their structure followed by a number corresponding to the number of silicon atoms present. When siloxanes are burned, the hydrocarbon fraction is lost and silicon is converted to silicates. The purpose of this study was to evaluate the adequacy of activated carbon gas samplers for quantitative analysis of siloxanes in biogas samples. Biogas samples were collected from a landfill and an anaerobic digester using multiple carbon sorbent tubes assembled in series. One set of samples was collected for 30min (sampling 6-L gas), and the second set was collected for 60min (sampling 12-L gas). Carbon particles were thermally desorbed and analyzed by Gas Chromatography Mass Spectrometry (GC/MS). The results showed that biogas sampling using a single tube would not adequately capture octamethyltrisiloxane (L3), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). Even with 4 tubes were used in series, D5 was not captured effectively. The single sorbent tube sampling method was adequate only for capturing trimethylsilanol (TMS) and hexamethyldisiloxane (L2). Affinity of siloxanes for activated carbon decreased with increasing molecular weight. Using multiple carbon sorbent tubes in series can be an appropriate method for developing a standard procedure for determining siloxane levels for low molecular weight siloxanes (up to D3). Appropriate quality assurance and quality control procedures should be developed for adequately quantifying the levels of the higher molecular weight siloxanes in biogas with sorbent tubes

  10. Field Sampling Plan for Closure of the Central Facilities Area Sewage Treatment Plant Lagoon 3 and Land Application Area

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Michael George [Idaho National Laboratory

    2016-10-01

    This field sampling plan describes sampling of the soil/liner of Lagoon 3 at the Central Facilities Area Sewage Treatment Plant. The lagoon is to be closed, and samples obtained from the soil/liner will provide information to determine if Lagoon 3 and the land application area can be closed in a manner that renders it safe to human health and the environment. Samples collected under this field sampling plan will be compared to Idaho National Laboratory background soil concentrations. If the concentrations of constituents of concern exceed the background level, they will be compared to Comprehensive Environmental Response, Compensation, and Liability Act preliminary remediation goals and Resource Conservation and Recovery Act levels. If the concentrations of constituents of concern are lower than the background levels, Resource Conservation and Recovery Act levels, or the preliminary remediation goals, then Lagoon 3 and the land application area will be closed. If the Resource Conservation and Recovery Act levels and/or the Comprehensive Environmental Response, Compensation, and Liability Act preliminary remediation goals are exceeded, additional sampling and action may be required.

  11. Local versus field scale soil heterogeneity characterization - a challenge for representative sampling in pollution studies

    Science.gov (United States)

    Kardanpour, Z.; Jacobsen, O. S.; Esbensen, K. H.

    2015-06-01

    This study is a contribution to development of a heterogeneity characterisation facility for "next generation" sampling aimed at more realistic and controllable pesticide variability in laboratory pots in experimental environmental contaminant assessment. The role of soil heterogeneity on quantification of a set of exemplar parameters, organic matter, loss on ignition (LOI), biomass, soil microbiology, MCPA sorption and mineralization is described, including a brief background on how heterogeneity affects sampling/monitoring procedures in environmental pollutant studies. The Theory of Sampling (TOS) and variographic analysis has been applied to develop a fit-for-purpose heterogeneity characterization approach. All parameters were assessed in large-scale profile (1-100 m) vs. small-scale (0.1-1 m) replication sampling pattern. Variographic profiles of experimental analytical results concludes that it is essential to sample at locations with less than a 2.5 m distance interval to benefit from spatial auto-correlation and thereby avoid unnecessary, inflated compositional variation in experimental pots; this range is an inherent characteristic of the soil heterogeneity and will differ among soils types. This study has a significant carrying-over potential for related research areas e.g. soil science, contamination studies, and environmental monitoring and environmental chemistry.

  12. EMI-resilient amplifier circuits

    CERN Document Server

    van der Horst, Marcel J; Linnenbank, André C

    2014-01-01

    This book enables circuit designers to reduce the errors introduced by the fundamental limitations and electromagnetic interference (EMI) in negative-feedback amplifiers.  The authors describe a systematic design approach for application specific negative-feedback amplifiers, with specified signal-to-error ratio (SER).  This approach enables designers to calculate noise, bandwidth, EMI, and the required bias parameters of the transistors used in  application specific amplifiers in order to meet the SER requirements.   ·         Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers; ·         Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements; ·         Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detr...

  13. Comparison and Field Validation of Binomial Sampling Plans for Oligonychus perseae (Acari: Tetranychidae) on Hass Avocado in Southern California.

    Science.gov (United States)

    Lara, Jesus R; Hoddle, Mark S

    2015-08-01

    Oligonychus perseae Tuttle, Baker, & Abatiello is a foliar pest of 'Hass' avocados [Persea americana Miller (Lauraceae)]. The recommended action threshold is 50-100 motile mites per leaf, but this count range and other ecological factors associated with O. perseae infestations limit the application of enumerative sampling plans in the field. Consequently, a comprehensive modeling approach was implemented to compare the practical application of various binomial sampling models for decision-making of O. perseae in California. An initial set of sequential binomial sampling models were developed using three mean-proportion modeling techniques (i.e., Taylor's power law, maximum likelihood, and an empirical model) in combination with two-leaf infestation tally thresholds of either one or two mites. Model performance was evaluated using a robust mite count database consisting of >20,000 Hass avocado leaves infested with varying densities of O. perseae and collected from multiple locations. Operating characteristic and average sample number results for sequential binomial models were used as the basis to develop and validate a standardized fixed-size binomial sampling model with guidelines on sample tree and leaf selection within blocks of avocado trees. This final validated model requires a leaf sampling cost of 30 leaves and takes into account the spatial dynamics of O. perseae to make reliable mite density classifications for a 50-mite action threshold. Recommendations for implementing this fixed-size binomial sampling plan to assess densities of O. perseae in commercial California avocado orchards are discussed.

  14. Separation and characterization of nanoparticles in complex food and environmental samples by field-flow fractionation

    DEFF Research Database (Denmark)

    Kammer, Frank von der; Legros, Samuel; Hofmann, Thilo

    2011-01-01

    The thorough analysis of natural nanoparticles (NPs) and engineered NPs involves the sequence of detection, identification, quantification and, if possible, detailed characterization. In a complex or heterogeneous sample, each step of this sequence is an individual challenge, and, given suitable...... has been applied for separation of various types of NP (e.g., organic macromolecules, and carbonaceous or inorganic NPs) in different types of media (e.g., natural waters, soil extracts or food samples).FFF can be coupled to different types of detectors that offer additional information...

  15. Time resolved X-ray Dark-Field Tomography Revealing Water Transport in a Fresh Cement Sample.

    Science.gov (United States)

    Prade, Friedrich; Fischer, Kai; Heinz, Detlef; Meyer, Pascal; Mohr, Jürgen; Pfeiffer, Franz

    2016-06-30

    Grating-based X-ray dark-field tomography is a promising technique for biomedical and materials research. Even if the resolution of conventional X-ray tomography does not suffice to resolve relevant structures, the dark-field signal provides valuable information about the sub-pixel microstructural properties of the sample. Here, we report on the potential of X-ray dark-field imaging to be used for time-resolved three-dimensional studies. By repeating consecutive tomography scans on a fresh cement sample, we were able to study the hardening dynamics of the cement paste in three dimensions over time. The hardening of the cement was accompanied by a strong decrease in the dark-field signal pointing to microstructural changes within the cement paste. Furthermore our results hint at the transport of water from certain limestone grains, which were embedded in the sample, to the cement paste during the process of hardening. This is indicated by an increasing scattering signal which was observed for two of the six tested limestone grains. Electron microscopy images revealed a distinct porous structure only for those two grains which supports the following interpretation of our results. When the water filled pores of the limestone grains empty during the experiment the scattering signal of the grains increases.

  16. Time resolved X-ray Dark-Field Tomography Revealing Water Transport in a Fresh Cement Sample

    Science.gov (United States)

    Prade, Friedrich; Fischer, Kai; Heinz, Detlef; Meyer, Pascal; Mohr, Jürgen; Pfeiffer, Franz

    2016-06-01

    Grating-based X-ray dark-field tomography is a promising technique for biomedical and materials research. Even if the resolution of conventional X-ray tomography does not suffice to resolve relevant structures, the dark-field signal provides valuable information about the sub-pixel microstructural properties of the sample. Here, we report on the potential of X-ray dark-field imaging to be used for time-resolved three-dimensional studies. By repeating consecutive tomography scans on a fresh cement sample, we were able to study the hardening dynamics of the cement paste in three dimensions over time. The hardening of the cement was accompanied by a strong decrease in the dark-field signal pointing to microstructural changes within the cement paste. Furthermore our results hint at the transport of water from certain limestone grains, which were embedded in the sample, to the cement paste during the process of hardening. This is indicated by an increasing scattering signal which was observed for two of the six tested limestone grains. Electron microscopy images revealed a distinct porous structure only for those two grains which supports the following interpretation of our results. When the water filled pores of the limestone grains empty during the experiment the scattering signal of the grains increases.

  17. Geologic Field Notes, Geochemical Analyses, and Field Photographs of Outcrops and Rock Samples from the Big Delta B-1 Quadrangle, East-Central Alaska

    Science.gov (United States)

    Day, Warren C.; O'Neill, J. Michael

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Alaska Department of Natural Resources Division of Mining, Land, and Water, has released a geologic map of the Big Delta B-1 quadrangle of east-central Alaska (Day and others, 2007). This companion report presents the major element oxide and trace element geochemical analyses, including those for gold, silver, and base metals, for representative rock units and for grab samples from quartz veins and mineralized zones within the quadrangle. Also included are field station locations, field notes, structural data, and field photographs based primarily on observations by W.C. Day with additions by J.M. O'Neill and B.M. Gamble, all of the U.S. Geological Survey. The data are provided in both Microsoft Excel spread sheet format and as a Microsoft Access database.

  18. Distribution of the Iberian Wolf (Canis lupus signatus in Galicia (NW Spain: Concordance Between Field Sampling and Questionnaires

    Directory of Open Access Journals (Sweden)

    P. Núñez-Quirós

    2009-06-01

    Full Text Available The information about wolf presence in Galicia (NW Spain obtained from questionnaires sent to wildlife rangers (163 with a 59.50% response and huntig associations (629 with a 28.29% response is compared to that obtained from field sampling involving the surveying of 305 UTM 10x10 km squares. The data were recorded as presence/non-presence in UTM 10x10 km squares. Wildlife rangers provided information on wolf presence in 58.03% of squares, Hunter’s Associations in 52.13% and field sampling in 63.60%. The three sources of information differed with respect to the number of grids with wolf presence/non-presence. The overall percentage of concordance (presence/non-presence between sampling and questionnaires was 70.16%. Concordance between field sampling and questionnaires was 85,57% for wolf presence and only 43,24% for wolf non-presence. Although the present results suggest that questionnaires provide reliable information in areas where wolves have usually been present, they may leed to overestimation of wolf presence on humanised land and underestimation in areas near provincial boundaries.

  19. Low-noise amplifier

    Directory of Open Access Journals (Sweden)

    V. B. Gulkov

    2012-11-01

    Full Text Available The mixture of signal and noise processing device is considered in this article. It contains two channels: the main channel (MC contains the mixture of signal and noise, and compensation channel (CC that extracts just a noise from the mixture. The feature of the processing circuit is that the mixture samples are formed by short impulses at the moments of passing signal through zero. Further antiphase noise is set in the channels, adder by which the noise is removed from mixture is set on the cannels output. Study of the described device was carried out for simulated AM signal and white Gaussian noise in simulation environment Matlab. The results are shown, that device reduces noise by 16 dB of power.

  20. Limit circuit prevents overdriving of operational amplifier

    Science.gov (United States)

    Openshaw, F. L.

    1967-01-01

    Cutoff-type high gain amplifier coupled by a diode prevents overdriving of operational amplifier. An amplified feedback signal offsets the excess input signal that tends to cause the amplifier to exceed its preset limit. The output is, therfore, held to the set clamp level.

  1. DSM-5 field trials in the United States and Canada, Part I: study design, sampling strategy, implementation, and analytic approaches.

    Science.gov (United States)

    Clarke, Diana E; Narrow, William E; Regier, Darrel A; Kuramoto, S Janet; Kupfer, David J; Kuhl, Emily A; Greiner, Lisa; Kraemer, Helena C

    2013-01-01

    This article discusses the design,sampling strategy, implementation,and data analytic processes of the DSM-5 Field Trials. The DSM-5 Field Trials were conducted by using a test-retest reliability design with a stratified sampling approach across six adult and four pediatric sites in the United States and one adult site in Canada. A stratified random sampling approach was used to enhance precision in the estimation of the reliability coefficients. A web-based research electronic data capture system was used for simultaneous data collection from patients and clinicians across sites and for centralized data management.Weighted descriptive analyses, intraclass kappa and intraclass correlation coefficients for stratified samples, and receiver operating curves were computed. The DSM-5 Field Trials capitalized on advances since DSM-III and DSM-IV in statistical measures of reliability (i.e., intraclass kappa for stratified samples) and other recently developed measures to determine confidence intervals around kappa estimates. Diagnostic interviews using DSM-5 criteria were conducted by 279 clinicians of varied disciplines who received training comparable to what would be available to any clinician after publication of DSM-5.Overall, 2,246 patients with various diagnoses and levels of comorbidity were enrolled,of which over 86% were seen for two diagnostic interviews. A range of reliability coefficients were observed for the categorical diagnoses and dimensional measures. Multisite field trials and training comparable to what would be available to any clinician after publication of DSM-5 provided “real-world” testing of DSM-5 proposed diagnoses.

  2. X-ray spectral properties of the AGN sample in the northern XMM-XXL field

    CERN Document Server

    Liu, Zhu; Georgakakis, Antonis; Menzel, Marie-Luise; Buchner, Johannes; Nandra, Kirpal; Salvato, Mara; Shen, Yue; Brusa, Marcella; Streblyanska, Alina

    2016-01-01

    In this paper we describe and publicly release a catalogue consisting of 8445 point-like X-ray sources detected in the XMM-XXL north survey. For the 2512 AGN which have reliable spectroscopy, we present the X-ray spectral fitting which has been computed with a Bayesian approach. We have also applied an X-ray spectral stacking method to different sub-samples. We confirm the well-known Iwasawa-Taniguchi effect in our luminosity-redshift sub-samples, and argue that such an effect is due to a decrease in the covering factor of a distant obscuring torus with increasing X-ray luminosity. By comparing the distribution of the reflection fraction, the ratio of the normalization of the reflected component to the direct radiation, we find that the low-luminosity, low-redshift sub-sample had systematically higher reflection fraction values than the high-redshift, high-luminosity one. On the other hand, no significant difference is found between samples having similar luminosity but different redshift, suggesting that the...

  3. Amplified graph C*-algebras

    CERN Document Server

    Eilers, Søren; Sørensen, Adam P W

    2011-01-01

    We provide a complete invariant for graph C*-algebras which are amplified in the sense that whenever there is an edge between two vertices, there are infinitely many. The invariant used is the standard primitive ideal space adorned with a map into {-1,0,1,2,...}, and we prove that the classification result is strong in the sense that isomorphisms at the level of the invariant always lift. We extend the classification result to cover more graphs, and give a range result for the invariant (in the vein of Effros-Handelman-Shen) which is further used to prove that extensions of graph C*-algebras associated to amplified graphs are again graph C*-algebras of amplified graphs.

  4. Capacitively-coupled chopper amplifiers

    CERN Document Server

    Fan, Qinwen; Huijsing, Johan H

    2017-01-01

    This book describes the concept and design of the capacitively-coupled chopper technique, which can be used in precision analog amplifiers. Readers will learn to design power-efficient amplifiers employing this technique, which can be powered by regular low supply voltage such as 2V and possibly having a +\\-100V input common-mode voltage input. The authors provide both basic design concepts and detailed design examples, which cover the area of both operational and instrumentation amplifiers for multiple applications, particularly in power management and biomedical circuit designs. Discusses basic working principles and details of implementation for proven designs; Includes a diverse set of applications, along with measurement results to demonstrate the effectiveness of the technique; Explains advantages and drawbacks of the technique, given particular circumstances.

  5. Determination of extremely low (236)U/(238)U isotope ratios in environmental samples by sector-field inductively coupled plasma mass spectrometry using high-efficiency sample introduction.

    Science.gov (United States)

    Boulyga, Sergei F; Heumann, Klaus G

    2006-01-01

    A method by inductively coupled plasma mass spectrometry (ICP-MS) was developed which allows the measurement of (236)U at concentration ranges down to 3 x 10(-14)g g(-1) and extremely low (236)U/(238)U isotope ratios in soil samples of 10(-7). By using the high-efficiency solution introduction system APEX in connection with a sector-field ICP-MS a sensitivity of more than 5,000 counts fg(-1) uranium was achieved. The use of an aerosol desolvating unit reduced the formation rate of uranium hydride ions UH(+)/U(+) down to a level of 10(-6). An abundance sensitivity of 3 x 10(-7) was observed for (236)U/(238)U isotope ratio measurements at mass resolution 4000. The detection limit for (236)U and the lowest detectable (236)U/(238)U isotope ratio were improved by more than two orders of magnitude compared with corresponding values by alpha spectrometry. Determination of uranium in soil samples collected in the vicinity of Chernobyl nuclear power plant (NPP) resulted in that the (236)U/(238)U isotope ratio is a much more sensitive and accurate marker for environmental contamination by spent uranium in comparison to the (235)U/(238)U isotope ratio. The ICP-MS technique allowed for the first time detection of irradiated uranium in soil samples even at distances more than 200 km to the north of Chernobyl NPP (Mogilev region). The concentration of (236)U in the upper 0-10 cm soil layers varied from 2 x 10(-9)g g(-1) within radioactive spots close to the Chernobyl NPP to 3 x 10(-13)g g(-1) on a sampling site located by >200 km from Chernobyl.

  6. Radionuclide Determination In Surface Water Samples By Inductively Coupled Plasma With Sector Field Mass Spectrometry (ICP-SFMS

    Directory of Open Access Journals (Sweden)

    E. T. Romero-Guzmán

    2016-08-01

    Full Text Available The determination of naturally occurring radionuclides in the environment by inductively coupled plasma mass spectrometry of high resolution (ICP-SFMS has gained recognition over the last fifteen years, relative to the radiometric techniques, as the result of improvement in instrumental performance, sample introduction equipment and sample preparation. With the increase in instrumental sensitivity, it is now possible to measure ultratrace levels of many radioisotopes. The aim of this work was to determined the natural radionuclides (232Th, 234U, 235U and 238U in surface water using Inductively Coupled PlasmaSector Field Mass Spectrometry (ICP-SFMS. The samples were sampling from Lerma river, State of Mexico at february to april 2015. The process of treatment of sample consisted in perform an acid digestion according to the 3015A USEPA method followed of the direct measurement in ICP-SFMS. Results obtained were: a identify the presence of 232Th, 234U, 235U and 238U isotopes in water, b isotopic ratios were for 234U/238U=1.133 ± 0.016. ICPSFMS has gained popularity in the field of radiochemistry, particularly as a method of detection for long lived-actinides.

  7. Television-optical operational amplifier.

    Science.gov (United States)

    Goetz, J; Häusler, G; Sesselmann, R

    1979-08-15

    The advantages of negative feedback are well known in electronics and extensively used in the operational amplifier. The properties of such a system are nearly independent of the parameters in the forward branch of the system; they are only determined by external elements in the backward branch. An optical analog of such an operational amplifier is reported. The essential operations, amplifications, and inversion of the circulating signals are carried out using a TV system. The capability of the system to compensate for spatial inhomogeneities and for nonlinearities is demonstrated. In addition, the system is able to create the inverse of a transfer function located in the feedback branch.

  8. Maximizing the chances of detecting pathogenic leptospires in mammals: the evaluation of field samples and a multi-sample-per-mammal, multi-test approach.

    Science.gov (United States)

    Tulsiani, S M; Graham, G C; Dohnt, M F; Burns, M-A; Craig, S B

    2011-03-01

    Identification of wild animals that harbour the causative leptospires, and the identification of the most important of these 'wild reservoirs' (in terms of threat to human health), are key factors in the epidemiology of human leptospirosis. In an epidemiological investigation in the Australian state of Queensland, in 2007-2008, samples were collected from fruit bats (Pteropus conspicillatus) and rodents (to investigate the potential role of fruit bats in the maintenance and transmission of leptospires to ground-dwelling rodents) and checked for pathogenic leptospires. The results of these studies have now been carefully analysed in attempts to see which method of detection and type of test sample were best. The effects of pentobarbitone sodium used to euthanize wild mammals before collection of necropsy samples, on the survival and detection of leptospires in vitro, were also explored. In the earlier field investigation, serum, renal tissue and urine were collected from wild mammals, for the detection of pathogenic leptospires by culture, the microscopic agglutination test (MAT), real-time PCR and silver impregnation of smears. Although 27.6% of the rodents investigated were found leptospire-positive, culture only yielded four isolates, probably because many cultures were contaminated. The main aims of the present study were to quantify the performance of the individual diagnostic tests and examine the reasons behind the high incidence of culture contamination. The results of sensitivity and specificity analyses for the different diagnostic tests indicated that isolation by culture (the definitive diagnostic test for leptospiral shedding) had perfect (100%) sensitivity when compared with the results of the PCR but a low specificity (40%). The MAT performed poorly, with a sensitivity of 50% when compared against the results of culture. The prevalence of leptospiral carriage revealed by the PCR-based investigation of kidney and urine samples (59.2%) was higher than

  9. Laboratory and field testing of bednet traps for mosquito (Diptera: Culicidae) sampling in West Java, Indonesia.

    Science.gov (United States)

    Stoops, Craig A; Gionar, Yoyo R; Rusmiarto, Saptoro; Susapto, Dwiko; Andris, Heri; Elyazar, Iqbal R F; Barbara, Kathryn A; Munif, Amrul

    2010-06-01

    Surveillance of medically important mosquitoes is critical to determine the risk of mosquito-borne disease transmission. The purpose of this research was to test self-supporting, exposure-free bednet traps to survey mosquitoes. In the laboratory we tested human-baited and unbaited CDC light trap/cot bednet (CDCBN) combinations against three types of traps: the Mbita Trap (MIBITA), a Tent Trap (TENT), and a modified Townes style Malaise trap (TSM). In the laboratory, 16 runs comparing MBITA, TSM, and TENT to the CDCBN were conducted for a total of 48 runs of the experiment using 13,600 mosquitoes. The TENT trap collected significantly more mosquitoes than the CDCBN. The CDCBN collected significantly more than the MBITA and there was no difference between the TSM and the CDCBN. Two field trials were conducted in Cibuntu, Sukabumi, West Java, Indonesia. The first test compared human-baited and unbaited CDCBN, TENT, and TSM traps during six nights over two consecutive weeks per month from January, 2007 to September, 2007 for a total of 54 trapnights. A total of 8,474 mosquitoes representing 33 species were collected using the six trapping methods. The TENT-baited trap collected significantly more mosquitoes than both the CDCBN and the TSM. The second field trial was a comparison of the baited and unbaited TENT and CDCBN traps and Human Landing Collections (HLCs). The trial was carried out from January, 2008 to May, 2008 for a total of 30 trap nights. A total of 11,923 mosquitoes were collected representing 24 species. Human Landing Collections captured significantly more mosquitoes than either the TENT or the CDCBN. The baited and unbaited TENT collected significantly more mosquitoes than the CDCBN. The TENT trap was found to be an effective, light-weight substitute for the CDC light-trap, bednet combination in the field and should be considered for use in surveys of mosquito-borne diseases such as malaria, arboviruses, and filariasis.

