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Sample records for spme measurements ranging

  1. SPME-Based Ca-History Method for Measuring SVOC Diffusion Coefficients in Clothing Material.

    Science.gov (United States)

    Cao, Jianping; Liu, Ningrui; Zhang, Yinping

    2017-08-15

    Clothes play an important role in dermal exposure to indoor semivolatile organic compounds (SVOCs). The diffusion coefficient of SVOCs in clothing material (D m ) is essential for estimating SVOC sorption by clothing material and subsequent dermal exposure to SVOCs. However, few studies have reported the measured D m for clothing materials. In this paper, we present the solid-phase microextraction (SPME) based C a -history method. To the best of our knowledge, this is the first try to measure D m with known relative standard deviation (RSD). A thin sealed chamber is formed by a circular ring and two pieces of flat SVOC source materials that are tightly covered by the targeted clothing materials. D m is obtained by applying an SVOC mass transfer model in the chamber to the history of gas-phase SVOC concentrations (C a ) in the chamber measured by SPME. D m 's of three SVOCs, di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and tris(1-chloro-2-propyl) phosphate (TCPP), in a cotton T-shirt can be obtained within 16 days, with RSD less than 3%. This study should prove useful for measuring SVOC D m in various sink materials. Further studies are expected to facilitate application of this method and investigate the effects of temperature, relative humidity, and clothing material on D m .

  2. Soliton microcomb range measurement

    Science.gov (United States)

    Suh, Myoung-Gyun; Vahala, Kerry J.

    2018-02-01

    Laser-based range measurement systems are important in many application areas, including autonomous vehicles, robotics, manufacturing, formation flying of satellites, and basic science. Coherent laser ranging systems using dual-frequency combs provide an unprecedented combination of long range, high precision, and fast update rate. We report dual-comb distance measurement using chip-based soliton microcombs. A single pump laser was used to generate dual-frequency combs within a single microresonator as counterpropagating solitons. We demonstrated time-of-flight measurement with 200-nanometer precision at an averaging time of 500 milliseconds within a range ambiguity of 16 millimeters. Measurements at distances up to 25 meters with much lower precision were also performed. Our chip-based source is an important step toward miniature dual-comb laser ranging systems that are suitable for photonic integration.

  3. Scalable improvement of SPME multipolar electrostatics in anisotropic polarizable molecular mechanics using a general short-range penetration correction up to quadrupoles.

    Science.gov (United States)

    Narth, Christophe; Lagardère, Louis; Polack, Étienne; Gresh, Nohad; Wang, Qiantao; Bell, David R; Rackers, Joshua A; Ponder, Jay W; Ren, Pengyu Y; Piquemal, Jean-Philip

    2016-02-15

    We propose a general coupling of the Smooth Particle Mesh Ewald SPME approach for distributed multipoles to a short-range charge penetration correction modifying the charge-charge, charge-dipole and charge-quadrupole energies. Such an approach significantly improves electrostatics when compared to ab initio values and has been calibrated on Symmetry-Adapted Perturbation Theory reference data. Various neutral molecular dimers have been tested and results on the complexes of mono- and divalent cations with a water ligand are also provided. Transferability of the correction is adressed in the context of the implementation of the AMOEBA and SIBFA polarizable force fields in the TINKER-HP software. As the choices of the multipolar distribution are discussed, conclusions are drawn for the future penetration-corrected polarizable force fields highlighting the mandatory need of non-spurious procedures for the obtention of well balanced and physically meaningful distributed moments. Finally, scalability and parallelism of the short-range corrected SPME approach are addressed, demonstrating that the damping function is computationally affordable and accurate for molecular dynamics simulations of complex bio- or bioinorganic systems in periodic boundary conditions. Copyright © 2016 Wiley Periodicals, Inc.

  4. Measurement of the isotope ratio of acetic acid in vinegar by HS-SPME-GC-TC/C-IRMS.

    Science.gov (United States)

    Hattori, Ryota; Yamada, Keita; Shibata, Hiroki; Hirano, Satoshi; Tajima, Osamu; Yoshida, Naohiro

    2010-06-23

    Acetic acid is the main ingredient of vinegar, and the worth of vinegar often depends on the fermentation of raw materials. In this study, we have developed a simple and rapid method for discriminating the fermentation of the raw materials of vinegar by measuring the hydrogen and carbon isotope ratio of acetic acid using head space solid-phase microextraction (HS-SPME) combined with gas chromatography-high temperature conversion or combustion-isotope ratio mass spectrometry (GC-TC/C-IRMS). The measurement of acetic acid in vinegar by this method was possible with repeatabilities (1sigma) of +/-5.0 per thousand for hydrogen and +/-0.4 per thousand for carbon, which are sufficient to discriminate the origin of acetic acid. The fermentation of raw materials of several vinegars was evaluated by this method.

  5. A SPME-based method for rapidly and accurately measuring the characteristic parameter for DEHP emitted from PVC floorings.

    Science.gov (United States)

    Cao, J; Zhang, X; Little, J C; Zhang, Y

    2017-03-01

    Semivolatile organic compounds (SVOCs) are present in many indoor materials. SVOC emissions can be characterized with a critical parameter, y 0 , the gas-phase SVOC concentration in equilibrium with the source material. To reduce the required time and improve the accuracy of existing methods for measuring y 0 , we developed a new method which uses solid-phase microextraction (SPME) to measure the concentration of an SVOC emitted by source material placed in a sealed chamber. Taking one typical indoor SVOC, di-(2-ethylhexyl) phthalate (DEHP), as the example, the experimental time was shortened from several days (even several months) to about 1 day, with relative errors of less than 5%. The measured y 0 values agree well with the results obtained by independent methods. The saturated gas-phase concentration (y sat ) of DEHP was also measured. Based on the Clausius-Clapeyron equation, a correlation that reveals the effects of temperature, the mass fraction of DEHP in the source material, and y sat on y 0 was established. The proposed method together with the correlation should be useful in estimating and controlling human exposure to indoor DEHP. The applicability of the present approach for other SVOCs and other SVOC source materials requires further study. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Uptake of Radionuclide Metals by SPME Fibers

    International Nuclear Information System (INIS)

    Duff, M; S Crump, S; Robert Ray, R; Keisha Martin, K; Donna Beals, D

    2006-08-01

    The Federal Bureau of Investigation (FBI) Laboratory currently does not have on site facilities for handling radioactive evidentiary materials and there are no established FBI methods or procedures for decontaminating high explosive (HE) and fire debris (FD) evidence while maintaining evidentiary value. One experimental method for the isolation of HE and FD residue involves using solid phase microextraction or SPME fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ( 239/240 Pu, 238 U, 237 Np, 85 Sr, 133 Ba, 137 Cs, 60 Co and 226 Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Zr, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE and FD residues. Our results from radiochemical and mass spectrometric analyses indicate these metals have little measurable affinity for these SPME fibers during conditions that are conducive to HE and FD residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection

  7. Range-Measuring Video Sensors

    Science.gov (United States)

    Howard, Richard T.; Briscoe, Jeri M.; Corder, Eric L.; Broderick, David

    2006-01-01

    Optoelectronic sensors of a proposed type would perform the functions of both electronic cameras and triangulation- type laser range finders. That is to say, these sensors would both (1) generate ordinary video or snapshot digital images and (2) measure the distances to selected spots in the images. These sensors would be well suited to use on robots that are required to measure distances to targets in their work spaces. In addition, these sensors could be used for all the purposes for which electronic cameras have been used heretofore. The simplest sensor of this type, illustrated schematically in the upper part of the figure, would include a laser, an electronic camera (either video or snapshot), a frame-grabber/image-capturing circuit, an image-data-storage memory circuit, and an image-data processor. There would be no moving parts. The laser would be positioned at a lateral distance d to one side of the camera and would be aimed parallel to the optical axis of the camera. When the range of a target in the field of view of the camera was required, the laser would be turned on and an image of the target would be stored and preprocessed to locate the angle (a) between the optical axis and the line of sight to the centroid of the laser spot.

  8. Phytoscreening with SPME: Variability Analysis.

    Science.gov (United States)

    Limmer, Matt A; Burken, Joel G

    2015-01-01

    Phytoscreening has been demonstrated at a variety of sites over the past 15 years as a low-impact, sustainable tool in delineation of shallow groundwater contaminated with chlorinated solvents. Collection of tree cores is rapid and straightforward, but low concentrations in tree tissues requires sensitive analytics. Solid-phase microextraction (SPME) is amenable to the complex matrix while allowing for solvent-less extraction. Accurate quantification requires the absence of competitive sorption, examined here both in laboratory experiments and through comprehensive examination of field data. Analysis of approximately 2,000 trees at numerous field sites also allowed testing of the tree genus and diameter effects on measured tree contaminant concentrations. Collectively, while these variables were found to significantly affect site-adjusted perchloroethylene (PCE) concentrations, the explanatory power of these effects was small (adjusted R(2) = 0.031). 90th quantile chemical concentrations in trees were significantly reduced by increasing Henry's constant and increasing hydrophobicity. Analysis of replicate tree core data showed no correlation between replicate relative standard deviation (RSD) and wood type or tree diameter, with an overall median RSD of 30%. Collectively, these findings indicate SPME is an appropriate technique for sampling and analyzing chlorinated solvents in wood and that phytoscreening is robust against changes in tree type and diameter.

  9. Measurement of Activity Coefficients at Infinite Dilution for Alcohols in [BMIM][CH3SO4] using HS-SPME/GC-FID

    Directory of Open Access Journals (Sweden)

    A. M. Elias

    Full Text Available ABSTRACT The activity coefficient at infinite dilution (&IN1 and distribution ratios at infinite dilution (&IN2 were determined for alkanols (methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, and 2-methyl-2-propanol in the ionic liquid (IL 1-butyl-3-methylimidazolium methyl sulfate ([BMIM][CH3SO4] by HS-SPME (Headspace - Solid Phase Micro Extraction at four temperatures (298.15, 313.15, 333.15, and 353.15K using headspace - solid phase microextraction (SPME-HS. The results showed significant agreement with literature data. In addition, partial molar excess enthalpies at infinite dilution (&IN3, excess Gibbs energies (&IN4, and excess entropies (&IN5 were calculated from the (&IN6 values.

  10. Role of nanoparticles in analytical solid phase microextraction (SPME)

    NARCIS (Netherlands)

    Zielinska, K.; Leeuwen, van H.P.

    2013-01-01

    Solid phase microextraction (SPME) is commonly used to measure the free concentration of fairly hydrophobic substances in aqueous media on the basis of their partitioning between sample solution and a solid phase. Here we study the role of nanoparticles that may sorb the analyte in the sample

  11. Further research on the photo-SPME of triclosan

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Prado, Lucia; Llompart, Maria; Lores, Marta; Fernandez-Alvarez, Maria; Garcia-Jares, Carmen; Cela, Rafael [Universidad de Santiago de Compostela, Departamento de Quimica Analitica, Nutricion y Bromatologia. Facultad de Quimica, Instituto de Investigacion y Analisis Alimentario, Santiago de Compostela (Spain)

    2006-04-15

    In this study the photoinduced degradation of triclosan has been investigated by photo-solid-phase microextraction (photo-SPME). In photo-SPME, photodegradation is carried out on the SPME fibre containing the target compound. Triclosan was extracted from aqueous solutions by use of polydimethylsiloxane SPME fibres and these were subsequently exposed to UV irradiation (power 8 W, wavelength 254 nm) for different times (from 2 to 60 min). The photodegradation kinetics of triclosan were investigated, the photoproducts generated were tentatively identified, and the photochemical behaviour of these products was studied by use of this on-fibre approach followed by gas chromatographic-mass spectrometric analysis. Eight photoproducts were tentatively identified, including chlorinated phenols, chlorohydroxydiphenyl ethers, 2,8-dichlorodibenzo-p-dioxin, and a possible dichlorodibenzodioxin isomer or dichlorohydroxydibenzofuran. The main photodegradation mechanisms were postulated and photodegradation pathways proposed. The effect of pH on triclosan degradation and on triclosan-to-dioxin conversion was also investigated. Triclosan degradation occurred, and generation of 2,8-dichlorodibenzo-p-dioxin was confirmed, throughout the pH range studied (from 3 to 9). (orig.)

  12. Is Solid Phase Microextraction (SPME) an appropriate method for extraction of volatile oxidation products from complex food systems

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Horn, Anna Frisenfeldt; Lu, Henna Fung Sieng

    Volatile secondary lipid oxidation products can be identified and quantified by GC-FID or GC-MS. An extraction step is, however, needed before GC analysis. A range of different extraction methods are available such as static headspace, dynamic headspace and SPME. Each of these methods has its...... advantages and drawbacks. Among the advantages of the SPME method are its high sensitivity compared to static headspace and that it is less laborious than the dynamic headspace method. For these reasons, the use of SPME has increased in both academia and industry during the last decade. The extraction...... for analysis of lipid oxidation during storage of complex food matrices. Examples on how uncontrollable factors have affected results obtained with the SPME method in the authors’ lab will be given and the appropriateness of the SPME method for the analysis of volatile oxidation products in selected food...

  13. Solid phase microextraction (SPME) for extraction of volatile oxidation products from complex food systems – Pros and cons

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Horn, Anna Frisenfeldt; Lu, Henna Fung Sieng

    Volatile secondary lipid oxidation products can be identified and quantified by GC-FID or GC-MS. An extraction step is, however, needed before GC analysis. A range of different extraction methods are available such as static headspace, dynamic headspace and SPME. Each of these methods has its...... advantages and drawbacks. Among the advantages of the SPME method are its high sensitivity compared to static headspace and that it is less laborious than the dynamic headspace method. For these reasons, the use of SPME has increased in both academia and industry during the last decade. The extraction...... for analysis of lipid oxidation during storage of complex food matrices. Examples on how uncontrollable factors have affected results obtained with the SPME method in the authors’ lab will be given and the appropriateness of the SPME method for the analysis of volatile oxidation products in selected food...

  14. Analysis of Volatile Markers for Virgin Olive Oil Aroma Defects by SPME-GC/FID: Possible Sources of Incorrect Data.

    Science.gov (United States)

    Oliver-Pozo, Celia; Aparicio-Ruiz, Ramón; Romero, Inmaculada; García-González, Diego L

    2015-12-09

    The need to explain virgin olive oil (VOO) aroma descriptors by means of volatiles has raised interest in applying analytical techniques for trapping and quantitating volatiles. Static headspace sampling with solid phase microextraction (SPME) as trapping material is one of the most applied solutions for analyzing volatiles. The use of an internal standard and the determination of the response factors of the main volatiles seem to guarantee the correct determination of volatile concentrations in VOOs by SPME-GC/FID. This paper, however, shows that the competition phenomena between volatiles in their adsorption to the SPME fiber, inherent in static headspace sampling, may affect the quantitation. These phenomena are more noticeable in the particular case of highly odorant matrices, such as rancid and vinegary VOOs with high intensity of defect. The competition phenomena can modify the measurement sensitivity, which can be observed in volatile quantitation as well as in the recording of internal standard areas in different matrices. This paper analyzes the bias of the peak areas and concentrations of those volatiles that are markers for each sensory defect of VOOs (rancid, vinegary, musty, and fusty) when the intensity and complexity of aroma are increased. Of the 17 volatile markers studied in this work, 10 presented some anomalies in the quantitation in highly odorant matrices due the competition phenomena. However, quantitation was not affected in the concentration ranges at which each volatile marker is typically found in the defective oils they were characteristic of, validating their use as markers.

  15. Compact range for variable-zone measurements

    Science.gov (United States)

    Burnside, Walter D.; Rudduck, Roger C.; Yu, Jiunn S.

    1988-08-02

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector.

  16. Method for covering a spme fibre with carbon nanotubes and resulting spme fibre

    OpenAIRE

    Bertrán, Enric; Jover Comas, Eric; García Céspedes, Jordi; Bayona Termens, Josep María

    2010-01-01

    [EN] The invention relates to a method for covering solid phase microextraction (SPME) fibres with carbon nanotubes (CNT), comprising the following operations: (i) depositing a layer of a metal material on the SPME fibre; (ii) applying a heat treatment in order to form catalytic metal nanoparticles in a reducing atmosphere; and (iii) applying carbon using chemical deposition techniques, thereby forming CNT on top ofthe metal nanoparticles. The invention also relates to a fibre obtain...

  17. Direct determination of anabolic steroids in pig urine by a new SPME-GC-MS method.

    Science.gov (United States)

    Zhang, Zhuomin; Duan, Hongbin; Zhang, Lan; Chen, Xi; Liu, Wei; Chen, Guonan

    2009-05-15

    A new solid phase microextraction (SPME) method coupled with gas chromatography-mass spectrometry (GC-MS) was developed for rapid determination of four anabolic steroids such as 3alpha-hydroxy-5alpha-androstane-17-one (HA), dihydrotestosterone (DHT), androstenedione (AD) and methyltestosterone (MT) in pig urine. SPME was used to extract the four anabolic compounds directly without derivatization. The optimum SPME sampling conditions were based on the home-made carbowax-divinylbenzene (CW-DVB) fiber coating during extraction at 40 degrees C for 50 min with 0.18 g/mL NaCl solution and 750 rpm stirring speed. The linear ranges of the proposed method were in the range of 8-640 pg/mL for HA and DHT and 16-510 pg/mL for AD and MT, respectively. The detection limits (S/N=3) were from 2 to 8 pg/mL for the four anabolic steroids. This SPME method provided very high enrichment factors for the four anabolic steroids, which were 1063-fold and 965-fold for HA and DHT at the concentration of 8 pg/mL and 207-fold and 451-fold for AD and MT at the concentration of 16 pg/mL, respectively. The recoveries ranged from 71.3 to 121%, and the RSDs were lower than 12.9%. The method was sensitive and reliable for determination of trace anabolic steroids in biological samples.

  18. Determination of benzene, toluene, ethylbenzene and xylene in field and laboratory by means of cold fiber SPME equipped with thermoelectric cooler and GC/FID method

    Directory of Open Access Journals (Sweden)

    Tajik Leila

    2017-09-01

    Full Text Available A simple and effective cooling device based on a thermoelectric cooler was applied to cool the SPME fiber. The device was used for quantitative extraction of aromatic hydrocarbons in the air. Several factors such as coating temperature, extraction temperature and relative humidity in the laboratory setting were optimized. Comparison of the results between the cold fiber SPME (CF-SPME and NIOSH 1501 method on standard test atmosphere indicated a satisfactory agreement. The CF-SPME and SPME method were also compared. The results revealed that CF-SPME has the most appropriate outcome for the extraction of aromatic hydrocarbons from the ambient air. The cold fiber SPME technique showed good results for several validation parameters. Under the optimized conditions, the limits of detection (LOD and the limits of quantification (LOQ ranged from 0.00019 to 0.00033 and 0.0006 to 0.001 ng ml−1, respectively. The intra-day relative standard deviation (RSD showed ranging from 4.8 to 10.5%.

  19. High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link

    Science.gov (United States)

    Yang, Guangning; Lu, Wei; Krainak, Michael; Sun, Xiaoli

    2016-01-01

    We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.

  20. Measurements of Capture Efficiency of Range Hoods in Homes

    DEFF Research Database (Denmark)

    Simone, Angela; Sherman, Max H.; Walker, Iain S.

    2015-01-01

    mapped the pollution distribution in the room, and showed that the pollutants escape more at the sides of the cooktop. These preliminary results suggest that more measurements should be conducted investigating the capture efficiency at different pollutant source temperature, size and location...... want a range hood to use little energy and have high capture efficiency to minimize the required air flow to capture the cooking pollutants. Currently there are no standards for rating range hoods for capture efficiency In this study, measurements of range hood capture efficiency were made a tight...... kitchen-room built in a laboratory chamber, and a methodology for standardizing measurement of capture efficiency was developed. The results for a wall mounted range hood, showed that up to half of the cooking pollutants were not captured at a flow rate of 230 m3/h. A more detailed set of measurements...

  1. A quantum inspired model of radar range and range-rate measurements with applications to weak value measurements

    Science.gov (United States)

    Escalante, George

    2017-05-01

    Weak Value Measurements (WVMs) with pre- and post-selected quantum mechanical ensembles were proposed by Aharonov, Albert, and Vaidman in 1988 and have found numerous applications in both theoretical and applied physics. In the field of precision metrology, WVM techniques have been demonstrated and proven valuable as a means to shift, amplify, and detect signals and to make precise measurements of small effects in both quantum and classical systems, including: particle spin, the Spin-Hall effect of light, optical beam deflections, frequency shifts, field gradients, and many others. In principal, WVM amplification techniques are also possible in radar and could be a valuable tool for precision measurements. However, relatively limited research has been done in this area. This article presents a quantum-inspired model of radar range and range-rate measurements of arbitrary strength, including standard and pre- and post-selected measurements. The model is used to extend WVM amplification theory to radar, with the receive filter performing the post-selection role. It is shown that the description of range and range-rate measurements based on the quantum-mechanical measurement model and formalism produces the same results as the conventional approach used in radar based on signal processing and filtering of the reflected signal at the radar receiver. Numerical simulation results using simple point scatterrer configurations are presented, applying the quantum-inspired model of radar range and range-rate measurements that occur in the weak measurement regime. Potential applications and benefits of the quantum inspired approach to radar measurements are presented, including improved range and Doppler measurement resolution.

  2. Measurement of positron range in matter in strong magnetic fields

    International Nuclear Information System (INIS)

    Hammer, B.E.; Christensen, N.L.

    1995-01-01

    Positron range is one factor that places a limitation on Positron Emission Tomography (PET) resolution. The distance a positron travels through matter before it annihilates with an electron is a function of its initial energy and the electron density of the medium. A strong magnetic field limits positron range when momentum components are transverse to the field. Measurement of positron range was determined by deconvolving the effects of detector response and radioactive distribution from the measured annihilation spread function. The annihilation spread function for a 0.5 mm bead of 68 Ga was measured with 0.2 and 1.0 mm wide slit collimators. Based on the annihilation spread function FWHM (Full Width at Half Maximum) for a 1.0 mm wide slit the median positron range in tissue equivalent material is 0.87, 0.50, 0.22 mm at 0, 5.0 and 9.4 T, respectively

  3. Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

    Science.gov (United States)

    Yassaa, N.; Custer, T.; Song, W.; Pech, F.; Kesselmeier, J.; Williams, J.

    2010-11-01

    A headspace solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS), 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) and 65 μm divinylbenzene-polydimethylsiloxane (DVB-PDMS). Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m-2 s-1 respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

  4. Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

    Directory of Open Access Journals (Sweden)

    N. Yassaa

    2010-11-01

    Full Text Available A headspace solid-phase microextraction (HS-SPME and gas chromatography/mass spectrometry (GC/MS system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS, 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS and 65 μm divinylbenzene-polydimethylsiloxane (DVB-PDMS. Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m−2 s−1 respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

  5. Smartphone photography utilized to measure wrist range of motion.

    Science.gov (United States)

    Wagner, Eric R; Conti Mica, Megan; Shin, Alexander Y

    2018-02-01

    The purpose was to determine if smartphone photography is a reliable tool in measuring wrist movement. Smartphones were used to take digital photos of both wrists in 32 normal participants (64 wrists) at extremes of wrist motion. The smartphone measurements were compared with clinical goniometry measurements. There was a very high correlation between the clinical goniometry and smartphone measurements, as the concordance coefficients were high for radial deviation, ulnar deviation, wrist extension and wrist flexion. The Pearson coefficients also demonstrated the high precision of the smartphone measurements. The Bland-Altman plots demonstrated 29-31 of 32 smartphone measurements were within the 95% confidence interval of the clinical measurements for all positions of the wrists. There was high reliability between the photography taken by the volunteer and researcher, as well as high inter-observer reliability. Smartphone digital photography is a reliable and accurate tool for measuring wrist range of motion. II.

  6. Spatial filtering velocimeter for vehicle navigation with extended measurement range

    Science.gov (United States)

    He, Xin; Zhou, Jian; Nie, Xiaoming; Long, Xingwu

    2015-05-01

    The idea of using spatial filtering velocimeter is proposed to provide accurate velocity information for vehicle autonomous navigation system. The presented spatial filtering velocimeter is based on a CMOS linear image sensor. The limited frame rate restricts high speed measurement of the vehicle. To extend measurement range of the velocimeter, a method of frequency shifting is put forward. Theoretical analysis shows that the frequency of output signal can be reduced and the measurement range can be doubled by this method when the shifting direction is set the same with that of image velocity. The approach of fast Fourier transform (FFT) is employed to obtain the power spectra of the spatially filtered signals. Because of limited frequency resolution of FFT, a frequency spectrum correction algorithm, called energy centrobaric correction, is used to improve the frequency resolution. The correction accuracy energy centrobaric correction is analyzed. Experiments are carried out to measure the moving surface of a conveyor belt. The experimental results show that the maximum measurable velocity is about 800deg/s without frequency shifting, 1600deg/s with frequency shifting, when the frame rate of the image is about 8117 Hz. Therefore, the measurement range is doubled by the method of frequency shifting. Furthermore, experiments were carried out to measure the vehicle velocity simultaneously using both the designed SFV and a laser Doppler velocimeter (LDV). The measurement results of the presented SFV are coincident with that of the LDV, but with bigger fluctuation. Therefore, it has the potential of application to vehicular autonomous navigation.

  7. Small Device For Short-Range Antenna Measurements Using Optics

    DEFF Research Database (Denmark)

    Yanakiev, Boyan Radkov; Nielsen, Jesper Ødum; Christensen, Morten

    2011-01-01

    This paper gives a practical solution for implementing an antenna radiation pattern measurement device using optical fibers. It is suitable for anechoic chambers as well as short range channel sounding. The device is optimized for small size and provides a cheap and easy way to make optical antenna...

  8. Measuring the relativistic perigee advance with satellite laser ranging

    CERN Document Server

    Iorio, L; Pavlis, E C

    2002-01-01

    The pericentric advance of a test body by a central mass is one of the classical tests of general relativity. Today, this effect is measured with radar ranging by the perihelion shift of Mercury and other planets in the gravitational field of the Sun, with a relative accuracy of the order of 10 sup - sup 2 -10 sup - sup 3. In this paper, we explore the possibility of a measurement of the pericentric advance in the gravitational field of Earth by analysing the laser-ranged data of some orbiting, or proposed, laser-ranged geodetic satellites. Such a measurement of the perigee advance would place limits on hypothetical, very weak, Yukawa-type components of the gravitational interaction with a finite range of the order of 10 sup 4 km. Thus, we show that, at the present level of knowledge of the orbital perturbations, the relative accuracy, achievable with suitably combined orbital elements of LAGEOS and LAGEOS II, is of the order of 10 sup - sup 3. With the corresponding measured value of (2 + 2 gamma - beta)/3, ...

  9. Recoil range distribution measurement in 20Ne + 181Ta reaction

    International Nuclear Information System (INIS)

    Tripathi, R.; Sudarshan, K.; Goswami, A.; Guin, R.; Reddy, A.V.R.

    2005-01-01

    In order to investigate linear momentum transfer in various transfer channels in 20 Ne + 181 Ta, recoil range distribution measurements have been carried out at E lab = 180 MeV, populating significant number of l-waves above l crit

  10. Measurements of short-range ordering in Ni3Al

    International Nuclear Information System (INIS)

    Okamoto, J.K.; Ahn, C.C.

    1992-01-01

    This paper reports on extended electron energy-loss fine structure (EXELFS) that has been used to measure short-range ordering in Ni 3 Al. Films of fcc Ni 3 Al with suppressed short-range order synthesized by vacuum evaporation of Ni 3 Al onto room temperature substrates. EXELFS data were taken from both Al K and Ni L 23 edges. The development of short-range order was observed after the samples were annealed for various times at temperatures below 350 degrees C. Upon comparison with ab initio planewave EXELFS calculations, it was found that the Warren-Cowley short-range order parameter a(1nn) changed by about -0.1 after 210 minutes of annealing at 150 degrees C

  11. Measuring the relativistic perigee advance with satellite laser ranging

    International Nuclear Information System (INIS)

    Iorio, Lorenzo; Ciufolini, Ignazio; Pavlis, Erricos C

    2002-01-01

    The pericentric advance of a test body by a central mass is one of the classical tests of general relativity. Today, this effect is measured with radar ranging by the perihelion shift of Mercury and other planets in the gravitational field of the Sun, with a relative accuracy of the order of 10 -2 -10 -3 . In this paper, we explore the possibility of a measurement of the pericentric advance in the gravitational field of Earth by analysing the laser-ranged data of some orbiting, or proposed, laser-ranged geodetic satellites. Such a measurement of the perigee advance would place limits on hypothetical, very weak, Yukawa-type components of the gravitational interaction with a finite range of the order of 10 4 km. Thus, we show that, at the present level of knowledge of the orbital perturbations, the relative accuracy, achievable with suitably combined orbital elements of LAGEOS and LAGEOS II, is of the order of 10 -3 . With the corresponding measured value of (2 + 2γ - β)/3, by using η = 4β - γ - 3 from lunar laser ranging, we could get an estimate of the PPN parameters γ and β with an accuracy of the order of 10 -2 -10 -3 . Nevertheless, these accuracies would be substantially improved in the near future with the new Earth gravity field models by the CHAMP and GRACE missions. The use of the perigee of LARES (LAser RElativity Satellite), with a suitable combination of orbital residuals including also the node and the perigee of LAGEOS II, would also further improve the accuracy of the proposed measurement

  12. Broadband Laser Ranging for Position Measurements in Shock Physics Experiments

    Science.gov (United States)

    Rhodes, Michelle; Bennett, Corey; Daykin, Edward; Younk, Patrick; Lalone, Brandon; Kostinski, Natalie

    2017-06-01

    Broadband laser ranging (BLR) is a recently developed measurement system that provides an attractive option for determining the position of shock-driven surfaces. This system uses broadband, picosecond (or femtosecond) laser pulses and a fiber interferometer to measure relative travel time to a target and to a reference mirror. The difference in travel time produces a delay difference between pulse replicas that creates a spectral beat frequency. The spectral beating is recorded in real time using a dispersive Fourier transform and an oscilloscope. BLR systems have been designed that measure position at 12.5-40 MHz with better than 100 micron accuracy over ranges greater than 10 cm. We will give an overview of the basic operating principles of these systems. Prepared by LLNL under Contract DE-AC52-07NA27344, by LANL under Contract DE-AC52-06NA25396, and by NSTec Contract DE-AC52-06NA25946.

  13. Lifetime measurements in the picosecond range: Achievements and Perspectives

    International Nuclear Information System (INIS)

    Kruecken, Reiner

    1999-01-01

    This contribution will review the recoil distance method (RDM), its current range of applications as well as future perspectives for the measurement of lifetimes in the picosecond range of excited nuclear levels. Recent Doppler-shift lifetime experiments with large gamma-ray spectrometers have achieved a new level of precision and sensitivity, providing new insights into nuclear structure physics. High precision RDM measurements of near-yrast states in various mass regions have revealed dynamic shape effects beyond the framework of collective models and have also allowed to study the interaction between coexisting shapes. The measurement of lifetimes in superdeformed bands has shown that lifetimes can be measured for nuclear excitations, which are only populated with a few percent of the production cross-section of a nucleus. These experiments have also enabled us to study the mechanism of the decay-out of superdeformed bands. Another example for the need of precise lifetime measurements is the recent verifications of the concept of 'magnetic rotation' in nuclei by the experimental observation of the characteristic drop of B(M1) values as a function of angular momentum. These recent breakthroughs have also opened new perspectives for the use of the RDM technique for more exotic regions of nuclei and nuclear excitations. Here the measurement of lifetimes in neutron rich nuclei, which are not accessible with conventional nuclear reactions using stable beams and targets, is of special interest. Possible experimental approaches and simple estimates for the feasibility of such experiments will be presented. (author)

  14. High-temperature absorbed dose measurements in the megagray range

    International Nuclear Information System (INIS)

    Balian, P.; Ardonceau, J.; Zuppiroli, L.

    1988-01-01

    Organic conductors of the tetraselenotetracene family have been tested as ''high-temperature'' absorbed dose dosimeters. They were heated up to 120 0 C and irradiated at this temperature with 1-MeV electrons in order to simulate, in a short time, a much longer γ-ray irradiation. The electric resistance increase of the crystal can be considered a good measurement of the absorbed dose in the range 10 6 Gy to a few 10 8 Gy and presumably one order of magnitude more. This dosimeter also permits on-line (in-situ) measurements of the absorbed dose without removing the sensor from the irradiation site. The respective advantages of organic and inorganic dosimeters at these temperature and dose ranges are also discussed. In this connection, we outline new, but negative, results concerning the possible use of silica as a high-temperature, high-dose dosimeter. (author)

  15. An overview of Broadband Laser Ranging Architecture and Measurement Considerations

    Science.gov (United States)

    Daykin, Edward; La Lone, Brandon; Miller, Edward; Younk, Patrick; Bennett, Corey; Catenacci, Jared; LLNL BLR Development Group Collaboration; LANL BLR Development Group Collaboration

    2017-06-01

    Broadband Laser Ranging (BLR) is a developmental diagnostic intended to measure the position of rapidly moving surfaces in combination with optical velocimetry. Design and employment of a BLR diagnostic on dynamic experiments requires consideration for both the inherent measurement system tradeoffs as well as architectural choices appropriate to the nature of investigation. The diagnostic uses spectral interferometry to measure distance by mapping femtosecond laser pulses to the time domain via chromatic dispersion within the fiber-optic architecture. The system parameters and governing equations that describe measurement range, resolution, and Doppler sensitivity will be discussed. We will also briefly review the impact of diagnostic architectural choices including: nature of interferometer, Interferometric dispersion matching, optical amplification, integration of optical velocimetry, BLR calibration, and field operability. To summarize we will present the architectural and operational approach currently being pursued by NSTec within an on-going collaboration between NSTec, Lawrence Livermore and Los Alamos National Labs. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.

  16. MTF measurement of IR optics in different temperature ranges

    Science.gov (United States)

    Bai, Alexander; Duncker, Hannes; Dumitrescu, Eugen

    2017-10-01

    Infrared (IR) optical systems are at the core of many military, civilian and manufacturing applications and perform mission critical functions. To reliably fulfill the demanding requirements imposed on today's high performance IR optics, highly accurate, reproducible and fast lens testing is of crucial importance. Testing the optical performance within different temperature ranges becomes key in many military applications. Due to highly complex IR-Applications in the fields of aerospace, military and automotive industries, MTF Measurement under realistic environmental conditions become more and more relevant. A Modulation Transfer Function (MTF) test bench with an integrated thermal chamber allows measuring several sample sizes in a temperature range from -40 °C to +120°C. To reach reliable measurement results under these difficult conditions, a specially developed temperature stable design including an insulating vacuum are used. The main function of this instrument is the measurement of the MTF both on- and off-axis at up to +/-70° field angle, as well as measurement of effective focal length, flange focal length and distortion. The vertical configuration of the system guarantees a small overall footprint. By integrating a high-resolution IR camera with focal plane array (FPA) in the detection unit, time consuming measurement procedures such as scanning slit with liquid nitrogen cooled detectors can be avoided. The specified absolute accuracy of +/- 3% MTF is validated using internationally traceable reference optics. Together with a complete and intuitive software solution, this makes the instrument a turn-key device for today's state-of- the-art optical testing.

  17. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Directory of Open Access Journals (Sweden)

    Filippo Arrichiello

    2013-11-01

    Full Text Available The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the

  18. SPME GC/MS determination of organochlorine pesticides in water samples

    Directory of Open Access Journals (Sweden)

    Yerbolat Sailaukhanuly

    2013-05-01

    Full Text Available Headspace solid phase microextraction (HS-SPME in combination with gas chromatography and mass-spectrometry (GC/MS was studied for analysis of water samples. The organochlorine pesticides (OCPs, p,p'-DDT, p,p'-DDD, and p,p'-DDE were collected and analyzed by GC/MS. To select of effective fiber coatings four types of SPME fibers were examined and compared. The parameters effecting the efficiency of HS-SPME such as extraction and pre-incubation time and extraction temperature, effect of solvent nature, ionic strength were studied to obtain optimal parameters. The method was developed using spiked water samples in a concentration range  10 - 500 ng/L. The calibration curve was linear over the studied concentration range with r≥0.9925. The detection limits varied from 1.57 to 2.08 ng/L. An authentic water samples from contaminated lake with OCPs were analyzed by developed method.

  19. Measuring Systems for Thermometer Calibration in Low-Temperature Range

    Science.gov (United States)

    Szmyrka-Grzebyk, A.; Lipiński, L.; Manuszkiewicz, H.; Kowal, A.; Grykałowska, A.; Jancewicz, D.

    2011-12-01

    The national temperature standard for the low-temperature range between 13.8033 K and 273.16 K has been established in Poland at the Institute of Low Temperature and Structure Research (INTiBS). The standard consists of sealed cells for realization of six fixed points of the International Temperature Scale of 1990 (ITS-90) in the low-temperature range, an adiabatic cryostat and Isotech water and mercury triple-point baths, capsule standard resistance thermometers (CSPRT), and AC and DC bridges with standard resistors for thermometers resistance measurements. INTiBS calibrates CSPRTs at the low-temperature fixed points with uncertainties less than 1 mK. In lower temperature range—between 2.5 K and about 25 K — rhodium-iron (RhFe) resistance thermometers are calibrated by comparison with a standard which participated in the EURAMET.T-K1.1 comparison. INTiBS offers a calibration service for industrial platinum resistance thermometers and for digital thermometers between 77 K and 273 K. These types of thermometers may be calibrated at INTiBS also in a higher temperature range up to 550°C. The Laboratory of Temperature Standard at INTiBS acquired an accreditation from the Polish Centre for Accreditation. A management system according to EN ISO/IEC 17025:2005 was established at the Laboratory and presented on EURAMET QSM Forum.

  20. Model-based cartilage thickness measurement in the submillimeter range

    International Nuclear Information System (INIS)

    Streekstra, G. J.; Strackee, S. D.; Maas, M.; Wee, R. ter; Venema, H. W.

    2007-01-01

    Current methods of image-based thickness measurement in thin sheet structures utilize second derivative zero crossings to locate the layer boundaries. It is generally acknowledged that the nonzero width of the point spread function (PSF) limits the accuracy of this measurement procedure. We propose a model-based method that strongly reduces PSF-induced bias by incorporating the PSF into the thickness estimation method. We estimated the bias in thickness measurements in simulated thin sheet images as obtained from second derivative zero crossings. To gain insight into the range of sheet thickness where our method is expected to yield improved results, sheet thickness was varied between 0.15 and 1.2 mm with an assumed PSF as present in the high-resolution modes of current computed tomography (CT) scanners [full width at half maximum (FWHM) 0.5-0.8 mm]. Our model-based method was evaluated in practice by measuring layer thickness from CT images of a phantom mimicking two parallel cartilage layers in an arthrography procedure. CT arthrography images of cadaver wrists were also evaluated, and thickness estimates were compared to those obtained from high-resolution anatomical sections that served as a reference. The thickness estimates from the simulated images reveal that the method based on second derivative zero crossings shows considerable bias for layers in the submillimeter range. This bias is negligible for sheet thickness larger than 1 mm, where the size of the sheet is more than twice the FWHM of the PSF but can be as large as 0.2 mm for a 0.5 mm sheet. The results of the phantom experiments show that the bias is effectively reduced by our method. The deviations from the true thickness, due to random fluctuations induced by quantum noise in the CT images, are of the order of 3% for a standard wrist imaging protocol. In the wrist the submillimeter thickness estimates from the CT arthrography images correspond within 10% to those estimated from the anatomical

  1. Analysis of flavor-related compounds from tabacco using SPME-GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Park, G.B.; Lee, S.G. [Korea Research Institute of Chemical Technology, Taejeon (Korea)

    2001-04-01

    The flavor-related compounds contained in tobacco were analyzed by selected ion monitoring (SIM) method using headspace SPME gas chromatography-mass spectrometry (GC-MS). Flavor-related compounds were estragole, pulegone, trans-anethole, safrole, piperonal, eugenol, methyleugenol, coumarin, trans-isoeugenol, trans-methyleugenol and myristicin More than one of the flavor-related compounds were detected in the range of 0.001-1.3 {mu}g/g from all brands of tobacco studied. The recovery was ranged from 89.1 to 102.9% and relative standard deviation was ranged from 2.6 to 25.2%. (author). 19 refs., 4 tabs., 2 figs.

  2. Lifetime measurements in the picosecond range: achievements and perspectives

    International Nuclear Information System (INIS)

    Kruecken, R.

    2000-01-01

    Recent developments in the measurement of lifetimes in the picosecond range using the recoil distance method (RDM) are reviewed. Results from recent RDM experiments on superdeformed bands in the mass-190 region, shears, bands in the neutron deficient lead isotopes, and ground state bands in the mass-130 region are presented. New experimental devices for lifetime experiments at Yale, such as the New Yale Plunger Device (N.Y.P.D.), the SPEctrometer for Doppler-shift Experiments at Yale (SPEEDY) and the plans for the gas-filled recoil separator SASSYER are presented. Perspectives for the use of the RDM technique in the study of exotic nuclei and its potential use with radioactive beams are discussed. (author)

  3. Picosecond X-ray streak camera dynamic range measurement

    Energy Technology Data Exchange (ETDEWEB)

    Zuber, C., E-mail: celine.zuber@cea.fr; Bazzoli, S.; Brunel, P.; Gontier, D.; Raimbourg, J.; Rubbelynck, C.; Trosseille, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Fronty, J.-P.; Goulmy, C. [Photonis SAS, Avenue Roger Roncier, BP 520, 19106 Brive Cedex (France)

    2016-09-15

    Streak cameras are widely used to record the spatio-temporal evolution of laser-induced plasma. A prototype of picosecond X-ray streak camera has been developed and tested by Commissariat à l’Énergie Atomique et aux Énergies Alternatives to answer the Laser MegaJoule specific needs. The dynamic range of this instrument is measured with picosecond X-ray pulses generated by the interaction of a laser beam and a copper target. The required value of 100 is reached only in the configurations combining the slowest sweeping speed and optimization of the streak tube electron throughput by an appropriate choice of high voltages applied to its electrodes.

  4. AN INDUCTION SENSOR FOR MEASURING CURRENTS OF NANOSECOND RANGE

    Directory of Open Access Journals (Sweden)

    S. P. Shalamov

    2016-11-01

    Full Text Available Purpose. A current meter based on the principle of electromagnetic induction is designed to register the current flowing in the rod lightning. The aim of the article is to describe the way of increasing the sensitivity of the converter by means of their serial communication. Methodology. The recorded current is in the nanosecond range. If compared with other methods, meters based on the principle of electromagnetic induction have several advantages, such as simplicity of construction, reliability, low cost, no need in a power source, relatively high sensitivity. Creation of such a meter is necessary, because in some cases there is no possibility to use a shunt. Transient properties of a meter are determined by the number of turns and the constant of integration. Sensitivity is determined by measuring the number of turns, the coil sectional area, the core material and the integration constant. For measuring the magnetic field pulses with a rise time of 5 ns to 50 ns a meter has turns from 5 to 15. The sensitivity of such a meter is low. When the number of turns is increased, the output signal and the front increase. Earlier described dependencies were used to select the main parameters of the converter. It was based on generally accepted and widely known equivalent circuit. The experience of created earlier pulse magnetic field meters was considered both for measuring the magnetic fields, and large pulse current. Originality. Series connection of converters has the property of a long line. The level of the transient response of the meter is calculated. The influence of parasitic parameters on the type of meter transient response is examined. The shown construction was not previously described. Practical value. The results of meter implementation are given. The design peculiarities of the given measuring instruments are shown.

  5. Optimization of Solid Phase Micro-Extraction (SPME for Monitoring Occupational Exposure to Ethyl Benzene

    Directory of Open Access Journals (Sweden)

    H. Heidari

    2009-08-01

    Full Text Available AbstractBackground and Objectives: Analytical methods for volatile organic compounds (VOCs in different samples need extraction of compounds, by applying hazardous solvents. Solid phase micro-extraction (SPME is a solvent-free equilibrium extraction method, in which proper calibration can allow quantitative determinations of VOCs at a very good sensitivity without the use of any organic solvent. VOCs are generally present in urine only at trace levels, therefore, a sensitive procedure is needed for their trace determinations. Throughout this study, headspace solid phase micro-extraction (HS-SPME was followed by GC-FID for ethyl benzene in spiked urine was optimized.Methods: In this study, the parameters influencing SPME and gas chromatography of ethyl benzene, including extraction time, temperature, desorption temperature, desorption time, salt addition, sample pH, sample volume and sample agitation were investigated. Results: Extraction procedure was performed at 30°C for 6 min, using 0.2 gml-1 of NaCl in the sample solution. The sample volume and sample pH were optimized at 5 ml and 7 (neutral pH, respectively. Desorption of the ethyl benzene was carried out for 60 sec. at 250°C. The method was also validated with three different spiked urine samples and illustrated an appropriate reproducibility over six consecutive days as well as six within-day experiments. During this investigation, parameters of accuracy, linearity, and detection limits of the procedure were also evaluated.Conclusion: The developed method of HS- SPME-GC-FID proved to be a simple, convenient, and practical procedure, and was successfully used for measuring of ethyl benzene in spiked urine.

  6. Measured long-range repulsive Casimir–Lifshitz forces

    Science.gov (United States)

    Munday, J. N.; Capasso, Federico; Parsegian, V. Adrian

    2014-01-01

    Quantum fluctuations create intermolecular forces that pervade macroscopic bodies1–3. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces4. However, as recognized in the theories of Casimir, Polder and Lifshitz5–7, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies8–11. Here we show experimentally that, in accord with theoretical prediction12, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir–Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction13–15. PMID:19129843

  7. Measured long-range repulsive Casimir-Lifshitz forces.

    Science.gov (United States)

    Munday, J N; Capasso, Federico; Parsegian, V Adrian

    2009-01-08

    Quantum fluctuations create intermolecular forces that pervade macroscopic bodies. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces. However, as recognized in the theories of Casimir, Polder and Lifshitz, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies. Here we show experimentally that, in accord with theoretical prediction, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir-Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction.

  8. Ionospheric Coherence Bandwidth Measurements in the Lower VHF Frequency Range

    Science.gov (United States)

    Suszcynsky, D. M.; Light, M. E.; Pigue, M. J.

    2015-12-01

    The United States Department of Energy's Radio Frequency Propagation (RFProp) experiment consists of a satellite-based radio receiver suite to study various aspects of trans-ionospheric signal propagation and detection in four frequency bands, 2 - 55 MHz, 125 - 175 MHz, 365 - 415 MHz and 820 - 1100 MHz. In this paper, we present simultaneous ionospheric coherence bandwidth and S4 scintillation index measurements in the 32 - 44 MHz frequency range collected during the ESCINT equatorial scintillation experiment. 40-MHz continuous wave (CW) and 32 - 44 MHz swept frequency signals were transmitted simultaneously to the RFProp receiver suite from the Reagan Test Site at Kwajalein Atoll in the Marshall Islands (8.7° N, 167.7° E) in three separate campaigns during the 2014 and 2015 equinoxes. Results show coherence bandwidths as small as ~ 1 kHz for strong scintillation (S4 > 0.7) and indicate a high degree of ionospheric variability and irregularity on 10-m spatial scales. Spread-Doppler clutter effects arising from preferential ray paths to the satellite due to refraction off of isolated density irregularities are also observed and are dominant at low elevation angles. The results are compared to previous measurements and available scaling laws.

  9. CENTIMETER COSMO-SKYMED RANGE MEASUREMENTS FOR MONITORING GROUND DISPLACEMENTS

    Directory of Open Access Journals (Sweden)

    F. Fratarcangeli

    2016-06-01

    Full Text Available The SAR (Synthetic Aperture Radar imagery are widely used in order to monitor displacements impacting the Earth surface and infrastructures. The main remote sensing technique to extract sub-centimeter information from SAR imagery is the Differential SAR Interferometry (DInSAR, based on the phase information only. However, it is well known that DInSAR technique may suffer for lack of coherence among the considered stack of images. New Earth observation SAR satellite sensors, as COSMO-SkyMed, TerraSAR-X, and the coming PAZ, can acquire imagery with high amplitude resolutions too, up to few decimeters. Thanks to this feature, and to the on board dual frequency GPS receivers, allowing orbits determination with an accuracy at few centimetres level, the it was proven by different groups that TerraSAR-X imagery offer the capability to achieve, in a global reference frame, 3D positioning accuracies in the decimeter range and even better just exploiting the slant-range measurements coming from the amplitude information, provided proper corrections of all the involved geophysical phenomena are carefully applied. The core of this work is to test this methodology on COSMO-SkyMed data acquired over the Corvara area (Bolzano – Northern Italy, where, currently, a landslide with relevant yearly displacements, up to decimeters, is monitored, using GPS survey and DInSAR technique. The leading idea is to measure the distance between the satellite and a well identifiable natural or artificial Persistent Scatterer (PS, taking in account the signal propagation delays through the troposphere and ionosphere and filtering out the known geophysical effects that induce periodic and secular ground displacements. The preliminary results here presented and discussed indicate that COSMO-SkyMed Himage imagery appear able to guarantee a displacements monitoring with an accuracy of few centimetres using only the amplitude data, provided few (at least one stable PS’s are

  10. Physical measurements for ion range verification in charged particle therapy

    International Nuclear Information System (INIS)

    Testa, M.

    2010-10-01

    This PhD thesis reports on the experimental investigation of the prompt photons created during the fragmentation of the carbon beam used in particle therapy. Two series of experiments have been performed at the GANIL and GSI facilities with 95 MeV/u and 305 MeV/u 12 C 6+ ion beams stopped in PMMA and water phantoms. In both experiments a clear correlation was obtained between the C-ion range and the prompt photon profile. A major issue of these measurements is the discrimination between the prompt photon signal (which is correlated with the ion path) and a vast neutron background uncorrelated with the Bragg-Peak position. Two techniques are employed to allow for this photon-neutron discrimination: the time-of-flight (TOF) and the pulse-shape-discrimination (PSD). The TOF technique allowed demonstrating the correlation of the prompt photon production and the primary ion path while the PSD technique brought great insights to better understand the photon and neutron contribution in TOF spectra. In this work we demonstrated that a collimated set-up detecting prompt photons by means of TOF measurements, could allow real-time control of the longitudinal position of the Bragg-peak under clinical conditions. In the second part of the PhD thesis a simulation study was performed with Geant4 Monte Carlo code to assess the influence of the main design parameters on the efficiency and spatial resolution achievable with a multidetector and multi-collimated Prompt Gamma Camera. Several geometrical configurations for both collimators and stack of detectors have been systematically studied and the considerations on the main design constraints are reported. (author)

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

    International Nuclear Information System (INIS)

    Wang Junxia; Tuduri, Ludovic; Mercury, Maud; Millet, Maurice; Briand, Olivier; Montury, Michel

    2009-01-01

    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 -1 for the exposed fiber and 0.166-0.929 mL min -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 -1 ) was consistent with that in the lab (34.5 mL min -1 ). SR for dichlorvos in the field (32.4 mL min -1 ) was consistent with that in the lab (34.5 mL min -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

  12. Fast quantitation of opioid isomers in human plasma by differential mobility spectrometry/mass spectrometry via SPME/open-port probe sampling interface.

    Science.gov (United States)

    Liu, Chang; Gómez-Ríos, Germán Augusto; Schneider, Bradley B; Le Blanc, J C Yves; Reyes-Garcés, Nathaly; Arnold, Don W; Covey, Thomas R; Pawliszyn, Janusz

    2017-10-23

    Mass spectrometry (MS) based quantitative approaches typically require a thorough sample clean-up and a decent chromatographic step in order to achieve needed figures of merit. However, in most cases, such processes are not optimal for urgent assessments and high-throughput determinations. The direct coupling of solid phase microextraction (SPME) to MS has shown great potential to shorten the total sample analysis time of complex matrices, as well as to diminish potential matrix effects and instrument contamination. In this study, we demonstrate the use of the open-port probe (OPP) as a direct and robust sampling interface to couple biocompatible-SPME (Bio-SPME) fibres to MS for the rapid quantitation of opioid isomers (i.e. codeine and hydrocodone) in human plasma. In place of chromatography, a differential mobility spectrometry (DMS) device was implemented to provide the essential selectivity required to quantify these constitutional isomers. Taking advantage of the simplified sample preparation process based on Bio-SPME and the fast separation with DMS-MS coupling via OPP, a high-throughput assay (10-15 s per sample) with limits of detection in the sub-ng/mL range was developed. Succinctly, we demonstrated that by tuning adequate ion mobility separation conditions, SPME-OPP-MS can be employed to quantify non-resolved compounds or those otherwise hindered by co-extracted isobaric interferences without further need of coupling to other separation platforms. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The Construction and Calibration of a LADAR (Laser Detection and Ranging) Cross-Section Measurement Range

    Science.gov (United States)

    1985-12-01

    resonator optics consist of two porro prisms which are oriented 900 from one another about the cavity’s optical axis. In other words, the roof edges of each... prism are perpendicular to one another. The Nd:YAG laser rod measures 5 mm in diameter by 75 mm long and is optically pumped by a Xenon flashlamp. Q...Switching of the laser is performed by a Pockels Cell. A dielectric polarizer is sealed between two right angle prisms which are joined symetrically

  14. Measurements on the extended range of the wake

    International Nuclear Information System (INIS)

    Kumbartzki, G.J.; Kroesing, G; Neuburger, H.

    1981-01-01

    The Coulomb explosion of H 2 + -ions at 28 MeV is used to probe the wake over a range of about 400 A in Al. Preliminary results give food agreement with the wavelength prediction of the simple plasma oscillation wake model. (author)

  15. Extending the range of turbidity measurement using polarimetry

    Science.gov (United States)

    Baba, Justin S.

    2017-11-21

    Turbidity measurements are obtained by directing a polarized optical beam to a scattering sample. Scattered portions of the beam are measured in orthogonal polarization states to determine a scattering minimum and a scattering maximum. These values are used to determine a degree of polarization of the scattered portions of the beam, and concentrations of scattering materials or turbidity can be estimated using the degree of polarization. Typically, linear polarizations are used, and scattering is measured along an axis that orthogonal to the direction of propagation of the polarized optical beam.

  16. A quantitative approach for pesticide analysis in grape juice by direct interfacing of a matrix compatible SPME phase to dielectric barrier discharge ionization-mass spectrometry.

    Science.gov (United States)

    Mirabelli, Mario F; Gionfriddo, Emanuela; Pawliszyn, Janusz; Zenobi, Renato

    2018-02-12

    We evaluated the performance of a dielectric barrier discharge ionization (DBDI) source for pesticide analysis in grape juice, a fairly complex matrix due to the high content of sugars (≈20% w/w) and pigments. A fast sample preparation method based on direct immersion solid-phase microextraction (SPME) was developed, and novel matrix compatible SPME fibers were used to reduce in-source matrix suppression effects. A high resolution LTQ Orbitrap mass spectrometer allowed for rapid quantification in full scan mode. This direct SPME-DBDI-MS approach was proven to be effective for the rapid and direct analysis of complex sample matrices, with limits of detection in the parts-per-trillion (ppt) range and inter- and intra-day precision below 30% relative standard deviation (RSD) for samples spiked at 1, 10 and 10 ng ml -1 , with overall performance comparable or even superior to existing chromatographic approaches.

  17. JV Task 92 - Alcoa/Retec SFE and SPME

    Energy Technology Data Exchange (ETDEWEB)

    Steven Hawthorne

    2009-02-15

    This report summarizes the work performed by the Energy & Environmental Research Center (EERC) under the U.S. Department of Energy Jointly Sponsored Research Program JV Task 92, which is a continuation of JV9. Successful studies performed in 1999 through the end of 2008 demonstrated the potential for using selective supercritical fluid extraction (SFE) and a solid-phase microextraction (SPME) method for measuring sediment pore water polycyclic aromatic hydrocarbons (PAHs) to mimic the bioavailability of PAHs from manufactured gas plant and aluminum smelter soils and sediments both in freshwater and saltwater locations. The studies that the EERC has performed with the commercial partners have continued to generate increased interest in both the regulatory communities and in the industries that have historically produced or utilized coal tar products. Both ASTM International and the U.S. Environmental Protection Agency (EPA) have accepted the pore water method developed at the EERC as standard methods. The studies have demonstrated the effectiveness of our techniques in predicting bioavailability of PAHs from ca. 250 impacted and background field sediments and soils. The field demonstrations from the final years of the project continued to build the foundation data for acceptance of our methods by the regulatory communities. The JV92 studies provide the single largest database in the world that includes measures of PAH bioavailability along with biological end points. These studies clearly demonstrated that present regulatory paradigms based on equilibrium partitioning greatly overpredict bioavailability. These investigations also laid the foundation for present (non-JV) studies being applied to PAHs and polychlorinated biphenyls (PCBs) at EPA Superfund sites, investigations into PAH and PCB bioavailability at U.S Department of Defense sites, and the application of the techniques to investigating the bioavailability of chlorinated dioxins and furans from impacted

  18. Intensity autocorrelation measurements of frequency combs in the terahertz range

    Science.gov (United States)

    Benea-Chelmus, Ileana-Cristina; Rösch, Markus; Scalari, Giacomo; Beck, Mattias; Faist, Jérôme

    2017-09-01

    We report on direct measurements of the emission character of quantum cascade laser based frequency combs, using intensity autocorrelation. Our implementation is based on fast electro-optic sampling, with a detection spectral bandwidth matching the emission bandwidth of the comb laser, around 2.5 THz. We find the output of these frequency combs to be continuous even in the locked regime, but accompanied by a strong intensity modulation. Moreover, with our record temporal resolution of only few hundreds of femtoseconds, we can resolve correlated intensity modulation occurring on time scales as short as the gain recovery time, about 4 ps. By direct comparison with pulsed terahertz light originating from a photoconductive emitter, we demonstrate the peculiar emission pattern of these lasers. The measurement technique is self-referenced and ultrafast, and requires no reconstruction. It will be of significant importance in future measurements of ultrashort pulses from quantum cascade lasers.

  19. Determination of the range of control limits in radioimmunoassay measurements

    International Nuclear Information System (INIS)

    Fiori, A.M.C.

    1981-01-01

    A grouping technique is proposed for control limits in radioimmunoassay measurements. It has the advantage of working with control limits of 99.7% without the inconvenience of the confidence intervals. The method is practical and simple. It provides considerable flexibility for the processing of data. As the number of samples increases, the control limits become better defined. (author) [es

  20. Lifetime measurements in the 10-13 s range

    International Nuclear Information System (INIS)

    Bellini, Dzh.; Foa, L.; Dzhordzhi, M.

    1984-01-01

    Semiconducting detectors used in experimental high energy physics are described. Performances of Ge- and Si detectors and telescopes developed on their base as well as some problems associated with separation of coherent and incoherent events are described in detail. New fields are considered of semiconductor detector application: lifetime measurements of heavy particles decaying via weak interaction, such as D-mesons as well as the procedure of determination of the meson production and disintegration point with a space resolution enabling one to measure the length of meson path. The space resolution of detectors operating as proportional chambeps approaches 10-20 μm. Principles of devising the electronics for active target processors are described, solid state detectors being used for the latter

  1. High Dynamic Range Nonlinear Measurement using Analog Cancellation

    Science.gov (United States)

    2012-10-01

    shield around sensitive areas. The target may also be sensitive to radiated coupling from the system and will benefit from a shield box or Faraday ... cage , if it is not already enclosed. On the shared measurement path and through the target, cross-channel coupling cannot be prevented, so low-PIM...testing is desired, traditional filtering is recommended, as the primary benefits of the analog canceller are effectively nullified. 2.4 Wideband

  2. Temperature measurement in the liquid helium range at pressure

    International Nuclear Information System (INIS)

    Itskevich, E.S.; Krajdenov, V.F.

    1978-01-01

    The use of bronze and germanium resistance thermometers and the use of a (Au + 0.07 % Fe)-Cu thermocouple for temperature measurements from 1.5 to 4.2 K in the hydrostatic compression of up to 10 kbar are considered. To this aim, the thermometer resistance as a function of temperature and pressure is measured. It is revealed that pressure does not change the thermometric response of the bronze resistance thermometer but only shifts it to the region of lower temperatures. The identical investigations of the germanium resistance thermometer shows that strong temperature dependence and the shift of its thermometric response under the influence of pressure make the use of germanium resistance thermometers in high-pressure chambers very inconvenient. The results of the analysis of the (Au + 0.07 % Fe) - Cu thermocouple shows that with a 2 per cent accuracy the thermocouple Seebeck coefficient does not depend on pressure. It permits to use this thermocouple for temperature measurements at high pressures

  3. Quantitation of (R)- and (S)-linalool in beer using solid phase microextraction (SPME) in combination with a stable isotope dilution assay (SIDA).

    Science.gov (United States)

    Steinhaus, Martin; Fritsch, Helge T; Schieberle, Peter

    2003-11-19

    A stable isotope dilution assay (SIDA) was developed for the quantitation of both linalool enantiomers using synthesized [2H(2)]R/S-linalool as the internal standard. For enrichment of the target compound from beer, a solid phase microextraction method (SPME) was developed. In comparison to the more time-consuming extraction/distillation cleanup of the beer samples, the results obtained by SPME/SIDA were very similar, even under nonequilibration conditions. Analysis of five different types of beer showed significant differences in the linalool concentrations, which were clearly correlated with the intensity of the hoppy aroma note as evaluated by a sensory panel. In addition, significant differences in the R/S ratios were measured in the beers. The SPME/SIDA yielded exact data independently from headspace sampling parameters, such as exposure time or ionic strength of the solution.

  4. Multivariate statistical analysis of hemlock (Tsuga) volatiles by SPME/GC/MS: insights into the phytochemistry of the hemlock woolly adelgid (Adelges tsugae Annand)

    Science.gov (United States)

    Anthony Lagalante; Frank Calvosa; Michael Mirzabeigi; Vikram Iyengar; Michael Montgomery; Kathleen Shields

    2007-01-01

    A previously developed single-needle, SPME/GC/MS technique was used to measure the terpenoid content of T. canadensis growing in a hemlock forest at Lake Scranton, PA (Lagalante and Montgomery 2003). The volatile terpenoid composition was measured over a 1-year period from June 2003 to May 2004 to follow the annual cycle of foliage development from...

  5. Analysis of aldehydes in human exhaled breath condensates by in-tube SPME-HPLC.

    Science.gov (United States)

    Wang, ShuLing; Hu, Sheng; Xu, Hui

    2015-11-05

    In this paper, polypyrrole/graphene (PPy/G) composite coating was prepared by a facile electrochemical polymerization strategy on the inner surface of a stainless steel (SS) tube. Based on the coating tube, a novel online in-tube solid-phase microextraction -high performance liquid chromatography (IT-SPME-HPLC) was developed and applied for the extraction of aldehydes in the human exhaled breath condensates (EBC). The hybrid PPy/G nanocomposite exhibits remarkable chemical and mechanical stability, high selectivity, and satisfactory extraction performance toward aldehyde compounds. Moreover, the proposed online IT-SPME-HPLC method possesses numerous superiorities, such as time and cost saving, process simplicity, high precision and sensitivity. Some parameters related to extraction efficiency were optimized systematically. Under the optimal conditions, the recoveries of the aldehyde compounds at three spiked concentration levels varied in the range of 85%-117%. Good linearity was obtained with excellent correlation coefficients (R(2)) being larger than 0.994. The relative standard deviations (n = 5) of the method ranged from 1.8% to 11.3% and the limits of detection were between 2.3 and 3.3 nmol L(-1). The successful application of the proposed method in human EBC indicated that it is a promising approach for the determination of trace aldehyde metabolites in complex EBC samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Optimization of Solid Phase Micro-Extraction (SPME for Monitoring Occupational Exposure to Ethyl Benzene

    Directory of Open Access Journals (Sweden)

    H Heidari

    2012-05-01

    Full Text Available

    Background and Objectives: Analytical methods for volatile organic compounds (VOCs in different samples need extraction of compounds, by applying hazardous solvents. Solid phase micro-extraction (SPME is a solvent-free equilibrium extraction method, in which proper calibration can allow quantitative determinations of VOCs at a very good sensitivity without the use of any organic solvent. VOCs are generally present in urine only at trace levels, therefore, a sensitive procedure is needed for their trace determinations. Throughout this study, headspace solid phase micro-extraction (HS-SPME was followed by GC-FID for ethyl benzene in spiked urine was optimized.

    Methods: In this study, the parameters influencing SPME and gas chromatography of ethyl benzene, including extraction time, temperature, desorption temperature, desorption time, salt addition, sample pH, sample volume and sample agitation were investigated.

    Results: Extraction procedure was performed at 30°C for 6 min, using 0.2 gml-1 of NaCl in the sample solution. The sample volume and sample pH were optimized at 5 ml and 7 (neutral pH, respectively. Desorption of the ethyl benzene was carried out for 60 sec. at 250°C. The method was also validated with three different spiked urine samples and illustrated an appropriate reproducibility over six consecutive days as well as six within-day experiments. During this investigation, parameters of accuracy, linearity, and detection limits of the procedure were also evaluated.

    Conclusion: The developed method of HS- SPME-GC-FID proved to be a simple, convenient, and practical procedure, and was successfully used for measuring of ethyl benzene in spiked urine.

  7. Quantitative Analysis of Bisphenol A Leached from Household Plastics by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry (SPME-GC-MS)

    Science.gov (United States)

    Johnson, Bettie Obi; Burke, Fernanda M.; Harrison, Rebecca; Burdette, Samantha

    2012-01-01

    The measurement of trace levels of bisphenol A (BPA) leached out of household plastics using solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) is reported here. BPA is an endocrine-disrupting compound used in the industrial manufacture of polycarbonate plastic bottles and epoxy resin can liners. This experiment…

  8. Determination of tetrachloroethylene and other volatile halogenated organic compounds in oil wastes by headspace SPME GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, D.; Bezzi, R.; Torri, C.; Galletti, P.; Tagliavini, E. [Bologna Univ., Ravenna (Italy). Lab. of Chemistry, C.I.R.S.A

    2007-09-15

    Oil wastes and slops are complex mixtures of hydrocarbons, which may contain a variety of contaminants including tetrachloroethylene (perchloroethylene, PCE) and other volatile halogenated organic compounds (VHOCs). The analytical determination of PCE at trace levels in petroleum-derived matrices is difficult to carry out in the presence of large amounts of hydrocarbon matrix components. In the following study, we demonstrate that headspace solid-phase microextraction (HS-SPME) combined with GC-MS analysis can be applied for the rapid measurement of PCE concentration in oil samples. The HS-SPME method was developed using liquid paraffin as matrix matching reference material for external and internal calibration and optimisation of experimental parameters. The limit of quantitation was 0.05 mg kg{sup -1}, and linearity was established up to 25 mg kg{sup -1}. The HS-SPME method was extended to several VHOCs, including trichloroethylene (TCE) in different matrices and was applied to the quantitative analysis of PCE and TCE in real samples.

  9. Selective molecularly imprinted polymer combined with restricted access material for in-tube SPME/UHPLC-MS/MS of parabens in breast milk samples

    International Nuclear Information System (INIS)

    Souza, Israel D.; Melo, Lidervan P.; Jardim, Isabel C.S.F.; Monteiro, Juliana C.S.; Nakano, Ana Marcia S.; Queiroz, Maria Eugênia C.

