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Sample records for large-volume injections coupled

  1. Targeted Screening and Quantification of dl-PCBs and Dioxins in Various Foodstuffs by Programmed-temperature Vaporizer Large-volume Injection Coupled to GC-MS.

    PubMed

    Ho, Ngoc Huy; Bugey, Aurélie; Zimmerli, Pierre; Nançoz, Joëlle; Ortelli, Didier; Edder, Patrick

    2014-10-01

    In 2009, high concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) were found in soils located near the municipal garbage incinerator of Geneva. The matter of food contamination in this area was raised. Based on exposure criteria, a strategy of analysis of animal fats has been established with farmers in the Geneva area. Most methods of analysis of dl-PCBs, dioxins and furans, are based on gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS) and considered as the reference methodology. An innovative approach was developed by programmed-temperature vaporizer large-volume injection (PTV-LV) and gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS) analysis. This analytical method was validated and was found suitable for screening and quantification of target compounds in animal fats (beef, pork, sheep, etc. ). PTV-LV coupled to GC-MS/MS appeared to be a good alternative compared to the GC-HRMS strategy, offering a good compromise between sensitivity, versatility of instrumentation, and economical aspects. A survey of 121 samples was conducted.

  2. Dispersive liquid-liquid microextraction for the determination of phenols by acetonitrile stacking coupled with sweeping-micellar electrokinetic chromatography with large-volume injection.

    PubMed

    He, Hui; Liu, Shuhui; Meng, Zhaofu; Hu, Shibing

    2014-09-26

    The current routes to couple dispersive liquid-liquid microextraction (DLLME) with capillary electrophoresis (CE) are evaporation of water immiscible extractants and backextraction of analytes. The former is not applicable to extractants with high boiling points, the latter being effective only for acidic or basic analytes, both of which limit the further application of DLLME-CE. In this study, with 1-octanol as a model DLLME extractant and six phenols as model analytes, a novel method based on acetonitrile stacking and sweeping is proposed to accomplish large-volume injection of 1-octanol diluted with a solvent-saline mixture before micellar electrokinetic chromatography. Brij-35 and β-cyclodextrin were employed as pseudostationary phases for sweeping and also for improving the compatibility of sample zone and aqueous running buffer. A short solvent-saline plug was used to offset the adverse effect of the water immiscible extractant on focusing efficiency. The key parameters affecting separation and concentration were systematically optimized; the effect of Brij-35 and 1-octanol on focusing mechanism was discussed. Under the optimized conditions, with ∼ 30-fold concentration enrichment by DLLME, the diluted extractant (8×) was then injected into the capillary with a length of 21 cm (42% of the total length), which yielded the overall improvements in sensitivity of 170-460. Limits of detection and qualification ranged from 0.2 to 1.0 ng/mL and 1.0 to 3.4 g/mL, respectively. Acceptable repeatability lower than 3.0% for migration time and 9.0% for peak areas were obtained. The developed method was successfully applied for analysis of the phenol pollutants in real water samples.

  3. [Determination of trace and ultra-trace level bromate in water by large volume sample injection with enrichment column for on-line preconcentration coupled with ion chromatography].

    PubMed

    Liu, Jing; He, Qingqing; Yang, Lili; Hu, Enyu; Wang, Meifei

    2015-10-01

    A method for the determination of trace and ultra-trace level bromate in water by ion chromatography with large volume sample injection for on-line preconcentration was established. A high capacity Dionex IonPac AG23 guard column was simply used as the enrichment column instead of the loop for the preconcentration of bromate. High purity KOH solution used as eluent for gradient elution was on-line produced by an eluent generator automatically. The results showed that a good linear relationship of bromate was exhibited in the range of 0.05-51.2 μg/L (r ≥ 0.999 5), and the method detection limit was 0.01 μg/L. Compared with conventional sample injection, the injection volume was up to 5 mL, and the enrichment factor of this method was about 240 times. This method was successfully applied for several real samples of pure water which were purchased in the supermarket, and the recoveries of bromate were between 90%-100% with the RSDs (n = 6) of 2.1%-6.4% at two spiked levels. This method without pretreatment is simple, and of high accuracy and precision. The preconcentration can be achieved by large volume sample injection. It is suitable for the analysis of trace and ultra-trace level bromate.

  4. Large volume injection in ion chromatography Separation of rubidium and strontium for on-line inductively coupled plasma mass spectrometry determination of strontium isotope ratios.

    PubMed

    García-Ruiz, Silvia; Moldovan, Mariella; García Alonso, J Ignacio

    2007-05-18

    Large volume injection, up to 5 mL, was evaluated and optimised for the on-line ion chromatographic separation of Rb and Sr before ICP-MS measurement of Sr isotope ratios. Flat-topped chromatographic peaks, ideally suited for multicollector ICP-MS isotope ratio measurements, could be obtained when the composition of the mobile phase (nitric acid and 18-crown-6 ether) was identical to the matrix of the sample. Under those conditions rubidium eluted at the dead volume of the column while strontium produced a flat-topped transient signal with several minutes of stable plateau. On-line data acquisition during several minutes at the plateau of Sr signal allowed high precision Sr isotope ratio measurement. The developed procedure was evaluated for Sr isotope ratio measurements on different types of samples, including cider, apples, apple leaves, and soil extracts, in the frame of a long-term project aiming at origin authentication using strontium isotope ratio measurements. It was observed that sample matrix caused broadening of the strontium chromatographic peak and loss of flat-topped peak profile. Under those circumstances the addition of the complexing crown-ether 18-crown-6 both to samples and chromatographic eluent provided two distinct advantages. First, a drastic increase in the retention of strontium was observed which could be modulated by increasing the concentration of nitric acid in the eluent up to 900 mM. This increase in the eluent HNO(3) concentration allowed the application of the method to acid soil digests and other high acidity samples. Second, the matrix of the sample did not affect any more the chromatographic peak profile and similar chromatographic separations could be obtained for samples and standards maintaining the flat-topped Sr peak profile. Sample preparation consisted of a simple 1:10 dilution of the cider or pre-treated solid samples by adding HNO(3) (900 mM) and 18-crown-6 ether (5mM) to obtain similar composition in the sample solution

  5. Multisystem organ failure after large volume injection of castor oil.

    PubMed

    Smith, Silas W; Graber, Nathan M; Johnson, Rudolph C; Barr, John R; Hoffman, Robert S; Nelson, Lewis S

    2009-01-01

    We report a case of multisystem organ failure after large volume subcutaneous injection of castor oil for cosmetic enhancement. An unlicensed practitioner injected 500 mL of castor oil bilaterally to the hips and buttocks of a 28-year-old male to female transsexual. Immediate local pain and erythema were followed by abdominal and chest pain, emesis, headache, hematuria, jaundice, and tinnitus. She presented to an emergency department 12 hours postinjection. Persistently hemolyzed blood samples complicated preliminary laboratory analysis. She rapidly deteriorated despite treatment and developed fever, tachycardia, hemolysis, thrombocytopenia, hepatitis, respiratory distress, and anuric renal failure. An infectious diseases evaluation was negative. After intensive supportive care, including mechanical ventilation and hemodialysis, she was discharged 11 days later, requiring dialysis for an additional 1.5 months. Castor oil absorption was inferred from recovery of the Ricinus communis biomarker, ricinine, in the patient's urine (41 ng/mL). Clinicians should anticipate multiple complications after unapproved methods of cosmetic enhancement.

  6. Determination of dioxin-like polychlorinated biphenyls in 1 mL whole blood using programmable temperature vaporization large volume injection coupled to gas chromatogram and high-resolution mass spectrometry.

    PubMed

    Shen, Haitao; Guan, Rongfa; Li, Jingguang; Zhang, Lei; Ren, Yiping; Xu, Xiaomin; Song, Yang; Zhao, Yunfeng; Han, Jianlong; Wu, Yongning

    2013-03-12

    A sensitive method based on programmable temperature vaporization large volume injection coupled to gas chromatogram and high-resolution mass spectrometry (PTV-GC-HRMS) has been developed for the determination of ultra trace levels of dioxin-like polychlorinated biphenyls (DL PCBs) in small amounts of human blood. Blood samples (1mL) were first extracted by column extraction and then purified with column chromatorgraphies. Final extracts (20μL) were introduced to the PTV injector under the solvent vent mode and detected by GC-HRMS (SIM mode). PTV parameters were observed by changing one factor at a time (practical conditions: vent flow: 50mLmin(-1), vent pressure: 0kPa and vent time: 0.1min), recoveries of most PCB congeners ranged from 55.1% to 108%, and method detection limits were in the range of 0.11-1.63pgg(-1).

  7. Selective determination of estrogenic compounds in water by microextraction by packed sorbents and a molecularly imprinted polymer coupled with large volume injection-in-port-derivatization gas chromatography-mass spectrometry.

    PubMed

    Prieto, A; Vallejo, A; Zuloaga, O; Paschke, A; Sellergen, B; Schillinger, E; Schrader, S; Möder, M

    2011-10-03

    A fully automated protocol consisting of microextraction by packed sorbents (MEPS) coupled with large volume injection-in-port-derivatization-gas chromatography-mass spectrometry (LVI-derivatization-GC-MS) was developed to determine endocrine disrupting compounds (EDCs) such as alkylphenols, bisphenol A, and natural and synthetic hormons in river and waste water samples. During method optimization, the extraction parameters as ion strength of the water sample, the MEPS extraction regime, the volume of organic solvent used for the elution/injection step, the type of elution solvents and the selectivity of the sorbents were studied. For optimum in-port-derivatization, 10 μL of the derivatization reagent N,O-bis(trimethylsilyl)triufloroacetamide with 1% of trimethylchlorosilane (BSTFA+1% TMCS) was used. 17β-Estradiol-molecularly imprinted polymer (MIP) and silica gel (modified with C-18) sorbents were examined for the enrichment of the target analytes from water samples and the obtained results revealed the high selectivity of the MIP material for extraction of substances with estrogen-like structures. Recovery values for most of the analytes ranged from 75 to 109% for the C18 sorbent and from 81 to 103% for the MIP material except for equilin (on C18 with only 57-66% recovery). Precision (n=4) of the entire analysis protocol ranged between 4% and 22% with both sorbents. Limits of detection (LODs) were at the low ngL(-1) level (0.02-87, C18 and 1.3-22, MIP) for the target analytes.

  8. Determination of polycyclic and nitro musks in environmental water samples by means of microextraction by packed sorbents coupled to large volume injection-gas chromatography-mass spectrometry analysis.

    PubMed

    Cavalheiro, J; Prieto, A; Monperrus, M; Etxebarria, N; Zuloaga, O

    2013-04-22

    In this work the development and validation of a new procedure for the simultaneous determination of 9 nitro and polycyclic musk compounds: musk ambrette (MA), musk ketone (MK), musk mosken (MM), celestolide (ADBI), phantolide (AHMI), tonalide (AHTN), traseolide (ATII), cashmeran (DPMI) and galaxolide (HHCB) in environmental water samples (estuarine and wastewater) using microextraction by packed sorbent (MEPS) followed by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS) was carried out. Apart from the optimization of the different variables affecting MEPS (i.e., nature of the sorbent, nature of the solvent elution, sample load, and elution/injection volume) extraction recovery was also evaluated, not only for water samples but also for environmental water matrices such as estuarine and waste water. The use of two deuterated analogs ([(2)H3]-AHTN and [(2)H15]-MX) was successfully evaluated in order to correct matrix effect in complex environmental matrices such as influent samples from wastewater treatment plants. Method detection limits (MDLs) ranged from 5 to 25 ng L(-1), 7 to 39 ng L(-1) and 8 to 84 ng L(-1) for influent, effluent and estuarine samples, respectively. Apparent recoveries were higher than 75% for all target compounds in all the matrices studied (estuarine water and wastewater) and the precision of the method, calculated as relative standard deviation (RSD), was below 13.2% at 200 ng L(-1) concentration level and below 14.9% at low level (20 ng L(-1) for all the target analytes, except for AHTN which was set at 40 ng L(-1) and HHCB at 90 ng L(-1), due to the higher MDL values presented by those target compounds). Finally, this MEPS procedure was applied to the determination of the target analytes in water samples, including estuarine and wastewater, from two estuaries, Urdaibai (Spain) and Adour (France) and an established stir-bar sorptive extraction-liquid desorption/large volume injection-gas chromatography

  9. Determination of organic priority pollutants and emerging compounds in wastewater and snow samples using multiresidue protocols on the basis of microextraction by packed sorbents coupled to large volume injection gas chromatography-mass spectrometry analysis.

    PubMed

    Prieto, A; Schrader, S; Moeder, M

    2010-09-17

    This paper describes the development and validation of a new procedure for the simultaneous determination of 41 multi-class priority and emerging organic pollutants in water samples using microextraction by packed sorbent (MEPS) followed by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). Apart from method parameter optimization the influence of humic acids as matrix components on the extraction efficiency of MEPS procedure was also evaluated. The list of target compounds includes polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), phthalate esters (PEs), nonylphenols (NPs), bisphenol A (BPA) and selected steroid hormones. The performance of the new at-line microextraction-LVI-GC-MS protocol was compared to standard solid-phase extraction (SPE) and LVI-GC-MS analysis. LODs for 100 mL samples (SPE) ranged from 0.2 to 736 ng L(-1) were obtained. LODs for 800 microL of sample (MEPS) were between 0.2 and 266 ng L(-1). In the case of MEPS methodology even a sample volume of only 800 microL allowed to detect the target compounds. These results demonstrate the high sensitivity of both procedures which permitted to obtain good recoveries (>75%) for all cases. The precision of the methods, calculated as relative standard deviation (RSD) was below 21% for all compounds and both methodologies. Finally, the developed methods were applied to the determination of target analytes in various samples, including snow and wastewater.

  10. Understanding Subcutaneous Tissue Pressure for Engineering Injection Devices for Large-Volume Protein Delivery.

    PubMed

    Doughty, Diane V; Clawson, Corbin Z; Lambert, William; Subramony, J Anand

    2016-07-01

    Subcutaneous injection allows for self-administration of monoclonal antibodies using prefilled syringes, autoinjectors, and on-body injector devices. However, subcutaneous injections are typically limited to 1 mL due to concerns of injection pain from volume, viscosity, and formulation characteristics. Back pressure can serve as an indicator for changes in subcutaneous mechanical properties leading to pain during injection. The purpose of this study was to investigate subcutaneous pressures and injection site reactions as a function of injection volume and flow rate. A pressure sensor in the fluid path recorded subcutaneous pressures in the abdomen of Yorkshire swine. The subcutaneous tissue accommodates large-volume injections and with little back pressure as long as low flow rates are used. A 1 mL injection in 10 seconds (360 mL/h flow rate) generated a pressure of 24.0 ± 3.4 kPa, whereas 10 mL delivered in 10 minutes (60 mL/h flow rate) generated a pressure of 7.4 ± 7.8 kPa. After the injection, the pressure decays to 0 over several seconds. The subcutaneous pressures and mechanical strain increased with increasing flow rate but not increasing dose volume. These data are useful for the design of injection devices to mitigate back pressure and pain during subcutaneous large-volume injection. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  11. A dynamical mechanism for large volumes with consistent couplings

    NASA Astrophysics Data System (ADS)

    Abel, Steven

    2016-11-01

    A mechanism for addressing the "decompactification problem" is proposed, which consists of balancing the vacuum energy in Scherk-Schwarzed theories against contributions coming from non-perturbative physics. Universality of threshold corrections ensures that, in such situations, the stable minimum will have consistent gauge couplings for any gauge group that shares the same N = 2 beta function for the bulk excitations as the gauge group that takes part in the minimisation. Scherk-Schwarz compactification from 6D to 4D in heterotic strings is discussed explicitly, together with two alternative possibilities for the non-perturbative physics, namely metastable SQCD vacua and a single gaugino condensate. In the former case, it is shown that modular symmetries gives various consistency checks, and allow one to follow soft-terms, playing a similar role to R-symmetry in global SQCD. The latter case is particularly attractive when there is nett Bose-Fermi degeneracy in the massless sector. In such cases, because the original Casimir energy is generated entirely by excited and/or non-physical string modes, it is completely immune to the non-perturbative IR physics. Such a separation between UV and IR contributions to the potential greatly simplifies the analysis of stabilisation, and is a general possibility that has not been considered before.

  12. Peak distortions arising from large-volume injections in supercritical fluid chromatography.

    PubMed

    Dai, Yun; Li, Geng; Rajendran, Arvind

    2015-05-01

    Preparative separations in supercritical fluid chromatography (SFC) involve the injection of large volumes of the solute. In SFC, the mobile phase is typically high pressure CO2+modifier and the solute to be injected is usually dissolved in the modifier. Two-types of injection methods, modifier-stream and mixed-stream, are common in commercial preparative SFC systems. In modifier-stream injection, the injection is made in the modifier stream which is later mixed with the CO2 stream, while in the mixed-stream injection, the injection is made in a mixed CO2+modifier stream. In this work a systematic experimental and modelling study of the two techniques is reported using single-enantiomers of flurbiprofen on Chiralpak AD-H with CO2+methanol as the mobile phase. While modifier-stream injection shows non-distorted peaks, mixed-stream injection results in severe peak-distortion. By comparing the modelling and experimental results, it is shown that the modifier "plug" introduced in the mixed-stream injection is the primary cause of the peak distortions. The experimental results also point to the possible existence of viscous fingering which contributes to further peak distortion.

  13. Large-volume flux closure during plasmoid-mediated reconnection in coaxial helicity injection

    SciTech Connect

    Ebrahimi, F.; Raman, R.

    2016-03-23

    A large-volume flux closure during transient coaxial helicity injection (CHI) in NSTX-U is demonstrated through resistive magnetohydrodynamics (MHD) simulations. Several major improvements, including the improved positioning of the divertor poloidal field coils, are projected to improve the CHI start-up phase in NSTX-U. Simulations in the NSTX-U configuration with constant in time coil currents show that with strong flux shaping the injected open field lines (injector flux) rapidly reconnect and form large volume of closed flux surfaces. This is achieved by driving parallel current in the injector flux coil and oppositely directed currents in the flux shaping coils to form a narrow injector flux footprint and push the injector flux into the vessel. As the helicity and plasma are injected into the device, the oppositely directed field lines in the injector region are forced to reconnect through a local Sweet-Parker type reconnection, or to spontaneously reconnect when the elongated current sheet becomes MHD unstable to form plasmoids. In these simulations for the first time, it is found that the closed flux is over 70% of the initial injector flux used to initiate the discharge. Furthermore, these results could work well for the application of transient CHI in devices that employ super conducting coils to generate and sustain the plasma equilibrium.

  14. Large-volume flux closure during plasmoid-mediated reconnection in coaxial helicity injection

    DOE Data Explorer

    Ebrahimi, F. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Raman, R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2016-04-01

    A large-volume flux closure during transient coaxial helicity injection (CHI) in NSTX-U is demonstrated through resistive magnetohydrodynamics (MHD) simulations. Several major improvements, including the improved positioning of the divertor poloidal field coils, are projected to improve the CHI start-up phase in NSTX-U. Simulations in the NSTX-U configuration with constant in time coil currents show that with strong flux shaping the injected open field lines (injector flux) rapidly reconnect and form large volume of closed flux surfaces. This is achieved by driving parallel current in the injector flux coil and oppositely directed currents in the flux shaping coils to form a narrow injector flux footprint and push the injector flux into the vessel. As the helicity and plasma are injected into the device, the oppositely directed field lines in the injector region are forced to reconnect through a local Sweet–Parker type reconnection, or to spontaneously reconnect when the elongated current sheet becomes MHD unstable to form plasmoids. In these simulations for the first time, it is found that the closed flux is over 70% of the initial injector flux used to initiate the discharge. These results could work well for the application of transient CHI in devices that employ super conducting coils to generate and sustain the plasma equilibrium.

  15. Large-volume flux closure during plasmoid-mediated reconnection in coaxial helicity injection

    DOE Data Explorer

    Ebrahimi, Fatima [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)] (ORCID:0000000331095367); Raman, Roger [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)] (ORCID:0000000220273271)

    2016-01-01

    A large-volume flux closure during transient coaxial helicity injection (CHI) in NSTX-U is demonstrated through resistive magnetohydrodynamics (MHD) simulations. Several major improvements, including the improved positioning of the divertor poloidal field coils, are projected to improve the CHI start-up phase in NSTX-U. Simulations in the NSTX-U configuration with constant in time coil currents show that with strong flux shaping the injected open field lines (injector flux) rapidly reconnect and form large volume of closed flux surfaces. This is achieved by driving parallel current in the injector flux coil and oppositely directed currents in the flux shaping coils to form a narrow injector flux footprint and push the injector flux into the vessel. As the helicity and plasma are injected into the device, the oppositely directed field lines in the injector region are forced to reconnect through a local Sweet–Parker type reconnection, or to spontaneously reconnect when the elongated current sheet becomes MHD unstable to form plasmoids. In these simulations for the first time, it is found that the closed flux is over 70% of the initial injector flux used to initiate the discharge. These results could work well for the application of transient CHI in devices that employ super conducting coils to generate and sustain the plasma equilibrium.

  16. Large-volume flux closure during plasmoid-mediated reconnection in coaxial helicity injection

    DOE PAGES

    Ebrahimi, F.; Raman, R.

    2016-03-23

    A large-volume flux closure during transient coaxial helicity injection (CHI) in NSTX-U is demonstrated through resistive magnetohydrodynamics (MHD) simulations. Several major improvements, including the improved positioning of the divertor poloidal field coils, are projected to improve the CHI start-up phase in NSTX-U. Simulations in the NSTX-U configuration with constant in time coil currents show that with strong flux shaping the injected open field lines (injector flux) rapidly reconnect and form large volume of closed flux surfaces. This is achieved by driving parallel current in the injector flux coil and oppositely directed currents in the flux shaping coils to form amore » narrow injector flux footprint and push the injector flux into the vessel. As the helicity and plasma are injected into the device, the oppositely directed field lines in the injector region are forced to reconnect through a local Sweet-Parker type reconnection, or to spontaneously reconnect when the elongated current sheet becomes MHD unstable to form plasmoids. In these simulations for the first time, it is found that the closed flux is over 70% of the initial injector flux used to initiate the discharge. Furthermore, these results could work well for the application of transient CHI in devices that employ super conducting coils to generate and sustain the plasma equilibrium.« less

  17. Capillary gas chromatographic analysis of nerve agents using large volume injections.

    PubMed

    Degenhardt-Langelaan, C E; Kientz, C E

    1996-02-02

    The use of large volume injections has been studied for the verification of intact organophosphorus chemical warfare agents in water samples. As the use of ethyl acetate caused severe detection problems new potential solvents were evaluated. With the developed procedure, the nerve agents sarin, tabun, soman, DFP and VX can be determined in freshly prepared water samples at ppt levels. Except for the nerve agent tabun all other agents added to the water samples were still present after 8 days at 20-60% levels, if the pH of the water sample is adjusted to ca. 5 shortly after sampling and adjusted to pH 7 for analysis.

  18. Trace analysis of environmental matrices by large-volume injection and liquid chromatography-mass spectrometry.

    PubMed

    Busetti, Francesco; Backe, Will J; Bendixen, Nina; Maier, Urs; Place, Benjamin; Giger, Walter; Field, Jennifer A

    2012-01-01

    The time-honored convention of concentrating aqueous samples by solid-phase extraction (SPE) is being challenged by the increasingly widespread use of large-volume injection (LVI) liquid chromatography-mass spectrometry (LC-MS) for the determination of traces of polar organic contaminants in environmental samples. Although different LVI approaches have been proposed over the last 40 years, the simplest and most popular way of performing LVI is known as single-column LVI (SC-LVI), in which a large-volume of an aqueous sample is directly injected into an analytical column. For the purposes of this critical review, LVI is defined as an injected sample volume that is ≥10% of the void volume of the analytical column. Compared with other techniques, SC-LVI is easier to set up, because it requires only small hardware modifications to existing autosamplers and, thus, it will be the main focus of this review. Although not new, SC-LVI is gaining acceptance and the approach is emerging as a technique that will render SPE nearly obsolete for many environmental applications. In this review, we discuss: the history and development of various forms of LVI; the critical factors that must be considered when creating and optimizing SC-LVI methods; and typical applications that demonstrate the range of environmental matrices to which LVI is applicable, for example drinking water, groundwater, and surface water including seawater and wastewater. Furthermore, we indicate direction and areas that must be addressed to fully delineate the limits of SC-LVI.

  19. ANALYSIS OF LOW-LEVEL PESTICIDES FROM HIGH-ELEVATION LAKE WATERS BY LARGE VOLUME INJECTION GCMS

    EPA Science Inventory

    This paper describes the method development for the determination of ultra-low level pesticides from high-elevation lake waters by large-volume injection programmable temperature vaporizer (LVI-PTV) GC/MS. This analytical method is developed as a subtask of a larger study, backgr...

  20. ANALYSIS OF LOW-LEVEL PESTICIDES FROM HIGH-ELEVATION LAKE WATERS BY LARGE VOLUME INJECTION GCMS

    EPA Science Inventory

    This paper describes the method development for the determination of ultra-low level pesticides from high-elevation lake waters by large-volume injection programmable temperature vaporizer (LVI-PTV) GC/MS. This analytical method is developed as a subtask of a larger study, backgr...

  1. Fast determination of 40 drugs in water using large volume direct injection liquid chromatography-tandem mass spectrometry.

    PubMed

    Boix, Clara; Ibáñez, María; Sancho, Juan V; Rambla, Javier; Aranda, José L; Ballester, Salomé; Hernández, Félix

    2015-01-01

    This work describes a rapid analytical method based on direct sample injection of water samples for the simultaneous identification/quantification of 40 emerging compounds, including pharmaceuticals and drugs of abuse. The water samples were analyzed by ultra-high-performance liquid chromatography coupled to hybrid triple quadrupole mass spectrometer (UHPLC-MS/MS QqQ). Taking profit of the increasing sensitivity of nowadays tandem mass spectrometers, direct sample injection of large volumes has been an attractive alternative to pre-concentration steps. In this work, the developed methodology has been validated at three concentration levels (10, 100 and 1000 ng/L) in 10 different water samples of different types (5 effluent wastewater and 5 surface water samples). The majority of compounds could be satisfactory validated at these concentrations, showing good recoveries and precision. With only few exceptions, the limits of quantification (LOQs), estimated from the sample chromatogram at lowest spiked level tested, were below 3 ng/L. The method was applied to the analysis of 10 effluent wastewater and 10 surface water samples. Venlafaxine was the compound most frequently detected (80%) in surface water, followed by acetaminophen (70%). Regarding effluent wastewater, valsartan and 4-acetyl aminoantipyrine were detected in 9 out of 10 samples analyzed. These two compounds together with 4-formyl aminoantipyrine and naproxen showed the highest concentrations (>2000 ng/L). In these cases, a dilution step was required for a correct quantification. As an additional evaluation of the method performance, the same water samples were analyzed in another laboratory by a second analytical methodology, based on on-line solid-phase-extraction coupled to LC-MS/MS (QqQ).

  2. Chronic daily intrathecal injections of a large volume of fluid increase mast cells in the thalamus of mice.

    PubMed

    Taiwo, Oludare B; Kovács, Katalin J; Larson, Alice A

    2005-09-14

    Mast cells are found in the central nervous system (CNS) as well as in the periphery. In the brain of mice, they are localized primarily in the thalamus and meninges. Although their numbers increase in response to stress, the mediator of their recruitment is not known. During studies in which drugs were delivered intrathecally in a volume sufficiently large to distribute to the brain, we discovered that repeated daily injections of this large volume increased the number of mast cells in the thalamus. The increase was not due to changes in electrolyte composition of the cerebrospinal fluid (CSF) as chronically administered artificial CSF produced similar effects. Repeated injections of even small volumes (2 mul) increased mast cells in the medial intralaminar (Med), ventral posterior (VP) and posterior (Po) nuclei. Increasing the volume injected daily to 20 mul increased mast cells in the lateral intralaminar (Lat), laterodorsal (LD), ventrolateral (VL) and lateral geniculate (LG) nuclei and further increased those in the lateral extension of the Po nucleus. Thus, small and large volumes augment distinct populations of mast cells. While stem cell factor (SCF) is abundant in the CNS and is chemotactic to mast cells in the periphery, thalamic mast cells in the rodent do not express c-kit, the SCF receptor, suggesting that this factor may not be responsible for the effect. Consistent with this, centrally injected SCF was incapable of increasing thalamic mast cell populations after either single or chronic (21 days) daily injections compared to the effect of saline alone. Although the mechanism is not known, repeated injections of a large volume of fluid dramatically increase mast cells in the CNS, a phenomenon that may be relevant to clinical conditions of increased CSF pressure or volume.

  3. Determination of multiclass pesticide residues in apple juice by gas chromatography-mass spectrometry with large-volume injection.

    PubMed

    Wang, Jian-Hua; Zhang, Yi-Bing; Wang, Xiu-Lin

    2006-10-01

    This study presents two GC-MS SIM methods, in combination with large-volume injection programmed-temperature vaporization (LVI-PTV) injection, for the determination of 141 pesticide residues in apple juice. The sample was extracted with ACN, and coextractives were removed with primary/secondary amine sorbent. ACN extract (20 microL) was injected into a PTV injection port in solvent vent mode, and the pesticides were determined by GC-MS using retention time locking software. Deuterium-labeled pesticides (surrogate standards) were used for analytical quality control. In the validation experiments, pesticides recoveries were found to be 70-121% with RSDs of 4.6-21% (n = 6).

  4. Search for spin coupled WIMPs with the large volume NaI(Tl) scintillators

    NASA Astrophysics Data System (ADS)

    Yoshida, S.; Ejiri, H.; Fushimi, K.; Hayashi, K.; Kishimoto, T.; Kudomi, N.; Kume, K.; Kuramoto, H.; Matsuoka, K.; Ohsumi, H.; Takahisa, K.; Tsujimoto, Y.; Umehara, S.

    2001-06-01

    The cold dark matter search has been carried out at Oto Cosmo Observatory with the large volume NaI(Tl) scintillators of ELEGANT V. The new limits on WIMPs could be obtained by the analysis of the annual modulation. .

  5. Multiresidue determination of pesticides in agricultural products by gas chromatography/mass spectrometry with large volume injection.

    PubMed

    Saito, Yukio; Kodama, Shuji; Matsunaga, Akinobu; Yamamoto, Atsushi

    2004-01-01

    A method is described for the rapid determination of pesticide residues in agricultural products. Pesticides were extracted from samples with acetonitrile. To remove pigments and fatty acids, an aliquot of the extract was cleaned up by a minicolumn that was packed both with graphitized carbon black and primary secondary amine. Analysis was performed by gas chromatography/ mass spectrometry with programmable temperature vaporizer-based large volume injection using a liner packed with phenylmethylsilicone chemically bonded silica. The method was evaluated for 114 pesticides by spiking into tomato, spinach, Japanese pear, grape, and brown rice at various concentrations of each pesticide (0.02-0.4 microg/g). The method, which gave good recovery (>60%) for 108 pesticides, is characterized by high cleanup efficiency and short cleanup time, and is useful as a rapid screening analysis.

  6. Determination of synthetic phenolic antioxidants in edible oils using microvial insert large volume injection gas-chromatography.

    PubMed

    Cacho, Juan Ignacio; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel

    2016-06-01

    Three synthetic phenolic antioxidants, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ), were determined in different edible vegetable oil samples. The analyses were carried out by gas chromatography-mass spectrometry (GC-MS) using microvial insert large volume injection (LVI). Several parameters affecting this sample introduction step, such as temperatures, times and gas flows, were optimised. Quantification was carried out by the matrix-matched calibration method using carvacrol as internal standard, providing quantification limits between 0.08 and 0.10 ng g(-1), depending on the compound. The three phenolic compounds were detected in several of the samples, BHT being the most frequently found. Recovery assays for oil samples spiked at two concentration levels, 2.5 and 10 ng g(-1), provided recoveries in the 86-115% range.

  7. Determination of acrylamide in drinking water by large-volume direct injection and ion-exclusion chromatography-mass spectrometry.

    PubMed

    Cavalli, S; Polesello, S; Saccani, G

    2004-06-11

    Acrylamide, a known neurotoxin and putative human carcinogen, has been included among the substances to be monitored in drinking water according to the European Union Directive 98/83 on potable water. This paper reports a new method based on the combination of ion-exclusion chromatographic separation and MS detection. Samples of drinking water have been directly injected in the microbore ICE-AS1 column and detected in the selected-ion monitoring mode by a single quadrupole system with electrospray ionization. Chromatographic conditions, such as eluent composition and flow rate, have been optimized by a central composite design experiment. Statistical analysis of data showed that the amount of acetonitrile fraction in the eluent mixture, composed by acetonitrile and formic acid solution, is the variable that most influences retention of the acrylamide peak. After optimization of MS detection parameters, this method has been validated for spiked drinking water samples. The effect of large-volume injection (up to 500 microl) has been also explored. Linearity was evaluated from 0.5 to 5 microg l(-1). Repeatability, expressed as R.S.D., was 16 and 12% at 0.5 and 1 microg l(-1) respectively. The limit of detection was 0.20 ppb with 500 microl injection volume.

  8. Determination of organophosphorus pesticides by gas chromatography with mass spectrometry using a large-volume injection technique after magnetic extraction.

    PubMed

    Nedaei, Maryam; Salehpour, Ali-Reza; Mozaffari, Shahla; Yousefi, Seyedeh Mahboobeh; Yousefi, Seyed Reza

    2014-09-01

    A fast and efficient method was developed for the extraction and determination of organophosphorus pesticides in water samples. Organophosphorus pesticides were extracted by solid-phase extraction using magnetic multi-walled carbon nanotubes and determined by gas chromatography with ion-trap mass spectrometry. Parameters affecting the extraction were investigated. Under optimum conditions of the method, 10 mg magnetic multi-walled carbon nanotubes were added into 10 mL sample. After 2 min, adsorbent particles settled at the bottom of test tube with a magnet. After removing aqueous supernatant, the analytes were desorbed with acetonitrile. Then, 70 μL of acetonitrile phase was injected into the gas chromatography and mass spectrometry system that had an ion-trap analyzer. To achieve high sensitivity, the large-volume-injection technique was used with a programmed temperature vaporization inlet, and the ion-trap mass spectrometer was operated in single ion storage mode. Under the best conditions, the enrichment factors and extraction recoveries were in the range of 113-124 and 74-103%, respectively. The limits of detection were between 3 and 15 ng/L, and the relative standard deviations were < 10%. This method was successfully used for the determination of organophosphorus pesticides in dam water, lagoon water, and river water samples with good reproducibility and recovery.

  9. Optimizations of packed sorbent and inlet temperature for large volume-direct aqueous injection-gas chromatography to determine high boiling volatile organic compounds in water.

    PubMed

    Yu, Bofan; Song, Yonghui; Han, Lu; Yu, Huibin; Liu, Yang; Liu, Hongliang

    2014-08-22

    For the expanded application area, fast trace analysis of certain high boiling point (i.e., 150-250 °C) volatile organic compounds (HVOCs) in water, a large volume-direct aqueous injection-gas chromatography (LV-DAI-GC) method was optimized for the following parameters: packed sorbent for sample on-line pretreatment, inlet temperature and detectors configuration. Using the composite packed sorbent self-prepared with lithium chloride and a type of diatomite, the method enabled safe injection of an approximately 50-100 μL sample at an inlet temperature of 150 °C in the splitless mode and separated HVOCs from water matrix in 2 min. Coupled with a flame ionization detector (FID), an electron capture detector (ECD) and a flame photometric detector (FPD), the method could simultaneously quantify 27 HVOCs that belong to seven subclasses (i.e., halogenated aliphatic hydrocarbons, chlorobenzenes, nitrobenzenes, anilines, phenols, polycyclic aromatic hydrocarbons and organic sulfides) in 26 min. Injecting a 50 μL sample without any enrichment step, such as cryotrap focusing, the limits of quantification (LOQs) for the 27 HVOCs was 0.01-3 μg/L. Replicate analyses of the 27 HVOCs spiked source and river water samples exhibited good precision (relative standard deviations ≤ 11.3%) and accuracy (relative errors ≤ 17.6%). The optimized LV-DAI-GC was robust and applicable for fast determination and automated continuous monitoring of HVOCs in surface water.

  10. Particle-associated polycyclic aromatic hydrocarbons near power plants as determined by large volume injection--GC/MS.

    PubMed

    Evagelopoulos, V; Albanis, T A; Kodona, El; Zoras, S

    2010-06-01

    PM(10) and PM(2.5) samples were collected at two locations in the heavy industrialized prefecture of Kozani, in North-western Greece; in the open-cast mines of Klitos area and in the urban area of city of Kozani. The samples were collected by the use of low volume samplers, for a period of 1 year every 6 d. An analytical method has been adapted for determining 16 particle-bound polycyclic aromatic hydrocarbons (PAHs) in PM(10) and PM(2.5). Samples were collected on poly-tetra-fluorinated-ethylene (PTFE) filters using low volume samplers, considered to be ideal for trapping various organic pollutants including PAHs. The extraction has been made in two stages. Firstly, by reflux and then by using ultrasound bath. Chromatographic analysis has been carried out by GC/MS with programmable temperature vaporizers (PTV) injector and large volume injection (LVI) technique. Mean daily concentrations of B[a]Py in PM(10)-bound particles were 0.57 ng m(-3) in Kozani and 0.58 ng m(-3) at Klitos, while in PM(2.5)-bound PAHs were 0.35 ng m(-3) and 0.30 ng m(-3) respectively. We were able to verify the sources of PAHs by the use of diagnostic ratios, which indicate oil or/and coal burning as the, possible, major PAHs pollutant source(s).

  11. Quantitative Determination of Fluorinated Alkyl Substances by Large-Volume-Injection LC/MS/MS—Characterization of Municipal Wastewaters

    PubMed Central

    Schultz, Melissa M.; Barofsky, Douglas F.; Field, Jennifer A.

    2008-01-01

    A quantitative method was developed for the determination of fluorinated alkyl substances in municipal wastewater influents and effluents. The method consisted of centrifugation followed by large-volume injection (500 μL) of the supernatant onto a liquid chromatograph with a reverse-phase column and detection by electrospray ionization, and tandem mass spectrometry (LC/MS/MS). The fluorinated analytes studied include perfluoroalkyl sulfonates, fluorotelomer sulfonates, perfluorocarboxylates, and select fluorinated alkyl sulfonamides. Recoveries of the fluorinated analytes from wastewater treatment plant (WWTP) raw influents and final effluent ranged from 77% – 96% and 80% – 99%, respectively. The lower limit of quantitation ranged from 0.5 to 3.0 ng/L depending on the analyte. The method was applied to flow-proportional composites of raw influent and final effluent collected over a 24 hr period from ten WWTPs nationwide. Fluorinated alkyl substances were observed in wastewater at all treatment plants and each plant exhibited unique distributions of fluorinated alkyl substances despite similarities in treatment processes. In nine out of the ten plants sampled, at least one class of fluorinated alkyl substances exhibited increased concentrations in the effluent as compared to the influent concentrations. In some instances, decreases in certain fluorinated analyte concentrations were observed and attributed to sorption to sludge. PMID:16433363

  12. Linear and cyclic methylsiloxanes in air by concurrent solvent recondensation-large volume injection-gas chromatography-mass spectrometry.

    PubMed

    Companioni-Damas, E Y; Santos, F J; Galceran, M T

    2014-01-01

    In the present work, a simple and fast method for the analysis of linear and cyclic methylsiloxanes in ambient air based on active sampling combined with gas chromatography - mass spectrometry (GC-MS) was developed. The retention efficiency of five sampling sorbents (activated coconut charcoal, Carbopack B, Cromosorb 102, Cromosorb 106 and Isolute ENV+) was evaluated and Isolute ENV+ was found to be the most effective. A volume of 2700 L of air can be sampled without significant losses of the most volatile methylsiloxanes. To improve the sensitivity of the GC-MS method, concurrent solvent recondensation - large volume injection (CSR-LVI), using volumes up to 30 µl of sample extract, is proposed and limits of quantification down to 0.03-0.45 ng m(-3), good linearity (r>0.999) and precision (RSD %<9%) were obtained. The developed method was applied to the analysis of ambient air. Concentrations of linear and cyclic methylsiloxanes in indoor air ranging from 3.9 to 319 ng m(-3) and between 48 and 292668 ng m(-3), were obtained, respectively, while levels from 6 to 22 ng m(-3) for linear and between 2.2 and 439 ng m(-3) for cyclic methylsiloxanes in outdoor air from Barcelona (Spain), were found.

  13. Detection of s-triazine pesticides in natural waters by modified large-volume direct injection HPLC.

    PubMed

    Beale, David J; Kaserzon, Sarit L; Porter, Nichola A; Roddick, Felicity A; Carpenter, Peter D

    2010-07-15

    There is a need for simple and inexpensive methods to quantify potentially harmful persistent pesticides often found in our water-ways and water distribution systems. This paper presents a simple, relatively inexpensive method for the detection of a group of commonly used pesticides (atrazine, simazine and hexazinone) in natural waters using large-volume direct injection high performance liquid chromatography (HPLC) utilizing a monolithic column and a single wavelength ultraviolet-visible light (UV-vis) detector. The best results for this system were obtained with a mobile phase made up of acetonitrile and water in a 30:70 ratio, a flow rate of 2.0 mL min(-1), and a detector wavelength of 230 nm. Using this method, we achieved retention times of less than three minutes, and detection limits of 5.7 microg L(-1) for atrazine, 4.7 microg L(-1) for simazine and 4.0 microg L(-1) for hexazinone. The performance of this method was validated with an inter-laboratory trial against a National Association of Testing Authorities (NATA) accredited liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method commonly used in commercial laboratories.

  14. Trace analysis of isothiazolinones in water samples by large-volume direct injection liquid chromatography tandem mass spectrometry.

    PubMed

    Speksnijder, P; van Ravestijn, J; de Voogt, P

    2010-08-06

    Isothiazolinones are used as preservatives, biocides and disinfectants in a variety of industrial and domestic applications. Some of the isothiazolinones are difficult to isolate from water due their high polarity. A sensitive and selective analytical method was developed and optimized for the determination of sub-microg/L levels of three isothiazolinones in water samples. Three isothiazolinones are described in this paper: 2-methyl-3-isothiazolinone, 5-chloro-2-methyl-3-isothiazolinone and 4,5-dichloro-2-methyl-3-isothiazolinone. The analytical method involves a robust large-volume direct on-column loop injection of 2 mL on an Aqua ODS HPLC column and tandem MS detection (HPLC-MS/MS). After filtration, samples are directly injected without further pretreatment. Detection limits of the individual target compounds were between 0.03 and 0.1 microg/L employing Multi-Reaction Monitoring (MRM) mass spectrometry. Based on the constant ratio of two selected product-ions together with the retention time, the identification is very selective and quantification is reliable. The method was successfully applied to real samples of membrane flushings, drinking water, surface waters and waste water. Additional investigations showed the instability of the isothiazolinones in river- and waste water. Preservation of river water and waste water samples with sodium azide (NaN(3)) promotes the stability of the isothiazolines in solution. In membrane flushings, waste water, surface waters and drinking water, levels of the three isothiazolinones were all below the limit of detection. In effluents of households containing washings from normal shampoo use, isothiazolinones could be detected.

  15. Micro liquid-liquid extraction combined with large-volume injection gas chromatography-mass spectrometry for the determination of haloacetaldehydes in treated water.

    PubMed

    Serrano, María; Silva, Manuel; Gallego, Mercedes

    2011-11-18

    Haloacetaldehydes (HAs) are becoming the most widespread disinfection by-products (DBPs) found in drinking water, besides trihalomethanes and haloacetic acids, generated by the interaction of chemical disinfectants with organic matter naturally present in water. Because of their high potential toxicity, HAs have currently received a singular attention, especially trichloroacetaldehyde (chloral hydrate, CH), the most common and abundant compound found in treated water. The aims of this study are focused on the miniaturisation of EPA Method 551.1, including some innovations such as the use of ethyl acetate as the extracting solvent, the enhancement of HAs stability in aqueous solutions by adjusting the pH ~3.2 and the use of a large-volume sample injection (30 μL) coupled to programmed temperature vaporizer-gas chromatography-mass spectrometry to improve both sensitivity and selectivity. In optimised experimental conditions, the limits of detection for the 7 HAs studied ranged from 6 to 20 ng/L. Swimming pools have recently been recognized as an important source of exposure to DBPs and as a result, in this research for the first time, HAs have been determined in this type of water. Two HAs have been found in the analysed water: CH at concentrations between 1.2-38 and 53-340 μg/L and dichloroacetaldehyde between 0.07-4.0 and 1.8-23 μg/L in tap and swimming pool waters, respectively.

  16. Development of a bar adsorptive micro-extraction-large-volume injection-gas chromatography-mass spectrometric method for pharmaceuticals and personal care products in environmental water matrices.

    PubMed

    Neng, N R; Nogueira, J M F

    2012-01-01

    The combination of bar adsorptive micro-extraction using activated carbon (AC) and polystyrene-divinylbenzene copolymer (PS-DVB) sorbent phases, followed by liquid desorption and large-volume injection gas chromatography coupled to mass spectrometry, under selected ion monitoring mode acquisition, was developed for the first time to monitor pharmaceutical and personal care products (PPCPs) in environmental water matrices. Assays performed on 25 mL water samples spiked (100 ng L(-1)) with caffeine, gemfibrozil, triclosan, propranolol, carbamazepine and diazepam, selected as model compounds, yielded recoveries ranging from 74% to 99% under optimised experimental conditions (equilibrium time, 16 h (1,000 rpm); matrix characteristics: pH 5, 5% NaCl for AC phase; LD: methanol/acetonitrile (1:1), 45 min). The analytical performance showed good precision (RSD < 18%), convenient detection limits (5-20 ng L(-1)) and excellent linear dynamic range (20-800 ng L(-1)) with remarkable determination coefficients (r(2) > 0.99), where the PS-DVB sorbent phase showed a much better efficiency. By using the standard addition methodology, the application of the present analytical approach on tap, ground, sea, estuary and wastewater samples allowed very good performance at the trace level. The proposed method proved to be a suitable sorption-based micro-extraction alternative for the analysis of priority pollutants with medium-polar to polar characteristics, showing to be easy to implement, reliable, sensitive and requiring a low sample volume to monitor PPCPs in water matrices.

  17. Determination of pesticides in seaweeds by pressurized liquid extraction and programmed temperature vaporization-based large volume injection-gas chromatography-tandem mass spectrometry.

    PubMed

    García-Rodríguez, D; Carro-Díaz, A M; Lorenzo-Ferreira, R A; Cela-Torrijos, R

    2010-04-23

    A rapid method for the simultaneous identification and quantification of pesticide residues in edible seaweed has been developed. Target analytes were three pyrethroid, a carbamate and two organophosphorus pesticides. The procedure consists of a pressurized liquid extraction (PLE) with integrated clean-up, followed by gas chromatography coupled to tandem mass spectrometry. Five PLE parameters were investigated using a screening design: temperature, static extraction time, number of cycles, percent of flush volume and quantitative composition of the n-hexane/ethyl acetate extraction solvent. The effect of the in-cell clean-up with Florisil and graphitized carbon black adsorbents was investigated using a Doehlert response surface design. Large volumes of sample extracts were injected using a programmed-temperature vaporizer (PTV-LVI) to improve both sensitivity and selectivity of measurements. Quantification was carried by the internal standard method with surrogate deuterated standards. The method showed excellent linearity (R2>0.999) and precision (relative standard deviation, RSD < or = 8%) for all compounds, with detection limits ranging from 0.3 pg g(-1) for chlorpyrifos-ethyl, to 3.0 pg g(-1) for carbaryl (23.1 pg g(-1) for deltamethrin). Recoveries in real seaweed samples were within the range 82-108%. The method was satisfactory validated for the analysis of wild and cultivated edible seaweeds. The presence of pyrethroid and organophosphorus pesticides in some of the samples was evidenced.

  18. GC/MS with post-column switching for large volume injection of headspace samples: sensitive determination of volatile organic compounds in human whole blood and urine.

    PubMed

    Watanabe, Kanako; Fujita, Hiroki; Hasegawa, Koutaro; Gonmori, Kunio; Suzuki, Osamu

    2011-02-15

    When volatile or semivolatile compounds are measured by headspace (HS) gas chromatography (GC)/mass spectrometry (MS), the maximum gas volume to be injected is usually 0.5-1.0 mL; over the volume, the MS detector automatically shuts down due to impairment of the vacuum rate of the MS ionization chamber. To overcome the problem, we modified the gas flow routes of a new type of GC/MS instrument to create a postcolumn switching system, which can eliminate the large volume of gas before introduction of target compounds into the MS ionization chamber. Our HS-GC/MS system enabled injection of as large as 5 mL of HS gas without any disturbance. As the first example analysis, we tried to establish the analysis of naphthalene and p-dichlorobenzene in human whole blood and urine by this method with large volume injection. The limits of detection for both compounds in whole blood and urine were as low as about 10 and 5 pg/mL, respectively. The validation data and actual measurements were also demonstrated. The new GC/MS system has great potential to analyze any type of volatile or semivolatile organic compounds in biological matrixes with very high sensitivity and full automation.

  19. Determination of nifuroxazide in biological fluids by automated high-performance liquid chromatography with large-volume injection.

    PubMed

    Guinebault, P R; Broquaire, M; Braithwaite, R A

    1981-01-16

    A high-performance liquid chromatographic method for the measurement of nifuroxazide in plasma is described. The technique is based on the single extraction of the drug from buffered plasma with chloroform, using nifuratel as internal standard. The chromatographic system consisted of a 15 cm x 4.6 mm I.D. stainless-steel column packed with Spherisorb ODS, 5 micrometer, and the mobile phase was acetonitrile-orthophosphoric acid (pH 2.5) (30:70). The method was able to measure accurately plasma nifuroxazide concentrations down to 2 ng . ml-1 using 2 ml of sample with no interference from endogenous compounds. The coefficients of variation of the method at 200 and 2 ng . ml-1 were 3% and 15%, respectively, and the calibration graph was linear in this range. The use of automatic injection makes the method suitable for the routine analysis of large numbers of samples.

  20. Analysis of linear and cyclic methylsiloxanes in sewage sludges and urban soils by concurrent solvent recondensation-large volume injection-gas chromatography-mass spectrometry.

    PubMed

    Companioni-Damas, E Y; Santos, F J; Galceran, M T

    2012-12-14

    Concurrent solvent recondensation-large volume injection (CSR-LVI) is a gas chromatography injection technique that is particularly suitable for determining volatile compounds. In the present work, we evaluated the applicability of this technique for the analysis of linear and cyclic methylsiloxanes in sewage sludges and soils after solvent extraction to prevent losses of low-molecular-weight compounds. The CSR-LVI injection method was optimised to achieve maximum sensitivity and good chromatographic peak shapes. A liner packed with deactivated glass wool and a 5 m × 0.32 mm I.D. uncoated fused-silica precolumn was used. This made it possible to inject extract volumes of up to 30 μl. Good linearity (r>0.9993) and precision (RSD <15%), with recoveries ranging from 80 to 100% and method limits of quantification from 0.03 to 0.4 ng g(-1) wet weight (0.04-1.5 ng g(-1) dry weight for sewage sludges and 0.01-0.5 ng g(-1) dry weight for soils) were obtained. The developed method was applied to the analysis of linear and cyclic methylsiloxanes in sewage sludges collected from several wastewater treatment plants in Catalonia (NE Spain) and urban soils from the city of Barcelona.

  1. A study of large-volume on-column injection GC-ECD for the ultratrace analysis of organochlorine pesticides in water.

    PubMed

    Concha-Graña, E; Fernández-Martínez, G; Fernández-Villarrenaga, V; Turnes-Carou, M I; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

    2009-05-15

    In this work, a large-volume on-column injection method for the analysis of 21 organochlorine pesticides, including HCH isomers, DDT derivatives and cyclodiene derivatives, was optimized. The solvent selected to carry out the study was ethyl acetate and the injection volume was 100 microl. Some factors were introduced in a Plackett-Burman design to determine their influence in the vaporization efficiency. The significant factors were then studied by a univariate procedure and sorted according to their importance on the response. The effect of the injection conditions on the peak resolution was also noted. The conditions selected according to sensitivity and resolution were: initial oven temperature 75 degrees C, injection speed 20 microl s(-1), solvent vapor exit (SVE) valve closure time 60 s, initial pressure 100 kPa and isothermal oven time 1 min. Analytical characteristics expressed in terms of precision, linear range, and limit of detection have been determined and compared with those obtained by splitless injection. The degradation of endrin and p,p'-DDT thermolabile pesticides was evaluated for both injection techniques. Finally the developed method was successfully applied to the ultratrace analysis of pesticides in natural waters. With this purpose a micro liquid-liquid extraction method using 2 ml of ethyl acetate to extract 10 ml of water sample was proposed. Recoveries between 69 and 107% were obtained with a very good precision (0.2-1.3%) for the studied pesticides, except for p,p'-DDD. Detection limits between 0.3 and 25 ng l(-1), which fulfill the limits established by the new water directive 2008/105/EC, were achieved. The MLLE method was compared with the SPE method by the analysis of some water samples using both procedures, and good concordance was obtained.

  2. Dispersive liquid-liquid microextraction for the determination of nitrophenols in soils by microvial insert large volume injection-gas chromatography-mass spectrometry.

    PubMed

    Cacho, J I; Campillo, N; Viñas, P; Hernández-Córdoba, M

    2016-07-22

    A rapid and sensitive procedure for the determination of six NPs in soils by gas chromatography and mass spectrometry (GC-MS) is proposed. Ultrasound assisted extraction (UAE) is used for NP extraction from soil matrices to an organic solvent, while the environmentally friendly technique dispersive liquid-liquid microextraction (DLLME) is used for the preconcentration of the resulting UAE extracts. NPs were derivatized by applying an "in-situ" acetylation procedure, before being injected into the GC-MS system using microvial insert large volume injection (LVI). Several parameters affecting UAE, DLLME, derivatization and injection steps were investigated. The optimized procedure provided recoveries of 86-111% from spiked samples. Precision values of the procedure (expressed as relative standard deviation, RSD) lower than 12%, and limits of quantification ranging from 1.3 to 2.6ngg(-1), depending on the compound, were obtained. Twenty soil samples, obtained from military, industrial and agricultural areas, were analyzed by the proposed method. Two of the analytes were quantified in two of the samples obtained from industrial areas, at concentrations in the 4.8-9.6ngg(-1) range.

  3. Pre-column dilution large volume injection ultra-high performance liquid chromatography-tandem mass spectrometry for the analysis of multi-class pesticides in cabbages.

    PubMed

    Zhong, Qisheng; Shen, Lingling; Liu, Jiaqi; Yu, Dianbao; Li, Siming; Yao, Jinting; Zhan, Song; Huang, Taohong; Hashi, Yuki; Kawano, Shin-ichi; Liu, Zhaofeng; Zhou, Ting

    2016-04-15

    Pre-column dilution large volume injection (PD-LVI), a novel sample injection technique for reverse phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), was developed in this study. The PD-LVI UHPLC-MS/MS system was designed by slightly modifying the commercial UHPLC-MS/MS equipment with a mixer chamber. During the procedure of PD-LVI, sample solution of 200μL was directly carried by the organic mobile phase to the mixer and diluted with the aqueous mobile phase. After the mixture was introduced to the UHPLC column in a mobile phase of acetonitrile-water (15/85, v/v), the target analytes were stacked on the head of the column until following separation. Using QuEChERS extraction, no additional steps such as solvent evaporation or residue redissolution were needed before injection. The features of PD-LVI UHPLC-MS/MS system were systematically investigated, including the injection volume, the mixer volume, the precondition time and the gradient elution. The efficiency of this approach was demonstrated by direct analysis of 24 pesticides in cabbages. Under the optimized conditions, low limits of detection (0.00074-0.8 ng/kg) were obtained. The recoveries were in the range of 63.3-109% with relative standard deviations less than 8.1%. Compared with common UHPLC-MS/MS technique, PD-LVI UHPLC-MS/MS showed significant advantages such as excellent sensitivity and reliability. The mechanism of PD-LVI was demonstrated to be based on the column-head stacking effect with pre-column dilution. Based on the results, PD-LVI as a simple and effective sample injection technique of reverse phase UHPLC-MS/MS for the analysis of trace analytes in complex samples showed a great promising prospect.

  4. Rapid and sensitive solid phase extraction-large volume injection-gas chromatography for the analysis of mineral oil saturated and aromatic hydrocarbons in cardboard and dried foods.

    PubMed

    Moret, Sabrina; Barp, Laura; Purcaro, Giorgia; Conte, Lanfranco S

    2012-06-22

    A rapid off-line solid phase extraction-large volume injection-gas chromatography-flame ionisation detection (SPE-LVI-GC-FID) method, based on the use of silver silica gel and low solvent consumption, was developed for mineral oil saturated hydrocarbon (MOSH) and mineral oil aromatic hydrocarbon (MOAH) determination in cardboard and dried foods packaged in cardboard. The SPE method was validated using LVI with a conventional on-column injector and the retention gap technique (which allowed to inject up to 50 μL of the sample). Detector response was linear over all the concentration range tested (0.5-250 μg/mL), recoveries were practically quantitative, repeatability was good (coefficients of variation lower than 7%) and limit of quantification adequate to quantify the envisioned limit of 0.15 mg/kg proposed in Germany for MOAH analysis in food samples packaged in recycled cardboard. Rapid heating of the GC oven allowed to increase sample throughput (3-4 samples per hour) and to enhance sensitivity. The proposed method was used for MOSH and MOAH determination in selected food samples usually commercialised in cardboard packaging. The most contaminated was a tea sample (102.2 and 7.9 mg/kg of MOSH and MOAH below n-C25, respectively), followed by a rice and a sugar powder sample, all packaged in recycled cardboard. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Enhanced detection of nitroaromatic explosive vapors combining solid-phase extraction-air sampling, supercritical fluid extraction, and large-volume injection-GC.

    PubMed

    Batlle, Ramón; Carlsson, Håkan; Tollbäck, Petter; Colmsjö, Anders; Crescenzi, Carlo

    2003-07-01

    A complete method for sampling and analyzing of energetic compounds in the atmosphere is described. The method consists of the hyphenation of several techniques: active air sampling using a solid-phase extraction cartridge to collect the analytes, extraction of the sorbed analytes by toluene/methyl tert-butyl ether modified supercritical fluid extraction (SFE), and analysis of the extract by large-volume injection GC-nitrogen/phosphorus detection. The GC system is equipped with a loop-type injection interface with an early solvent vapor exit, a utilizing concurrent solvent evaporation technique. Chemometric approaches, based on a Plackett-Burman screening design and a central composite design for response surface modeling, were used to determine the optimum SFE conditions. The relative standard deviations of the optimized method were determined to be 4.3 to 7.7%, giving raise to method detection limits ranging from 0.06 to 0.36 ng in the sampling cartridge, equivalent to 6.2-36.4 pg/L in the atmosphere, standard sampling volume 10 L. The analytical method was applied to characterize headspace composition above military grade trinitrotoluene (TNT). Results confirm that 2,4-dinitrotoluene (DNT) and 1,3-dinitrobenzene (DNB) constitute the largest vapor flux, but TNT, 2,6-DNT, and trinitrobenzene TNB were also consistently detected in all the samples.

  6. Highly selective solid-phase extraction and large volume injection for the robust gas chromatography-mass spectrometric analysis of TCA and TBA in wines.

    PubMed

    Insa, S; Anticó, E; Ferreira, V

    2005-09-30

    A reliable solid-phase extraction (SPE) method for the simultaneous determination of 2,4,6-trichloroanisole (TCA) and 2,4,6-tribromoanisole (TBA) in wines has been developed. In the proposed procedure 50 mL of wine are extracted in a 1 mL cartridge filled with 50 mg of LiChrolut EN resins. Most wine volatiles are washed up with 12.5 mL of a water:methanol solution (70%, v/v) containing 1% of NaHCO3. Analytes are further eluted with 0.6 mL of dichloromethane. A 40 microL aliquot of this extract is directly injected into a PTV injector operated in the solvent split mode, and analysed by gas chromatography (GC)-ion trap mass spectrometry using the selected ion storage mode. The solid-phase extraction, including sample volume and rinsing and elution solvents, and the large volume GC injection have been carefully evaluated and optimized. The resulting method is precise (RSD (%) < 6% at 100 ng L(-1)), sensitive (LOD were 0.2 and 0.4 ng/L for TCA and TBA, respectively), robust (the absolute recoveries of both analytes are higher than 80% and consistent wine to wine) and friendly to the GC-MS system (the extract is clean, simple and free from non-volatiles).

  7. [Simultaneous determination of 103 pesticide residues in cabbages and apples using programmable temperature vaporizer-based large volume injection by gas chromatography-negative chemical ionization mass spectrometry].

    PubMed

    Dong, Jing; Pan, Yuxiang; Qin, Yaping; Lü, Jianxia; Yu, Qiongwei

    2010-07-01

    A gas chromatography-mass spectrometric (GC-MS) method has been established for the simultaneous determination of 103 pesticide residues in cabbages and apples using programmable temperature vaporizer-based large volume injection (PTV-LVI) and negative chemical ionization (NCI). It was found that much lower detection limits for the investigated pesticides can be obtained. Prior to GC-NCI/MS analysis, the optimized parameters of PTV-LVI were as follows: inlet temperature was set at 45 degrees C, split vent flow rate was 20 mL/min, evaporation time was 1 min and evaporation temperature was set at 60 degrees C. The volume of injection was 10 microL. Co-extractives were removed from the acetonitrile extracts using solid phase extraction with octadecyl (200 mg) and primary secondary amine (100 mg) sorbents. Matrix matched calibration solutions were used for all the analyses. To evaluate performance of the method, validation experiments were carried out in cabbages and apples at two spiking levels (5 and 10 microg/kg). The average recoveries ranged from 58.5% to 113.2%, and the relative standard deviations (RSDs, n = 6) were in the range of 3.3% - 14.5%. The limits of detection (S/N = 3) were less than 5 microg/kg for all the pesticides. The results show that this method is simple, rapid, sensitive and specific. It is appropriate for the simultaneous identification and quantification of the multi-residues in cabbages and apples.

  8. Plasma properties in a large-volume, cylindrical and asymmetric radio-frequency capacitively coupled industrial-prototype reactor

    NASA Astrophysics Data System (ADS)

    Lazović, Saša; Puač, Nevena; Spasić, Kosta; Malović, Gordana; Cvelbar, Uroš; Mozetič, Miran; Radetić, Maja; Petrović, Zoran Lj

    2013-02-01

    We have developed a large-volume low-pressure cylindrical plasma reactor with a size that matches industrial reactors for treatment of textiles. It was shown that it efficiently produces plasmas with only a small increase in power as compared with a similar reactor with 50 times smaller volume. Plasma generated at 13.56 MHz was stable from transition to streamers and capable of long-term continuous operation. An industrial-scale asymmetric cylindrical reactor of simple design and construction enabled good control over a wide range of active plasma species and ion concentrations. Detailed characterization of the discharge was performed using derivative, Langmuir and catalytic probes which enabled determination of the optimal sets of plasma parameters necessary for successful industry implementation and process control. Since neutral atomic oxygen plays a major role in many of the material processing applications, its spatial profile was measured using nickel catalytic probe over a wide range of plasma parameters. The spatial profiles show diffusion profiles with particle production close to the powered electrode and significant wall losses due to surface recombination. Oxygen atom densities range from 1019 m-3 near the powered electrode to 1017 m-3 near the wall. The concentrations of ions at the same time are changing from 1016 to the 1015 m-3 at the grounded chamber wall.

  9. On-line liquid chromatography-mass spectrometry with dilution line to achieve large volume urine injection for the improvement of sensitivity.

    PubMed

    Liu, Min; Yan, Wei; Lin, Jin-Ming; Hashi, Yuki; Liu, Li-Bin; Wei, Yanlin

    2008-07-11

    A unique automated on-line high-performance liquid chromatography-mass spectrometry (LC-MS) method was developed allowing injection of a large volume of urine for the improvement of sensitivity using estrogens as analytes. The urine sample was precipitated by acetonitrile (sample:acetonitrile, 1:2, v/v) to remove most proteins. Then the supernatant was directly delivered at 0.3 mL/min by a pump, which broke through the limit of autosampler with fixed loop. Then the sample was loaded onto a restricted access media (RAM) pre-column after on-line dilution with NH(4)Ac solution which was delivered by another pump under high flow-rate. After the addition of on-line dilution line, the content of organic solvent in the sample aliquot was sharply decreased so that the analytes were effectively trapped by pre-column. In addition, another 6-port valve was added to selectively deliver the effluent containing analytes into MS, which minimized the pollution of the MS and matrix effect. After optimization of the condition of extraction method, 3 mL sample (containing 1 mL urine) could be successfully enriched. The injection volume increased 10 times compared with conventional on-line LC-MS methods for biofluid analysis, significantly improving sensitivity. Moreover, no obvious increase of column pressure was observed after 300 injections. The method was validated by spiking urine. Linearity was determined by sample which was in the range of 1-500 ng/mL. The process efficiency ranged from 70.2 to 106% with RSDs less than 15% with the exception of a few analytes. The limit of detection (LOD) and quantification (LOQ) ranged from 0.3 to 2 ng/mL and 1 to 8 ng/mL, respectively, corresponding a decrease of 1-2 orders of magnitude compared with those of off-line and on-line methods.

  10. Determination of endocrine disrupting chemicals and antiretroviral compounds in surface water: A disposable sorptive sampler with comprehensive gas chromatography - Time-of-flight mass spectrometry and large volume injection with ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Wooding, Madelien; Rohwer, Egmont R; Naudé, Yvette

    2017-05-05

    Many rural dwellers and inhabitants of informal settlements in South Africa are without access to treated water and collect untreated water from rivers and dams for personal use. Endocrine disrupting chemicals (EDCs) have been detected in surface water and wildlife of South Africa. EDCs are often present in complex environmental matrices at ultra-trace levels complicating detection thereof. We report a simplified multi-residue approach for the detection and quantification of EDCs, emerging EDCs, and antiretroviral drugs in surface water. A low cost (less than one US dollar), disposable, sorptive extraction sampler was prepared in-house. The disposable samplers consisted of polydimethylsiloxane (PDMS) tubing fashioned into a loop which was then placed in water samples to concentrate EDCs and emerging pollutants. The PDMS samplers were thermally desorbed directly in the inlet of a GC, thereby eliminating the need for expensive consumable cryogenics. Comprehensive gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was used for compound separation and identification. Linear retention indices of EDCs and emerging pollutants were determined on a proprietary Crossbond(®) phase Rtx(®)-CLPesticides II GC capillary column. In addition, large volume injection of surface water into an ultra-performance liquid chromatograph tandem mass spectrometer (UPLC-MS/MS) was used as complementary methodology for the detection of less volatile compounds. Large volume injection reduced tedious and costly sample preparation steps. Limits of detection for the GC method ranged from 1 to 98pg/l and for the LC method from 2 to 135ng/l. Known and emerging EDCs such as pharmaceuticals, personal care products and pesticides, as well as the antiretroviral compounds, efavirenz and nevirapine, were detected in surface water from South Africa at concentration levels ranging from 0.16ng/l to 227ng/l.

  11. Analysis of iodinated haloacetic acids in drinking water by reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry with large volume direct aqueous injection.

    PubMed

    Li, Yongtao; Whitaker, Joshua S; McCarty, Christina L

    2012-07-06

    A large volume direct aqueous injection method was developed for the analysis of iodinated haloacetic acids in drinking water by using reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry in the negative ion mode. Both the external and internal standard calibration methods were studied for the analysis of monoiodoacetic acid, chloroiodoacetic acid, bromoiodoacetic acid, and diiodoacetic acid in drinking water. The use of a divert valve technique for the mobile phase solvent delay, along with isotopically labeled analogs used as internal standards, effectively reduced and compensated for the ionization suppression typically caused by coexisting common inorganic anions. Under the optimized method conditions, the mean absolute and relative recoveries resulting from the replicate fortified deionized water and chlorinated drinking water analyses were 83-107% with a relative standard deviation of 0.7-11.7% and 84-111% with a relative standard deviation of 0.8-12.1%, respectively. The method detection limits resulting from the external and internal standard calibrations, based on seven fortified deionized water replicates, were 0.7-2.3 ng/L and 0.5-1.9 ng/L, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Determination of polybrominated diphenyl ethers and polychlorinated biphenyls in fishery and aquaculture products using sequential solid phase extraction and large volume injection gas chromatography/tandem mass spectrometry.

    PubMed

    Lu, Dasheng; Lin, Yuanjie; Feng, Chao; Wang, Dongli; Qiu, Xinlei; Jin, Yu'e; Xiong, Libei; Jin, Ying; Wang, Guoquan

    2014-01-15

    A new method was developed to determine polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in fishery and aquaculture products. Samples were extracted by an accelerated solvent extraction system and cleaned up by sequential solid phase extraction (SPE) including dispersive SPE (D-SPE) and tandem SPE. PBDEs and PCBs were analyzed by a large-volume injection gas chromatography triple quadrupole mass spectrometry (LVI-GC-QqQ-MS/MS). Good linearity (R(2)≥0.9958) was achieved. Method detection limits (MDLs) were 0.16-3.3pgg(-1) (wet weight, ww) for PBDEs and 0.13-0.97pgg(-1)ww for PCBs. Mean recoveries were 60-140% with relative standard deviations (RSDs) of less than 20% in weever fish, scallop and shrimp samples spiked at a lower level of 13-31pgg(-1)ww and a higher level of 50-125pgg(-1)ww. Certified reference materials were analyzed with acceptable results. The method reduced solvent consumption, analytical time and labor, and is suitable for the routine analysis of PBDEs and PCBs in fishery and aquaculture products.

  13. Particulate contamination and stability of three additives in 0.9% sodium chloride injection in plastic and glass large-volume containers.

    PubMed

    Stokes, T F; Sumner, E D; Needham, T E

    1975-08-01

    The effect of particulate matter and stability of three parenteral drugs upon addition to glass and flexible polyvinyl chloride containers of 0.9% sodium chloride injection was studied. Aminophylline, lidocaine hydrochloric and metaraminol bitartrate were added to the solution in therapeutic quantities using techniques normally practiced by the hospital pharmacist. Statistical comparisons of the amount of particulate matter present were made for each solution consisting of drug added to plastic and glass bottles, drug filtered through a 0.22-mum filter and then added to the solution in plastic bags, controls for bags and bottles, and solutions with adjusted pH values to simulate the pH attained after addition of the drug to the solution. A correlation appeared to exist between the quantity of particulate matter and the amount of unfiltered drug solution added to the large-volume parenteral containers. Differences in storage and handling had an influence on the initial quantity of particles found in the plastic bags, no significant change in concentration of the drugs occurred during the 24-hour test period.

  14. Polycyclic aromatic hydrocarbon emissions in diesel exhaust using gas chromatography-mass spectrometry with programmed temperature vaporization and large volume injection

    NASA Astrophysics Data System (ADS)

    Vieira de Souza, Carolina; Corrêa, Sergio Machado

    2015-02-01

    Diesel engines are significant sources of Polycyclic Aromatic Compounds (PAHs) in urban atmospheres. These compounds are widely known for their carcinogenic potential and mutagenic properties. In this study, a method was developed for the analysis of 16 priorities PAHs using gas chromatography-mass spectrometry (GC-MS) with programmable temperature vaporizer large volume injection (PTV-LVI), which allowed to be obtained detection limits below 2.0 ng mL-1. This method was evaluated in samples from stratified particulate matter and gas phase from the emissions of diesel vehicle employing diesel commercial S10 (sulfur 10 mg L-1) and B5 (biodiesel 5% v/v). A sampling system that does not employ exhaust products dilution was used to evaluate the PAHs gas-particle partition. Six PAHs were identified in extracts and gas-phase PAHs took percentage of 80% in the total PAHs emissions. The sampling system without dilution not caused a strong nucleation/condensation of the most volatile PAHs. PAHs size-particle distribution was found in higher levels in the accumulation mode.

  15. Offline Solid-phase Extraction Large-volume Injection-Gas chromatography for the Analysis of Mineral Oil-saturated Hydrocarbons in Commercial Vegetable Oils.

    PubMed

    Liu, Lingling; Huang, Hua; Wu, Yanwen; Li, Bingning; Ouyang, Jie

    2017-09-01

    An offline solid-phase extraction (SPE) approach combined with a large-volume injection (LVI)-gas chromatography-flame ionization detector (LVI-GC-FID) is improved for routine analysis of mineral oil saturated hydrocarbons (MOSH) in vegetable oils. The key procedure of the method consists in using offline SPE columns for MOSH purification. The SPE column packed with 1% Ag-activated silica gel was used to separate MOSH from triglycerides and olefins in variety of vegetable oils. The eluent of MOSH fraction was only 3 mL and the concentration step was quick with little evaporation loss. The limit of quantification (LOQ) of the method was 2.5 mg/kg and the linearity ranged from 2 to 300 mg/kg. The accuracy was assessed by measuring the recoveries from spiked oil samples and was higher than 90%. Twenty-seven commercial vegetable oils were analyzed, and different levels of MOSH contamination were detected with the highest being 259.4 mg/kg. The results suggested that it is necessary to routinely detect mineral oil contamination in vegetable oils for food safety.

  16. Microwave-assisted extraction and large-volume injection gas chromatography tandem mass spectrometry determination of multiresidue pesticides in edible seaweed.

    PubMed

    García-Rodríguez, D; Carro, A M; Cela, R; Lorenzo, R A

    2010-09-01

    A microwave-assisted extraction method followed by clean-up with solid-phase extraction (SPE) combined with large-volume injection gas chromatography-tandem mass spectrometry (LVI-GC-MS/MS) for the analysis of 17 pesticides in wild and aquaculture edible seaweeds has been developed. An experimental central composite design was employed to evaluate the effects of the main variables potentially affecting the extraction (temperature, time, and solvent volume) and to optimize the process. The most effective microwave extraction conditions were achieved at 125 °C and 12 min with 24 mL of hexane/ethyl acetate (80:20). SPE clean-up of the extracts with graphitized carbon and Florisil, optimized by means of the experimental design, proved to be efficient in the removal of matrix interferences. The analytical recoveries were close to 100% for all the analytes, with relative standard deviations lower than 13%. The limits of detection ranged from 0.3 to 23.1 pg g(-1) and the limits of quantification were between 2.3 and 76.9 pg g(-1), far below the maximum residue levels established by the European Union for pesticides in seaweed. The results obtained prove the suitability of the microwave-assisted extraction for the routine analysis of pesticides in aquaculture and wild seaweed samples.