  10. Drilling, Sampling, and Well-Installation Plan for the IFC Well Field, 300 Area

    Energy Technology Data Exchange (ETDEWEB)

    Bjornstad, Bruce N.; Horner, Jacob A.

    2008-05-05

    The 300 Area was selected as a location for an IFC because it offers excellent opportunities for field research on the influence of mass-transfer processes on uranium in the vadose zone and groundwater. The 300 Area was the location of nuclear fuel fabrication facilities and has more than 100 waste sites. Two of these waste sites, the North and South Process Ponds received large volumes of process waste from 1943 to 1975 and are thought to represent a significant source of the groundwater uranium plume in the 300 Area. Geophysical surveys and other characterization efforts have led to selection of the South Process Pond for the IFC.

  11. Field applications of the second-generation Environmental Sample Processor (ESP) for remote detection of harmful algae: 2006-2007

    OpenAIRE

    Greenfield, Dianne I.; Marin III, Roman; Doucette, Gregory J.; Mikulski, Christina; Jones, Kelly; Jensen, Scott; Roman, Brent; Alvarado, Nilo; Feldman, Jason; Scholin, Chris

    2008-01-01

    We assess the application of the second-generation Environmental Sample Processor (ESP) for the detection of harmful algal bloom (HAB) species in field and laboratory settings using two molecular probe techniques: a sandwich hybridization assay (SHA) and fluorescent in situ hybridization (FISH). During spring 2006, the first time this new instrument was deployed, the ESP successfully automated application of DNA probe arrays for various HAB species and other planktonic taxa, but non-specific ...

  12. Magnetic Fields of Be Stars: Preliminary Results from a Hybrid Analysis of the MiMeS Sample

    Science.gov (United States)

    Wade, G. A.; Petit, V.; Grunhut, J. H.; Neiner, C.; MiMeS Collaboration

    2016-11-01

    In the context of the MiMeS survey of magnetism in massive stars, 85 classical Be stars were observed in circular polarization with the aim of detecting magnetic fields at their surfaces. No direct evidence of such fields is found, in contrast to the significant rate of detection (5-10%) in non-Be B-type stars. In this paper we describe the sample properties, the methodology and the data quality. We describe a novel method, previously applied to Herbig Ae/Be stars, that allows us to infer upper limits on organized (dipolar) magnetic fields present in the photospheres of our targets. We review the characteristics and robustness of this null result, and discuss its implications.

  13. Field and Lab Methods to Reduce Sampling Variation in Soil Carbon

    Science.gov (United States)

    Mattson, K. G.; Zhang, J.

    2015-12-01

    Natural variability in soil and detrital carbon sampling is typically large enough that it hinders accurate assessment of standing stock and changes that may occur following disturbances and experimental treatments. We are developing carbon budgets in forests of Northern California and wish to see how experimental canopy thinning may affect carbon cycling in these forests. In the pre-treatment phase, we have sought methods to quantify detrital carbon pools in an accurate and efficient manner. We have found that small soil excavations 15 cm diameter to a depth of 10 cm work very well to reduce variation an avoid introducing sampling biases. We excavate a pit carefully of uniform dimensions using cutting chisels and scoops. We fill the void created using small pebbles contained in a small net and then weigh the pebbles to obtain a volume estimate of the soil collected. The samples are sorted moist through a series of sieves of 6, 4, and 2 mm into rocks, live roots, dead roots, woody debris, and remaining soil and its organic matter. From a single sample, we estimate proportional rock volume, fine soil bulk density (soil bulk density of the 2 mm fraction), live roots, dead roots, woody debris, and proportion of organic matter in the 2 mm fraction. The standard deviations of soil measures (soil carbon, loss on ignition, bulk density, rock volume, live and dead root mass) were universally reduced over similar measures by soil corers, in some instances by up to 5-fold. Coefficient of variation using excavation pits are typically 5 to 10 %, whereas cores were 20 to 30 %. We have observed that variation in soil organic matter is more a function of variation in soil bulk density than with variation in percent soil organic matter content. As a result, we often see increased soil organic matter stores at depths below 10 cm. Soils beneath highly decayed logs show increases in soil carbon in the mineral soil suggesting woody debris is a source of soil carbon. Below

  14. Detection of pesticides residues in water samples from organic and conventional paddy fields of Ledang, Johor, Malaysia

    Science.gov (United States)

    Abdullah, Md Pauzi; Othman, Mohamed Rozali; Ishak, Anizan; Nabhan, Khitam Jaber

    2016-11-01

    Pesticides have been used extensively by the farmers in Malaysia during the last few decades. Sixteen water samples, collected from paddy fields both organic and conventional, from Ledang, Johor, were analyzed to determine the occurrence and distribution of organochlorine (OCPs) and organophosphorus (OPPs) pesticide residues. GC-ECD instrument was used to identify and determine the concentrations of these pesticide residues. Pesticide residues were detected in conventional fields in the range about 0.036-0.508 µg/L higher than detected in organic fields about 0.015-0.428 µg/L. However the level of concentration of pesticide residues in water sample from both paddy fields are in the exceed limit for human consumption, according to European Economic Commission (EEC) (Directive 98/83/EC) at 0.1 µg/L for any pesticide or 0.5 µg/L for total pesticides. The results that the organic plot is still contaminated with pesticides although pesticides were not use at all in plot possibly from historical used as well as from airborne contamination.

  15. Biocompatible channels for field-flow fractionation of biological samples: correlation between surface composition and operating performance.

    Science.gov (United States)

    Roda, Barbara; Cioffi, Nicola; Ditaranto, Nicoletta; Zattoni, Andrea; Casolari, Sonia; Melucci, Dora; Reschiglian, Pierluigi; Sabbatini, Luigia; Valentini, Antonio; Zambonin, Pier Giorgio

    2005-02-01

    Biocompatible methods capable of rapid purification and fractionation of analytes from complex natural matrices are increasingly in demand, particularly at the forefront of biotechnological applications. Field-flow fractionation is a separation technique suitable for nano-sized and micro-sized analytes among which bioanalytes are an important family. The objective of this preliminary study is to start a more general approach to field-flow fractionation for bio-samples by investigation of the correlation between channel surface composition and biosample adhesion. For the first time we report on the use of X-ray photoelectron spectroscopy (XPS) to study the surface properties of channels of known performance. By XPS, a polar hydrophobic environment was found on PVC material commonly used as accumulation wall in gravitational field-flow fractionation (GrFFF), which explains the low recovery obtained when GrFFF was used to fractionate a biological sample such as Staphylococcus aureus. An increase in separation performance was obtained first by conditioning the accumulation wall with bovine serum albumin and then by using the ion-beam sputtering technique to cover the GrFFF channel surface with a controlled inert film. XPS analysis was also employed to determine the composition of membranes used in hollow-fiber flow field-flow fractionation (HF FlFFF). The results obtained revealed homogeneous composition along the HF FlFFF channel both before and after its use for fractionation of an intact protein such as ferritin.

  16. Qualitative analysis of SBS modifier in asphalt pavements using field samples

    Science.gov (United States)

    Chi, Fengxia; Liu, Zhifei

    2017-06-01

    Series of tests are implemented to analysis the related characteristics of common asphalt and unknown asphalt mainly using Fourier Transform Infrared (FTIR) and Dynamic Shear Rheometer (DSR) for chemical compositions and rheological properties of asphalt, respectively. In addition, a series of mechanical properties were performed on asphalt mixtures, including indirect tensile strength test and three point bending test at low temperature. Experimental results indicated that compared with common asphalt, the characteristic absorption peak of the unknown asphalt are appeared at 966cm-1and 699cm-1, which are accordant with the SBS modifier. The results of DSR indicated that the unknown asphalt’s complex modulus is higher and the phase angle is lower. The mechanical tests indicated that some properties of the unknown mixture samples are increased by 24.7%∼41.8% compared with common pavement sample, like the indirect tensile strength, the bending test at low temperature and indirect tensile resilient modulus. Comprehensive analysis indicates that SBS modifier is existed in the unknown asphalt pavement.

  17. Water adsorption at high temperature on core samples from The Geysers geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1998-06-01

    The quantity of water retained by rock samples taken from three wells located in The Geysers geothermal reservoir, California, was measured at 150, 200, and 250 C as a function of pressure in the range 0.00 {le} p/p{sub 0} {le} 0.98, where p{sub 0} is the saturated water vapor pressure. Both adsorption (increasing pressure) and desorption (decreasing pressure) runs were made in order to investigate the nature and the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were performed on the same rock samples. Nitrogen or krypton adsorption and desorption isotherms at 77 K were used to obtain BET specific surface areas, pore volumes and their distributions with respect to pore sizes. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A qualitative correlation was found between the surface properties obtained from nitrogen adsorption and the mineralogical and petrological characteristics of the solids. However, there is in general no proportionality between BET specific surface areas and the capacity of the rocks for water adsorption at high temperatures. The results indicate that multilayer adsorption rather than capillary condensation is the dominant water storage mechanism at high temperatures.

  18. Thermal recovery of NIF amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, S.; Marshall, C.; Petty, C.; Smith, L.; van Wonterghem, B.; Mills, S.

    1997-02-01

    The issue of thermal recovery of the NIF amplifiers has taken on increased emphasis as program goals move toward increasing the shot rate to once every four hours. This paper addresses the technical issues associated with achieving thermal recovery in the NIF amplifiers. We identify two temperature related thermal recovery quantities: (1) the difference between the average slab temperature and the temperature of other surfaces in the amplifier cavity, and (2) the temperature difference in the slab over the aperture. The first quantity relates to optical disturbances in the gas column in the system, while the second quantity is associated with optical aberrations in the laser media itself. Calculations and experiments are used to quantify recovery criteria, and develop cooling approaches. The cooling approaches discussed are (1) active cooling of the flashlamps with ambient gas and chilled gas, and (2) active cooling of the slab edge cladding. Calculations indicate that the NIF baseline cooling approach of 20 cfm per lamp ambient temperature gas flow in both the central and side flashlamp cassettes is capable of meeting thermal recovery requirements for an 8 hour shot period, while to achieve a 4 hour shot period requires use of chilled gas and edge cladding cooling. In addition, the effect of changing the amplifier cavity and beamtube fill gas from nitrogen to helium is addressed, showing that a factor of 8 reduction in the sensitivity to thermal disturbances is possible. 6 refs., 9 figs., 1 tab.

  19. Dielectric waveguide amplifiers and lasers

    NARCIS (Netherlands)

    Pollnau, Markus

    The performance of semiconductor amplifiers and lasers has made them the preferred choice for optical gain on a micro-chip. In the past few years, we have demonstrated that also rare-earth-ion-doped dielectric waveguides show remarkable performance, ranging from a small-signal gain per unit length

  20. On-field measurement trial of 4×128 Gbps PDM-QPSK signals by linear optical sampling

    Science.gov (United States)

    Bin Liu; Wu, Zhichao; Fu, Songnian; Feng, Yonghua; Liu, Deming

    2017-02-01

    Linear optical sampling is a promising characterization technique for advanced modulation formats, together with digital signal processing (DSP) and software-synchronized algorithm. We theoretically investigate the acquisition of optical sampling, when the high-speed signal under test is either periodic or random. Especially, when the profile of optical sampling pulse is asymmetrical, the repetition frequency of sampling pulse needs careful adjustment in order to obtain correct waveform. Then, we demonstrate on-field measurement trial of commercial four-channel 128 Gbps polarization division multiplexing quadrature phase shift keying (PDM-QPSK) signals with truly random characteristics by self-developed equipment. A passively mode-locked fiber laser (PMFL) with a repetition frequency of 95.984 MHz is used as optical sampling source, meanwhile four balanced photo detectors (BPDs) with 400 MHz bandwidth and four-channel analog-to-digital convertor (ADC) with 1.25 GS/s sampling rate are used for data acquisition. The performance comparison with conventional optical modulation analyzer (OMA) verifies that the self-developed equipment has the advantages of low cost, easy implementation, and fast response.

  1. It's about time; Repeated field sampling and flexible UAV platforms for a changing globe

    Science.gov (United States)

    Crutsinger, G.

    2015-12-01

    Unmanned Aerial Vehicles (UAVs) are quickly being adopted across the field sciences and will revolutionizing the speed and spatial scale of data collection. As a result, UAVs will alleviate much of the burden placed on boots-on-the-ground researchers as they seek to address fundamental scientific questionsa ssociated with global change. Concurrently, UAVs will initiate a rapid rise in time-series data, whether from monitoring weather patterns, measuring shifts in phenology due to a warming temperatures, or tracking range expansion and contraction of species. The challenges within the scientific community will be in the standardization of data collection, protocol sharing, and data management. The emergence of flexible aerial platforms within the commercial UAV space with multiple sensor configurations, open software application development, and cloud-based services should do much to address these challenges, but only if there is close collaboration between the industry and academic research partners.

  2. Hausdorff-type Measures of the Sample Path of Gaussian Random Fields

    Institute of Scientific and Technical Information of China (English)

    Zhen-long Chen; San-yang Liu

    2005-01-01

    Let φ be a Hausdorff measure function and ∧ be an infinite increasing sequence of positive integers.The Hausdorff-type measure φ - m∧ associated to φ and ∧ is studied. Let X(t)(t ∈ RN) be certain Gaussian random fields in Rd. We give the exact Hausdorff measure of the graph set GrX([0, 1]N), and evaluate the exact φ - m∧ measure of the image and graph set of X(t). A necessary and sufficient condition on the sequence ∧ is given so that the usual Hausdorff measure function for X([0, 1]N) and GrX([0,1]N) are still the correct measure functions. If the sequence ∧ increases faster, then some smaller measure functions will give positive and finite (φ, ∧)-Hausdorff measure for X([0, 1]N) and GTX([0, 1]N).

  3. Field Sampling Plan for the Operable Units 6-05 and 10-04 Remedial Action, Phase IV

    Energy Technology Data Exchange (ETDEWEB)

    R. Wells

    2006-11-14

    This Field Sampling Plan outlines the collection and analysis of samples in support of Phase IV of the Waste Area Group 10, Operable Units 6-05 and 10-04 remedial action. Phase IV addresses the remedial actions to areas with the potential for unexploded ordnance at the Idaho National Laboratory Site. These areas include portions of the Naval Proving Ground, the Arco High-Altitude Bombing Range, and the Twin Buttes Bombing Range. The remedial action consists of removal and disposal of ordnance by high-order detonation, followed by sampling to determine the extent, if any, of soil that might have been contaminated by the detonation activities associated with the disposal of ordnance during the Phase IV activities and explosives during the Phase II activities.

  4. Two-photon luminescence contrast by tip-sample coupling in femtosecond near-field optical microscopy

    Science.gov (United States)

    Horneber, Anke; Wackenhut, Frank; Braun, Kai; Wang, Xiao; Wang, Jiyong; Zhang, Dai; Meixner, Alfred J.

    2017-01-01

    We investigate the role of tip-sample interaction in nonlinear optical scanning near-field microscopy. The experiment was performed by tightly focusing femtosecond laser pulses onto a sharp gold tip that was positioned in close proximity to the surface of a sample with gold nanostructures on a Si-substrate by shear force feedback. The nonlinear optical signal consists of two-photon photoluminescence and second harmonic signal from the gold tip and the gold nanostructures. These signals can be used to characterize different coupling parameters such as geometry, material and width of the tip-sample gap and enable to reveal the mechanism responsible for the image contrast. Under the excitation with 776-nm and 110-fs laser pulses nonlinear imaging is almost background free and yields super resolution showing features with dimensions significantly below the diffraction limit with a signal intensity following quadratic excitation power law.

  5. Utilization of 100 mb midlatitude height fields as an indicator of sampling effects on total ozone variations

    Science.gov (United States)

    Miller, A. J.; Nagatani, R. M.; Laver, J. D.; Korty, B.

    1979-01-01

    Midlatitude 100-mb height fields are employed to determine the effects of ground based sampling locations on measurements of variations in the total ozone content of the atmosphere. The precision of the zonal average heights computed by the technique of Angell and Korshover (1978) from data over ozone sampling areas at 50 deg N is compared to the zonal average computed from the entire data set. Linear regressions of ozone contents determined by an analysis of backscatter UV satellite data with respect to 100 mb heights are utilized to transform zonal differences in height to ozone levels. The zonal average total ozone sampling error is found to be on the order of 2% for midlatitudes of the Northern hemisphere, indicating that the general shape of ozone trends determined by ground-based observations appears to be real and the increase of ozone from the mid-1960's to the early 1970's may be greater than previously suggested.

  6. Using adaptive sampling and triangular meshes for the processing and inversion of potential field data

    Science.gov (United States)

    Foks, Nathan Leon

    The interpretation of geophysical data plays an important role in the analysis of potential field data in resource exploration industries. Two categories of interpretation techniques are discussed in this thesis; boundary detection and geophysical inversion. Fault or boundary detection is a method to interpret the locations of subsurface boundaries from measured data, while inversion is a computationally intensive method that provides 3D information about subsurface structure. My research focuses on these two aspects of interpretation techniques. First, I develop a method to aid in the interpretation of faults and boundaries from magnetic data. These processes are traditionally carried out using raster grid and image processing techniques. Instead, I use unstructured meshes of triangular facets that can extract inferred boundaries using mesh edges. Next, to address the computational issues of geophysical inversion, I develop an approach to reduce the number of data in a data set. The approach selects the data points according to a user specified proxy for its signal content. The approach is performed in the data domain and requires no modification to existing inversion codes. This technique adds to the existing suite of compressive inversion algorithms. Finally, I develop an algorithm to invert gravity data for an interfacing surface using an unstructured mesh of triangular facets. A pertinent property of unstructured meshes is their flexibility at representing oblique, or arbitrarily oriented structures. This flexibility makes unstructured meshes an ideal candidate for geometry based interface inversions. The approaches I have developed provide a suite of algorithms geared towards large-scale interpretation of potential field data, by using an unstructured representation of both the data and model parameters.

  7. Modeling and analysis of overmodulation in erbium-doped fiber amplifiers including amplified spontaneous emission

    Science.gov (United States)

    Sharma, Reena; Raghuwanshi, Sanjeev Kumar

    2017-02-01

    Line surveillance and management information in erbium-doped fiber amplifiers (EDFAs) can be broadcast by modulating the amplitude of the low-frequency lightwave information signal, the process termed as overmodulation in the literature. This paper presents systematic solutions for the overmodulated pump and information signal transfer functions for EDFA. It includes amplified spontaneous emission (ASE) that has an impact on outcomes in the high-gain system. To the extent of our belief, the methodical model simulated with the current approach leads to a distinct perspective of an outcome in the respective field. The test bed described here is realistic. It specifically represents the overmodulation behavior in an EDFA under the influence of ASE.

  8. NGSI FY15 Final Report. Innovative Sample Preparation for in-Field Uranium Isotopic Determinations

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Thomas M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Meyers, Lisa [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-10

    Our FY14 Final Report included an introduction to the project, background, literature search of uranium dissolution methods, assessment of commercial off the shelf (COTS) automated sample preparation systems, as well as data and results for dissolution of bulk quantities of uranium oxides, and dissolution of uranium oxides from swipe filter materials using ammonium bifluoride (ABF). Also, discussed were reaction studies of solid ABF with uranium oxide that provided a basis for determining the ABF/uranium oxide dissolution mechanism. This report details the final experiments for optimizing dissolution of U3O8 and UO2 using ABF and steps leading to development of a Standard Operating Procedure (SOP) for dissolution of uranium oxides on swipe filters.

  9. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland: Volume 2, Quality Assurance Project Plan

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, S.; Martino, L.; Patton, T.

    1995-03-01

    J-Field encompasses about 460 acres at the southern end of the Gunpowder Neck Peninsula in the Edgewood Area of APG (Figure 2.1). Since World War II, the Edgewood Area of APG has been used to develop, manufacture, test, and destroy chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). For the purposes of this project, J-Field has been divided into eight geographic areas or facilities that are designated as areas of concern (AOCs): the Toxic Burning Pits (TBP), the White Phosphorus Burning Pits (WPP), the Riot Control Burning Pit (RCP), the Robins Point Demolition Ground (RPDG), the Robins Point Tower Site (RPTS), the South Beach Demolition Ground (SBDG), the South Beach Trench (SBT), and the Prototype Building (PB). The scope of this project is to conduct a remedial investigation/feasibility study (RI/FS) and ecological risk assessment to evaluate the impacts of past disposal activities at the J-Field site. Sampling for the RI will be carried out in three stages (I, II, and III) as detailed in the FSP. A phased approach will be used for the J-Field ecological risk assessment (ERA).

  10. Effect of sample container morphology on agglomeration dynamics of magnetic nanoparticles under magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Dae Seong; Kim, Hack Jin [Dept. of Chemistry, Chungnam National University, Daejeon (Korea, Republic of)

    2016-12-15

    The superparamagnetic magnetite nanoparticles have been used extensively in medical and biological applications, and agglomeration of magnetic nanoparticles is employed in the purification of water and proteins. The magnetic weight can be measured with a conventional electronic balance. Details of the experimental setup have been previously reported. That is, complex energy landscape involved in the agglomeration is changing with progress. Simulation of colloidal magnetic particles under magnetic field shows that the chain of particles is energetically more favorable than the ring and that the transition barrier between the chain and the ring is very low. The energy barriers among entangled nanoparticles of the agglomerate seem to be much more complicated than those among colloidal particles. The energy barrier distributions at 1000 min are similar for the two containers; however, the trend of blue shift and broadening is much more evident in the case of conical tube. These results indicate that the potential energy surface for agglomeration is modified more significantly in the conical tube which makes the agglomerate denser.

  11. A CMOS current-mode operational amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1993-01-01

    A fully differential-input, differential-output, current-mode operational amplifier (COA) is described. The amplifier utilizes three second-generation current conveyors (CCIIs) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanced...... current-mode feedback amplifier or a constant bandwidth in a transimpedance feedback amplifier. The amplifier is found to have a gain-bandwidth product of 3 MHz, an offset current of 0.8 μA (signal range ±700 μA), and a (theoretically) unlimited slew rate. The amplifier is realized in a standard CMOS 2...