    2016-01-01

    A new molecularly imprinted polymer modified with restricted access material (a hydrophilic external layer), (MIP-RAM) was synthesized via polymerization in situ in an open fused silica capillary. This stationary phase was used as sorbent for in-tube solid phase microextraction (in-tube SPME) to determine parabens in breast milk samples by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Scanning electron micrographs (SEM) illustrate MIP surface modification after glycerol dimethacrylate (hydrophilic monomer) incorporation. The interaction between parabens and MIP-RAM was investigated by Fourier-transform infrared (FTIR) spectroscopy. The Scatchard plot for MIP-RAM presented two linear parts with different slopes, illustrating binding sites with high- and low-affinity. Endogenous compounds exclusion from the MIP-RAM capillary was demonstrated by in-tube SPME/LC-UV assays carried out with blank milk samples. The in-tube SPME/UHPLC-MS/MS method presented linear range from 10 ng mL"−"1 (LLOQ) to 400 ng mL"−"1 with coefficients of determination higher than 0.99, inter-assay precision with coefficient of variation (CV) values ranging from 2 to 15%, and inter-assay accuracy with relative standard deviation (RSD) values ranging from −1% to 19%. Analytical validation parameters attested that in-tube SPME/UHPLC-MS/MS is an appropriate method to determine parabens in human milk samples to assess human exposure to these compounds. Analysis of breast milk samples from lactating women demonstrated that the proposed method is effective. - Highlights: • Molecularly imprinted polymer modified with a hydrophilic external layer (RAM-MIP) was synthesized in a silica capillary. • RAM-MIP capillary, used as sorbent for in-tube SPME, established specific interaction with parabens present in milk samples. • The matrix components that interacted only with the hydrophilic external layer (non-adsorptive network) were excluded. • The

  10. Selective molecularly imprinted polymer combined with restricted access material for in-tube SPME/UHPLC-MS/MS of parabens in breast milk samples

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Israel D.; Melo, Lidervan P. [Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Jardim, Isabel C.S.F. [Instituto de Química, Universidade Estadual de Campinas, Campinas, SP (Brazil); Monteiro, Juliana C.S.; Nakano, Ana Marcia S. [Escola de Enfermagem de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Queiroz, Maria Eugênia C., E-mail: mariaeqn@ffclrp.usp.br [Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2016-08-17

    A new molecularly imprinted polymer modified with restricted access material (a hydrophilic external layer), (MIP-RAM) was synthesized via polymerization in situ in an open fused silica capillary. This stationary phase was used as sorbent for in-tube solid phase microextraction (in-tube SPME) to determine parabens in breast milk samples by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Scanning electron micrographs (SEM) illustrate MIP surface modification after glycerol dimethacrylate (hydrophilic monomer) incorporation. The interaction between parabens and MIP-RAM was investigated by Fourier-transform infrared (FTIR) spectroscopy. The Scatchard plot for MIP-RAM presented two linear parts with different slopes, illustrating binding sites with high- and low-affinity. Endogenous compounds exclusion from the MIP-RAM capillary was demonstrated by in-tube SPME/LC-UV assays carried out with blank milk samples. The in-tube SPME/UHPLC-MS/MS method presented linear range from 10 ng mL{sup −1} (LLOQ) to 400 ng mL{sup −1} with coefficients of determination higher than 0.99, inter-assay precision with coefficient of variation (CV) values ranging from 2 to 15%, and inter-assay accuracy with relative standard deviation (RSD) values ranging from −1% to 19%. Analytical validation parameters attested that in-tube SPME/UHPLC-MS/MS is an appropriate method to determine parabens in human milk samples to assess human exposure to these compounds. Analysis of breast milk samples from lactating women demonstrated that the proposed method is effective. - Highlights: • Molecularly imprinted polymer modified with a hydrophilic external layer (RAM-MIP) was synthesized in a silica capillary. • RAM-MIP capillary, used as sorbent for in-tube SPME, established specific interaction with parabens present in milk samples. • The matrix components that interacted only with the hydrophilic external layer (non-adsorptive network) were excluded.

  11. Microextração por fase sólida SPME, Solid Phase Micro-Extration

    Directory of Open Access Journals (Sweden)

    Antonio Luiz Pires Valente

    2000-08-01

    Full Text Available Fundamental aspects of Solid Phase Micro-Extraction (SPME are discussed in the present paper. The application of SPME as a microtechnique of sample preparation for gas chromatographic analysis is considered and related to existing theoretical models. Both research prototypes and commercial SPME devices are considered.

  12. A home-made SPME fiber coating for Arson Analysis

    International Nuclear Information System (INIS)

    Umi Khairul Ahmad; Abdul Rahim Yacob; Selvaraju, Geetha

    2008-01-01

    A number of adsorbents are available commercially as coatings for SPME fibers but some analytical methodologies might demand specific properties for the extraction of selected compounds, special coatings that have particular volume and a selectivity towards particular analytes. This paper presents a simple, fast, effective and environmental friendly methodology for the determination of accelerants in arson samples using headspace solid-phase micro extraction coupled to gas chromatography. A new fiber prepared by sol-gel method, containing 1:1 molar ratio of octyltriethoxysilane (C 8 -TEOS): methyltrimethoxysilane (MTMOS) was employed in this technique. The efficiency of the new fiber coating prepared by sol-gel technology for the determination of accelerants was compared to that of commercial PDMS/ DVB fibers. Poly dimethylsiloxane divinylbenzene (PDMS/ DVB) is the most common fiber coating for the extraction of hydrocarbon compounds. Compared with commercial PDMS/ DVB fiber, the new homemade fiber exhibited higher extraction capability and good selectivity for accelerants. The homemade fiber was also applied for the simulated arson samples. The home-made SPME adsorbent was shown to be a good alternative to commercially available fiber for the determination of accelerants in arson cases. (author)

  13. Method of high precision interval measurement in pulse laser ranging system

    Science.gov (United States)

    Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong

    2013-09-01

    Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.

  14. Field measurements of biogenic volatile organic compounds in the atmosphere using solid-phase microextraction Arrow

    Science.gov (United States)

    Feijó Barreira, Luís Miguel; Duporté, Geoffroy; Rönkkö, Tuukka; Parshintsev, Jevgeni; Hartonen, Kari; Hyrsky, Lydia; Heikkinen, Enna; Jussila, Matti; Kulmala, Markku; Riekkola, Marja-Liisa

    2018-02-01

    Biogenic volatile organic compounds (BVOCs) emitted by terrestrial vegetation participate in a diversity of natural processes. These compounds impact both short-range processes, such as on plant protection and communication, and long-range processes, for example by participating in aerosol particle formation and growth. The biodiversity of plant species around the Earth, the vast assortment of emitted BVOCs, and their trace atmospheric concentrations contribute to the substantial remaining uncertainties about the effects of these compounds on atmospheric chemistry and physics, and call for the development of novel collection devices that can offer portability with improved selectivity and capacity. In this study, a novel solid-phase microextraction (SPME) Arrow sampling system was used for the static and dynamic collection of BVOCs from a boreal forest, and samples were subsequently analyzed on site by gas chromatography-mass spectrometry (GC-MS). This system offers higher sampling capacity and improved robustness when compared to traditional equilibrium-based SPME techniques, such as SPME fibers. Field measurements were performed in summer 2017 at the Station for Measuring Ecosystem-Atmosphere Relations (SMEAR II) in Hyytiälä, Finland. Complementary laboratory tests were also performed to compare the SPME-based techniques under controlled experimental conditions and to evaluate the effect of temperature and relative humidity on their extraction performance. The most abundant monoterpenes and aldehydes were successfully collected. A significant improvement on sampling capacity was observed with the new SPME Arrow system over SPME fibers, with collected amounts being approximately 2 × higher for monoterpenes and 7-8 × higher for aldehydes. BVOC species exhibited different affinities for the type of sorbent materials used (polydimethylsiloxane (PDMS)-carbon wide range (WR) vs. PDMS-divinylbenzene (DVB)). Higher extraction efficiencies were obtained with dynamic

  15. Simple and accurate quantification of BTEX in ambient air by SPME and GC-MS.

    Science.gov (United States)

    Baimatova, Nassiba; Kenessov, Bulat; Koziel, Jacek A; Carlsen, Lars; Bektassov, Marat; Demyanenko, Olga P

    2016-07-01

    Benzene, toluene, ethylbenzene and xylenes (BTEX) comprise one of the most ubiquitous and hazardous groups of ambient air pollutants of concern. Application of standard analytical methods for quantification of BTEX is limited by the complexity of sampling and sample preparation equipment, and budget requirements. Methods based on SPME represent simpler alternative, but still require complex calibration procedures. The objective of this research was to develop a simpler, low-budget, and accurate method for quantification of BTEX in ambient air based on SPME and GC-MS. Standard 20-mL headspace vials were used for field air sampling and calibration. To avoid challenges with obtaining and working with 'zero' air, slope factors of external standard calibration were determined using standard addition and inherently polluted lab air. For polydimethylsiloxane (PDMS) fiber, differences between the slope factors of calibration plots obtained using lab and outdoor air were below 14%. PDMS fiber provided higher precision during calibration while the use of Carboxen/PDMS fiber resulted in lower detection limits for benzene and toluene. To provide sufficient accuracy, the use of 20mL vials requires triplicate sampling and analysis. The method was successfully applied for analysis of 108 ambient air samples from Almaty, Kazakhstan. Average concentrations of benzene, toluene, ethylbenzene and o-xylene were 53, 57, 11 and 14µgm(-3), respectively. The developed method can be modified for further quantification of a wider range of volatile organic compounds in air. In addition, the new method is amenable to automation. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Comparison of Spot and Time Weighted Averaging (TWA Sampling with SPME-GC/MS Methods for Trihalomethane (THM Analysis

    Directory of Open Access Journals (Sweden)

    Don-Roger Parkinson

    2016-02-01

    Full Text Available Water samples were collected and analyzed for conductivity, pH, temperature and trihalomethanes (THMs during the fall of 2014 at two monitored municipal drinking water source ponds. Both spot (or grab and time weighted average (TWA sampling methods were assessed over the same two day sampling time period. For spot sampling, replicate samples were taken at each site and analyzed within 12 h of sampling by both Headspace (HS- and direct (DI- solid phase microextraction (SPME sampling/extraction methods followed by Gas Chromatography/Mass Spectrometry (GC/MS. For TWA, a two day passive on-site TWA sampling was carried out at the same sampling points in the ponds. All SPME sampling methods undertaken used a 65-µm PDMS/DVB SPME fiber, which was found optimal for THM sampling. Sampling conditions were optimized in the laboratory using calibration standards of chloroform, bromoform, bromodichloromethane, dibromochloromethane, 1,2-dibromoethane and 1,2-dichloroethane, prepared in aqueous solutions from analytical grade samples. Calibration curves for all methods with R2 values ranging from 0.985–0.998 (N = 5 over the quantitation linear range of 3–800 ppb were achieved. The different sampling methods were compared for quantification of the water samples, and results showed that DI- and TWA- sampling methods gave better data and analytical metrics. Addition of 10% wt./vol. of (NH42SO4 salt to the sampling vial was found to aid extraction of THMs by increasing GC peaks areas by about 10%, which resulted in lower detection limits for all techniques studied. However, for on-site TWA analysis of THMs in natural waters, the calibration standard(s ionic strength conditions, must be carefully matched to natural water conditions to properly quantitate THM concentrations. The data obtained from the TWA method may better reflect actual natural water conditions.

  17. Range measurements of keV hydrogen ions in solid oxygen and carbon monoxide

    International Nuclear Information System (INIS)

    Schou, J.; Soerensen, H.; Andersen, H.H.; Nielsen, M.; Rune, J.

    1984-01-01

    Ranges of 1.3-3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen. The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result agrees with that previously found for solid nitrogen. (orig.)

  18. Enhanced Strain Measurement Range of an FBG Sensor Embedded in Seven-Wire Steel Strands.

    Science.gov (United States)

    Kim, Jae-Min; Kim, Chul-Min; Choi, Song-Yi; Lee, Bang Yeon

    2017-07-18

    FBG sensors offer many advantages, such as a lack of sensitivity to electromagnetic waves, small size, high durability, and high sensitivity. However, their maximum strain measurement range is lower than the yield strain range (about 1.0%) of steel strands when embedded in steel strands. This study proposes a new FBG sensing technique in which an FBG sensor is recoated with polyimide and protected by a polyimide tube in an effort to enhance the maximum strain measurement range of FBG sensors embedded in strands. The validation test results showed that the proposed FBG sensing technique has a maximum strain measurement range of 1.73% on average, which is 1.73 times higher than the yield strain of the strands. It was confirmed that recoating the FBG sensor with polyimide and protecting the FBG sensor using a polyimide tube could effectively enhance the maximum strain measurement range of FBG sensors embedded in strands.

  19. Analysis of the volatiles in the headspace above the plasmodium and sporangia of the slime mould (Physarum polycephalum) by SPME-GCMS

    OpenAIRE

    Kateb, Huda al; Costello, Ben de Lacy

    2013-01-01

    Solid phase micro-extraction (SPME) coupled with Gas Chromatography Mass Spectrometry (GC-MS) was used to extract and analyse the volatiles in the headspace above the plasmodial and sporulating stages of the slime mould Physarum Polycephalum. In total 115 compounds were identified from across a broad range of chemical classes. Although more (87) volatile organic compounds (VOCs) were identified when using a higher incubation temperature of 75oC, a large number of compounds (79) were still ide...

  20. Development of source range measurement instrument in Xi'an pulsed reactor

    CERN Document Server

    Wang Li

    2002-01-01

    Source range measurement instrument in Xi'an pulsed reactor is key equipment of low-side measuring in source range. At the same time, it is also weighty component of out-of-pile neutron-flux level observation system. The authors have done some researching and renovating based on the similar type devices used in nuclear reactor to improve the meter sensitivity, measuring range, noise proof features, reliability in running and maintainability which belong to the main performance index of the instrument. The design ideas, configurations, working principle, performance indexes, technique features and effect in utilizing are introduced briefly

  1. Determination of volatile organic compounds (VOCs) using tedlar bag/solid-phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) in ambient and workplace air

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Hwan; Lee, Dai Woon [Yonsei Univ., Seoul (Korea, Republic of); Hwang, Seung Man; Heo, Gwi Suk [Korea Research Institute of Standards and Science, Taejon (Korea, Republic of)

    2002-03-01

    SPME techniques have proven to be very useful tools in the analysis of wide VOCs in the air. In this study, we estimated VOCs in ambient and workplace air using a Tedlar ba/SPME/GC/MS system. The calibration curve was set to be linear over the range of 1-30 ppbv. The detection limits ranged from 10 pptv 0.93 ppbv for all VOCs. Reproducibility of TO-14 target gas mixtures by SPME/GC/MS averaged at 8.8 R.S.D (%). Air toxic VOCs (hazardous air pollutants, HAPs) containing a total of forty halohydrocarbons, aromatics, and haloaro-matic carbons could be analyzed with significant accuracy, detection limit and linearity at low ppbv level. Only reactive VOCs with low molecular weight, such as chloromethane, vinylchloride, ethylchloride and 1,2-dichloro-ethane, yielded relatively poor results using this technique. In ambient air samples, ten VOCs were identified and quantified after external calibration. VOC concentration in ambient and workplace air ranged from 0.04 to 1.85 ppbv. The overall process was successfully applied to identify and quantify VOCs in ambient/workplace air.

  2. Determination of volatile organic compounds (VOCs) using tedlar bag/solid-phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) in ambient and workplace air

    International Nuclear Information System (INIS)

    Lee, Jae Hwan; Lee, Dai Woon; Hwang, Seung Man; Heo, Gwi Suk

    2002-01-01

    SPME techniques have proven to be very useful tools in the analysis of wide VOCs in the air. In this study, we estimated VOCs in ambient and workplace air using a Tedlar ba/SPME/GC/MS system. The calibration curve was set to be linear over the range of 1-30 ppbv. The detection limits ranged from 10 pptv 0.93 ppbv for all VOCs. Reproducibility of TO-14 target gas mixtures by SPME/GC/MS averaged at 8.8 R.S.D (%). Air toxic VOCs (hazardous air pollutants, HAPs) containing a total of forty halohydrocarbons, aromatics, and haloaro-matic carbons could be analyzed with significant accuracy, detection limit and linearity at low ppbv level. Only reactive VOCs with low molecular weight, such as chloromethane, vinylchloride, ethylchloride and 1,2-dichloro-ethane, yielded relatively poor results using this technique. In ambient air samples, ten VOCs were identified and quantified after external calibration. VOC concentration in ambient and workplace air ranged from 0.04 to 1.85 ppbv. The overall process was successfully applied to identify and quantify VOCs in ambient/workplace air

  3. Quantification of transformation products of rocket fuel unsymmetrical dimethylhydrazine in soils using SPME and GC-MS.

    Science.gov (United States)

    Bakaikina, Nadezhda V; Kenessov, Bulat; Ul'yanovskii, Nikolay V; Kosyakov, Dmitry S

    2018-07-01

    Determination of transformation products (TPs) of rocket fuel unsymmetrical dimethylhydrazine (UDMH) in soil is highly important for environmental impact assessment of the launches of heavy space rockets from Kazakhstan, Russia, China and India. The method based on headspace solid-phase microextraction (HS SPME) and gas chromatography-mass spectrometry is advantageous over other known methods due to greater simplicity and cost efficiency. However, accurate quantification of these analytes using HS SPME is limited by the matrix effect. In this research, we proposed using internal standard and standard addition calibrations to achieve proper combination of accuracies of the quantification of key TPs of UDMH and cost efficiency. 1-Trideuteromethyl-1H-1,2,4-triazole (MTA-d3) was used as the internal standard. Internal standard calibration allowed controlling matrix effects during quantification of 1-methyl-1H-1,2,4-triazole (MTA), N,N-dimethylformamide (DMF), and N-nitrosodimethylamine (NDMA) in soils with humus content < 1%. Using SPME at 60 °C for 15 min by 65 µm Carboxen/polydimethylsiloxane fiber, recoveries of MTA, DMF and NDMA for sandy and loamy soil samples were 91-117, 85-123 and 64-132%, respectively. For improving the method accuracy and widening the range of analytes, standard addition and its combination with internal standard calibration were tested and compared on real soil samples. The combined calibration approach provided greatest accuracies for NDMA, DMF, N-methylformamide, formamide, 1H-pyrazole, 3-methyl-1H-pyrazole and 1H-pyrazole. For determination of 1-formyl-2,2-dimethylhydrazine, 3,5-dimethylpyrazole, 2-ethyl-1H-imidazole, 1H-imidazole, 1H-1,2,4-triazole, pyrazines and pyridines, standard addition calibration is more suitable. However, the proposed approach and collected data allow using both approaches simultaneously. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. HS-SPME-GC-MS Analysis of onion (Allium cepa L. and shallot (Allium ascalonicum L.

    Directory of Open Access Journals (Sweden)

    D’Auria, M.

    2017-06-01

    Full Text Available The volatile organic compounds of onion and shallot were determined via HS-SPME-GC-MS. The main components were dipropyldisulphide and allylpropyldisulphide. Thiopropanal S-oxide were detected only in onion volatiles. In shallot is interesting the presence of 2-methyl-2-pentenal, a compound with an intense fruity aroma, that can characterize the different aroma between onion and shallot. The SPME-GC-MS analysis of shallot after absorption on the SPME fiber at 50°C showed the presence of new compounds, whose structures have been discussed.

  5. Comparison of two methods of surface profile extraction from multiple ultrasonic range measurements

    NARCIS (Netherlands)

    Barshan, B; Baskent, D

    Two novel methods for surface profile extraction based on multiple ultrasonic range measurements are described and compared. One of the methods employs morphological processing techniques, whereas the other employs a spatial voting scheme followed by simple thresholding. Morphological processing

  6. Spacecraft Trajectory Estimation Using a Sampled-Data Extended Kalman Filter with Range-Only Measurements

    National Research Council Canada - National Science Library

    Erwin, R. S; Bernstein, Dennis S

    2005-01-01

    .... In this paper we use a sampled-data extended Kalman Filter to estimate the trajectory or a target satellite when only range measurements are available from a constellation or orbiting spacecraft...

  7. The Development of a Tactical-Level Full Range Leadership Measurement Instrument

    Science.gov (United States)

    2010-03-01

    full range leadership theory has become established as the predominant and most widely researched theory on leadership . The most commonly used survey...instrument to assess full range leadership theory is the Multifactor Leadership Questionnaire, originally developed by Bass in 1985. Although much...existing literature to develop a new full range leadership theory measurement instrument that effectively targets low- to mid-level supervisors, or

  8. Nuevos desarrollos metodológicos en SPME

    OpenAIRE

    Ríos Acevedo, John Jairo

    2016-01-01

    La Microextracción en fase sólida (SPME) ha experimentado un rápido desarrollo desde su introducción hace más de 20 años teniendo un gran impacto sobre las prácticas de muestreo y preparación de muestra en áreas como análisis químico, bioanálisis, los alimentos y las ciencias ambientales. Sin embargo, en otras áreas como análisis clínico, ciencias farmacéuticas y médicas, se espera un crecimiento en sus aplicaciones. El objetivo fundamental de la presente investigación ha sido la implementaci...

  9. Selective molecularly imprinted polymer combined with restricted access material for in-tube SPME/UHPLC-MS/MS of parabens in breast milk samples.

    Science.gov (United States)

    Souza, Israel D; Melo, Lidervan P; Jardim, Isabel C S F; Monteiro, Juliana C S; Nakano, Ana Marcia S; Queiroz, Maria Eugênia C

    2016-08-17

    A new molecularly imprinted polymer modified with restricted access material (a hydrophilic external layer), (MIP-RAM) was synthesized via polymerization in situ in an open fused silica capillary. This stationary phase was used as sorbent for in-tube solid phase microextraction (in-tube SPME) to determine parabens in breast milk samples by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Scanning electron micrographs (SEM) illustrate MIP surface modification after glycerol dimethacrylate (hydrophilic monomer) incorporation. The interaction between parabens and MIP-RAM was investigated by Fourier-transform infrared (FTIR) spectroscopy. The Scatchard plot for MIP-RAM presented two linear parts with different slopes, illustrating binding sites with high- and low-affinity. Endogenous compounds exclusion from the MIP-RAM capillary was demonstrated by in-tube SPME/LC-UV assays carried out with blank milk samples. The in-tube SPME/UHPLC-MS/MS method presented linear range from 10 ng mL(-1) (LLOQ) to 400 ng mL(-1) with coefficients of determination higher than 0.99, inter-assay precision with coefficient of variation (CV) values ranging from 2 to 15%, and inter-assay accuracy with relative standard deviation (RSD) values ranging from -1% to 19%. Analytical validation parameters attested that in-tube SPME/UHPLC-MS/MS is an appropriate method to determine parabens in human milk samples to assess human exposure to these compounds. Analysis of breast milk samples from lactating women demonstrated that the proposed method is effective. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Coherent change detection and interferometric ISAR measurements in the folded compact range

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, K.W.

    1996-08-01

    A folded compact range configuration has been developed ant the Sandia National Laboratories` compact range antenna and radar-cross- section measurement facility as a means of performing indoor, environmentally-controlled, far-field simulations of synthetic aperture radar (SAR) measurements of distributed target samples (i.e. gravel, sand, etc.). The folded compact range configuration has previously been used to perform coherent-change-detection (CCD) measurements, which allow disturbances to distributed targets on the order of fractions of a wavelength to be detected. This report describes follow-on CCD measurements of other distributed target samples, and also investigates the sensitivity of the CCD measurement process to changes in the relative spatial location of the SAR sensor between observations of the target. Additionally, this report describes the theoretical and practical aspects of performing interferometric inverse-synthetic-aperture-radar (IFISAR) measurements in the folded compact range environment. IFISAR measurements provide resolution of the relative heights of targets with accuracies on the order of a wavelength. Several examples are given of digital height maps that have been generated from measurements performed at the folded compact range facility.

  11. Range and number-of-levels effects in derived and stated measures of attribute importance

    NARCIS (Netherlands)

    Verlegh, PWJ; Schifferstein, HNJ; Wittink, DR

    We study how the range of variation and the number of ttribute levels affect five measures of attribute importance: full profile conjoint estimates, ranges in attribute level attractiveness ratings. regression coefficients. graded paired comparisons. and self-reported ratings, We find that all

  12. An emittance measurement system for a wide range of bunch charges

    International Nuclear Information System (INIS)

    Dunham, B.; Engwall, D.; Hofler, A.; Keesee, M.; Legg, R.

    1997-01-01

    As a part of the emittance measurements planned for the FEL injector at the Thomas Jefferson National Accelerator Facility (Jefferson Lab), the authors have developed an emittance measurement system that covers the wide dynamic range of bunch charges necessary to fully characterize the high-DC-voltage photocathode gun. The measurements are carried out with a variant of the classical two-slit method using a slit to sample the beam in conjunction with a wire scanner to measure the transmitted beam profile. The use of commercial, ultra-low noise picoammeters makes it possible to cover the wide range of desired bunch charges, with the actual measurements made over the range of 0.25 pC to 125 pC. The entire system, including its integration into the EPICS control system, is discussed

  13. Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber

    Directory of Open Access Journals (Sweden)

    Dongxia Ren

    2018-01-01

    Full Text Available A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS combined with solid phase microextraction (SPME with multiwalled carbon nanotubes (MWCNTs coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1–50 ng mL−1 and for cypermethrin, fenvalerate, and deltamethrin in 5–50 ng mL−1. The correlation coefficients were in the range of 0.9948–0.9999. The average recoveries of 7 pyrethroids were 94.2%–107.3% and the relative standard deviations (RSDs were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL−1. The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.

  14. Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber.

    Science.gov (United States)

    Ren, Dongxia; Sun, Chengjun; Ma, Guanqun; Yang, Danni; Zhou, Chen; Xie, Jiayu; Li, Yongxin

    2018-01-01

    A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS) combined with solid phase microextraction (SPME) with multiwalled carbon nanotubes (MWCNTs) coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN) solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1-50 ng mL -1 and for cypermethrin, fenvalerate, and deltamethrin in 5-50 ng mL -1 . The correlation coefficients were in the range of 0.9948-0.9999. The average recoveries of 7 pyrethroids were 94.2%-107.3% and the relative standard deviations (RSDs) were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL -1 . The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.

  15. Improving the On-Line Extraction of Polar Compounds by IT-SPME with Silica Nanoparticles Modified Phases

    Directory of Open Access Journals (Sweden)

    Pascual Serra-Mora

    2018-02-01

    Full Text Available In the present work the extraction efficiency of in-tube solid-phase microextraction (IT-SPME for polar herbicides has been evaluated using extractive capillaries coated with different polymeric sorbents. For this purpose, aqueous solutions of herbicides with a wide range of polarities, including some highly polar compounds (log Kow < 1, have been directly processed by IT-SPME coupled on-line to capillary liquid chromatography with UV-diode array detection. For extraction, commercially available capillary columns coated with polydimethylsiloxane (PDMS and polyetilenglicol (PEG-based phases have been used, and the results have been compared with those obtained with a synthesized tetraethyl orthosilicate (TEOS-trimethoxyethylsilane (MTEOS polymer, as well as the same polymer reinforced with silica nanoparticles (SiO2 NPs. The SiO2 NPs functionalized TEOS-MTEOS coating provided the best results for most herbicides, especially for the most polar compounds. On the basis of the results obtained, conditions for the quantification of the herbicides tested are described using a SiO2 NPs reinforced TEOS-MTEOS coated capillary. The proposed method provided satisfactory linearity up to concentrations of 200 μg/L. The precision was also suitable, with relative standard deviations (RSDs values ≤9% (n = 3, and the limits of detection (LODs were within the 0.5–7.5 µg/L range. The method has been applied to different water samples and the extract obtained from an agricultural soil.

  16. Investigation of complete and incomplete fusion in 20Ne + 51V system using recoil range measurement

    Directory of Open Access Journals (Sweden)

    Ali Sabir

    2015-01-01

    Full Text Available Recoil range distributions of evaporation residues, populated in 20Ne + 51V reaction at Elab ≈ 145 MeV, have been studied to determine the degree of momentum transferred through the complete and incomplete fusion reactions. Evaporation residues (ERs populated through the complete and incomplete fusion reactions have been identified on the basis of their recoil range in the Al catcher medium. Measured recoil range of evaporation residues have been compared with the theoretical value calculated using the code SRIM. Range integrated cross section of observed ERs have been compared with the value predicted by statistical model code PACE4.

  17. Expanding the dynamic measurement range for polymeric nanoparticle pH sensors

    DEFF Research Database (Denmark)

    Sun, Honghao; Almdal, Kristoffer; Andresen, Thomas Lars

    2011-01-01

    Conventional optical nanoparticle pH sensors that are designed for ratiometric measurements in cells have been based on utilizing one sensor fluorophore and one reference fluorophore in each nanoparticle, which results in a relatively narrow dynamic measurement range. This results in substantial...

  18. A comparison on radar range profiles between in-flight measurements and RCS-predictions

    NARCIS (Netherlands)

    Heiden, R. van der; Ewijk, L.J. van; Groen, F.C.A.

    1998-01-01

    The validation of Radar Cross Section (RCS) prediction techniques against real measurements is crucial to acquire confidence in predictions when measurements are nut available. In this paper we present the results of a comparison on one-dimensional signatures, i.e. radar range profiles. The profiles

  19. Using disposable solid-phase microextraction (SPME) to determine the freely dissolved concentration of polybrominated diphenyl ethers (PBDEs) in sediments

    International Nuclear Information System (INIS)

    Jia Fang; Cui Xinyi; Wang Wei; Delgado-Moreno, Laura; Gan, Jay

    2012-01-01

    Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants (BFRs). The ubiquity and persistence of PBDEs in sediment have raised concerns over their environmental fate and ecological risks. Due to strong affinity for sediment organic matter, environmental fate and bioavailability of PBDEs closely depend on their phase distribution. In this study, disposable polydimethylsiloxane (PDMS) fiber was used to derive the freely dissolved concentration (C free ) of PBDEs in sediment porewater as a measurement of bioavailability. The PDMS-to-water partition coefficient (log K PDMS ) was 5.46–5.83 for BDE 47, 99, and 153. In sediments, PBDEs were predominantly sorbed to the sediment phase, with C free accounting for free of PBDEs decreased as their bromination or sediment organic carbon content increased. The strong association with dissolved organic matter (DOM) implies a potential for facilitated offsite transport and dispersion in the environment that depends closely on the stability of sediment aggregates. - Highlights: ► A disposable SPME method was developed for measuring C free of PBDEs in sediment. ► C free decreased with increasing congener bromination or sediment OC content. ► C free of PBDEs accounted for DOC values suggest a high probability for DOM-facilitated offsite transport. - A SPME method based on disposable PDMS fibers was developed for measuring the freely dissolved concentration of PBDEs (C free ) in sediment porewater.

  20. Differentiation of wines according to grape variety and geographical origin based on volatiles profiling using SPME-MS and SPME-GC/MS methods.

    Science.gov (United States)

    Ziółkowska, Angelika; Wąsowicz, Erwin; Jeleń, Henryk H

    2016-12-15

    Among methods to detect wine adulteration, profiling volatiles is one with a great potential regarding robustness, analysis time and abundance of information for subsequent data treatment. Volatile fraction fingerprinting by solid-phase microextraction with direct analysis by mass spectrometry without compounds separation (SPME-MS) was used for differentiation of white as well as red wines. The aim was to differentiate between varieties used for wine production and to also differentiate wines by country of origin. The results obtained were compared to SPME-GC/MS analysis in which compounds were resolved by gas chromatography. For both approaches the same type of statistical procedure was used to compare samples: principal component analysis (PCA) followed by linear discriminant analysis (LDA). White wines (38) and red wines (41) representing different grape varieties and various regions of origin were analysed. SPME-MS proved to be advantageous in use due to better discrimination and higher sample throughput. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Improved measurement linearity and precision for AMCW time-of-flight range imaging cameras.

    Science.gov (United States)

    Payne, Andrew D; Dorrington, Adrian A; Cree, Michael J; Carnegie, Dale A

    2010-08-10

    Time-of-flight range imaging systems utilizing the amplitude modulated continuous wave (AMCW) technique often suffer from measurement nonlinearity due to the presence of aliased harmonics within the amplitude modulation signals. Typically a calibration is performed to correct these errors. We demonstrate an alternative phase encoding approach that attenuates the harmonics during the sampling process, thereby improving measurement linearity in the raw measurements. This mitigates the need to measure the system's response or calibrate for environmental changes. In conjunction with improved linearity, we demonstrate that measurement precision can also be increased by reducing the duty cycle of the amplitude modulated illumination source (while maintaining overall illumination power).

  2. A comparison study on a sulfonated graphene-polyaniline nanocomposite coated fiber for analysis of nicotine in solid samples through the traditional and vacuum-assisted HS-SPME.

    Science.gov (United States)

    Ghiasvand, Alireza; Koonani, Samira; Yazdankhah, Fatemeh; Farhadi, Saeid

    2018-02-05

    A simple, rapid, and reliable headspace solid-phase microextraction (HS-SPME) procedure, reinforced by applying vacuum in the extraction vial, was developed. It was applied for the extraction of nicotine in solid samples prior to determination by gas chromatography-flame ionization detection (GC-FID). First, the surface of a narrow stainless steel wire was made porous and adhesive by platinization to obtain a durable, higher surface area, and resistant fiber. Then, a thin film of sulfonated graphene/polyaniline (Sulf-G/PANI) nanocomposite was synthesized and simultaneously coated on the platinized fiber using the electrophoretic deposition (EPD) method. It was demonstrated that the extraction efficiency remarkably increased by applying the reduced-pressure condition in the extraction vial. To evaluate the conventional HS-SPME and vacuum-assisted HS-SPME (VA-HS-SPME) platforms, all experimental parameters affecting the extraction efficiency including desorption time and temperature, extraction time and temperature and moisture content of sample matrix were optimized. The highest extraction efficiency was obtained at 60°C, 10min (extraction temperature and time) and 280°C, 2min (desorption condition), for VA-HS-SPME strategy, while for conventional HS-SPME the extraction and desorption conditions found to be 100°C, 30min and 280°C, 2min, respectively. The Sulf-G/PANI coated fiber showed high thermal stability, good chemical/mechanical resistance, and long lifetime. For analysis of nicotine in solid samples using VA-HS-SPME-GC-FID, linear dynamic range (LDR) was 0.01-30μgg -1 (R 2 =0.996), the relative standard deviation (RSD%, n=6), for analyses of 1μgg -1 nicotine was calculated 3.4% and limit of detection (LOD) found to be 0.002μgg -1 . The VA-HS-SPME-GC-FID strategy was successfully carried out for quantitation of nicotine in hair and tobacco real samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Determination of fatty acids and volatile compounds in fruits of rosehip(Rosa L.) species by HS-SPME/GC-MS and Im-SPME/GC-MS techniques

    OpenAIRE

    MURATHAN, ZEHRA TUĞBA; ZARIFIKHOSROSHAHI, MOZGAN; KAFKAS, NESİBE EBRU

    2016-01-01

    In this study, we aimed to compare fatty acid and volatile compound compositions of four rosehip species, namely Rosa pimpinellifolia, R. Villosa, R. Canina, and R. Dumalis, by gas chromatography with flame ionization detector (GC/FID) and headspace and immersion solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME/GC-MS and Im-SPME/GC-MS) techniques. The total lipid contents in fruits of the rosehip species varied from 5.83% (R. Villosa) to 7.84% (R. Dumalis). A total of...

  4. An impedance bridge measuring the capacitance ratio in the high frequency range up to 1 MHz

    International Nuclear Information System (INIS)

    Kim, Dan Bee; Lee, Hyung Kew; Kim, Wan-Seop

    2017-01-01

    This paper describes a 2-terminal-pair impedance bridge, measuring the capacitance ratio in the high frequency range up to 1 MHz. The bridge was configured with two voltage sources and a phase control unit which enabled the bridge balance by synchronizing the voltage sources with an enhanced phase resolution. Without employing the transformers such as inductive voltage divider, injection and detection transformers, etc, the bridge system is quite simple to set up, and the balance procedure is quick and easy. Using this dual-source coaxial bridge, the 1:1 and 10:1 capacitance ratios were measured with 1 pF–1 nF capacitors in the frequency range from 1 kHz to 1 MHz. The measurement values obtained by the dual-source bridge were then compared with reference values measured using a commercial precision capacitance bridge of AH2700A, the Z -matrix method developed by ourselves, and the 4-terminal-pair coaxial bridge by the Czech Metrological Institute. All the measurements agreed within the reference uncertainty range of an order of 10 −6 –10 −5 , proving the bridge ability as a trustworthy tool for measuring the capacitance ratio in the high frequency range. (paper)

  5. Development of an SPME-GC-MS/MS method for the determination of pesticides in rainwater: Laboratory and field experiments

    International Nuclear Information System (INIS)

    Sauret-Szczepanski, Nathalie; Mirabel, Philippe; Wortham, Henri

    2006-01-01

    A solid-phase microextraction - coupled to a gas chromatography - ion trap tandem mass spectrometry (SPME-GC-MS/MS) method was developed for the quantitative determination in rainwater of 8 pesticides amongst the most used in France and 3 triazines metabolites. The main factors affecting the SPME process were studied. Using a 3 mL sample, the method developed showed good linearity for concentrations ranging from 0.05 to 50 μg L -1 with correlation coefficients between 0.997 and 0.9999 and relative standard deviations (% RSD) below 14%. The study of matrix effects showed that rainwater was too diluted to have any significant influence on the extraction efficiency. To validate the method, a field campaign was carried out on the rain events, which occurred in Strasbourg during a one-year period. The rain concentrations showed patterns of high pesticide concentrations during spring months, which were correlated to the spraying periods of most of these substances. - Solid-phase microextraction efficiency of pesticides in rainwater was optimized

  6. Passive Sampling and Analysis of Naphthalene in Internal Combustion Engine Exhaust with Retracted SPME Device and GC-MS

    Directory of Open Access Journals (Sweden)

    Nassiba Baimatova

    2017-07-01

    Full Text Available Exhaust gases from internal combustion engines are the main source of urban air pollution. Quantification of Polycyclic aromatic hydrocarbons (PAHs in the exhaust gases is needed for emissions monitoring, enforcement, development, and testing of control technologies. The objective was to develop quantification of gaseous naphthalene in diesel engine exhaust based on diffusion-controlled extraction onto a retracted solid-phase microextraction (SPME fiber coating and analysis on gas chromatography-mass spectrometry (GC-MS. Extraction of naphthalene with retracted fibers followed Fick’s law of diffusion. Extracted mass of naphthalene was proportional to Cg, t, Dg, T and inversely proportional to Z. Method detection limit (p = 0.95 was 11.5 ppb (0.06 mg·m−3 at t = 9 h, Z = 10 mm and T = 40 °C, respectively. It was found that the % mass extracted of naphthalene by SPME needle assembly depended on the type of fiber. Storage time at different temperatures did not affect analyte losses extracted by polydimethylsiloxane (PDMS 100 µm fiber. The developed method was tested on exhaust gases from idling pickup truck and tractor, and compared side-by-side with a direct injection of sampled exhaust gas method. Time-weighted average (TWA concentrations of naphthalene in exhaust gases from idling pickup truck and a tractor ranged from 0.08 to 0.3 mg·m−3 (15.3–53.7 ppb.

  7. Note: long range and accurate measurement of deep trench microstructures by a specialized scanning tunneling microscope.

    Science.gov (United States)

    Ju, Bing-Feng; Chen, Yuan-Liu; Zhang, Wei; Zhu, Wule; Jin, Chao; Fang, F Z

    2012-05-01

    A compact but practical scanning tunneling microscope (STM) with high aspect ratio and high depth capability has been specially developed. Long range scanning mechanism with tilt-adjustment stage is adopted for the purpose of adjusting the probe-sample relative angle to compensate the non-parallel effects. A periodical trench microstructure with a pitch of 10 μm has been successfully imaged with a long scanning range up to 2.0 mm. More innovatively, a deep trench with depth and step height of 23.0 μm has also been successfully measured, and slope angle of the sidewall can approximately achieve 67°. The probe can continuously climb the high step and exploring the trench bottom without tip crashing. The new STM could perform long range measurement for the deep trench and high step surfaces without image distortion. It enables accurate measurement and quality control of periodical trench microstructures.

  8. Impedance measurements on a fast transition-edge sensor for optical and near-infrared range

    International Nuclear Information System (INIS)

    Taralli, E; Portesi, C; Lolli, L; Monticone, E; Rajteri, M; Novikov, I; Beyer, J

    2010-01-01

    Impedance measurements of superconducting transition-edge sensors (TESs) are a powerful tool to obtain information about the TES thermal and electrical properties. We apply this technique to a 20 μm x 20 μm Ti/Au TES, suitable for application in the optical and near-infrared range, and extend the measurements up to 250 kHz in order to obtain a complete frequency response in the complex plane. From these measurements we obtain important thermal and electrical device parameters such as heat capacity C, thermal conductance G and effective thermal time constant τ eff that will be compared with the corresponding values obtained from noise measurements.

  9. Method for sampling and analysis of volatile biomarkers in process gas from aerobic digestion of poultry carcasses using time-weighted average SPME and GC-MS.

    Science.gov (United States)

    Koziel, Jacek A; Nguyen, Lam T; Glanville, Thomas D; Ahn, Heekwon; Frana, Timothy S; Hans van Leeuwen, J

    2017-10-01

    A passive sampling method, using retracted solid-phase microextraction (SPME) - gas chromatography-mass spectrometry and time-weighted averaging, was developed and validated for tracking marker volatile organic compounds (VOCs) emitted during aerobic digestion of biohazardous animal tissue. The retracted SPME configuration protects the fragile fiber from buffeting by the process gas stream, and it requires less equipment and is potentially more biosecure than conventional active sampling methods. VOC concentrations predicted via a model based on Fick's first law of diffusion were within 6.6-12.3% of experimentally controlled values after accounting for VOC adsorption to the SPME fiber housing. Method detection limits for five marker VOCs ranged from 0.70 to 8.44ppbv and were statistically equivalent (p>0.05) to those for active sorbent-tube-based sampling. The sampling time of 30min and fiber retraction of 5mm were found to be optimal for the tissue digestion process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Determination of organotin compounds by headspace solid-phase microextraction-gas chromatography-pulsed flame-photometric detection (HS-SPME-GC-PFPD)

    Energy Technology Data Exchange (ETDEWEB)

    Bravo, Manuel [Universite de Pau et des Pays de L' Adour, Laboratoire de Chimie Analytique, LCABIE, UMR CNRS 5034, Pau (France); Pontificia Universidad Catolica de Valparaiso, Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Valparaiso (Chile); Lespes, Gaetane; Gautier, Martine Potin [Pontificia Universidad Catolica de Valparaiso, Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Valparaiso (Chile); Gregori, Ida de; Pinochet, Hugo [Universite de Pau et des Pays de L' Adour, Laboratoire de Chimie Analytique, LCABIE, UMR CNRS 5034, Pau (France)

    2005-12-01

    A method based on Headspace solid-phase microextraction (HS-SPME, with a 100 {mu}m PDMS-fiber) in combination with gas-chromatography and pulsed flame-photometric detection (GC-PFPD) has been investigated for simultaneous determination of eight organotin compounds. Monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPhT), and the semi-volatile diphenyltin (DPhT), triphenyltin (TPhT), monooctyltin (MOcT), and dioctyltin (DOcT) were determined after derivatization with sodium tetraethylborate. The conditions used for the extraction and preconcentration step were optimised by experimental design methodology. Tripropyltin (TPrT) and diheptyltin (DHepT) were used as internal standards for quantification of volatile and semi-volatile organotin compounds, respectively. The analytical precision (RSD) for ten successive injections of a standard mixture containing all the organic tin compounds ranged between 2 and 11%. The limits of detection for all the organotin compounds were sub ng (Sn) L{sup -1} in water and close to ng (Sn) kg{sup -1} in sediments. The accuracy of the method was evaluated by analysis of two certified reference material (CRM) sediment samples. The HS-SPME-GC-PFPD was then applied to the analysis of three harbour sediment samples. The results showed that headspace SPME is an attractive tool for analysis of organotin compounds in solid environmental matrices. (orig.)

  11. Assessment of health status by molecular measures in adults ranging from middle-aged to old

    DEFF Research Database (Denmark)

    Waaijer, M. E. C.; Westendorp, R. G. J.; Goldeck, D.

    2017-01-01

    In addition to measures already used in clinical practice, molecular measures have been proposed to assess health status, but these have not yet been introduced into clinical practice. We aimed to test the association of functional capacity measures used in current practice and molecular measures...... with age and health status. The cohort consisted of 178 middle-aged to old participants of the Leiden Longevity Study (range 42-82years). We tested associations between functional capacity measures (physical tests: grip strength, 4-meter walk, chair stand test; cognitive tests: Stroop test, digit symbol...... substitution test and 15-picture learning test) with age and with cardiovascular or metabolic disease as a measure of the health status. These associations with age and health status were also tested for molecular measures (C reactive protein (CRP), numbers of senescent p16INK4a positive cells in the epidermis...

  12. Evaluation of Soil Loss and Erosion Control Measures on Ranges and Range Structures at Installations in Temperate Climates

    Science.gov (United States)

    2006-06-01

    Soil Loss Equation ( USLE ) and the Revised Universal Soil Loss Equation (RUSLE) continue to be widely accepted methods for estimating sediment loss...range areas. Therefore, a generalized design methodology using the Universal Soil Loss Equation ( USLE ) is presented to accommodate the variations...constructed use the slope most suitable to the area topography (3:1 or 4:1). Step 4: Using the Universal Soil Loss equation, USLE , find the values of A

  13. Adaptive digital fringe projection technique for high dynamic range three-dimensional shape measurement.

    Science.gov (United States)

    Lin, Hui; Gao, Jian; Mei, Qing; He, Yunbo; Liu, Junxiu; Wang, Xingjin

    2016-04-04

    It is a challenge for any optical method to measure objects with a large range of reflectivity variation across the surface. Image saturation results in incorrect intensities in captured fringe pattern images, leading to phase and measurement errors. This paper presents a new adaptive digital fringe projection technique which avoids image saturation and has a high signal to noise ratio (SNR) in the three-dimensional (3-D) shape measurement of objects that has a large range of reflectivity variation across the surface. Compared to previous high dynamic range 3-D scan methods using many exposures and fringe pattern projections, which consumes a lot of time, the proposed technique uses only two preliminary steps of fringe pattern projection and image capture to generate the adapted fringe patterns, by adaptively adjusting the pixel-wise intensity of the projected fringe patterns based on the saturated pixels in the captured images of the surface being measured. For the bright regions due to high surface reflectivity and high illumination by the ambient light and surfaces interreflections, the projected intensity is reduced just to be low enough to avoid image saturation. Simultaneously, the maximum intensity of 255 is used for those dark regions with low surface reflectivity to maintain high SNR. Our experiments demonstrate that the proposed technique can achieve higher 3-D measurement accuracy across a surface with a large range of reflectivity variation.

  14. Comparison of the atmospheric- and reduced-pressure HS-SPME strategies for analysis of residual solvents in commercial antibiotics using a steel fiber coated with a multiwalled carbon nanotube/polyaniline nanocomposite.

    Science.gov (United States)

    Ghiasvand, Ali Reza; Nouriasl, Kolsoum; Yazdankhah, Fatemeh

    2018-01-01

    A low-cost, sensitive and reliable reduced-pressure headspace solid-phase microextraction (HS-SPME) setup was developed and evaluated for direct extraction of residual solvents in commercial antibiotics, followed by determination by gas chromatography with flame ionization detection (GC-FID). A stainless steel narrow wire was made porous and adhesive by platinization by a modified electrophoretic deposition method and coated with a polyaniline/multiwalled carbon nanotube nanocomposite. All experimental variables affecting the extraction efficiency were investigated for both atmospheric-pressure and reduced-pressure conditions. Comparison of the optimal experimental conditions and the results demonstrated that the reduced-pressure strategy leads to a remarkable increase in the extraction efficiency and reduction of the extraction time and temperature (10 min, 25 °Ϲ vs 20 min, 40 °Ϲ). Additionally, the reduced-pressure strategy showed better analytical performances compared with those obtained by the conventional HS-SPME-GC-FID method. Limit of detections, linear dynamic ranges, and relative standard deviations of the reduced-pressure HS-SPME procedure for benzene, toluene, ethylbenzene, and xylene (BTEX) in injectable solid drugs were obtained over the ranges of 20-100 pg g -1 , 0.02-40 μg g -1 , and 2.8-10.2%, respectively. The procedure developed was successful for the analysis of BTEX in commercial containers of penicillin, ampicillin, ceftriaxone, and cefazolin. Graphical abstract Schematic representation of the developed RP-HS-SPME setup.

  15. Smartphone-based accelerometry is a valid tool for measuring dynamic changes in knee extension range of motion

    DEFF Research Database (Denmark)

    Støve, Morten Pallisgaard; Palsson, Thorvaldur Skuli; Hirata, Rogerio Pessoto

    2018-01-01

    Introduction: Measurement of static joint range of motion is used extensively in orthopaedic and rehabilitative communities to benchmark treatment efficacy. Static measures are, however, insufficient in providing detailed information about patient impairments. Dynamic range of motion measures cou...

  16. Measurement of the Lense-Thirring drag on high-altitude, laser-ranged artificial satellites

    International Nuclear Information System (INIS)

    Ciufolini, I.

    1986-01-01

    We describe a new method of measuring the Lense-Thirring relativistic nodal drag using LAGEOS together with another high-altitude, laser-ranged, similar satellite with appropriately chosen orbital parameters. We propose, for this purpose, that a future satellite such as LAGEOS II have an inclination supplementary to that of LAGEOS. The experiment proposed here would provide a method for experimental verification of the general relativistic formulation of Mach's principle and measurement of the gravitomagnetic field

  17. Stable isotope dilution assay (SIDA) and HS-SPME-GCMS quantification of key aroma volatiles for fruit and sap of Australian mango cultivars.

    Science.gov (United States)

    San, Anh T; Joyce, Daryl C; Hofman, Peter J; Macnish, Andrew J; Webb, Richard I; Matovic, Nicolas J; Williams, Craig M; De Voss, James J; Wong, Siew H; Smyth, Heather E

    2017-04-15

    Reported herein is a high throughput method to quantify in a single analysis the key volatiles that contribute to the aroma of commercially significant mango cultivars grown in Australia. The method constitutes stable isotope dilution analysis (SIDA) in conjunction with headspace (HS) solid-phase microextraction (SPME) coupled with gas-chromatography mass spectrometry (GCMS). Deuterium labelled analogues of the target analytes were either purchased commercially or synthesised for use as internal standards. Seven volatiles, hexanal, 3-carene, α-terpinene, p-cymene, limonene, α-terpinolene and ethyl octanoate, were targeted. The resulting calibration functions had determination coefficients (R 2 ) ranging from 0.93775 to 0.99741. High recovery efficiencies for spiked mango samples were also achieved. The method was applied to identify the key aroma volatile compounds produced by 'Kensington Pride' and 'B74' mango fruit and by 'Honey Gold' mango sap. This method represents a marked improvement over current methods for detecting and measuring concentrations of mango fruit and sap volatiles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Alpha Beam Energy Determination Using a Range Measuring Device for Radioisotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jun Yong; Kim, Byeon Gil; Hong, Seung Pyo; Kim, Ran Young; Chun, Kwon Soo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2016-05-15

    The threshold energy of the {sup 209}Bi(α,3n){sup 210} At reaction is at about 30MeV. Our laboratory suggested an energy measurement method to confirm the proton-beam's energy by using a range measurement device. The experiment was performed energy measurement of alpha beam. The alpha beam of energy 29 MeV has been extracted from the cyclotron for the production of {sup 211}At. This device was composed of four parts: an absorber, a drive shaft, and a servo motor and a Faraday cup. The drive shaft was mounted on the absorber and connects with the axis of the servo motor and rotates linearly and circularly by this servo motor. A Faraday cup is for measuring the beam flux. As this drive shaft rotates, the thickness of the absorber varies depending on the rotation angle of the absorber. The energy of the alpha particle accelerated and extracted from MC-50 cyclotron was calculated with the measurement of the particle range in Al foil and using ASTAR, SRIM, MCNPX software. There were a little discrepancy between the expected energy and the calculated energy within the 0.5MeV error range. We have a plan to make an experiment with various alpha particle energies and another methodology, for example, the cross section measurement of the nuclear reaction.

  19. Varying the item format improved the range of measurement in patient-reported outcome measures assessing physical function

    DEFF Research Database (Denmark)

    Liegl, Gregor; Gandek, Barbara; Fischer, H. Felix

    2017-01-01

    precision between the short forms using different item formats. Results: Sufficient unidimensionality of all short-form items and the original PF item bank was supported. Compared to formats A and B, format C increased the range of reliable measurement by about 0.5 standard deviations on the positive side...

  20. Partitioning of the pesticide trifluralin between dissolved organic matter and water using automated SPME-GC/MS

    KAUST Repository

    Caupos, Emilie

    2014-10-04

    Solid-phase microextraction (SPME) was used to determine the equilibrium association constant for a pesticide, trifluralin (TFR), with dissolved organic matter (DOM). After optimization of the SPME method for the analysis of TFR, partition coefficients (K DOM) with three different sources of DOM were determined in buffered solutions at pH 7. Commercial humic acids and DOM fractions isolated from two surface waters were used. The values of log K DOMvaried from 4.3 to 5.8, depending on the nature of the organic material. A good correlation was established between log K DOMand DOM properties (as measured with the H/O atomic ratio and UV absorbance), in agreement with literature data. This is consistent with the effect of polarity and aromaticity for governing DOM-pollutant associations, regardless of the origin of DOM. This association phenomenon is relevant to better understand the behavior of pesticides in the environment since it controls part of pesticide leaching and fate in aquatic systems.

  1. Long-range correlations of serial FEV1 measurements in emphysematous patients and normal subjects

    DEFF Research Database (Denmark)

    Dirksen, A; Holstein-Rathlou, N H; Madsen, F

    1998-01-01

    are autocorrelated. The purpose of this study was to describe the correlation structure in time series of FEV1 measurements. Nineteen patients with severe alpha1-antitrypsin deficiency (phenotype PiZ) and moderate to severe emphysema and two subjects with normal lungs were followed for several years with daily self......In obstructive lung disease the annual change in lung function is usually estimated from serial measurements of forced expiratory volume in 1 s (FEV1). Frequent measurements in each patient may not improve this estimate because data are not statistically independent; i.e., the measurements...... measurements show long-range correlations. The practical implication is that FEV1 need not be measured more often than once every 3 mo in studies of the long-term trends in lung function....

  2. Baking enables McLeod gauge to measure in ultrahigh vacuum range

    Science.gov (United States)

    Kreisman, W. S.

    1965-01-01

    Accurate measurements in the ultrahigh vacuum range by a conventional McLeod gage requires degassing of the gage's glass walls. A closed system, in which mercury is forced into the gage by gravity alone, and in which the gage components are baked out for long periods, is used to achieve this degassing.

  3. Calibration Standards for Surface Topography Measuring Systems down to Nanometric Range

    DEFF Research Database (Denmark)

    Trumpold, H.; De Chiffre, Leonardo; Andreasen, Jan Lasson

    compression and injection moulded plastic negatives and Ni-negatives have been made from which again Ni-positives were produced. The replication processes showed negligible deviations from the Pt and Pa values compared to the primary standards. An important prerequisite is the cleanliness of the surfaces......Background For the precise and accurate measurement of surface topography a whole range of surface detection systems is available. With their application in research and production problems arise due to the lack of traceable standard artefacts for the instrument calibration in X, Y and Z directions...... and for the calibration of filters. Existing ISO standards on calibration specimens are inadequate and limited in that they only cover contacting instruments and only partially the measuring ranges for these instruments. The whole range of non-contacting instruments are not covered despite their increasing use...

  4. Scintillator-CCD camera system light output response to dosimetry parameters for proton beam range measurement

    Energy Technology Data Exchange (ETDEWEB)

    Daftari, Inder K., E-mail: idaftari@radonc.ucsf.edu [Department of Radiation Oncology, 1600 Divisadero Street, Suite H1031, University of California-San Francisco, San Francisco, CA 94143 (United States); Castaneda, Carlos M.; Essert, Timothy [Crocker Nuclear Laboratory,1 Shields Avenue, University of California-Davis, Davis, CA 95616 (United States); Phillips, Theodore L.; Mishra, Kavita K. [Department of Radiation Oncology, 1600 Divisadero Street, Suite H1031, University of California-San Francisco, San Francisco, CA 94143 (United States)

    2012-09-11

    The purpose of this study is to investigate the luminescence light output response in a plastic scintillator irradiated by a 67.5 MeV proton beam using various dosimetry parameters. The relationship of the visible scintillator light with the beam current or dose rate, aperture size and the thickness of water in the water-column was studied. The images captured on a CCD camera system were used to determine optimal dosimetry parameters for measuring the range of a clinical proton beam. The method was developed as a simple quality assurance tool to measure the range of the proton beam and compare it to (a) measurements using two segmented ionization chambers and water column between them, and (b) with an ionization chamber (IC-18) measurements in water. We used a block of plastic scintillator that measured 5 Multiplication-Sign 5 Multiplication-Sign 5 cm{sup 3} to record visible light generated by a 67.5 MeV proton beam. A high-definition digital video camera Moticam 2300 connected to a PC via USB 2.0 communication channel was used to record images of scintillation luminescence. The brightness of the visible light was measured while changing beam current and aperture size. The results were analyzed to obtain the range and were compared with the Bragg peak measurements with an ionization chamber. The luminescence light from the scintillator increased linearly with the increase of proton beam current. The light output also increased linearly with aperture size. The relationship between the proton range in the scintillator and the thickness of the water column showed good linearity with a precision of 0.33 mm (SD) in proton range measurement. For the 67.5 MeV proton beam utilized, the optimal parameters for scintillator light output response were found to be 15 nA (16 Gy/min) and an aperture size of 15 mm with image integration time of 100 ms. The Bragg peak depth brightness distribution was compared with the depth dose distribution from ionization chamber measurements

  5. Spin motion determination of the Envisat satellite through laser ranging measurements from a single pass measured by a single station

    Science.gov (United States)

    Pittet, Jean-Noël; Šilha, Jiří; Schildknecht, Thomas

    2018-02-01

    The Satellite Laser Ranging (SLR) technology is used to accurately determine the position of space objects equipped with so-called retro-reflectors or retro-reflector arrays (RRA). This type of measurement allows to measure the range to the spacecraft with high precision, which leads to determination of very accurate orbits for these targets. Non-active spacecraft, which are not attitude controlled any longer, tend to start to spin or tumble under influence of the external and internal torques and forces. If the return signal is measured for a non-spherical non-active rotating object, the signal in the range residuals with respect to the reference orbit is more complex. For rotating objects the return signal shows an oscillating pattern or patterns caused by the RRA moving around the satellite's centre of mass. This behaviour is projected onto the radial component measured by the SLR. In our work, we demonstrate how the SLR ranging technique from one sensor to a satellite equipped with a RRA can be used to precisely determine its spin motion during one passage. Multiple SLR measurements of one target over time allow to accurately monitor spin motion changes which can be further used for attitude predictions. We show our solutions of the spin motion determined for the non-active ESA satellite Envisat obtained from measurements acquired during years 2013-2015 by the Zimmerwald SLR station, Switzerland. All the necessary parameters are defined for our own so-called point-like model which describes the motion of a point in space around the satellite centre of mass.

  6. Polymeric pH nanosensor with extended measurement range bearing octaarginine as cell penetrating peptide

    DEFF Research Database (Denmark)

    Ke, Peng; Sun, Honghao; Liu, Mingxing

    2016-01-01

    A synthetic peptide octaarginine which mimics human immunodeficiency virus-1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental pH-s......H-sensitive fluorophores in a same nanoparticle. The authors believe that this triple fluorescent pH sensor provides a new tool to pH measurements that can have application in cellular uptake mechanism study and new nanomedicine design.......A synthetic peptide octaarginine which mimics human immunodeficiency virus-1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental p...

  7. LUMOS - A Sensitive and Reliable Optode System for Measuring Dissolved Oxygen in the Nanomolar Range

    DEFF Research Database (Denmark)

    Lehner, Philipp; Larndorfer, Christoph; Garcia-Robledo, Emilio

    2015-01-01

    Most commercially available optical oxygen sensors target the measuring range of 300 to 2 mu mol L-1. However these are not suitable for investigating the nanomolar range which is relevant for many important environmental situations. We therefore developed a miniaturized phase fluorimeter based...... for read out of less sensitive optical oxygen sensors based on the same or similar indicator dyes, for example for monitoring oxygen at physiological conditions. The presented sensor system exhibits lower noise, higher resolution and higher sensitivity than the electrochemical STOX sensor previously used...... measurement system called the LUMOS (Luminescence Measuring Oxygen Sensor). It consists of a readout device and specialized "sensing chemistry" that relies on commercially available components. The sensor material is based on palladium(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin embedded...

  8. An extended set-value observer for position estimation using single range measurements

    DEFF Research Database (Denmark)

    Marcal, Jose; Jouffroy, Jerome; Fossen, Thor I.

    the observability of the system is briefly discussed and an extended set-valued observer is presented, with some discussion about the effect of the measurements noise on the final solution. This observer estimates bounds in the errors assuming that the exogenous signals are bounded, providing a safe region......The ability of estimating the position of an underwater vehicle from single range measurements is important in applications where one transducer marks an important geographical point, when there is a limitation in the size or cost of the vehicle, or when there is a failure in a system...... of transponders. The knowledge of the bearing of the vehicle and the range measurements from a single location can provide a solution which is sensitive to the trajectory that the vehicle is following, since there is no complete constraint on the position estimate with a single beacon. In this paper...

  9. Smartphone Photography as a Tool to Measure Knee Range of Motion.

    Science.gov (United States)

    Mica, Megan Conti; Wagner, Eric R; Shin, Alexander Y

    2018-01-01

    The objective of this study was to validate measuring knee range of motion (ROM) from smartphone photography. Thirty-two participants (64 knees) obtained smartphone photographs of knee flexion and extension. Surgeons obtained the same photographs and goniometric measurement of ROM. ROM was measured using Adobe Photoshop. Goniometer versus digital measurements, participant versus surgeon photographs, and interobserver measurements were analyzed. The average difference in goniometer and digital photograph measurements was 5°. The interclass correlation was .642(L) and .656(R). The Bland-Altman plots demonstrated that 29/32 digital measurements were within the 95% confidence interval (CI). Participants' versus researchers' photographs averaged a 2° difference. The interclass correlation was .924(L) and .91(R). Bland-Altman plots demonstrated that 31/32 measurements were within the 95% CI. Interobserver reliability averaged aROMdifference of 5°. The concordance coefficients were .647(L) and .723(R). Bland-Altman plots demonstrated that 30 of 32 digital measurements were within the 95% CI. Measuring knee ROM using smartphone digital photography is valid and reliable. (Journal of Surgical Orthopaedic Advances 27(1):52-57, 2018).

  10. Error Analysis of Relative Calibration for RCS Measurement on Ground Plane Range

    Directory of Open Access Journals (Sweden)

    Wu Peng-fei

    2012-03-01

    Full Text Available Ground plane range is a kind of outdoor Radar Cross Section (RCS test range used for static measurement of full-size or scaled targets. Starting from the characteristics of ground plane range, the impact of environments on targets and calibrators is analyzed during calibration in the RCS measurements. The error of relative calibration produced by the different illumination of target and calibrator is studied. The relative calibration technique used in ground plane range is to place the calibrator on a fixed and auxiliary pylon somewhere between the radar and the target under test. By considering the effect of ground reflection and antenna pattern, the relationship between the magnitude of echoes and the position of calibrator is discussed. According to the different distances between the calibrator and target, the difference between free space and ground plane range is studied and the error of relative calibration is calculated. Numerical simulation results are presented with useful conclusions. The relative calibration error varies with the position of calibrator, frequency and antenna beam width. In most case, set calibrator close to the target may keep the error under control.

  11. Approach for measuring the chemistry of individual particles in the size range critical for cloud formation.

    Science.gov (United States)

    Zauscher, Melanie D; Moore, Meagan J K; Lewis, Gregory S; Hering, Susanne V; Prather, Kimberly A

    2011-03-15

    Aerosol particles, especially those ranging from 50 to 200 nm, strongly impact climate by serving as nuclei upon which water condenses and cloud droplets form. However, the small number of analytical methods capable of measuring the composition of particles in this size range, particularly at the individual particle level, has limited our knowledge of cloud condensation nuclei (CCN) composition and hence our understanding of aerosols effect on climate. To obtain more insight into particles in this size range, we developed a method which couples a growth tube (GT) to an ultrafine aerosol time-of-flight mass spectrometer (UF-ATOFMS), a combination that allows in situ measurements of the composition of individual particles as small as 38 nm. The growth tube uses water to grow particles to larger sizes so they can be optically detected by the UF-ATOFMS, extending the size range to below 100 nm with no discernible changes in particle composition. To gain further insight into the temporal variability of aerosol chemistry and sources, the GT-UF-ATOFMS was used for online continuous measurements over a period of 3 days.

  12. Novel gravimetric measurement technique for quantitative volume calibration in the sub-microliter range

    International Nuclear Information System (INIS)

    Liang, Dong; Zengerle, Roland; Steinert, Chris; Ernst, Andreas; Koltay, Peter; Bammesberger, Stefan; Tanguy, Laurent

    2013-01-01

    We present a novel measurement method based on the gravimetric principles adapted from the ASTM E542 and ISO 4787 standards for quantitative volume determination in the sub-microliter range. Such a method is particularly important for the calibration of non-contact micro dispensers as well as other microfluidic devices. The novel method is based on the linear regression analysis of continuously monitored gravimetric results and therefore is referred to as ‘gravimetric regression method (GRM)’. In this context, the regression analysis is necessary to compensate the mass loss due to evaporation that is significant for very small dispensing volumes. A full assessment of the measurement uncertainty of GRM is presented and results in a standard measurement uncertainty around 6 nl for dosage volumes in the range from 40 nl to 1 µl. The GRM has been experimentally benchmarked with a dual-dye ratiometric photometric method (Artel Inc., Westbrook, ME, USA), which can provide traceability of measurement to the International System of Units (SI) through reference standards maintained by NIST. Good precision (max. CV = 2.8%) and consistency (bias around 7 nl in the volume range from 40 to 400 nl) have been observed comparing the two methods. Based on the ASTM and ISO standards on the one hand and the benchmark with the photometric method on the other hand, two different approaches for establishing traceability for the GRM are discussed. (paper)

  13. Comprehensive Measurement of Atmospheric Aerosols with a Wide Range Aerosol Spectrometer

    International Nuclear Information System (INIS)

    Keck, L; Pesch, M; Grimm, H

    2011-01-01

    A wide range aerosol spectrometer (WRAS) was used for comprehensive long term measurements of aerosol size distributions. The system combines the results of an optical aerosol spectrometer with the results of a Scanning Mobility Particle Sizer (SMPS) to record essentially the full size range (5 nm - 32 μm) of atmospheric particles in 72 channels. Measurements were carried out over one year (2009) at the Global Atmospheric Watch (GAW)-Station Hohenpeissenberg, Bavaria. Total particle number concentrations obtained from the aerosol size distributions were compared to the total number concentrations measured by a Condensation Particle Counter (CPC). The comparison showed an excellent agreement of the data. The high time resolution of 5 minutes allows the combination of the measured size distributions with meteorological data and correlations to gaseous pollutants (CO, NOx and SO2). A good correlation of particle number and CO concentrations was found for long distance transported small particles, which were probably mainly soot particles. Correlations to NOx were observed for aerosols from local sources such as traffic emissions. The formation of secondary aerosols from gaseous precursors was also observed. Episodes of relatively high concentration of particles in the range of 2-3 μm were probably caused by pollen.

  14. Volatile emerging contaminants in melon fruits, analysed by HS-SPME-GC-MS.

    Science.gov (United States)

    Cincotta, Fabrizio; Verzera, Antonella; Tripodi, Gianluca; Condurso, Concetta

    2018-03-01

    The aim of this research was to develop and validate a headspace-solid phase micro-extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method for the determination of volatile emerging contaminants in fruit. The method showed good precision (RSD ≤ 14%) and satisfactory recoveries (99.1-101.7%) and LOD and LOQ values ranging between 0.011-0.033 μg kg -1 and 0.037-0.098 μg kg -1 , respectively. The method was applied to investigate the content of volatile emerging contaminants in two varieties of melon fruit (Cucumis melo L.) cultivated adjoining high-risk areas. Glycol ethers, BHT, BHA and BTEX (benzene, toluene, ethylbenzene and xylene) were determined in melon fruit pulps for the first time, with different sensitivities depending on sample and variety. Although the amount of the volatile contaminants in the melon samples were in the order of µg kg -1 , the safety of vegetable crops cultivated near risk areas should be more widely considered. The results showed that this accurate and reproducible method can be useful for routine safety control of fruits and vegetables.

  15. 10.23  Mcps laser pseudo-code ranging system with 0.33  mm (1σ) pseudo-range measurement precision.

    Science.gov (United States)

    Yu, Xiaonan; Tong, Shoufeng; Zhang, Lei; Dong, Yan; Zhao, Xin; Qiao, Yue

    2017-07-01

    The inter-satellite laser link is the backbone of the next inter-satellite information network, and ranging and communication are the main functions of the inter-satellite laser link. This study focuses on the inter-satellite laser ranging based on the pseudo-code correlation technology. In this paper, several typical laser-ranging methods have been compared and we determined that the laser pseudo-code ranging architecture is more suitable for the inter-satellite laser communication link. The pseudo-code ranging system is easy to combine with a digital communication system, and we used it to calculate integer ambiguity by modulating the time information. The main challenge of the ranging system is range precision, which is the main focus of this paper. First, the framework of the pseudo-code ranging system is introduced; the ranging architecture of dual one-way ranging is used to eliminate the clock error between the two transceivers, and then the uncertainty of the phase detector is analyzed. In the analysis, the carrier to noise ratio and the ranging code rate are constrained by the laser communication link margin and the electronic hardware limitation. Therefore, the relationship between the sampling depth and the phase detector uncertainty is verified. A series of optical fiber channel laser pseudo-code ranging experiments demonstrated the effects of sampling depth on the ranging precision. By adjusting the depth of storage, such as the depth of 1.6 Mb, we obtained a pseudo-range measurement precision of 0.33 mm (1σ), which is equivalent to 0.0001 times code subdivision of 10.23 Mcps pseudo-code. This paper has achieved high precision in a pseudo-range measurements, which is the foundation of the inter-satellite laser link.