  17. Quantitation of fluoride ion released sarin in red blood cell samples by gas chromatography-chemical ionization mass spectrometry using isotope dilution and large-volume injection.

    PubMed

    Jakubowski, E M; McGuire, J M; Evans, R A; Edwards, J L; Hulet, S W; Benton, B J; Forster, J S; Burnett, D C; Muse, W T; Matson, K; Crouse, C L; Mioduszewski, R J; Thomson, S A

    2004-01-01

    A new method for measuring fluoride ion released isopropyl methylphosphonofluoridate (sarin, GB) in the red blood cell fraction was developed that utilizes an autoinjector, a large-volume injector port (LVI), positive ion ammonia chemical ionization detection in the SIM mode, and a deuterated stable isotope internal standard. This method was applied to red blood cell (RBC) and plasma ethyl acetate extracts from spiked human and animal whole blood samples and from whole blood of minipigs, guinea pigs, and rats exposed by whole-body sarin inhalation. Evidence of nerve agent exposure was detected in plasma and red blood cells at low levels of exposure. The linear method range of quantitation was 10-1000 pg on-column with a detection limit of approximately 2-pg on-column. In the course of method development, several conditions were optimized for the LVI, including type of injector insert, injection volume, initial temperature, pressure, and flow rate. RBC fractions had advantages over the plasma with respect to assessing nerve agent exposure using the fluoride ion method especially in samples with low serum butyrylcholinesterase activity.

  18. Sol-gel polydimethylsiloxane/poly(vinylalcohol)-coated stir bar sorptive extraction of organophosphorus pesticides in honey and their determination by large volume injection GC.

    PubMed

    Yu, Chunhe; Hu, Bin

    2009-01-01

    A PDMS/poly(vinylalcohol) (PDMS/PVA) film prepared through a sol-gel process was coated on stir bars for sorptive extraction, followed by liquid desorption and large volume injection-GC-flame photometric detector (LVI-GC-FPD) for the determination of five organophosphorus pesticides (OPPs) (phorate, fenitrothion, malathion, parathion, and quinalphos) in honey. The preparation reproducibility of PDMS/PVA-coated stir bar ranged from 4.3 to 13.4% (n = 4) in one batch, and from 6.0 to 12.6% (n = 4) in batch to batch. And one prepared stir bar can be used for more than 50 times without apparent coating loss. The significant parameters affecting stir bar sorptive extraction (SBSE) were investigated and optimized. The LODs for five OPPs ranged from 0.013 (parathion) to 0.081 microg/L (phorate) with the RSDs ranging from 5.3 to 14.2% (c = 1 microg/L, n = 6). The proposed method was successfully applied to the analysis of five OPPs in honey.

  19. Direct large volume injection ultra-high performance liquid chromatography-tandem mass spectrometry determination of artificial sweeteners sucralose and acesulfame in well water.

    PubMed

    Wu, Minghuo; Qian, Yichao; Boyd, Jessica M; Hrudey, Steve E; Le, X Chris; Li, Xing-Fang

    2014-09-12

    Acesulfame (ACE) and sucralose (SUC) have become recognized as ideal domestic wastewater contamination indicators. Liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analysis is commonly used; however, the sensitivity of SUC is more than two orders of magnitude lower than that of ACE, limiting the routine monitoring of SUC. To address this issue, we examined the ESI behavior of both ACE and SUC under various conditions. ACE is ionic in aqueous solution and efficiently produces simple [M-H](-) ions, but SUC produces multiple adduct ions, limiting its sensitivity. The formic acid (FA) adducts of SUC [M+HCOO](-) are sensitively and reproducibly generated under the LC-MS conditions. When [M+HCOO](-) is used as the precursor ion for SUC detection, the sensitivity increases approximately 20-fold compared to when [M-H](-) is the precursor ion. To further improve the limit of detection (LOD), we integrated the large volume injection approach (500μL injection) with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), which reduced the method detection limit (MDL) to 0.2ng/L for ACE and 5ng/L for SUC. To demonstrate the applicability of this method, we analyzed 100 well water samples collected in Alberta. ACE was detected in 24 wells at concentrations of 1-1534ng/L and SUC in 8 wells at concentrations of 65-541ng/L. These results suggest that wastewater is the most likely source of ACE and SUC impacts in these wells, suggesting the need for monitoring the quality of domestic well water. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Application of large volume injection GC-MS to analysis of organic compounds in the extracts and leachates of municipal solid waste incineration fly ash.

    PubMed

    Korenková, Eva; Matisová, Eva; Slobodník, Jaroslav

    2006-01-01

    Organic solvent and water extracts of fly ash from a Milan (Italy) municipal solid waste incinerator (MSWI) were analyzed by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS) with programmable temperature vaporizer (PTV). Using injection volumes of 10-100 microl, typically over a hundred compounds were detected in organic solvent extracts and ca. 35% of them could be tentatively identified from their electron impact ionization mass spectra. A protocol for the determination of the maximum amount of a potential environmental pollutant available for leaching (availability test) was developed for four selected target compounds: pentachlorobenzene (PeCB), hexachlorobenzene (HxCB), o-terphenyl (o-TPH) and m-terphenyl (m-TPH). Key parameters, extraction time and liquid-to-solid ratio (L/S), were studied in more detail. Recoveries of PeCB, HxCB and o-TPH spiked into the fly ash samples at two concentration levels ranged from 38% to 53% for freshly spiked and from 14% to 40% for 40-day aged fly ash. Recoveries of m-TPH were 8% to 11% from freshly spiked and less than 3% from aged spiked fly ash. The native amounts in Milan MSWI fly ash, determined in an interlaboratory exercise using the developed protocol, were 31 ng/g PeCB, 34 ng/g HxCB, 72 ng/g o-TPH and 4.4 ng/g m-TPH. A separate methodology was developed for the determination of compounds extracted from fly ash by water (leaching test). Following 8-h sonication at L/S 20, the leached amounts of PeCB, HxCB and o-TPH were 1.1, 3.1 and 6.0 ng/g fly ash, respectively.

  1. Application of large volume injection GC-MS to analysis of organic compounds in the extracts and leachates of municipal solid waste incineration fly ash

    SciTech Connect

    Korenkova, Eva; Slobodnik, Jaroslav

    2006-07-01

    Organic solvent and water extracts of fly ash from a Milan (Italy) municipal solid waste incinerator (MSWI) were analyzed by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS) with programmable temperature vaporizer (PTV). Using injection volumes of 10-100 {mu}l, typically over a hundred compounds were detected in organic solvent extracts and ca. 35% of them could be tentatively identified from their electron impact ionization mass spectra. A protocol for the determination of the maximum amount of a potential environmental pollutant available for leaching (availability test) was developed for four selected target compounds: pentachlorobenzene (PeCB), hexachlorobenzene (HxCB), o-terphenyl (o-TPH) and m-terphenyl (m-TPH). Key parameters, extraction time and liquid-to-solid ratio (L/S), were studied in more detail. Recoveries of PeCB, HxCB and o-TPH spiked into the fly ash samples at two concentration levels ranged from 38% to 53% for freshly spiked and from 14% to 40% for 40-day aged fly ash. Recoveries of m-TPH were 8% to 11% from freshly spiked and less than 3% from aged spiked fly ash. The native amounts in Milan MSWI fly ash, determined in an interlaboratory exercise using the developed protocol, were 31 ng/g PeCB, 34 ng/g HxCB, 72 ng/g o-TPH and 4.4 ng/g m-TPH. A separate methodology was developed for the determination of compounds extracted from fly ash by water (leaching test). Following 8-h sonication at L/S 20, the leached amounts of PeCB, HxCB and o-TPH were 1.1, 3.1 and 6.0 ng/g fly ash, respectively.

  2. Fully automated determination of macrocyclic musk fragrances in wastewater by microextraction by packed sorbents and large volume injection gas chromatography-mass spectrometry.

    PubMed

    Vallecillos, Laura; Pocurull, Eva; Borrull, Francesc

    2012-11-16

    A fully automated method has been developed for the determination of eight macrocyclic musk fragrances in urban wastewater. The procedure includes the enrichment of the analytes by microextraction by packed sorbent (MEPS) followed by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). The main factors in the MEPS technique were optimized. For all of the analytes, the highest enrichment factors were achieved when 4 mL samples were extracted by using C18 MEPS-sorbent and 50 μL of ethyl acetate were used for desorption. The eluate was directly analysed by GC-MS. Detection limits were found to be between 5 ng L(-1) and 10 ng L(-1), depending on the target analytes. In addition, under optimized conditions, the method gave good levels of intra-day and inter-day repeatability in wastewater samples with relative standard deviation (RSD) (n=3, 1,000 ng L(-1)) less than 5% and 9%, respectively. The applicability of the method was tested with wastewater samples from two influent and effluent urban wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed the presence of most of the macrocylic musks at concentrations higher than the method quantification limits (MQLs), being the most abundant analyte ambrettolide at 9.29 μg L(-1). In addition, the analyses of effluent urban wastewater showed a decrease in the concentrations with macrocyclic musk concentrations of between not detected (n.d.) and 2.26 μg L(-1) being detected.

  3. Determination of cyclic volatile methylsiloxanes in water, sediment, soil, biota, and biosolid using large-volume injection-gas chromatography-mass spectrometry.

    PubMed

    Wang, De-Gao; Alaee, Mehran; Steer, Helena; Tait, Tara; Williams, Zackery; Brimble, Samantha; Svoboda, Lewina; Barresi, Enzo; Dejong, Maryl; Schachtschneider, Joanne; Kaminski, Ed; Norwood, Warren; Sverko, Ed

    2013-10-01

    Several methods were developed to detect the cyclic volatile methylsiloxanes (cVMSs) including octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in water, sediment, soil, biota, and biosolid samples. Analytical techniques employed to optimize measurement of this compound class in various matrices included membrane-assisted solvent extraction in water, liquid-solid extraction for sediment, soil, biota, and biosolid samples. A subsequent analysis of the extract was conducted by large-volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). These methods employed no evaporative techniques to avoid potential losses and contamination of the volatile siloxanes. To compensate for the inability to improve detection limits by concentrating final sample extract volumes we used a LVI-GC-MS. Contamination during analysis was minimized by using a septumless GC configuration to avoid cVMS's associated with septum bleed. These methods performed well achieving good linearity, low limits of detection, good precision, recovery, and a wide dynamic range. In addition, stability of cVMS in water and sediment was assessed under various storage conditions. D4 and D5 in Type-I (Milli-Q) water stored at 4°C were stable within 29d; however, significant depletion of D6 (60-70%) occurred only after 3d. Whereas cVMS in sewage influent and effluent were stable at 4°C within 21d. cVMS in sediment sealed in amber glass jars at -20°C and in pentane extracts in vials at -15°C were stable during 1month under both storage conditions.

  4. The determination of acrylamide in environmental and drinking waters by large-volume injection - hydrophilic-interaction liquid chromatography and tandem mass spectrometry.

    PubMed

    Backe, Will J; Yingling, Virginia; Johnson, Todd

    2014-03-21

    A simple and sensitive analytical method was developed to quantify levels of acrylamide in environmental and drinking waters. The analytical method consisted of solvent exchanging acrylamide from 2mL of water into 2mL of dichloromethane using acetonitrile as an intermediate. The sample was then directly analyzed by large-volume (750μL) injection - hydrophilic-interaction liquid chromatography and tandem mass spectrometry. The method detection limit and reporting level were 2.4ng/L and 17ng/L of acrylamide, respectively. The recovery of acrylamide during solvent exchange was 95±2.8% and the matrix effects were 12±2.2% in river water. The use of atmospheric-pressure chemical ionization reduced matrix effects; however, it also reduced method sensitivity by a factor of 2.2 compared to electrospray ionization. Matrix effects were compensated for by the use of an isotopically-labeled internal standard and the method accuracy was 89±3.0% at 25ng/L of acrylamide and 102±2.6% at 250ng/L of acrylamide. The precision of the method was less than 6% relative standard deviation at both 25ng/L and 250ng/L of acrylamide. Samples from a sand-and-gravel mine and a drinking-water treatment plant were acquired to demonstrate the method. The concentrations of acrylamide at the sand-and-gravel mine were up to 280ng/L. In the drinking-water treatment plant, the concentration of acrylamide was approximately double in the finished drinking water when compared to other stages in the drinking-water treatment process. Disinfection or fluoridation may result in higher concentrations of acrylamide in finished drinking water; however, further research in this area is necessary. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Suspect screening and target quantification of multi-class pharmaceuticals in surface water based on large-volume injection liquid chromatography and time-of-flight mass spectrometry.

    PubMed

    Vergeynst, Leendert; Van Langenhove, Herman; Joos, Pieter; Demeestere, Kristof

    2014-04-01

    The ever-growing number of emerging micropollutants such as pharmaceuticals requests rapid and sensitive full-spectrum analytical techniques. Time-of-flight high-resolution mass spectrometry (TOF-HRMS) is a promising alternative for the state-of-the-art tandem mass spectrometry instruments because of its ability to simultaneously screen for a virtually unlimited number of suspect analytes and to perform target quantification. The challenge for such suspect screening is to develop a strategy, which minimizes the false-negative rate without restraining numerous false-positives. At the same time, omitting laborious sample enrichment through large-volume injection ultra-performance liquid chromatography (LVI-UPLC) avoids selective preconcentration. A suspect screening strategy was developed using LVI-UPLC-TOF-MS aiming the detection of 69 multi-class pharmaceuticals in surface water without the a priori availability of analytical standards. As a novel approach, the screening takes into account the signal-intensity-dependent accurate mass error of TOF-MS, hereby restraining 95 % of the measured suspect pharmaceuticals present in surface water. Application on five Belgian river water samples showed the potential of the suspect screening approach, as exemplified by a false-positive rate not higher than 15 % and given that 30 out of 37 restrained suspect compounds were confirmed by the retention time of analytical standards. Subsequently, this paper discusses the validation and applicability of the LVI-UPLC full-spectrum HRMS method for target quantification of the 69 pharmaceuticals in surface water. Analysis of five Belgian river water samples revealed the occurrence of 17 pharmaceuticals in a concentration range of 17 ng L(-1) up to 3.1 μg L(-1).

  6. Online in situ analysis of selected semi-volatile organic compounds in water by automated microscale solid-phase extraction with large-volume injection/gas chromatography/mass spectrometry.

    PubMed

    Li, Yongtao; George, John E; McCarty, Christina L

    2007-12-28

    A fully automated analytical method was developed for the online in situ analysis of selected semi-volatile organic compounds in water. The method used a large-volume injection/gas chromatography/mass spectrometry coupled with a fully automated microscale solid-phase extraction technique, which was based on x-y-z robotic techniques. Water samples were extracted by using a 96-well solid-phase extraction plate. For most analytes included in this study, the obtained linear calibrations ranged from 0.05 to 5.0 microg/L with correlation coefficients of 0.996-1.000, the method detection limits were less than 0.1 microg/L, and the relative recoveries were in the range of 70-120% with a relative standard deviation of less than 15% for fortified reagent water samples. The applications to chlorinated tap water, well water, and river water have been validated. The obtained results were similar to those resulting from fortified reagent water samples for all analytes except metribuzin, bromacil, aldrin, and methoxychlor. Matrix effects were observed for these analytes. In general, this fully automated analytical method was rugged, reliable, and easy to operate, and was capable of providing real-time data to water treatment and distribution systems as well as water reservation and protection systems. In addition, the method could reduce the analytical costs associated with sample collection, transportation, storage, and preparation.

  7. Solid-phase extraction combined with large volume injection-programmable temperature vaporization-gas chromatography-mass spectrometry for the multiresidue determination of priority and emerging organic pollutants in wastewater.

    PubMed

    Bizkarguenaga, E; Ros, O; Iparraguirre, A; Navarro, P; Vallejo, A; Usobiaga, A; Zuloaga, O

    2012-07-20

    In the present work the simultaneous extraction for the multiresidue determination in wastewater samples of organic compounds such as polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), pesticides, polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PEs), alkylphenols (APs), bisphenol A (BPA) or hormones included in different lists of priority and emerging pollutants because of their action as endocrine disrupting compounds (EDCs) was developed. Different solid phase extraction (SPE) variables such as the nature of the solid phase (Oasis-HLC, C18 and Lichrolut), the sample volume, the addition of MeOH and NaCl, the pH of the water phase and the volume of the eluent solvent were optimized in order to analyze simultaneously the priority and emerging families of pollutants mentioned above. Good recoveries were obtained for Milli-Q water (80-120%), however, since the use of deuterated analogues and dilution of the sample did not correct the matrix effect, additional SPE clean-up step using Florisil® cartridges was necessary to obtain good results for wastewater samples (80-125%). In order to improve the limits of detection (LODs), large volume injection (LVI) using programmable temperature vaporizer (PTV) coupled to gas chromatography-mass spectrometry (GC-MS) was also optimized. Since analytes losses in the case of the most volatile congeners occurred during the derivatization step and no separation of the derivatized and the non-derivatized analytes was possible during SPE elution, two different injections were optimized for each analyte group. LODs were in good agreement with those found in the literature and relative standard deviations (RSDs) were in the 10-25% range for Milli-Q and 12-30% for wastewater samples. The method was finally applied to the determination of target analytes in three different wastewater treatment plants (WWTPs, Bakio, Gernika and Galindo (Spain)) and in one water purification plant (WPP) in Zornotza (Spain).

  8. Deep eutectic solvent magnetic bucky gels in developing dispersive solid phase extraction: Application for ultra trace analysis of organochlorine pesticides by GC-micro ECD using a large-volume injection technique.

    PubMed

    Yousefi, Seyedeh Mahboobeh; Shemirani, Farzaneh; Ghorbanian, Sohrab Ali

    2017-06-01

    Novel deep eutectic solvent (DES) magnetic bucky gels (MBG) were formed by choline chloride/urea deep eutectic solvent and magnetic multi-walled carbon nanotube nanocomposite (MMWCNT) and were used in developing dispersive solid-phase extraction (dSPE) method. The hydrophilic DES based MBGs were developed with the features of magnetic susceptibility to permit fast injection of sorbent into the aqueous sample, rapid retrieval of the sorbent, high dispersion of MWCNT in water and compatibility with GC. In this work we investigated the application of DESs as a new class of carriers for CNT based nanofluids. In this gel DES acts simultaneously as a carrier and stabilizer for MMWCNT nanoparticles. By combining the MWCNT nanocomposite and DES, a highly stable (stability against sedimentation) viscous magnetic bucky gel or soft material was prepared without any additional stabilizer. This gel possesses fluidity, stability, magnetic properties and the unique strong sorbing properties of MWCNT simultaneously. We used the advantages of this magnetic DES based soft material in developing a new DES magnetic bucky gel based dispersive solid phase extraction. By coupling this method with GC- micro ECD and using large-volume-injection technique we achieved low LOD values which is a necessity in the ultra trace analysis of organochlorine pesticides (OCPs) in environmental water samples. Under the optimized conditions, the enrichment factors were in the range of 270-340. The limits of detection were between 0.04 and 0.27ng/L and the relative standard deviations were <10%. This method was successfully used for the determination of OCPs with good reproducibility and recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

    2017-08-01

    In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be < 4.3% and 2.1% respectively. Good recoveries for ethylene and sulfur dioxide from fruit samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS.

  10. Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis.

    PubMed

    Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

    2017-08-05

    In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4(+) strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be <4.3% and 2.1% respectively. Good recoveries for ethylene and sulfur dioxide from fruit samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Stir-bar-sorptive extraction and liquid desorption combined with large-volume injection gas chromatography-mass spectrometry for ultra-trace analysis of musk compounds in environmental water matrices.

    PubMed

    Silva, Ana Rita M; Nogueira, J M F

    2010-03-01

    Stir-bar-sorptive extraction with liquid desorption followed by large-volume injection and capillary gas chromatography coupled to mass spectrometry in selected ion monitoring acquisition mode (SBSE-LD/LVI-GC-MS(SIM)) has been developed to monitor ultra-traces of four musks (celestolide (ADBI), galaxolide (HHCB), tonalide (AHTN) and musk ketone (MK)) in environmental water matrices. Instrumental calibration (LVI-GC-MS(SIM)) and experimental conditions that could affect the SBSE-LD efficiency are discussed. Assays performed on 30-mL water samples spiked at 200 ng L(-1) under optimized experimental conditions yielded recoveries ranging from 83.7 ± 8.1% (MK) to 107.6 ± 10.8% (HHCB). Furthermore, the experimental data were in very good agreement with predicted theoretical equilibria described by octanol-water partition coefficients (K (PDMS/W) ≈ K (O/W)). The methodology also showed excellent linear dynamic ranges for the four musks studied, with correlation coefficients higher than 0.9961, limits of detection and quantification between 12 and 19 ng L(-1) and between 41 and 62 ng L(-1), respectively, and suitable precision (< 20%). Application of this method for analysis of the musks in real water matrices such as tap, river, sea, and urban wastewater samples resulted in convenient selectivity, high sensitivity and accuracy using the standard addition methodology. The proposed method (SBSE-LD/LVI-GC-MS(SIM)) was shown to be feasible and sensitive, with a low-sample volume requirement, for determination of musk compounds in environmental water matrices at the ultra-trace level, overcoming several disadvantages presented by other sample-preparation techniques.

  12. New strategies to screen for endocrine-disrupting chemicals in the Portuguese marine environment utilizing large volume injection-capillary gas chromatography-mass spectrometry combined with retention time locking libraries (LVI-GC-MS-RTL).

    PubMed

    Almeida, C; Serôdio, P; Florêncio, M H; Nogueira, J M F

    2007-04-01

    A new analytical strategy to screen for endocrine-disrupting chemicals (EDCs) in environmental matrices is presented. The strategy uses solid-phase extraction followed by large volume injection and capillary gas chromatography coupled to mass spectrometry combined with retention time locking libraries (SPE-LVI-GC-MS-RTL). Characterization of the proposed methodology (SPE-LVI-GC-MS) for selected classes of EDCs enabled high reproducibility and robustness at the ultratrace level. The RTL databases used allowed hundreds of non-target semivolatiles (i.e., pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls and other classes of suspected EDCs from a great number of unknown environmental matrices) to be simultaneously screened for in an easy, fast and remarkable manner. The application of the proposed methodology to real environmental samples demonstrated its remarkable selectivity and sensitivity at the ultratrace level. Screening assessments performed on water and sediment matrices from eight Portuguese estuaries and coastal waters identified EDC "hotspots." These EDCs mainly come from agricultural and a wide variety of industrial sources, and include pesticides and pesticide metabolites, phenolic derivatives and polycyclic aromatic hydrocarbons, which are included in the lists of priority substances published by international environmental agencies. The estuaries that contained relatively high levels of pesticides were Guadiana, Sado and Mondego, while Minho, Douro and Formosa showed enhanced levels of phenolic derivatives. Dibutyltin and tributyltin, selected as target compounds to be monitored by SPE-LVI-GC-MS in the selected ion monitoring mode, were shown to be widespread contaminants at trace levels in almost all of the sediment matrices assessed. The reliability of the proposed methodology undoubtedly makes it a valuable tool that could replace other analytical strategies currently used to screen for EDCs present in the environment at

  13. Phase transfer membrane supported liquid-liquid-liquid microextraction combined with large volume sample injection capillary electrophoresis-ultraviolet detection for the speciation of inorganic and organic mercury.

    PubMed

    Li, Pingjing; Zhang, Xing; Hu, Bin

    2011-12-30

    In this paper, a novel sample pretreatment technique termed phase transfer based liquid-liquid-liquid microextraction (PT-LLLME) was proposed for the simultaneous extraction of inorganic and organic mercury species. In PT-LLLME, an intermediate solvent (acetonitrile) was added into the donor phase to improve the contacting between target mercury species and complexing reagent. Meanwhile, a membrane supported (MS)-LLLME unit was designed to realize the PT-LLLME procedure. By using nylon membrane as supporting carrier, larger than 50 μL of acceptor solution could be hung up. Following PT/MS-LLLME, the acceptor solutions were directly analyzed by large volume sample stacking capillary electrophoresis/ultraviolet detection (LVSS-CE/UV). Accordingly, a new method of PT/MS-LLLME combined with LVSS-CE/UV was developed for the simultaneous speciation of inorganic and organic mercury species. Parameters affecting the extraction efficiency of PT/MS-LLLME were investigated in details. Under the optimized conditions, enrichment factors (EFs) ranging from 160- to 478-fold were obtained for the extraction of target mercury species by PT/MS-LLLME. By combining PT/MS-LLLME with LVSS-CE/UV, EFs were magnified up to 12,138-fold and the limits of detection (at a signal-to-noise ratio of 3) were at sub ppb level. The established approach of PT/MS-LLLME-LVSS-CE/UV was successfully applied to simultaneous determination of inorganic and organic mercury species in biological samples and environmental water samples.

  14. Plasmoids formation in a laboratory and large-volume flux closure during simulations of Coaxial Helicity Injection in NSTX-U

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Fatima

    2016-10-01

    In NSTX-U, transient Coaxial Helicity Injection (CHI) is the primary method for current generation without reliance on the solenoid. A CHI discharge is generated by driving current along open field lines (the injector flux) that connect the inner and outer divertor plates on NSTX/NSTX-U, and has generated over 200 kA of toroidal current on closed flux surfaces in NSTX. Extrapolation of the concept to larger devices requires an improved understanding of the physics of flux closure and the governing parameters that maximizes the fraction of injected flux that is converted to useful closed flux. Here, through comprehensive resistive MHD NIMROD simulations conducted for the NSTX and NSTX-U geometries, two new major findings will be reported. First, formation of an elongated Sweet-Parker current sheet and a transition to plasmoid instability has for the first time been demonstrated by realistic global simulations. This is the first observation of plasmoid instability in a laboratory device configuration predicted by realistic MHD simulations and then supported by experimental camera images from NSTX. Second, simulations have now, for the first time, been able to show large fraction conversion of injected open flux to closed flux in the NSTX-U geometry. Consistent with the experiment, simulations also show that reconnection could occur at every stage of the helicity injection phase. The influence of 3D effects, and the parameter range that supports these important new findings is now being studied to understand the impact of toroidal magnetic field and the electron temperature, both of which are projected to increase in larger ST devices. Work supported by DOE DE-SC0010565.

  15. New approach to large-volume injection in reversed-phase high performance liquid chromatography: determination of atrazine and hydroxyatrazine in soil samples.

    PubMed

    Hutta, Milan; Chalányová, Mária; Halko, Radoslav; Góra, Róbert; Rybár, Ivan; Pajchl, Marek; Dokupilová, Svetlana

    2006-08-01

    A well established method of direct injection of larger than conventional sample volumes ranging from 0.1 mL to 10 mL in HPLC is the injection valve method in which a loop of tubing is totally or partially filled with sample. Recent HPLC pumps have a flow-rate setting accuracy of +/- 1-2% over a flow-rate range from 0.1 mL/min to 10 mL/min and the flow stability is 0.2% or less. Quarternary low pressure gradient pumps are widely available and used, but all their hydraulic lines are seldom utilised. The idea of using one line of a common commercial HPLC quaternary low-pressure pump for direct on-column injection (pumping) of large sample volumes ranging from 1 mL to 100 mL was tested. This approach was evaluated during practical work on the development of an RP-HPLC method of determination of residual atrazine and hydroxyatrazine. In lysimetric environmental experiments hydroxyatrazine was formed in situ in a soil column by hydrolysis of atrazine. The results proved the applicability of this approach not only in experiments with model mixtures of analytes at microg/L levels in solutions. Analysis of 20 mL of soil leachates and extracts of soil samples containing atrazine and hydroxyatrazine at the 10 microg/kg level (in dry soil) revealed that good figures-of-merit were preserved, even in the presence of a large excess of humic substances.

  16. Arsenic speciation in water and snow samples by adsorption onto PHEMA in a micro-pipette-tip and GFAAS detection applying large-volume injection.

    PubMed

    Döker, Serhat; Uzun, Lokman; Denizli, Adil

    2013-01-15

    A miniaturized solid phase extraction procedure has been developed for ultra-trace determination of inorganic arsenic species. Arsenic(III) as pyrrolidinedithiocarbamate complex was selectively adsorbed on 30 mg poly(hydroxyethyl methacrylate) (PHEMA) micro beads, which is simply packed into a micro-pipette-tip. The adsorbed arsenic was quantitatively eluted by 700 μL 0.25 M NH(3) and determined by graphite furnace atomic absorption spectrometry (GFAAS). Injection of larger volume (i.e., 50 μL v.s. conventional 10-20 μL) eluent into graphite furnace and the use of Mg(NO(3))(2) as chemical modifier have improved atomic absorption signal intensity (sensitivity as characteristic mass of 25 pg) and precision (RSD of 2.6%, c=10 μg L(-1), n=11). Total arsenic amount was determined after reduction of arsenic(V) to arsenic(III) by thiourea-HCl system. As(V) concentration was calculated by the difference between As(III) and total arsenic. The detection limit (3s) of the method was found as 10 ng L(-1) As(III) with an enrichment factor of 86. The relative standard deviation and relative error for six replicate determinations of 0.5 μg L(-1) As(III) were found to be 4.0% and -0.7%, respectively. The method was successfully applied to drinking water, snow and reference water (SEM-2011) samples. When the samples were spiked with 0.5 and 1.0 μg L(-1) As(III) and As(V), the recoveries varied between 96 and 100%.

  17. Application of a novel large-volume injection method using a stomach-shaped inlet liner in capillary gas chromatographic trace analysis of dioxins in human milk and plasma.

    PubMed

    Saito, Koichi; Ohmura, Atsuko; Takekuma, Mikiko; Sasano, Ryoichi; Matsuki, Yasuhiko; Nakazawa, Hiroyuki

    2007-06-01

    A newly developed large-volume injection (LVI) technique that employs a unique stomach-shaped inlet liner (SSIL) inside of a programmable temperature vaporizer was used for the determination of trace amounts of dioxins in human milk and plasma. The initial temperature and the initial dwelling time of the inlet and the kind of solvent used were found to be critical in determining the analytical sensitivity of dioxins due to the loss of these relatively volatile compounds during solvent vaporization. Human milk and plasma were purified and fractionated by pre-packed multi-layered silica-gel chromatography and activated carbon silica-gel column chromatography. A 20-microL aliquot of the fraction collected from the chromatography with toluene was directly applied to the LVI system in high-resolution gas chromatography/high-resolution mass spectrometry. Excellent correlation (r > 0.97) between the values obtained by the LVI method using the SSIL device and those by the conventional regular-volume splitless injection method was obtained for PCDDs, PCDFs and non-ortho PCBs in human milk and plasma samples.

  18. Silicone rod extraction followed by liquid desorption-large volume injection-programmable temperature vaporiser-gas chromatography-mass spectrometry for trace analysis of priority organic pollutants in environmental water samples.

    PubMed

    Delgado, Alejandra; Posada-Ureta, Oscar; Olivares, Maitane; Vallejo, Asier; Etxebarria, Nestor

    2013-12-15

    In this study a priority organic pollutants usually found in environmental water samples were considered to accomplish two extraction and analysis approaches. Among those compounds organochlorine compounds, pesticides, phthalates, phenols and residues of pharmaceutical and personal care products were included. The extraction and analysis steps were based on silicone rod extraction (SR) followed by liquid desorption in combination with large volume injection-programmable temperature vaporiser (LVI-PTV) and gas chromatography-mass spectrometry (GC-MS). Variables affecting the analytical response as a function of the programmable temperature vaporiser (PTV) parameters were firstly optimised following an experimental design approach. The SR extraction and desorption conditions were assessed afterwards, including matrix modification, time extraction, and stripping solvent composition. Subsequently, the possibility of performing membrane enclosed sorptive coating extraction (MESCO) as a modified extraction approach was also evaluated. The optimised method showed low method detection limits (3-35 ng L(-1)), acceptable accuracy (78-114%) and precision values (<13%) for most of the studied analytes regardless of the aqueous matrix. Finally, the developed approach was successfully applied to the determination of target analytes in aqueous environmental matrices including estuarine and wastewater samples.

  19. Integrated strong cation-exchange hybrid monolith coupled with capillary zone electrophoresis and simultaneous dynamic pH junction for large-volume proteomic analysis by mass spectrometry.

    PubMed

    Zhang, Zhenbin; Sun, Liangliang; Zhu, Guijie; Yan, Xiaojing; Dovichi, Norman J

    2015-06-01

    A sulfonate-silica hybrid strong cation-exchange (SCX) monolith was synthesized at the proximal end of a capillary zone electrophoresis column and used for on-line solid-phase extraction (SPE) sample preconcentration. Sample was prepared in an acidic buffer and deposited onto the SCX-SPE monolith and eluted using a basic buffer. Electrophoresis was performed in an acidic buffer. This combination of buffers results in formation of a dynamic pH junction, which allows use of relatively large elution buffer volume while maintaining peak efficiency and resolution. All experiments were performed with a 50 µm ID capillary, a 1cm long SCX-SPE monolith, a 60cm long separation capillary, and a electrokinetically pumped nanospray interface. The volume of the capillary is 1.1 µL. By loading 21 µL of a 1×10(-7) M angiotensin II solution, an enrichment factor of 3000 compared to standard electrokinetic injection was achieved on this platform while retaining efficient electrophoretic performance (N=44,000 plates). The loading capacity of the sulfonate SCX hybrid monolith was determined to be ~15 pmol by frontal analysis with 10(-5) M angiotensin II. The system was also applied to the analysis of a 10(-4) mg/mL bovine serum albumin tryptic digest; the protein coverage was 12% and 11 peptides were identified. Finally, by loading 5.5 µL of a 10(-3) mg/mL E. coli digest, 109 proteins and 271 peptides were identified in a 20 min separation; the median separation efficiency generated by these peptides was 25,000 theoretical plates. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Integrated strong cation-exchange hybrid monolith coupled with capillary zone electrophoresis and simultaneous dynamic pH junction for large-volume proteomic analysis by mass spectrometry

    PubMed Central

    Zhang, Zhenbin; Sun, Liangliang; Zhu, Guijie; Yan, Xiaojing

    2015-01-01

    A sulfonate-silica hybrid strong cation-exchange (SCX) monolith was synthesized at the proximal end of a capillary zone electrophoresis column and used for on-line solid-phase extraction (SPE) sample preconcentration. Sample was prepared in an acidic buffer and deposited onto the SCX-SPE monolith and eluted using a basic buffer. Electrophoresis was performed in an acidic buffer. This combination of buffers results in formation of a dynamic pH junction, which allows use of relatively large elution buffer volume while maintaining peak efficiency and resolution. All experiments were performed with a 50 µm ID capillary, a 1-cm long SCX-SPE monolith, a 60-cm long separation capillary, and a electrokinetically pumped nanospray interface. The volume of the capillary is 1.1 µL. By loading 21 µL of a 1 × 10−7 M angiotensin II solution, an enrichment factor of 3000 compared to standard electrokinetic injection was achieved on this platform while retaining efficient electrophoretic performance (N = 44 000 plates). The loading capacity of the sulfonate SCX hybrid monolith was determined to be ~15 pmol by frontal analysis with 10−5 M angiotensin II. The system was also applied to the analysis of a 10−4 mg/mL bovine serum albumin tryptic digest; the protein coverage was 12% and 11 peptides were identified. Finally, by loading 5.5 µL of a 10−3 mg/mL E. coli digest, 109 proteins and 271 peptides were identified in a 20 min separation; the median separation efficiency generated by these peptides was 25,000 theoretical plates. PMID:25863379

  1. Determination of ethyl glucuronide in hair samples of Chinese people by protein precipitation (PPT) and large volume injection-gas chromatography-tandem mass spectrometry (LVI-GC/MS/MS).

    PubMed

    Shi, Yan; Shen, Baohua; Xiang, Ping; Yan, Hui; Shen, Min

    2010-11-15

    Ethyl glucuronide (EtG) has been shown to be a suitable marker of excessive alcohol consumption. Determination of EtG in hair samples may help to differentiate social drinkers from alcoholics, and this testing can be widely used in forensic science, treatment programs, workplaces, military bases as well as driving ability test to provide legal proof of drinking. A method for determination of EtG in hair samples using large volume injection-gas chromatography-tandem mass spectrometry (LVI-GC/MS/MS) was developed and validated. Hair samples (in 1 mL deionized water) were ultrasonicated for 1h and incubated overnight; these samples were then deproteinated to remove impurities and derivatisated with 15 μL of pyridine and 30 μL of BSTFA. EtG was detected using GC/MS/MS in multiple-reaction monitoring mode. This method exhibited good linearity: y=0.0036 x+0.0437, R²=0.9993, the limit of detection and the limit of quantification were 5 pg/mg and 10 pg/mg, respectively. The extraction recoveries were more than 60%, and the inter-day and intra-day relative standard deviations (RSD) were less than 15%. This method has been applied to the analysis of EtG in hair samples from 21 Chinese subjects. The results for samples obtained from all of those who were teetotallers were negative, and the results for the other 15 samples ranged from 10 to 78 pg/mg, except for one negative sample. These data are the basis for interpretation of alcohol abuse.

  2. Routine analysis of off-flavor compounds in water at sub-part-per-trillion level by large-volume injection GC/MS with programmable temperature vaporizing inlet.

    PubMed

    Zhang, Lifeng; Hu, Ruikang; Yang, Zhaoguang

    2006-02-01

    "Earthy-musty" off-flavor problem in water samples are due to organic compounds present at the sub-part-per-trillion level. Most of the developments in the analysis of tastes and odorous compounds focus on the extraction pre-concentration technique, with detection at picogram per liter level of the earthy-musty off-flavor compounds difficult to be achieved. The objective of this study is to develop a new method involving the large-volume injection (LVI) GC/MS via programmable temperature vaporizing (PTV) inlet and continuous liquid-liquid extraction, to attain analytical sensitivity equal to or better than olfactory sensitivity. Six "earthy-musty" organic compounds, 2-methylisoborneol (MIB), geosmin, 2,4,6-trichloroanisole, 2,3,6-trichloroanisole, 2,3,4-trichloroanisole and 2,4,6-tribromoanisole, were used as probes for this study. It was found that LVI via PTV could greatly improve system sensitivity towards off-flavor compound detection. Variable instrument conditions and sample preparation conditions were studied in detail. This reliable and efficient method has been optimized and validated. The method detection limit were found to be from 35 to 70 pg/L for haloanisoles, 50 pg/L for geosmin and 0.34 ng/L for MIB, with relative standard deviation of calibration curve ranging from 4.7% to 15.1% and recovery ranging from 58% to 96%. This method has been successfully applied to test off-flavor compounds in different types of water samples with satisfactory results.

  3. A novel method for the rapid determination of polyethoxylated tallow amine surfactants in water and sediment using large volume injection with high performance liquid chromatography and tandem mass spectrometry.

    PubMed

    Ross, Andrew R S; Liao, Xiangjun

    2015-08-19

    Polyethoxylated tallow amine (POEA) surfactants have been used in many glyphosate-based herbicide formulations for agricultural, industrial and residential weed control. The potential for release of these compounds into the environment is of increasing concern due to their toxicity towards aquatic organisms. Current methods for analysis of POEA surfactants require significant time and effort to achieve limits of quantification that are often higher than the concentrations at which biological effects have been observed (as low as 2 ng mL(-1)). We have developed a rapid and robust method for quantifying the POEA surfactant mixture MON 0818 at biologically relevant concentrations in fresh water, sea water and lake sediment using reversed phase high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry. Water samples preserved by 1:1 v/v dilution with methanol are analyzed directly following centrifugation. Sediment samples undergo accelerated solvent extraction in aqueous methanol prior to analysis. Large volume (100 μL) sample injection and multiple reaction monitoring of a subset of the most abundant POEA homologs provide limits of quantification of 0.5 and 2.9 ng mL(-1) for MON 0818 in fresh water and sea water, respectively, and 2.5 ng g(-1) for total MON 0818 in lake sediment. Average recoveries of 93 and 75% were achieved for samples of water and sediment, respectively spiked with known amounts of MON 0818. Precision and accuracy for the analysis of water and sediment samples were within 10 and 16%, respectively based upon replicate analyses of calibration standards and representative samples. Results demonstrate the utility of the method for quantifying undegraded MON 0818 in water and sediment, although a more comprehensive method may be needed to identify and determine other POEA mixtures and degradation profiles that might occur in the environment.

  4. Analysis of llicit and illicit drugs in waste, surface and lake water samples using large volume direct injection high performance liquid chromatography--electrospray tandem mass spectrometry (HPLC-MS/MS).

    PubMed

    Berset, Jean-Daniel; Brenneisen, Rudolf; Mathieu, Christoph

    2010-11-01

    Llicit and illicit drugs represent a recent group of emerging contaminants and have been found in the aquatic environment. A HPLC-MS/MS method was developed using direct injection (DI) of larger volumes and a polar endcapped reversed-phase (RP) column to measure drug components in water samples belonging to the cocaine group, opiates, amphetamine-like stimulants and metabolites thereof. After validation, including sensitivity, linearity, recovery, precision and matrix effect studies, most drugs could be detected with limits of quantitation (LOQ) of 20 ng L(-1) in wastewater (WW) and 0.2 ng L(-1) in surface water. The major substances found in influents and effluents were cocaine (COC), benzoylecgonine (BE), morphine (MO), methadone (MD) and its main metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) with concentrations up to 2 μg L(-1), followed by codeine (COD) and the amphetamines which ranged between 20 and 400 ng L(-1). Except for MO, COD and EDDP levels were generally lower in the effluents. River and lake water contained trace amounts of mainly BE, MD and EDDP from the high pg L(-1) to the low ng L(-1) level. Monitoring COC and BE levels over 11 consecutive days in influents and effluents suggests a consumption preference on week-end days. Finally, measuring an influent after a major music event revealed that sewage treatment plants (STPs) are exposed, for a limited period of time, to high concentration peaks of COC and BE as well as amphetamine-like stimulants such as ecstasy (MDMA).

  5. Pills, injections and audiotapes: reaching couples in Pakistan.

    PubMed

    Collumbien, Martine; Douthwaite, Megan

    2003-01-01

    An innovative social marketing intervention in Pakistan distributes audiocassettes via chemist shops and Lady Health Visitors (LHVs) to reach women in a segregated society with accurate information on hormonal contraceptives. Operations research was done to assess the utility of the cassette in knowledge dissemination and adoption of hormonal use. In total 187 structured questionnaires were completed with couples who had obtained a cassette. Listeners were significantly more knowledgeable than non-listeners about correct use of hormonals (OR = 8.6 for women and OR = 12.7 for men). Hormonal use increased from 12% to 25%. LHVs also organized discussion groups for women, and attending such a chat group was the strongest predictor for adoption of pills and injectables (OR = 4.15). Equivalent male groups are suggested to reach apprehensive men. By providing accurate information to urban couples and by acquiring a knowledgeable critical mass of satisfied users, the cassette could be a powerful catalyst to further contraceptive diffusion.

  6. Safety considerations in large-volume lipoplasty.

    PubMed

    Giese, S Y

    2001-11-01

    Proper patient selection, diligent fluid management, and attention to body temperature are important safety considerations in large-volume lipoplasty (LVL). Complications related to fluid overload, lidocaine toxicity, coagulopathies, and lengthy combined surgical procedures are preventable and not directly linked to LVL technique. Benefits as well as morbidity and mortality from LVL can be weighed against risk factors such as obesity, a prediabetic condition, and/or adverse effects of weight-loss medications. The author describes how she incorporates safeguards into her LVL procedures. (Aesthetic Surg J 2001;21:545-548.).

  7. Large volume flow-through scintillating detector

    DOEpatents

    Gritzo, Russ E.; Fowler, Malcolm M.

    1995-01-01

    A large volume flow through radiation detector for use in large air flow situations such as incinerator stacks or building air systems comprises a plurality of flat plates made of a scintillating material arranged parallel to the air flow. Each scintillating plate has a light guide attached which transfers light generated inside the scintillating plate to an associated photomultiplier tube. The output of the photomultiplier tubes are connected to electronics which can record any radiation and provide an alarm if appropriate for the application.

  8. Concentration of Enteroviruses from Large Volumes of Water

    PubMed Central

    Sobsey, Mark D.; Wallis, Craig; Henderson, Marilyn; Melnick, Joseph L.

    1973-01-01

    An improved method for concentrating viruses from large volumes of clean waters is described. It was found that, by acidification, viruses in large volumes of water could be efficiently adsorbed to epoxy-fiber-glass and nitrocellulose filters in the absence of exogenously added salts. Based upon this finding, a modified version of our previously described virus concentration system was developed for virus monitoring of clean waters. In this procedure the water being tested is acidified by injection of N HCl prior to passage through a virus adsorber consisting of a fiber-glass cartridge depth filter and an epoxy-fiber-glass membrane filter in series. The adsorbed viruses are then eluted with a 1-liter volume of pH 11.5 eluent and reconcentrated by adsorption to and elution from a small epoxy-fiber-glass filter series. With this method small quantities of poliovirus in 100-gallon (378.5-liter) volumes of tapwater were concentrated nearly 40,000-fold with an average virus recovery efficiency of 77%. Images PMID:16349972

  9. Ultra-rapid formation of large volumes of evolved magma

    NASA Astrophysics Data System (ADS)

    Michaut, C.; Jaupart, C.

    2006-10-01

    We discuss evidence for, and evaluate the consequences of, the growth of magma reservoirs by small increments of thin (⋍ 1-2 m) sills. For such thin units, cooling proceeds faster than the nucleation and growth of crystals, which only allows a small amount of crystallization and leads to the formation of large quantities of glass. The heat balance equation for kinetic-controlled crystallization is solved numerically for a range of sill thicknesses, magma injection rates and crustal emplacement depths. Successive injections lead to the accumulation of poorly crystallized chilled magma with the properties of a solid. Temperatures increase gradually with each injection until they become large enough to allow a late phase of crystal nucleation and growth. Crystallization and latent heat release work in a positive feedback loop, leading to catastrophic heating of the magma pile, typically by 200 °C in a few decades. Large volumes of evolved melt are made available in a short time. The time for the catastrophic heating event varies as Q- 2 , where Q is the average magma injection rate, and takes values in a range of 10 5-10 6 yr for typical geological magma production rates. With this mechanism, storage of large quantities of magma beneath an active volcanic center may escape detection by seismic methods.

  10. Fully Coupled Well Models for Fluid Injection and Production

    SciTech Connect

    White, Mark D.; Bacon, Diana H.; White, Signe K.; Zhang, Z. F.

    2013-08-05

    Wells are the primary engineered component of geologic sequestration systems with deep subsurface reservoirs. Wells provide a conduit for injecting greenhouse gases and producing reservoirs fluids, such as brines, natural gas, and crude oil, depending on the target reservoir. Well trajectories, well pressures, and fluid flow rates are parameters over which well engineers and operators have control during the geologic sequestration process. Current drilling practices provided well engineers flexibility in designing well trajectories and controlling screened intervals. Injection pressures and fluids can be used to purposely fracture the reservoir formation or to purposely prevent fracturing. Numerical simulation of geologic sequestration processes involves the solution of multifluid transport equations within heterogeneous geologic media. These equations that mathematically describe the flow of fluid through the reservoir formation are nonlinear in form, requiring linearization techniques to resolve. In actual geologic settings fluid exchange between a well and reservoir is a function of local pressure gradients, fluid saturations, and formation characteristics. In numerical simulators fluid exchange between a well and reservoir can be specified using a spectrum of approaches that vary from totally ignoring the reservoir conditions to fully considering reservoir conditions and well processes. Well models are a numerical simulation approach that account for local conditions and gradients in the exchange of fluids between the well and reservoir. As with the mathematical equations that describe fluid flow in the reservoir, variation in fluid properties with temperature and pressure yield nonlinearities in the mathematical equations that describe fluid flow within the well. To numerically simulate the fluid exchange between a well and reservoir the two systems of nonlinear multifluid flow equations must be resolved. The spectrum of numerical approaches for resolving

  11. SUSY's Ladder: reframing sequestering at Large Volume

    NASA Astrophysics Data System (ADS)

    Reece, Matthew; Xue, Wei

    2016-04-01

    Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague other supersymmetric theories. We study SUSY's Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. This gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.

  12. LARGE volume string compactifications at finite temperature

    SciTech Connect

    Anguelova, Lilia; Calò, Vincenzo; Cicoli, Michele E-mail: v.calo@qmul.ac.uk

    2009-10-01

    We present a detailed study of the finite-temperature behaviour of the LARGE Volume type IIB flux compactifications. We show that certain moduli can thermalise at high temperatures. Despite that, their contribution to the finite-temperature effective potential is always negligible and the latter has a runaway behaviour. We compute the maximal temperature T{sub max}, above which the internal space decompactifies, as well as the temperature T{sub *}, that is reached after the decay of the heaviest moduli. The natural constraint T{sub *} < T{sub max} implies a lower bound on the allowed values of the internal volume V. We find that this restriction rules out a significant range of values corresponding to smaller volumes of the order V ∼ 10{sup 4}l{sub s}{sup 6}, which lead to standard GUT theories. Instead, the bound favours values of the order V ∼ 10{sup 15}l{sub s}{sup 6}, which lead to TeV scale SUSY desirable for solving the hierarchy problem. Moreover, our result favours low-energy inflationary scenarios with density perturbations generated by a field, which is not the inflaton. In such a scenario, one could achieve both inflation and TeV-scale SUSY, although gravity waves would not be observable. Finally, we pose a two-fold challenge for the solution of the cosmological moduli problem. First, we show that the heavy moduli decay before they can begin to dominate the energy density of the Universe. Hence they are not able to dilute any unwanted relics. And second, we argue that, in order to obtain thermal inflation in the closed string moduli sector, one needs to go beyond the present EFT description.

  13. Large-volume sampling and preconcentration for trace explosives detection.

    SciTech Connect

    Linker, Kevin Lane

    2004-05-01

    A trace explosives detection system typically contains three subsystems: sample collection, preconcentration, and detection. Sample collection of trace explosives (vapor and particulate) through large volumes of airflow helps reduce sampling time while increasing the amount of dilute sample collected. Preconcentration of the collected sample before introduction into the detector improves the sensitivity of the detector because of the increase in sample concentration. By combining large-volume sample collection and preconcentration, an improvement in the detection of explosives is possible. Large-volume sampling and preconcentration is presented using a systems level approach. In addition, the engineering of large-volume sampling and preconcentration for the trace detection of explosives is explained.

  14. MICROSCALE FLOW INJECTION AND MICROBORE HIGH-PERFORMANCE LIQUID CHROMATORGRAPHY COUPLED WITH INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY VIA A HIGH-EFFICIENCY NEBULIZER

    EPA Science Inventory

    A high-effeciency nebulizer has been used for coupling microscale flow injection and microbore high-performance liquid chromatography with inductively coupled plasma mass spectrometry (ICPMS). The microscale flow injection system was configured to minimize band broadening between...

  15. Electron kinetics in capacitively coupled plasmas modulated by electron injection

    NASA Astrophysics Data System (ADS)

    Zhang, Ya; Peng, Yanli; Innocenti, Maria Elena; Jiang, Wei; Wang, Hong-yu; Lapenta, Giovanni

    2017-09-01

    The controlling effect of an electron injection on the electron energy distribution function (EEDF) and on the energetic electron flux, in a capacitive radio-frequency argon plasma, is studied using a one-dimensional particle-in-cell/Monte Carlo collisions model. The input power of the electron beam is as small as several tens of Watts with laboratory achievable emission currents and energies. With the electron injection, the electron temperature decreases but with a significant high energy tail. The electron density, electron temperature in the sheath, and electron heating rate increase with the increasing emission energy. This is attributed to the extra heating of the energetic electrons in the EEDF tail. The non-equilibrium EEDF is obtained for strong non-local distributions of the electric field, electron heating rate, excitation, and ionization rate, indicating the discharge has transited from a volume heating (α-mode dominated) into a sheath heating (γ-mode dominated) type. In addition, the electron injection not only modifies the self-bias voltage, but also enhances the electron flux that can reach the electrodes. Moreover, the relative population of energetic electrons significantly increases with the electron injection compared to that without the electron injection, relevant for modifying the gas and surface chemistry reactions.

  16. Effects of outer top gas injection on ICRF coupling in ASDEX Upgrade: towards modelling of ITER gas injection

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Bobkov, V.; Noterdaeme, J.-M.; Tierens, W.; Bilato, R.; Carralero, D.; Coster, D.; Jacquot, J.; Jacquet, P.; Lunt, T.; Pitts, R. A.; Rohde, V.; Siegl, G.; Fuenfgelder, H.; Aguiam, D.; Silva, A.; Colas, L.; Ceccuzzi, S.; the ASDEX Upgrade Team

    2017-07-01

    The influence of outer top gas injection on the scrape-off layer (SOL) density and ion cyclotron range of frequency (ICRF) coupling has been studied in ASDEX Upgrade (AUG) L-mode plasmas for the first time. The three-dimensional (3D) edge plasma fluid and neutral transport code EMC3-EIRENE is used to simulate the SOL plasma density, and the 3D wave code RAPLICASOL is used to compute the ICRF coupling resistance with the calculated density. Improvements have been made in the EMC3-EIRENE simulations by fitting transport parameters separately for each gas puffing case. It is found that the calculated local density profiles and coupling resistances are in good agreement with the experimental ones. The results indicate that the SOL density increase depends sensitively on the spreading of the injected outer top gas. If more gas enters into the main chamber through the paths near the top of vessel, the SOL density increase will be more toroidally uniform; if more gas chooses the paths closer to the mid-plane, then the SOL density increase will be more local and more significant. Among the various local gas puffing methods, the mid-plane gas valve close to the antenna is still the best option in terms of improving ICRF coupling. Differences between the outer top gas puffing in AUG and the outer top gas puffing in ITER are briefly summarized. Instructive suggestions for ITER and future plans for ITER gas injection simulations are discussed.

  17. Sparticle spectra from Large-Volume String Compactifications

    SciTech Connect

    Conlon, Joseph P.

    2007-11-20

    Large-volume models are a promising approach to stabilising moduli and generating the weak hierarchy through TeV-supersymmetry. I describe the pattern of sparticle mass spectra that arises in these models.

  18. Soil Nitrogen Response to Coupling Cover Crops with Manure Injection

    USDA-ARS?s Scientific Manuscript database

    Coupling winter small grain cover crops (CC) with manure (M) application may increase retention of manure nitrogen (N) in corn-soybean cropping systems. The objective of this research was to quantify soil N changes after application of liquid swine M (Sus scrofa L.) at target N rates of 112, 224, an...

  19. Efficient coupling of starlight into single mode photonics using Adaptive Injection (AI)

    NASA Astrophysics Data System (ADS)

    Norris, Barnaby; Cvetojevic, Nick; Gross, Simon; Arriola, Alexander; Tuthill, Peter; Lawrence, Jon; Richards, Samuel; Goodwin, Michael; Zheng, Jessica

    2016-08-01

    Using single-mode fibres in astronomy enables revolutionary techniques including single-mode interferometry and spectroscopy. However, injection of seeing-limited starlight into single mode photonics is extremely difficult. One solution is Adaptive Injection (AI). The telescope pupil is segmented into a number of smaller subapertures each with size r0, such that seeing can be approximated as a single tip / tilt / piston term for each subaperture, and then injected into a separate fibre via a facet of a segmented MEMS deformable mirror. The injection problem is then reduced to a set of individual tip tilt loops, resulting in high overall coupling efficiency.

  20. Reporting of HIV risk behaviors by injection drug using heterosexual couples in methadone maintenance.

    PubMed

    Wells, E A; Clark, L L; Calsyn, D A; Saxon, A J; Jackson, T R; Wrede, A F

    1994-08-01

    This study sought to identify differences within injection drug using (IDU) couples in reporting of sexual and needle risk behavior. Subjects were thirty-nine heterosexual couples entering methadone maintenance. In 33.3% of couples, one member reported sharing needles while the other member reported no sharing. In 12.9% of couples, one member reported sharing injection equipment, while the other member reported no sharing. Agreement was 77.4% between members of monogamous couples regarding frequency of condom use, 80.7% regarding vaginal intercourse with condoms, and 25.8% regarding vaginal intercourse without condoms. Within couples, a number of differences between members of the couple in injection equipment sharing were noted, suggesting that individuals who attempt to protect themselves by not sharing injection equipment may be placed at risk by their sexual partners. Further clinical and research efforts should be directed toward reducing barriers to behavior that would protect both partners. Implications for self-report measurement of HIV risk behavior and for preventive interventions are discussed.

  1. The Coupling Impedance of the RHIC Injection Kicker System

    SciTech Connect

    Hahn, H.; Ratti, A.

    1996-08-30

    The RHIC injection kicker is configured as a "C" cross section magnet with interspersed ferrite (Nickel-Zinc ferrite with high permeability and resistivity for use at frequencies up to ~100 MHz) and dielectric (sintered mixture of Magnesium Titanat and Calcium Titanat with high dielectric constant ε~100) blocks as shown in Fig. 1. The deflection properties of the kicker are dominated (~85%) by the magnetic field and thus by the ferrite properties and its geometrical configuration. The dielectric block provide the capacitance required to achieve a transmission line kicker (<50 nsec current rise time) and to reduce the characteristic impedance so as to match the 50/Ω of the Blumlein pulser. The dielectric blocks impose the de-facto voltage limit of the kicker and represent one of the primary design limitations.

  2. Injection coupling with high amplitude transverse modes: Experimentation and simulation

    NASA Astrophysics Data System (ADS)

    Mery, Yoann; Ducruix, Sébastien; Scouflaire, Philippe; Candel, Sébastien

    2009-06-01

    High frequency combustion instabilities have technical importance in the design of liquid rocket engines. These phenomena involve a strong coupling between transverse acoustic modes and combustion. They are currently being investigated by combining experimentation and numerical simulations. On the experimental level, the coupling is examined in a model scale system featuring a multiple injector combustor (MIC) comprising five coaxial injectors fed with liquid oxygen and gaseous methane. This system is equipped with a novel VHAM actuator (Very High Amplitude Modulator) which comprises two nozzles and a rotating toothed wheel blocking the nozzles in an alternate fashion. This device was designed to obtain the highest possible levels of transverse oscillation in the MIC. After a brief review of the VHAM, this article reports cold flow experiments using this modulator. Velocity maps obtained under resonant conditions using the VHAM are examined at different instants during a cycle of oscillation. Experimental data are compared with numerical pressure and velocity fields obtained from an acoustic solver. The good agreement observed in the nozzle vicinity indicates that numerical simulations can be used to analyze the complex flow field generated by the VHAM. To cite this article: Y. Mery et al., C. R. Mecanique 337 (2009).

  3. Evaluation of Bacillus oleronius as a Biological Indicator for Terminal Sterilization of Large-Volume Parenterals.

    PubMed

    Izumi, Masamitsu; Fujifuru, Masato; Okada, Aki; Takai, Katsuya; Takahashi, Kazuhiro; Udagawa, Takeshi; Miyake, Makoto; Naruyama, Shintaro; Tokuda, Hiroshi; Nishioka, Goro; Yoden, Hikaru; Aoki, Mitsuo

    2016-01-01

    In the production of large-volume parenterals in Japan, equipment and devices such as tanks, pipework, and filters used in production processes are exhaustively cleaned and sterilized, and the cleanliness of water for injection, drug materials, packaging materials, and manufacturing areas is well controlled. In this environment, the bioburden is relatively low, and less heat resistant compared with microorganisms frequently used as biological indicators such as Geobacillus stearothermophilus (ATCC 7953) and Bacillus subtilis 5230 (ATCC 35021). Consequently, the majority of large-volume parenteral solutions in Japan are manufactured under low-heat sterilization conditions of F0 <2 min, so that loss of clarity of solutions and formation of degradation products of constituents are minimized. Bacillus oleronius (ATCC 700005) is listed as a biological indicator in "Guidance on the Manufacture of Sterile Pharmaceutical Products Produced by Terminal Sterilization" (guidance in Japan, issued in 2012). In this study, we investigated whether B. oleronius is an appropriate biological indicator of the efficacy of low-heat, moist-heat sterilization of large-volume parenterals. Specifically, we investigated the spore-forming ability of this microorganism in various cultivation media and measured the D-values and z-values as parameters of heat resistance. The D-values and z-values changed depending on the constituents of large-volume parenteral products. Also, the spores from B. oleronius showed a moist-heat resistance that was similar to or greater than many of the spore-forming organisms isolated from Japanese parenteral manufacturing processes. Taken together, these results indicate that B. oleronius is suitable as a biological indicator for sterility assurance of large-volume parenteral solutions subjected to low-heat, moist-heat terminal sterilization.

  4. Benchmark initiative on coupled multiphase flow and geomechanical processes during CO2 injection

    NASA Astrophysics Data System (ADS)

    Benisch, K.; Annewandter, R.; Olden, P.; Mackay, E.; Bauer, S.; Geiger, S.

    2012-12-01

    CO2 injection into deep saline aquifers involves multiple strongly interacting processes such as multiphase flow and geomechanical deformation, which threat to the seal integrity of CO2 repositories. Coupled simulation codes are required to establish realistic prognoses of the coupled process during CO2 injection operations. International benchmark initiatives help to evaluate, to compare and to validate coupled simulation results. However, there is no published code comparison study so far focusing on the impact of coupled multiphase flow and geomechanics on the long-term integrity of repositories, which is required to obtain confidence in the predictive capabilities of reservoir simulators. We address this gap by proposing a benchmark study. A wide participation from academic and industrial institutions is sought, as the aim of building confidence in coupled simulators become more plausible with many participants. Most published benchmark studies on coupled multiphase flow and geomechanical processes have been performed within the field of nuclear waste disposal (e.g. the DECOVALEX project), using single-phase formulation only. As regards CO2 injection scenarios, international benchmark studies have been published comparing isothermal and non-isothermal multiphase flow processes such as the code intercomparison by LBNL, the Stuttgart Benchmark study, the CLEAN benchmark approach and other initiatives. Recently, several codes have been developed or extended to simulate the coupling of hydraulic and geomechanical processes (OpenGeoSys, ELIPSE-Visage, GEM, DuMuX and others), which now enables a comprehensive code comparison. We propose four benchmark tests of increasing complexity, addressing the coupling between multiphase flow and geomechanical processes during CO2 injection. In the first case, a horizontal non-faulted 2D model consisting of one reservoir and one cap rock is considered, focusing on stress and strain regime changes in the storage formation and the

  5. AUTOMATED ANALYSIS OF AQUEOUS SAMPLES CONTAINING PESTICIDES, ACIDIC/BASIC/NEUTRAL SEMIVOLATILES AND VOLATILE ORGANIC COMPOUNDS BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GC/MS

    EPA Science Inventory

    Data is presented on the development of a new automated system combining solid phase extraction (SPE) with GC/MS spectrometry for the single-run analysis of water samples containing a broad range of organic compounds. The system uses commercially available automated in-line 10-m...

  6. A METHOD FOR AUTOMATED ANALYSIS OF 10 ML WATER SAMPLES CONTAINING ACIDIC, BASIC, AND NEUTRAL SEMIVOLATILE COMPOUNDS LISTED IN USEPA METHOD 8270 BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GAS CHROMATOGRAPHY/MASS SPECTROMETRY

    EPA Science Inventory

    Data is presented showing the progress made towards the development of a new automated system combining solid phase extraction (SPE) with gas chromatography/mass spectrometry for the single run analysis of water samples containing a broad range of acid, base and neutral compounds...

  7. AUTOMATED ANALYSIS OF AQUEOUS SAMPLES CONTAINING PESTICIDES, ACIDIC/BASIC/NEUTRAL SEMIVOLATILES AND VOLATILE ORGANIC COMPOUNDS BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GC/MS

    EPA Science Inventory

    Data is presented on the development of a new automated system combining solid phase extraction (SPE) with GC/MS spectrometry for the single-run analysis of water samples containing a broad range of organic compounds. The system uses commercially available automated in-line 10-m...

  8. A METHOD FOR AUTOMATED ANALYSIS OF 10 ML WATER SAMPLES CONTAINING ACIDIC, BASIC, AND NEUTRAL SEMIVOLATILE COMPOUNDS LISTED IN USEPA METHOD 8270 BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GAS CHROMATOGRAPHY/MASS SPECTROMETRY

    EPA Science Inventory

    Data is presented showing the progress made towards the development of a new automated system combining solid phase extraction (SPE) with gas chromatography/mass spectrometry for the single run analysis of water samples containing a broad range of acid, base and neutral compounds...

  9. Ultrafast spin tunneling and injection in coupled nanostructures of InGaAs quantum dots and quantum well

    SciTech Connect

    Yang, Xiao-Jie Kiba, Takayuki; Yamamura, Takafumi; Takayama, Junichi; Subagyo, Agus; Sueoka, Kazuhisa; Murayama, Akihiro

    2014-01-06

    We investigate the electron-spin injection dynamics via tunneling from an In{sub 0.1}Ga{sub 0.9}As quantum well (QW) to In{sub 0.5}Ga{sub 0.5}As quantum dots (QDs) in coupled QW-QDs nanostructures. These coupled nanostructures demonstrate ultrafast (5 to 20 ps) spin injection into the QDs. The degree of spin polarization up to 45% is obtained in the QDs after the injection, essentially depending on the injection time. The spin injection and conservation are enhanced with thinner barriers due to the stronger electronic coupling between the QW and QDs.

  10. Large volume continuous counterflow dialyzer has high efficiency

    NASA Technical Reports Server (NTRS)

    Mandeles, S.; Woods, E. C.

    1967-01-01

    Dialyzer separates macromolecules from small molecules in large volumes of solution. It takes advantage of the high area/volume ratio in commercially available 1/4-inch dialysis tubing and maintains a high concentration gradient at the dialyzing surface by counterflow.

  11. Coherent motility measurements of biological objects in a large volume

    NASA Astrophysics Data System (ADS)

    Ebersberger, J.; Weigelt, G.; Li, Yajun

    1986-05-01

    We have performed space-time intensity cross-correlation measurements of boiling image plane speckle interferograms to investigate the motility of a large number of small biological objects. Experiments were carried out with Artemia Salina species at various water temperatures. The advantage of this method is the fact that many objects in a large volume can be measured simultaneously.

  12. Technologies for imaging neural activity in large volumes

    PubMed Central

    Ji, Na; Freeman, Jeremy; Smith, Spencer L.

    2017-01-01

    Neural circuitry has evolved to form distributed networks that act dynamically across large volumes. Collecting data from individual planes, conventional microscopy cannot sample circuitry across large volumes at the temporal resolution relevant to neural circuit function and behaviors. Here, we review emerging technologies for rapid volume imaging of neural circuitry. We focus on two critical challenges: the inertia of optical systems, which limits image speed, and aberrations, which restrict the image volume. Optical sampling time must be long enough to ensure high-fidelity measurements, but optimized sampling strategies and point spread function engineering can facilitate rapid volume imaging of neural activity within this constraint. We also discuss new computational strategies for the processing and analysis of volume imaging data of increasing size and complexity. Together, optical and computational advances are providing a broader view of neural circuit dynamics, and help elucidate how brain regions work in concert to support behavior. PMID:27571194

  13. Novel injection methods for substitution of irradiation under different coupling routes of electromagnetic interference

    NASA Astrophysics Data System (ADS)

    Lu, Xinfu; Wei, Guanghui; Pan, Xiaodong

    2013-03-01

    At present, the maximum electromagnetic radiated field strength which can be simulated is not able to satisfy the requirements of electromagnetic environment effects tests on electronic systems. To broaden the effective frequency range of the current injection technique, new current injection methods were put forward for substitution of the radiation. A wide-band current injection device was designed based on the symmetric directional coupler principle. With a typical antenna receiving system under test, the validity of the methods were analyzed by theory and verified by experiments when the Equipment Under Test (EUT) had different coupling routes of electromagnetic interference (EMI). The results indicate that: firstly, the relationship between radiated fields and injected voltage is linear, even if the responses of the system are non-linear; secondly, the method is valid even if the test frequency is up to gigahertz; thirdly, the novel methods of current injection are able to substitute for irradiation effectively when the antenna and the interconnected cable are the main coupling routes of EMI respectively.

  14. Large volume multiple-path nuclear pumped laser

    NASA Technical Reports Server (NTRS)

    Hohl, F.; Deyoung, R. J. (Inventor)

    1981-01-01

    Large volumes of gas are excited by using internal high reflectance mirrors that are arranged so that the optical path crosses back and forth through the excited gaseous medium. By adjusting the external dielectric mirrors of the laser, the number of paths through the laser cavity can be varied. Output powers were obtained that are substantially higher than the output powers of previous nuclear laser systems.

  15. Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria

    SciTech Connect

    Rutqvist, J.; Vasco, D.W.; Myer, L.

    2009-11-01

    In Salah Gas Project in Algeria has been injecting 0.5-1 million tonnes CO{sub 2} per year over the past five years into a water-filled strata at a depth of about 1,800 to 1,900 m. Unlike most CO{sub 2} storage sites, the permeability of the storage formation is relatively low and comparatively thin with a thickness of about 20 m. To ensure adequate CO{sub 2} flow-rates across the low-permeability sand-face, the In Salah Gas Project decided to use long-reach (about 1 to 1.5 km) horizontal injection wells. In an ongoing research project we use field data and coupled reservoir-geomechanical numerical modeling to assess the effectiveness of this approach and to investigate monitoring techniques to evaluate the performance of a CO{sub 2}-injection operation in relatively low permeability formations. Among the field data used are ground surface deformations evaluated from recently acquired satellite-based inferrometry (InSAR). The InSAR data shows a surface uplift on the order of 5 mm per year above active CO{sub 2} injection wells and the uplift pattern extends several km from the injection wells. In this paper we use the observed surface uplift to constrain our coupled reservoir-geomechanical model and conduct sensitivity studies to investigate potential causes and mechanisms of the observed uplift. The results of our analysis indicates that most of the observed uplift magnitude can be explained by pressure-induced, poro-elastic expansion of the 20 m thick injection zone, but there could also be a significant contribution from pressure-induced deformations within a 100 m thick zone of shaly sands immediately above the injection zone.

  16. Monitoring of binder removal from injection molded ceramics using air-coupled ultrasound at high temperature.

    PubMed

    Wright, W D; Hutchins, D A

    1999-01-01

    A pair of capacitance-type air-coupled ultrasonic transducers have been constructed that were capable of operating in air at temperatures of 500 to 600 degrees C. These devices were then used to monitor the pyrolytic removal of organic binder from injection molded silicon nitride ceramic components using air-coupled ultrasound inside a furnace at elevated temperatures. Through-thickness waveforms were obtained in the ceramic and compared with simultaneous measurements of the mass of the sample. Both the ultrasonic velocity and signal amplitudes could be used to monitor the change in mass of the injection molded ceramic, and other phenomena (such as softening and redistribution of the binder) were observed.

  17. Spin injection beyond the diffusive limit in the presence of spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Liefeith, Lennart-Knud; Tholapi, Rajkiran; Ishikura, Tomotsugu; Hänze, Max; Hartmann, Robert; Slobodskyy, Taras; Hansen, Wolfgang

    2017-02-01

    Spin injection from epitaxial iron into InGaAs/InAs quantum wells is observed using an all-electric nonlocal setup. From the choice of material, a significant spin-orbit interaction (SOI) is expected. The contact separation of the spin-valve devices is in the order of the mean free path so that the transport is at the transition between diffusive and ballistic. With an established purely diffusive model a spin-injection efficiency of 77 % is determined from the data. This value is very large compared to previous observations on diffusive spin-valve devices on similar material systems. Motivated by similar results on ballistic spin-valve devices in a material system with small spin-orbit coupling, a recent model was suggested in which a ballistic spin-dephasing length was pointed out to be the crucial length scale. With this model and an experimentally determined spin-orbit coupling parameter of α =4 ×10-12 eV m, very high spin-injection efficiencies are still determined in our quantum wells. We suggest that the spin-dephasing length to be used in the model must be larger due to the crystallographic anisotropy of the spin-orbit coupling, i.e., in our setup the SOI stabilizes the spin in the crystal direction of the spin-polarized current.

  18. Accessibility and Analysis to NASA's New Large Volume Missions

    NASA Astrophysics Data System (ADS)

    Hausman, J.; Gangl, M.; McAuley, J.; Toaz, R., Jr.

    2016-12-01

    Each new satellite mission continues to measure larger volumes of data than the last. This is especially true with the new NASA satellite missions NISAR and SWOT, launching in 2020 and 2021, which will produce petabytes of data a year. A major concern is how will users be able to analyze such volumes? This presentation will show how cloud storage and analysis can help overcome and accommodate multiple users' needs. While users may only need gigabytes of data for their research, the data center will need to leverage the processing power of the cloud to perform search and subsetting capabilities over the large volume of data. There is also a vast array of user types that require different tools and services to access and analyze the data. Some users need global data to run climate models, while others require small, dynamic regions with lots of analysis and transformations. There will also be a need to generate data that have different inputs or correction algorithms that the project may not be able to provide as those will be very specialized for specific regions or evolve quicker than what the project can reprocess. By having the data and tools side by side, users will be able to access the data they require and analyze it all in one place. By placing data in the cloud, users can analyze the data there, shifting the current "download and analyze" paradigm to "log-in and analyze". The cloud will provide adequate processing power needed to analyze large volumes of data, subset small regions over large volumes of data, and regenerate/reformat data to the specificity each user requires.