  12. CMOS Current-mode Operational Amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1992-01-01

    A fully differential-input differential-output current-mode operational amplifier (COA) is described. The amplifier utilizes three second generation current-conveyors (CCII) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanced...... current-mode feedback amplifier or a constant bandwidth in a transimpedance feedback amplifier. The amplifier is found to have a gain bandwidth product of 8 MHz, an offset current of 0.8 ¿A (signal-range ±700¿A) and a (theoretically) unlimited slew-rate. The amplifier is realized in a standard CMOS 2...

  13. Irreversibility line and magnetic field dependence of the critical current in superconducting MgB sub 2 bulk samples

    CERN Document Server

    Gioacchino, D D; Tripodi, P; Grimaldi, G

    2003-01-01

    The third harmonic components of the ac susceptibility of MgB sub 2 bulk samples have been measured as a function of applied magnetic fields, together with standard magnetization cycles. The irreversibility line (IL) of the magnetic field has been extracted from the onset of the third harmonic components. Using a (1 - t) supalpha glass/liquid best fit where alpha 1.27 IL shows a coherent length xi divergence with exponent nu = 0.63, which indicates a 3D behaviour. Moreover, using the numerical solution of the non-linear magnetic diffusion equation, considering the creep model in a 3D vortex glass, a good description of the vortex dynamics has been obtained. The behaviour of the magnetization amplitude (approx Hz) and the ac susceptibility signals (kHz), at different applied magnetic fields, 3.5 T < H sub d sub c < 4.5 T, and at the reduced temperature 0.86 < t < 0.93 (T = 22 K), shows that the superconducting dynamic response of vortices in the MgB sub 2 samples is not evidently dependent on the f...

  14. Spatial Distribution and Minimum Sample Size for Overwintering Larvae of the Rice Stem Borer Chilo suppressalis (Walker) in Paddy Fields.

    Science.gov (United States)

    Arbab, A

    2014-10-01

    The rice stem borer, Chilo suppressalis (Walker), feeds almost exclusively in paddy fields in most regions of the world. The study of its spatial distribution is fundamental for designing correct control strategies, improving sampling procedures, and adopting precise agricultural techniques. Field experiments were conducted during 2011 and 2012 to estimate the spatial distribution pattern of the overwintering larvae. Data were analyzed using five distribution indices and two regression models (Taylor and Iwao). All of the indices and Taylor's model indicated random spatial distribution pattern of the rice stem borer overwintering larvae. Iwao's patchiness regression was inappropriate for our data as shown by the non-homogeneity of variance, whereas Taylor's power law fitted the data well. The coefficients of Taylor's power law for a combined 2 years of data were a = -0.1118, b = 0.9202 ± 0.02, and r (2) = 96.81. Taylor's power law parameters were used to compute minimum sample size needed to estimate populations at three fixed precision levels, 5, 10, and 25% at 0.05 probabilities. Results based on this equation parameters suggesting that minimum sample sizes needed for a precision level of 0.25 were 74 and 20 rice stubble for rice stem borer larvae when the average larvae is near 0.10 and 0.20 larvae per rice stubble, respectively.

  15. Characterization of Intracellular and Extracellular Saxitoxin Levels in Both Field and Cultured Alexandrium spp. Samples from Sequim Bay, Washington

    Directory of Open Access Journals (Sweden)

    Vera L. Trainer

    2008-05-01

    Full Text Available Traditionally, harmful algal bloom studies have primarily focused on quantifying toxin levels contained within the phytoplankton cells of interest. In the case of paralytic shellfish poisoning toxins (PSTs, intracellular toxin levels and the effects of dietary consumption of toxic cells by planktivores have been well documented. However, little information is available regarding the levels of extracellular PSTs that may leak or be released into seawater from toxic cells during blooms. In order to fully evaluate the risks of harmful algal bloom toxins in the marine food web, it is necessary to understand all potential routes of exposure. In the present study, extracellular and intracellular PST levels were measured in field seawater samples (collected weekly from June to October 2004- 2007 and in Alexandrium spp. culture samples isolated from Sequim Bay, Washington. Measurable levels of intra- and extra-cellular toxins were detected in both field and culture samples via receptor binding assay (RBA and an enzyme-linked immunosorbent assay (ELISA. Characterization of the PST toxin profile in the Sequim Bay isolates by preMar. column oxidation and HPLC-fluorescence detection revealed that gonyautoxin 1 and 4 made up 65 ± 9.7 % of the total PSTs present. Collectively, these data confirm that extracellular PSTs are present during blooms of Alexandrium spp. in the Sequim Bay region.

  16. A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages

    CERN Document Server

    Kirkpatrick, J Davy; Barman, Travis S; Burgasser, Adam J; Looper, Dagny L; Tinney, C G; Gelino, Christopher R; Lowrance, Patrick J; Liebert, James; Carpenter, John M; Hillenbrand, Lynne A; Stauffer, John R

    2008-01-01

    Using a large sample of optical spectra of late-type dwarfs, we identify a subset of late-M through L field dwarfs that, because of the presence of low-gravity features in their spectra, are believed to be unusually young. From a combined sample of 303 field L dwarfs, we find observationally that 7.6+/-1.6% are younger than 100 Myr. This percentage is in agreement with theoretical predictions once observing biases are taken into account. We find that these young L dwarfs tend to fall in the southern hemisphere (Dec < 0 deg) and may be previously unrecognized, low-mass members of nearby, young associations like Tucana-Horologium, TW Hydrae, beta Pictoris, and AB Doradus. We use a homogeneously observed sample of roughly one hundred and fifty 6300-10000 Angstrom spectra of L and T dwarfs taken with the Low-Resolution Imaging Spectrometer at the W. M. Keck Observatory to examine the strength of the 6708-A Li I line as a function of spectral type and further corroborate the trends noted by Kirkpatrick et al. (...

  17. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    LI JingZhen

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating,high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,st the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10~8-5×10~9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10~7-10~(14) fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polarization and wavelength,and even quantum properties of photon.In the cascaded system of electromagnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  18. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating, high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,at the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10 8 ―5×10 9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10 7 ―10 14 fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polari- zation and wavelength,and even quantum properties of photon.In the cascaded system of electro- magnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  19. DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Non Q. (San Diego, CA); Clarke, John (Berkeley, CA)

    1993-01-01

    A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced.

  20. DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Fan, N.Q.; Clarke, J.

    1993-10-19

    A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced. 7 figures.

  1. Quantifying Marine Emissions of Biogenic Volatile Organic Compounds Using Laboratory Measurements of Plankton Monocultures and Field Samples

    Science.gov (United States)

    Sabolis, A. W.; Meskhidze, N.; Kamykowski, D.; Reed, R. E.

    2010-12-01

    Marine biogenic volatile organic compounds (BVOCs) have been suggested to contribute significant portion of the organic carbon present in ocean atmosphere. In this study emission rates of 40 different hydrocarbons are quantified for lab-grown non-axenic phytoplankton monocultures and ambient samples from the Pamlico-Neuse Estuary, NC. The outcome of environmental conditions on production of BVOCs was examined for different light and temperature conditions. These different regimes are considered proxies for physiological stress-induced effects observed in natural ecosystems. The samples were incubated in a climate controlled room; they were then transferred to smaller volumes (200 ml) for analysis. BVOCs accumulated in the water and headspace above the water were measured by bubbling hydrocarbon-free gas mixture through the sample and passing the gas stream through a gas chromatography/mass spectrometry system equipped with a sample pre-concentrator. Inside the pre-concentrator, the compounds were trapped on a sorbent material, heated, and flushed into the GC-MS column. The pre-concentrator/GC-MS system gave at least 1000 times magnification of the sample concentrations, allowing detection of low ppt levels of hydrocarbons. Here we report results for lab-grown diatoms Thalassiosira weissflogii and Thalassiosira pseudonana, prymnesiophyte Pleurochrysis carterae, and dinoflagellates Karina brevis and Procentrum minimum, as well as field samples. To make results widely usable, all the emissions are normalized to Chlorophyll-a (Chl-a) concentration and cell counts. Our results show that diatoms had the highest isoprene production rate of 2.8 μmol (g Chl-a)-1 h-1 with ranges between 1.4 and 3.6 μmol (g Chl-a)-1 h-1 at light levels between 90 and 900 μE m-2 s-1, respectively. The prymnesiophyte and dinoflagellate species had isoprene production rates of 1.3±0.4 μmol (g Chl-a)-1 h-1 with a similar light dependency as diatoms. Field samples had comparable isoprene

  2. Linearisation of RF Power Amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck

    2001-01-01

    This thesis deals with linearisation techniques of RF power amplifiers (PA), PA design techniques and integration of the necessary building blocks in a CMOS technology. The opening chapters introduces the theory of transmitter architectures, RF-signal representation and the principles of digital...... modulation. Furthermore different types of power amplifiers, models and measures of non-linearities are presented. A chapter is also devoted to different types of linearisation systems. The work carried out and described in this thesis can be divided into a more theoretical and system oriented treatment...... the polar loop architecture and it’s suitability to modern digital transmitters is discussed. A proposal of an architecture that is suitable for digital transmitters, which means that it has an interface to the digital back-end, defined by low-pass signals in polar form, is presented. Simulation guidelines...

  3. Combination of microsecond and nanosecond pulsed electric field treatments for inactivation of Escherichia coli in water samples.

    Science.gov (United States)

    Žgalin, Maj Kobe; Hodžić, Duša; Reberšek, Matej; Kandušer, Maša

    2012-10-01

    Inactivation of microorganisms with pulsed electric fields is one of the nonthermal methods most commonly used in biotechnological applications such as liquid food pasteurization and water treatment. In this study, the effects of microsecond and nanosecond pulses on inactivation of Escherichia coli in distilled water were investigated. Bacterial colonies were counted on agar plates, and the count was expressed as colony-forming units per milliliter of bacterial suspension. Inactivation of bacterial cells was shown as the reduction of colony-forming units per milliliter of treated samples compared to untreated control. According to our results, when using microsecond pulses the level of inactivation increases with application of more intense electric field strengths and with number of pulses delivered. Almost 2-log reductions in bacterial counts were achieved at a field strength of 30 kV/cm with eight pulses and a 4.5-log reduction was observed at the same field strength using 48 pulses. Extending the duration of microsecond pulses from 100 to 250 μs showed no improvement in inactivation. Nanosecond pulses alone did not have any detectable effect on inactivation of E. coli regardless of the treatment time, but a significant 3-log reduction was achieved in combination with microsecond pulses.

  4. Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

    Science.gov (United States)

    Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    The Geysers geothermal field in northern California, with about 2000-MW electrical capacity, is the largest geothermal field in the world. Despite its importance as a resource and as an example of a vapor-dominated reservoir, very few complete geochemical analyses of the steam have been published (Allen and Day, 1927; Truesdell and others, 1987). This report presents data from 90 steam, gas, and condensate samples from wells in The Geysers geothermal field in northern California. Samples were collected between 1978 and 1991. Well attributes include sampling date, well name, location, total depth, and the wellhead temperature and pressure at which the sample was collected. Geochemical characteristics include the steam/gas ratio, composition of noncondensable gas (relative proportions of CO2, H2S, He, H2, O2, Ar, N2, CH4, and NH3), and isotopic values for deltaD and delta18O of H2O, delta13C of CO2, and delta34S of H2S. The compilation includes 81 analyses from 74 different production wells, 9 isotopic analyses of steam condensate pumped into injection wells, and 5 complete geochemical analyses on gases from surface fumaroles and bubbling pools. Most samples were collected as saturated steam and plot along the liquid-water/steam boiling curve. Steam-togas ratios are highest in the southeastern part of the geothermal field and lowest in the northwest, consistent with other studies. Wells in the Northwest Geysers are also enriched in N2/Ar, CO2 and CH4, deltaD, and delta18O. Well discharges from the Southeast Geysers are high in steam/gas and have isotopic compositions and N2/Ar ratios consistent with recharge by local meteoric waters. Samples from the Central Geysers show characteristics found in both the Southeast and Northwest Geysers. Gas and steam characteristics of well discharges from the Northwest Geysers are consistent with input of components from a high-temperature reservoir containing carbonrich gases derived from the host Franciscan rocks. Throughout the

  5. 338-GHz Semiconductor Amplifier Module

    Science.gov (United States)

    Samoska, Lorene A.; Gaier, Todd C.; Soria, Mary M.; Fung, King Man; Rasisic, Vesna; Deal, William; Leong, Kevin; Mei, Xiao Bing; Yoshida, Wayne; Liu, Po-Hsin; Uyeda, Jansen; Lai, Richard

    2010-01-01

    Research findings were reported from an investigation of new gallium nitride (GaN) monolithic millimeter-wave integrated circuit (MMIC) power amplifiers (PAs) targeting the highest output power and the highest efficiency for class-A operation in W-band (75-110 GHz). W-band PAs are a major component of many frequency multiplied submillimeter-wave LO signal sources. For spectrometer arrays, substantial W-band power is required due to the passive lossy frequency multipliers.

  6. Extension of Studies with 3M Empore TM and Selentec MAG *SEP SM Technologies for Improved Radionuclide Field Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Beals, D.M. [Westinghouse Savannah River Company, AIKEN, SC (United States); Bibler, J.P.; Brooks, D.A.

    1996-07-10

    The Savannah River Technology Center is evaluating new field sampling methodologies to more easily determine concentrations of radionuclides in aqueous systems. One methodology studied makes use of 3M EmporeTM disks. The disks are composed of selective resins embedded in a Teflon support. The disks remove the ion of interest from aqueous solutions when the solution is passed through the disk. The disk can then be counted directly to quantify the isotope of interest. Four types of disks were studied during this work: for the extraction of technetium (two types), cesium, plutonium, and strontium. A sampler has been developed for automated, unattended, in situ use of the EmporeTM disks.

  7. Counting and differentiating aquatic biotic nanoparticles by full-field interferometry: from laboratory tests to Tara Oceans sample analysis

    CERN Document Server

    Boccara, Martine; Bryan, Catherine Venien; Bailly-Bechet, Marc; Bowler, Chris; Boccara, Albert Claude

    2016-01-01

    There is a huge abundance of viruses and membrane vesicles in seawater. We describe a new full-field, incoherently illuminated, shot-noise limited, common-path interferometric detection method that we couple with the analysis of Brownian motion to detect, quantify, and differentiate biotic nanoparticles. We validated the method with calibrated nanoparticles and homogeneous DNA or RNA.viruses. The smallest virus size that we characterized with a suitable signal-to-noise ratio was around 30 nm in diameter. Analysis of Brownian motions revealed anisotropic trajectories for myoviruses.We further applied the method for vesicles detection and for analysis of coastal and oligotrophic samples from Tara Oceans circumnavigation.

  8. Balanced Turbo Field Echo with Extended k-space Sampling: A Fast Technique for the Thoracic Ductography.

    Science.gov (United States)

    Nomura, Takakiyo; Niwa, Tetsu; Kazama, Toshiki; Sekiguchi, Tatsuya; Okazaki, Takashi; Shibukawa, Shuhei; Nishio, Hiroaki; Obara, Makoto; Imai, Yutaka

    2016-10-11

    We evaluated the visibility of the thoracic duct by fast balanced turbo field echo with extended k-space sampling (bTFEe). The thoracic duct of 10 healthy volunteers was scanned by bTFEe using a 1.5-T magnetic resonance imaging (MRI), which was acquired in approximately 2 minutes. Three-dimensional (3D) turbo spin-echo (TSE) was obtained for comparison. The thoracic duct including draining location of the venous system was overall well visualized on bTFEe, compared to TSE.

  9. SubPatch: random kd-tree on a sub-sampled patch set for nearest neighbor field estimation

    Science.gov (United States)

    Pedersoli, Fabrizio; Benini, Sergio; Adami, Nicola; Okuda, Masahiro; Leonardi, Riccardo

    2015-02-01

    We propose a new method to compute the approximate nearest-neighbors field (ANNF) between image pairs using random kd-tree and patch set sub-sampling. By exploiting image coherence we demonstrate that it is possible to reduce the number of patches on which we compute the ANNF, while maintaining high overall accuracy on the final result. Information on missing patches is then recovered by interpolation and propagation of good matches. The introduction of the sub-sampling factor on patch sets also allows for setting the desired trade off between accuracy and speed, providing a flexibility that lacks in state-of-the-art methods. Tests conducted on a public database prove that our algorithm achieves superior performance with respect to PatchMatch (PM) and Coherence Sensitivity Hashing (CSH) algorithms in a comparable computational time.

  10. Multiscale modeling of polycrystalline graphene: A comparison of structure and defect energies of realistic samples from phase field crystal models

    Science.gov (United States)

    Hirvonen, Petri; Ervasti, Mikko M.; Fan, Zheyong; Jalalvand, Morteza; Seymour, Matthew; Vaez Allaei, S. Mehdi; Provatas, Nikolas; Harju, Ari; Elder, Ken R.; Ala-Nissila, Tapio

    2016-07-01

    We extend the phase field crystal (PFC) framework to quantitative modeling of polycrystalline graphene. PFC modeling is a powerful multiscale method for finding the ground state configurations of large realistic samples that can be further used to study their mechanical, thermal, or electronic properties. By fitting to quantum-mechanical density functional theory (DFT) calculations, we show that the PFC approach is able to predict realistic formation energies and defect structures of grain boundaries. We provide an in-depth comparison of the formation energies between PFC, DFT, and molecular dynamics (MD) calculations. The DFT and MD calculations are initialized using atomic configurations extracted from PFC ground states. Finally, we use the PFC approach to explicitly construct large realistic polycrystalline samples and characterize their properties using MD relaxation to demonstrate their quality.

  11. High power regenerative laser amplifier

    Science.gov (United States)

    Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

    1994-02-08

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

  12. Small and lightweight power amplifiers

    Science.gov (United States)

    Shams, Qamar A.; Barnes, Kevin N.; Fox, Robert L.; Moses, Robert W.; Bryant, Robert G.; Robinson, Paul C.; Shirvani, Mir

    2002-07-01

    The control of u wanted structural vibration is implicit in most of NASA's programs. Currently several approaches to control vibrations in large, lightweight, deployable structures and twin tail aircraft at high angles of attack are being evaluated. The Air Force has been examining a vertical tail buffet load alleviation system that can be integrated onboard an F/A-18 and flown. Previous wind tunnel and full-scale ground tests using distributed actuators have shown that the concept works; however, there is insufficient rom available onboard an F/A-18 to store current state-of- the-art system components such as amplifiers, DC-to-DC converter and a computer for performing vibration suppression. Sensor processing, power electronics, DC-to-DC converters, and control electronics that may be collocated with distributed actuators, are particularly desirable. Such electronic system would obviate the need for complex, centralized, control processing and power distribution components that will eliminate the weight associated with lengthy wiring and cabling networks. Several small and lightweight power amplifiers ranging from 300V pp to 650V pp have been designed using off the shelf components for different applications. In this paper, the design and testing of these amplifiers will be presented under various electrical loads.

  13. SPS RF System Amplifier plant

    CERN Multimedia

    1977-01-01

    The picture shows a 2 MW, 200 MHz amplifier plant with feeder lines. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X.

  14. Analog circuit design designing high performance amplifiers

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The third volume Designing High Performance Amplifiers applies the concepts from the first two volumes. It is an advanced treatment of amplifier design/analysis emphasizing both wideband and precision amplification.

  15. Higher order mode optical fiber Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Friis, Søren Michael Mørk; Usuga Castaneda, Mario A.

    2016-01-01

    We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations.......We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations....

  16. Visible-infrared self-amplified spontaneous emission amplifier free electron laser undulator

    Science.gov (United States)

    Carr, Roger; Cornacchia, Max; Emma, Paul; Nuhn, Heinz-Dieter; Poling, Ben; Ruland, Robert; Johnson, Erik; Rakowsky, George; Skaritka, John; Lidia, Steve; Duffy, Pat; Libkind, Marcus; Frigola, Pedro; Murokh, Alex; Pellegrini, Claudio; Rosenzweig, James; Tremaine, Aaron

    2001-12-01

    The visible-infrared self-amplified spontaneous emission amplifier (VISA) free electron laser (FEL) is an experimental device designed to show self-amplified spontaneous emission (SASE) to saturation in the near infrared to visible light energy range. It generates a resonant wavelength output from 800-600 nm, so that silicon detectors may be used to characterize the optical properties of the FEL radiation. VISA is designed to show how SASE FEL theory corresponds with experiment in this wavelength range, using an electron beam with emittance close to that planned for the future Linear Coherent Light Source at SLAC. VISA comprises a 4 m pure permanent magnet undulator with four 99 cm segments, each of 55 periods, 18 mm long. The undulator has distributed focusing built into it, to reduce the average beta function of the 70-85 MeV electron beam to about 30 cm. There are four FODO cells per segment. The permanent magnet focusing lattice consists of blocks mounted on either side of the electron beam, in the undulator gap. The most important undulator error parameter for a free electron laser is the trajectory walk-off, or lack of overlap of the photon and electron beams. Using pulsed wire magnet measurements and magnet shimming, we were able to control trajectory walk-off to less than +/-50 μm per field gain length.

  17. Visible-infrared self-amplified spontaneous emission amplifier free electron laser undulator

    Directory of Open Access Journals (Sweden)

    Roger Carr

    2001-12-01

    Full Text Available The visible-infrared self-amplified spontaneous emission amplifier (VISA free electron laser (FEL is an experimental device designed to show self-amplified spontaneous emission (SASE to saturation in the near infrared to visible light energy range. It generates a resonant wavelength output from 800–600 nm, so that silicon detectors may be used to characterize the optical properties of the FEL radiation. VISA is designed to show how SASE FEL theory corresponds with experiment in this wavelength range, using an electron beam with emittance close to that planned for the future Linear Coherent Light Source at SLAC. VISA comprises a 4 m pure permanent magnet undulator with four 99 cm segments, each of 55 periods, 18 mm long. The undulator has distributed focusing built into it, to reduce the average beta function of the 70–85 MeV electron beam to about 30 cm. There are four FODO cells per segment. The permanent magnet focusing lattice consists of blocks mounted on either side of the electron beam, in the undulator gap. The most important undulator error parameter for a free electron laser is the trajectory walk-off, or lack of overlap of the photon and electron beams. Using pulsed wire magnet measurements and magnet shimming, we were able to control trajectory walk-off to less than ±50 μm per field gain length.

  18. Statistical properties of the surface velocity field in the northern Gulf of Mexico sampled by GLAD drifters

    Science.gov (United States)

    Mariano, A. J.; Ryan, E. H.; Huntley, H. S.; Laurindo, L. C.; Coelho, E.; Griffa, A.; Özgökmen, T. M.; Berta, M.; Bogucki, D.; Chen, S. S.; Curcic, M.; Drouin, K. L.; Gough, M.; Haus, B. K.; Haza, A. C.; Hogan, P.; Iskandarani, M.; Jacobs, G.; Kirwan, A. D.; Laxague, N.; Lipphardt, B.; Magaldi, M. G.; Novelli, G.; Reniers, A.; Restrepo, J. M.; Smith, C.; Valle-Levinson, A.; Wei, M.