  16. Novel birefringence interrogation for Sagnac loop interferometer sensor with unlimited linear measurement range.

    Science.gov (United States)

    He, Haijun; Shao, Liyang; Qian, Heng; Zhang, Xinpu; Liang, Jiawei; Luo, Bin; Pan, Wei; Yan, Lianshan

    2017-03-20

    A novel demodulation method for Sagnac loop interferometer based sensor has been proposed and demonstrated, by unwrapping the phase changes with birefringence interrogation. A temperature sensor based on Sagnac loop interferometer has been used to verify the feasibility of the proposed method. Several tests with 40 °C temperature range have been accomplished with a great linearity of 0.9996 in full range. The proposed scheme is universal for all Sagnac loop interferometer based sensors and it has unlimited linear measurable range which overwhelming the conventional demodulation method with peak/dip tracing. Furthermore, the influence of the wavelength sampling interval and wavelength span on the demodulation error has been discussed in this work. The proposed interrogation method has a great significance for Sagnac loop interferometer sensor and it might greatly enhance the availability of this type of sensors in practical application.

  17. Absolute distance measurement with extension of nonambiguity range using the frequency comb of a femtosecond laser

    Science.gov (United States)

    Jang, Yoon-Soo; Lee, Keunwoo; Han, Seongheum; Lee, Joohyung; Kim, Young-Jin; Kim, Seung-Woo

    2014-12-01

    We revisit the method of synthetic wavelength interferometry (SWI) for absolute measurement of long distances using the radio-frequency harmonics of the pulse repetition rate of a mode-locked femtosecond laser. Our intention here is to extend the nonambiguity range (NAR) of the SWI method using a coarse virtual wavelength synthesized by shifting the pulse repetition rate. The proposed concept of NAR extension is experimentally verified by measuring a ˜13-m distance with repeatability of 9.5 μm (root-mean-square). The measurement precision is estimated to be 31.2 μm in comparison with an incremental He-Ne laser interferometer. This extended SWI method is found to be well suited for long-distance measurements demanded in the fields of large-scale precision engineering, geodetic survey, and future space missions.

  18. Generalized weighted ratio method for accurate turbidity measurement over a wide range.

    Science.gov (United States)

    Liu, Hongbo; Yang, Ping; Song, Hong; Guo, Yilu; Zhan, Shuyue; Huang, Hui; Wang, Hangzhou; Tao, Bangyi; Mu, Quanquan; Xu, Jing; Li, Dejun; Chen, Ying

    2015-12-14

    Turbidity measurement is important for water quality assessment, food safety, medicine, ocean monitoring, etc. In this paper, a method that accurately estimates the turbidity over a wide range is proposed, where the turbidity of the sample is represented as a weighted ratio of the scattered light intensities at a series of angles. An improvement in the accuracy is achieved by expanding the structure of the ratio function, thus adding more flexibility to the turbidity-intensity fitting. Experiments have been carried out with an 850 nm laser and a power meter fixed on a turntable to measure the light intensity at different angles. The results show that the relative estimation error of the proposed method is 0.58% on average for a four-angle intensity combination for all test samples with a turbidity ranging from 160 NTU to 4000 NTU.

  19. Potentiometric Measurement of Transition Ranges and Titration Errors for Acid/Base Indicators

    Science.gov (United States)

    Flowers, Paul A.

    1997-07-01

    Sophomore analytical chemistry courses typically devote a substantial amount of lecture time to acid/base equilibrium theory, and usually include at least one laboratory project employing potentiometric titrations. In an effort to provide students a laboratory experience that more directly supports their classroom discussions on this important topic, an experiment involving potentiometric measurement of transition ranges and titration errors for common acid/base indicators has been developed. The pH and visually-assessed color of a millimolar strong acid/base system are monitored as a function of added titrant volume, and the resultant data plotted to permit determination of the indicator's transition range and associated titration error. Student response is typically quite positive, and the measured quantities correlate reasonably well to literature values.

  20. Measurement range of phase retrieval in optical surface and wavefront metrology

    International Nuclear Information System (INIS)

    Brady, Gregory R.; Fienup, James R.

    2009-01-01

    Phase retrieval employs very simple data collection hardware and iterative algorithms to determine the phase of an optical field. We have derived limitations on phase retrieval, as applied to optical surface and wavefront metrology, in terms of the speed of beam (i.e., f-number or numerical aperture) and amount of aberration using arguments based on sampling theory and geometrical optics. These limitations suggest methodologies for expanding these ranges by increasing the complexity of the measurement arrangement, the phase-retrieval algorithm, or both. We have simulated one of these methods where a surface is measured at unusual conjugates

  1. A liquid crystalline medium for measuring residual dipolar couplings over a wide range of temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hong; Eberstadt, Matthias; Olejniczak, Edward T.; Meadows, Robert P.; Fesik, Stephen W. [Abbott Laboratories (United States)

    1998-10-15

    A mixture of dilauroyl phosphatidylcholine (DLPC) and 3-(cholamidopropyl)dimethylammonio-2-hydroxyl-1-propane sulfonate (CHAPSO) in water forms disc shaped bicelles that become ordered at high magnetic fields over a wide range of temperatures. As illustrated for the FK506 binding protein (FKBP), large residual dipolar couplings can be measured for proteins dissolved in low concentrations (5% w/v) of a DLPC/CHAPSO medium at a molar ratio of 4.2:1. This system is especially useful for measuring residual dipolar couplings for molecules that are only stable at low temperatures.

  2. Is goniometry suitable for measuring ankle range of motion in female ballet dancers? An initial comparison with radiographic measurement.

    Science.gov (United States)

    Russell, Jeffrey A; Shave, Ruth M; Kruse, David W; Nevill, Alan M; Koutedakis, Yiannis; Wyon, Matthew A

    2011-06-01

    Female ballet dancers require extreme ankle motion to attain the demi-plié (weight-bearing full dorsiflexion [DF]) and en pointe (weight-bearing full plantar flexion [PF]) positions of ballet. However, techniques for assessing this amount of motion have not yet received sufficient scientific scrutiny. Therefore, the purpose of this study was to examine possible differences between weight-bearing goniometric and radiographic ankle range of motion measurements in female ballet dancers. Ankle range of motion in 8 experienced female ballet dancers was assessed by goniometry and 2 radiographic measurement methods. The latter were performed on 3 mediolateral x-rays, in demi-plié, neutral, and en pointe positions; one of them used the same landmarks as goniometry. DF values were not significantly different among the methods, but PF values were (P ballet dancers and suggest that goniometry may not be ideal for assessing ankle range of motion in these individuals. Therefore, further research is needed to standardize how DF and PF are measured in ballet dancers. Diagnostic, Level I.

  3. Ground based mobile isotopic methane measurements in the Front Range, Colorado

    Science.gov (United States)

    Vaughn, B. H.; Rella, C.; Petron, G.; Sherwood, O.; Mielke-Maday, I.; Schwietzke, S.

    2014-12-01

    Increased development of unconventional oil and gas resources in North America has given rise to attempts to monitor and quantify fugitive emissions of methane from the industry. Emission estimates of methane from oil and gas basins can vary significantly from one study to another as well as from EPA or State estimates. New efforts are aimed at reconciling bottom-up, or inventory-based, emission estimates of methane with top-down estimates based on atmospheric measurements from aircraft, towers, mobile ground-based vehicles, and atmospheric models. Attributing airborne measurements of regional methane fluxes to specific sources is informed by ground-based measurements of methane. Stable isotopic measurements (δ13C) of methane help distinguish between emissions from the O&G industry, Confined Animal Feed Operations (CAFO), and landfills, but analytical challenges typically limit meaningful isotopic measurements to individual point sampling. We are developing a toolbox to use δ13CH4 measurements to assess the partitioning of methane emissions for regions with multiple methane sources. The method was applied to the Denver-Julesberg Basin. Here we present data from continuous isotopic measurements obtained over a wide geographic area by using MegaCore, a 1500 ft. tube that is constantly filled with sample air while driving, then subsequently analyzed at slower rates using cavity ring down spectroscopy (CRDS). Pressure, flow and calibration are tightly controlled allowing precise attribution of methane enhancements to their point of collection. Comparisons with point measurements are needed to confirm regional values and further constrain flux estimates and models. This effort was made in conjunction with several major field campaigns in the Colorado Front Range in July-August 2014, including FRAPPÉ (Front Range Air Pollution and Photochemistry Experiment), DISCOVER-AQ, and the Air Water Gas NSF Sustainability Research Network at the University of Colorado.

  4. Time Biases in laser ranging measurements; impacts on geodetic products (Reference Frame and Orbitography)

    Science.gov (United States)

    Belli, A.; Exertier, P.; Lemoine, F. G.; Chinn, D. S.; Zelensky, N. P.

    2017-12-01

    The GGOS objectives are to maintain a geodetic network with an accuracy of 1 mm and a stability of 0.1 mm per year. For years, the laser ranging technique, which provide very accurate absolute distances to geodetic targets enable to determine the scale factor as well as coordinates of the geocenter. In order to achieve this goal, systematic errors appearing in the laser ranging measurements must be considered and solved. In addition to Range Bias (RB), which is the primary source of uncertainty of the technique, Time Bias (TB) has been recently detected by using the Time Transfer by Laser Link (T2L2) space instrument capability on-board the satellite Jason-2. Instead of determining TB through the precise orbit determination that is applied to commonly used geodetic targets like LAGEOS to estimate global geodetic products, we have developed, independently, a dedicated method to transfer time between remote satellite laser ranging stations. As a result, the evolving clock phase shift to UTC of around 30 stations has been determined under the form of time series of time bias per station from 2008 to 2016 with an accuracy of 3-4 ns. It demonstrated the difficulty, in terms of Time & Frequency used technologies, to locally maintain accuracy and long term stability at least in the range of 100 ns that is the current requirement for time measurements (UTC) for the laser ranging technique. Because some laser ranging stations oftently exceed this limit (from 100 ns to a few μs) we have been studying these effects first on the precision orbit determination itself, second on the station positioning. We discuss the impact of TB on LAGEOS and Jason-2 orbits, which appears to affect the along-track component essentially. We also investigate the role of TB in global geodetic parameters as the station coordinates. Finally, we propose to provide the community with time series of time bias of laser ranging stations, under the form of a data- handling-file in order to be included in

  5. Modified application of HS-SPME for quality evaluation of essential oil plant materials.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Szewczyk, Joanna; Dybowski, Michal P

    2016-01-01

    The main limitation in the standard application of head space analysis employing solid phase microextraction (HS-SPME) for the evaluation of plants as sources of essential oils (EOs) are different quantitative relations of EO components from those obtained by direct analysis of EO which was got in the steam distillation (SD) process from the same plant (EO/SD). The results presented in the paper for thyme, mint, sage, basil, savory, and marjoram prove that the quantitative relations of EO components established by HS-SPME procedure and direct analysis of EO/SD are similar when the plant material in the HS-SPME process is replaced by its suspension in oil of the same physicochemical character as that of SPME fiber coating. The observed differences in the thyme EO composition estimated by both procedures are insignificant (F(exp)SPME procedure proposed in this paper substantially shortens the evaluation time of plant material quality and thus may improve the efficiency of analytical laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Application of solid phase micro extraction (SPME) in profiling hydrocarbons in oil spill cases

    International Nuclear Information System (INIS)

    Zuraidah Abdullah Munir; Norashikin Saim; Nurul Huda Mamat Ghani

    2008-01-01

    In environmental forensic, it is extremely important to have a fast and reliable method in identifying sources of spilled oil and petroleum products. In this study, solid phase micro extraction (SPME) method coupled to gas chromatography-mass spectrometry was developed for the analysis of hydrocarbons in diesel and petroleum contaminated soil samples. Optimization of SPME parameters such as extraction time, extraction temperature and desorption time, was performed using 100-μm poly dimethylsiloxane (PDMS) fiber. These parameters were studied at three levels by means of a central composite experimental design and the optimum experimental conditions were determined using response surface method. The developed SPME method was applied to determine the profiles of hydrocarbons in several oil contaminated soil sample. The SPME method was also used to study the effects of weathering on the profiles of hydrocarbons in unleaded gasoline, diesel and kerosene contaminated soil samples. After several days, significant losses of the lighter hydrocarbons were observed compared to the heavier ones. From these data, SPME method can be used to differentiate possible candidate sources in oil spill cases. (author)

  7. A High Dynamic-Range Beam Position Measurement System for ELSA-2

    CERN Document Server

    Balleyguier, P; Guimbal, P; Borrion, H

    2003-01-01

    New beamlines are presently under construction for ELSA, a 20 MeV electron linac located at Bruyères-le-Châtel. These lines need a beam position measurement system filling the following requirements: small footprint, wide dynamic range, single-bunch/multi-bunch capability, simple design. We designed a compact 4-stripline sensor and an electronic treatment chain based on logarithmic amplifiers. This paper presents the design, cold and hot test results.

  8. Identification of long-range transport of aerosols over Austria using EARLINET lidar measurements

    Science.gov (United States)

    Camelia, Talianu

    2018-04-01

    The aims of the study is to identify the paths of the long-range transported aerosols over Austria and their potential origin, and to estimate their properties, using lidar measurements from EARLINET stations closest to Austria from Germany and Romania and aerosol transport models. As of now, there is no lidar station in Austria. The study is part of a project to estimate the usefulness of a lidar station located in Vienna, Austria.

  9. Electron density values of various human tissues: in vitro Compton scatter measurements and calculated ranges

    International Nuclear Information System (INIS)

    Shrimpton, P.C.

    1981-01-01

    Accurate direct measurements of electron density have been performed on specimens from 10 different tissue types of the human body, representing the major organs, using a Compton scatter technique. As a supplement to these experimental values, calculations have been carried out to determine the electron densities expected for these tissue types. The densities observed are in good agreement with the broad ranges deduced from the basic data previously published. The results of both the in vitro sample measurements and the approximate calculations indicate that the electron density of most normal healthy soft tissue can be expected to fall within the fairly restricted range of +- 5% around 3.4 X 10 23 electrons per cm 3 . The obvious exception to this generalisation is the result for lung tissue, which falls considerably below this range owing to the high air content inherent in its construction. In view of such an overall limited variation with little difference between tissues, it would appear that electron density alone is likely to be a rather poor clinical parameter for tissue analysis, with high accuracy and precision being essential in any in vivo Compton measurements for imaging or diagnosis on specific organs. (author)

  10. Laser Ranging in Solar System: Technology Developments and New Science Measurement Capabilities

    Science.gov (United States)

    Sun, X.; Smith, D. E.; Zuber, M. T.; Mcgarry, J.; Neumann, G. A.; Mazarico, E.

    2015-12-01

    Laser Ranging has played a major role in geodetic studies of the Earth over the past 40 years. The technique can potentially be used in between planets and spacecrafts within the solar system to advance planetary science. For example, a direct measurement of distances between planets, such as Mars and Venus would make significant improvements in understanding the dynamics of the whole solar system, including the masses of the planets and moons, asteroids and their perturbing interactions, and the gravity field of the Sun. Compared to the conventional radio frequency (RF) tracking systems, laser ranging is potentially more accurate because it is much less sensitive to the transmission media. It is also more efficient because the laser beams are much better focused onto the targets than RF beams. However, existing laser ranging systems are all Earth centric, that is, from ground stations on Earth to orbiting satellites in near Earth orbits or lunar orbit, and to the lunar retro-reflector arrays deployed by the astronauts in the early days of lunar explorations. Several long distance laser ranging experiments have been conducted with the lidar in space, including a two-way laser ranging demonstration between Earth and the Mercury Laser Altimeter (MLA) on the MESSENGER spacecraft over 24 million km, and a one way laser transmission and detection experiment over 80 million km between Earth and the Mars Orbiting Laser Altimeter (MOLA) on the MGS spacecraft in Mars orbit. A one-way laser ranging operation has been carried out continuously from 2009 to 2014 between multiple ground stations to LRO spacecraft in lunar orbit. The Lunar Laser Communication Demonstration (LLCD) on the LADEE mission has demonstrated that a two way laser ranging measurements, including both the Doppler frequency and the phase shift, can be obtained from the subcarrier or the data clocks of a high speed duplex laser communication system. Plans and concepts presently being studied suggest we may be

  11. On the theory of SODAR measurement techniques[SOund Detection And Ranging

    Energy Technology Data Exchange (ETDEWEB)

    Antoniou, I.; Joergensen, H.E. [Risoe National Lab. (Denmark); Ormel, F. [Energy Research Center of the Netherlands (Netherlands); Bradley, S.; Huenerbein, S. von [University of Salford (United Kingdom); Emeis, S. [Forschungszentrum Karlsruhe GmbH (Germany); Warmbier, G. [GWU-Umwelttechnik Gmbh (Germany)

    2003-04-01

    The need for alternative means to measure the wind speed for wind energy purposes has increased with the increase of the size of wind turbines. The cost and the technical difficulties for performing wind speed measurements has also increased with the size of the wind turbines, since it is demanded that the wind speed has to be measured at the rotor centre of the turbine and the size of both the rotor and the hub height have grown following the increase in the size of the wind turbines. The SODAR (SOund Detection And Ranging) is an alternative to the use of cup anemometers and offers the possibility of measuring both the wind speed distribution with height and the wind direction. At the same time the SODAR presents a number of serious drawbacks such as the low number of measurements per time period, the dependence of the ability to measure on the atmospheric conditions and the difficulty of measuring at higher wind speeds due to either background noise or the neutral condition of the atmosphere. Within the WISE project (EU project number NNE5-2001-297), a number of work packages have been defined in order to deal with the SODAR. The present report is the result of the work package 1. Within this package the objective has been to present and achieve the following: 1) An accurate theoretic model that describes all the relevant aspects of the interaction of the sound beam with the atmosphere in the level of detail needed for wind energy applications. 2) Understanding of dependence of SODAR performance on hard- and software configuration. 3) Quantification of principal difference between SODAR wind measurement and wind speed measurements with cup anemometers with regard to power performance measurements.

  12. ANALYTICAL APPROACH OF THE VOLATILE FRACTION OF Solanum quitoense BY HS-SPME/GC-MS

    Directory of Open Access Journals (Sweden)

    EDUARDO CORPAS IGUARÁN

    2017-07-01

    Full Text Available The species of lulo fruit (Solanum quitoense, predominant in Colombia, is a promising fruit for both national and international market due to its flavor and nutritional characteristics, which generated the interest to know the volatile composition of its pulp. After adjusting, the chromatographic conditions necessary to analyze volatile fraction of this fruit, the effect of the temperature and time of adsorption was measured through the headspace - solid phase microextraction (HS-SPME and gas chromatography - mass spectrometry (GC-MS, on the area of volatile compounds of S. quitoense, by applying the experimental design of a factor. The descriptive analysis suggested that the adsorption at 60°C and 30 minutes promoted optimal recovery of volatiles as well as internal standard (1-Octanol, with recovery of 99,66% at 60ºC, while the non-parametric test Kruskal-Wallis showed statistical differences in the effect of time (P= 0,018, but not of the temperature adsorption (P= 0,058 upon the volatiles compounds area. A predominance of esters (48,98%, aldehydes (18,37%, and alcohols (14,29% was observed and also were found compounds of greatest area such as 3-hexen-1-ol acetate, acetic acid methyl ester, and acetic acid hexyl ester. These metabolites determine the characteristic aroma from lulo pulp and influence the consumer preference.

  13. A Newly Designed Fiber-Optic Based Earth Pressure Transducer with Adjustable Measurement Range

    Directory of Open Access Journals (Sweden)

    Hou-Zhen Wei

    2018-03-01

    Full Text Available A novel fiber-optic based earth pressure sensor (FPS with an adjustable measurement range and high sensitivity is developed to measure earth pressures for civil infrastructures. The new FPS combines a cantilever beam with fiber Bragg grating (FBG sensors and a flexible membrane. Compared with a traditional pressure transducer with a dual diaphragm design, the proposed FPS has a larger measurement range and shows high accuracy. The working principles, parameter design, fabrication methods, and laboratory calibration tests are explained in this paper. A theoretical solution is derived to obtain the relationship between the applied pressure and strain of the FBG sensors. In addition, a finite element model is established to analyze the mechanical behavior of the membrane and the cantilever beam and thereby obtain optimal parameters. The cantilever beam is 40 mm long, 15 mm wide, and 1 mm thick. The whole FPS has a diameter of 100 mm and a thickness of 30 mm. The sensitivity of the FPS is 0.104 kPa/με. In addition, automatic temperature compensation can be achieved. The FPS’s sensitivity, physical properties, and response to applied pressure are extensively examined through modeling and experiments. The results show that the proposed FPS has numerous potential applications in soil pressure measurement.

  14. Multi-functional measurement systems for studying photon-hadron interactions in the intermediate energy range

    International Nuclear Information System (INIS)

    Baranov, P.S.; Vol'nov, M.I.; Eliseev, A.N.

    1983-01-01

    The PION multifunctional time-of-flight measurement system operating on-line with the D-116 computer is described. The system is designed to study proton-hadron interaction processes using the PACHRA synchrotron beam. The following devices are involved into the basic permanent system equipment: two gamma telescope counters, neutron spectrometer, scintillation mass spectrometer, and also cryogenic liquid hydrogen and liquid deuterium targets, ionization chambers, and quantometer. The time-of-flight neutron spectrometer consists of 4 coordinate-sensitive scintillation counters, before which the logic detector operating in the anticoincidence regime is placed. Information acquisition and measurement system control are accomplished by the computer using the CAMAK modules. The above system allows one to observe at the same time different physical processes and to carry out simultaneous measurements in a wide energy range

  15. Standardization of radiation protection measurements in mixed fields of an extended energy range

    International Nuclear Information System (INIS)

    Hoefert, M.; Stevenson, G.R.

    1977-01-01

    The improved ICRU concept of dose equivalent index aims at standardizing both area and personnel dose measurements so that the results on the dosimetry of external irradiations in radiation protection become compatible. It seems that for photon and neutron energies up to 3 and 20 MeV respectively the realization of dose-equivalent index is straightforward, but the inclusion of higher energies and/or other types of radiation will lead both to conceptual and practical difficulties. It will be shown that practical measurements in mixed radiation fields of an extended energy range for protection purposes will overestimate the standardized quantity. While area measurements can be performed to represent a good approximation, greater uncertainties have to be accepted in personnel dosimetry for stray radiation fields around GeV proton accelerators

  16. Measurements and correlations of turbulent burning velocities over wide ranges of fuels and elevated pressures

    KAUST Repository

    Bradley, Derek; Lawes, Malcolm; Liu, Kexin; Mansour, Morkous S.

    2013-01-01

    The implosion technique has been used to extend measurements of turbulent burning velocities over greater ranges of fuels and pressures. Measurements have been made up to 3.5 MPa and at strain rate Markstein numbers as low as 23. The implosion technique, with spark ignition at two opposite wall positions within a fan-stirred spherical bomb is capable of measuring turbulent burning velocities, at higher pressures than is possible with central ignition. Pressure records and schlieren high speed photography define the rate of burning and the smoothed area of the flame front. The first aim of the study was to extend the previous measurements with ethanol and propane-air, with further measurements over wider ranges of fuels and equivalence ratios with mixtures of hydrogen, methane, 10% hydrogen-90% methane, toluene, and i-octane, with air. The second aim was to study further the low turbulence regime in which turbulent burning co-exists with laminar flame instabilities. Correlations are presented of turbulent burning velocity normalised by the effective rms turbulent velocity acting on the flame front, ut=u0k , with the Karlovitz stretch factor, K, for different strain rate Markstein numbers, a decrease in which increases ut=u0k . Experimental correlations are presented for the present measurements, combined with previous ones. Different burning regimes are also identified, extending from that of mixed turbulence/laminar instability at low values of K to that at high values of K, in which ut=u0k is gradually reduced due to increasing localised flame extinctions. © 2012 The Combustion Institute.

  17. Feasibility of RACT for 3D dose measurement and range verification in a water phantom.

    Science.gov (United States)

    Alsanea, Fahed; Moskvin, Vadim; Stantz, Keith M

    2015-02-01

    The objective of this study is to establish the feasibility of using radiation-induced acoustics to measure the range and Bragg peak dose from a pulsed proton beam. Simulation studies implementing a prototype scanner design based on computed tomographic methods were performed to investigate the sensitivity to proton range and integral dose. Derived from thermodynamic wave equation, the pressure signals generated from the dose deposited from a pulsed proton beam with a 1 cm lateral beam width and a range of 16, 20, and 27 cm in water using Monte Carlo methods were simulated. The resulting dosimetric images were reconstructed implementing a 3D filtered backprojection algorithm and the pressure signals acquired from a 71-transducer array with a cylindrical geometry (30 × 40 cm) rotated over 2π about its central axis. Dependencies on the detector bandwidth and proton beam pulse width were performed, after which, different noise levels were added to the detector signals (using 1 μs pulse width and a 0.5 MHz cutoff frequency/hydrophone) to investigate the statistical and systematic errors in the proton range (at 20 cm) and Bragg peak dose (of 1 cGy). The reconstructed radioacoustic computed tomographic image intensity was shown to be linearly correlated to the dose within the Bragg peak. And, based on noise dependent studies, a detector sensitivity of 38 mPa was necessary to determine the proton range to within 1.0 mm (full-width at half-maximum) (systematic error ionizing radiation-induced acoustics can be used to verify dose distribution and proton range with centi-Gray sensitivity. Realizing this technology into the clinic has the potential to significantly impact beam commissioning, treatment verification during particle beam therapy and image guided techniques.

  18. Application of Microextraction Techniques Including SPME and MESI to the Thermal Degradation of Polymers: A Review.

    Science.gov (United States)

    Kaykhaii, Massoud; Linford, Matthew R

    2017-03-04

    Here, we discuss the newly developed micro and solventless sample preparation techniques SPME (Solid Phase Microextraction) and MESI (Membrane Extraction with a Sorbent Interface) as applied to the qualitative and quantitative analysis of thermal oxidative degradation products of polymers and their stabilizers. The coupling of these systems to analytical instruments is also described. Our comprehensive literature search revealed that there is no previously published review article on this topic. It is shown that these extraction techniques are valuable sample preparation tools for identifying complex series of degradation products in polymers. In general, the number of products identified by traditional headspace (HS-GC-MS) is much lower than with SPME-GC-MS. MESI is particularly well suited for the detection of non-polar compounds, therefore number of products identified by this technique is not also to the same degree of SPME. Its main advantage, however, is its ability of (semi-) continuous monitoring, but it is more expensive and not yet commercialized.

  19. SPME GC/MS Analysis of Three Ornithogalum L. species from Turkey

    Directory of Open Access Journals (Sweden)

    Gülin Renda

    2016-01-01

    Full Text Available In this study, a solid phase micro extraction (SPME method with gas chromatography-mass spectrometry (GC-MS was used for analysis of volatile compounds in flowers and bulbs of three Ornithogalum species. The samples of flowers and bulbs of Ornithogalum sigmoideum, Ornithogalum orthophyllum, Ornithogalum oligophyllum was separately analyzed by SPME-GC-MS. A comparison of volatile compounds was made between species and the parts studied. A total of 70 compounds were identified and different volatile compounds were determined in distinct parts of the species. The major volatile organic compound of the flowers of O. sigmoideum and O. ornithogalum was furan (54.5% and 57.0% respectively. For O. oligophyllum the major volatile organic compound was nonanal (19.2%. Analyses revealed that SPME-GC-MS method is appropriate for the analysis of volatile compounds of Ornithogalum species.

  20. Comparative analysis of the aroma chemicals of Melissa officinalis using hydrodistillation and HS-SPME techniques

    Directory of Open Access Journals (Sweden)

    Shakeel-u- Rehman

    2017-05-01

    Full Text Available Headspace solid-phase micro extraction (HS-SPME coupled with gas chromatography–mass spectrometry (GC–MS has been used for the chemical analysis of Melissa officinalis (leaves cultivated in Institute Germplasm. The HS-SPME analysis led to the identification of 22 components constituting 99.1% of the total volatile constituents present in the leaves whereas its hydrodistillate led to the identification of 24 volatile constituents constituting 98.1% of the volatile material. The chemical composition of the SPME and hydrodistilled extract of M. officinalis leaves comprised mainly of oxygenated monoterpenes (78.5% and 57.8% respectively and sesquiterpene hydrocarbons (14.9% and 29.7% respectively. The major components identified in the HS-SPME extract were citronellal (31.1%, citronellol (18.3%, β-caryophyllene (12.0%, (E-citral (11.9%, (Z-citral (9.6%, geraniol (3.6%, (Z-β-ocimene (3.1% and 1-octen-3-ol (2.0% whereas hydrodistilled essential oil was rich in (Z-citral (19.6%, β-caryophyllene (13.2%, (E-citral (11.2%, citronellal (10.2%, germacrene-d (8.3%, δ-3-carene (5.0%, 6-methyl-5-hepten-2-one (3.7% and citronellyl acetate (3.7%. The comparative analysis of volatile constituents of M. officinalis leaf extract using HS-SPME and hydrodistillation techniques shows both qualitative as well as quantitative differences. The current study is the first report involving rapid analysis of volatile components of M. officinalis by HS-SPME.

  1. CFD comparison with centrifugal compressor measurements on a wide operating range

    Directory of Open Access Journals (Sweden)

    Arnou D.

    2013-04-01

    Full Text Available Centrifugal compressors are widely used in industrial applications thanks to their high efficiency. They are able to provide a wide operating range before reaching the flow barrier or surge limits. Performances and range are described by compressor maps obtained experimentally. After a description of performance test rig, this article compares measured centrifugal compressor performances with computational fluid dynamics results. These computations are performed at steady conditions with R134a refrigerant as fluid. Navier-Stokes equations, coupled with k-ε turbulence model, are solved by the commercial software ANSYS-CFX by means of volume finite method. Input conditions are varied in order to calculate several speed lines. Theoretical isentropic efficiency and theoretical surge line are finally compared to experimental data.

  2. Varying the item format improved the range of measurement in patient-reported outcome measures assessing physical function.

    Science.gov (United States)

    Liegl, Gregor; Gandek, Barbara; Fischer, H Felix; Bjorner, Jakob B; Ware, John E; Rose, Matthias; Fries, James F; Nolte, Sandra

    2017-03-21

    Physical function (PF) is a core patient-reported outcome domain in clinical trials in rheumatic diseases. Frequently used PF measures have ceiling effects, leading to large sample size requirements and low sensitivity to change. In most of these instruments, the response category that indicates the highest PF level is the statement that one is able to perform a given physical activity without any limitations or difficulty. This study investigates whether using an item format with an extended response scale, allowing respondents to state that the performance of an activity is easy or very easy, increases the range of precise measurement of self-reported PF. Three five-item PF short forms were constructed from the Patient-Reported Outcomes Measurement Information System (PROMIS®) wave 1 data. All forms included the same physical activities but varied in item stem and response scale: format A ("Are you able to …"; "without any difficulty"/"unable to do"); format B ("Does your health now limit you …"; "not at all"/"cannot do"); format C ("How difficult is it for you to …"; "very easy"/"impossible"). Each short-form item was answered by 2217-2835 subjects. We evaluated unidimensionality and estimated a graded response model for the 15 short-form items and remaining 119 items of the PROMIS PF bank to compare item and test information for the short forms along the PF continuum. We then used simulated data for five groups with different PF levels to illustrate differences in scoring precision between the short forms using different item formats. Sufficient unidimensionality of all short-form items and the original PF item bank was supported. Compared to formats A and B, format C increased the range of reliable measurement by about 0.5 standard deviations on the positive side of the PF continuum of the sample, provided more item information, and was more useful in distinguishing known groups with above-average functioning. Using an item format with an extended

  3. Measurement of Shoulder Range of Motion in Patients with Adhesive Capsulitis Using a Kinect.

    Directory of Open Access Journals (Sweden)

    Seung Hak Lee

    Full Text Available Range of motion (ROM measurements are essential for the evaluation for and diagnosis of adhesive capsulitis of the shoulder (AC. However, taking these measurements using a goniometer is inconvenient and sometimes unreliable. The Kinect (Microsoft, Seattle, WA, USA is gaining attention as a new motion detecting device that is nonintrusive and easy to implement. This study aimed to apply Kinect to measure shoulder ROM in AC; we evaluated its validity by calculating the agreement of the measurements obtained using Kinect with those obtained using goniometer and assessed its utility for the diagnosis of AC. Both shoulders of 15 healthy volunteers and affected shoulders of 12 patients with AC were included in the study. The passive and active ROM of each were measured with a goniometer for flexion, abduction, and external rotation. Their active shoulder motions for each direction were again captured using Kinect and the ROM values were calculated. The agreement between the two measurements was tested with the intraclass correlation coefficient (ICC. Diagnostic performance using the Kinect ROM was evaluated with Cohen's kappa value. The cutoff values of the limited ROM were determined in the following ways: the same as passive ROM values, reflecting the mean difference, and based on receiver operating characteristic curves. The ICC for flexion/abduction/external rotation between goniometric passive ROM and the Kinect ROM were 0.906/0.942/0.911, while those between active ROMs and the Kinect ROMs were 0.864/0.932/0.925. Cohen's kappa values were 0.88, 0.88, and 1.0 with the cutoff values in the order above. Measurements of the shoulder ROM using Kinect show excellent agreement with those taken using a goniometer. These results indicate that the Kinect can be used to measure shoulder ROM and to diagnose AC as an alternative to goniometer.

  4. Validation of a photography-based goniometry method for measuring joint range of motion.

    Science.gov (United States)

    Blonna, Davide; Zarkadas, Peter C; Fitzsimmons, James S; O'Driscoll, Shawn W

    2012-01-01

    A critical component of evaluating the outcomes after surgery to restore lost elbow motion is the range of motion (ROM) of the elbow. This study examined if digital photography-based goniometry is as accurate and reliable as clinical goniometry for measuring elbow ROM. Instrument validity and reliability for photography-based goniometry were evaluated for a consecutive series of 50 elbow contractures by 4 observers with different levels of elbow experience. Goniometric ROM measurements were taken with the elbows in full extension and full flexion directly in the clinic (once) and from digital photographs (twice in a blinded random manner). Instrument validity for photography-based goniometry was extremely high (intraclass correlation coefficient: extension = 0.98, flexion = 0.96). For extension and flexion measurements by the expert surgeon, systematic error was negligible (0° and 1°, respectively). Limits of agreement were 7° (95% confidence interval [CI], 5° to 9°) and -7° (95% CI, -5° to -9°) for extension and 8° (95% CI, 6° to 10°) and -7° (95% CI, -5° to -9°) for flexion. Interobserver reliability for photography-based goniometry was better than that for clinical goniometry. The least experienced observer's photographic goniometry measurements were closer to the reference measurements than the clinical goniometry measurements. Photography-based goniometry is accurate and reliable for measuring elbow ROM. The photography-based method relied less on observer expertise than clinical goniometry. This validates an objective measure of patient outcome without requiring doctor-patient contact at a tertiary care center, where most contracture surgeries are done. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  5. Inertial sensors as measurement tools of elbow range of motion in gerontology

    Science.gov (United States)

    Sacco, G; Turpin, JM; Marteu, A; Sakarovitch, C; Teboul, B; Boscher, L; Brocker, P; Robert, P; Guerin, O

    2015-01-01

    Background and purpose Musculoskeletal system deterioration among the aging is a major reason for loss of autonomy and directly affects the quality of life of the elderly. Articular evaluation is part of physiotherapeutic assessment and helps in establishing a precise diagnosis and deciding appropriate therapy. Reference instruments are valid but not easy to use for some joints. The main goal of our study was to determine reliability and intertester reproducibility of the MP-BV, an inertial sensor (the MotionPod® [MP]) combined with specific software (BioVal [BV]), for elbow passive range-of-motion measurements in geriatrics. Methods This open, monocentric, randomized study compared inertial sensor to inclinometer in patients hospitalized in an acute, post-acute, and long-term-care gerontology unit. Results Seventy-seven patients (mean age 83.5±6.4 years, sex ratio 1.08 [male/female]) were analyzed. The MP-BV was reliable for each of the three measurements (flexion, pronation, and supination) for 24.3% (CI 95% 13.9–32.8) of the patients. Separately, the percentages of reliable measures were 59.7% (49.2–70.5) for flexion, 68.8% (58.4–79.5) for pronation, and 62.3% (51.2–73.1) for supination. The intraclass correlation coefficients were 0.15 (0.07–0.73), 0.46 (0.27–0.98), and 0.50 (0.31–40 0.98) for flexion, pronation, and supination, respectively. Conclusion This study shows the convenience of the MP-BV in terms of ease of use and of export of measured data. However, this instrument seems less reliable and valuable compared to the reference instruments used to measure elbow range of motion in gerontology. PMID:25759568

  6. Exploring the range of energy savings likely from energy efficiency retrofit measures in Ireland's residential sector

    International Nuclear Information System (INIS)

    Dineen, D.; Ó Gallachóir, B.P.

    2017-01-01

    This paper estimates the potential energy savings in the Irish residential sector by 2020 due to the introduction of an ambitious retrofit programme. We estimate the technical energy savings potential of retrofit measures targeting energy efficiency of the space and water heating end uses of the 2011 stock of residential dwellings between 2012 and 2020. We build eight separate scenarios, varying the number of dwellings retrofitted and the depth of retrofit carried out in order to investigate the range of energy savings possible. In 2020 the estimated technical savings potential lies in the range from 1713 GWh to 10,817 GWh, but is more likely to fall within the lower end of this range, i.e. between 1700 and 4360 GWh. When rebound effects are taken into account this reduces further to 1100 GWh and 2800 GWh per annum. The purpose of this paper was to test the robustness of the NEEAP target savings for residential retrofit, i.e. 3000 GWh by 2020. We conclude that this target is technically feasible but very challenging and unlikely to be achieved based on progress to date. It will require a significant shift towards deeper retrofit measures compared to what has been achieved by previous schemes. - Highlights: • Paper estimates range of energy savings likely from Irish residential retrofit. • Achieving NEEAP target savings of 3000 GWh by 2020 is feasible but very challenging. • Likely savings of 1100–2800 GWh per annum in 2020, including rebound. • NEEAP target unlikely to be achieved based on current trends.

  7. An adaptive scheme for robot localization and mapping with dynamically configurable inter-beacon range measurements.

    Science.gov (United States)

    Torres-González, Arturo; Martinez-de Dios, Jose Ramiro; Ollero, Anibal

    2014-04-25

    This work is motivated by robot-sensor network cooperation techniques where sensor nodes (beacons) are used as landmarks for range-only (RO) simultaneous localization and mapping (SLAM). This paper presents a RO-SLAM scheme that actuates over the measurement gathering process using mechanisms that dynamically modify the rate and variety of measurements that are integrated in the SLAM filter. It includes a measurement gathering module that can be configured to collect direct robot-beacon and inter-beacon measurements with different inter-beacon depth levels and at different rates. It also includes a supervision module that monitors the SLAM performance and dynamically selects the measurement gathering configuration balancing SLAM accuracy and resource consumption. The proposed scheme has been applied to an extended Kalman filter SLAM with auxiliary particle filters for beacon initialization (PF-EKF SLAM) and validated with experiments performed in the CONET Integrated Testbed. It achieved lower map and robot errors (34% and 14%, respectively) than traditional methods with a lower computational burden (16%) and similar beacon energy consumption.

  8. Apparatus intended for measuring heat capacity and heat transfer down to mK range

    International Nuclear Information System (INIS)

    Hebral, B.; Frossati, G.; Godfrin, H.; Schumacher, G.; Thoulouze, D.

    1978-01-01

    A cryogenic apparatus to perform heat capacity and heat transfer measurements in the range 1.5 mK-50 mK is described. Measurements are performed in an adiabatic demagnetization cell attached to a dilution refrigerator. Heat capacity measurements were effected on CMN-helium systems; the CMN specific heat was deduced above 1.6 mK when using liquid 3 He or a mixture 1.1% 3 He - 98.9% 4 He. A specific heat anomaly was observed with 4 He below 10 mK. It does not seen possible to interprete it by simple thermal equilibrium considerations. The superfluid 3 He heat capacity was also deduced from the results obtained with liquid 3 He under pressure. In heat transfer measurements at the interface CMN-mixture 3 He- 4 He, the temperature dependence of the thermal boundary resistance is in rather good agreement with other powder results. The measured resistances are larger than those predicted by the classical phonon process [fr

  9. Wind field reconstruction from nacelle-mounted lidar short-range measurements

    Directory of Open Access Journals (Sweden)

    A. Borraccino

    2017-05-01

    Full Text Available Profiling nacelle lidars probe the wind at several heights and several distances upstream of the rotor. The development of such lidar systems is relatively recent, and it is still unclear how to condense the lidar raw measurements into useful wind field characteristics such as speed, direction, vertical and longitudinal gradients (wind shear. In this paper, we demonstrate an innovative method to estimate wind field characteristics using nacelle lidar measurements taken within the induction zone. Model-fitting wind field reconstruction techniques are applied to nacelle lidar measurements taken at multiple distances close to the rotor, where a wind model is combined with a simple induction model. The method allows robust determination of free-stream wind characteristics. The method was applied to experimental data obtained with two different types of nacelle lidar (five-beam Demonstrator and ZephIR Dual Mode. The reconstructed wind speed was within 0.5 % of the wind speed measured with a mast-top-mounted cup anemometer at 2.5 rotor diameters upstream of the turbine. The technique described in this paper overcomes measurement range limitations of the currently available nacelle lidar technology.

  10. Linearity improvement on wide-range log signal of neutron measurement system for HANARO

    International Nuclear Information System (INIS)

    Kim, Young-Ki; Tuetken, Jeffrey S.

    1998-01-01

    This paper discusses engineering activities for improving the linearity characteristics of the Log Power signal from the neutron measurement system for HANARO. This neutron measurement system uses a fission chamber based detector which covers 10.3 decade-wide range from 10 -8 % full power(FP) up to 200%FP, The Log Power signal is designed to control the reactor at low power levels where most of the reactor physics tests are carried out. Therefore, the linearity characteristics of the Log Power signal is the major factor for accurate reactor power control. During the commissioning of the neutron measurement system, it was found that the linearity characteristics of the Log Power signal, especially near 10 -2 %FP, were not accurate enough for controlling the reactor during physics testing. Analysis of the system linearity data directly measured with reactor operating determined that the system was not operating per the design characteristics established from previous installations. The linearity data, which were taken as the reactor was increased in power, were sent to manufacturer's engineering group and a follow-up measures based on the analysis were then fed back to the field. Through step by step trouble-shooting activities, which included minor circuit modifications and alignment procedure changes, the linearity characteristics have been successfully improved and now exceed minimum performance requirements. This paper discusses the trouble-shooting techniques applied, the changes in the linearity characteristics, special circumstances in the HANARO application and the final resolution. (author)

  11. Feasibility of RACT for 3D dose measurement and range verification in a water phantom

    Energy Technology Data Exchange (ETDEWEB)

    Alsanea, Fahed [School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907-2051 (United States); Moskvin, Vadim [Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, Indiana 46202-5289 (United States); Stantz, Keith M., E-mail: kstantz@purdue.edu [School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907-2051 and Radiology and Imaging Sciences, Indiana University School of Medicine, 950 West Walnut Street, Indianapolis, Indiana 46202-5289 (United States)

    2015-02-15

    Purpose: The objective of this study is to establish the feasibility of using radiation-induced acoustics to measure the range and Bragg peak dose from a pulsed proton beam. Simulation studies implementing a prototype scanner design based on computed tomographic methods were performed to investigate the sensitivity to proton range and integral dose. Methods: Derived from thermodynamic wave equation, the pressure signals generated from the dose deposited from a pulsed proton beam with a 1 cm lateral beam width and a range of 16, 20, and 27 cm in water using Monte Carlo methods were simulated. The resulting dosimetric images were reconstructed implementing a 3D filtered backprojection algorithm and the pressure signals acquired from a 71-transducer array with a cylindrical geometry (30 × 40 cm) rotated over 2π about its central axis. Dependencies on the detector bandwidth and proton beam pulse width were performed, after which, different noise levels were added to the detector signals (using 1 μs pulse width and a 0.5 MHz cutoff frequency/hydrophone) to investigate the statistical and systematic errors in the proton range (at 20 cm) and Bragg peak dose (of 1 cGy). Results: The reconstructed radioacoustic computed tomographic image intensity was shown to be linearly correlated to the dose within the Bragg peak. And, based on noise dependent studies, a detector sensitivity of 38 mPa was necessary to determine the proton range to within 1.0 mm (full-width at half-maximum) (systematic error < 150 μm) for a 1 cGy Bragg peak dose, where the integral dose within the Bragg peak was measured to within 2%. For existing hydrophone detector sensitivities, a Bragg peak dose of 1.6 cGy is possible. Conclusions: This study demonstrates that computed tomographic scanner based on ionizing radiation-induced acoustics can be used to verify dose distribution and proton range with centi-Gray sensitivity. Realizing this technology into the clinic has the potential to significantly

  12. Prediction of Partition Coefficients of Organic Compounds for SPME/PDMS

    Directory of Open Access Journals (Sweden)

    Liao Hsuan-Yu

    2016-01-01

    Full Text Available The partition coefficients of 51 organic compounds between SPME/PDMS and gas were compiled from the literature sources in this study. The effect of physicochemical properties and descriptors on the partitioning process of partition coefficients was explicated by the correlation analysis. The PDMS-gas partition coefficients were well correlated to the molecular weight of organic compounds (r = 0.832, p < 0.05. An empirical model, consisting of the molecular weight and the polarizability, was developed to appropriately predict the partition coefficients of organic compounds. The empirical model for estimating the PDMS-gas partition coefficient will contribute to the practical applications of the SPME technique.

  13. Analysis and suppression of reflections in far-field antenna measurement ranges

    OpenAIRE

    Sierra Castañer, Manuel; Cano Facila, Francisco Jose; Foged, Lars Jacob; Saccardi, Francesco; Nader Kawassaki, Guilherme; Raimundi, Lucas dos Reis; Vilela Rezende, Stefano Albino

    2013-01-01

    This paper presents the analysis of the reflections in two kind of spherical far field ranges: one if the classical acquisition where the AUT is rotated and the second one corresponds to the systems where the AUT is fixed and the antenna probe is rotated. In large far field systems this is not possible, but this can be used to the measurement of small antennas, for instance, with the SATIMO StarGate system. In both cases, it is assumed that only one frequency is acquired and the results shoul...

  14. Skin perfusion measurement: the normal range, the effects of ambient temperature and its clinical application

    International Nuclear Information System (INIS)

    Henry, R.E.; Malone, J.M.; Daly, M.J.; Hughes, J.H.; Moore, W.S.

    1982-01-01

    Quantitation of skin perfusion provides objective criteria to determine the optimal amputation level in ischemic limb disease, to assess the maturation of pedicle flaps in reconstructive surgery, and to select appropriate treatment for chronic skin ulcers. A technique for measurement of skin perfusion using intradermal (ID) Xe-133 and a gamma camera/minicomputer system was previously reported. An update of this procedure is now reported, the normal range for the lower extremity in men, observations on the effects of ambient temperature, and an experience using the procedure to determine amputation level

  15. Measurement based scenario analysis of short-range distribution system planning

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Bak-Jensen, Birgitte; Chen, Zhe

    2009-01-01

    This paper focuses on short-range distribution system planning using a probabilistic approach. Empirical probabilistic distributions of load demand and distributed generations are derived from the historical measurement data and incorporated into the system planning. Simulations with various...... feasible scenarios are performed based on a local distribution system at Støvring in Denmark. Simulation results provide more accurate and insightful information for the decision-maker when using the probabilistic analysis than using the worst-case analysis, so that a better planning can be achieved....

  16. Human-Induced Effects on RSS Ranging Measurements for Cooperative Positioning

    DEFF Research Database (Denmark)

    Della Rosa, Francescantonio; Pelosi, Mauro; Nurmi, Jari

    2012-01-01

    of human-induced perturbations for enhancing the final positioning accuracy through cooperative schemes has been assessed. It has been proved that the effect of cooperation is very limited if human factors are not taken into account when performing experimental activities.......We present experimental evaluations of human-induced perturbations on received-signal-strength-(RSS-) based ranging measurements for cooperative mobile positioning. To the best of our knowledge, this work is the first attempt to gain insight and understand the impact of both body loss and hand grip...... on the RSS for enhancing proximity measurements among neighbouring devices in cooperative scenarios. Our main contribution is represented by experimental investigations. Analysis of the errors introduced in the distance estimation using path-loss-based methods has been carried out. Moreover, the exploitation...

  17. Measurement of the cosmic optical background using the long range reconnaissance imager on New Horizons.

    Science.gov (United States)

    Zemcov, Michael; Immel, Poppy; Nguyen, Chi; Cooray, Asantha; Lisse, Carey M; Poppe, Andrew R

    2017-04-11

    The cosmic optical background is an important observable that constrains energy production in stars and more exotic physical processes in the universe, and provides a crucial cosmological benchmark against which to judge theories of structure formation. Measurement of the absolute brightness of this background is complicated by local foregrounds like the Earth's atmosphere and sunlight reflected from local interplanetary dust, and large discrepancies in the inferred brightness of the optical background have resulted. Observations from probes far from the Earth are not affected by these bright foregrounds. Here we analyse the data from the Long Range Reconnaissance Imager (LORRI) instrument on NASA's New Horizons mission acquired during cruise phase outside the orbit of Jupiter, and find a statistical upper limit on the optical background's brightness similar to the integrated light from galaxies. We conclude that a carefully performed survey with LORRI could yield uncertainties comparable to those from galaxy counting measurements.

  18. Measure of the albedo of a warm plasma in the XUV range

    Science.gov (United States)

    Busquet, Michel; Thais, Frederic; Geoffroy, Ghita; Raffestin, Didier

    2009-11-01

    It has been shown in a recent experience at PALS [1] that the radiative precursor celerity in front of a strong radiative shock is sensitive to the lateral radiative losses, thus to the albedo of the wall of a ``radiative shock tube.'' In the experiment presented here, we measure the albedo of various materials (Al, Cu, Au) heated by a Xenon gaz at temperature around 30 eV. The Xenon gas was heated by the ALISE laser in CESTA in Bordeaux (France). The emission of Xenon with and without the reflecting samples is measured with a spatially resolving XUV spectrograph in the 30-250 eV range. [4pt] [1] M. Busquet et al, HEDP 3, 8 (2007)

  19. A compact design for monochromatic OSL measurements in the wavelength range 380-1020 NM

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Poolton, N.R.J.; Willumsen, F.

    1994-01-01

    automated Riso TL/OSL dating apparatus, thus allowing for either routine scanning or more detailed thermo-optical investigations. The high throughput efficiency of the unit means that the existing 75 W tungsten-halogen lamp can be directly used for such measurements on both quartz and feldspar samples......The development and performance of a compact module is described that allows for the monochromatic illumination of samples in the wavelength range 380-1020 nm, enabling the measurement of energy-resolved optically stimulated luminescence. The unit is designed to couple directly to the existing....... The design allows for rapid spectral scanning with a choice of resolution of anywhere between 10 and 80 nm: stray light levels are less than 0.01%. The unit can equally be used for recording wavelength-resolved emission spectra, whether photo-excited or thermally stimulated; the capabilities of the system...

  20. Photopolarimetric properties of leaf and vegetation covers over a wide range of measurement directions

    Science.gov (United States)

    Sun, Zhongqiu; Peng, Zhiyan; Wu, Di; Lv, Yunfeng

    2018-02-01

    The optical scattering property of the target is the essential signal for passive remote sensing applications. To deepen our understanding of the light reflected from vegetation, we present results of photopolarimetric laboratory measurements from single leaf and two vegetation covers (planophile and erectophile) over a wide range of viewing directions. The bidirectional polarized reflectance factor (BPRF) was used to characterize the polarization property of our samples. We observed positive and negative polarization (-BPRFQ) of all samples in the forward scattering and backward scattering directions, respectively. Based on the comparison of the BPRF among single leaf, planophile vegetation and erectophile vegetation, our measurements demonstrate that the orientation of the leaf is a key factor in describing the amount of polarization in the forward scattering direction. Our measurements also validated certain model results stating that (1) specular reflection generates a portion of polarization in the forward scattering direction and diffuses scattering of polarized light in all hemisphere directions, (2) BPRFU is anti-symmetric in the principal plane from a recent study in which the authors simulated the polarized reflectance of vegetation cover using the vector radiative transfer theory. These photopolarimetric measurement results, which can be completely explained by the theoretical results, are useful in remote sensing applications to vegetation.

  1. Long-range active retroreflector to measure the rotational orientation in conjunction with a laser tracker

    Science.gov (United States)

    Hofherr, O.; Wachten, Christian; Müller, C.; Reinecke, H.

    2014-11-01

    High precision optical non-contact position measurement is a key technology in modern engineering. Laser trackers (LT) accurately determine x-y-z coordinates of passive retroreflectors. Next-generation systems answer the need to measure an object`s rotational orientation (pitch, yaw, roll). So far, these devices are based either on photogrammetry or on enhanced retroreflectors. Here we present a new method to measure all six degrees of freedom in conjunction with a LT. The basic principle is to analyze the orientation to the LT's beam path by coupling-out laser radiation. The optical design is inspired by a cat's eye retroreflector equipped with an integrated beam splitter layer. The optical spherical aberration is compensated, which reduces the divergence angle for the reflected beam by one order of magnitude compared to an uncompensated standard system of the same size. The wave front distortion is reduced to less than 0.1 λ @ 633 nm for beam diameters up to 8 mm. Our active retroreflector is suitable for long-range measurements for a distance > 10 m.

  2. A straightforward method for measuring the range of apparent density of microplastics.

    Science.gov (United States)

    Li, Lingyun; Li, Mengmeng; Deng, Hua; Cai, Li; Cai, Huiwen; Yan, Beizhan; Hu, Jun; Shi, Huahong

    2018-10-15

    Density of microplastics has been regarded as the primary property that affect the distribution and bioavailability of microplastics in the water column. For measuring the density of microplastis, we developed a simple and rapid method based on density gradient solutions. In this study, we tested four solvents to make the density gradient solutions, i.e., ethanol (0.8 g/cm 3 ), ultrapure water (1.0 g/cm 3 ), saturated NaI (1.8 g/cm 3 ) and ZnCl 2 (1.8 g/cm 3 ). Density of microplastics was measured via observing the float or sink status in the density gradient solutions. We found that density gradient solutions made from ZnCl 2 had a larger uncertainty in measuring density than that from NaI, most likely due to a higher surface tension of ZnCl 2 solution. Solutions made from ethanol, ultrapure water, and NaI showed consistent density results with listed densities of commercial products, indicating that these density gradient solutions were suitable for measuring microplastics with a density range of 0.8-1.8 g/cm 3 . Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Application of a vortex shedding flowmeter to the wide range measurement of high temperature gas flow

    International Nuclear Information System (INIS)

    Baker, S.P.; Ennis, R.M. Jr.; Herndon, P.G.

    1981-01-01

    A single flowmeter was required for helium gas measurement in a Gas Cooled Fast Breeder Reactor loss of coolant simulator. Volumetric flow accuracy of +-1.0% of reading was required over the Reynolds Number range 6 x 10 3 to 1 x 10 6 at flowing pressures from 0.2 to 9 MPa (29 to 1305 psia) at 350 0 C (660 0 F) flowing temperature. Because of its inherent accuracy and rangeability, a vortex shedding flowmeter was selected and specially modified to provide for a remoted thermal sensor. Experiments were conducted to determine the relationship between signal attenuation and sensor remoting geometry, as well as the relationship between gas flow parameters and remoted thermal sensor signal for both compressed air and helium gas. Based upon the results of these experiments, the sensor remoting geometry was optimized for this application. The resultant volumetric flow rangeability was 155:1. The associated temperature increase at the sensor position was 9 0 C above ambient (25 0 F) at a flowing temperature of 350 0 C. The volumetric flow accuracy was measured over the entire 155:1 flow range at parametric values of flowing density. A volumetric flow accuracy of +- % of reading was demonstrated

  4. Density Measurements of Waste Cooking Oil Biodiesel and Diesel Blends Over Extended Pressure and Temperature Ranges

    Directory of Open Access Journals (Sweden)

    Thanh Xuan NguyenThi

    2018-05-01

    Full Text Available Density and compressibility are primordial parameters for the optimization of diesel engine operation. With this objective, these properties were reported for waste cooking oil biodiesel and its blends (5% and 10% by volume mixed with diesel. The density measurements were performed over expanded ranges of pressure (0.1 to 140 MPa and temperature (293.15 to 353.15 K compatible with engine applications. The isothermal compressibility was estimated within the same experimental range by density differentiation. The Fatty Acid Methyl Esters (FAMEs profile of the biodiesel was determined using a Gas Chromatography–Mass Spectrometry (GC-MS technique. The storage stability of the biodiesel was assessed in terms of the reproducibility of the measured properties. The transferability of this biodiesel fuel was discussed on the basis of the standards specifications that support their use in fuel engines. Additionally, this original set of data represents meaningful information to develop new approaches or to evaluate the predictive capability of models previously developed.

  5. Measuring sensitivity in pharmacoeconomic studies. Refining point sensitivity and range sensitivity by incorporating probability distributions.

    Science.gov (United States)

    Nuijten, M J

    1999-07-01

    The aim of the present study is to describe a refinement of a previously presented method, based on the concept of point sensitivity, to deal with uncertainty in economic studies. The original method was refined by the incorporation of probability distributions which allow a more accurate assessment of the level of uncertainty in the model. In addition, a bootstrap method was used to create a probability distribution for a fixed input variable based on a limited number of data points. The original method was limited in that the sensitivity measurement was based on a uniform distribution of the variables and that the overall sensitivity measure was based on a subjectively chosen range which excludes the impact of values outside the range on the overall sensitivity. The concepts of the refined method were illustrated using a Markov model of depression. The application of the refined method substantially changed the ranking of the most sensitive variables compared with the original method. The response rate became the most sensitive variable instead of the 'per diem' for hospitalisation. The refinement of the original method yields sensitivity outcomes, which greater reflect the real uncertainty in economic studies.

  6. A rapid screening procedure for the analysis of proliferation compounds in complex matrices using solid phase microextraction (SPME) and SPME with in-situ derivatization

    International Nuclear Information System (INIS)

    Alcaraz, A.; Hulsey, S.S.; Andresen, B.D.

    1995-01-01

    A variety of methods have been established using advanced chromatographic techniques and new detection systems for the analysis of chemical signatures associated with nuclear and chemical weapon (CW) proliferation. Most of these analytical methods are used in the laboratory and seldom applied in the field. The Chemical Weapons Convention (an international treaty to ban chemical weapons) may require the rapid on-site analysis of environmental samples which contain CW agents, their precursors, and/or their degradation products. In addition to the fact that certain countries are involved in CW non-compliance, there is a current uncertainty regarding nuclear proliferation. This also creates new demands on sample work-up and analytical instrumentation use in the field. The isolation and identification of unique chemical signatures in complex samples such as soils, waste tanks, and decontamination solutions would determine non-compliance. However, a primary area of detection research continues to be sample preparation. Most of the established sample cleanup technologies involve liquid/liquid, Soxhlet, or most recently, solid phase extraction (SPE). Despite the success of these traditional sample preparation techniques, they are time consuming and require multi-step procedures (especially when preparing samples for gas chromatographic mass-spectrometric analysis). The goal of this work is to demonstrate the advantages of utilizing SPME and SPME in-situ derivatization techniques to eliminate time consuming steps necessary to prepare a sample for on-site GC-MS. The authors' approach was to compare two SPME fibers and to develop methods to facilitate the isolation of polar and moderately polar proliferation compounds from complex environmental samples. This work will help to evaluate current SPME technologies for use during on-site environmental monitoring analysis

  7. Measurement of peak impact loads differ between accelerometers - Effects of system operating range and sampling rate.

    Science.gov (United States)

    Ziebart, Christina; Giangregorio, Lora M; Gibbs, Jenna C; Levine, Iris C; Tung, James; Laing, Andrew C

    2017-06-14

    A wide variety of accelerometer systems, with differing sensor characteristics, are used to detect impact loading during physical activities. The study examined the effects of system characteristics on measured peak impact loading during a variety of activities by comparing outputs from three separate accelerometer systems, and by assessing the influence of simulated reductions in operating range and sampling rate. Twelve healthy young adults performed seven tasks (vertical jump, box drop, heel drop, and bilateral single leg and lateral jumps) while simultaneously wearing three tri-axial accelerometers including a criterion standard laboratory-grade unit (Endevco 7267A) and two systems primarily used for activity-monitoring (ActiGraph GT3X+, GCDC X6-2mini). Peak acceleration (gmax) was compared across accelerometers, and errors resulting from down-sampling (from 640 to 100Hz) and range-limiting (to ±6g) the criterion standard output were characterized. The Actigraph activity-monitoring accelerometer underestimated gmax by an average of 30.2%; underestimation by the X6-2mini was not significant. Underestimation error was greater for tasks with greater impact magnitudes. gmax was underestimated when the criterion standard signal was down-sampled (by an average of 11%), range limited (by 11%), and by combined down-sampling and range-limiting (by 18%). These effects explained 89% of the variance in gmax error for the Actigraph system. This study illustrates that both the type and intensity of activity should be considered when selecting an accelerometer for characterizing impact events. In addition, caution may be warranted when comparing impact magnitudes from studies that use different accelerometers, and when comparing accelerometer outputs to osteogenic impact thresholds proposed in literature. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  8. An Innovative Rapid Method for Analysis of 10 Organophosphorus Pesticide Residues in Wheat by HS-SPME-GC-FPD/MSD.

    Science.gov (United States)

    Du, Xin; Ren, YongLin; Beckett, Stephen J

    2016-01-01

    The rapid detection of pesticide residues in wheat has become a top food security priority. A solvent-free headspace solid-phase microextraction (HS-SPME) has been evaluated for rapid screening of organophosphorus pesticide (OPP) residues in wheat with high sensitivity. Individual wheat samples (1.7 g), spiked with 10 OPPs, were placed in a 4 mL sealed amber glass vial and heated at 60°C for 45 min. During this time, the OPP residues were extracted with a 50 μm/30 μm divinylbenzene (DVB)/carboxen (CAR)/plasma desorption mass spectroscopy polydimethylsiloxane (PDMS) fiber from the headspace above the sample. The fiber was then removed and injected into the GC injection port at 250°C for desorption of the extracted chemicals. The multiple residues were identified by a GC mass spectrometer detector (GC-MSD) and quantified with a GC flame photometric detector (GC-FPD). Seven spiked levels of 10 OPPs on wheat were analyzed. The GC responses for a 50 μm/30 μm DVB/CAR/PDMS fiber increased with increasing spiking levels, yielding significant (R(2) > 0.98) linear regressions. The lowest LODs of the multiple pesticide standards were evaluated under the conditions of the validation study in a range of levels from 0 (control) to 100 ng of pesticide residue per g of wheat that separated on a low-polar GC capillary column (Agilent DB-35UI). The results of the HS-SPME method were compared with the QuEChERS AOAC 2007.01 method and they showed several advantages over the latter. These included improved sensitivity, selectivity, and simplicity.

  9. A screening method for polycyclic aromatic hydrocarbons determination in water by headspace SPME with GC-FID

    Energy Technology Data Exchange (ETDEWEB)

    Zuazagoitia, D.; Millan, E.; Garcia, R. [Univ. of Pais Vasco, Donostia-San Sebastian (Spain). Dept. of Applied Chemistry

    2007-11-15

    A simple method for determination of polycyclic aromatic hydrocarbons (PAHs) in water using headspace solid-phase microextraction (HS-SPME) with gas chromatography-flame ionisation detector (GC-FID) was developed. In order to obtain the convenient experimental conditions for HS-SPME extraction an experimental design with two steps was accomplished. A 2{sup 6-2} fractional factorial design and central composite design (CCD) considering three significant factors were used. Naphthalene, anthracene and fluoranthene were chosen as representatives of two, three and four aromatic rings, and the global response of three PAHs was used for the results, evaluation. The chosen extraction conditions were: 85 {mu}m polyacrylate fibre; 50 C temperature; 60 min time; 20 mL-dissolution volume (in 40 mL glass vial); without salt addition; and 2 min desorption time. The procedure was extended to other seven PAHs (acenaphthylene, acenaphthene, fluorene, phenanthrene, pyrene, chrysene and benzo(a)anthracene) and the analytical characteristics were checked. The limit of detection (LOD) was from 0.08 (anthracene) to 0.20 {mu}g L{sup -1} (naphthalene). The precision expressed as relative standard deviation (RSD in %) using 50 {mu}g L{sup -1} of each analyte ranged from 6.8 to 17 %. The method was applied to the analysis of the surface waters and leaching waters of contaminated soils from Gipuzkoa (North Spain). The PAHs were not detected in surface water samples. Most of the PAHs were found in the leachates from contaminated soils showing a maximum global value of 75.5 {mu}g L{sup -1}. (orig.)

  10. At Home Photography-Based Method for Measuring Wrist Range of Motion.

    Science.gov (United States)

    Trehan, Samir K; Rancy, Schneider K; Johnsen, Parker H; Hillstrom, Howard J; Lee, Steve K; Wolfe, Scott W

    2017-11-01

    Purpose  To determine the reliability of wrist range of motion (WROM) measurements based on digital photographs taken by patients at home compared with traditional measurements done in the office with a goniometer. Methods  Sixty-nine postoperative patients were enrolled in this study at least 3 months postoperatively. Active and passive wrist flexion/extension and radial/ulnar deviation were recorded by one of the two attending surgeons with a 1-degree resolution goniometer at the last postoperative office visit. Patients were provided an illustrated instruction sheet detailing how to take digital photographic images at home in six wrist positions (active and passive flexion/extension, and radial/ulnar deviation). Wrist position was measured from digital images by both the attending surgeons in a randomized, blinded fashion on two separate occasions greater than 2 weeks apart using the same goniometer. Reliability analysis was performed using the intraclass correlation coefficient to assess agreement between clinical and photography-based goniometry, as well as intra- and interobserver agreement. Results  Out of 69 enrolled patients, 30 (43%) patients sent digital images. Of the 180 digital photographs, only 9 (5%) were missing or deemed inadequate for WROM measurements. Agreement between clinical and photography-based measurements was "almost perfect" for passive wrist flexion/extension and "substantial" for active wrist flexion/extension and radial/ulnar deviation. Inter- and intraobserver agreement for the attending surgeons was "almost perfect" for all measurements. Discussion  This study validates a photography-based goniometry protocol allowing accurate and reliable WROM measurements without direct physician contact. Passive WROM was more accurately measured from photographs than active WROM. This study builds on previous photography-based goniometry literature by validating a protocol in which patients or their families take and submit their own

  11. Accelerated ice-sheet mass loss in Antarctica from 18-year satellite laser ranging measurements

    Directory of Open Access Journals (Sweden)

    Shuanggen Jin

    2016-02-01

    Full Text Available Accurate estimate of the ice-sheet mass balance in Antarctic is very difficult due to complex ice sheet condition and sparse in situ measurements. In this paper, the low-degree gravity field coefficients of up to degree and order 5 derived from Satellite Laser Ranging (SLR measurements are used to determine the ice mass variations in Antarctica for the period 1993–2011. Results show that the ice mass is losing with -36±13 Gt/y in Antarctica, -42±11 Gt/y in the West Antarctica and 6±10 Gt/y in the East Antarctica from 1993 to 2011. The ice mass variations from the SLR 5×5 have a good agreement with the GRACE 5×5, GRACE 5×5 (1&2 and GRACE (60×60 for the entire continent since 2003, but degree 5 from SLR is not sufficient to quantify ice losses in West and East Antarctica, respectively. The rate of ice loss in Antarctica is -28±17 Gt/y for 1993-2002 and -55±17 Gt/y for 2003-2011, indicating significant accelerated ice mass losses since 2003. Furthermore, the results from SLR are comparable with GRACE measurements.

  12. Realization of High Dynamic Range Imaging in the GLORIA Network and Its Effect on Astronomical Measurement

    Directory of Open Access Journals (Sweden)

    Stanislav Vítek

    2016-01-01

    Full Text Available Citizen science project GLORIA (GLObal Robotic-telescopes Intelligent Array is a first free- and open-access network of robotic telescopes in the world. It provides a web-based environment where users can do research in astronomy by observing with robotic telescopes and/or by analyzing data that other users have acquired with GLORIA or from other free-access databases. Network of 17 telescopes allows users to control selected telescopes in real time or schedule any more demanding observation. This paper deals with new opportunity that GLORIA project provides to teachers and students of various levels of education. At the moment, there are prepared educational materials related to events like Sun eclipse (measuring local atmosphere changes, Aurora Borealis (calculation of Northern Lights height, or transit of Venus (measurement of the Earth-Sun distance. Student should be able to learn principles of CCD imaging, spectral analysis, basic calibration like dark frames subtraction, or advanced methods of noise suppression. Every user of the network can design his own experiment. We propose advanced experiment aimed at obtaining astronomical image data with high dynamic range. We also introduce methods of objective image quality evaluation in order to discover how HDR methods are affecting astronomical measurements.