  19. Electrolyte and plasma enzyme analyses during large-volume liposuction.

    PubMed

    Lipschitz, Avron H; Kenkel, Jeffrey M; Luby, Maureen; Sorokin, Evan; Rohrich, Rod J; Brown, Spencer A

    2004-09-01

    Substantial fluid shifts occur during liposuction as wetting solution is infiltrated subcutaneously and fat is evacuated, causing potential electrolyte imbalances. In the porcine model for large-volume liposuction, plasma aspartate aminotransferase and alanine transaminase levels were elevated following liposuction. These results raised concerns for possible mechanical injury and/or lidocaine-induced hepatocellular toxicity in a clinical setting. The first objective of this human model study was to explore the effect of the liposuction procedure on electrolyte balance. The second objective was to determine whether elevated plasma aminotransferase levels were observed subsequent to large-volume liposuction. Five female volunteers underwent three-stage, ultrasound-assisted liposuction. Blood samples were collected perioperatively. Plasma levels of sodium, potassium, venous carbon dioxide, blood urea nitrogen, chloride, and creatinine were determined. Liver function analyte levels were measured, including albumin, total protein, aspartate aminotransferase, and alanine transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, and total bilirubin. To further define intracellular enzyme release, creatine kinase levels were measured. Mild hyponatremia was evident postoperatively (134 to 136 mmol/liter) in four patients. Hypokalemia was evident intraoperatively in all subjects (mean +/- SEM; 3.3 +/- 0.16 mmol/liter; range, 3.0 to 3.4 mmol/liter). Hypoalbuminemia and hypoproteinemia were observed throughout the study (baseline: 2.9 +/- 0.2 g/dl; range, 2.6 to 3.5 g/dl), decreasing to 10 to 40 percent 24 hours postoperatively (2.0 +/- 0.2 g/dl; range, 1.7 to 2.1 g/dl). Aspartate aminotransferase, alanine transaminase, and creatine kinase levels were significantly elevated after the procedure (190 +/- 47.1 U/liter, 50 +/- 7.7 U/liter, and 11,219 +/- 2556.7 U/liter, respectively) (p < 0.01). Release of antidiuretic hormone and even mildly hypotonic intravenous fluid

  20. Coupled Reactive Transport Modeling of CO2 Injection in Mt. Simon Sandstone Formation, Midwest USA

    NASA Astrophysics Data System (ADS)

    Liu, F.; Lu, P.; Zhu, C.; Xiao, Y.

    2009-12-01

    CO2 sequestration in deep geological formations is one of the promising options for CO2 emission reduction. While several large scale CO2 injections in saline aquifers have shown to be successful for the short-term, there is still a lack of fundamental understanding on key issues such as CO2 storage capacity, injectivity, and security over multiple spatial and temporal scales that need to be addressed. To advance these understandings, we applied multi-phase coupled reactive mass transport modeling to investigate the fate of injected CO2 and reservoir responses to the injection into Mt. Simon Formation. We developed both 1-D and 2-D reactive transport models in a radial region of 10,000 m surrounding a CO2 injection well to represent the Mt. Simon sandstone formation, which is a major regional deep saline reservoir in the Midwest, USA. Supercritical CO2 is injected into the formation for 100 years, and the modeling continues till 10,000 years to monitor both short-term and long-term behavior of injected CO2 and the associated rock-fluid interactions. CO2 co-injection with H2S and SO2 is also simulated to represent the flue gases from coal gasification and combustion in the Illinois Basin. The injection of CO2 results in acidified zones (pH ~3 and 5) adjacent to the wellbore, causing progressive water-rock interactions in the surrounding region. In accordance with the extensive dissolution of authigenic K-feldspar, sequential precipitations of secondary carbonates and clay minerals are predicted in this zone. The vertical profiles of CO2 show fingering pattern from the top of the reservoir to the bottom due to the density variation of CO2-impregnated brine, which facilitate convection induced mixing and solubility trapping. Most of the injected CO2 remains within a radial distance of 2500 m at the end of 10,000 years and is sequestered and immobilized by solubility and residual trapping. Mineral trapping via secondary carbonates, including calcite, magnesite

  1. A direct injection high-efficiency nebulizer for inductively coupled plasma mass spectrometry.

    PubMed

    McLean, J A; Zhang, H; Montaser, A

    1998-03-01

    A simple, relatively low-cost direct injection high-efficiency nebulizer (DIHEN) is introduced for argon inductively coupled plasma (Ar ICP) spectrometry. The DIHEN may be operated at solution uptake rates of 1-100 microL/min. Analytical performance indexes for the DIHEN and fundamental characteristics of the aerosol produced are obtained using an ICP mass spectrometer (ICPMS) and a two-dimensional phase Doppler particle analyzer (2D PDPA), respectively. Results are compared to those obtained with a conventional crossflow pneumatic nebulizer (PN), equipped with a Scott-type spray chamber. Droplet sizes and velocities produced with the DIHEN are smaller than those reported for the direct injection nebulizer (DIN). The DIHEN offers optimal sensitivity at low injector gas flow rates (approximately 0.25 L/min) and high rf power (approximately 1.5 kW). For the 17 elements tested, detection limits (ppt) and sensitivities achieved with the DIHEN (at 85 microL/min) are similar to, or better than, those obtained on the same instrument using the PN (at 1 mL/min). However, because the primary aerosol is injected directly into the plasma, oxide-to-metal ion ratios (MO+/M+) are high, as in the case of the DIN. The utility of the DIHEN for the analysis of small-volume samples is demonstrated by microscale flow injection analysis (muFIA) of Cr bound to human lung DNA. Detection of Cr at the femtogram level is feasible.

  2. Concentration of enteroviruses from large volumes of tap water, treated sewage, and seawater.

    PubMed Central

    Gerba, C P; Farrah, S R; Goyal, S M; Wallis, C; Melnick, J L

    1978-01-01

    Methods are described for the efficient concentration of an enterovirus from large volumes of tap water, sewage, and seawater. Virus in acidified water (pH 3.5) in the presence of aluminum chloride was adsorbed to a 10-inch (ca. 25.4 cm) fiberglass depth cartridge and a 10-inch pleated epoxy-fiberglass filter in a series at flow rates of up to 37.8 liters (10 gallons) per min. Adsorbed viruses were eluted from the filters with glycine buffer (pH 10.5 to 11.5), and the eluate was reconcentrated by using a combination of aluminum flocculation followed by hydroextraction. With this procedure, poliovirus in large volumes of tap water, seawater, and sewage could be concentrated with an average efficiency of 52, 53, and 50%, respectively. It was demonstrated that this method is capable of detecting surface solid-associated viruses originating from sewage treatment plants. No difference in virus recovery between laboratory batch studies and a set-up with acid-salt injection was found. This unified scheme for the concentration of viruses has many advantages over previously described systems. These include: high operating flow rates, low weight and small size, effectiveness with a variety of waters with widely varying qualities, and filters with a high resistance to clogging. PMID:205175

  3. High density three-dimensional localization microscopy across large volumes

    PubMed Central

    Legant, Wesley R.; Shao, Lin; Grimm, Jonathan B.; Brown, Timothy A.; Milkie, Daniel E.; Avants, Brian B.; Lavis, Luke D.; Betzig, Eric

    2016-01-01

    Extending three-dimensional (3D) single molecule localization microscopy away from the coverslip and into thicker specimens will greatly broaden its biological utility. However, localizing molecules in 3D with high precision in such samples, while simultaneously achieving the extreme labeling densities required for high resolution of densely crowded structures is challenging due to the limitations both of conventional imaging modalities and of conventional labeling techniques. Here, we combine lattice light sheet microscopy with newly developed, freely diffusing, cell permeable chemical probes with targeted affinity towards either DNA, intracellular membranes, or the plasma membrane. We use this combination to perform high localization precision, ultra-high labeling density, multicolor localization microscopy in samples up to 20 microns thick, including dividing cells and the neuromast organ of a zebrafish embryo. We also demonstrate super-resolution correlative imaging with protein specific photoactivable fluorophores, providing a mutually compatible, single platform alternative to correlative light-electron microscopy over large volumes. PMID:26950745

  4. Large volume water sprays for dispersing warm fogs

    NASA Astrophysics Data System (ADS)

    Keller, V. W.; Anderson, B. J.; Burns, R. A.; Lala, G. G.; Meyer, M. B.

    A new method for dispersing of warm fogs which impede visibility and alter schedules is described. The method uses large volume recycled water sprays to create curtains of falling drops through which the fog is processed by the ambient wind and spray-induced air flow; the fog droplets are removed by coalescence/rainout. The efficiency of this fog droplet removal process depends on the size spectra of the spray drops and optimum spray drop size is calculated as between 0.3-1.0 mm in diameter. Water spray tests were conducted in order to determine the drop size spectra and temperature response of sprays produced by commercially available fire-fighting nozzles, and nozzle array tests were utilized to study air flow patterns and the thermal properties of the overall system. The initial test data reveal that the fog-dispersal procedure is effective.

  5. Large volume water sprays for dispersing warm fogs

    NASA Technical Reports Server (NTRS)

    Keller, V. W.; Anderson, B. J.; Burns, R. A.; Lala, G. G.; Meyer, M. B.

    1986-01-01

    A new method for dispersing of warm fogs which impede visibility and alter schedules is described. The method uses large volume recycled water sprays to create curtains of falling drops through which the fog is processed by the ambient wind and spray-induced air flow; the fog droplets are removed by coalescence/rainout. The efficiency of this fog droplet removal process depends on the size spectra of the spray drops and optimum spray drop size is calculated as between 0.3-1.0 mm in diameter. Water spray tests were conducted in order to determine the drop size spectra and temperature response of sprays produced by commercially available fire-fighting nozzles, and nozzle array tests were utilized to study air flow patterns and the thermal properties of the overall system. The initial test data reveal that the fog-dispersal procedure is effective.

  6. Large-Volume High-Pressure Mineral Physics in Japan

    NASA Astrophysics Data System (ADS)

    Liebermann, Robert C.; Prewitt, Charles T.; Weidner, Donald J.

    American high-pressure research with large sample volumes developed rapidly in the 1950s during the race to produce synthetic diamonds. At that time the piston cylinder, girdle (or belt), and tetrahedral anvil devices were invented. However, this development essentially stopped in the late 1950s, and while the diamond anvil cell has been used extensively in the United States with spectacular success for high-pressure experiments in small sample volumes, most of the significant technological advances in large-volume devices have taken place in Japan. Over the past 25 years, these technical advances have enabled a fourfold increase in pressure, with many important investigations of the chemical and physical properties of materials synthesized at high temperatures and pressures that cannot be duplicated with any apparatus currently available in the United States.

  7. Two-Dimensional Array Beam Scanning Via Externally and Mutually Injection Locked Coupled Oscillators

    NASA Technical Reports Server (NTRS)

    Pogorzelski, Ronald J.

    2000-01-01

    Some years ago, Stephan proposed an approach to one dimensional (linear) phased array beam steering which requires only a single phase shifter. This involves the use of a linear array of voltage-controlled electronic oscillators coupled to nearest neighbors. The oscillators are mutually injection locked by controlling their coupling and tuning appropriately. Stephan's approach consists of deriving two signals from a master oscillator, one signal phase shifted with respect to the other by means of a single phase shifter. These two signals are injected into the end oscillators of the array. The result is a linear phase progression across the oscillator array. Thus, if radiating elements are connected to each oscillator and spaced uniformly along a line, they will radiate a beam at an angle to that line determined by the phase gradient which is, in turn, determined by the phase difference between the injection signals.The beam direction is therefore controlled by adjusting this phase difference. Recently, Pogorzelski and York presented a formulation which facilitates theoretical analysis of the above beam steering technique. This was subsequently applied by Pogorzelski in analysis of two dimensional beam steering using perimeter detuning of a coupled oscillator array. The formulation is based on a continuum model in which the oscillator phases are represented by a continuous function satisfying a partial differential equation of diffusion type. This equation can be solved via the Laplace transform and the resulting solution exhibits the dynamic behavior of the array as the beam is steered. Stephan's beam steering technique can be similarly generalized to two-dimensional arrays in which the beam control signals are applied to the oscillators on the perimeter of the array. In this paper the continuum model for this two-dimensional case is developed and the dynamic solution for the corresponding aperture phase function is obtained. The corresponding behavior of the

  8. Spin injection and spin-orbit coupling in low-dimensional semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Heedt, Sebastian; Wehrmann, Isabel; Gerster, Thomas; Wenk, Paul; Kettemann, Stefan; Sladek, Kamil; Hardtdegen, Hilde; Bringer, Andreas; Schubert, Jürgen; Demarina, Natalia; Grützmacher, Detlev; Schäpers, Thomas

    2014-08-01

    Due to their strong spin-orbit coupling III-V semiconductor nanowires are excellent candidates for electrical spin manipulation. Therefore, a major goal is to tailor spin-orbit coupling in these devices. Direct electrical spin injection into quasi one-dimensional nanowires is demonstrated. Furthermore, the weak antilocalization effect was investigated in InAs nanowires. The quantum corrections to the conductivity are interpreted by developing a quasi-one-dimensional diffusive model. It turns out that by means of doping and electric gating the spin-lifetimes can be tuned significantly. By creating few-electron quantum dots inside these devices the impact of the confinement on the spin relaxation properties is investigated.

  9. Parametric Oscillation, Frequency Mixing, and Injection Locking of Strongly Coupled Nanomechanical Resonator Modes

    NASA Astrophysics Data System (ADS)

    Seitner, Maximilian J.; Abdi, Mehdi; Ridolfo, Alessandro; Hartmann, Michael J.; Weig, Eva M.

    2017-06-01

    We study locking phenomena of two strongly coupled, high quality factor nanomechanical resonator modes to a common parametric drive at a single drive frequency in different parametric driving regimes. By controlled dielectric gradient forces we tune the resonance frequencies of the flexural in-plane and out-of-plane oscillation of the high stress silicon nitride string through their mutual avoided crossing. For the case of the strong common parametric drive signal-idler generation via nondegenerate parametric two-mode oscillation is observed. Broadband frequency tuning of the very narrow linewidth signal and idler resonances is demonstrated. When the resonance frequencies of the signal and idler get closer to each other, partial injection locking, injection pulling, and complete injection locking to half of the drive frequency occurs depending on the pump strength. Furthermore, satellite resonances, symmetrically offset from the signal and idler by their beat note, are observed, which can be attributed to degenerate four-wave mixing in the highly nonlinear mechanical oscillations.

  10. Analyses of Injection-Coupled Combustion Instability from J-2X Gas Generator Development

    NASA Technical Reports Server (NTRS)

    Hulka, James R.; Kenny, R. Jeremy; Protz, Chris; Casiano, Matthew

    2011-01-01

    During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, combustion instabilities were observed near the frequency of the first longitudinal acoustic mode of the hot gas combustion chamber duct. These instabilities were similar to intermediate-frequency or buzz-type instabilities as described in historical programs, except for several aspects: 1) the frequencies were low, in the realm of chug; 2) at times the instability oscillation amplitudes were quite large, with peak-to-peak amplitudes exceeding 50% of the mean chamber pressure along with the appearance of harmonics; 3) the chamber excitation was related to but not exactly at the first longitudinal combustion chamber acoustic mode; and 4) the injector provided mass flow rate oscillations induced by capacitance and inertance effects in the injector rather than by organ pipe resonances of the coaxial oxidizer posts. This type of combustion instability is referred to as "injection coupling" because one critical driving source of the instability is mass flow rate oscillations from the injector. However, the type of injection coupling observed here is different than observed in previous instances of buzz instability with coaxial injectors, because of the lower frequencies and lack of influence from the oxidizer post organ pipe resonances. Test data and preliminary analyses of the initial combustion instabilities were presented in several papers at the 5th Liquid Propulsion Subcommittee meeting. Since that time, additional hot-fire tests with several new hardware configurations have been conducted, and additional analyses have been completed. The analytical models described in previous papers have been updated to include the influences of new geometrical configurations, including a different oxidizer injector manifold configuration and a branch pipe in the hot gas duct that supplies gaseous helium during the start transient to pre-spin the turbine. In addition, the

  11. Studying coupled hydrological and micro-biological processes by means of tracer injections and mathematical models

    NASA Astrophysics Data System (ADS)

    Worman, A.; Kjellin, J. P.; Lindahl, A.; Johansson, H.

    2005-05-01

    To throw light on coupled hydrological, chemical and microbiological processes in treatment wetlands, this study uses both radioactive water and reactive tracers. A tracer mixture consisting of tritiated water, P-32 in the form of PO4- and N-15 in the form of N2O was injected to the 2.6 hectare large Ekeby wetland, Sweden. From the breakthrough curves of tritium, the mean residence time of water in pond 1 can be estimated to be about 3 to 3.5 days. The total injected activity of phosphorus was 17.98 GBq and about 13.73 GBq was recovered at the outlet during the investigation period ending 10 days and 16 hours after the start of the injection. This implies that 24% of the phosphate solution was removed in the November - December period in which the experiment was performed. The total injected amount of N-15 was 42.1 grams and 29.6 grams was retained at the effluent. This means that 30% of the nitrogen was either retained in the wetland or removed due to denitrification. An analysis of regular monitoring data shows that the annual removal rate in the entire wetland (each flow line passes two ponds in series) is about 50% for total phosphorus and 25% for total nitrogen. Probably, the most important mechanism for this removal is adsorption onto particulate matter and deposition. Analyses of vegetation material indicate that a certain (minor) fraction was adsorbed to submersed and emerging macrophytes, like Elodera Canadensis, Thypa sp. (Cattail) and Glyceria sp. (Manna grass). A 2D mathematical model for both water flow and solute transport could explain the N-transport through the wetland. The model accounts for the rate-limited exchange with bed sediments and denitrification in the water and bed sediment. Independent batch tests indicate a particularly high microbiological activity in the bed sediments. The rate-limited exchange with the bed limits also the denitrification capacity of the wetland.

  12. Testing large volume water treatment and crude oil ...

    EPA Pesticide Factsheets

    Report EPA’s Homeland Security Research Program (HSRP) partnered with the Idaho National Laboratory (INL) to build the Water Security Test Bed (WSTB) at the INL test site outside of Idaho Falls, Idaho. The WSTB was built using an 8-inch (20 cm) diameter cement-mortar lined drinking water pipe that was previously taken out of service. The pipe was exhumed from the INL grounds and oriented in the shape of a small drinking water distribution system. Effluent from the pipe is captured in a lagoon. The WSTB can support drinking water distribution system research on a variety of drinking water treatment topics including biofilms, water quality, sensors, and homeland security related contaminants. Because the WSTB is constructed of real drinking water distribution system pipes, research can be conducted under conditions similar to those in a real drinking water system. In 2014, WSTB pipe was experimentally contaminated with Bacillus globigii spores, a non-pathogenic surrogate for the pathogenic B. anthracis, and then decontaminated using chlorine dioxide. In 2015, the WSTB was used to perform the following experiments: • Four mobile disinfection technologies were tested for their ability to disinfect large volumes of biologically contaminated “dirty” water from the WSTB. B. globigii spores acted as the biological contaminant. The four technologies evaluated included: (1) Hayward Saline C™ 6.0 Chlorination System, (2) Advanced Oxidation Process (A

  13. SUSY’s Ladder: Reframing sequestering at Large Volume

    SciTech Connect

    Reece, Matthew; Xue, Wei

    2016-04-07

    Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague other supersymmetric theories. We study SUSY's Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. As a result, this gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.

  14. New Large Volume Press Beamlines at the Canadian Light Source

    NASA Astrophysics Data System (ADS)

    Mueller, H. J.; Hormes, J.; Lauterjung, J.; Secco, R.; Hallin, E.

    2013-12-01

    The Canadian Light Source, the German Research Centre for Geosciences and the Western University recently agreed to establish two new large volume press beamlines at the Canadian Lightsource. As the first step a 250 tons DIA-LVP will be installed at the IDEAS beamline in 2014. The further development is associated with the construction of a superconducting wiggler beamline at the Brockhouse sector. A 1750 tons DIA LVP will be installed there about 2 years later. Up to the completion of this wiggler beamline the big press will be used for offline high pressure high temperature experiments under simulated Earth's mantle conditions. In addition to X-ray diffraction, all up-to-date high pressure techniques as ultrasonic interferometry, deformation analyses by X-radiography, X-ray densitometry, falling sphere viscosimetry, multi-staging etc. will be available at both beamlines. After the required commissioning the beamlines will be open to the worldwide user community from Geosciences, general material sciences, physics, chemistry, biology etc. based on the evaluation and ranking of the submitted user proposals by an international review panel.

  15. Large volume high-pressure cell for inelastic neutron scattering

    NASA Astrophysics Data System (ADS)

    Wang, W.; Sokolov, D. A.; Huxley, A. D.; Kamenev, K. V.

    2011-07-01

    Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm3. The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe2.

  16. SUSY’s Ladder: Reframing sequestering at Large Volume

    DOE PAGES

    Reece, Matthew; Xue, Wei

    2016-04-07

    Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague othermore » supersymmetric theories. We study SUSY's Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. As a result, this gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.« less

  17. Large volume high-pressure cell for inelastic neutron scattering.

    PubMed

    Wang, W; Sokolov, D A; Huxley, A D; Kamenev, K V

    2011-07-01

    Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm(3). The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe(2).

  18. Large volume high-pressure cell for inelastic neutron scattering

    SciTech Connect

    Wang, W.; Kamenev, K. V.; Sokolov, D. A.; Huxley, A. D.

    2011-07-15

    Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm{sup 3}. The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe{sub 2}.

  19. Relevance of genetic counselling in couples prior to intracytoplasmic sperm injection.

    PubMed

    Pauer, H U; Hinney, B; Michelmann, H W; Krasemann, E W; Zoll, B; Engel, W

    1997-09-01

    Since the first reports of successful pregnancies after treatment with intracytoplasmic sperm injection (ICSI) in humans numerous attempts have been made to assess the genetic risks of this highly invasive technique. During the study period (February 1995-November 96), 142 couples were referred to our genetic counselling unit prior to ICSI. In three couples, genetic counselling revealed a high recurrence risk for a monogenic disease (myotonic dystrophy, hereditary ataxia and polycystic kidney disease). In nine out of 128 men (7%) an abnormal karyotype was identified, including three Robertsonian translocations, two reciprocal translocations, three sex chromosome aberrations and one case with centric fission of chromosome no. 7. A total of 14 men refused chromosomal analysis. Only one of the 122 women examined had an abnormal karyotype (47, XXX). Five out of six men with congenital bilateral absence of the vas deferens (CBAVD) had at least one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Three had mutations in both CFTR alleles, including one case in which the second mutation was the 5T allele. One patient with CBAVD and a single Delta F508 CFTR mutation also had left renal agenesis. In conclusion, we strongly recommend that genetic counselling, chromosomal analysis and, in the case of CBAVD, screening for CFTR mutations should be offered to all couples with a diagnosis of male or idiopathic infertility.

  20. Seismicity induced by CO2 injection: lesson learned from coupled hydro-mechanical modeling

    NASA Astrophysics Data System (ADS)

    Rinaldi, Antonio Pio; Rutqvist, Jonny; Urpi, Luca; Cappa, Frederic; Jeanne, Pierre; Vilarrasa, Victor

    2017-04-01

    Overpressure caused by the direct injection of CO2 into a deep sedimentary system may produce changes in the state of stress, as well as, have an impact on the sealing capabilities of the targeted system. The importance of geomechanics including the potential for reactivating faults associated with large-scale geologic carbon sequestration operations has recently become more widely recognized. In this context, here we review and summarize some recent modeling efforts, aimed at understanding the possible seismicity induced by CO2 storage and its relation to potential leakage to shallow groundwater aquifer during active injection. The simulations were conducted using TOUGH-FLAC, a simulator for coupled multiphase flow and geomechanical modeling. We carried out both quasi-static and dynamic simulations, with an explicit representation of a fault. In the case of quasi-static modeling, a strain softening Mohr-Coulomb model was used to model a slip-weakening fault slip behavior, enabling modeling of sudden slip that was interpreted as a seismic event, with a moment magnitude evaluated using formulas from seismology. In the case of dynamic modeling, we simulate the fault behavior as strain-softening or rate-dependent, analyzing the frequency behavior at surface and the possible effects of friction properties on slip. This work aims at studying the fault responses during carbon dioxide injection, focusing on the short-term (5 years) integrity of the storage repository, and hence, on the potential leakage towards shallow groundwater aquifers. We account for stress/strain-dependent permeability and study both the fault reactivation and the leakage through the fault zone. We analyze several scenarios related to the injected amount of CO2 (and hence related to potential overpressure) involving both minor and major faults, and study induced seismicity and leakage for different stress/strain permeability coupling functions, as well as increasing the complexity of the system in

  1. The mechanism for large-volume fluid pumping via reversible snap-through of dielectric elastomer

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Wang, Yingxi; Foo, Choon Chiang; Godaba, Hareesh; Zhu, Jian; Yap, Choon Hwai

    2017-08-01

    Giant deformation of dielectric elastomers (DEs) via electromechanical instability (or the "snap-through" phenomenon) is a promising mechanism for large-volume fluid pumping. Snap-through of a DE membrane coupled with compressible air has been previously investigated. However, the physics behind reversible snap-through of a DE diaphragm coupled with incompressible fluid for the purpose of fluid pumping has not been well investigated, and the conditions required for reversible snap-through in a hydraulic system are unknown. In this study, we have proposed a concept for large-volume fluid pumping by harnessing reversible snap-through of the dielectric elastomer. The occurrence of snap-through was theoretically modeled and experimentally verified. Both the theoretical and experimental pressure-volume curves of the DE membrane under different actuation voltages were used to design the work loop of the pump, and the theoretical work loop agreed with the experimental work loop. Furthermore, the feasibility of reversible snap-through was experimentally verified, and specific conditions were found necessary for this to occur, such as a minimum actuation voltage, an optimal range of hydraulic pressure exerted on the DE membrane and a suitable actuation frequency. Under optimal working conditions, we demonstrated a pumping volume of up to 110 ml per cycle, which was significantly larger than that without snap-through. Furthermore, we have achieved fluid pumping from a region of low pressure to another region of high pressure. Findings of this study would be useful for real world applications such as the blood pump.

  2. Maternal age and intracytoplasmic sperm injection outcome in infertile couples at Khartoum, Sudan

    PubMed Central

    Ahmed, Mohamed; Shareef, Osama; Adam, Ishag; Rayis, Duria

    2015-01-01

    Background Intracytoplasmic sperm injection (ICSI) was considered as the mainstay of treatment for male infertility. Nowadays, the scope of ICSI has been widened to include other causes of infertility. There are few published data on ICSI in countries with low incomes. Aims A cross-sectional study was conducted at Saad AbuAlla and Banoun Centers, Khartoum, Sudan to investigate outcomes of ICSI and to determine the parameters that might predict pregnancy success rate following ICSI. Methods The study included 191 infertile couples who underwent 296 ICSI cycles between 1st April 2013 and 31 March 2014. Results One hundred and ninety one couples (comprising 296 cycles of ICSI) were enrolled to the study. The mean (SD) number of retrieved oocytes was 9.7 (7.5).  The mean (SD) number of transferred embryos was 2.9 (1.0). Out of these, 50 (26.2%) and 40 (20.9%) had chemical and clinical pregnancy, respectively. Thirty–six couples (18.8%) and five couples (2.6%) had miscarriage and had ectopic pregnancy, respectively. Under logistic regression, younger age (OR = 0.8, 95% CI= 0.81 ─ 0.96, P = 0.004) and endometrial thickness (OR = 1.3, 95% CI= 1.07─1.60, P = 0.009) were the significant predictors for the success of ICSI in inducing pregnancy. Conclusion                 The rates of successful fertilisation and pregnancy-to-term rates in this setting depend mainly on the maternal age. PMID:27347370

  3. Rapid determination of plutonium isotopes in environmental samples using sequential injection extraction chromatography and detection by inductively coupled plasma mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2009-10-01

    This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed by detection of isolated analytes with inductively coupled plasma mass spectrometry (ICP-MS). The method has been devised for the determination of Pu isotopes at environmentally relevant concentrations, whereby it has been successfully applied to the analyses of large volumes/amounts of samples, for example, 100-200 g of soil and sediment, 20 g of seaweed, and 200 L of seawater following analyte preconcentration. The investigation of the separation capability of the assembled SI system revealed that up to 200 g of soil or sediment can be treated using a column containing about 0.70 g of TEVA resin. The analytical results of Pu isotopes in the reference materials showed good agreement with the certified or reference values at the 0.05 significance level. Chemical yields of Pu ranged from 80 to 105%, and the decontamination factors for uranium, thorium, mercury and lead were all above 10(4). The duration of the in-line extraction chromatographic run was <1.5 h, and the proposed setup was able to handle up to 20 samples (14 mL each) in a fully automated mode using a single chromatographic column. The SI manifold is thus suitable for rapid and automated determination of Pu isotopes in environmental risk assessment and emergency preparedness scenarios.

  4. Coupling microdialysis with flow-injection chemiluminescence detection for a protein-drug interaction study.

    PubMed

    Chen, Hua; Gong, Zhengjun; Zhang, Zhujun

    2006-06-16

    The interaction of metronidazole (MTZ) and human serum albumin (HSA) was studied using the coupling system of on-line microdialysis sampling with flow-injection chemiluminescence detection (FI-MD-CL). The interested drug and HSA were mixed in different molar ratios in 0.067 mol L(-1) phosphate buffer (pH 7.4) and incubated at 37 degrees C in a water-bath. Then the microdialysis probe was put into the MTZ-HSA mixed solution and sampled at a perfusion rate of 5 microL min(-1). The microdialysates was determined using flow-injection chemiluminescence. In vitro recovery (R) of MTZ under experimental conditions was approximately 25.2% with a R.S.D. of about 3.2%. The values estimated for the binding constant (K) and the number of the binding sites (n) were found to be 1.50 x 10(3)L mol(-1) and 1.89, respectively. The values of nK obtained using Scatchard analysis and Klotz plot were found to be quite similar. The method provided a reliable and simple technique for the study of drug-protein interaction.

  5. A Scanning Transmission Electron Microscopy (STEM) Approach to Analyzing Large Volumes of Tissue to Detect Nanoparticles

    PubMed Central

    Kempen, Paul J.; Thakor, Avnesh S.; Zavaleta, Cristina; Gambhir, Sanjiv S.; Sinclair, Robert

    2013-01-01

    The use of nanoparticles for the diagnosis and treatment of cancer requires the complete characterization of their toxicity, including accurately locating them within biological tissues. Owing to their size, traditional light microscopy techniques are unable to resolve them. Transmission electron microscopy provides the necessary spatial resolution to image individual nanoparticles in tissue but is severely limited by the very small analysis volume, usually on the order of tens of cubic microns. In this work we developed a scanning transmission electron microscopy (STEM) approach to analyze large volumes of tissue for the presence of polyethylene glycol coated Raman-active-silica-gold-nanoparticles (PEG-R-Si-Au-NPs). This approach utilizes the simultaneous bright and dark field imaging capabilities of STEM along with careful control of the image contrast settings to readily identify PEG-R-Si-Au-NPs in mouse liver tissue without the need for additional time consuming analytical characterization. We utilized this technique to analyze 243,000 µm3 of mouse liver tissue for the presence of PEG-R-Si-Au-NPs. Nanoparticles injected into the mice intravenously via the tail-vein accumulated in the liver while those injected intrarectally did not, indicating that they remain in the colon and do not pass through the colon wall into the systemic circulation. PMID:23803218

  6. A scanning transmission electron microscopy approach to analyzing large volumes of tissue to detect nanoparticles.

    PubMed

    Kempen, Paul J; Thakor, Avnesh S; Zavaleta, Cristina; Gambhir, Sanjiv S; Sinclair, Robert

    2013-10-01

    The use of nanoparticles for the diagnosis and treatment of cancer requires the complete characterization of their toxicity, including accurately locating them within biological tissues. Owing to their size, traditional light microscopy techniques are unable to resolve them. Transmission electron microscopy provides the necessary spatial resolution to image individual nanoparticles in tissue, but is severely limited by the very small analysis volume, usually on the order of tens of cubic microns. In this work, we developed a scanning transmission electron microscopy (STEM) approach to analyze large volumes of tissue for the presence of polyethylene glycol-coated Raman-active-silica-gold-nanoparticles (PEG-R-Si-Au-NPs). This approach utilizes the simultaneous bright and dark field imaging capabilities of STEM along with careful control of the image contrast settings to readily identify PEG-R-Si-Au-NPs in mouse liver tissue without the need for additional time-consuming analytical characterization. We utilized this technique to analyze 243,000 mm³ of mouse liver tissue for the presence of PEG-R-Si-Au-NPs. Nanoparticles injected into the mice intravenously via the tail vein accumulated in the liver, whereas those injected intrarectally did not, indicating that they remain in the colon and do not pass through the colon wall into the systemic circulation.

  7. Striped Bass, morone saxatilis, egg incubation in large volume jars

    USGS Publications Warehouse

    Harper, C.J.; Wrege, B.M.; Jeffery, Isely J.

    2010-01-01

    The standard McDonald jar was compared with a large volume jar for striped bass, Morone saxatilis, egg incubation. The McDonald jar measured 16 cm in diameter by 45 cm in height and had a volume of 6 L. The experimental jar measured 0.4 m in diameter by 1.3 m in height and had a volume of 200 L. The hypothesis is that there is no difference in percent survival of fry hatched in experimental jars compared with McDonald jars. Striped bass brood fish were collected from the Coosa River and spawned using the dry spawn method of fertilization. Four McDonald jars were stocked with approximately 150 g of eggs each. Post-hatch survival was estimated at 48, 96, and 144 h. Stocking rates resulted in an average egg loading rate (??1 SE) in McDonald jars of 21.9 ?? 0.03 eggs/mL and in experimental jars of 10.9 ?? 0.57 eggs/mL. The major finding of this study was that average fry survival was 37.3 ?? 4.49% for McDonald jars and 34.2 ?? 3.80% for experimental jars. Although survival in experimental jars was slightly less than in McDonald jars, the effect of container volume on survival to 48 h (F = 6.57; df = 1,5; P > 0.05), 96 h (F = 0.02; df = 1, 4; P > 0.89), and 144 h (F = 3.50; df = 1, 4; P > 0.13) was not statistically significant. Mean survival between replicates ranged from 14.7 to 60.1% in McDonald jars and from 10.1 to 54.4% in experimental jars. No effect of initial stocking rate on survival (t = 0.06; df = 10; P > 0.95) was detected. Experimental jars allowed for incubation of a greater number of eggs in less than half the floor space of McDonald jars. As hatchery production is often limited by space or water supply, experimental jars offer an alternative to extending spawning activities, thereby reducing labor and operations cost. As survival was similar to McDonald jars, the experimental jar is suitable for striped bass egg incubation. ?? Copyright by the World Aquaculture Society 2010.

  8. Phonon-coupled trap-assisted charge injection in metal-nitride-oxide-silicon/silicon-oxide-nitride-oxide-silicon structures

    NASA Astrophysics Data System (ADS)

    Nasyrov, K. A.; Shaimeev, S. S.; Gritsenko, V. A.; Han, J. H.

    2009-06-01

    A phonon-coupled trap model is proposed for trap-assisted injection mechanism in silicon-oxide-nitride-oxide-silicon (SONOS)/metal-nitride-oxide-silicon (MNOS) structures at low voltages. On the basis of this model, a theory of charge injection in SONOS/MNOS has been developed. Charge injection experimental data was fitted by this theory. Obtained trap parameters are close to those previously reported [K. A. Nasyrov et al., J. Appl. Phys. 96, 4293 (2004)], where the current dependence on temperature and electric field was investigated in MNOS.

  9. COMPARISON OF TWO DIFFERENT SOLID PHASE EXTRACTION/LARGE VOLUME INJECTION PROCEDURES FOR METHOD 8270

    EPA Science Inventory

    Two solid phase (SPE) and one traditional continuous liquid-liquid extraction method are compared for analysis of Method 8270 SVOCs. Productivity parameters include data quality, sample volume, analysis time and solvent waste.

    One SPE system, unique in the U.S., uses aut...

  10. COMPARISON OF TWO DIFFERENT SOLID PHASE EXTRACTION/LARGE VOLUME INJECTION PROCEDURES FOR METHOD 8270

    EPA Science Inventory

    Two solid phase (SPE) and one traditional continuous liquid-liquid extraction method are compared for analysis of Method 8270 SVOCs. Productivity parameters include data quality, sample volume, analysis time and solvent waste.

    One SPE system, unique in the U.S., uses aut...

  11. Effect of feedback elements on the phase locking properties of fiber lasers via mutual injection coupling

    NASA Astrophysics Data System (ADS)

    Lei, Bing; Liu, Wei; Shi, Jianhua; Yao, Tianfu; Feng, Ying

    2015-10-01

    Coherent combining of several multi-wavelength fiber lasers is a promising approach to suppress the nonlinear effects and improve the output power. Passive phase locking of two multi-wavelength fiber lasers has been demonstrated by using mutual injection coupling and spatial filtering technique, and the effect of feedback elements on the phase locking properties has been investigated in detail. Three different kinds of feedback elements, fiber Bragg grating (FBG), fiber loop mirror (FLM) and fiber reflection mirror (FRM) are employed as the component laser's high reflection mirror to construct the phase locking array respectively. Compared with the traditional feedback element FBG, the FLM is made of a 3dB fiber coupler and provide high reflection feedback in a wide spectral range for fiber laser, and the FRM is also a wide-band reflector with the fiber end coated by multilayer dielectric film. When the FLM and FRM are employed as the component laser's feedback elements, a large number of longitudinal modes operate simultaneously and the spectra vary continuously. Fortunately, stable phase locking has been obtained as long as the single-mode filtering fiber is introduced into the feedback loop, and obvious interference patterns with high fringe visibility have been observed in far field. The phased array's output power can also keep stable at the same time, and its amount is higher than the case of using FBG. In conclusion, the research results indicate that efficient phase locking of several multi-wavelength fiber lasers can also be achieved by passive self-adjusting method and higher output power can be obtained compared with the usual coherent combining of narrow-band laser beams, as long as necessary optical coupling is introduced among component lasers and proper spatial filtering measures are adopted.

  12. A large bore-direct injection high efficiency nebulizer for inductively coupled plasma spectrometry

    PubMed

    Acon; McLean; Montaser

    2000-04-15

    A large bore-direct injection high efficiency nebulizer (IB-DIHEN) is introduced that is less prone to capillary blockage and optimally operates at low nebulizer gas pressures compared with the conventional DIHEN used for inductively coupled plasma (ICP) spectrometries. The aerosol quality is examined using a two-dimensional phase Doppler particle analyzer (2D PDPA), and analytical figures of merits are acquired by ICP mass spectrometry. Compared with the DIHEN, the LB-DIHEN produces larger droplets, but the velocity distributions and mean droplet velocities are narrower and lower, respectively, providing longer residence times for the droplets in the plasma. High RF power (1500 W), low nebulizer gas flow rates (0.25-0.35 L/min), and low solution uptake rates (80-110 microL/min) are required to operate the LB-DIHEN at optimum conditions for ICPMS. Detection limits and sensitivities measured with the LB-DIHEN are superior to those of a conventional nebulizer-spray chamber combination, but precision is inferior. The performance of the LB-DIHEN is further explored in the determination of trace elements in an herbal extract.

  13. Cannabis agonist injection effect on the coupling architecture in cortex of WAG/Rij rats during absence seizures

    NASA Astrophysics Data System (ADS)

    Sysoeva, Marina V.; Kuznetsova, Galina D.; van Rijn, Clementina M.; Sysoev, Ilya V.

    2016-04-01

    WAG/Rij rats are well known genetic model of absence epilepsy, which is traditionally considered as a nonconvulsive generalised epilepsy of unknown aetiology. In current study the effect of (R)-(+)-WIN 55,212-2 (cannabis agonist) injection on the coupling between different parts of cortex was studied on 27 male 8 month old rats using local field potentials. Recently developed non-linear adapted Granger causality approach was used as a primary method. It was shown that first 2 hours after the injection the coupling between most channel pairs rises in comparison with the spontaneous activity, whilst long after the injection (2-6 hours) it drops down. The coupling increase corresponds to the mentioned before treatment effect, when the number and the longitude of seizures significantly decreases. However the subsequent decrease of the coupling in the cortex is accompanied by the dramatic increase of the longitude and the number of seizures. This assumes the hypothesis that a relatively higher coupling in the cortical network can prevent the seizure propagation and generalisation.

  14. Influence of high-conductivity buffer composition on field-enhanced sample injection coupled to sweeping in CE.

    PubMed

    Anres, Philippe; Delaunay, Nathalie; Vial, Jérôme; Thormann, Wolfgang; Gareil, Pierre

    2013-02-01

    The aim of this work was to clarify the mechanism taking place in field-enhanced sample injection coupled to sweeping and micellar EKC (FESI-Sweep-MEKC), with the utilization of two acidic high-conductivity buffers (HCBs), phosphoric acid or sodium phosphate buffer, in view of maximizing sensitivity enhancements. Using cationic model compounds in acidic media, a chemometric approach and simulations with SIMUL5 were implemented. Experimental design first enabled to identify the significant factors and their potential interactions. Simulation demonstrates the formation of moving boundaries during sample injection, which originate at the initial sample/HCB and HCB/buffer discontinuities and gradually change the compositions of HCB and BGE. With sodium phosphate buffer, the HCB conductivity increased during the injection, leading to a more efficient preconcentration by staking (about 1.6 times) than with phosphoric acid alone, for which conductivity decreased during injection. For the same injection time at constant voltage, however, a lower amount of analytes was injected with sodium phosphate buffer than with phosphoric acid. Consequently sensitivity enhancements were lower for the whole FESI-Sweep-MEKC process. This is why, in order to maximize sensitivity enhancements, it is proposed to work with sodium phosphate buffer as HCB and to use constant current during sample injection. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Twinning in vapour-grown, large volume Cd1-xZnxTe crystals

    NASA Astrophysics Data System (ADS)

    Tanner, B. K.; Mullins, J. T.; Pym, A. T. G.; Maneuski, D.

    2016-08-01

    The onset of twinning from (2 bar 1 bar 1 bar) to (1 bar 3 bar 3 bar) in large volume Cd1-xZnxTe crystals, grown by vapour transport on (2 bar 1 bar 1 bar) , often referred to as (211)B, oriented GaAs seeds, has been investigated using X-ray diffraction imaging (X-ray topography). Twinning is not associated with strains at the GaAs/CdTe interface as the initial growth was always in (2 bar 1 bar 1 bar) orientation. Nor is twinning related to lattice strains associated with injection of Zn subsequent to initial nucleation and growth of pure CdTe as in both cases twinning occurred after growth of several mm length of Cd1-xZnxTe. While in both cases examined, there was a region of disturbed growth prior to the twinning transition, in neither crystal does this strain appear to have nucleated the twinning process. In both cases, un-twinned material remained after twinning was observed, the scale of the resulting twin boundaries being sub-micron. Simultaneous twinning across the whole sample surface was observed in one sample, whereas in the other, twinning was nucleated at different points and times in the growth.

  16. Large-volume sample stacking-capillary electrophoresis used for the determination of 3-nitrotyrosine in rat urine.

    PubMed

    Maeso, Nuria; Cifuentes, Alejandro; Barbas, Coral

    2004-09-25

    Large-volume sample stacking using the electroosmotic flow (EOF) pump technique has been investigated for the quantification of 3-nitrotyrosine in urine of diabetic rats. The best separation conditions for these highly complex samples were obtained using capillary electrophoresis (CE) in the reversed polarity mode (i.e., injecting at the cathode and detecting at the anode) using cetyltrimethylammonium bromide (CTAB) in the running buffer. The optimum CE separation conditions were achieved using a phosphate buffer prepared with 0.15M phosphoric acid and 0.5 mM CTAB adjusted to pH 6.4 with sodium hydroxide. In such CE conditions, the limit of detection (LOD) was 1.77 microM for 3-nitrotyrosine with normal injection mode, meanwhile with the large-volume sample stacking technique a more than 20-fold improvement was observed (i.e., LOD = 0.08 microM was obtained) without noticeable loss of resolution. This value allowed the detection of 3-nitrotyrosine in urine from diabetic rats. To our knowledge, this work is one of the few applications showing the great possibilities of these stacking procedures to analyse biological samples by CE.

  17. Impact of localized gas injection on ICRF coupling and SOL parameters in JET-ILW H-mode plasmas

    NASA Astrophysics Data System (ADS)

    Lerche, E.; Goniche, M.; Jacquet, P.; Van Eester, D.; Bobkov, V.; Colas, L.; Czarnecka, A.; Brezinsek, S.; Brix, M.; Crombe, K.; Graham, M.; Groth, M.; Monakhov, I.; Mathurin, T.; Matthews, G.; Meneses, L.; Noble, C.; Petrzilka, V.; Rimini, F.; Shaw, A.

    2015-08-01

    Recent JET-ILW [1,2] experiments reiterated the importance of tuning the plasma fuelling in order to optimize ion cyclotron resonance frequency (ICRF) heating in high power H-mode discharges. By fuelling the plasma from gas injection modules (GIMs) located in the mid-plane and on the top of the machine instead of adopting the more standardly used divertor GIMs, a considerable increase of the ICRF antenna coupling resistances was achieved with moderate gas injection rates (<1.5 × 1022 e/s). This effect is explained by an increase of the scrape-off-layer density in front of the antennas when mid-plane and top fuelling is used. By distributing the gas injection to optimize the coupling of all ICRF antenna arrays simultaneously, a substantial increase in the ICRF power capability and reliability was attained. Although similar core/pedestal plasma properties were observed for the different injection cases, the experiments indicate that the RF-induced impurity sources are reduced when switching from divertor to main chamber gas injection.

  18. Large-Volume Resonant Microwave Discharge for Plasma Cleaning of a CEBAF 5-Cell SRF Cavity

    SciTech Connect

    J. Mammosser, S. Ahmed, K. Macha, J. Upadhyay, M. Nikoli, S. Popovi, L. Vuakovi

    2012-07-01

    We report the preliminary results on plasma generation in a 5-cell CEBAF superconducting radio-frequency (SRF) cavity for the application of cavity interior surface cleaning. CEBAF currently has {approx}300 of these five cell cavities installed in the Jefferson Lab accelerator which are mostly limited by cavity surface contamination. The development of an in-situ cavity surface cleaning method utilizing a resonant microwave discharge could lead to significant CEBAF accelerator performance improvement. This microwave discharge is currently being used for the development of a set of plasma cleaning procedures targeted to the removal of various organic, metal and metal oxide impurities. These contaminants are responsible for the increase of surface resistance and the reduction of RF performance in installed cavities. The CEBAF five cell cavity volume is {approx} 0.5 m2, which places the discharge in the category of large-volume plasmas. CEBAF cavity has a cylindrical symmetry, but its elliptical shape and transversal power coupling makes it an unusual plasma application, which requires special consideration of microwave breakdown. Our preliminary study includes microwave breakdown and optical spectroscopy, which was used to define the operating pressure range and the rate of removal of organic impurities.

  19. Scanning laser optical computed tomography system for large volume 3D dosimetry

    NASA Astrophysics Data System (ADS)

    Dekker, Kurtis H.; Battista, Jerry J.; Jordan, Kevin J.

    2017-04-01

    Stray light causes artifacts in optical computed tomography (CT) that negatively affect the accuracy of radiation dosimetry in gels or solids. Scatter effects are exacerbated by a large dosimeter volume, which is desirable for direct verification of modern radiotherapy treatment plans such as multiple-isocenter radiosurgery. The goal in this study was to design and characterize an optical CT system that achieves high accuracy primary transmission measurements through effective stray light rejection, while maintaining sufficient scan speed for practical application. We present an optical imaging platform that uses a galvanometer mirror for horizontal scanning, and a translation stage for vertical movement of a laser beam and small area detector for minimal stray light production and acceptance. This is coupled with a custom lens-shaped optical CT aquarium for parallel ray sampling of projections. The scanner images 15 cm diameter, 12 cm height cylindrical volumes at 0.33 mm resolution in approximately 30 min. Attenuation coefficients reconstructed from CT scans agreed with independent cuvette measurements within 2% for both absorbing and scattering solutions as well as small 1.25 cm diameter absorbing phantoms placed within a large, scattering medium that mimics gel. Excellent linearity between the optical CT scanner and the independent measurement was observed for solutions with between 90% and 2% transmission. These results indicate that the scanner should achieve highly accurate dosimetry of large volume dosimeters in a reasonable timeframe for clinical application to radiotherapy dose verification procedures.

  20. Scanning laser optical computed tomography system for large volume 3D dosimetry.

    PubMed

    Dekker, Kurtis H; Battista, Jerry J; Jordan, Kevin J

    2017-04-07

    Stray light causes artifacts in optical computed tomography (CT) that negatively affect the accuracy of radiation dosimetry in gels or solids. Scatter effects are exacerbated by a large dosimeter volume, which is desirable for direct verification of modern radiotherapy treatment plans such as multiple-isocenter radiosurgery. The goal in this study was to design and characterize an optical CT system that achieves high accuracy primary transmission measurements through effective stray light rejection, while maintaining sufficient scan speed for practical application. We present an optical imaging platform that uses a galvanometer mirror for horizontal scanning, and a translation stage for vertical movement of a laser beam and small area detector for minimal stray light production and acceptance. This is coupled with a custom lens-shaped optical CT aquarium for parallel ray sampling of projections. The scanner images 15 cm diameter, 12 cm height cylindrical volumes at 0.33 mm resolution in approximately 30 min. Attenuation coefficients reconstructed from CT scans agreed with independent cuvette measurements within 2% for both absorbing and scattering solutions as well as small 1.25 cm diameter absorbing phantoms placed within a large, scattering medium that mimics gel. Excellent linearity between the optical CT scanner and the independent measurement was observed for solutions with between 90% and 2% transmission. These results indicate that the scanner should achieve highly accurate dosimetry of large volume dosimeters in a reasonable timeframe for clinical application to radiotherapy dose verification procedures.

  1. Evaluation of a direct injection nebulizer interface for flow injection analysis and high performance liquid chromatography with inductively coupled plasma-atomic emission spectroscopic detection

    SciTech Connect

    LaFreniere, K.E.

    1986-06-01

    A direct injection nebulizer (DIN) was designed, developed, and evaluated to determine its potential utilization as an effective interface for flow injection analysis (FIA) and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma-atomic emission spectroscopic detection. The analytical figures of merit for the DIN when used as an interface for FIA-ICP-AES were found to be comparable to or better than those obtained with conventional pneumatic nebulization in terms of limits of detection (LODs), reproducibility, linearity, and interelement effects. Stable plasma operation was maintained for the DIN sample introduction of a variety of pure organic solvents, including acetonitrile, methanol, methylisobutylketone, and pyridine. The HPLC-DIN-ICP-AES facility was specifically applied for the speciation of inorganic and organometallic species contained in synthetic mixtures, vanilla extracts, and a variety of energy-related materials, such as shale oil process water, coal extracts, shale oil, crude oil, and an SRC II. Suggestions for future research are also considered. 227 refs., 44 figs., 15 tabs.

  2. Coupled Mechanical and Thermal Modeling of Frictional Melt Injection to Constrain Physical Conditions of the Earthquake Source Region

    NASA Astrophysics Data System (ADS)

    Sawyer, W.; Resor, P. G.

    2016-12-01

    Pseudotachylyte, a fault rock formed through coseismic frictional melting, provides an important record of coseismic mechanics. In particular, injection veins formed at a high angle to the fault surface have been used to estimate rupture directivity, velocity, pulse length, stress and strength drop, as well as slip weakening distance and wall rock stiffness. These studies, however, have generally treated injection vein formation as a purely elastic process and have assumed that processes of melt generation, transport, and solidification have little influence on the final vein geometry. Using a modified analytical approximation of injection vein formation based on a dike intrusion model we find that the timescales of quenching and flow propagation are similar for a composite set of injection veins compiled from the Asbestos Mountain Fault, USA (Rowe et al., 2012), Gole Larghe Fault Zone, Italy (Griffith et al., 2012) and the Fort Foster Brittle Zone. This indicates a complex, dynamic process whose behavior is not fully captured by the current approach. To assess the applicability of the simplifying assumptions of the dike model when applied to injection veins we employ a finite-element time-dependent model of injection vein formation. This model couples elastic deformation of the wall rock with the fluid dynamics and heat transfer of the frictional melt. The final geometry of many injection veins is unaffected by the inclusion of these processes. However, some injection veins are found to be flow limited, with a final geometry reflecting cooling of the vein before it reaches an elastic equilibrium with the wall rock. In these cases, numerical results are significantly different from the dike model, and two basic assumptions of the dike model, self-similar growth and a uniform pressure gradient, are shown to be false. Additionally, we apply the finite-element model to provide two new constraints on the Fort Foster coseismic environment: a lower limit on the initial

  3. Estimating maximum sustainable injection pressure duringgeological sequestration of CO2 using coupled fluid flow andgeomechanical fault-slip analysis

    SciTech Connect

    Rutqvist, J.; Birkholzer, J.; Cappa, F.; Tsang, C.-F.

    2006-10-17

    This paper demonstrates the use of coupled fluid flow andgeomechanical fault slip (fault reactivation) analysis to estimate themaximum sustainable injection pressure during geological sequestration ofCO2. Two numerical modeling approaches for analyzing faultslip areapplied, one using continuum stress-strain analysis and the other usingdiscrete fault analysis. The results of these two approaches to numericalfault-slip analyses are compared to the results of a more conventionalanalytical fault-slip analysis that assumes simplified reservoirgeometry. It is shown that the simplified analytical fault-slip analysismay lead to either overestimation or underestimation of the maximumsustainable injection pressure because it cannot resolve importantgeometrical factors associated with the injection induced spatialevolution of fluid pressure and stress. We conclude that a fully couplednumerical analysis can more accurately account for the spatial evolutionof both insitu stresses and fluid pressure, and therefore results in amore accurate estimation of the maximum sustainable CO2 injectionpressure.

  4. Designing an elastomeric binder for large-volume-change electrodes for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Chen, Zonghai

    It is of commercial importance to develop high capacity negative and positive electrode materials for lithium-ion batteries to meet the energy requirements of portable electronic devices. Excellent capacity retention has been achieved for thin sputtered films of amorphous Si, Ge and Si-Sn alloys even when cycled to 2000 mAh/g and above, which suggests that amorphous alloys are capable of extended cycling. However, PVDF-based composite electrodes incorporating a-Si0.64Sn0.36/Ag powder (10 wt% silver coating) (˜10mum) still suffer from severe capacity fading because of the huge volumetric changes of a-Si0.64Sn0.36/Ag during charge/discharge cycling. It is the objective of this thesis to understand the problem scientifically and to propose practical solutions to solve this problem. Mechanical studies of binders for lithium battery electrodes have never been reported in the literature. The mechanical properties of commonly used binders, such as poly(vinylidene fluoride) (PVDF), haven't been challenged because commercially used active materials, such as LiCoO2 and graphite, have small volumetric changes (<10%) during charge/discharge cycling. However, the recently proposed metallic alloys have huge volumetric changes (up to 250%) during cycling. In this case, the mechanical properties of the binder become critical. A tether model is proposed to qualitatively understand the capacity fading of high-volume-change electrodes, and to predict the properties of a good binder system. A crosslinking/coupling route was used to modify the binder system according to the requirements of the tether model. A poly(vinylidene fluoride-tetrafluoroethylenepropylene)-based elastomeric binder system was designed to successfully improve the capacity retention of a-Si0.64 Sn0.36/Ag composite electrodes. In this thesis, it has also proven nontrivial to maximize the capacity retention of large-volume-change electrodes even when a fixed elastomeric binder system was used. The parameters that

  5. A Thermo-Hydro-Mechanical coupled Numerical modeling of Injection-induced seismicity on a pre-existing fault

    NASA Astrophysics Data System (ADS)

    Kim, Jongchan; Archer, Rosalind

    2017-04-01

    In terms of energy development (oil, gas and geothermal field) and environmental improvement (carbon dioxide sequestration), fluid injection into subsurface has been dramatically increased. As a side effect of these operations, a number of injection-induced seismic activities have also significantly risen. It is known that the main causes of induced seismicity are changes in local shear and normal stresses and pore pressure as well. This mechanism leads to increase in the probability of earthquake occurrence on permeable pre-existing fault zones predominantly. In this 2D fully coupled THM geothermal reservoir numerical simulation of injection-induced seismicity, we investigate the thermal, hydraulic and mechanical behavior of the fracture zone, considering a variety of 1) fault permeability, 2) injection rate and 3) injection temperature to identify major contributing parameters to induced seismic activity. We also calculate spatiotemporal variation of the Coulomb stress which is a combination of shear stress, normal stress and pore pressure and lastly forecast the seismicity rate on the fault zone by computing the seismic prediction model of Dieterich (1994).

  6. An instrument for collecting discrete large-volume water samples suitable for ecological studies of microorganisms

    NASA Astrophysics Data System (ADS)

    Wommack, K. Eric; Williamson, Shannon J.; Sundbergh, Arthur; Helton, Rebekah R.; Glazer, Brian T.; Portune, Kevin; Craig Cary, S.

    2004-11-01

    Microbiological investigations utilizing molecular genetic approaches to characterize microbial communities can require large volume water samples, tens to hundreds of liters. The requirement for large volume samples can be especially challenging in deep-sea hydrothermal vent environments of the oceanic ridge system. By and large studies of these environments rely on deep submergence vehicles. However collection of large volume (>100 L) water samples adjacent to the benthos is not feasible due to weight considerations. To address the technical difficulty of collecting large volume water samples from hydrothermal diffuse flow environments, a semi-autonomous large-volume water sampler (LVWS) was designed. The LVWS is capable of reliably collecting and bringing to the surface 120 L water samples from diffuse flow environments. Microscopy, molecular genetic and chemical analyses of water samples taken from 9°N East Pacific Rise are shown to demonstrate the utility of the LVWS for studies of near-benthos environments. To our knowledge this is the first report of virioplankton abundance within diffuse-flow waters of a deep-sea hydrothermal vent environment. Because of its simple design and relatively low cost, the LVWS should be applicable to a variety of studies which require large-volume water samples collected immediately adjacent to the benthos.

  7. Sensitive determination of barbiturates in biological matrix by capillary electrophoresis using online large-volume sample stacking.

    PubMed

    Fan, Liu-Yin; He, Ting; Tang, Yun-Yun; Zhang, Wei; Song, Chao-Jin; Zhao, Xia; Zhao, Xiao-Yu; Cao, Cheng-Xi

    2012-05-01

    In China, some forensic cases are caused by barbiturates. Thus, the determination of trace level barbiturates in body fluid is important for the poisoning investigation. In this study, an online large-volume sample stacking (LVSS) with polarity switching in capillary electrophoresis (CE) was applied for the sensitive determination of barbiturates. This technique involves injecting a large volume of sample into a capillary and removing the sample matrix plug out of the capillary by reversing the polarity. Quantitation limit obtained was 0.048, 0.057, 0.039, and 0.015 μg/mL for secobarbital, amobarbital, barbital, and phenobarbital (signal-to-noise ratio = 9). By using LVSS, the stacking was simply achieved at 171.7-, 169.7-, 202.7-, and 169.1-fold for the above four barbiturates. The relative standard deviation values of intraday and interday were <2.11% and 4.69%, respectively. Recoveries were ranged from 83.7 to 105.2%. Finally, the trace analysis method was applied to the analysis of real forensic specimens and has achieved satisfactory results. © 2012 American Academy of Forensic Sciences.

  8. A comparison of continuous pneumatic nebulization and flow injection-direct injection nebulization for sample introduction in inductively coupled plasma-mass spectrometry

    SciTech Connect

    Crain, J.S.; Kiely, J.T.

    1995-08-01

    Dilute nitric acid blanks and solutions containing Ni, Cd, Pb, and U (including two laboratory waste samples) were analyzed eighteen times over a two-month period using inductively coupled plasma-mass spectrometry (ICP-MS). Two different sample introduction techniques were employed: flow injection-direct injection nebulization (FI-DIN) and continuous pneumatic nebulization (CPN). Using comparable instrumental measurement procedures, FI-DIN analyses were 33% faster and generated 52% less waste than CPN analyses. Instrumental limits of detection obtained with FI-DIN and CPN were comparable but not equivalent (except in the case of Pb) because of nebulizer-related differences in sensitivity (i.e., signal per unit analyte concentration) and background. Substantial and statistically significant differences were found between FI-DIN and CPN Ni determinations, and in the case of the laboratory waste samples, there were also small but statistically significant differences between Cd determinations. These small (2 to 3%) differences were not related to polyatomic ion interference (e.g., {sup 95}Mo{sup 16}O{sup +}), but in light of the time savings and waste reduction to be realized, they should not preclude the use of FI-DIN in place of CPN for determination of Cd, Pb, U and chemically.

  9. A comparison of continuous pneumatic nebulization and flow injection-direction injection nebulization for sample introduction in inductively coupled plasma-mass spectrometry

    SciTech Connect

    Crain, J.S.; Kiely, J.T.

    1997-08-01

    Samples containing Ni, Cd, Pb, and U were analyzed eighteen times over a two-month period using inductively coupled plasma-mass spectrometry (ICP-MS). Sample introduction was accomplished by either flow injection-direct injection nebulization (FI-DIN) or continuous pneumatic nebulization (CPN). Using comparable instrumental measurement procedures, FI-DIN analyses were 33% faster and generated 52% less waste than CPN analyses. Instrumental limits of detection obtained with FI-DIN and CPN were comparable but not equivalent (except in the case of Pb) because of nebulizer-related differences in sensitivity (i.e., signal per unit analyte concentration) and background. Substantial and statistically significant differences were found between FI-DIN and CPN Ni determinations, and in the case of laboratory waste samples, there were also small but statistically significant differences between Cd determinations. These small (2 to 3%) differences were not related to polyatomic ion interference (e.g., {sup 95}Mo{sup 16}O{sup +}), but in light of the time and waste savings to be realized, they should not preclude the use of FI-DIN in place of CPN for determination of Cd, Pb, U, and similar elements present at trace concentrations.

  10. Inductively coupled plasma mass spectrometric detection for multielement flow injection analysis and elemental speciation by reversed-phase liquid chromatography

    SciTech Connect

    Thompson, J.J.; Houk, R.S.

    1986-10-01

    The feasibility of using an inductively coupled plasma mass spectrometer as a multielement detector for flow injection analysis (FIA) and ion-pair reversed-phase liquid chromatography was investigated. Sample introduction was by ultrasonic nebulization with aerosol desolvation. Absolute detection limits for FIA ranged from 0.01 to 0.1 ng for most elements using 10-..mu..L injection. Over 30 elements were surveyed for their response to both anionic and cationic ion pairing reagents. The separation and selective detection of various As and Se species were demonstrated, yielding detection limits near 0.1 ng (as element) for all six species present. Determination of 15 elements in a single injection with multiple ion monitoring produced similar detection limits. Isotope ratios were measured with sufficient precision (better than 2%) and accuracy (about 1%) on eluting peaks of Cd and Pb to demonstrate that liquid chromatography/inductively coupled plasma mass spectrometry should make speciation studies with stable tracer isotopes feasible.

  11. Assessing in situ crystal-liquid separation in a fossil, large-volume, silicic, magma reservoir

    NASA Astrophysics Data System (ADS)

    Eddy, M. P.

    2016-12-01

    The origin of high-SiO2 rhyolites is controversial. Geochemical gradients in large ignimbrites and regional-scale variations in pluton geochemistry suggest that some of these magmas are generated through differentiation of silicic (>65 wt% SiO2) parent melts in upper crustal magma `mush' zones. This process predicts that large volumes of vertically stratified silicic cumulate should be present within the upper crustal plutonic record. Nevertheless, the number of individual plutons with this type of stratification is limited and geochronologic data has demonstrated that many large, upper crustal plutonic complexes were emplaced at rates too slow (< 0.003 km3/a) and durations too long (>> 1 Ma) to construct a large mush. These observations have led to an alternative hypothesis whereby high-SiO2rhyolites form within the middle or lower crust with little to no differentiation in the upper crust. The Eocene Golden Horn batholith, WA offers a unique opportunity to test the efficiency of crystal-liquid separation. This composite batholith was emplaced at 7-8 km depth and is composed of several distinct magmatic sheets. U-Pb zircon geochronology from the largest sheet, a >424 km3 body of granodiorite and granite with a distinctive rapakivi texture, suggests that it was built at magma emplacement rates compatible with building a large silicic mush. Initial field and geochemical evidence, including lenticular bodies of leucogranite at high elevations and systematic vertical variations in whole rock geochemistry in a short vertical section, suggest that this fossil magma reservoir may have undergone some degree of crystal-liquid separation. I expand on these initial results and present new detailed geologic mapping of textural and compositional variation within a 1 km vertical section coupled with new whole rock geochemical measurements and zircon trace element data to assess the degree to which in situ differentiation may have occurred within this fossil magma reservoir.

  12. Modeling of fluid injection and withdrawal induced fault activation using discrete element based hydro-mechanical and dynamic coupled simulator

    NASA Astrophysics Data System (ADS)

    Yoon, Jeoung Seok; Zang, Arno; Zimmermann, Günter; Stephansson, Ove

    2016-04-01

    Operation of fluid injection into and withdrawal from the subsurface for various purposes has been known to induce earthquakes. Such operations include hydraulic fracturing for shale gas extraction, hydraulic stimulation for Enhanced Geothermal System development and waste water disposal. Among these, several damaging earthquakes have been reported in the USA in particular in the areas of high-rate massive amount of wastewater injection [1] mostly with natural fault systems. Oil and gas production have been known to induce earthquake where pore fluid pressure decreases in some cases by several tens of Mega Pascal. One recent seismic event occurred in November 2013 near Azle, Texas where a series of earthquakes began along a mapped ancient fault system [2]. It was studied that a combination of brine production and waste water injection near the fault generated subsurface pressures sufficient to induced earthquakes on near-critically stressed faults. This numerical study aims at investigating the occurrence mechanisms of such earthquakes induced by fluid injection [3] and withdrawal by using hydro-geomechanical coupled dynamic simulator (Itasca's Particle Flow Code 2D). Generic models are setup to investigate the sensitivity of several parameters which include fault orientation, frictional properties, distance from the injection well to the fault, amount of fluid withdrawal around the injection well, to the response of the fault systems and the activation magnitude. Fault slip movement over time in relation to the diffusion of pore pressure is analyzed in detail. Moreover, correlations between the spatial distribution of pore pressure change and the locations of induced seismic events and fault slip rate are investigated. References [1] Keranen KM, Weingarten M, Albers GA, Bekins BA, Ge S, 2014. Sharp increase in central Oklahoma seismicity since 2008 induced by massive wastewater injection, Science 345, 448, DOI: 10.1126/science.1255802. [2] Hornbach MJ, DeShon HR

  13. Determination of trace bismuth in human serum by cloud point extraction coupled flow injection inductively coupled plasma optical emission spectrometry.

    PubMed

    Sun, Mei; Wu, Qianghua

    2011-09-15

    A cloud point extraction method for the preconcentration of ultra-trace bismuth in human serum prior to its determination by inductively coupled plasma optical emission spectrometry had been developed in this paper. The cloud point extraction method was based on the complex of Bi(III) with 8-hydroxyquinoline and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time were investigated in detail. An enrichment factor of 81 was obtained for the preconcentration of Bi(III) with 25 mL solution. Under the optimal conditions, the detection limit of Bi(III) is 0.12 μg L(-1). The relative standard deviation (n = 7) of determination was 2.3%, values of recovery of bismuth were from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination trace bismuth in human serum. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Reagents regeneration flow injection analysis (RRFIA) for spectrophotometric determination of methamphetamine coupled with solvent extraction.

    PubMed

    Teshima, Norio; Fukui, Nobukazu; Sakai, Tadao

    2005-12-15

    Methamphetamine (MPA), being a stimulant drug, reacts with tetrabromophenolphthalein ethyl ester (TBPEH) to form a red-violet ion associate, TBPEHMPA, in 1,2-dichloroethane (DCE) at pH 9. The maximum absorption wavelength was at 570nm. After measuring, yellow TBPEH with DCE could be regenerated by mixing with the buffer solution at pH 3. The regenerated TBPEH/DCE could be reused as an ion association reagent and extracting solvent. In addition, the reagent regeneration could be performed by the on-line flow injection system and the cyclic flow injection analysis system was demonstrated for the determination of MPA without consumption of ion association reagent and organic solvent. The calibration curve was linear in the range of 0.5-3.5x10(-5)M with good repeatability. The sample throughput was 20h(-1).

  15. Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

    PubMed Central

    Ojeda, Catalina Bosch; Rojas, Fuensanta Sánchez

    2006-01-01

    Optical techniques for chemical analysis are well established and sensors based on these techniques are now attracting considerable attention because of their importance in applications such as environmental monitoring, biomedical sensing, and industrial process control. On the other hand, flow injection analysis (FIA) is advisable for the rapid analysis of microliter volume samples and can be interfaced directly to the chemical process. The FIA has become a widespread automatic analytical method for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, and ease of assembling. In this paper, an overview of flow injection determinations by using optical chemical sensors is provided, and instrumentation, sensor design, and applications are discussed. This work summarizes the most relevant manuscripts from 1980 to date referred to analysis using optical chemical sensors in FIA.

  16. Low energy prompt gamma-ray tests of a large volume BGO detector.

    PubMed

    Naqvi, A A; Kalakada, Zameer; Al-Anezi, M S; Raashid, M; Khateeb-ur-Rehman; Maslehuddin, M; Garwan, M A

    2012-01-01

    Tests of a large volume Bismuth Germinate (BGO) detector were carried out to detect low energy prompt gamma-rays from boron and cadmium-contaminated water samples using a portable neutron generator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup. Inspite of strong interference between the sample- and the detector-associated prompt gamma-rays, an excellent agreement has been observed between the experimental and calculated yields of the prompt gamma-rays, indicating successful application of the large volume BGO detector in the PGNAA analysis of bulk samples using low energy prompt gamma-rays. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Comprehensive analysis of chemical constituents in Xingxiong injection by high performance liquid chromatography coupled with mass spectrometry.

    PubMed

    Guo, Long; Dou, Li-Li; Duan, Li; Liu, Ke; Bi, Zhi-Ming; Li, Ping; Liu, E-Hu

    2015-09-01

    Xingxiong injection (XXI) is a widely used Chinese herbal formula prepared by the folium ginkgo extract and ligustrazine for the treatment of cardiovascular and cerebrovascular diseases. Compared with the pharmacological studies, chemical analysis and quality control studies on this formula are relatively limited. In the present study, a high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS) method was applied to comprehensive analysis of constituents in XXI. According to the fragmentation rules and previous reports, thirty ginkgo flavonoids, four ginkgo terpene lactones, and one alkaloid were identified. A high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QQQ MS) method was then applied to quantify ten major constituents in XXI. The method validation results indicated that the developed method had desirable specificity, linearity, precision and accuracy. The total contents of ginkgo flavonoids were about 22.05-25.51 μg·mL(-1) and the ginkgo terpene lactones amounts were about 4.41-8.70 μg·mL(-1) in six batches of XXI samples, respectively. Furthermore, cosine ratio algorithm and distance measurements were employed to evaluate the similarity of XXI samples, and the results demonstrated a high-quality consistency. This work could provide comprehensive information on the quality control of Xingxiong injection, which be helpful in the establishment of a rational quality control standard. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  18. Natural conception following total fertilization failure with intracytoplasmic sperm injection in a couple with unexplained infertility: a case report.

    PubMed

    Codreanu, Dorina; Coricovac, Anca; Mirzan, Luminita; Dracea, Laura; Marinescu, B; Boleac, I

    2013-01-01

    With the introduction of intracytoplasmic sperm injection (ICSI), couples with severe male factor infertility have been able to achieve fertilization and clinical pregnancy rates comparable to other in vitro fertilization patients. However, despite the utilization of microsurgical sperm injection techniques, failure of fertilization still occurs in a few patients. How such fertilization failure after ICSI might impact later ICSI treatments is less understood. We report a case of total fertilization failure after ICSI using sperm from a normozoospermic husband of a patient with unexplained infertility. Six months after the cancelled cycle, the couple conceived naturally. Unfortunately, it was an ectopic pregnancy, which required laparoscopy and surgical removal of the right fallopian tube. This case shows that a failed ICSI cycle, therefore, does not imply a hopeless prognosis for future ICSI treatment. Moreover, in cases with unexplained ICSI failure, natural conception can subsequently occur. The aim of this study is two-fold: to discuss a rare case of a spontaneous pregnancy after total fertilization failure with ICSI and to develop counseling material for patients and doctors who are faced with such a rare situation. To our knowledge, this is the first report of a case of spontaneous pregnancy after total fertilization failure with ICSI.

  19. Large-volume data delivery from low-Earth orbit to ground using efficient single-mode optical receivers

    NASA Astrophysics Data System (ADS)

    Robinson, B. S.; Schieler, C. M.; Boroson, D. M.

    2016-03-01

    Space systems operating in low-Earth orbit are often constrained by how much data can be delivered from space to ground. Traditional data delivery approaches are often limited by either large link losses associated with transmission via a geosynchronous relay satellite or short contact times and spectrum-constrained data rates associated with direct-to-Earth radio-frequency links. Direct-to-Earth optical communication links from low-Earth orbit based on fiber telecommunications technologies that can operate at high data rates (> 100 Gb/s per wavelength channel) can enable the delivery of extremely large volumes of data from space to ground. We analyze the performance of such systems and discuss the performance gains that are enabled by coupling the received signal to an efficient single-mode-fiber-based receiver, even in the presence of turbulence-induced losses.

  20. Determination of ambroxol hydrochloride, methylparaben and benzoic acid in pharmaceutical preparations based on sequential injection technique coupled with monolithic column.

    PubMed

    Satínský, Dalibor; Huclová, Jitka; Ferreira, Raquel L C; Montenegro, Maria Conceição B S M; Solich, Petr

    2006-02-13

    The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method. In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography (SIC) technique with UV detection. A Chromolith SpeedROD RP-18e, 50-4.6 mm column with 10 mm precolumn and a FIAlab 3000 system with a six-port selection valve and 5 ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-tetrahydrofuran-0.05M acetic acid (10:10:90, v/v/v), pH 3.75 adjusted with triethylamine, flow rate 0.48 mlmin(-1), UV-detection was at 245 nm. The analysis time was <11 min. A new SIC method was validated and compared with HPLC. The method was found to be useful for the routine analysis of the active compounds ambroxol and preservatives (methylparaben or benzoic acid) in various pharmaceutical syrups and drops.

  1. Plasma sheet injections into the inner magnetosphere: Two-way coupled OpenGGCM-RCM model results

    NASA Astrophysics Data System (ADS)

    Cramer, W. D.; Raeder, J.; Toffoletto, F. R.; Gilson, M.; Hu, B.