    2016-07-01

    The Grand LAgrangian Deployment (GLAD) used multiscale sampling and GPS technology to observe time series of drifter positions with initial drifter separation of O(100 m) to O(10 km), and nominal 5 min sampling, during the summer and fall of 2012 in the northern Gulf of Mexico. Histograms of the velocity field and its statistical parameters are non-Gaussian; most are multimodal. The dominant periods for the surface velocity field are 1-2 days due to inertial oscillations, tides, and the sea breeze; 5-6 days due to wind forcing and submesoscale eddies; 9-10 days and two weeks or longer periods due to wind forcing and mesoscale variability, including the period of eddy rotation. The temporal e-folding scales of a fitted drifter velocity autocorrelation function are bimodal with time scales, 0.25-0.50 days and 0.9-1.4 days, and are the same order as the temporal e-folding scales of observed winds from nearby moored National Data Buoy Center stations. The Lagrangian integral time scales increase from coastal values of 8 h to offshore values of approximately 2 days with peak values of 3-4 days. The velocity variance is large, O>(1>) m2/s2, the surface velocity statistics are more anisotropic, and increased dispersion is observed at flow bifurcations. Horizontal diffusivity estimates are O>(103>) m2/s in coastal regions with weaker flow to O>(105>) m2/s in flow bifurcations, a strong jet, and during the passage of Hurricane Isaac. The Gulf of Mexico surface velocity statistics sampled by the GLAD drifters are a strong function of the feature sampled, topography, and wind forcing.

  19. Influence of high-conductivity buffer composition on field-enhanced sample injection coupled to sweeping in CE.

    Science.gov (United States)

    Anres, Philippe; Delaunay, Nathalie; Vial, Jérôme; Thormann, Wolfgang; Gareil, Pierre

    2013-02-01

    The aim of this work was to clarify the mechanism taking place in field-enhanced sample injection coupled to sweeping and micellar EKC (FESI-Sweep-MEKC), with the utilization of two acidic high-conductivity buffers (HCBs), phosphoric acid or sodium phosphate buffer, in view of maximizing sensitivity enhancements. Using cationic model compounds in acidic media, a chemometric approach and simulations with SIMUL5 were implemented. Experimental design first enabled to identify the significant factors and their potential interactions. Simulation demonstrates the formation of moving boundaries during sample injection, which originate at the initial sample/HCB and HCB/buffer discontinuities and gradually change the compositions of HCB and BGE. With sodium phosphate buffer, the HCB conductivity increased during the injection, leading to a more efficient preconcentration by staking (about 1.6 times) than with phosphoric acid alone, for which conductivity decreased during injection. For the same injection time at constant voltage, however, a lower amount of analytes was injected with sodium phosphate buffer than with phosphoric acid. Consequently sensitivity enhancements were lower for the whole FESI-Sweep-MEKC process. This is why, in order to maximize sensitivity enhancements, it is proposed to work with sodium phosphate buffer as HCB and to use constant current during sample injection. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Optimization of crude enzyme preparation methods for analysis of glutamine synthetase activity in phytoplankton and field samples

    Institute of Scientific and Technical Information of China (English)

    WANG Yujue; WANG Dazhi; HONG Huasheng

    2009-01-01

    Glutamine synthetase (GS) is an important enzyme involved in nitrogen assimilation and metabolism in marine phytoplankton. However, little work has been done in situ due to the limitation of crude enzyme preparation methods. In this study, three enzyme preparation methods, high-speed centrifugation (HC, <10 000 g), ultracentrifugation (UC, 70 000 g), and ultrafiltration (UF) with 100 kμ, molecular weight cutoff, were compared using two diatom species (Asterionellopsis glacialis and Thalassiosira weissflogii), and two dinoflagellate species (Alexandrium catenella and Prorocentrum donghaiense) as experimental materials together with field samples collected from Xiamen Harbor, China. The results showed that HC is the best method to prepare crude enzymes for glutamine synthetase activity (GSA) in diatom species and diatom-dominant samples, while UF is the best method to extract GS from dinoflagellate species and dinoflagellate-dominant samples. For the HC method, the optimal centrifugal speed and time were 10 000 g and 35 min, respectively, and under these conditions, the highest GSA was obtained in all samples. This study indicates that both methods (HC and UF) overcome the limitation of centrifugal speed and could be applied to in situ GSA analysis, especially at sea.

  1. High-frequency graphene voltage amplifier.

    Science.gov (United States)

    Han, Shu-Jen; Jenkins, Keith A; Valdes Garcia, Alberto; Franklin, Aaron D; Bol, Ageeth A; Haensch, Wilfried

    2011-09-14

    While graphene transistors have proven capable of delivering gigahertz-range cutoff frequencies, applying the devices to RF circuits has been largely hindered by the lack of current saturation in the zero band gap graphene. Herein, the first high-frequency voltage amplifier is demonstrated using large-area chemical vapor deposition grown graphene. The graphene field-effect transistor (GFET) has a 6-finger gate design with gate length of 500 nm. The graphene common-source amplifier exhibits ∼5 dB low frequency gain with the 3 dB bandwidth greater than 6 GHz. This first AC voltage gain demonstration of a GFET is attributed to the clear current saturation in the device, which is enabled by an ultrathin gate dielectric (4 nm HfO(2)) of the embedded gate structures. The device also shows extrinsic transconductance of 1.2 mS/μm at 1 V drain bias, the highest for graphene FETs using large-scale graphene reported to date.

  2. Improved charge amplifier using hybrid hysteresis compensation

    Science.gov (United States)

    Amin-Shahidi, Darya; Trumper, David L.

    2013-08-01

    We present a novel charge amplifier, with a robust feedback circuit and a method for compensating piezoelectric actuator's hysteresis at low frequencies. The amplifier uses a modified feedback circuit which improves robustness to the addition of series load impedance such as in cabling. We also describe a hybrid hysteresis compensation method for enabling the charge amplifier to reduce hysteresis at low frequencies. Experimental results demonstrate the utility of the new amplifier design.

  3. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk;

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  4. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  5. Implications of the field sampling procedure of the LUCAS Topsoil Survey for uncertainty in soil organic carbon concentrations.

    Science.gov (United States)

    Lark, R. M.; Rawlins, B. G.; Lark, T. A.

    2014-05-01

    The LUCAS Topsoil survey is a pan-European Union initiative in which soil data were collected according to standard protocols from 19 967 sites. Any inference about soil variables is subject to uncertainty due to different sources of variability in the data. In this study we examine the likely magnitude of uncertainty due to the field-sampling protocol. The published sampling protocol (LUCAS, 2009) describes a procedure to form a composite soil sample from aliquots collected to a depth of between approximately 15-20. A v-shaped hole to the target depth is cut with a spade, then a slice is cut from one of the exposed surfaces. This methodology gives rather less control of the sampling depth than protocols used in other soil and geochemical surveys, this may be a substantial source of variation in uncultivated soils with strong contrasts between an organic-rich A-horizon and an underlying B-horizon. We extracted all representative profile descriptions from soil series recorded in the memoir of the 1:250 000-scale map of Northern England (Soil Survey of England and Wales, 1984) where the base of the A-horizon is less than 20 cm below the surface. The Soil Associations in which these 14 series are significant members cover approximately 17% of the area of Northern England, and are expected to be the mineral soils with the largest organic content. Soil Organic Carbon content and bulk density were extracted for the A- and B-horizons, along with the thickness of the horizons. Recorded bulk density, or prediction by a pedotransfer function, were also recorded. For any proposed angle of the v-shaped hole, the proportions of A- and B-horizon in the resulting sample may be computed by trigonometry. From the bulk density and SOC concentration of the horizons, the SOC concentration of the sample can be computed. For each Soil Series we drew 1000 random samples from a trapezoidal distribution of angles, with uniform density over the range corresponding to depths 15-20 cm and

  6. Evaluating the roles of biotransformation, spatial concentration differences, organism home range, and field sampling design on trophic magnification factors.

    Science.gov (United States)

    Kim, Jaeshin; Gobas, Frank A P C; Arnot, Jon A; Powell, David E; Seston, Rita M; Woodburn, Kent B

    2016-05-01

    Trophic magnification factors (TMFs) are field-based measurements of the bioaccumulation behavior of chemicals in food-webs. TMFs can provide valuable insights into the bioaccumulation behavior of chemicals. However, bioaccumulation metrics such as TMF may be subject to considerable uncertainty as a consequence of systematic bias and the influence of confounding variables. This study seeks to investigate the role of systematic bias resulting from spatially-variable concentrations in water and sediments and biotransformation rates on the determination of TMF. For this purpose, a multibox food-web bioaccumulation model was developed to account for spatial concentration differences and movement of organisms on chemical concentrations in aquatic biota and TMFs. Model calculated and reported field TMFs showed good agreement for persistent polychlorinated biphenyl (PCB) congeners and biotransformable phthalate esters (PEs) in a marine aquatic food-web. Model testing showed no systematic bias and good precision in the estimation of the TMF for PCB congeners but an apparent underestimation of model calculated TMFs, relative to reported field TMFs, for PEs. A model sensitivity analysis showed that sampling designs that ignore the presence of concentration gradients may cause systematically biased and misleading TMF values. The model demonstrates that field TMFs are most sensitive to concentration gradients and species migration patterns for substances that are subject to a low degree of biomagnification or trophic dilution. The model is useful in anticipating the effect of spatial concentration gradients on the determination of the TMF; guiding species collection strategies in TMF studies; and interpretation of the results of field bioaccumulation studies in study locations where spatial differences in chemical concentration exist.

  7. A new method to detect and correct sample tilt in scanning transmission electron microscopy bright-field imaging.

    Science.gov (United States)

    Brown, H G; Ishikawa, R; Sánchez-Santolino, G; Lugg, N R; Ikuhara, Y; Allen, L J; Shibata, N

    2017-02-01

    Important properties of functional materials, such as ferroelectric shifts and octahedral distortions, are associated with displacements of the positions of lighter atoms in the unit cell. Annular bright-field scanning transmission electron microscopy is a good experimental method for investigating such phenomena due to its ability to image light and heavy atoms simultaneously. To map atomic positions at the required accuracy precise angular alignment of the sample with the microscope optical axis is necessary, since misalignment (tilt) of the specimen contributes to errors in position measurements of lighter elements in annular bright-field imaging. In this paper it is shown that it is possible to detect tilt with the aid of images recorded using a central bright-field detector placed within the inner radius of the annular bright-field detector. For a probe focus near the middle of the specimen the central bright-field image becomes especially sensitive to tilt and we demonstrate experimentally that misalignment can be detected with a precision of less than a milliradian, as we also confirm in simulation. Coma in the probe, an aberration that can be misidentified as tilt of the specimen, is also investigated and it is shown how the effects of coma and tilt can be differentiated. The effects of tilt may be offset to a large extent by shifting the diffraction plane detector an amount equivalent to the specimen tilt and we provide an experimental proof of principle of this using a segmented detector system. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A High-performance Small Signal Amplifier

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    According to questions in the design of high quality small signal amplifier, this paper gave a new-type high performance small signal amplifier. The paper selected the operational amplifier of ICL Company and designed a new-type circuit with simple, low cost and excellent performance.

  9. low pump power photonic crystal fibre amplifiers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Broeng, Jes; Bjarklev, Anders Overgaard

    2003-01-01

    Designs of low pump power optical amplifiers, based on photonic crystal fibres are presented. The potential of these fibre amplifiers is investigated, and it is demonstrated that such amplifiers may deliver gains of more than 15 dB at 1550 nm with less than 1 mW of optical pump power....

  10. Remote Acquisition Amplifier For 50-Ohm Cable

    Science.gov (United States)

    Amador, Jose J.

    1995-01-01

    Buffer-amplifier unit designed to drive 50-Ohm cables up to 100 ft. (30 m) long, compensating for attenuation in cables and enabling remote operation of oscilloscopes. Variable resistor provides for adjustment of gain of amplifier, such that overall gain from input terminals of amplifier to output end of cable set to unity.

  11. Bio-isolated DC operational amplifier

    Science.gov (United States)

    Lee, R. D.

    1974-01-01

    Possibility of shocks from leakage currents can be reduced by use of isolated preamplifiers. Amplifier consists of battery-powered operational amplifier coupled by means of light-emitting diodes to another amplifier which may be grounded and operated from ac power mains or separate battery supply.

  12. Amplified Fiber-Loop Ringdown Spectroscopy

    Science.gov (United States)

    Litman, Jessica; Barnes, Jack; Loock, Hans-Peter

    2009-06-01

    Many commercial liquid chemical analysis systems, such as high-performance liquid chromatography (HPLC) or capillary electrophoresis consist of a separation followed by optical detection. Besides small volumes and low detection limits, the system should also allow the detection of a large variety of analytes. Existing absorption and fluorescence detectors are often not very sensitive or require labelling. Here, an absorption detector is presented based on cavity ring-down spectroscopy (CRDS) where the optical cavity is made from fibre optic waveguides and the light source is a continuous wave (cw) diode laser. The purpose of this project is to increase the detection of analytes through their overtone absorption in the telecom region at 1300 to 1500 nm. This is done by increasing the ratio of desired loss (extinction caused by the sample), to undesirable loss (due to the waveguides or solvents) through amplification of the ringdown signal using a gain-clamped erbium doped fibre amplifier (EDFA). The amplified cavity has a round-trip time of 750 ns and we achieved a detection limit of at most 250 ppm when measuring acetylene at 1532.83 nm. The application of our method to detection of dissolved analytes or particles in liquids will be discussed.

  13. Sexing birds using random amplified polymorphic DNA (RAPD) markers

    NARCIS (Netherlands)

    Lessells, C.M.; Mateman, A.C.

    1998-01-01

    We used random amplified polymorphic DNA (RAPD) markers to sex birds from small tissue (usually blood) samples. Arbitrarily chosen 10-mer PCR primers were screened with DNA from known-sex individuals for the production of a bright female-specific band. Suitable primers were found for seven bird spec

  14. A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages

    Science.gov (United States)

    Kirkpatrick, J. Davy; Cruz, Kelle L.; Barman, Travis S.; Burgasser, Adam J.; Looper, Dagny L.; Tinney, C. G.; Gelino, Christopher R.; Lowrance, Patrick J.; Liebert, James; Carpenter, John M.; Hillenbrand, Lynne A.; Stauffer, John R.

    2008-12-01

    Using a large sample of optical spectra of late-type dwarfs, we identify a subset of late-M through L field dwarfs that, because of the presence of low-gravity features in their spectra, are believed to be unusually young. From a combined sample of 303 field L dwarfs, we find observationally that 7.6% +/- 1.6% are younger than 100 Myr. This percentage is in agreement with theoretical predictions once observing biases are taken into account. We find that these young L dwarfs tend to fall in the southern hemisphere (decl . verified, this result would reinforce the caveat first cited by Kirkpatrick and coworkers that the lithium test should be used with caution when attempting to confirm the substellar nature of the youngest brown dwarfs. Most of the spectroscopic data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Other spectroscopic data were collected at the Subaru Telescope, the twin telescopes of the Gemini Observatory, the Magellan-Clay Telescope, the Kitt Peak National Observatory Mayall Telescope, and the Cerro Tololo Interamerican Observatory Blanco Telescope.

  15. Room-temperature electron spin amplifier based on Ga(In)NAs alloys.

    Science.gov (United States)

    Puttisong, Yuttapoom; Buyanova, Irina A; Ptak, Aaron J; Tu, Charles W; Geelhaar, Lutz; Riechert, Henning; Chen, Weimin M

    2013-02-06

    The first experimental demonstration of a spin amplifier at room temperature is presented. An efficient, defect-enabled spin amplifier based on a non-magnetic semiconductor, Ga(In)NAs, is proposed and demonstrated, with a large spin gain (up to 2700% at zero field) for conduction electrons and a high cut-off frequency of up to 1 GHz.

  16. A programmable log-linear amplifier for wide range nuclear power measuring channels

    Science.gov (United States)

    Khaleeq, M. Tahir; Alam, Mahmood; Ghumman, Iftikhar Ahmad

    2002-12-01

    A programmable log-linear amplifier has been developed for nuclear channels. The amplifier can be programmed for logarithmic, linear or log-linear mode of operation. In the log-linear mode, the amplifier operates partially in log mode and automatically switches to linear mode at any preset point. The log-linear mode is used for wide range operation of nuclear channels and, hence, the amplifier will improve the fault finding capabilities of the nuclear channels used in power range. The amplifier is tested at nuclear reactor and the results are found in very good agreement with the designed specifications. This article presents design and construction of the amplifier and field test results.

  17. FPGA-Based Digital Current Switching Power Amplifiers Used in Magnetic Bearing Systems

    Science.gov (United States)

    Wang, Yin; Zhang, Kai; Dong, Jinping

    For a traditional two-level current switching power amplifier (PA) used in a magnetic bearing system, its current ripple is obvious. To increase its current ripple performance, three-level amplifiers are designed and their current control is generally based on analog and logical circuits. So the required hardware is complex and a performance increase from the hardware adjustment is difficult. To solve this problem, a FPGA-based digital current switching power amplifier (DCSPA) was designed. Its current ripple was obviously smaller than a two-level amplifier and its control circuit was much simpler than a tri-level amplifier with an analog control circuit. Because of the field-programmable capability of a FPGA chip used, different control algorithms including complex nonlinear algorithms could be easily implemented in the amplifier and their effects could be compared with the same hardware.

  18. Note: Development of a wideband amplifier for cryogenic scanning tunneling microscopy

    Science.gov (United States)

    Zhang, Chao; Jeon, Hoyeon; Oh, Myungchul; Lee, Minjun; Kim, Sungmin; Yi, Sunwouk; Lee, Hanho; Zoh, Inhae; Yoo, Yongchan; Kuk, Young

    2017-06-01

    A wideband cryogenic amplifier has been developed for low temperature scanning tunneling microscopy. The amplifier consisting of a wideband complementary metal oxide semiconductor field effect transistors operational amplifier together with a feedback resistor of 100 kΩ and a capacitor is mounted within a 4 K Dewar. This amplifier has a wide bandwidth and is successfully applied to scanning tunneling microscopy applications at low temperatures down to ˜7 K. The quality of the designed amplifier is validated by high resolution imaging. More importantly, the amplifier has also proved to be capable of performing scanning tunneling spectroscopy measurements, showing the detection of the Shockley surface state of the Au(111) surface and the superconducting gap of Nb(110).

  19. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2003-01-01

    In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. The amplifier is constructed in a fully differential topology to maximize noise rejection. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved....... A continuous-time current-steering offset-compensation technique is utilized in order to minimize the noise contribution and to minimize dynamic impact on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0...

  20. Log amplifier with pole-zero compensation

    Science.gov (United States)

    Brookshier, William

    1987-01-01

    A logarithmic amplifier circuit provides pole-zero compensation for improved stability and response time over 6-8 decades of input signal frequency. The amplifier circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedback loop. The compensated output signal is provided by the second operational amplifier with the log elements, i.e., resistors, and the compensating capacitors in each of the feedback loops having equal values so that each break point or pole is offset by a compensating break point or zero.

  1. Low-noise amplifiers for satellite communications

    Science.gov (United States)

    Whelehan, J.

    1984-02-01

    It is pointed out that over the past several years significant advances have been made in the overall capability of both microwave and mm-wave receivers. This is particularly apparent in the telecom market. Integral parts of advanced receiver technology are low-noise receivers. The advances currently being achieved in low-noise technology are partly based on developments in GaAs semiconductor technology. The development of high-cutoff-frequency beam lead mixer diodes has led to the development of mm-wave low-noise mixers with excellent low-noise capability. The advanced techniques are now being employed in field-deployable systems. Low noise is an important factor in satellite communications applications. Attention is given to C-band fixed satellite service, C-band parametric amplifiers, C-band FET, and X band, the Ku band, and the 30/20 GHz band.

  2. Supernovae in the Subaru Deep Field: An Initial Sample, and Type Ia Rate, out to Redshift 1.6

    CERN Document Server

    Poznanski, Dovi; Yasuda, Naoki; Foley, Ryan J; Doi, Mamoru; Filippenko, Alexei V; Fukugita, Masataka; Gal-Yam, Avishay; Jannuzi, Buell T; Morokuma, Tomoki; Oda, Takeshi; Schweiker, Heidi; Sharon, Keren; Silverman, Jeffrey M; Totani, Tomonori

    2007-01-01

    Large samples of high-redshift supernovae (SNe) are potentially powerful probes of cosmic star formation, metal enrichment, and SN physics. We present initial results from a new deep SN survey, based on re-imaging in the R, i', z' bands, of the 0.25 deg2 Subaru Deep Field (SDF), with the 8.2-m Subaru telescope and Suprime-Cam. In a single new epoch consisting of two nights of observations, we have discovered 33 SNe, down to a z'-band magnitude of 26.3 (AB). We have measured the photometric redshifts of the SN host galaxies, obtained Keck spectroscopic redshifts for 17 of the host galaxies, and classified the SNe using the Bayesian photometric algorithm of Poznanski et al. (2007) that relies on template matching. After correcting for biases in the classification, 55% of our sample consists of Type Ia supernovae and 45% of core-collapse SNe. The redshift distribution of the SNe Ia reaches z ~ 1.6, with a median of z ~ 1.2. The core-collapse SNe reach z ~ 1.0, with a median of z ~ 0.5. Our SN sample is comparabl...

  3. The psychometric properties of the personality inventory for DSM-5 in an APA DSM-5 field trial sample.

    Science.gov (United States)

    Quilty, Lena C; Ayearst, Lindsay; Chmielewski, Michael; Pollock, Bruce G; Bagby, R Michael

    2013-06-01

    Section 3 of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) includes a hybrid model of personality pathology, in which dimensional personality traits are used to derive one of seven categorical personality disorder diagnoses. The Personality Inventory for DSM-5 (PID-5) was developed by the DSM-5 Personality and Personality Disorders workgroup and their consultants to produce a freely available instrument to assess the personality traits within this new system. To date, the psychometric properties of the PID-5 have been evaluated primarily in undergraduate student and community adult samples. In the current investigation, we extend this line of research to a psychiatric patient sample who participated in the APA DSM-5 Field Trial (Centre for Addiction and Mental Health site). A total of 201 psychiatric patients (102 men, 99 women) completed the PID-5 and the Revised NEO Personality Inventory (NEO PI-R). The internal consistencies of the PID-5 domain and facet trait scales were acceptable. Results supported the unidimensional structure of all trait scales but one, and the convergence between the PID-5 and analogous NEO PI-R scales. Evidence for discriminant validity was mixed. Overall, the current investigation provides support for the psychometric properties of this diagnostic instrument in psychiatric samples.