  13. An absolute measurement of 252Cf prompt fission neutron spectrum at low energy range

    International Nuclear Information System (INIS)

    Lajtai, A.; Dyachenko, P.P.; Kutzaeva, L.S.; Kononov, V.N.; Androsenko, P.A.; Androsenko, A.A.

    1983-01-01

    Prompt neutron energy spectrum at low energies (25 keV 252 Cf spontaneous fission has been measured with a time-of-flight technique on a 30 cm flight-path. Ionization chamber and lithium-glass were used as fission fragment and neutron detectors, respectively. Lithium glasses of NE-912 (containing 6 Li) and of NE-913 (containing 7 Li) 45 mm in diameter and 9.5 mm in thickness have been employed alternatively, for the registration of fission neutrons and gammas. For the correct determination of the multiscattering effects - the main difficulty of the low energy neutron spectrum measurements - a special geometry for the neutron detector was used. Special attention was paid also to the determination of the absolute efficiency of the neutron detector. The real response function of the spectrometer was determined by a Monte-Carlo calculation. The scattering material content of the ionization chamber containing a 252 Cf source was minimized. As a result of this measurement a prompt fission neutron spectrum of Maxwell type with a T=1.42 MeV parameter was obtained at this low energy range. We did not find any neutron excess or irregularities over the Maxwellian. (author)

  14. Measurements of long-range enhanced collisional velocity drag through plasma wave damping

    Science.gov (United States)

    Affolter, M.; Anderegg, F.; Dubin, D. H. E.; Driscoll, C. F.

    2018-05-01

    We present damping measurements of axial plasma waves in magnetized, multispecies ion plasmas. At high temperatures T ≳ 10-2 eV, collisionless Landau damping dominates, whereas, at lower temperatures T ≲ 10-2 eV, the damping arises from interspecies collisional drag, which is dependent on the plasma composition and scales roughly as T-3 /2 . This drag damping is proportional to the rate of parallel collisional slowing, and is found to exceed classical predictions of collisional drag damping by as much as an order of magnitude, but agrees with a new collision theory that includes long-range collisions. Centrifugal mass separation and collisional locking of the species occur at ultra-low temperatures T ≲ 10-3 eV, which reduce the drag damping from the T-3 /2 collisional scaling. These mechanisms are investigated by measuring the damping of higher frequency axial modes, and by measuring the damping in plasmas with a non-equilibrium species profile.

  15. Measurement of the extreme ankle range of motion required by female ballet dancers.

    Science.gov (United States)

    Russell, Jeffrey A; Kruse, David W; Nevill, Alan M; Koutedakis, Yiannis; Wyon, Matthew A

    2010-12-01

    Female ballet dancers require extreme ankle motion, especially plantar flexion, but research about measuring such motion is lacking. The purposes of this study were to determine in a sample of ballet dancers whether non-weight-bearing ankle range of motion is significantly different from the weight-bearing equivalent and whether inclinometric plantar flexion measurement is a suitable substitute for standard plantar flexion goniometry. Fifteen female ballet dancers (5 university, 5 vocational, and 5 professional dancers; age 21 ± 3.0 years) volunteered. Subjects received 5 assessments on 1 ankle: non-weight-bearing goniometry dorsiflexion (NDF) and plantar flexion (NPF), weight-bearing goniometry in the ballet positions demi-plié (WDF) and en pointe (WPF), and non-weight-bearing plantar flexion inclinometry (IPF). Mean NDF was significantly lower than WDF (17° ± 1.3° vs 30° ± 1.8°, P ballet proficiency. The authors conclude that assessment of extreme ankle motion in female ballet dancers is challenging, and goniometry and inclinometry appear to measure plantar flexion differently.

  16. Gamma compensated pulsed ionization chamber wide range neutron/reactor power measurement system

    International Nuclear Information System (INIS)

    Ellis, W.H.

    1975-01-01

    An improved method and system of pulsed mode operation of ionization chambers is described in which a single sensor system with gamma compensation is provided by sampling, squaring, automatic gate selector, and differential amplifier circuit means, employed in relation to chambers sensitized to neutron plus gamma and gamma only to subtract out the gamma component, wherein squaring functions circuits, a supplemental high performance pulse rate system, and operational and display mode selection and sampling gate circuits are utilized to provide automatic wide range linear measurement capability for neutron flux and reactor power. Neon is employed as an additive in the ionization chambers to provide independence of ionized gas kinetics temperature effects, and the pulsed mode of operation provide independence of high temperature insulator leakage effects. (auth)

  17. Using SPME fibers and Tenax to predict the bioavailability of pyrethroids and chlorpyrifos in field sediments

    International Nuclear Information System (INIS)

    Harwood, Amanda D.; Landrum, Peter F.; Weston, Donald P.; Lydy, Michael J.

    2013-01-01

    The presence of pyrethroids in both urban and agricultural sediments at levels lethal to invertebrates has been well documented. However, variations in bioavailability among sediments make accurate predictions of toxicity based on whole sediment concentrations difficult. A proposed solution to this problem is the use of bioavailability-based estimates, such as solid phase microextraction (SPME) fibers and Tenax beads. This study compared three methods to assess the bioavailability and ultimately toxicity of pyrethroid pesticides including field-deployed SPME fibers, laboratory-exposed SPME fibers, and a 24-h Tenax extraction. The objective of the current study was to compare the ability of these methods to quantify the bioavailable fraction of pyrethroids in contaminated field sediments that were toxic to benthic invertebrates. In general, Tenax proved a more sensitive method than SPME fibers and a correlation between Tenax extractable concentrations and mortality was observed. - Highlights: ► Can use bioavailability-based methods for pyrethroids in sediments. ► Tenax was a more sensitive technique. ► Tenax extractable concentrations relate to invertebrate mortality. - This research provides an important first step in using bioavailability-based techniques for estimating the bioavailability and toxicity of hydrophobic pesticides in field sediments.

  18. SPME as a tool in WEA - CONCAWE Contribution to OSPAR Demonstration Project 2005 - 2006

    NARCIS (Netherlands)

    Leslie, H.A.

    2006-01-01

    This document represents a compilation of various data and deliverables from the study programme. An executive summary is followed by the presentation of data generated in an interlaboratory study of effluents assessed using both EGOM-LLE and biomimetic SPME methods.

  19. Development of a GC-MS-SPME Method for the Determination of Amines in Meteorites

    Science.gov (United States)

    Hilts, R. W.; Skelhorne, A. W.; Simkus, D.; Herd, C. D. K.

    2016-08-01

    A GC-MS-SPME analytical method for the direct determination of amines in aqueous solution has been developed. The key step in the procedure is the conversion of the amines into their non-volatile ammonium salts by protonation with HCl.

  20. SDE and SPME Analysis of Flavor Compounds in Jin Xuan Oolong Tea.

    Science.gov (United States)

    Sheibani, Ershad; Duncan, Susan E; Kuhn, David D; Dietrich, Andrea M; O'Keefe, Sean F

    2016-02-01

    Simultaneous distillation-extraction (SDE) and solid phase micro extraction (SPME) are procedures used for the isolation of flavor compounds in foods. The purpose of this study was to optimize SDE conditions (solvent and time) and to compare SDE with SPME for the isolation of flavor compounds in Jin Xuan oolong tea using GC-MS and GC-O. The concentration of volatile compounds isolated with diethyl ether was higher (P < 0.05) than for dichloromethane and concentration was higher at 40 min (P < 0.05) than 20 or 60 min extractions. For SDE, 128 volatiles were identified using GC-MS and 45 aroma active compounds using GC-O. Trans-nerolidol was the most abundant compound in oolong tea. The number of volatiles identified using GC-MS was lower in SPME than SDE. For SPME, 59 volatiles and 41 aroma active compounds were identified. The composition of the volatiles isolated by the 2 methods differed considerably but provided complementary information. © 2016 Institute of Food Technologists®

  1. Dynamic speciation analysis of atrazine in aqueous latex nanoparticle dispersions using solid phase microextraction (SPME)

    NARCIS (Netherlands)

    Benhabib, K.; Town, R.M.; Leeuwen, van H.P.

    2009-01-01

    Solid phase microextraction (SPME) is applied in the dynamic speciation analysis of the pesticide atrazine in an aqueous medium containing sorbing latex nanoparticles. It is found that the overall rate of extraction of the analyte is faster than in the absence of nanoparticles and governed by the

  2. High Resolution and Large Dynamic Range Resonant Pressure Sensor Based on Q-Factor Measurement

    Science.gov (United States)

    Gutierrez, Roman C. (Inventor); Stell, Christopher B. (Inventor); Tang, Tony K. (Inventor); Vorperian, Vatche (Inventor); Wilcox, Jaroslava (Inventor); Shcheglov, Kirill (Inventor); Kaiser, William J. (Inventor)

    2000-01-01

    A pressure sensor has a high degree of accuracy over a wide range of pressures. Using a pressure sensor relying upon resonant oscillations to determine pressure, a driving circuit drives such a pressure sensor at resonance and tracks resonant frequency and amplitude shifts with changes in pressure. Pressure changes affect the Q-factor of the resonating portion of the pressure sensor. Such Q-factor changes are detected by the driving/sensing circuit which in turn tracks the changes in resonant frequency to maintain the pressure sensor at resonance. Changes in the Q-factor are reflected in changes of amplitude of the resonating pressure sensor. In response, upon sensing the changes in the amplitude, the driving circuit changes the force or strength of the electrostatic driving signal to maintain the resonator at constant amplitude. The amplitude of the driving signals become a direct measure of the changes in pressure as the operating characteristics of the resonator give rise to a linear response curve for the amplitude of the driving signal. Pressure change resolution is on the order of 10(exp -6) torr over a range spanning from 7,600 torr to 10(exp -6) torr. No temperature compensation for the pressure sensor of the present invention is foreseen. Power requirements for the pressure sensor are generally minimal due to the low-loss mechanical design of the resonating pressure sensor and the simple control electronics.

  3. 2D fluorescence spectra measurement of six kinds of bioagents simulants by short range Lidar

    Science.gov (United States)

    Sanpedro, Man

    2018-02-01

    Pantoea agglomerans (Pan), Staphylococcus aureus (Sta), Bacillus globigii (BG) and Escherichia coli (EH), these four kinds of bioagents simulants of were cultured and then their growth curves were measured, the generation time was 0.99h, 0.835h, 1.07h and 1.909h, respectively. A small short range fluorescence lidar working at wavelengths of 266nm and 355nm was designed and used to measure the two-dimensional fluorescence spectra of bioagents simulants in the amino acid segment and NADH segment, respectively. In a controllable fluorescence measurement chamber, the two-dimensional fluorescence spectra of vegetative liquid bacterial aerosols as well as BSA and OVA, two protein toxinic simulants were measured with a resolution of 4nm. The two-dimensional fluorescence spectral shape of Pan, Sta, EH and BG, BSA and OVA were consistent with the standard fluorescent component tryptophan in the amino acid band with FWHM of 60nm, but the central wavelength of the fluorescence spectra of these simulants blue/purple shifted obviously as affected by the external biochemical environment, concentration and ratio of different bacterial internal fluorophores, so the energy level between the excited state and the ground state of the fluorescence molecule increased. Differently, weak NADH fluorescence spectra with 100nm FWHM inside the four vegetative bacteria aerosols were detected, but Rayleigh scattering, Raman scattering contribution of water, nitrogen in the fluorescence spectra could not be effectively extracted. The second - order derivative fluorescence spectra of four simulants showed that the high - order processing and recognition of the fluorescence spectra was feasible.

  4. pH-dependent equilibrium isotope fractionation associated with the compound specific nitrogen and carbon isotope analysis of substituted anilines by SPME-GC/IRMS.

    Science.gov (United States)

    Skarpeli-Liati, Marita; Turgeon, Aurora; Garr, Ashley N; Arnold, William A; Cramer, Christopher J; Hofstetter, Thomas B

    2011-03-01

    Solid-phase microextraction (SPME) coupled to gas chromatography/isotope ratio mass spectrometry (GC/IRMS) was used to elucidate the effects of N-atom protonation on the analysis of N and C isotope signatures of selected aromatic amines. Precise and accurate isotope ratios were measured using polydimethylsiloxane/divinylbenzene (PDMS/DVB) as the SPME fiber material at solution pH-values that exceeded the pK(a) of the substituted aniline's conjugate acid by two pH-units. Deviations of δ(15)N and δ(13)C-values from reference measurements by elemental analyzer IRMS were small (IRMS. Under these conditions, the detection limits for accurate isotope ratio measurements were between 0.64 and 2.1 mg L(-1) for δ(15)N and between 0.13 and 0.54 mg L(-1) for δ(13)C, respectively. Substantial inverse N isotope fractionation was observed by SPME-GC/IRMS as the fraction of protonated species increased with decreasing pH leading to deviations of -20‰ while the corresponding δ(13)C-values were largely invariant. From isotope ratio analysis at different solution pHs and theoretical calculations by density functional theory, we derived equilibrium isotope effects, EIEs, pertinent to aromatic amine protonation of 0.980 and 1.001 for N and C, respectively, which were very similar for all compounds investigated. Our work shows that N-atom protonation can compromise accurate compound-specific N isotope analysis of aromatic amines.

  5. Development of prompt gamma measurement system for in vivo proton beam range verification

    International Nuclear Information System (INIS)

    Min, Chul Hee

    2011-02-01

    In radiation therapy, most research has focused on reducing unnecessary radiation dose to normal tissues and critical organs around the target tumor volume. Proton therapy is considered to be one of the most promising radiation therapy methods with its physical characteristics in the dose distribution, delivering most of the dose just before protons come to rest at the so-named Bragg peak; that is, proton therapy allows for a very high radiation dose to the tumor volume, effectively sparing adjacent critical organs. However, the uncertainty in the location of the Bragg peak, coming from not only the uncertainty in the beam delivery system and the treatment planning method but also anatomical changes and organ motions of a patient, could be a critical problem in proton therapy. In spite of the importance of the in vivo dose verification to prevent the misapplication of the Bragg peak and to guarantee both successful treatment and patient safety, there is no practical methodology to monitor the in vivo dose distribution, only a few attempts have been made so far. The present dissertation suggests the prompt gamma measurement method for monitoring of the in vivo proton dose distribution during treatment. As a key part of the process of establishing the utility of this method, the verification of the clear relationship between the prompt gamma distribution and the proton dose distribution was accomplished by means of Monte Carlo simulations and experimental measurements. First, the physical properties of prompt gammas were investigated on the basis of cross-section data and Monte Carlo simulations. Prompt gammas are generated mainly from proton-induced nuclear interactions, and then emitted isotropically in less than 10 -9 sec at energies up to 10 MeV. Simulation results for the prompt gamma yield of the major elements of a human body show that within the optimal energy range of 4-10 MeV the highest number of prompt gammas is generated from oxygen, whereas over the

  6. Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range

    Directory of Open Access Journals (Sweden)

    B. C. Baier

    2017-09-01

    Full Text Available Chemical models must correctly calculate the ozone formation rate, P(O3, to accurately predict ozone levels and to test mitigation strategies. However, air quality models can have large uncertainties in P(O3 calculations, which can create uncertainties in ozone forecasts, especially during the summertime when P(O3 is high. One way to test mechanisms is to compare modeled P(O3 to direct measurements. During summer 2014, the Measurement of Ozone Production Sensor (MOPS directly measured net P(O3 in Golden, CO, approximately 25 km west of Denver along the Colorado Front Range. Net P(O3 was compared to rates calculated by a photochemical box model that was constrained by measurements of other chemical species and that used a lumped chemical mechanism and a more explicit one. Median observed P(O3 was up to a factor of 2 higher than that modeled during early morning hours when nitric oxide (NO levels were high and was similar to modeled P(O3 for the rest of the day. While all interferences and offsets in this new method are not fully understood, simulations of these possible uncertainties cannot explain the observed P(O3 behavior. Modeled and measured P(O3 and peroxy radical (HO2 and RO2 discrepancies observed here are similar to those presented in prior studies. While a missing atmospheric organic peroxy radical source from volatile organic compounds co-emitted with NO could be one plausible solution to the P(O3 discrepancy, such a source has not been identified and does not fully explain the peroxy radical model–data mismatch. If the MOPS accurately depicts atmospheric P(O3, then these results would imply that P(O3 in Golden, CO, would be NOx-sensitive for more of the day than what is calculated by models, extending the NOx-sensitive P(O3 regime from the afternoon further into the morning. These results could affect ozone reduction strategies for the region surrounding Golden and possibly other areas that do not comply with national ozone

  7. Auroral radar measurements at 16-cm wavelength with high range and time resolution

    International Nuclear Information System (INIS)

    Schlegel, K.; Turunen, T.; Moorcroft, D.R.

    1990-01-01

    Auroral radar measurements performed with the EISCAT facility are presented. Backscatter cross sections of the irregularities produced by the two-stream (Farley-Buneman) or gradient drift plasma instabilities have been recorded with a range separation of 1.5 km, corresponding to a spacing of successive values in height of about 0.4 km. The apparent height profiles of the backscatter have a width of about 5-6 km and occur between 95 and 112 km altitude, with a mean at 104 km. Very often, fast motions of the backscatter layers are observed which can be explained as fast moving ionospheric structures controlled by magnetospheric convection. The maximal time resolution of the measurements is 12.5 ms. The statistics of the backscatter amplitudes at this time resolution is close to a Rice distribution with a Rice parameter a ∼ 3.7. The observed backscatter spectra do not change significantly in shape when the integration time is reduced from 5 s to 100 ms

  8. Prototype system for proton beam range measurement based on gamma electron vertex imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Han Rim [Neutron Utilization Technology Division, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057 (Korea, Republic of); Kim, Sung Hun; Park, Jong Hoon [Department of Nuclear Engineering, Hanyang University, Seongdong-gu, Seoul 04763 (Korea, Republic of); Jung, Won Gyun [Heavy-ion Clinical Research Division, Korean Institute of Radiological & Medical Sciences, Seoul 01812 (Korea, Republic of); Lim, Hansang [Department of Electronics Convergence Engineering, Kwangwoon University, Seoul 01897 (Korea, Republic of); Kim, Chan Hyeong, E-mail: chkim@hanyang.ac.kr [Department of Nuclear Engineering, Hanyang University, Seongdong-gu, Seoul 04763 (Korea, Republic of)

    2017-06-11

    In proton therapy, for both therapeutic effectiveness and patient safety, it is very important to accurately measure the proton dose distribution, especially the range of the proton beam. For this purpose, recently we proposed a new imaging method named gamma electron vertex imaging (GEVI), in which the prompt gammas emitting from the nuclear reactions of the proton beam in the patient are converted to electrons, and then the converted electrons are tracked to determine the vertices of the prompt gammas, thereby producing a 2D image of the vertices. In the present study, we developed a prototype GEVI system, including dedicated signal processing and data acquisition systems, which consists of a beryllium plate (= electron converter) to convert the prompt gammas to electrons, two double-sided silicon strip detectors (= hodoscopes) to determine the trajectories of those converted electrons, and a plastic scintillation detector (= calorimeter) to measure their kinetic energies. The system uses triple coincidence logic and multiple energy windows to select only the events from prompt gammas. The detectors of the prototype GEVI system were evaluated for electronic noise level, energy resolution, and time resolution. Finally, the imaging capability of the GEVI system was tested by imaging a {sup 90}Sr beta source, a {sup 60}Co gamma source, and a 45-MeV proton beam in a PMMA phantom. The overall results of the present study generally show that the prototype GEVI system can image the vertices of the prompt gammas produced by the proton nuclear interactions.

  9. The wide range in-core neutron measurement system used in the Windscale AGR concluding experiments

    International Nuclear Information System (INIS)

    Goodings, A.; Budd, J.; Wilson, I.

    1982-06-01

    The Windscale AGR Concluding Experiments included a comparison of theoretical and experimental power transients and required measurements of neutron flux as a function of position and time within the reactor core. These measurements were specified to cover as wide as possible working range and had to be made against the in-core gamma background of up to 4 x 10 7 R(hr) - 1 . The detectors were required to operate in special, channels cooled by reactor inlet carbon dioxide and the overall system needed a response time such that it could follow transients with doubling times down to 2s with an accuracy of 2 or 3%. These problems were solved by the use of gas ion fission chambers operating in the current fluctuation or Campbelling mode with unusually low filling pressures and fitted with special trilaminax mineral insulated cables. Ten detectors were built and nine were installed in the reactor, three in each of three special stringers at different radial positions. The paper describes the specification against which this system was built, the design process for the detectors, and commissioning experiments together with some of the problems which were encountered. (U.K.)

  10. Rapid response and wide range neutronic power measuring systems for fast pulsed reactors

    International Nuclear Information System (INIS)

    Sumita, Kenji; Iida, Toshiyuki; Wakayama, Naoaki.

    1976-01-01

    This paper summarizes our investigation on design principles of the rapid, stable and wide range neutronic power measuring system for fast pulsed reactors. The picoammeter, the logarithmic amplifier, the reactivity meter and the neutron current chamber are the items of investigation. In order to get a rapid response, the method of compensation for the stray capacitance of the feedback circuits and the capacitance of signal cables is applied to the picoammeter, the logarithmic amplifier and the reactivity meter with consideration for the stability margin of a whole detecting system. The response of an ionization current chamber and the method for compensating the ion component of the chamber output to get optimum responses high pass filters are investigated. Statistical fluctuations of the current chamber output are also considered in those works. The optimum thickness of the surrounding moderator of the neutron detector is also discussed from the viewpoint of the pulse shape deformation and the neutron sensitivity increase. The experimental results are reported, which were observed in the pulse operations of the one shot fast pulsed reactor ''YAYOI'' and the one shot TRIGA ''NSRR'' with the measuring systems using those principles. (auth.)

  11. Absolute Hugoniot measurements for CH foams in the 2-9 Mbar range

    Science.gov (United States)

    Aglitskiy, Y.; Velikovich, A. L.; Karasik, M.; Schmitt, A. J.; Serlin, V.; Weaver, J. L.; Oh, J.; Obenschain, S. P.; Cochrane, K. R.

    2018-03-01

    Absolute Hugoniot measurements for empty plastic foams at ˜10% of solid polystyrene density and supporting rad-hydro simulation results are reported. Planar foam slabs, ˜400 μm thick and ˜500 μm wide, some of which were covered with a 10 μm solid plastic ablator, were directly driven by 4 ns long Nike krypton-fluoride 248 nm wavelength laser pulses that produced strong shock waves in the foam. The shock and mass velocities in our experiments were up to 104 km/s and 84 km/s, respectively, and the shock pressures up to ˜9 Mbar. The motion of the shock and ablation fronts was recorded using side-on monochromatic x-ray imaging radiography. The steadiness of the observed shock and ablation fronts within ˜1% has been verified. The Hugoniot data inferred from our velocity measurements agree with the predictions of the SESAME and CALEOS equation-of-state models near the highest pressure ˜9 Mbar and density compression ratio ˜5. In the lower pressure range 2-5 Mbar, a lower shock density compression is observed than that predicted by the models. Possible causes for this discrepancy are discussed.

  12. Outlier Detection in GNSS Pseudo-Range/Doppler Measurements for Robust Localization

    Directory of Open Access Journals (Sweden)

    Salim Zair

    2016-04-01

    Full Text Available In urban areas or space-constrained environments with obstacles, vehicle localization using Global Navigation Satellite System (GNSS data is hindered by Non-Line Of Sight (NLOS and multipath receptions. These phenomena induce faulty data that disrupt the precise localization of the GNSS receiver. In this study, we detect the outliers among the observations, Pseudo-Range (PR and/or Doppler measurements, and we evaluate how discarding them improves the localization. We specify a contrario modeling for GNSS raw data to derive an algorithm that partitions the dataset between inliers and outliers. Then, only the inlier data are considered in the localization process performed either through a classical Particle Filter (PF or a Rao-Blackwellization (RB approach. Both localization algorithms exclusively use GNSS data, but they differ by the way Doppler measurements are processed. An experiment has been performed with a GPS receiver aboard a vehicle. Results show that the proposed algorithms are able to detect the ‘outliers’ in the raw data while being robust to non-Gaussian noise and to intermittent satellite blockage. We compare the performance results achieved either estimating only PR outliers or estimating both PR and Doppler outliers. The best localization is achieved using the RB approach coupled with PR-Doppler outlier estimation.

  13. Measurement of transparency ratios for protons from short-range correlated pairs

    Science.gov (United States)

    Hen, O.; Hakobyan, H.; Shneor, R.; Piasetzky, E.; Weinstein, L. B.; Brooks, W. K.; May-Tal Beck, S.; Gilad, S.; Korover, I.; Beck, A.; Adhikari, K. P.; Aghasyan, M.; Amaryan, M. J.; Anefalos Pereira, S.; Arrington, J. R.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fleming, J. A.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Harrison, N.; Heddle, D.; Hicks, K.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Klein, F. J.; Koirala, S.; Kubarovsky, A.; Kubarovsky, V.; Kuhn, S. E.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Martinez, D.; Mayer, M.; McKinnon, B.; Mineeva, T.; Mokeev, V.; Montgomery, R. A.; Moutarde, H.; Munevar, E.; Munoz Camacho, C.; Mustapha, B.; Nadel-Turonski, P.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Phelps, E.; Phillips, J. J.; Pisano, S.; Pivnyuk, N.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tian, Ye; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vlassov, A.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zheng, X.; Zonta, I.

    2013-05-01

    Nuclear transparency, Tp (A), is a measure of the average probability for a struck proton to escape the nucleus without significant re-interaction. Previously, nuclear transparencies were extracted for quasi-elastic A (e ,e‧ p) knockout of protons with momentum below the Fermi momentum, where the spectral functions are well known. In this Letter we extract a novel observable, the transparency ratio, Tp (A) /Tp(12 C), for knockout of high-missing-momentum protons from the breakup of short-range correlated pairs (2N-SRC) in Al, Fe and Pb nuclei relative to C. The ratios were measured at momentum transfer Q2 ⩾ 1.5(GeV /c) 2 and xB ⩾ 1.2 where the reaction is expected to be dominated by electron scattering from 2N-SRC. The transparency ratios of the knocked-out protons coming from 2N-SRC breakup are 20-30% lower than those of previous results for low missing momentum. They agree with Glauber calculations and agree with renormalization of the previously published transparencies as proposed by recent theoretical investigations. The new transparencies scale as A - 1 / 3, which is consistent with dominance of scattering from nucleons at the nuclear surface.

  14. Sensitivity analysis of nacelle lidar free stream wind speed measurements to wind-induction reconstruction model and lidar range configuration

    DEFF Research Database (Denmark)

    Svensson, Elin; Borraccino, Antoine; Meyer Forsting, Alexander Raul

    The sensitivity of nacelle lidar wind speed measurements to wind-induction models and lidar range configurations is studied using experimental data from the Nørrekær Enge (NKE) measurement campaign and simulated lidar data from Reynold-Averaged Navier Stokes (RANS) aerodynamic computational fluid...... the ZDM was configured to measure at five distances. From the configured distances, a large number of range configurations were created and systematically tested to determine the sensitivity of the reconstructed wind speeds to the number of ranges, minimum range and maximum range in the range......) of the fitting residuals. The results demonstrate that it is not possible to use RANS CFD simulated lidar data to determine optimal range configurations for real-time nacelle lidars due to their perfect (unrealistic) representation of the simulated flow field. The recommended range configurations are therefore...

  15. Cloud cover detection combining high dynamic range sky images and ceilometer measurements

    Science.gov (United States)

    Román, R.; Cazorla, A.; Toledano, C.; Olmo, F. J.; Cachorro, V. E.; de Frutos, A.; Alados-Arboledas, L.

    2017-11-01

    This paper presents a new algorithm for cloud detection based on high dynamic range images from a sky camera and ceilometer measurements. The algorithm is also able to detect the obstruction of the sun. This algorithm, called CPC (Camera Plus Ceilometer), is based on the assumption that under cloud-free conditions the sky field must show symmetry. The symmetry criteria are applied depending on ceilometer measurements of the cloud base height. CPC algorithm is applied in two Spanish locations (Granada and Valladolid). The performance of CPC retrieving the sun conditions (obstructed or unobstructed) is analyzed in detail using as reference pyranometer measurements at Granada. CPC retrievals are in agreement with those derived from the reference pyranometer in 85% of the cases (it seems that this agreement does not depend on aerosol size or optical depth). The agreement percentage goes down to only 48% when another algorithm, based on Red-Blue Ratio (RBR), is applied to the sky camera images. The retrieved cloud cover at Granada and Valladolid is compared with that registered by trained meteorological observers. CPC cloud cover is in agreement with the reference showing a slight overestimation and a mean absolute error around 1 okta. A major advantage of the CPC algorithm with respect to the RBR method is that the determined cloud cover is independent of aerosol properties. The RBR algorithm overestimates cloud cover for coarse aerosols and high loads. Cloud cover obtained only from ceilometer shows similar results than CPC algorithm; but the horizontal distribution cannot be obtained. In addition, it has been observed that under quick and strong changes on cloud cover ceilometers retrieve a cloud cover fitting worse with the real cloud cover.

  16. The wide range in-core neutron measurement system used in the Windscale AGR concluding experiments

    International Nuclear Information System (INIS)

    Goodings, A.; Budd, J.; Wilson, I.

    1982-06-01

    The Windscale AGR concluding experiments included a comparison of theoretical and experimental power transients and required measurements of neutron flux as a function of position and time within the reactor core. These measurements were specified to cover a working range as wide as possible and had to be made against the in-core gamma background of up to 4 x 10 7 R(hr) - 1 . The detectors were required to operate in special channels cooled by reactor inlet CO 2 and the overall system needed a response time such that it could follow transients with doubling times down to 2s with an accuracy of 2 or 3%. These problems were solved by the use of gas ion fission chambers operating in the current fluctuation or ''Campbelling'' mode. Their neutron to gamma sensitivity ratio was optimised by the use of unusually low filling pressures and they were fitted with special ''trilaminax'' mineral insulated cables to minimise the effects of electrical interference at the 100 kHz channel centre frequency. Ten detectors were built and nine were installed in the reactor, three in each of three special stringers at different radial positions. All were processed and tested for operation at 350 deg. C and their fissile coatings (430 μg cm - 1 of natural uranium) were matched to give individual neutron sensitivities with a population spread better than +- 6% about the mean. The mean absolute sensitivities were determined to about +- 5% against manganese foils in the NESTOR reactor at AEE Winfrith. The detectors were complemented by special signal processing channels which provided current fluctuation sensitivity and appropriate output signals to the experiment data acquisition system. These channels also permitted dc measurement of chamber current for more precise flux determination near reactor full power

  17. Optimization of total vaporization solid-phase microextraction (TV-SPME) for the determination of lipid profiles of Phormia regina, a forensically important blow fly species.

    Science.gov (United States)

    Kranz, William; Carroll, Clinton; Dixon, Darren; Picard, Christine; Goodpaster, John

    2017-11-01

    A new method has been developed for the determination of fatty acids, sterols, and other lipids which naturally occur within pupae of the blow fly Phormia regina. The method relies upon liquid extraction in non-polar solvent, followed by derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) w/ 1% trimethylchlorsilane (TMCS) carried out inside the sample vial. The analysis is facilitated by total vaporization solid-phase microextraction (TV-SPME), with gas chromatography-mass spectrometry (GC-MS) serving as the instrumentation for analysis. The TV-SPME delivery technique is approximately a factor of five more sensitive than traditional liquid injection, which may alleviate the need for rotary evaporation, reconstitution, collection of high performance liquid chromatography fractions, and many of the other pre-concentration steps that are commonplace in the current literature. Furthermore, the ability to derivatize the liquid extract in a single easy step while increasing sensitivity represents an improvement over current derivatization methods. The most common lipids identified in fly pupae were various saturated and unsaturated fatty acids ranging from lauric acid (12:0) to arachinoic acid (20:4), as well as cholesterol. The concentrations of myristic acid (14:0), palmitelaidic acid (16:2), and palmitoleic acid (16:1) were the most reliable indicators of the age of the pupae. Graphical abstract Blow fly pupae were extracted prior to emerging as adults. The extracts were analyzed via total vaporization solid-phase microextraction (TV-SPME), revealing a complex mixture of lipids that could be associated with the age of the insect. This information may assist in determining a post-mortum interval (PMI) in a death investigation.

  18. Why do Ladybugs Smell Bad? In-vivo Quantification of Odorous Insect Kairomones with SPME and Multidimensional GC-MS-Olfactometry

    International Nuclear Information System (INIS)

    Cai Lingshuang; Koziel, Jacek A.; O'Neal, Matthew E.

    2009-01-01

    Winemakers, small fruit growers, and homeowners are concerned with noxious compounds released by multicolored Asian ladybird beetles (Harmonia axyridis, Coleoptera: Coccinellidae). New method based on headspace solid phase microextraction (HS-SPME) coupled with multidimensional gas chromatography mass spectrometry--olfactometry (MDGC-MS-O) system was developed for extraction, isolation and simultaneous identification of compounds responsible for the characteristic odor of live H. axyridis. Four methoxypyrazines (MPs) were identified in headspace volatiles of live H. axyridis as those responsible for the characteristic odor: 2, 5-dimethy1-3-methoxypyrazine (DMMP), 2-isopropy1-3-methoxypyrazine (IPMP), 2-sec-buty1-3-methoxypyrazine (SBMP), and 2-isobuty1-3-methoxypyrazine (IBMP). To the best of our knowledge this is the first report of H. axyridis releasing DMMP and the first report of this compound being a component of the H. axyridis characteristic odor. Quantification of three MPs (IPMP, SBMP and IBMP) emitted from live H. axyridis were performed using external calibration with HS-SPME and direct injections. A linear relationship (R 2 >0.9958 for all 3 MPs) between MS response and concentration of standard was observed over a concentration range from 0.1 ng L -1 to 0.05 μg L -1 for HS-SPME-GC-MS. The method detection limits (MDL) based on multidimensional GC-MS approach for three MPs were estimated to be between 0.020 ng L -1 . to 0.022 ng L -1 . This methodology is applicable for in vivo determination of odor-causing chemicals associated with emissions of volatiles from insects.

  19. Inertial sensors as measurement tools of elbow range of motion in gerontology

    Directory of Open Access Journals (Sweden)

    Sacco G

    2015-02-01

    Full Text Available G Sacco,1–3,* JM Turpin,3,4,* A Marteu,5 C Sakarovitch,6 B Teboul,2 L Boscher,4,5 P Brocker,4 P Robert,1–3 O Guerin2,3,7 1Memory Center, Claude Pompidou Institut, Department of Geriatrics, University Hospital of Nice, Nice, France; 2Centre d’Innovation et d’Usages en Santé (CIU-S, University Hospital of Nice, Cimiez Hospital, Nice, France; 3CoBTeK Cognition Behaviour Technology EA 7276, Research Center Edmond and Lily Safra, Nice Sophia-Antipolis University, Nice, France; 4Rehabilitation Unit, Department of Geriatrics, University Hospital of Nice, Cimiez Hospital, Nice, France; 5Rehabilitation Unit, Department of Neurosciences, University Hospital of Nice, L’Archet Hospital, Nice, France; 6Department of Clinical Research and Innovation, University Hospital of Nice, Cimiez Hospital, Nice, France; 7Acute Geriatrics Unit, Department of Geriatrics, University Hospital of Nice, Cimiez Hospital, Nice, France *These authors contributed equally to this work Background and purpose: Musculoskeletal system deterioration among the aging is a major reason for loss of autonomy and directly affects the quality of life of the elderly. Articular evaluation is part of physiotherapeutic assessment and helps in establishing a precise diagnosis and deciding appropriate therapy. Reference instruments are valid but not easy to use for some joints. The main goal of our study was to determine reliability and intertester reproducibility of the MP-BV, an inertial sensor (the MotionPod® [MP] combined with specific software (BioVal [BV], for elbow passive range-of-motion measurements in geriatrics. Methods: This open, monocentric, randomized study compared inertial sensor to inclinometer in patients hospitalized in an acute, post-acute, and long-term-care gerontology unit. Results: Seventy-seven patients (mean age 83.5±6.4 years, sex ratio 1.08 [male/female] were analyzed. The MP-BV was reliable for each of the three measurements (flexion, pronation, and

  20. Development of SPME-LC-MS method for screening of eight beta-blockers and bronchodilators in plasma and urine samples.

    Science.gov (United States)

    Goryński, Krzysztof; Kiedrowicz, Alicja; Bojko, Barbara

    2016-08-05

    The current work describes the development and validation of a simple, efficient, and fast method using solid phase microextraction coupled to liquid chromatography-tandem mass spectrometry (SPME-LC-MS/MS) for the concomitant measurement of eight beta-blockers and bronchodilators in plasma and urine. The presented assay enables quantitative determination of acebutolol, atenolol, fenoterol, nadolol, pindolol, procaterol, sotalol, and timolol. In this work, samples were prepared on a high-throughput platform using the 96-well plate format of the thin film solid phase microextraction (TFME) system, and a biocompatible extraction phase made of hydrophilic-lipophilic balance particles. Analytes were separated on a pentafluorophenyl column (100mm×2.1mm, 3μm) by gradient elution using an UPLC Nexera coupled with an LCMS-8060 mass spectrometer. The mobile phase consisted of water-acetonitrile (0.1% formic acid) at a flow rate of 0.4mLmin(-1). The linearity of the method was checked within therapeutic blood-plasma concentrations, and shown to adequately reflect typically expected concentrations of future study samples. Post-extraction addition experiments showed that the matrix effect ranged in plasma from 98% for procaterol to 115% for nadolol, and in urine, from 85% for nadolol and pindolol to 119% for atenolol. The method was successfully validated using Food and Drug Administration (FDA) guidelines, and met all acceptance criteria for bioanalytical assays at five concentration levels for all selected drugs. The final protocol can be successfully applied for monitoring concentrations of the selected drugs in both plasma and urine matrices obtained from patients or athletes. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Critical micelle concentration values for different surfactants measured with solid-phase microextraction fibers

    NARCIS (Netherlands)

    Haftka, Joris J H; Scherpenisse, Peter; Oetter, G??nter; Hodges, Geoff; Eadsforth, Charles V.; Kotthoff, Matthias; Hermens, Joop L M

    The amphiphilic nature of surfactants drives the formation of micelles at the critical micelle concentration (CMC). Solid-phase microextraction (SPME) fibres were used in the present study to measure CMC values of twelve nonionic, anionic, cationic and zwitterionic surfactants. The SPME derived CMC

  2. Measurements with vertically viewing charge exchange analyzers during ion cyclotron range of frequencies heating in TFTR

    International Nuclear Information System (INIS)

    Kaita, R.; Hammett, G.W.; Gammel, G.; Goldston, R.J.; Medley, S.S.; Scott, S.D.; Young, K.M.

    1988-01-01

    The utility of charge exchange neutral particle analyzers for studying energetic ion distributions in high-temperature plasmas has been demonstrated in a variety of tokamak experiments. Power deposition profiles have been estimated in the Princeton large torus (PLT) from particle measurements as a function of energy and angle during heating in the ion cyclotron range of frequencies (ICRF) and extensive studies of this heating mode are planned for the upcoming operational period in the tokamak fusion test reactor (TFTR). Unlike the horizontally scanning analyzer on PLT, the TFTR system consists of vertical sightlines intersecting a poloidal cross section of the plasma. A bounce-averaged Fokker--Planck program, which includes a quasilinear operator to calculate ICRF-generated energetic ions, is used to simulate the charge exchange flux expected during fundamental hydrogen heating. These sightlines also cross the trajectory of a diagnostic neutral beam (DNB), and it may be possible to observe the fast ion tail during 3 He minority heating, if the DNB is operated in helium for double charge exchange neutralization

  3. Thermal/vacuum measurements of the Herschel space telescope by close-range photogrammetry

    Science.gov (United States)

    Parian, J. Amiri; Cozzani, A.; Appolloni, M.; Casarosa, G.

    2017-11-01

    In the frame of the development of a videogrammetric system to be used in thermal vacuum chambers at the European Space Research and Technology Centre (ESTEC) and other sites across Europe, the design of a network using micro-cameras was specified by the European Space agency (ESA)-ESTEC. The selected test set-up is the photogrammetric test of the Herschel Satellite Flight Model in the ESTEC Large Space Simulator. The photogrammetric system will be used to verify the Herschel Telescope alignment and Telescope positioning with respect to the Cryostat Vacuum Vessel (CVV) inside the Large Space Simulator during Thermal-Vacuum/Thermal-Balance test phases. We designed a close-range photogrammetric network by heuristic simulation and a videogrammetric system with an overall accuracy of 1:100,000. A semi-automated image acquisition system, which is able to work at low temperatures (-170°C) in order to acquire images according to the designed network has been constructed by ESA-ESTEC. In this paper we will present the videogrammetric system and sub-systems and the results of real measurements with a representative setup similar to the set-up of Herschel spacecraft which was realized in ESTEC Test Centre.

  4. Measurements on rotating ion cyclotron range of frequencies induced particle fluxes in axisymmetric mirror plasmas

    International Nuclear Information System (INIS)

    Hatakeyama, R.; Hershkowitz, N.; Majeski, R.; Wen, Y.J.; Brouchous, D.B.; Proberts, P.; Breun, R.A.; Roberts, D.; Vukovic, M.; Tanaka, T.

    1997-01-01

    A comparison of phenomenological features of plasmas is made with a special emphasis on radio-frequency induced transport, which are maintained when a set of two closely spaced dual half-turn antennas in a central cell of the Phaedrus-B axisymmetric tandem mirror [J. J. Browning et al., Phys. Fluids B 1, 1692 (1989)] is phased to excite electromagnetic fields in the ion cyclotron range of frequencies (ICRF) with m=-1 (rotating with ions) and m=+1 (rotating with electrons) azimuthal modes. Positive and negative electric currents are measured to flow axially to the end walls in the cases of m=-1 and m=+1 excitations, respectively. These parallel nonambipolar ion and electron fluxes are observed to be accompanied by azimuthal ion flows in the same directions as the antenna-excitation modes m. The phenomena are argued in terms of radial particle fluxes due to a nonambipolar transport mechanism [Hojo and Hatori, J. Phys. Soc. Jpn. 60, 2510 (1991); Hatakeyama et al., J. Phys. Soc. Jpn. 60, 2815 (1991), and Phys. Rev. E 52, 6664 (1995)], which are induced when azimuthally traveling ICRF waves are absorbed in the magnetized plasma column. copyright 1997 American Institute of Physics

  5. LHC MD2877: Beam-beam long range impact on coupling measurements

    CERN Document Server

    Wenninger, Jorg; Carlier, Felix Simon; Coello De Portugal - Martinez Vazquez, Jaime Maria; Fuchsberger, Kajetan; Hostettler, Michi; Persson, Tobias Hakan Bjorn; Tomas Garcia, Rogelio; Valuch, Daniel; Garcia-Tabares Valdivieso, Ana; CERN. Geneva. ATS Department

    2018-01-01

    The LHC is now operating with a tune separation of ∼0.004 in collision. This puts tight constraints on the allowed transverse coupling since a |C−| larger than a fraction of the fractional tune split may lead to beam instabilities. In the last years a new tool based on the ADT used in a similar way as an AC-dipole to excite the beam was developed. The ADT AC-dipole gives coherent oscillations without increasing the beam emittance. These oscillations are analyzed automatically to obtain the value of the coupling. A coupling measurement campaign was done in 2017 and while the correction converged and stayed rather constant over time it was observed that depending on the target bunch and filling scheme the results could vary by Δ|C−| ∼ 0.002. In this MD report we investigated 3 different bunches, one with Long Range Beam-Beam (LRBB) in IPs 1 and 5, one with LRBB in all IPs and one with no LRBB. The results indicate that there are differences in coupling between the bunches experiencing different LR...

  6. Measurement and description of three-dimensional shoulder range of motion with degrees of freedom interactions.

    Science.gov (United States)

    Haering, Diane; Raison, Maxime; Begon, Mickael

    2014-08-01

    The shoulder is the most mobile joint of the human body due to bony constraint scarcity and soft tissue function unlocking several degrees of freedom (DOF). Clinical evaluation of the shoulder range of motion (RoM) is often limited to a few monoplanar measurements where each DOF varies independently. The main objective of this study was to provide a method and its experimental approach to assess shoulder 3D RoM with DOF interactions. Sixteen participants performed four series of active arm movements with maximal amplitude consisting in (1) elevations with fixed arm axial rotations (elevation series), (2) axial rotations at different elevations (rotation series), both in five planes of elevation, (3) free arm movements with the instruction to fill the largest volume in space while varying hand orientation (random series), and (4) a combination of elevation and rotation series (overall series). A motion analysis system combined with an upper limb kinematic model was used to estimate the 3D joint kinematics. Thoracohumeral Euler angles with correction were chosen to represent rotations. The angle-time-histories were treated altogether to analyze their 3D interaction. Then, all 3D angular poses were included into a nonconvex hull representing the RoM space accounting for DOF interactions. The effect of series of movements (n = 4) on RoM volumes was tested with a one-way repeated-measures ANOVA followed by Bonferroni posthoc analysis. A normalized 3D RoM space was defined by including 3D poses common to a maximal number of participants into a hull of average volume. A significant effect of the series of movements (p measured the largest RoM with an average volume of 3.46 ± 0.89 million cubic degrees. The main difference between the series of movements was due to axial rotation. A normalized RoM hull with average volume was found by encompassing arm poses common to more than 50% of the participants. In general, the results confirmed and characterized the complex 3D

  7. Cannabinoids determination in oral fluid by SPME-GC/MS and UHPLC-MS/MS and its application on suspected drivers.

    Science.gov (United States)

    Anzillotti, Luca; Castrignanò, Erika; Strano Rossi, Sabina; Chiarotti, Marcello

    2014-12-01

    The confirmation of Δ9-tetrahydrocannabinol (THC) in oral fluid (OF) is an important issue for assessing Driving Under the Influence of Drugs (DUID). The aim of this research was to develop a highly sensitive method with minimal sample pre-treatment suitable for the analysis of small OF volumes (100 μL) for the confirmation of cannabinoids in DUID cases. Two methods were compared for the confirmation of THC in residual OF samples, obtained from a preliminary on-site screening with commercial devices. An ultra high performance LC-MS (UHPLC-MS/MS) method and an SPME-GC/MS method were hence developed. 100 μL of the residual mixture OF/preservative buffer or neat OF was simply added to 10 μL of THC-D3 (1 μg/mL) and submitted to the two different analyses: A - direct injection of 10 μL in UHPLC-MS/MS in positive electrospray ionisation (ESI) mode and B - sampling for 30 min with SPME (100 μm polydimethylsiloxane or PDMS fibre) and direct injection by desorption of the fibre in the GC injection port. The lowest limit of detection (LLOD) of THC was 2 ng/mL in UHPLC-MS/MS and 0.5 ng/mL in SPME-GC/MS. In addition, cannabidiol (CBD) and cannabinol (CBN) could be detected in GC/MS equipment at 2 ng/mL, whilst in UHPLC-MS/MS the LLOD was 20 ng/mL. Both methods were applied to 70 samples coming from roadside tests. By SPME-GC/MS analysis, THC was confirmed in 42 samples, whilst CBD was detected in 21 of them, along with CBN in 14 samples. THC concentrations ranged from traces below the lowest limit of quantification or LLOQ (2 ng/mL) up to 690 ng/mL. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Validity and reliability of using photography for measuring knee range of motion: a methodological study

    Directory of Open Access Journals (Sweden)

    Adie Sam

    2011-04-01

    Full Text Available Abstract Background The clinimetric properties of knee goniometry are essential to appreciate in light of its extensive use in the orthopaedic and rehabilitative communities. Intra-observer reliability is thought to be satisfactory, but the validity and inter-rater reliability of knee goniometry often demonstrate unacceptable levels of variation. This study tests the validity and reliability of measuring knee range of motion using goniometry and photographic records. Methods Design: Methodology study assessing the validity and reliability of one method ('Marker Method' which uses a skin marker over the greater trochanter and another method ('Line of Femur Method' which requires estimation of the line of femur. Setting: Radiology and orthopaedic departments of two teaching hospitals. Participants: 31 volunteers (13 arthritic and 18 healthy subjects. Knee range of motion was measured radiographically and photographically using a goniometer. Three assessors were assessed for reliability and validity. Main outcomes: Agreement between methods and within raters was assessed using concordance correlation coefficient (CCCs. Agreement between raters was assessed using intra-class correlation coefficients (ICCs. 95% limits of agreement for the mean difference for all paired comparisons were computed. Results Validity (referenced to radiographs: Each method for all 3 raters yielded very high CCCs for flexion (0.975 to 0.988, and moderate to substantial CCCs for extension angles (0.478 to 0.678. The mean differences and 95% limits of agreement were narrower for flexion than they were for extension. Intra-rater reliability: For flexion and extension, very high CCCs were attained for all 3 raters for both methods with slightly greater CCCs seen for flexion (CCCs varied from 0.981 to 0.998. Inter-rater reliability: For both methods, very high ICCs (min to max: 0.891 to 0.995 were obtained for flexion and extension. Slightly higher coefficients were obtained

  9. Development of a HS-SPME-GC-MS/MS Method for the Quantitation of Thymol and Carvacrol in Bovine Matrices and To Determine Residue Depletion in Milk and Tissues.

    Science.gov (United States)

    Armorini, Sara; Yeatts, James E; Mullen, Keena A E; Mason, Sharon E; Mehmeti, Elmira; Anderson, Kevin L; Washburn, Steve P; Baynes, Ronald E

    2016-10-11

    Thymol and carvacrol may be present in several phytoceutical products but there are no well-defined methods to measure these compounds in meat and milk from treated animals. U.S. regulatory authorities deem their presence as an adulteration of food. A rapid and sensitive HS-SPME-GC-MS/MS method was developed for the detection of thymol and carvacrol in bovine milk, plasma, liver, kidney, and fat. Inter- and intraday precision values were all less than 15.7 and 20.2% for thymol and carvacrol, respectively. The accuracy was in ranges of 69.9-111.8% for thymol and 74.0-119.2% for carvacrol. With the exception of fat tissue, stability studies showed that both compounds are stable over a 2 month period. A pilot pharmacokinetic study was conducted to evaluate the developed analytical method and to provide initial estimates of thymol and carvacrol depletion in plasma, milk, and several tissues. Treatment of lactating dairy cattle with phytoceutical products containing these substances resulted in low but measurable residue levels at 96 h for liver and 36 h for milk with very short apparent plasma and milk half-lives (<3.0 h).

  10. Photon Pressure Force on Space Debris TOPEX/Poseidon Measured by Satellite Laser Ranging

    Science.gov (United States)

    Kucharski, D.; Kirchner, G.; Bennett, J. C.; Lachut, M.; Sośnica, K.; Koshkin, N.; Shakun, L.; Koidl, F.; Steindorfer, M.; Wang, P.; Fan, C.; Han, X.; Grunwaldt, L.; Wilkinson, M.; Rodríguez, J.; Bianco, G.; Vespe, F.; Catalán, M.; Salmins, K.; del Pino, J. R.; Lim, H.-C.; Park, E.; Moore, C.; Lejba, P.; Suchodolski, T.

    2017-10-01

    The (TOPography EXperiment) TOPEX/Poseidon (T/P) altimetry mission operated for 13 years before the satellite was decommissioned in January 2006, becoming a large space debris object at an altitude of 1,340 km. Since the end of the mission, the interaction of T/P with the space environment has driven the satellite's spin dynamics. Satellite laser ranging (SLR) measurements collected from June 2014 to October 2016 allow for the satellite spin axis orientation to be determined with an accuracy of 1.7°. The spin axis coincides with the platform yaw axis (formerly pointing in the nadir direction) about which the body rotates in a counterclockwise direction. The combined photometric and SLR data collected over the 11 year time span indicates that T/P has continuously gained rotational energy at an average rate of 2.87 J/d and spins with a period of 10.73 s as of 19 October 2016. The satellite attitude model shows a variation of the cross-sectional area in the Sun direction between 8.2 m2 and 34 m2. The direct solar radiation pressure is the main factor responsible for the spin-up of the body, and the exerted photon force varies from 65 μN to 228 μN around the mean value of 138.6 μN. Including realistic surface force modeling in orbit propagation algorithms will improve the prediction accuracy, giving better conjunction warnings for scenarios like the recent close approach reported by the ILRS Space Debris Study Group—an approximate 400 m flyby between T/P and Jason-2 on 20 June 2017.

  11. Long-Range Channel Measurements on Small Terminal Antennas Using Optics

    DEFF Research Database (Denmark)

    Yanakiev, Boyan; Nielsen, Jesper Ødum; Christensen, Morten

    2012-01-01

    In this paper, details are given on a novel measurement device for radio propagation-channel measurements. To avoid measurement errors due to the conductive cables on small terminal antennas, as well as to improve the handling of the prototypes under investigation, an optical measurement device has...

  12. Investigation of hopped frequency waveforms for range and velocity measurements of radar targets

    CSIR Research Space (South Africa)

    Kathree, U

    2015-10-01

    Full Text Available In the field of radar, High Range Resolution (HRR) profiles are often used to improve target tracking accuracy in range and to allow the radar system to produce an image of an object using techniques such as inverse synthetic aperture radar (ISAR...

  13. Determination of plant growth rate and growth temperature range from measurement of physiological parameters

    Science.gov (United States)

    R. S. Criddle; B. N. Smith; L. D. Hansen; J. N. Church

    2001-01-01

    Many factors influence species range and diversity, but temperature and temperature variability are always major global determinants, irrespective of local constraints. On a global scale, the ranges of many taxa have been observed to increase and their diversity decrease with increasing latitude. On a local scale, gradients in species distribution are observable with...

  14. HP-SPME of volatile polycyclic aromatic hydrocarbons from water using multiwalled carbon nanotubes coated on a steel fiber through electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoudi, S.; Noroozian, E. [Shahid Bahonar Univ., Kerman (Iran, Islamic Republic of). Dept. of Chemistry

    2012-08-15

    A headspace solid-phase microextraction (SPME) method using a stainless steel wire electrophoretically coated with dodecylsulfate modified multiwalled carbon nanotubes was used for the gas chromatographic (GC) determination of polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Electrophoretic deposition was easily carried out from an aqueous sodium dodecylsulfate medium. The effects of various parameters on the efficiency of SPME process, such as extraction time, extraction temperature, ionic strength, desorption time, and desorption temperature were studied. Under optimized conditions, the detection limits for the various PAHs studied varied from 0.03 to 0.07 ng mL{sup -1}. The inter-day and intra-day relative standard deviations at a 10 ng mL{sup -1} concentration level (n = 7) using a single-fiber were from 5.5 to 9.7 and 4.1 to 8.5 %, respectively. The fiber-to-fiber RSD% (n = 3) was between 7.3 and 11.1 %. The linear ranges were between 0.1 and 100 ng mL{sup -1}. The method was successfully applied to the analysis of a real sample with the recoveries from 88 to 105 % for 5 ng mL{sup -1} and 89 to 101 % for 0.5 ng mL{sup -1} samples. (orig.)

  15. Application of robust NiTi-ZrO2-PEG SPME fiber in the determination of haloanisoles in cork stopper samples

    International Nuclear Information System (INIS)

    Budziak, Dilma; Martendal, Edmar; Carasek, Eduardo

    2008-01-01

    In this study, a novel solid-phase microextraction (SPME) fiber obtained using sol-gel technology was applied in the determination of off-flavor compounds (2,4,6-trichloroanisole (TCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA)) present in cork stopper samples. A NiTi alloy previously electrodeposited with zirconium oxide was used as the substrate for a poly(ethylene glycol) (PEG) coating. Scanning electronic microscopy showed good uniformity of the coating and allowed the coating thickness to be estimated as around 17 μm. The optimization of the main parameters influencing the extraction efficiency, such as cork sample mass, sodium chloride mass, extraction temperature and extraction time were optimized using a full factorial design, followed by a Doehlert design. The optimum conditions were: 20 min of extraction at 70 deg. C using 60 mg of the cork sample and 10 mL of water saturated with sodium chloride in a 20 mL amber vial with constant magnetic stirring. Satisfactory detection limits between 2.5 and 5.1 ng g -1 were obtained, as well as good precision (R.S.D. in the range of 5.8-12.0%). Recovery tests were performed on three different cork samples, and values between 83 and 119% were obtained. The proposed SPME fiber was compared with commercially available fibers and good results were achieved, demonstrating its applicability

  16. Evaluation of the volatile profile of Tuber liyuanum by HS-SPME with GC-MS.

    Science.gov (United States)

    Liu, Changjiao; Li, Yu

    2017-04-01

    The volatile components of Tuber liyuanum were determined by HS-SPME with GC-MS for the first time. The effects of different fibre coating, extraction time, extraction temperature and sample amount were studied to get optimal extraction conditions. The optimal conditions were SPME fibre of Carboxen/PDMS, extraction time of 40 min, extraction temperature of 80 °C, sample amount of 2 g. Under these conditions 57 compounds in volatile of T. liyuanum were detected with a resemblance percentage above 80%. Aldehydes and aromatics were the main chemical families identified. The contribution of 3-Octanone(11.67%), phenylethyl alcohol (10.60%), isopentana (9.29%) and methylbutana (8.06%) for the total volatile profile were more significant in T. liyuanum than other compounds.

  17. Solid Phase Microextraction (SPME in Determination of Pesticide Residues in Soil Samples

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2011-01-01

    Full Text Available The basic principles and application possibilities of the methods based on solid phase microextraction (SPME in the analysis of pesticide residues in soil samples are presented in the paper. The most important experimental parameters which affect SPME efficacy inpesticide determination (type and thickness of microextraction fiber, duration of microextraction,temperature at which it is conducted, effect of addition of salts (the effect of efflorescence,temperature and time of desorption, the choice of optimal solvent for pesticide exctraction from the soil and the optimal number of extraction steps, as well as general guidelines for their optimization are also shown. In the end, current applications of SPMEmethods in the analysis of pesticide residues in soil samples are presented.

  18. Comparison of SPME Methods for Determining Volatile Compounds in Milk, Cheese, and Whey Powder

    Directory of Open Access Journals (Sweden)

    Michael H. Tunick

    2013-11-01

    Full Text Available Solid phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but conditions have to be adjusted to maximize release while not generating new compounds that are absent in the original sample. Queso Fresco, a fresh non-melting cheese, may be heated at 60 °C for 30 min; in contrast, compounds are produced in milk when exposed to light and elevated temperatures, so milk samples are heated as little as possible. Products such as dehydrated whey protein are more stable and can be exposed to longer periods (60 min of warming at lower temperature (40 °C without decomposition, allowing for capture and analysis of many minor components. The techniques for determining the volatiles in dairy products by SPME and GC-MS have to be optimized to produce reliable results with minimal modifications and analysis times.

  19. Evaluation of knee range of motion: Correlation between measurements using a universal goniometer and a smartphone goniometric application.

    Science.gov (United States)

    Dos Santos, Rafael Aparecido; Derhon, Viviane; Brandalize, Michelle; Brandalize, Danielle; Rossi, Luciano Pavan

    2017-07-01

    Goniometers are commonly used to measure range of motion in the musculoskeletal system. Recently smartphone goniometry applications have become available to clinicians. Compare angular measures using a universal goniometer and a smartphone application. Thirty four healthy women with at least 20° of limited range of motion regarding knee extension were recruited. Knee flexion angles of the dominant limb were measured with a universal goniometer and the ROM © goniometric application for the smartphone. Three trained examiners compared the two assessment tools. Strong correlations were found between the measures of the universal goniometer and smartphone application (Pearson's correlation and interclass correlation coefficient > 0.93). The measurements with both devices demonstrated low dispersion and little variation. Measurements obtained using the smartphone goniometric application analyzed are as reliable as those of a universal goniometer. This application is therefore a useful tool for the evaluation of knee range of motion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Measuring Earth: Current status of the GRACE Follow-On Laser Ranging Interferometer

    Science.gov (United States)

    Schütze, Daniel; LRI Team

    2016-05-01

    The GRACE mission that was launched in 2002 has impressively proven the feasibility of low-orbit satellite-to-satellite tracking for Earth gravity observations. Especially mass transport related to Earth's hydrological system could be well resolved both spatially and temporally. This allows to study processes such as polar ice sheet decline and ground water depletion in great detail. Owing to GRACE's success, NASA and GFZ will launch the successor mission GRACE Follow-On in 2017. In addition to the microwave ranging system, GRACE Follow-On will be the first mission to use a Laser Ranging Interferometer as technology demonstrator to track intersatellite distance changes with unprecedented precision. This new ranging device inherits some of the technologies which have been developed for the future spaceborne gravitational wave detector LISA. I will present the architecture of the Laser Ranging Interferometer, point out similarities and differences to LISA, and conclude with the current status of the flight hardware production.

  1. Polycyclic aromatic hydrocarbons bioavailability in industrial and agricultural soils: Linking SPME and Tenax extraction with bioassays.

    Science.gov (United States)

    Guo, Meixia; Gong, Zongqiang; Li, Xiaojun; Allinson, Graeme; Rookes, James; Cahill, David

    2017-06-01

    The aims of this study were to evaluate the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in industrial and agricultural soils using chemical methods and a bioassay, and to study the relationships between the methods. This was conducted by comparing the quantities of PAHs extracted from two manufactured gas plant (MGP) soils and an agricultural soil with low level contamination by solid-phase micro-extraction (SPME) and Tenax-TA extraction with the quantities taken up by the earthworm (Eisenia fetida). In addition, a biodegradation experiment was conducted on one MGP soil (MGP-A) to clarify the relationship between PAH removal by biodegradation and the variation in PAH concentrations in soil pore water. Results demonstrated that the earthworm bioassay could not be used to examine PAH bioavailability in the tested MGP soils; which was the case even in the diluted MGP-A soils after biodegradation. However, the bioassay was successfully applied to the agricultural soil. These results suggest that earthworms can only be used for bioassays in soils with low toxicity. In general, rapidly desorbing concentrations extracted by Tenax-TA could predict PAH concentrations accumulated in earthworms (R 2 =0.66), while SPME underestimated earthworm concentrations by a factor of 2.5. Both SPME and Tenax extraction can provide a useful tool to predict PAH bioavailability for earthworms, but Tenax-TA extraction was proven to be a more sensitive and precise method than SPME for the prediction of earthworm exposure in the agricultural soil. Copyright © 2017. Published by Elsevier Inc.

  2. Determination of Sesquiterpenes in Wines by HS-SPME Coupled with GC-MS

    OpenAIRE

    Cincotta, Fabrizio; Verzera, Antonella; Tripodi, Gianluca; Condurso, Concetta

    2015-01-01

    The sesquiterpene compounds present in red wines were characterized and quantified by Headspace Solid-Phase Microextraction in combination with Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS). Sixteen sesquiterpenes were identified, mainly hydrocarbons but also derived oxygenated compounds. Sesquiterpenes were acyclic, monocyclic, byciclic and tryciclic. Sesquiterpenes were detected in SIM (selected ion monitoring) mode using their characteristics ions. All the sesquiterpenes were identi...

  3. Prediction of Partition Coefficients of Organic Compounds for SPME/PDMS

    OpenAIRE

    Liao Hsuan-Yu; Huang Miao-Ling; Lu Yu-Ting; Chao Keh-Ping

    2016-01-01

    The partition coefficients of 51 organic compounds between SPME/PDMS and gas were compiled from the literature sources in this study. The effect of physicochemical properties and descriptors on the partitioning process of partition coefficients was explicated by the correlation analysis. The PDMS-gas partition coefficients were well correlated to the molecular weight of organic compounds (r = 0.832, p < 0.05). An empirical model, consisting of the molecular weight and the polarizability, was ...

  4. A hydrogel based nanosensor with an unprecedented broad sensitivity range for pH measurements in cellular compartments

    DEFF Research Database (Denmark)

    Zhang, M.; Søndergaard, Rikke Vicki; Ek, Pramod Kumar

    2015-01-01

    Optical pH nanosensors have been applied for monitoring intracellular pH in real-time for about two decades. However, the pH sensitivity range of most nanosensors is too narrow, and measurements that are on the borderline of this range may not be correct. Furthermore, ratiometric measurements...... of acidic intracellular pH (pH sensor, a fluorophore based nanosensor, with an unprecedented broad measurement range from pH 1.4 to 7.0. In this nanosensor, three p......H-sensitive fluorophores (difluoro-Oregon Green, Oregon Green 488, and fluorescein) and one pH-insensitive fluorophore (Alexa 568) were covalently incorporated into a nanoparticle hydrogel matrix. With this broad range quadruple-labelled nanosensor all physiological relevant pH levels in living cells can be measured...

  5. Fractional momentum transfer in incomplete fusion reaction: measurement of recoil range distributions in 20Ne + 159Tb system

    International Nuclear Information System (INIS)

    Ali, R.; Singh, D.; Pachouri, Dipti; Afzal Ansari, M.; Rashid, M.H.

    2007-01-01

    The recoil range distribution (RRD) of several residues have been measured for the system 20 Ne + 159 Tb at 165 MeV beam energy by collecting the recoiling residues in the Al-catcher foils of varying thickness

  6. A high area, porous and resistant platinized stainless steel fiber coated by nanostructured polypyrrole for direct HS-SPME of nicotine in biological samples prior to GC-FID quantification.

    Science.gov (United States)

    Abdolhosseini, Sana; Ghiasvand, Alireza; Heidari, Nahid

    2017-09-01

    The surface of a stainless steel fiber was made porous, resistant and cohesive using electrophoretic deposition and coated by the nanostructured polypyrrole using an amended in-situ electropolymerization method. The coated fiber was applied for direct extraction of nicotine in biological samples through a headspace solid-phase microextraction (HS-SPME) method followed by GC-FID determination. The effects of the important experimental variables on the efficiency of the developed HS-SPME-GC-FID method, including pH of sample solution, extraction temperature and time, stirring rate, and ionic strength were evaluated and optimized. Under the optimal experimental conditions, the calibration curve was linear over the range of 0.1-20μgmL -1 and the detection limit was obtained 20ngmL -1 . Relative standard deviation (RSD, n=6) was calculated 7.6%. The results demonstrated the superiority of the proposed fiber compared with the most used commercial types. The proposed HS-SPME-GC-FID method was successfully used for the analysis of nicotine in urine and human plasma samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Investigation of fractional momentum transfer: measurement of forward recoil ranges in 16O + natTm collisions

    International Nuclear Information System (INIS)

    Singh, Pushpendra P.; Unnati; Sharma, Manoj Kumar; Singh, B.P.; Prasad, R.; Rakesh Kumar; Golda, K.S.; Bhardwaj, H.D.

    2006-01-01

    For better understanding of complete fusion and incomplete fusion in heavy ion reactions a programme of precise measurements of excitation functions, recoil range distribution and angular distributions of recoils has been undertaken. In the present contribution the recoil range distribution for the residues have been measured at ≅ 6 MeV/nucleon, using recoil-catcher technique followed by off-line gamma-spectroscopy

  8. SPME as a promising tool in translational medicine and drug discovery: From bench to bedside.

    Science.gov (United States)

    Goryński, Krzysztof; Goryńska, Paulina; Górska, Agnieszka; Harężlak, Tomasz; Jaroch, Alina; Jaroch, Karol; Lendor, Sofia; Skobowiat, Cezary; Bojko, Barbara

    2016-10-25

    Solid phase microextraction (SPME) is a technology where a small amount of an extracting phase dispersed on a solid support is exposed to the sample for a well-defined period of time. The open-bed geometry and biocompatibility of the materials used for manufacturing of the devices makes it very convenient tool for direct extraction from complex biological matrices. The flexibility of the formats permits tailoring the method according the needs of the particular application. Number of studies concerning monitoring of drugs and their metabolites, analysis of metabolome of volatile as well as non-volatile compounds, determination of ligand-protein binding, permeability and compound toxicity was already reported. All these applications were performed in different matrices including biological fluids and tissues, cell cultures, and in living animals. The low invasiveness of in vivo SPME, ability of using very small sample volumes and analysis of cell cultures permits to address the rule of 3R, which is currently acknowledged ethical standard in R&D labs. In the current review systematic evaluation of the applicability of SPME to studies required to be conduct at different stages of drug discovery and development and translational medicine is presented. The advantages and challenges are discussed based on the examples directly showing given experimental design or on the studies, which could be translated to the models routinely used in drug development process. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Headspace sorptive solid phase microextraction (HS-SPME) combined with a spectrophotometry system: A simple glass devise for extraction and simultaneous determination of cyanide and thiocyanate in environmental and biological samples.