    2017-05-01

    Plasma sheet injections associated with low flux tube entropy bubbles have been found to be the primary means of mass transport from the plasma sheet to the inner magnetosphere. This phenomenon has been primarily studied with satellite data and stand-alone ring current models with artificial boundary conditions. This study introduces a new two-way coupling between a kinetic ring current model (Rice Convection Model, or RCM) and a global magnetosphere MHD model (Open Geospace General Circulation Model, or OpenGGCM). Multiple geomagnetic storms and one period of quiet are modeled to track and characterize inward flow behavior. Simulations show that (1) there is a clear association of plasma sheet injections with bubbles, (2) the majority of inward plasma transport in the magnetotail beyond 6.6 RE is due to bubbles, regardless of storm activity, and (3) the average peak velocity of injections is higher for increasing downtail distances, stronger storms (when compared with storms having similar drivers), and storms driven by corotating interaction regions (when compared with coronal mass ejection-driven storms of similar strength).

  2. Characterization of large volume 3.5″×8″ LaBr3:Ce detectors

    NASA Astrophysics Data System (ADS)

    Giaz, A.; Pellegri, L.; Riboldi, S.; Camera, F.; Blasi, N.; Boiano, C.; Bracco, A.; Brambilla, S.; Ceruti, S.; Coelli, S.; Crespi, F. C. L.; Csatlòs, M.; Frega, S.; Gulyàs, J.; Krasznahorkay, A.; Lodetti, S.; Million, B.; Owens, A.; Quarati, F.; Stuhl, L.; Wieland, O.

    2013-11-01

    The properties of large volume cylindrical 3.5″×8″ (89 mm×203 mm) LaBr3:Ce scintillation detectors coupled to the Hamamatsu R10233-100SEL photo-multiplier tube were investigated. These crystals are among the largest ones ever produced and still need to be fully characterized to determine how these detectors can be utilized and in which applications. We tested the detectors using monochromatic γ-ray sources and in-beam reactions producing γ rays up to 22.6 MeV; we acquired PMT signal pulses and calculated detector energy resolution and response linearity as a function of γ-ray energy. Two different voltage dividers were coupled to the Hamamatsu R10233-100SEL PMT: the Hamamatsu E1198-26, based on straightforward resistive network design, and the “LABRVD”, specifically designed for our large volume LaBr3:Ce scintillation detectors, which also includes active semiconductor devices. Because of the extremely high light yield of LaBr3:Ce crystals we observed that, depending on the choice of PMT, voltage divider and applied voltage, some significant deviation from the ideally proportional response of the detector and some pulse shape deformation appear. In addition, crystal non-homogeneities and PMT gain drifts affect the (measured) energy resolution especially in case of high-energy γ rays. We also measured the time resolution of detectors with different sizes (from 1″×1″ up to 3.5″×8″), correlating the results with both the intrinsic properties of PMTs and GEANT simulations of the scintillation light collection process. The detector absolute full energy efficiency was measured and simulated up to γ-rays of 30 MeV

  3. In vitro fertilization and intracytoplasmic sperm injection for couples with unexplained infertility after failed direct intraperitoneal insemination.

    PubMed

    Takeuchi, S; Minoura, H; Shibahara, T; Shen, X; Futamura, N; Toyoda, N

    2000-10-01

    The objective was to determine the optimal insemination technique in patients undergoing in vitro fertilization (IVF) after failed direct intraperitoneal insemination (DIPI) and the outcome of intracytoplasmic sperm injection (ICSI) in such cases. In case-control studies, 53 couples with unexplained infertility who underwent IVF after four failed DIPI cycles were compared with 75 couples with tubal or endometriosis infertility as controls. Thirty couples with unexplained infertility after failing to conceive with DIPI and conventional IVF who underwent ICSI and 58 couples with male-factor infertility as controls also were compared. Fertilization cleavage, embryo quality, implantation, and pregnancy were compared after IVF and after ICSI. There was a significant difference in fertilization rates after IVF between cases of unexplained infertility after failing to conceive with DIPI (40.4%) and patients with tubal or endometriosis infertility (67.9%). There also was a significant difference in total fertilization failure rates between the two groups (30.4% and 3.9%, respectively). There was a slight but significant difference in numbers of fertilized oocytes after ICSI between patients with low fertilization rate undergoing IVF after failing to conceive DIPI (85.8%) and patients with male factor (90.4%). Total fertilization failure was not observed in these cases. Couples with unexplained infertility after failing to conceive with DIPI show a failed fertilization or a low fertilization rate after IVF. However, they demonstrated a good chance of becoming pregnant after subsequent ICSI, even with statistically significant difference in fertilization rate as compared with male-factor cases.

  4. Microwave injection and coupling optimization in ECR and MDIS ion sources

    NASA Astrophysics Data System (ADS)

    Torrisi, Giuseppe; Caruso, Antonio; Castro, Giuseppe; Celona, Luigi; Gammino, Santo; Leonardi, Ornella; Longhitano, Alberto; Mascali, David; Naselli, Eugenia; Neri, Lorenzo; Sorbello, Gino

    2017-07-01

    The fundamental aspect of coupling between microwave and plasma of the Electron Cyclotron Resonance Ion Source (ECRIS) and Microwave Discharge Ion Source (MDIS) is hereinafter treated together with “ad hoc” microwave-based plasma diagnostics, as a key element for the next progress and variations with respect to the classical ECR heating mechanism. The future challenges for the production of higher-charge states, higher beam intensity, and high absolute ionization efficiency also demand for the exploration of new heating schemes and synergy between experiments and modeling. An overview concerning microwave transport and coupling issues in plasma-based ion sources for particle accelerator will be given in the paper, along with perspectives for the design of next generation sources.

  5. A New Electropositive Filter for Concentrating Enterovirus and Norovirus from Large Volumes of Water - MCEARD

    EPA Science Inventory

    The detection of enteric viruses in environmental water usually requires the concentration of viruses from large volumes of water. The 1MDS electropositive filter is commonly used for concentrating enteric viruses from water but unfortunately these filters are not cost-effective...

  6. Development of a Solid Phase Extraction Method for Agricultural Pesticides in Large-Volume Water Samples

    EPA Science Inventory

    An analytical method using solid phase extraction (SPE) and analysis by gas chromatography/mass spectrometry (GC/MS) was developed for the trace determination of a variety of agricultural pesticides and selected transformation products in large-volume high-elevation lake water sa...

  7. A New Electropositive Filter for Concentrating Enterovirus and Norovirus from Large Volumes of Water - MCEARD

    EPA Science Inventory

    The detection of enteric viruses in environmental water usually requires the concentration of viruses from large volumes of water. The 1MDS electropositive filter is commonly used for concentrating enteric viruses from water but unfortunately these filters are not cost-effective...

  8. Development of a Solid Phase Extraction Method for Agricultural Pesticides in Large-Volume Water Samples

    EPA Science Inventory

    An analytical method using solid phase extraction (SPE) and analysis by gas chromatography/mass spectrometry (GC/MS) was developed for the trace determination of a variety of agricultural pesticides and selected transformation products in large-volume high-elevation lake water sa...

  9. The role of in vitro fertilization and intracytoplasmic sperm injection in couples with unexplained infertility after failed intrauterine insemination.

    PubMed

    Ruiz, A; Remohí, J; Minguez, Y; Guanes, P P; Simón, C; Pellicer, A

    1997-07-01

    To determine an optimal insemination technique in patients undergoing IVF after failed IUI and the role of intracytoplasmic sperm injection (ICSI) in such cases. Prospective, randomized study in couples with unexplained infertility (n = 63) and mild endometriosis (n = 7) undergoing IVF after four IUI cycles. Sibling oocytes were randomized into standard IVF or ICSI insemination according to the order of retrieval. In vitro fertilization program at the Instituto Valenciano de Infertilidad, Valencia, Italy. Seventy couples with unexplained infertility undergoing IVF after failing to conceive with controlled ovarian stimulation and IUI. In vitro fertilization and ICSI. Fertilization, cleavage, and embryo quality were compared in IVF- and ICSI-inseminated oocytes. There was no significant difference in fertilization rates between ICSI (60.4%) and conventional IVF (54.0%). Similarly, there was no difference in embryo quality between both groups. There was no total fertilization failure in ICSI-inseminated oocytes, whereas 8 (11.4%) of 70 cases showed absence of fertilization when conventional IVF was used. Couples with unexplained infertility and mild endometriosis failing to conceive with IUI and undergoing IVF have an 11.4% chance of fertilization failure that can be overcome easily by using ICSI in at least some oocytes. ICSI, however, is not superior to IVF as an insemination technique in most cases. These data should be used in counseling patients.

  10. Coupled Flow and Deformation Modeling of Carbon Dioxide Migration in the Presence of a Caprock Fracture during Injection

    SciTech Connect

    Siriwardane, Hema J; Gondle, Raj K; Bromhal, Grant S

    2013-08-01

    Understanding the transport of carbon dioxide (CO{sub 2}) during long-term CO{sub 2} injection into a typical geologic reservoir, such as a saline aquifer, could be complicated because of changes in geochemical, hydrogeological, and hydromechanical behavior. While the caprock layer overlying the target aquifer is intended to provide a tight, impermeable seal in securing injected CO{sub 2}, the presence of geologic uncertainties, such as a caprock fracture or fault, may provide a channel for CO{sub 2} leakage. There could also be a possibility of the activation of a new or existing dormant fault or fracture, which could act as a leakage pathway. Such a leakage event during CO{sub 2} injection may lead to a different pressure and ground response over a period of time. In the present study, multiphase fluid flow simulations in porous media coupled with geomechanics were used to investigate the overburden geologic response and plume behavior during CO{sub 2} injection in the presence of a hypothetical permeable fractured zone in a caprock, existing or activated. Both single-phase and multiphase fluid flow simulations were performed. The CO{sub 2} migration through an existing fractured zone leads to changes in the fluid pressure in the overburden geologic layers and could have a significant impact on ground deformation behavior. Results of the study show that pressure signatures and displacement patterns are significantly different in the presence of a fractured zone in the caprock layer. The variation in pressure and displacement signatures because of the presence of a fractured zone in the caprock at different locations may be useful in identifying the presence of a fault/fractured zone in the caprock. The pressure signatures can also serve as a mechanism to identify the activation of leakage pathways through the caprock during CO{sub 2} injection. Pressure response and ground deformation behavior from sequestration modeling could be useful in the development of

  11. Determination of organomercury in biological reference materials by inductively coupled plasma mass spectrometry using flow injection analysis

    SciTech Connect

    Beauchemin, D.; Siu, K.W.; Berman, S.S.

    1988-12-01

    Inductively coupled plasma mass spectrometry was used for the determination of organomercury in two marine biological standard reference materials for trace metals (dogfish muscle tissue DORM-1 and lobster hepatopancreas TORT-1). In most parts of this study, the organomercury was extracted as the chloride from the material with toluene and back extracted into an aqueous medium of cysteine acetate. Since the final extracts contained more than 4% sodium, isotope dilution and flow injection analysis were used to respectively counter the effect of concomitant elements and avoid clogging the interface. Comparison of results with gas chromatography shows that the only significant organomercury is methyl-mercury. At least 93% of mercury in DORM-1 and 39% of mercury in TORT-1 exist as methylmercury.

  12. Intelligent foreign particle inspection machine for injection liquid examination based on modified pulse-coupled neural networks.

    PubMed

    Ge, Ji; Wang, Yaonan; Zhou, Bowen; Zhang, Hui

    2009-01-01

    A biologically inspired spiking neural network model, called pulse-coupled neural networks (PCNN), has been applied in an automatic inspection machine to detect visible foreign particles intermingled in glucose or sodium chloride injection liquids. Proper mechanisms and improved spin/stop techniques are proposed to avoid the appearance of air bubbles, which increases the algorithms' complexity. Modified PCNN is adopted to segment the difference images, judging the existence of foreign particles according to the continuity and smoothness properties of their moving traces. Preliminarily experimental results indicate that the inspection machine can detect the visible foreign particles effectively and the detection speed, accuracy and correct detection rate also satisfying the needs of medicine preparation.

  13. Intelligent Foreign Particle Inspection Machine for Injection Liquid Examination Based on Modified Pulse-Coupled Neural Networks

    PubMed Central

    Ge, Ji; Wang, YaoNan; Zhou, BoWen; Zhang, Hui

    2009-01-01

    A biologically inspired spiking neural network model, called pulse-coupled neural networks (PCNN), has been applied in an automatic inspection machine to detect visible foreign particles intermingled in glucose or sodium chloride injection liquids. Proper mechanisms and improved spin/stop techniques are proposed to avoid the appearance of air bubbles, which increases the algorithms' complexity. Modified PCNN is adopted to segment the difference images, judging the existence of foreign particles according to the continuity and smoothness properties of their moving traces. Preliminarily experimental results indicate that the inspection machine can detect the visible foreign particles effectively and the detection speed, accuracy and correct detection rate also satisfying the needs of medicine preparation. PMID:22412318

  14. Determination of propafenone hydrochloride by flow-injection analysis coupled with resonance light scattering detection.

    PubMed

    Hu, Xiaoli; Xu, Dongpo; Liu, Shaopu; Liu, Zhongfang; Liu, Sa

    2009-01-01

    A simple, sensitive and rapid flow injection analysis (FIA) method with resonance light scattering (RLS) was described for the determination of propafenone (PPF). The method was based on the ion-association reaction of 12-tungstophosphoric acid (TP) with propafenone. In pH 1.0 acidic medium, TP reacted with PPF to form an ion-associate complex, which resulted in a significant enhancement of RLS intensity. The maximum scattering peak was located at 340 nm, the RLS intensity was proportional to the concentration of PPF in the range 0.003-9.0 microg/mL, and the detection limit (3sigma) of 1.0 ng/mL was obtained at a sampling rate of 60 samples/h. The feasible reaction conditions and FIA parameters for the system were optimized. The method proposed in this paper shows satisfactory reproducibility with a relative standard deviation (RSD) of 2.1% for 10 successive determinations of 2.0 microg/mL PPF. The present method had been successfully applied to the determination of PPF in serum samples and pharmaceutical samples. The results obtained were in agreement with the method used in the Chinese Pharmacopoeia.

  15. Local cooling, plasma reheating and thermal pinching induced by single aerosol droplets injected into an inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Chan, George C.-Y.; Hieftje, Gary M.

    2016-07-01

    The injection of a single micrometer-sized droplet into an analytical inductively coupled plasma (ICP) perturbs the plasma and involves three sequential effects: local cooling, thermal pinching and plasma reheating. Time-resolved two-dimensional monochromatic imaging of the load-coil region of an ICP was used to monitor this sequence of plasma perturbations. When a microdroplet enters the plasma, it acts as a local heat sink and cools the nearby plasma region. The cooling effect is considered local, although the cooling volume can be large and extends 6 mm from the physical location of the vaporizing droplet. The liberated hydrogen, from decomposition of water, causes a thermal pinch effect by increasing the thermal conductivity of the bulk plasma and accelerating heat loss at the plasma periphery. As a response to the heat loss, the plasma shrinks in size, which increases its power density. Plasma shrinkage starts around the same time when the microdroplet enters the plasma and lasts at least 2 ms after the droplet leaves the load-coil region. Once the vaporizing droplet passes through a particular plasma volume, that volume is reheated to an even higher temperature than under steady-state conditions. Because of the opposing effects of plasma cooling and reheating, the plasma conditions are different upstream (downward) and downstream (upward) from a vaporizing droplet - cooling dominates the downstream region whereas reheating controls in the upstream domain. The boundary between the local cooling and reheating zones is sharp and is only ~ 1 mm thick. The reheating effect persists a relatively long time in the plasma, at least up to 4 ms after the droplet moves out of the load-coil region. The restoration of plasma equilibrium after the perturbation induced by microdroplet injection is slow. Microdroplet injection also induces a momentary change in plasma impedance, and the impedance change was found to correlate qualitatively with the different stages of plasma

  16. Studies on Mixed-Gas Plasmas and Segmented Flow Injection for Use with Inductively Coupled Plasma Mass Spectrometry.

    NASA Astrophysics Data System (ADS)

    Craig, Jane Mary

    In this thesis, mixed gas plasmas and flow injection into air bubbles were investigated for use with inductively coupled plasma mass spectrometry (ICP-MS), in order to improve the technique's analytical capabilities. The mixed gas plasmas were created in two different ways: (i) by adding another gas, either argon, nitrogen, or hydrogen, to the nebulizer gas flow using a sheathing device or (ii) by adding nitrogen to the plasma gas flow. The introduction of each sheathing gas led to degraded analyte sensitivity but generally improved plasma stability, resulting in improved detection limits for a few elements. Introduction of nitrogen into the plasma gas, under the same operating conditions used for an all-argon plasma, resulted in degraded sensitivity but improved signal-to-noise and signal-to-background ratios for Cr, Fe, and Se. The tolerance of ICP-MS to effects caused by the concomitant elements Na and K was improved by addition of nitrogen to the plasma gas flow. Flow injection using a segmented air/water carrier resulted in improved precision, sensitivity, and detection limits compared to those obtained using an all-water carrier. The enhancement in sensitivity was found to be mass dependent and was attributable to more than simply a reduction in dispersion. Under optimized operating conditions, using segmented flow injection resulted in similar or improved detection limits for all analytes except Se when compared to those obtained using continuous nebulization. Changing the gas used to segment the carrier stream did not result in appreciable changes in analyte signals or positions of maximum ionization within the plasma, indicating that the fundamental properties of the plasma did not change. The tolerance of ICP-MS to effects caused by the concomitant elements Na and Ca was not improved by using a segmented carrier compared to that experienced using an all-water carrier.

  17. Sensitive kinetic-catalytic spectrophotometric method for cobalt determination using a chip coupled to a multisyringe flow injection analysis system.

    PubMed

    Abouhiat, Fatima Zohra; Henríquez, Camelia; El Yousfi, Farida; Cerdà, Víctor

    2017-05-01

    The development of an automated kinetic-catalytic spectrophotometric method for cobalt determination is presented. The method is based on the catalytic effect of Co in the oxidation of hydroxybenzoic acid by H2O2 in basic media. The method has been automated using a multisyringe flow injection system coupled to a monolithic flow conduit called chip (chip-MSFIA). All reagents and sample are simultaneously propelled into the chip to achieve an efficient mixing. The reaction product is monitored at 482nm. The reaction takes place very fast at room temperature, thus the fixed-time method is applied to quantify Co concentration in samples. Variables such as, reagents concentration, pH, flow rate and reaction time have been optimized to improve the selectivity and sensitivity of the proposed system. Under optimal conditions, Co may be determined in the range 0.02-10.00μgL(-1) achieving a limit of detection of 0.02μgL(-1) and an injection throughput of 68h(-1). Relative standard deviations are below 3%. The method has been successfully applied to water samples and a pharmaceutical formulation. The accuracy of the method has been validated by add-recovery tests and satisfactory recoveries from 91% to 97% were obtained.

  18. Effect of increasing paternal body mass index on pregnancy and live birth rates in couples undergoing intracytoplasmic sperm injection.

    PubMed

    Umul, M; Köse, S A; Bilen, E; Altuncu, A G; Oksay, T; Güney, M

    2015-04-01

    In this study, our purpose was to investigate the possible effect of paternal obesity on intracytoplasmic sperm injection (ICSI) outcomes on the basis of clinical pregnancy outcome. Antropometric measurements of 155 couples, referred to our infertility clinic and who underwent an ICSI cycle, have been evaluated. The study sample were divided into three groups with respect to paternal body mass index (BMI), as normal weight (BMI: 20-24.9), overweight (BMI: 25-29.9) and obese (BMI ≥ 30). Results of conventional semen analysis were also analysed. Clinical pregnancy data, including fertilisation rate, implantation rate, clinical pregnancy rate and live birth rate, were evaluated. Paternal obesity was a significant negative factor for sperm concentration and sperm motility (P = 0.03 and P = 0.01 respectively). A significant decrease of clinical pregnancy rate and live birth rate was associated with increased paternal BMI (P = 0.04 and P = 0.03 respectively). We have not determined a significant difference among groups in terms of fertilisation rate and implantation rate. This study demonstrates that increasing paternal BMI has a negative influence on ICSI success, including clinical pregnancy rate and live birth rate. There is a need for further studies to point the importance of lifestyle changes in order to overcome the negative influence of paternal obesity on couple's fertility.

  19. High Energy Performance Tests of Large Volume LaBr{sub 3}:Ce Detector

    SciTech Connect

    Naqvi, A.A.; Gondal, M.A.; Khiari, F.Z.; Dastageer, M.A.; Maslehuddin, M.M.; Al-Amoudi, O.S.B.

    2015-07-01

    High energy prompt gamma ray tests of a large volume cylindrical 100 mm x 100 mm (height x diameter) LaBr{sub 3}:Ce detector were carried out using a portable neutron generator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup. In this study prompt gamma-rays yield were measured from water samples contaminated with toxic elements such nickel, chromium and mercury compounds with gamma ray energies up to 10 MeV. The experimental yield of prompt gamma-rays from toxic elements were compared with the results of Monte Carlo calculations. In spite of its higher intrinsic background due to its larger volume, an excellent agreement between the experimental and calculated yields of high energy gamma-rays from Ni, Cr and Hg samples has been achieved for the large volume LaBr{sub 3}:Ce detector. (authors)

  20. A universal and flexible theodolite-camera system for making accurate measurements over large volumes

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohu; Zhu, Zhaokun; Yuan, Yun; Li, Lichun; Sun, Xiangyi; Yu, Qifeng; Ou, Jianliang

    2012-11-01

    Typically, optical measurement systems can achieve high accuracy over a limited volume, or cover a large volume with low accuracy. In this paper, we propose a universal way of integrating a camera with a theodolite to construct a theodolite-camera (TC) measurement system that can make measurements over a large volume with high accuracy. The TC inherits the advantages of high flexibility and precision from theodolite and camera, but it avoids the need to perform elaborate adjustments on the camera and theodolite. The TC provides a universal and flexible approach to the camera-on-theodolite system. We describe three types of TC based separately on: (i) a total station; (ii) a theodolite; and (iii) a general rotation frame. We also propose three corresponding calibration methods for the different TCs. Experiments have been conducted to verify the measuring accuracy of each of the three types of TC.

  1. Assembly, operation and disassembly manual for the Battelle Large Volume Water Sampler (BLVWS)

    SciTech Connect

    Thomas, V.W.; Campbell, R.M.

    1984-12-01

    Assembly, operation and disassembly of the Battelle Large Volume Water Sampler (BLVWS) are described in detail. Step by step instructions of assembly, general operation and disassembly are provided to allow an operator completely unfamiliar with the sampler to successfully apply the BLVWS to his research sampling needs. The sampler permits concentration of both particulate and dissolved radionuclides from large volumes of ocean and fresh water. The water sample passes through a filtration section for particle removal then through sorption or ion exchange beds where species of interest are removed. The sampler components which contact the water being sampled are constructed of polyvinylchloride (PVC). The sampler has been successfully applied to many sampling needs over the past fifteen years. 9 references, 8 figures.

  2. HYBRID BRIDGMAN ANVIL DESIGN: AN OPTICAL WINDOW FOR IN-SITU SPECTROSCOPY IN LARGE VOLUME PRESSES

    SciTech Connect

    Lipp, M J; Evans, W J; Yoo, C S

    2005-07-29

    The absence of in-situ optical probes for large volume presses often limits their application to high-pressure materials research. In this paper, we present a unique anvil/optical window-design for use in large volume presses, which consists of an inverted diamond anvil seated in a Bridgman type anvil. A small cylindrical aperture through the Bridgman anvil ending at the back of diamond anvil allows optical access to the sample chamber and permits direct optical spectroscopy measurements, such as ruby fluorescence (in-situ pressure) or Raman spectroscopy. This performance of this anvil-design has been demonstrated by loading KBr to a pressure of 14.5 GPa.

  3. Mechanically Cooled Large-Volume Germanium Detector Systems for Nuclear Explosion Monitoring DOENA27323-1

    SciTech Connect

    Hull, E.L.

    2006-07-28

    Compact maintenance free mechanical cooling systems are being developed to operate large volume germanium detectors for field applications. To accomplish this we are utilizing a newly available generation of Stirling-cycle mechanical coolers to operate the very largest volume germanium detectors with no maintenance. The user will be able to leave these systems unplugged on the shelf until needed. The flip of a switch will bring a system to life in ~ 1 hour for measurements. The maintenance-free operating lifetime of these detector systems will exceed 5 years. These features are necessary for remote long-duration liquid-nitrogen free deployment of large-volume germanium gamma-ray detector systems for Nuclear Explosion Monitoring. The Radionuclide Aerosol Sampler/Analyzer (RASA) will greatly benefit from the availability of such detectors by eliminating the need for liquid nitrogen at RASA sites while still allowing the very largest available germanium detectors to be reliably utilized.

  4. The large volume radiometric calorimeter system: A transportable device to measure scrap category plutonium

    SciTech Connect

    Duff, M.F.; Wetzel, J.R.; Breakall, K.L.; Lemming, J.F.

    1987-01-01

    An innovative design concept has been used to design a large volume calorimeter system. The new design permits two measuring cells to fit in a compact, nonevaporative environmental bath. The system is mounted on a cart for transportability. Samples in the power range of 0.50 to 12.0 W can be measured. The calorimeters will receive samples as large as 22.0 cm in diameter by 43.2 cm high, and smaller samples can be measured without lengthening measurement time or increasing measurement error by using specially designed sleeve adapters. This paper describes the design considerations, construction, theory, applications, and performance of the large volume calorimeter system. 2 refs., 5 figs., 1 tab.

  5. The large volume calorimeter for measuring the pressure cooker'' shipping container

    SciTech Connect

    Kasperski, P.W.; Duff, M.F.; Wetzel, J.R. ); Baker, L.B.; MacMurdo, K.W. )

    1991-01-01

    A precise, low wattage, large volume calorimeter system has been developed at Mound to measure two configurations of the 12081 containment vessel. This system was developed and constructed to perform verification measurements at the Savannah River Site. The calorimeter system has performance design specifications of {plus minus}0.3% error above the 2-watt level, and {plus minus}(0.03% plus 0.006 watts) at power levels below 2 watts (one sigma). Data collected during performance testing shows measurement errors well within this range, even down to 0.1-watt power levels. The development of this calorimeter shows that ultra-precise measurements can be achieved on extremely large volume sample configurations. 1 ref., 5 figs.

  6. Technical note: rapid, large-volume resuscitation at resuscitative thoracotomy by intra-cardiac catheterization

    PubMed Central

    Cawich, Shamir O; Naraynsingh, Vijay

    2016-01-01

    An emergency thoracotomy may be life-saving by achieving four goals: (i) releasing cardiac tamponade, (ii) controlling haemorrhage, (iii) allowing access for internal cardiac massage and (iv) clamping the descending aorta to isolate circulation to the upper torso in damage control surgery. We theorize that a new goal should be achieving rapid, large-volume fluid resuscitation and we describe a technique to achieve this. PMID:27887010

  7. Direct liquid sample introduction for flow injection analysis and liquid chromatography with inductively coupled argon plasma spectrometric detection

    SciTech Connect

    Lawrence, K.E.; Rice, G.W.; Fassel, V.A.

    1984-02-01

    The coupling of flow injection analysis (FIA) or high-performance liquid chromatography (HPLC) techniques to inductively coupled plasma atomic emission spectrometry (ICP-AES) offers new and attractive approaches for the determination of elemental concentrations in a wide variety of sample matrices. One of the most attractive features that FIA offers is a rapid and precise means of automating sample introduction into an ICP for simultaneous, multielement analysis at the trace, minor, and major constituent level with minimal sample consumption. The utilization of the ICP as a detector for HPLC retains most of the advantages of FIA-ICP, while providing the analyst with a powerful and versatile means of compound separation. This added dimension becomes particularly important when metal speciation is of primary interest, rather than total metal content. To date, the coupling of FIA and HPLC to the ICP has only been accomplished using conventional cross-flow, concentric, or Babington-type pneumatic nebulizers. Limits of detection under these conditions have generally been observed to be poorer when compared to conventional continuous sample flow conditions. These limitations have been attributed to the large dead-volume and the sample losses associated with conventional nebulizers and band broadening of eluents from FIA transfer tubing or HPLC columns prior to entering the nebulizer unit. In an effort to resolve these difficulties, a microconcentric nebulizer has been developed which is inserted directly into the tip of a conventional sample introduction tube of an ICP torch. Preliminary data on the potential utility of direct liquid sample introduction into the ICP are presented. 12 references, 6 figures, 1 table.

  8. 3D cell-printing of large-volume tissues: Application to ear regeneration.

    PubMed

    Lee, Jung-Seob; Kim, Byung Soo; Seo, Dong Hwan; Park, Jeong Hun; Cho, Dong-Woo

    2017-01-17

    The three-dimensional (3D) printing of large-volume cells, printed in a clinically relevant size, is one of the most important challenges in the field of tissue engineering. However, few studies have reported the fabrication of large-volume cell-printed constructs (LCCs). To create LCCs, appropriate fabrication conditions should be established: factors involved include fabrication time, residence time, and temperature control of the cell-laden hydrogel in the syringe to ensure high cell viability and functionality. The prolonged time required for 3D printing of LCCs can reduce cell viability and result in insufficient functionality of the construct, because the cells are exposed to a harsh environment during the printing process. In this regard, we present an advanced 3D cell-printing system composed of a clean air workstation, humidifier, and Peltier system, which provides a suitable printing environment for production of LCCs with high cell viability. We confirmed that the advanced 3D cell-printing system was capable of providing enhanced printability of hydrogels and fabricating an ear-shaped LCC with high cell viability. In vivo results for the ear-shaped LCC also showed that printed chondrocytes proliferated sufficiently and differentiated into cartilage tissue. Thus, we conclude that the advanced 3D cell-printing system is a versatile tool to create cell-printed constructs for the generation of large-volume tissues.

  9. Geophysics Under Pressure: Large-Volume Presses Versus the Diamond-Anvil Cell

    NASA Astrophysics Data System (ADS)

    Hazen, R. M.

    2002-05-01

    Prior to 1970, the legacy of Harvard physicist Percy Bridgman dominated high-pressure geophysics. Massive presses with large-volume devices, including piston-cylinder, opposed-anvil, and multi-anvil configurations, were widely used in both science and industry to achieve a range of crustal and upper mantle temperatures and pressures. George Kennedy of UCLA was a particularly influential advocate of large-volume apparatus for geophysical research prior to his death in 1980. The high-pressure scene began to change in 1959 with the invention of the diamond-anvil cell, which was designed simultaneously and independently by John Jamieson at the University of Chicago and Alvin Van Valkenburg at the National Bureau of Standards in Washington, DC. The compact, inexpensive diamond cell achieved record static pressures and had the advantage of optical access to the high-pressure environment. Nevertheless, members of the geophysical community, who favored the substantial sample volumes, geothermally relevant temperature range, and satisfying bulk of large-volume presses, initially viewed the diamond cell with indifference or even contempt. Several factors led to a gradual shift in emphasis from large-volume presses to diamond-anvil cells in geophysical research during the 1960s and 1970s. These factors include (1) their relatively low cost at time of fiscal restraint, (2) Alvin Van Valkenburg's new position as a Program Director at the National Science Foundation in 1964 (when George Kennedy's proposal for a Nation High-Pressure Laboratory was rejected), (3) the development of lasers and micro-analytical spectroscopic techniques suitable for analyzing samples in a diamond cell, and (4) the attainment of record pressures (e.g., 100 GPa in 1975 by Mao and Bell at the Geophysical Laboratory). Today, a more balanced collaborative approach has been adopted by the geophysics and mineral physics community. Many high-pressure laboratories operate a new generation of less expensive

  10. An automated method of on-line extraction coupled with flow injection and capillary electrophoresis for phytochemical analysis.

    PubMed

    Chen, Hongli; Ding, Xiuping; Wang, Min; Chen, Xingguo

    2010-11-01

    In this study, an automated system for phytochemical analysis was successfully fabricated for the first time in our laboratory. The system included on-line decocting, filtering, cooling, sample introducing, separation, and detection, which greatly simplified the sample preparation and shortened the analysis time. Samples from the decoction extract were drawn every 5 min through an on-line filter and a condenser pipe to the sample loop from which 20-μL samples were injected into the running buffer and transported into a split-flow interface coupling the flow injection and capillary electrophoresis systems. The separation of glycyrrhetinic acid (GTA) and glycyrrhizic acid (GA) took less than 5 min by using a 10 mM borate buffer (adjusted pH to 8.8) and +10 kV voltage. Calibration curves showed good linearity with correlation coefficients (R) more than 0.9991. The intra-day repeatabilities (n = 5, expressed as relative standard deviation) of the proposed system, obtained using GTA and GA standards, were 1.1% and 0.8% for migration time and 0.7% and 0.9% for peak area, respectively. The mean recoveries of GTA and GA in the off-line extract of Glycyrrhiza uralensis Fisch root were better than 99.0%. The limits of detection (signal-to-noise ratio = 3) of the proposed method were 6.2 μg/mL and 6.9 μg/mL for GTA and GA, respectively. The dynamic changes of GTA and GA on the decoction time were obtained during the on-line decoction process of Glycyrrhiza uralensis Fisch root.

  11. THE DEVELOPMENT OF IODINE BASED IMPINGER SOLUTIONS FOR THE EFFICIENT CAPTURE OF HG USING DIRECT INJECTION NEBULIZATION - INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ANALYSIS

    EPA Science Inventory

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hgo) in EPA Method 5 type sampling. An iodine based impinger solutoin proved to be ver...

  12. THE DEVELOPMENT OF IODINE BASED IMPINGER SOLUTIONS FOR THE EFFICIENT CAPTURE OF HG USING DIRECT INJECTION NEBULIZATION - INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ANALYSIS

    EPA Science Inventory

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hgo) in EPA Method 5 type sampling. An iodine based impinger solutoin proved to be ver...

  13. Temperature-dependent spin injection dynamics in InGaAs/GaAs quantum well-dot tunnel-coupled nanostructures

    SciTech Connect

    Chen, S. L. Takayama, J.; Murayama, A.; Kiba, T.; Yang, X. J.

    2016-03-21

    Time-resolved optical spin orientation spectroscopy was employed to investigate the temperature-dependent electron spin injection in In{sub 0.1}Ga{sub 0.9}As quantum well (QW) and In{sub 0.5}Ga{sub 0.5}As quantum dots (QDs) tunnel-coupled nanostructures with 4, 6, and 8 nm-thick GaAs barriers. The fast picosecond-ranged spin injection from QW to QD excited states (ES) was observed to speed up with temperature, as induced by pronounced longitudinal-optical (LO)-phonon-involved multiple scattering process, which contributes to a thermally stable and almost fully spin-conserving injection within 5–180 K. The LO-phonon coupling was also found to cause accelerated electron spin relaxation of QD ES at elevated temperature, mainly via hyperfine interaction with random nuclear field.

  14. Large-volume paracentesis with indwelling peritoneal catheter and albumin infusion: a community hospital study

    PubMed Central

    Martin, Daniel K.; Walayat, Saqib; Jinma, Ren; Ahmed, Zohair; Ragunathan, Karthik; Dhillon, Sonu

    2016-01-01

    Background The management of ascites can be problematic. This is especially true in patients with diuretic refractory ascites who develop a tense abdomen. This often results in hypotension and decreased venous return with resulting renal failure. In this paper, we further examine the risks and benefits of utilizing an indwelling peritoneal catheter to remove large-volume ascites over a 72-h period while maintaining intravascular volume and preventing renal failure. Methods We retrospectively reviewed charts and identified 36 consecutive patients undergoing continuous large-volume paracentesis with an indwelling peritoneal catheter. At the time of drain placement, no patients had signs or laboratory parameters suggestive of spontaneous bacterial peritonitis. The patients underwent ascitic fluid removal through an indwelling peritoneal catheter and were supported with scheduled albumin throughout the duration. The catheter was used to remove up to 3 L every 8 h for a maximum of 72 h. Regular laboratory and ascitic fluid testing was performed. All patients had a clinical follow-up within 3 months after the drain placement. Results An average of 16.5 L was removed over the 72-h time frame of indwelling peritoneal catheter maintenance. The albumin infusion utilized correlated to 12 mg/L removed. The average creatinine trend improved in a statistically significant manner from 1.37 on the day of admission to 1.21 on the day of drain removal. No patients developed renal failure during the hospital course. There were no documented episodes of neutrocytic ascites or bacterial peritonitis throughout the study review. Conclusion Large-volume peritoneal drainage with an indwelling peritoneal catheter is safe and effective for patients with tense ascites. Concomitant albumin infusion allows for maintenance of renal function, and no increase in infectious complications was noted. PMID:27802853

  15. Stroke volume variation as a guide for fluid resuscitation in patients undergoing large-volume liposuction.

    PubMed

    Jain, Anil Kumar; Khan, Asma M

    2012-09-01

    : The potential for fluid overload in large-volume liposuction is a source of serious concern. Fluid management in these patients is controversial and governed by various formulas that have been advanced by many authors. Basically, it is the ratio of what goes into the patient and what comes out. Central venous pressure has been used to monitor fluid therapy. Dynamic parameters, such as stroke volume and pulse pressure variation, are better predictors of volume responsiveness and are superior to static indicators, such as central venous pressure and pulmonary capillary wedge pressure. Stroke volume variation was used in this study to guide fluid resuscitation and compared with one guided by an intraoperative fluid ratio of 1.2 (i.e., Rohrich formula). : Stroke volume variation was used as a guide for intraoperative fluid administration in 15 patients subjected to large-volume liposuction. In another 15 patients, fluid resuscitation was guided by an intraoperative fluid ratio of 1.2. The amounts of intravenous fluid administered in the groups were compared. : The mean amount of fluid infused was 561 ± 181 ml in the stroke volume variation group and 2383 ± 1208 ml in the intraoperative fluid ratio group. The intraoperative fluid ratio when calculated for the stroke volume variation group was 0.936 ± 0.084. All patients maintained hemodynamic parameters (heart rate and systolic, diastolic, and mean blood pressure). Renal and metabolic indices remained within normal limits. : Stroke volume variation-guided fluid application could result in an appropriate amount of intravenous fluid use in patients undergoing large-volume liposuction. : Therapeutic, II.

  16. Separation and detection of isoquinoline alkaloids using MEEKC coupled with field-amplified sample injection induced by ACN.

    PubMed

    Yu, Li-Shuang; Xu, Xue-Qin; Huang, Lu; Lin, Jin-Ming; Chen, Guo-Nan

    2009-02-01

    New methods based on MEEKC coupling with field-amplified sample injection (FASI) induced by ACN were proposed for five isoquinoline alkaloids (berberine, palmatine, jatrorrhizine, sinomenine and homoharringtonine) in no salt and high salt sample solution (HS). For the separation of five isoquinoline alkaloids, a running buffer composed of 18 mM sodium cholate, 2.4% v/v butan-1-ol, 0.6% v/v ethyl acetate, 10% v/v (or 30% v/v) methanol and 87.0% v/v (or 67% v/v) 5 mM Na2B4O7~10 mM NaH2PO4 buffer (pH 7.5) was developed. In order to improve the sensitivity, FASI induced by ACN was applied to increase the detection sensitivity. The detection limit was found to be as low as 0.0002 microg/mL in no salt sample solution and 0.062 microg/mL in HS. The method has been applied for the analysis of human urine spiked with analytes, and the assay results were proved to be satisfactory, and also the determination of berberine in urine sample after oral administration berberine.

  17. On-line flow injection-cloud point preconcentration of polycyclic aromatic hydrocarbons coupled with high-performance liquid chromatography.

    PubMed

    Li, Cheuk Fai; Wong, Jonathan W C; Huie, Carmen W; Choi, Martin M F

    2008-12-19

    Cloud point methodology has been used to develop a novel preconcentration and an analytical method for polycyclic aromatic hydrocarbons (PAHs) in soil sample. The nonionic surfactant Tergitol 15-S-7 was successfully used as the surfactant-mediated extractant in both ultrasonic and microwave-assisted extractions. Over 90% of recoveries for various PAHs in soil were obtained under the optimal experimental conditions. The extracts were then preconcentrated and analyzed by our proposed on-line coupling method "flow injection-cloud point preconcentration-high-performance liquid chromatography" (FI-CPP-HPLC) equipped with a fluorescence detector and an excitation/emission wavelength program. The preconcentration system and optimal working conditions were established. The limit of detection of the FI-CPE-HPLC system ranges from 0.101 to 0.456 microg/L for the selected PAHs, i.e., phenanthrene, pyrene, chrysene, benzo[k]fluoranthene and benzo[a]pyrene. Our proposed technique provides a reliable, simple and automatic analytical method for the determination of PAHs in environmental soil samples.

  18. Global analysis of chemical constituents in Shengmai injection using high performance liquid chromatography coupled with tandem mass spectrometry.

    PubMed

    Li, Fei; Cheng, Tao-fang; Dong, Xin; Li, Ping; Yang, Hua

    2016-01-05

    This study aimed to develop a specific and reliable method to comprehensively analyze the chemical constituents in Shengmai injection (SMI) using high performance liquid chromatography coupled with tandem mass spectrometry. The qualitative analysis of SMI was achieved on a Kromasil 100-5C18 column, and the results demonstrated that a total of sixty-two compounds in SMI were unambiguously assigned or tentatively identified, and further, twenty-one compounds including fourteen saponins, six lignans and one L-borneol-7-O-[β-D-apiofuranosyl (1→6)]-β-D-gluco-pyranoside were quantified by HPLC-MS. Furthermore, L-borneol-7-O-[β-D-apio-furanosyl (1→6)]-β-D-glucopyranoside, originated from Radix ophiopogonis, was identified and quantified in SMI for the first time. The method validation results indicated that the methods were simple, specific and reliable. All the investigated compounds showed good linearity (r(2)≥0.9992) with a relatively wide concentration range and acceptable recovery at 90.13-109.09%. Consequently, the developed methods were successfully applied to ten batches of SMI samples analysis. The proposed methods may provide a useful and comprehensive reference for the quality control of SMI, and thus to provide supporting data for the quality control and application of SMI clinically. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Determination of some rare earth elements in seawater by inductively coupled plasma mass spectrometry using flow injection preconcentration

    NASA Astrophysics Data System (ADS)

    Vicente, O.; Padró, A.; Martinez, L.; Olsina, R.; Marchevsky, E.

    1998-08-01

    An on-line Eu, Tb, Ho, Tm and Lu preconcentration and determination system implemented with inductively coupled plasma mass spectrometry (ICP-MS) associated to a flow injection (FI) method was studied. Quinolin-8-ol and Amberlite XAD-7 were used for the retention of Eu, Tb, Ho, Tm and Lu, at pH 10.0. The rare earth elements were re-extracted from the microcolumn with nitric acid. The values of detection limits (DL) obtained for the preconcentration of 100 ml of aqueous solution of Eu, Tb, Ho, Tm and Lu were 0.016, 0.0023, 0.0017, 0.0035 and 0.0015 pg ml -1, respectively, with a relative standard deviation (RSD) of about 2.0%. The calibration graphs obtained by using the preconcentration system for Eu, Tb, Ho, Tm and Lu were linear at levels near the detection limits up to at least 1 ng ml -1. The method was succesfully applied to the determination of Eu, Tb, Ho, Tm and Lu in seawater samples.

  20. Flow-injection technique for determination of uranium and thorium isotopes in urine by inductively coupled plasma mass spectrometry.

    PubMed

    Benkhedda, Karima; Epov, Vladimir N; Evans, R Douglas

    2005-04-01

    A sensitive and efficient flow-injection (FI) preconcentration and matrix-separation technique coupled to sector field ICP-mass spectrometry (SF-ICP-MS) has been developed and validated for simultaneous determination of ultra-low levels of uranium (U) and thorium (Th) in human urine. The method is based on selective retention of U and Th from a urine matrix, after microwave digestion, on an extraction chromatographic TRU resin, as an alternative to U/TEVA resin, and their subsequent elution with ammonium oxalate. Using a 10 mL sample, the limits of detection achieved for 238U and 232Th were 0.02 and 0.03 ng L(-1), respectively. The accuracy of the method was checked by spike-recovery measurements. Levels of U and Th in human urine were found to be in the ranges 1.86-5.50 and 0.176-2.35 ng L(-1), respectively, well in agreement with levels considered normal for non-occupationally exposed persons. The precision obtained for five replicate measurements of a urine sample was 2 and 3% for U and Th, respectively. The method also enables on-line measurements of the 235U/238U isotope ratios in urine. Precision of 0.82-1.04% (RSD) was obtained for 235U/238U at low ng L(-1) levels, using the FI transient signal approach.

  1. Rational approach for self-limiting current injection transformers confirmed by coupled electromagnetic-thermal FEM simulation

    NASA Astrophysics Data System (ADS)

    Farhadi, Mustafa; Heydari, Hossein

    2011-07-01

    Current injection transformer (CIT) systems are within the major group of the standard-type test of high current components in the electrical industry. The present precious approach contemplates an arrangement for a rational design of a self-current limiting transformer (SLT) being integrated by a single unit 25 kA CIT system for fast overcurrent detection in stipulated current tests. This paper describes mathematical formulations based on an electric models and the dominant effects of an auxiliary winding on the rate of the self-limiting process of the system. This requires the evaluation of multiphysical (i.e. coupling of the electromagnetic and thermal parts) finite element modelling and simulations for three different approaches to suit the designer's choice. An overcurrent causes a considerable distortion of axial leakage flux, which in turn produces high radial forces. The transient analysis of the leakage flux densities and the corresponding electromagnetic forces on windings of the CIT and proposed SLT are the other objects of this paper. Moreover, the distribution of the flux density and the corresponding localized losses within the SLT core are further objects of this paper. However, this paper will mark another important event in superconductor technology and augment efficiency and compactness from which a lower overall cost of the CIT system could be attainable.

  2. Prospects of the search for neutrino bursts from supernovae with Baksan large volume scintillation detector

    NASA Astrophysics Data System (ADS)

    Petkov, V. B.

    2016-11-01

    Observing a high-statistics neutrino signal from the supernova explosions in the Galaxy is a major goal of low-energy neutrino astronomy. The prospects for detecting all flavors of neutrinos and antineutrinos from the core-collapse supernova (ccSN) in operating and forthcoming large liquid scintillation detectors (LLSD) are widely discussed now. One of proposed LLSD is Baksan Large Volume Scintillation Detector (BLVSD). This detector will be installed at the Baksan Neutrino Observatory (BNO) of the Institute for Nuclear Research, Russian Academy of Sciences, at a depth of 4800 m.w.e. Low-energy neutrino astronomy is one of the main lines of research of the BLVSD.

  3. Incarceration of umbilical hernia: a rare complication of large volume paracentesis

    PubMed Central

    Khodarahmi, Iman; Shahid, Muhammad Usman; Contractor, Sohail

    2015-01-01

    We present two cases of umbilical hernia incarceration following large volume paracentesis (LVP) in patients with cirrhotic ascites. Both patients became symptomatic within 48 hours after the LVP. Although being rare, given the significantly higher mortality rate of cirrhotic patients undergoing emergent herniorrhaphy, this complication of LVP is potentially serious. Therefore, it is recommended that patients be examined closely for the presence of umbilical hernias before removal of ascitic fluid and an attempt should be made for external reduction of easily reducible hernias, if a hernia is present. PMID:26629305

  4. Fan-beam scanning laser optical computed tomography for large volume dosimetry

    NASA Astrophysics Data System (ADS)

    Dekker, K. H.; Battista, J. J.; Jordan, K. J.

    2017-05-01

    A prototype scanning-laser fan beam optical CT scanner is reported which is capable of high resolution, large volume dosimetry with reasonable scan time. An acylindrical, asymmetric aquarium design is presented which serves to 1) generate parallel-beam scan geometry, 2) focus light towards a small acceptance angle detector, and 3) avoid interference fringe-related artifacts. Preliminary experiments with uniform solution phantoms (11 and 15 cm diameter) and finger phantoms (13.5 mm diameter FEP tubing) demonstrate that the design allows accurate optical CT imaging, with optical CT measurements agreeing within 3% of independent Beer-Lambert law calculations.

  5. Cryogenic loading of large volume presses for high-pressure experimentation and synthesis of novel materials

    SciTech Connect

    Lipp, M J; Evans, W J; Yoo, C S

    2005-01-21

    We present an efficient easily implemented method for loading cryogenic fluids in a large volume press. We specifically apply this method to the high-pressure synthesis of an extended solid derived from CO using a Paris-Edinburgh cell. This method employs cryogenic cooling of Bridgman type WC anvils well insulated from other press components, condensation of the load gas within a brass annulus surrounding the gasket between the Bridgman anvils. We demonstrate the viability of the described approach by synthesizing macroscopic amounts (several milligrams) of polymeric CO-derived material, which were recovered to ambient conditions after compression of pure CO to 5 GPa or above.

  6. Large Volume, Optical and Opto-Mechanical Metrology Techniques for ISIM on JWST

    NASA Technical Reports Server (NTRS)

    Hadjimichael, Theo

    2015-01-01

    The final, flight build of the Integrated Science Instrument Module (ISIM) element of the James Webb Space Telescope is the culmination of years of work across many disciplines and partners. This paper covers the large volume, ambient, optical and opto-mechanical metrology techniques used to verify the mechanical integration of the flight instruments in ISIM, including optical pupil alignment. We present an overview of ISIM's integration and test program, which is in progress, with an emphasis on alignment and optical performance verification. This work is performed at NASA Goddard Space Flight Center, in close collaboration with the European Space Agency, the Canadian Space Agency, and the Mid-Infrared Instrument European Consortium.

  7. Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six times.

    PubMed

    Bojanic, Ines; Dubravcic, Klara; Batinic, Drago; Cepulic, Branka Golubic; Mazic, Sanja; Hren, Darko; Nemet, Damir; Labar, Boris

    2011-04-01

    Large-volume leukapheresis (LVL) differs from standard leukapheresis by increased blood flow and an altered anticoagulation regimen. An open issue is to what degree a further increase in processed blood volume is reasonable in terms of higher yields and safety. In 30 LVL performed in patients with hematologic malignancies, 6 total blood volumes were processed. LVL resulted in a higher CD34+ cell yield without a change in graft quality. Although a marked platelet decrease can be expected, LVL is safe and can be recommended as the standard procedure for patients who mobilize low numbers of CD34+ cells and when high number of CD34+ cells are required.

  8. Incarceration of umbilical hernia: a rare complication of large volume paracentesis.

    PubMed

    Khodarahmi, Iman; Shahid, Muhammad Usman; Contractor, Sohail

    2015-09-01

    We present two cases of umbilical hernia incarceration following large volume paracentesis (LVP) in patients with cirrhotic ascites. Both patients became symptomatic within 48 hours after the LVP. Although being rare, given the significantly higher mortality rate of cirrhotic patients undergoing emergent herniorrhaphy, this complication of LVP is potentially serious. Therefore, it is recommended that patients be examined closely for the presence of umbilical hernias before removal of ascitic fluid and an attempt should be made for external reduction of easily reducible hernias, if a hernia is present.

  9. Large-volume en-bloc staining for electron microscopy-based connectomics

    PubMed Central

    Hua, Yunfeng; Laserstein, Philip; Helmstaedter, Moritz

    2015-01-01

    Large-scale connectomics requires dense staining of neuronal tissue blocks for electron microscopy (EM). Here we report a large-volume dense en-bloc EM staining protocol that overcomes the staining gradients, which so far substantially limited the reconstructable volumes in three-dimensional (3D) EM. Our protocol provides densely reconstructable tissue blocks from mouse neocortex sized at least 1 mm in diameter. By relaxing the constraints on precise topographic sample targeting, it makes the correlated functional and structural analysis of neuronal circuits realistic. PMID:26235643

  10. Monitoring a large volume CO2 injection: Year two results from SECARB project at Denbury’s Cranfield, Mississippi, USA

    USGS Publications Warehouse

    Hovorka, Susan D.; Meckel, Timothy A.; Trevino, Ramon H.; Lu, Jiemin; Nicot, Jean-Philippe; Choi, Jong-Won; Freeman, David; Cook, Paul; Daley, Thomas M.; Ajo-Franklin, Jonathan B.; Freifeild, Barry M.; Doughty, Christine; Carrigan, Charles R.; La Brecque, Doug; Kharaka, Yousif K.; Thordsen, James J.; Phelps, Tommy J.; Yang, Changbing; Romanak, Katherine D.; Zhang, Tongwei; Holt, Robert M.; Lindler, Jeffery S.; Butsch, Robert J.

    2011-01-01

    Reservoir characterization based on cores, historic and new wireline log data, production history, hydrologic tests, fluid analysis, and a three-D seismic survey have been used in multiple numerical models to predict reservoir response in order to design effective monitoring strategies and optimize deployment. History matching of observed response to predicted response is used to interpret r

  11. ANALYSIS OF LOW-LEVEL PESTICIDES FROM HIGH-ELEVATION LAKE WATERS BY LARGE-VOLUME INJECTION GCMS

    EPA Science Inventory

    Pesticides are among the factors being proposed as causal agents for amphibian population declines in the Sierra Nevada range of California, USA. We hypothesize that agricultural pesticides applied in the San Joaquin Valley west of the mountains are volatilized or eroded, transpo...

  12. Colloids Versus Albumin in Large Volume Paracentesis to Prevent Circulatory Dysfunction: Evidence-based Case Report.

    PubMed

    Widjaja, Felix F; Khairan, Paramita; Kamelia, Telly; Hasan, Irsan

    2016-04-01

    Large volume paracentesis may cause paracentesis induced circulatory dysfunction (PICD). Albumin is recommended to prevent this abnormality. Meanwhile, the price of albumin is too expensive and there should be another alternative that may prevent PICD. This report aimed to compare albumin to colloids in preventing PICD. Search strategy was done using PubMed, Scopus, Proquest, dan Academic Health Complete from EBSCO with keywords of "ascites", "albumin", "colloid", "dextran", "hydroxyethyl starch", "gelatin", and "paracentesis induced circulatory dysfunction". Articles was limited to randomized clinical trial and meta-analysis with clinical question of "In hepatic cirrhotic patient undergone large volume paracentesis, whether colloids were similar to albumin to prevent PICD". We found one meta-analysis and four randomized clinical trials (RCT). A meta analysis showed that albumin was still superior of which odds ratio 0.34 (0.23-0.51). Three RCTs showed the same results and one RCT showed albumin was not superior than colloids. We conclude that colloids could not constitute albumin to prevent PICD, but colloids still have a role in patient who undergone paracentesis less than five liters.

  13. Controlled ice nucleation--Is it really needed for large-volume sperm cryopreservation?

    PubMed

    Saragusty, Joseph; Osmers, Jan-Hendrik; Hildebrandt, Thomas Bernd

    2016-04-15

    Controlled ice nucleation (CIN) is an integral stage of slow freezing process when relatively large volumes (usually 1 mL or larger) of biological samples in suspension are involved. Without it, a sample will supercool to way below its melting point before ice crystals start forming, resulting in multiple damaging processes. In this study, we tested the hypothesis that when freezing large volumes by the directional freezing technique, a CIN stage is not needed. Semen samples collected from ten bulls were frozen in 2.5-mL HollowTubes in a split-sample manner with and without a CIN stage. Thawed samples were evaluated for viability, acrosome integrity, rate of normal morphology, and, using computer-aided sperm analysis system, for a wide range of motility parameters that were also evaluated after 3 hours of incubation at 37 °C. Analysis of the results found no difference between freezing with and without CIN stage in any and all of the 29 parameters compared (P > 0.1 for all). This similarity was maintained through 3 hours of incubation at 37 °C. Possibly, because of its structure, the directional freezing device promotes continuous ice nucleation so a specific CIN stage is no longer needed, thus reducing costs, energy use, and carbon footprint. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Development of large volume double ring penning plasma discharge source for efficient light emissions.

    PubMed

    Prakash, Ram; Vyas, Gheesa Lal; Jain, Jalaj; Prajapati, Jitendra; Pal, Udit Narayan; Chowdhuri, Malay Bikas; Manchanda, Ranjana

    2012-12-01

    In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd(2)Fe(14)B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of ~0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is ~2 × 10(11) cm(-3), which is around one order of magnitude larger than that of single ring arrangement.

  15. Specific detection of DNA using quantum dots and magnetic beads for large volume samples

    SciTech Connect

    Kim, Yeon S.; Kim, Byoung CHAN; Lee, Jin Hyung; Kim, Jungbae; Gu, Man Bock

    2006-10-01

    Here we present a sensitive DNA detection protocol using quantum dots (QDs) and magnetic beads (MBs) for large volume samples. In this study, QDs, conjugated with streptavidin, were used to produce fluorescent signals while magnetic beads (MBs) were used to isolate and concentrate the signals. The presence of target DNAs lead to the sandwich hybridization between the functionalized QDs, the target DNAs and the MBs. In fact, the QDs-MBs complex, which is bound using the target DNA, can be isolated and then concentrated. The binding of the QDs to the surface of the MBs was confirmed by confocal microscopy and Cd elemental analysis. It was found that the fluorescent intensity was proportional to concentration of the target DNA, while the presence of noncomplementary DNA produced no significant fluorescent signal. In addition, the presence of low copies of target DNAs such as 0.5 pM in large volume samples up to 40 ml were successfully detected by using a magnet-assisted concentration protocol which consequently results in the enhancement of the sensitivity more than 100-fold.

  16. Development of large volume double ring penning plasma discharge source for efficient light emissions

    SciTech Connect

    Prakash, Ram; Vyas, Gheesa Lal; Jain, Jalaj; Prajapati, Jitendra; Pal, Udit Narayan; Chowdhuri, Malay Bikas; Manchanda, Ranjana

    2012-12-15

    In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd{sub 2}Fe{sub 14}B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of {approx}0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is {approx}2 Multiplication-Sign 10{sup 11} cm{sup -3}, which is around one order of magnitude larger than that of single ring arrangement.

  17. Clinical, biochemical, and hormonal changes after a single, large-volume paracentesis in cirrhosis with ascites.

    PubMed

    Gentile, S; Angelico, M; Bologna, E; Capocaccia, L

    1989-03-01

    The use of paracentesis has recently been reproposed as a safe and effective alternative to diuretics for management of ascites. We have investigated the clinical and biochemical effects of large-volume paracentesis in 19 cirrhotics with tense ascites, and the relative changes in the hormones involved in sodium and water renal handling. Plasma renin activity (PRA), aldosterone (PA), and arginine vasopressin (AVP) levels and conventional liver and renal function tests were measured before and after 1, 2, and 7 days after the paracentesis. No complications were observed, but patients regained 37% of the weight lost after 1 wk. Percent weight regained was significantly and directly correlated with PA concentration measured before the paracentesis. No changes were recorded after paracentesis in biochemical and clinical data, except for a significant drop in diastolic blood pressure. No changes in AVP levels were observed. A significant increase in PA occurred after paracentesis, with a maximum peak after 48 h. The increase in PA was not accompanied by changes in PRA, but was associated with a reduction of urinary sodium excretion. A relevant fraction of body aldosterone was confined to the ascitic fluid. We conclude that the clinical results of a large-volume paracentesis can be predicted in part on the basis of PA measurement, and that removal of ascites is followed by an increase of PA of uncertain origin and effectiveness.

  18. Real-time visualization of large volume datasets on standard PC hardware.

    PubMed

    Xie, Kai; Yang, Jie; Zhu, Y M

    2008-05-01

    In medical area, interactive three-dimensional volume visualization of large volume datasets is a challenging task. One of the major challenges in graphics processing unit (GPU)-based volume rendering algorithms is the limited size of texture memory imposed by current GPU architecture. We attempt to overcome this limitation by rendering only visible parts of large CT datasets. In this paper, we present an efficient, high-quality volume rendering algorithm using GPUs for rendering large CT datasets at interactive frame rates on standard PC hardware. We subdivide the volume dataset into uniform sized blocks and take advantage of combinations of early ray termination, empty-space skipping and visibility culling to accelerate the whole rendering process and render visible parts of volume data. We have implemented our volume rendering algorithm for a large volume data of 512 x 304 x 1878 dimensions (visible female), and achieved real-time performance (i.e., 3-4 frames per second) on a Pentium 4 2.4GHz PC equipped with NVIDIA Geforce 6600 graphics card ( 256 MB video memory). This method can be used as a 3D visualization tool of large CT datasets for doctors or radiologists.

  19. Determination of phosphodiesterase type V inhibitors in wastewater by direct injection followed by liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Causanilles, Ana; Emke, Erik; de Voogt, Pim

    2016-09-15

    A simple, fast and reliable analytical method for the determination of phosphodiesterase type V inhibitors in wastewater was developed and validated. The method was based on direct injection followed by liquid chromatography coupled to tandem mass spectrometry with triple quadrupole as mass analyzer. Transformation products and analogues were included in the target list besides the three active pharmaceutical ingredients (sildenafil, vardenafil and tadalafil). The method performance was thoroughly investigated, including the analyte stability in wastewater and matrix effect. All target compounds presented linear fits between their LOD and 500ng/L. The quantification limits ranged from 1.6 to 30ng/L for all compounds except for n-octylnortadalafil (LOQ: 100ng/L); precision calculated as intraday repeatability was lower than 30%; accuracy calculated as procedural recovery ranged successfully between 85 and 105% in all cases. The method was applied to samples collected during three week-long monitoring campaigns performed in 2013, 2014 and 2015 in three Dutch cities. Only sildenafil and its two metabolites, desmethyl- and desethylsildenafil, were present with normalized loads ranging from LOQ to 8.3, 11.8 and 21.6mg/day/1000 inh, respectively. Two additional week-long sets of samples were collected in Amsterdam at the time that a festival event took place, bringing around 350,000 visitors to the city. The difference in drug usage patterns was statistically studied: "weekday" versus "weekend", "normal" versus "atypical" week; and results discussed. The metabolite to parent drug concentration ratio evolution during consecutive years was discussed, leading to several possible explanations that should be further investigated. Finally, wastewater-based epidemiology approach was applied to back-calculate sildenafil consumption.

  20. Safety limit of large-volume hepatic radiofrequency ablation in a rat model.

    PubMed

    Ng, Kelvin K; Lam, Chi Ming; Poon, Ronnie T; Shek, Tony W; Ho, David W; Fan, Sheung Tat

    2006-03-01

    Large-volume hepatic radiofrequency ablation (RFA) has been used to treat large liver tumors, but its safety limit is unknown. This study aimed to investigate the possible systemic responses of large-volume hepatic RFA and to estimate its safety limit in normal and cirrhotic rats. Large-volume hepatic RFA causes a significant systemic inflammatory reaction. Experimental study. University teaching hospital. Using the Cool-tip RF System (Radionics, Burlington, Mass), RFA was performed for different percentages of the liver volume by weight in normal and cirrhotic Sprague-Dawley rats. Changes in concentrations of serum inflammatory markers (tumor necrosis factor alpha [TNF-alpha] and interleukin [IL] 6), functions of various end organs, and survival rates were assessed. In the normal liver groups, the concentrations of TNF-alpha and IL-6 were significantly elevated in the early postoperative period when 50% (mean +/- SD TNF-alpha concentration, 130.3 +/- 15.6 pg/mL; mean +/- SD IL-6 concentration, 163.2 +/- 12.2 pg/mL) and 60% (mean +/- SD TNF-alpha concentration, 145.7 +/- 13.0 pg/mL; mean +/- SD IL-6 concentration, 180.8 +/- 11.0 pg/mL) of the liver volume were ablated compared with the control group (mean +/- SD TNF-alpha concentration, 30.4 +/- 9.9 pg/mL, P<.001; mean +/- SD IL-6 concentration, 28.4 +/- 6.7 pg/mL, P<.001). The concentrations of TNF-alpha and IL-6 in other groups remained similar to those in the control group. Thrombocytopenia, prolonged clotting time, and interstitial pneumonitis occurred when 50% and 60% of the liver volume were ablated. The 4-week survival rates were 100%, 60%, and 0% when 40%, 50%, and 60%, respectively, of the liver volume were ablated. Similar systemic inflammatory responses and poor survival rates were observed among the cirrhotic liver groups when 30% and 40% of the liver volume were ablated. The normal rats can tolerate RFA of 40% of the liver volume with minimal morbidity and no mortality whereas the cirrhotic rats can

  1. Predicting nurse staffing needs for a labor and birth unit in a large-volume perinatal service.

    PubMed

    Simpson, Kathleen Rice

    2015-01-01

    This project was designed to test a nurse staffing model for its ability to accurately determine staffing needs for a large-volume labor and birth unit based on a staffing gap analysis using the nurse staffing guidelines from the Association of Women's Health, Obstetric and Neonatal Nurses (AWHONN). The staffing model and the AWHONN staffing guidelines were found to be reliable methods to predict staffing needs for a large-volume labor and birth unit.

  2. Calcium isolation from large-volume human urine samples for 41Ca analysis by accelerator mass spectrometry.

    PubMed

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-08-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for (41)Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after (41)Ca administration during which human samples, collected over a lifetime, provide (41)Ca:Ca ratios that are significantly above background.

  3. The core collapse supernova rate from 24 years of data of the Large Volume Detector

    NASA Astrophysics Data System (ADS)

    Bruno, G.; Fulgione, W.; Molinario, A.; Vigorito, C.; LVD Collaboration

    2017-09-01

    The Large Volume Detector (LVD) at INFN Laboratori Nazionali del Gran Sasso, Italy is a 1 kt liquid scintillator neutrino observatory mainly designed to study low energy neutrinos from Gravitational Stellar Collapses (GSC) with 100% efficiency over the entire Galaxy. Here we summarize the results of the search for supernova neutrino bursts over the full data set lasting from June 1992 to May 2016 for a total live time of 8211 days. In the lack of a positive observation, either in standalone mode or in coincidence with other experiments, we establish the upper limit to the rate of GSC event in the Milky Way: 0.1 year‑1 at 90% c.l..

  4. The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry

    PubMed Central

    Henningsson, Per; Michaelis, Dirk; Nakata, Toshiyuki; Schanz, Daniel; Geisler, Reinhard; Schröder, Andreas; Bomphrey, Richard J.

    2015-01-01

    Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin–Helmholtz instability in the shear layer behind the flapping wings. PMID:26040598

  5. Aerodynamics of the Large-Volume, Flow-Through Detector System. Final report

    SciTech Connect

    Reed, H.; Saric, W.; Laananen, D.; Martinez, C.; Carrillo, R.; Myers, J.; Clevenger, D.

    1996-03-01

    The Large-Volume Flow-Through Detector System (LVFTDS) was designed to monitor alpha radiation from Pu, U, and Am in mixed-waste incinerator offgases; however, it can be adapted to other important monitoring uses that span a number of potential markets, including site remediation, indoor air quality, radon testing, and mine shaft monitoring. Goal of this effort was to provide mechanical design information for installation of LVFTDS in an incinerator, with emphasis on ability to withstand the high temperatures and high flow rates expected. The work was successfully carried out in three stages: calculation of pressure drop through the system, materials testing to determine surrogate materials for wind-tunnel testing, and wind-tunnel testing of an actual configuration.

  6. Measurement of the velocity of neutrinos from the CNGS beam with the large volume detector.

    PubMed

    Agafonova, N Yu; Aglietta, M; Antonioli, P; Ashikhmin, V V; Bari, G; Bertoni, R; Bressan, E; Bruno, G; Dadykin, V L; Fulgione, W; Galeotti, P; Garbini, M; Ghia, P L; Giusti, P; Kemp, E; Mal'gin, A S; Miguez, B; Molinario, A; Persiani, R; Pless, I A; Ryasny, V G; Ryazhskaya, O G; Saavedra, O; Sartorelli, G; Shakyrianova, I R; Selvi, M; Trinchero, G C; Vigorito, C; Yakushev, V F; Zichichi, A; Razeto, A

    2012-08-17

    We report the measurement of the time of flight of ∼17 GeV ν(μ) on the CNGS baseline (732 km) with the Large Volume Detector (LVD) at the Gran Sasso Laboratory. The CERN-SPS accelerator has been operated from May 10th to May 24th 2012, with a tightly bunched-beam structure to allow the velocity of neutrinos to be accurately measured on an event-by-event basis. LVD has detected 48 neutrino events, associated with the beam, with a high absolute time accuracy. These events allow us to establish the following limit on the difference between the neutrino speed and the light velocity: -3.8 × 10(-6) < (v(ν)-c)/c < 3.1 × 10(-6) (at 99% C.L.). This value is an order of magnitude lower than previous direct measurements.

  7. Determination of 137Cs in large volume seawater using Cu-hexacyanoferrate cartridge filters

    NASA Astrophysics Data System (ADS)

    Visetpotjanakit, S.; Tumnoi, Y.

    2017-06-01

    A simple method to determine 137Cs in seawater has been developed based on the use of a Cu-hexacyanoferrate scavenger. The Cu-hexacyanoferrate supported on cotton wound cartridge filter was used to absorb 137Cs from seawater by passing large volumes over the cartridge filters with flowrate of 240 L hr-1. Results from the Cu-hexacyanoferrate method were proved acceptable for accuracy with bias below ± 20 % i.e. - 9.16 to + 18.55 % when compared with the traditional ammonium molybdophosphate pre-concentration method. This developed method is cost-effective and less time consuming. In addition it can be easily performed at sampling fields.

  8. AC Magnetic Properties of Large Volume of Water — Susceptibility Measurement in Unshielded Environment

    NASA Astrophysics Data System (ADS)

    Tsukada, Keiji; Kiwa, Toshihiko; Masuda, Yuuki

    2006-10-01

    To investigate the effect of low-frequency magnetic-field exposure of a human body, the low-frequency AC magnetic property of a large volume of water was measured by low-frequency magnetic field exposure (from 50 Hz to 1.2 kHz). The results indicate that the AC magnetic property of water is due to diamagnetism in the low-frequency range. The phase between the main magnetic field and the generated magnetic field remained constant at about 180°. Results were not affected by conductivity or pH. Moreover, the magnetic-field strength from water showed a susceptibility frequency dependence proportional to the frequency above approximately 400 Hz. Because of the incremental effects of susceptibility, the magnetic field from water was measured using a conventional magnetic sensor (magnetic resistive; MR) in an unshielded environment.

  9. Monte Carlo calculations of the HPGe detector efficiency for radioactivity measurement of large volume environmental samples.

    PubMed

    Azbouche, Ahmed; Belgaid, Mohamed; Mazrou, Hakim

    2015-08-01

    A fully detailed Monte Carlo geometrical model of a High Purity Germanium detector with a (152)Eu source, packed in Marinelli beaker, was developed for routine analysis of large volume environmental samples. Then, the model parameters, in particular, the dead layer thickness were adjusted thanks to a specific irradiation configuration together with a fine-tuning procedure. Thereafter, the calculated efficiencies were compared to the measured ones for standard samples containing (152)Eu source filled in both grass and resin matrices packed in Marinelli beaker. From this comparison, a good agreement between experiment and Monte Carlo calculation results was obtained highlighting thereby the consistency of the geometrical computational model proposed in this work. Finally, the computational model was applied successfully to determine the (137)Cs distribution in soil matrix. From this application, instructive results were achieved highlighting, in particular, the erosion and accumulation zone of the studied site.

  10. The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry.

    PubMed

    Henningsson, Per; Michaelis, Dirk; Nakata, Toshiyuki; Schanz, Daniel; Geisler, Reinhard; Schröder, Andreas; Bomphrey, Richard J

    2015-07-06

    Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin-Helmholtz instability in the shear layer behind the flapping wings.

  11. Mechanically Cooled Large-Volume Germanium Detector Systems for Neclear Explosion Monitoring DOENA27323-2

    SciTech Connect

    Hull, E.L.

    2006-10-30

    Compact maintenance free mechanical cooling systems are being developed to operate large volume high-resolution gamma-ray detectors for field applications. To accomplish this we are utilizing a newly available generation of Stirling-cycle mechanical coolers to operate the very largest volume germanium detectors with no maintenance. The user will be able to leave these systems unplugged on the shelf until needed. The maintenance-free operating lifetime of these detector systems will exceed 5 years. Three important factors affect the operation of mechanically cooled germanium detectors: temperature, vacuum, and vibration. These factors will be studied in the laboratory at the most fundamental levels to insure a solid understanding of the physical limitations each factor places on a practical mechanically cooled germanium detector system. Using this knowledge, mechanically cooled germanium detector prototype systems will be designed and fabricated.

  12. Isolation of organic acids from large volumes of water by adsorption chromatography

    USGS Publications Warehouse

    Aiken, George R.

    1984-01-01

    The concentrations of dissolved organic carbon from most natural waters ranges from 1 to 20 milligrams carbon per liter, of which approximately 75 percent are organic acids. These acids can be chromatographically fractionated into hydrophobic organic acids, such as humic substances, and hydrophilic organic acids. To effectively study any of these organic acids, they must be isolated from other organic and inorganic species, and concentrated. Usually, large volumes of water must be processed to obtain sufficient quantities of material, and adsorption chromatography on synthetic, macroporous resins has proven to be a particularly effective method for this purpose. The use of the nonionic Amberlite XAD-8 and Amberlite XAD-4 resins and the anion exchange resin Duolite A-7 for isolating and concentrating organic acids from water is presented.

  13. Plastic embedding immunolabeled large-volume samples for three-dimensional high-resolution imaging.

    PubMed

    Gang, Yadong; Liu, Xiuli; Wang, Xiaojun; Zhang, Qi; Zhou, Hongfu; Chen, Ruixi; Liu, Ling; Jia, Yao; Yin, Fangfang; Rao, Gong; Chen, Jiadong; Zeng, Shaoqun

    2017-08-01

    High-resolution three-dimensional biomolecule distribution information of large samples is essential to understanding their biological structure and function. Here, we proposed a method combining large sample resin embedding with iDISCO immunofluorescence staining to acquire the profile of biomolecules with high spatial resolution. We evaluated the compatibility of plastic embedding with an iDISCO staining technique and found that the fluorophores and the neuronal fine structures could be well preserved in the Lowicryl HM20 resin, and that numerous antibodies and fluorescent tracers worked well upon Lowicryl HM20 resin embedding. Further, using fluorescence Micro-Optical sectioning tomography (fMOST) technology combined with ultra-thin slicing and imaging, we were able to image the immunolabeled large-volume tissues with high resolution.