  4. Spectroscopic amplifier for pin diode; Amplificador espectroscopico para diodo Pin

    Energy Technology Data Exchange (ETDEWEB)

    Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R., E-mail: bebe.luna_s@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  5. Update on Waveguide-Embedded Differential MMIC Amplifiers

    Science.gov (United States)

    Kangaslahti, Pekka; Schleht, Erich

    2010-01-01

    There is an update on the subject matter of Differential InP HEMT MMIC Amplifiers Embedded in Waveguides (NPO-42857) NASA Tech Briefs, Vol. 33, No. 9 (September 2009), page 35. To recapitulate: Monolithic microwave integrated-circuit (MMIC) amplifiers of a type now being developed for operation at frequencies of hundreds of gigahertz contain InP high-electron-mobility transistors (HEMTs) in a differential configuration. The MMICs are designed integrally with, and embedded in, waveguide packages. The instant work does not mention InP HEMTs but otherwise reiterates part of the subject matter of the cited prior article, with emphasis on the following salient points: An MMIC is mounted in the electric-field plane ("E-plane") of a waveguide and includes a finline transition to each differential-amplifier stage. The differential configuration creates a virtual ground within each pair of transistor-gate fingers, eliminating the need for external radio-frequency grounding. This work concludes by describing a single-stage differential submillimeter-wave amplifier packaged in a rectangular waveguide and summarizing results of tests of this amplifier at frequencies of 220 and 305 GHz.

  6. Design of A Microwave Amplifier for Wireless Application

    Directory of Open Access Journals (Sweden)

    M. H. Ullah

    2012-01-01

    Full Text Available Problem statement: Low-Noise Amplifiers (LNA are very indispensable components in the design of numerous types of communication receivers employed in microwave technology. This paper is presents the design and development of low bias(Vce = 8v, Ic =10 mA single stage low noise microwave amplifier operating in 1.5GHZ frequency range, Gain 13dB ± 0.5dB, input/output return loss Approach: The principal design target is to obtain a minimum noise figure while concomitantly achieving a maximum gain by presenting the optimum noise impedance (Zopt which is characteristically implemented by adding a matching circuit between the source and the input of the amplifier. Results: The proposed low-noise amplifier for microwave wireless application is designed, simulated and optimized using Serenade Harmonica (by Ansoft Corporation and Advance Design System (ADS software by Agilent. Conclusion: In this paper a low-noise amplifier operated at 1.5 GHz. is designed because of the significant roles played in the field of microwave communication technology, which includes the application in the output stage of a transmitter where the signals needs to be strengthen before transmission.

  7. Physical properties of two core samples from Well 34-9RD2 at the Coso geothermal field, California

    Science.gov (United States)

    Morrow, C.A.; Lockner, D.A.

    2006-01-01

    The Coso geothermal field, located along the Eastern California Shear Zone, is composed of fractured granitic rocks above a shallow heat source. Temperatures exceed 640 ?F (~338 ?C) at a depth of less than 10000 feet (3 km). Permeability varies throughout the geothermal field due to the competing processes of alteration and mineral precipitation, acting to reduce the interconnectivity of faults and fractures, and the generation of new fractures through faulting and brecciation. Currently, several hot regions display very low permeability, not conducive to the efficient extraction of heat. Because high rates of seismicity in the field indicate that the area is highly stressed, enhanced permeability can be stimulated by increasing the fluid pressure at depth to induce faulting along the existing network of fractures. Such an Enhanced Geothermal System (EGS), planned for well 46A-19RD, would greatly facilitate the extraction of geothermal fluids from depth by increasing the extent and depth of the fracture network. In order to prepare for and interpret data from such a stimulation experiment, the physical properties and failure behavior of the target rocks must be fully understood. Various diorites and granodiorites are the predominant rock types in the target area of the well, which will be pressurized from 10000 feet measured depth (MD) (3048m MD) to the bottom of the well at 13,000 feet MD (3962 m MD). Because there are no core rocks currently available from well 46A-19RD, we report here on the results of compressive strength, frictional sliding behavior, and elastic measurements of a granodiorite and diorite from another well, 34-9RD2, at the Coso site. Rocks cored from well 34-9RD2 are the deepest samples to date available for testing, and are representative of rocks from the field in general.

  8. High temperature charge amplifier for geothermal applications

    Science.gov (United States)

    Lindblom, Scott C.; Maldonado, Frank J.; Henfling, Joseph A.

    2015-12-08

    An amplifier circuit in a multi-chip module includes a charge to voltage converter circuit, a voltage amplifier a low pass filter and a voltage to current converter. The charge to voltage converter receives a signal representing an electrical charge and generates a voltage signal proportional to the input signal. The voltage amplifier receives the voltage signal from the charge to voltage converter, then amplifies the voltage signal by the gain factor to output an amplified voltage signal. The lowpass filter passes low frequency components of the amplified voltage signal and attenuates frequency components greater than a cutoff frequency. The voltage to current converter receives the output signal of the lowpass filter and converts the output signal to a current output signal; wherein an amplifier circuit output is selectable between the output signal of the lowpass filter and the current output signal.

  9. Audio power amplifier design handbook

    CERN Document Server

    Self, Douglas

    2013-01-01

    This book is essential for audio power amplifier designers and engineers for one simple reason...it enables you as a professional to develop reliable, high-performance circuits. The Author Douglas Self covers the major issues of distortion and linearity, power supplies, overload, DC-protection and reactive loading. He also tackles unusual forms of compensation and distortion produced by capacitors and fuses. This completely updated fifth edition includes four NEW chapters including one on The XD Principle, invented by the author, and used by Cambridge Audio. Cro

  10. Increased DNA amplification success of non-invasive genetic samples by successful removal of inhibitors from faecal samples collected in the field

    DEFF Research Database (Denmark)

    Hebert, Louise; Darden, Safi K.; Pedersen, Bo Vest;

    2011-01-01

    The use of non-invasive genetic sampling (NGS) is becoming increasingly important in the study of wild animal populations. Obtaining DNA from faecal samples is of particular interest because faeces can be collected without deploying sample capture devices. However, PCR amplification of DNA...... extracted from faeces is problematic because of high concentrations of inhibitors. Here we present a method for increasing the successful application of donor DNA extracted from faecal samples through inhibitor reduction. After standard extraction with a DNA stool kit we used a ‘Concentrated Chelex...... Treatment’ (CCT) that increased the amplification success from 31.7 to 61.4% of loci. Our results suggest that darker supernatant and samples with more precipitate contain more inhibitors than lighter samples and samples with little or no precipitate. We expect the use of this technique to have wide...

  11. Integrating silicon nanowire field effect transistor, microfluidics and air sampling techniques for real-time monitoring biological aerosols.

    Science.gov (United States)

    Shen, Fangxia; Tan, Miaomiao; Wang, Zhenxing; Yao, Maosheng; Xu, Zhenqiang; Wu, Yan; Wang, Jindong; Guo, Xuefeng; Zhu, Tong

    2011-09-01

    Numerous threats from biological aerosol exposures, such as those from H1N1 influenza, SARS, bird flu, and bioterrorism activities necessitate the development of a real-time bioaerosol sensing system, which however is a long-standing challenge in the field. Here, we developed a real-time monitoring system for airborne influenza H3N2 viruses by integrating electronically addressable silicon nanowire (SiNW) sensor devices, microfluidics and bioaerosol-to-hydrosol air sampling techniques. When airborne influenza H3N2 virus samples were collected and delivered to antibody-modified SiNW devices, discrete nanowire conductance changes were observed within seconds. In contrast, the conductance levels remained relatively unchanged when indoor air or clean air samples were delivered. A 10-fold increase in virus concentration was found to give rise to about 20-30% increase in the sensor response. The selectivity of the sensing device was successfully demonstrated using H1N1 viruses and house dust allergens. From the simulated aerosol release to the detection, we observed a time scale of 1-2 min. Quantitative polymerase chain reaction (qPCR) tests revealed that higher virus concentrations in the air samples generally corresponded to higher conductance levels in the SiNW devices. In addition, the display of detection data on remote platforms such as cell phone and computer was also successfully demonstrated with a wireless module. The work here is expected to lead to innovative methods for biological aerosol monitoring, and further improvements in each of the integrated elements could extend the system to real world applications.

  12. Isolation of Legionella species from Noyu (unattended natural hot springs in mountains and fields) samples in Japan.

    Science.gov (United States)

    Furuhata, Katsunori; Edagawa, Akiko; Ishizaki, Naoto; Fukuyama, Masafumi

    2013-01-01

    In order to understand the habitation conditions of the bacteria of the genus Legionella in Noyu (unattended natural hot springs in mountains and fields) in Japan, isolation of Legionella spp. was attempted in the Noyu samples from 11 prefectures nationwide between May and September 2012, and the following results were obtained. Overall, Legionella spp. was isolated from 16 of 43 samples (37.2%). The species was isolated from the Hokkaido region to the Chugoku region but not from the Shikoku region to the Kyushu region. The number of bacteria detected was usually small, less than 5.0 × 10(1) CFU/100 ml, as found in 11 samples (68.8%), while counts of 10(2) or more to 10(3) or less CFU/100 ml were found in two samples (12.5%). Legionella pneumophila was the most commonly found strain, with 19 strains (90.5%) found, and was the dominant species. Regarding the serogrouping, four strains (21.1%) fell under group 1, the most common grouping, followed by three strains (15.8%) in group 3, two strains (10.5%) in group 5, etc. Moreover, the detected bacterial strains other than L. pneumophila included two strains (9.5%) of L. londiniensis. The temperature of the Noyu from which Legionella spp. was isolated was between 33.1°C and 41.5°C with a pH ranging from 5.2 to 8.1. The present report is the first report to clarify the habitation conditions of strains of Legionella spp. isolated from Noyu in Japan.

  13. Residue levels of captan and trichlorfon in field-treated kaki fruits, individual versus composite samples, and after household processing.

    Science.gov (United States)

    Fernández-Cruz, M L; Grimalt, S; Villarroya, M; López, F J; Llanos, S; García-Baudín, J M

    2006-06-01

    The dissipation of residue levels of captan and trichlorfon in field-treated kaki crops was studied according to good laboratory practices to propose maximum residue limits (MRLs). Residue levels of captan and trichlorfon were analysed by GC/MS and LC-MS/MS, respectively. Residue levels of captan and trichlorfon permitted one to propose MRLs in kaki of 3 and 5 mg kg(-1), respectively. The behaviour of these residues was also studied after peeling and cooking, and in individual fruits versus composite samples. Residue levels of these compounds for individual fruits suggested that a variability factor up to three could be set for the acute risk assessment. Levels of captan decreased by more than 90% after peeling and completely after cooking. Trichlorfon penetrates into the flesh in a proportion of 70% of the residue at the pre-harvest interval. Cooking resulted in a decrease of 27% of residue levels of trichlorfon.

  14. Single Ion Quantum Lock-In Amplifier

    CERN Document Server

    Kotler, Shlomi; Glickman, Yinnon; Keselman, Anna; Ozeri, Roee

    2011-01-01

    We report on the implementation of a quantum analog to the classical lock-in amplifier. All the lock-in operations: modulation, detection and mixing, are performed via the application of non-commuting quantum operators on the electronic spin state of a single trapped Sr+ ion. We significantly increase its sensitivity to external fields while extending phase coherence by three orders of magnitude, to more than one second. With this technique we measure magnetic fields with sensitivity of 25 pT/sqrt(Hz) and light shifts with an uncertainty below 140 mHz after 1320 seconds of averaging. These sensitivities are limited by quantum projection noise and, to our knowledge, are more than two orders of magnitude better than with other single-spin probe technologies. In fact, our reported sensitivity is sufficient for the measurement of parity non-conservation, as well as the detection of the magnetic field of a single electronic-spin one micrometer from an ion-detector with nanometer resolution. As a first application ...

  15. Effect of an absorbent overlay on the residual stress field induced by laser shock processing on aluminum samples

    Energy Technology Data Exchange (ETDEWEB)

    Rubio-Gonzalez, C. [Centro de Ingenieria y Desarrollo Industrial, Pie de la Cuesta No. 702, Desarrollo San Pablo, Queretaro, Qro. 76130 (Mexico)]. E-mail: crubio@cidesi.mx; Gomez-Rosas, G. [Departamento de Ciencias Exactas y Tecnologicas, Centro Universitario de los Lagos, Universidad de Guadalajara. Lagos de Moreno Jal. (Mexico); Ocana, J.L. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Molpeceres, C. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Banderas, A. [Centro de Ingenieria y Desarrollo Industrial, Pie de la Cuesta No. 702, Desarrollo San Pablo, Queretaro, Qro. 76130 (Mexico); Porro, J. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Morales, M. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain)

    2006-07-15

    Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field, which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy are used in this investigation. A convergent lens is used to deliver 2.5 J, 8 ns laser pulses by a Q-switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 1.5 mm onto aluminum samples. Density of 2500 pulses/cm{sup 2} with infrared (1064 nm) radiation was used. The effect of an absorbent overlay on the residual stress field using this LSP setup and this energy level is evaluated. Residual stress distribution as a function of depth is assessed by the hole drilling method. It is observed that the overlay makes the compressive residual stress profile move to the surface. This effect is explained on the basis of the vaporization of the coat layer suppressing thermal effects on the metallic substrate. The effect of coating the specimen surface before LSP treatment may have advantages on improving wear and contact fatigue properties of this aluminum alloy.

  16. The Evolution of the Field and Cluster Morphology-Density Relation for Mass-Selected Samples of Galaxies

    CERN Document Server

    Van der Wel, A; Franx, M; Illingworth, G D; Postman, M P; Kelson, D D; Labbé, I; Blakeslee, J P; Ford, H C

    2007-01-01

    The Sloan Digital Sky Survey (SDSS) and photometric/spectroscopic surveys in the GOODS-South field (the Chandra Deep Field-South, CDFS) are used to construct volume-limited, stellar mass-selected samples of galaxies at redshifts 02.5. The fraction of E+S0 galaxies is 43+/-3%$ at z~0.03 and 48+/-7% at z~0.8, i.e., it has not changed significantly since z~0.8. When combined with recent results for cluster galaxies in the same redshift range, we find that the morphology-density relation for galaxies more massive than 0.5M* has remained constant since at least z~0.8. This implies that galaxies evolve in mass, morphology and density such that the morphology-density relation does not change. In particular, the decline of star formation activity and the accompanying increase in the stellar mass density of red galaxies since z~1 must happen without large changes in the early-type galaxy fraction in a given environment.

  17. High power RF solid state power amplifier system

    Science.gov (United States)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2011-01-01

    A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

  18. Exponentially-Biased Ground-State Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians

    CERN Document Server

    Mandrà, Salvatore; Katzgraber, Helmut G

    2016-01-01

    We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground-state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated to a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009)]. These results suggest that more complex driving Hamiltonians, which introduce transitions between all states with equal weights, are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.

  19. Determination of plutonium concentrations and isotope ratios in environmental samples with a double-focusing sector field ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Rodushkin, I. [Svensk Grundaemnesanalys AB, Luleaa University of Technology, S-971 87 Luleaa (Sweden); Lindahl, P. [Department of Radiation Physics, Lund University, S-221 85 Lund (Sweden); Holm, E. [Department of Radiation Physics, Lund University, S-221 85 Lund (Sweden); Roos, P. [Department of Radiation Physics, Lund University, S-221 85 Lund (Sweden)

    1999-03-01

    An analytical method for the ultratrace and isotopic analysis of plutonium in sediment samples using a double focusing sector field ICP mass spectrometer (ICP-SMS) is described. A detection limit for plutonium in the sub-fg ml{sup -1} range was achieved. The ICP-SMS results were in acceptable agreement with alpha spectrometry. At the low fg ml{sup -1} level a precision in isotope ratio measurements of 2-10% RSD was achieved. Accuracy of the results was assessed by {sup 238}U/{sup 235}U and {sup 205}Tl/{sup 203}Tl isotope ratio determinations using isotopic standards and a natural Tl standard solution, respectively. It was shown that correction for {sup 238}UH{sup +} and {sup 238}UH{sup +}{sub 2} is necessary for both plutonium concentration and isotopic composition determinations. From a practical standpoint, the use of ICP-SMS for plutonium measurements is an attractive alternative to techniques such as alpha spectrometry and thermal ionization mass spectrometry (TIMS) due to its higher throughput and ability to measure both concentration and isotopic ratio on the same sample.

  20. Versatile pulsed laser setup for depth profiling analysis of multilayered samples in the field of cultural heritage

    Science.gov (United States)

    Mendes, N. F. C.; Osticioli, I.; Striova, J.; Sansonetti, A.; Becucci, M.; Castellucci, E.

    2009-04-01

    The present study considers the use of a nanosecond pulsed laser setup capable of performing laser induced breakdown spectroscopy (LIBS) and pulsed Raman spectroscopy for the study of multilayered objects in the field of cultural heritage. Controlled etching using the 4th harmonic 266 nm emission of a Nd:YAG laser source with a 8 ns pulse duration was performed on organic films and mineral strata meant to simulate different sequence of layers usually found in art objects such as in easel and mural paintings. The process of micro ablation coupled with powerful spectroscopic techniques operating with the same laser source, constitutes an interesting alternative to mechanical sampling especially when dealing with artworks such as ceramics and metal works which are problematic due to their hardness and brittleness. Another case is that of valuable pieces where sampling is not an option and the materials to analyse lie behind the surface. The capabilities and limitations of such instrumentation were assessed through several tests in order to characterize the trend of the laser ablation on different materials. Monitored ablation was performed on commercial sheets of polyethylene terephthalate (PET), a standard material of known thickness and mechanical stability, and rabbit glue, an adhesive often used in works of art. Measurements were finally carried out on a specimen with a stratigraphy similar to those found in real mural paintings.

  1. Integral field optical spectroscopy of a representative sample of ULIRGs: II. Two-dimensional kpc-scale extinction structure

    CERN Document Server

    García-Marín, M; Arribas, S

    2009-01-01

    We investigate the two-dimensional kpc-scale structure of the extinction in a representative sample of local ULIRGs using the Halpha/Hbeta line ratio.We use optical integral field spectroscopy obtained with the INTEGRAL instrument at the William Herschel Telescope. Complementary optical and near-IR high angular resolution HST images have also been used. The extinction exhibits a very complex and patchy structure in ULIRGs on kpc scales, from basically transparent regions to others deeply embedded in dust (Av~0.0 to Av~8.0 mag). Nuclear extinction covers a broad range in Av from 0.6 to 6 mag, 69% of the nuclei having Av>2.0 mag. Extinction in the external regions is substantially lower than in the nuclei with 64% of the ULIRGs in the sample having median Av of less than 2 mag for the entire galaxy. While post-coalescence nuclei tend to cluster around Av values of 2 to 3 mag, pre-coalescence nuclei appear more homogeneously distributed over the entire 0.4 mag

  2. A Quantitative Approach for Collocating NEON's Sensor-Based Ecological Measurements and in-situ Field Sampling and Observations

    Science.gov (United States)

    Zulueta, R. C.; Metzger, S.; Ayres, E.; Luo, H.; Meier, C. L.; Barnett, D.; Sanclements, M.; Elmendorf, S.

    2013-12-01

    The National Ecological Observatory Network (NEON) is a continental-scale research platform currently in development to assess the causes of ecological change and biological responses to change across a projected 30-year timeframe. A suite of standardized sensor-based measurements (i.e., Terrestrial Instrument System (TIS) measurements) and in-situ field sampling and observations (i.e., Terrestrial Observation System (TOS) activities) will be conducted across 20 ecoclimatic domains in the U.S. where NEON is establishing 60 terrestrial research sites. NEON's TIS measurements and TOS activities are designed to observe the temporal and spatial dynamics of key drivers and ecological processes and responses to change within each of the 60 terrestrial research sites. The TIS measurements are non-destructive and designed to provide in-situ, continuous, and areally integrated observations of the surrounding ecosystem and environment, while TOS sampling and observation activities are designed to encompass a hierarchy of measurable biological states and processes including diversity, abundance, phenology, demography, infectious disease prevalence, ecohydrology, and biogeochemistry. To establish valid relationships between these drivers and site-specific responses, two contradicting requirements must be fulfilled: (i) both types of observations shall be representative of the same ecosystem, and (ii) they shall not significantly influence one another. Here we outline the theoretical background and algorithmic process for determining areas of mutual representativeness and exclusion around NEON's TIS measurements and develop a procedure which quantitatively optimizes this trade-off through: (i) quantifying the source area distributions of TIS measurements, (ii) determining the ratio of user-defined impact threshold to effective impact area for different TOS activities, and (iii) determining the range of feasible distances between TIS locations and TOS activities. This approach

  3. First Results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics of Lensed Galaxies at Cosmic Noon

    Science.gov (United States)

    Mason, Charlotte A.; Treu, Tommaso; Fontana, Adriano; Jones, Tucker; Morishita, Takahiro; Amorin, Ricardo; Bradač, Maruša; Quinn Finney, Emily; Grillo, Claudio; Henry, Alaina; Hoag, Austin; Huang, Kuang-Han; Schmidt, Kasper B.; Trenti, Michele; Vulcani, Benedetta

    2017-03-01

    We present the first results of the K-band Multi-Object Spectrometer (KMOS) Lens-Amplified Spectroscopic Survey, a new ESO Very Large Telescope large program, doing multi-object integral field spectroscopy of galaxies gravitationally lensed behind seven galaxy clusters selected from the Hubble Space Telescope (HST) Grism Lens-Amplified Survey from Space. Using the power of the cluster magnification, we are able to reveal the kinematic structure of 25 galaxies at 0.7≲ z≲ 2.3, in four cluster fields, with stellar masses 7.8≲ {log}({M}\\star / {M}ȯ )≲ 10.5. This sample includes five sources at z> 1 with lower stellar masses than in any previous kinematic integral field unit (IFU) surveys. Our sample displays a diversity in kinematic structure over this mass and redshift range. The majority of our kinematically resolved sample is rotationally supported, but with a lower ratio of rotational velocity to velocity dispersion than in the local universe, indicating the fraction of dynamically hot disks changes with cosmic time. We find that no galaxies with stellar mass objects more faithfully than slit spectrographs. With artificial slits, we estimate that slit spectrographs miss, on average, 60% of the total flux of emission lines, which decreases rapidly if the emission line is spatially offset from the continuum.

  4. Numerical model of frequency converter based on four-wave mixing in semiconductor amplifiers

    DEFF Research Database (Denmark)

    Cassioli, D.; Scotti, S.; Mecozzi, A.

    1999-01-01

    We describe a numerical model of the dynamics of a semiconductor optical amplifier that includes the description of the nonlinear optical processes within the waveguide and the longitudinal inhomogeneity caused by the saturating field....