    Science.gov (United States)

    Al-Saidi, H M; Al-Harbi, Sami A; Aljuhani, E H; El-Shahawi, M S

    2016-10-01

    A simple, low cost and efficient headspace sorptive solid phase microextraction (HS-SPME) method for determination of cyanide has been developed. The system comprises of a glass tube with two valves and a moveable glass slide fixed at its centre. It includes an acceptor phase polyurethane foam treated mercury (II) dithizonate [Hg(HDz)2-PUF] complex fixed inside by a septum cap in a cylindrical configuration (5.0cm length and 1.0cm diameter). The extraction is based upon the contact of the acceptor phase to the headspace and subsequently measuring the absorbance of the recovered mercury (II) dithizonate from PUFs sorbent. Unlike other HSSE, extraction and back - extractions was carried out in a closed system, thereby improving the analytical performance by preventing the analyte loss. Under the optimized conditions, a linear calibration plot in the range of 1.0-50.0µmolL(-1) was achieved with limits of detection (LOD) and quantification (LOQ) of 0.34, 1.2µmolL(-1) CN(-), respectively. Simultaneous analysis of cyanide and thiocyanate in saliva was also performed with satisfactory recoveries. Copyright © 2016. Published by Elsevier B.V.

  10. 110. PTB seminar: Dose rate measurements of ionizing radiation in the range of natural ambient radiation. Proceedings

    International Nuclear Information System (INIS)

    Lauterbach, U.; Pessara, W.; Woehler-Figgen, S.

    1997-12-01

    Measuring instruments for radiation dose measurement in the range of natural ambient radiation are not subject to legal obligations for calibration and the PTB received numerous requests in the past, asking for measures to be taken in order to ensure reliability of measuring results in this range of radiation. This has induced PTB to organise the seminar, intended to present the current status of measuring technology in this field, reveal problems encountered in practical applications, and discuss suitable ction for quality assurance. The papers of the seminar report the measuring performance and capabilities of the available instruments, results of comparative analyses of measurements, and resulting proposed action for quality assurance. Discussions concluding the sessions are also presented in the processdings volume. (orig./CB) [de

  11. An optical distance sensor : tilt robust differential confocal measurement with mm range and nm uncertainty

    NARCIS (Netherlands)

    Cacace, L.A.

    2009-01-01

    Compared with conventional high-end optical systems, application of freeform optics offers many advantages. Their widespread use, however, is held back by the lack of a suitable measurement method.The NANOMEFOS project aims at realizing a universal freeform measurement machine to fill that void.The

  12. High dynamic range isotope ratio measurements using an analog electron multiplier

    Czech Academy of Sciences Publication Activity Database

    Williams, P.; Lorinčík, Jan; Franzreb, K.; Herwig, R.

    2013-01-01

    Roč. 45, č. 1 (2013), s. 549-552 ISSN 0142-2421 R&D Projects: GA MŠk ME 894 Institutional support: RVO:67985882 Keywords : Isotope ratios * electron multiplier * dynamic range Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.393, year: 2013

  13. Determination of infinite dilution activity coefficients using HS-SPME/GC/FID for hydrocarbons in furfural at temperatures of (298.15, 308.15, and 318.15) K

    International Nuclear Information System (INIS)

    Arantes Furtado, Filipe; Vieira Coelho, Gerson Luiz

    2012-01-01

    Highlights: ► Two approaches were proposed using SPME on determination of infinite dilution activity coefficients. ► Infinite dilution activity coefficients of nine solutes in solvent furfural at T = (298.15, 308.15, and 318.15) K. ► Fiber–gas partition coefficients of nine solutes on PDMS at T = (298.15, 308.15, and 318.15) K. ► Optical microscopy analysis and statistical tests to measure possible damages on fiber coating. ► Advantages and limitations of methodology proposed were discussed. - Abstract: A new methodology using the headspace solid phase microextraction (HS-SPME) technique has been used to evaluate the infinite dilution activity coefficient (γ 12 ∞ ) of nine hydrocarbons (alkanes, cycloalkanes, and aromatics) in furfural solvent. The main objective of this study was to validate a faster and lower cost methodology expanding the use of HS-SPME to determine infinite dilution activity of solutes in organic solvents. Two approaches were proposed for the determination of γ 12 ∞ in order to use this technique (HS-SPME). In addition, the fiber–gas partition coefficients (K fg ) for each analyte at each of the studied temperatures were determined. The activity and partition coefficients have been reported at temperatures of (298.15, 308.15, and 318.15) K. The data were compared with the literature infinite dilution data determined by other methods such as liquid–gas chromatography (GLC) and gas stripping. Partial molar excess enthalpies of mixing at infinite dilution for each solute have been determined. The fibers were tested before and after each experiment, using statistical methods to ensure that their properties do not change during the experiments. The fibers were also analyzed by optical microscopy to evaluate possible surface damage by comparing them with new fibers. The activity coefficient values correlated well with the data in the literature and showed average deviations less than 10%.

  14. High resolution kilometric range optical telemetry in air by radio frequency phase measurement

    Czech Academy of Sciences Publication Activity Database

    Guillory, J.; Šmíd, Radek; García-Márquez, J.; Truong, D.; Alexandre, CH.; Wallerand, J. P.

    2016-01-01

    Roč. 87, č. 7 (2016), 075105:1-6 ISSN 0034-6748 Institutional support: RVO:68081731 Keywords : distance-measuring instrument * index Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.515, year: 2016

  15. Atmospheric particles acting as ice forming nuclei in different size ranges and cloud condensation nuclei measurements

    International Nuclear Information System (INIS)

    Santachiara, G.; Di Matteo, L.; Belosi, F.; Prodi, F.

    2009-01-01

    Measurements of ice nuclei (I N) in different size classes of aerosol P M1, P M2.5, PM10, and total suspended particles (Tsp) were performed at a rural site (S.Pietro Capofiume, in the Po Valley, Italy). Simultaneous measurements of particle number concentrations were also made with a condensation nucleus counter (CN C-TSI), along with particle concentration in different size classes starting from diameter d > 0.3 μm (Optical Spectrometer Grimm, Mod.1.108). No correlation is observed between I N and the particle number concentration measured with the condensation nuclei counter, and there is only a weak correlation with the particle concentration measured using the optical counter, thus confirming the contribution of the accumulation and coarse aerosol fraction. A positive correlation is observed between supersaturation with respect to ice and water values and ice nuclei number concentration, and an exponential dependence of I N on temperature is found. In addition, cloud concentration nuclei (C CN) were measured. The present measurements reveal a diurnal trend, with lower values at about midday and higher ones during the night, a similar trend between C CN and the relative humidity, and opposite to the mixing layer height.

  16. Comparison of the measurement of heart rate in adult free-range chickens (Gallus domesticus) by auscultation and electrocardiography.

    Science.gov (United States)

    Smith, C F; Gavaghan, B J; McSweeney, D; Powell, V; Lisle, A

    2014-12-01

    To compare the heart rates of adult free-range chickens (Gallus domesticus) measured by auscultation with a stethoscope with those measured simultaneously using electrocardiography (ECG). With each bird in a standing position, estimation of the heart rate was performed by placing a mark on paper for every 4 beats for roosters and 8 beats for hens as detected by auscultation over 30 s, while simultaneous ECG was performed. Heart rates measured by auscultation showed a high correlation (r = 0.97) with those measured by ECG. There was a high correlation between the heart rates of adult free-range chickens measured by auscultation with a stethoscope and those measured simultaneously using ECG. © 2014 Australian Veterinary Association.

  17. Comparison of three different concepts of high dynamic range and dependability optimised current measurement digitisers for beam loss systems

    CERN Document Server

    Viganò, W; Effinger, E; Venturini, G G; Zamantzas, C

    2012-01-01

    Three Different Concepts of High Dynamic Range and Dependability Optimised Current Measurement Digitisers for Beam Loss Systems will be compared on this paper. The first concept is based on Current to Frequency Conversion, enhanced with an ADC for extending the dynamic range and decreasing the response time. A summary of 3 years’ worth of operational experience with such a system for LHC beam loss monitoring will be given. The second principle is based on an Adaptive Current to Frequency Converter implemented in an ASIC. The basic parameters of the circuit are discussed and compared with measurements. Several measures are taken to harden both circuits against single event effects and to make them tolerant for operation in radioactive environments. The third circuit is based on a Fully Differential Integrator for enhanced dynamic range, where laboratory and test installation measurements will be presented. All circuits are designed to avoid any dead time in the acquisition and have reliability and fail safe...

  18. Infrared Line Intensities for Formaldehyde from Simultaneous Measurements in the Infrared and Far Infrared Spectral Ranges

    Science.gov (United States)

    Fissiaux, L.; Földes, T.; Tchana, F. Kwabia; Daumont, L.; Lepère, M.; Vander Auwera, J.

    2011-06-01

    Formaldehyde (H_2CO) is an important intermediate compound in the degradation of the volatile organic compounds (VOCs), including methane, in the terrestrial troposphere. Its observation using optical remote sensing in the infrared range relies on the 3.6 and 5.7 μm absorption bands. Band and individual line intensities have been reported in both ranges. With the present work, we aim to also derive infrared line intensities for formaldehyde, however relying on pure rotation line intensities and the known electric dipole moment to determine the particle density. Indeed, because formaldehyde polymerizes or degrades easily, the gas phase may contain polymerization or degradation products. Spectra of H_2CO diluted in 10 hPa of N_2 were therefore simultaneously recorded in the 20-60 Cm-1 and 3.6 μm ranges, respectively using a Bruker IFS125HR Fourier transform spectrometer and a tunable diode laser. see A. Perrin, D. Jacquemart, F. Kwabia Tchana, N. Lacome, J. Quant. Spectrosc. Radiat. Transfer 110 (2009) 700-716, and references therein

  19. Measured electric field intensities near electric cloud discharges detected by the Kennedy Space Center's Lightning Detection and Ranging System, LDAR

    Science.gov (United States)

    Poehler, H. A.

    1977-01-01

    For a summer thunderstorm, for which simultaneous, airborne electric field measurements and Lightning Detection and Ranging (LDAR) System data was available, measurements were coordinated to present a picture of the electric field intensity near cloud electrical discharges detected by the LDAR System. Radar precipitation echos from NOAA's 10 cm weather radar and measured airborne electric field intensities were superimposed on LDAR PPI plots to present a coordinated data picture of thunderstorm activity.

  20. Instrumental measurement of iridium abundances in the part-per-trillion range following neutron activation

    International Nuclear Information System (INIS)

    Alvarez, L.W.; Asaro, F.; Goulding, F.S.; Landis, D.A.; Madden, N.W.; Malone, D.F.

    1988-01-01

    An automated gamma-ray coincidence spectrometer has been constructed which, following neutron activation, can measure iridium (Ir) abundances of the order of 25 parts-per-trillion (ppt) in rock samples 500 times more rapidly than previously possible by instrumental techniques used at the Lawrence Berkeley Laboratory. Twin intrinsic Ge gamma-ray detectors count coincidences between the 316.5 and 468.1 keV gamma rays of 192 Ir, and together with a mineral-oil-based Compton suppression shield provide a sensitivity of 50 ppt Ir in 7 minute measurements of 100 mg limestone samples subsequent to irradiation in the University of Missouri reactor. Over 3000 samples have been measured, and in collaboration with many geologists and paleontologists from around the world, anomalous amounts of Ir have been detected in rocks with approximate ages of 12, 39, 67, 91, 150 and 3500 million years. Modifications are nearly complete to measure ten other elements very important to geochemical studies simultaneously (in the singles rather than the coincidence mode) with the Ir measurements

  1. Measurements of transition probabilities in the range from vacuum ultraviolet to infrared

    International Nuclear Information System (INIS)

    Peraza Fernandez, M.C.

    1992-01-01

    In this memory we describe the design, testing and calibration of different spectrometers to measure transition probabilities from the vacuum ultraviolet to the infrared spectral region. For the infrared measurements we have designed and performed a phase sensitive detection system, using an InGaAs photodiode like detector. With this system we have determined the transition probabilities of infrared lines of KrI and XeI. For these lines we haven't found previous measurements. In the vacuum ultraviolet spectral region we have designed a 3 m normal incidence monochromator where we have installed an optical multichannel analyzer. We have tested its accurate working, obtaining the absorption spectrum of KrI. In the visible region we have obtained the emission spectrum of Al using different spectral: hallow-cathode lamp and Nd: YAG laser produced Al plasma. With these spectra we have determined different atomic parameters like transition probabilities and electron temperatures.(author). 83 refs

  2. Optoelectronic device for the measurement of the absolute linear position in the micrometric displacement range

    Science.gov (United States)

    Morlanes, Tomas; de la Pena, Jose L.; Sanchez-Brea, Luis M.; Alonso, Jose; Crespo, Daniel; Saez-Landete, Jose B.; Bernabeu, Eusebio

    2005-07-01

    In this work, an optoelectronic device that provides the absolute position of a measurement element with respect to a pattern scale upon switch-on is presented. That means that there is not a need to perform any kind of transversal displacement after the startup of the system. The optoelectronic device is based on the process of light propagation passing through a slit. A light source with a definite size guarantees the relation of distances between the different elements that constitute our system and allows getting a particular optical intensity profile that can be measured by an electronic post-processing device providing the absolute location of the system with a resolution of 1 micron. The accuracy of this measuring device is restricted to the same limitations of any incremental position optical encoder.

  3. Facility for the measurement of proton polarization in the range 50-70 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, M; Sakaguchi, H; Sakamoto, H; Ogawa, H; Cynshi, O; Kobayashi, S [Kyoto Univ. (Japan). Dept. of Physics; Kato, S [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies; Matsuoka, N; Hatanaka, K; Noro, T [Osaka Univ., Toyonaka (Japan). Research Center for Nuclear Physics

    1983-07-01

    A proton polarimetry facility based on silicon analyzers combined with high-purity germanium detectors is described. The scattering efficiency is 1.5 x 10/sup -5/ at 60 MeV with an effective analyzing power of 0.71 and the energy resolution is about 300 keV fwhm. The facility has succeeded in measuring the depolarization in p-/sup 13/C elastic scattering separated clearly from inelastic events. In order to use a silicon detector as an analyzer target, measurements of cross sections and analyzing powers have been performed at proton energies of 65, 60, 55, 50 and 45 MeV.

  4. High resolution kilometric range optical telemetry in air by radio frequency phase measurement

    Energy Technology Data Exchange (ETDEWEB)

    Guillory, Joffray; García-Márquez, Jorge; Truong, Daniel; Wallerand, Jean-Pierre [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Šmíd, Radek [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Institute of Scientific Instruments of the CAS, Kralovopolska 147, 612 64 Brno (Czech Republic); Alexandre, Christophe [Centre d’Études et de Recherche en Informatique et Communications (CEDRIC), Cnam, 292 rue St-Martin, 75003 Paris (France)

    2016-07-15

    We have developed an optical Absolute Distance Meter (ADM) based on the measurement of the phase accumulated by a Radio Frequency wave during its propagation in the air by a laser beam. In this article, the ADM principle will be described and the main results will be presented. In particular, we will emphasize how the choice of an appropriate photodetector can significantly improve the telemeter performances by minimizing the amplitude to phase conversion. Our prototype, tested in the field, has proven its efficiency with a resolution better than 15 μm for a measurement time of 10 ms and distances up to 1.2 km.

  5. Surface Roughness Measurements Utilizing Long-Range Surface-Plasma Waves

    Science.gov (United States)

    1984-11-01

    8217 The theory dealt only with the depen- modes, one symmetric and one antisymmetric, dence of the real wave vector on the real part of that propagate...quantity, while the wave vector is complex. It is shown that for both the supported and unsup- From Eqs. (1) and (2) one obtains the real implic- ported...Opt. Soc. sabbatical leave from the University of Toledo. Am.). Optical feild enhancemeft by long-range surface- I" ouT In O’ in OUT way@, plasma waves

  6. Patient Self-Assessed Passive Range of Motion of the Knee Cannot Replace Health Professional Measurements

    DEFF Research Database (Denmark)

    Borgbjerg, Jens; Madsen, Frank; Odgaard, Anders

    2017-01-01

    The purpose of this study was to investigate whether patients can accurately self-assess their knee passive range of motion (PROM). A picture-based questionnaire for patient self-assessment of knee PROM was developed and posted to patients. The self-assessed PROM from 58 patients was compared...... (≥ 10-degree flexion contracture). Surgeon- and patient-assessed knee PROM showed a mean difference (95% limits of agreement) of -2.1 degrees (-42.5 to 38.3 degrees) for flexion and -8.1 degrees (-28.8 to 12.7 degrees) for extension. The sensitivity of patient self-assessed PROM in identifying knee...

  7. Range measurements and track kinetics in Dielectric Nuclear Track Detectors (DNTDs)

    Energy Technology Data Exchange (ETDEWEB)

    Aframian, A

    1981-01-01

    Observations of nuclear track development profiles and the kinetics of etched tracks in sensitive dielectric nuclear track detectors indicate three separate phases: the inception phase or the cone phase, the transition phase and the sphere phase. Continued etching of the sphere phase to through-tracks yields accurate range data for particles of different masses and energies and minimum critical angles of registration for each particle. The present results show an energy resolution of 40 keV (fwhm) for 5.48 MeV alpha-particles emitted from Am-241.

  8. A compact, large-range interferometer for precision measurement and inertial sensing

    Science.gov (United States)

    Cooper, S. J.; Collins, C. J.; Green, A. C.; Hoyland, D.; Speake, C. C.; Freise, A.; Mow-Lowry, C. M.

    2018-05-01

    We present a compact, fibre-coupled interferometer with high sensitivity and a large working range. We propose to use this interferometer as a readout mechanism for future inertial sensors, removing a major limiting noise source, and in precision positioning systems. The interferometer’s peak sensitivity is 2 × 10-{14} m \\sqrt{Hz-1} at 70 Hz and 7 × 10-{11} m \\sqrt{Hz-1} at 10 mHz. If deployed on a GS-13 geophone, the resulting inertial sensing output will be limited by the suspension thermal noise of the reference mass from 10 mHz to 2 Hz.

  9. A measurement of auroral electrons in the 1–10 MeV range

    NARCIS (Netherlands)

    Gils, J.N. van; Beek, H.F. van; Fetter, L.D. de; Hendrickx, R.V.

    Particle fluxes have been measured by means of shielded Geiger-Müller telescopes mounted m a rocket, which was launched from ESRANGE(Kiruna) into a diffuse aurora. The analysis of the dependence of the counting rates on altitude indicates that a weak flux of energetic electrons, 1–10 MeV, has been

  10. Constraints on the design of flow measuring structures over a large dynamic flow range

    International Nuclear Information System (INIS)

    Hickey, M.J.; Holmes, R.M.

    1979-01-01

    Topographical restraints for design storm flow are described as sharp-crested weirs for low flows in series with broad-crested weirs for the high flows. These design selections are considered to be most economical while providing the specified flow measuring capabilities for movement of radionuclides from the solid waste disposal areas into the surface streams around ORNL

  11. A 100 GHz Polarimetric Compact Radar Range for Scale-Model Radar Cross Section Measurements

    Science.gov (United States)

    2013-10-01

    common radar bands. ACKNOWLEDGEMENTS The authors wish to thank David Jillson (UML STL – Electrical Engineer) for efforts involved in RF and DC wiring...Waldman J., Fetterman H.R., Duffy P.E., Bryant T.G., Tannenwald P.E., “Submillimeter Model Measurements and Their Applications to Millimeter Radar

  12. Natural Variation of Volatile Compounds in Virgin Olive Oil Analyzed by HS-SPME/GC-MS-FID

    Directory of Open Access Journals (Sweden)

    Carlos Sanz

    2018-04-01

    Full Text Available Virgin olive oil is unique among plant oils for its high levels of oleic acid, and the presence of a wide range of minor components, which are responsible for both its health-promoting properties and characteristic aroma, and only produced when olives are crushed during the industrial process used for oil production. The genetic variability of the major volatile compounds comprising the oil aroma was studied in a representative sample of olive cultivars from the World Olive Germplasm Collection (IFAPA, Cordoba, Spain, by means of the headspace solid-phase microextraction/gas chromatography–mass spectrometry–flame ionization detection (HS-SPME/GC-MS-FID. The analytical data demonstrated that a high variability is found for the content of volatile compounds in olive species, and that most of the volatile compounds found in the oils were synthesized by the enzymes included in the so-called lipoxygenase pathway. Multivariate analysis allowed the identification of cultivars that are particularly interesting, in terms of volatile composition and presumed organoleptic quality, which can be used both to identify old olive cultivars that give rise to oils with a high organoleptic quality, and in parent selection for olive breeding programs.

  13. Analysis of volatile compounds in gluten-free bread crusts with an optimised and validated SPME-GC/QTOF methodology.

    Science.gov (United States)

    Pico, Joana; Antolín, Beatriz; Román, Laura; Gómez, Manuel; Bernal, José

    2018-04-01

    The aroma of bread crust, as one of the first characteristics perceived, is essential for bread acceptance. However, gluten-free bread crusts exhibit weak aroma. A SPME-GC/QTOF methodology was optimised with PCA and RSM and validated for the quantification of 44 volatile compounds in bread crust, extracting 0.75 g of crust at 60 °C for 51 min. LODs ranged between 3.60 and 1760 μg Kg -1 , all the R 2 were higher than 0.99 and %RSD for precision and %Er for accuracy were lower than 9% and 12%, respectively. A commercial wheat bread crust was quantified, and furfural was the most abundant compound. Bread crusts of wheat starch and of japonica rice, basmati rice and teff flours were also quantified. Teff flour and wheat starch crusts were very suitable for improving gluten-free bread crust aroma, due to their similar content in 2-acetyl-1-pyrroline and 4-hydroxy-2,5-dimethyl-3(2H)-furanone compared to wheat flour crust and also for their high content in pyrazines. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Measuring Pulse Rate Variability using Long-Range, Non-Contact Imaging Photoplethysmography

    Science.gov (United States)

    2016-08-20

    contains color . 14. ABSTRACT Camera-based measurement of the blood volume pulse via non-contact, imaging photoplethysmography is a very popular approach...ECG) for each window were calculated in beats per minute (bpm). The periodogram method with a Hamming window was used to estimate mean pulse...11 Hz. Independent component analysis (ICA) was then used to decompose the normalized, bandpass-filtered, color -channel signals into independent

  15. A study on the excore neutron flux monitoring system for the wide range measurement

    International Nuclear Information System (INIS)

    Han, Sang Jun; Jeong, Dae Won; Baek, Kwang Il; Lee, Jeong Yang; Ha, Jae Hong

    1995-11-01

    This paper describes a study in which only one kind of neutron detector were used in the advanced ENFMS. The conceptual design was performed for overall system with unified fission chamber. The system consists of detector, junction box, wide-range amplifier and signal processing device. Also the requirements of 10CFR50 App. R were considered in design. On the other hand, through computer simulation, the characteristics of pulse-count mode and MSV mode was scrutinized and each noise withstanding capability was analyzed. The results say that 3rd moment has the more stable characteristics to background noise than MSV method. Also, to remain the integrity of information against noise, during installation and operation, the overall system of KSNP was analyzed from a view of noise. By administration for the cause of noise and noise-coupling paths, through the full understanding of noise characteristics, the transfer of the noise source can be minimized. (Author)

  16. n-p Short-Range Correlations from (p,2p+n) Measurements

    Science.gov (United States)

    Tang, A.; Watson, J. W.; Aclander, J.; Alster, J.; Asryan, G.; Averichev, Y.; Barton, D.; Baturin, V.; Bukhtoyarova, N.; Carroll, A.; Gushue, S.; Heppelmann, S.; Leksanov, A.; Makdisi, Y.; Malki, A.; Minina, E.; Navon, I.; Nicholson, H.; Ogawa, A.; Panebratsev, Yu.; Piasetzky, E.; Schetkovsky, A.; Shimanskiy, S.; Zhalov, D.

    2003-01-01

    We studied the 12C(p,2p+n) reaction at beam momenta of 5.9, 8.0, and 9.0 GeV/c. For quasielastic (p,2p) events pf, the momentum of the knocked-out proton before the reaction, was compared (event by event) with pn, the coincident neutron momentum. For |pn|>kF=0.220 GeV/c (the Fermi momentum) a strong back-to-back directional correlation between pf and pn was observed, indicative of short-range n-p correlations. From pn and pf we constructed the distributions of c.m. and relative motion in the longitudinal direction for correlated pairs. We also determined that 49±13% of events with |pf|>kF had directionally correlated neutrons with |pn|>kF.

  17. Inferring bread doneness with air-pulse/ultrasonic ranging measurements of the loaf elastic response

    Science.gov (United States)

    Faeth, Loren Elbert

    This research marks the discovery of a method by which bread doneness may be determined based on the elastic properties of the loaf as it bakes. The purpose of the study was to determine if changes in bread characteristics could be determined by non-contact methods during baking, as the basis for improved control of the baking process. Current control of the baking process is based on temperature and dwell time, which are determined by experience to produce a produce which is approximately ``done.'' There is no direct measurement of the property of interest, doneness. An ultrasonic measurement system was developed to measure the response of the loaf to an external stimulus. ``Doneness,'' as reflected in the internal elastic consistency of the bakery product, is assessed in less than 1/2 second, and requires no closer approach to the moving bakery product than about 2 inches. The system is designed to be compatible with strapped bread pans in a standard traveling-tray commercial oven.

  18. [Comparing the ranges of defect measured with standard white on white and Pulsar perimetries].

    Science.gov (United States)

    González de la Rosa, M; González-Hernández, M; García-Feijoo, J; Sánchez Méndez, M; García-Sánchez, J

    2011-04-01

    Normal thresholds on Pulsar perimetry fall faster than those of standard perimetry in the peripheral visual field. Two related studies were performed. Firstly, the frequency distributions of glaucoma defects on standard automated perimetry (SAP) and the relationship of the centre and periphery (Study A) were studied first, followed by an attempt to establish the limits of pulsar perimetry (Study B). A: frequency of defects was calculated in 78.663 SAP perimetries (G1-TOP, Octopus 1-2-3, Haag-Streit). Study B: 204 eyes with mean defect (MD-SAP) lower than 9 dB were examined 8.92 ± 4.19 times with SAP (TOP-32, Octopus 311) and temporal modulation perimetry (T30W, Pulsar Perimeter, Haag-Streit). Study A: 50.7% of the SAP examinations showed MD values lower than 9 dB and 32.7% bellow 6 dB. The MD correlation of the central 20° with the MD of the most peripheral points was r=0.933. Study B: in cases with MD-TOP-32 lower than 6 dB, SAP had the maximum possibility of detecting defect in 0.02% of points and Pulsar in 0.29%. In subjects with MD-TOP-32 between 6 and 9 dB frequencies were 0.38% in SAP and 3.5% in Pulsar (5.1% for eccentricities higher than 20°). Pulsar allows detecting defects, without range limitations, in the initial half of SAP frequencies expected on glaucoma patients. In order to study the progression of deeper defects the examination should focus on the central points, where the dynamic range of both systems is more equivalent. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  19. Screening for γ-Nonalactone in the Headspace of Freshly Cooked Non-Scented Rice Using SPME/GC-O and SPME/GC-MS

    Directory of Open Access Journals (Sweden)

    Jie Yu Chen

    2009-08-01

    Full Text Available The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O analysis and identified by gas chromatography-mass spectrometry (GC-MS analysis in the headspace above the freshly cooked non-scented rice samples extracted by using a modified headspace solid-phase microextraction (SPME method. This component had a mass spectrum with a characteristic ion peak at m/z 85 (100% and a linear retention index (RI of 2,023 on a DB Wax column, consistent with those of an authentic sample of γ-nonalactone. The odor characterization of a strong, sweet, coconut-like aroma of this compound was also validated by GC-O comparison with the authentic compound.

  20. Respiration rate of stream insects measured in situ along a large altitude range

    DEFF Research Database (Denmark)

    Rostgaard, S.; Jacobsen, D.

    2005-01-01

    Field studies of respiration in stream insects are few in comparison with laboratory studies. To evaluate the influence of temperature and oxygen along altitudinal gradients we measured the respiration rate of fully acclimatized larval Trichoptera, Plecoptera and Ephemeroptera under similar field...... at 100 and 50% oxygen saturation indicated that highland animals reduced their oxygen uptake more than their counterparts in the lowland when oxygen availability decreased. The temperature response of respiration calculated between the insect assemblages at different altitudes showed a mean assemblage Q...

  1. Light detection and ranging measurements of wake dynamics. Part II: two-dimensional scanning

    DEFF Research Database (Denmark)

    Trujillo, Juan-José; Bingöl, Ferhat; Larsen, Gunner Chr.

    2011-01-01

    the instantaneous transversal wake position which is quantitatively compared with the prediction of the Dynamic Wake Meandering model. The results, shown for two 10-min time series, suggest that the conjecture of the wake behaving as a passive tracer is a fair approximation; this corroborates and expands...... the results of one-dimensional measurements already presented in the first part of this paper. Consequently, it is now possible to separate the deterministic and turbulent parts of the wake wind field, thus enabling capturing the wake in the meandering frame of reference. The results correspond, qualitatively...

  2. Frequency Comb Driven Raman Transitions in the THz Range: High Precision Isotope Shift Measurements in Ca+

    DEFF Research Database (Denmark)

    Meyer, Steffen

    2017-01-01

    and frequency resolved optical gating (FROG) are used, and the two frequency comb systems used for the experiments are thoroughly characterized, a Coherent Mira Ti:sapph oscillator and a MenloSystems fiber based frequency comb system. The potential of frequency comb driven Raman transitions is shown...... transition frequencies typically are on the order of a few THz. High precision measurements on these ions have many intriguing applications, for example the test of time-variations of fundamental constants, ultracold chemistry on the quantum level, and quantum information and computing, to name just a few...

  3. Multiple internal standard normalization for improving HS-SPME-GC-MS quantitation in virgin olive oil volatile organic compounds (VOO-VOCs) profile.

    Science.gov (United States)

    Fortini, Martina; Migliorini, Marzia; Cherubini, Chiara; Cecchi, Lorenzo; Calamai, Luca

    2017-04-01

    The commercial value of virgin olive oils (VOOs) strongly depends on their classification, also based on the aroma of the oils, usually evaluated by a panel test. Nowadays, a reliable analytical method is still needed to evaluate the volatile organic compounds (VOCs) and support the standard panel test method. To date, the use of HS-SPME sampling coupled to GC-MS is generally accepted for the analysis of VOCs in VOOs. However, VOO is a challenging matrix due to the simultaneous presence of: i) compounds at ppm and ppb concentrations; ii) molecules belonging to different chemical classes and iii) analytes with a wide range of molecular mass. Therefore, HS-SPME-GC-MS quantitation based upon the use of external standard method or of only a single internal standard (ISTD) for data normalization in an internal standard method, may be troublesome. In this work a multiple internal standard normalization is proposed to overcome these problems and improving quantitation of VOO-VOCs. As many as 11 ISTDs were used for quantitation of 71 VOCs. For each of them the most suitable ISTD was selected and a good linearity in a wide range of calibration was obtained. Except for E-2-hexenal, without ISTD or with an unsuitable ISTD, the linear range of calibration was narrower with respect to that obtained by a suitable ISTD, confirming the usefulness of multiple internal standard normalization for the correct quantitation of VOCs profile in VOOs. The method was validated for 71 VOCs, and then applied to a series of lampante virgin olive oils and extra virgin olive oils. In light of our results, we propose the application of this analytical approach for routine quantitative analyses and to support sensorial analysis for the evaluation of positive and negative VOOs attributes. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Radiometric characterization of six soils in the microwave X-range through complex permittivity measurements

    International Nuclear Information System (INIS)

    Palme, U.W.

    1987-10-01

    Estimating and monitoring up-to-date soil moisture conditions over extensive areas through passive (or active) microwave remote sensing techniques requires the knowledge of the complex relative permittivity (ε r * ) in function of soil moisture. X-band measurements of ε r * for different moisture conditions were made in laboratory for soil samples of six important Soils (PV 2 , LV 3 , LR d , LE 1 , SAP and Sc). Using a theoretical model and computational programmes developed, these measurements allowed estimates of the emissive characteristics of the soils that would be expected with the X-Band Microwave Radiometer built at INPE. The results, new, for soils from tropical regions, showed that only the physical characteristics and properties of the soils are not sufficient to explain the behaviour of ε r * in function of soil moisture, indicating that the chemical and/or mineralogical properties of the soils do have an important contribution. The results also showed thast ε r * in function of soil moisture depends on soil class. (author) [pt

  5. Evaluation of expansion algorithm of measurement range suited for 3D shape measurement using two pitches of projected grating with light source-stepping method

    Science.gov (United States)

    Sakaguchi, Toshimasa; Fujigaki, Motoharu; Murata, Yorinobu

    2015-03-01

    Accurate and wide-range shape measurement method is required in industrial field. The same technique is possible to be used for a shape measurement of a human body for the garment industry. Compact 3D shape measurement equipment is also required for embedding in the inspection system. A shape measurement by a phase shifting method can measure the shape with high spatial resolution because the coordinates can be obtained pixel by pixel. A key-device to develop compact equipment is a grating projector. Authors developed a linear LED projector and proposed a light source stepping method (LSSM) using the linear LED projector. The shape measurement euipment can be produced with low-cost and compact without any phase-shifting mechanical systems by using this method. Also it enables us to measure 3D shape in very short time by switching the light sources quickly. A phase unwrapping method is necessary to widen the measurement range with constant accuracy for phase shifting method. A general phase unwrapping method with difference grating pitches is often used. It is one of a simple phase unwrapping method. It is, however, difficult to apply the conventional phase unwrapping algorithm to the LSSM. Authors, therefore, developed an expansion unwrapping algorithm for the LSSM. In this paper, an expansion algorithm of measurement range suited for 3D shape measurement using two pitches of projected grating with the LSSM was evaluated.

  6. Using satellite laser ranging to measure ice mass change in Greenland and Antarctica

    Directory of Open Access Journals (Sweden)

    J. A. Bonin

    2018-01-01

    Full Text Available A least squares inversion of satellite laser ranging (SLR data over Greenland and Antarctica could extend gravimetry-based estimates of mass loss back to the early 1990s and fill any future gap between the current Gravity Recovery and Climate Experiment (GRACE and the future GRACE Follow-On mission. The results of a simulation suggest that, while separating the mass change between Greenland and Antarctica is not possible at the limited spatial resolution of the SLR data, estimating the total combined mass change of the two areas is feasible. When the method is applied to real SLR and GRACE gravity series, we find significantly different estimates of inverted mass loss. There are large, unpredictable, interannual differences between the two inverted data types, making us conclude that the current 5×5 spherical harmonic SLR series cannot be used to stand in for GRACE. However, a comparison with the longer IMBIE time series suggests that on a 20-year time frame, the inverted SLR series' interannual excursions may average out, and the long-term mass loss estimate may be reasonable.

  7. Using satellite laser ranging to measure ice mass change in Greenland and Antarctica

    Science.gov (United States)

    Bonin, Jennifer A.; Chambers, Don P.; Cheng, Minkang

    2018-01-01

    A least squares inversion of satellite laser ranging (SLR) data over Greenland and Antarctica could extend gravimetry-based estimates of mass loss back to the early 1990s and fill any future gap between the current Gravity Recovery and Climate Experiment (GRACE) and the future GRACE Follow-On mission. The results of a simulation suggest that, while separating the mass change between Greenland and Antarctica is not possible at the limited spatial resolution of the SLR data, estimating the total combined mass change of the two areas is feasible. When the method is applied to real SLR and GRACE gravity series, we find significantly different estimates of inverted mass loss. There are large, unpredictable, interannual differences between the two inverted data types, making us conclude that the current 5×5 spherical harmonic SLR series cannot be used to stand in for GRACE. However, a comparison with the longer IMBIE time series suggests that on a 20-year time frame, the inverted SLR series' interannual excursions may average out, and the long-term mass loss estimate may be reasonable.

  8. Nanocomposite-Based Microstructured Piezoresistive Pressure Sensors for Low-Pressure Measurement Range

    Directory of Open Access Journals (Sweden)

    Vasileios Mitrakos

    2018-01-01

    Full Text Available Piezoresistive pressure sensors capable of detecting ranges of low compressive stresses have been successfully fabricated and characterised. The 5.5 × 5 × 1.6 mm3 sensors consist of a planar aluminium top electrode and a microstructured bottom electrode containing a two-by-two array of truncated pyramids with a piezoresistive composite layer sandwiched in-between. The responses of two different piezocomposite materials, a Multiwalled Carbon Nanotube (MWCNT-elastomer composite and a Quantum Tunneling Composite (QTC, have been characterised as a function of applied pressure and effective contact area. The MWCNT piezoresistive composite-based sensor was able to detect pressures as low as 200 kPa. The QTC-based sensor was capable of detecting pressures as low as 50 kPa depending on the contact area of the bottom electrode. Such sensors could find useful applications requiring the detection of small compressive loads such as those encountered in haptic sensing or robotics.

  9. Study of incomplete fusion sensitivity to projectile structure from forward recoil range distribution measurement

    International Nuclear Information System (INIS)

    Kumar, Harish; Tali, Suhail A.; Afzal Ansari, M.

    2017-01-01

    Recently, the projectile structure is found to affect the incomplete fusion (ICF) process by using α- and non-α-cluster structured projectiles which is explored in terms of projectile α-Q-value and is still limited only for a very few systems. Keeping in view the recent aspects especially the projectile structure effect on ICF, the present work is carried out in the series of experiment by using α- and non-α-cluster structured projectiles. Presently, the FRRDs of evaporation residues (ERs) produced in 13 C + 175 Lu system have been measured at ≈ 88 MeV energy. In this work, an attempt has been made to have a better knowledge of projectile α-Q-value effect on ICF

  10. Rhodamine 800 as reference substance for fluorescence quantum yield measurements in deep red emission range

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, A., E-mail: andrea.alessi@eni.com [Centro Ricerche per le Energie non Convenzionali, Istituto eni Donegani, e.n.i. S.p.A., Via G. Fauser 4, 28100 Novara (Italy); Salvalaggio, M. [Centro Ricerche per le Energie non Convenzionali, Istituto eni Donegani, e.n.i. S.p.A., Via G. Fauser 4, 28100 Novara (Italy); Ruzzon, G. [HORIBA Jobin Yvon Srl, Via Cesare Pavese 35/AB, 20090 Opera Milano (Italy)

    2013-02-15

    The determination of fluorescence quantum yields ({Phi}{sub f}) of deep red dyes emitting at 635-900 nm is difficult due to lack of suitable standards. In this work, we propose a commercial dye, rhodamine 800 (Rho800), as reference standard which belongs to the family of xanthenes. The quantum yield of rhodamine 800 in absolute ethanol has been studied using a relative method with cresyl violet (CV) and rhodamine 101 (Rho101) as references, and an absolute fluorometric method by integrating sphere measurements. - Highlights: Black-Right-Pointing-Pointer A red emitting dye Rhodamine 800 was electronic spectroscopy characterized. Black-Right-Pointing-Pointer Its fluorescence quantum yield was studied using a relative and an absolute method. Black-Right-Pointing-Pointer The values found are greater than the values currently known in the literature.

  11. Application of HS-SPME-GC-MS method for the detection of active moulds on historical parchment.

    Science.gov (United States)

    Sawoszczuk, Tomasz; Syguła-Cholewińska, Justyna; Del Hoyo-Meléndez, Julio M

    2017-03-01

    The goal of this work was to analyse the profile of microbial volatile organic compounds (MVOCs) emitted by moulds growing on parchment samples, in search of particular volatiles mentioned in the literature as indicators of active mould growth. First, the growth of various moulds on samples of parchment was assessed. Those species that showed collagenolytic activity were then inoculated on two types of media: samples of parchment placed on media and on media containing amino acids that are elements of the structure of collagen. All samples were prepared inside 20-ml vials (closed system). In the first case, the media did not contain any sources of organic carbon, nitrogen, or sulphur, i.e. parchment was the only nutrient for the moulds. A third type of sample was historical parchment prepared in a Petri dish without a medium and inoculated with a collagenolytically active mould (open system). The MVOCs emitted by moulds were sampled with the headspace-SPME method. Volatiles extracted on DVB/CAR/PDMS fibres were analysed in a gas chromatography-mass spectrometry system. Qualitative and quantitative analyses of chromatograms were carried out in search of indicators of metabolic activity. The results showed that there are three groups of volatiles that can be used for the detection of active forms of moulds on parchment objects. To the best of our knowledge, this is the first work to measure MVOCs emitted by moulds growing on parchment.

  12. Pose and Shape Reconstruction of a Noncooperative Spacecraft Using Camera and Range Measurements

    Directory of Open Access Journals (Sweden)

    Renato Volpe

    2017-01-01

    Full Text Available Recent interest in on-orbit proximity operations has pushed towards the development of autonomous GNC strategies. In this sense, optical navigation enables a wide variety of possibilities as it can provide information not only about the kinematic state but also about the shape of the observed object. Various mission architectures have been either tested in space or studied on Earth. The present study deals with on-orbit relative pose and shape estimation with the use of a monocular camera and a distance sensor. The goal is to develop a filter which estimates an observed satellite’s relative position, velocity, attitude, and angular velocity, along with its shape, with the measurements obtained by a camera and a distance sensor mounted on board a chaser which is on a relative trajectory around the target. The filter’s efficiency is proved with a simulation on a virtual target object. The results of the simulation, even though relevant to a simplified scenario, show that the estimation process is successful and can be considered a promising strategy for a correct and safe docking maneuver.

  13. How to measure atomic diffusion processes in the sub-nanometer range

    International Nuclear Information System (INIS)

    Schmidt, H.; Gupta, M.; Gutberlet, T.; Stahn, J.; Bruns, M.

    2008-01-01

    Self-diffusion of the atomic constituents in the solid state is a fundamental transport process that controls various materials properties. With established methods of diffusivity determination it is only possible to measure diffusion processes on a length scale down to 10 nm at corresponding diffusivities of 10 -23 m 2 s -1 . However, for complex materials like amorphous or nano-structured solids the given values are often not sufficient for a proper characterization. Consequently, it is necessary to detect diffusion length well below 1 nm. Here, we present the method of neutron reflectometry on isotope multilayers. For two model systems, an amorphous semiconductor and an amorphous metallic alloy, the efficiency of this method is demonstrated to detect minimum diffusion lengths of only 0.6-0.7 nm. It is further shown that diffusivities can be derived which are more than two orders of magnitude lower than those obtainable with conventional methods. Prospects of this method in order to solve actual kinetic problems in materials science are given

  14. Attenuation on an Earth-space path measured in the wavelength range of 8 to 14 micrometers.

    Science.gov (United States)

    Wilson, R W

    1970-06-19

    A telescope operating over the wavelength range of 8 to 14 micrometers has been added to the Crawford Hill sun tracker for the purpose of measuring attenuation in that atmospheric window. Over a 9-month period the attenuation (typically from clouds) exceeded 10, 20, and 30 decibels for 48, 43, and 34 percent of the time.

  15. Total photoabsorption cross section on nuclei measured in energy range 0.5-2.6 GeV

    International Nuclear Information System (INIS)

    Mirazita, M.

    1998-03-01

    The total photoabsorption cross section on several nuclei has been measured in the energy range 0.5 - 2.6 GeV. Nuclear data show a significant reduction of the absorption strength with respect to the free nucleon case suggesting a shadowing effect at low energies

  16. Tilted Magnetic Levitation Enables Measurement of the Complete Range of Densities of Materials with Low Magnetic Permeability.

    Science.gov (United States)

    Nemiroski, Alex; Soh, Siowling; Kwok, Sen Wai; Yu, Hai-Dong; Whitesides, George M

    2016-02-03

    Magnetic levitation (MagLev) of diamagnetic or weakly paramagnetic materials suspended in a paramagnetic solution in a magnetic field gradient provides a simple method to measure the density of small samples of solids or liquids. One major limitation of this method, thus far, has been an inability to measure or manipulate materials outside of a narrow range of densities (0.8 g/cm(3) MagLev"-to increase the range of densities that can be levitated magnetically. Tilting the MagLev device relative to the gravitational vector enables the magnetic force to be decreased (relative to the magnetic force) along the axis of measurement. This approach enables many practical measurements over the entire range of densities observed in matter at ambient conditions-from air bubbles (ρ ≈ 0) to osmium and iridium (ρ ≈ 23 g/cm(3)). The ability to levitate, simultaneously, objects with a broad range of different densities provides an operationally simple method that may find application to forensic science (e.g., for identifying the composition of miscellaneous objects or powders), industrial manufacturing (e.g., for quality control of parts), or resource-limited settings (e.g., for identifying and separating small particles of metals and alloys).

  17. Synthesis of Algorithm for Range Measurement Equipment to Track Maneuvering Aircraft Using Data on Its Dynamic and Kinematic Parameters

    Science.gov (United States)

    Pudovkin, A. P.; Panasyuk, Yu N.; Danilov, S. N.; Moskvitin, S. P.

    2018-05-01

    The problem of improving automated air traffic control systems is considered through the example of the operation algorithm synthesis for a range measurement channel to track the aircraft, using its kinematic and dynamic parameters. The choice of the state and observation models has been justified, the computer simulations have been performed and the results of the investigated algorithms have been obtained.

  18. 40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specification

    Science.gov (United States)

    2010-07-01

    ... Measurements Required, and Maximum Discrepancy Specification C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges..., June 22, 2010, table C-1 to subpart C was revised, effective Aug. 23, 2010. For the convenience of the...

  19. VOLATILE COMPOUNDS OF LITHRAEA CAUSTICA (LITRE) DETERMINATED BY SOLID PHASE MICRO-EXTRACTION (SPME)

    OpenAIRE

    GARBARINO, JUAN A; SALVATORE, GIUSEPPE; PIVANOVO, MARISA; CHAMY, MARÍA CRISTINA; NICOLETTI, MARCELLO; DE IOANNES, ALFREDO

    2002-01-01

    The head space of the aerial parts of Lithraea caustica was analyzed by Solid Phase Micro-Extraction (SPME) technique, obtaining as main volatile compounds the monoterpenes, myrcene, a -pinene, , p-cymene and limonene, as well as the sesquiterpene caryophylene. De las partes áereas de Lithraea caustica y usando la técnica de Micro-Extracción en Fase Sólida (MEFS), fueron identificados y cuantificados los principales compuestos volátiles: los monoterpenos, mirceno, a -pineno, p-cimeno y lim...

  20. Improving Student Understanding of Qualitative and Quantitative Analysis via GC/MS Using a Rapid SPME-Based Method for Determination of Trihalomethanes in Drinking Water

    Science.gov (United States)

    Huang, Shu Rong; Palmer, Peter T.

    2017-01-01

    This paper describes a method for determination of trihalomethanes (THMs) in drinking water via solid-phase microextraction (SPME) GC/MS as a means to develop and improve student understanding of the use of GC/MS for qualitative and quantitative analysis. In the classroom, students are introduced to SPME, GC/MS instrumentation, and the use of MS…

  1. Use of solid-phase microextraction (SPME) for the determination of methadone and EDDP in human hair by GC-MS.

    Science.gov (United States)

    Lucas, A C; Bermejo, A M; Tabernero, M J; Fernández, P; Strano-Rossi, S

    2000-01-10

    Solid-phase microextraction (SPME) is a new extraction technique with many advantages: small sample volume, simplicity, quickness and solvent-free. It is mainly applied to environmental analysis, but is also useful for the extraction of drugs from biological samples. In this paper the use of SPME is proposed for the determination of methadone and its main metabolite EDDP in hair by GC-MS. The hair samples were washed, cut into 1-mm segments, and incubated with Pronase E for 12 h. A 100-micron polydimethylsiloxane (PDMS) film fibre was submerged for 30 min in a diluted solution of the hydrolysis liquid (1:4 with borax buffer) containing methadone-d3 and EDDP-d3 as internal standards. Once the microextraction was concluded the fibre was directly inserted into the CG injection port. Linearity was found for methadone and EDDP in the range studied, 1.0-50 ng/mg hair, with correlation coefficients higher than 0.99. Interassay relative standard deviation (R.S.D) was determined to be less than 13.30% for methadone and less than 8.94% for EDDP, at 3.0 and 30.0 ng/mg. Analytical recoveries were close to 100% for both compounds on spiked samples. The method was applied to the analysis of real hair samples from eight patients of a methadone maintenance programme. The concentration of methadone in hair ranged from 2.45 to 78.10 ng/mg, and for EDDP from 0.98 to 7.76 ng/mg of hair.

  2. Headspace-SPME-GC/MS as a simple cleanup tool for sensitive 2,6-diisopropylphenol analysis from lipid emulsions and adaptable to other matrices.

    Science.gov (United States)

    Pickl, Karin E; Adamek, Viktor; Gorges, Roland; Sinner, Frank M

    2011-07-15

    Due to increased regulatory requirements, the interaction of active pharmaceutical ingredients with various surfaces and solutions during production and storage is gaining interest in the pharmaceutical research field, in particular with respect to development of new formulations, new packaging material and the evaluation of cleaning processes. Experimental adsorption/absorption studies as well as the study of cleaning processes require sophisticated analytical methods with high sensitivity for the drug of interest. In the case of 2,6-diisopropylphenol - a small lipophilic drug which is typically formulated as lipid emulsion for intravenous injection - a highly sensitive method in the concentration range of μg/l suitable to be applied to a variety of different sample matrices including lipid emulsions is needed. We hereby present a headspace-solid phase microextraction (HS-SPME) approach as a simple cleanup procedure for sensitive 2,6-diisopropylphenol quantification from diverse matrices choosing a lipid emulsion as the most challenging matrix with regard to complexity. By combining the simple and straight forward HS-SPME sample pretreatment with an optimized GC-MS quantification method a robust and sensitive method for 2,6-diisopropylphenol was developed. This method shows excellent sensitivity in the low μg/l concentration range (5-200μg/l), good accuracy (94.8-98.8%) and precision (intraday-precision 0.1-9.2%, inter-day precision 2.0-7.7%). The method can be easily adapted to other, less complex, matrices such as water or swab extracts. Hence, the presented method holds the potential to serve as a single and simple analytical procedure for 2,6-diisopropylphenol analysis in various types of samples such as required in, e.g. adsorption/absorption studies which typically deal with a variety of different surfaces (steel, plastic, glass, etc.) and solutions/matrices including lipid emulsions. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Accurate dew-point measurement over a wide temperature range using a quartz crystal microbalance dew-point sensor

    Science.gov (United States)

    Kwon, Su-Yong; Kim, Jong-Chul; Choi, Buyng-Il

    2008-11-01

    Quartz crystal microbalance (QCM) dew-point sensors are based on frequency measurement, and so have fast response time, high sensitivity and high accuracy. Recently, we have reported that they have the very convenient attribute of being able to distinguish between supercooled dew and frost from a single scan through the resonant frequency of the quartz resonator as a function of the temperature. In addition to these advantages, by using three different types of heat sinks, we have developed a QCM dew/frost-point sensor with a very wide working temperature range (-90 °C to 15 °C). The temperature of the quartz surface can be obtained effectively by measuring the temperature of the quartz crystal holder and using temperature compensation curves (which showed a high level of repeatability and reproducibility). The measured dew/frost points showed very good agreement with reference values and were within ±0.1 °C over the whole temperature range.

  4. A novel method of range measuring for a mobile robot based on multi-sensor information fusion

    International Nuclear Information System (INIS)

    Zhang Yi; Luo Yuan; Wang Jifeng

    2005-01-01

    The traditional measuring range for a mobile robot is based on a sonar sensor. Because of different working environments, it is very difficult to obtain high precision by using just one single method of range measurement. So, a hybrid sonar sensor and laser scanner method is put forward to overcome these shortcomings. A novel fusion model is proposed based on basic theory and a method of information fusion. An optimal measurement result has been obtained with information fusion from different sensors. After large numbers of experiments and performance analysis, a conclusion can be drawn that the laser scanner and sonar sensor method with multi-sensor information fusion have a higher precision than the single method of sonar. It can also be the same with different environments

  5. Development of a Microfluidic Open Interface with Flow Isolated Desorption Volume for the Direct Coupling of SPME Devices to Mass Spectrometry.

    Science.gov (United States)

    Tascon, Marcos; Alam, Md Nazmul; Gómez-Ríos, Germán Augusto; Pawliszyn, Janusz

    2018-02-20

    Technologies that efficiently integrate the sampling and sample preparation steps with direct introduction to mass spectrometry (MS), providing simple and sensitive analytical workflows as well as capabilities for automation, can generate a great impact in a vast variety of fields, such as in clinical, environmental, and food-science applications. In this study, a novel approach that facilitates direct coupling of Bio-SPME devices to MS using a microfluidic design is presented. This technology, named microfluidic open interface (MOI), which operates under the concept of flow-isolated desorption volume, consists of an open-to-ambient desorption chamber (V ≤ 7 μL) connected to an ionization source. Subsequently, compounds of interest are transported to the ionization source by means of the self-aspiration process intrinsic of these interfaces. Thus, any ionization technology that provides a reliable and constant suction, such as electrospray ionization (ESI), atmospheric-pressure chemical ionization (APCI), or inductively coupled plasma ionization (ICP), can be hyphenated to MOI. Using this setup, the desorption chamber is used to release target compounds from the coating, while the isolation of the flow enables the ionization source to be continuously fed with solvent, all without the necessity of employment of additional valves. As a proof of concept, the design was applied to an ESI-MS/MS system for experimental validation. Furthermore, numerical simulations were undertaken to provide a detailed understanding of the fluid flow pattern inside the interface, then used to optimize the system for better efficiency. The analytical workflow of the developed Bio-SPME-MOI-MS setup consists of the direct immersion of SPME fibers into the matrix to extract/enrich analytes of interest within a short period of time, followed by a rinsing step with water to remove potentially adhering proteins, salts, and/or other interfering compounds. Next, the fiber is inserted into the

  6. SU-F-T-184: 3D Range-Modulator for Scanned Particle Therapy: Development, Monte Carlo Simulations and Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Simeonov, Y; Penchev, P; Ringbaek, T Printz [University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen (Germany); Brons, S [Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); Weber, U [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Zink, K [University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen (Germany); University Hospital Giessen-Marburg, Marburg (Germany)

    2016-06-15

    Purpose: Active raster scanning in particle therapy results in highly conformal dose distributions. Treatment time, however, is relatively high due to the large number of different iso-energy layers used. By using only one energy and the so called 3D range-modulator irradiation times of a few seconds only can be achieved, thus making delivery of homogeneous dose to moving targets (e.g. lung cancer) more reliable. Methods: A 3D range-modulator consisting of many pins with base area of 2.25 mm2 and different lengths was developed and manufactured with rapid prototyping technique. The form of the 3D range-modulator was optimised for a spherical target volume with 5 cm diameter placed at 25 cm in a water phantom. Monte Carlo simulations using the FLUKA package were carried out to evaluate the modulating effect of the 3D range-modulator and simulate the resulting dose distribution. The fine and complicated contour form of the 3D range-modulator was taken into account by a specially programmed user routine. Additionally FLUKA was extended with the capability of intensity modulated scanning. To verify the simulation results dose measurements were carried out at the Heidelberg Ion Therapy Center (HIT) with a 400.41 MeV 12C beam. Results: The high resolution measurements show that the 3D range-modulator is capable of producing homogeneous 3D conformal dose distributions, simultaneously reducing significantly irradiation time. Measured dose is in very good agreement with the previously conducted FLUKA simulations, where slight differences were traced back to minor manufacturing deviations from the perfect optimised form. Conclusion: Combined with the advantages of very short treatment time the 3D range-modulator could be an alternative to treat small to medium sized tumours (e.g. lung metastasis) with the same conformity as full raster-scanning treatment. Further simulations and measurements of more complex cases will be conducted to investigate the full potential of the 3D

  7. Validation of accuracy and reliability of a simple measurement device for the lumber range of motion (SMD-L-ROM)

    International Nuclear Information System (INIS)

    Kato, Nakayuki; Fujiwara, Atsushi; Honda, Toshio; Taneichi, Hiroshi

    2007-01-01

    It is important to evaluate mobility of the lumbar spine for assessment of lumbar spinal disorders and their therapeutic effects. We developed a simple measurement device for the lumbar range of motion (SMD-L-ROM) which can be installed on the trunk. SMD-L-ROM allows to evaluate mobility of the lumbar spine without x-ray exposure. Accuracy and reliability of the measurement device was assessed in this article. SMD-L-ROM comprises two metallic immobilization plates (IPs) with a vertically installed bar and a rubber band for fixation of IP to the trunk. Two IPs were installed at the level of Th12 and the sacrum. Range of motion (ROM) of the lumbar spine was measured by using SMD-L-ROM and radiographic modalities (X-ray and CT). Consistency of the measured values by both of SMD-L-ROM and radiographic modalities was evaluated. Furthermore, inter- and intra-observer agreement of measured values by SMD-L-ROM was assessed. Regarding measurement of ROM, there was a high correlation between SMD-L-ROM and X-ray/CT especially in the sagittal and axial plane. There was no significant difference in the average values of ROM between the two methods. On the other hand, SMD-L-ROM did not detect accurate position of the lumbar spine in all dimensions. There were no inter- and intra-observer errors of measured values by SMD-L-ROM. ROM of the lumbar spine was simply and economically measured with SMD-L-ROM. Accuracy and reliability of SMD-L-ROM was good enough for ROM measurement in the lumbar spine. (author)

  8. An approach to determination of phenolic compounds in seawater using SPME-GC-MS based on SWCNTs coating

    Science.gov (United States)

    Zhu, Jia; Wang, Ying; Zeng, Lin

    2016-08-01

    Phenolic compounds have become one kind of the important pollutants of the marine environment. Single-walled Carbon nanotubes, as one-dimensional nano materials, have light weight and perfect hexagonal structure of connections, with many unusual mechanical, chemical and electrical properties. In recent years, with the research of carbon nanotubes and other nano materials, the application prospect is also constantly discussed. In this paper, homemade single-walled carbon nanotubes (SWCNTs) coating was used for establishing an analytical approach to the determination of five kinds of phenolic compounds in seawater using SPME-GC-MS. Optimal conditions: After saturation was conducted with NaCl, and pH was adjusted to 2.0 with H2SO4, the extract was immersed in a water bath at 40°C for GC-MS determination through 40-min agitating extraction at 500 rmin-1 and 3-min desorption at 280°C. The liniearities ranged between 0.01-100 μg L-1, and the determination limits ranged between 1.5-10 ng L-1. The relative standard deviation (RSD, n = 5) was less than 6.5%. For the phenolic compounds obtained from the spiked recovery test for actual seawater samples, the rates of recovery were 87.5%-101.7%, and the RSDs were less than 8.8%, which met the requirements of determination. Due to its simplicity, high efficiency and low consumption, this approach is suitable for the analysis of trace amounts of phenolic compounds in marine waters.

  9. Optimization of Biochemical Screening Methods for Volatile and Unstable Sesquiterpenoids Using HS-SPME-GC-MS

    Directory of Open Access Journals (Sweden)

    Trine Bundgaard Andersen

    2015-06-01

    Full Text Available HS-SPME-GC-MS has been suggested as a fast and robust analytical platform for the product characterization of sesquiterpene synthases. The choice of fiber and injection temperature can have a significant effect on the observed product profile, due to the chemical rearrangements that can occur on the fiber material. Here we present a systematic study on the effects of fiber choice and injection port temperature on the observed sesquiterpenoid profile of four sesquiterpene synthases expressed in Nicotiana benthamiana. We found that the absorbent material PDMS was much less likely to support acid-induced rearrangement of sesquiterpenoids when compared to the adsorbent materials PDMS/DVB, PDMS/CAR, and PDMS/CAR/DVB. Furthermore, utilizing an injection port temperature at 160 °C almost eliminated the inherent thermal instability of germacrene sesquiterpenoids. Thus, for fast screening of sesquiterpene synthases, the results suggest that PDMS fibers and an injection temperature of 160 °C provide a fast and reproducible HS-SPME GC-MS method when using H2 as carrier gas.

  10. Polyelectrolyte coatings prevent interferences from charged nanoparticles in SPME speciation analysis

    International Nuclear Information System (INIS)

    Zielińska, Katarzyna; Leeuwen, Herman P. van

    2014-01-01

    Highlights: • For the first time SPME fiber is coated with polyelectrolyte layer. • Sorption of nanoparticles on the solid phase surface is prevented. • Polyelectrolyte-modified fiber enables extraction of free analyte in presence of sorbing nanoparticles. - Abstract: In this work we present a new approach for protection of the fiber in solid phase microextraction (SPME) from interfering charged particles present in the sample medium. It involves coating of commercial poly(dimethylsiloxane) extraction phase with polyelectrolyte layer composed of poly(diallyldimethylammonium chloride), and poly(sodium 4-styrenesulfonate). The modified fiber provides reproducible, convenient and fast extraction capabilities toward the model analyte, triclosan (TCS). A negatively charged polyelectrolyte coating prevents sorbing oxidic nanoparticles from both partitioning into the PDMS phase and aggregation at its surface. The results for the TCS/nanoparticle sample show that the polyelectrolyte layer-modified solid phase extracts just the free form of the organic compound and enables dynamic speciation analysis of the nanoparticulate target analyte complex

  11. Analysis of Organic Volatile Flavor Compounds in Fermented Stinky Tofu Using SPME with Different Fiber Coatings

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2012-03-01

    Full Text Available The organic volatile flavor compounds in fermented stinky tofu (FST were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu.

  12. Quantification of Polyfunctional Thiols in Wine by HS-SPME-GC-MS Following Extractive Alkylation.

    Science.gov (United States)

    Musumeci, Lauren E; Ryona, Imelda; Pan, Bruce S; Loscos, Natalia; Feng, Hui; Cleary, Michael T; Sacks, Gavin L

    2015-07-06

    Analyses of key odorous polyfunctional volatile thiols in wines (3-mercaptohexanol (3-MH), 3-mercaptohexylacetate (3-MHA), and 4-mercapto-4-methyl-2-pentanone (4-MMP)) are challenging due to their high reactivity and ultra-trace concentrations, especially when using conventional gas-chromatography electron impact mass spectrometry (GC-EI-MS). We describe a method in which thiols are converted to pentafluorobenzyl (PFB) derivatives by extractive alkylation and the organic layer is evaporated prior to headspace solid phase microextraction (HS-SPME) and GC-EI-MS analysis. Optimal parameters were determined by response surface area modeling. The addition of NaCl solution to the dried SPME vials prior to extraction resulted in up to less than fivefold improvement in detection limits. Using 40 mL wine samples, limits of detection for 4-MMP, 3-MH, and 3-MHA were 0.9 ng/L, 1 ng/L, and 17 ng/L, respectively. Good recovery (90%-109%) and precision (5%-11% RSD) were achieved in wine matrices. The new method was used to survey polyfunctional thiol concentrations in 61 commercial California and New York State wines produced from V. vinifera (Riesling, Gewürztraminer, Cabernet Sauvignon, Sauvignon blanc and non-varietal rosé wines), V. labruscana (Niagara), and Vitis spp. (Cayuga White). Mean 4-MMP concentrations in New York Niagara (17 ng/L) were not significantly different from concentrations in Sauvignon blanc, but were significantly higher than 4-MMP in other varietal wines.

  13. Analysis of organic micropollutants in drinking water using SPME and GC-MS

    International Nuclear Information System (INIS)

    Guidotti, M.; Ravaioli, G.

    1999-01-01

    In this work the purpose was to develop accurate and reproducible methods for the qualitative and quantitative analysis of pesticides/herbicides, phthalates, chlorinated solvents, trihalomethanes, polycyclic aromatic hydrocarbons (PAHs) and chlorophenols in drinking waters, using solid-phase micro extraction and GC-MS techniques. The SPME developed by J. Pawliszyn and co-workers, consists of an fused silica fibre, coated with an appropriate absorbent phase, hosted inside the needle of a holder that looks like a GC-syringe; the needle pierces the septum of a sealed vial and the fibre is lowered, by depressing the plunger of the holder, into the liquid (or in the headspace, if that is the case) that contains the analytes of interest. After a set period of time, necessary to reach the partitioning equilibrium, the fibre is retracted inside the needle, the needle is inserted into the GC injector port and the fibre pushed in the heated injector. Here the compounds of interest (that have adsorbed onto the fibre) are thermally desorbed and analysed by GC-MS. After three minutes the fibre is extracted and is ready for a new analysis. The SPME technique has already found many applications in food and environmental analysis. Many of the analytes investigated in this research are listed Italian legislation as possible pollutants of drinking waters and their presence and concentrations require monitoring. The list of compounds included in this work is reported in Table 1

  14. Potential semiochemicals in urine from free ranging wolverines (Gulo gulo Pallas, 1780)

    Science.gov (United States)

    William F. Wood; Jeffrey P. Copeland; Richard E. Yates; Iman K. Horsey; Lynne R. McGreevy

    2009-01-01

    Urine deposition has been observed as an important scent-marking behaviour among wolverines (Gulo gulo, Mustelinae, Mustelidae). Solid phase microextraction (SPME) of headspace volatiles of the urine from free ranging wolverines were examined by gas chromatography-mass spectrometry (GC-MS). Urine samples were collected directly from the bladder of live-trapped animals...

  15. Measurement of double differential cross sections of secondary neutrons in the incident energy range 9-13 MeV

    International Nuclear Information System (INIS)

    Tang Hongqing; Qi Bujia; Zhou Zuying; Sa Jun; Ke Zunjian; Sui Qingchang; Xia Haihong; Shen Guanren

    1992-01-01

    The status and technique of double differential cross section measurement of secondary neutrons in the incident neutron energy range 9 to 13 MeV is reviewed with emphasis on the work done at CIAE. There are scarce measurements of secondary neutron double differential cross sections in this energy region up to now. A main difficulty for this is lack of an applicable monoenergetic neutron source. When monoenergetic neutron energy reaches 8 Me/v, the break-up neutrons from the d + D or p + T reaction starts to become significant. It is difficult to get a pure secondary neutron spectrum induced only by monoenergetic neutrons. To solve this problem an abnormal fast neutron TOF facility was designed and tested. Double differential neutron emission cross sections of 238 U and 209 Bi at 10 MeV were obtained by combining the data measured by both normal and abnormal TOF spectrometers and a good agreement between measurement and calculation was achieved

  16. Measuring Relativistic effects in the field of the Earth with Laser Ranged Satellites and the LARASE research program

    Science.gov (United States)

    Lucchesi, David; Anselmo, Luciano; Bassan, Massimo; Magnafico, Carmelo; Pardini, Carmen; Peron, Roberto; Pucacco, Giuseppe; Stanga, Ruggero; Visco, Massimo

    2017-04-01

    The main goal of the LARASE (LAser RAnged Satellites Experiment) research program is to obtain refined tests of Einstein's theory of General Relativity (GR) by means of very precise measurements of the round-trip time among a number of ground stations of the International Laser Ranging Service (ILRS) network and a set of geodetic satellites. These measurements are guaranteed by means of the powerful and precise Satellite Laser Ranging (SLR) technique. In particular, a big effort of LARASE is dedicated to improve the dynamical models of the LAGEOS, LAGEOS II and LARES satellites, with the objective to obtain a more precise and accurate determination of their orbit. These activities contribute to reach a final error budget that should be robust and reliable in the evaluation of the main systematic errors sources that come to play a major role in masking the relativistic precession on the orbit of these laser-ranged satellites. These error sources may be of gravitational and non-gravitational origin. It is important to stress that a more accurate and precise orbit determination, based on more reliable dynamical models, represents a fundamental prerequisite in order to reach a sub-mm precision in the root-mean-square of the SLR range residuals and, consequently, to gather benefits in the fields of geophysics and space geodesy, such as stations coordinates knowledge, geocenter determination and the realization of the Earth's reference frame. The results reached over the last year will be presented in terms of the improvements achieved in the dynamical model, in the orbit determination and, finally, in the measurement of the relativistic precessions that act on the orbit of the satellites considered.

  17. A system for using the air radioactivity measurements in a long range model to forecast cloud evolution

    Energy Technology Data Exchange (ETDEWEB)

    Galmarini, S.; Graziani, G. (Commission of the European Communities, Ispra (Italy). Joint Research Centre); Grippa, G.; De Cort, M. (Maind srl, Milan (Italy))

    1993-01-01

    A procedure was developed in the past to reduce uncertainties in long range transport model predictions mainly due to inputing windfield data to atmospheric transport models which are the result of the forecasts of global or regional circulation models. Measurements available in real-time of the air concentrations from national monitoring grids have been used to reduce the uncertainties. The system is based on a long range transport model which can run using a limited amount of meteorological information, and an interpolation routine which generates a new area source from the air measurements, available in real-time, at ground level. The procedure has now been fully automated and is available on a PC, with graphical output, to ease its use in emergency situations. The system requires a connection to the ECMWF network for meteorological input data and to a radiological data bank (ECURIE) or national monitoring networks for monitoring data. (author).