  14. Improved large-volume sampler for the collection of bacterial cells from aerosol.

    PubMed

    White, L A; Hadley, D J; Davids, D E; Naylor, R

    1975-03-01

    A modified large-volume sampler was demonstrated to be an efficient device for the collection of mono-disperse aerosols of rhodamine B and poly-disperse aerosols of bacterial cells. Absolute efficiency for collection of rhodamine B varied from 100% with 5-mum particles to about 70% with 0.5-mum particles. The sampler concentrated the particles from 950 liters of air into a flow of between 1 and 2 ml of collecting fluid per min. Spores of Bacillus subtilis var. niger were collected at an efficiency of about 82% compared to the collection in the standard AGI-30 sampler. In the most desirable collecting fluids tested, aerosolized cells of Serratia marcescens, Escherichia coli, and Aerobacter aerogenes were collected at comparative efficiencies of approximately 90, 80, and 90%, respectively. The modified sampler has practical application in the study of aerosol transmission of respiratory pathogens.

  15. Plastic embedding immunolabeled large-volume samples for three-dimensional high-resolution imaging

    PubMed Central

    Gang, Yadong; Liu, Xiuli; Wang, Xiaojun; Zhang, Qi; Zhou, Hongfu; Chen, Ruixi; Liu, Ling; Jia, Yao; Yin, Fangfang; Rao, Gong; Chen, Jiadong; Zeng, Shaoqun

    2017-01-01

    High-resolution three-dimensional biomolecule distribution information of large samples is essential to understanding their biological structure and function. Here, we proposed a method combining large sample resin embedding with iDISCO immunofluorescence staining to acquire the profile of biomolecules with high spatial resolution. We evaluated the compatibility of plastic embedding with an iDISCO staining technique and found that the fluorophores and the neuronal fine structures could be well preserved in the Lowicryl HM20 resin, and that numerous antibodies and fluorescent tracers worked well upon Lowicryl HM20 resin embedding. Further, using fluorescence Micro-Optical sectioning tomography (fMOST) technology combined with ultra-thin slicing and imaging, we were able to image the immunolabeled large-volume tissues with high resolution. PMID:28856037

  16. Floating substructure flexibility of large-volume 10MW offshore wind turbine platforms in dynamic calculations

    NASA Astrophysics Data System (ADS)

    Borg, Michael; Melchior Hansen, Anders; Bredmose, Henrik

    2016-09-01

    Designing floating substructures for the next generation of 10MW and larger wind turbines has introduced new challenges in capturing relevant physical effects in dynamic simulation tools. In achieving technically and economically optimal floating substructures, structural flexibility may increase to the extent that it becomes relevant to include in addition to the standard rigid body substructure modes which are typically described through linear radiation-diffraction theory. This paper describes a method for the inclusion of substructural flexibility in aero-hydro-servo-elastic dynamic simulations for large-volume substructures, including wave-structure interactions, to form the basis of deriving sectional loads and stresses within the substructure. The method is applied to a case study to illustrate the implementation and relevance. It is found that the flexible mode is significantly excited in an extreme event, indicating an increase in predicted substructure internal loads.

  17. A pyramid-based approach to visual exploration of a large volume of vehicle trajectory data

    NASA Astrophysics Data System (ADS)

    Sun, Jing; Li, Xiang

    2012-12-01

    Advances in positioning and wireless communicating technologies make it possible to collect large volumes of trajectory data of moving vehicles in a fast and convenient fashion. These data can be applied to traffic studies. Behind this application, a methodological issue that still requires particular attention is the way these data should be spatially visualized. Trajectory data physically consists of a large number of positioning points. With the dramatic increase of data volume, it becomes a challenge to display and explore these data. Existing commercial software often employs vector-based indexing structures to facilitate the display of a large volume of points, but their performance downgrades quickly when the number of points is very large, for example, tens of millions. In this paper, a pyramid-based approach is proposed. A pyramid method initially is invented to facilitate the display of raster images through the tradeoff between storage space and display time. A pyramid is a set of images at different levels with different resolutions. In this paper, we convert vector-based point data into raster data, and build a gridbased indexing structure in a 2D plane. Then, an image pyramid is built. Moreover, at the same level of a pyramid, image is segmented into mosaics with respect to the requirements of data storage and management. Algorithms or procedures on grid-based indexing structure, image pyramid, image segmentation, and visualization operations are given in this paper. A case study with taxi trajectory data in Shanghai is conducted. Results demonstrate that the proposed method outperforms the existing commercial software.

  18. Mechanically Cooled Large-Volume Germanium Detector Systems for Nuclear Explosion Monitoring

    SciTech Connect

    Hull, Ethan L.; Pehl, Richard H.; Lathrop, James R.; Martin, Gregory N.; Mashburn, R. B.; Miley, Harry S.; Aalseth, Craig E.; Hossbach, Todd W.; Bowyer, Ted W.

    2006-09-21

    Compact maintenance free mechanical cooling systems are being developed to operate large volume (~570 cm3, ~3 kg, 140% or larger) germanium detectors for field applications. We are using a new generation of Stirling-cycle mechanical coolers for operating the very largest volume germanium detectors with absolutely no maintenance or liquid nitrogen requirements. The user will be able to leave these systems unplugged on the shelf until needed. The flip of a switch will bring a system to life in ~1 hour for measurements. The maintenance-free operating lifetime of these detector systems will exceed five years. These features are necessary for remote long-duration liquid-nitrogen free deployment of large-volume germanium gamma-ray detector systems for Nuclear Explosion Monitoring (NEM). The Radionuclide Aerosol Sampler/Analyzer (RASA) will greatly benefit from the availability of such detectors by eliminating the need for liquid nitrogen at RASA sites while still allowing the very largest available germanium detectors to be utilized. These mechanically cooled germanium detector systems being developed here will provide the largest, most sensitive detectors possible for use with the RASA. To provide such systems, the appropriate technical fundamentals are being researched. Mechanical cooling of germanium detectors has historically been a difficult endeavor. The success or failure of mechanically cooled germanium detectors stems from three main technical issues: temperature, vacuum, and vibration. These factors affect one another. There is a particularly crucial relationship between vacuum and temperature. These factors will be experimentally studied both separately and together to insure a solid understanding of the physical limitations each factor places on a practical mechanically cooled germanium detector system for field use. Using this knowledge, a series of mechanically cooled germanium detector prototype systems are being designed and fabricated. Our collaborators

  19. Large-volume liposuction and prevention of type 2 diabetes: a preliminary report.

    PubMed

    Narsete, Thomas; Narsete, Michele; Buckspan, Randy; Ersek, Robert

    2012-04-01

    This report presents a preliminary study investigating the effects of large-volume liposuction on the parameters that determine type 2 diabetes. The study enrolled 31 patients with a body mass index (BMI) exceeding 30 kg/m(2) over a 1-year period. All the liposuction procedures were performed with the patient under local anesthesia using ketamine/valium sedation. Pre- and postoperative blood pressure, fasting glucose, glycosylated hemoglobin (HbA1C), weight, and BMI were evaluated for 16 of the 30 patients who returned for a follow-up visit 3 to 12 months postoperatively. The average aspirate was 8,455 ml without dermolipectomy and 5,795 ml with dermolipectomy. The data reveal a trend of improvement in blood sugar levels associated with weight loss that helps the patients. The average blood sugar level dropped 18% in our return patients, and the average weight loss was 9.2%. The average drop in BMI was 6.2%, and HbA1C showed a decrease of 2.3%. The patients with the best weight loss had the best reduction in blood sugar level and blood pressure. No transfers to the hospital and no thromboebolism occurred for any of the 31 patients. One dehiscence, two wound infections, and three seromas were reported. The authors hypothesize that large-volume liposuction in their series may have motivated some to diet, which could be explored in a larger series with control groups. Liposuction alone did not improve obesity but helped to motivate some of the patients to lose weight. These patients had the best results.

  20. Two-field Kaehler moduli inflation in large volume moduli stabilization

    SciTech Connect

    Yang, Huan-Xiong; Ma, Hong-Liang E-mail: hlma@mail.ustc.edu.cn

    2008-08-15

    In this paper we present a two-field inflation model, which is distinctive in having a non-canonical kinetic Lagrangian and comes from the large volume approach to the moduli stabilization in flux compactification of type IIB superstring on a Calabi-Yau orientifold with h{sup (1,2)}>h{sup (1,1)}{>=}4. The Kaehler moduli are classified as the volume modulus, heavy moduli and two light moduli. The axion-dilaton, complex structure moduli and all heavy Kaehler moduli including the volume modulus are frozen by a non-perturbatively corrected flux superpotential and the {alpha}{sup '}-corrected Kaehler potential in the large volume limit. The minimum of the scalar potential at which the heavy moduli are stabilized provides the dominant potential energy for the surviving light Kaehler moduli. We consider a simplified case where the axionic components in the light Kaehler moduli are further stabilized at the potential minimum and only the geometrical components are taken as scalar fields to drive an assisted-like inflation. For a certain range of moduli stabilization parameters and inflation initial conditions, we obtain a nearly flat power spectrum of the curvature perturbation, with n{sub s} Almost-Equal-To 0.96 at Hubble exit, and an inflationary energy scale of 3 Multiplication-Sign 10{sup 14} GeV. In our model, there is significant correlation between the curvature and isocurvature perturbations on super-Hubble scales, so at the end of inflation a great deal of the curvature power spectrum originates from this correlation.

  1. Rapid concentration of Bacillus and Clostridium spores from large volumes of milk, using continuous flow centrifugation.

    PubMed

    Agoston, Réka; Soni, Kamlesh A; McElhany, Katherine; Cepeda, Martha L; Zuckerman, Udi; Tzipori, Saul; Mohácsi-Farkas, Csilla; Pillai, Suresh D

    2009-03-01

    Deliberate or accidental contamination of foods such as milk, soft drinks, and drinking water with infectious agents or toxins is a major concern to health authorities. There is a critical need to develop technologies that can rapidly and efficiently separate and concentrate biothreat agents from food matrices. A key limitation of current centrifugation and filtration technologies is that they are batch processes with extensive hands-on involvement and processing times. The objective of our studies was to evaluate the continuous flow centrifugation (CFC) technique for the rapid separation and concentration of bacterial spores from large volumes of milk. We determined the effectiveness of the CFC technology for concentrating approximately 10(3) bacterial spores in 3.7 liters (1 gal) of whole milk and skim milk, using Bacillus subtilis, Bacillus atrophaeus, and Clostridium sporogenes spores as surrogates for biothreat agents. The spores in the concentrated samples were enumerated by using standard plating techniques. Three independent experiments were performed at 10,000 rpm and 0.7 liters/min flow rate. The mean B. subtilis spore recoveries were 71.3 and 56.5% in skim and whole milk, respectively, and those for B. atrophaeus were 55 and 59.3% in skim and whole milk, respectively. In contrast, mean C. sporogenes spore recoveries were 88.2 and 78.6% in skim and whole milk, respectively. The successful use of CFC to concentrate these bacterial spores from 3.7 liters of milk in 10 min shows promise for rapidly concentrating other spores from large volumes of milk.

  2. Studies on plasma production in a large volume system using multiple compact ECR plasma sources

    NASA Astrophysics Data System (ADS)

    Tarey, R. D.; Ganguli, A.; Sahu, D.; Narayanan, R.; Arora, N.

    2017-01-01

    This paper presents a scheme for large volume plasma production using multiple highly portable compact ECR plasma sources (CEPS) (Ganguli et al 2016 Plasma Source Sci. Technol. 25 025026). The large volume plasma system (LVPS) described in the paper is a scalable, cylindrical vessel of diameter  ≈1 m, consisting of source and spacer sections with multiple CEPS mounted symmetrically on the periphery of the source sections. Scaling is achieved by altering the number of source sections/the number of sources in a source section or changing the number of spacer sections for adjusting the spacing between the source sections. A series of plasma characterization experiments using argon gas were conducted on the LVPS under different configurations of CEPS, source and spacer sections, for an operating pressure in the range 0.5-20 mTorr, and a microwave power level in the range 400-500 W per source. Using Langmuir probes (LP), it was possible to show that the plasma density (~1  -  2  ×  1011 cm-3) remains fairly uniform inside the system and decreases marginally close to the chamber wall, and this uniformity increases with an increase in the number of sources. It was seen that a warm electron population (60-80 eV) is always present and is about 0.1% of the bulk plasma density. The mechanism of plasma production is discussed in light of the results obtained for a single CEPS (Ganguli et al 2016 Plasma Source Sci. Technol. 25 025026).

  3. Building high-performance system for processing a daily large volume of Chinese satellites imagery

    NASA Astrophysics Data System (ADS)

    Deng, Huawu; Huang, Shicun; Wang, Qi; Pan, Zhiqiang; Xin, Yubin

    2014-10-01

    The number of Earth observation satellites from China increases dramatically recently and those satellites are acquiring a large volume of imagery daily. As the main portal of image processing and distribution from those Chinese satellites, the China Centre for Resources Satellite Data and Application (CRESDA) has been working with PCI Geomatics during the last three years to solve two issues in this regard: processing the large volume of data (about 1,500 scenes or 1 TB per day) in a timely manner and generating geometrically accurate orthorectified products. After three-year research and development, a high performance system has been built and successfully delivered. The high performance system has a service oriented architecture and can be deployed to a cluster of computers that may be configured with high end computing power. The high performance is gained through, first, making image processing algorithms into parallel computing by using high performance graphic processing unit (GPU) cards and multiple cores from multiple CPUs, and, second, distributing processing tasks to a cluster of computing nodes. While achieving up to thirty (and even more) times faster in performance compared with the traditional practice, a particular methodology was developed to improve the geometric accuracy of images acquired from Chinese satellites (including HJ-1 A/B, ZY-1-02C, ZY-3, GF-1, etc.). The methodology consists of fully automatic collection of dense ground control points (GCP) from various resources and then application of those points to improve the photogrammetric model of the images. The delivered system is up running at CRESDA for pre-operational production and has been and is generating good return on investment by eliminating a great amount of manual labor and increasing more than ten times of data throughput daily with fewer operators. Future work, such as development of more performance-optimized algorithms, robust image matching methods and application

  4. Scaled synthesis of boron nitride nanotubes, nanoribbons, and nanococoons using direct feedstock injection into an extended-pressure, inductively-coupled thermal plasma.

    PubMed

    Fathalizadeh, Aidin; Pham, Thang; Mickelson, William; Zettl, Alex

    2014-08-13

    A variable pressure (up to 10 atm) powder/gas/liquid injection inductively coupled plasma system has been developed and used to produce high-quality boron nitride nanotubes (BNNTs) at continuous production rates of 35 g/h. Under suitable conditions, collapsed BN nanotubes (i.e., nanoribbons), and closed shell BN capsules (i.e., nanococoons) are also obtained. The process is adaptable to a large variety of feedstock materials.

  5. Scaled Synthesis of Boron Nitride Nanotubes, Nanoribbons, and Nanococoons Using Direct Feedstock Injection into an Extended-Pressure, Inductively-Coupled Thermal Plasma

    NASA Astrophysics Data System (ADS)

    Fathalizadeh, Aidin; Pham, Thang; Mickelson, William; Zettl, Alex

    2015-03-01

    A variable pressure (up to 10 atm) powder or gas injection inductively coupled plasma system has been developed and used to produce high-quality boron nitride nanotubes (BNNTs) at continuous production rates of 35 g/h. Under suitable conditions, collapsed BN nanotubes (i.e., nanoribbons), and closed shell BN capsules (i.e., nanococoons) are also obtained. The process is adaptable to a large variety of feedstock materials.

  6. First-principles study of the effects on ferromagnetic coupling in Mn/GaAs digital ferromagnetic heterostructure by free holes Injection and Be co-dopant

    NASA Astrophysics Data System (ADS)

    Qian, Meichun; Pickett, Warren; Fong, C. Y.

    2006-03-01

    We use density functional theory to study the effect of free holes injection and Be co-dopant on the ferromagnetic coupling in Mn/GaAs digital ferromagnetic heterostructure (DFH). The injection of free holes is simulated by assigning a range of concentrations of missing electrons in unit cell. The δ-layer doping of Mn atoms in GaAs introduces three spin-polarized hole bands which are the consequence of hybridization between the d-states of the Mn atoms and the p-states of the nearest neighboring As atoms. The distribution of hole charge density shows that these spin-polarized holes are confined to the vicinity of the Mn δ-layer. After the injection of free holes, the Fermi energy EF is lowered, then the number of spin-polarized holes in the layer of MnAs is increased monotonously. We characterize the ferromagnetic coupling by the total energy difference between the ferromagnetic and the antiferromagnetic phases , EFA, per one pair of Mn atoms. The results of EFA, EF, and the projected spin-polarized holes at Mn and the nearest neighboring As atoms are shown as a function of concentration of the injected free holes. We demonstrate the enhancement of the ferromagnetic coupling, which is in agreement with the experimental results of Nazmul et al.^[1]. In contract, after the Be co-dopant in Mn/GaAs-DFH, the ferromagnetic coupling is deteriorated. We will give the explanation. [1] A. M. Nazmul et at. Phys. Rev. B67, 241308(R) (2003).

  7. Inductively coupled plasma mass spectrometry with a twin quadrupole instrument using laser ablation sample introduction and monodisperse dried microparticulate injection

    SciTech Connect

    Allen, Lloyd A.

    1996-10-17

    The focus of this dissertation is the use of a twin quadrupole inductively coupled plasma mass spectrometer (ICP-MS) for the simultaneous detection of two m/z values. The twin quadrupole ICP-MS is used with laser ablation sample introduction in both the steady state (10 Hz) and single pulse modes. Steady state signals are highly correlated and the majority of flicker noise cancels when the ratio is calculated. Using a copper sample, the isotope ratio 63Cu+/65Cu+ is measured with a relative standard deviation (RSD) of 0.26%. Transient signals for single laser pulses are also obtained. Copper isotope ratio measurements for several laser pulses are measured with an RSD of 0.85%. Laser ablation (LA) is used with steel samples to assess the ability of the twin quadrupole ICP-MS to eliminate flicker noise of minor components of steel samples. Isotopic and internal standard ratios are measured in the first part of this work. The isotope ratio 52Cr+/53Cr+ (Cr present at 1.31 %) can be measured with an RSD of 0.06 % to 0.1 %. For internal standard elements, RSDs improve from 1.9 % in the Cr+ signal to 0.12% for the ratio of 51V+ to 52Cr+. In the second part of this work, one mass spectrometer is scanned while the second channel measures an individual m/z value. When the ratio of these two signals is calculated, the peak shapes in the mass spectrum are improved significantly. Pulses of analyte and matrix ions from individual drops are measured simultaneously using the twin quadrupole ICP-MS with monodisperse dried microparticulate injection (MDMI). At modest Pb concentrations (500 ppm), a shoulder on the leading edge of the Li+ signal becomes apparent. Space charge effects are consistent with the disturbances seen.

  8. An experimental study on the excitation of large volume airguns in a small volume body of water

    NASA Astrophysics Data System (ADS)

    Wang, Baoshan; Yang, Wei; Yuan, Songyong; Guo, Shijun; Ge, Hongkui; Xu, Ping; Chen, Yong

    2010-12-01

    A large volume airgun array is effective in generating seismic waves, which is extensively used in large volume bodies of water such as oceans, lakes and reservoirs. So far, the application of large volume airguns is subject to the distribution of large volume bodies of water. This paper reports an attempt to utilize large volume airguns in a small body of water as a seismic source for seismotectonic studies. We carried out a field experiment in Mapaoquan pond, Fangshan district, Beijing, during the period 25-30 May 2009. Bolt LL1500 airguns, each with volumes of 2000 in3, the largest commercial airguns available today, were used in this experiment. We tested the excitation of the airgun array with one or two guns. The airgun array was placed 7-11 m below the water's surface. The near- and far-field seismic motions induced by the airgun source were recorded by a 100 km long seismic profile composed of 16 portable seismometers and a 100 m long strong motion seismograph profile, respectively. The following conclusions can be drawn from this experiment. First, it is feasible to excite large volume airguns in a small volume body of water. Second, seismic signals from a single shot of one airgun can be recognized at the offset up to 15 km. Taking advantage of high source repeatability, we stacked records from 128 shots to enhance the signal-to-noise ratio, and direct P-waves can be easily identified at the offset ~50 km in stacked records. Third, no detectable damage to fish or near-field constructions was caused by the airgun shots. Those results suggest that large volume airguns excited in small bodies of water can be used as a routinely operated seismic source for mid-scale (tens of kilometres) subsurface explorations and monitoring under various running conditions.

  9. Two-step large-volume magnetic separation combined with PCR assay for sensitive detection of Listeria monocytogenes in pasteurized milk.

    PubMed

    Luo, Dan; Huang, Xiaolin; Mao, Yan; Chen, Chaochao; Li, Fulai; Xu, Hengyi; Xiong, Yonghua

    2017-10-01

    Immunomagnetic separation (IMS) is an effective tool for the preconcentration and purification of food-borne pathogens from complex food samples because of its high capture efficiency (CE). In conventional IMS, antibodies are usually conjugated on the surface of magnetic beads (MB); the random orientation and conformation changes of antibodies on the MB surface can decrease their bioactivity. Moreover, the Brownian motion of immobilized antibodies is weakened, thereby rendering their binding efficiency with bacteria lower than that of free antibodies. Thus, abundant antibodies are commonly required to ensure high CE for IMS, particularly for large volumes. In this study, a 2-step large-volume magnetic separation (10 mL) was proposed to preconcentrate Listeria monocytogenes from pasteurized milk. First, the biotinylated anti-L. monocytogenes monoclonal antibodies (mAb) were bound with L. monocytogenes in 10 mL of diluted milk through an antigen-antibody interaction, and then streptavidin-labeled MB were used to capture biotin-mAb coated with L. monocytogenes by biotin and streptavidin interaction. Under optimal conditions, the CE of 2-step magnetic separation was >90% with L. monocytogenes concentrations ranging from 8 × 10(0) to 8 × 10(4) cfu/mL, whereas the amount of biotin-mAb was 14 fold lower than that of the conventional IMS method. Coupled with a PCR assay, the detection limit of the proposed method was 8 × 10(0) cfu/mL in pure culture and 8 × 10(1) cfu/mL in pasteurized milk without any pre-enrichment process. Moreover, the overall detection time, including sample preparation, large-volume magnetic separation, and PCR, took less than 7 h. In summary, the developed 2-step large-volume IMS combined with PCR was highly sensitive and low cost and, thus, has considerable potential for the rapid screening of food-borne pathogenic bacteria. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Large volume of water samples introduced in dispersive liquid-liquid microextraction for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry.

    PubMed

    Nie, Jing; Chen, Fujiang; Song, Zhiyu; Sun, Caixia; Li, Zuguang; Liu, Wenhan; Lee, Mawrong

    2016-10-01

    A novel method of large volume of water samples directly introduced in dispersive liquid-liquid microextraction was developed, which is based on ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas (CO2) breaking down the emulsion for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry. This technique makes low-density extraction solvent toluene (180 μL) dissolve in 200 mL of samples containing 0.05 mol L(-1) of HCl and 5 % of NaCl (w/v) to form a well emulsion by synergy of ultrasound and manual shaking, and injects NaHCO3 solution (1.0 mol L(-1)) to generate CO2 achieving phase separation with the assistance of ultrasound. The entire process is accomplished within 8 min. The injection of NaHCO3 to generate CO2 achieves phase separation that breaks through the centrifugation limited large volume aqueous samples. In addition, the device could be easily cleaned, and this kind of vessel could be reconfigured for any volume of samples. Under optimal conditions, the low limits of detection ranging from 0.7 to 51.7 ng L(-1), wide linearity, and enrichment factors obtained were in the range 924-3669 for different triazole fungicides. Southern end of the Beijing-Hangzhou Grand Canal water (Hangzhou, China) was used to verify the applicability of the developed method. Graphical Abstract Flow chart of ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas breaking down the emulsion.

  11. Large-volume liposuction: a review of 631 consecutive cases over 12 years.

    PubMed

    Commons, G W; Halperin, B; Chang, C C

    2001-11-01

    Since the advent of epinephrine-containing wetting solutions and sophisticated fluid management techniques, increasingly larger and larger volumes of liposuction aspirations have been reported. Unfortunately, with these larger volumes of liposuction being routinely performed, greater rates of complications have also been reported, with the worst of these resulting in deaths. In a response to the increasing concerns over the safety of large-volume liposuction, a critical review of the senior author's own series has been performed to evaluate risks and benefits and to recommend guidelines for safe and effective large-volume liposuction. A retrospective chart review was performed on 631 consecutive patients who underwent liposuction procedures of at least 3000 cc total aspirate. All procedures were performed by the same senior surgeon between January of 1986 and March of 1998. Before September of 1996, traditional liposuction techniques were used. After September of 1996, ultrasound-assisted liposuction was performed. The superwet technique of fluid management was employed for all procedures performed after 1991. The particulars of the surgical and anesthetic techniques used are reviewed in the article. Data collection included preoperative patient demographics, preoperative and postoperative weights and measurements, and preoperative and postoperative photographs. Total aspirate volumes, fluid intakes, and fluid outputs were measured, and all complications were tallied. Average follow-up was 1 year. Results showed the majority of patients to be women, aged 17 to 74 years old. Of the preoperative weights, 98.7 percent were within 50 pounds of ideal chart weight. Total aspirate volumes ranged from 3 to 17 liters, with 94.5 percent of these under 10 liters. Fluid balance measurements showed an average of 120 cc/kg positive fluid balance at the end of the procedure, with none of these patients experiencing any significant fluid balance abnormalities. Cosmetic results

  12. COUPLING

    DOEpatents

    Frisch, E.; Johnson, C.G.

    1962-05-15

    A detachable coupling arrangement is described which provides for varying the length of the handle of a tool used in relatively narrow channels. The arrangement consists of mating the key and keyhole formations in the cooperating handle sections. (AEC)

  13. Determination of 235U enrichment with a large volume CZT detector

    NASA Astrophysics Data System (ADS)

    Mortreau, Patricia; Berndt, Reinhard

    2006-01-01

    Room-temperature CdZnTe and CdTe detectors have been routinely used in the field of Nuclear Safeguards for many years [Ivanov et al., Development of large volume hemispheric CdZnTe detectors for use in safeguards applications, ESARDA European Safeguards Research and Development Association, Le Corum, Montpellier, France, 1997, p. 447; Czock and Arlt, Nucl. Instr. and Meth. A 458 (2001) 175; Arlt et al., Nucl. Instr. and Meth. A 428 (1999) 127; Lebrun et al., Nucl. Instr. and Meth. A 448 (2000) 598; Aparo et al., Development and implementation of compact gamma spectrometers for spent fuel measurements, in: Proceedings, 21st Annual ESARDA, 1999; Arlt and Rudsquist, Nucl. Instr. and Meth. A 380 (1996) 455; Khusainov et al., High resolution pin type CdTe detectors for the verification of nuclear material, in: Proceedings, 17th Annual ESARDA European Safeguards Research and Development Association, 1995; Mortreau and Berndt, Nucl. Instr. and Meth. A 458 (2001) 183; Ruhter et al., UCRL-JC-130548, 1998; Abbas et al., Nucl. Instr. and Meth. A 405 (1998) 153; Ruhter and Gunnink, Nucl. Instr. and Meth. A 353 (1994) 716]. Due to their performance and small size, they are ideal detectors for hand-held applications such as verification of spent and fresh fuel, U/Pu attribute tests as well as for the determination of 235U enrichment. The hemispherical CdZnTe type produced by RITEC (Riga, Latvia) [Ivanov et al., 1997] is the most widely used detector in the field of inspection. With volumes ranging from 2 to 1500 mm 3, their spectral performance is such that the use of electronic processing to correct the pulse shape is not required. This paper reports on the work carried out with a large volume (15×15×7.5 mm 3) and high efficiency hemispherical CdZnTe detector for the determination of 235U enrichment. The measurements were made with certified uranium samples whose enrichment ranging from 0.31% to 92.42%, cover the whole range of in-field measurement conditions. The interposed

  14. Alfapump® system vs. large volume paracentesis for refractory ascites: A multicenter randomized controlled study.

    PubMed

    Bureau, Christophe; Adebayo, Danielle; Chalret de Rieu, Mael; Elkrief, Laure; Valla, Dominique; Peck-Radosavljevic, Markus; McCune, Anne; Vargas, Victor; Simon-Talero, Macarena; Cordoba, Juan; Angeli, Paolo; Rosi, Silvia; MacDonald, Stewart; Malago, Massimo; Stepanova, Maria; Younossi, Zobair M; Trepte, Claudia; Watson, Randall; Borisenko, Oleg; Sun, Sun; Inhaber, Neil; Jalan, Rajiv

    2017-06-21

    Patients with refractory ascites (RA) require repeated large volume paracenteses (LVP), which involves frequent hospital visits and is associated with a poor quality-of-life. This study assessed safety and efficacy of an automated, low-flow pump (alfapump® [AP]) compared with LVP standard of care [SoC]. A randomized controlled trial, in seven centers, with six month patient observation was conducted. Primary outcome was time to first LVP. Secondary outcomes included paracentesis requirement, safety, health-related quality-of-life (HRQoL), and survival. Nutrition, hemodynamics, and renal injury biomarkers were assessed in a sub-study at three months. Sixty patients were randomized and 58 were analyzed (27 AP, 31 SoC, mean age 61.9years, mean MELD 11.7). Eighteen patients were included in the sub-study. Compared with SoC, median time to first LVP was not reached after six months in the AP group, meaning a significant reduction in LVP requirement for the AP patients (AP, median not reached; SoC, 15.0days (HR 0.13; 95%CI 13.0-22.0; p<0.001), and AP patients also showed significantly improved Chronic Liver Disease Questionnaire (CLDQ) scores compared with SoC patients (p<0.05 between treatment arms). Improvements in nutritional parameters were observed for hand-grip strength (p=0.044) and body mass index (p<0.001) in the sub-study. Compared with SoC, more AP patients reported adverse events (AEs; 96.3% vs. 77.4%, p=0.057) and serious AEs (85.2 vs. 45.2%, p=0.002). AEs consisted predominantly of acute kidney injury in the immediate post-operative period, and re-intervention for pump related issues, and were treatable in most cases. Survival was similar in AP and SoC. The AP system is effective for reducing the need for paracentesis and improving HRQoL in cirrhotic patients with RA. Although the frequency of Quality of Life (and by inference hospitalizations) was significantly higher in the AP group, they were generally limited and did not impact survival. www

  15. Storage and eruption of large volumes of rhyolite lava: Example from Solfatara Plateau, Yellowstone Caldera

    NASA Astrophysics Data System (ADS)

    Befus, K.; Gardner, J. E.; Zinke, R.

    2010-12-01

    The cataclysmic volcanic history of Yellowstone caldera has been extensively documented in both popular media and scholarly journals. High-silica magmas should erupt explosively because of their high viscosity and volatile content; however, numerous passively-erupted, large-volume rhyolite lava flows have also erupted from Yellowstone caldera. We use petrologic observations of one such flow, the Solfatara Plateau obsidian lava, to provide insights into the eruptive dynamics and pre-eruptive magmatic conditions of large-volume rhyolite lava. Solfatara Plateau, a 7 km3 high-silica rhyolite lava that extends 4-15 km from vent, erupted 103±8 ka within the Yellowstone caldera1. Quartz and sanidine are the dominant phenocrysts, with crystal contents of 5-10% throughout. FTIR analyses of glass inclusions in quartz and sanidine phenocrysts indicate that pre-eruptive dissolved volatile contents were up to 3.0 wt. % H2O and 250 ppm CO2. Myrmekite blebs partially envelop quartz and sanidine phenocrysts in all samples from along the margins of the flow (up to 3 km from flow front). Sanidines in samples from near vent are unzoned at Or49±2. Those at the flow front have similar cores, but rims are more sodic (Or44±6). Alkali feldspars in myrmekite range from Or27 to Or50. Petrologic observations, such as heavily embayed quartz phenocrysts and dissolution of myrmekite indicate disequilibrium within the system, likely as a result of significant heating that caused portions of the magma body to go from near-solidus to near-liquidus conditions prior to erupting. When it did erupt, volatile loss during eruptive ascent led to undercooling and significant microlite crystallization of Fe-Ti oxide and clinopyroxene microlites. Fe-Ti microlites occur as roughly equidimensional crystals, 1-10 µm across, as well as high-aspect-ratio needles, 3-60 µm long. Clinopyroxene microlites occur primarily as individual prismatic crystals, but also occur as linked, curved chains or as overgrowths

  16. Hierarchical imaging: a new concept for targeted imaging of large volumes from cells to tissues.

    PubMed

    Wacker, Irene; Spomer, Waldemar; Hofmann, Andreas; Thaler, Marlene; Hillmer, Stefan; Gengenbach, Ulrich; Schröder, Rasmus R

    2016-12-12

    Imaging large volumes such as entire cells or small model organisms at nanoscale resolution seemed an unrealistic, rather tedious task so far. Now, technical advances have lead to several electron microscopy (EM) large volume imaging techniques. One is array tomography, where ribbons of ultrathin serial sections are deposited on solid substrates like silicon wafers or glass coverslips. To ensure reliable retrieval of multiple ribbons from the boat of a diamond knife we introduce a substrate holder with 7 axes of translation or rotation specifically designed for that purpose. With this device we are able to deposit hundreds of sections in an ordered way in an area of 22 × 22 mm, the size of a coverslip. Imaging such arrays in a standard wide field fluorescence microscope produces reconstructions with 200 nm lateral resolution and 100 nm (the section thickness) resolution in z. By hierarchical imaging cascades in the scanning electron microscope (SEM), using a new software platform, we can address volumes from single cells to complete organs. In our first example, a cell population isolated from zebrafish spleen, we characterize different cell types according to their organelle inventory by segmenting 3D reconstructions of complete cells imaged with nanoscale resolution. In addition, by screening large numbers of cells at decreased resolution we can define the percentage at which different cell types are present in our preparation. With the second example, the root tip of cress, we illustrate how combining information from intermediate resolution data with high resolution data from selected regions of interest can drastically reduce the amount of data that has to be recorded. By imaging only the interesting parts of a sample considerably less data need to be stored, handled and eventually analysed. Our custom-designed substrate holder allows reproducible generation of section libraries, which can then be imaged in a hierarchical way. We demonstrate, that EM

  17. Physiological and Psychological Changes Following Liposuction of Large Volumes of Fat in Overweight and Obese Women

    PubMed Central

    Geliebter, Allan; Krawitz, Emily; Ungredda, Tatiana; Peresechenski, Ella; Giese, Sharon Y.

    2016-01-01

    Background Liposuction can remove a substantial amount of body fat. We investigated the effects of liposuction of large volumes of fat on anthropometrics, body composition (BIA), metabolic hormones, and psychological measures in overweight/obese women. To our knowledge, this is the first study to examine both physiological and psychological changes following liposuction of large volumes of fat in humans. Method Nine premenopausal healthy overweight/obese women (age = 35.9 ± 7.1 SD, weight = 84.4 kg ± 13.6, BMI = 29.9 kg/m2 ± 2.9) underwent liposuction, removing 3.92 kg ± 1.04 SD of fat. Following an overnight fast, height, weight, waist, and hip circumferences were measured at baseline (one week pre-surgery) and post-surgery (wk 1,4,12). Blood samples were drawn for fasting concentrations of glucose, insulin, leptin, and ghrelin. The Body Shape Questionnaire (BSQ), Body Dysmorphic Disorder (BDD) Examination Self-Report (BDDE-SR), and Zung Self-Rating Depression Scale (ZDS) were administered. Results Body weight, BMI, waist circumference, and body fat consistently decreased over time (p < .05). Glucose did not change significantly, but insulin decreased from wk 1 to wk 12 (p < .05). Leptin decreased from baseline to wk 1 (p = .01); ghrelin increased but not significantly. Changes in body fat and waist circumference (baseline to wk 1) correlated positively with changes in insulin during that period, and correlated inversely with changes in ghrelin (p < .05). BSQ scores decreased significantly over time (p = .004), but scores for BDDE-SR (p = .10) and ZDS (p = .24) did not change significantly. Conclusion Liposuction led to significant decreases in body weight and fat, waist circumference, and leptin levels. Changes in body fat and waist circumference correlated with concurrent changes in the adipose-related hormones, insulin and ghrelin (baseline to wk 1), and body shape perception improved. Thus, besides the obvious cosmetic effects, liposuction led to several

  18. Pathways of deep cyclones associated with large volume changes (LVCs) and major Baltic inflows (MBIs)

    NASA Astrophysics Data System (ADS)

    Lehmann, Andreas; Höflich, Katharina; Post, Piia; Myrberg, Kai

    2016-04-01

    Large volume changes (LVCs) and major Baltic inflows (MBIs) are essential processes for the water exchange and renewal of the deep stagnant deep water in the Baltic Sea deep basins. MBIs are considered as subset of LVCs transporting with the large water volume a big amount of highly saline and oxygenated water into the Baltic Sea. Since the early 1980s the frequency of MBIs has dropped drastically from 5 to 7 events to only one inflow per decade, and long lasting periods without MBIs became the usual state. Only in January 1993, 2003 and December 2014 MBIs occurred that were able to interrupt the stagnation periods in the deep basins of the Baltic Sea. However, in spite of the decreasing frequency of MBIs, there is no obvious decrease of LVCs. Large volume changes have been calculated for the period 1887-2014 filtering daily time series of Landsort sea surface elevation anomalies. The Landsort sea level is known to reflect the mean sea level of the Baltic Sea very well. Thus, LVCs can be calculated from the mean sea level variations. The cases with local minimum and maximum difference resulting of at least 100 km³ of water volume change have been chosen for a closer study of characteristic pathways of deep cyclones. The average duration of a LVC is about 40 days. During this time, 5-6 deep cyclones will move along characteristic storm tracks. We obtained three main routes of deep cyclones which were associated with LVCs, but also with the climatology. One is approaching from the west at about 58-62°N, passing the northern North Sea, Oslo, Sweden and the Island of Gotland, while a second, less frequent one, is approaching from the west at about 65°N, crossing Scandinavia south-eastwards passing the Sea of Bothnia and entering Finland. A third very frequent one is entering the study area north of Scotland turning north-eastwards along the northern coast of Scandinavia. Thus, the conditions for a LVC to happen are a temporal clustering of deep cyclones in certain

  19. "Don't think I'm going to leave you over it": Accounts of changing hepatitis C status among couples who inject drugs.

    PubMed

    Rance, Jake; Treloar, Carla; Fraser, Suzanne; Bryant, Joanne; Rhodes, Tim

    2017-04-01

    While the health-related benefits of intimate partnership are well documented, little attention has been paid to couples exposed to high levels of social stigma and exclusion. In this project we investigated an important site of stigma for partnerships by collecting accounts of changing hepatitis C (HCV) status ("sero-change") among couples that inject drugs. We explored what these accounts reveal about the meaning of HCV for these couples, and how this understanding contributes to our collective efforts at prevention and care. Drawing from a large dataset of qualitative interviews with couples, we focussed on those containing reports of sero-change. By adopting a methodology that positioned partnerships rather than individuals as the primary unit of analysis, we addressed the commonplace tendency to either overlook or discount as dysfunctional, the sexual relationships of people who inject drugs. While some couples sought greater biomedical understanding as a means of coming to terms with sero-change, others drew on alternative logics or "rationalities" that sat firmly outside conventional biomedical discourse (privileging notions of kinship, for example). Regardless of which explanatory framework they drew on, participants ultimately prioritised the security of their relationship over the dangers of viral infection. Effectively engaging couples in HCV prevention and care requires acknowledging and working with the competing priorities and complex realities of such partnerships beyond simply the identification of viral risk. The "new era" of direct acting antiviral treatments will provide ongoing opportunities to learn to integrate biomedical information within more socially sophisticated, relationally aware approaches. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Large volume sample stacking for rapid and sensitive determination of antidiabetic drug metformin in human urine and serum by capillary electrophoresis with contactless conductivity detection.

    PubMed

    Tůma, Petr

    2014-06-06

    Two CE methods with contactless conductivity detection have been developed for determining the oral antidiabetic drug metformin in human urine and blood. The determination of metformin is performed on a separation capillary with an effective length of 14 cm, using a maximum voltage of 30 kV and with a small injection of 50-fold diluted urine into the capillary. Under these conditions, the migration time of metformin is 35s and the LOD is 0.3 μM. Large-volume sample stacking was used to determine low metformin levels in serum. The injection of a sample of serum deproteinized with acetonitrile was 10 times greater compared to the injected amount of urine. This enabled reduction of the LOD to 0.03 μM and the metformin migration time equalled 86 s. The undesirable solvent from sample zone was forced out of the capillary to ensure rapidity and good repeatability of the determination. The RSD values for the migration time are 0.1% for urine and 0.7% for serum; RSD for the peak areas equalled 1.4% for urine and 2.6% for serum. The developed CE technique was tested on performance of routine analyses of metformin in the urine and serum of patients suffering from type II diabetes mellitus. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Curling probe measurement of large-volume pulsed plasma confined by surface magnetic field

    NASA Astrophysics Data System (ADS)

    Pandey, Anil; Sakakibara, Wataru; Matsuoka, Hiroyuki; Nakamura, Keiji; Sugai, Hideo; Chubu University Team; DOWA Thermotech Collaboration

    2015-09-01

    Curling probe (CP) has recently been developed which enables the local electron density measurement even in plasma for non-conducting film CVD. The electron density is obtained from a shift of resonance frequency of spiral antenna in discharge ON and OFF monitored by a network analyzer (NWA). In case of a pulsed glow discharge, synchronization of discharge pulse with frequency sweep of NWA must be established. In this paper, we report time and space-resolved CP measurement of electron density in a large volume plasma (80 cm diameter, 110 cm length) confined by surface magnetic field (multipole cusp field ~0.03 T). For plasma-aided modification of metal surface, the plasma is produced by 1 kV glow discharge at pulse frequency of 0.3 - 25 kHz with various duty ratio in gas (Ar, N2, C2H2) at pressure ~ 1 Pa. A radially movable CP revealed a remarkable effect of surface magnetic confinement: detach of plasma from the vessel wall and a fairly uniform plasma in the central region. In afterglow phase, the electron density was observed to decrease much faster in C2H2 discharge than in Ar discharge.

  2. Large-volume lateral magma transport from the Mull volcano: An insight to magma chamber processes

    NASA Astrophysics Data System (ADS)

    Ishizuka, Osamu; Taylor, Rex N.; Geshi, Nobuo; Mochizuki, Nobutatsu

    2017-04-01

    Long-distance lateral magma transport within the crust has been inferred for various magmatic systems including oceanic island volcanoes, mid-oceanic ridges, and large igneous provinces. However, studying the physical and chemical properties of active fissure systems is difficult. Hence, this study investigates the movement of magma away from the Mull volcano in the North Atlantic Igneous Province, where erosion has exposed its upper crustal dike networks. Magmatic lineations within dikes indicate that the magma flow in the Mull dike suite changed from near vertical to horizontal within 30 km of the volcanic center. This implies that distal dikes were fed by lateral magma transport from Mull. Geochemical characteristics indicate that many <50 km long dikes have deep crustal signatures, reflecting storage and assimilation in Lewisian basement. Following crystallization and assimilation in the lower crust, magma fed an upper crustal reservoir, where further fractionation and incorporation of Moinian rocks generated felsic compositions. Distal dikes are andesitic and reflect events in which large volumes of mafic and felsic magma were combined by mixing between lower and upper crustal reservoirs to generate the 30-80 km3 required to supply the long-distance dikes. Once propagated, compositions along dikes were not significantly affected by assimilation and crystallization. Supplying the distal dikes with magma would have required a large-scale evacuation of the crustal reservoirs that acted as a potential trigger for explosive volcanism and the caldera formation recorded in Mull central complex.

  3. A new large-volume metal reference standard for radioactive waste management

    PubMed Central

    Tzika, F.; Hult, M.; Stroh, H.; Marissens, G.; Arnold, D.; Burda, O.; Kovář, P.; Suran, J.; Listkowska, A.; Tyminski, Z.

    2016-01-01

    A new large-volume metal reference standard has been developed. The intended use is for calibration of free-release radioactivity measurement systems and is made up of cast iron tubes placed inside a box of the size of a Euro-pallet (80 × 120 cm). The tubes contain certified activity concentrations of 60Co (0.290±0.006 Bq g−1) and 110mAg (3.05±0.09 Bq g−1) (reference date: 30 September 2013). They were produced using centrifugal casting from a smelt into which 60Co was first added and then one piece of neutron irradiated silver wire was progressively diluted. The iron castings were machined to the desirable dimensions. The final material consists of 12 iron tubes of 20 cm outer diameter, 17.6 cm inner diameter, 40 cm length/height and 245.9 kg total mass. This paper describes the reference standard and the process of determining the reference activity values. PMID:25977349

  4. A Novel Technique for Endovascular Removal of Large Volume Right Atrial Tumor Thrombus

    SciTech Connect

    Nickel, Barbara; McClure, Timothy Moriarty, John

    2015-08-15

    Venous thromboembolic disease is a significant cause of morbidity and mortality, particularly in the setting of large volume pulmonary embolism. Thrombolytic therapy has been shown to be a successful treatment modality; however, its use somewhat limited due to the risk of hemorrhage and potential for distal embolization in the setting of large mobile thrombi. In patients where either thrombolysis is contraindicated or unsuccessful, and conventional therapies prove inadequate, surgical thrombectomy may be considered. We present a case of percutaneous endovascular extraction of a large mobile mass extending from the inferior vena cava into the right atrium using the Angiovac device, a venovenous bypass system designed for high-volume aspiration of undesired endovascular material. Standard endovascular methods for removal of cancer-associated thrombus, such as catheter-directed lysis, maceration, and exclusion, may prove inadequate in the setting of underlying tumor thrombus. Where conventional endovascular methods either fail or are unsuitable, endovascular thrombectomy with the Angiovac device may be a useful and safe minimally invasive alternative to open resection.

  5. Alginate Hydrogel Microencapsulation Inhibits Devitrification and Enables Large-Volume Low-CPA Cell Vitrification.

    PubMed

    Huang, Haishui; Choi, Jung Kyu; Rao, Wei; Zhao, Shuting; Agarwal, Pranay; Zhao, Gang; He, Xiaoming

    2015-11-25

    Cryopreservation of stem cells is important to meet their ever-increasing demand by the burgeoning cell-based medicine. The conventional slow freezing for stem cell cryopreservation suffers from inevitable cell injury associated with ice formation and the vitrification (i.e., no visible ice formation) approach is emerging as a new strategy for cell cryopreservation. A major challenge to cell vitrification is intracellular ice formation (IIF, a lethal event to cells) induced by devitrification (i.e., formation of visible ice in previously vitrified solution) during warming the vitrified cells at cryogenic temperature back to super-zero temperatures. Consequently, high and toxic concentrations of penetrating cryoprotectants (i.e., high CPAs, up to ~8 M) and/or limited sample volumes (up to ~2.5 μl) have been used to minimize IIF during vitrification. We reveal that alginate hydrogel microencapsulation can effectively inhibit devitrification during warming. Our data show that if ice formation were minimized during cooling, IIF is negligible in alginate hydrogel-microencapsulated cells during the entire cooling and warming procedure of vitrification. This enables vitrification of pluripotent and multipotent stem cells with up to ~4 times lower concentration of penetrating CPAs (up to 2 M, low CPA) in up to ~100 times larger sample volume (up to ~250 μl, large volume).

  6. Major risk from rapid, large-volume landslides in Europe (EU Project RUNOUT)

    NASA Astrophysics Data System (ADS)

    Kilburn, Christopher R. J.; Pasuto, Alessandro

    2003-08-01

    Project RUNOUT has investigated methods for reducing the risk from large-volume landslides in Europe, especially those involving rapid rates of emplacement. Using field data from five test sites (Bad Goisern and Köfels in Austria, Tessina and Vajont in Italy, and the Barranco de Tirajana in Gran Canaria, Spain), the studies have developed (1) techniques for applying geomorphological investigations and optical remote sensing to map landslides and their evolution; (2) analytical, numerical, and cellular automata models for the emplacement of sturzstroms and debris flows; (3) a brittle-failure model for forecasting catastrophic slope failure; (4) new strategies for integrating large-area Global Positioning System (GPS) arrays with local geodetic monitoring networks; (5) methods for raising public awareness of landslide hazards; and (6) Geographic Information System (GIS)-based databases for the test areas. The results highlight the importance of multidisciplinary studies of landslide hazards, combining subjects as diverse as geology and geomorphology, remote sensing, geodesy, fluid dynamics, and social profiling. They have also identified key goals for an improved understanding of the physical processes that govern landslide collapse and runout, as well as for designing strategies for raising public awareness of landslide hazards and for implementing appropriate land management policies for reducing landslide risk.

  7. Large-volume ultralow background germanium-germanium coincidence/anticoincidence gamma-ray spectrometer

    SciTech Connect

    Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.; Avignone, F.T. III; Miley, H.S.; Moore, R.S.

    1984-03-01

    A large volume (approx. 1440 cm/sup 3/), multicrystal, high resolution intrinsic germanium gamma-ray spectrometer has been designed based on 3 generations of experiments. The background from construction materials used in standard commercial configurations has been reduced by at least two orders of magnitude. Data taken with a 132 cm/sup 3/ prototype detector, installed in the Homestake Gold Mine, are presented. The first application of the full scale detector will be an ultrasensitive search for neutrinoless and two-neutrino double beta decay of /sup 76/Ge. The size and geometrical configuration of the crystals is chosen to optimize detection of double decay to the first excited state of /sup 76/Se with subsequent emission of a 559 keV gamma ray. The detector will be sufficiently sensitive for measuring the neutrinoless double beta decay to the ground state to establish a minimum half life of 1.4.10/sup 24/ y. Application of the large spectrometer system to the analysis of low level environmental and biological samples is discussed.

  8. Gain characteristics of large volume CuBr laser active media

    NASA Astrophysics Data System (ADS)

    Gubarev, F. A.; Troitskiy, V. O.; Trigub, M. V.; Sukhanov, V. B.

    2011-05-01

    The paper presents the experimental results on how the active additive HBr and the temperatures of the containers with CuBr influence the gain characteristics of large volume (8 cm bore, 90 cm long) CuBr laser active media with the external heating of the active zone of the gas discharge tube (GDT). It has been demonstrated that an increase in the concentration of CuBr vapors results in the contraction of the gain profile of the active medium, consistent with the increase of the gain factor in the axial region of GDT. The contraction is also imposed by HBr addition. Despite the fact that we used the external heating of GDT at the pump power of 1.5 kW and less, the energy input is still not sufficient to produce the effective generation for large active volume lasers; and it is evident from the small gain profile width. The maximum gain profile width under experimental conditions (consider Pout/ Pin > 2) was 3 cm; this value was obtained without HBr-additive within the active volume, while the concentration of CuBr vapors being significantly less than optimal, that corresponds to the maximum average lasing power.

  9. Detecting boosted dark matter from the Sun with large volume neutrino detectors

    SciTech Connect

    Berger, Joshua; Cui, Yanou; Zhao, Yue E-mail: ycui@perimeterinstitute.ca

    2015-02-01

    We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

  10. A Novel Technique for Endovascular Removal of Large Volume Right Atrial Tumor Thrombus.

    PubMed

    Nickel, Barbara; McClure, Timothy; Moriarty, John

    2015-08-01

    Venous thromboembolic disease is a significant cause of morbidity and mortality, particularly in the setting of large volume pulmonary embolism. Thrombolytic therapy has been shown to be a successful treatment modality; however, its use somewhat limited due to the risk of hemorrhage and potential for distal embolization in the setting of large mobile thrombi. In patients where either thrombolysis is contraindicated or unsuccessful, and conventional therapies prove inadequate, surgical thrombectomy may be considered. We present a case of percutaneous endovascular extraction of a large mobile mass extending from the inferior vena cava into the right atrium using the Angiovac device, a venovenous bypass system designed for high-volume aspiration of undesired endovascular material. Standard endovascular methods for removal of cancer-associated thrombus, such as catheter-directed lysis, maceration, and exclusion, may prove inadequate in the setting of underlying tumor thrombus. Where conventional endovascular methods either fail or are unsuitable, endovascular thrombectomy with the Angiovac device may be a useful and safe minimally invasive alternative to open resection.

  11. Alginate Hydrogel Microencapsulation Inhibits Devitrification and Enables Large-Volume Low-CPA Cell Vitrification

    PubMed Central

    Huang, Haishui; Choi, Jung Kyu; Rao, Wei; Zhao, Shuting; Agarwal, Pranay; Zhao, Gang

    2015-01-01

    Cryopreservation of stem cells is important to meet their ever-increasing demand by the burgeoning cell-based medicine. The conventional slow freezing for stem cell cryopreservation suffers from inevitable cell injury associated with ice formation and the vitrification (i.e., no visible ice formation) approach is emerging as a new strategy for cell cryopreservation. A major challenge to cell vitrification is intracellular ice formation (IIF, a lethal event to cells) induced by devitrification (i.e., formation of visible ice in previously vitrified solution) during warming the vitrified cells at cryogenic temperature back to super-zero temperatures. Consequently, high and toxic concentrations of penetrating cryoprotectants (i.e., high CPAs, up to ~8 M) and/or limited sample volumes (up to ~2.5 μl) have been used to minimize IIF during vitrification. We reveal that alginate hydrogel microencapsulation can effectively inhibit devitrification during warming. Our data show that if ice formation were minimized during cooling, IIF is negligible in alginate hydrogel-microencapsulated cells during the entire cooling and warming procedure of vitrification. This enables vitrification of pluripotent and multipotent stem cells with up to ~4 times lower concentration of penetrating CPAs (up to 2 M, low CPA) in up to ~100 times larger sample volume (up to ~250 μl, large volume). PMID:26640426

  12. Plasma response to electron energy filter in large volume plasma device

    SciTech Connect

    Sanyasi, A. K.; Awasthi, L. M.; Mattoo, S. K.; Srivastava, P. K.; Singh, S. K.; Singh, R.; Kaw, P. K.

    2013-12-15

    An electron energy filter (EEF) is embedded in the Large Volume Plasma Device plasma for carrying out studies on excitation of plasma turbulence by a gradient in electron temperature (ETG) described in the paper of Mattoo et al. [S. K. Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. In this paper, we report results on the response of the plasma to the EEF. It is shown that inhomogeneity in the magnetic field of the EEF switches on several physical phenomena resulting in plasma regions with different characteristics, including a plasma region free from energetic electrons, suitable for the study of ETG turbulence. Specifically, we report that localized structures of plasma density, potential, electron temperature, and plasma turbulence are excited in the EEF plasma. It is shown that structures of electron temperature and potential are created due to energy dependence of the electron transport in the filter region. On the other hand, although structure of plasma density has origin in the particle transport but two distinct steps of the density structure emerge from dominance of collisionality in the source-EEF region and of the Bohm diffusion in the EEF-target region. It is argued and experimental evidence is provided for existence of drift like flute Rayleigh-Taylor in the EEF plasma.

  13. On `light' fermions and proton stability in `big divisor' D3/ D7 large volume compactifications

    NASA Astrophysics Data System (ADS)

    Misra, Aalok; Shukla, Pramod

    2011-06-01

    Building on our earlier work (Misra and Shukla, Nucl. Phys. B 827:112, 2010; Phys. Lett. B 685:347-352, 2010), we show the possibility of generating "light" fermion mass scales of MeV-GeV range (possibly related to the first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-brane restricted to (in principle) stacks of fluxed D7-branes wrapping the "big" divisor Σ B . This part of the paper is an expanded version of the latter half of Sect. 3 of a published short invited review (Misra, Mod. Phys. Lett. A 26:1, 2011) written by one of the authors [AM]. Further, we also show that there are no SUSY GUT-type dimension-five operators corresponding to proton decay, and we estimate the proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be 1061 years. Based on GLSM calculations in (Misra and Shukla, Nucl. Phys. B 827:112, 2010) for obtaining the geometric Kähler potential for the "big divisor," using further the Donaldson's algorithm, we also briefly discuss in the first of the two appendices the metric for the Swiss-Cheese Calabi-Yau used, which we obtain and which becomes Ricci flat in the large-volume limit.

  14. A uniform laminar air plasma plume with large volume excited by an alternating current voltage

    NASA Astrophysics Data System (ADS)

    Li, Xuechen; Bao, Wenting; Chu, Jingdi; Zhang, Panpan; Jia, Pengying

    2015-12-01

    Using a plasma jet composed of two needle electrodes, a laminar plasma plume with large volume is generated in air through an alternating current voltage excitation. Based on high-speed photography, a train of filaments is observed to propagate periodically away from their birth place along the gas flow. The laminar plume is in fact a temporal superposition of the arched filament train. The filament consists of a negative glow near the real time cathode, a positive column near the real time anode, and a Faraday dark space between them. It has been found that the propagation velocity of the filament increases with increasing the gas flow rate. Furthermore, the filament lifetime tends to follow a normal distribution (Gaussian distribution). The most probable lifetime decreases with increasing the gas flow rate or decreasing the averaged peak voltage. Results also indicate that the real time peak current decreases and the real time peak voltage increases with the propagation of the filament along the gas flow. The voltage-current curve indicates that, in every discharge cycle, the filament evolves from a Townsend discharge to a glow one and then the discharge quenches. Characteristic regions including a negative glow, a Faraday dark space, and a positive column can be discerned from the discharge filament. Furthermore, the plasma parameters such as the electron density, the vibrational temperature and the gas temperature are investigated based on the optical spectrum emitted from the laminar plume.

  15. Development testing of large volume water sprays for warm fog dispersal

    NASA Technical Reports Server (NTRS)

    Keller, V. W.; Anderson, B. J.; Burns, R. A.; Lala, G. G.; Meyer, M. B.; Beard, K. V.

    1986-01-01

    A new brute-force method of warm fog dispersal is described. The method uses large volume recycled water sprays to create curtains of falling drops through which the fog is processed by the ambient wind and spray induced air flow. Fog droplets are removed by coalescence/rainout. The efficiency of the technique depends upon the drop size spectra in the spray, the height to which the spray can be projected, the efficiency with which fog laden air is processed through the curtain of spray, and the rate at which new fog may be formed due to temperature differences between the air and spray water. Results of a field test program, implemented to develop the data base necessary to assess the proposed method, are presented. Analytical calculations based upon the field test results indicate that this proposed method of warm fog dispersal is feasible. Even more convincingly, the technique was successfully demonstrated in the one natural fog event which occurred during the test program. Energy requirements for this technique are an order of magnitude less than those to operate a thermokinetic system. An important side benefit is the considerable emergency fire extinguishing capability it provides along the runway.

  16. Detecting Boosted Dark Matter from the Sun with Large Volume Neutrino Detectors

    SciTech Connect

    Berger, Joshua; Cui, Yanou; Zhao, Yue; /Stanford U., ITP /Stanford U., Phys. Dept.

    2015-04-02

    We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

  17. Curling probe measurement of a large-volume pulsed plasma with surface magnetic confinement

    NASA Astrophysics Data System (ADS)

    Pandey, A.; Tashiro, H.; Sakakibara, W.; Nakamura, K.; Sugai, H.

    2016-12-01

    A curling probe (CP) based on microwave resonance is applied to the measurement of electron density in a pulsed DC glow discharge under surface magnetic confinement (SMC) provided by a number of permanent magnets on a chamber wall. Owing to the SMC effects, a 1 m scale large-volume plasma is generated by a relatively low voltage (~1 kV) at low pressure (~1 Pa) in various gases (Ar, CH4, and C2H2). Temporal variation of the electron density is measured for pulse frequency f  =  0.5-25 kHz for various discharge-on times (T ON) with a high resolution time (~0.2 µs), using the on-point mode. In general, the electron density starts to increase at time t  =  0 after turn-on of the discharge voltage, reaches peak density at t  =  T ON, and then decreases after turn-off. The peak electron density is observed to increase with the pulse frequency f for constant T ON owing to the residual plasma. This dependence is successfully formulated using a semi-empirical model. The spatio-temporal evolution of the cathode sheath in the pulsed discharge is revealed by a 1 m long movable CP. The measured thickness of the high-voltage cathode fall in a steady state coincides with the value of the so-called Child-Langmuir sheath.

  18. Spectroscopic properties of large-volume virtual Frisch-grid CdMnTe detectors

    NASA Astrophysics Data System (ADS)

    Kim, K. H.; Park, Chansun; Kim, Pilsu; Cho, Shinhaeng; Lee, Jinseo; Hong, T. K.; Hossain, A.; Bolotnikov, A. E.; James, R. B.

    2015-06-01

    CdMnTe(CMT) is a promising alternative material for use as a room-temperature radiation detector. Frisch-grid detectors have a simple configuration and outstanding spectral performance compared with other single-carrier collection techniques. The energy resolution of large-volume virtual Frisch-grid CMT detectors was tested by using several isotopes such as 57Co, 22 Na, 133Ba, and 137Cs together or separately. Energy resolutions of 6.7% and 2.1% were obtained for 122-keV 57Co and 662-keV 137Cs gamma rays, respectively, without using any additional signal processing techniques. Also, a 12-mm-thick CMT detector detected the 511-keV and 1.277-MeV gamma peaks of 22Na with values of the full width at half maximum (FWHM) of 2.7% and 1.5%, respectively. In addition, multiple low- and high-energy gamma peaks of 133Ba were well separated. The mobilitylifetime product calculated from the shift of the 662-keV photo-peak vs. bias by using Hecht's equation was 7 × 10 -3 cm2/V. These results show the possibility of using CMT detectors in response to various requirements for gamma-ray detection at room-temperature.

  19. Effect of large volume paracentesis on plasma volume--a cause of hypovolemia

    SciTech Connect

    Kao, H.W.; Rakov, N.E.; Savage, E.; Reynolds, T.B.

    1985-05-01

    Large volume paracentesis, while effectively relieving symptoms in patients with tense ascites, has been generally avoided due to reports of complications attributed to an acute reduction in intravascular volume. Measurements of plasma volume in these subjects have been by indirect methods and have not uniformly confirmed hypovolemia. We have prospectively evaluated 18 patients (20 paracenteses) with tense ascites and peripheral edema due to chronic liver disease undergoing 5 liter paracentesis for relief of symptoms. Plasma volume pre- and postparacentesis was assessed by a /sup 125/I-labeled human serum albumin dilution technique as well as by the change in hematocrit and postural blood pressure difference. No significant change in serum sodium, urea nitrogen, hematocrit or postural systolic blood pressure difference was noted at 24 or 48 hr after paracentesis. Serum creatinine at 24 hr after paracentesis was unchanged but a small but statistically significant increase in serum creatinine was noted at 48 hr postparacentesis. Plasma volume changed -2.7% (n = 6, not statistically significant) during the first 24 hr and -2.8% (n = 12, not statistically significant) during the 0- to 48-hr period. No complications from paracentesis were noted. These results suggest that 5 liter paracentesis for relief of symptoms is safe in patients with tense ascites and peripheral edema from chronic liver disease.

  20. Detecting boosted dark matter from the Sun with large volume neutrino detectors

    NASA Astrophysics Data System (ADS)

    Berger, Joshua; Cui, Yanou; Zhao, Yue

    2015-02-01

    We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

  1. A large volume cell for in situ neutron diffraction studies of hydrothermal crystallizations.

    PubMed

    Xia, Fang; Qian, Gujie; Brugger, Joël; Studer, Andrew; Olsen, Scott; Pring, Allan

    2010-10-01

    A hydrothermal cell with 320 ml internal volume has been designed and constructed for in situ neutron diffraction studies of hydrothermal crystallizations. The cell design adopts a dumbbell configuration assembled with standard commercial stainless steel components and a zero-scattering Ti-Zr alloy sample compartment. The fluid movement and heat transfer are simply driven by natural convection due to the natural temperature gradient along the fluid path, so that the temperature at the sample compartment can be stably sustained by heating the fluid in the bottom fluid reservoir. The cell can operate at temperatures up to 300 °C and pressures up to 90 bars and is suitable for studying reactions requiring a large volume of hydrothermal fluid to damp out the negative effect from the change of fluid composition during the course of the reactions. The capability of the cell was demonstrated by a hydrothermal phase transformation investigation from leucite (KAlSi(2)O(6)) to analcime (NaAlSi(2)O(6)⋅H(2)O) at 210 °C on the high intensity powder diffractometer Wombat in ANSTO. The kinetics of the transformation has been resolved by collecting diffraction patterns every 10 min followed by Rietveld quantitative phase analysis. The classical Avrami/Arrhenius analysis gives an activation energy of 82.3±1.1 kJ  mol(-1). Estimations of the reaction rate under natural environments by extrapolations agree well with petrological observations.

  2. A large volume cell for in situ neutron diffraction studies of hydrothermal crystallizations

    NASA Astrophysics Data System (ADS)

    Xia, Fang; Qian, Gujie; Brugger, Joël; Studer, Andrew; Olsen, Scott; Pring, Allan

    2010-10-01

    A hydrothermal cell with 320 ml internal volume has been designed and constructed for in situ neutron diffraction studies of hydrothermal crystallizations. The cell design adopts a dumbbell configuration assembled with standard commercial stainless steel components and a zero-scattering Ti-Zr alloy sample compartment. The fluid movement and heat transfer are simply driven by natural convection due to the natural temperature gradient along the fluid path, so that the temperature at the sample compartment can be stably sustained by heating the fluid in the bottom fluid reservoir. The cell can operate at temperatures up to 300 °C and pressures up to 90 bars and is suitable for studying reactions requiring a large volume of hydrothermal fluid to damp out the negative effect from the change of fluid composition during the course of the reactions. The capability of the cell was demonstrated by a hydrothermal phase transformation investigation from leucite (KAlSi2O6) to analcime (NaAlSi2O6ṡH2O) at 210 °C on the high intensity powder diffractometer Wombat in ANSTO. The kinetics of the transformation has been resolved by collecting diffraction patterns every 10 min followed by Rietveld quantitative phase analysis. The classical Avrami/Arrhenius analysis gives an activation energy of 82.3±1.1 kJ mol-1. Estimations of the reaction rate under natural environments by extrapolations agree well with petrological observations.

  3. Pressure calibration in solid pressure transmitting medium in large volume press.

    PubMed

    Yan, Xiaozhi; Ren, Xiangting; He, Duanwei

    2016-12-01

    The pressure limit in the large-volume-press (LVP) is increasing, but the in situ pressure calibration in LVP is still not a well resolved problem. The variation of the electrical resistance of the manganin with pressure in a hydrostatic condition is well known and is widely used in the pressure calibration in LVP. However, the hydrostatic pressure condition is hard to be maintained for the unavoidable solidification of the pressure transmitting medium (PTM) with pressure increasing. Moreover, our understanding about the relationship between pressure and manganin's resistance in a solid transmitting medium is still limited. Therefore, it is difficult to calibrate higher pressure using manganin. We measured the electrical resistance of manganin under pressure in pyrophyllite, MgO, and NaCl, respectively. The results show a linear relationship between the resistance and pressure in the same PTM with good reproducibility. In addition, the resistance-pressure relationships of manganin in different PTM are obviously different. So the resistance of manganin in a given solid PTM can be satisfactorily used as a pressure gauge only in the same PTM but cannot be used in other pressure media. Our results make it possible to calibrate higher pressure in a solid pressure transmitting medium in LVP.

  4. A scale down process for the development of large volume cryopreservation☆

    PubMed Central

    Kilbride, Peter; Morris, G. John; Milne, Stuart; Fuller, Barry; Skepper, Jeremy; Selden, Clare

    2014-01-01

    The process of ice formation and propagation during cryopreservation impacts on the post-thaw outcome for a sample. Two processes, either network solidification or progressive solidification, can dominate the water–ice phase transition with network solidification typically present in small sample cryo-straws or cryo-vials. Progressive solidification is more often observed in larger volumes or environmental freezing. These different ice phase progressions could have a significant impact on cryopreservation in scale-up and larger volume cryo-banking protocols necessitating their study when considering cell therapy applications. This study determines the impact of these different processes on alginate encapsulated liver spheroids (ELS) as a model system during cryopreservation, and develops a method to replicate these differences in an economical manner. It was found in the current studies that progressive solidification resulted in fewer, but proportionally more viable cells 24 h post-thaw compared with network solidification. The differences between the groups diminished at later time points post-thaw as cells recovered the ability to undertake cell division, with no statistically significant differences seen by either 48 h or 72 h in recovery cultures. Thus progressive solidification itself should not prove a significant hurdle in the search for successful cryopreservation in large volumes. However, some small but significant differences were noted in total viable cell recoveries and functional assessments between samples cooled with either progressive or network solidification, and these require further investigation. PMID:25219980

  5. Exploring the limiting timing resolution for large volume CZT detectors with waveform analysis.

    PubMed

    Meng, L J; He, Z

    2005-09-11

    This paper presents a study for exploring the limiting timing resolution that can be achieved with a large volume 3-D position sensitive CZT detector. The interaction timing information was obtained by fitting the measured cathode waveforms to pre-defined waveform models. We compared the results from using several different waveform models. Timing resolutions, of ~9.5 ns for 511 keV full-energy events and ~11.6 ns for all detected events with energy deposition above 250 keV, were achieved with a detailed modeling of the cathode waveform as a function of interaction location and energy deposition. This detailed modeling also allowed us to derive a theoretical lower bound for the error on estimated interaction timing. Both experimental results and theoretical predications matched well, which indicated that the best timing resolution achievable in the 1 cm(3) CZT detector tested is ~10 ns. It is also showed that the correlation between sampled amplitudes in cathode waveforms is an important limiting factor for the achievable timing resolution.

  6. Exploring the limiting timing resolution for large volume CZT detectors with waveform analysis

    PubMed Central

    Meng, L.J.; He, Z.

    2016-01-01

    This paper presents a study for exploring the limiting timing resolution that can be achieved with a large volume 3-D position sensitive CZT detector. The interaction timing information was obtained by fitting the measured cathode waveforms to pre-defined waveform models. We compared the results from using several different waveform models. Timing resolutions, of ~9.5 ns for 511 keV full-energy events and ~11.6 ns for all detected events with energy deposition above 250 keV, were achieved with a detailed modeling of the cathode waveform as a function of interaction location and energy deposition. This detailed modeling also allowed us to derive a theoretical lower bound for the error on estimated interaction timing. Both experimental results and theoretical predications matched well, which indicated that the best timing resolution achievable in the 1 cm3 CZT detector tested is ~10 ns. It is also showed that the correlation between sampled amplitudes in cathode waveforms is an important limiting factor for the achievable timing resolution. PMID:28260808

  7. Bretylium tosylate intravenous admixture compatibility. I: Stability in common large-volume parenteral solutions.

    PubMed

    Lee, Y C; Baaske, D M; Amann, A H; Carter, J E; Mooers, M A; Wagenknecht, D M; Lai, C M

    1980-06-01

    The stability of bretylium tosylate in 11 common large-volume parenteral solutions was studied. Two containers of each solution, one glass and one plastic (except for mannitol and sodium bicarbonate solutions, which were available in glass only), were stored at each of the following conditions: intense light (1400-2000 foot candles), ambient room temperature with normal light, 40 degrees C, and 4 degrees C. All samples were tested at 0 and 24 hours; some samples were also tested at 48 hours and 7 days. Testing included measurement for optical density at 4000 and 600 nm, pH level, and bretylium content as determined by HPLC. The admixtures remained clear and colorless, except that mannitol precipitated out of mannitol solutions stored at 4 degrees C. No appreciable changes in pH were observed. HPLC assays showed no significant changes in bretylium tosylate concentrations. Bretylium tosylate is compatible with each of the 11 common intravenous solutions chosen for investigation under the storage conditions studied. Admixtures with mannitol should not be refrigerated, because mannitol crystallizes from solution at refrigerator temperatures.

  8. A new large-volume metal reference standard for radioactive waste management.

    PubMed

    Tzika, F; Hult, M; Stroh, H; Marissens, G; Arnold, D; Burda, O; Kovář, P; Suran, J; Listkowska, A; Tyminski, Z

    2016-03-01

    A new large-volume metal reference standard has been developed. The intended use is for calibration of free-release radioactivity measurement systems and is made up of cast iron tubes placed inside a box of the size of a Euro-pallet (80 × 120 cm). The tubes contain certified activity concentrations of (60)Co (0.290 ± 0.006 Bq g(-1)) and (110m)Ag (3.05 ± 0.09 Bq g(-1)) (reference date: 30 September 2013). They were produced using centrifugal casting from a smelt into which (60)Co was first added and then one piece of neutron irradiated silver wire was progressively diluted. The iron castings were machined to the desirable dimensions. The final material consists of 12 iron tubes of 20 cm outer diameter, 17.6 cm inner diameter, 40 cm length/height and 245.9 kg total mass. This paper describes the reference standard and the process of determining the reference activity values. © The Author 2015. Published by Oxford University Press.

  9. A large volume uniform plasma generator for the experiments of electromagnetic wave propagation in plasma

    SciTech Connect

    Yang Min; Li Xiaoping; Xie Kai; Liu Donglin; Liu Yanming

    2013-01-15

    A large volume uniform plasma generator is proposed for the experiments of electromagnetic (EM) wave propagation in plasma, to reproduce a 'black out' phenomenon with long duration in an environment of the ordinary laboratory. The plasma generator achieves a controllable approximate uniform plasma in volume of 260 mm Multiplication-Sign 260 mm Multiplication-Sign 180 mm without the magnetic confinement. The plasma is produced by the glow discharge, and the special discharge structure is built to bring a steady approximate uniform plasma environment in the electromagnetic wave propagation path without any other barriers. In addition, the electron density and luminosity distributions of plasma under different discharge conditions were diagnosed and experimentally investigated. Both the electron density and the plasma uniformity are directly proportional to the input power and in roughly reverse proportion to the gas pressure in the chamber. Furthermore, the experiments of electromagnetic wave propagation in plasma are conducted in this plasma generator. Blackout phenomena at GPS signal are observed under this system and the measured attenuation curve is of reasonable agreement with the theoretical one, which suggests the effectiveness of the proposed method.