  5. Locoregional MYCN-amplified neuroblastoma.

    Science.gov (United States)

    Morales La Madrid, Andres; Volchenboum, Samuel; Gastier-Foster, Julie M; Pyatt, Robert; Liu, Don; Pytel, Peter; Lavarino, Cinzia; Rodriguez, Eva; Cohn, Susan L

    2012-10-01

    MYCN-amplification is strongly associated with other high-risk prognostic factors and poor outcome in neuroblastoma. Infrequently, amplification of MYCN has been identified in localized tumors with favorable biologic features. Outcome for these children is difficult to predict and optimal treatment strategies remain unclear. We report a 5-month-old who presented with an MYCN-amplified INSS stage 3, pelvic neuroblastoma. The tumor had favorable histology, hyperdiploidy, and lacked 1p36 and 11q23 aberrations. Although the patient met the criteria for high-risk neuroblastoma, because of the discordant prognostic markers we elected to treat her according to an intermediate-risk protocol. She remains event-free more than 18 months.

  6. Transverse pumped laser amplifier architecture

    Science.gov (United States)

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  7. Vent 7504 of the San Francisco Volcanic Field (SFVF), Arizona: Sample Geochemistry and Implications for Cone Formation

    Science.gov (United States)

    Needham, D. H.; Eppler, D. B.; Bleacher, J. E.; Skinner, J. A.; Evans, C. A.; Feng, W.; Gruener, J. E.; Whitson, P. A.; Janoiko, B. A.; Mertzman, S. A.

    2015-12-01

    Vent 7504 is a complex structure in the SFVF that has 3 unit classes: a central cone with exposed dikes and cinder-covered rheomorphic facies; a SE/NW-trending ridge north of the cone with cinder-covered rheomorphic facies; and three discrete lava flows that emanate to the N from the ridge and to the SW and NW from the cone. Field observations suggest the ridge was the northern crest of an initial, larger cone. The NW portion of this cone was most likely disrupted during a catastrophic breach of lava that had accumulated within the cone; this third of three lava flows carried rafted packages of the rheomorphic cone facies to the NW, forming the linear N ridge. The final phase of pyroclastic activity was concentrated in the SW portion of the original cone, covering the top of the cone with cinders and forming the more traditional conic-shaped construct observed today. This study describes the geochemistry of 9 samples collected from the mapped units (2 from the cone, 1 from the N ridge, 1 from the N lava flow, 2 from the SW lava flow, and 3 from the NW lava flow) to further constrain the formation of Vent 7504. Geochemical analyses including back-scatter electron scanning electron microscopy and laboratory X-ray fluorescence spectroscopy were conducted on the 9 collected samples to measure bulk rock and olivine phenocryst compositions. Major element concentrations in the bulk rock and olivine compositions are strongly clustered in all samples, indicating they likely originated from a single magmatic source. Bulk rock SiO2 (~47.5 wt%) and alkali (Na2O + K2O, ~2.7 wt% + 0.71 wt%) concentrations are consistent with a basaltic classification for these samples. Trends in major elements relative to MgO are observed for the olivine phenocrysts: SiO2, Al2O3, Na2O, and TiO2 remain constant relative to MgO, but strong linear trends are observed in MnO, FeO, and NiO relative to MgO. These linear trends are expected given the potential for bivalent cation exchanges in the

  8. Dependence of B1+ and B1− Field Patterns of Surface Coils on the Electrical Properties of the Sample and the MR Operating Frequency

    Science.gov (United States)

    Vaidya, Manushka V.; Collins, Christopher M.; Sodickson, Daniel K.; Brown, Ryan; Wiggins, Graham C.; Lattanzi, Riccardo

    2016-01-01

    In high field MRI, the spatial distribution of the radiofrequency magnetic (B1) field is usually affected by the presence of the sample. For hardware design and to aid interpretation of experimental results, it is important both to anticipate and to accurately simulate the behavior of these fields. Fields generated by a radiofrequency surface coil were simulated using dyadic Green’s functions, or experimentally measured over a range of frequencies inside an object whose electrical properties were varied to illustrate a variety of transmit (B1+) and receive (B1−) field patterns. In this work, we examine how changes in polarization of the field and interference of propagating waves in an object can affect the B1 spatial distribution. Results are explained conceptually using Maxwell’s equations and intuitive illustrations. We demonstrate that the electrical conductivity alters the spatial distribution of distinct polarized components of the field, causing “twisted” transmit and receive field patterns, and asymmetries between |B1+| and |B1−|. Additionally, interference patterns due to wavelength effects are observed at high field in samples with high relative permittivity and near-zero conductivity, but are not present in lossy samples due to the attenuation of propagating EM fields. This work provides a conceptual framework for understanding B1 spatial distributions for surface coils and can provide guidance for RF engineers.

  9. Dependence of B1+ and B1- Field Patterns of Surface Coils on the Electrical Properties of the Sample and the MR Operating Frequency.

    Science.gov (United States)

    Vaidya, Manushka V; Collins, Christopher M; Sodickson, Daniel K; Brown, Ryan; Wiggins, Graham C; Lattanzi, Riccardo

    2016-02-01

    In high field MRI, the spatial distribution of the radiofrequency magnetic ( B1) field is usually affected by the presence of the sample. For hardware design and to aid interpretation of experimental results, it is important both to anticipate and to accurately simulate the behavior of these fields. Fields generated by a radiofrequency surface coil were simulated using dyadic Green's functions, or experimentally measured over a range of frequencies inside an object whose electrical properties were varied to illustrate a variety of transmit [Formula: see text] and receive [Formula: see text] field patterns. In this work, we examine how changes in polarization of the field and interference of propagating waves in an object can affect the B1 spatial distribution. Results are explained conceptually using Maxwell's equations and intuitive illustrations. We demonstrate that the electrical conductivity alters the spatial distribution of distinct polarized components of the field, causing "twisted" transmit and receive field patterns, and asymmetries between [Formula: see text] and [Formula: see text]. Additionally, interference patterns due to wavelength effects are observed at high field in samples with high relative permittivity and near-zero conductivity, but are not present in lossy samples due to the attenuation of propagating EM fields. This work provides a conceptual framework for understanding B1 spatial distributions for surface coils and can provide guidance for RF engineers.

  10. Dynamics of Soliton Cascades in Fiber Amplifiers

    CERN Document Server

    Arteaga-Sierra, F R; Agrawal, Govind P

    2016-01-01

    We study numerically the formation of cascading solitons when femtosecond optical pulses are launched into a fiber amplifier with less energy than required to form a soliton of equal duration. As the pulse is amplified, cascaded fundamental solitons are created at different distances, without soliton fission, as each fundamental soliton moves outside the gain bandwidth through the Raman-induced spectral shifts. As a result, each input pulse creates multiple, temporally separated, ultrashort pulses of different wavelengths at the amplifier output. The number of pulses depends not only on the total gain of the amplifier but also on the width of input pulses.

  11. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann;

    2012-01-01

    study of a 1 QW photonic crystal amplifier. Net gain is achieved which enables laser oscillation in photonic crystal micro cavities. The ability to freely tailor the dispersion in a semiconductor optical amplifier makes it possible to raise the optical gain considerably over a certain bandwidth......We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission...

  12. Reflection amplifiers in self-regulated learning

    NARCIS (Netherlands)

    Verpoorten, Dominique

    2012-01-01

    Verpoorten, D. (2012). Reflection amplifiers in self-regulated learning. Doctoral thesis. November, 9, 2012, Heerlen, The Netherlands: Open Universiteit (CELSTEC). Datawyse / Universitaire Pers Maastricht.

  13. Design of an 1800nm Raman amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    2013-01-01

    We present the experimental results for a Raman amplifier that operates at 1810 nm and is pumped by a Raman fiber laser at 1680 nm. Both the pump laser and the Raman amplifier is polarization maintaining. A challenge when scaling Raman amplifiers to longer wavelengths is the increase...... in transmission loss, but also the reduction in the Raman gain coefficient as the amplifier wavelength is increased. Both polarization components of the Raman gain is characterized, initially for linearly co-polarized signal and pump, subsequently linearly polarized orthogonal signal and pump. The noise...

  14. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Heaney, M.B. (California Univ., Berkeley, CA (USA). Dept. of Physics Lawrence Berkeley Lab., CA (USA))

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al{sub 2}O{sub 3}/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 {times} 10{sup 17} in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO{sub 3} crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

  15. Nuclear magnetic resonance experiments with DC SQUID amplifiers

    Science.gov (United States)

    Heaney, M. B.

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting Quantum Interference Devices) with Nb/Al2O3/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 x 10(exp 17) in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO3 crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

  16. Three-dimensional temperature fields of the North Patagonian Sea recorded by Magellanic penguins as biological sampling platforms

    Science.gov (United States)

    Sala, Juan E.; Pisoni, Juan P.; Quintana, Flavio

    2017-04-01

    Temperature is a primary determinant of biogeographic patterns and ecosystem processes. Standard techniques to study the ocean temperature in situ are, however, particularly limited by their time and spatial coverage, problems which might be partially mitigated by using marine top predators as biological platforms for oceanographic sampling. We used small archival tags deployed on 33 Magellanic penguins (Spheniscus magellanicus), and obtained 21,070 geo-localized profiles of water temperature, during late spring of 2008, 2011, 2012 and 2013; in a region of the North Patagonian Sea with limited oceanographic records in situ. We compared our in situ data of sea surface temperature (SST) with those available from satellite remote sensing; to describe the three-dimensional temperature fields around the area of influence of two important tidal frontal systems; and to study the inter-annual variation in the three-dimensional temperature fields. There was a strong positive relationship between satellite- and animal-derived SST data although there was an overestimation by remote-sensing by a maximum difference of +2 °C. Little inter-annual variability in the 3-dimensional temperature fields was found, with the exception of 2012 (and to a lesser extent in 2013) where the SST was significantly higher. In 2013, we found weak stratification in a region which was unexpected. In addition, during the same year, a warm small-scale vortex is indicated by the animal-derived temperature data. This allowed us to describe and better understand the dynamics of the water masses, which, so far, have been mainly studied by remote sensors and numerical models. Our results highlight again the potential of using marine top predators as biological platforms to collect oceanographic data, which will enhance and accelerate studies on the Southwest Atlantic Ocean. In a changing world, threatened by climate change, it is urgent to fill information gaps on the coupled ocean-atmosphere system

  17. Ping-pong auto-zero amplifier with glitch reduction

    Science.gov (United States)

    Larson, Mark R [Maple Grove, MN

    2008-01-22

    A ping-pong amplifier with reduced glitching is described. The ping-pong amplifier includes a nulling amplifier coupled to a switching network. The switching network is used to auto-zero a ping amplifier within a ping-pong amplifier. The nulling amplifier drives the output of a ping amplifier to a proper output voltage level during auto-zeroing of the ping amplifier. By being at a proper output voltage level, glitches associated with transitioning between a ping amplifier and a pong amplifier are reduced or eliminated.

  18. A CMOS Integrating Amplifier for the PHENIX Ring Imaging Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Wintenberg, A.L.; Jones, J.P. Jr.; Young, G.R. [Oak Ridge National Lab., TN (United States); Moscone, C.G. [Tennessee Univ., Knoxville, TN (United States)

    1997-11-01

    A CMOS integrating amplifier has been developed for use in the PHENIX Ring Imaging Cherenkov (RICH) detector. The amplifier, consisting of a charge-integrating amplifier followed by a variable gain amplifier (VGA), is an element of a photon measurement system comprising a photomultiplier tube, a wideband, gain of 10 amplifier, the integrating amplifier, and an analog memory followed by an ADC and double correlated sampling implemented in software. The integrating amplifier is designed for a nominal full scale input of 160 pC with a gain of 20 mV/pC and a dynamic range of 1000:1. The VGA is used for equalizing gains prior to forming analog sums for trigger purposes. The gain of the VGA is variable over a 3:1 range using a 5 bits digital control, and the risetime is held to approximately 20 ns using switched compensation in the VGA. Details of the design and results from several prototype devices fabricated in 1.2 {micro}m Orbit CMOS are presented. A complete noise analysis of the integrating amplifier and the correlated sampling process is included as well as a comparison of calculated, simulated and measured results.

  19. Near-field reflection backscattering apertureless optical microscopy: Application to spectroscopy experiments on opaque samples, comparison between lock-in and digital photon counting detection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Diziain, S. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Bijeon, J.-L. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France)]. E-mail: bijeon@utt.fr; Adam, P.-M. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Lamy de la Chapelle, M. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Thomas, B. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Deturche, R. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Royer, P. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France)

    2007-01-15

    An apertureless scanning near-field optical microscope (ASNOM) in reflection backscattering configuration is designed to conduct spectroscopic experiments on opaque samples constituted of latex beads. The ASNOM proposed takes advantage of the depth-discrimination properties of confocal microscopes to efficiently extract the near-field optical signal. Given their importance in a spectroscopic experiment, we systematically compare the lock-in and synchronous photon counting detection methods. Some results of Rayleigh's scattering in the near field of the test samples are used to illustrate the possibilities of this technique for reflection backscattering spectroscopy.

  20. The GOODS-MUSIC sample: a multicolour catalog of near-IR selected galaxies in the GOODS-South field

    CERN Document Server

    Grazian, A; De Santis, C; Fontana, A; Gallozzi, S; Giallongo, E; Nonino, M; Salimbeni, S; Vanzella, E

    2006-01-01

    We present a high quality multiwavelength (from 0.3 to 8.0 micron) catalog of the large and deep area in the GOODS Southern Field covered by the deep near-IR observations obtained with the ESO VLT. The catalog is entirely based on public data: in our analysis, we have included the F435W, F606W, F775W and F850LP ACS images, the JHKs VLT data, the Spitzer data provided by IRAC instrument (3.6, 4.5, 5.8 and 8.0 micron), and publicly available U-band data from the 2.2ESO and VLT-VIMOS. We describe in detail the procedures adopted to obtain this multiwavelength catalog. In particular, we developed a specific software for the accurate "PSF-matching" of space and ground-based images of different resolution and depth (ConvPhot), of which we analyse performances and limitations. We have included both z-selected, as well as Ks-selected objects, yielding a unique, self-consistent catalog. The largest fraction of the sample is 90% complete at z~26 or Ks~23.8 (AB scale). Finally, we cross-correlated our data with all the ...

  1. The Renormalization Effects in the Microstrip-SQUID Amplifier

    CERN Document Server

    Berman, G P; Tsifrinovich, V I

    2011-01-01

    The peculiarities of the microstrip-DC SQUID amplifier caused by the resonant structure of the input circuit are analyzed. It is shown that the mutual inductance, that couples the input circuit and the SQUID loop, depends on the frequency of electromagnetic field. The renormalization of the SQUID parameters due to the screening effect of the input circuit vanishes when the Josephson frequency is much greater than the signal frequency.

  2. Distributed feedback laser amplifiers combining the functions of amplifiers and channel filters

    DEFF Research Database (Denmark)

    Wang, Z.; Durhuus, T.; Mikkelsen, Benny;

    1994-01-01

    A dynamic model for distributed feedback amplifiers, including the mode coupled equations and the carrier rate equation, is established. The presented mode coupled equations have taken into account the interaction between fast changing optical signal and the waveguide with corrugations. By showin...... the possibility of amplifying 100 ps pulses without pulse broadening, we anticipate that a distributed feedback amplifier can be used as a combined amplifier and channel filter in high bit rate transmission systems....

  3. Amplified spontaneous emission and its restraint in a terawatt Ti:sapphire amplifier

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Amplified spontaneous emission (ASE) and its restraint in a femtosecond Ti: sapphire chirped_pulse amplifier were investigated. The noises arising from ASE were effectively filtered out in the spatial, temporal and spectral domain. Pulses as short as 38 fs were amplified to peak power of 1.4 TW. The power ratio between the amplified femtosecond pulse and the ASE was higher than 106:1.

  4. The Pathological and Physiological Roles of IL-6 Amplifier Activation

    Directory of Open Access Journals (Sweden)

    Masaaki Murakami, Toshio Hirano

    2012-01-01

    Full Text Available The NFκB-triggered positive feedback loop for IL-6 signaling in type 1 collagen+ non-immune cells (IL-6 amplifier was first discovered to be a synergistic signal that is activated following IL-17A and IL-6 stimulation in type 1 collagen+ non-immune cells. Subsequent disease models have shown that it can also be stimulated by the simultaneous activation of NFκB and STAT3, functions as a local chemokine inducer, and acts as a mechanism for local inflammation, particularly chronic ones like rheumatoid arthritis and a multiple sclerosis. Moreover, we have recently shown that hyper activation of the IL-6 amplifier via regional neural activation establishes a gateway for immune cells including autoreactive T cells to pass the blood-brain barrier at dorsal vessels in 5th lumbar cord. Here we review how the IL-6 amplifier is activated by neural activation and the physiological relevance of the gateway to the central nervous system. Accumulating evidences continues to suggest that the IL-6 amplifier offers a potential molecular mechanism for the relationship between neural activation and the development of inflammatory diseases, which could establish a new interdisciplinary field that fuses neurology and immunology.

  5. High Average Power Optical FEL Amplifiers

    CERN Document Server

    Ben-Zvi, I; Litvinenko, V

    2005-01-01

    Historically, the first demonstration of the FEL was in an amplifier configuration at Stanford University. There were other notable instances of amplifying a seed laser, such as the LLNL amplifier and the BNL ATF High-Gain Harmonic Generation FEL. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance a 100 kW average power FEL. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting energy recovery linacs combine well with the high-gain FEL amplifier to produce unprecedented average power FELs with some advantages. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Li...

  6. Self-pulsation in Raman fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, Martin Erland Vestergaard; Ott, Johan Raunkjær; Rottwitt, Karsten

    2009-01-01

    Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated.......Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated....

  7. BROADBAND TRAVELLING WAVE SEMICONDUCTOR OPTICAL AMPLIFIER

    DEFF Research Database (Denmark)

    2010-01-01

    Broadband travelling wave semiconductor optical amplifier (100, 200, 300, 400, 800) for amplification of light, wherein the amplifier (100, 200, 300, 400, 800) comprises a waveguide region (101, 201, 301, 401, 801) for providing confinement of the light in transverse directions and adapted...

  8. Triple-mode single-transistor graphene amplifier and its applications.

    Science.gov (United States)

    Yang, Xuebei; Liu, Guanxiong; Balandin, Alexander A; Mohanram, Kartik

    2010-10-26

    We propose and experimentally demonstrate a triple-mode single-transistor graphene amplifier utilizing a three-terminal back-gated single-layer graphene transistor. The ambipolar nature of electronic transport in graphene transistors leads to increased amplifier functionality as compared to amplifiers built with unipolar semiconductor devices. The ambipolar graphene transistors can be configured as n-type, p-type, or hybrid-type by changing the gate bias. As a result, the single-transistor graphene amplifier can operate in the common-source, common-drain, or frequency multiplication mode, respectively. This in-field controllability of the single-transistor graphene amplifier can be used to realize the modulation necessary for phase shift keying and frequency shift keying, which are widely used in wireless applications. It also offers new opportunities for designing analog circuits with simpler structure and higher integration densities for communications applications.

  9. Calculation of susceptibility through multiple orientation sampling (COSMOS): a method for conditioning the inverse problem from measured magnetic field map to susceptibility source image in MRI.

    Science.gov (United States)

    Liu, Tian; Spincemaille, Pascal; de Rochefort, Ludovic; Kressler, Bryan; Wang, Yi

    2009-01-01

    Magnetic susceptibility differs among tissues based on their contents of iron, calcium, contrast agent, and other molecular compositions. Susceptibility modifies the magnetic field detected in the MR signal phase. The determination of an arbitrary susceptibility distribution from the induced field shifts is a challenging, ill-posed inverse problem. A method called "calculation of susceptibility through multiple orientation sampling" (COSMOS) is proposed to stabilize this inverse problem. The field created by the susceptibility distribution is sampled at multiple orientations with respect to the polarization field, B(0), and the susceptibility map is reconstructed by weighted linear least squares to account for field noise and the signal void region. Numerical simulations and phantom and in vitro imaging validations demonstrated that COSMOS is a stable and precise approach to quantify a susceptibility distribution using MRI.

  10. Linear models for airborne-laser-scanning-based operational forest inventory with small field sample size and highly correlated LiDAR data

    Science.gov (United States)

    Junttila, Virpi; Kauranne, Tuomo; Finley, Andrew O.; Bradford, John B.

    2015-01-01

    Modern operational forest inventory often uses remotely sensed data that cover the whole inventory area to produce spatially explicit estimates of forest properties through statistical models. The data obtained by airborne light detection and ranging (LiDAR) correlate well with many forest inventory variables, such as the tree height, the timber volume, and the biomass. To construct an accurate model over thousands of hectares, LiDAR data must be supplemented with several hundred field sample measurements of forest inventory variables. This can be costly and time consuming. Different LiDAR-data-based and spatial-data-based sampling designs can reduce the number of field sample plots needed. However, problems arising from the features of the LiDAR data, such as a large number of predictors compared with the sample size (overfitting) or a strong correlation among predictors (multicollinearity), may decrease the accuracy and precision of the estimates and predictions. To overcome these problems, a Bayesian linear model with the singular value decomposition of predictors, combined with regularization, is proposed. The model performance in predicting different forest inventory variables is verified in ten inventory areas from two continents, where the number of field sample plots is reduced using different sampling designs. The results show that, with an appropriate field plot selection strategy and the proposed linear model, the total relative error of the predicted forest inventory variables is only 5%–15% larger using 50 field sample plots than the error of a linear model estimated with several hundred field sample plots when we sum up the error due to both the model noise variance and the model’s lack of fit.

  11. Ultrafast disk lasers and amplifiers

    Science.gov (United States)

    Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

    2012-03-01

    Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

  12. A CHI wiggler ubitron amplifier experiment: Wiggler characterization

    Energy Technology Data Exchange (ETDEWEB)

    Taccetti, J.M.; Jackson, R.H.; Freund, H.P. [Naval Research Lab., Washington, DC (United States)] [and others

    1995-12-31

    A 35 GHz CHI (Coaxial Hybrid Iron) wiggler ubitron amplifier experiment is under construction at the Naval Research Laboratory. The CHI wiggler configuration has the potential of generating high wiggler magnetic fields at short periods with excellent beam focusing and transport properties. This makes it a desirable configuration for the generation of high power coherent radiation in relatively compact systems. The CHI wiggler consists of alternating rings of magnetic and non-magnetic materials concentric with a central rod of similar alternating design but shifted along the axis by half a period. Once inserted in a solenoidal magnetic field, the CHI structure deforms the axial field to create a radial field oscillating with the same periodicity as the rings. An annular electron beam is propagated through the coaxial gap where the oscillating radial field imparts an azimuthal wiggle motion. The principal goals of the experiment are to investigate the performance tradeoffs involved in the CHI configuration for high frequency amplifiers operating at low voltages with small wiggler periods. The nominal design parameters are a center frequency of 35 GHz, wiggler period of 0.75 cm, and beam voltage of approximately 150 kV. Calculations have shown an intrinsic (untapered) efficiency of {approximately} 7% when operating at 6.3 kG axial field (wiggler field, B{sub w}{approximately}1270 G). The calculated gain was 36 dB, saturating at a distance of 46 cm. These parameters yield an instantaneous amplifier bandwidth of {approximately} 25%. There appears to be room for further improvement in efficiency, a matter which will be scrutinized more closely in the final design. A prototype CHI wiggler is presently being fabricated for use in conjunction with an existing 30 kG superconducting solenoid. The performance properties of the prototype will be characterized and compared with linear and non-linear calculations.