  18. Highly accurate nuclear and electronic stopping cross sections derived using Monte Carlo simulations to reproduce measured range data

    Science.gov (United States)

    Wittmaack, Klaus; Mutzke, Andreas

    2017-03-01

    We have examined and confirmed the previously unexplored concept of using Monte Carlo calculations in combination with measured projected ranges of ions implanted in solids to derive a quantitative description of nuclear interaction and electronic stopping. The study involved 98 ranges of 11B in Si between 1 keV and 8 MeV, contained in 12 sets of 10 different groups. Systematic errors by up to ±8% were removed to establish a refined data base with 93 ranges featuring only statistical uncertainties (±1.8%). The Monte Carlo calculations could be set up to reproduce the refined ranges with a mean ratio 1.002 ± 1.7%. The input parameters required for this very high level of agreement are as follows. Nuclear interaction is best described by the Kr-C potential, but in obligatory combination with the Lindhard-Scharff (LS) screening length. Up to 300 keV, the electronic stopping cross section is proportional to the projectile velocity, Se = kSe,LS, with k = 1.46 ± 0.01. At higher energies, Se falls progressively short of kSe,LS. Around the Bragg peak, i.e., between 0.8 and 10 MeV, Se is modeled by an adjustable function serving to tailor the peak shape properly. Calculated and measured isotope effects for ranges of 10B and 11B in Si agree within the experimental uncertainty (±0.25%). The range-based Se,R(E) reported here predicts the scarce experimental data derived from the energy loss in projectile transmission through thin Si foils to within 2% or better. By contrast, Se(E) data of available stopping power tables exhibit deviations from Se,R(E) between -40% and +14%.

  19. Measurement of the uranium-235 fission cross section over the neutron energy range 1 to 6 MeV

    International Nuclear Information System (INIS)

    Barton, D.M.; Diven, B.C.; Hansen, G.E.; Jarvis, G.A.; Koontz, P.G.; Smith, R.K.

    1976-01-01

    The ratio of the fission cross section of 235 U to the scattering cross section of 1 H was measured in the 1- to 6-MeV range using monoenergetic neutrons from a pulsed 3 H(p,n) 3 He source. In this measurement, solid-state detectors determined fission fragment and recoil proton emissions from back-to-back U(99.7%) and polyethylene disks. Timing permitted discrimination against room-scattered neutron backgrounds. Absolute values for 235 U(n,f) are obtained using the Hopkins-Breit evaluation of the hydrogen-scattering cross section

  20. Reproducibility of range of motion and muscle strength measurements in patients with hip osteoarthritis – an interrater study

    DEFF Research Database (Denmark)

    Poulsen, Erik; Christensen, Henrik Wulff; Penny, Jeannette Østergaard

    2012-01-01

    ABSTRACT: BACKGROUND: Assessment of range of motion (ROM) and muscle strength is fundamental in the clinical diagnosis of hip osteoarthritis (OA) but reproducibility of these measurements has mostly involved clinicians from secondary care and has rarely reported agreement parameters. Therefore......, the primary objective of the study was to determine the inter-rater reproducibility of ROM and muscle strength measurements. Furthermore, the reliability of the overall assessment of clinical hip OA was evaluated. Reporting is in accordance with proposed guidelines for the reporting of reliability...... differentiate between hips with or without osteoarthritis....

  1. Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET

    DEFF Research Database (Denmark)

    Eriksson, J.; Nocente, M.; Binda, F.

    2015-01-01

    Observations made in a JET experiment aimed at accelerating deuterons to the MeV range by third harmonic radio-frequency (RF) heating coupled into a deuterium beam are reported. Measurements are based on a set of advanced neutron and gamma-ray spectrometers that, for the first time, observe......-ray spectroscopy based on a one-dimensional model and by a consistency check among the individual measurement techniques. A systematic difference is seen between the two lines of sight and is interpreted to originate from the sensitivity of the oblique detectors to the pitch-angle structure of the distribution...

  2. Airborne Measurements of CO2 Column Concentration and Range Using a Pulsed Direct-Detection IPDA Lidar

    Science.gov (United States)

    Abshire, James B.; Ramanathan, Anand; Riris, Haris; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Weaver, Clark J.; Browell, Edward V.

    2013-01-01

    We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flights over a variety of surface and cloud conditions near the US. These included over a stratus cloud deck over the Pacific Ocean, to a dry lake bed surrounded by mountains in Nevada, to a desert area with a coal-fired power plant, and from the Rocky Mountains to Iowa, with segments with both cumulus and cirrus clouds. Most flights were to altitudes >12 km and had 5-6 altitude steps. Analyses show the retrievals of lidar range, CO2 column absorption, and CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, through thin clouds, between cumulus clouds, and to stratus cloud tops. The retrievals shows the decrease in column CO2 due to growing vegetation when flying over Iowa cropland as well as a sudden increase in CO2 concentration near a coal-fired power plant. For regions where the CO2 concentration was relatively constant, the measured CO2 absorption lineshape (averaged for 50 s) matched the predicted shapes to better than 1% RMS error. For 10 s averaging, the scatter in the retrievals was typically 2-3 ppm and was limited by the received signal photon count. Retrievals were made using atmospheric parameters from both an atmospheric model and from in situ temperature and pressure from the aircraft. The retrievals had no free parameters and did not use empirical adjustments, and >70% of the measurements passed screening and were used in analysis. The differences between the lidar-measured retrievals and in situ measured average CO2 column concentrations were 6 km.

  3. Reliability and responsiveness of a goniometric device for measuring the range of motion in the dart-throwing motion plane.

    Science.gov (United States)

    Kasubuchi, Kenji; Dohi, Yoshihiro; Fujita, Hiroyuki; Fukumoto, Takahiko

    2018-02-26

    Dart-throwing motion (DTM) is an important component of wrist function and, consequently, has the potential to become an evaluation tool in rehabilitation. However, no measurement method is currently available to reliably measure range of motion (ROM) of the wrist in the DTM plane. To determine the reliability and responsiveness of a goniometric device to measure wrist ROM in the DTM plane. ROM of the wrist in the DTM plane was measured in 70 healthy participants. The intra-class correlation coefficient (ICC) was used to evaluate the relative reliability of measurement, and a Bland-Altman analysis conducted to establish its absolute reliability, including the 95% limits of agreement (95% LOA). The standard error of the measurement (SEM) and minimal detectable change at the 95% confidence level (MDC 95 ) were calculated as measures of responsiveness. The intra-rater ICC was 0.87, and an inter-rater ICC of 0.71. There was no evidence of a fixed or proportional bias. For intra- and inter-rater reliability, 95% LOA ranged from -13.83 to 11.12 and from -17.75 to 16.19, respectively. The SEM and MDC 95 were 4.5° and 12.4°, respectively, for intra-rater reliability, and 6.0° and 16.6°, respectively, for inter-rater reliability. The ROM of the wrist in the DTM plane was measured with fair-to-good reliability and responsiveness and, therefore, has the potential to become an evaluation tool for rehabilitation.

  4. Free tropospheric measurements of CS2 over a 45 deg N to 45 deg S latitude range

    Science.gov (United States)

    Tucker, B. J.; Maroulis, P. J.; Bandy, A. R.

    1985-01-01

    The mean value obtained from 52 free tropospheric measurements of CS2 over the 45 deg N-45 deg S latitude range was 5.7 pptv, with standard deviation and standard error of 1.9 and 0.3 pptv, respectively. Large fluctuations in the CS2 concentration are observed which reflect the apparent short atmospheric residence time and inhomogeneities in the surface sources of CS2. The amounts of CS2 in the Northern and Southern Hemispheres are statistically equal.

  5. Measurement of pair production cross sections in Ge for the 1. 238-3. 548 MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R K; Singh, K; Sahota, H S

    1985-02-28

    Pair production cross sections have been determined for the 1.238-3.548 MeV energy range in germanium (Z = 32) using a Ge(Li) gamma ray detector. The experimental results have been compared with the theoretical cross sections of previous workers. The results of the present measurements agree with the Bethe-Heitler results down to 1.771 MeV. However, at 1.238 MeV the experimental results are higher than all the theories.

  6. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor

    Directory of Open Access Journals (Sweden)

    Yanzhi Zhao

    2016-08-01

    Full Text Available Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  7. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor.

    Science.gov (United States)

    Zhao, Yanzhi; Zhang, Caifeng; Zhang, Dan; Shi, Zhongpan; Zhao, Tieshi

    2016-08-11

    Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR) joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  8. A wide-frequency range AC magnetometer to measure the specific absorption rate in nanoparticles for magnetic hyperthermia

    International Nuclear Information System (INIS)

    Garaio, E.; Collantes, J.M.; Garcia, J.A.; Plazaola, F.; Mornet, S.; Couillaud, F.; Sandre, O.

    2014-01-01

    Measurement of specific absorption rate (SAR) of magnetic nanoparticles is crucial to assert their potential for magnetic hyperthermia. To perform this task, calorimetric methods are widely used. However, those methods are not very accurate and are difficult to standardize. In this paper, we present AC magnetometry results performed with a lab-made magnetometer that is able to obtain dynamic hysteresis-loops in the AC magnetic field frequency range from 50 kHz to 1 MHz and intensities up to 24 kA m −1 . In this work, SAR values of maghemite nanoparticles dispersed in water are measured by AC magnetometry. The so-obtained values are compared with the SAR measured by calorimetric methods. Both measurements, by calorimetry and magnetometry, are in good agreement. Therefore, the presented AC magnetometer is a suitable way to obtain SAR values of magnetic nanoparticles. - Highlights: • We propose AC magnetometry as a method to measure the specific absorption rate (SAR) of magnetic nanoparticles suitable for magnetic hyperthermia therapy. • We have built a lab-made AC magnetometer, which is able to measure magnetic dynamic hysteresis-loops of nanoparticle dispersions. • The device works with AC magnetic field intensities up to 24 kA m −1 in a frequency range from 75 kHz to 1 MHz. • The SAR values of maghemite nanoparticles around 12 nm in magnetic diameter dispersed in water are measured by the lab-made magnetometer and different calorimetric methods. • Although all methods are in good agreement, several factors (probe location, thermal inertia, losses, etc.) make calorimetric method less accurate than AC magnetometry

  9. Precise predictions of H2O line shapes over a wide pressure range using simulations corrected by a single measurement

    Science.gov (United States)

    Ngo, N. H.; Nguyen, H. T.; Tran, H.

    2018-03-01

    In this work, we show that precise predictions of the shapes of H2O rovibrational lines broadened by N2, over a wide pressure range, can be made using simulations corrected by a single measurement. For that, we use the partially-correlated speed-dependent Keilson-Storer (pcsdKS) model whose parameters are deduced from molecular dynamics simulations and semi-classical calculations. This model takes into account the collision-induced velocity-changes effects, the speed dependences of the collisional line width and shift as well as the correlation between velocity and internal-state changes. For each considered transition, the model is corrected by using a parameter deduced from its broadening coefficient measured for a single pressure. The corrected-pcsdKS model is then used to simulate spectra for a wide pressure range. Direct comparisons of the corrected-pcsdKS calculated and measured spectra of 5 rovibrational lines of H2O for various pressures, from 0.1 to 1.2 atm, show very good agreements. Their maximum differences are in most cases well below 1%, much smaller than residuals obtained when fitting the measurements with the Voigt line shape. This shows that the present procedure can be used to predict H2O line shapes for various pressure conditions and thus the simulated spectra can be used to deduce the refined line-shape parameters to complete spectroscopic databases, in the absence of relevant experimental values.

  10. [Research on the range of motion measurement system for spine based on LabVIEW image processing technology].

    Science.gov (United States)

    Li, Xiaofang; Deng, Linhong; Lu, Hu; He, Bin

    2014-08-01

    A measurement system based on the image processing technology and developed by LabVIEW was designed to quickly obtain the range of motion (ROM) of spine. NI-Vision module was used to pre-process the original images and calculate the angles of marked needles in order to get ROM data. Six human cadaveric thoracic spine segments T7-T10 were selected to carry out 6 kinds of loads, including left/right lateral bending, flexion, extension, cis/counterclockwise torsion. The system was used to measure the ROM of segment T8-T9 under the loads from 1 Nm to 5 Nm. The experimental results showed that the system is able to measure the ROM of the spine accurately and quickly, which provides a simple and reliable tool for spine biomechanics investigators.

  11. Characterization of Fish Sauce Aroma Impact Compounds Using GC-MS, SPME-Osme-GCO, and Stevens' Power Law Exponents

    Science.gov (United States)

    The objectives of this study were to characterize volatile compounds and to determine the characteristic aromas associated with impact compounds in 4 fish sauces using solid-phase micro-extraction, gas chromatography-mass spectrometry, Osme, and gas chromatography olfactometry (SPME-Osme-GCO) couple...

  12. HS-SPME-GC-MS ANALYSIS OF VOLATILE AND SEMI-VOLATILE COMPOUNDS FROM DRIED LEAVES OF Mikania glomerata Sprengel

    Directory of Open Access Journals (Sweden)

    Esmeraldo A. Cappelaro

    2015-03-01

    Full Text Available This paper reports on the identification of volatile and semi-volatile compounds and a comparison of the chromatographic profiles obtained by Headspace Solid-Phase Microextraction/Gas Chromatography with Mass Spectrometry detection (HS-SPME-GC-MS of dried leaves of Mikania glomerata Sprengel (Asteraceae, also known as 'guaco.' Three different types of commercial SPME fibers were tested: polydimethylsiloxane (PDMS, polydimethylsiloxane/divinylbenzene (PDMS/DVB and polyacrylate (PA. Fifty-nine compounds were fully identified by HS-SPME-HRGC-MS, including coumarin, a marker for the quality control of guaco-based phytomedicines; most of the other identified compounds were mono- and sesquiterpenes. PA fibers performed better in the analysis of coumarin, while PDMS-DVB proved to be the best choice for a general and non-selective analysis of volatile and semi-volatile guaco-based compounds. The SPME method is faster and requires a smaller sample than conventional hydrodistillation of essential oils, providing a general overview of the volatile and semi-volatile compounds of M. glomerata.

  13. Recent Developments and Applications of Solid Phase Microextraction (SPME in Food and Environmental Analysis—A Review

    Directory of Open Access Journals (Sweden)

    Sybille Merkle

    2015-06-01

    Full Text Available Solid-phase microextraction (SPME is a simple, sensitive, rapid and solvent-free technique for the extraction of analytes from gaseous, liquid and solid samples and takes a leading position among microextraction methods. Application of SPME in sample preparation has been increasing continuously over the last decade. It is most often used as an automatized fiber injection system coupled to chromatographic separation modules for the extraction of volatile and semivolatile organic compounds and also allows for the trace analysis of compounds in complex matrices. Since SPME was first introduced in the early 1990s, several modifications have been made to adapt the procedure to specific application requirements. More robust fiber assemblies and coatings with higher extraction efficiencies, selectivity and stability have been commercialized. Automation and on-line coupling to analytical instruments have been achieved in many applications and new derivatization strategies as well as improved calibration procedures have been developed to overcome existing limitations regarding quantitation. Furthermore, devices using tubes, needles or tips for extraction instead of a fiber have been designed. In the field of food analysis, SPME has been most often applied to fruit/vegetables, fats/oils, wine, meat products, dairy and beverages whereas environmental applications focus on the analysis of air, water, soil and sediment samples.

  14. Screening of transformation products in soils contaminated with unsymmetrical dimethylhydrazine using headspace SPME and GC-MS

    NARCIS (Netherlands)

    Kenessov, B.N.; Koziel, J.A.; Grotenhuis, J.T.C.; Carlsen, L.

    2010-01-01

    The paper describes a novel SPME-based approach for sampling and analysis of transformation products of highly reactive and toxic unsymmetrical dimethylhydrazine (UDMH) which is used as a fuel in many Russian, European, Indian, and Chinese heavy cargo carrier rockets. The effects of several

  15. Shoulder range of motion measures as risk factors for shoulder and elbow injuries in high school softball and baseball players.

    Science.gov (United States)

    Shanley, Ellen; Rauh, Mitchell J; Michener, Lori A; Ellenbecker, Todd S; Garrison, J Craig; Thigpen, Charles A

    2011-09-01

    Range of motion deficits in shoulder external rotation (ER), internal rotation (IR), total rotation range of motion (ER + IR), and horizontal adduction (HA) have been retrospectively associated with overhand athletes' arm injuries. The authors expected the incidence of upper extremity injury in high school softball and baseball players with side-to-side shoulder range of motion deficits to be greater than the incidence of upper extremity injury in players with normal shoulder range of motion. Cohort study (prognosis); Level of evidence, 2. High school softball and baseball players (N = 246) participated. Before the start of the season, passive shoulder ER, IR, and HA were assessed at 90° of abduction with the scapula stabilized. Relative risk (RR) was calculated to examine range of motion measure, by categorical criteria, and risk of upper extremity injury. Twenty-seven shoulder and elbow injuries (9 softball, 18 baseball) were observed during the season. The dominant shoulder of all injured players and baseball players displayed a significant decrease in HA (P = .05) and IR (P = .04). The dominant shoulder total rotation of injured baseball players displayed a significant decrease (mean difference = 8.0° ± 0.1°; P = .05) as compared with the dominant shoulder of uninjured baseball players. Players who displayed a decrease of ≥25° of IR in the dominant shoulder were at 4 times greater risk of upper extremity injury compared with players with a .05). There are large mean deficits in shoulder IR and HA between injured and noninjured players, but not in ER or total rotation. Passive shoulder IR loss ≥25° as compared bilaterally was predictive of arm injury. Shoulder range of motion deficits differed between sports and appeared more predictive of injury for baseball players.

  16. Current Practices of Measuring and Reference Range Reporting of Free and Total Testosterone in the United States.

    Science.gov (United States)

    Le, Margaret; Flores, David; May, Danica; Gourley, Eric; Nangia, Ajay K

    2016-05-01

    The evaluation and management of male hypogonadism should be based on symptoms and on serum testosterone levels. Diagnostically this relies on accurate testing and reference values. Our objective was to define the distribution of reference values and assays for free and total testosterone by clinical laboratories in the United States. Upper and lower reference values, assay methodology and source of published reference ranges were obtained from laboratories across the country. A standardized survey was reviewed with laboratory staff via telephone. Descriptive statistics were used to tabulate results. We surveyed a total of 120 laboratories in 47 states. Total testosterone was measured in house at 73% of laboratories. At the remaining laboratories studies were sent to larger centralized reference facilities. The mean ± SD lower reference value of total testosterone was 231 ± 46 ng/dl (range 160 to 300) and the mean upper limit was 850 ± 141 ng/dl (range 726 to 1,130). Only 9% of laboratories where in-house total testosterone testing was performed created a reference range unique to their region. Others validated the instrument recommended reference values in a small number of internal test samples. For free testosterone 82% of laboratories sent testing to larger centralized reference laboratories where equilibrium dialysis and/or liquid chromatography with mass spectrometry was done. The remaining laboratories used published algorithms to calculate serum free testosterone. Reference ranges for testosterone assays vary significantly among laboratories. The ranges are predominantly defined by limited population studies of men with unknown medical and reproductive histories. These poorly defined and variable reference values, especially the lower limit, affect how clinicians determine treatment. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  17. Oxidative Stress Biomarkers in Exhaled Breath of Workers Exposed to Crystalline Silica Dust by SPME-GC-MS.

    Science.gov (United States)

    Jalali, Mahdi; Zare Sakhvidi, Mohammad Javad; Bahrami, Abdulrahman; Berijani, Nima; Mahjub, Hussein

    2016-01-01

    Silicosis is considered an oxidative stress related disease that can lead to the development of lung cancer. In this study, our purpose was to analysis of volatile organic compounds (VOCs) in the exhaled breath of workers exposed to silica containing dust and compare peak area of these compounds with silicosis patients and healthy volunteers (smokers and nonsmokers) groups. In this cross sectional case-control study, the exhaled breath of 69 subjects including workers exposed to silica (n=20), silicosis patient (n=4), healthy non-smoker (n=20) and healthy smoker (n=25) were analyzed. We collected breath samples using 3-liter Tedlar bags. The VOCs were extracted with solid phase micro-extraction (SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). Personal exposure intensity was measured according to NIOSH 7601 method. Respiratory parameters were measured using spirometry. Seventy percent and 100% of the exposures to crystalline silica dust exceeded from 8 h TWA ACGIH TLVs in case and positive control groups, respectively. A significant negative correlation was found between dust exposure intensity and FEV1/FVC when exposure and positive control groups were studied in a group (r2=-0.601, P<0.001). Totally, forty VOCs were found in all exhaled breath samples. Among the VOCs, the mean of peak area acetaldehyde, hexanal, nonanal, decane, pentad cane, 2-propanol and 3-hydroxy-2-butanone were higher in exhaled breath of the workers exposed to silica and silicosis patient compared to the healthy smoker and nonsmoker controls. In some cases the difference was significant (P<0.05). The analysis of some VOCs in exhaled breath of subjects is appropriate biomarker to determine of exposure to silica.

  18. Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range

    Science.gov (United States)

    Zuber, Ralf; Sperfeld, Peter; Riechelmann, Stefan; Nevas, Saulius; Sildoja, Meelis; Seckmeyer, Gunther

    2018-04-01

    A compact array spectroradiometer that enables precise and robust measurements of solar UV spectral direct irradiance is presented. We show that this instrument can retrieve total ozone column (TOC) accurately. The internal stray light, which is often the limiting factor for measurements in the UV spectral range and increases the uncertainty for TOC analysis, is physically reduced so that no other stray-light reduction methods, such as mathematical corrections, are necessary. The instrument has been extensively characterised at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. During an international total ozone measurement intercomparison at the Izaña Atmospheric Observatory in Tenerife, the high-quality applicability of the instrument was verified with measurements of the direct solar irradiance and subsequent TOC evaluations based on the spectral data measured between 12 and 30 September 2016. The results showed deviations of the TOC of less than 1.5 % from most other instruments in most situations and not exceeding 3 % from established TOC measurement systems such as Dobson or Brewer.

  19. Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields

    Science.gov (United States)

    Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

    2018-01-01

    High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (Hc2) and critical temperature (Tc). The critical current (Ic) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new Ic measurement system that can carry out accurate Ic measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The Ic measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa2Cu3O7-x(YBCO) tapes Ic determination with different temperatures and magnetic fields.

  20. Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields.

    Science.gov (United States)

    Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

    2018-01-01

    High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (H c2 ) and critical temperature (T c ). The critical current (I c ) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new I c measurement system that can carry out accurate I c measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The I c measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa 2 Cu 3 O 7-x (YBCO) tapes I c determination with different temperatures and magnetic fields.

  1. Long-range weight functions in fundamental measure theory of the non-uniform hard-sphere fluid

    International Nuclear Information System (INIS)

    Hansen-Goos, Hendrik

    2016-01-01

    We introduce long-range weight functions to the framework of fundamental measure theory (FMT) of the non-uniform, single-component hard-sphere fluid. While the range of the usual weight functions is equal to the hard-sphere radius R , the modified weight functions have range 3 R . Based on the augmented FMT, we calculate the radial distribution function g (r) up to second order in the density within Percus’ test particle theory. Consistency of the compressibility and virial routes on this level allows us to determine the free parameter γ of the theory. As a side result, we obtain a value for the fourth virial coefficient B 4 which deviates by only 0.01% from the exact result. The augmented FMT is tested for the dense fluid by comparing results for g (r) calculated via the test particle route to existing results from molecular dynamics simulations. The agreement at large distances (r   >  6 R) is significantly improved when the FMT with long-range weight functions is used. In order to improve agreement close to contact (r   =  2 R) we construct a free energy which is based on the accurate Carnahan–Starling equation of state, rather than the Percus–Yevick compressibility equation underlying standard FMT. (paper)

  2. The concurrent validity and reliability of the Leg Motion system for measuring ankle dorsiflexion range of motion in older adults

    Directory of Open Access Journals (Sweden)

    Carlos Romero Morales

    2017-01-01

    Full Text Available Background New reliable devices for range of motion (ROM measures in older adults are necessary to improve knowledge about the functional capability in this population. Dorsiflexion ROM limitation is associated with ankle injuries, foot pain, lower limb disorders, loss of balance, gait control disorders and fall risk in older adults. The aim of the present study was to assess the validity and reliability of the Leg Motion device for measuring ankle dorsiflexion ROM in older adults. Methods Adescriptive repeated-measures study was designed to test the reliability of Leg Motion in thirty-three healthy elderly patients older than 65 years. The subjects had to meet the following inclusion and exclusion criteria in their medical records: older than 65 years; no lower extremity injury for at least one year prior to evaluation (meniscopathy, or fractures and any chronic injuries (e.g., osteoarthritis; no previous hip, knee or ankle surgery; no neuropathic alterations and no cognitive conditions (e.g., Alzheimer’s disease or dementia. Participants were recruited through the person responsible for the physiotherapist area from a nursing center. The subjects were evaluated in two different sessions at the same time of day, and there was a break of two weeks between sessions. To test the validity of the Leg Motion system, the participants were measured in a weight-bearing lunge position using a classic goniometer with 1° increments, a smartphone with an inclinometer standard app (iPhone 5S® with 1° increments and a measuring tape that could measure 0.1 cm. All testing was performed while the patients were barefoot. The researcher had ten years of experience as a physiotherapist using goniometer, tape measure and inclinometer devices. Results Mean values and standard deviations were as follows: Leg Motion (right 5.15 ± 3.08; left 5.19 ± 2.98, tape measure (right 5.12 ± 3.08; left 5.12 ± 2.80, goniometer (right 45.87° ± 4.98; left 44

  3. Reference range levels of polycyclic aromatic hydrocarbons in the US population by measurement of urinary monohydroxy metabolites

    International Nuclear Information System (INIS)

    Grainger, James; Huang, Wenlin; Patterson, Donald G.; Turner, Wayman E.; Pirkle, James; Caudill, Samuel P.; Wang, Richard Y.; Needham, Larry L.; Sampson, Eric J.

    2006-01-01

    We developed a gas chromatography isotope-dilution high-resolution mass spectrometry (GC/Id-HRMS) method for measuring 14 polycyclic aromatic hydrocarbon (PAH) metabolites representing seven parent PAHs in 3 mL of urine at low parts-per-trillion levels. PAH levels were determined in urine samples collected in 1999 and 2000 from approximately 2400 participants in the National Health and Nutrition Examination Survey, and, for the first time, reference range values were calculated for these metabolites in the US population. Using this GC/ID-HRMS method, we found detectable concentrations for monohydroxy metabolite isomers of fluorene, phenanthrene, fluoranthene, pyrene, and chrysene, benzo[c]phenanthrene, and benz[a]anthracene. Some monohydroxy metabolite isomers of benzo[c]phenanthrene, chrysene, and benz[a]anthracene exhibited low detection frequencies that did not allow for geometric mean calculations. Our study results enabled us to establish a reference range for the targeted PAHs in the general US population

  4. Validity and test-retest reliability of manual goniometers for measuring passive hip range of motion in femoroacetabular impingement patients.

    Directory of Open Access Journals (Sweden)

    Nussbaumer Silvio

    2010-08-01

    Full Text Available Abstract Background The aims of this study were to evaluate the construct validity (known group, concurrent validity (criterion based and test-retest (intra-rater reliability of manual goniometers to measure passive hip range of motion (ROM in femoroacetabular impingement patients and healthy controls. Methods Passive hip flexion, abduction, adduction, internal and external rotation ROMs were simultaneously measured with a conventional goniometer and an electromagnetic tracking system (ETS on two different testing sessions. A total of 15 patients and 15 sex- and age-matched healthy controls participated in the study. Results The goniometer provided greater hip ROM values compared to the ETS (range 2.0-18.9 degrees; P P Conclusions The present study suggests that goniometer-based assessments considerably overestimate hip joint ROM by measuring intersegmental angles (e.g., thigh flexion on trunk for hip flexion rather than true hip ROM. It is likely that uncontrolled pelvic rotation and tilt due to difficulties in placing the goniometer properly and in performing the anatomically correct ROM contribute to the overrating of the arc of these motions. Nevertheless, conventional manual goniometers can be used with confidence for longitudinal assessments in the clinic.

  5. Accurate dew-point measurement over a wide temperature range using a quartz crystal microbalance dew-point sensor

    International Nuclear Information System (INIS)

    Kwon, Su-Yong; Kim, Jong-Chul; Choi, Buyng-Il

    2008-01-01

    Quartz crystal microbalance (QCM) dew-point sensors are based on frequency measurement, and so have fast response time, high sensitivity and high accuracy. Recently, we have reported that they have the very convenient attribute of being able to distinguish between supercooled dew and frost from a single scan through the resonant frequency of the quartz resonator as a function of the temperature. In addition to these advantages, by using three different types of heat sinks, we have developed a QCM dew/frost-point sensor with a very wide working temperature range (−90 °C to 15 °C). The temperature of the quartz surface can be obtained effectively by measuring the temperature of the quartz crystal holder and using temperature compensation curves (which showed a high level of repeatability and reproducibility). The measured dew/frost points showed very good agreement with reference values and were within ±0.1 °C over the whole temperature range

  6. Validity and intra-rater reliability of an android phone application to measure cervical range-of-motion.

    Science.gov (United States)

    Quek, June; Brauer, Sandra G; Treleaven, Julia; Pua, Yong-Hao; Mentiplay, Benjamin; Clark, Ross Allan

    2014-04-17

    Concurrent validity and intra-rater reliability using a customized Android phone application to measure cervical-spine range-of-motion (ROM) has not been previously validated against a gold-standard three-dimensional motion analysis (3DMA) system. Twenty-one healthy individuals (age:31 ± 9.1 years, male:11) participated, with 16 re-examined for intra-rater reliability 1-7 days later. An Android phone was fixed on a helmet, which was then securely fastened on the participant's head. Cervical-spine ROM in flexion, extension, lateral flexion and rotation were performed in sitting with concurrent measurements obtained from both a 3DMA system and the phone.The phone demonstrated moderate to excellent (ICC = 0.53-0.98, Spearman ρ = 0.52-0.98) concurrent validity for ROM measurements in cervical flexion, extension, lateral-flexion and rotation. However, cervical rotation demonstrated both proportional and fixed bias. Excellent intra-rater reliability was demonstrated for cervical flexion, extension and lateral flexion (ICC = 0.82-0.90), but poor for right- and left-rotation (ICC = 0.05-0.33) using the phone. Possible reasons for the outcome are that flexion, extension and lateral-flexion measurements are detected by gravity-dependent accelerometers while rotation measurements are detected by the magnetometer which can be adversely affected by surrounding magnetic fields. The results of this study demonstrate that the tested Android phone application is valid and reliable to measure ROM of the cervical-spine in flexion, extension and lateral-flexion but not in rotation likely due to magnetic interference. The clinical implication of this study is that therapists should be mindful of the plane of measurement when using the Android phone to measure ROM of the cervical-spine.

  7. A comparison of sample preparation methods for extracting volatile organic compounds (VOCs) from equine faeces using HS-SPME.

    Science.gov (United States)

    Hough, Rachael; Archer, Debra; Probert, Christopher

    2018-01-01

    Disturbance to the hindgut microbiota can be detrimental to equine health. Metabolomics provides a robust approach to studying the functional aspect of hindgut microorganisms. Sample preparation is an important step towards achieving optimal results in the later stages of analysis. The preparation of samples is unique depending on the technique employed and the sample matrix to be analysed. Gas chromatography mass spectrometry (GCMS) is one of the most widely used platforms for the study of metabolomics and until now an optimised method has not been developed for equine faeces. To compare a sample preparation method for extracting volatile organic compounds (VOCs) from equine faeces. Volatile organic compounds were determined by headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GCMS). Factors investigated were the mass of equine faeces, type of SPME fibre coating, vial volume and storage conditions. The resultant method was unique to those developed for other species. Aliquots of 1000 or 2000 mg in 10 ml or 20 ml SPME headspace were optimal. From those tested, the extraction of VOCs should ideally be performed using a divinylbenzene-carboxen-polydimethysiloxane (DVB-CAR-PDMS) SPME fibre. Storage of faeces for up to 12 months at - 80 °C shared a greater percentage of VOCs with a fresh sample than the equivalent stored at - 20 °C. An optimised method for extracting VOCs from equine faeces using HS-SPME-GCMS has been developed and will act as a standard to enable comparisons between studies. This work has also highlighted storage conditions as an important factor to consider in experimental design for faecal metabolomics studies.

  8. Optimization of HS-SPME/GC-MS analysis and its use in the profiling of illicit ecstasy tablets (Part 1).

    Science.gov (United States)

    Bonadio, Federica; Margot, Pierre; Delémont, Olivier; Esseiva, Pierre

    2009-05-30

    A headspace solid-phase microextraction procedure (HS-SPME) was developed for the profiling of traces present in 3,4-methylenedioxymethylampethamine (MDMA). Traces were first extracted using HS-SPME and then analyzed by gas chromatography-mass spectroscopy (GC-MS). The HS-SPME conditions were optimized using varying conditions. Optimal results were obtained when 40 mg of crushed MDMA sample was heated at 80 degrees C for 15 min, followed by extraction at 80 degrees C for 15 min with a polydimethylsiloxane/divinylbenzene coated fibre. A total of 31 compounds were identified as traces related to MDMA synthesis, namely precursors, intermediates or by-products. In addition some fatty acids used as tabletting materials and caffeine used as adulterant, were also detected. The use of a restricted set of 10 target compounds was also proposed for developing a screening tool for clustering samples having close profile. 114 seizures were analyzed using an SPME auto-sampler (MultiPurpose Samples MPS2), purchased from Gerstel GMBH & Co. (Germany), and coupled to GC-MS. The data was handled using various pre-treatment methods, followed by the study of similarities between sample pairs based on the Pearson correlation. The results show that HS-SPME, coupled with the suitable statistical method is a powerful tool for distinguishing specimens coming from the same seizure and specimens coming from different seizures. This information can be used by law enforcement personnel to visualize the ecstasy distribution network as well as the clandestine tablet manufacturing.

  9. Airborne lidar measurements to investigate the impact of long-range transported dust on shallow marine trade wind convection

    Science.gov (United States)

    Gross, S.; Gutleben, M.; Wirth, M.; Ewald, F.

    2017-12-01

    Aerosols and clouds are still main contributors to uncertainties in estimates and interpretation of the Earth's changing energy budget. Their interaction with the Earth's radiation budged has a direct component by scattering and absorbing solar and terrestrial radiation, and an indirect component, e.g. as aerosols modify the properties and thus the life-time of clouds or by changing the atmosphere's stability. Up to know now sufficient understanding in aerosol-cloud interaction and climate feedback is achieved. Thus studies with respect to clouds, aerosols, their interaction and influence on the radiation budged are highly demanded. In August 2016 the NARVAL-II (Next-generation airborne remote sensing for validation studies) mission took place. Measurements with a combined active (high spectral resolution and water vapor differential absorption lidar and cloud radar) and passive remote sensing (microwave radiometer, hyper spectral imager, radiation measurements) payload were performed with the German high altitude and long-range research aircraft HALO over the subtropical North-Atlantic Ocean to study shallow marine convection during the wet and dusty season. With this, NARVAL-II is follow-up of the NARVAL-I mission which took place during the dry and dust free season in December 2013. During NARVAL-II the measurement flights were designed the way to sample dust influenced areas as well as dust free areas in the trades. One main objective was to investigate the optical and macro physical properties of the dust layer, differences in cloud occurrence in dusty and non-dusty areas, and to study the influence of aerosols on the cloud properties and formation. This allows comparisons of cloud and aerosol distribution as well as their environment between the dry and the wet season, and of cloud properties and distribution with and without the influence of long-range transported dust across the Atlantic Ocean. In our presentation we will give an overview of the NARVAL

  10. Airborne Measurements of CO2 Column Absorption and Range Using a Pulsed Direct-Detection Integrated Path Differential Absorption Lidar

    Science.gov (United States)

    Abshire, James B.; Riris, Haris; Weaver, Clark J.; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Browell, Edward V.

    2013-01-01

    We report on airborne CO2 column absorption measurements made in 2009 with a pulsed direct-detection lidar operating at 1572.33 nm and utilizing the integrated path differential absorption technique. We demonstrated these at different altitudes from an aircraft in July and August in flights over four locations in the central and eastern United States. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The lidar measurement statistics were also calculated for each flight as a function of altitude. The optical depth varied nearly linearly with altitude, consistent with calculations based on atmospheric models. The scatter in the optical depth measurements varied with aircraft altitude as expected, and the median measurement precisions for the column varied from 0.9 to 1.2 ppm. The altitude range with the lowest scatter was 810 km, and the majority of measurements for the column within it had precisions between 0.2 and 0.9 ppm.

  11. Determinação de herbicidas usados no cultivo de arroz irrigado na região sul do estado de Santa Catarina através da SPME-GC-ECD Determination of herbicides used in irrigated rice cultivation in the south of Santa Catarina using SPME-GC-ECD

    Directory of Open Access Journals (Sweden)

    Léa L. F. Costa

    2008-01-01

    Full Text Available Evaluation of the pollution by the herbicides alachlor, propanil and atrazine in water samples from four rivers in the cities of Turvo and Meleiro, south of Santa Catarina State, was made using the SPME-GC-ECD method. The proposed method was optimized and validated. The correlation coefficients were higher than 0.997 and linear ranges of the analytical curves were 0.1-4; 0.1-2.5 and 0.1-5 µg L-1 for atrazine, alachlor and propanil, respectively. The herbicides were quantified by GC-ECD and identified by GC-MS. Both of the selected rivers presented contamination by at least one of the studied herbicides.

  12. Calibration and uncertainties in gas microflow measurement in the range of 2–200 µg s−1 of nitrogen

    International Nuclear Information System (INIS)

    Barbe, J; Dijoux, F; Yardin, C; Macé, T; Vaslin-Reimann, S

    2010-01-01

    Today the field of chemistry needs calibration in gas microflow measurement for applications such as thin film deposition, catalysis or the automotive industry. Few European metrology laboratories conduct this type of calibration. In France no laboratory can calibrate below 20 µg s −1 . To meet this growing need, LNE has developed a calibration bench using the method of 'traced gas' in the range of 2–200 µg s −1 . The method and the uncertainty estimation of the calibration bench and calibration results of three laminar flowmeters of Molbloc type and industrial flowmeters are presented in this paper

  13. Upper limit on a stochastic background of gravitational waves from seismic measurements in the range 0.05-1 Hz.

    Science.gov (United States)

    Coughlin, Michael; Harms, Jan

    2014-03-14

    In this Letter, we present an upper limit of ΩGW<1.2×108 on an isotropic stochastic gravitational-wave (GW) background integrated over a year in the frequency range 0.05-1 Hz, which improves current upper limits from high-precision laboratory experiments by about 9 orders of magnitude. The limit is obtained using the response of Earth itself to GWs via a free-surface effect described more than 40 years ago by Dyson. The response was measured by a global network of broadband seismometers selected to maximize the sensitivity.

  14. Sampling and analytical procedures for the determination of VOCs released into air from natural and anthropogenic sources: A comparison between SPME (Solid Phase Micro Extraction) and ST (Solid Trap) methods

    International Nuclear Information System (INIS)

    Tassi, F.; Capecchiacci, F.; Buccianti, A.; Vaselli, O.

    2012-01-01

    In the present study, two sampling and analytical methods for VOC determination in fumarolic exhalations related to hydrothermal-magmatic reservoirs in volcanic and geothermal areas and biogas released from waste landfills were compared: (a) Solid Traps (STs), consisting of three phase (Carboxen B, Carboxen C and Carbosieve S111) absorbent stainless steel tubes and (b) Solid Phase Micro Extraction (SPME) fibers, composed of DiVinylBenzene (DVB), Carboxen and PolyDimethylSiloxane. These techniques were applied to pre-concentrate VOCs discharged from: (i) low-to-high temperature fumaroles collected at Vulcano Island, Phlegrean Fields (Italy), and Nisyros Island (Greece), (ii) recovery wells in a solid waste disposal site located near Florence (Italy). A glass condensing system cooled with water was used to collect the dry fraction of the fumarolic gases, in order to allow more efficient VOC absorption avoiding any interference by water vapor and acidic gases, such as SO 2 , H 2 S, HF and HCl, typically present at relatively high concentrations in these fluids. Up to 37 organic species, in the range of 40–400 m/z, were determined by coupling gas chromatography to mass spectrometry (GC–MS). This study shows that the VOC compositions of fumaroles and biogas determined via SPME and ST are largely consistent and can be applied to the analysis of VOCs in gases released from different natural and anthropogenic environments. The SPME method is rapid and simple and more appropriate for volcanic and geothermal emissions, where VOCs are present at relatively high concentrations and prolonged gas sampling may be hazardous for the operator. The ST method, allowing the collection of large quantities of sample, is to be preferred to analyze the VOC composition of fluids from diffuse emissions and air, where these compounds are present at relatively low concentrations.

  15. Validity of clinical outcome measures to evaluate ankle range of motion during the weight-bearing lunge test.

    Science.gov (United States)

    Hall, Emily A; Docherty, Carrie L

    2017-07-01

    To determine the concurrent validity of standard clinical outcome measures compared to laboratory outcome measure while performing the weight-bearing lunge test (WBLT). Cross-sectional study. Fifty participants performed the WBLT to determine dorsiflexion ROM using four different measurement techniques: dorsiflexion angle with digital inclinometer at 15cm distal to the tibial tuberosity (°), dorsiflexion angle with inclinometer at tibial tuberosity (°), maximum lunge distance (cm), and dorsiflexion angle using a 2D motion capture system (°). Outcome measures were recorded concurrently during each trial. To establish concurrent validity, Pearson product-moment correlation coefficients (r) were conducted, comparing each dependent variable to the 2D motion capture analysis (identified as the reference standard). A higher correlation indicates strong concurrent validity. There was a high correlation between each measurement technique and the reference standard. Specifically the correlation between the inclinometer placement at 15cm below the tibial tuberosity (44.9°±5.5°) and the motion capture angle (27.0°±6.0°) was r=0.76 (p=0.001), between the inclinometer placement at the tibial tuberosity angle (39.0°±4.6°) and the motion capture angle was r=0.71 (p=0.001), and between the distance from the wall clinical measure (10.3±3.0cm) to the motion capture angle was r=0.74 (p=0.001). This study determined that the clinical measures used during the WBLT have a high correlation with the reference standard for assessing dorsiflexion range of motion. Therefore, obtaining maximum lunge distance and inclinometer angles are both valid assessments during the weight-bearing lunge test. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Design of transmission-type phase holograms for a compact radar-cross-section measurement range at 650 GHz.

    Science.gov (United States)

    Noponen, Eero; Tamminen, Aleksi; Vaaja, Matti

    2007-07-10

    A design formalism is presented for transmission-type phase holograms for use in a submillimeter-wave compact radar-cross-section (RCS) measurement range. The design method is based on rigorous electromagnetic grating theory combined with conventional hologram synthesis. Hologram structures consisting of a curved groove pattern on a 320 mmx280 mm Teflon plate are designed to transform an incoming spherical wave at 650 GHz into an output wave generating a 100 mm diameter planar field region (quiet zone) at a distance of 1 m. The reconstructed quiet-zone field is evaluated by a numerical simulation method. The uniformity of the quiet-zone field is further improved by reoptimizing the goal field. Measurement results are given for a test hologram fabricated on Teflon.

  17. Development of Measurement Device of Working Radius of Crane Based on Single CCD Camera and Laser Range Finder

    Science.gov (United States)

    Nara, Shunsuke; Takahashi, Satoru

    In this paper, what we want to do is to develop an observation device to measure the working radius of a crane truck. The device has a single CCD camera, a laser range finder and two AC servo motors. First, in order to measure the working radius, we need to consider algorithm of a crane hook recognition. Then, we attach the cross mark on the crane hook. Namely, instead of the crane hook, we try to recognize the cross mark. Further, for the observation device, we construct PI control system with an extended Kalman filter to track the moving cross mark. Through experiments, we show the usefulness of our device including new control system of mark tracking.

  18. Wide-range measurement of thermal effusivity using molybdenum thin film with low thermal conductivity for thermal microscopes

    Science.gov (United States)

    Miyake, Shugo; Matsui, Genzou; Ohta, Hiromichi; Hatori, Kimihito; Taguchi, Kohei; Yamamoto, Suguru

    2017-07-01

    Thermal microscopes are a useful technology to investigate the spatial distribution of the thermal transport properties of various materials. However, for high thermal effusivity materials, the estimated values of thermophysical parameters based on the conventional 1D heat flow model are known to be higher than the values of materials in the literature. Here, we present a new procedure to solve the problem which calculates the theoretical temperature response with the 3D heat flow and measures reference materials which involve known values of thermal effusivity and heat capacity. In general, a complicated numerical iterative method and many thermophysical parameters are required for the calculation in the 3D heat flow model. Here, we devised a simple procedure by using a molybdenum (Mo) thin film with low thermal conductivity on the sample surface, enabling us to measure over a wide thermal effusivity range for various materials.

  19. HS-SPME analysis of volatile organic compounds of coniferous needle litter

    Science.gov (United States)

    Isidorov, V. A.; Vinogorova, V. T.; Rafałowski, K.

    The composition of volatile emission of Scots pine ( Pinus sylvestris) and spruce ( Picea exelsa) litter was studied by gas chromatography-mass spectrometry (GC-MS) and samples were collected by solid-phase microextraction (SPME) method. The list of identified compounds includes over 60 organic substances of different classes. It was established that volatile emission contain not only components of essential oils of pine and spruce needles but also a large number of organic compounds which are probably secondary metabolites of litter-decomposing fungi. They include lower carbonyl compounds and alcohols as well as products of terpene dehydration and oxidation. These data show that the processes of litter decomposition are an important source of reactive organic compounds under canopy of coniferous forests.

  20. Differentiation of Toxic Molds via Headspace SPME-GC/MS and Canine Detection

    Directory of Open Access Journals (Sweden)

    Kenneth G. Furton

    2007-08-01

    Full Text Available Indoor mold growth has recently become a concern in the legal world in regards to insurance litigation. Hazardous mold exposure to humans has been linked to many acute and chronic adverse health effects including death. As it grows, mold produces several types of primary and secondary metabolites, including microbial volatile organic compounds (MVOCs. Microbial volatile organic compound emission may be used as a preliminary indication of a mold infestation that is invisible to the unaided eye. The objective of the study is to identify the unique odor signatures of three species of molds, Aspergillus versicolor, Penicillium chrysogenum, and Stachybotrys chartarum by SPME-GC/MS analysis. Determining the compounds that are emitted by the selected species has made it possible to conduct validation studies of canine detection of these mold species through a series of field tests.

  1. Authenticity of raspberry flavor in food products using SPME-chiral-GC-MS

    DEFF Research Database (Denmark)

    Hansen, Anne-Mette Sølvbjerg; Frandsen, Henrik Lauritz; Fromberg, Arvid

    2015-01-01

    A fast and simple method for authenticating raspberry flavors from food products was developed. The two enantiomers of the compound (E)-α-ionone from raspberry flavor were separated on a chiral gas chromatographic column. Based on the ratio of these two enantiomers the naturalness of a raspberry...... flavor can be evaluated due to the fact that a natural flavor will consist almost exclusively of the R enantiomer, while a chemical synthesis of the same compound will result in a racemic mixture. 27 food products containing raspberry flavors where investigated using SPME-chiral-GC-MS. We found raspberry...... distribution of the R and S isomer. Two products were labelled to contain natural raspberry flavors but were found to contain almost equal amounts of both enantiomers indicating a presence of synthetic raspberry flavors only. Additionally, two products labelled to contain both raspberry juice and flavor showed...

  2. Use of solid phase microextraction (SPME) for profiling the volatile metabolites produced by Glomerella cingulata.

    Science.gov (United States)

    Miyazawa, Mitsuo; Kimura, Minako; Yabe, Yoshito; Tsukamoto, Daisuke; Sakamoto, Masaya; Horibe, Isao; Okuno, Yoshiharu

    2008-01-01

    The profile of volatile organic compounds (VOCs) released from Glomerella cingulata using solid phase microextraction (SPME) with different fibers, Polydimethylsiloxane (PDMS), Polydimethylsiloxane/Divinylbenzene (PDMS/DVB), Carboxen/Polydimethylsiloxane (CAR/PDMS) and Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), was investigated. C4-C6 aliphatic alcohols were the predominant fraction of VOCs isolated by CAR/PDMS fiber. Sesquiterpene hydrocarbons represented 20.3% of VOCs isolated by PDMS fiber. During the growth phase, Ochracin was produced in the large majority of VOCs. 3-Methylbutanol and phenylethyl alcohol were found in the log phase of it. Alcohols were found in cultures of higher age, while sesquiterpenes were found to be characteristic of initial growth stage of G. cingulata.

  3. Precise Measurement of the $\\bar{p}p$ Total Cross-Section in the ISR Energy Range

    CERN Multimedia

    2002-01-01

    The major aim of this experiment is the precise measurement of the antiproton-proton total cross-section in the ISR energy range, using the total-rate method. The proton-proton total cross-section is remeasured with the same method and the same apparatus, and a precision of 0.5\\% is expected for both cross-sections. The total-rate method consists in the simultaneous measurement of the total interaction rate and the ISR luminosity. This is done with a set of scintillation-counter hodoscopes covering over 99.99\\% of the solid angle, which are sensitive to over 95\\% of all interactions. In addition to these detectors, small-angle drift-tube hodoscopes are used to measure the differential elastic cross-section as a function of the momentum transfert t. The total cross-section can be measured independently by extrapolating this differential cross-section to the forward direction and invoking the optical theorem. A study of the general features of charged-particle production is performed using finely divided scinti...

  4. Changes in SPME-extracted volatile compounds from Iberian ham during ripening

    Directory of Open Access Journals (Sweden)

    García, Carmen

    2009-07-01

    Full Text Available A headspace SPME procedure was tested to study the evolution of volatile compounds during the ripening of Iberian hams from pigs reared in a Montanera system (outdoorbased, with acorn and pasture available and a HO-Pienso system (indoor-based, with a high oleic acid concentrate. The effect of the ripening time on volatile compounds was more marked than the effect of feeding system. Most volatile compounds affected by the ripening time were compounds that come from Strecker and Maillard reactions, which increased significantly ( p Un procedimiento de microextración en fase sólida (SPME en espacio de cabeza fue ensayado para estudiar la evolución de los compuestos volátiles durante la curación de Jamones Ibéricos de cerdos criados en régimen de montanera (en libertad, con bellotas y pasto disponible y un sistema OH-Pienso (estabulados, con un pienso alto en ácido oléico. El efecto del tiempo de curación en los compuestos volátiles fue más marcado que el efecto de la alimentación. La mayoría de los compuestos volátiles afectados por el tiempo de curación fueron compuestos que proceden de la reacción de Strecker y Maillard, que se incrementaron significativamente (p p < 0.05. Algunos de ellos (ácido butanoico, 2,6- dimetilpiracina y 1-octen-3-ol fueron más abundantes en jamones de Montanera que en jamones de Pienso. Estas pequeñas diferencias podrían ser importantes porque los compuestos involucrados han sido identificados como aromas del jamón Ibérico.

  5. Quantification of Polyfunctional Thiols in Wine by HS-SPME-GC-MS Following Extractive Alkylation

    Directory of Open Access Journals (Sweden)

    Lauren E. Musumeci

    2015-07-01

    Full Text Available Analyses of key odorous polyfunctional volatile thiols in wines (3-mercaptohexanol (3-MH, 3-mercaptohexylacetate (3-MHA, and 4-mercapto-4-methyl-2-pentanone (4-MMP are challenging due to their high reactivity and ultra-trace concentrations, especially when using conventional gas-chromatography electron impact mass spectrometry (GC-EI-MS. We describe a method in which thiols are converted to pentafluorobenzyl (PFB derivatives by extractive alkylation and the organic layer is evaporated prior to headspace solid phase microextraction (HS-SPME and GC-EI-MS analysis. Optimal parameters were determined by response surface area modeling. The addition of NaCl solution to the dried SPME vials prior to extraction resulted in up to less than fivefold improvement in detection limits. Using 40 mL wine samples, limits of detection for 4-MMP, 3-MH, and 3-MHA were 0.9 ng/L, 1 ng/L, and 17 ng/L, respectively. Good recovery (90%–109% and precision (5%–11% RSD were achieved in wine matrices. The new method was used to survey polyfunctional thiol concentrations in 61 commercial California and New York State wines produced from V. vinifera (Riesling, Gewürztraminer, Cabernet Sauvignon, Sauvignon blanc and non-varietal rosé wines, V. labruscana (Niagara, and Vitis spp. (Cayuga White. Mean 4-MMP concentrations in New York Niagara (17 ng/L were not significantly different from concentrations in Sauvignon blanc, but were significantly higher than 4-MMP in other varietal wines.

  6. A pressurized ion chamber monitoring system for environmental radiation measurements utilizing a wide-range temperature-compensated electrometer

    International Nuclear Information System (INIS)

    Stevenick, W. Van

    1994-01-01

    The performance of a complete pressurized ion chamber (PIC) radiation monitoring system is described. The design incorporates an improved temperature-compensated electrometer which is stable to ±3 · 10 -16 A over the environmental range of temperature (-40 to +40 C). Using a single 10 11 Ω feed-back resistor, the electrometer accurately measures currents over a range from 3 · 10 -15 A to 3 · 10 -11 A. While retaining the sensitivity of the original PIC system (the instrument responds readily to small background fluctuations on the order of 0.1 μR h -1 ), the new system measures radiation levels up to the point where the collection efficiency of the ion chamber begins to drop off, typically ∼27 pA at 1 mR h -1 . A data recorder and system controller was designed using the Tattletale trademark Model 4A computer. Digital data is stored on removable solid-state, credit-card style memory cards

  7. Sources and characteristics of summertime organic aerosol in the Colorado Front Range: perspective from measurements and WRF-Chem modeling

    Directory of Open Access Journals (Sweden)

    R. Bahreini

    2018-06-01

    Full Text Available The evolution of organic aerosols (OAs and their precursors in the boundary layer (BL of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014 was analyzed by in situ measurements and chemical transport modeling. Measurements indicated significant production of secondary OA (SOA, with enhancement ratio of OA with respect to carbon monoxide (CO reaching 0.085±0.003 µg m−3 ppbv−1. At background mixing ratios of CO, up to  ∼  1.8 µg m−3 background OA was observed, suggesting significant non-combustion contribution to OA in the Front Range. The mean concentration of OA in plumes with a high influence of oil and natural gas (O&G emissions was  ∼  40 % higher than in urban-influenced plumes. Positive matrix factorization (PMF confirmed a dominant contribution of secondary, oxygenated OA (OOA in the boundary layer instead of fresh, hydrocarbon-like OA (HOA. Combinations of primary OA (POA volatility assumptions, aging of semi-volatile species, and different emission estimates from the O&G sector were used in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem simulation scenarios. The assumption of semi-volatile POA resulted in greater than a factor of 10 lower POA concentrations compared to PMF-resolved HOA. Including top-down modified O&G emissions resulted in substantially better agreements in modeled ethane, toluene, hydroxyl radical, and ozone compared to measurements in the high-O&G-influenced plumes. By including emissions from the O&G sector using the top-down approach, it was estimated that the O&G sector contributed to  <  5 % of total OA, but up to 38 % of anthropogenic SOA (aSOA in the region. The best agreement between the measured and simulated median OA was achieved by limiting the extent of biogenic hydrocarbon aging and consequently biogenic SOA (bSOA production. Despite a lower production of bSOA in

  8. Pulsed Lidar Measurements of Atmospheric CO2 Column Absorption and Range During the ASCENDS 2009-2011 Airborne Campaigns

    Science.gov (United States)

    Abshire, J. B.; Weaver, C. J.; Riris, H.; Mao, J.; Sun, X.; Allan, G. R.; Hasselbrack, W. E.; Browell, E. V.

    2012-01-01

    We have developed a pulsed lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS mission and have demonstrated the CO2 and O2 measurements from aircraft. Our technique uses two pulsed lasers allowing simultaneous measurement of a single CO2 absorption line near 1572 nm, O2 extinction in the Oxygen A-band, surface height and backscatter profile. The lasers are stepped in wavelength across the CO2 line and an O2 line doublet during the measurement. The column densities for the CO2 and O2 are estimated from the differential optical depths (DOD) of the scanned absorption lines via the IPDA technique. For the 2009 ASCENDS campaign we flew the CO2 lidar only on a Lear-25 aircraft, and measured the absorption line shapes of the CO2 line using 20 wavelength samples per scan. Measurements were made at stepped altitudes from 3 to 12.6 km over the Lamont OK, central Illinois, North Carolina, and over the Virginia Eastern Shore. Although the received signal energies were weaker than expected for ASCENDS, clear C02 line shapes were observed at all altitudes. Most flights had 5-6 altitude steps with 200-300 seconds of recorded measurements per step. We averaged every 10 seconds of measurements and used a cross-correlation approach to estimate the range to the scattering surface and the echo pulse energy at each wavelength. We then solved for the best-fit CO2 absorption line shape, and calculated the DOD of the fitted CO2 line, and computed its statistics at the various altitude steps. We compared them to CO2 optical depths calculated from spectroscopy based on HITRAN 2008 and the column number densities calculated from the airborne in-situ readings. The 2009 measurements have been analyzed in detail and they were similar on all flights. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. They showed the expected nearly the linear dependence of DOD vs

  9. Reliability of measuring half-cycle cervical range of motion may be increased using a spirit level for calibration.

    Science.gov (United States)

    Wilke, Jan; Niederer, Daniel; Vogt, Lutz; Banzer, Winfried

    2018-02-01

    Assessments of range of motion (ROM) represent an essential part of clinical diagnostics. Ultrasonic movement analyses have been demonstrated to provide reliable results when analyzing complete amplitudes (e.g., flexion-extension). However, due to subjective determination of the starting position, the assessment of half-cycle movements (e.g, flexion only) is less reproducible. The present study aimed to examine the reliability of measuring half-cycle cervical ROM using a spirit level for calibration. 20 healthy subjects (30 ± 12yrs, 7♂, 13♀) participated in the randomized, controlled, cross-over trial. In two testing sessions with one week of wash-out in between, cervical ROM was measured by means of an ultrasonic 3D movement analysis system using a test-retest design (baseline and 5 min post baseline). The sessions differed with reference to the mask carrying the ultrasound markers. It was removed during the 5 min break (mask off) or not (mask on). To determine the resting position, a bull's eye spirit level was used in each measurement. With ICC values of 0.90-0.98 (mask on, p spirit level. In contrast to subjective determination of the starting position, analyzing complete movement planes does not increase reliability. Using a defined and objective zero positioning allows the evaluation of repositioning tasks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinquan [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Sun, Xiaodong, E-mail: sun.200@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Liu, Yang [Nuclear Engineering Program, Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, VA 24061 (United States)

    2016-12-15

    This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

  11. Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

    International Nuclear Information System (INIS)

    Zhou, Xinquan; Sun, Xiaodong; Liu, Yang

    2016-01-01

    This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

  12. Differential cross section measurement of elastic scattering 12C(p,p)12C in the astrophysical range of energy

    International Nuclear Information System (INIS)

    Baktibayev, M.K.; Burminskii, V.P.; Burtebaev, N.; Dzazairov -Kakhramanov, V.; Hassan, S.F.; Satpaev, N.K.; Zazulin, D.M.

    2004-01-01

    Full text: The fulfillment of planned works on measurements of differential cross sections of elastic scattering of protons on nuclear 12 C at the energy region of 350†1050 keV suggests the preparation of thin self - supporting carbon target. The self - supporting target is necessary in order to perform investigations in the total angular range. In the future last data will be used in order to determine optical potentials and scattering phases for this nuclear in the energy range of astrophysical interest. There was prepared target layer of the 12 C with natural composition of carbon and of thickness of 17.4 μg/cm 2 . The spraying was conducted in the vacuum evaporation installation (VUP - 4) by an electron bombardment method. Carbon was sprayed on a glass plate with previously deposited of layer salt. After a heating during 12 hours at the temperature of 150 o C the film of carbon was floated from glass plate and self - supporting target has been picked up on the specially prepared target frame. In order to determine thickness of target there was used the resonance chamber, installed in the protons channel of the accelerator RAC - 2 - 1 (INP NNC RK), with the help of which there was measured energy loss of the protons beam during the passage through target, disposed in the central chamber. For this purpose there was used the reaction 27 Al(p,γ) 28 Si with narrow resonance with E R = 992 keV and with detection of gamma-quanta with E γ = 1779 keV. On shift of the resonance E R =992 keV in the reaction 27 Al(p,γ) 28 Si, which takes place owing to protons energy loss in the thickness of carbon film, and using table values of brake quantities S(E p )[MeV·cm 2 /g] [1], there was determined thickness of this fine film. Such the method allows to determine thicknesses of films in the interval of (10 † 100) mcg/cm 2 with the accuracy of not worse than 5%. In the present work there were carried out measurements of angular distributions of cross sections of the

  13. Validation of Measured Damping Trends for Flight-Like Vehicle Panel/Equipment including a Range of Cable Harness Assemblies

    Science.gov (United States)

    Smith, Andrew M.; Davis, R. Benjamin; LaVerde, Bruce T.; Fulcher, Clay W.; Jones, Douglas C.; Waldon, James M.; Craigmyle, Benjamin B.

    2012-01-01

    This validation study examines the effect on vibroacoustic response resulting from the installation of cable bundles on a curved orthogrid panel. Of interest is the level of damping provided by the installation of the cable bundles and whether this damping could be potentially leveraged in launch vehicle design. The results of this test are compared with baseline acoustic response tests without cables. Damping estimates from the measured response data are made using a new software tool that leverages a finite element model of the panel in conjunction with advanced optimization techniques. While the full test series is not yet complete, the first configuration of cable bundles that was assessed effectively increased the viscous critical damping fraction of the system by as much as 0.02 in certain frequency ranges.

  14. Synthesis and Characterization of a Micelle-Based pH Nanosensor with an Unprecedented Broad Measurement Range

    DEFF Research Database (Denmark)

    Ek, Pramod Kumar; Feldborg, Lise N.; Almdal, Kristoffer

    2013-01-01

    A new cross-linked micelle pH nanosensor design was investigated. The nanosensor synthesis was based on self-assembly of an amphiphilic triblock copolymer, poly(ethylene glycol)-b-poly(2-amino ethyl methacrylate)-b-poly(coumarin methacrylate) (PEG-b-PAEMA-b-PCMA), which was synthesized by isolated...... irradiation (320 nm pH nanosensors by binding the pH-sensitive fluorophores oregon green 488 and 2′,7′-bis-(2-carboxyethyl)-5-(and-6......) carboxyfluorescein and a reference fluorophore Alexa 633 to the PAEMA shell region of the micelles. Fluorescence measurements show that these pH nanosensors are sensitive in a surprisingly broad pH range of 3.4–8.0, which is hypothesized to be due to small differences in the individual fluorophores’ local...

  15. Long-term measurements of carbonaceous aerosols in the Eastern Mediterranean: evidence of long-range transport of biomass burning

    Directory of Open Access Journals (Sweden)

    J. Sciare

    2008-09-01

    Full Text Available Long-term (5-year measurements of Elemental Carbon (EC and Organic Carbon (OC in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island. A multi-analytical approach (including thermal, optical, and thermo-optical techniques was applied for these EC and OC measurements. Light absorbing dust aerosols were shown to poorly contribute (+12% on a yearly average to light absorption coefficient (babs measurements performed by an optical method (aethalometer. Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March–April and July–September. The contribution of biomass burning to the concentrations of EC and OC was shown to be rather small (20 and 14%, respectively, on a yearly basis, although this contribution could be much higher on a monthly basis and showed important seasonal and interannual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC have shown that the monthly mean WSOC/OC ratio remains stable throughout the year (0.45±0.12, suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A.D.<1.5μm showed that the mass contribution of organic matter (POM was found to be essentially invariable during the year (monthly average of 26±5%.

  16. Long-term measurements of carbonaceous aerosols in the Eastern Mediterranean: evidence of long-range transport of biomass burning

    International Nuclear Information System (INIS)

    Sciare, J.; Oikonomou, K.; Favez, O.; Cachier, H.; Liakakou, E.; Markaki, Z.; Mihalopoulos, N.

    2008-01-01

    Long-term (5-year) measurements of Elemental Carbon (EC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these EC and OC measurements. Light absorbing dust aerosols were shown to poorly contribute (+12% on a yearly average) to light absorption coefficient (b(abs)) measurements performed by an optical method (aethalometer). Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March-April and July-September). The contribution of biomass burning to the concentrations of EC and OC was shown to be rather small (20 and 14%, respectively, on a yearly basis), although this contribution could be much higher on a monthly basis and showed important seasonal and inter annual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC) have shown that the monthly mean WSOC/ OC ratio remains stable throughout the year (0.45 ± 0.12), suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA) formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A. D.≤ 1.5 μm) showed that the mass contribution of organic matter (POM) was found to be essentially invariable during the year (monthly average of 26 ± 5%). (authors)

  17. Validace HPLC metody stanovení piroxikamu v plasmě s využitím SPME a deproteinace

    OpenAIRE

    Kuželová, Kristýna

    2015-01-01

    Validation of HPLC evaluatoin of piroxicam in plasma using SPME and precipitation Rigorous Thesis Mgr. Kristýna Kuželová Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Department of Pharmaceutical Chemistry and Drug Control, Heyrovského 1203, Hradec Králové The purpose of this thesis was bioanalytical evalution of piroxicam using High Performance Liquid Chromatagraphy (HPLC). Piroxicam was isolated from plasma using SPME and protein precipitacion. Plasma was adjusted to ...

  18. The range and effectiveness of short-term measures to reduce traffic emissions during high air pollution episodes

    International Nuclear Information System (INIS)

    Elsom, Derek M.

    1999-01-01

    Concern for continuing poor urban air quality, caused primarily by motor vehicles emissions, and the slow progress being made towards reducing total vehicle emissions by long-term measures, such as improving fuel and vehicle technologies, has prompted some authorities to try to reduce the severity and duration of high air pollution episodes by implementing short-term traffic restraint measures. This paper reviews the range of episodic air quality management schemes applied in cities around the world and comments on the effectiveness of such schemes. The difficulty of targeting vehicles according to the contribution they make to the air quality problem is highlighted. The problem of some schemes simply causing a displacement of the area of excessive vehicle emissions rather than reducing total emissions is reviewed. Rapid developments in telematics and improved urban air quality and traffic monitoring networks (e.g. Urban Traffic Management and Control systems) may offer significant improvements in the effectiveness of episodic management schemes in the future. (Author)

  19. Measurement of vortex velocities over a wide range of vortex age, downstream distance and free stream velocity

    Science.gov (United States)

    Rorke, J. B.; Moffett, R. C.

    1977-01-01

    A wind tunnel test was conducted to obtain vortex velocity signatures over a wide parameter range encompassing the data conditions of several previous researchers while maintaining a common instrumentation and test facility. The generating wing panel was configured with both a revolved airfoil tip shape and a square tip shape and had a semispan aspect of 4.05/1.0 with a 121.9 cm span. Free stream velocity was varied from 6.1 m/sec to 76.2 m/sec and the vortex core velocities were measured at locations 3, 6, 12, 24 and 48 chordlengths downstream of the wing trailing edge, yielding vortex ages up to 2.0 seconds. Wing pitch angles of 6, 8, 9 and 12 deg were investigated. Detailed surface pressure distributions and wing force measurements were obtained for each wing tip configuration. Correlation with vortex velocity data taken in previous experiments is good. During the rollup process, vortex core parameters appear to be dependent primarily on vortex age. Trending in the plateau and decay regions is more complex and the machanisms appear to be more unstable.

  20. Thermal conductivity of a wide range of alternative refrigerants measured with an improved guarded hot-plate apparatus

    International Nuclear Information System (INIS)

    Hammerschmidt, U.

    1995-01-01

    The thermal conductivity of the refrigerants R22, R123, R134a, R142b, R143a, and R152a has been determined as a function of temperature in the range from 300 to 460 K. Measurements were carried out at atmospheric pressure with an improved guarded hot-plate apparatus. The width of the instrument's gas layer and the temperature difference across the metering section were varied to detect any stray heat transfer. Radiation correction factors were derived from IR absorption spectra. The uncertainty of the measurements is estimated to be 2% at a standard deviation of less than 0.1%. Our data sets are compared with corresponding hot wire results. In contrast to the generally preferred hot wire technique, with its possible electrical and chemical interactions between the wire and the polar refrigerant, there are no such difficulties using a guarded hot-plate apparatus. Our data sets may thus contribute to the discussions on discrepancies in thermal conductivity values from various authors using hot wire as one particular method

  1. PSYCHE CPMG-HSQMBC: An NMR Spectroscopic Method for Precise and Simple Measurement of Long-Range Heteronuclear Coupling Constants.