  10. Evaluation of Large Volume SrI2(Eu) Scintillator Detectors

    SciTech Connect

    Sturm, B W; Cherepy, N J; Drury, O B; Thelin, P A; Fisher, S E; Magyar, A F; Payne, S A; Burger, A; Boatner, L A; Ramey, J O; Shah, K S; Hawrami, R

    2010-11-18

    There is an ever increasing demand for gamma-ray detectors which can achieve good energy resolution, high detection efficiency, and room-temperature operation. We are working to address each of these requirements through the development of large volume SrI{sub 2}(Eu) scintillator detectors. In this work, we have evaluated a variety of SrI{sub 2} crystals with volumes >10 cm{sup 3}. The goal of this research was to examine the causes of energy resolution degradation for larger detectors and to determine what can be done to mitigate these effects. Testing both packaged and unpackaged detectors, we have consistently achieved better resolution with the packaged detectors. Using a collimated gamma-ray source, it was determined that better energy resolution for the packaged detectors is correlated with better light collection uniformity. A number of packaged detectors were fabricated and tested and the best spectroscopic performance was achieved for a 3% Eu doped crystal with an energy resolution of 2.93% FWHM at 662keV. Simulations of SrI{sub 2}(Eu) crystals were also performed to better understand the light transport physics in scintillators and are reported. This study has important implications for the development of SrI{sub 2}(Eu) detectors for national security purposes.

  11. Screening anaphylactic components of MaiLuoNing injection by using rat basophilic leukemia-2H3 cell membrane chromatography coupled with HPLC-ESI-TOF-MS.

    PubMed

    Han, Shengli; Lv, Yanni; Xue, Wenjing; Cao, Jiao; Cui, Ronghua; Zhang, Tao

    2016-02-01

    MaiLuoNing injection is a traditional Chinese medicine that used clinically since the 1950s in China. However, anaphylactic reactions, through the potentiation of mast cell degranulation, have been reported. In the present study, a rat basophilic leukemia-2H3 cell membrane chromatography coupled with high-performance liquid chromatography and electrospray ionization-ion trap-time of flight-mass spectrometry method was established for screening, analyzing, and identifying the potential anaphylactic components of MaiLuoNing injection. Harpagoside, a potential degranulator of rat basophilic leukemia-2H3 cells, was retained in rat basophilic leukemia-2H3 cell membrane chromatography. We aimed to evaluate the retained components to determine which of those were capable of inducing degranulation of basophilic leukemia cells. A β-hexosaminidase assay revealed that harpagoside can induce rat basophilic leukemia-2H3 cell degranulation in a dose-dependent manner. BLBA/c mice also exhibit passive cutaneous anaphylaxis in response to harpagoside. These results indicate that rat basophilic leukemia-2H3 cell membrane chromatography coupled with high-performance liquid chromatography and electrospray ionization ion trap time-of-flight mass spectrometry is effective in screening for the anaphylactic components of MaiLuoNing injection.

  12. Determination of malachite green in fish water samples by cloud-point extraction coupled to cation-selective exhaustive injection and sweeping-MEKC.

    PubMed

    Luo, Xubiao; Jiang, Xin; Tu, Xinman; Luo, Shenglian; Yan, Liushui; Chen, Bo

    2010-01-01

    We have employed a high-sensitivity off-line coupled with on-line preconcentration method, cloud-point extraction (CPE)/cation-selective exhaustive injection (CSEI) and sweeping-MEKC, for the analysis of malachite green. The variables that affect CPE were investigated. The optimal conditions were 250 g/L of Triton X-100, 10% of Na(2)SO(4) (w/v), heat-assisted at 60 degrees C for 20 min. We monitored the effects of several of the CSEI-sweeping-MEKC parameters - including the type of BGE, the concentrations of SDS, the injection length of the high-conductivity buffer, and the injection time of the sample - to optimize the separation process. The optimal BGE was 50 mM citric acid (pH 2.2) containing 100 mM SDS. In addition, electrokinetic injection of the sample at 15 kV for 800 s provided both high separation efficiency and enhanced sweeping sensitivity. The sensitivity enhancement for malachite green was 1.9 x 10(4) relative to CZE; the coefficients of determination exceeded 0.9928. The LOD, based on an S/N of 3:1, of CSEI-sweeping-MEKC was 0.87 ng/mL; in contrast, when using off-line CPE/CSEI-sweeping-MEKC the sensitivity increased to 69.6 pg/mL. This proposed method was successfully applied to determine trace amounts of malachite green in fish water samples.

  13. Simultaneous determination of nanomolar nitrite and nitrate in seawater using reverse flow injection analysis coupled with a long path length liquid waveguide capillary cell.

    PubMed

    Feng, Sichao; Zhang, Min; Huang, Yongming; Yuan, Dongxing; Zhu, Yong

    2013-12-15

    A reverse flow injection analysis (rFIA) method coupled with 1m liquid waveguide capillary cell and spectrophotometric detection for simultaneous determination of nanomolar nitrite and nitrate in seawater was developed. The design of two analytical channels sharing the same detection system in the proposed method allowed the analysis of both nitrite and nitrate with single sample injection. Different strategies of reagent injection were investigated to obtain a higher sensitivity and a better peak shape. A dual-wavelength detection mode was chosen to eliminate the light source shifting and sample matrix interference. Experimental parameters were optimized based on a univariate experimental design and the matrix effect from seawater was preliminarily investigated. The proposed method had high sensitivity with detection limit of 0.6 nmol L(-1) for both nitrite and nitrate. The linearity was 2-500 nmol L(-1) for both analytes, and the upper limit could be extended by choosing a lower sensitivity detection wavelength. The analytical results of 26 surface seawater samples obtained with the proposed method showed good agreement with those using a reference method operated using an automated segmented flow analyzer. The proposed method could greatly minimize the trouble introduced by bubbles in the segmented flow analyzer. It also had the advantages of high precision and high sample throughput (nitrite and nitrate detected in triplicate; 5 h(-1)). Compared to normal flow injection analysis, the rFIA method is superior due to its lower reagent consumption, less dispersion of sample, as well as higher sensitivity.

  14. Pyrometry in the Multianvil Press: New approach for temperature measurement in large volume press experiments

    NASA Astrophysics Data System (ADS)

    Sanehira, T.; Wang, Y.; Prakapenka, V.; Rivers, M. L.

    2008-12-01

    Temperature measurement in large volume press experiments has been based on thermocouple emf, which has well known problems: unknown pressure dependence of emf [e.g., 1], chemical reaction between thermocouple and other materials, deformation related texture development in the thermocouple wires [2], and so on. Thus, different techniques to measure temperatures in large volume press experiments other than thermocouples are required to measure accurate temperatures under high pressures. Here we report a new development using pyrometry in the multianvil press, where temperatures are derived on the basis of spectral radiometry. Several high pressure runs were conducted using the 1000 ton press with a DIA module installed at 13 ID-D GSECARS beamline at Advanced Photon Source (APS) [3]. The cubic pressure medium, 14 mm edge length, was made of soft-fired pyrophyllite with a graphite furnace. A moissanite (SiC) single crystal was built inside the pressure medium as a window for the thermal emission signal to go through. An MgO disk with 1.0 mm thickness was inserted in a gap between the top of the SiC crystal and thermocouple hot junction. The bottom of the window crystal was in direct contact with the tip of the anvil, which had a 1.5 mm diameter hole drilled all the way through the anvil axis. An optical fiber was inserted in this hole and the open end of fiber was in contact with the SiC crystal. Thermal spectral radiance from the inner cell assembly was obtained via the fiber and recorded by an Ocean Optics HP2000 spectrometer. The system response of spectrometer was calibrated by a tungsten ribbon ramp (OL550S, Optronic Laboratories, Inc.) with standard of spectral radiance. The cell assembly was compressed up to target value of 15 tons and then temperature was increased up to 1573 K. Radiation spectra were mainly obtained above 873 K and typical integration time was 1 ms or 10 ms. Data collection was done in the process of increase and decrease of temperature. In

  15. Annealing as grown large volume CZT single crystals increased spectral resolution

    SciTech Connect

    Dr. Longxia Li

    2008-03-19

    The spectroscopic performance of current large-volume Cadmium 10% Zinc Telluride, Cd{sub 0.9}Zn{sub 0.1}Te, (CZT) detectors is impaired by cumulative effect of tellurium precipitates (secondary phases) presented in CZT single-crystal grown by low-pressure Bridgman techniques(1). This statistical effect may limit the energy resolution of large-volume CZT detectors (typically 2-5% at 662 keV for 12-mm thick devices). The stochastic nature of the interaction prevents the use of any electronic or digital charge correction techniques without a significant reduction in the detector efficiency. This volume constraint hampers the utility of CZT since the detectors are inefficient at detecting photons >1MeV and/or in low fluency situations. During the project, seven runs CZT ingots have been grown, in these ingots the indium dopant concentrations have been changed in the range between 0.5ppm to 6ppm. The I-R mapping imaging method has been employed to study the Te-precipitates. The Teprecipitates in as-grown CZT wafers, and after annealing wafers have been systematically studied by using I-R mapping system (home installed, resolution of 1.5 {micro}m). We employed our I-R standard annealing CZT (Zn=4%) procedure or two-steps annealing into radiation CZT (Zn=10%), we achieved the 'non'-Te precipitates (size < 1 {micro}m) CZT n+-type with resistivity > 10{sup 9-10} {Omega}-cm. We believe that the Te-precipitates are the p-type defects, its reducing number causes the CZT became n+-type, therefore we varied or reduced the indium dapant concentration during the growth and changed the Te-precipitates size and density by using different Cd-temperature and different annealing procedures. We have made the comparisons among Te-precipitates size, density and Indium dopant concentrations, and we found that the CZT with smaller size of Te-precipitates is suitable for radiation uses but non-Te precipitates is impossible to be used in the radiation detectors, because the CZT would became

  16. Long term average rates of large-volume explosive volcanism are not average

    NASA Astrophysics Data System (ADS)

    Connor, C.; Kiyosugi, K.

    2011-12-01

    How good are our estimates of long term recurrence rates of large magnitude explosive volcanic eruptions? To investigate this question, we created a data set of all known explosive eruptions in Japan since 1.8 Ma and VEI magnitude 4 or greater. This data set contains 696 explosive eruptions. We use this data set to consider the change in apparent recurrence rate of large volume explosive eruptions through time. Assuming there has been little change in recurrence rate of volcanism since 2.25 Ma, apparent changes are due to erosion of explosive eruption deposits and a lower rate of identification of older deposits preserved in the geologic record. Surprisingly, one half of the eruptions in the data set occurred within the last 65 ka. 77% of the total eruptions occurred since 200 ka; the oldest eruption in the database is 2.25 Ma. Overall, there is a roughly exponential decrease in the numbers of eruptions of a given magnitude identified in the geological record as a function of time. This result clearly indicates that even large magnitude eruptions are significantly under-reported. In addition, percentages of explosive eruptions in the entire data set by eruption magnitude are: VEI 4 (40%), VEI 5 (42%), VEI 6 (13%) and VEI 7 (5%). Because it is reasonable to assume that smaller eruptions occur much more frequently, fewer VEI 4 eruptions than VEI 5 eruptions indicates that small eruptions are missing in this data set. We quantify these variations by plotting survivor functions, noting that there is little change in apparent rate of activity (or the preservation potential of deposits) with geographic and tectonic setting in Japan. These data indicate that eruption probabilities based on long term recurrence rate may underestimate rates of activity. This result also indicates there is considerable uncertainty about the future recurrence rate of large magnitude eruptions, as our best estimates of frequency are based on an unrealistically short record.

  17. Random forest classification of large volume structures for visuo-haptic rendering in CT images

    NASA Astrophysics Data System (ADS)

    Mastmeyer, Andre; Fortmeier, Dirk; Handels, Heinz

    2016-03-01

    For patient-specific voxel-based visuo-haptic rendering of CT scans of the liver area, the fully automatic segmentation of large volume structures such as skin, soft tissue, lungs and intestine (risk structures) is important. Using a machine learning based approach, several existing segmentations from 10 segmented gold-standard patients are learned by random decision forests individually and collectively. The core of this paper is feature selection and the application of the learned classifiers to a new patient data set. In a leave-some-out cross-validation, the obtained full volume segmentations are compared to the gold-standard segmentations of the untrained patients. The proposed classifiers use a multi-dimensional feature space to estimate the hidden truth, instead of relying on clinical standard threshold and connectivity based methods. The result of our efficient whole-body section classification are multi-label maps with the considered tissues. For visuo-haptic simulation, other small volume structures would have to be segmented additionally. We also take a look into these structures (liver vessels). For an experimental leave-some-out study consisting of 10 patients, the proposed method performs much more efficiently compared to state of the art methods. In two variants of leave-some-out experiments we obtain best mean DICE ratios of 0.79, 0.97, 0.63 and 0.83 for skin, soft tissue, hard bone and risk structures. Liver structures are segmented with DICE 0.93 for the liver, 0.43 for blood vessels and 0.39 for bile vessels.

  18. Testbed for large volume surveillance through distributed fusion and resource management

    NASA Astrophysics Data System (ADS)

    Valin, Pierre; Guitouni, Adel; Bossé, Éloi; Wehn, Hans; Yates, Richard; Zwick, Harold

    2007-04-01

    DRDC Valcartier has initiated, through a PRECARN partnership project, the development of an advanced simulation testbed for the evaluation of the effectiveness of Network Enabled Operations in a coastal large volume surveillance situation. The main focus of this testbed is to study concepts like distributed information fusion, dynamic resources and networks configuration management, and self synchronising units and agents. This article presents the requirements, design and first implementation builds, and reports on some preliminary results. The testbed allows to model distributed nodes performing information fusion, dynamic resource management planning and scheduling, as well as configuration management, given multiple constraints on the resources and their communications networks. Two situations are simulated: cooperative and non-cooperative target search. A cooperative surface target behaves in ways to be detected (and rescued), while an elusive target attempts to avoid detection. The current simulation consists of a networked set of surveillance assets including aircraft (UAVs, helicopters, maritime patrol aircraft), and ships. These assets have electrooptical and infrared sensors, scanning and imaging radar capabilities. Since full data sharing over datalinks is not feasible, own-platform data fusion must be simulated to evaluate implementation and performance of distributed information fusion. A special emphasis is put on higher-level fusion concepts using knowledge-based rules, with level 1 fusion already providing tracks. Surveillance platform behavior is also simulated in order to evaluate different dynamic resource management algorithms. Additionally, communication networks are modeled to simulate different information exchange concepts. The testbed allows the evaluation of a range of control strategies from independent platform search, through various levels of platform collaboration, up to a centralized control of search platforms.

  19. High Pressure Research in the Large-Volume Press at the Advanced Photon Source

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Shen, G.

    2013-05-01

    We present an overview of current status of high-pressure research using large-volume presses (LVP) at both GSECARS (Sector 13) and HPCAT (Sector 16) at the third-generation synchrotron facility of the Advanced Photon Source (APS), Argonne National Laboratory. These combined facilities provide a wide range of research capabilities for the high pressure community. The 230 ton Paris-Edinburgh device (jointly developed by HPCAT and GSECARS, with partial support from COMPRES) at the bending magnet (BM) beamline 16-BM-B has been used primarily for studies on liquids and glasses. We use the multi-angle energy-dispersive diffraction technique to probe structures of non-crystalline materials, and ultrasonic and falling sphere techniques to measure elasticity and viscosity of these materials. These capabilities allow us to examine the close link between structure and physical properties of non-crystalline metarials. The 1000 ton system at the insertion device (ID) beamline 13-ID-D is used extensively for acoustic velocity measurement for solids and melts. The newly developed DDIA-30 module, when used in a double-stage apparatus with sintered diamond anvils, can generate pressures in excess of 40 GPa routinely. DDIA-30 can also be used as a deformation device for larger samples or higher pressure experiments. The 250 ton system at beamline 13-BM-D as just been upgraded and can accommodate a variety of LVP techniques. Among them the D-DIA and the high-pressure x-ray tomography microscope (HPXTM) are at high demand. The D-DIA has been used for deformation at mantle conditions in both ductile and brittle regime, with acoustic emission detection. The HPXTM has been used to study volumetric properties of glasses and melts as well as 3D microstructure imaging under pressure. Latest scientific results will be highlighted.

  20. Measurements of Elastic and Inelastic Properties under Simulated Earth's Mantle Conditions in Large Volume Apparatus

    NASA Astrophysics Data System (ADS)

    Mueller, H. J.

    2012-12-01

    The interpretation of highly resolved seismic data from Earths deep interior require measurements of the physical properties of Earth's materials under experimental simulated mantle conditions. More than decade ago seismic tomography clearly showed subduction of crustal material can reach the core mantle boundary under specific circumstances. That means there is no longer space for the assumption deep mantle rocks might be much less complex than deep crustal rocks known from exhumation processes. Considering this geophysical high pressure research is faced the challenge to increase pressure and sample volume at the same time to be able to perform in situ experiments with representative complex samples. High performance multi anvil devices using novel materials are the most promising technique for this exciting task. Recent large volume presses provide sample volumes 3 to 7 orders of magnitude bigger than in diamond anvil cells far beyond transition zone conditions. The sample size of several cubic millimeters allows elastic wave frequencies in the low to medium MHz range. Together with the small and even adjustable temperature gradients over the whole sample this technique makes anisotropy and grain boundary effects in complex systems accessible for elastic and inelastic properties measurements in principle. The measurements of both elastic wave velocities have also no limits for opaque and encapsulated samples. The application of triple-mode transducers and the data transfer function technique for the ultrasonic interferometry reduces the time for saving the data during the experiment to about a minute or less. That makes real transient measurements under non-equilibrium conditions possible. A further benefit is, both elastic wave velocities are measured exactly simultaneously. Ultrasonic interferometry necessarily requires in situ sample deformation measurement by X-radiography. Time-resolved X-radiography makes in situ falling sphere viscosimetry and even the

  1. A pomegranate-inspired nanoscale design for large-volume-change lithium battery anodes.

    PubMed

    Liu, Nian; Lu, Zhenda; Zhao, Jie; McDowell, Matthew T; Lee, Hyun-Wook; Zhao, Wenting; Cui, Yi

    2014-03-01

    Silicon is an attractive material for anodes in energy storage devices, because it has ten times the theoretical capacity of its state-of-the-art carbonaceous counterpart. Silicon anodes can be used both in traditional lithium-ion batteries and in more recent Li-O2 and Li-S batteries as a replacement for the dendrite-forming lithium metal anodes. The main challenges associated with silicon anodes are structural degradation and instability of the solid-electrolyte interphase caused by the large volume change (∼300%) during cycling, the occurrence of side reactions with the electrolyte, and the low volumetric capacity when the material size is reduced to a nanometre scale. Here, we propose a hierarchical structured silicon anode that tackles all three of these problems. Our design is inspired by the structure of a pomegranate, where single silicon nanoparticles are encapsulated by a conductive carbon layer that leaves enough room for expansion and contraction following lithiation and delithiation. An ensemble of these hybrid nanoparticles is then encapsulated by a thicker carbon layer in micrometre-size pouches to act as an electrolyte barrier. As a result of this hierarchical arrangement, the solid-electrolyte interphase remains stable and spatially confined, resulting in superior cyclability (97% capacity retention after 1,000 cycles). In addition, the microstructures lower the electrode-electrolyte contact area, resulting in high Coulombic efficiency (99.87%) and volumetric capacity (1,270 mAh cm(-3)), and the cycling remains stable even when the areal capacity is increased to the level of commercial lithium-ion batteries (3.7 mAh cm(-2)).

  2. The Combination of Tissue Dissection and External Volume Expansion Generates Large Volumes of Adipose Tissue.

    PubMed

    He, Yunfan; Dong, Ziqing; Xie, Gan; Zhou, Tao; Lu, Feng

    2017-04-01

    Noninvasive external volume expansion device has been applied to stimulate nonsurgical breast enlargement in clinical settings. Although previous results demonstrate the capacity of external volume expansion to increase the number of adipocytes, this strategy alone is insufficient to reconstruct soft-tissue defects or increase breast mass. The authors combined a minimally invasive tissue dissection method with external volume expansion to generate large volumes of adipose tissue. In vitro, various densities of adipose-derived stem cells were prepared to evaluate relations between cell contacts and cell proliferation. In vivo, dorsal adipose tissue of rabbits was thoroughly dissected and the external volume expansion device was applied to maintain the released state. External volume expansion without tissue dissection served as the control. In the dissection group, the generated adipose tissue volume was much larger than that in the control group at all time points. A larger number of proliferating cells appeared in the dissection samples than in the control samples at the early stage after tissue dissection. At low cell density, adipose-derived stem cells displayed an increasing proliferation rate compared to high cell density. Protein expression analysis revealed that cell proliferation was mediated by a similar mechanism both in vivo and in vitro, involving the release of cell contact inhibition and Hippo/Yes-associated protein pathway activation. Adipose tissue dissection releases cell-to-cell contacts and induces adipose-derived stem cell proliferation. Preexpanded adipose-derived stem cells undergo adipogenesis under the adipogenic environment created by external volume expansion, leading to better adipose regeneration compared with the control.

  3. Hepatic Arterial Embolization and Chemoembolization in the Management of Patients with Large-Volume Liver Metastases

    SciTech Connect

    Kamat, Paresh P.; Gupta, Sanjay Ensor, Joe E.; Murthy, Ravi; Ahrar, Kamran; Madoff, David C.; Wallace, Michael J.; Hicks, Marshall E.

    2008-03-15

    The purpose of this study was to assess the role of hepatic arterial embolization (HAE) and chemoembolization (HACE) in patients with large-volume liver metastases. Patients with metastatic neuroendocrine tumors, melanomas, or gastrointestinal stromal tumors (GISTs) with >75% liver involvement who underwent HAE or HACE were included in the study. Radiologic response, progression-free survival (PFS), overall survival (OS), and postprocedure complications were assessed. Sixty patients underwent 123 treatment sessions. Of the 48 patients for whom follow-up imaging was available, partial response was seen in 12 (25%) patients, minimal response in 6 (12%), stable disease in 22 (46%), and progressive disease in 8 (17%). Median OS and PFS were 9.3 and 4.9 months, respectively. Treatment resulted in radiologic response or disease stabilization in 82% and symptomatic response in 65% of patients with neuroendocrine tumors. Patients with neuroendocrine tumors had higher response rates (44% vs. 27% and 0%; p = 0.31) and longer PFS (9.2 vs. 2.0 and 2.3 months; p < 0.0001) and OS (17.9 vs. 2.4 and 2.3 months; p < 0.0001) compared to patients with melanomas and GISTs. Major complications occurred in 21 patients after 23 (19%) of the 123 sessions. Nine of the 12 patients who developed major complications resulting in death had additional risk factors-carcinoid heart disease, sepsis, rapidly worsening performance status, or anasarca. In conclusion, in patients with neuroendocrine tumors with >75% liver involvement, HAE/HACE resulted in symptom palliation and radiologic response or disease stabilization in the majority of patients. Patients with hepatic metastases from melanomas and GISTs, however, did not show any appreciable benefit from this procedure. Patients with massive liver tumor burden, who have additional risk factors, should not be subjected to HAE/HACE because of the high risk of procedure-related mortality.

  4. Addressing challenges in bar-code scanning of large-volume infusion bags.

    PubMed

    Raman, Kirthana; Heelon, Mark; Kerr, Gary; Higgins, Thomas L

    2011-08-01

    A hospital pharmacy's efforts to identify and address challenges with bedside scanning of bar codes on large-volume parenteral (LVP) infusion bags are described. Bar-code-assisted medication administration (BCMA) has been shown to reduce medication errors and improve patient safety. After the pilot implementation of a BCMA system and point-of-care scanning procedures at a medical center's intensive care unit, it was noted that nurses' attempted bedside scans of certain LVP bags for product identification purposes often were not successful. An investigation and root-cause analysis, including observation of nurses' scanning technique by a multidisciplinary team, determined that the scanning failures stemmed from the placement of two bar-code imprints-one with the product identification code and another, larger imprint with the expiration date and lot number-adjacently on the LVP bags. The nursing staff was educated on a modified scanning technique, which resulted in significantly improved success rates in the scanning of the most commonly used LVP bags. Representatives of the LVP bag manufacturer met with hospital staff to discuss the problem and corrective measures. As part of a subsequent infusion bag redesign, the manufacturer discontinued the use of the bar-code imprint implicated in the scanning failures. Failures in scanning LVP bags were traced to problematic placement of bar-code imprints on the bags. Interdisciplinary collaboration, consultation with the bag manufacturer, and education of the nursing and pharmacy staff resulted in a reduction in scanning failures and the manufacturer's removal of one of the bar codes from its LVP bags.

  5. Large volume leukapheresis maximizes the progenitor cell yield for allogeneic peripheral blood progenitor donation.

    PubMed

    Kobbe, G; Soehngen, D; Heyll, A; Fischer, J; Thiele, K P; Aul, C; Wernet, P

    1997-04-01

    We have investigated the efficiency and safety of large volume leukapheresis (LVL) for the collection of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood progenitor cells (PBPCs) from healthy donors. In six apheresis sessions in four healthy individuals on a COBE-BCT Spectra cell separator (median processed volume 3.5 X total blood volume, TBV, range 3.3-4.4 X TBV), harvested cells were collected sequentially into three single bags. The collection bags were changed after processing 33%, 66%, and 100% of the prospective apheresis volume, allowing analysis of PBPCs collected at different periods during one harvest. Mononuclear cells (MNCs), CD34+ cells, CD34+ subsets, and lymphocyte subsets were determined in each bag. Substantially more PBPCs were harvested than were in the circulation before G-CSF administration preceding LVL (median 171%, range 69-267%), reflecting progenitor release during the procedure. In donors 1 and 3, the CD34+ cell yields decreased in the third bag to 53% and 42% of that collected in the first bag, whereas the progenitor cell yields in donors 2 and 4 were stable or rose during the procedure, achieving in the third bag 157% and 105% of the number of CD34+ cells collected in the first bag. Minor changes were found in the subsets of CD34+ cells, lymphocytes, and monocytes collected at different periods during a single harvest. LVL was well tolerated. Reversible thombocytopenia developed in all cases. No late effects attributable to LVL or G-CSF were found in the 4 donors and 16 other healthy individuals who have undergone LVL in our institution. We conclude that LVL is safe and maximizes PBPC yields for allogeneic transplantation.

  6. Large-volume leukapheresis for peripheral blood stem cell collection in patients with hematologic malignancies.

    PubMed

    Malachowski, M E; Comenzo, R L; Hillyer, C D; Tiegerman, K O; Berkman, E M

    1992-10-01

    Large-volume leukapheresis (LVL, 15-35 L) was performed in two groups of patients (n = 10) with hematologic malignancies to obtain peripheral blood stem cells for bone marrow rescue following high-dose chemotherapy. The target cell count was 7 x 10(8) mononuclear cells (MNCs = lymphocytes and monocytes) per kg of body weight. Group A patients (n = 4) were studied on Day 1 of LVL, and components were collected from them as four sequential samples. Total MNCs collected averaged 1.29 x 10(10), total colony-forming-units granulocyte-macrophage (CFU-GM) averaged 12.1 x 10(6), and a 1.8-fold mobilization of CFU-GM was observed (p < 0.05, Sample 1 vs. Sample 4). Group B patients (n = 6) were studied throughout the three consecutive planned days of 5-hour LVL. An average of three LVL procedures per patient was performed (range, 1.25-4), and an average of 27 L (range, 24-33) of blood per LVL was processed. The blood:ACD-A ratio was 24:1 with 3000 units of heparin per 500 mL of ACD-A; heparin was also added to the collection bags. The component had an average hematocrit (Hct) of 0.02 and MNC content of 93 percent. The patients' pre-LVL and post-LVL average Hct varied significantly (before Day 1, 0.36 +/- 0.08; after Day 3, 0.28 +/- 0.06; p < 0.05). Platelet counts also decreased, with post-Day 3 counts averaging 19 percent of the average pre-Day 1 counts (p < 0.05). A decrease in the average MNC count after LVL was significant on Day 1 only (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Safety of large-volume leukapheresis for collection of peripheral blood progenitor cells.

    PubMed

    Reik, R A; Noto, T A; Fernandez, H F

    1997-01-01

    Large volume leukapheresis (LVL) reduces the number of procedures required to obtain adequate peripheral blood progenitor cells (PBPCs) for autologous hematopoietic reconstitution. LVL involves the processing of > 15 L or 5 patient blood volumes using high flow rates. We report our experience with LVL evaluating its efficiency and adverse effects in 71 adult patients with hematologic or solid organ malignancies. All were mobilized with chemotherapy and granulocyte colony-stimulating factor (G-CSF). All collections used a double lumen apheresis catheter. Mean values per LVL were as follows: blood processed, 24.6 L; patient blood volumes processed, 5.9; ACD-A used, 1,048 ml; heparin used, 6,148 units; collect time, 290 min; blood flow rate, 89 ml/min. Eighty percent of the collections were completed in one or two procedures to obtain > or = 6.0 x 10(8) MNCs/kg body weight. The most frequent side effect (39%) was parasthesia due to citrate-related hypocalcemia. This was managed with oral calcium supplements and/or slower flow rates. Post-LVL electrolyte changes were generally asymptomatic. Prophylactic oral potassium supplements were administered in 57% of cases. Other reactions included hypotension (4%), prolonged parasthesia (1.4%), and headache (1.4%). Catheter problems in 9 (13%) of the procedures were attributed to clot formation (37%) or positional effects (63%). No bleeding occurred. Post-LVL decreases in hematocrit and platelet count averaged 3.5% and 46%, respectively. Six (4%) of the procedures required red blood cell transfusions. Platelet transfusions were given in 19 (13%) of the procedures. We conclude that adverse reactions with LVL are similar to those reported for conventional PBPC collections, making it safe and efficacious as an outpatient procedure.

  8. Collection of more hematopoietic progenitor cells with large volume leukapheresis in patients with multiple myeloma.

    PubMed

    Desikan, K R; Jagannath, S; Siegel, D; Nelson, J; Bracy, D; Barlogie, B; Tricot, G

    1998-02-01

    Reinfusion of mobilized peripheral blood stem cells (PBSC) after high dose chemotherapy accelerates hematopoietic recovery. Because of the relatively low content of hematopoietic progenitors in the peripheral blood even after mobilization, multiple leukapheresis procedures are necessary to reach the required target number of CD34 cells to ensure prompt engraftment post-transplantation. Our previous studies have shown that the highest proportions of hematopoietic progenitors cells (CD34) are collected during the first three days of apheresis, whereas peak levels of myeloma cells are observed during subsequent days. Therefore, large volume leukapheresis (LVL), defined as processing of greater than 3 blood volumes or a total of at least 15 liters, was explored in 23 myeloma patients, undergoing 91 procedures; 14 patients were mobilized with high dose cyclophosphamide (6g/m2) and hematopoietic growth factors and 9 with G-CSF only. CD34 yields were measured separately for the first and last two hours of collection. We observed no decrease in CD34 cells/kg during the last two hours of collection and when the LVL collections were compared to historical matched controls, mobilized with the same regimen, the median quantity of CD34 cells/kg/liter collected remained equivalent during all days of apheresis. When compared to G-CSF only, mobilization with high dose cyclophosphamide appeared to result in superior hematopoietic stem cell collections. Interestingly, the G-CSF group experienced a progressive decrease in platelets during consecutive days of LVL, while the opposite was seen in the cyclophosphamide group. LVL procedures were not associated with a higher complication rate than standard volume apheresis. We conclude that LVL procedures allow collection of more CD34 cell per session while not jeopardizing progenitor cell collections during subsequent sessions. Since more CD34 cells are collected, fewer days are required to attain the optimal target of progenitor cells

  9. Hematopoietic progenitor cell large volume leukapheresis (LVL) on the Fenwal Amicus blood separator.

    PubMed

    Burgstaler, Edwin A; Pineda, Alvaro A; Winters, Jeffrey L

    2004-01-01

    A technique for large volume leukapheresis (LVL) for hematopoietic progenitor cell (HPC) collection using the Fenwal Amicus is presented. It was compared to standard collections (STD) with regard to CD34+ cell yields and cross-cellular content. Optimal cycle volumes and machine settings were evaluated for LVL procedures. A total of 68 patients underwent 80 HPC collection procedures. Because of differences in CD34+ cell yields associated with peripheral white blood cell counts (WBC), the comparison was divided into groups of 20 with WBC < or =35 x 10(9)/L (< or =35 K) and those >35 x 10(9)/L (>35 K). Baseline CD34+ cell counts (peripheral count when patient started HPC collection) were used (median 18-23 cells/microl). Significantly more whole blood (corrected for anticoagulant) was processed with LVL (LVL 20 l vs. STD 13.5 l). For < or =35 K, median CD34+ x 10(6), WBC x 10(9), RBC ml, Plt x 10(11) yields/collection were 183, 21.2, 14, 0.8, respectively, for STD vs. 307, 22.1, 11, 1.0, respectively, for LVL. For >35 K, median CD34+ x 10(6), WBC x 10(9), RBC ml, Plt x 10(11) yields/collection were 189, 32.7, 15, 1.4, respectively, for STD vs. 69, 40.8, 21, 1.3, respectively, for LVL. We have described a method of LVL using the Amicus that, in patients with pre-procedure WBC < or =35 x 10(9)/L, collects more CD34+ cells than a standard procedure with acceptable cross-cellular content. This method is not recommended when pre-procedure WBC counts are >35 x 10(9)/L.

  10. Lobe Emplacement of a Large-Volume, Evolved lava flow: Large-scale Pahoehoe

    NASA Astrophysics Data System (ADS)

    Semple, A. M.; Gregg, T.; Bonnichsen, B.; Godchaux, M.

    2006-12-01

    The Bruneau-Jarbidge eruptive center (BJEC) in southwestern Idaho is responsible for more than 10 large- volume lava flows ranging from a few km3 to > 200 km3. These Miocene flows have high SiO2 contents of between 70 and 75 wt% and range in thickness from a few tens of meters to 200 m thick. Well exposed in deep canyon walls, these flows typically display massive, columnar jointed interiors which give way to marginal outcrops with more lobate upper surfaces and more irregular jointing. Also observed at the most distal reaches are sub-circular shaped outcrops about 6 15 m across exposed in the canyon walls. These sub-circular outcrops display a specific jointing pattern, and are inferred to be the cross- section of individual flow lobes. These lobes tend to display a massive exterior rind of 1 1.5 m thickness with crude jointing perpendicular to the outside. Inside this massive exterior is an area of densely jointed rock, where the joints are roughly concentric to the exterior rind and are 1 4 cm thick. Not always present is a massive center that has crude radial jointing. This pattern of jointing probably results from the passage of the rhyolite lavas under a solidified carapace, with the sub-concentric jointing caused by lava shearing between the mobile lobe interior and the exterior carapace. In this way, the emplacement of these lavas appears to be similar to that of pahoehoe, in which lava advances by lobes or toes protruding from the flow front and there is coalescence of the flow lobes in the flow interior.

  11. Geochemical correlation of three large-volume ignimbrites from the Yellowstone hotspot track, Idaho, USA

    NASA Astrophysics Data System (ADS)

    Ellis, Ben S.; Branney, M. J.; Barry, T. L.; Barfod, D.; Bindeman, I.; Wolff, J. A.; Bonnichsen, B.

    2012-01-01

    Three voluminous rhyolitic ignimbrites have been identified along the southern margin of the central Snake River Plain. As a result of wide-scale correlations, new volume estimates can be made for these deposits: ~350 km3 for the Steer Basin Tuff and Cougar Point Tuff XI, and ~1,000 km3 for Cougar Point Tuff XIII. These volumes exclude any associated regional ashfalls and correlation across to the north side of the plain, which has yet to be attempted. Each correlation was achieved using a combination of methods including field logging, whole rock and mineral chemistry, magnetic polarity, oxygen isotope signature and high-precision 40Ar/39Ar geochronology. The Steer Basin Tuff, Cougar Point Tuff XI and Cougar Point Tuff XIII have deposit characteristics typical of `Snake River (SR)-type' volcanism: they are very dense, intensely welded and rheomorphic, unusually well sorted with scarce pumice and lithic lapilli. These features differ significantly from those of deposits from the better-known younger eruptions of Yellowstone. The ignimbrites also exhibit marked depletion in δ18O, which is known to characterise the SR-type rhyolites of the central Snake River Plain, and cumulatively represent ~1,700 km3 of low δ18O rhyolitic magma (feldspar values 2.3-2.9‰) erupted within 800,000 years. Our work reduces the total number of ignimbrites recognised in the central Snake River Plain by 6, improves the link with the ashfall record of Yellowstone hotspot volcanism and suggests that more large-volume ignimbrites await discovery through detailed correlation work amidst the vast ignimbrite record of volcanism in this bimodal large igneous province.

  12. [Determination of Pb and Cd in atomospheric particulates by flame atomic absorption spectrometry coupled with on-line flow injection pretreatment with ultrasonic leaching].

    PubMed

    Gao, Yan; Wang, Dong-hai; Lin, Yu-bin; Li, Jian-yi; Kong, Qing-zhen

    2003-04-01

    In this paper, the method for extracting the metals from the filter membrane of the atomospheric particulates with ultrasonic leaching was reported. The dissolution conditions of kinds and acidity as well as the interference conditions were studied. The method of determination Pb and Cd of the atomospheric particulates by flame atomic absorption spectrometry coupled with on-line flow injection preconcentration was proved to be rapid and accuracy. The recoveries are more than 97%. The relative standard deviation of six samples are less than 2.6%.

  13. On Application of Analytical Model for Drain-Coupling Split-Gate Flash: Analytical Solution to Source-Side Injection Multilevel Programming

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Hsiung; Wu, Meng-Chyi; Chu, Wen-Ting; Lin, Chrong-Jong; Lin, Yung-Tao; Wang, Chung S.

    2006-01-01

    In this paper, we present an analytical solution for evaluating the ramped-pulse programming behaviors of the drain-coupling source-side injection split-gate flash for multilevel charge storage. Starting with the programming model, the relations of the storage charge, read current and peak lateral field to the ramped-pulse programming time are analytically expressed as functions of electrical, technological and physical parameters and agree well with experimental results. The program speed and program accuracy, including the effects of electrical bias and process variations, are analytically estimated.

  14. Current-injection two-color lasing in a wafer-bonded coupled multilayer cavity with InGaAs multiple quantum wells

    NASA Astrophysics Data System (ADS)

    Minami, Yasuo; Ota, Hiroto; Lu, Xiangmeng; Kumagai, Naoto; Kitada, Takahiro; Isu, Toshiro

    2017-04-01

    Current-injection two-color lasing has been demonstrated using a GaAs/AlGaAs coupled multilayer cavity that is a good candidate for novel terahertz-emitting devices based on difference-frequency generation (DFG) inside the structure. The coupled cavity structure was fabricated by the direct wafer bonding of (001)- and (113)B-oriented epitaxial wafers for the efficient DFG of two modes in the (113)B side cavity, and two types of InGaAs multiple quantum wells (MQWs) were introduced only in the (001) side cavity as optical gain materials. The threshold behavior was clearly observed in the current–light output curve even at room temperature. Two-color lasing was successfully observed when the gain peaks of MQWs were considerably tuned to the cavity modes by the operating temperature.

  15. Effect of filtration rates on hollow fiber ultrafilter concentration of viruses and protozoans from large volumes of water

    EPA Science Inventory

    Aims: To describe the ability of tangential flow hollow-fiber ultrafiltration to recover viruses from large volumes of water when run either at high filtration rates or lower filtration rates and recover Cryptosporidium parvum at high filtration rates. Methods and Results: Wate...

  16. Effect of filtration rates on hollow fiber ultrafilter concentration of viruses and protozoans from large volumes of water

    EPA Science Inventory

    Aims: To describe the ability of tangential flow hollow-fiber ultrafiltration to recover viruses from large volumes of water when run either at high filtration rates or lower filtration rates and recover Cryptosporidium parvum at high filtration rates. Methods and Results: Wate...

  17. Effect of sperm DNA fragmentation on clinical outcomes for Chinese couples undergoing in vitro fertilization or intracytoplasmic sperm injection.

    PubMed

    Xue, Lin-Tao; Wang, Rui-Xue; He, Bing; Mo, Wei-Ying; Huang, Li; Wang, Shi-Kai; Mao, Xian-Bao; Cheng, Jun-Ping; Huang, Yue-Yue; Liu, RuiZhi

    2016-12-01

    Objective To investigate the effect of sperm DNA fragmentation on the fertilization rate, embryo development and pregnancy outcome of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in a cohort of Chinese couples. Methods Infertile couples that had undergone assisted reproductive technology at our centre between January 2011 and December 2013 were included in this retrospective study. Fractions of prepared sperm samples were evaluated for sperm DNA fragmentation on the day of oocyte recovery. Results Of the 550 couples selected, 415 had undergone IVF and 135 ICSI. Sperm DNA fragmentation rate was significantly negatively correlated with the fertilization rate in the ICSI cycles but not the IVF cycles. No association was found between sperm DNA fragmentation and cleavage rate or good quality embryo formation rates in IVF or ICSI cycles. Receiver operating characteristic (ROC) curve analysis showed that the sperm DNA fragmentation rate was a statistically significant prognostic indicator of the clinical fertilization rate in ICSI cycles; a rate > 22.3% was associated with a lower fertilization rate following ICSI compared with a rate ≤ 22.3%. Conclusions High values of sperm DNA fragmentation were associated with a low fertilization rate following ICSI but were not associated with alterations in pregnancy or live birth rates in either ICSI or IVF in this cohort of Chinese couples.

  18. The Use of Cryogenically Cooled 5A Molecular Sieves for Large Volume Reduction of Tritiated Hydrogen Gas

    SciTech Connect

    Antoniazzi, A.B.; Bartoszek, F.E.; Sherlock, A.M.

    2006-07-01

    A commercial hydrogen isotope separation system based on gas chromatography (AGC-ISS) has been built. The system operates in two modes: stripping and volume reduction. The purpose of the stripping mode is to reduce a large volume of tritiated hydrogen gas to a small volume of tritium rich hydrogen gas. The results here illustrate the effectiveness of the AGC-ISS in the stripping and volume reduction phases. Column readiness for hydrogen isotope separation is confirmed by room temperature air separation tests. Production runs were initially carried out using natural levels of deuterium (110-160 ppm) in high purity hydrogen. After completion of the deuterium/hydrogen runs the system began operations with tritiated hydrogen. The paper presents details of the AGC-ISS design and results of tritium tests. The heart of the AGC-ISS consists of two packed columns (9 m long, 3.8 cm OD) containing 5A molecular sieve material of 40/60 mesh size. Each column has 5 individually controlled heaters along the length of the column and is coiled around an inverted inner dewar. The coiled column and inner dewar are both contained within an outer dewar. In this arrangement liquid nitrogen, used to cryogenically cool the columns, flows into and out off the annular space defined by the two dewars, allowing for alternate heating and cooling cycles. Tritiated hydrogen feed is injected in batch quantities. The batch size is variable with the maximum quantity restricted by the tritium concentration in the exhausted hydrogen. The stripping operations can be carried out in full automated mode or in full manual mode. The average cycle time between injections is about 75 minutes. To date, the maximum throughput achieved is 10.5 m{sup 3}/day. A total of 37.8 m{sup 3} of tritiated hydrogen has been processed during commissioning. The system has demonstrated that venting of >99.95% of the feed gas is possible while retaining 99.98% of the tritium. At a maximum tritium concentration of {approx}7 GBq

  19. Intracellular injections of lucifer yellow into lightly fixed mitral cells reveal neuronal dye-coupling in the developing rat olfactory bulb.

    PubMed

    Paternostro, M A; Reyher, C K; Brunjes, P C

    1995-01-14

    We report that intracellular injections of Lucifer Yellow into lightly fixed mitral cells revealed dye-coupling between mitral cells and between mitral and granule cells in the form of discrete, radially oriented cell clusters. Dye-coupling was observed in animals as early as postnatal day 10 (P10) and at least until P30. In P10 rats, a mean of 2.5 dye-coupled mitral cells and 27 granule cells were observed per column. Mean column depth and width were 169 microns and 86 microns respectively. Most of the dye-filled granule cells were found within 150 microns of the mitral cell layer. No significant changes were found at P20. By P30, the mean number of granule cells per column increased to 42 and the addition of granule cells occurred in areas proximal to the mitral cell layer. Immunocytochemical results indicate that the developing bulb contains a large concentration of the gap junction protein Connexin 43 (Cx43). Cx43-like immunoreactivity was found at all ages examined, with the most intense staining in the nerve and glomerular layers. Less intense Cx43-like immunoreactivity was found in both the mitral and granule cell layers, with Cx43-like immunoreactive puncta observed between and around cell body profiles. Freeze-fracture analysis revealed the presence of gap junction-like plaques on mitral cells, further suggesting that the dye-coupling occurred across interneuronal gap junctions. Neuronal coupling during development could provide an inter-cellular pathway for the passage of relevant developmental signals which could influence the formation and/or strengthening of synaptic contacts. The coupling could also be involved in the synchronization of neuronal activity, which may be important for olfactory coding.

  20. GMP Cryopreservation of Large Volumes of Cells for Regenerative Medicine: Active Control of the Freezing Process

    PubMed Central

    Massie, Isobel; Selden, Clare; Hodgson, Humphrey; Gibbons, Stephanie; Morris, G. John

    2014-01-01

    μg/mL/24 h were obtained which, compared well with control ELS (viability −98.1%±0.9%; viable cell numbers −18.3±1.0 million nuclei/mL alginate; and protein secretion −18.7±1.8 μg/mL/24 h). Large volume GMP cryopreservation of ELS is possible with good functional recovery using the VIA Freeze and may also be applied to other regenerative medicine applications. PMID:24410575

  1. GMP cryopreservation of large volumes of cells for regenerative medicine: active control of the freezing process.

    PubMed

    Massie, Isobel; Selden, Clare; Hodgson, Humphrey; Fuller, Barry; Gibbons, Stephanie; Morris, G John

    2014-09-01

    μg/mL/24 h were obtained which, compared well with control ELS (viability -98.1% ± 0.9%; viable cell numbers -18.3 ± 1.0 million nuclei/mL alginate; and protein secretion -18.7 ± 1.8 μg/mL/24 h). Large volume GMP cryopreservation of ELS is possible with good functional recovery using the VIA Freeze and may also be applied to other regenerative medicine applications.

  2. Pathways of deep cyclones associated with large volume changes (LVCs) and major Baltic inflows (MBIs)

    NASA Astrophysics Data System (ADS)

    Lehmann, Andreas; Höflich, Katharina; Post, Piia; Myrberg, Kai

    2017-03-01

    Large volume changes (LVCs) and major Baltic inflows (MBIs) are essential processes for the water exchange and renewal of the stagnant water in the Baltic Sea deep basins. These strong inflows are known to be forced by persistent westerly wind conditions. In this study, MBIs are considered as subset of LVCs transporting with the large water volume a big amount of highly saline and oxygenated water into the Baltic Sea. Since the early 1980s the frequency of MBIs has dropped drastically from 5 to 7 events to only one inflow per decade, and long lasting periods without MBIs became the usual state. Only in January 1993, 2003 and December 2014 MBIs occurred that were able to interrupt the stagnation periods in the deep basins of the Baltic Sea. However, in spite of the decreasing frequency of MBIs, there is no obvious decrease of LVCs. The Landsort sea level is known to reflect the mean sea level of the Baltic Sea very well, and hence LVCs have been calculated for the period 1887-2015 filtering daily time series of Landsort sea surface elevation anomalies. The cases with local minimum and maximum difference resulting in at least 60 km3 of water volume change excluding the volume change due to runoff have been chosen for a closer study (1948-2013) of characteristic pathways of deep cyclones. The average duration of LVCs is about 40 days. During this time, 5-6 deep cyclones move along characteristic storm tracks. Furthermore, MBIs are characterized by even higher cyclonic activity compared to average LVCs. We obtained four main routes of deep cyclones which were associated with LVCs, but also with the climatology. One is approaching from the west at about 56-60°N, passing the northern North Sea, northern Denmark, Sweden and the Island of Gotland. A second broad corridor of frequent cyclone pathways enters the study area north of Scotland between 60 and 66°N turning north-eastwards along the northern coast of Scandinavia. This branch bifurcates into smaller routes. One

  3. 3D porous sol-gel matrix incorporated microdevice for effective large volume cell sample pretreatment.

    PubMed

    Lee, Chan Joo; Jung, Jae Hwan; Seo, Tae Seok

    2012-06-05

    In this study, we demonstrated an effective sample pretreatment microdevice that could perform the capture, purification, and release of pathogenic bacteria with a large-volume sample and at a high speed and high-capture yield. We integrated a sol-gel matrix into the microdevice which forms three-dimensional (3D) micropores for the cell solution to pass through and provides a large surface area for the immobilization of antibodies to capture the target Staphylococcus aureus (S. aureus) cells. The antibody was linked to the surface of the sol-gel via a photocleavable linker, allowing the cell-captured antibody moiety to be released by UV irradiation. In addition to the optimization of the antibody immobilization and UV cleavage processes, the cell-capture efficiency was maximized by controlling the sample flow rate with a pumping scheme (3 steps, 5 steps: 3 steps with one flutter step, 7 steps: 3 steps with two flutter steps) and the pumping time (100, 200, and 300 ms). A quantitative capture analysis was performed by targeting a specific gene site of protein A of S. aureus in real-time PCR (RT-PCR). While the 3-step process with an actuation time of 100 ms showed the fastest flow rate (1 mL sample processing time in 10 min), the pumping scheme with the 7-step process and the 300 ms actuation time revealed the highest cell-capture efficiency. A limit of detection study with the 7-step and the 300 ms pumping scheme demonstrated that 100 cells per 100 μL were detected with a 70% yield, and even a single cell could be analyzed via on-chip sample preparation. Thus, our novel sol-gel based microdevice was proven more cost-effective, simple, and efficient in terms of its sample pretreatment ability compared to the use of a conventional 2D flat microdevice. This proposed sample pretreatment device can be further incorporated to an analytical functional unit to realize a micrototal analysis system (μTAS) with sample-in-answer-out capability in the fields of biomedical

  4. Process Improvement to Enhance Quality in a Large Volume Labor and Birth Unit.

    PubMed

    Bell, Ashley M; Bohannon, Jessica; Porthouse, Lisa; Thompson, Heather; Vago, Tony

    using the Lean process, frontline clinicians identified areas that needed improvement, developed and implemented successful strategies that addressed each gap, and enhanced the quality and safety of care for a large volume perinatal service.

  5. Coupled reservoir-geomechanical analysis of the potential fortensile and shear failure associated with CO2 injection in multilayeredreservoir-caprock systems

    SciTech Connect

    Rutqvist, J.; Birkholzer, J.T.; Tsang, C.-F.

    2007-03-27

    Coupled reservoir-geomechanical simulations were conductedto study the potential for tensile and shear failure e.g., tensilefracturing and shear slip along pre-existing fractures associated withunderground CO2 injection in a multilayered geological system. Thisfailure analysis aimed to study factors affecting the potential forbreaching a geological CO2 storage system and to study methods forestimating the maximum CO2 injection pressure that could be sustainedwithout causing such a breach. We pay special attention to geomechanicalstress changes resulting from upward migration of the CO2 and how theinitial stress regime affects the potential for inducing failure. Weconclude that it is essential to have an accurate estimate of thethree-dimensional in situ stress field to support the design andperformance assessment of a geological CO2 injection operation. Moreover,we also conclude that it is important to consider mechanical stresschanges that might occur outside the region of increased reservoir fluidpressure (e.g., in the overburden rock) between the CO2-injectionreservoir and the ground surface.

  6. Injection-port derivatization coupled to GC-MS/MS for the analysis of glycosylated and non-glycosylated polyphenols in fruit samples.

    PubMed

    Marsol-Vall, Alexis; Balcells, Mercè; Eras, Jordi; Canela-Garayoa, Ramon

    2016-08-01

    Polyphenols, including glycosylated polyphenols, were analyzed via a procedure based on injection-port derivatization coupled to gas chromatography-tandem mass spectrometry (GC-MS/MS). The polyphenols in lyophilized fruit samples were extracted with an acidified MeOH mixture assisted by ultrasound. Samples were dried under vacuum, and carbonyl groups were protected with methoxylamine. Free hydroxyl groups were subsequently silylated in-port. Mass fragmentations of 17 polyphenol and glycosylated polyphenol standards were examined using Multiple Reaction Monitoring (MRM) as the acquisition mode. Furthermore, in-port derivatization was optimized in terms of optimal injection port temperature, derivatization time and sample: N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) volume ratio. A C18 solid-phase-extraction clean-up method was used to reduce matrix effects and injection liner degradation. Using this clean-up method, recoveries for samples spiked at 1 and 10μg/g ranged from 52% to 98%, depending on the chemical compound. Finally, the method was applied to real fruit samples containing the target compounds. The complete chromatographic runtime was 15min, which is faster than reported for recent HPLC methods able to analyze similar compounds.

  7. Method for the quantification of vanadyl porphyrins in fractions of crude oils by High Performance Liquid Chromatography-Flow Injection-Inductively Coupled Plasma Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Wandekoken, Flávia G.; Duyck, Christiane B.; Fonseca, Teresa C. O.; Saint'Pierre, Tatiana D.

    2016-05-01

    High performance liquid chromatography hyphenated by flow injection to inductively coupled plasma mass spectrometry (HPLC-FI-ICP-MS) was used to investigate V linked to porphyrins present in fractions of crude oil. First, the crude oil sample was submitted to fractionation by preparative liquid chromatography with UV detection, at the porphyrin Soret band wavelength (400 nm). The obtained porphyrin fractions were then separated in a 250 mm single column, in the HPLC, and eluted with different mobile phases (methanol or methanol:toluene (80:20; v:v)). The quantification of V-porphyrins in the fractions eluted from HPLC was carried out by online measuring the 51V isotope in the ICP-MS, against vanadyl octaethylporphine standard solutions (VO-OEP), prepared in the same solvent as the mobile phase, and injected post-column directly into the plasma. A 20 μg L- 1 Ge in methanol was used as internal standard for minimizing non-spectral interference, such as short-term variations due to injection. The mathematical treatment of the signal based on Fast Fourier Transform smoothing algorithm was employed to improve the precision. The concentrations of V as V-porphyrins were between 2.7 and 11 mg kg- 1 in the fractions, which were close to the total concentration of V in the porphyrin fractions of the studied crude oil.

  8. PBPC collection techniques: standard versus large volume leukapheresis (LVL) in donors and in patients.

    PubMed

    Gasová, Zdenka; Marinov, Iuri; Vodvárková, Sárka; Böhmová, Martina; Bhuyian-Ludvíková, Zdenka

    2005-04-01

    Transplantations of autologous and allogeneic peripheral blood progenitor cells (PBPC) are able to assure a complete hematopoietic and immunologic reconstitution in patients. PBPC are collected by leukapheresis technique after prior mobilization therapy, but procedures and results remain still highly variable and are poorly characterized. An optimum regimen for PBPC collections has not yet been recommended, but 2-3 total blood volumes (TBV) of the donor or patient are regarded as a standard. Another promising technique is large volume leukapheresis (LVL) with processing of 3-6 TBV of donor or patient. The aim of this paper is to find the most efficient and safe collection technique for an individual donor or patient and, consequently minimize the number of procedures required. Finding the optimal collection procedure would be helpful while considering which method would be preferred in an individual donor or patient with respect to the result of mobilization, health state and required yield of CD 34+ cells for transplantation. We evaluated the results in a total of 134 standard and LVL procedures, which were performed in 21 well mobilized donors (Group I), in 65 well mobilized patients (Group II), and in 14 weakly mobilized patients (Group III) with hemato-oncological diseases. A precollection concentration of CD 34+ cells in peripheral blood higher than 20 x 10(3)/mL was considered to be the criterion for efficient mobilization. Such levels of concentration indicating the start of PBPC collections could be easily reached in Group I of donors and Group II of well mobilized patients. Heavily pretreated patients at advanced stages of disease (Group III) did not respond to mobilization sufficiently and had a concentration of CD 34+ cells lower than 20x10(3)/mL. LVL technique made it possible to obtain higher numbers of CD 34+ cells than in the standard collection in well mobilized donors (Group I), well mobilized patients (Group II), and even in weakly mobilized

  9. A novel CE microchip with micro pillars column & double-L injection design for Capacitance Coupled Contactless Conductivity detection technology

    NASA Astrophysics Data System (ADS)

    Wang, Yineng; Messina, Walter; Cao, Xi; Hogan, Anna; van Zalen, Ed; Moore, Eric

    2016-10-01

    This novel capillary electrophoresis microchip, or also known as μTAS (micro total analysis system) was designed to separate complex aqueous based compounds, similar to commercial CE & microchip (capillary electrophoresis) systems, but more compact. This system can be potentially used for mobile/portable chemical analysis equipment. Un-doped silicon wafer & ultra-thin borofloat glass (Pyrex) wafers have been used to fabricate the device. Double-L injection feature, micro pillars column, bypass separation channel & hybrid- referenced C4D electrodes were designed to achieve a high SNR (signal to noise ratio), easy- separation, for a durable and reusable μTAS for CE use.

  10. Fabrics, Facies And Flow Through A Large-Volume Ignimbrite: Pampa De Oxaya, Chile.

    NASA Astrophysics Data System (ADS)

    Platzman, Ellen; Cooper, Frances

    2016-04-01

    Large volume pyroclastic currents form during some of the most destructive volcanic eruptions on the planet, yet because they are underrepresented in the geological record they remain poorly understood. The Miocene Oxaya ignimbrites, exposed along the western Andean slopes in northern Chile, form one of the largest ignimbrite provinces on earth. We use anisotropy of magnetic susceptibility (AMS) in conjunction with rock magnetic measurements to investigate flow behavior and depositional processes in one of the largest members of the Oxaya succession, the Cardones ignimbrite. Despite its prominence the location of the source caldera remains unknown and fundamental processes remain poorly constrained. During 2012 nearly 8km (7,773m) of core was recovered from the early Miocene ignimbrites in 11 holes at elevations ranging from 2336m to 3805m along the Andean escarpment east of Arica, Chile. The drill cores are remarkable in that they penetrate through the entirety of the ignimbrite sequence and into the basement below. Samples for this study were collected from a > 1 km long core drilled at an altitude 3692m. The core sampled 981 m of Cardones ignimbrite and 15 m of underlying sediments and volcaniclastics before penetrating 148 m of basement. Detailed measurements of the variation in bulk magnetic properties including natural remanent magnetization (NRM), susceptibility, ARM, and IRM, were used to monitor changes in concentration, composition and grainsize of the magnetic components though the ignimbrite. AMS in conjunction with detailed rock magnetic measurements were used to constrain flow processes. The data reveal a well-defined flow direction and systematic variations in flow processes with depth. Low field bulk magnetic susceptibility averages 3.2x10-3 SI. Rock magnetic studies and petrographic examination indicate that magnetite is likely to be the dominant magnetic phase although paramagnetic mineral phases also contribute to the magnetic fabric. The degree

  11. The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate

    USGS Publications Warehouse

    Maughan, L.L.; Christiansen, E.H.; Best, M.G.; Gromme, C.S.; Deino, A.L.; Tingey, D.G.

    2002-01-01

    Unusual monotonous intermediate ignimbrites consist of phenocryst-rich dacite that occurs as very large volume (> 1000 km3) deposits that lack systematic compositional zonation, comagmatic rhyolite precursors, and underlying plinian beds. They are distinct from countless, usually smaller volume, zoned rhyolite-dacite-andesite deposits that are conventionally believed to have erupted from magma chambers in which thermal and compositional gradients were established because of sidewall crystallization and associated convective fractionation. Despite their great volume, or because of it, monotonous intermediates have received little attention. Documentation of the stratigraphy, composition, and geologic setting of the Lund Tuff - one of four monotonous intermediate tuffs in the middle-Tertiary Great Basin ignimbrite province - provides insight into its unusual origin and, by implication, the origin of other similar monotonous intermediates. The Lund Tuff is a single cooling unit with normal magnetic polarity whose volume likely exceeded 3000 km3. It was emplaced 29.02 ?? 0.04 Ma in and around the coeval White Rock caldera which has an unextended north-south diameter of about 50 km. The tuff is monotonous in that its phenocryst assemblage is virtually uniform throughout the deposit: plagioclase > quartz ??? hornblende > biotite > Fe-Ti oxides ??? sanidine > titanite, zircon, and apatite. However, ratios of phenocrysts vary by as much as an order of magnitude in a manner consistent with progressive crystallization in the pre-eruption chamber. A significant range in whole-rock chemical composition (e.g., 63-71 wt% SiO2) is poorly correlated with phenocryst abundance. These compositional attributes cannot have been caused wholly by winnowing of glass from phenocrysts during eruption, as has been suggested for the monotonous intermediate Fish Canyon Tuff. Pumice fragments are also crystal-rich, and chemically and mineralogically indistinguishable from bulk tuff. We

  12. Nonmedical-grade Injections of Permanent Fillers

    PubMed Central

    Bayers, Stephanie; Beer, Michael; Beer, Kenneth

    2013-01-01

    Silicone injections may result in complications that bring patients to a dermatologist or plastic surgeon. These complications may be due to the use of nonmedical grade products, large volume injections, incorrect placement of the product, or a combination of the above. Frequently, complications result when injections are performed by unlicensed practitioners. Individuals who undergo large volume procedures may develop a variety of life-threatening problems ranging from infections to pulmonary emboli. Once they develop problems, these patients often present to licensed and board-certified physicians for treatment. Based on a review of the literature, this article provides a management algorithm for various complications. In addition, a medicolegal perspective is presented. Finally, the transgender experience as it relates to silicone injections is also reviewed. PMID:23630638

  13. Automated sample preparation coupled to sequential injection chromatography: on-line filtration and dilution protocols prior to separation.

    PubMed

    Zacharis, Constantinos K; Verdoukas, Aspasia; Tzanavaras, Paraskevas D; Themelis, Demetrius G

    2009-04-05

    Sequential injection chromatography (SIC) is a valuable tool in analytical chemistry as it can combine the automation capabilities of low pressure continuous flow techniques and the separation power of HPLC into a single instrumental configuration. The present study reports an automated SI setup allowing on-line filtration and dilution of the samples before separation through a short monolithic column. The applicability of the procedure was evaluated by studying the behavior of acyclovir formulations under forced degradation conditions. Minimal sample preparation is required prior to analysis. Thorough validation of the on-line dilution SIC assay was carried out and proved its validity in terms of critical parameters such as precision, accuracy and robustness. The results were evaluated by parallel experiments and analysis using the procedure recommended by the USP based on conventional HPLC using particulate-based column.

  14. A computer-assisted metal analyser using flow injection coupled with direct current plasma–optical emission spectroscopy

    PubMed Central

    Brennan, M. C.; Simons, R. A.; Svehla, G.; Stockwell, P. B.

    1990-01-01

    An automated routine method was developed for the determination of trace metals using a flow injection system into a direct current plasma spectrometer. The characteristic emission in the ‘Spectra- Metrics’ three-electrode jet is channelled through an echelle grating to the detector of the instrument. The emission signal is continuously recorded, and, after digitalization, calculated and recorded by a Touchstone software package and interface card. The software has facilities for recording peaks, generating calibration curves, calculating and printing results, enhancing line sensitivities, monitoring signal response and for filter noise, recalibration, background correction, status monitoring and general diagnostics. Up to 70 elements can be determined both in aqueous and non-aqueous media. PMID:18925272

  15. Patient-specific quality assurance for spot scanning proton beams using a large-volume liquid scintillator detector

    NASA Astrophysics Data System (ADS)

    Robertson, D.; Beddar, S.

    2017-05-01

    A large-volume liquid scintillator detector was used to measure individual energy layers from a clinical prostate treatment plan on a scanning proton beam system. Lateral and beam’s-eye view images of the dose distribution were acquired with two CCD cameras facing adjacent sides of a scintillator tank. The measured dose images were compared with calculated dose distributions from a validated Monte Carlo model. The measured and calculated dose distributions showed good agreement, with the exception of the Bragg peak region of the lateral view, which exhibited ionization quenching. The beam’s-eye and lateral views achieved gamma analysis passing rates of 99.7% and 92.5%, respectively, using gamma criteria of 3%, 3 mm. Large-volume scintillator detectors show promise for quick and accurate measurements of patient treatment fields for scanning proton beam systems.

  16. Large Volume Coagulation Utilizing Multiple Cavitation Clouds Generated by Array Transducer Driven by 32 Channel Drive Circuits

    NASA Astrophysics Data System (ADS)

    Nakamura, Kotaro; Asai, Ayumu; Sasaki, Hiroshi; Yoshizawa, Shin; Umemura, Shin-ichiro

    2013-07-01

    High-intensity focused ultrasound (HIFU) treatment is a noninvasive treatment, in which focused ultrasound is generated outside the body and coagulates a diseased tissue. The advantage of this method is minimal physical and mental stress to the patient, and the disadvantage is the long treatment time caused by the smallness of the therapeutic volume by a single exposure. To improve the efficiency and shorten the treatment time, we are focusing attention on utilizing cavitation bubbles. The generated microbubbles can convert the acoustic energy into heat with a high efficiency. In this study, using the class D amplifiers, which we have developed, to drive the array transducer, we demonstrate a new method to coagulate a large volume by a single HIFU exposure through generating cavitation bubbles distributing in a large volume and vibrating all of them. As a result, the coagulated volume by the proposed method was 1.71 times as large as that of the conventional method.

  17. Design and Analysis of A Beacon-Less Routing Protocol for Large Volume Content Dissemination in Vehicular Ad Hoc Networks

    PubMed Central

    Hu, Miao; Zhong, Zhangdui; Ni, Minming; Baiocchi, Andrea

    2016-01-01

    Large volume content dissemination is pursued by the growing number of high quality applications for Vehicular Ad hoc NETworks(VANETs), e.g., the live road surveillance service and the video-based overtaking assistant service. For the highly dynamical vehicular network topology, beacon-less routing protocols have been proven to be efficient in achieving a balance between the system performance and the control overhead. However, to the authors’ best knowledge, the routing design for large volume content has not been well considered in the previous work, which will introduce new challenges, e.g., the enhanced connectivity requirement for a radio link. In this paper, a link Lifetime-aware Beacon-less Routing Protocol (LBRP) is designed for large volume content delivery in VANETs. Each vehicle makes the forwarding decision based on the message header information and its current state, including the speed and position information. A semi-Markov process analytical model is proposed to evaluate the expected delay in constructing one routing path for LBRP. Simulations show that the proposed LBRP scheme outperforms the traditional dissemination protocols in providing a low end-to-end delay. The analytical model is shown to exhibit a good match on the delay estimation with Monte Carlo simulations, as well. PMID:27809285

  18. Design and Analysis of A Beacon-Less Routing Protocol for Large Volume Content Dissemination in Vehicular Ad Hoc Networks.

    PubMed

    Hu, Miao; Zhong, Zhangdui; Ni, Minming; Baiocchi, Andrea

    2016-11-01

    Large volume content dissemination is pursued by the growing number of high quality applications for Vehicular Ad hoc NETworks(VANETs), e.g., the live road surveillance service and the video-based overtaking assistant service. For the highly dynamical vehicular network topology, beacon-less routing protocols have been proven to be efficient in achieving a balance between the system performance and the control overhead. However, to the authors' best knowledge, the routing design for large volume content has not been well considered in the previous work, which will introduce new challenges, e.g., the enhanced connectivity requirement for a radio link. In this paper, a link Lifetime-aware Beacon-less Routing Protocol (LBRP) is designed for large volume content delivery in VANETs. Each vehicle makes the forwarding decision based on the message header information and its current state, including the speed and position information. A semi-Markov process analytical model is proposed to evaluate the expected delay in constructing one routing path for LBRP. Simulations show that the proposed LBRP scheme outperforms the traditional dissemination protocols in providing a low end-to-end delay. The analytical model is shown to exhibit a good match on the delay estimation with Monte Carlo simulations, as well.

  19. Spirometry with bronchodilator test: effect that the use of large-volume spacers with antistatic treatment has on test response.

    PubMed

    Araújo, Flávia de Barros; Corrêa, Ricardo de Amorim; Pereira, Luis Fernando Ferreira; Silveira, Carla Discacciati; Mancuso, Eliane Viana; Rezende, Nilton Alves de

    2011-01-01

    To evaluate whether the use of inhaled albuterol via a metered-dose inhaler with a large-volume spacer with antistatic treatment modifies the bronchodilator test results when compared with the usual technique (no spacer). A prospective study involving 24 patients, 18-45 years of age, clinically suspected of having asthma, and under treatment at the Outpatient Pulmonary Clinic of the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. All of the patients underwent two bronchodilator tests: one with and one without the use of a large-volume spacer. There was no significant difference in the variation of FEV1 prior to and after bronchodilator use between the two techniques (mean ΔFEV1 = 0.01 L; 95% CI: -0.05 to 0.06; p = 0.824). No statistically significant difference was found between the two techniques regarding the qualitative results on the bronchodilator test (p = 1.00). There was concordance between the techniques in terms of the bronchodilator test results (kappa coefficient = 0.909; p < 0.005). According to the results of this study, the use of large-volume spacers does not significantly modify bronchodilator test results.

  20. Mechanically Cooled Large-Volume Germanium Detector Systems for Nuclear Explosion Monitoring

    DTIC Science & Technology

    2007-09-01

    produced Stirling -cycle mechanical coolers provide the basis for this evolution. When properly instrumented, these systems can cool the very largest...as 50 K. The system is free of microphonic noise with the cooler operating at full power. The lower detector operating temperature, coupled with...570 cm3, ~ 3 kg, ~ 140 %, or larger) for field use in rugged conditions. A new generation of Stirling -cycle mechanical cooler is being used to reliably

  1. Characterization of Large Volume 3.5″ x 8″ LaBr3:Ce Detectors for the HECTOR+ array

    NASA Astrophysics Data System (ADS)

    Camera, F.; Giaz, A.; Pellegri, L.; Riboldi, S.; Blasi, N.; Boiano, C.; Bracco, A.; Brambilla, S.; Ceruti, S.; Coelli, S.; Crespi, F. C. L.; Csatlòs, M.; Krasznahorkay, A.; Gulyàs, J.; Lodetti, S.; Frega, S.; Miani, A.; Million, B.; Stuhl, L.; Wieland, O.

    2014-03-01

    A selection of the properties of large volume, cylindrical 3.5" x 8" LaBr3:Ce scintillation detectors coupled to a 3.5" PMT (model R10233-1000SEL from HAMAMATSU) and a special designed Voltage Divider (LABRVD) will be discussed. A number of 10 of such detectors constitute the HECTOR+ array which, in fall 2012, measured at GSI coupled to the AGATA DEMOSTRATOR at the PRESPEC experimental setup. These crystals are among the largest ever produced and needed to be characterized. We have performed several tests and here we discuss, in particular, the energy resolution measured using monochromatic γ-ray sources and in-beam reactions producing γ-rays up to 22.6 MeV. As already measured in two previous works a saturation in the energy resolution was observed in case of high energy gamma rays. Crystal non-homogeneities and PMT gain drifts can affect the resolution of measurements especially in case of high energy γ-rays.

  2. Flow Injection Analysis Coupled with Carbon Electrodes as the Tool for Analysis of Naphthoquinones with Respect to Their Content and Functions in Biological Samples

    PubMed Central

    Babula, Petr; Huska, Dalibor; Hanustiak, Pavel; Baloun, Jiri; Krizkova, Sona; Adam, Vojtech; Hubalek, Jaromir; Havel, Ladislav; Zemlicka, Milan; Horna, Ales; Beklova, Miroslava; Kizek, Rene

    2006-01-01

    Naphthoquinones are one of the groups of secondary metabolites widespread in nature, where they mostly appear as chromatic pigments. They embody broad-range of biological actions from phytotoxic to fungicidal. An anticancer effect of naphthoquinones stimulates an interest in determination and characterization of single derivatives of 1,2- and 1,4-quinones in biological samples. The main aim of this work was to suggest a technique suitable to determine lawsone, juglone and/or plumbagin in biological samples and to study of their influence on BY-2 tobacco cells. The BY-2 tobacco cells were cultivated in the presence of the naphthoquinones of interest (500 μg.l-1) for 24 h and then the morphological changes were observed. We found out that naphthoquinones triggered the programmed cell death at BY-2 cells, which can be confirmed by the apoptotic bodies in nucleus. After that we suggested and optimized different electrochemical techniques such differential pulse voltammetry (DPV) coupled with hanging mercury drop (HMDE) and carbon paste electrode, micro flow device coupled with carbon screen printed electrodes and flow injection analysis coupled with Coulochem III detector to determine them. The detection limits of naphthoquinones of interest were expressed as 3S/N and varied from units to hundreds of ng per millilitres according to methods used. Moreover, we utilized DPV coupled with HMDE and micro flow device to determine content of juglone in leaves Persian walnut (Juglans regia). We determined that the leaves contained juglone tenths of g per 100 g of fresh weight. The results obtained show the convincing possibilities of using of these methods in analysis of plant secondary metabolites.

  3. Balancing Vibrations at Harmonic Frequencies by Injecting Harmonic Balancing Signals into the Armature of a Linear Motor/Alternator Coupled to a Stirling Machine

    NASA Technical Reports Server (NTRS)

    Holliday, Ezekiel S. (Inventor)

    2014-01-01

    Vibrations at harmonic frequencies are reduced by injecting harmonic balancing signals into the armature of a linear motor/alternator coupled to a Stirling machine. The vibrations are sensed to provide a signal representing the mechanical vibrations. A harmonic balancing signal is generated for selected harmonics of the operating frequency by processing the sensed vibration signal with adaptive filter algorithms of adaptive filters for each harmonic. Reference inputs for each harmonic are applied to the adaptive filter algorithms at the frequency of the selected harmonic. The harmonic balancing signals for all of the harmonics are summed with a principal control signal. The harmonic balancing signals modify the principal electrical drive voltage and drive the motor/alternator with a drive voltage component in opposition to the vibration at each harmonic.

  4. [On-line determination of niobium and tantalum in soil and geochemical exploration samples by inductively coupled plasma atomic emission spectrometry with solvent extraction flow injection].