  13. Design and performance of the beamlet amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Erlandson, A.C.; Rotter, M.D.; Frank, M.D.; McCracken, R.W.

    1996-06-01

    In future laser systems, such as the National Ignition Facility (NIF), multi-segment amplifiers (MSAs) will be used to amplify the laser beam to the required levels. As a prototype of such a laser architecture, the authors have designed, built, and tested flash-lamp-pumped, Nd:Glass, Brewster-angle slab MSAs for the Beamlet project. In this article, they review the fundamentals of Nd:Glass amplifiers, describe the MSA geometry, discuss parameters that are important in amplifier design, and present our results on the characterization of the Beamlet MSAs. In particular, gain and beam steering measurements show that the Beamlet amplifiers meet all optical performance specifications and perform close to model predictions.

  14. Amplified OTDR systems for multipoint corrosion monitoring.

    Science.gov (United States)

    Nascimento, Jehan F; Silva, Marcionilo J; Coêlho, Isnaldo J S; Cipriano, Eliel; Martins-Filho, Joaquim F

    2012-01-01

    We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

  15. Amplified OTDR Systems for Multipoint Corrosion Monitoring

    Directory of Open Access Journals (Sweden)

    Joaquim F. Martins-Filho

    2012-03-01

    Full Text Available We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

  16. Design of an 1800 nm Raman Amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    , also extended band amplifiers are required. As a solution to the latter challenge, Raman amplifiers are suggested as promising candidates. The main hurdle when designing a long wavelength Raman amplifier is the increased intrinsic fiber attenuation which as a consequence leads to an increase...... in the pump power requirement and deteriorated noise properties. Here we demonstrate a Raman amplifier designed for signal wavelengths around 1800 nm. The amplification fiber is an OFS PM Raman fiber, and is pumped by a Raman fiber laser emitting at 1680 nm [4]. The amplifier was pumped co......-polarized and backward, with respect to the singal. In Fig. 2 a measured Raman on/off gain exceeding 9 dB for 285 mW of injected pump power is obtained in a 4.35 km long fiber. A broadband supercontinuum source was used as a signal from 1700 nm to 1900 nm....

  17. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2001-01-01

    In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved. A continuous-time offset-compensation technique is utilized in order to minimize impact...... on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0.5 μm CMOS single poly, n-well process. The prototype amplifier features a gain of 80 dB over a 3.6 kHz bandwidth, a CMRR of more than 87 dB and a PSRR...

  18. Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Lee Spangler; Ross Bricklemyer; David Brown

    2012-03-15

    There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laboratory based soil characterization typically requires significant soil processing, which is time and resource intensive. This severely limits application for large-region soil characterization. Thus, development of rapid and accurate methods for characterizing soils are needed to map soil properties for precision agriculture applications, improve regional and global soil carbon (C) stock and flux estimates and efficiently map sub-surface metal contamination, among others. The greatest gains for efficient soil characterization will come from collecting soil data in situ, thus minimizing soil sample transportation, processing, and lab-based measurement costs. Visible and near-infrared diffuse reflectance spectroscopy (VisNIR) and laser-induced breakdown spectroscopy (LIBS) are two complementary, yet fundamentally different spectroscopic techniques that have the potential to meet this need. These sensors have the potential to be mounted on a soil penetrometer and deployed for rapid soil profile characterization at field and landscape scales. Details of sensor interaction, efficient data management, and appropriate statistical analysis techniques for model calibrations are first needed. In situ or on-the-go VisNIR spectroscopy has been proposed as a rapid and inexpensive tool for intensively mapping soil texture and organic carbon (SOC). While lab-based VisNIR has been established as a viable technique for estimating various soil properties, few experiments have compared the predictive accuracy of on-the-go and lab-based VisNIR. Eight north central Montana wheat fields were intensively interrogated using on-the-go and lab-based VisNIR. Lab-based spectral data consistently provided more accurate predictions than on-the-go data. However, neither in situ

  19. First Results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics of Lensed Galaxies at Cosmic Noon

    CERN Document Server

    Mason, Charlotte A; Fontana, Adriano; Jones, Tucker; Morishita, Takahiro; Amorin, Ricardo; Bradac, Marusa; Finney, Emily; Henry, Alaina; Hoag, Austin; Huang, Kuang-Han; Schmidt, Kasper B; Trenti, Michele; Vulcani, Benedetta

    2016-01-01

    We present the first results of the KMOS Lens-Amplified Spectroscopic Survey (KLASS), a new ESO Very Large Telescope (VLT) large program, doing multi-object integral field spectroscopy of galaxies gravitationally lensed behind seven galaxy clusters selected from the HST Grism Lens-Amplified Survey from Space (GLASS). Using the power of the cluster magnification we are able to reveal the kinematic structure of 25 galaxies at $0.7 \\lesssim z \\lesssim 2.3$, in four cluster fields, with stellar masses $8 \\lesssim \\log{(M_\\star/M_\\odot)} \\lesssim 11$. This sample includes 5 sources at $z>1$ with lower stellar masses than in any previous kinematic IFU surveys. Our sample displays a diversity in kinematic structure over this mass and redshift range. The majority of our kinematically resolved sample is rotationally supported, but with a lower ratio of rotational velocity to velocity dispersion than in the local universe, indicating the fraction of dynamically hot disks changes with cosmic time. We find no galaxies wi...

  20. Extraction of PCR-amplifiable genomic DNA from Bacillus anthracisspores

    Energy Technology Data Exchange (ETDEWEB)

    Torok, Tamas

    2003-05-19

    Bacterial endospore disruption and nucleic acid extractionresulting in DNA of PCR-amplifiable quality and quantity are not trivial.Responding to the needs of the Hazardous Materials Response Unit (HMRU),Laboratory Division, Federal Bureau of Investigation, protocols weredeveloped to close these gaps. Effectiveness and reproducibility of thetechniques were validated with laboratory grown pure spores of Bacillusanthracis and its close phylogenetic neighbors, and with spiked soils anddamaged samples.

  1. Processing of Communication Signal Using Operational Transconductance Amplifier

    OpenAIRE

    Roy, A.; Ghosh, K.; Mondal, S; Ray, B. N.

    2010-01-01

    This paper proposes a signal processing methodology of communication system and realized that circuits using operational transconductance amplifier (OTA). Two important classes of communication circuit, delta modulator and compander have been designed using that procedure. In the first implementation coded pulse modulation system is demonstrated which employ sampling, quantizing and coding to convert analog waveforms to digital signals while the second gives data compression and expansion in ...

  2. Characterizing forest structure variations across an intact tropical peat dome using field samplings and airborne LiDAR.

    Science.gov (United States)

    Nguyen, Ha T; Hutyra, Lucy R; Hardiman, Brady S; Raciti, Steve M

    2016-03-01

    Tropical peat swamp forests (PSF) are one of the most carbon dense ecosystems on the globe and are experiencing substantial natural and anthropogenic disturbances. In this study, we combined direct field sampling and airborne LiDAR to empirically quantify forest structure and aboveground live biomass (AGB) across a large, intact tropical peat dome in Northwestern Borneo. Moving up a 4 m elevational gradient, we observed increasing stem density but decreasing canopy height, crown area, and crown roughness. These findings were consistent with hypotheses that nutrient and hydrological dynamics co-influence forest structure and stature of the canopy individuals, leading to reduced productivity towards the dome interior. Gap frequency as a function of gap size followed a power law distribution with a shape factor (λ) of 1.76 ± 0.06. Ground-based and dome-wide estimates of AGB were 217.7 ± 28.3 Mg C/ha and 222.4 ± 24.4 Mg C/ha, respectively, which were higher than previously reported AGB for PSF and tropical forests in general. However, dome-wide AGB estimates were based on height statistics, and we found the coefficient of variation on canopy height was only 0.08, three times less than stem diameter measurements, suggesting LiDAR height metrics may not be a robust predictor of AGB in tall tropical forests with dense canopies. Our structural characterization of this ecosystem advances the understanding of the ecology of intact tropical peat domes and factors that influence biomass density and landscape-scale spatial variation. This ecological understanding is essential to improve estimates of forest carbon density and its spatial distribution in PSF and to effectively model the effects of disturbance and deforestation in these carbon dense ecosystems.

  3. Comparison between a near-field and a far-field indexing approach for characterization of a polycrystalline sample volume containing more than 1500 grains

    NARCIS (Netherlands)

    Nervo, L.; King, A.; Wright, J.P.; Ludwig, W.; Reischig, P.; Quinta da Fonseca, J.; Preuss, M.

    2014-01-01

    A comparison of the performance of X-ray diffraction tomography, a near-field diffraction technique, and a far-field diffraction technique for indexing X-ray diffraction data of polycrystalline materials has been carried out by acquiring two sets of diffraction data from the same polycrystalline sam

  4. Phased array of high-power, coherent, monolithic flared amplifier master oscillator power amplifiers

    Science.gov (United States)

    Osinski, J. S.; Mehuys, D.; Welch, D. F.; Waarts, R. G.; Major, J. S., Jr.; Dzurko, K. M.; Lang, R. J.

    1995-01-01

    A monolithically integrated array of InGaAs/AlGaAs flared amplifiers driven by a single DBR laser through a power splitter network and individually addressed phase modulators is described. Phase adjustment of ≳2π per element by free-carrier effects is verified by monitoring the interference pattern of all four emitters, and typically requires <15 mA of current to obtain a 2π phase shift. Phase matching is achieved among all four diffraction-limited emitters at a pulsed output power of ≳5 W, and, combined with the proper external lensing, could therefore result in an ultranarrow, single-lobed far-field pattern whose width is determined by the extended aperture of the array.

  5. High-Power Amplifier Compatible Internally Sensed Optical Phased Array for Space Debris Tracking and Maneuvering

    Science.gov (United States)

    Roberts, L.; Francis, S.; Sibley, P.; Ward, R.; Smith, C.; McClelland, D.; Shaddock, D.

    2016-09-01

    Optical phased arrays (OPAs) provide a way to scale optical power beyond the capabilities of conventional CW lasers via coherent beam combination. By stabilising the relative output phase of multiple spatially separate lasers, OPAs form a coherent optical wavefront in the far field. Since the phase of each laser can be controlled independently, OPAs also have the ability to manipulate the distribution of optical power in the far field, and therefore may provide the capability to compensate for atmospheric turbulence. Combined with their inherent scalability and high power handling capabilities, OPAs are a promising technology for CW space debris ranging and manoeuvring. The OPA presented here is unique in its ability to sense the phase of each laser internally, without requiring any external sampling optics between it and the telescope. This allows the internally sensed OPA to be constructed entirely within fibre, utilising high-power fiber amplifiers to scale optical power beyond the limits of any conventional single lasers. The total power that can be delivered by each emitter in the OPA is limited only by the onset of stimulated Brillouin scattering, a non-linear effect that clamps the amount of power that can be delivered through a fiber waveguide. A three element internally sensed OPA developed at the Australian National University has been demonstrated to coherently combine three commercial 15 Watt fiber amplifiers with an output phase stability of one 200th of a wavelength. We have also demonstrated the ability to dynamically manipulate the distribution of optical power in the far-field at a bandwidth of up to 10 kHz. Since the OPA's control system is implemented using field-programmable gate-array technology, the system may be scaled beyond 100 emitters, potentially reaching the kilowatt level optical powers required to perturb the orbit of space debris.

  6. True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

    Directory of Open Access Journals (Sweden)

    Viviani Ferreira

    2013-03-01

    Full Text Available Aerophytic cyanobacteria are commonly found growing on rocks, tree trunks and soil, but the diversity of these organisms is still poorly known. This complex group is very problematic considering the taxonomic arrangement and species circumscription, especially when taking into account tropical populations. In this work, 20 samples of aerophytic cyanobacteria from 15 distinct sampling sites were collected along a tropical rainforest area at the São Paulo State (Brazil. Samples were dried at room temperature after the collection, and once in the laboratory, they were rehydrated and analyzed. The taxonomic study resulted in the record and description of nine species of true-branched cyanobacteria pertaining to the genera Spelaeopogon (one specie, Hapalosiphon (two species and Stigonema (six species. The similarity of the flora found when compared to surveys conducted in other geographical regions was relatively low. These differences could be addressed to ecological conditions of the habitats, to the extension of the area surveyed or even to taxonomic misinterpretations. The molecular assessment of 16S rDNA on the basis of field material was successful for two morphospecies, Hapalosiphon sp. and Stigonema ocellatum; however, their relationships with other populations and species revealed to be uncertain. The results of the floristic survey and of the molecular approach evidenced the fragile delimitation of some genera and species in the true branched group of cyanobacteria.Las bacterias aerofíticas crecen comúnmente en las rocas, troncos de árboles y el suelo, pero la diversidad de estos organismos todavía es poco conocida. Este complejo grupo es muy problématico considerando la disposición taxónomica y la circunscripción de las especies, especialmente cuando se toman en cuenta las poblaciones tropicales. En esta investigación, 20 muestras de cianobacterias aerofíticas de 15 distintos sitios de muestro fueron recolectadas a lo largo de

  7. Measuring Optimal Length of the Amplifying Fiber in Different Working Conditions of the Amplifier

    Directory of Open Access Journals (Sweden)

    Radek Poboril

    2014-01-01

    Full Text Available The aim of this article is to highlight possible unwanted behaviour of an EDFA optical amplifier during temperature changes. After a brief introduction dealing with amplifiers and doped fibers in general we focus on the assembly of our own EDFA amplifier with standard construction and the IsoGain I-6 amplifying fiber, and on the parameters of its individual components. Since an erbium doped fiber has usually no direct thermal stabilization, temperature changes can affect performance of the entire amplifier. The next part of the article therefore describes the impacts of such changes on behaviour of our amplifier. At the very end we performed a measurement of the amplifier deployed in the actual WDM-PON the description of which can be found in the last chapter.

  8. High power Ka band TWT amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Golkowski, C.; Ivers, J.D.; Nation, J.A.; Wang, P.; Schachter, L.

    1999-07-01

    Two high power 35 GHz TWT amplifiers driven by a relativistic pencil, 850 kV, 200A electron beam have been assembled and tested. The first had a dielectric slow wave structure and was primarily used to develop diagnostics, and to gain experience in working with high power systems in Ka band. The source of the input power for the amplifier was a magnetron producing a 30 kW, 200ns long pulse of which 10 kW as delivered to the experiment. The 30 cm long dielectric (Teflon) amplifier produced output power levels of about 1 MW with a gain of about 23 dB. These results are consistent with expectations from PIC code simulations for this arrangement. The second amplifier, which is a single stage disk loaded slow wave structure, has been designed. It consists of one hundred uniform cells with two sets of ten tapered calls at the ends to lower the reflection coefficient. The phase advance per cell is {pi}/2. The amplifier passband extends from 28 to 40 GHz. It is designed to increase the output power to about 20 MW. The amplifier is in construction and will be tested in the near future. Details of the design of both systems will be provided and initial results from the new amplifier presented.

  9. Numerical Modelling of Spontaneous Emission in Optical Parametric Amplifiers

    DEFF Research Database (Denmark)

    Friis, Søren Michael Mørk; Andersen, Ulrik Lund; Rottwitt, Karsten

    2013-01-01

    Fiber optical parametric processes offer a wide range of applications including phase sensitive as well as phase insensitive amplification, wavelength conversion and signal regeneration. One of the difficult challenges is any of these applications is to predict their associated noise performance....... However, it is well accepted that one contribution to the noise performance originates from vacuum fluctuations. In this work we show a novel approach to predict the spontaneous radiation from a parametric amplifier. In the approach the propagating fields are treated as a sum of a classical mean field...

  10. Temperature dependent low-field measurements of the magnetocaloric ΔT with sub-mK resolution in small volume and thin film samples

    Energy Technology Data Exchange (ETDEWEB)

    Döntgen, J.; Rudolph, J. [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Gottschall, T.; Gutfleisch, O. [Institut für Materialwissenschaft, TU Darmstadt, 64287 Darmstadt (Germany); Salomon, S. [Institut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Ludwig, A. [Institut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Materials Research Department, Ruhr-Universität Bochum, 44780 Bochum (Germany); Hägele, D., E-mail: daniel.haegele@rub.de [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Materials Research Department, Ruhr-Universität Bochum, 44780 Bochum (Germany)

    2015-01-19

    We present temperature dependent ΔT measurements of the magnetocaloric effect in a thin film sample of Gd, employing magnetomodulation and detection of thermal radiation. A bulk sample of the metamagnetic material LaFe{sub 11.05}Co{sub 0.91}Si{sub 1.04} shows a strong broadening of the ΔT peak for increasing field amplitudes between 4 and 45 mT. Bulk Gd in comparison shows only a weak broadening. All investigated samples exhibit a clear quadratic dependence of ΔT on the external field H{sub ext} at the ΔT peak maximum, contrary to earlier predictions. An analytic expression is derived that interpolates between the H{sub ext}{sup 2}-behavior at low and the well-known H{sub ext}{sup 2/3}-behavior at high fields.

  11. Gold Nanoparticle Labels Amplify Ellipsometric Signals

    Science.gov (United States)

    Venkatasubbarao, Srivatsa

    2008-01-01

    The ellipsometric method reported in the immediately preceding article was developed in conjunction with a method of using gold nanoparticles as labels on biomolecules that one seeks to detect. The purpose of the labeling is to exploit the optical properties of the gold nanoparticles in order to amplify the measurable ellipsometric effects and thereby to enable ultrasensitive detection of the labeled biomolecules without need to develop more-complex ellipsometric instrumentation. The colorimetric, polarization, light-scattering, and other optical properties of nanoparticles depend on their sizes and shapes. In the present method, these size-and-shape-dependent properties are used to magnify the polarization of scattered light and the diattenuation and retardance of signals derived from ellipsometry. The size-and-shape-dependent optical properties of the nanoparticles make it possible to interrogate the nanoparticles by use of light of various wavelengths, as appropriate, to optimally detect particles of a specific type at high sensitivity. Hence, by incorporating gold nanoparticles bound to biomolecules as primary or secondary labels, the performance of ellipsometry as a means of detecting the biomolecules can be improved. The use of gold nanoparticles as labels in ellipsometry has been found to afford sensitivity that equals or exceeds the sensitivity achieved by use of fluorescence-based methods. Potential applications for ellipsometric detection of gold nanoparticle-labeled biomolecules include monitoring molecules of interest in biological samples, in-vitro diagnostics, process monitoring, general environmental monitoring, and detection of biohazards.

  12. Effect of Soliton Propagation in Fiber Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The propagation of optical solitons in fiber amplifiers is discussed by considering a model that includes linear high order dispersion, two-photon absorption, nonlinear high-order dispersion, self-induced Ramam and five-order nonlinear effects. Based on travelling wave method, the solutions of the nonlinear Schrdinger equations, and the influence on soliton propagation as well as high-order effect in the fiber amplifier are discussed in detail. It is found that because of existing five-order nonlinear effect, the solution is not of secant hyperbola type, but shows high gain state of the fiber amplifier which is very favourable to the propagation of solitons.

  13. Experimental design of laminar proportional amplifiers

    Science.gov (United States)

    Hellbaum, R. F.

    1976-01-01

    An experimental program was initiated at Langley Research Center to study the effects of various parameters on the design of laminar proportional beam deflection amplifiers. Matching and staging of amplifiers to obtain high-pressure gain was also studied. Variable parameters were aspect ratio, setback, control length, receiver distance, receiver width, width of center vent, and bias pressure levels. Usable pressure gains from 4 to 19 per stage can now be achieved, and five amplifiers were staged together to yield pressure gains up to 2,000,000.

  14. High Efficiency Microwave Power Amplifier (HEMPA) Design

    Science.gov (United States)

    Sims, W. Herbert

    2004-01-01

    This paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  15. Fundamentals of RF and microwave transistor amplifiers

    CERN Document Server

    Bahl, Inder J

    2009-01-01

    A Comprehensive and Up-to-Date Treatment of RF and Microwave Transistor Amplifiers This book provides state-of-the-art coverage of RF and microwave transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power, high-efficiency, and high-voltage. Topics covered include modeling, analysis, design, packaging, and thermal and fabrication considerations. Through a unique integration of theory and practice, readers will learn to solve amplifier-related design problems ranging from matching networks to biasing and stability. More than 240 problems are included to help read

  16. An Envelope Hammerstein Model for Power Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Hua-Dong Wang; Song-Bai He; Jing-Fu Bao; Zheng-De Wu

    2007-01-01

    In this paper, an envelope Hammerstein(EH) model is introduced to describe dynamic inputoutput characteristics of RF power amplifiers. In the modeling approach, we use a new truncation method and an established nonlinear time series method to determine model structure. Then, we discuss the process of model parameter extraction in detailed. Finally, a 2 W WCDMA power amplifier is measured to verify the performance of EH model, and good agreement between model output and measurement result shows our model can accurately predict output characteristic of the power amplifier.

  17. Achieving and maintaining cleanliness in NIF amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, A. K.; Horvath, J. A.; Letts, S. A.; Menapace, J. A.; Stowers, I. F.

    1998-07-28

    Cleanliness measurements made on AMPLAB prototype National Ignition Facility (NIF) laser amplifiers during assembly, cassette transfer, and amplifier operation are summarized. These measurements include particle counts from surface cleanliness assessments using filter swipe techniques and from airborne particle monitoring. Results are compared with similar measurements made on the Beamlet and Nova lasers and in flashlamp test fixtures. Observations of Class 100,000 aerosols after flashlamp firings are discussed. Comparisons are made between typical damage densities on laser amplifier optics from Novette, NOVA, Beamlet, and AMPLAB.