    Science.gov (United States)

    Timári, István; Szilágyi, László; Kövér, Katalin E

    2015-09-28

    Among the NMR spectroscopic parameters, long-range heteronuclear coupling constants convey invaluable information on torsion angles relevant to glycosidic linkages of carbohydrates. A broadband homonuclear decoupled PSYCHE CPMG-HSQMBC method for the precise and direct measurement of multiple-bond heteronuclear couplings is presented. The PSYCHE scheme built into the pulse sequence efficiently eliminates unwanted proton-proton splittings from the heteronuclear multiplets so that the desired heteronuclear couplings can be determined simply by measuring frequency differences between peak maxima of pure antiphase doublets. Moreover, PSYCHE CPMG-HSQMBC can provide significant improvement in sensitivity as compared to an earlier Zangger-Sterk-based method. Applications of the proposed pulse sequence are demonstrated for the extraction of (n)J((1)H,(77)Se) and (n)J((1)H,(13)C) values, respectively, in carbohydrates; further extensions can be envisioned in any J-based structural and conformational studies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Measurements and Monte Carlo calculations with the extended-range Bonner sphere spectrometer at high-energy mixed fields

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00406842; Bay, Aurelio; Silari, Marco; Aroua, Abbas

    The use of spectrometry to provide information for neutron radiation protection has become an increasingly important activity over recent years. The need for spectral data arises because neither area survey instruments nor personal dosimeters give the correct dose equivalent results at all neutron energies. It is important therefore to know the spectra of the fields in which these devices are used. One of the systems most commonly employed in neutron spectrometry and dosimetry is the Bonner Sphere Spectrometers (BSS). The extended- range BSS that was used for this work, consists of 7 spheres with an overall response to neutrons up to 2 GeV. A 3He detector is used as a thermal counter in the centre of each sphere. In the context of this thesis the BSS was calibrated in monoenergetic neutron fields at low and intermediate energies. It was also used for measurements in several high energy mixed fields. These measurements have led to the calculation of neutron yields and spectral fluences from unshielded targets....

  3. A study of the normal interpedicular distance of the spine in Korean teenagers (Estimation of normal range by roentgenographic measurement)

    International Nuclear Information System (INIS)

    Lee, Myung Uk

    1979-01-01

    The radiological measurement of the interpedicular disease using a routine antero-posterior view of the spine gives important clinical criteria in evaluation of the intraspinal tumor and stenosis of the spinal canal, and aids for diagnosis of the lesions. In 1934 Elsberg and Dyke reported values of interpedicular distance as determined on roentgenograms for spine of white adult, and in 1968 Song prepared normal values of interpedicular distance for Korean adult. The present investigation was undertaken to provide normal interpedicular distance of Korean teenagers. The author observed the antero-posterior films of the spine of 200 normal teenagers which were composed of 100 male and 100 female. The normal values of the interpedicular distance of Korean teenagers were obtained, as well as 90% tolerance range for clinical use. In this statistical analysis, there were noted significant differences between male and female, and each age groups. It was observed that average male measurement were consistently larger than female by about 1 mm and the growth of the spinal canal appeared to be continued.

  4. Development and validation of an SPME-GC method for a degradation kinetics study of propiconazole I, propiconazole II and tebuconazole in blueberries in Concordia, the main production area of Argentina.

    Science.gov (United States)

    Munitz, Martín S; Medina, María B; Montti, María I T

    2017-05-01

    An analytical method for the simultaneous determination of propiconazole isomers and tebuconazole residues in blueberries was developed using solid-phase microextraction (SPME) coupled to gas chromatography. Confirmation was performed by gas chromatography-mass spectrometry in selected-ion monitoring mode. The SPME fibre coating selected was CWX-DVB, and the pH was adjusted to 7 with NaOH. The method is selective with adequate precision and high accuracy and sensitivity. Recoveries ranged between 97.4% and 98.9% for all compounds; and detection and quantification limits were respectively 0.21 and 0.49 μg kg -1 for propiconazole I; 0.16 and 0.22 μg kg -1 for propiconazole II; and 0.16 and 0.48 μg kg -1 for tebuconazole. The degradation of these fungicides in blueberries followed first-order rate kinetics. The half-life times for flowering and fruit set applications were respectively 4.0 and 10.3 days for propiconazole I, 4.0 and 11.4 days for propiconazole II, and 3.5 and 12.4 days for tebuconazole.

  5. Ultrafast Screening and Quantitation of Pesticides in Food and Environmental Matrices by Solid-Phase Microextraction-Transmission Mode (SPME-TM) and Direct Analysis in Real Time (DART).

    Science.gov (United States)

    Gómez-Ríos, Germán Augusto; Gionfriddo, Emanuela; Poole, Justen; Pawliszyn, Janusz

    2017-07-05

    The direct interface of microextraction technologies to mass spectrometry (MS) has unquestionably revolutionized the speed and efficacy at which complex matrices are analyzed. Solid Phase Micro Extraction-Transmission Mode (SPME-TM) is a technology conceived as an effective synergy between sample preparation and ambient ionization. Succinctly, the device consists of a mesh coated with polymeric particles that extracts analytes of interest present in a given sample matrix. This coated mesh acts as a transmission-mode substrate for Direct Analysis in Real Time (DART), allowing for rapid and efficient thermal desorption/ionization of analytes previously concentrated on the coating, and dramatically lowering the limits of detection attained by sole DART analysis. In this study, we present SPME-TM as a novel tool for the ultrafast enrichment of pesticides present in food and environmental matrices and their quantitative determination by MS via DART ionization. Limits of quantitation in the subnanogram per milliliter range can be attained, while total analysis time does not exceed 2 min per sample. In addition to target information obtained via tandem MS, retrospective studies of the same sample via high-resolution mass spectrometry (HRMS) were accomplished by thermally desorbing a different segment of the microextraction device.

  6. HS-SPME AS AN EFFICIENT TOOL FOR DISCRIMINATING CHEMOTYPES OF Lippia alba (Mill. N. E. Brown

    Directory of Open Access Journals (Sweden)

    Aiêrta C. C. da Silva

    Full Text Available Lippia alba (Mill. N. E. Brown (Verbenaceae is a medicinal plant for which several biological activities are reported, such as sedative, anxiolytic, anti-ulcer, antifungal, antimicrobial, antioxidant, antispasmodic, anti-nociceptive and anti-inflammatory. It is characterized by the production of essential oils which have been used to classify the plant in different chemotypes. In the Northeast region of Brazil, the presence of three chemotypes are reported: myrcene-citral (chemotype I, limonene-citral (chemotype II and carvone-limonene (chemotype III. In this work, headspace-solid phase microextraction (HS-SPME was used on the analysis of the volatile organic compounds (VOCs of three chemotypes of L. alba from the Northeast region of Brazil, and compared to the essential oils of the plants extracted by hydrodistillation. Volatile compounds from each chemotype were more effectively differentiated when extracted by HS-SPME than by hydrodistillation.

  7. Extraction with SPME and Synthesis of 2-Methyl-6-vinylpyrazine by a ‘One Pot’ Reaction Using Microwaves

    Directory of Open Access Journals (Sweden)

    René Arzuffi

    2009-06-01

    Full Text Available A synthesis of 2-methyl-6-vinylpyrazine was carried out by way of a ‘one pot’ reaction. In order to establish the efficiency of this synthesis the extraction of the volatiles released by male papaya fruit flies was performed by SPME (solid phase micro-extraction. The compound was separated and identified using GC/MSD (gas chromatography/mass spectrometry detector.

  8. Elucidating the sorption mechanism of “mixed-mode” SPME using the basic drug amphetamine as a model compound

    International Nuclear Information System (INIS)

    Peltenburg, Hester; Groothuis, Floris A.; Droge, Steven T.J.; Bosman, Ingrid J.; Hermens, Joop L.M.

    2013-01-01

    Graphical abstract: -- Highlights: •C18/propylsulfonic acid “mixed-mode” SPME fiber is efficient in sampling amphetamine. •Both protonated and neutral species of amphetamine sorb to the mixed-mode fiber. •Sorption of organic cations to this mixed-mode fiber depends on pH and salinity. •Amphetamine has a 20× higher affinity to the mixed-mode coating than to polyacrylate. -- Abstract: We studied the sorption of amphetamine as a model drug to represent small, polar organic cations to a new SPME coating combining C18 and propylsulfonic acid. This combination of hydrophobic and strong cation exchange (SCX) groups was compared to conventional SPME fibers with polyacrylate (PA) or C18 coating. The affinity of amphetamine at physiological pH (PBS) was 20 to 180 times greater for the new C18/SCX coating than for C18 alone and PA of different coating thickness. As amphetamine is a base and >99% protonated at physiological pH, this enhanced affinity is attributed to the ion-exchange phase in the coating. Tests at pH above the pK a of amphetamine show that, when normalized to the coating volume, neutral amphetamine also has a higher affinity compared to PA. As ion-exchange groups are not unlimitedly present in the coating, amphetamine isotherms level off to a saturation concentration on the C18/SCX fiber at the highest tested aqueous concentrations. Also, other cations (Na + , K + , Ca 2+ ) compete for the SCX sites and decrease the sorption coefficients, e.g. by 1.7 log units when comparing Milli-Q water with PBS. The C18/SCX fiber provides improved sensitivity over some of the classic SPME fibers. However, care should be taken near the cation exchange capacity of the fiber and the fiber should be calibrated in an appropriate matrix so as to eliminate competition effects

  9. Wide Dynamic Range Multiband Infrared Radiometer for In-Fire Measurements of Wildland Fire Radiant Flux Density

    Science.gov (United States)

    Kremens, R.; Dickinson, M. B.; Hardy, C.; Skowronski, N.; Ellicott, E. A.; Schroeder, W.

    2016-12-01

    We have developed a wide dynamic range (24-bit) data acquisition system for collection of radiant flux density (FRFD) data from wildland fires. The data collection subsystem was designed as an Arduino `shield' and incorporates a 24-bit analog-to-digital converter, precision voltage reference, real time clock, microSD card interface, audible annuciator and interface for various digital communication interfaces (RS232, I2C, SPI, etc.). The complete radiometer system consists of our custom-designed `shield', a commercially available Arduino MEGA computer circuit board and a thermopile sensor -amplifier daughter board. Software design and development is greatly assisted by the availability of a library of public-domain, user-implemented software. The daughter board houses a 5-band radiometer using thermopiles designed for this experiment (Dexter Research Corp., Dexter, MI) to allow determination of the total FRFD from the fire (using a wide band thermopile with a KRS-5 window, 0.1 - 30 um), the FRFD as would be received by an orbital asset like MODIS (3.95 um center wavelength (CWL) and 10.95 CWL, corresponding to MODIS bands 21/22 and 31, respectively) and wider bandpass (0.1-5.5 um and 8-14 um) corresponding to the FRFD recorded by `MWIR' and `LWIR' imaging systems. We required a very wide dynamic range system in order to be able to record the flux density from `cold' ground before the fire, through the `hot' flaming combustion stage, to the `cool' phase after passage of the fire front. The recording dynamic range required (with reasonable resolution at the lowest temperatures) is on the order of 106, which is not currently available in commercial instrumentation at a price point, size or feature set that is suitable for wildland fire investigations. The entire unit, along with rechargeable battery power supply is housed in a fireproof aluminum chassis box, which is then mounted on a mast at a height of 5 - 7 m above the fireground floor. We will report initial

  10. A Headspace Solid Phase Microextraction (HS-SPME method for the chromatographic determination of alkylpyrazines in cocoa samples

    Directory of Open Access Journals (Sweden)

    Pini Gláucia F.

    2004-01-01

    Full Text Available A Headspace Solid Phase Microextraction (HS-SPME procedure for isolation and determination of alkylpyrazines in cocoa liquor, using Gas Chromatography with Flame Ionization Detection (GC-FID for the separation and detection of the analytes, is presented here. The HS-SPME operational conditions were optimized using extractions of samples spiked with known amounts of alkylpyrazines typically found on cocoa products. The maximum extraction efficiency was obtained using SPME fibers coated with 65 µm Carbowax/divinylbenzene. Additionally, the best results were achieved with extraction temperature of 60 ºC, 15 min of sample/headspace equilibration time and 45 min extraction time. It was also observed that suspending the samples in saturated aqueous NaCl solution during extractions resulted in a significant increment on the peak areas. This procedure was found to be effective to determine the so-called pyrazinic ratios (quotient between peak areas of alkylpyrazines, which are useful as quality parameters for cocoa liquor.

  11. Essential oil from Rhaponticum acaule L. roots: Comparative study using HS-SPME/GC/GC–MS and hydrodistillation techniques

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    Batoul Benyelles

    2014-12-01

    Full Text Available The composition of essential oil extracted from Rhaponticum acaule L. roots growing wild in Algeria was studied by hydrodistillation (HD and by Head-Space Solid Phase Micro-Extraction (HS-SPME. Quantitative but not qualitative differences have been found in the chemical composition of both analysed samples depending on the extraction method. However, the oil obtained from R. acaule roots shows that aliphatic alcohols were found to be the major class (69.2%, followed by the terpenes (5.5%, alkenes (5.2% and alkynes (4.0%. In both cases the analysis were carried out using Gas Chromatography (GC and Gas Chromatography–Mass Spectrometry (GC–MS. Our study shows that HS-SPME extraction could be considered as an alternative technique for the isolation of volatiles from plant. 25 components were identified in oil vs. 39 in the HS-SPME. However the oil composition of roots was mainly represented by a variety of aliphatic hydrocarbons (alcohols, aldehydes and ketones and terpenes which are known for their antimicrobial activities.

  12. Development of a Direct Headspace Collection Method from Arabidopsis Seedlings Using HS-SPME-GC-TOF-MS Analysis

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    Kazuki Saito

    2013-04-01

    Full Text Available Plants produce various volatile organic compounds (VOCs, which are thought to be a crucial factor in their interactions with harmful insects, plants and animals. Composition of VOCs may differ when plants are grown under different nutrient conditions, i.e., macronutrient-deficient conditions. However, in plants, relationships between macronutrient assimilation and VOC composition remain unclear. In order to identify the kinds of VOCs that can be emitted when plants are grown under various environmental conditions, we established a conventional method for VOC profiling in Arabidopsis thaliana (Arabidopsis involving headspace-solid-phase microextraction-gas chromatography-time-of-flight-mass spectrometry (HS-SPME-GC-TOF-MS. We grew Arabidopsis seedlings in an HS vial to directly perform HS analysis. To maximize the analytical performance of VOCs, we optimized the extraction method and the analytical conditions of HP-SPME-GC-TOF-MS. Using the optimized method, we conducted VOC profiling of Arabidopsis seedlings, which were grown under two different nutrition conditions, nutrition-rich and nutrition-deficient conditions. The VOC profiles clearly showed a distinct pattern with respect to each condition. This study suggests that HS-SPME-GC-TOF-MS analysis has immense potential to detect changes in the levels of VOCs in not only Arabidopsis, but other plants grown under various environmental conditions.

  13. Nanoparticle-Incorporated PDMS Film as an Improved Performance SPME Fiber for Analysis of Volatile Components of Eucalyptus Leaf

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    Parviz Aberoomand Azar

    2013-01-01

    Full Text Available A new fabrication strategy was proposed to prepare polydimethylsiloxane (PDMS- coated solid-phase microextraction (SPME on inexpensive and unbreakable Cu fiber. PDMS was covalently bonded to the Cu substrate using self-assembled monolayer (SAM of (3-mercaptopropyltrimethoxysilane (3MPTS as binder. To increase the performance of the fiber, the incorporation effect of some nanomaterials including silica nanoparticles (NPs, carbon nanotubes (CNTs, and carboxylated carbon nanotubes (CNT-COOH to PDMS coating was compared. The surface morphology of the prepared fibers was characterized by scanning electron microscopy (SEM, and their applicability was evaluated through the extraction of some volatile organic compounds (VOCs of Eucalyptus leaf in headspace mode, and parameters affecting the extraction efficiency including extraction temperature and extraction time were optimized. Extracted compounds were analyzed by GC-MS instrument. The results obtained indicated that prepared fibers have some advantages relative to previously prepared SPME fibers, such as higher thermal stability and improved performance of the fiber. Also, results showed that SPME is a fast, simple, quick, and sensitive technique for sampling and sample introduction of Eucalyptus VOCs.

  14. Evaluation of long-range transport potential of selected brominated flame retardants with measured 1-octanol-air partition coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jeong; Kwon, Jung Hwan [Div. of Environmental Science and Ecological Engineering, Korea University, Seoul (Korea, Republic of)

    2016-10-15

    Various alternative flame retardants are used in many countries since polybrominated diphenyl ethers (PBDEs) were classified as persistent organic pollutants (POPs). However, difficulties in the evaluation of the long-range transport potential (LRTP) of the alternatives are related to the lack of information on their physicochemical properties, which govern their environmental fates and transport. Based on the simulation of LRTP using OECD P{sub OV} and LRTP Screening Tool, five alternative brominated flame retardants (BFRs) (hexabromobenzene [HBB], 2,3,4,5,6-pentabromotoluene [PBT], 2,3,4,5,6-pentabromoethylbenzene [PBEB], 2-ethylhexyl 2,3,4,5-tetrabromobenzoate [TBB], and 1,2,4,5-tetrabromo-3,6-dimethylbenzene [TBX]), and 3 PBDEs (BDE-28, BDE-47, and BDE-99) were chosen to perform a refined assessment. This was done using an experimentally measured 1-octanol–air partition coefficient (K{sub OA}) for the calculation of the air–water partition coefficient (K{sub AW}) required for the model. The four selected alternative BFRs (HBB, PBT, PBEB, TBX) have K{sub OA} values close to the in silico estimation used in the screening evaluation. On the other hand, the measured K{sub OA} value for TBB was two orders of magnitude lower than the estimated value used in the screening simulation. The refined simulation showed that characteristic travel distance (CTD) and transfer efficiency (TE) for HBB, PBT, PBEB, and TBX were greater than those for BDE-28, whereas CTD and TE for TBB were lower than those for BDE-28. This suggested that TBB has a lower LRTP than BDE-28, considering the refined partition coefficients.

  15. Wide range of body composition measures are associated with cognitive function in community-dwelling older adults.

    Science.gov (United States)

    Won, Huiloo; Abdul Manaf, Zahara; Mat Ludin, Arimi Fitri; Shahar, Suzana

    2017-04-01

    Studies of the association between body composition, both body fat and body muscle, and cognitive function are rarely reported. The aim of the present study was to determine the association between a wide range of body composition measures with cognitive function in older adults. A total of 2322 Malaysian older adults aged 60 years and older were recruited using multistage random sampling in a population-based cross-sectional study. Out of 2322 older adults recruited, 2309 (48% men) completed assessments on cognitive function and body composition. Cognitive functions were assessed using the Malay version of the Mini-Mental State Examination, the Bahasa Malaysia version of Montreal Cognitive Assessment, Digit Span Test, Digit Symbol Test and Rey Auditory Verbal Learning Test. Body composition included body mass index, mid-upper arm circumference, waist circumference, calf circumference, waist-to-hip ratio, percentage body fat and skeletal muscle mass. The association between body composition and cognitive functions was analyzed using multiple linear regression. After adjustment for age, education years, hypertension, hypercholesterolemia, diabetes mellitus, depression, smoking status and alcohol consumption, we found that calf circumference appeared as a significant predictor for all cognitive tests among both men and women (P cognitive tests among women (P Cognitive Assessment among men (P older adults for optimal cognitive function. Geriatr Gerontol Int 2017; 17: 554-560. © 2016 Japan Geriatrics Society.

  16. Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

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    Adam Sweetman

    2014-04-01

    Full Text Available In principle, non-contact atomic force microscopy (NC-AFM now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

  17. Differences in active range of motion measurements in the upper extremity of patients with writer's cramp compared with healthy controls.

    Science.gov (United States)

    Srivanitchapoom, Prachaya; Shamim, Ejaz A; Diomi, Pierre; Hattori, Takaaki; Pandey, Sanjay; Vorbach, Sherry; Park, Jung E; Wu, Tianxia; Auh, Sungyoung; Hallett, Mark

    Exploratory case-control study. Writer's cramp (WC) is a type of focal hand dystonia. The central nervous system plays a role in its pathophysiology, but abnormalities in the affected musculoskeletal components may also be relevant. We compared the active range of motion (ROM) in patients with WC and healthy volunteers (HVs) and correlated the findings with disease duration and severity. Affected limb joints were measured with goniometers. Patients were assessed at least 3 months after their last botulinum toxin (botulinum neurotoxin) injection, and strength was clinically normal. t tests were used to compare the ROMs of WC with matched HVs. The Spearman correlation coefficient assessed the relationship of active ROMs to the disease duration and handwriting subscore of the Dystonia Disability Scale. ROMs of D1 metacarpophalangeal (MCP) joint extension as well as D2 and D5 MCP flexion were significantly smaller in WC, and distal interphalangeal joint extension in D3 and D5 was significantly greater compared with HVs. There were negative correlations between D2 MCP flexion and disease duration and with Dystonia Disability Scale. Abnormalities in ROMs in WC were found. Severity and disease duration correlated with reduced D2 MCP flexion. This may be related to intrinsic biomechanical abnormalities, co-contraction of muscles, or a combination of subclinical weakness and atrophy from repeated botulinum neurotoxin injections. Hand biomechanical properties should not be ignored in the pathophysiology of WC. 2c. Copyright © 2016 Hanley & Belfus. All rights reserved.

  18. The relationship between general measures of fitness, passive range of motion and whole-body movement quality.

    Science.gov (United States)

    Frost, David; Andersen, Jordan; Lam, Thomas; Finlay, Tim; Darby, Kevin; McGill, Stuart

    2013-01-01

    The goal of this study was to establish relationships between fitness (torso endurance, grip strength and pull-ups), hip range of motion (ROM) (extension, flexion, internal and external rotation) and movement quality in an occupational group with physical work demands. Fifty-three men from the emergency task force of a major city police force were investigated. The movement screen comprised standing and seated posture, gait, segmental spine motion and 14 tasks designed to challenge whole-body coordination. Relationships were established between each whole-body movement task, the measures of strength, endurance and ROM. In general, fitness and ROM were not strongly related to the movement quality of any task. This has implications for worker training, in that strategies developed to improve ROM or strength about a joint may not enhance movement quality. Worker-centered injury prevention can be described as fitting workers to tasks by improving fitness and modifying movement patterns; however, the current results show weak correlations between strength, endurance and ROM, and the way individuals move. Therefore, the development of occupation-specific injury prevention strategies may require both fitness and movement-oriented objectives.

  19. New insight on biological interaction analysis: new nanocrystalline mixed metal oxide SPME fiber for GC-FID analysis of BTEX and its application in human hemoglobin-benzene interaction studies.

    Directory of Open Access Journals (Sweden)

    Reza Hosseinzadeh

    Full Text Available Nanocrystalline mixed metal oxides (MMO of various metal cations were synthesized and were used for coating a piece of copper wire as a new high sensitive solid phase micro extraction (SPME fiber in extraction and determination of BTEX compounds from the headspace of aqueous samples prior to GC-FID analysis. Under optimum extraction conditions, the proposed fiber exhibited low detection limits, and quantification limits, good reproducibility, simple and fast preparation method, high fiber capacity and high thermal and mechanical durability. These are some of the most important advantages of the new fiber. The proposed fiber was used for human hemoglobin upon interaction with benzene. Binding isotherm, Scatchard and Klotz logarithmic plots were constructed using HS-SPME-GC data, accurately. The obtained binding isotherm analyzed using Hill method. The Hill parameters have been obtained by calculating saturation parameter from the ratio of measured chromatographic peak areas in the presence and absence of hemoglobin. In this interaction, Hill coefficient and Hill constant determined as (nH = 6.14 and log KH = 6.47 respectively. These results reveal the cooperativity of hemoglobin upon interaction with benzene.

  20. SPME-GC-MS analysis of commercial henna samples (Lawsonia inermis L.).

    Science.gov (United States)

    Mengoni, Tamara; Peregrina, Dolores Vargas; Censi, Roberta; Cortese, Manuela; Ricciutelli, Massimo; Maggi, Filippo; Di Martino, Piera

    2016-01-01

    The aim of this work was to provide a characterisation of volatile constituents from different commercial batches of henna (Lawsonia inermis) leaves of different geographic origin. Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used for the purpose. A total of 72 components were identified by GC-MS in the headspace of different henna samples which proved to differ considerably from each other, because they were characterised by different classes of components, mainly aliphatic compounds (9.0-64.7%), terpenoids (5.8-45.5%) and aromatics (7.9-45.2%), with alkanes (0.9-18.5%), aldehydes (2.1-18.8%) and carboxylic acids (3.1-29.3%), monoterpenes (3.4-30.0%) and sesquiterpenes (0.8-23.7%) and phenyl propanoids (0.6-43.1%), being the most abundant, respectively. Major representatives of these groups were n-hexadecane (0.5-4.7%), (2E)-hexenal (0.5-11.7%) and acetic acid (2.8-24.5%), limonene (0.8-14.7%), carvol (3.8-7.1%), geranyl acetone (1.4-7.9%) and (E)-caryophyllene (3.3-8.4%), and (E)-anethole (0.6-35.0%), respectively. We assume that factors such as the manufacturing process, the storage conditions and the different geographic origin of the samples may contribute to such variability.

  1. Determination of Sesquiterpenes in Wines by HS-SPME Coupled with GC-MS

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    Fabrizio Cincotta

    2015-07-01

    Full Text Available The sesquiterpene compounds present in red wines were characterized and quantified by Headspace Solid-Phase Microextraction in combination with Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS. Sixteen sesquiterpenes were identified, mainly hydrocarbons but also derived oxygenated compounds. Sesquiterpenes were acyclic, monocyclic, byciclic and tryciclic. Sesquiterpenes were detected in SIM (selected ion monitoring mode using their characteristics ions. All the sesquiterpenes were identified by mass spectral data, linear retention indices (LRI, literature data and injection of standards where available. Quantitative results were obtained using the method of standard additions. The method showed an average LOD = 0.05 µg L−1 and LOQ = 0.15 µg L−1. The monocyclic sesquiterpene with the germacrene skeleton, Germacrene D and the bicyclic sesquiterpene with the muurolane skeleton, α-muurolene were present in all the wine samples analysed. Syrah wines were the samples richest in sesquiterpenes in agreement with their typical spicy and woody notes. The results evidenced the possibility to use sesquiterpenes for wine authenticity and traceability.

  2. Analysis of Five Earthy-Musty Odorants in Environmental Water by HS-SPME/GC-MS

    Directory of Open Access Journals (Sweden)

    Zhen Ding

    2014-01-01

    Full Text Available The pressing issue of earthy and musty odor compounds in natural waters, which can affect the organoleptic properties of drinking water, makes it a public health concern. A simple and sensitive method for simultaneous analysis of five odorants in environmental water was developed by headspace solid-phase microextraction (HS-SPME coupled to chromatography-mass spectrometry (GC-MS, including geosmin (GSM and 2-methylisoborneol (2-MIB, as well as dimethyl trisulfide (DMTS, β-cyclocitral, and β-ionone. Based on the simple modification of original magnetic stirrer purchased from CORNING (USA, the five target compounds can be separated within 23 min, and the calibration curves show good linearity with a correlation coefficient above 0.999 (levels = 5. The limits of detection (LOD are all below 1.3 ng L−1, and the relative standard deviation (%RSD is between 4.4% and 9.9% (n = 7 and recoveries of the analytes from water samples are between 86.2% and 112.3%. In addition, the storage time experiment indicated that the concentrations did not change significantly for GSM and 2-MIB if they were stored in canonical environment. In conclusion, the method in this study could be applied for monitoring these five odorants in natural waters.

  3. Fingerprint of volatiles from plant extracts based on SPME-GC-MS

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    Ezequias P. Siqueira

    Full Text Available The Laboratory of Chemistry of Natural Products has an ex situ collection of extracts from organisms of the biodiversity aiming at bioprospecting. Nowadays the collection has about 4000 extracts from 1000 different species. Extracts are used to identify new bioactive compounds that could be useful for developing new drugs against neglected diseases like leishmaniosis, Chagas disease, malaria and tuberculosis. After biologic assays, the bioactive extracts need to be prepared in larger quantity to allow isolation and characterization of the bioactive component. At this time, it is important to not only confirm the bioactivity of new extract but also check if its composition is similar to the old one. It was evaluated the ability of Solid Phase Microextraction and Gas Chromatography-Mass Spectrometry analysis (SPME-GC-MS. It was used the AMDIS (Automatic Mass Spectral Deconvolution and Identification System software as tools to collect and to compare the chromatographic profiles of each extract (fingerprint. Forty six samples were analyzed, it was possible to infer from the composition of each sample and common compounds. Nine groups of samples, collected at different time, were analyzed and seasonal modifications between then could be elucidated. The results showed that this methodology can be used to monitor the composition of extracts, allowing to monitor chemical changes that may occur during storage periods and to investigate the occurrence of a determined component in different extracts.

  4. Authenticity of raspberry flavor in food products using SPME-chiral-GC-MS.

    Science.gov (United States)

    Hansen, Anne-Mette S; Frandsen, Henrik L; Fromberg, Arvid

    2016-05-01

    A fast and simple method for authenticating raspberry flavors from food products was developed. The two enantiomers of the compound (E)-α-ionone from raspberry flavor were separated on a chiral gas chromatographic column. Based on the ratio of these two enantiomers, the naturalness of a raspberry flavor can be evaluated due to the fact that a natural flavor will consist almost exclusively of the R enantiomer, while a chemical synthesis of the same compound will result in a racemic mixture. Twenty-seven food products containing raspberry flavors where investigated using SPME-chiral-GC-MS. We found raspberry jam, dried raspberries, and sodas declared to contain natural aroma all contained almost only R-(E)-α-ionone supporting the content of natural raspberry aroma. Six out of eight sweets tested did not indicate a content of natural aroma on the labeling which was in agreement with the almost equal distribution of the R and S isomer. Two products were labeled to contain natural raspberry flavors but were found to contain almost equal amounts of both enantiomers indicating a presence of synthetic raspberry flavors only. Additionally, two products that were labeled to contain both raspberry juice and flavor showed equal amounts of both enantiomers, indicating the presence of synthetic flavor.

  5. Study of flavour compounds from orange juices by HS-SPME and GC-MS

    Science.gov (United States)

    Schmutzer, G.; Avram, V.; Covaciu, F.; Feher, I.; Magdas, A.; David, L.; Moldovan, Z.

    2013-11-01

    The flavour of the orange juices, which gives the taste and odour of the product, is an important criterion about the products quality for consumers. A fresh single strength and two commercial orange juices (obtained from concentrate) flavour profile were studied using a selective and sensitive gas chromatography - mass spectrometry (GC-MS) analytical system, after a solvent free, single step preconcentration and extraction technique, the headspace solid phase microextraction (HP-SPME). In the studied orange juices 55 flavour compounds were detected and classified as belonging to the esters, alcohols, ketones, monoterpenes and sesquiterpenes chemical families. The fresh single strength orange juice was characterized by high amount of esters, monoterpenes and sesquiterpenes. Limonene and valencene were the most abundant flavours in this fresh natural orange juice. Alcohols and ketones were found in higher concentration in the commercial orange juices made from concentrate, than in the single strength products. Nevertheless, in commercial juices the most abundant flavour was limonene and α-terpineol. The results highlight clear differences between fresh singles strength orange juice and juice from concentrate. The orange juices reconstructed from concentrate, made in Romania, present low quantity of flavour compounds, suggesting the absence or a low rearomatization process, but extraneous components were not detected.

  6. Development of a HS-SPME-GC/MS protocol assisted by chemometric tools to study herbivore-induced volatiles in Myrcia splendens.

    Science.gov (United States)

    Souza Silva, Érica A; Saboia, Giovanni; Jorge, Nina C; Hoffmann, Camila; Dos Santos Isaias, Rosy Mary; Soares, Geraldo L G; Zini, Claudia A

    2017-12-01

    A headspace solid phase microextraction (HS-SPME) method combined with gas chromatography-mass spectrometry (GC/MS) was developed and optimized for extraction and analysis of volatile organic compounds (VOC) of leaves and galls of Myrcia splendens. Through a process of optimization of main factors affecting HS-SPME efficiency, the coating divivnilbenzene-carboxen-polydimethylsiloxane (DVB/Car/PDMS) was chosen as the optimum extraction phase, not only in terms of extraction efficiency, but also for its broader analyte coverage. Optimum extraction temperature was 30°C, while an extraction time of 15min provided the best compromise between extraction efficiencies of lower and higher molecular weight compounds. The optimized protocol was demonstrated to be capable of sampling plant material with high reproducibility, considering that most classes of analytes met the 20% RSD FDA criterion. The optimized method was employed for the analysis of three classes of M. splendens samples, generating a final list of 65 tentatively identified VOC, including alcohols, aldehydes, esters, ketones, phenol derivatives, as well as mono and sesquiterpenes. Significant differences were evident amongst the volatile profiles obtained from non-galled leaves (NGL) and leaf-folding galls (LFG) of M. splendens. Several differences pertaining to amounts of alcohols and aldehydes were detected between samples, particularly regarding quantities of green leaf volatiles (GLV). Alcohols represented about 14% of compounds detected in gall samples, whereas in non-galled samples, alcohol content was below 5%. Phenolic derived compounds were virtually absent in reference samples, while in non-galled leaves and galls their content ranged around 0.2% and 0.4%, respectively. Likewise, methyl salicylate, a well-known signal of plant distress, amounted for 1.2% of the sample content of galls, whereas it was only present in trace levels in reference samples. Chemometric analysis based on Heatmap associated

  7. A low-power tool for measuring acceleration, pressure, and temperature (APT) with wide dynamic range and bandwidth

    Science.gov (United States)

    Heesemann, Martin; Davis, Earl E.; Paros, Jerome; Johnson, Greg; Meldrum, Robert; Scherwath, Martin; Mihaly, Steven

    2017-04-01

    We present a new tool that facilitates the study of inter-related geodetic, geodynamic, seismic, and oceanographic phenomena. It incorporates a temperature compensated tri-axial accelerometer developed by Quartz Seismic Sensors, Inc., a pressure sensor built by Paroscientific Inc., and a low-power, high-precision frequency counter developed by Bennest Enterprises Ltd. and built by RBR, Ltd. The sensors are housed in a 7 cm o.d. titanium pressure case designed for use to full ocean depths (withstands more than 20 km of water pressure). Sampling intervals are programmable from 0.08 s to 1 hr; standard memory can store up to 130 million samples; total power consumption is roughly 115 mW when operating continuously and proportionately lower when operating intermittently (e.g., 2 mW average at 1 sample per min). Serial and USB communications protocols allow a variety of autonomous and cable-connection options. Measurement precision of the order of 10-8 of full scale (e.g., pressure equivalent to 4000 m water depth, acceleration = +/- 3 g) allows observations of pressure and acceleration variations of 0.4 Pa and 0.3 μm s-2. Long-term variations in vertical acceleration are sensitive to displacement through the gravity gradient down to a level of roughly 2 cm, and variations in horizontal acceleration are sensitive to tilt down to a level of 0.03 μrad. With the large dynamic ranges, high sensitivities and broad bandwidth (6 Hz to DC), ground motion associated with microseisms, strong and weak seismic ground motion, tidal loading, and slow and rapid geodynamic deformation - all normally studied using disparate instruments - can be observed with a single tool. Installation in the marine environment is accomplished by pushing the tool roughly 1 m vertically below the seafloor with a submersible or remotely operated vehicle, with no profile remaining above the seafloor to cause current-induced noise. The weight of the tool is designed to match the sediment it displaces to

  8. A Novel Multi-View-Angle Range Images Generation Method for Measurement of Complicated Polyhedron in 3D Space

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    Deming Kong

    2017-01-01

    Full Text Available A new kind of generation method is proposed in this paper to acquire range images for complicated polyhedron in 3D space from a series of view angles. In the proposed generation method, concept of three-view drawing in mechanical cartography is introduced into the range image generation procedure. Negative and positive directions of x-, y-, and z-axes are selected as the view angles to generate the range images for complicated polyhedron in 3D space. Furthermore, a novel iterative operation of mathematical morphology is proposed to ensure that satisfactory range images can be generated for the polyhedron from all the selected view angles. Compared with the existing method based on single view angle and interpolation operation, structure features contained in surface of the complicated polyhedron can be represented more consistently with the reality by using the proposed multi-view-angle range images generation method. The proposed generation method is validated by using an experiment.

  9. HS-SPME-GC-MS/MS Method for the Rapid and Sensitive Quantitation of 2-Acetyl-1-pyrroline in Single Rice Kernels.

    Science.gov (United States)

    Hopfer, Helene; Jodari, Farman; Negre-Zakharov, Florence; Wylie, Phillip L; Ebeler, Susan E

    2016-05-25

    Demand for aromatic rice varieties (e.g., Basmati) is increasing in the US. Aromatic varieties typically have elevated levels of the aroma compound 2-acetyl-1-pyrroline (2AP). Due to its very low aroma threshold, analysis of 2AP provides a useful screening tool for rice breeders. Methods for 2AP analysis in rice should quantitate 2AP at or below sensory threshold level, avoid artifactual 2AP generation, and be able to analyze single rice kernels in cases where only small sample quantities are available (e.g., breeding trials). We combined headspace solid phase microextraction with gas chromatography tandem mass spectrometry (HS-SPME-GC-MS/MS) for analysis of 2AP, using an extraction temperature of 40 °C and a stable isotopologue as internal standard. 2AP calibrations were linear between the concentrations of 53 and 5380 pg/g, with detection limits below the sensory threshold of 2AP. Forty-eight aromatic and nonaromatic, milled rice samples from three harvest years were screened with the method for their 2AP content, and overall reproducibility, observed for all samples, ranged from 5% for experimental aromatic lines to 33% for nonaromatic lines.

  10. Degradation product emission from historic and modern books by headspace SPME/GC-MS: evaluation of lipid oxidation and cellulose hydrolysis.

    Science.gov (United States)

    Clark, Andrew J; Calvillo, Jesse L; Roosa, Mark S; Green, David B; Ganske, Jane A

    2011-04-01

    Volatile organic compounds emitted from a several decade series of bound periodicals (1859-1939) printed on ground wood paper, as well as historical books dating from the 1500s to early 1800s made from cotton/linen rag, were studied using an improved headspace SPME/GC-MS method. The headspace over the naturally aging books, stored upright in glass chambers, was monitored over a 24-h period, enabling the identification of a wide range of organic compounds emanating from the whole of the book. The detection of particular straight chain aldehydes, as well as characteristic alcohols, alkenes and ketones is correlated with oxidative degradation of the C(18) fatty acid constituency of paper. The relative importance of hydrolytic and oxidative chemistry involved in paper aging in books published between 1560 and 1939 was examined by comparing the relative abundances of furfural (FUR) a known cellulose hydrolysis product, and straight chain aldehydes (SCA) produced from the oxidation of fatty acids in paper. The relative abundance of furfural is shown to increase across the 379-year publication time span. A comparison of relative SCA peak areas across the series of books examined reveals that SCA emission is more important in the cotton/linen rag books than in the ground wood books.

  11. Close Range Photogrammetry in Space - Measuring the On-Orbit Clearance between Hardware on the International Space Station

    Science.gov (United States)

    Liddle, Donn

    2017-01-01

    When photogrammetrists read an article entitled "Photogrammetry in Space" they immediately think of terrestrial mapping using satellite imagery. However in the last 19 years the roll of close range photogrammetry in support of the manned space flight program has grown exponentially. Management and engineers have repeatedly entrusted the safety of the vehicles and their crews to the results of photogrammetric analysis. In February 2010, the Node 3 module was attached to the port side Common Berthing Mechanism (CBM) of the International Space Station (ISS). Since this was not the location at which the module was originally designed to be located on the ISS, coolant lines containing liquid ammonia, were installed externally from the US Lab to Node 3 during a spacewalk. During mission preparation I had developed a plan and a set of procedures to have the astronauts acquire stereo imagery of these coolant lines at the conclusion of the spacewalk to enable us to map their as-installed location relative to the rest of the space station. Unfortunately, the actual installation of the coolant lines took longer than expected and in an effort to wrap up the spacewalk on time, the mission director made a real-time call to drop the photography. My efforts to reschedule the photography on a later spacewalk never materialized, so rather than having an as-installed model for the location of coolant lines, the master ISS CAD database continued to display an as-designed model of the coolant lines. Fast forward to the summer of 2015, the ISS program planned to berth a Japanese cargo module to the nadir Common Berthing Mechanism (CBM), immediately adjacent to the Node 3 module. A CAD based clearance analysis revealed a negative four inch clearance between the ammonia lines and a thruster nozzle on the port side of the cargo vehicle. Recognizing that the model of the ammonia line used in the clearance analysis was "as-designed" rather than "as-installed", I was asked to determine the

  12. Rapid measurement of 13C-enrichment of acetic, propionic and butyric acids in plasma with solid phase microextraction coupled to gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Moreau, N.M.; Delepee, R.; Maume, D.; Le Bizec, B.; Nguyen, P.G.; Champ, M.M.; Martin, L.J.; Dumon, H.J.

    2004-01-01

    An analytical procedure based on solid phase microextraction (SPME) has been developed to quantify [1- 13 C]-labelled short-chain fatty acids (SCFAs)--mainly acetic, propionic and butyric acids--in a small volume (120 μl) of deproteinised plasma (corresponding to 200 μl of raw plasma) by gas chromatography-mass spectrometry (GC-MS) analysis. Simultaneous SCFA extraction was optimal after 5 min using a 75 μm Carboxen/polydimethylsiloxane-coated fiber. The base peak of the three analytes has been characterised by middle-resolution mass spectrometry (R>6000). All these data allowed the specificity reinforcement of the measure. The validation of the method also considered the linearity and the repeatability of the [ 13 C]SCFA measurements by SPME-GC-MS. Results were linear in a range from 5 to 100 mol% of [ 13 C]SCFA enrichment and the method provided a good intra-day (R.S.D. 13 C]butyric acid) by cecal infusion before blood sampling in portal vein. Results of [1- 13 C]butyric acid enrichment showed an excellent correlation (r 2 =0.9832; n=30) with data obtained on the same samples using a previously published procedure based on diethyl extraction and derivatisation before GC-MS analyses. SPME coupled to GC-MS appears to be a powerful analytical tool for the direct isotopic measurements of low deproteinised plasma volume avoiding consequently preliminary treatment such as extraction or derivatisation. The presented method could be of great interest for real time [ 13 C]SCFA plasma determination of in metabolic in vivo studies in small animal models

  13. Long-term measurements of carbonaceous aerosols in the eastern Mediterranean: evidence of long-range transport of biomass burning

    OpenAIRE

    Sciare , J.; Oikonomou , K.; Favez , O.; Markaki , Z.; Liakakou , E.; Cachier , H.; Mihalopoulos , N.

    2008-01-01

    International audience; Long-term (5-yr) measurements of Black Carbon (BC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these BC and OC measurements. Light absorbing dust aerosols have shown to poorly contribute (+17% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical m...

  14. Long-term measurements of carbonaceous aerosols in the Eastern Mediterranean: evidence of long-range transport of biomass burning

    OpenAIRE

    Sciare, J.; Oikonomou, K.; Favez, O.; Liakakou, E.; Markaki, Z.; Cachier, H.; Mihalopoulos, N.

    2008-01-01

    Long-term (5-year) measurements of Elemental Carbon (EC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these EC and OC measurements. Light absorbing dust aerosols were shown to poorly contribute (+12% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical m...

  15. Sensitive multiresidue method by HS-SPME/GC-MS for 10 volatile organic compounds in urine matrix: a new tool for biomonitoring studies on children.

    Science.gov (United States)

    Antonucci, Arianna; Vitali, Matteo; Avino, Pasquale; Manigrasso, Maurizio; Protano, Carmela

    2016-08-01

    A HS-SPME method coupled with GC-MS analysis has been developed for simultaneously measuring the concentration of 10 volatile organic compounds (VOCs) (benzene, toluene, ethylbenzene, o-, m-, and p-xylene, methyl tert-butyl ether, ethyl tert-butyl ether, 2-methyl-2-butyl methyl ether, and diisopropyl ether) in urine matrix as a biomonitoring tool for populations at low levels of exposure to such VOCs. These compounds, potentially toxic for human health, are common contaminants of both outdoor and indoor air, as they are released by autovehicular traffic; some of them are also present in environmental tobacco smoke (ETS). Thus, the exposure to these pollutants cannot be neglected and should be assessed. The low limits of detection and quantification (LODs and LOQs <6.5 and 7.5 ng L(-1), respectively) and the high reproducibility (CVs <4 %) make the developed method suited for biomonitoring populations exposed at low levels such as children. Further, the method is cost-effective and low in time-consumption; therefore, it is useful for investigating large populations. It has been applied to children exposed to traffic pollution and/or ETS; the relevant results are reported, and the relevant implications are discussed.

  16. Effect of the type of frying culinary fat on volatile compounds isolated in fried pork loin chops by using SPME-GC-MS.

    Science.gov (United States)

    Ramírez, María Rosario; Estévez, Mario; Morcuende, David; Cava, Ramón

    2004-12-15

    The effect of the type of frying culinary fat (olive oil, sunflower oil, butter, and pig lard) on volatile compounds isolated from fried pork loin chops (m. Longissimus dorsi) was measured by SPME-GC-MS. Frying modified the fatty acid composition of lipids from pork loin chops, which tended to be similar to that of the culinary fat used to fry. Volatile compounds formed from the oxidation of fatty acids increased, such as aldehydes, ketones, alcohols, and hydrocarbons. Besides, each culinary fat used modified the volatile profiles in fried meat differently. Sunflower oil-fried pork loin chops presented the highest aldehyde aliphatic content, probably due to their highest content of polyunsaturated acids. Hexanal, the most abundant aldehyde in fried samples, presented the most elevated content in sunflower oil-fried pork loin chops. In addition, these samples presented more heterocyclic compounds from the Maillard reaction than other fried samples. Volatiles detected in olive oil-fried pork loin chops were mainly lipid-derived compounds such as pentan-1-ol, hexanal, hept-2-enal, nonanal, decanal, benzaldehyde, and nonan-2-one. Butter-fried pork loins were abundant in ketones with a high number of carbons (heptan-2-one, nonan-2-one, undecan-2-one, tridecanone, and heptadecan-2-one). Pig lard-fried pork loin chops presented some Strecker aldehydes isolated in only these samples, such as 2-methylbutanal and 3-(methylthio)propanal, and a sulfur compound (dimethyl disulfide) related to Strecker aldehydes.

  17. Is digital photography an accurate and precise method for measuring range of motion of the hip and knee?

    Science.gov (United States)

    Russo, Russell R; Burn, Matthew B; Ismaily, Sabir K; Gerrie, Brayden J; Han, Shuyang; Alexander, Jerry; Lenherr, Christopher; Noble, Philip C; Harris, Joshua D; McCulloch, Patrick C

    2017-09-07

    Accurate measurements of knee and hip motion are required for management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion at the hip and knee. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. Using infrared motion capture analysis as the reference standard, hip flexion/abduction/internal rotation/external rotation and knee flexion/extension were measured using visual estimation, goniometry, and photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard, while precision was defined by the proportion of measurements within either 5° or 10°. Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. Although two statistically significant differences were found in measurement accuracy between the three techniques, neither of these differences met clinical significance (difference of 1.4° for hip abduction and 1.7° for the knee extension). Precision of measurements was significantly higher for digital photography than: (i) visual estimation for hip abduction and knee extension, and (ii) goniometry for knee extension only. There was no clinically significant difference in measurement accuracy between the three techniques for hip and knee motion. Digital photography only showed higher precision for two joint motions (hip abduction and knee extension). Overall digital photography shows equivalent accuracy and near-equivalent precision to visual estimation and goniometry.

  18. Final Environmental Assessment for the Bridge Replacement and Scour Protection Measures at Avon Park Air Force Range, Florida

    Science.gov (United States)

    2012-03-01

    stipulated in the permit. Potential indigo snake refugia: gopher tortoise burrows , active or inactive, other holes, ground cavities, and root hollows...holes, cavities, and snake refugia other than gopher tortoise burrows will be inspected each morning before planned site manipulation of a particular...University 1999 Years Experience: 12 Larry McLain Operational Transportation Manager and Range Maintenance Manager Clarence Morgan Rangeland

  19. Headspace solid-phase microextraction (HS-SPME) and liquid-liquid extraction (LLE): comparison of the performance in classification of ecstasy tablets. Part 2.

    Science.gov (United States)

    Bonadio, Federica; Margot, Pierre; Delémont, Olivier; Esseiva, Pierre

    2008-11-20

    Headspace solid-phase microextraction (HS-SPME) is assessed as an alternative to liquid-liquid extraction (LLE) currently used for 3,4-methylenedioxymethampethamine (MDMA) profiling. Both methods were compared evaluating their performance in discriminating and classifying samples. For this purpose 62 different seizures were analysed using both extraction techniques followed by gas chromatography-mass spectroscopy (GC-MS). A previously validated method provided data for HS-SPME, whereas LLE data were collected applying a harmonized methodology developed and used in the European project CHAMP. After suitable pre-treatment, similarities between sample pairs were studied using the Pearson correlation. Both methods enable to distinguish between samples coming from the same pre-tabletting batches and samples coming from different pre-tabletting batches. This finding emphasizes the use of HS-SPME as an effective alternative to LLE, with additional advantages such as sample preparation and a solvent-free process.

  20. Methodical evaluation and improvement of matrix compatible PDMS-overcoated coating for direct immersion solid phase microextraction gas chromatography (DI-SPME-GC)-based applications.

    Science.gov (United States)

    Souza-Silva, Érica A; Gionfriddo, Emanuela; Shirey, Robert; Sidisky, Len; Pawliszyn, Janusz

    2016-05-12

    The main quest for the implementation of direct SPME to complex matrices has been the development of matrix compatible coatings that provide sufficient sensitivity towards the target analytes. In this context, we present here a thorough evaluation of PDMS-overcoated fibers suitable for simultaneous extraction of different polarities analytes, while maintaining adequate matrix compatibility. For this, eleven analytes were selected, from various application classes (pesticides, industrial chemicals and pharmaceuticals) and with a wide range of log P values (ranging from 1.43 to 6). The model matrix chosen was commercial Concord grape juice, which is rich in pigments such as anthocyanins, and contains approximately 20% of sugar (w/w). Two types of PDMS, as well as other intrinsic factors associated with the PDMS-overcoated fiber fabrication are studied. The evaluation showed that the PDMS-overcoated fibers considerably slowed down the coating fouling process during direct immersion in complex matrices of high sugar content. Longevity differences could be seen between the two types of PDMS tested, with a proprietary Sylgard(®) giving superior performance because of lesser amount of reactive groups and enhanced hydrophobicity. Conversely, the thickness of the outer layer did not seem to have a significant effect on the fiber lifetime. We also demonstrate that the uniformity of the overcoated PDMS layer is paramount to the achievement of reliable data and extended fiber lifetime. Employing the optimum overcoated fiber, limits of detection (LOD) in the range of 0.2-1.3 ng/g could be achieved. Additional improvement is attainable by introducing washing of the coatings after desorption, so that any carbon build-up (fouling) left on the coating surface after thermal desorption can be removed. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. In-flight measurements and RCS-predictions: A comparison on broad-side radar range profiles of a Boeing 737

    NARCIS (Netherlands)

    Heiden, R. van der; Ewijk, L.J. van; Groen, F.C.A.

    1997-01-01

    The validation of Radar Cross Section (RCS) prediction techniques against real measurements is crucial to acquire confidence in predictions when measurements are not available. In this paper we present the first results of a comparison on one dimensional images, i.e., radar range profiles. The

  2. Acoustic and Perceptual Measurement of Expressive Prosody in High-Functioning Autism: Increased Pitch Range and What it Means to Listeners

    Science.gov (United States)

    Nadig, Aparna; Shaw, Holly

    2012-01-01

    Are there consistent markers of atypical prosody in speakers with high functioning autism (HFA) compared to typically-developing speakers? We examined: (1) acoustic measurements of pitch range, mean pitch and speech rate in conversation, (2) perceptual ratings of conversation for these features and overall prosody, and (3) acoustic measurements of…

  3. A Supra-Thermal Energetic Particle detector (STEP) for composition measurements in the range approximately 20 keV/nucleon to 1 MeV/nucleon

    Science.gov (United States)

    Mason, G. M.; Gloeckler, G.

    1981-01-01

    A detector system is described, employing a time-of-flight versus residual energy technique which allows measurement of particle composition (H-Fe), energy spectral and anisotropies in an energy range unaccessible with previously flown sensors. Applications of this method to measurements of the solar wind ion composition are discussed.

  4. A supra-thermal energetic particle detector /STEP/ for composition measurements in the range of about 20 keV/nucleon to 1 MeV/nucleon

    Science.gov (United States)

    Mason, G. M.; Gloeckler, G.

    1981-01-01

    A novel detector system is described, employing a time-of-flight versus residual energy technique which allows measurement of particle composition (H-Fe), energy spectra and anisotropies in an energy range unaccessible with previously flown sensors. Applications of this method to measurements of the solar wind ion composition are also discussed.

  5. X-Band high range resolution radar measurements of sea surface forward scatter at low grazing angles

    CSIR Research Space (South Africa)

    Smit, JC

    2008-05-01

    Full Text Available in the sea surface forward scatter component exists. Based on this measurement, we propose a temporal correlation extension to an existing low-angle propagation model, together with a correlation filter structure to realize the correlation extension...

  6. Is digital photography an accurate and precise method for measuring range of motion of the shoulder and elbow?

    Science.gov (United States)

    Russo, Russell R; Burn, Matthew B; Ismaily, Sabir K; Gerrie, Brayden J; Han, Shuyang; Alexander, Jerry; Lenherr, Christopher; Noble, Philip C; Harris, Joshua D; McCulloch, Patrick C

    2018-03-01

    Accurate measurements of shoulder and elbow motion are required for the management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. Using infrared motion capture analysis as the reference standard, shoulder flexion/abduction/internal rotation/external rotation and elbow flexion/extension were measured using visual estimation, goniometry, and digital photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard (motion capture analysis), while precision was defined by the proportion of measurements within the authors' definition of clinical significance (10° for all motions except for elbow extension where 5° was used). Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. Although statistically significant differences were found in measurement accuracy between the three techniques, none of these differences met the authors' definition of clinical significance. Precision of the measurements was significantly higher for both digital photography (shoulder abduction [93% vs. 74%, p < 0.001], shoulder internal rotation [97% vs. 83%, p = 0.001], and elbow flexion [93% vs. 65%, p < 0.001]) and goniometry (shoulder abduction [92% vs. 74%, p < 0.001] and shoulder internal rotation [94% vs. 83%, p = 0.008]) than visual estimation. Digital photography was more precise than goniometry for measurements of elbow flexion only [93% vs. 76%, p < 0.001]. There was no clinically significant difference in measurement accuracy between the three techniques for shoulder and elbow motion. Digital photography showed higher measurement precision compared to visual estimation for shoulder abduction, shoulder

  7. Two efficient methods for measuring hydrophone frequency response in the 100 kHz to 2 MHz range

    International Nuclear Information System (INIS)

    Harris, G R; Maruvada, S; Gammell, P M

    2004-01-01

    As new medical applications of ultrasound emerge with operating frequencies in the hundreds of kilohertz to low megahertz region, it becomes more important to have convenient calibration methods for hydrophones in this frequency range. Furthermore, short diagnostic ultrasound pulses affected by finite amplitude distortion require that the hydrophone frequency response be known well below the center frequency. National standards laboratories can provide accurate calibration data at these frequencies, but the two methods now employed, laser interferometry and three-transducer reciprocity, are both single-frequency techniques, and they can be time-consuming procedures. Therefore, two efficient methods for generating a wideband acoustic pressure spectrum have been implemented to cover this frequency range. In one method a high-voltage pulse generator was used to excite a thick piezoelectric ceramic disk, producing a plane-wave acoustic pressure transient <1 μs in duration with peak amplitude of about 40 kPa. In the other technique, time delay spectrometry (TDS), a purpose-built 1-3 piezoelectric composite source transducer weakly focused at 20 cm was swept over the 0-2 MHz range. Its transmitting voltage response at 1 MHz was 11 kPa/V. The broadband pulse technique has the advantage of being simpler to implement, but TDS has a much greater signal-to-noise ratio because of the frequency-swept narrowband filter employed

  8. Solid-phase microextraction (SPME) as a tool to predict the bioavailability and toxicity of pyrene to the springtail, Folsomia candida, under various soil conditions

    DEFF Research Database (Denmark)

    Styrishave, Bjarne; Mortensen, Mads; Krogh, Paul Henning

    2008-01-01

    The porewater concentrations of pyrene were estimated by a negligible depletive solid-phase microextraction (SPME) method. The effects of organic matter (OM) and soil aging on the bioavailability of pyrene in soil were investigated by generation of reproductive effect concentrations (EC50...... increased with increasing OM and aging of the soil. The increase of the OM content in the soil reduced the extractability of pyrene by SPME, as well as the toxicity of pyrene. An aging effect was demonstrated in Askov soil, EC50 values increased with increased contact time. The amounts of pyrene extracted...

  9. Areal-averaged trace gas emission rates from long-range open-path measurements in stable boundary layer conditions

    Directory of Open Access Journals (Sweden)

    K. Schäfer

    2012-07-01

    Full Text Available Measurements of land-surface emission rates of greenhouse and other gases at large spatial scales (10 000 m2 are needed to assess the spatial distribution of emissions. This can be readily done using spatial-integrating micro-meteorological methods like flux-gradient methods which were evaluated for determining land-surface emission rates of trace gases under stable boundary layers. Non-intrusive path-integrating measurements are utilized. Successful application of a flux-gradient method requires confidence in the gradients of trace gas concentration and wind, and in the applicability of boundary-layer turbulence theory; consequently the procedures to qualify measurements that can be used to determine the flux is critical. While there is relatively high confidence in flux measurements made under unstable atmospheres with mean winds greater than 1 m s−1, there is greater uncertainty in flux measurements made under free convective or stable conditions. The study of N2O emissions of flat grassland and NH3 emissions from a cattle lagoon involves quality-assured determinations of fluxes under low wind, stable or night-time atmospheric conditions when the continuous "steady-state" turbulence of the surface boundary layer breaks down and the layer has intermittent turbulence. Results indicate that following the Monin-Obukhov similarity theory (MOST flux-gradient methods that assume a log-linear profile of the wind speed and concentration gradient incorrectly determine vertical profiles and thus flux in the stable boundary layer. An alternative approach is considered on the basis of turbulent diffusivity, i.e. the measured friction velocity as well as height gradients of horizontal wind speeds and concentrations without MOST correction for stability. It is shown that this is the most accurate of the flux-gradient methods under stable conditions.

  10. Reliability of knee joint range of motion and circumference measurements after total knee arthroplasty: does tester experience matter?

    DEFF Research Database (Denmark)

    Jakobsen, Thomas Linding; Christensen, Malene; Christensen, Stine Sommer

    2010-01-01

    : The design was an intra-tester, inter-tester and intra-day reliability study. Nineteen outpatients (10 females) having received a TKA were examined by an inexperienced and an experienced physiotherapist. Following a standardized protocol, active and passive knee joint ROM and circumference measurements were...

  11. Calorimetry for dose measurement at electron accelerators in the 80-120 keV energy range

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.; Duane, S.

    2005-01-01

    and the calorimeter absorber influences significantly the response of the calorimeter and a thermal model was applied to quantify this effect. All three calorimeters are capable of measuring absolute dose, and can thus be used for calibration of other dosimeters. (C) 2005 Elsevier Ltd. All rights reserved....

  12. Neutron-induced activation measurements and EXFOR compilations in the energy range up to 20 MeV

    International Nuclear Information System (INIS)

    Semkova, V.; Otuka, N.

    2015-01-01

    Accurate neutron-induced activation cross-section data are of interest in many fields of science and applications. Such data are needed for calculations and analysis of neutron transport, activation of materials, gas production and radiation damage, dose rates etc. Experimental data provide bases for the parameterization of reaction cross section calculations, and for the assessment of nuclear models and evaluated data libraries. Activation technique in combination with gamma spectrometry is well known and widely used method for neutron-induced reaction cross-section measurements. However, in some cases considerable differences exist between the results from different experiments. A careful consideration of the all factors that may affect each particular measurement is needed in order to obtain reliable data. Measured data are of little value until they are made conveniently available for users and evaluators. The International Network of Nuclear Reaction Data Centres (NRDC) collaborates in collection, compilation and dissemination of experimental nuclear reaction data in the EXFOR data library. In the present work some aspects of the 58 Ni(n,p) 58 Co activation cross-section measurements at two different experimental facilities and EXFOR compilation files will be presented

  13. Validation of techniques for simulating long range dispersal and deposition of atmospheric pollutants based upon measurements after the Chernobyl accident

    International Nuclear Information System (INIS)

    Tveten, U.

    1987-02-01

    Problem specifications and a time schedule for an international study of computerized simulation of transfrontier atmospheric contamination are presented. Started on the initiative of the Nordic Liaison Committee for Atomic Energy, the study will be based on international measurements after the Chernobyl accident

  14. A system to measure isomeric state half-lives in the 10 ns to 10 μs range

    Energy Technology Data Exchange (ETDEWEB)

    Toufen, D. L., E-mail: dennis@if.usp.br [Institute of Physics, University of São Paulo, C.P. 66318, 05315-970 São Paulo, São Paulo (Brazil); Federal Institute of Education, Science and Technology of São Paulo - IFSP, 07115-000 Guarulhos, São Paulo (Brazil); Allegro, P. R. P.; Medina, N. H.; Oliveira, J. R. B.; Cybulska, E. W.; Seale, W. A.; Ribas, R. V. [Institute of Physics, University of São Paulo, C.P. 66318, 05315-970 São Paulo, São Paulo (Brazil); Linares, R. [Fluminense Federal University, 24220-900 Niterói, Rio de Janeiro (Brazil); Silveira, M. A. G. [Universitary Center of FEI, 09850-901 São Bernardo do Campo, São Paulo (Brazil)

    2014-07-15

    The Isomeric State Measurement System (SISMEI) was developed to search for isomeric nuclear states produced by fusion-evaporation reactions. The SISMEI consists of 10 plastic phoswich telescopes, two lead shields, one NaI(Tl) scintillation detector, two Compton suppressed HPGe γ-ray detectors, and a cone with a recoil product catcher. The new system was tested at the 8 UD Pelletron tandem accelerator of the University of São Paulo with the measurement of two known isomeric states: {sup 54}Fe, 10{sup +} state (E = 6527.1 (11) keV, T{sub 1/2} = 364(7) ns) and the 5/2{sup +} state of {sup 19}F (E = 197.143 (4) keV, T{sub 1/2} = 89.3 (10) ns). The results indicate that the system is capable of identifying delayed transitions, of measuring isomeric state lifetimes, and of identifying the feeding transitions of the isomeric state through the delayed γ-γ coincidence method. The measured half-life for the 10{sup +} state was T{sub 1/2} = 365(14) ns and for the 5/2{sup +} state, 100(36) ns.

  15. A system to measure isomeric state half-lives in the 10 ns to 10 μs range

    Science.gov (United States)

    Toufen, D. L.; Allegro, P. R. P.; Medina, N. H.; Oliveira, J. R. B.; Cybulska, E. W.; Seale, W. A.; Linares, R.; Silveira, M. A. G.; Ribas, R. V.

    2014-07-01

    The Isomeric State Measurement System (SISMEI) was developed to search for isomeric nuclear states produced by fusion-evaporation reactions. The SISMEI consists of 10 plastic phoswich telescopes, two lead shields, one NaI(Tl) scintillation detector, two Compton suppressed HPGe γ-ray detectors, and a cone with a recoil product catcher. The new system was tested at the 8 UD Pelletron tandem accelerator of the University of São Paulo with the measurement of two known isomeric states: 54Fe, 10+ state (E = 6527.1 (11) keV, T1/2 = 364(7) ns) and the 5/2+ state of 19F (E = 197.143 (4) keV, T1/2 = 89.3 (10) ns). The results indicate that the system is capable of identifying delayed transitions, of measuring isomeric state lifetimes, and of identifying the feeding transitions of the isomeric state through the delayed γ-γ coincidence method. The measured half-life for the 10+ state was T1/2 = 365(14) ns and for the 5/2+ state, 100(36) ns.

  16. Tequila authenticity assessment by headspace SPME-HRGC-IRMS analysis of 13C/12C and 18O/16O ratios of ethanol.

    Science.gov (United States)

    Aguilar-Cisneros, Blanca O; López, Mercedes G; Richling, Elke; Heckel, Frank; Schreier, Peter

    2002-12-18

    By use of headspace SPME sampling and a PLOT column, on-line capillary gas chromatography-isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the delta(13)C(VPDB) and delta(18)O(VSMOW) values of ethanol in authentic (n = 14) and commercial tequila samples (n = 15) as well as a number of other spirits (n = 23). Whereas with delta(13)C(VPDB) values ranging from -12.1 to -13.2 per thousand and from -12.5 to -14.8 per thousand similar variations were found for 100% agave and mixed tequilas, respectively, the delta(18)O(VSMOW) data differed slightly within these categories: ranges from +22.1 to +22.8 per thousand and +20.8 to +21.7 per thousand were determined for both the authentic 100% agave and mixed products, respectively. The data recorded for commercial tequilas were less homogeneous; delta(13)C(VPDB) data from -10.6 to -13.9 per thousand and delta(18)O(VSMOW) values from +15.5 to +22.7 per thousand were determined in tequilas of both categories. Owing to overlapping data, attempts to differentiate between white, rested, and aged tequilas within each of the two categories failed. In addition, discrimination of tequila samples from other spirits by means of delta(13)C(VPDB) and delta(18)O(VSMOW) data of ethanol was restricted to the products originating from C(3) as well as C(4)/CAM raw materials.

  17. Modified HS-SPME for determination of quantitative relations between low-molecular oxygen compounds in various matrices.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Szewczyk, Joanna; Dybowski, Michal P

    2016-09-07

    Similar quantitative relations between individual constituents of the liquid sample established by its direct injection can be obtained applying Polydimethylsiloxane (PDMS) fiber in the headspace solid phase microextraction (HS-SPME) system containing the examined sample suspended in methyl silica oil. This paper proves that the analogous system composed of sample suspension/emulsion in polyethylene glycol (PEG) and Carbowax fiber allows to get similar quantitative relations between components of the mixture as those established by its direct analysis, but only for polar constituents. It is demonstrated for essential oil (EO) components of savory, sage, mint and thyme, and of artificial liquid mixture of polar constituents. The observed differences in quantitative relations between polar constituents estimated by both applied procedures are insignificant (Fexp < Fcrit). The presented results indicates that wider applicability of the system composed of a sample suspended in the oil of the same physicochemical character as that of used SPME fiber coating strongly depends on the character of interactions between analytes-suspending liquid and analytes-fiber coating. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. A sensitive method using SPME pre-concentration for the quantification of aromatic amines in indoor air.

    Science.gov (United States)

    Lucaire, Vincent; Schwartz, Jean-Jacques; Delhomme, Olivier; Ocampo-Torres, Ruben; Millet, Maurice

    2018-03-01

    Monitoring the levels of aliphatic and aromatic amines (AA) in indoor air is important to protect human health because of exposure to these compounds through diet and inhalation. A sampling and analytical method using XAD-2 cartridges and gas chromatography coupled to mass spectrometry used for assessing 25 AA in different smoking and non-smoking indoor environment was developed. After sampling and delivering 1 m 3 of air (6-8 h sampling), an adsorbent was ultrasonically extracted with acetonitrile, concentrated to 1 mL and diluted in 25 mL of water (pH = 9; 5% NaCl), and then extracted for 40 min at 80 °C using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber and injected in a GC/MS system. With this method, 22 of the 25 AA can be analyzed with detection limits up to five times lower than that of classic liquid injection. Benzylamine, 3-aminophenol, and 4-aminophenol were not detected with the solid-phase micro-extraction (SPME) method. It can be assumed that aminophenols required a derivatization step for their analysis by GC as these molecules were not detected regardless of the injection mode used. Graphical abstract Analysis of aromatic amines in indoor air by SPME-GC/MS.

  19. Experimental design-based isotope-dilution SPME-GC/MS method development for the analysis of smoke flavouring products.

    Science.gov (United States)

    Giri, Anupam; Zelinkova, Zuzana; Wenzl, Thomas

    2017-12-01

    For the implementation of Regulation (EC) No 2065/2003 related to smoke flavourings used or intended for use in or on foods a method based on solid-phase micro extraction (SPME) GC/MS was developed for the characterisation of liquid smoke products. A statistically based experimental design (DoE) was used for method optimisation. The best general conditions to quantitatively analyse the liquid smoke compounds were obtained with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre, 60°C extraction temperature, 30 min extraction time, 250°C desorption temperature, 180 s desorption time, 15 s agitation time, and 250 rpm agitation speed. Under the optimised conditions, 119 wood pyrolysis products including furan/pyran derivatives, phenols, guaiacol, syringol, benzenediol, and their derivatives, cyclic ketones, and several other heterocyclic compounds were identified. The proposed method was repeatable (RSD% <5) and the calibration functions were linear for all compounds under study. Nine isotopically labelled internal standards were used for improving quantification of analytes by compensating matrix effects that might affect headspace equilibrium and extractability of compounds. The optimised isotope dilution SPME-GC/MS based analytical method proved to be fit for purpose, allowing the rapid identification and quantification of volatile compounds in liquid smoke flavourings.