    PubMed

    Ai, J; Tang, Z Y

    2001-10-01

    A new method for the determination of trace niobium and tantalum in soil and geochemical exploration samples by inductively coupled plasma atomic emission spectrometry with solvent extraction flow injection was proposed. The niobium and tantalum were extracted with the mixed solvent of MIBK and TBP at 1 mol.L-1 HF and 4 mol.L-1 H2SO4. Experiment conditions and manifold parameters were investigated in detail. The detection limits were 0.5 x 10(-12) g.L-1 and 0.8 x 10(-12) g.L-1. The proposed method was rapid, simple and accurate, it has been applied to the determination of trace niobium and tantalum in national standard samples. The results were in good agreement with certified values with precisions of 4.5% and 5.1% RSD (n = 10). The sample throughput for niobium and tantalum is 20.h-1.

  5. Management of Dupuytren contracture with ultrasound-guided lidocaine injection and needle aponeurotomy coupled with osteopathic manipulative treatment.

    PubMed

    Sampson, Steven; Meng, Michael; Schulte, Adam; Trainor, Drew; Montenegro, Roberto; Aufiero, Danielle

    2011-02-01

    Dupuytren contracture is a debilitating disease that characteristically presents as a firm nodularity on the palmar surface of the hand with coalescing cords of soft tissue on the webs and digits. With few nonsurgical modalities providing clinical benefits, open surgical procedures are the standard of care for patients with this condition. However, recent studies have associated surgical intervention with many complications, necessitating further exploration of nonsurgical treatment options. We describe the case of a 64-year-old woman who presented with decreased extension of the fourth and fifth digits on the upper extremities bilaterally; previous conservative treatment regimens had been unsuccessful. After a diagnostic ultrasound, the patient was diagnosed as having Dupuytren contracture and underwent 5 treatments consisting of ultrasound-guided dry-needle aponeurotomy, lidocaine injections, and osteopathic manipulative treatment. During the fifth treatment session, the patient experienced dramatic relief of her symptoms after a palpable release during the manual manipulation portion of her therapeutic regimen. At 2-week follow-up, the patient was symptom-free. Based on this desirable outcome, the authors suggest future research be directed at minimally invasive therapeutic options in the management of Dupuytren contracture.

  6. A simple crunching of the AGS 'bare' machine ORM data - February 2007 - to extract some aspects of AGS transverse coupling at injection and extraction

    SciTech Connect

    Ahrens, L.

    2010-11-01

    The objective of this note is to (once again) explore the AGS 'ORM' (orbit response matrix) data taken (by Operations) early during the 2007 run with an AGS bare machine and gold beam. Indeed the present motivation is to extract as much information about the AGS inherent transverse coupling as possible - from general arguments and the copious ORM data. And taking this one step further, (though not accomplished yet) the goal really should be to tell the model how to describe this coupling. 'Bare' as used here means the AGS with no quadrupole, sextupole or octupole magnets powered. Only the main (combined-function) magnet string and dipole bumps necessary to optimize beam survival are powered. 'ORM data' means the systematic recording of the equilibrium orbit beam position monitor response to powering individual dipole corrector magnets. The 'matrix' results from looking at the effect of each of the (12 superperiods X 4 dipoles per superperiod) 'kicks' on each of the (12 X 6) pick up electrodes (pues) in each transverse plane. So then we have two (48 X 72) matrices of numbers from the ORM data. (Though 'pue' usually refers to the hardware in the vacuum chamber and 'bpm' to the beam position monitoring system, the two labels will be used casually here.) The exercise is carried out at two magnet rigidities, injection (AGS field {approx}434 Gauss) and extraction to RHIC ({approx}9730 Gauss), - a ratio of rigidities of about 22.4. Since we stick with a bare machine, we are also stuck with the bare tunes which means the tunes are rather close together and near 8.75. Injection: (h,v) {approx} (8.73, 8.76).

  7. Characterization of metabolites in rats after intravenous administration of salvianolic acid for injection by ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.

    PubMed

    Miao, Jingzhuo; Sun, Wanyang; Huang, Jingyi; Liu, Xiaolin; Li, Shuming; Han, Xiaoping; Tong, Ling; Sun, Guoxiang

    2016-09-01

    It is an essential requirement to clarify the metabolites of traditional Chinese medicine (TCM) injections, which contain numerous ingredients, to assess their safe and effective use in clinic. Salvianolic acid for injection (SAFI), made from hydrophilic phenolic acids in Salvia miltiorrhiza Bunge, has been widely used for the treatment of cerebrovascular diseases, but information on its metabolites in vivo is still lacking. In the present study, we aimed to holistically characterize the metabolites of the main active ingredients in rat plasma, bile, urine and feces following intravenous administration of SAFI. An ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) method was developed. Combining information on retention behaviors, multistage mass spectra and literature data, a total of eight prototypes and 52 metabolites were tentatively characterized. Metabolites originated from rosmarinic acid and salvianolic acid B comprised the majority of identified compounds. Meanwhile, four metabolites derived from salvianolic acid D and five from salvianolic acid B are reported for the first time. This study revealed that methylation, sulfation and glucuronidation were the major metabolic pathways of phenolic acids in SAFI in vivo. Furthermore, the developed UPLC/Q-TOF-MS method could also benefit the metabolic investigation of extracts and preparations in TCM with hydrophilic ingredients. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Relationship between progesterone level on the day of human chorionic gonadotropin administration with outcomes of intra-cytoplasmic sperm injection in infertile couples

    PubMed Central

    Hajishafiha, Mahsomeh; Shahbazi, Zahra; Pakniyat, AbdolGhader; Oshnouei, Sima; Kiarang, Nazila

    2015-01-01

    Background: Gonadotropin-releasing hormone agonists or antagonists are used in assisted reproductive technique cycles as premature luteinizing hormone secretion inhibition. Studies have been reported different and contradictory results on the serum progesterone effect on intra-cytoplasmic sperm injection. Objective: The purpose of this study was to evaluate the effect of serum progesterone level on the day of Human chorionic gonadotropin (HCG) administration on the intra-cytoplasmic sperm injection (ICSI) outcome in infertile women. Materials and Methods: 249 infertile couples candidated for ICSI were enrolled in the study. Their serum progesterone level on the day of HCG administration was measured and according to serum level, patients were divided into four groups of less than 0.9, 0.9-1.4, 1.5-1.9, and ≥2 ng/mL. The four groups were compared with each other regarding fertility outcomes. Results: Pregnancy rate was not significantly different among the four groups (p>0.05). Also, there was no significant difference among the groups regarding frequency of abortion and ectopic pregnancy. Conclusion: Serum progesterone level on the day of HCG administration does not have any significant effect on pregnancy outcomes, including abortion, ectopic pregnancy, and pregnancy rate in patients undergoing ICSI treatment. PMID:26494986

  9. A bulk liquid membrane-flow injection (BLM-FI) coupled system for the preconcentration and determination of vanadium in saline waters.

    PubMed

    Pinto, Juan J; García-Vargas, Manuel; Moreno, Carlos

    2013-01-15

    A bulk liquid membrane-flow injection (BLM-FI) system has been developed for the preconcentration and spectrophotometric determination of vanadium in saline waters. The preconcentration step was based on a bulk liquid membrane containing Aliquat 336 (acting as a carrier) dissolved in dodecane/dodecanol. Vanadium species were chemically pumped due to the pH gradient between the sample (pH 3.2) and the receiving solution (pH 9.8). Vanadium transport through the membrane was monitored by a new and sensitive spectrophotometric method based on its reaction with di-2-pyridyl ketone benzoylhydrazone (dPKBH) in an acidic medium. As a consequence of membrane transport, vanadium was recovered in an ammonium solution, where total vanadium concentration was spectrophotometrically determined at 375 nm, as the pentavalent species, by using a flow injection analysis (FIA) system. Under optimal conditions, this FIA system provided a detection limit of 4.7 μg L(-1) (3s(blank)/m) and RSD 2.72%, for vanadium determination in saline samples. Both preconcentration and determination steps were previously optimized by modified simplex methodologies. The proposed coupled method was successfully applied to the determination of vanadium in a certified reference material (TMDA-62) and in two seawater samples.

  10. Determination of As, Hg and Pb in herbs using slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry.

    PubMed

    Tai, Chia-Yi; Jiang, Shiuh-Jen; Sahayam, A C

    2016-02-01

    Analysis of herbs for As, Hg and Pb has been carried out using slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) with flow injection vapor generation. Slurry containing 0.5% m/v herbal powder, 0.1% m/v citric acid and 2% v/v HCl was injected into the VG-ICP-MS system for the determination of As, Hg and Pb that obviate dissolution and mineralization. Standard addition and isotope dilution methods were used for quantifications in selected herbal powders. This method has been validated by the determination of As, Hg and Pb in NIST standard reference materials SRM 1547 Peach Leaves and SRM 1573a Tomato Leaves. The As, Hg and Pb analysis results of the reference materials agreed with the certified values. The precision obtained by the reported procedure was better than 7% for all determinations. The detection limit estimated from standard addition curve was 0.008, 0.003, and 0.007 ng mL(-1) for As, Hg and Pb, respectively.

  11. Vitamin D status and fertility outcomes during winter among couples undergoing in vitro fertilization/intracytoplasmic sperm injection.

    PubMed

    Neville, Grace; Martyn, Fiona; Kilbane, Mark; O'Riordan, Mairead; Wingfield, Mary; McKenna, Malachi; McAuliffe, Fionnuala M

    2016-11-01

    To assess the vitamin D status of men and women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI), and to investigate associations between vitamin D status and fertility variables. A cross-sectional prospective study was undertaken of men and women attending a fertility clinic in Ireland for IVF/ICSI between January and March 2014. Vitamin D status was determined by measurement of serum 25-hydroxyvitamin D (25(OH)D). Questionnaires examined knowledge and practices concerning vitamin D. Fertility variables and pregnancy outcomes were assessed in relation to vitamin D status. Overall, 73 men and 64 women provided blood samples. Among men, no correlation was found between 25(OH)D and total motility (ρ=0.069, P=0.562), progressive motility (ρ=0.066, P=0.576), count (ρ=0.001, P=0.996), or morphology (ρ=-0.034, P=0.774) of sperm. Additionally, there was no association between 25(OH)D and ongoing pregnancy rates (P=0.158). There was no difference in 25(OH)D between men with and without male factor subfertility issues (P=0.856). Among women, there was no significant correlation between 25(OH)D and anti-Müllerian hormone (P=0.629) or number of collected (P=0.198) and fertilized oocytes (P=0.136). There was no difference in 25(OH)D between women with and without ongoing pregnancy (P=0.222). No correlation was found between fertility variables or pregnancy outcomes and male or female vitamin D status. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  12. Large volume sample stacking with EOF and sweeping in CE for determination of common preservatives in cosmetic products by chemometric experimental design.

    PubMed

    Cheng, Yi-Cian; Wang, Chun-Chi; Chen, Yen-Ling; Wu, Shou-Mei

    2012-05-01

    This study proposes a capillary electrophoresis method incorporating large volume sample stacking, EOF and sweeping for detection of common preservatives used in cosmetic products. The method was developed using chemometric experimental design (fractional factorial design and central composite design) to determine multiple separation variables by efficient steps. The samples were loaded by hydrodynamic injection (10 psi, 90 s), and separated by phosphate buffer (50 mM, pH 3) containing 30% methanol and 80 mM SDS at -20 kV. During method validation, calibration curves were found to be linear over a range of 5-100 μg/mL for butyl paraben and isobutyl paraben; 0.05-10 μg/mL for ethyl paraben; 0.2-50 μg/mL for dehydroacetic acid; 0.5-70 μg/mL for methyl paraben; 5-350 μg/mL for sorbic acid; 0.02-450 μg/mL for p-hydroxybenzoic acid and 0.05-10 μg/mL for salicylic acid and benzoic acid. The analytes were analysed simultaneously and their detection limits (S/N = 3) were down to 0.005-2 μg/mL. The analysis method was successfully used for detection of preservatives used in commercial cosmetics.

  13. Determination of As, Cd, Pb, and Hg in urine using inductively coupled plasma mass spectrometry with the direct injection high efficiency nebulizer

    NASA Astrophysics Data System (ADS)

    Minnich, Michael G.; Miller, Derek C.; Parsons, Patrick J.

    2008-03-01

    The application of the large-bore direct injection high efficiency nebulizer (LB-DIHEN) for the determination of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in urine by inductively coupled plasma mass spectrometry (ICP-MS) is described. The LB-DIHEN is compared with the standard method using a concentric pneumatic nebulizer and cyclonic spray chamber. In addition to the toxicological significance of As, Cd, Pb, and Hg, these elements represent a cross-section of analytical issues including spectral interferences (e.g., 40Ar 35Cl + on 75As + and 98Mo 16O + on 114Cd +) and memory effects (Hg). In this study, the low sample consumption of the LB-DIHEN is used to reduce the volume of urine needed for analysis, and to reduce the volume of final diluted sample required for analysis. Eliminating the spray chamber and reducing the dead volume of the nebulizer reduces memory effects, especially for analytes such as Hg. The Dynamic Reaction Cell (DRC) is used in this study to attenuate the background level of ArCl + in spite of the increase in the solvent load and, in turn, the urine matrix (chloride) delivered to the plasma by the LB-DIHEN. This is the first report on coupling the LB-DIHEN to a standard autosampler for unattended sample analysis. The robustness of direct injection nebulization for routine analysis and the issues associated with automation of the sample introduction process are discussed. Although the figures of merit (sensitivity, limit of detection, and precision) determined for both nebulizers are slightly poorer for the LB-DIHEN than for the concentric pneumatic nebulizer, there is not a clinically significant difference between the results for both sample introduction systems. The accuracy of results is assessed using archived urine materials that are circulated by several different proficiency testing (PT) programs and external quality assessment schemes (EQAS). Results obtained using the LB-DIHEN were within the acceptable range

  14. The intravenous injection of oxidized LDL- or Apolipoprotein B100 – Coupled splenocytes promotes Th1 polarization in wildtype and Apolipoprotein E – Deficient mice

    SciTech Connect

    Steinmetz, Martin; Ponnuswamy, Padmapriya; Laurans, Ludivine; Esposito, Bruno; Tedgui, Alain; Mallat, Ziad

    2015-08-14

    Background: Th1 responses in atherosclerosis are mainly associated with the aggravation of atherosclerotic plaques, whereas Th2 responses lead to a less pronounced disease in mouse models. The fixation of antigens on cells by means of ethylene carbodiimide (ECDI), and subsequent injection of these antigen-coupled splenocytes (Ag-SP) to induce tolerance against the attached antigens, has been successfully used to treat murine type 1 diabetes or encephalomyelitis in. We analyzed this approach in a mouse model for atherosclerosis. Methods and results: OTII-transgenic mice that were treated with a single dose of 5 × 10{sup 7} OVA-coupled splenocytes (OVA-SP), had decreased splenocyte proliferation, and lower IFNγ production in vitro upon antigen recall. However, in vivo CD4 cell activation was increased. To try lipoprotein-derived, “atherosclerosis-associated” antigens, we first tested human oxidized LDL. In wild type mice, an increase of IFNγ production upon in vitro recall was detected in the oxLDL-SP group. In Apolipoprotein E − deficient (ApoE−/−) mice that received oxLDL-SP every 5 weeks for 20 weeks, we did not find any difference of atherosclerotic plaque burden, but again increased IFNγ production. To overcome xenogenous limitations, we then examined the effects of mouse Apolipoprotein B100 peptides P3 and P6. ApoB100-SP treatment again promoted a more IFNγ pronounced response upon in vitro recall. Flow cytometry analysis of cytokine secreting spleen cells revealed CD4 positive T cells to be mainly the source for IFNγ. In ApoE−/− mice that were administered ApoB100-SP during 20 weeks, the atherosclerotic plaque burden in aortic roots as well as total aorta was unchanged compared to PBS treated controls. Splenocyte proliferation upon antigen recall was not significantly altered in ApoB100-SP treated ApoE−/− mice. Conclusion: Although we did not observe a relevant anti-atherosclerotic benefit, the treatment with antigen-coupled

  15. Syringe injectable electronics

    PubMed Central

    Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

    2015-01-01

    Seamless and minimally-invasive three-dimensional (3D) interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating syringe injection and subsequent unfolding of submicrometer-thick, centimeter-scale macroporous mesh electronics through needles with a diameter as small as 100 micrometers. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with > 90% device yield. We demonstrate several applications of syringe injectable electronics as a general approach for interpenetrating flexible electronics with 3D structures, including (i) monitoring of internal mechanical strains in polymer cavities, (ii) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (iii) in vivo multiplexed neural recording. Moreover, syringe injection enables delivery of flexible electronics through a rigid shell, delivery of large volume flexible electronics that can fill internal cavities and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics. PMID:26053995

  16. Syringe-injectable electronics

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Fu, Tian-Ming; Cheng, Zengguang; Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

    2015-07-01

    Seamless and minimally invasive three-dimensional interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating the syringe injection (and subsequent unfolding) of sub-micrometre-thick, centimetre-scale macroporous mesh electronics through needles with a diameter as small as 100 μm. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with >90% device yield. We demonstrate several applications of syringe-injectable electronics as a general approach for interpenetrating flexible electronics with three-dimensional structures, including (1) monitoring internal mechanical strains in polymer cavities, (2) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (3) in vivo multiplexed neural recording. Moreover, syringe injection enables the delivery of flexible electronics through a rigid shell, the delivery of large-volume flexible electronics that can fill internal cavities, and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics.

  17. Syringe-injectable electronics.

    PubMed

    Liu, Jia; Fu, Tian-Ming; Cheng, Zengguang; Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M

    2015-07-01

    Seamless and minimally invasive three-dimensional interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating the syringe injection (and subsequent unfolding) of sub-micrometre-thick, centimetre-scale macroporous mesh electronics through needles with a diameter as small as 100 μm. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with >90% device yield. We demonstrate several applications of syringe-injectable electronics as a general approach for interpenetrating flexible electronics with three-dimensional structures, including (1) monitoring internal mechanical strains in polymer cavities, (2) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (3) in vivo multiplexed neural recording. Moreover, syringe injection enables the delivery of flexible electronics through a rigid shell, the delivery of large-volume flexible electronics that can fill internal cavities, and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics.

  18. Soft SUSY breaking parameters and RG running of squark and slepton masses in large volume Swiss Cheese compactifications

    NASA Astrophysics Data System (ADS)

    Misra, Aalok; Shukla, Pramod

    2010-03-01

    We consider type IIB large volume compactifications involving orientifolds of the Swiss Cheese Calabi-Yau WCP[1,1,1,6,9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the “big” divisor ΣB (as opposed to the “small” divisor usually done in the literature thus far) as well as supporting D7-brane fluxes. After reviewing our proposal of [1] (Misra and Shukla, 2010) for resolving a long-standing tension between large volume cosmology and phenomenology pertaining to obtaining a 10 GeV gravitino in the inflationary era and a TeV gravitino in the present era, and summarizing our results of [1] (Misra and Shukla, 2010) on soft supersymmetry breaking terms and open-string moduli masses, we discuss the one-loop RG running of the squark and slepton masses in mSUGRA-like models (using the running of the gaugino masses) to the EW scale in the large volume limit. Phenomenological constraints and some of the calculated soft SUSY parameters identify the D7-brane Wilson line moduli as the first two generations/families of squarks and sleptons and the D3-brane (restricted to the big divisor) position moduli as the two Higgses for MSSM-like models at TeV scale. We also discuss how the obtained open-string/matter moduli make it easier to impose FCNC constraints, as well as RG flow of off-diagonal squark mass(-squared) matrix elements.

  19. The Long-Term Clinical Outcomes Following Autogenous Bone Grafting for Large-Volume Defects of the Knee

    PubMed Central

    Delano, Mark; Spector, Myron; Pittsley, Andrew; Gottschalk, Alexander

    2014-01-01

    Objective: We report the long-term clinical outcomes of patients who underwent autogenous bone grafting of large-volume osteochondral defects of the knee due to osteochondritis dessicans (OCD) and osteonecrosis (ON). This is the companion report to one previous published on the biological response. We hypothesized that these grafts would integrate with host bone and the articular surface would form fibrocartilage providing an enduring clinical benefit. Design: Three groups (patients/knees) were studied: OCD without a fragment (n = 12/13), OCD with a partial fragment (n = 14/16), and ON (n = 25/26). Twenty-five of 52 patients were available for clinical follow-up between 12 and 21 years. Electronic medical records provided comparison clinical information. In addition, there were plain film radiographs, MRIs, plus repeat arthroscopy and biopsy on 14 patients. Results: Autogenous bone grafts integrated with the host bone. MRI showed soft tissue covering all the grafts at long-term follow-up. Biopsy showed initial surface fibrocartilage that subsequently converted to fibrocartilage and hyaline cartilage at 20 years. OCD patients had better clinical outcomes than ON patients. No OCD patients were asymptomatic at anytime following surgery. Half of the ON patients came to total knee replacement within 10 years. Conclusions: Autogenous bone grafting provides an alternative biological matrix to fill large-volume defects in the knee as a singular solution integrating with host bone and providing an enduring articular cartilage surface. The procedure is best suited for those with OCD. The treatment for large-volume articular defects by this method remains salvage in nature and palliative in outcome. PMID:26069688

  20. IMPLICATION FOR THE CORE-COLLAPSE SUPERNOVA RATE FROM 21 YEARS OF DATA OF THE LARGE VOLUME DETECTOR

    SciTech Connect

    Agafonova, N. Y.; Ashikhmin, V. V.; Dadykin, V. L.; Dobrynina, E. A.; Enikeev, R. I.; Malgin, A. S.; Aglietta, M.; Badino, G.; Bertoni, R.; Fulgione, W.; Galeotti, P.; Gomez, F.; Antonioli, P.; Bari, G.; Garbini, M.; Giusti, P.; Bressan, E.; Bruno, G.; Ghia, P. L.; Kemp, E. E-mail: fulgione@to.infn.it; Collaboration: LVD Collaboration; and others

    2015-03-20

    The Large Volume Detector (LVD) has been continuously taking data since 1992 at the INFN Gran Sasso National Laboratory. The LVD is sensitive to neutrino bursts from gravitational stellar collapses with full detection probability over the Galaxy. We have searched for neutrino bursts in LVD data taken over 7,335 days of operation. No evidence of neutrino signals has been found between 1992 June and 2013 December. The 90% C.L. upper limit on the rate of core collapse and failed supernova explosions out to distances of 25 kpc is found to be 0.114 yr{sup −1}.

  1. The use of large volume low pressure nasal saline with fluticasone propionate for the treatment of pediatric acute rhinosinusitis.

    PubMed

    Tugrul, Selahattin; Dogan, Remzi; Eren, Sabri Baki; Meric, Aysenur; Ozturan, Orhan

    2014-08-01

    Fluticasone propionate and nasal saline irrigation have been used in the treatment of sinonasal diseases for a long time. Our study investigates the effect of the combination of large volume low pressure nasal saline irrigation and fluticasone propionate for the treatment of pediatric acute rhinosinusitis. Ninety-one pediatric patients with acute rhinosinusitis were included in our study. The patients were randomized into two groups. The first group (n=45) was treated with standard therapy (antibiotherapy+nasal decongestant) for 2 weeks, the second group was treated with the large volume low pressure nasal saline+fluticasone propionate combination for 3 weeks. The clinical scores, radiologic evaluations (X-ray Waters view), peak nasal inspiratory flow (PNIF) measurements, total symptom scores and hematologic parameters (WBC, CRP, ESR) of the patients were evaluated and compared. There were no significant differences in between the two groups regarding age, gender, height and weight. Even though the clinical scores of Group 2 improved more rapidly, there were no significant differences in between groups regarding clinical scores by the 21st day. There were no significant differences in post treatment radiologic evaluations (Waters graphy). Both groups had significant improvement of their post treatment PNIF values, yet the improvement was more marked in Group 2 than in Group 1. The rhinorrhea, nasal congestion, throat itching and cough symptoms improved more rapidly in Group 2 than in Group 1. Post-treatment nose itching and sneezing symptoms were significantly less in Group 2. The values of hematologic parameters were significantly reduced at the end of the 3rd week in both groups. Our study is a first in investigating the combined use of large volume low pressure nasal saline and fluticasone propionate in acute pediatric rhinosinusitis, and the results reveal that the combination therapy was effective. Low pressure large volume nasal saline+fluticasone propionate

  2. Effects of large volume, ice-cold intravenous fluid infusion on respiratory function in cardiac arrest survivors.

    PubMed

    Jacobshagen, Claudius; Pax, Anja; Unsöld, Bernhard W; Seidler, Tim; Schmidt-Schweda, Stephan; Hasenfuss, Gerd; Maier, Lars S

    2009-11-01

    International guidelines for cardiopulmonary resuscitation recommend mild hypothermia (32-34 degrees C) for 12-24h in comatose survivors of cardiac arrest. To induce therapeutic hypothermia a variety of external and intravascular cooling devices are available. A cheap and effective method for inducing hypothermia is the infusion of large volume, ice-cold intravenous fluid. There are concerns regarding the effects of rapid infusion of large volumes of fluid on respiratory function in cardiac arrest survivors. We have retrospectively studied the effects of high volume cold fluid infusion on respiratory function in 52 resuscitated cardiac arrest patients. The target temperature of 32-34 degrees C was achieved after 4.1+/-0.5h (cooling rate 0.48 degrees C/h). During this period 3427+/-210 mL ice-cold fluid was infused. Despite significantly reduced LV-function (EF 35.8+/-2.2%) the respiratory status of these patients did not deteriorate significantly. On intensive care unit admission the mean PaO(2) was 231.4+/-20.6 mmHg at a F(i)O(2) of 0.82+/-0.03 (PaO(2)/F(i)O(2)=290.0+/-24.1) and a PEEP level of 7.14+/-0.31 mbar. Until reaching the target temperature of large volume, ice-cold fluid is an effective and inexpensive method for inducing therapeutic hypothermia. Resuscitation from cardiac arrest is associated with a deterioration in respiratory function. The infusion of large volumes of cold fluid does not cause a statistically significant further deterioration in respiratory function. A larger, randomized and prospective study is required to assess the efficacy and safety of ice-cold fluid infusion for

  3. Feasibility of large volume tumor ablation using multiple-mode strategy with fast scanning method: A numerical study

    NASA Astrophysics Data System (ADS)

    Wu, Hao; Shen, Guofeng; Qiao, Shan; Chen, Yazhu

    2017-03-01

    Sonication with fast scanning method can generate homogeneous lesions without complex planning. But when the target region is large, switching focus too fast will reduce the heat accumulation, the margin of which may not ablated. Furthermore, high blood perfusion rate will reduce this maximum volume that can be ablated. Therefore, fast scanning method may not be applied to large volume tumor. To expand the therapy scope, this study combines the fast scan method with multiple mode strategy. Through simulation and experiment, the feasibility of this new strategy is evaluated and analyzed.

  4. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions.

    PubMed

    Chen, Wei-Ni; Jiang, Shiuh-Jen; Chen, Yen-Ling; Sahayam, A C

    2015-02-20

    A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v L-cysteine, 0.5 μg mL(-1) Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng g(-1) for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample.

  5. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of As, Cd, and Hg in cereals.

    PubMed

    Chen, Feng-Yi; Jiang, Shiuh-Jen

    2009-08-12

    A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of As, Cd, and Hg in cereals using flow injection chemical vapor generation (VG) as the sample introduction system. A slurry containing 6% m/v flour, 0.7% m/v thiourea, 0.4 microg mL(-1) Co(II), and 2.5% v/v HCl was injected into a VG-ICP-MS system for the determination of As, Cd, and Hg without dissolution and mineralization. Because the sensitivities of the elements studied in the slurry and that of aqueous solution were quite different, a standard addition method and an isotope dilution method were used for the determination of As, Cd, and Hg in selected cereal samples. The influences of vapor generation conditions and slurry preparation on the ion signals were reported. The effectiveness of the vapor generation sample introduction technique in alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied for the determination of As, Cd, and Hg in NIST SRM 1567a Wheat Flour reference material, NIST SRM 1568a Rice Flour reference material, and cereal samples obtained from local market. The As, Cd, and Hg analysis results of the reference materials agreed with the certified values. The method detection limits estimated from standard addition curves were about 0.10, 0.16, and 0.07 ng g(-1) for As, Cd, and Hg, respectively, in the original cereal samples.

  6. A simple method for the production of large volume 3D macroporous hydrogels for advanced biotechnological, medical and environmental applications

    PubMed Central

    Savina, Irina N.; Ingavle, Ganesh C.; Cundy, Andrew B.; Mikhalovsky, Sergey V.

    2016-01-01

    The development of bulk, three-dimensional (3D), macroporous polymers with high permeability, large surface area and large volume is highly desirable for a range of applications in the biomedical, biotechnological and environmental areas. The experimental techniques currently used are limited to the production of small size and volume cryogel material. In this work we propose a novel, versatile, simple and reproducible method for the synthesis of large volume porous polymer hydrogels by cryogelation. By controlling the freezing process of the reagent/polymer solution, large-scale 3D macroporous gels with wide interconnected pores (up to 200 μm in diameter) and large accessible surface area have been synthesized. For the first time, macroporous gels (of up to 400 ml bulk volume) with controlled porous structure were manufactured, with potential for scale up to much larger gel dimensions. This method can be used for production of novel 3D multi-component macroporous composite materials with a uniform distribution of embedded particles. The proposed method provides better control of freezing conditions and thus overcomes existing drawbacks limiting production of large gel-based devices and matrices. The proposed method could serve as a new design concept for functional 3D macroporous gels and composites preparation for biomedical, biotechnological and environmental applications. PMID:26883390

  7. 3-D EM exploration of the hepatic microarchitecture – lessons learned from large-volume in situ serial sectioning

    PubMed Central

    Shami, Gerald John; Cheng, Delfine; Huynh, Minh; Vreuls, Celien; Wisse, Eddie; Braet, Filip

    2016-01-01

    To-date serial block-face scanning electron microscopy (SBF-SEM) dominates as the premier technique for generating three-dimensional (3-D) data of resin-embedded biological samples at an unprecedented depth volume. Given the infancy of the technique, limited literature is currently available regarding the applicability of SBF-SEM for the ultrastructural investigation of tissues. Herein, we provide a comprehensive and rigorous appraisal of five different SBF-SEM sample preparation protocols for the large-volume exploration of the hepatic microarchitecture at an unparalleled X, Y and Z resolution. In so doing, we qualitatively and quantitatively validate the use of a comprehensive SBF-SEM sample preparation protocol, based on the application of heavy metal fixatives, stains and mordanting agents. Employing the best-tested SBF-SEM approach, enabled us to assess large-volume morphometric data on murine parenchymal cells, sinusoids and bile canaliculi. Finally, we integrated the validated SBF-SEM protocol with a correlative light and electron microscopy (CLEM) approach. The combination of confocal scanning laser microscopy and SBF-SEM provided a novel way to picture subcellular detail. We appreciate that this multidimensional approach will aid the subsequent research of liver tissue under relevant experimental and disease conditions. PMID:27834401

  8. 3-D EM exploration of the hepatic microarchitecture - lessons learned from large-volume in situ serial sectioning.

    PubMed

    Shami, Gerald John; Cheng, Delfine; Huynh, Minh; Vreuls, Celien; Wisse, Eddie; Braet, Filip

    2016-11-11

    To-date serial block-face scanning electron microscopy (SBF-SEM) dominates as the premier technique for generating three-dimensional (3-D) data of resin-embedded biological samples at an unprecedented depth volume. Given the infancy of the technique, limited literature is currently available regarding the applicability of SBF-SEM for the ultrastructural investigation of tissues. Herein, we provide a comprehensive and rigorous appraisal of five different SBF-SEM sample preparation protocols for the large-volume exploration of the hepatic microarchitecture at an unparalleled X, Y and Z resolution. In so doing, we qualitatively and quantitatively validate the use of a comprehensive SBF-SEM sample preparation protocol, based on the application of heavy metal fixatives, stains and mordanting agents. Employing the best-tested SBF-SEM approach, enabled us to assess large-volume morphometric data on murine parenchymal cells, sinusoids and bile canaliculi. Finally, we integrated the validated SBF-SEM protocol with a correlative light and electron microscopy (CLEM) approach. The combination of confocal scanning laser microscopy and SBF-SEM provided a novel way to picture subcellular detail. We appreciate that this multidimensional approach will aid the subsequent research of liver tissue under relevant experimental and disease conditions.

  9. Boron-doped diamond heater and its application to large-volume, high-pressure, and high-temperature experiments.

    PubMed

    Shatskiy, Anton; Yamazaki, Daisuke; Morard, Guillaume; Cooray, Titus; Matsuzaki, Takuya; Higo, Yuji; Funakoshi, Ken-ichi; Sumiya, Hitoshi; Ito, Eiji; Katsura, Tomoo

    2009-02-01

    A temperature of 3500 degrees C was generated using a diamond resistance heater in a large-volume Kawai-type high-pressure apparatus. Re and LaCrO(3) have conventionally been used for heaters in high-pressure studies but they cannot generate temperatures higher than 2900 degrees C and make in situ x-ray observations difficult due to their high x-ray absorption. Using a boron-doped diamond heater overcomes these problems and achieves stable temperature generation for pressure over 10 GPa. The heater starting material is a cold-compressed mixture of graphite with boron used to avoid the manufacturing difficulties due to the extreme hardness of diamond. The diamond heater was synthesized in situ from the boron-graphite mixture at temperature of 1600+/-100 degrees C and pressure of 20 GPa. By using the proposed technique, we have employed the diamond heater for high-temperature generation in a large-volume high-pressure apparatus. Achievement of temperatures above 3000 degrees C allows us to measure the melting points of the important constituents in earth's mantle (MgSiO(3), SiO(2), and Al(2)O(3)) and core (Fe and Ni) at extremely high pressures.

  10. A simple method for the production of large volume 3D macroporous hydrogels for advanced biotechnological, medical and environmental applications

    NASA Astrophysics Data System (ADS)

    Savina, Irina N.; Ingavle, Ganesh C.; Cundy, Andrew B.; Mikhalovsky, Sergey V.

    2016-02-01

    The development of bulk, three-dimensional (3D), macroporous polymers with high permeability, large surface area and large volume is highly desirable for a range of applications in the biomedical, biotechnological and environmental areas. The experimental techniques currently used are limited to the production of small size and volume cryogel material. In this work we propose a novel, versatile, simple and reproducible method for the synthesis of large volume porous polymer hydrogels by cryogelation. By controlling the freezing process of the reagent/polymer solution, large-scale 3D macroporous gels with wide interconnected pores (up to 200 μm in diameter) and large accessible surface area have been synthesized. For the first time, macroporous gels (of up to 400 ml bulk volume) with controlled porous structure were manufactured, with potential for scale up to much larger gel dimensions. This method can be used for production of novel 3D multi-component macroporous composite materials with a uniform distribution of embedded particles. The proposed method provides better control of freezing conditions and thus overcomes existing drawbacks limiting production of large gel-based devices and matrices. The proposed method could serve as a new design concept for functional 3D macroporous gels and composites preparation for biomedical, biotechnological and environmental applications.

  11. Model for the intrusion of batholiths associated with the eruption of large-volume ash-flow tuffs.

    PubMed

    Whitney, J A; Stormer, J C

    1986-01-31

    Pyroclastic eruption and the intrusion of batholiths associated with large-volume ash-flow tuffs may be driven by a decrease in reservoir pressure caused by the low density of the magma column due to vesiculation. Batholithic intrusion would then be accomplished by the subsidence and settling of kilometer-sized crustal blocks through the magma chamber, resulting in eventual collapse to form large caldera structures at the surface. Such a model does not require the formation of a large, laterally extensive, shallow magma chamber before the onset of large-volume ash-flow eruptions. Eruption could commence directly from a deeper reservoir, with only a small channelway being opened to the surface before the onset of catastrophic ash-flow eruptions of the scale of Yellowstone or Long Valley. Such a model has wide-ranging implications, and explains many of the problems inherent in the simple collapse model involving shallow magna chambers as well as the process and timing of batholith intrusion in such cases.

  12. Large-volume hot spots in gold spiky nanoparticle dimers for high-performance surface-enhanced spectroscopy.

    PubMed

    Li, Anran; Li, Shuzhou

    2014-11-07

    Hot spots with a large electric field enhancement usually come in small volumes, limiting their applications in surface-enhanced spectroscopy. Using a finite-difference time-domain method, we demonstrate that spiky nanoparticle dimers (SNPD) can provide hot spots with both large electric field enhancement and large volumes because of the pronounced lightning rod effect of spiky nanoparticles. We find that the strongest electric fields lie in the gap region when SNPD is in a tip-to-tip (T-T) configuration. The enhancement of electric fields (|E|(2)/|E0|(2)) in T-T SNPD with a 2 nm gap can be as large as 1.21 × 10(6). And the hot spot volume in T-T SNPD is almost 7 times and 5 times larger than those in the spike dimer and sphere dimer with the same gap size of 2 nm, respectively. The hot spot volume in SNPD can be further improved by manipulating the arrangements of spiky nanoparticles, where crossed T-T SNPD provides the largest hot spot volume, which is 1.5 times that of T-T SNPD. Our results provide a strategy to obtain hot spots with both intense electric fields and large volume by adding a bulky core at one end of the spindly building block in dimers.

  13. Time-lapsed, large-volume, high-resolution intravital imaging for tissue-wide analysis of single cell dynamics.

    PubMed

    Entenberg, David; Pastoriza, Jessica M; Oktay, Maja H; Voiculescu, Sonia; Wang, Yarong; Sosa, Maria Soledad; Aguirre-Ghiso, Julio; Condeelis, John

    2017-09-01

    Pathologists rely on microscopy to diagnose disease states in tissues and organs. They utilize both high-resolution, high-magnification images to interpret the staining and morphology of individual cells, as well as low-magnification overviews to give context and location to these cells. Intravital imaging is a powerful technique for studying cells and tissues in their native, live environment and can yield sub-cellular resolution images similar to those used by pathologists. However, technical limitations prevent the straightforward acquisition of low-magnification images during intravital imaging, and they are hence not typically captured. The serial acquisition, mosaicking, and stitching together of many high-resolution, high-magnification fields of view is a technique that overcomes these limitations in fixed and ex vivo tissues. The technique however, has not to date been widely applied to intravital imaging as movements caused by the living animal induce image distortions that are difficult to compensate for computationally. To address this, we have developed techniques for the stabilization of numerous tissues, including extremely compliant tissues, that have traditionally been extremely difficult to image. We present a novel combination of these stabilization techniques with mosaicked and stitched intravital imaging, resulting in a process we call Large-Volume High-Resolution Intravital Imaging (LVHR-IVI). The techniques we present are validated and make large volume intravital imaging accessible to any lab with a multiphoton microscope. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Underground low flux neutron background measurements in LSM using a large volume (1m3) spherical proportional counter

    NASA Astrophysics Data System (ADS)

    Savvidis, I.; Giomataris, I.; Bougamont, E.; Irastorza, I.; Aune, S.; Chapelier, M.; Charvin, P. H.; Colas, P.; Derre, J.; Ferrer, E.; Gerbier, G.; Gros, M.; Mangier, P.; Navick, X. F.; Salin, P.; Vergados, J. D.; Zampalo, M.

    2010-01-01

    A large volume (1m3) spherical proportional counter has been developed at CEA/Saclay, for low flux neutron measurements. The high voltage is applied to a small sphere 15mm in diameter, located in the center of the counter and the wall of the counter is grounded. Neutrons can be measured successfully, with high sensitivity, using 3He gas in the detector. The proton and tritium energy deposition in the drift gaseous volume, from the reaction 3He(n,p)3H, can provide the neutron spectra from thermal neutrons up to several MeV. The detector has been installed in the underground laboratory in Modane (LSM) to measure the neutron background. The sphere has been has been filled with gas mixture of Ar + 2% CH4 +3gr He-3, at 275 mbar. The thermal neutron peak is well separated from the cosmic ray and gamma background, permitting of neutron flux calculation. Other potential applications requiring large volume of about 10 m in radius are described in detail in reference

  15. Human immunodeficiency type-1 virus (HIV-1) infection in serodiscordant couples (SDCs) does not have an impact on embryo quality or intracytoplasmic sperm injection (ICSI) outcome.

    PubMed

    Melo, Marco Antonio Barreto; Meseguer, Marcos; Bellver, José; Remohí, José; Pellicer, Antonio; Garrido, Nicolás

    2008-01-01

    To evaluate the embryo quality in our program for human immunodeficiency type-1 virus (HIV-1) serodiscordant couples (SDCs) with the male infected in comparison with a tubal-factor infertility control group. Retrospective case-control study. Instituto Valenciano de Infertilidad, Valencia, Spain. Thirty SDC and 79 control couples without HIV-1 infection attending for intracytoplasmic sperm injection (ICSI). Only first cycles were considered. Controlled ovarian hyperstimulation and ICSI in both groups; sperm wash, nested polymerase chain reaction (PCR) in semen sample, and capacitation by swim-up after thawing the semen sample in the SDC group; and sperm capacitation by swim-up after thawing the semen sample in the control group. ICSI procedure and embryo characteristics (fertilization, cleavage, embryo morphology, and development) and cycle outcome (ongoing pregnancy and miscarriage rates). Fertilization and cleavage rates were similar between the groups. On days 2 and 3 of embryo development, very similar embryo features were found between the groups. There was no difference in mean number of optimal embryos on day 3. When embryos were cultured up to 5-6 days, a significant increase in embryo blockage was found in the SDC group compared with the control group. The mean number of optimal blastocysts on day 6 was comparable in both groups. No difference was found regarding the number of cryopreserved and transferred embryos or implantation, pregnancy, multiple pregnancy, or miscarriage rates between the groups. HIV-1 infection in SDCs with infected males does not appear to have a significantly negative impact on embryo development or ICSI outcome.

  16. Continuous ultrasound-assisted extraction coupled to flow injection-pervaporation, derivatization, and spectrophotometric detection for the determination of ammonia in cigarettes.

    PubMed

    Caballo-López, A; Luque de Castro, M D

    2006-04-01

    A dynamic system for the continuous removal of ammonia from cigarettes with ultrasound assistance and iterative change of the flow direction of the extractant through the sample cell has been developed. A 0.1-g sample of cigarette was subjected to 7 min of ultrasound-assisted extraction (application and duration of pulse 0.7 s, output amplitude 85% of the converter nominal amplitude), and 1 M NaOH solution was used both as extractant and as carrier in the dynamic system. The ultrasound-assisted extractor was coupled to a pervaporation unit through a flow injection interface in order to develop a fully automated method. In arriving at the pervaporator, the ammonia is transferred from the donor-carrier stream to an acceptor stream, where the classical Berthelot reaction takes place--thus favoring pervaporation. The blue complex formed is spectrophotometrically monitored at 655 nm. The method was applied to the determination of ammonia in a selection of 10 European cigarette brands and Kentucky Reference 2R4F cigarettes.

  17. Solid-phase chelate extractive preconcentration of heavy metal ions prior to their ultratrace determination by microsample injection system coupled flame atomic absorption spectrometry.

    PubMed

    Sarı, Serdar; Kartal, Aslıhan Arslan; Elçi, Aydan; Akdoğan, Abdullah; Höl, Aysen; Siyal, Ali Nawaz; Elçi, Latif

    2013-01-01

    Chromosorb-105 resin/1-(2-pyridylazo)-2-naphthol (PAN) system was developed for solid phase chelate extractive preconcentration of heavy metal ions. The metal ions on Chromosorb-105 resin column were eluted with 3.0 mL of 2.0 mol L-1 HNO3 and determined by microsample injection system coupled flame atomic spectrometry (MIS-FAAS) using 75.0 µL of sample solution for single element determination. The influence of pH, resin amount, reagent amount, flow rate and volume of eluent and sample solution was optimized. The quantitative recoveries (≥95%) of Fe(III), Zn(II), Cu(II) and Pb(II) ions were achieved at pH 9; resin amount, 700 mg; reagent amount, 6.0 µmol; flow rate of eluent and sample solution, 1.0 mL min-1 and 5.0 mL min-1, respectively. The limit of detection and limit of quantification of understudied analytes were found to be 0.17-1.74 µg L-1 and 0.40-2.98 µg L-1, respectively with preconcentration factor of 150-300. The proposed method was validated by analysis of waste water (BCR-715) as a certified reference material. The method was applied successfully for ultratrace determination of studied metal ions in tap water and hot spring water samples.

  18. In-line electrochemical reagent generation coupled to a flow injection biamperometric system for the determination of sulfite in beverage samples.

    PubMed

    de Paula, Nattany T G; Barbosa, Elaine M O; da Silva, Paulo A B; de Souza, Gustavo C S; Nascimento, Valberes B; Lavorante, André F

    2016-07-15

    This work reports an in-line electrochemical reagent generation coupled to a flow injection biamperometric procedure for the determination of SO3(2-). The method was based on a redox reaction between the I3(-) and SO3(2-) ions, after the diffusion of SO2 through a gas diffusion chamber. Under optimum experimental conditions, a linear response ranging from 1.0 to 12.0 mg L(-1) (R=0.9999 and n=7), a detection and quantification limit estimated at 0.26 and 0.86 mg L(-1), respectively, a standard deviation relative of 0.4% (n=10) for a reference solution of 4.0 mg L(-1) SO3(2-) and sampling throughput for 40 determinations per hour were achieved. Addition and recovery tests with juice and wine samples were performed resulting in a range between 92% and 110%. There were no significant differences at a 95% confidence level in the analysis of eight samples when comparing the new method with a reference procedure.

  19. Quantitative real-time monitoring of chemical reactions by autosampling flow injection analysis coupled with atmospheric pressure chemical ionization mass spectrometry.

    PubMed

    Zhu, Zhenqian; Bartmess, John E; McNally, Mary Ellen; Hoffman, Ron M; Cook, Kelsey D; Song, Liguo

    2012-09-04

    Although qualitative and/or semiquantitative real-time monitoring of chemical reactions have been reported with a few mass spectrometric approaches, to our knowledge, no quantitative mass spectrometric approach has been reported so far to have a calibration valid up to molar concentrations as required by process control. This is mostly due to the absence of a practical solution that could well address the sample overloading issue. In this study, a novel autosampling flow injection analysis coupled with an atmospheric pressure chemical ionization mass spectrometry (FIA/APCI-MS) system, consisting of a 1 μL automatic internal sample injector, a postinjection splitter with 1:10 splitting ratio, and a detached APCI source connected to the mass spectrometer using a 4.5 in. long, 0.042 in. inner diameter (ID) stainless-steel capillary, was thus introduced. Using this system together with an optional FIA solvent modifier, e.g., 0.05% (v/v) isopropylamine, a linear quantitative calibration up to molar concentration has been achieved with 3.4-7.2% relative standard deviations (RSDs) for 4 replicates. As a result, quantitative real-time monitoring of a model reaction was successfully performed at the 1.63 M level. It is expected that this novel autosampling FIA/APCI-MS system can be used in quantitative real-time monitoring of a wide range of reactions under diverse reaction conditions.

  20. Determination of arsenic in traditional Chinese medicine by microwave digestion with flow injection-inductively coupled plasma mass spectrometry (FI-ICP-MS).

    PubMed

    Ong, E S; Yong, Y L; Woo, S O

    1999-01-01

    A simple, rapid, and sensitive method with high sample throughput was developed for determining arsenic in traditional Chinese medicine (TCM) in the form of uncoated tablets, sugar-coated tablets, black pills, capsules, powders, and syrups. The method involves microwave digestion with flow injection-inductively coupled plasma mass spectrometry (FI-ICP-MS). Method precision was 2.7-10.1% (relative standard deviation, n = 6) for different concentrations of arsenic in different TCM samples analyzed by different analysts on different days. Method accuracy was checked with a certified reference material (sea lettuce, Ulva lactuca, BCR CRM 279) for external calibration and by spiking arsenic standard into different TCMs. Recoveries of 89-92% were obtained for the certified reference material and higher than 95% for spiked TCMs. Matrix interference was insignificant for samples analyzed by the method of standard addition. Hence, no correction equation was used in the analysis of arsenic in the samples studied. Sample preparation using microwave digestion gave results that were very similar to those obtained by conventional wet acid digestion using nitric acid.

  1. Ultrasound-assisted dispersive liquid-liquid microextraction of tetracycline drugs from egg supplements before flow injection analysis coupled to a liquid waveguide capillary cell.

    PubMed

    Rodríguez, Michael Pérez; Pezza, Helena Redigolo; Pezza, Leonardo

    2016-09-01

    A simple, rapid, and efficient ultrasound-assisted dispersive liquid-liquid microextraction (US-DLLME) method was developed for extraction of tetracycline residues from egg supplement samples, with subsequent determination by flow injection analysis (FIA) coupled to a liquid waveguide capillary cell (LWCC) and a controlled temperature heating bath. Tetracyclines react with diazotized p-sulfanilic acid, in a slightly alkaline medium, to form azo compounds that can be measured at 435 nm. The reaction sensitivity improved substantially (5.12-fold) using an in-line heating temperature of 45 °C. Multivariate methodology was used to optimize the factors affecting the extraction efficiency, considering the volumes of extraction and disperser solvents, sonication time, extraction time, and centrifugation time. Good linearity in the range 30-600 μg L(-1) was obtained for all the tetracyclines, with regression coefficients (r) higher than 0.9974. The limits of detection ranged from 6.4 to 11.1 μg L(-1), and the recoveries were in the range 85.7-96.4 %, with relative standard deviation lower than 9.8 %. Analyte recovery was improved by approximately 6 % when the microextraction was assisted by ultrasound. The results obtained with the proposed US-DLLME-FIA method were confirmed by a reference HPLC method and showed that the egg supplement samples analyzed were suitable for human consumption.

  2. Flow injection on-line displacement/solid phase extraction system coupled with flame atomic absorption spectrometry for selective trace silver determination in water samples.

    PubMed

    Christou, Chrysoula K; Anthemidis, Aristidis N

    2009-04-15

    A novel flow injection (FI) on-line displacement solid phase extraction preconcentration and/or separation method coupled with FAAS in order to minimize interference from other metals was developed for trace silver determination. The proposed method involved the on-line formation and subsequently pre-sorption of lead diethyldithiocarbamate (Pb-DDTC) into a column packed with PTFE-turnings. The preconcentration and/or separation of the Ag(I) took place through a displacement reaction between Ag(I) and Pb(II) of the pre-sorbed Pb-DDTC. Finally, the retained analyte was eluted with isobutyl methyl ketone (IBMK) and delivered directly to nebulizer for measuring. Interference from co-existing ions with lower DDTC complex stability in comparison with Pb-DDTC, was eliminated without need for any masking reagent. With 120 s of preconcentration time at a sample flow rate of 7.6 mL min(-1), an enhancement factor of 110 and a detection limit (3s) of 0.2 microg L(-1) were obtained. The precision (RSD, n=10) was 3.1% at the 10 mug L(-1) level. The developed method was successfully applied to trace silver determination in a variety of environmental water samples and certified reference material.

  3. Cadmium determination in natural water samples with an automatic multisyringe flow injection system coupled to a flow-through screen printed electrode.

    PubMed

    Henríquez, C; Laglera, L M; Alpizar, M J; Calvo, J; Arduini, F; Cerdà, V

    2012-07-15

    Heavy metals, as cadmium, attract a rising attention in environmental studies due to their increasing release by human activities and acute toxicity. In situ analytical methods are needed to minimize current uncertainties caused by the transport and conservation of samples. Here, we present the completely automatic determination of Cd in natural waters using a newly developed screen printed electrode sensor (SPE), inserted in a homemade purpose-built flow cell coupled to a Multi-Syringe Flow Injection Analysis system (MSFIA). The working electrode of SPEs was constituted by a carbon film modified with Nafion. Cd was plated on an in situ bismuth film and determined using Square Wave Anodic Stripping Voltammetry. Different chemical conditions of deposition and stripping were studied. A sample/acetic buffer mixture was found to be a well suited medium to form the Bi film and perform the analysis. Cd was quantified via calibration by on line standard additions. The limit of detection was found to be 0.79μgL(-1), well below the limit stipulated by the European directive (5μgL(-1)). Good sample throughput (14h(-1)) and low consumption of reagent and sample (1.3mL) were also obtained in line with previous works in Cd flow analysis.

  4. On-column polymer-imbedded graphite inlet electrode for capillary electrophoresis coupled on-line with flow injection analysis in a poly(dimethylsiloxane) interface.

    PubMed

    Samskog, Jenny; Bergström, Sara K; Jönsson, Mats; Klett, Oliver; Wetterhall, Magnus; Markides, Karin E

    2003-06-01

    A method for coupling an electrophoretic driven separation to a liquid flow, using conventional fused-silica capillaries and a soft polymeric interface is presented. A novel design of the electrode providing high voltage to the electrophoretic separation was also developed. The electrode consisted of a conductive polyimide/graphite imbedded coating immobilized onto the capillary electrophoresis (CE) column inlet. This integrated electrode gave the same separation performance as a commonly used platinum electrode. The on-column electrode also showed good electrochemical stability in chronoamperometric experiments. In addition, with this electrode design, the electrode position relative to the inlet end of the CE column will always be constant and well defined. The on-line flow injection analysis (FIA)-CE system was used with electrospray ionization (ESI)-time of flight (TOF)-mass spectrometry detection. The preparation of the PDMS (poly(dimethylsiloxane)) interface for FIA-CE is described in detail and used for initial tests of the on-column polymer-imbedded graphite inlet electrode. In this interface, a pressure-driven liquid flow, a make up CE electrolyte and a CE column inlet meet in a two-level cross (95 microm ID) in the PDMS structure, enabling independent flow characterization.

  5. Coupled pressure and velocity distributions in a pressure-driven flow inside a long pipe with fluid injection through porous walls.

    NASA Astrophysics Data System (ADS)

    Frenkel, Alexander L.; Bolshinskiy, Leonid

    2008-04-01

    We are studying steady flows of Newtonian liquids in pipes with porous walls. One end of the pipe is closed; the ambient liquid is injected through the pipe wall under the Darcy-Weisbach law and exits at the open end with a pressure that is kept below the uniform fluid pressure outside the pipe walls. The inside pressure varies with the axial coordinate and is coupled with the varying axial velocity averaged over the cross-section of the pipe. For a long pipe, the Karman-Polhausen averaging of Navier-Stokes equations is used for both laminar and turbulent flow regimes. We obtain a boundary value problem for a nonlinear second-order differential equation governing the velocity distribution and explore numerous flow regimes by numerically solving it. Hence, the pipe pressure is found as a quadratic expression in terms of the velocity derivative. At sufficiently high Reynolds numbers, quite unlike the standard pipe flow with uniform velocity, even the turbulent friction turns out negligible in comparison with the pressure gradient required for accelerating the liquid toward the exit. The inertial approximation allows for an analytic solution. The nonzero-gravity generalization is obtained, and applications to channels with fine-mesh screen walls utilized for the delivery of liquid propellant to the engine at low gravity, are discussed.

  6. Direct determination of copper and iodine in milk and milk powder in alkaline solution by flow injection inductively coupled plasma mass spectrometry.

    PubMed

    Stürup, S; Büchert, A

    1996-01-01

    The development and evaluation of a flow injection inductively coupled plasma mass spectrometric (FI-ICP-MS) method for the determination of copper and iodine in milk and milk powder has been described. The sample preparation is based simply on the dilution of the sample by an alkaline solution containing 0.05 mol/l potassium hydroxide and 0.07 mol/l tetramethylammonium hydroxide. Possible matrix interferences on the determination of copper were alleviated by the use of standard addition calibration. Detection limits (3s) were 0.94 microg l(-1) and 0.45 microg l(-1) for copper and iodine, respectively. Four different certified milk powder reference materials were analysed and the concentrations found were in a good agreement with the certified values indicating that the method is unbiased. Due to the simplicity of the method a high sample throughput is possible, approximately 90 samples can be analysed in one day. More than 100 samples of Danish raw milk were analysed and median values of 0.050 mg kg(-1) of Cu and 0.084 mg kg(-1) of I were found.

  7. Performance of different preconcentration columns used in sequential injection analysis and inductively coupled plasma-mass spectrometry for multielemental determination in seawater

    NASA Astrophysics Data System (ADS)

    Jiménez, María. S.; Velarte, Rosario; Castillo, Juan R.

    2002-03-01

    A simple, versatile and economical method of sequential injection analysis and inductively coupled plasma-mass spectrometry with matrix removal in two different ion-exchange resins for the determination of Al, As, Co, Cu, Mn, Mo, Ni, Pb and V is reported. The resins used, both of which contain the iminodiacetic acid functional group, were Chelex 100 and Metpac CC-1. With both resins, a matrix removal step (alkaline and alkaline-earth metals) with ammonium acetate is required before elution of the analytes with 2 M HNO 3. The procedure was validated by analyzing CASS-3 seawater reference material and good agreement was found with the certified values. Precision ( n=8) for the nine elements was in the range 0.8-4.9% for the Chelex 100 column and the recoveries ranged from 87.4 to 107.9%, except for Cu (78.7%) and Pb (74.9%), owing to the formation of hydroxides. For the Metpac CC-1 column, precision for the nine elements was in the range 1.2-7.1% and the recoveries between 91.7 and 109.3%, except for Al (127.2%), Co (118.5%) and Ni (127.5%) due to contamination problems.

  8. Determination of rare earth elements in geological samples by inductively coupled plasma atomic emission spectrometry with flow injection liquid-liquid extraction.

    PubMed

    Xu, Zhifang; Liu, Congqiang; Zhang, Hongxiang; Ma, Yingjun; Lin, Soulin

    2003-12-01

    A direct sampling with organic solvent extracts for simultaneous multi-element determination implemented with inductively coupled plasma atomic emission spectrometry (ICP-AES) associated with a flow injection liquid-liquid extraction (FI-LLE) sample preconcentration method was studied. The "robustness" of the plasma discharge with tributyl phosphate (TBP) loading was diagnosed by using the Mg II 279.55 nm and Mg I 285.21 nm lines intensity ratio. A FI-LLE preconcentration system for rare earth elements (REEs)-nitrate-TBP was established by using a laboratory-designed phase separator. For these elements, an average sensitivity enhancement factor of 64 was obtained with respect to ICP-AES sampling with aqueous solutions. The precision of the method was characterized by a relative standard deviation (%RSD) of 1.8 - 5.2%. A throughput of 27 samples per hour can be achieved with an organic solvent consumption of less than 200 microl per determination. Good results were obtained for the analysis of standard reference materials.

  9. The intravenous injection of oxidized LDL- or Apolipoprotein B100--Coupled splenocytes promotes Th1 polarization in wildtype and Apolipoprotein E--Deficient mice.

    PubMed

    Steinmetz, Martin; Ponnuswamy, Padmapriya; Laurans, Ludivine; Esposito, Bruno; Tedgui, Alain; Mallat, Ziad

    2015-08-14

    Th1 responses in atherosclerosis are mainly associated with the aggravation of atherosclerotic plaques, whereas Th2 responses lead to a less pronounced disease in mouse models. The fixation of antigens on cells by means of ethylene carbodiimide (ECDI), and subsequent injection of these antigen-coupled splenocytes (Ag-SP) to induce tolerance against the attached antigens, has been successfully used to treat murine type 1 diabetes or encephalomyelitis in. We analyzed this approach in a mouse model for atherosclerosis. OTII-transgenic mice that were treated with a single dose of 5 × 10(7) OVA-coupled splenocytes (OVA-SP), had decreased splenocyte proliferation, and lower IFNγ production in vitro upon antigen recall. However, in vivo CD4 cell activation was increased. To try lipoprotein-derived, "atherosclerosis-associated" antigens, we first tested human oxidized LDL. In wild type mice, an increase of IFNγ production upon in vitro recall was detected in the oxLDL-SP group. In Apolipoprotein E - deficient (ApoE-/-) mice that received oxLDL-SP every 5 weeks for 20 weeks, we did not find any difference of atherosclerotic plaque burden, but again increased IFNγ production. To overcome xenogenous limitations, we then examined the effects of mouse Apolipoprotein B100 peptides P3 and P6. ApoB100-SP treatment again promoted a more IFNγ pronounced response upon in vitro recall. Flow cytometry analysis of cytokine secreting spleen cells revealed CD4 positive T cells to be mainly the source for IFNγ. In ApoE-/- mice that were administered ApoB100-SP during 20 weeks, the atherosclerotic plaque burden in aortic roots as well as total aorta was unchanged compared to PBS treated controls. Splenocyte proliferation upon antigen recall was not significantly altered in ApoB100-SP treated ApoE-/- mice. Although we did not observe a relevant anti-atherosclerotic benefit, the treatment with antigen-coupled splenocytes in its present form already impacts the immune responses and

  10. Measurement of elemental speciation by liquid chromatography -- inductively coupled plasma mass spectrometry (LC-ICP-MS) with the direct injection nebulizer (DIN)

    SciTech Connect

    Shum, Sam

    1993-05-01

    This thesis is divided into 4 parts: elemental speciation, speciation of mercury and lead compounds by microbore column LC-ICP-MS with direct injection nebulization, spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer, and elemental speciation by anion exchange and size exclusion chromatography with detection by ICP-MS with direct injection nebulization.

  11. Etanercept Injection

    MedlinePlus

    ... injection comes as a solution (liquid) in a prefilled syringe and an automatic injection device, and as a ... etanercept injection.If your medication comes in a prefilled syringe or automatic injection device, use each syringe or ...

  12. The combination of octreotide and midodrine is not superior to albumin in preventing recurrence of ascites after large-volume paracentesis.

    PubMed

    Bari, Khurram; Miñano, Cecilia; Shea, Martha; Inayat, Irteza B; Hashem, Hashem J; Gilles, Hochong; Heuman, Douglas; Garcia-Tsao, Guadalupe

    2012-10-01

    Large-volume paracentesis (LVP) is the treatment of choice for patients with cirrhosis and refractory ascites. However, LVP can lead to postparacentesis circulatory dysfunction (PCD), which is associated with faster ascites recurrence and renal failure. PCD results from vasodilatation, which reduces effective blood volume, and is prevented by intravenous administration of albumin. Vasoconstrictors could be used instead of albumin and, with longer use, prevent PCD and delay ascites recurrence. We performed a multicenter, randomized, double-blind, placebo-controlled trial to compare albumin with the vasoconstrictor combination of octreotide and midodrine in patients with refractory ascites who underwent LVP. Patients in the albumin group received a single intravenous dose of albumin at the time of LVP plus placebos for midodrine and octreotide (n = 13). Patients in the vasoconstrictor group received saline solution (as a placebo for albumin), 10 mg of oral midodrine (3 times/day), and a monthly 20-mg intramuscular injection of long-acting octreotide (n = 12). Patients were followed up until recurrence of ascites. The median times to recurrence of ascites were 10 days in the albumin group and 8 days in the vasoconstrictor group (P = .318). There were no significant differences in PCD between the albumin group (18%) and the vasoconstrictor group (25%, P = .574). When ascites recurred, serum levels of creatinine were higher in the vasoconstrictor group (1.2 vs 0.9 mg/dL in the albumin group; P = .051). The combination of midodrine and octreotide after LVP is not superior to albumin in delaying recurrence of ascites or preventing PCD in patients with cirrhosis. Outcomes appear to be worse in patients given octreotide and midodrine. ClinicalTrials.gov number, NCT00108355. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

  13. The Combination of Octreotide and Midodrine is not Superior to Albumin in Preventing Recurrence of Ascites after Large-Volume Paracentesis

    PubMed Central

    Bari, Khurram; Minano, Cecilia; Shea, Martha; Inayat, Irteza B.; Hashem, Hashem J.; Gilles, HoChong; Heuman, Douglas; Garcia-Tsao, Guadalupe

    2012-01-01

    Background & Aims Large-volume paracentesis (LVP) is the treatment of choice for patients with cirrhosis and refractory ascites. However, LVP can lead to post-paracentesis circulatory dysfunction (PCD), which is associated with faster ascites recurrence and renal failure. PCD results from vasodilatation, which reduces effective blood volume, and is prevented by intravenous administration of albumin. Vasoconstrictors could be used instead of albumin and, with longer use, prevent PCD and delay ascites recurrence. Methods We performed a multicenter, randomized, double-blind, placebo controlled trial to compare albumin with the vasoconstrictor combination of octreotide and midodrine in patients with refractory ascites who underwent LVP. Patients in the albumin group received a single intravenous dose of albumin at the time of LVP plus placebos for midodrine and octreotide (n=13). Patients in the vasoconstrictor group received saline solution (as a placebo for albumin), 10 mg of oral midodrine (3 times daily), and a monthly, 20 mcg intra-muscular injection of long-acting octreotide (n=12). Patients were followed until recurrence of ascites. Results The median times to recurrence of ascites were 10 days in the albumin group and 8 days in the vasoconstrictor group (P=.318). There were no significant differences in PCD between the albumin group (18%) and the vasoconstrictor group (25%, P=.574). When ascites recurred, serum levels of creatinine were higher in the vasoconstrictor group (1.2 vs 0.9 mg/dL in the albumin group, P=.051). Conclusions The combination of midodrine and octreotide after LVP is not superior to albumin in delaying recurrence of ascites or preventing PCD in patients with cirrhosis. Outcomes appear to be worse in patients given octreotide and midodrine. PMID:22801062

  14. Magnetostructural martensitic transformations with large volume changes and magneto-strains in all-d-metal Heusler alloys

    NASA Astrophysics Data System (ADS)

    Wei, Z. Y.; Liu, E. K.; Li, Y.; Han, X. L.; Du, Z. W.; Luo, H. Z.; Liu, G. D.; Xi, X. K.; Zhang, H. W.; Wang, W. H.; Wu, G. H.

    2016-08-01

    The all-d-metal Mn2-based Heusler ferromagnetic shape memory alloys Mn50Ni40-xCoxTi10 (x = 8 and 9.5) are realized. With a generic comparison between d-metal Ti and main-group elements in lowering the transformation temperature, the magnetostructural martensitic transformations are established by further introducing Co to produce local ferromagnetic Mn-Co-Mn configurations. A 5-fold modulation and (3, -2) stacking of [00 10] of martensite are determined by X-ray diffraction and HRTEM analysis. Based on the transformation, a large magneto-strain of 6900 ppm and a large volume change of -2.54% are observed in polycrystalline samples, which makes the all-d-metal magnetic martensitic alloys of interest for magnetic/pressure multi-field driven applications.

  15. Large Volume Self-Organization of Polymer/Nanoparticle Hybrids with Millimeter Scale Grain Sizes using Brush Block Copolymers

    NASA Astrophysics Data System (ADS)

    Song, Dongpo; Watkins, James

    The lack of sufficient long-range order in self-assembled nanostructures is a bottleneck for many nanotechnology applications. In this work, we report that exceptionally large volume of highly ordered arrays (single grains) on the order of millimeters in scale can be rapidly created through a unique innate guiding mechanism of brush block copolymers (BBCPs). The grain volume is over 1 billion times larger relative to that of typical self-assembled linear BCPs (LBCPs). The use of strong interactions between nanoparticles (NPs) and BBCPs enables the high loadings of functional materials, up to 76 wt% (46 vol%) in the target domain, while maintaining excellent long-range order. Overall this work provides a simple route to precisely control the spatial orientation of functionalities at nanometer length scales over macroscopic volumes, thereby enabling the production of hybrid materials for many important applications.

  16. A 3D time reversal cavity for the focusing of high-intensity ultrasound pulses over a large volume

    NASA Astrophysics Data System (ADS)

    Robin, J.; Arnal, B.; Tanter, M.; Pernot, M.

    2017-02-01

    Shock wave ultrasound therapy techniques, increasingly used for non-invasive surgery, require extremely high pressure amplitudes in precise focal spots, and large high-power transducers arranged on a spherical shell are usually used to achieve that. This solution allows limited steering of the beam around the geometrical focus of the device at the cost of a large number of transducer elements, and the treatment of large and moving organs like the heart is challenging or impossible. This paper validates numerically and experimentally the possibility of using a time reversal cavity (TRC) for the same purpose. A 128-element, 1 MHz power transducer combined with different multiple scattering media in a TRC was used. We were able to focus high-power ultrasound pulses over a large volume in a controlled manner, with a limited number of transducer elements. We reached sufficiently high pressure amplitudes to erode an Ultracal® target over a 10 cm2 area.

  17. A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device

    NASA Astrophysics Data System (ADS)

    Srivastava, P. K.; Singh, S. K.; Sanyasi, A. K.; Awasthi, L. M.; Mattoo, S. K.

    2016-07-01

    This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltage protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.

  18. Magnetostructural martensitic transformations with large volume changes and magneto-strains in all-d-metal Heusler alloys

    SciTech Connect

    Wei, Z. Y.; Liu, E. K. Xi, X. K.; Zhang, H. W.; Wang, W. H.; Wu, G. H.; Li, Y.; Han, X. L.; Du, Z. W.; Luo, H. Z.; Liu, G. D.

    2016-08-15

    The all-d-metal Mn{sub 2}-based Heusler ferromagnetic shape memory alloys Mn{sub 50}Ni{sub 40−x}Co{sub x}Ti{sub 10} (x = 8 and 9.5) are realized. With a generic comparison between d-metal Ti and main-group elements in lowering the transformation temperature, the magnetostructural martensitic transformations are established by further introducing Co to produce local ferromagnetic Mn-Co-Mn configurations. A 5-fold modulation and (3, −2) stacking of [00 10] of martensite are determined by X-ray diffraction and HRTEM analysis. Based on the transformation, a large magneto-strain of 6900 ppm and a large volume change of −2.54% are observed in polycrystalline samples, which makes the all-d-metal magnetic martensitic alloys of interest for magnetic/pressure multi-field driven applications.

  19. A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device.

    PubMed

    Srivastava, P K; Singh, S K; Sanyasi, A K; Awasthi, L M; Mattoo, S K

    2016-07-01

    This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltage protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.

  20. Detection of triazole deicing additives in soil samples from airports with low, mid, and large volume aircraft deicing activities.

    PubMed

    McNeill, K S; Cancilla, D A

    2009-03-01

    Soil samples from three USA airports representing low, mid, and large volume users of aircraft deicing fluids (ADAFs) were analyzed by LC/MS/MS for the presence of triazoles, a class of corrosion inhibitors historically used in ADAFs. Triazoles, specifically the 4-methyl-1H-benzotriazole and the 5-methyl-1H-benzotriazole, were detected in a majority of samples and ranged from 2.35 to 424.19 microg/kg. Previous studies have focused primarily on ground and surface water impacts of larger volume ADAF users. The detection of triazoles in soils at low volume ADAF use airports suggests that deicing activities may have a broader environmental impact than previously considered.

  1. Systems and methods for the detection of low-level harmful substances in a large volume of fluid

    DOEpatents

    Carpenter, Michael V.; Roybal, Lyle G.; Lindquist, Alan; Gallardo, Vincente

    2016-03-15

    A method and device for the detection of low-level harmful substances in a large volume of fluid comprising using a concentrator system to produce a retentate and analyzing the retentate for the presence of at least one harmful substance. The concentrator system performs a method comprising pumping at least 10 liters of fluid from a sample source through a filter. While pumping, the concentrator system diverts retentate from the filter into a container. The concentrator system also recirculates at least part of the retentate in the container again through the filter. The concentrator system controls the speed of the pump with a control system thereby maintaining a fluid pressure less than 25 psi during the pumping of the fluid; monitors the quantity of retentate within the container with a control system, and maintains a reduced volume level of retentate and a target volume of retentate.

  2. The importance of preoperative hemoglobin evaluation in large volume liposuction: lessons learned from our 15-year experience.

    PubMed

    Choudry, Umar H; Hyza, Petr; Lane, Jason; Petty, Paul

    2008-09-01

    Liposuction of >5 L of total aspirate at one setting is defined as large volume liposuction (LVL). A retrospective chart review was performed on all patients who underwent LVL from January 1990 to June 2005. Sixty-two patients underwent LVL. The mean volume of total aspirate was 8 L (5.0-11.7 L). There were a total of 6 patients who had complications. These included symptomatic postoperative anemia requiring blood transfusions on postoperative day 1 (n = 5), and an expanding hematoma requiring operative evacuation without transfusion (n = 1). Two of the patients who had blood transfusions had a history of gastric bypass and all of the patients were preoperatively anemic (<11.5 mg/dL). The mean follow up was 38 months. LVL is safe when performed in healthy patients under strict guidelines. Hemoglobin levels of all potential LVL patients should be checked preoperatively, and surgery should be withheld for levels <12 g/dL.

  3. Yardea Dacite -large-volume, high-temperature felsic volcanism from the Middle Proterozoic of South Australia

    SciTech Connect

    Creaser, R.A.; White, A.J.R. )

    1991-01-01

    The Yardea Dacite is a large-volume felsic volcanic unit from the Middle Proterozoic Gawler Range Volcanics of South Australia; it has been previously described as an ignimbrite. However, some samples contain no petrographic evidence for a pyroclastic origin, but have characteristics compatible with final crystallization from a nonfragmented magma. These samples may have erupted as lavas, but others are likely to be extremely densely welded ignimbrites, suggesting a compound nature for the unit. Geothermometry and phase equilibria indicate that the Yardea Dacite originated from a high-temperature ({approximately}1,000{degree}C) felsic magma with a low water content ({le}2%). The Yardea Dacite is not associated with a known caldera of the Valles type, and shares many characteristics of recently described Cenozoic felsic volcanic rocks from the western United States, interpreted as rheoignimbrites or as unusually extensive lavas.

  4. A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device

    SciTech Connect

    Srivastava, P. K. Singh, S. K.; Sanyasi, A. K.; Awasthi, L. M. Mattoo, S. K.

    2016-07-15

    This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltage protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.

  5. A large volume particulate and water multi-sampler with in situ preservation for microbial and biogeochemical studies

    NASA Astrophysics Data System (ADS)

    Breier, J. A.; Sheik, C. S.; Gomez-Ibanez, D.; Sayre-McCord, R. T.; Sanger, R.; Rauch, C.; Coleman, M.; Bennett, S. A.; Cron, B. R.; Li, M.; German, C. R.; Toner, B. M.; Dick, G. J.