  18. The Grism Lens-amplified Survey from Space (GLASS). X. Sub-kiloparsec Resolution Gas-phase Metallicity Maps at Cosmic Noon behind the Hubble Frontier Fields Cluster MACS1149.6+2223

    Science.gov (United States)

    Wang, Xin; Jones, Tucker A.; Treu, Tommaso; Morishita, Takahiro; Abramson, Louis E.; Brammer, Gabriel B.; Huang, Kuang-Han; Malkan, Matthew A.; Schmidt, Kasper B.; Fontana, Adriano; Grillo, Claudio; Henry, Alaina L.; Karman, Wouter; Kelly, Patrick L.; Mason, Charlotte A.; Mercurio, Amata; Rosati, Piero; Sharon, Keren; Trenti, Michele; Vulcani, Benedetta

    2017-03-01

    We combine deep Hubble Space Telescope grism spectroscopy with a new Bayesian method to derive maps of gas-phase metallicity for 10 star-forming galaxies at high redshift (1.2≲ z≲ 2.3). Exploiting lensing magnification by the foreground cluster MACS1149.6+2223, we reach sub-kiloparsec spatial resolution and push the limit of stellar mass associated with such high-z spatially resolved measurements below {10}8 {M}ȯ for the first time. Our maps exhibit diverse morphologies, indicative of various effects such as efficient radial mixing from tidal torques, rapid accretion of low-metallicity gas, and other physical processes that can affect the gas and metallicity distributions in individual galaxies. Based upon an exhaustive sample of all existing sub-kiloparesec resolution metallicity gradient measurements at high z, we find that predictions given by analytical chemical evolution models assuming a relatively extended star-formation profile in the early disk-formation phase can explain the majority of observed metallicity gradients, without involving galactic feedback or radial outflows. We observe a tentative correlation between stellar mass and metallicity gradients, consistent with the “downsizing” galaxy formation picture that more massive galaxies are more evolved into a later phase of disk growth, where they experience more coherent mass assembly at all radii and thus show shallower metallicity gradients. In addition to the spatially resolved analysis, we compile a sample of homogeneously cross-calibrated integrated metallicity measurements spanning three orders of magnitude in stellar mass at z ∼ 1.8. We use this sample to study the mass–metallicity relation (MZR) and find that the slope of the observed MZR can rule out the momentum-driven wind model at a 3σ confidence level.

  19. Amplified radio emission from cosmic ray air showers in thunderstorms

    CERN Document Server

    Buitink, S; Asch, T; Badea, F; Bähren, L; Bekk, K; Bercuci, A; Bertaina, M; Biermann, P L; Blumer, J; Bozdog, H; Brancus, I M; Bruggemann, M; Buchholz, P; Butcher, H; Chiavassa, A; Cossavella, F; Daumiller, K; Di Pierro, F; Doll, P; Engel, R; Falcke, H; Gemmeke, H; Ghia, P L; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Horneffer, A; Huege, T; Kampert, K H; Kolotaev, Y; Krömer, O; Kuijpers, J; Lafebre, S; Mathes, H J; Mayer, H J; Meurer, C; Milke, J; Mitrica, B; Morello, C; Navarra, G; Nehls, S; Nigl, A; Obenland, R; Oehlschläger, J; Ostapchenko, S; Over, S; Petcu, M; Petrovic, J; Pierog, T; Plewnia, S; Rebel, H; Risse, A; Roth, M; Schieler, H; Sima, O; Singh, K; Stumpert, M; Toma, G; Trinchero, G C; Ulrich, H; Van Buren, J; Walkowiak, W; Weindl, A; Wochele, J; Zabierowski, J; Zensus, J A; Zimmermann, D; Buitink, Stijn

    2007-01-01

    Cosmic ray air showers produce radio emission, consisting in large part of geosynchrotron emission. Since the radiation mechanism is based on particle acceleration, the atmospheric electric field can play an important role. Especially inside thunderclouds large electric fields can be present. We examine the contribution of an electric field to the emission mechanism theoretically and experimentally. Two mechanisms of amplification of radio emission are considered: the acceleration radiation of the shower particles and the radiation from the current that is produced by ionization electrons moving in the electric field. We selected and evaluated LOPES data recorded during thunderstorms, periods of heavy cloudiness and periods of cloudless weather. We find that during thunderstorms the radio emission can be strongly enhanced. No amplified pulses were found during periods of cloudless sky or heavy cloudiness, suggesting that the electric field effect for radio air shower measurements can be safely ignored during ...

  20. Multilayer-graphene-based amplifier of surface acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Yurchenko, Stanislav O., E-mail: st.yurchenko@mail.ru; Komarov, Kirill A. [Bauman Moscow State Technical University, 2-nd Baumanskaya str. 5, Moscow 105005 (Russian Federation); Pustovoit, Vladislav I. [Scientific and Technological Center of Unique Instrumentation, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-05-15

    The amplification of surface acoustic waves (SAWs) by a multilayer graphene (MLG)-based amplifier is studied. The conductivity of massless carriers (electrons or holes) in graphene in an external drift electric field is calculated using Boltzmann’s equation. At some carrier drift velocities, the real part of the variable conductivity becomes negative and MLG can be employed in SAW amplifiers. Amplification of Blustein’s and Rayleigh’s SAWs in CdS, a piezoelectric hexagonal crystal of the symmetry group C{sub 6v}, is considered. The corresponding equations for SAW propagation in the device are derived and can be applied to other substrate crystals of the same symmetry. The results of the paper indicate that MLG can be considered as a perspective material for SAW amplification and related applications.

  1. Multilayer-graphene-based amplifier of surface acoustic waves

    Directory of Open Access Journals (Sweden)

    Stanislav O. Yurchenko

    2015-05-01

    Full Text Available The amplification of surface acoustic waves (SAWs by a multilayer graphene (MLG-based amplifier is studied. The conductivity of massless carriers (electrons or holes in graphene in an external drift electric field is calculated using Boltzmann’s equation. At some carrier drift velocities, the real part of the variable conductivity becomes negative and MLG can be employed in SAW amplifiers. Amplification of Blustein’s and Rayleigh’s SAWs in CdS, a piezoelectric hexagonal crystal of the symmetry group C6v, is considered. The corresponding equations for SAW propagation in the device are derived and can be applied to other substrate crystals of the same symmetry. The results of the paper indicate that MLG can be considered as a perspective material for SAW amplification and related applications.

  2. Compact cladding-pumped planar waveguide amplifier and fabrication method

    Science.gov (United States)

    Bayramian, Andy J.; Beach, Raymond J.; Honea, Eric; Murray, James E.; Payne, Stephen A.

    2003-10-28

    A low-cost, high performance cladding-pumped planar waveguide amplifier and fabrication method, for deployment in metro and access networks. The waveguide amplifier has a compact monolithic slab architecture preferably formed by first sandwich bonding an erbium-doped core glass slab between two cladding glass slabs to form a multi-layer planar construction, and then slicing the construction into multiple unit constructions. Using lithographic techniques, a silver stripe is deposited and formed at a top or bottom surface of each unit construction and over a cross section of the bonds. By heating the unit construction in an oven and applying an electric field, the silver stripe is then ion diffused to increase the refractive indices of the core and cladding regions, with the diffusion region of the core forming a single mode waveguide, and the silver diffusion cladding region forming a second larger waveguide amenable to cladding pumping with broad area diodes.

  3. Full-field quantitative phase imaging by white-light interferometry with active phase stabilization and its application to biological samples

    Science.gov (United States)

    Li, Xinhong; Yamauchi, Toyohiko; Iwai, Hidenao; Yamashita, Yutaka; Zhang, Haijun; Hiruma, Teruo

    2006-06-01

    We report a Koehler-illumination-based full-field, actively stabilized, low-coherence phase-shifting interferometer, which is built on a white-light Michelson interferometer. By using a phase-stepping technique we can obtain full-field phase images of the sample. An actively stabilized phase-lock circuit is employed in the system to reduce phase noise. An application to human epithelial cells (HeLa cells) is achieved in our experiment. The advancement of this technique rests in its ability to take images of unstained biological samples quantitatively and on a nanometer scale.

  4. Towards high concentration enhancement of microfluidic temperature gradient focusing of sample solutes using combined AC and DC field induced Joule heating.

    Science.gov (United States)

    Ge, Zhengwei; Wang, Wei; Yang, Chun

    2011-04-07

    It is challenging to continuously concentrate sample solutes in microfluidic channels. We present an improved electrokinetic technique for enhancing microfluidic temperature gradient focusing (TGF) of sample solutes using combined AC and DC field induced Joule heating effects. The introduction of an AC electric field component services dual functions: one is to produce Joule heat for generating temperature gradient; the other is to suppress electroosmotic flow. Consequently the required DC voltages for achieving sample concentration by Joule heating induced TGF are reduced, thereby leading to smaller electroosmotic flow (EOF) and thus backpressure effects. As a demonstration, the proposed technique can lead to concentration enhancement of sample solutes of more than 2500-fold, which is much higher than the existing literature reported microfluidic concentration enhancement by utilizing the Joule heating induced TGF technique.

  5. Virus isolation vs RT-PCR: which method is more successful in detecting VHSV and IHNV in fish tissue sampled under field conditions?

    DEFF Research Database (Denmark)

    Knüsel, R.; Bergmann, S. M.; Einer-Jensen, Katja;

    2007-01-01

    (total of 859 fish) originating from a field survey on the occurrence of VHSV and IHNV in farmed and wild salmonids in Switzerland. These samples represented all sites with fish that were either identified as virus-positive by means of virus isolation (three sites, four positive tissue sample pools) and......This study compared the results of reverse transcription-polymerase chain reaction (RT-PCR) and traditional virus isolation on cell culture in detection of viral haemorrhagic septicaemia virus (VHSV) and infectious haematopoietic necrosis virus (IHNV). RT-PCR was used for 172 tissue sample pools....../or demonstrated positive anti-VHSV-antibody titres (83 sites, 121 positive blood samples) in a serum plaque neutralization test (SPNT). The RT-PCR technique confirmed the four VHSV-positive tissue sample pools detected by virus isolation and additionally identified one VHSV-positive sample that showed positive...

  6. Use of Homogeneously-Sized Carbon Steel Ball Bearings to Study Microbially-Influenced Corrosion in Oil Field Samples

    Directory of Open Access Journals (Sweden)

    Gerrit eVoordouw

    2016-03-01

    Full Text Available Microbially-influenced corrosion (MIC contributes to the general corrosion rate (CR, which is typically measured with carbon steel coupons. Here we explore the use of carbon steel ball bearings, referred to as beads (55.0 ± 0.3 mg; Ø = 0.238 cm, for determining CRs. CRs for samples from an oil field in Oceania incubated with beads were determined by the weight loss method, using acid treatment to remove corrosion products. The release of ferrous and ferric iron was also measured and CRs based on weight loss and iron determination were in good agreement. Average CRs were 0.022 mm/yr for 8 produced waters with high numbers (105/ml of acid-producing bacteria (APB, but no sulfate-reducing bacteria (SRB. Average CRs were 0.009 mm/yr for 5 central processing facility (CPF waters, which had no APB or SRB due to weekly biocide treatment and 0.036 mm/yr for 2 CPF tank bottom sludges, which had high numbers of APB (106/ml and SRB (108/ml. Hence, corrosion monitoring with carbon steel beads indicated that biocide treatment of CPF waters decreased the CR, except where biocide did not penetrate. The CR for incubations with 20 ml of a produced water decreased from 0.061 to 0.007 mm/yr when increasing the number of beads from 1 to 40. CRs determined with beads were higher than those with coupons, possibly also due to a higher weight of iron per unit volume used in incubations with coupons. Use of 1 ml syringe columns, containing carbon steel beads and injected with 10 ml/day of SRB-containing medium for 256 days gave a CR of 0.11 mm/yr under flow conditions. The standard deviation of the distribution of residual bead weights, a measure for the unevenness of the corrosion, increased with increasing CR. The most heavily corroded beads showed significant pitting. Hence the use of uniformly sized carbon steel beads offers new opportunities for screening and monitoring of corrosion including determination of the distribution of corrosion rates, which allows

  7. Star formation in the local Universe from the CALIFA sample. I. Calibrating the SFR using integral field spectroscopy data

    Science.gov (United States)

    Catalán-Torrecilla, C.; Gil de Paz, A.; Castillo-Morales, A.; Iglesias-Páramo, J.; Sánchez, S. F.; Kennicutt, R. C.; Pérez-González, P. G.; Marino, R. A.; Walcher, C. J.; Husemann, B.; García-Benito, R.; Mast, D.; González Delgado, R. M.; Muñoz-Mateos, J. C.; Bland-Hawthorn, J.; Bomans, D. J.; Del Olmo, A.; Galbany, L.; Gomes, J. M.; Kehrig, C.; López-Sánchez, Á. R.; Mendoza, M. A.; Monreal-Ibero, A.; Pérez-Torres, M.; Sánchez-Blázquez, P.; Vilchez, J. M.; Califa Collaboration

    2015-12-01

    Context. The star formation rate (SFR) is one of the main parameters used to analyze the evolution of galaxies through time. The need for recovering the light reprocessed by dust commonly requires the use of low spatial resolution far-infrared data. Recombination line luminosities provide an alternative, although uncertain dust-extinction corrections based on narrowband imaging or long-slit spectroscopy have traditionally posed a limit to their applicability. Integral field spectroscopy (IFS) is clearly the way to overcome this kind of limitation. Aims: We obtain integrated Hα, ultraviolet (UV) and infrared (IR)-based SFR measurements for 272 galaxies from the CALIFA survey at 0.005 extinction-corrected Hα luminosities provide a good measure of the SFR and to shed light on the origin of the discrepancies between tracers. Updated calibrations referred to Hα are provided. The well-defined selection criteria and large statistics allow us to carry out this analysis globally and split by properties, including stellar mass and morphological type. Methods: We derive integrated, extinction-corrected Hα fluxes from CALIFA, UV surface and asymptotic photometry from GALEX and integrated WISE 22 μm and IRAS fluxes. Results: We find that the extinction-corrected Hα luminosity agrees with the hybrid updated SFR estimators based on either UV or Hα plus IR luminosity over the full range of SFRs (0.03-20 M⊙ yr-1). The coefficient that weights the amount of energy produced by newly-born stars that is reprocessed by dust on the hybrid tracers, aIR, shows a large dispersion. However, this coefficient does not became increasingly small at high attenuations, as expected if significant highly-obscured Hα emission were missed, i.e., after a Balmer decrement-based attenuation correction is applied. Lenticulars, early-type spirals, and type-2 AGN host galaxies show smaller coefficients because of the contribution of optical photons and AGN to dust heating. Conclusions: In the

  8. Highly sensitive detection of five typical fluoroquinolones in low-fat milk by field-enhanced sample injection based CE in bubble cell capillary

    OpenAIRE

    Deng, Yan; Gasilova, Natalia; Qiao, Liang; Zhou, Ying-Lin; Zhang, Xin-Xiang; Girault, Hubert H.

    2014-01-01

    Fluoroquinolones are a group of synthetic antibiotics with a broad activity spectrum against mycoplasma, gram-positive and gram-negative bacteria. Due to the extensive use of fluoroquinolones in farming and veterinary science, there is a constant need in the analytical methods able to efficiently monitor their residues in food products of animal origin, regulated by Commission Regulation (European Union) no. 37/2010. Herein, field-enhanced sample injection for sample stacking prior the CZE se...

  9. Active phase and polarization locking of a 1.4 kW fiber amplifier.

    Science.gov (United States)

    Goodno, Gregory D; McNaught, Stuart J; Rothenberg, Joshua E; McComb, Timothy S; Thielen, Peter A; Wickham, Michael G; Weber, Mark E

    2010-05-15

    A three-stage Yb-fiber amplifier emitted 1.43 kW of single-mode power when seeded with a 25 GHz linewidth master oscillator (MO). The amplified output was polarization stabilized and phase locked using active heterodyne phase control. A low-power sample of the output beam was coherently combined to a second fiber amplifier with 90% visibility. The measured combining efficiency agreed with estimated decoherence effects from fiber nonlinearity, linewidth, and phase-locking accuracy. This is the highest-power fiber laser that has been coherently locked using any method that allows brightness scaling.

  10. Comparison of geochemical data obtained using four brine sampling methods at the SECARB Phase III Anthropogenic Test CO2 injection site, Citronelle Oil Field, Alabama

    Science.gov (United States)

    Conaway, Christopher; Thordsen, James J.; Manning, Michael A.; Cook, Paul J.; Trautz, Robert C.; Thomas, Burt; Kharaka, Yousif K.

    2016-01-01

    The chemical composition of formation water and associated gases from the lower Cretaceous Paluxy Formation was determined using four different sampling methods at a characterization well in the Citronelle Oil Field, Alabama, as part of the Southeast Regional Carbon Sequestration Partnership (SECARB) Phase III Anthropogenic Test, which is an integrated carbon capture and storage project. In this study, formation water and gas samples were obtained from well D-9-8 #2 at Citronelle using gas lift, electric submersible pump, U-tube, and a downhole vacuum sampler (VS) and subjected to both field and laboratory analyses. Field chemical analyses included electrical conductivity, dissolved sulfide concentration, alkalinity, and pH; laboratory analyses included major, minor and trace elements, dissolved carbon, volatile fatty acids, free and dissolved gas species. The formation water obtained from this well is a Na–Ca–Cl-type brine with a salinity of about 200,000 mg/L total dissolved solids. Differences were evident between sampling methodologies, particularly in pH, Fe and alkalinity. There was little gas in samples, and gas composition results were strongly influenced by sampling methods. The results of the comparison demonstrate the difficulty and importance of preserving volatile analytes in samples, with the VS and U-tube system performing most favorably in this aspect.

  11. A Carbon Nanotube-based NEMS Parametric Amplifier for Enhanced Radio Wave Detection and Electronic Signal Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Aleman, B J; Sussman, A; Zettl, A [Physics Department, University of California, Berkeley, CA 94720 (United States); Mickelson, W, E-mail: azettl@berkeley.edu [Center of Integrated Nanomechanical Systems, University of California, Berkeley, CA 94720 (United States)

    2011-07-20

    We propose a scheme for a parametric amplifier based on a single suspended carbon nanotube field-emitter. This novel electromechanical nanotube device acts as a phase-sensitive, variable-gain, band-pass-filtering amplifier for electronic signal processing and, at the same time, can operate as a variable-sensitivity, tuneable detector and transducer of radio frequency electromagnetic waves. The amplifier can exhibit infinite gain at pumping voltages much less than 10 Volts. Additionally, the amplifier's low overhead power consumption (10-1000 nW) make it exceptionally attractive for ultra-low-power applications.

  12. Self-pulsation in Raman fiber amplifiers

    OpenAIRE

    Pedersen, Martin Erland Vestergaard; Ott, Johan Raunkjær; Rottwitt, Karsten

    2009-01-01

    Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated.

  13. Laser Cooled High-Power Fiber Amplifier

    CERN Document Server

    Nemova, Galina

    2009-01-01

    A theoretical model for laser cooled continuous-wave fiber amplifier is presented. The amplification process takes place in the Tm3+-doped core of the fluoride ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass fiber. The cooling process takes place in the Yb3+:ZBLAN fiber cladding. It is shown that for each value of the pump power and the amplified signal there is a distribution of the concentration of the Tm3+ along the length of the fiber amplifier, which provides its athermal operation. The influence of a small deviation in the value of the amplified signal on the temperature of the fiber with the fixed distribution of the Tm3+ions in the fiber cladding is investigated.

  14. Operational Amplifier Experiments for the Chemistry Laboratory.

    Science.gov (United States)

    Braun, Robert D.

    1996-01-01

    Provides details of experiments that deal with the use of operational amplifiers and are part of a course in instrumental analysis. These experiments are performed after the completion of a set of electricity and electronics experiments. (DDR)

  15. High Energy Single Frequency Resonant Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...

  16. CMOS current amplifiers : speed versus nonlinearity

    OpenAIRE

    2000-01-01

    This work deals with analogue integrated circuit design using various types of current-mode amplifiers. These circuits are analysed and realised using modern CMOS integration technologies. The dynamic nonlinearities of these circuits are discussed in detail as in the literature only linear nonidealities and static nonlinearities are conventionally considered. For the most important open-loop current-mode amplifier, the second-generation current-conveyor (CCII), a macromodel is derived tha...

  17. Quantum cloning with an optical fiber amplifier

    CERN Document Server

    Fasel, S; Ribordy, G; Scarani, V; Zbinden, H; Fasel, Sylvain; Gisin, Nicolas; Ribordy, Gregoire; Scarani, Valerio; Zbinden, Hugo

    2002-01-01

    It has been shown theoretically that a light amplifier working on the physical principle of stimulated emission should achieve optimal quantum cloning of the polarization state of light. We demonstrate close-to-optimal universal quantum cloning of polarization in a standard fiber amplifier for telecom wavelengths. For cloning $1\\to 2$ we find a fidelity of 0.82, the optimal value being ${5/6}=0.83$.

  18. Efficient Power Amplifier for Motor Control

    Science.gov (United States)

    Brown, R. J.

    1986-01-01

    Pulse-width-modulated amplifier supplies high current as efficiently as low current needed for starting and running motor. Key to efficiency of motor-control amplifier is V-channel metal-oxide/semiconductor transistor Q1. Device has low saturation resistance. However, has large gate input capacitance and small margin between its turn-on voltage and maximum allowable gate-to-source voltage. Circuits for output stages overcome limitations of VMOS device.

  19. MMIC Amplifiers for 90 to 130 GHz

    Science.gov (United States)

    Samoska, Lorene; Pukala, David; Peralta, Alejandro; Bryerton, Eric; Morgan, Matt; Boyd, T.; Hu, Ming; Schmitz, Adele

    2007-01-01

    This brief describes two monolithic microwave integrated-circuit (MMIC) amplifier chips optimized to function in the frequency range of 90 to 130 GHz, covering nearly all of F-band (90 - 140 GHz). These amplifiers were designed specifically for local-oscillator units in astronomical radio telescopes such as the Atacama Large Millimeter Array (ALMA). They could also be readily adapted for use in electronic test equipment, automotive radar systems, and communications systems that operate between 90 and 130 GHz.

  20. Use of a field portable X-Ray fluorescence analyzer to determine the concentration of lead and other metals in soil samples.

    Science.gov (United States)

    Clark, S; Menrath, W; Chen, M; Roda, S; Succop, P

    1999-01-01

    Field portable methods are often needed in risk characterization, assessment and management to rapidly determine metal concentrations in environmental samples. Examples are for determining: "hot spots" of soil contamination, whether dust wipe lead levels meet housing occupancy standards, and worker respiratory protection levels. For over 30 years portable X-Ray Fluorescence (XRF) analyzers have been available for the in situ, non-destructive, measurement of lead in paint. Recent advances made possible their use for analysis of airborne dust filter samples, soil, and dust wipes. Research at the University of Cincinnati with the NITON 700 Series XRF instrument (40 millicurie Cadmium 109 source, L X-Rays) demonstrated its proficiency on air sample filters (NIOSH Method No. 7702, "Lead by Field Portable XRF; limit of detection 6 microg per sample; working range 17-1,500 microg/m3 air). Research with lead dust wipe samples from housing has also shown promising results. This XRF instrument was used in 1997 in Poland on copper smelter area soil samples with the cooperation of the Wroclaw Medical Academy and the Foundation for the Children from the Copper Basin (Legnica). Geometric mean soil lead concentrations were 200 ppm with the portable XRF, 201 ppm with laboratory-based XRF (Kevex) and 190 ppm using atomic absorption (AA). Correlations of field portable XRF and AA results were excellent for samples sieved to less than 125 micrometers with R-squared values of 0.997, 0.957, and 0.976 for lead, copper and zinc respectively. Similarly, correlations were excellent for soil sieved to less than 250 micrometers, where R-squared values were 0. 924, 0.973, and 0.937 for lead, copper and zinc, respectively. The field portable XRF instrument appears to be useful for the determination of soil pollution by these metals in industrial regions.