  20. Characterization of the volatile components in green tea by IRAE-HS-SPME/GC-MS combined with multivariate analysis.

    Science.gov (United States)

    Yang, Yan-Qin; Yin, Hong-Xu; Yuan, Hai-Bo; Jiang, Yong-Wen; Dong, Chun-Wang; Deng, Yu-Liang

    2018-01-01

    In the present work, a novel infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for rapid determination of the volatile components in green tea. The extraction parameters such as fiber type, sample amount, infrared power, extraction time, and infrared lamp distance were optimized by orthogonal experimental design. Under optimum conditions, a total of 82 volatile compounds in 21 green tea samples from different geographical origins were identified. Compared with classical water-bath heating, the proposed technique has remarkable advantages of considerably reducing the analytical time and high efficiency. In addition, an effective classification of green teas based on their volatile profiles was achieved by partial least square-discriminant analysis (PLS-DA) and hierarchical clustering analysis (HCA). Furthermore, the application of a dual criterion based on the variable importance in the projection (VIP) values of the PLS-DA models and on the category from one-way univariate analysis (ANOVA) allowed the identification of 12 potential volatile markers, which were considered to make the most important contribution to the discrimination of the samples. The results suggest that IRAE-HS-SPME/GC-MS technique combined with multivariate analysis offers a valuable tool to assess geographical traceability of different tea varieties.

  1. Characterization of the volatile components in green tea by IRAE-HS-SPME/GC-MS combined with multivariate analysis.

    Directory of Open Access Journals (Sweden)

    Yan-Qin Yang

    Full Text Available In the present work, a novel infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME followed by gas chromatography-mass spectrometry (GC-MS was developed for rapid determination of the volatile components in green tea. The extraction parameters such as fiber type, sample amount, infrared power, extraction time, and infrared lamp distance were optimized by orthogonal experimental design. Under optimum conditions, a total of 82 volatile compounds in 21 green tea samples from different geographical origins were identified. Compared with classical water-bath heating, the proposed technique has remarkable advantages of considerably reducing the analytical time and high efficiency. In addition, an effective classification of green teas based on their volatile profiles was achieved by partial least square-discriminant analysis (PLS-DA and hierarchical clustering analysis (HCA. Furthermore, the application of a dual criterion based on the variable importance in the projection (VIP values of the PLS-DA models and on the category from one-way univariate analysis (ANOVA allowed the identification of 12 potential volatile markers, which were considered to make the most important contribution to the discrimination of the samples. The results suggest that IRAE-HS-SPME/GC-MS technique combined with multivariate analysis offers a valuable tool to assess geographical traceability of different tea varieties.

  2. Application of HS-SPME and GC-MS to characterization of volatile compounds emitted from Osmanthus flowers.

    Science.gov (United States)

    Deng, Chunhui; Song, Guoxin; Hu, Yaoming

    2004-12-01

    Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was developed for characterization of volatile compounds emitted from two varieties Osmanthus flowers of O. fragrans var. latifolius and O. fragrans var. thunbergii. The SPME parameters were studied, the optimum conditions of a 65 microm carbowax/divinylbenzene (CW/DVB), extraction temperature of 22 degrees C and extraction time of 10 min were obtained and applied to extraction of the volatile emissions. Fourteen compounds released from both varieties of Osmanthus flowers were separated and identified by GC-MS, which mainly included alpha-linalool, beta-linalool, trans-linalool oxide, cis-linalool oxide, alpha-lonone, beta-lonone, capraldehyde and decalactone. By comparing their peak areas, we found that the sums of the fourteen compounds from the two Osmanthus flowers were very close, while the relative contents of individual volatile compounds in the two emissions were very different. The relative content of alpha-linalool and beta-linalool in O. fragrans var. latifolius were 39.46% and 0.51%, while in O. fragrans var. thunbergii were 9.53% and 27.71%. Due to their different relative contents, the two varieties of flower have different fragrances.

  3. Characterisation of the volatile profile of coconut water from five varieties using an optimised HS-SPME-GC analysis.

    Science.gov (United States)

    Prades, Alexia; Assa, Rebecca Rachel Ablan; Dornier, Manuel; Pain, Jean-Pierre; Boulanger, Renaud

    2012-09-01

    Coconut (Cocos nucifera L.) water is a refreshing tropical drink whose international market has recently been growing. However, little is yet known about its physicochemical composition, particularly its aroma. This study set out to characterise the volatile profile of water from five coconut varieties. Aroma compounds were characterised by headspace solid phase microextraction gas chromatography (HS-SPME-GC) analysis. An experimental design was established to optimise SPME conditions, leading to an equilibration time of 10 min followed by an extraction time of 60 min at 50 °C. Accordingly, immature coconut water from WAT (West African Tall), PB121 (MYD × WAT Hybrid), MYD (Malayan Yellow Dwarf), EGD (Equatorial Guinea Green Dwarf) and THD (Thailand Aromatic Green Dwarf) palms was analysed and described. Ketones were mainly present in the Tall and Hybrid varieties, whereas aldehydes were most abundant in the Dwarf palms. Tall coconut water was characterised by a high lactone content. THD exhibited a high ethyl octanoate level. The cluster analysis of the volatile fraction from the five coconut cultivars was found to be related to their genetic classification. The volatile compounds of immature coconut water from five varieties were characterised for the first time. Volatile profile analysis could be a useful tool for the selection of Dwarf coconut varieties, which are mainly consumed as a beverage. Copyright © 2012 Society of Chemical Industry.

  4. Total cross section measurements for νμ, ν-barμ interactions in 3 - 30 GeV energy range with IHEP - JINR neutrino detector

    International Nuclear Information System (INIS)

    Anikeev, V.B.; Belikov, S.V.; Borisov, A.A.

    1995-01-01

    The results of total cross section measurements for the ν μ , ν-bar μ interactions with isoscalar target in the 3 - 30 GeV energy range have been presented. The data were obtained with the IHEP - JINR Neutrino Detector in the 'natural' neutrino beams of the U - 70 accelerator. The significant deviation from the linear dependence for σ tot versus neutrino energy is determined in the energy range less than 15 GeV. 46 refs., 10 figs., 5 tabs

  5. Measurements of radiological data of some amino acids in the energy range 0.122-1.330MeV

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, Rajkumar M., E-mail: rajml358@gmail.com; More, Chaitali V.; Surung, Bharat S.; Raut, Siddheshwar D.; Pawar, Pravina P., E-mail: pravinapawar4@gmail.com [Department of physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India)

    2016-05-06

    Radiological parameters such as μ{sub m}, σ{sub t}, σ{sub e}, Z{sub eff} and N{sub eff} of amino acids, namely Lysine (C{sub 6}H{sub 15}N{sub 2}O{sub 2}), Histidine (C{sub 6}H{sub 9}N{sub 3}O{sub 2}) and Arginine (C{sub 6}H{sub 15}N{sub 4}O{sub 2}), were measured using NaI (Tl)-based gamma spectrometry. Radioactive sources used in the study are {sup 57}Co, {sup 133}Ba, {sup 137}Cs, {sup 54}Mn, {sup 60}Co and {sup 22}Na. Gamma ray transmission method in a narrow beam good geometry set up was used in the study. The measured data were compared against XCOM-based data. The agreement is within 2%.

  6. Measurements versus Predictions for a Hybrid (Hydrostatic Plus Hydrodynamic) Thrust Bearing for a Range of Orifice Diameters

    Science.gov (United States)

    2010-05-01

    Type of Lubrication for a Tilting Pad Thrust Bearing ,” ASME Journal of Lubrication Technology, 96 Ser F (1), pp. 22-27. [9] Gregory, R.S., 1974...1986, “Measurements of Maximum Temperature in Tilting - Pad Thrust Bearings ,” Technical Preprints - Presented at the ASLE 41st Annual Meeting. (ASLE...Safar [7] provides a modified Reynolds number analysis on hydrostatic thrust bearing performance parameters including the effects of tilt . Finally, San

  7. Resonance absorption measurements of atom concentrations in reacting gas mixtures. II. Calibration of microwave sources over a wide temperature range

    International Nuclear Information System (INIS)

    Chiang, C.; Lifshitz, A.; Skinner, G.B.; Wood, D.R.

    1979-01-01

    A series of experiments was carried out to calibrate three different microwave discharge lamps for analysis for D or H atoms, using Lyman-α absorption. Known concentrations of D atoms were produced in a shock tube by the reaction of 0.05--4 ppm D 2 with N 2 O in argon at 1800--3000 K. H atoms were produced by dissociation of 2,2,3,3-tetramethylbutane (10 ppm in argon) at 980--1140 K. These absorption data were compared with the absorption calculated from Lyman-α line shapes reported in an earlier paper, good agreement being found. These experiments provide a sound basis for obtaining the temperature and concentration dependence of the absorption coefficient over a wide temperature range, for H and D concentrations between 10 -12 and 10 -10 mole/cc

  8. On the long-range dependence properties of annual precipitation using a global network of instrumental measurements

    Science.gov (United States)

    Tyralis, Hristos; Dimitriadis, Panayiotis; Koutsoyiannis, Demetris; O'Connell, Patrick Enda; Tzouka, Katerina; Iliopoulou, Theano

    2018-01-01

    The long-range dependence (LRD) is considered an inherent property of geophysical processes, whose presence increases uncertainty. Here we examine the spatial behaviour of LRD in precipitation by regressing the Hurst parameter estimate of mean annual precipitation instrumental data which span from 1916-2015 and cover a big area of the earth's surface on location characteristics of the instrumental data stations. Furthermore, we apply the Mann-Kendall test under the LRD assumption (MKt-LRD) to reassess the significance of observed trends. To summarize the results, the LRD is spatially clustered, it seems to depend mostly on the location of the stations, while the predictive value of the regression model is good. Thus when investigating for LRD properties we recommend that the local characteristics should be considered. The application of the MKt-LRD suggests that no significant monotonic trend appears in global precipitation, excluding the climate type D (snow) regions in which positive significant trends appear.

  9. Edge measurements during ICRF [ion cyclotron range of frequency] heating on the PLT [Princeton Large Torus] tokamak

    International Nuclear Information System (INIS)

    Lehrman, I.S.; Colestock, P.L.; McNeill, D.H.; Greene, G.J.; Bernabei, S.; Hosea, J.C.; Ono, M.; Shohet, J.L.; Wilson, J.R.

    1989-04-01

    Edge measurements have been conducted on the PLT tokamak under a variety of operating conditions in order to ascertain the relevant processes at work in coupling rf power to plasmas. The edge density is found to increase significantly with the application of ICRF, and electron heating occurs in the vicinity of the Faraday shield surrounding the antenna. Spectroscopic measurements indicate that the energized antenna is a significant particle source. The relative increase of metallic impurities was found to be /approximately/2.7 times larger than the corresponding increase in deuterium. In addition, the relative increase of deuterium and impurities was /approximately/3--4 times greater at the energized antenna than at other locations around the torus. Model calculations show that for deuterium released from the Faraday shield, the D/sub α/ emission is localized radially to a region within 4 cm of the antenna. A correlation was found between the edge density and the D/sub α/ intensity that justifies its use as a measure of the particle source rate. 26 refs., 14 figs

  10. Determining Damping Trends from a Range of Cable Harness Assemblies on a Launch Vehicle Panel from Test Measurements

    Science.gov (United States)

    Smith, Andrew; Davis, R. Ben; LaVerde, Bruce; Jones, Douglas

    2012-01-01

    The team of authors at Marshall Space Flight Center (MSFC) has been investigating estimating techniques for the vibration response of launch vehicle panels excited by acoustics and/or aero-fluctuating pressures. Validation of the approaches used to estimate these environments based on ground tests of flight like hardware is of major importance to new vehicle programs. The team at MSFC has recently expanded upon the first series of ground test cases completed in December 2010. The follow on tests recently completed are intended to illustrate differences in damping that might be expected when cable harnesses are added to the configurations under test. This validation study examines the effect on vibroacoustic response resulting from the installation of cable bundles on a curved orthogrid panel. Of interest is the level of damping provided by the installation of the cable bundles and whether this damping could be potentially leveraged in launch vehicle design. The results of this test are compared with baseline acoustic response tests without cables. Damping estimates from the measured response data are made using a new software tool that employs a finite element model (FEM) of the panel in conjunction with advanced optimization techniques. This paper will report on the \\damping trend differences. observed from response measurements for several different configurations of cable harnesses. The data should assist vibroacoustics engineers to make more informed damping assumptions when calculating vibration response estimates when using model based analysis approach. Achieving conservative estimates that have more flight like accuracy is desired. The paper may also assist analysts in determining how ground test data may relate to expected flight response levels. Empirical response estimates may also need to be adjusted if the measured response used as an input to the study came from a test article without flight like cable harnesses.

  11. Investigating Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range Transport

    Science.gov (United States)

    Ryoo, Ju-Mee; Johnson, Matthew S.; Iraci, Laura T.; Yates, Emma L.; Pierce, R. Bradley; Tanaka, Tomoaki; Gore, Warren

    2016-01-01

    High ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOSchem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7% and 7.6%, respectively) compared to that from LT (64.1%), but the relative ozone concentration coming from LS and UT is high (38.4% and 20.95%, respectively) compared to that from LT (17.7%). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.

  12. Investigation of Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range Transport

    Science.gov (United States)

    Ryoo, Ju-Mee; Johnson, Matthew S.; Iraci, Laura T.; Yates, Emma L.; Pierce, R. Bradley; Tanaka, Tomoaki; Gore, Warren

    2015-01-01

    High ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOS-chem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7 and 7.6, respectively) compared to that from LT (64.1), but the relative ozone concentration coming from LS and UT is high (38.4 and 20.95, respectively) compared to that from LT (17.7). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.

  13. Polymeric nanosensors for measuring the full dynamic pH range of endosomes and lysosomes in mammalian cells

    DEFF Research Database (Denmark)

    Sun, Honghao; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki

    2009-01-01

    Polymer nanoparticle sensors have been constructed for studying pH in the endocytic pathway in mammalian cells. The pH sensors for fluorescence ratiometric measurements were prepared using inverse microemulsion polymerization with rhodamine as reference fluorophor and fluorescein and oregon green...... was used to introduce a net positive charge in the cationic particles. It was found that the positively charged particle sensors were internalized spontaneously by HepG2 cancer cells. These new pH nanosensors are potential tools in time resolved quantification of pH in the endocytic pathway of living cells....

  14. Radiometric measurements of wall temperatures in the 800 K to 1150 K range for a quartz radiant heating tube

    International Nuclear Information System (INIS)

    Blevins, L.G.; Sivathanu, Y.R.; Gore, J.P.; Shahien, M.A.

    1995-01-01

    Many industrial applications require heat transfer to a load in an inert environment, which can be achieved by using gas-fired radiant tubes. A radiant tube consists of a flame confined in a cylindrical metal or ceramic chamber. The flame heats the tube wall, which in turn radiates to the load. One important characteristic of radiant heating tubes is wall temperature uniformity. Numerical models of radiant tubes have been used to predict wall temperatures, but there is a lack of experimental data for validation. Recently, Namazian et al., Singh and Gorski, and Peters et al. have measured wall temperature profiles of radiant tubes using thermocouples. 13 refs., 3 figs

  15. Gastric emptying in rats following administration of a range of different fats measured as acetaminophen concentration in plasma

    DEFF Research Database (Denmark)

    Porsgaard, Trine; Straarup, Ellen Marie; Høy, Carl-Erik

    2003-01-01

    an indirect measure of gastric emptying. Emulsified fats with added acetaminophen were fed by gavage to rats, and the plasma concentration of acetaminophen was followed for 3 h by repeated blood sampling from the carotid artery. The fats administered included rapeseed, corn, and fish oils, lard, and cocoa...... in gastric emptying between the groups fed the different fats, except for the emptying of tridecanoin (tri-10:0) that was statistically significantly slower than that of randomized oil, cocoa butter, and rapeseed oil (p

  16. Quality assessment and consistency check of measured nuclear data up to 20 MeV including the range of resonances

    International Nuclear Information System (INIS)

    Boedy, Z.T.

    1984-09-01

    This is the final report of a research contract with the IAEA. The object is the compilation and evaluation of all the data on (n,t) and (n,3He) reactions cross-sections, respectively. The main results of the research are given (some discrepancies in the experimental data; analytic formulas for an empirical description of the data, separately for the even and odd nuclei with z>20; methods to extrapolate to energies where measurements are missing; mass regions where data are needed), and publications by the authors with the detailed results are quoted

  17. Metamaterial near-field sensor for deep-subwavelength thickness measurements and sensitive refractometry in the terahertz frequency range

    International Nuclear Information System (INIS)

    Reinhard, Benjamin; Schmitt, Klemens M.; Neu, Jens; Wollrab, Viktoria; Beigang, Rene; Rahm, Marco

    2012-01-01

    We present a metamaterial-based terahertz (THz) sensor for thickness measurements of subwavelength-thin materials and refractometry of liquids and liquid mixtures. The sensor operates in reflection geometry and exploits the frequency shift of a sharp Fano resonance minimum in the presence of dielectric materials. We obtained a minimum thickness resolution of 12.5 nm (1/16 000 times the wavelength of the THz radiation) and a refractive index sensitivity of 0.43 THz per refractive index unit. We support the experimental results by an analytical model that describes the dependence of the resonance frequency on the sample material thickness and the refractive index.

  18. Metamaterial near-field sensor for deep-subwavelength thickness measurements and sensitive refractometry in the terahertz frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Reinhard, Benjamin; Schmitt, Klemens M.; Neu, Jens [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern (Germany); Wollrab, Viktoria; Beigang, Rene; Rahm, Marco [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern (Germany); Fraunhofer Institute for Physical Measurement Techniques IPM, 79110 Freiburg (Germany)

    2012-05-28

    We present a metamaterial-based terahertz (THz) sensor for thickness measurements of subwavelength-thin materials and refractometry of liquids and liquid mixtures. The sensor operates in reflection geometry and exploits the frequency shift of a sharp Fano resonance minimum in the presence of dielectric materials. We obtained a minimum thickness resolution of 12.5 nm (1/16 000 times the wavelength of the THz radiation) and a refractive index sensitivity of 0.43 THz per refractive index unit. We support the experimental results by an analytical model that describes the dependence of the resonance frequency on the sample material thickness and the refractive index.

  19. Reliability of the American Medical Association guides' model for measuring spinal range of motion. Its implication for whole-person impairment rating.

    Science.gov (United States)

    Nitschke, J E; Nattrass, C L; Disler, P B; Chou, M J; Ooi, K T

    1999-02-01

    Repeated measures design for intra- and interrater reliability. To determine the intra- and interrater reliability of the lumbar spine range of motion measured with a dual inclinometer, and the thoracolumbar spine range of motion measured with a long-arm goniometer, as recommended in the American Medical Association Guides. The American Medical Association Guides (2nd and 4th editions) recommend using measurements of thoracolumbar and lumbar range of movement, respectively, to estimate the percentage of permanent impairment in patients with chronic low back pain. However, the reliability of this method of estimating impairment has not been determined. In all, 34 subjects participated in the study, 21 women with a mean age of 40.1 years (SD, +/- 11.1) and 13 men with a mean age of 47.7 years (SD, +/- 12.1). Measures of thoracolumbar flexion, extension, lateral flexion, and rotation were obtained with a long-arm goniometer. Lumbar flexion, extension, and lateral flexion were measured with a dual inclinometer. Measurements were taken by two examiners on one occasion and by one examiner on two occasions approximately 1 week apart. The results showed poor intra- and interrater reliability for all measurements taken with both instruments. Measurement error expressed in degrees showed that measurements taken by different raters exhibited systematic as well as random differences. As a result, subjects measured by two different examiners on the same day, with either instrument, could give impairment ratings ranging between 0% and 18% of the whole person (excluding rotation), in which percentage impairment is calculated using the average range of motion and the average systematic and random error in degrees for the group for each movement (flexion, extension, and lateral flexion). The poor reliability of the American Medical Association Guides' spinal range of motion model can result in marked variation in the percentage of whole-body impairment. These findings have

  20. Measurement of long-range correlations in pp collisions characterized by presence of a Z-boson

    CERN Document Server

    Milov, Alexander; The ATLAS collaboration

    2017-01-01

    Recent measurements of correlations between two particles separated in pesudorapidity and azimuthal angles have shown striking similarities between results obtained in pp, and in p+A and A+A collision systems. In pp collision system, unlike in the p+A and A+A systems, the strength of the correlations quantified by the anisotropy parameter $v_2$ does not show any dependence on the charged-particle multiplicity. Recent theoretical models suggest that this can be due to lack of correlation between the charged-particle multiplicity and the impact parameter of the pp collision. An independent handle on the impact parameter can be obtained by requiring the presence of a hard-scattering process in the collision. This talk presents the first measurement of two-particle correlations in pp collisions with a Z boson identified via its dimuon decay channel. The analysis uses ATLAS data recorded under nominal pp luminosities, and a procedure to correct for contribution of the tracks coming from pileup vertices is used. Th...

  1. Measurement of long-range correlations in pp collisions characterized by presence of a Z boson with the ATLAS detector

    CERN Document Server

    Cole, Brian; The ATLAS collaboration

    2018-01-01

    Recent measurements of correlations between two particles separated in pseudorapidity and azimuthal angles have shown striking similarities between results obtained in pp, p+A and A+A collision systems. In the pp collision system, unlike in p+A and A+A collisions, the strength of the correlations, quantified by the anisotropy parameter v2, shows little dependence on the observed charged-particle multiplicity. Recent theoretical models suggest that this can result from an intrinsically weak correlation between the charged-particle multiplicity and the impact parameter of the pp collision. An independent handle on the impact parameter can be obtained in principle by requiring the presence of a hard-scattering process in the collision. This talk presents the first measurement of two-particle correlations in pp collisions with a presence of Z boson identified via its μμ decay channel. The analysis uses ATLAS data recorded with nominal pp luminosity with high pileup. A new procedure is used to correct for the co...

  2. Development of a Method for Measuring the Range of Colors Indicated by Terms Used on Color Samples and Digital Cameras

    OpenAIRE

    畑田, 明信; Hatada, Akinobu

    2009-01-01

     色を指す言葉が示す色空間上の範囲は、その言葉を使う人間の文化的な背景や個人的な嗜好に大きく左右される。このような色を指す言葉が示す色の範囲を測定するための方法は一般的には存在しない。本研究では実験協力者に色見本帳に色を指す言葉に対応する色見本に印をつけてもらい、それをデジタルスチルカメラで撮影した画像から、物理的な色範囲に変換する手法の開発を行った。Color gamut of color word would be different by each personality, background of culture. In other hand, there is no standard method for measuring a gamut of color word. This paper reports a trial of developing a new method of measuring color gamut of color word, and some practical test result by pilot system. It use co...

  3. Thermoregulation of the bovine scrotum 1: measurements of free-range animals in a paddock and pen

    Science.gov (United States)

    Wallage, Andrea L.; Johnston, S. D.; Lisle, A. T.; Beard, L.; Lees, A. M.; Collins, C. W.; Gaughan, J. B.

    2017-08-01

    The bull's scrotum and scrotal cord vasculature has traditionally been regarded as a thermoregulatory device for maintaining optimal testicular temperature for normal spermatogenesis. This assumption has mostly been derived from discrete measurements using thermocouples with limited data correlating continuous scrotal temperature (ST) to body temperature (BT). From mid-summer to early autumn, four Wagyu bulls (9-18 months) were surgically implanted with two data loggers (DL) logging at 30 min intervals: one on the right hand side flank and the other was attached to the visceral vaginal tunic of the mid-testis. Bulls were firstly housed in a paddock (PK) for 13 days and then moved to individual pens (IP), again for 13 days. Repeated measures analysis modelled the long-term and diurnal trends in BT and ST. While both day and time of day (TOD) were significant effects for ST at both housing locations ( P behavioural changes. Reporting concurrent and continuous BT and ST will allow further investigation into factors influencing bovine ST and should be useful in selecting bulls with high degrees of thermoregulation capacity.

  4. Development of a LiF-filter for measuring plasma fluctuations in the far ultraviolet radiation spectral range

    International Nuclear Information System (INIS)

    Schittenhelm, M.

    1991-06-01

    The investigations of fluctuations and anomalous transport lie at hart of the tokamak research program, especially in the shear zone close to and beyond the last closed flux surface. Until now fluctuation measurements using plasma radiation were only made on the edge of the plasma, since they rely on the H α emission. In order to measure electron density fluctuations with good spatial and temporal resolution in the shear zone, the OVI doublet (2s-2p) can be observed. These are very strong impurity emission lines in the VUV region (103.2 nm and 103.8 nm) emitted from a narrow layer close to the separatrix. To get an image of this layer and to achieve enough intensity for a good temporal resolution, it is necessary to develop a filter with high transmission. A possible candidate is lithium fluoride (LiF), which transmits light at shorter wavelength than other materials. By cooling LiF crystals from 300 K to 220 K the cutoff wavelength decreases from 105 nm to about 103 nm. This master thesis presents a detailed investigation of the transmission of LiF near the cutoff wavelength. Crystal sheets produced by different manufactures were tested and the temperature dependence of the cutoff edge was investigated. (orig./AH)

  5. Use of boron nitride for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements

    Science.gov (United States)

    Radulović, Vladimir; Trkov, Andrej; Jaćimović, Radojko; Gregoire, Gilles; Destouches, Christophe

    2016-12-01

    A recent experimental irradiation and measurement campaign using containers made from boron nitride (BN) at the Jožef Stefan Institute (JSI) TRIGA Mark II reactor in Ljubljana, Slovenia, has shown the applicability of BN for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements. The first part of the paper focuses on the determination of the transmission function of a BN container through Monte Carlo calculations and experimental measurements. The second part presents the process of tayloring the sensitivity of integral activation measurements to specific needs and a selection of suitable radiative capture reactions for neutron spectrum characterization in the epithermal range. A BN container used in our experiments and its qualitative effect on the neutron spectrum in the irradiation position employed is displayed in the Graphical abstract.

  6. Measurement of long-range angular correlations and azimuthal anisotropies in high-multiplicity p +Au collisions at √{sNN}=200 GeV

    Science.gov (United States)

    Aidala, C.; Akiba, Y.; Alfred, M.; Andrieux, V.; Aoki, K.; Apadula, N.; Asano, H.; Ayuso, C.; Azmoun, B.; Babintsev, V.; Bandara, N. S.; Barish, K. N.; Bathe, S.; Bazilevsky, A.; Beaumier, M.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Blau, D. S.; Boer, M.; Bok, J. S.; Brooks, M. L.; Bryslawskyj, J.; Bumazhnov, V.; Butler, C.; Campbell, S.; Canoa Roman, V.; Cervantes, R.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Citron, Z.; Connors, M.; Cronin, N.; Csanád, M.; Csörgő, T.; Danley, T. W.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dion, A.; Dixit, D.; Do, J. H.; Drees, A.; Drees, K. A.; Dumancic, M.; Durham, J. M.; Durum, A.; Elder, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fan, W.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukuda, Y.; Gal, C.; Gallus, P.; Garg, P.; Ge, H.; Giordano, F.; Goto, Y.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; He, X.; Hemmick, T. K.; Hill, J. C.; Hill, K.; Hollis, R. S.; Homma, K.; Hong, B.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Imai, K.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ito, Y.; Ivanishchev, D.; Jacak, B. V.; Jezghani, M.; Ji, Z.; Jiang, X.; Johnson, B. M.; Jorjadze, V.; Jouan, D.; Jumper, D. S.; Kang, J. H.; Kapukchyan, D.; Karthas, S.; Kawall, D.; Kazantsev, A. V.; Khachatryan, V.; Khanzadeev, A.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, M. H.; Kim, M.; Kincses, D.; Kistenev, E.; Klatsky, J.; Kline, P.; Koblesky, T.; Kotov, D.; Kudo, S.; Kurita, K.; Kwon, Y.; Lajoie, J. G.; Lallow, E. O.; Lebedev, A.; Lee, S.; Leitch, M. J.; Leung, Y. H.; Lewis, N. A.; Li, X.; Lim, S. H.; Liu, L. D.; Liu, M. X.; Loggins, V.-R.; Loggins, V.-R.; Lovasz, K.; Lynch, D.; Majoros, T.; Makdisi, Y. I.; Makek, M.; Malaev, M.; Manko, V. I.; Mannel, E.; Masuda, H.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Mendoza, M.; Mignerey, A. C.; Mihalik, D. E.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Mitsuka, G.; Miyasaka, S.; Mizuno, S.; Montuenga, P.; Moon, T.; Morrison, D. P.; Morrow, S. I. M.; Murakami, T.; Murata, J.; Nagai, K.; Nagashima, K.; Nagashima, T.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakano, K.; Nattrass, C.; Niida, T.; Nouicer, R.; Novák, T.; Novitzky, N.; Novotny, R.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ottino, G. J.; Ozawa, K.; Pantuev, V.; Papavassiliou, V.; Park, J. S.; Park, S.; Pate, S. F.; Patel, M.; Peng, W.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perezlara, C. E.; Perry, J.; Petti, R.; Phipps, M.; Pinkenburg, C.; Pisani, R. P.; Pun, A.; Purschke, M. L.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richford, D.; Rinn, T.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Runchey, J.; Safonov, A. S.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, K.; Sato, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shioya, T.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Smith, K. L.; Snowball, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Syed, S.; Sziklai, J.; Takeda, A.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Tarnai, G.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Towell, C. L.; Towell, R. S.; Tserruya, I.; Ueda, Y.; Ujvari, B.; van Hecke, H. W.; Vazquez-Carson, S.; Velkovska, J.; Virius, M.; Vrba, V.; Vukman, N.; Wang, X. R.; Wang, Z.; Watanabe, Y.; Watanabe, Y. S.; Wong, C. P.; Woody, C. L.; Xu, C.; Xu, Q.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamamoto, H.; Yanovich, A.; Yin, P.; Yoo, J. H.; Yoon, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zharko, S.; Zou, L.; Phenix Collaboration

    2017-03-01

    We present measurements of long-range angular correlations and the transverse momentum dependence of elliptic flow v2 in high-multiplicity p +Au collisions at √{s NN}=200 GeV. A comparison of these results to previous measurements in high-multiplicity d +Au and 3He+Au collisions demonstrates a relation between v2 and the initial collision eccentricity ɛ2, suggesting that the observed momentum-space azimuthal anisotropies in these small systems have a collective origin and reflect the initial geometry. Good agreement is observed between the measured v2 and hydrodynamic calculations for all systems, and an argument disfavoring theoretical explanations based on initial momentum-space domain correlations is presented. The set of measurements presented here allows us to leverage the distinct intrinsic geometry of each of these systems to distinguish between different theoretical descriptions of the long-range correlations observed in small collision systems.

  7. The SCANDAL facility - How to measure elastic neutron scattering in the 50-130 MeV range

    International Nuclear Information System (INIS)

    Klug, Joakim

    2001-01-01

    The interest in neutrons of energies above 20 MeV is growing rapidly, since new applications are being developed or have been identified. Transmutation of nuclear waste and cancer therapy with neutron beams are two research fields that would benefit from new neutron scattering data at these energies. A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has been developed and installed at the neutron beam facility of the The Svedberg Laboratory in Uppsala. It can be used to study the (n,n), (n,p) and (n,d) reactions. This thesis describes the layout of the setup, the experimental procedure, and data analysis principles. The performance of the spectrometer is illustrated with measurements of the (n,p) and (n,n) reactions on 1 H and 12 C. In addition, the neutron beam facility is described in some detail

  8. First measurement of the VESUVIO neutron spectrum in the 30–80 MeV energy range using a Proton Recoil Telescope technique

    International Nuclear Information System (INIS)

    Cazzaniga, C; Tardocchi, M; Croci, G; Grosso, G; Rebai, M; Gorini, G; Frost, C; Rhodes, N J; Schooneveld, E M; Giacomelli, L; Hjalmarsson, A

    2013-01-01

    Measurements of the fast neutron energy spectrum at the ISIS spallation source are reported. The measurements were performed with a Proton Recoil Telescope consisting of a thin plastic foil placed in the neutron beam and two scintillator detectors. Results in the neutron energy range 30 MeV n < 80 MeV are in good agreement with Monte Carlo simulations of the neutron spectrum

  9. First measurement of the VESUVIO neutron spectrum in the 30-80 MeV energy range using a Proton Recoil Telescope technique

    Science.gov (United States)

    Cazzaniga, C.; Tardocchi, M.; Croci, G.; Frost, C.; Giacomelli, L.; Grosso, G.; Hjalmarsson, A.; Rebai, M.; Rhodes, N. J.; Schooneveld, E. M.; Gorini, G.

    2013-11-01

    Measurements of the fast neutron energy spectrum at the ISIS spallation source are reported. The measurements were performed with a Proton Recoil Telescope consisting of a thin plastic foil placed in the neutron beam and two scintillator detectors. Results in the neutron energy range 30 MeV < En < 80 MeV are in good agreement with Monte Carlo simulations of the neutron spectrum.

  10. Absorption spectroscopy and multi-angle scattering measurements in the visible spectral range for the geographic classification of Italian exravirgin olive oils

    Science.gov (United States)

    Mignani, Anna G.; Ciaccheri, Leonardo; Cimato, Antonio; Sani, Graziano; Smith, Peter R.

    2004-03-01

    Absorption spectroscopy and multi-angle scattering measurements in the visible spectral range are innovately used to analyze samples of extra virgin olive oils coming from selected areas of Tuscany, a famous Italian region for the production of extra virgin olive oil. The measured spectra are processed by means of the Principal Component Analysis method, so as to create a 3D map capable of clustering the Tuscan oils within the wider area of Italian extra virgin olive oils.

  11. Experimental time resolved measurement of fluence and energy spectra of photons emitted by a pulsed X-ray generator in the range 5-300 keV

    International Nuclear Information System (INIS)

    Vie, M.; Baboulet, J.P.

    1989-01-01

    We have developed: - A sensor to measure locally X ray fluence rate amplitude and variation versus time during X ray pulses, - A spectrometer based on ROSS method to measure absolute X ray spectrum versus time during X ray pulses. This metrology is used to characterise single shot X ray pulsed sources emitting photons in the range of 5 to 300 keV. Fluence domain is between 10 -9 and 5 10 -4 J. cm -2 with a few nanoseconds time resolution [fr

  12. This week?s Citation Classic: 'Stickel, L. F. A comparison of certain methods of measuring ranges of small mammals. J. Mammalogy 35: 1-15, 1954.'

    Science.gov (United States)

    Stickel, L.F.

    1986-01-01

    During my first employment as a junior biologist conducting food habits analyses at the Patuxent Research Refuge (now Patuxent Wildlife Research Center) of the US Fish and Wildlife Service, the first station director, Arnold L. Nelson, gave each staff biologist the opportunity to spend a little time conducting field studies on the 2,600-acre research area. These studies were to help in ecological evaluation of the area, but also, no doubt, functioned as a morale builder for biologists daily engaged in difficult, demanding and confining laboratory work. I undertook to measure the population density of small mammals in different habitats. The state-of-the-art methods recommended to me and prevalent in the literature worried me, especially after preliminary field work. Reading the classic, paper by W.H. Burt [Terrioriality and home range concepts as applied to mammals. J. Mammalogy 24:346-352, 1943] was a turning point for me in seeing that knowledge of home-range size was the key to measuring population density. My first papers employed these concepts in field evaluations. However, they could give-only limited attention to the question of how home ranges could be measured. Furthermore, the importance of knowledge of the home range to habitat evaluation and to understanding animal behavior was becoming increasingly apparent. Advocacy of many different methods of measuring home ranges appeared in the literature. It did not seem possible to evaluate them objectively. It occurred to me that artificial populations could be used to help in understanding the mechanisms of measuring home ranges. The effects of random trap-visiting, bias toward central traps, trap-spacing, range shape, and other factors could be considered. So grids of traps were inked onto oversize graph paper, and simulated ranges were cut from plastic to be tossed as randomly as possible on the trap-grids. It was a slow, laborious job. Analysis showed that random captures in artificial populations produced

  13. Depth Dose Measurement using a Scintillating Fiber Optic Dosimeter for Proton Therapy Beam of the Passive-Scattering Mode Having Range Modulator Wheel

    Science.gov (United States)

    Hwang, Ui-Jung; Shin, Dongho; Lee, Se Byeong; Lim, Young Kyung; Jeong, Jong Hwi; Kim, Hak Soo; Kim, Ki Hwan

    2018-05-01

    To apply a scintillating fiber dosimetry system to measure the range of a proton therapy beam, a new method was proposed to correct for the quenching effect on measuring an spread out Bragg peak (SOBP) proton beam whose range is modulated by a range modulator wheel. The scintillating fiber dosimetry system was composed of a plastic scintillating fiber (BCF-12), optical fiber (SH 2001), photo multiplier tube (H7546), and data acquisition system (PXI6221 and SCC68). The proton beam was generated by a cyclotron (Proteus-235) in the National Cancer Center in Korea. It operated in the double-scattering mode and the spread out of the Bragg peak was achieved by a spinning range modulation wheel. Bragg peak beams and SOBP beams of various ranges were measured, corrected, and compared to the ion chamber data. For the Bragg peak beam, quenching equation was used to correct the quenching effect. On the proposed process of correcting SOBP beams, the measured data using a scintillating fiber were separated by the Bragg peaks that the SOBP beam contained, and then recomposed again to reconstruct an SOBP after correcting for each Bragg peak. The measured depth-dose curve for the single Bragg peak beam was well corrected by using a simple quenching equation. Correction for SOBP beam was conducted with a newly proposed method. The corrected SOBP signal was in accordance with the results measured with an ion chamber. We propose a new method to correct for the SOBP beam from the quenching effect in a scintillating fiber dosimetry system. This method can be applied to other scintillator dosimetry for radiation beams in which the quenching effect is shown in the scintillator.

  14. Static and Dynamic Accuracy of an Innovative Miniaturized Wearable Platform for Short Range Distance Measurements for Human Movement Applications

    Directory of Open Access Journals (Sweden)

    Stefano Bertuletti

    2017-06-01

    Full Text Available Magneto-inertial measurement units (MIMU are a suitable solution to assess human motor performance both indoors and outdoors. However, relevant quantities such as step width and base of support, which play an important role in gait stability, cannot be directly measured using MIMU alone. To overcome this limitation, we developed a wearable platform specifically designed for human movement analysis applications, which integrates a MIMU and an Infrared Time-of-Flight proximity sensor (IR-ToF, allowing for the estimate of inter-object distance. We proposed a thorough testing protocol for evaluating the IR-ToF sensor performances under experimental conditions resembling those encountered during gait. In particular, we tested the sensor performance for different (i target colors; (ii sensor-target distances (up to 200 mm and (iii sensor-target angles of incidence (AoI (up to 60 ∘ . Both static and dynamic conditions were analyzed. A pendulum, simulating the oscillation of a human leg, was used to generate highly repeatable oscillations with a maximum angular velocity of 6 rad/s. Results showed that the IR-ToF proximity sensor was not sensitive to variations of both distance and target color (except for black. Conversely, a relationship between error magnitude and AoI values was found. For AoI equal to 0 ∘ , the IR-ToF sensor performed equally well both in static and dynamic acquisitions with a distance mean absolute error <1.5 mm. Errors increased up to 3.6 mm (static and 11.9 mm (dynamic for AoI equal to ± 30 ∘ , and up to 7.8 mm (static and 25.6 mm (dynamic for AoI equal to ± 60 ∘ . In addition, the wearable platform was used during a preliminary experiment for the estimation of the inter-foot distance on a single healthy subject while walking. In conclusion, the combination of magneto-inertial unit and IR-ToF technology represents a valuable alternative solution in terms of accuracy, sampling frequency, dimension and power consumption

  15. Kinetic energy measurement of hydrogen in LHD peripheral plasma with a multi-wavelength-range fine-resolution spectrometer

    International Nuclear Information System (INIS)

    Fujii, Keisuke; Mizushiri, Keisuke; Nishioka, Tomomi; Shikama, Taiichi; Iwamae, Atsushi; Goto, Motoshi; Morita, Shigeru; Hasuo, Masahiro

    2010-01-01

    We have simultaneously measured high resolution emission spectra of the hydrogen atomic Balmer-α, -β, -γ lines and molecular Fulcher-α band for a LHD peripheral plasma generated under a central magnetic field strength of 0.4 T. It is found that the velocity distributions of excited atoms calculated from the Balmer-α, -β, and -γ line shapes show similar profiles to each other. The translational kinetic energy corresponding to the average velocity is about 13 eV, which is about 300 times larger than the rotational energy of hydrogen molecules estimated from the line intensities in the Fulcher-α band. The velocity distributions differ from Maxwellian and have a high velocity tail over 1x10 5 m/s. A correlation between the high velocity tail and the electron temperature and density is seen and suggesting the excited atoms having such high velocities to be generated by the charge exchange collisions from high velocity protons in the peripheral region.

  16. Monitoring of persistent organic pollutants in seawater of the Pearl River Estuary with rapid on-site active SPME sampling technique

    International Nuclear Information System (INIS)

    Huang, Siming; He, Shuming; Xu, Hao; Wu, Peiyan; Jiang, Ruifen; Zhu, Fang; Luan, Tiangang; Ouyang, Gangfeng

    2015-01-01

    An on-site active solid-phase microextraction (SPME) sampling technique coupled with gas chromatography-mass spectrometry (GC–MS) for sampling and monitoring 16 polycyclic aromatic hydrocarbons (PAHs) and 8 organochlorine pesticides (OCPs) in seawater was developed. Laboratory experiments demonstrated that the sampling-rate calibration method was practical and could be used for the quantification of on-site sampling. The proposed method was employed for field tests which covered large amounts of water samples in the Pearl River Estuary in rainy and dry seasons. The on-site SPME sampling method can avoid the contamination of sample, the losses of analytes during sample transportation, as well as the usage of solvent and time-consuming sample preparation process. Results indicated that the technique with the designed device can address the requirement of modern environment water analysis. In addition, the sources, bioaccumulation and potential risk to human of the PAHs and OCPs in seawater of the Pearl River Estuary were discussed. - Highlights: • SPME on-site active sampling technique was developed and validated. • The technique was employed for field tests in the Pearl River Estuary. • 16 PAHs and 8 OCPs in the seawater of Pearl River Estuary were monitored. • The potential risk of the PAHs and OCPs in Pearl River Estuary were discussed. - An on-site active SPME sampling technique was developed and successfully applied for sampling and monitoring 16 PAHs and 8 OCPs in the Pearl River Estuary

  17. Sol-gel-based SPME fiber as a reliable sampling technique for studying biogenic volatile organic compounds released from Clostridium tetani.

    Science.gov (United States)

    Ghader, Masoud; Shokoufi, Nader; Es-Haghi, Ali; Kargosha, Kazem

    2017-11-01

    A novel and efficient headspace solid-phase microextraction (HS-SPME) method, followed by gas chromatography mass spectrometry (GC-MS), was developed to study volatile organic compounds (VOCs) emerging from microorganisms. Two homemade SPME fibers, a semi-polar poly (dimethylsiloxane) (PDMS) fiber, and a polar polyethylene glycol (PEG) fiber, along with two commercial fibers (PDMS and PDMS/DVB) were used to collect VOCs emerging from Clostridium tetani which was cultured in different media. The adsorbed VOCs were desorbed and identified, in vitro, using GC-MS. The adsorption efficiency was improved by optimizing the time duration of adsorption and desorption. About 50 components were identified by the proposed method. The main detected compounds appeared to be sulfur containing compounds such as butanethioic acid S-methyl ester, dimethyl trisulfide, and dimethyl tetrasulfide. These volatile sulfur containing compounds are derived from amino acids containing the sulfur element, which probably coexist in the mentioned bacterium or are added to the culture media. The developed HS-SPME-GC-MS method allowed the determination of the chemical fingerprint of Clostridium tetani volatile constituents, and thus provides a new, simple, and reliable tool for studying the growth of microorganisms. Graphical abstract Investigation of biogenic VOCs released from Clostridium tetani using SPME-GC-MS.

  18. Rapid sampling of BTEX in air by SPME in the city of Nice and at the Nice-Cote d'Azur airport

    International Nuclear Information System (INIS)

    Tumbiolo, S.; Gal, J.F.; Maria, P.Ch.; Laborde, P.; Teton, S.

    2006-01-01

    This article presents the results of a tentative application of Solid Phase Micro Extraction (SPME) to the analysis of BTEX (benzene, toluene, ethyl-benzene and xylenes) at the μg/m 3 level in indoor and outdoor air. The salient features of the method validation are reported. Sampling by QUALITAIR using Radiello passive samplers, was carried out from 2001 to 2004 in the city of Nice and its airport. Urban traffic impact was proved, but a link between BTX concentrations and the variations of airport activities was not clearly established. During the same period, several samplings were performed using SPME. Taking into account the short (30 minutes) sampling time, rapid changes of BTEX concentrations were evidenced, as for example the start of airplane engines. As field studies have shown, SPME technique appears as a method of choice for fast qualitative analysis and quantitative determination of Volatile Organic Compounds (VOC). The small dimensions of the SPME sampling system and the short sampling time let envisage its utilisation for the rapid diagnostic and the monitoring of indoor air quality. (author)

  19. Measurement of the specific heat of small vanadium particles in the normal- and superconducting state in the temperature range of 1.5-12 K

    International Nuclear Information System (INIS)

    Vergara Garcia, O.

    1982-01-01

    The specific heat of small crystalline vanadium particles in form of polyeders with diameters between 2.9 and 13.2 mm was measured in the temperature range of 1.5-12 K. Quantum effects are interpreted in the frame of theoretical models. (BEF)

  20. Empirical ranking of a wide range of WC-Co grades in terms of their abrasion resistance measured by the ASTM standard B 611-85 test

    CSIR Research Space (South Africa)

    O'Quigley, DGF

    1997-01-01

    Full Text Available This paper reports the results of a comprehensive investigation into the abrasion resistance of WC-Co alloys, as measured by the ASTM Standard B 611-85 test. The alloys ranged from 3 to 50 wt% and from 0.6 to 5 mu-m average grain size. Careful...

  1. Gamma-ray multiplicity measurements for the determination of the initial angular momentum ranges in normal and fast fission processes

    International Nuclear Information System (INIS)

    El Masri, Y.; Steckmeyer, J.C.; Martin, V.; Bizard, G.; Brou, R.; Laville, J.L.; Regimbart, R.; Tamain, B.; Peter, J.

    1990-01-01

    Gamma-ray multiplicities (first and second moments) have been measured, in the 220 MeV 20 Ne+ nat Re and 315 meV 40 Ar+ 165 Ho reactions, as a function of fission fragment masses and centre-of-mass total kinetic energies. The two reactions lead to the same fusion nucleus, 205 At, at the same excitation energy (167 MeV). The experimental critical angular momentum for the fission process in the Ne+Re system (91±3) ℎ is close to I Bf=0 (∝80 ℎ) while in the Ar+Ho reaction this critical angular momentum (136±4) ℎ is much larger than I Bf=0 value, favoring the occurrence of the fast fission process. The observed widths of the fission fragment mass distribution: (42±2) u in the Ne+Re system and (56±4) u in the Ar+Ho reaction strengthen this hypothesis. For both compound nucleus fission and fast fission components in Ar+Ho, the total spin values obtained in absolute magnitude and in their dependence on the mass asymmetry are well described by assuming rigid rotation of the fissioning complex and statistical excitation of some collective rotational modes such as 'Bending' and 'Wriggling' according to the Schmitt-Pacheco model. These modes, however, are not all fully excited, their degrees of excitation are approximately the same for both fission components. From theoretical estimates of equilibration times, one anticipates the 'Tilting' mode to be by far the last to be excited, and from its non-excitation in the present data together with the excitation of bending and wriggling, a time interval of about 10 -21 s to 2x10 -20 s can be derived for the reaction time of both normal fission and fast fission. (orig./HSI)

  2. Simultaneous determination of salicylic, 3-methyl salicylic, 4-methyl salicylic, acetylsalicylic and benzoic acids in fruit, vegetables and derived beverages by SPME-LC-UV/DAD.

    Science.gov (United States)

    Aresta, Antonella; Zambonin, Carlo

    2016-03-20

    Salicylic and benzoic acid are phenolic acids occurring in plant cells, thus they can be present in fruit and vegetables at various levels. They possess anti-inflammatory and antimicrobial properties, however they may induce symptoms and health problems in a small percentage of the population. Therefore, a low phenolic acid diet may be of clinical benefit to such individuals. In order to achieve this goal, the concentration of these substances in different food and beverages should be assessed. The present work describes for the first time a new method, based on solid phase microextraction (polydimethylsiloxane-divinylbenzene fiber) coupled to liquid chromatography with UV diode array detection, for the simultaneous determination of salicylic acid, 3-methyl salicylic acid, 4-methyl salicylic acid, acetylsalicylic acid and benzoic acid in selected fruit, vegetables and beverages. All the aspects influencing fiber adsorption (time, temperature, pH, salt addition) and desorption (desorption and injection time, desorption solvent mixture composition) of the analytes have been investigated. An isocratic separation was performed using an acetonitrile-phosphate buffer (pH 2.8; 2 mM) mixture (70:30, v/v) as the mobile phase. The estimated LOD and LOQ values (μg/mL) were in the range 0.002-0.028 and 0.007-0.095. The within-day and day-to-day precision values (RSD%) were between 4.7-6.1 and 6.6-9.4, respectively. The method has been successfully applied to the analysis of fava beans, blueberries, kiwi, tangerines, lemons, oranges and fruit juice (lemon and blueberry) samples. The major advantage of the method is that it only requires simple homogenization and/or centrifugation and dilution steps prior to SPME and injection in the LC system. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Characterization of fish sauce aroma-impact compounds using GC-MS, SPME-Osme-GCO, and Stevens' power law exponents.

    Science.gov (United States)

    Pham, A J; Schilling, M W; Yoon, Y; Kamadia, V V; Marshall, D L

    2008-05-01

    The objectives of this study were to characterize volatile compounds and to determine the characteristic aromas associated with impact compounds in 4 fish sauces using solid-phase micro-extraction, gas chromatography-mass spectrometry, Osme, and gas chromatography olfactometry (SPME-Osme-GCO) coupled with Stevens' Power Law. Compounds were separated using GCMS and GCO and were identified with the mass spectral database, aroma perceived at the sniffing port, retention indices, and verification of compounds by authentic standards in the GCMS and GCO. Aromas that were isolated and present in all 4 fish sauce samples at all concentrations included fishy (trimethylamine), pungent and dirty socks (combination of butanoic, pentanoic, hexanoic, and heptanoic acids), cooked rice and buttery popcorn (2,6-dimethyl pyrazine), and sweet and cotton candy (benzaldehyde). All fish sauces contained the same aromas as determined by GCO and GCMS (verified using authentic standard compounds), but the odor intensity associated with each compound or group of compounds was variable for different fish sauce samples. Stevens' Power Law exponents were also determined using this analytical technique, but exponents were not consistent for the same compounds that were found in all fish sauces. Stevens' Power Law exponents ranged from 0.14 to 0.37, 0.24 to 0.34, 0.09 to 0.21, and 0.10 to 0.35 for dirty socks, fishy, buttery popcorn, and sweet aromas, respectively. This demonstrates that there is variability in Stevens' Power Law exponents for odorants within fish sauce samples.

  4. Optimization of an analytical methodology for the determination of alkyl- and methoxy-phenolic compounds by HS-SPME in biomass smoke

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Francisco J.; Afonso, Ana M.; Gonzalez, Venerando; Ayala, Juan H. [University of La Laguna, Campus de Anchieta, Department of Analytical Chemistry, Nutrition and Food Science, La Laguna (Spain)

    2006-08-15

    A sampling and analysis method for the determination of 21 phenolic compounds in smoke samples from biomass combustion has been developed. The smoke is used to make smoked foods, following an artisanal procedure used in some parts of the Canary Islands. The sampling system consists of a Bravo H air sampler, two impingers, each one containing an aqueous solution of sodium hydroxide 0.1 mol L{sup -1}, followed by a silica gel trap. The variables optimized to reach the best sampling conditions were volume of absorbent solution and sampling flow. Under the optimum conditions, 100 mL of absorbent solution of NaOH 0.10 mol L{sup -1} and 2 L min{sup -1} for the sampling flow, sampling efficiencies are higher than 80%. Analysis of phenolic compounds was carried out by headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). Five different fiber coatings were employed in this study. By means of a central composite design, extraction time, salt concentration, and pH of the solution were optimized: 65-{mu}m carbowax-divinylbenzene, extraction time 90 min, concentration in NaCl of 35% (m/v), and pH 2 yielded the highest response. Detection limits of phenol and their alkyl derivatives, guaiacol and eugenol, are between 1.13 and 4.60 ng mL{sup -1}. 3-Methoxyphenol, 2,6-dimethoxyphenol, and vanillin have detection limits considerably higher. Good linearity (R {sup 2}{>=}0.98) was observed for all calibration curves in the established ranges. The reproducibility of the method (RSD, relative standard deviation) was found to oscillate between 7 and 18% (generally close or lower than 10%). (orig.)

  5. Detection of DDT and its metabolites in two estuaries of South China using a SPME-based device: First report of p,p'-DDMU in water column

    International Nuclear Information System (INIS)

    Xing Yuanna; Guo Ying; Xie Mei; Shen Rulang; Zeng, Eddy Y.

    2009-01-01

    A solid-phase microextration-based sampling method was employed to determine the concentrations of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (DDE) and 1-chloro-2,2-bis(p-chlorophenyl)ethene (DDMU), in two estuarine bays, Daya Bay and Hailing Bay, of South China. Six DDT components including p,p'-DDT, o,p'-DDD, p,p'-DDD, o,p'-DDE, p,p'-DDE, and p,p'-DDMU were detected in Hailing Bay, while only p,p'-DDD was found in Daya Bay. p,p'-DDD was the most abundant DDT component in both bays, sharply different from the previous finding in the water column of the Palos Verdes Shelf, California, USA that p,p'-DDE was prevalent. In addition, the occurrence of p,p'-DDMU (with a range of 0.047-0.21 ng/L in Hailing Bay) has not been reported around the globe, and its presence in our study region appeared to stem from dehydrochlorination of p,p'-DDD, favored under aerobic conditions, but further investigations are clearly needed to confirm the mechanism for generation of DDMU in estuarine environments. - DDT and its metabolites, particularly p,p'-DDMU, are detected in the water column of two estuarine bays in South China using a SPME-based sampler

  6. Alanine-EPR dosimetry for measurements of ionizing radiation absorbed doses in the range 0.5-10 kGy

    CERN Document Server

    Peimel-Stuglik, Z

    2001-01-01

    The usefulness of two, easy accessible alanine dosimeters (ALANPOL from IChTJ and foil dosimeter from Gamma Service, Radeberg, Germany) to radiation dose measurement in the range of 0.5-10 kGy, were investigated. In both cases, the result of the test was positive. The foil dosemeter from Gamma Service is recommended for dose distribution measurements in fantoms or products, ALANPOL - for routine measurements. The EPR-alanine method based on the described dosimeters can be successfully used, among others, in the technology of radiation protection of food.

  7. Photoacoustic and filter measurements related to aerosol light absorption during the Northern Front Range Air Quality Study (Colorado 1996/1997)

    Science.gov (United States)

    Moosmüller, H.; Arnott, W. P.; Rogers, C. F.; Chow, J. C.; Frazier, C. A.; Sherman, L. E.; Dietrich, D. L.

    1998-11-01

    A new photoacoustic instrument for the measurement of aerosol light absorption was collocated with conventional aerosol instrumentation during the 1996-1997 winter intensive monitoring period of the Northern Front Range Air Quality Study. Measurements of the light absorption efficiency for black carbon were 5 m2/g at 685 nm and 10 m2/g at 532 nm, and for elemental carbon, they were 3.6 m2/g at 685 nm. We show that these values together with previous photoacoustic measurements of aerosol light absorption shed some light on the wavelength dependence of absorption efficiency for carbonaceous aerosol in the visible and near-visible region. Integrating plate type filter measurements of aerosol light absorption result in far larger values than those measured with the photoacoustic instrument. We demonstrate that a recently published correction technique [Horvath, 1997] can yield improved agreement.

  8. Signature of biased range in the non-dynamical Chern-Simons modified gravity and its measurements with satellite-satellite tracking missions: theoretical studies

    Science.gov (United States)

    Qiang, Li-E.; Xu, Peng

    2015-08-01

    Having great accuracy in the range and range rate measurements, the GRACE mission and the planed GRACE follow on mission can in principle be employed to place strong constraints on certain relativistic gravitational theories. In this paper, we work out the range observable of the non-dynamical Chern-Simons modified gravity for the satellite-to-satellite tracking (SST) measurements. We find out that a characteristic time accumulating range signal appears in non-dynamical Chern-Simons gravity, which has no analogue found in the standard parity-preserving metric theories of gravity. The magnitude of this Chern-Simons range signal will reach a few times of cm for each free flight of these SST missions, here is the dimensionless post-Newtonian parameter of the non-dynamical Chern-Simons theory. Therefore, with the 12 years data of the GRACE mission, one expects that the mass scale of the non-dynamical Chern-Simons gravity could be constrained to be larger than eV. For the GRACE FO mission that scheduled to be launched in 2017, the much stronger bound that eV is expected.

  9. Determinação do coeficiente de atividade em diluição infinita de hidrocarbonetos em furfural a 298,15 K por SPME-GC/FID

    Directory of Open Access Journals (Sweden)

    Filipe Arantes Furtado

    2010-01-01

    Full Text Available In this work a new method (SPME-GC/FID was developed to analyze the activity of binary liquid mixtures. The purpose is to demonstrate that SPME is capable to be used to determinate activity coefficients at infinite dilution knowing the fiber properties, with a lower cost than the conventional methods encountered in literature such as GLC. The activity coefficients at infinite dilution in furfural for n-hexane, n-heptane and cyclohexane at 298.15 K was determined using SPME and deviations of literature data was about 7%.

  10. Volatile compound changes during shelf life of dried Boletus edulis: comparison between SPME-GC-MS and PTR-ToF-MS analysis.

    Science.gov (United States)

    Aprea, Eugenio; Romano, Andrea; Betta, Emanuela; Biasioli, Franco; Cappellin, Luca; Fanti, Marco; Gasperi, Flavia

    2015-01-01

    Drying process is commonly used to allow long time storage of valuable porcini mushrooms (Boletus edulis). Although considered a stable product dried porcini flavour changes during storage. Monitoring of volatile compounds during shelf life may help to understand the nature of the observed changes. In the present work two mass spectrometric techniques were used to monitor the evolution of volatile compounds during commercial shelf life of dried porcini. Solid phase microextraction (SPME) coupled to gas chromatography - mass spectrometry (GC-MS) allowed the identification of 66 volatile compounds, 36 of which reported for the first time, monitored during the commercial shelf life of dried porcini. Proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS) , a direct injection mass spectrometric technique, was shown to be a fast and sensitive instrument for the general monitoring of volatile compound evolution during storage of dried porcini. Furthermore, PTR-ToF-MS grants access to compounds whose determination would otherwise require lengthy pre-concentration and/or derivatization steps such as ammonia and small volatile amines. The two techniques, both used for the first time to study dried porcini, provided detailed description of time evolution of volatile compounds during shelf life. Alcohols, aldehydes, ketones and monoterpenes diminish during the storage while carboxylic acids, pyrazines, lactones and amines increase. The storage temperature modifies the rate of the observed changes influencing the final quality of the dried porcini. We showed the advantages of both techniques, suggesting a strategy to be adopted to follow time evolution of volatile compounds in food products during shelf life, based on the identification of compounds by GC-MS and the rapid time monitoring by PTR-ToF-MS measurements in order to maximize the advantages of both techniques. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Caracterización de los compuestos del aroma en rones colombianos por HS-SPME-GC-MS-O

    Directory of Open Access Journals (Sweden)

    Jazmín Osorio Monsalve

    2016-11-01

    Full Text Available Se identificaron por primera vez 46 compuestos volátiles olfativamente activos con actividad aromática significativa presentes en rones comerciales de Colombia. Lo anterior, mediante microextracción en fase sólida en modo espacio de cabeza (HS-SPME, acoplada a cromatografía de gases con detectores de espectrometría de masas y olfatometría (GC-MS-O. Dentro de los compuestos identificados se encuentran ésteres, compuestos aromáticos, alcoholes, acetales, lactonas y furfural. De esos 46 compuestos, nueve están presentes en todos los rones estudiados y algunos otros son característicos solo de la marca.

  12. Phytoscreening for chlorinated solvents using rapid in vitro SPME sampling: Application to urban plume in Verl, Germany

    Science.gov (United States)

    Limmer, M.A.; Balouet, J.-C.; Karg, F.; Vroblesky, D.A.; Burken, J.G.

    2011-01-01

    Rapid detection and delineation of contaminants in urban settings is critically important in protecting human health. Cores from trees growing above a plume of contaminated groundwater in Verl, Germany, were collected in 1 day, with subsequent analysis and plume mapping completed over several days. Solid-phase microextraction (SPME) analysis was applied to detect tetrachloroethene (PCE) and trichloroethene (TCE) to below nanogram/liter levels in the transpiration stream of the trees. The tree core concentrations showed a clear areal correlation to the distribution of PCE and TCE in the groundwater. Concentrations in tree cores were lower than the underlying groundwater, as anticipated; however, the tree core water retained the PCE:TCE signature of the underlying groundwater in the urban, populated area. The PCE:TCE ratio can indicate areas of differing degradation activity. Therefore, the phytoscreening analysis was capable not only of mapping the spatial distribution of groundwater contamination but also of delineating zones of potentially differing contaminant sources and degradation. The simplicity of tree coring and the ability to collect a large number of samples in a day with minimal disruption or property damage in the urban setting demonstrates that phytoscreening can be a powerful tool for gaining reconnaissance-level information on groundwater contaminated by chlorinated solvents. The use of SPME decreases the detection level considerably and increases the sensitivity of phytoscreening as an assessment, monitoring, and phytoforensic tool. With rapid, inexpensive, and noninvasive methods of detecting and delineating contaminants underlying homes, as in this case, human health can be better protected through screening of broader areas and with far faster response times. ?? 2011 American Chemical Society.

  13. X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility.

    Science.gov (United States)

    Reverdin, Charles; Thais, Frédéric; Loisel, Guillaume; Busquet, M; Bastiani-Ceccotti, S; Blenski, T; Caillaud, T; Ducret, J E; Foelsner, W; Gilles, D; Gilleron, F; Pain, J C; Poirier, M; Serres, F; Silvert, V; Soullie, G; Turck-Chieze, S; Villette, B

    2012-10-01

    An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution ∼ 50. It has been used at the LULI-2000 laser facility at École Polytechnique (France) to measure the Δn = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

  14. X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility

    International Nuclear Information System (INIS)

    Reverdin, Charles; Caillaud, T.; Gilleron, F.; Pain, J. C.; Silvert, V.; Soullie, G.; Villette, B.; Thais, Frédéric; Loisel, Guillaume; Blenski, T.; Poirier, M.; Busquet, M.; Bastiani-Ceccotti, S.; Serres, F.; Ducret, J. E.; Foelsner, W.; Gilles, D.; Turck-Chieze, S.

    2012-01-01

    An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution ∼ 50. It has been used at the LULI-2000 laser facility at École Polytechnique (France) to measure the Δn = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

  15. Measurement of angularly dependent spectra of betatron gamma-rays from a laser plasma accelerator with quadrant-sectored range filters

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Rhee, Yong Joo; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Shin, Jung Hun; Yoo, Byung Ju; Jo, Sung Ha; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 61005 (Korea, Republic of); Hojbota, Calin; Bae, Lee Jin; Jung, Jaehyung; Cho, Min Sang; Cho, Byoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 61005 (Korea, Republic of)

    2016-07-15

    Measurement of angularly dependent spectra of betatron gamma-rays radiated by GeV electron beams from laser wakefield accelerators (LWFAs) are presented. The angle-resolved spectrum of betatron radiation was deconvolved from the position dependent data measured for a single laser shot with a broadband gamma-ray spectrometer comprising four-quadrant sectored range filters and an unfolding algorithm, based on the Monte Carlo code GEANT4. The unfolded gamma-ray spectra in the photon energy range of 0.1–10 MeV revealed an approximately isotropic angular dependence of the peak photon energy and photon energy-integrated fluence. As expected by the analysis of betatron radiation from LWFAs, the results indicate that unpolarized gamma-rays are emitted by electrons undergoing betatron motion in isotropically distributed orbit planes.

  16. X-ray extended-range technique for precision measurement of the x-ray mass attenuation coefficient and IM(F) for copper using synchrotron radiation

    International Nuclear Information System (INIS)

    Tran, C.Q.; Paterson, D.; Barnea, Z.; Cookson, D.J.; Chantler, C.T.

    2000-01-01

    Full text: Complex X-ray form factors are used in crystallography, material science, medical diagnosis refractive index studies and XAFS. We introduce the X-ray Extended-Range Technique for measurements of the imaginary component of the atomic form factor. We achieve accuracies of 0.27%-0.5% for copper from 8.84 keV to 20 keV. Discrepancies between measurements using earlier experimental techniques are 10%. We achieve reproducibility of 0.02%. New methods of computation are required to approach the accuracy of our data. Results probe the transform of atomic orbital wavefunctions and long-range order. Discrepancies of order 10% between current theory and experiments can be addressed

  17. X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility

    Energy Technology Data Exchange (ETDEWEB)

    Reverdin, Charles; Caillaud, T.; Gilleron, F.; Pain, J. C.; Silvert, V.; Soullie, G.; Villette, B. [CEA, DAM, DIF, 91297 Arpajon (France); Thais, Frederic; Loisel, Guillaume; Blenski, T.; Poirier, M. [CEA, DSM, IRAMIS, Service Photons, Atomes et Molecules, 91191 Gif-sur-Yvette (France); Busquet, M. [ARTEP Inc, Ellicott City, Maryland 21042 (United States); Bastiani-Ceccotti, S.; Serres, F. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); Ducret, J. E. [CELIA, UMR5107, CEA, CNRS, Universite de Bordeaux, 33400 Talence (France); Foelsner, W. [Max Planck Instituet fuer Quantum Optik, 85748 Garching (Germany); Gilles, D.; Turck-Chieze, S. [CEA, DSM, IRFU, Service d' astrophysique, 91191 Gif-sur-Yvette (France)

    2012-10-15

    An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution {approx} 50. It has been used at the LULI-2000 laser facility at Ecole Polytechnique (France) to measure the {Delta}n = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

  18. Accurate and stable equal-pressure measurements of water vapor transmission rate reaching the 10-6 g m-2 day-1 range

    Science.gov (United States)

    Nakano, Yoichiro; Yanase, Takashi; Nagahama, Taro; Yoshida, Hajime; Shimada, Toshihiro

    2016-10-01

    The water vapor transmission rate (WVTR) of a gas barrier coating is a critically important parameter for flexible organic device packaging, but its accurate measurement without mechanical stress to ultrathin films has been a significant challenge in instrumental analysis. At the current stage, no reliable results have been reported in the range of 10-6 g m-2 day-1 that is required for organic light emitting diodes (OLEDs). In this article, we describe a solution for this difficult, but important measurement, involving enhanced sensitivity by a cold trap, stabilized temperature system, pumped sealing and calibration by a standard conductance element.

  19. Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range

    Energy Technology Data Exchange (ETDEWEB)

    Canada, J.; Maj, A. [Departamento de Termodinamica Aplicada, Universidad Politecnica de Valencia, Camino de Vera, s/n. 46022 Valencia (Spain); Utrillas, M.P.; Martinez-Lozano, J.A.; Pedros, R.; Gomez-Amo, J.L. [Departamento de Fisica de la Tierra y Termodinamica, Facultat de Fisica, Universitat de Valencia, 46100 Burjassot (Valencia) (Spain)

    2007-10-15

    An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectro radiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330-1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth. (author)

  20. Measurement of secondary neutrons and gamma rays produced by neutron interactions in aluminum over the incident energy range 1 to 20 MeV

    International Nuclear Information System (INIS)

    Morgan, G.L.

    1975-11-01

    The spectra of secondary neutrons and gamma rays produced by neutron interaction in a thin sample (approximately 1/6 mean free path) of aluminum have been measured as a function of the incident neutron energy over the range 1 to 20 MeV. Data were taken at an angle of 125 0 . A linac (ORELA) was used as a neutron source with a 47-m flight path. Incident energy was determined by time-of-flight, while secondary spectra were determined by pulse-height unfolding techniques. The results of the measurements are presented in forms suitable for comparison to calculations based on the evaluated data files. (6 tables, 4 figures)