    2014-12-01

    A new tool was developed for large volume sampling to facilitate marine microbiology and biogeochemical studies. It was developed for remotely operated vehicle and hydrocast deployments, and allows for rapid collection of multiple sample types from the water column and dynamic, variable environments such as rising hydrothermal plumes. It was used successfully during a cruise to the hydrothermal vent systems of the Mid-Cayman Rise. The Suspended Particulate Rosette V2 large volume multi-sampling system allows for the collection of 14 sample sets per deployment. Each sample set can include filtered material, whole (unfiltered) water, and filtrate. Suspended particulate can be collected on filters up to 142 mm in diameter and pore sizes down to 0.2 μm. Filtration is typically at flowrates of 2 L min-1. For particulate material, filtered volume is constrained only by sampling time and filter capacity, with all sample volumes recorded by digital flowmeter. The suspended particulate filter holders can be filled with preservative and sealed immediately after sample collection. Up to 2 L of whole water, filtrate, or a combination of the two, can be collected as part of each sample set. The system is constructed of plastics with titanium fasteners and nickel alloy spring loaded seals. There are no ferrous alloys in the sampling system. Individual sample lines are prefilled with filtered, deionized water prior to deployment and remain sealed unless a sample is actively being collected. This system is intended to facilitate studies concerning the relationship between marine microbiology and ocean biogeochemistry.

  6. SyPRID sampler: A large-volume, high-resolution, autonomous, deep-ocean precision plankton sampling system

    NASA Astrophysics Data System (ADS)

    Billings, Andrew; Kaiser, Carl; Young, Craig M.; Hiebert, Laurel S.; Cole, Eli; Wagner, Jamie K. S.; Van Dover, Cindy Lee

    2017-03-01

    The current standard for large-volume (thousands of cubic meters) zooplankton sampling in the deep sea is the MOCNESS, a system of multiple opening-closing nets, typically lowered to within 50 m of the seabed and towed obliquely to the surface to obtain low-spatial-resolution samples that integrate across 10 s of meters of water depth. The SyPRID (Sentry Precision Robotic Impeller Driven) sampler is an innovative, deep-rated (6000 m) plankton sampler that partners with the Sentry Autonomous Underwater Vehicle (AUV) to obtain paired, large-volume plankton samples at specified depths and survey lines to within 1.5 m of the seabed and with simultaneous collection of sensor data. SyPRID uses a perforated Ultra-High-Molecular-Weight (UHMW) plastic tube to support a fine mesh net within an outer carbon composite tube (tube-within-a-tube design), with an axial flow pump located aft of the capture filter. The pump facilitates flow through the system and reduces or possibly eliminates the bow wave at the mouth opening. The cod end, a hollow truncated cone, is also made of UHMW plastic and includes a collection volume designed to provide an area where zooplankton can collect, out of the high flow region. SyPRID attaches as a saddle-pack to the Sentry vehicle. Sentry itself is configured with a flight control system that enables autonomous survey paths to low altitudes. In its verification deployment at the Blake Ridge Seep (2160 m) on the US Atlantic Margin, SyPRID was operated for 6 h at an altitude of 5 m. It recovered plankton samples, including delicate living larvae, from the near-bottom stratum that is seldom sampled by a typical MOCNESS tow. The prototype SyPRID and its next generations will enable studies of plankton or other particulate distributions associated with localized physico-chemical strata in the water column or above patchy habitats on the seafloor.

  7. On-line UV-photooxidation with peroxodisulfate for automated flow injection and for high-performance liquid chromatography coupled to hydride generation atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Tsalev, Dimiter L.; Sperling, Michael; Welz, Bernhard

    2000-04-01

    An automated on-line UV photooxidation with peroxodisulfate of some environmentally relevant organoarsenic and organotin compounds in a system built from commercially available modules has been studied and optimised with a view to both species-independent quantification of the total arsenic or tin in samples containing different organic species by flow injection hydride generation atomic absorption spectrometry (FI-HGAAS) and speciation analysis by coupled high-performance liquid chromatography (HPLC) with HGAAS detection. For organoarsenicals, the reaction with alkaline peroxodisulfate in a 10-15-m knotted reactor for >1.5 min insures >90% transformation of inorganic As(III) and six organoarsenic species to arsenate: monomethylarsonate, dimethylarsinate, arsenobetaine, arsenocholine, trimethylarsine oxide and tetramethylarsonium. For organotins, the UV photooxidation with acidic peroxodisulfate at 95-100°C provides recoveries of >80% for the inorganic tin, dimethyltin, trimethyltin, triethyltin, tripropyltin, triphenyltin, monobutyltin, dibutyltin and tributyltin but only approximately 15% for tetrabutyltin. The best characteristic masses in integrated absorbance ( Aint) and peak-height ( Ap) measurements, respectively, are 30 pg and 480 pg for arsenic(V) and 22 pg and 410 pg for tin(IV), employing 100-μl injections. The RSDs are 5.5% and 8.5% at 5 ng As(V) levels and 4.3% and 6.4% at 10 ng Sn(IV) levels in Aint and Ap modes, respectively. The limits of detection (LOD, 3σ) for As are 7 μg l -1 and 4 μg l -1 in FI-UV-HGAAS and HPLC-UV-HGAAS, respectively. The LODs for i-Sn(IV) are 2 μg l -1 in FI-UV-HGAAS, with both Aint and Ap measurements. The sample throughput rates are 20 and 12 samples per hour with 10-m and 15-m knotted reactors (i.d. 0.5 mm), respectively. Urine certified reference materials containing 0.052-0.48 μg ml -1 As have been analysed for their total arsenic content.

  8. The development of iodine based impinger solutions for the efficient capture of Hg0 using direct injection nebulization-inductively coupled plasma mass spectrometry analysis.

    PubMed

    Hedrick, E; Lee, T G; Biswas, P; Zhuang, Y

    2001-09-15

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hg0) in EPA Method 5 type sampling. An iodine based impinger solution proved to be very efficient for Hg0 capture and was amenable to direct analysis by DIN-ICP/MS. Hg0 capture efficiency using aqueous iodine (I3-) was comparable to Hg0 capture using acidified potassium permanganate impinger solutions which were analyzed by cold vapor atomic absorption spectrometry (CVAAS), with greater than 98% capture of Hg0 in the first oxidizing impinger. Using DIN-ICP/MS, it was demonstrated for the first time that iodine can be generated just prior to impinger sampling for efficiently oxidizing Hg0 and retaining it in solution as HgI4(2-). Due to the increased interest in Hg speciation from combustion sources and the potential for using DIN-ICP/MS for multiple metals analyses, an impinger sampling train for gaseous Hg speciation and multiple metals analyses using DIN-ICP/MS analyses is presented. The unique feature of such a sampling train is that each impinger solution in the series is amenable to direct analysis by DIN-ICP/MS. A bituminous coal was combusted in a bench scale coal system, and gaseous Hg species (oxidized and elemental) were determined using the proposed impinger train. The DIN-ICP/MS instrumental detection limit was 0.003 ppb, and MDLs ranged from 0.007 to 0.116 microg/L (ppb) in a variety of impinger solutions used for Hg capture.

  9. On-line coupling of Micro-Extraction by Packed Sorbent with Sequential Injection Chromatography system for direct extraction and determination of betaxolol in human urine.

    PubMed

    Šrámková, Ivana; Chocholouš, Petr; Sklenářová, Hana; Šatínský, Dalibor

    2015-10-01

    A novel approach for automation of Micro-Extraction by Packed Sorbent (MEPS), a solid phase extraction technique, is presented, enabling precise and repeatable liquid handling due to the employment of sequential injection technique. The developed system was used for human urine sample clean-up and pre-concentration of betaxolol before its separation and determination. A commercial MEPS C-18 cartridge was integrated into an SIChrom™ system. The chromatographic separation was performed on a monolithic High Resolution C18 (50×4.6 mm) column which was coupled on-line in the system with Micro-Extraction using an additional selection valve. A mixture of acetonitrile and aqueous solution of 0.5% triethylamine with acetic acid, pH adjusted to 4.5 in ratio 30:70 was used as a mobile phase for elution of betaxolol from MEPS directly onto the monolithic column where the separation took place. Betaxolol was quantified by a fluorescence detector at wavelengths λ(ex)=220 nm and λ(em)=305 nm. The linear calibration range of 5-400 ng mL(-1), with limit of detection 1.5 ng mL(-1) and limit of quantification 5 ng mL(-1) and correlation r=0.9998 for both the standard and urine matrix calibration were achieved. The system recovery was 105±5%; 100±4%; 108±1% for three concentration levels of betaxolol in 10 times diluted urine - 5, 20 and 200 ng mL(-1), respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. A flow injection analyser conductometric coupled system for the field analysis of free dissolved CO2 and total dissolved inorganic carbon in natural waters.

    PubMed

    Martinotti, Valter; Balordi, Marcella; Ciceri, Giovanni

    2012-05-01

    A flow injection analyser coupled with a gas diffusion membrane and a conductometric microdetector was adapted for the field analysis of natural concentrations of free dissolved CO2 and dissolved inorganic carbon in natural waters and used in a number of field campaigns for marine water monitoring. The dissolved gaseous CO2 presents naturally, or that generated by acidification of the sample, is separated by diffusion using a hydrophobic semipermeable gas porous membrane, and the permeating gas is incorporated into a stream of deionised water and measured by means of an electrical conductometric microdetector. In order to make the system suitable and easy to use for in-field measurements aboard oceanographic ships, the single components of the analyser were compacted into a robust and easy to use system. The calibration of the system is carried out by using standard solutions of potassium bicarbonate at two concentration ranges. Calibration and sample measurements are carried out inside a temperature-constant chamber at 25 °C and in an inert atmosphere (N2). The detection and quantification limits of the method, evaluated as 3 and 10 times the standard deviation of a series of measurements of the matrix solution were 2.9 and 9.6 μmol/kg of CO2, respectively. Data quality for dissolved inorganic carbon was checked with replicate measurements of a certified reference material (A. Dickson, Scripps Institution of Oceanography, University of California, San Diego), both accuracy and repeatability were -3.3% and 10%, respectively. Optimization, performance qualification of the system and its application in various natural water samples are reported and discussed. In the future, the calibration step will be operated automatically in order to improve the analytical performance and the applicability will be increased in the course of experimental surveys carried out both in marine and freshwater ecosystems. Considering the present stage of development of the method, it

  11. Flow Injection Photochemical Vapor Generation Coupled with Miniaturized Solution-Cathode Glow Discharge Atomic Emission Spectrometry for Determination and Speciation Analysis of Mercury.

    PubMed

    Mo, Jiamei; Li, Qing; Guo, Xiaohong; Zhang, Guoxia; Wang, Zheng

    2017-09-15

    A novel, compact, and green method was developed for the determination and speciation analysis of mercury, based on flow injection photochemical vapor generation (PVG) coupled with miniaturized solution cathode glow discharge-atomic emission spectroscopy (SCGD-AES). The SCGD was generated between a miniature hollow titanium tube and a solution emerging from a glass capillary. Cold mercury vapor (Hg(0)) was generated by PVG and subsequently delivered to the SCGD for excitation, and finally the emission signals were recorded by a miniaturized spectrograph. The detection limits (DLs) of Hg(II) and methylmercury (MeHg) were both determined to be 0.2 μg L(-1). Moreover, mercury speciation analysis could also be performed by using different wavelengths and powers from the UV lamp and irradiation times. Both Hg(II) and MeHg can be converted to Hg(0) for the determination of total mercury (T-Hg) with 8 W/254 nm UV lamp and 60 s irradiation time; while only Hg(II) can be reduced to Hg(0) and determined selectively with 4 W/365 nm UV lamp and 20 s irradiation time. Then, the concentration of MeHg can be calculated by subtracting the Hg(II) from the T-Hg. Because of its similar sensitivity and DL at 8 W/254 nm, the simpler and less toxic Hg(II) was used successfully as a primary standard for the quantification of T-Hg. The novel PVG-SCGD-AES system provides not only a 365-fold improvement in the DL for Hg(II) but also a nonchromatographic method for the speciation analysis of mercury. After validating its accuracy, this method was successfully used for mercury speciation analysis of water and biological samples.

  12. Extraction of trace amounts of mercury with sodium dodecyle sulphate-coated magnetite nanoparticles and its determination by flow injection inductively coupled plasma-optical emission spectrometry.

    PubMed

    Faraji, Mohammad; Yamini, Yadollah; Rezaee, Mohammad

    2010-05-15

    A new method for solid-phase extraction and preconcentration of trace amounts Hg(II) from environmental samples was developed by using sodium dodecyle sulphate-coated magnetite nanoparticles (SDS-coated Fe(3)O(4) NPs) as a new extractant. The procedure is based on the adsorption of the analyte, as mercury-Michler's thioketone [Hg(2)(TMK)(4)](2+) complex on the negatively charged surface of the SDS-coated Fe(3)O(4) NPs and then elution of the preconcentrated mercury from the surface of the SDS-coated Fe(3)O(4) NPs prior to its determination by flow injection inductively coupled plasma-optical emission spectrometry. The effects of pH, TMK concentration, SDS and Fe(3)O(4) NPs amounts, eluent type, sample volume and interfering ions on the recovery of the analyte were investigated. Under optimized conditions, the calibration curve was linear in the range of 0.2-100ngmL(-1) with r(2)=0.9994 (n=8). The limit of detection for Hg(II) determination was 0.04ngmL(-1). Also, relative standard deviation (R.S.D.) for the determination of 2 and 50ngmL(-1) of Hg(II) was 5.2 and 4.7% (n=6), respectively. Due to the quantitative extraction of Hg(II) from 1000mL of the sample solution an enhancement factor as large as 1230-fold can be obtained. The proposed method has been validated using a certified reference materials, and also the method has been applied successfully for the determination of Hg(II) in aqueous samples.

  13. PULSED SPLITLESS AND LARGE-VOLUME INJECTION IN CAPILLARY GAS CHROMATOGRAPHY MASS SPECTROMETRY FOR THE DETERMINATION OF ULTRA-TRACE LEVEL PESTICIDE RESIDUES

    EPA Science Inventory

    The possible presence of ultra-trace levels (sub- parts per trillion) of pesticides in pristine aquatic environments (e.g., alpine lakes) would raise questions regarding potential effects on biota. One hypothesis is that agricultural pesticides that are heavily applied in the San...

  14. PULSED SPLITLESS AND LARGE-VOLUME INJECTION IN CAPILLARY GAS CHROMATOGRAPHY MASS SPECTROMETRY FOR THE DETERMINATION OF ULTRA-TRACE LEVEL PESTICIDE RESIDUES

    EPA Science Inventory

    The possible presence of ultra-trace levels (sub- parts per trillion) of pesticides in pristine aquatic environments (e.g., alpine lakes) would raise questions regarding potential effects on biota. One hypothesis is that agricultural pesticides that are heavily applied in the San...

  15. Application of ultradisperse magnetic adsorbents for removal of small concentrations of pollutants from large volumes of water

    NASA Astrophysics Data System (ADS)

    Nechitailo, Galina S.; Kuznetsov, Anatoli; Kuznetsov, Oleg

    2016-07-01

    Pollution of natural bodies of water (rivers, lakes, ground water, etc) is unfortunately very common, both from natural sources like volcanic activity; and, even more importantly, from human activity, including disposal of industrial and municipal waste, mining, etc. Many toxic substances are harmful for humans and other organisms even in very low concentrations (e.g., less than 1 µg/L of cadmium is harmful, for Hg it is 0.5 µg/L, for phenol - 1 µg/L), and can remain in water for decades or longer. Cleaning large volumes of water even from low concentrations of pollutants is a challenging technological task and is very expensive. We propose to use suspension of ultradisperse magnetic adsorbents, for example, nanostructured ferro-carbon particles, produced by plasmachemical technique, for removing small concentrations of pollutants from large volumes of water. The suspension is introduced into the water. Due to their small sizes and densities similar to water (we measured the density of FC-4 ferro-carbon to be about 1 g/cm3; presumably due to porosity) the particles do not sediment for a long time (hours, days or longer), move due to Brownian motion and adsorb a variety of substances from the water. The particle surface can be modified to provide selectivity of the adsorption. Sorption capacities of ferro-carbon adsorbents is in dozens of percent. Therefore, to collect 1 kg of a pollutant, 2 to 20 kg of the adsorbents is required. Then the particles with the adsorbed contaminant can be collected (e.g., downstream of the river) using a variety of magnetic traps. The traps can consist of ferromagnetic wires and permanent magnets, a variety of simple and inexpensive designs are available. As a model system, the kinetics of adsorption of a highly diluted (0.002 mg/ml) aqueous solution of a low molecular weight compound (toluidine blue) by a small concentration of a ferro-carbon powder (FC-4) was studied by spectrophotometry. Before each measurement, the particles

  16. Planning, Designing, Building, and Moving a Large Volume Maternity Service to a New Labor and Birth Unit.

    PubMed

    Thompson, Heather; Legorreta, Kimberly; Maher, Mary Ann; Lavin, Melanie M

    Our health system recognized the need to update facility space and associated technology for the labor and birth unit within our large volume perinatal service to improve the patient experience, and enhance safety, quality of care, and staff satisfaction. When an organization decides to invest $30 million dollars in a construction project such as a new labor and birth unit, many factors and considerations are involved. Financial support, planning, design, and construction phases of building a new unit are complex and therefore require strong interdisciplinary collaboration, leadership, and project management. The new labor and birth unit required nearly 3 years of planning, designing, and construction. Patient and family preferences were elicited through consumer focus groups. Multiple meetings with the administrative and nursing leadership teams, staff nurses, nurse midwives, and physicians were held to generate ideas for improvement in the new space. Involving frontline clinicians and childbearing women in the process was critical to success. The labor and birth unit moved to a new patient tower in a space that was doubled in square footage and geographically now on three separate floors. In the 6 months prior to the move, many efforts were made in our community to share our new space. The marketing strategy was very detailed and creative with ongoing input from the nursing leadership team. The nursing staff was involved in every step along the way. It was critical to have champions as workflow teams emerged. We hosted simulation drills and tested scenarios with new workflows. Move day was rehearsed with representatives of all members of the perinatal team participating. These efforts ultimately resulted in a move time of ~5 hours. Birth volumes increased 7% within the first 6 months. After 3 years in our new space, our birth volumes have risen nearly 15% and are still growing. Key processes and roles responsible for a successful build, efficient and safe move

  17. A magnetic sorbent for the efficient and rapid extraction of organic micropollutants from large-volume environmental water samples.

    PubMed

    Zhang, Mancheng; Zhou, Qing; Li, Aimin; Shuang, Chendong; Wang, Wei; Wang, Mengqiao

    2013-11-05

    A magnetic solid-phase extraction (MSPE) method based on a novel magnetic sorbent was proposed for the extraction of target compounds from large-volume water samples. First, magnetic hypercrosslinked microspheres (NAND-1) were prepared via membrane emulsification-suspension polymerization and post crosslinking reaction. To ensure that the Fe3O4 nanoparticles could completely pass through the membrane without blocking the pores, oleic acid was used to modify the Fe3O4 nanoparticles, which enhanced lipophilicity and monodispersity of the magnetite nanoparticles. The obtained NAND-1 microspheres exhibited super paramagnetic characteristics and excellent magnetic responsiveness with a saturation magnetization of 2.53 emu/g. In addition, a uniform particle size (~8 μm) and a large average surface area (1303.59 m(2)/g) were also observed, which were both beneficial for the extraction of the target compounds. Thus, NAND-1 has the potential to simultaneously exhibit good extraction efficiencies toward different types of organic micropollutants (OMPs), including triazines, carbamazepine and diethyl phthalate. The conditions of the MSPE based on NAND-1 were optimized by single factor and orthogonal design experiments. This MSPE method needed only a small amount of sorbent (50mg/L) for the extraction of OMPs from a large-volume aquatic sample (5L) and reached equilibrium in a short amount of time (30 min). Moreover, the solution volume, the pH, and the salinity had insignificant influences on the extraction of the eight target OMPs. Under the optimum conditions, the recoveries of the eight OMPs calculated by analyzing the spiked samples were from 91.7% to 99.4%. The NAND-1 could be recycled ten times and still achieve recoveries of the eight OMPs higher than 86%. The limits of detection of the eight OMPs ranged from 1.76 to 27.56 ng/L, and the limits of quantification were from 5.71 to 92.05 ng/L. These results indicated that the proposed method, based on the use of NAND-1

  18. On-line solid-phase extraction using a C₁₈ minicolumn coupled to a flow injection system for determination of caffeine in green and roasted coffee beans.

    PubMed

    Salinas-Vargas, María E; Cañizares-Macías, María P

    2014-03-15

    A novel and fast method based on the solid phase extraction (SPE) coupled to a flow injection system for the determination of caffeine in coffee beans was developed. The caffeine extraction of coffee beans was carried out with hot water. A C18 reverse-phase mini-column was coupled to a continuous flow manifold to carry out the on-line SPE and the quantification of caffeine from aqueous extracts. Column length, retention time, elution volume, extracting solution and injection volume were evaluated. The retention time was of 90s and the elution was carried out with 400 μL of a methanol:water mixture (25:75). The proposed on-line SPE was compared against a chloroform extraction from aqueous extracts. With the proposed method the sample preparation was minimised and the sample throughput was increased (10 determination/h) because no dilution was required. Green coffee beans and beans with different roasting degree were analyzed.

  19. [Online enrichment ability of restricted-access column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride].

    PubMed

    Zhang, Xiaohui; Wang, Rong; Xie, Hua; Yin, Qiang; Li, Xiaoyun; Jia, Zhengping; Wu, Xiaoyu; Zhang, Juanhong; Li, Wenbin

    2013-05-01

    The online enrichment ability of the restricted-access media (RAM) column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride in plasma was studied. The RAM-HPLC system consisted of an RAM column as enrichment column and a C18 column as analytical column coupled via the column switching technique. The effects of the injection volume on the peak area and the systematic pressure were studied. When the injection volume was less than 100 microL, the peak area increased with the increase of the injection volume. However, when the injection volume was more than 80 microL, the pressure of whole system increased obviously. In order to protect the whole system, 80 microL was chosen as the maximum injection volume. The peak areas of ordinary injection and the large volume injection showed a good linear relationship. The enrichment ability of RAM-HPLC system was satisfactory. The system was successfully used for the separation and detection of the trace benazepril hydrochloride in rat plasma after its administration. The sensitivity of HPLC can be improved by RAM pre-enrichment. It is a simple and economic measurement method.

  20. Pegfilgrastim Injection

    MedlinePlus

    Pegfilgrastim comes as a solution (liquid) in prefilled injection syringes and in a pre-filled automatic injection device (On-body Injector) to inject subcutaneously (under the skin). If you are using pegfilgrastim to ...

  1. Cabazitaxel Injection

    MedlinePlus

    ... injection is used along with prednisone to treat prostate cancer (cancer of a male reproductive organ) that has ... cabazitaxel injection is usually used in men with prostate cancer. If used by pregnant women, cabazitaxel injection can ...

  2. Ondansetron Injection

    MedlinePlus

    Zofran® Injection ... Ondansetron injection is used to prevent nausea and vomiting caused by cancer chemotherapy and surgery. Ondansetron is in a ... medications: or any of the ingredients in ondansetron injection. Ask your pharmacist for a list of the ...

  3. Zircon U-Pb geochronology of the Mount Givens Granodiorite: Implications for the genesis of large volumes of eruptible magma

    NASA Astrophysics Data System (ADS)

    Frazer, Ryan E.; Coleman, Drew S.; Mills, Ryan D.

    2014-04-01

    The Mount Givens Granodiorite, a large pluton in the central Sierra Nevada batholith, California, is similar in area to zoned intrusive suites yet is comparatively chemically and texturally homogenous. New zircon U-Pb geochronology indicates that the pluton was constructed over at least 7 Ma from 97.92 ± 0.06 Ma to 90.87 ± 0.05 Ma. Combining the new geochronology with the exposed volume of the pluton yields an estimated magma flux of <0.001 km3/a. The geochronologic data are at odds with the previously speculated links between plutons such as the Mount Givens Granodiorite and large-volume homogeneous ignimbrites (often termed monotonous intermediates). Existing data indicate that large plutons accumulate at rates of ≤0.001 km3/a, 1-2 orders of magnitude less than fluxes calculated for dated monotonous intermediates. If monotonous intermediates are remobilized, erupted plutons accumulated at rates comparable to dated examples, they should preserve a record of zircon growth of up to 10 Ma. Alternatively, the long history of zircon growth recorded in plutons may be erased during the processes of reheating and remobilization that precede supervolcano eruption. However, zircon dissolution modeling, based on hypothetical temperature-time histories for preeruptive monotonous intermediates, indicates that rejuvenation events would not sufficiently dissolve zircon. We suggest that eruptions of monotonous intermediates occur during high magmatic flux events, leaving little behind in the intrusive rock record, whereas low fluxes favor pluton accumulation.

  4. Eruption and emplacement of flood basalt. An example from the large-volume Teepee Butte Member, Columbia River Basalt Group

    SciTech Connect

    Reidel, S.P. ); Tolan, T.L. )

    1992-12-01

    Flows of the Teepee Butte Member, Grande Ronde Basalt, issued from a vent system in southeastern Washington, northeastern Oregon, and western Idaho. Three distinct basalt flows were erupted: the Limekiln Rapids flow, the Joseph Creek flow, and the Pruitt Draw flow. Together these mappable flows cover more than 52,000 km[sup 2] and have a volume exceeding 5,000 km[sup 3]. A portion of the vent system for the Joseph Creek flow is exposed in cross section in Joseph Canyon, Washington; it is one of the best preserved Columbia River Basalt Group vent complexes known. The vent complex is about 1 km in cross section, 30 m high, and composed of deposits characteristic of Hawaiian-type volcanism. The vent is asymmetrical; the eastern rampart consists of intercalated pyroclastic deposits and thin pahoehoe flows; the western rampart is composed wholly of pahoehoe flows. Flows of the Teepee Butte Member are compositionally homogeneous and were emplaced as sheet flows, each having several local flow units. Our study supports the importance of linear vent systems and the westward Palouse Slope, along with the large-volume lava flows, in controlling the distribution of Columbia River Basalt Group flows. Other factors, including the number of active fissure segments and topography, modified the shape of the flows and the number of flow units. 45 refs., 19 figs., 2 tabs.

  5. Development and sea trials of a subsea holographic camera for large volume in-situ recording of marine organisms

    NASA Astrophysics Data System (ADS)

    Watson, John; Alexander, Stephen J.; Craig, Gary; Hendry, David C.; Hobson, Peter R.; Lampitt, R. S.; Marteau, J.-M.; Nareid, Helge; Nebrensky, J. J.; Player, Michael A.; Saw, Kevin; Tipping, Keith

    2002-06-01

    We describe the development, construction and sea testing of An underwater holographic camera (HoloCam) for in situ recording of marine organisms and particles in large volumes of sea water. HoloCam comprises a laser, power supply, holographic recording optics, and plate holders, a water- tight housing and a support frame. Added to this are control electronics such that the entire camera is remotely operable and controllable from ship or dock-side. Uniquely the camera can simultaneously record both in-line and off-axis holograms using a pulsed frequency double Nd:YAG laser. In- line holography is capable of producing images of organisms with a resolution of better than 10 micrometers . Off-axis holograms of aquatic systems of up to 50,000 cm3 volume, have been recorded. Following initial laboratory testing, the holo-camera was evaluated in an observation tank and ultimately was tested in Loch Etive, Scotland. In-line and off-axis holograms were recorded to a depth of 100 m. We will present result on the ste dives and evaluation of the camera performance.

  6. Large-volume excitation of air, argon, nitrogen and combustible mixtures by thermal jets produced by nanosecond spark discharges

    NASA Astrophysics Data System (ADS)

    Stepanyan, Sergey; Hayashi, Jun; Salmon, Arthur; Stancu, Gabi D.; Laux, Christophe O.

    2017-04-01

    This work presents experimental observations of strong expanding thermal jets following the application of nanosecond spark discharges. These jets propagate in a toroidal shape perpendicular to the interelectrode axis, with high velocities of up to 30 m s-1 and over distances of the order of a cm. Their propagation length is much larger than the thermal expansion region produced by the conventional millisecond sparks used in car engine ignition, thus greatly improving the volumetric excitation of gas mixtures. The shape and velocity of the jets is found to be fairly insensitive to the shape of the electrodes. In addition, their spatial extent is found to increase with the number of nanosecond sparks and with the discharge voltage, and to decrease slightly with the pressure between 1 and 7 atm at constant applied voltage. Finally, this thermal jet phenomenon is observed in experiments conducted with many types of gas mixtures, including air, nitrogen, argon, and combustible CH4/air mixtures. This makes nanosecond repetitively pulsed discharges particularly attractive for aerodynamic flow control or plasma-assisted combustion because of their ability to excite large volumes of gas, typically about 100 times the volume of the discharge.

  7. Novel experimental design for high pressure-high temperature electrical resistance measurements in a "Paris-Edinburgh" large volume press.

    PubMed

    Matityahu, Shlomi; Emuna, Moran; Yahel, Eyal; Makov, Guy; Greenberg, Yaron

    2015-04-01

    We present a novel experimental design for high sensitivity measurements of the electrical resistance of samples at high pressures (0-6 GPa) and high temperatures (300-1000 K) in a "Paris-Edinburgh" type large volume press. Uniquely, the electrical measurements are carried out directly on a small sample, thus greatly increasing the sensitivity of the measurement. The sensitivity to even minor changes in electrical resistance can be used to clearly identify phase transitions in material samples. Electrical resistance measurements are relatively simple and rapid to execute and the efficacy of the present experimental design is demonstrated by measuring the electrical resistance of Pb, Sn, and Bi across a wide domain of temperature-pressure phase space and employing it to identify the loci of phase transitions. Based on these results, the phase diagrams of these elements are reconstructed to high accuracy and found to be in excellent agreement with previous studies. In particular, by mapping the locations of several well-studied reference points in the phase diagram of Sn and Bi, it is demonstrated that a standard calibration exists for the temperature and pressure, thus eliminating the need for direct or indirect temperature and pressure measurements. The present technique will allow simple and accurate mapping of phase diagrams under extreme conditions and may be of particular importance in advancing studies of liquid state anomalies.

  8. Novel experimental design for high pressure-high temperature electrical resistance measurements in a "Paris-Edinburgh" large volume press

    NASA Astrophysics Data System (ADS)

    Matityahu, Shlomi; Emuna, Moran; Yahel, Eyal; Makov, Guy; Greenberg, Yaron

    2015-04-01

    We present a novel experimental design for high sensitivity measurements of the electrical resistance of samples at high pressures (0-6 GPa) and high temperatures (300-1000 K) in a "Paris-Edinburgh" type large volume press. Uniquely, the electrical measurements are carried out directly on a small sample, thus greatly increasing the sensitivity of the measurement. The sensitivity to even minor changes in electrical resistance can be used to clearly identify phase transitions in material samples. Electrical resistance measurements are relatively simple and rapid to execute and the efficacy of the present experimental design is demonstrated by measuring the electrical resistance of Pb, Sn, and Bi across a wide domain of temperature-pressure phase space and employing it to identify the loci of phase transitions. Based on these results, the phase diagrams of these elements are reconstructed to high accuracy and found to be in excellent agreement with previous studies. In particular, by mapping the locations of several well-studied reference points in the phase diagram of Sn and Bi, it is demonstrated that a standard calibration exists for the temperature and pressure, thus eliminating the need for direct or indirect temperature and pressure measurements. The present technique will allow simple and accurate mapping of phase diagrams under extreme conditions and may be of particular importance in advancing studies of liquid state anomalies.

  9. Colorimetric paper-based detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from large volumes of agricultural water.

    PubMed

    Bisha, Bledar; Adkins, Jaclyn A; Jokerst, Jana C; Chandler, Jeffrey C; Pérez-Méndez, Alma; Coleman, Shannon M; Sbodio, Adrian O; Suslow, Trevor V; Danyluk, Michelle D; Henry, Charles S; Goodridge, Lawrence D

    2014-06-09

    This protocol describes rapid colorimetric detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from large volumes (10 L) of agricultural waters. Here, water is filtered through sterile Modified Moore Swabs (MMS), which consist of a simple gauze filter enclosed in a plastic cartridge, to concentrate bacteria. Following filtration, non-selective or selective enrichments for the target bacteria are performed in the MMS. For colorimetric detection of the target bacteria, the enrichments are then assayed using paper-based analytical devices (µPADs) embedded with bacteria-indicative substrates. Each substrate reacts with target-indicative bacterial enzymes, generating colored products that can be detected visually (qualitative detection) on the µPAD. Alternatively, digital images of the reacted µPADs can be generated with common scanning or photographic devices and analyzed using ImageJ software, allowing for more objective and standardized interpretation of results. Although the biochemical screening procedures are designed to identify the aforementioned bacterial pathogens, in some cases enzymes produced by background microbiota or the degradation of the colorimetric substrates may produce a false positive. Therefore, confirmation using a more discriminatory diagnostic is needed. Nonetheless, this bacterial concentration and detection platform is inexpensive, sensitive (0.1 CFU/ml detection limit), easy to perform, and rapid (concentration, enrichment, and detection are performed within approximately 24 hr), justifying its use as an initial screening method for the microbiological quality of agricultural water.

  10. Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water

    PubMed Central

    Bisha, Bledar; Adkins, Jaclyn A.; Jokerst, Jana C.; Chandler, Jeffrey C.; Pérez-Méndez, Alma; Coleman, Shannon M.; Sbodio, Adrian O.; Suslow, Trevor V.; Danyluk, Michelle D.; Henry, Charles S.; Goodridge, Lawrence D.

    2014-01-01

    This protocol describes rapid colorimetric detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from large volumes (10 L) of agricultural waters. Here, water is filtered through sterile Modified Moore Swabs (MMS), which consist of a simple gauze filter enclosed in a plastic cartridge, to concentrate bacteria. Following filtration, non-selective or selective enrichments for the target bacteria are performed in the MMS. For colorimetric detection of the target bacteria, the enrichments are then assayed using paper-based analytical devices (µPADs) embedded with bacteria-indicative substrates. Each substrate reacts with target-indicative bacterial enzymes, generating colored products that can be detected visually (qualitative detection) on the µPAD. Alternatively, digital images of the reacted µPADs can be generated with common scanning or photographic devices and analyzed using ImageJ software, allowing for more objective and standardized interpretation of results. Although the biochemical screening procedures are designed to identify the aforementioned bacterial pathogens, in some cases enzymes produced by background microbiota or the degradation of the colorimetric substrates may produce a false positive. Therefore, confirmation using a more discriminatory diagnostic is needed. Nonetheless, this bacterial concentration and detection platform is inexpensive, sensitive (0.1 CFU/ml detection limit), easy to perform, and rapid (concentration, enrichment, and detection are performed within approximately 24 hr), justifying its use as an initial screening method for the microbiological quality of agricultural water. PMID:24962090

  11. A Large Volume Double Channel 1H-X RF Probe for Hyperpolarized Magnetic Resonance at 0.0475 Tesla

    PubMed Central

    Coffey, Aaron M.; Shchepin, Roman V.; Wilkens, Ken; Waddell, Kevin W.; Chekmenev, Eduard Y.

    2012-01-01

    In this work we describe a large volume 340 mL 1H-X magnetic resonance (MR) probe for studies of hyperpolarized compounds at 0.0475 T. 1H/13C and 1H/15N probe configurations are demonstrated with the potential for extension to 1H/129Xe. The primary applications of this probe are preparation and quality assurance of 13C and 15N hyperpolarized contrast agents using PASADENA (parahydrogen and synthesis allow dramatically enhanced nuclear alignment) and other parahydrogen-based methods of hyperpolarization. The probe is efficient and permits 62 μs 13C excitation pulses at 5.3 Watts, making it suitable for portable operation. The sensitivity and detection limits of this probe, tuned to 13C, are compared with a commercial radio frequency (RF) coil operating at 4.7 T. We demonstrate that low field MR of hyperpolarized contrast agents could be as sensitive as conventional high field detection and outline potential improvements and optimization of the probe design for preclinical in vivo MRI. PASADENA application of this low-power probe is exemplified with 13C hyperpolarized 2-hydroxyethyl propionate-1-13C,2,3,3-d3. PMID:22706029

  12. Changing the metabolic profile by large-volume liposuction: a clinical study conducted with 123 obese women.

    PubMed

    D'Andrea, Francesco; Grella, Roberto; Rizzo, Maria Rosaria; Grella, Elisa; Grella, Rodolfo; Nicoletti, Gianfranco; Barbieri, Michelangela; Paolisso, Giuseppe

    2005-01-01

    Adipose tissue is a metabolically active tissue. The hypertrophic fat cells of obese patients produce increased quantities of leptin and tumor necrosis factor-alpha (TNF-alpha) and are less sensitive to insulin. This study aimed to determine whether aspirating large amounts of these subcutaneous fat cells by large-volume liposuction (LVL), could change the metabolic profile in 123 obese women. All the patients had a main central body fat distribution (waist-hip ratio, 0.91+/-0.01) and a body mass index of 32.8 +/- 0.8 kg/m). They were studied for 90 days after LVL to determine their changes in insulin sensitivity, resting metabolic rate, serum adipocytokines, and inflammatory marker levels. During 3 months of follow-up evaluation, LVL resulted in a significantly improved insulin sensitivity, resting metabolic rate, serum adipocytokines, and inflammatory marker levels. Such parameters correlate with a decrease in fat mass and waist-hip ratio. Interestingly, no significant changes were seen between the first (21 days) and second (90 days) metabolic determinations after LVL. However, these findings, confirm other preliminary data published previously, and could change the actual role of LVL in the multidisciplinary treatment of obesity.

  13. Large volume collapse observed in the phase transition in cubic PbCrO[subscript 3] perovskite

    SciTech Connect

    Xiao, Wansheng; Tan, Dayong; Xiong, Xiaolin; Liu, Jing; Xu, Jian

    2010-08-27

    When cubic PbCrO{sub 3} perovskite (Phase I) is squeezed up to {approx}1.6 GPa at room temperature, a previously undetected phase (Phase II) has been observed with a 9.8% volume collapse. Because the structure of Phase II can also be indexed into a cubic perovskite as Phase I, the transition between Phases I and II is a cubic to cubic isostructural transition. Such a transition appears independent of the raw materials and synthesizing methods used for the cubic PbCrO{sub 3} perovskite sample. In contrast to the high-pressure isostructural electronic transition that appears in Ce and SmS, this transition seems not related with any change of electronic state, but it could be possibly related on the abnormally large volume and compressibility of the PbCrO{sub 3} Phase I. The physical mechanism behind this transition and the structural and electronic/magnetic properties of the condensed phases are the interesting issues for future studies.

  14. Equivalence of two steroid-containing inhalers: easyhaler multidose powder inhaler compared with conventional aerosol with large-volume spacer.

    PubMed

    Koskela, T; Hedman, J; Ekroos, H; Kauppinen, R; Leinonen, M; Silvasti, M; Tukiainen, H

    2000-01-01

    An equivalence study was conducted in which the efficacy and safety of a daily dose of 800 microgram of beclomethasone diproprionate administered via a multidose powder inhaler, Easyhaler, and via a metered-dose inhaler (MDI) with a large-volume spacer were compared in adult, newly diagnosed, steroid-naive asthmatic patients. Acceptability of the medications was also compared. One hundred and forty-four patients were recruited into the double-blind, double-dummy, randomised, parallel-group multicentre study. The study treatment period was 8 weeks. It was preceded by a 2-week run-in period. Morning and evening peak expiratory flow (PEF), numbers of inhalations of a sympathomimetic and asthma symptoms were recorded daily. Spirometry and histamine challenge were performed, and health-related quality of life and morning serum cortisol levels measured during control visits. Criteria indicating treatment equivalence were met. The mean of the primary outcome variable, morning PEF, increased significantly, from 426 to 461 litres/min in the Easyhaler group and from 436 to 467 litres/min in the MDI+spacer group. Similar improvements between groups were also seen in relation to all secondary variables. Changes in serum cortisol levels were minor. In 6 out of 10 questions about device acceptability, the majority of patients rated Easyhaler as better than the MDI+spacer combination. It was concluded that the devices tested were equivalent in terms of efficacy and safety. Copyright 2000 S. Karger AG, Basel.

  15. Feasibility, efficacy, and safety of a simple insulin infusion protocol in a large volume cardiac surgery unit in India.

    PubMed

    Bansal, Beena; Mithal, Ambrish; Carvalho, Pravin; Mehta, Yatin; Trehan, Naresh

    2015-01-01

    Inpatient hyperglycemia management is essential, but difficult to achieve especially in a large volume cardiac surgery setup, thus necessitating use of nurse-led insulin protocols. A rapid flux of nurses dealing with a huge workload has been a cause for traditionally not using nurse-led protocols in most Indian institutes. The challenges we faced were to have a simple protocol for the nurses to accept it without compromising on glycemic control. Therefore, this observational study was planned to measure the efficacy and safety of the insulin infusion protocol in cardiac surgery patients. Insulin protocol was implemented, using seven fixed columns of infusion with the nurse making decisions to initiate and titrate doses based on simple rules. Blood glucose (BG) data captured from blood gas analyzers (glucometrics) in the intervention group (i.e., after protocol implementation) were compared to control group (i.e., before the protocol implementation). The mean BG for the first 48 h was lower in the intervention group as compared to control group, without an increase in the episodes of hypoglycemia. The nurses found the protocol easy to understand, less time-consuming and there was no protocol deviation over 8 months after implementation. A small change in the process, allowing nurses to titrate insulin doses based on some rules and having seven fixed columns of insulin infusion rates, improved glycemic control and efficiency.

  16. a Method to Achieve Large Volume, High Accuracy Photogrammetric Measurements Through the Use of AN Actively Deformable Sensor Mounting Platform

    NASA Astrophysics Data System (ADS)

    Sargeant, B.; Robson, S.; Szigeti, E.; Richardson, P.; El-Nounu, A.; Rafla, M.

    2016-06-01

    When using any optical measurement system one important factor to consider is the placement of the sensors in relation to the workpiece being measured. When making decisions on sensor placement compromises are necessary in selecting the best placement based on the shape and size of the object of interest and the desired resolution and accuracy. One such compromise is in the distance the sensors are placed from the measurement surface, where a smaller distance gives a higher spatial resolution and local accuracy and a greater distance reduces the number of measurements necessary to cover a large area reducing the build-up of errors between measurements and increasing global accuracy. This paper proposes a photogrammetric approach whereby a number of sensors on a continuously flexible mobile platform are used to obtain local measurements while the position of the sensors is determined by a 6DoF tracking solution and the results combined to give a single set of measurement data within a continuous global coordinate system. The ability of this approach to achieve both high accuracy measurement and give results over a large volume is then tested and areas of weakness to be improved upon are identified.

  17. Nd, Sr, and O isotopic variations in metaluminous ash-flow tuffs and related volcanic rocks at the Timber Mountain/Oasis Valley Caldera, Complex, SW Nevada: implications for the origin and evolution of large-volume silicic magma bodies

    USGS Publications Warehouse

    Farmer, G.L.; Broxton, D.E.; Warren, R.G.; Pickthorn, W.

    1991-01-01

    Nd, Sr and O isotopic data were obtained from silicic ash-flow tuffs and lavas at the Tertiary age (16-9 Ma) Timber (Mountain/Oasis Valley volcanic center (TMOV) in southern Nevada, to assess models for the origin and evolution of the large-volume silicic magma bodies generated in this region. The large-volume (>900 km3), chemically-zoned, Topopah Spring (TS) and Tiva Canyon (TC) members of the Paintbrush Tuff, and the Rainier Mesa (RM) and Ammonia Tanks (AT) members of the younger Timber Mountain Tuff all have internal Nd and Sr isotopic zonations. In each tuff, high-silica rhyolites have lower initial e{open}Nd values (???1 e{open}Nd unit), higher87Sr/86Sr, and lower Nd and Sr contents, than cocrupted trachytes. The TS, TC, and RM members have similar e{open}Nd values for high-silica rhyolites (-11.7 to -11.2) and trachytes (-10.5 to -10.7), but the younger AT member has a higher e{open}Nd for both compositional types (-10.3 and -9.4). Oxygen isotope data confirm that the TC and AT members were derived from low e{open}Nd magmas. The internal Sr and Nd isotopic variations in each tuff are interpreted to be the result of the incorporation of 20-40% (by mass) wall-rock into magmas that were injected into the upper crust. The low e{open}Nd magmas most likely formed via the incorporation of low ??18O, hydrothermally-altered, wall-rock. Small-volume rhyolite lavas and ash-flow tuffs have similar isotopic characteristics to the large-volume ash-flow tuffs, but lavas erupted from extracaldera vents may have interacted with higher ??18O crustal rocks peripheral to the main magma chamber(s). Andesitic lavas from the 13-14 Ma Wahmonie/Salyer volcanic center southeast of the TMOV have low e{open}Nd (-13.2 to -13.8) and are considered on the basis of textural evidence to be mixtures of basaltic composition magmas and large proportions (70-80%) of anatectic crustal melts. A similar process may have occurred early in the magmatic history of the TMOV. The large-volume rhyolites

  18. Continuous soil VOCl measurements with automated flux chambers and micro-ECD gas chromatography coupled with the thermal desorption and cooled injection systems

    NASA Astrophysics Data System (ADS)

    Molodovskaya, M. S.; Svensson, T.; Pitts, A.; Delmonte, J.; Nesic, Z.; Oberg, G.

    2010-12-01

    automated chamber was continuously pumped through the glass tubes filled with carbon-based absorbent (Carbotrap 300) to capture and retain VOCl. At the end of each measurement period, the tubes are brought back to the lab, and the content is analyzed by Agilent 7890 GC/micro-ECD coupled with the Gerstel Thermal Desorption System (TDS) and Cooled Injection System (CIS). The ultra sensitive micro-ECD detection and high-efficiency capillary column (Rtx®-VMS, 20m x 0.18mm ID x 1.0µm) allows rapid separation and quantification of the mid-weight VOCl such as chloroform, carbon tetrachloride, 1,1,1-trichloroethane and bromochloromethane. The GC-method dynamic range is linear within 0.1-200.0ng, and the analytical precision is determined to be 4%. The described system can be used for the analysis of soil/atmosphere exchange of VOCl at the detection limit of 1.9ng m-2 h-1, which is far below previously reported average soil emission levels from forest soils. The high precision GC analysis combined with the automatic chambers makes it possible to study the high spatial and temporal variability of soil VOCl fluxes.

  19. Pharmacokinetic-pharmacodynamic study of subcutaneous injection of depot nandrolone decanoate using dried blood spots sampling coupled with ultrapressure liquid chromatography tandem mass spectrometry assays.

    PubMed

    Singh, Gurmeet K S; Turner, Leo; Desai, Reena; Jimenez, Mark; Handelsman, David J

    2014-07-01

    Testosterone (T) and nandrolone (N) esters require deep im injections by medical personnel but these often deposit injectate into sc fat so that more convenient sc self-administration may be feasible. To investigate the feasibility and pharmacology of sc injection of N decanoate in healthy men using dried blood spot (DBS) for frequent blood sampling without clinic visits. Healthy male volunteers received 100 mg N decanoate by a single sc injection. Finger-prick capillary blood was spotted onto filter paper before injection daily at home for 21 d and stored at room temperature. Venous whole blood was also spotted onto filter paper before and weekly for 3 wk after injection. DBS were extracted for assay of N and T by liquid chromatography tandem mass spectrometry in a single batch with serum concentrations estimated with adjustment for capillary blood sample volume and hematocrit to define peak (N) or nadir (T) time and concentration from individual daily measurements. Daily serum N peaked 2.50 ± 0.25 (SEM) ng/mL at a median (range) of 6 (4-13) days causing a reduction in serum T from 3.50 ± 0.57 ng/mL at baseline to a nadir of 0.38 ± 0.13 (SEM) ng/mL (89 ± 3% suppression) at a median (range) of 8 (5-16) days. Simultaneously sampled capillary, venous whole blood, and serum gave almost identical results for serum T and N. Finger-pricks and sc injections were well tolerated. This study demonstrates that A) DBS sampling with liquid chromatography mass spectrometry steroid analysis achieves frequent time sampling in the community without requiring clinic visits, venesection, or frozen serum storage, and B) androgen esters in an oil vehicle can be delivered effectively by sc injection, thus avoiding the need for medically supervised deep-im injections.

  20. Comprehensive gas chromatography with Time of Flight MS and large volume introduction for the detection of fluoride-induced regenerated nerve agent in biological samples.

    PubMed

    van der Meer, J A; Trap, H C; Noort, D; van der Schans, M J

    2010-05-15

    Recently, several methods have been developed to verify exposure to nerve agents. Most of these methods, such as the fluoride reactivation technique and the analysis of inhibited phosphonylated butyrylcholinesterase (BuChE), are based on mass spectrometry. The high specificity of the mass spectrometer might also imply a disadvantage, because the acquisition mass, i.e. the identity of the analyte must be known beforehand in order to direct the MS analysis in the most sensitive mode. In real cases, the identity of the nerve agent is not always known beforehand and the mass spectrometer should be operated in a scanning mode, with the consequence that sensitivity of the method will be lower. Comprehensive GC, or GC x GC, is a technique which offers enhanced separation. The implied larger selectivity of the GC separation allows mass spectrometry to be conducted in a less specific, scanning, mode. By the use of this configuration, the identity of the nerve agent does not have to be known beforehand but can be traced. In order to be able to detect lower concentrations and assess lower exposure levels, a large volume injection technique was developed allowing sample sizes up to 100 microL. The technique was tested with plasma samples that had been inhibited with various nerve agents. Subsequently, the cholinesterase-bound nerve agent was regenerated by the fluoride reactivation technique. Using the newly developed comprehensive GC-MS method it was possible to detect nerve agent at an exposure level of 1% BuChE inhibition, which is approximately 70 pg nerve agent/mL. These low exposure levels cannot be verified with a cholinesterase (ChE) activity assay. Moreover, the identity of the regenerated nerve agent was verified by the mass spectrum that was generated by the TOF mass spectrometer. This paper presents a technique able to deliver full-scan data on the analysis of nerve agents in biomedical samples at relevant exposure levels (1% BuChE inhibition). This full-scan data

  1. Large-volume lava flows fed by a deep magmatic reservoir at Ağrı Dağı (Ararat) volcano, Eastern Turkey

    NASA Astrophysics Data System (ADS)

    Karaoğlu, Özgür; Elshaafi, Abdelsalam; Salah, Mohamed K.; Browning, John; Gudmundsson, Agust

    2017-02-01

    Ağrı Dağı (Ararat), whilst being the tallest volcano in Turkey, is largely understudied. Two predominant peaks, Greater and Lesser Ağrı, make up the main edifice, which has been built during four main phases. The most recent phase consisted of two volcanic eruptions. The respective surface area and volume of the first volcanic eruption were estimated at 96 km2 and 3.2 km3, whereas those of the second eruption were much smaller with the surface area and volume estimated at 25 km2 and 0.6 km3. It is unusual for stratovolcanoes to produce basaltic eruptions of more than 3 km3, although these and larger volumes are not uncommon in flood basalt-type eruptions. Large basaltic eruptions from stratovolcanoes normally require volcano-tectonic forcing (e.g. subsidence of collapse caldera and graben). However, there is no evidence for such volcano-tectonic forcing, during the most recent eruptions at Ağrı Dağı (Ararat), and therefore, their comparatively large volume basaltic lavas need to be explained in a different way. Here, we present an analytical method for calculating the source volume needed to supply magma to the eruptions at Ağrı Dağı. We found that the lava flow of 3.2 km3 was likely fed by a very large magma reservoir (˜13,000 km3), while the second flow of 0.6 km3 was fed by a reservoir of a much smaller effective size (or ˜2000 km3). `Effective size' depends on what fraction of the reservoir participates in the eruption. We propose that the entire reservoir supplied magma to the larger eruption, but only one of its compartments (about one fifth of the total volume of the reservoir) supplied magma to the smaller eruption. Although seismic tomography indicates a magma reservoir at great depths (>20-30 km) below the Ağrı Dağı volcano, geochemical constraints on some of the later-formed rocks suggest an interaction between a shallow chamber (at 8-10-km depth) and the deep reservoir approximately 0.5 Ma. We provide numerical models whose results

  2. Sequential injection-bead injection-lab-on-valve coupled to high-performance liquid chromatography for online renewable micro-solid-phase extraction of carbamate residues in food and environmental samples.

    PubMed

    Vichapong, Jitlada; Burakham, Rodjana; Srijaranai, Supalax; Grudpan, Kate

    2011-07-01

    A sequential injection-bead injection-lab-on-valve system was hyphenated to HPLC for online renewable micro-solid-phase extraction of carbamate insecticides. The carbamates studied were isoprocarb, methomyl, carbaryl, carbofuran, methiocarb, promecarb, and propoxur. LiChroprep(®) RP-18 beads (25-40 μm) were employed as renewable sorbent packing in a microcolumn situated inside the LOV platform mounted above the multiposition valve of the sequential injection system. The analytes sorbed by the microcolumn were eluted using 80% acetonitrile in 0.1% acetic acid before online introduction to the HPLC system. Separation was performed on an Atlantis C-18 column (4.6 × 150 mm, 5 μm) utilizing gradient elution with a flow rate of 1.0 mL/min and a detection wavelength at 270 nm. The sequential injection system offers the means of performing automated handling of sample preconcentration and matrix removal. The enrichment factors ranged between 20 and 125, leading to limits of detection (LODs) in the range of 1-20 μg/L. Good reproducibility was obtained with relative standard deviations of <0.7 and 5.4% for retention time and peak area, respectively. The developed method has been successfully applied to the determination of carbamate residues in fruit, vegetable, and water samples.

  3. Flowing and growing: a microanalytical and isotopic investigation of a large volume rhyolite lava flow at Yellowstone

    NASA Astrophysics Data System (ADS)

    Severin, Z.; Bindeman, I. N.; Lackey, J.

    2013-12-01

    Why large-volume rhyolitic magmas with identical properties and volatile budgets erupt as both pyroclastic rocks forming calderas, and quiet lava flows, has remained a long standing question at Yellowstone and volcanic centers worldwide. We have investigated the youngest lava flow of Yellowstone - the Central Plateau member (0.2-0.07 Ma) in attempt to better understand the following aspects of a large-volume (≤54 km^3) lava flow: 1) how long it takes to erupt; 2) how chemically and isotopically homogenous it is; and 3) how syneruptive cooling affects isotopic and chemical composition. We also analyze the homogeneity of the 112 ka, 37 km^3, low-δ^18O Summit Lake lava flow, which formed by remelting of hydrothermally altered and buried materials. On the surface twenty samples were collected along a southwest-northeast transect from the flow vent to the lava flow edge. We examined these samples petrographically and chemically, employing whole rock geochemistry, the titanium content of quartz phenocrysts to calculate relative temperature of growth using the Ti-in-quartz thermometer (TitaniQ), and the δ^18O of volcanic glass. The Ti content of quartz is useful for inferring the temperature, pressure, and/or chemical conditions of quartz crystallization. We also used cathodoluminescence imaging (CL) on a scanning electron microscopy (SEM) to distinguish quartz cores from overgrowths. Values of δ^18O are relatively homogeneous across the flow (4.60 × 0.59‰, n=20), showing no systematic variation with distance from the vent. Whole-rock major element composition is also homogenous across the flow (SiO2 = 75.08-77.03 wt.%). However, precise grid-counting reveals a general increase in the percent of phenocrysts (4.4-7.3%) and also the ratio of quartz to feldspar (40:60). CL shows that all quartz phenocrysts display a renewed growth as a dark ~200 μm-thick rims upon by bright cores. Among the quartz phenocrysts, Ti generally decreases from 139×39 ppm in bright cores

  4. Simplification and validation of a large volume polyurethane foam sampler for the analysis of persistent hydrophobic compounds in drinking water.

    PubMed

    Choi, J W; Lee, J H; Moon, B S; Kannan, K

    2008-08-01

    The use of a large volume polyurethane foam (PUF) sampler was validated for rapid extraction of persistent organic pollutants (POPs), such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), in raw water and treated water from drinking water plants. To validate the recovery of target compounds in the sampling process, a (37)Cl-labeled standard was spiked into the 1st PUF plug prior to filtration. An accelerated solvent extraction method, as a pressurized liquid extractor (PLE), was optimized to extract the PUF plug. For sample preparation, tandem column chromatography (TCC) clean-up was used for rapid analysis. The recoveries of labeled compounds in the analytical method were 80-110% (n = 9). The optimized PUF-PLE-TCC method was applied in the analysis of raw water and treated potable water from seven drinking water plants in South Korea. The sample volume used was between 18 and 102 L for raw water at a flow rate of 0.4-2 L min(-1), 95 and 107 L for treated water at a flow rate of 1.5-2.2 L min(-1). Limit of quantitation (LOQ) was a function of sample volume and it decreased with increasing sample volume. The LOQ of PCDD/Fs in raw waters analyzed by this method was 3-11 times lower than that described using large-size disk-type solid phase extraction (SPE) method. The LOQ of PCDD/F congeners in raw water and treated water were 0.022-3.9 ng L(-1) and 0.018-0.74 ng L(-1), respectively. Octachlorinated dibenzo-p-dioxin (OCDD) was found in some raw water samples, while their concentrations were well below the tentative criterion set by the Japanese Environmental Ministry for drinking water. OCDD was below the LOQ in the treated drinking water.

  5. Hard X- and γ-ray measurements with a large volume coplanar grid CdZnTe detector

    NASA Astrophysics Data System (ADS)

    Owens, Alan; Buslaps, T.; Gostilo, V.; Graafsma, H.; Hijmering, R.; Kozorezov, A.; Loupilov, A.; Lumb, D.; Welter, E.

    2006-07-01

    The recent introduction of coplanar grid techniques has led to resurgence in interest in developing large volume compound semiconductor detectors that have a reasonable γ-ray response but also good spectroscopic resolution. We report the results of a series of hard X- and γ-ray measurements on a large 15×15 mm 2, 10 mm thick CdZnTe coplanar grid detector. The measurements were carried out at the HASYLAB and ESRF synchrotron radiation facilities using highly monochromatic pencil beams across the energy range 20-800 keV. Additional full-area measurements were carried out using radioactive sources. All measurements were carried out at room temperature. The measured energy resolution under full-area illumination was 8 and 12 keV FWHM at 59.95 and 662 keV, respectively. Under pencil beam illumination, the measured resolutions were essentially the same. The detector energy response function was found to be linear over the energy range 20-1400 keV with an average rms nonlinearity of 1.4%, consistent with statistics. The spatial uniformity of the detector was evaluated at 30, 60 and 180 keV by raster scanning a 20×20 μm 2 monoenergetic X-ray beam across the active area. Apart from a few localized areas, the detector response was found to uniform at the few percent level, consistent with statistics. At 180 keV, the nonuniformity in the energy response due to the grids was estimated to be at the 0.7% level.

  6. Successful treatment of a LifeSite Hemodialysis Access System pocket infection with large-volume kanamycin solution irrigation.

    PubMed

    Ross, John R

    2003-07-01

    Bridge devices-dialysis catheters and subcutaneous access devices-play a critical role in increasing the placement of arteriovenous (AV) fistulas by providing hemodialysis vascular access while AV fistulas mature. The LifeSite Hemodialysis Access System (Vasca Inc, Tewskburg, MA), a fully implantable, subcutaneous dual valve access system, has been shown to have lower complication rates, higher blood flow rates, and better long-term device survival than conventional tunneled hemodialysis catheters, indicating it may better meet the requirements for optimally bridging to a fistula. This case study of a 48-year-old black man undergoing chronic hemodialysis for renal failure because of insulin-dependent diabetes describes a simple approach for resolving localized pocket infections associated with the LifeSite System by drip irrigation of the valves and tissue pockets with an antibiotic solution. Eight weeks after implantation of the LifeSite System, the patient exhibited symptoms of infection of the lateral LifeSite valve tissue pocket, which on culture was shown to be caused by Staphylococcus aureus. Flushing the LifeSite valve and tissue pocket with a large volume of kanamycin solution, in conjunction with intravenous vancomycin and routine irrigation of the valve with isopropyl alcohol, resolved the infection after 1 treatment. The LifeSite System successfully bridged the patient to a transposed basilic vein fistula created through a 2-stage surgical procedure. The LifeSite System provided uninterrupted access for hemodialysis over a period of 6 months while the fistula matured. The LifeSite System should allow surgeons to attempt fistula construction in more patients, including diabetics, access-challenged patients, and patients with small vessels, who may benefit from a nontraditional surgical approach toward fistula creation.

  7. Acoustic detection of cracks in the anvil of a large-volume cubic high-pressure apparatus

    SciTech Connect

    Yan, Zhaoli Tian, Hao; Cheng, Xiaobin; Yang, Jun; Chen, Bin

    2015-12-15

    A large-volume cubic high-pressure apparatus with three pairs of tungsten carbide anvils is the most popular device for synthetic diamond production. Currently, the consumption of anvils is one of the important costs for the diamond production industry. If one of the anvils is fractured during the production process, the other five anvils in the apparatus may be endangered as a result of a sudden loss of pressure. It is of critical importance to detect and replace cracked anvils before they fracture for reduction of the cost of diamond production and safety. An acoustic detection method is studied in this paper. Two new features, nested power spectrum centroid and modified power spectrum variance, are proposed and combined with linear prediction coefficients to construct a feature vector. A support vector machine model is trained for classification. A sliding time window is proposed for decision-level information fusion. The experiments and analysis show that the recognition rate of anvil cracks is 95%, while the false-alarm rate is as low as 5.8 × 10{sup −4} during a time window; this false-alarm rate indicates that at most one false alarm occurs every 2 months at a confidence level of 90%. An instrument to monitor anvil cracking was designed based on a digital signal processor and has been running for more than eight months in a diamond production field. In this time, two anvil-crack incidents occurred and were detected by the instrument correctly. In addition, no false alarms occurred.

  8. Fully automated circulating tumor cell isolation platform with large-volume capacity based on lab-on-a-disc.

    PubMed

    Park, Jong-Myeon; Kim, Minseok S; Moon, Hui-Sung; Yoo, Chang Eun; Park, Donghyun; Kim, Yeon Jeong; Han, Kyung-Yeon; Lee, June-Young; Oh, Jin Ho; Kim, Sun Soo; Park, Woong-Yang; Lee, Won-Yong; Huh, Nam

    2014-04-15

    Full automation with high purity for circulating tumor cell (CTC) isolation has been regarded as a key goal to make CTC analysis a "bench-to-bedside" technology. Here, we have developed a novel centrifugal microfluidic platform that can isolate the rare cells from a large volume of whole blood. To isolate CTCs from whole blood, we introduce a disc device having the biggest sample capacity as well as manipulating blood cells for the first time. The fully automated disc platform could handle 5 mL of blood by designing the blood chamber having a triangular obstacle structure (TOS) with lateral direction. To guarantee high purity that enables molecular analysis with the rare cells, CTCs were bound to the microbeads covered with anti-EpCAM to discriminate density between CTCs and blood cells and the CTCs being heavier than blood cells were only settled under a density gradient medium (DGM) layer. To understand the movement of CTCs under centrifugal force, we performed computational fluid dynamics simulation and found that their major trajectories were the boundary walls of the DGM chamber, thereby optimizing the chamber design. After whole blood was inserted into the blood chamber of the disc platform, size- and density-amplified cancer cells were isolated within 78 min, with minimal contamination as much as approximately 12 leukocytes per milliliter. As a model of molecular analysis toward personalized cancer treatment, we performed epidermal growth factor receptor (EGFR) mutation analysis with HCC827 lung cancer cells and the isolated cells were then successfully detected for the mutation by PCR clamping and direct sequencing.

  9. Large volume inside the cage leading incomplete interbody bone fusion and residual back pain after posterior lumbar interbody fusion.

    PubMed

    Takeuchi, Mikinobu; Kamiya, Mitsuhiro; Wakao, Norimitsu; Hirasawa, Atsuhiko; Kawanami, Katsuhisa; Osuka, Koji; Takayasu, Masakazu

    2015-07-01

    The purpose of this study is to compare intervertebral bone fusion and clinical outcomes in L4-5 posterior lumbar interbody fusion (PLIF) using the same posterior instrumentation with four combinations of one of three types of interbody cage with one of two bone grafts, iliac and local or only local. In 67 patients who underwent L4-5 PLIF, 19 patients had the Brantigan cage and iliac and local bone graft, 18 with the TELAMON C cage and iliac and local bone graft, 16 with the TELAMON C cage and local bone graft (TL), and 14 with the OIC PEEK cage and local bone graft. Clinical assessments were based on Japanese Orthopaedic Association (JOA) scores and on the visual analogue scale (VAS). The bone fusion assessments were based on radiography and CT scans according to the Brantigan, Steffee, and Fraser criteria. More than 2 years after surgery, these assessments were made. In the results, the fusion outcome for the group receiving TL was significantly less than those for the other three groups. In TL, multivariate logistic regression analysis showed that the inside volume of the cage of ≥2.0 mL was the only significant factor for incomplete fusion. Moreover, the VAS (low back pain) score was significantly higher for TL than for the other three groups. In conclusions, we believe that the large volume inside the cage (≥2.0 mL) with local bone graft may lead incomplete interbody bone fusion and residual postsurgical low back pain after PLIF.

  10. Acoustic detection of cracks in the anvil of a large-volume cubic high-pressure apparatus

    NASA Astrophysics Data System (ADS)

    Yan, Zhaoli; Chen, Bin; Tian, Hao; Cheng, Xiaobin; Yang, Jun

    2015-12-01

    A large-volume cubic high-pressure apparatus with three pairs of tungsten carbide anvils is the most popular device for synthetic diamond production. Currently, the consumption of anvils is one of the important costs for the diamond production industry. If one of the anvils is fractured during the production process, the other five anvils in the apparatus may be endangered as a result of a sudden loss of pressure. It is of critical importance to detect and replace cracked anvils before they fracture for reduction of the cost of diamond production and safety. An acoustic detection method is studied in this paper. Two new features, nested power spectrum centroid and modified power spectrum variance, are proposed and combined with linear prediction coefficients to construct a feature vector. A support vector machine model is trained for classification. A sliding time window is proposed for decision-level information fusion. The experiments and analysis show that the recognition rate of anvil cracks is 95%, while the false-alarm rate is as low as 5.8 × 10-4 during a time window; this false-alarm rate indicates that at most one false alarm occurs every 2 months at a confidence level of 90%. An instrument to monitor anvil cracking was designed based on a digital signal processor and has been running for more than eight months in a diamond production field. In this time, two anvil-crack incidents occurred and were detected by the instrument correctly. In addition, no false alarms occurred.

  11. Acoustic detection of cracks in the anvil of a large-volume cubic high-pressure apparatus.

    PubMed

    Yan, Zhaoli; Chen, Bin; Tian, Hao; Cheng, Xiaobin; Yang, Jun

    2015-12-01

    A large-volume cubic high-pressure apparatus with three pairs of tungsten carbide anvils is the most popular device for synthetic diamond production. Currently, the consumption of anvils is one of the important costs for the diamond production industry. If one of the anvils is fractured during the production process, the other five anvils in the apparatus may be endangered as a result of a sudden loss of pressure. It is of critical importance to detect and replace cracked anvils before they fracture for reduction of the cost of diamond production and safety. An acoustic detection method is studied in this paper. Two new features, nested power spectrum centroid and modified power spectrum variance, are proposed and combined with linear prediction coefficients to construct a feature vector. A support vector machine model is trained for classification. A sliding time window is proposed for decision-level information fusion. The experiments and analysis show that the recognition rate of anvil cracks is 95%, while the false-alarm rate is as low as 5.8 × 10(-4) during a time window; this false-alarm rate indicates that at most one false alarm occurs every 2 months at a confidence level of 90%. An instrument to monitor anvil cracking was designed based on a digital signal processor and has been running for more than eight months in a diamond production field. In this time, two anvil-crack incidents occurred and were detected by the instrument correctly. In addition, no false alarms occurred.

  12. Large-volume leukaphereses may be more efficient than standard-volume leukaphereses for collection of peripheral blood progenitor cells.

    PubMed

    Passos-Coelho, J L; Machado, M A; Lúcio, P; Leal-Da-Costa, F; Silva, M R; Parreira, A

    1997-10-01

    To overcome the need for multiple leukaphereses to collect enough PBPC for autologous transplantation, large-volume leukaphereses (LVL) are used to process multiple blood volumes per session. We compared the efficiency of CD34+ cell collection by LVL (n = 63; median blood volumes processed 11.1) with that of standard-volume leukaphereses (SVL) (n = 38; median blood volumes processed 1.9). To achieve this in patients with different peripheral blood concentrations of CD34+ cells, we analyzed the ratio of CD34+ cells collected per unit of blood volume processed, divided by the number of CD34+ cells in total blood volume at the beginning of apheresis. For LVL, 30% (9%-323%) of circulating CD34+ cells were collected per blood volume compared with 42% (7%-144%) for SVL (p = 0.02). However, in LVL patients, peripheral blood CD34+ cells/L decreased a median of 54% during LVL (similar data for SVL not available). The number of CD34+ cells collected per blood volume processed after 4 and 8 blood volumes and at the end of LVL were 0.32 (0.01-2.05), 0.24 (0.01-1.68), and 0.22 (0.01-2.40) x 10(6) CD34+ cells/kg, respectively (p = 0.0007), despite the 54% decrease in peripheral blood CD34+ cells/L throughout LVL. A median 66% decrease in the platelet count was also observed during LVL. Thus, LVL may be more efficient than SVL for PBPC collection, allowing, in most patients, the collection in one LVL of sufficient PBPC to support autologous transplantation.

  13. Large-volume leukapheresis for peripheral blood progenitor cell collection in low body weight pediatric patients: a single center experience.

    PubMed

    Cecyn, Karin Zattar; Seber, Adriana; Ginani, Valéria Cortez; Gonçalves, Alexandra Vieira; Caram, Eliana Maria; Oguro, Tsutomu; Oliveira, Olga Maria Wanderley; Carvalho, Maria Mercês; Bordin, José Orlando

    2005-06-01

    Peripheral blood progenitor cells (PBPC) have became the preferred source of stem cells for autologous transplantation because of easier accessibility, rapid engraftment, and lower tumor cell contamination. In pediatric patients is very important to optimize peripheral blood stem cells (PBSC) harvesting to obtain a sufficient number of cells with a reduced number of leukapheresis. In this study we prospectively analyzed data on 43 large volume leukapheresis (LVL) from 20 consecutive low body weight pediatric patients with various malignancies. Patients' mean body weight was 16.6 kg (range, 8.9-32.0 kg), and the median age was 4 years (range, 1-10 y ears). Instead of saline, it was used irradiated and leukoreduced red blood cell (RBC) units to prime the machine in 15 patients weighting 25 kg or less. The median number of LVL was 2 (range, 1-4) and a mean of 5.2 patient's blood volume was processed per session lasting 165 min (range, 118-239). The mean number of CD34+ cells, one day before leukapheresis was 49 mm(-3) (range, 9-219). The PBPC collection yielded 24.7 x 10(8) total nucleated cells/kg (range, 6.2-74.0), 10.7 x 10(6) kg(-1) CD34+ cells (range, 3.6-53.7); 49.8 x 10(4) CFU-GM/kg (range, 6.4-198.1), and 65.6 x 10(4) BFU-E/kg (range, 7.6-198.1). The platelet count decreased significantly after each procedure 39.8 +/- 9.1 x 10(9) mm(-3) (range, 18.000-76.000) (p < 0.001). In conclusion, our data show that LVL for collection of PBPC in low weight pediatric patients is a safe and efficient procedure, but it may expose the patient to the risk of thrombocytopenia.

  14. Large volume leukapheresis is efficient and safe even in small children up to 15 kg body weight

    PubMed Central

    Bojanic, Ines; Mazic, Sanja; Rajic, Ljubica; Jakovljevic, Gordana; Stepan, Jasminka; Cepulic, Branka Golubic

    2017-01-01

    Background The collection of peripheral blood stem cells, although now a routine procedure, is still a challenge in low body weight children because of specific technical and clinical issues. For paediatric patients it is crucial to obtain an adequate number of CD34+ cells with the minimum number of procedures: this can be done using large volume leukapheresis (LVL). Materials and methods We analysed the efficacy and safety of 54 autologous LVL performed in 50 children (33 [66%] males and 17 [34%] females), median age 2 years (range, 1–5) and median body weight 12 kg (range, 6–15). The procedures were performed with a COBE Spectra previously primed with red blood cells; ACD-A solution and heparin were used as anticoagulants. Results The target CD34+ cell dose (≥5×10/kg body weight) were collected with one LVL in 46 (92%) patients, while four (8%) patients needed another procedure. All our LVL were well tolerated. Side effects were observed in five (9.2%) patients and one procedure had to be discontinued because of catheter-related haemorrhage. The platelet count decreased significantly (p<0.001) after each procedure but without bleeding or need for transfusion support. Discussion Our experience confirms that LVL is efficient and safe even in small children, if the procedure is adjusted considering the weight and age of child. The most important factors are good venous access, adequate preparation of the child’s electrolyte status, and surroundings in which the small child as well as parents feel comfortable, and can tolerate the procedure better. Although a median platelet loss of 50% can be expected, LVL is safe and reduces the overall number of procedures required. It can be recommended for peripheral blood stem cell collection even in small body weight children with malignant diseases, particularly those who mobilise low numbers of CD34+ cells. PMID:27136428

  15. Multiple myeloma patients receiving large volume leukapheresis efficiently yield enough CD34+ cells to allow double transplants.

    PubMed

    Zubair, A C; Rymer, R; Young, J; Keeton, U; Befort, R; Nolot, B; Evans, C; Bleach, T; Torloni, A

    2009-01-01

    Current protocols for myeloma patients require more than one autologous transplant. We performed a retrospective study to determine the cost-effectiveness of large volume leukapheresis (LVL) compared with standard volume leukapheresis (SVL) collection when two transplants are required. We evaluated 87 patients who underwent a cumulative total of 260 LVL and SVL collections. The median product volume per collection was 356 ml for LVL, and this was significantly higher than the median product volume per collection for SVL (median 149.5 ml, P < 0.001). The median total CD34+ cell yield/kg was 6.4 x 10(6) for LVL and 5.2 x 10(6) for SVL. This difference was statistically significant (P = 0.005). Because the target CD34+ cell dose for a single transplant was 3 x 10(6)/kg at our institution, overall the LVL yields enough CD34+ cells that could allow for two transplants. Therefore, more patients in the LVL